Tagged: Neutrino physics Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 12:11 pm on January 24, 2023 Permalink | Reply
    Tags: "Ways to weigh a neutrino", Another process that produces a neutrino is electron capture: A proton in an unstable nucleus captures an electron from the inner shell and converts to a neutron and ejects a neutrino., , , For decades scientists have tried to find a way to measure the mass of the lightest matter particle known to exist. Three new approaches now have a chance to succeed., In a process called beta decay a neutron in an unstable nucleus transforms into a proton to restore balance. As the neutron becomes a proton it emits a negatively charged electron—and a neutrino., Neutrino physics, , Neutrinos are very very small. But they outnumber the other fundamental particles by a factor of 10 billion., , , They probably influenced the formation of structures in the early universe so knowing their mass is critical to closing gaps in our understanding of the cosmos., To measure directly or indirectly-that is the question.   

    From “Symmetry”: “Ways to weigh a neutrino” 

    Symmetry Mag

    From “Symmetry”

    1.24.23
    Elise Overgaard

    For decades scientists have tried to find a way to measure the mass of the lightest matter particle known to exist. Three new approaches now have a chance to succeed.

    In 1980, Hamish Robertson was a tenured professor at Michigan State. He’d been there since his postdoc in 1971, and he was content. “I want to stress how valued and happy I felt there,” he says. “It was, and still is, an outstanding place.”

    But he and his friend and colleague, Tom Bowles, had begun to hatch an idea that would take him far from MSU. They were devising a new experiment to measure the mass of the elusive and perplexingly light neutrino.

    Neutrinos are the only fundamental particles whose mass we still don’t know. As their name implies, neutrinos are very very small. But they outnumber the other fundamental particles by a factor of 10 billion.

    Their collective abundance makes it likely that they probably influenced the formation of structures in the early universe so knowing their mass is critical to closing gaps in our understanding of the cosmos.

    But how do you measure something with a mass so small it approaches zero? Hundreds of physicists, including Robertson, have devoted their careers to solving this problem, and they’re seeing progress. Research projects underway in Europe and the United States fuel a sense of optimism that the task can be accomplished.

    To measure directly or indirectly-that is the question

    If you were asked to weigh something—your dog for example—how would you do it?

    You could set the dog in your car, watch the compression, measure how many inches the car is displaced, then convert that into a measurement of the dog’s mass. You’d need to know the weight of the car, the technical specifications of the shocks, how much air is in the tires, and something about spring constants. That’s an indirect (and hard) way.

    Alternatively, you could simply set the dog on a bathroom scale.

    The decision on which approach to use, direct versus indirect, depends on what resources you have available. If you don’t have a bathroom scale, an indirect measurement using your car could hypothetically be your best option.

    When it comes to neutrinos, scientists have faced a similar situation.

    In 1987, astrophysicists interested in the mass of neutrinos got an assist from a rare nearby supernova. The spectral data they collected from the stellar explosion helped them make an indirect measurement that gave them an upper limit on the neutrino mass. As in the car example, they used mathematical models, known quantities, and interactions between many parts of a system to make a calculation.

    Cosmologists have also made an indirect measurement by looking for the imprint of neutrino mass on faint radiation in space called the cosmic microwave background [CMB], says Diana Parno, an associate professor at Carnegie Mellon University and US spokesperson for the Karlsruhe Tritium Neutrino direct mass experiment, or KATRIN.

    “What we would ideally like is an Earth-based measurement of the neutrino mass, and then we can compare that against the cosmological measurement,” Parno says.

    So, while cosmologists and astrophysicists look to the sky, experimentalists like Robertson, Bowles and Parno take the direct approach to searching for the neutrino mass. It’s tough—the ghostly particles don’t interact with electromagnetic fields or the nuclear strong force, and they’re so light that gravity barely pulls on them. Experimentalists have to get creative.

    Building a bathroom scale for neutrinos

    Back in 1980, Robertson and Bowles developed a new idea for making a direct neutrino mass measurement.

    But there were only a few places that had the equipment, the funding and other resources required for the experiment they wanted to propose. The DOE’s Los Alamos National Laboratory was one of them.

    Bowles already worked in Los Alamos, and he wanted Robertson to join him. Robertson was tempted. “Since I first was aware of science as a child, I knew about Los Alamos. I always thought it would be the most extraordinary place to be,” he says.

    To convince Robertson to take the dive, Bowles invited him to visit the lab. One night he treated Robertson to dinner at Southwest restaurant Rancho de Chimayo. “On the way back, we stopped the car and turned off the lights,” Robertson says. “We got out so I could marvel at the spectacular carpet of stars in the clear mountain air.”

    Robertson was sold. He was ready to embark on the journey to measure neutrino mass.

    So how does one go about building a bathroom scale for neutrinos? If you have a squirmy dog that won’t sit on the scale, you can weigh yourself alone, then weigh yourself with your pet. The difference between the two is the weight of the dog. Neutrino researchers use that same idea, taking advantage of processes that produce neutrinos.

    In a process called beta decay a neutron in an unstable nucleus transforms into a proton to restore balance. As the neutron becomes a proton it emits a negatively charged electron—and a neutrino.

    Another process that produces a neutrino is electron capture: A proton in an unstable nucleus captures an electron from the inner shell and converts to a neutron and ejects a neutrino.

    In both cases the events produce a very specific amount of energy—you can look it up in a table. That exact amount of energy is the difference between the mass of the parent atom and the mass of the daughter atom. And that energy is shared between the products: the neutrino and the electron in beta decay, or the neutrino and the excited daughter atom in electron capture.

    Experimentalists measure energies, hence they can determine the energy taken by the neutrino. Then they take advantage of that old reliable equation E = mc2 and convert the neutrino’s energy to mass.

    Awkward space in the Standard Model

    Why is investigating the mass of neutrinos so alluring to scientists like Robertson and Bowles? Because the unresolved problem has shaken scientists’ understanding of the universe.

    The Standard Model of particle physics—our current best explanation of the fundamental forces and particles that make up everything—predicts that neutrinos should have no mass.

    But oscillation experiments in the 1990s showed that they must have mass.

    “Neutrino mass is our first laboratory evidence for physics beyond the Standard Model, and that’s so cool,” Parno says.

    As Robertson explains: “Neutrinos are the only matter particles for which the Standard Model made a prediction for what its mass would be. And that prediction was wrong.

    “We have examples of things that are not in the Standard Model. Gravity is not in the Standard Model. The mass of quarks is not predicted. But there is only this one case where the Standard Model actually made a prediction, and it got it wrong.”

    The upper limit for the neutrino mass, as determined indirectly by cosmology, is roughly one millionth the mass of the next lightest particle, the electron. That’s like the gap between one mouse, which weighs roughly 25 grams, and five elephants, which together weigh roughly 25,000 kilograms. “That’s an enormous gap,” says Parno. “It’s awkward to have this empty space in the Standard Model.”

    The gap means that neutrino masses might be special. Or they might not be. But until we have a measurement to work with, we can’t really say anything definitive. So making that measurement is a crucial first step.

    Even if researchers achieved a result for the mass of the neutrino, the work would not be done. It would help rule out some theories and models, but there would still be questions, says Patrick Huber, neutrino theorist and director of the Center for Neutrino Physics at Virginia Tech.

    “It’s not like once you have the measurement, you immediately select the right model,” he says. “It’s not like every theorist has predicted a certain neutrino mass, and somebody has the right theory once it’s measured. But it would lead to a whole bunch of broader questions.”

    Huber has dedicated his career to neutrinos for this exact reason. “If they see the neutrino mass, this will be very exciting. But what would be even more exciting is if they’re not seeing the neutrino mass where they should have seen it, because that means something new is happening,” he says. “Then we are forced to really start thinking anew.”

    A ghost worth chasing

    Back to the 1980s—Bowles’s persuasion had worked. “The siren song of Los Alamos was too strong to resist,” Robertson says.

    Robertson’s wife was also interested in heading out west. As a female nuclear physicist in a male-dominated lab in the ’70s, she had faced an uphill battle to navigate her career. Together, husband and wife secured jobs at the lab and flew down to buy a house. “On the glide path into Albuquerque, I still remember the feeling of elation,” Robertson says. “It was a new beginning.”

    A few months later, they officially made the move, with their 6-month-old son in tow.

    In 1972 a Swedish physicist named Karl-Erik Bergkvist had declared a new neutrino mass limit: 55 electronvolts. Robertson, Bowles and their colleagues thought they could do better. Their idea was to study beta decay using tritium, a radioactive isotope of hydrogen. Bergkvist had also used tritium, but it was a form implanted into aluminum. Robertson and Bowles wanted to use it in a more pure, gaseous form.

    The lab administration was open to their project. “They said, ‘How much money do you need?’ Well, I had no idea,” Robertson says. So he threw out a number. “They said, ‘Okay, fine.’ So that was it. Off we went.”

    With that funding—which in the end wasn’t quite enough, but at least got them started—they pushed the limit down to about 10 electronvolts. Importantly, they had proved that tritium decay experiments could work.

    In 1988, Robertson shifted gears and joined the Sudbury Neutrino Observatory.

    In 2001 the group demonstrated neutrino oscillation—a finding that proved neutrinos have mass and that eventually earned the 2015 Nobel Prize in Physics.

    Having confirmed that neutrinos have mass, scientists returned to the quest to build a bathroom scale for neutrinos. The KATRIN experiment [above] was forming, and the collaboration members asked everyone who had worked on a tritium experiment in the past to join. Robertson had moved to the University of Washington by then, but he joined the collaboration happily, even offering to design and provide the detector system for the project.

    Nestled in Karlsruhe, Germany, the KATRIN experiment now relies on contributions from 150 researchers from seven countries.

    Parno is one of those researchers. Like others, she was drawn to the experiment by the thrill of chasing something unknown. “Neutrinos are really weird,” she says. “They keep on surprising and confusing us. I think neutrinos still have a lot to teach us.”

    KATRIN is the most advanced direct mass measurement experiment. The KATRIN collaboration published an exciting result in February 2022: Neutrinos must weigh less than 0.8 electronvolts [Nature Physics (below)].

    Fig. 1: Illustration of the 70-m-long KATRIN beamline.
    3
    The main components are labelled. The transport of β-electrons and magnetic adiabatic collimation of their momenta p are illustrated [a–f]. View into the tritium source depicts three systematic effects: molecular excitations during β-decay (a), scattering of electrons off the gas molecules (b) and spatial distribution of the electric potential in the source Usrc(r, z) (c). The view into the spectrometer illustrates the main background processes arising from radon decays inside the volume of the spectrometer (d), highly excited Rydberg atoms sputtered off from the structural material via α-decays of 210Po (e) and positive ions created in a Penning trap between the two spectrometers (f). Low-energy electrons, created in the volume as a consequence of radon decays or Rydberg-atom ionizations, can be accelerated by qUana towards the focal-plane detector, making them indistinguishable from signal electrons.

    Oscillation experiments provided a floor, and the KATRIN result provides a ceiling. “We are closing in,” Robertson says.

    This range is much tighter than the one from the indirect astrophysical supernova measurement. “The supernova limit is about 5.7 electronvolts, about seven times looser than the current KATRIN limit,” Parno says.

    And it’s close to the limit from cosmological indirect measurements, which is somewhere in the range 0.12 to 0.5 electronvolts, depending which parameters are used in the model, Robertson says.

    KATRIN’s 0.8 electronvolt number is the new benchmark for all direct mass experiments, but other inventive scientists are on KATRIN’s heels.

    New approaches

    In 2009, Joe Formaggio, a professor at the Massachusetts Institute of Technology, and Benjamin Monreal, an associate professor at Case Western Reserve University, had another tritium-based idea, which became the foundation of the neutrino mass experiment known as Project 8.

    “They proposed just a really beautiful idea,” Robertson says. “It’s one of those ideas where you say: Oh yeah, I wish I thought of that!”

    Robertson has worked with the Project 8 team since its inception. The experiment also uses tritium decay, but Project 8 determines the energy of the emitted electron differently. They measure the frequency of the electron’s cyclotron radiation—the microwave radiation that escapes from charged particles in circular orbit in a magnetic field.

    “The amount of power radiated is really very small, but you can measure it,” Robertson says.

    Various aspects of the experiment are still being developed and tested. If the new approach works as planned, the Project 8 team hopes to measure the neutrino mass with a sensitivity of approximately 0.04 electronvolts.

    The third technique currently under investigation as a way to directly measure neutrino mass uses molecules of the holmium isotope 163Ho. It’s challenging as well, says researcher Loredana Gastaldo, Junior Professor at the Kirchhoff Institute for Physics at the University of Heidelberg and spokesperson of the Electron Capture 163Ho, or ECHo, experiment.

    “If you want to learn more about neutrinos, you need to be creative, to find an original and clever method that allows you to really learn something about them,” she says. “The neutrinos don’t give anything up as a present, so you need to sweat a lot to gain a little bit more understanding.”

    The ECHo experiment relies on electron capture events in 163Ho. Scientists implant 163Ho ions in microcalorimeters, a totally different type of detector than the ones used in KATRIN and Project 8. “The idea is that if energy is deposited into the detector, there is an increase of temperature … and we can measure this extremely small increase in temperature with very precise thermometers,” Gastaldo says.

    Each project is different, but through human ingenuity (and persistence), direct mass measurement experiments are making strides.

    Let’s get together

    Robertson, who is now a professor emeritus at the Center for Experimental Nuclear Physics and Astrophysics at the University of Washington in Seattle, officially retired in 2017. But he’s still working on Project 8.

    The collaboration is younger than KATRIN and, so far, has done only proof-of-concept experiments. The next step is to create a full-blown large-scale detector.

    “Some days you get up and you learn something that is just not going to work,” Robertson says. “And you say: Oh my goodness, we’re doomed.

    “And then you work for another week or two—or a month or a year—and you talk to your friends, and somebody has an idea, and suddenly the sun comes out again, and that problem is solved, and you move on.

    “I still work at this 24/7 because I really love this experiment.”

    And he’s not alone. Parno, Gastaldo and Huber are just a few of the hundreds of other neutrino experts who have dedicated their careers to finding the mass of the neutrino. And they all rely on each other.

    “We are all learning from all the other groups,” Gastaldo says. “And this makes the collaborations really alive and with super interesting discussions in which all of us are gaining a lot of knowledge.”

    To maximize neutrino physicists’ ability to learn from each other, Gastaldo organized a conference, called “NuMass”, in 2016. The inaugural meeting was a gathering of 40 scientists from the US and Europe, all with different expertise. “The discussions were so deep it was unbelievable,” Gastaldo says.

    The group repeated the conference in 2018, 2020 and 2022.

    “I think it’s fantastically interesting to have so many different fields of knowledge that turn out to be necessary in order to unlock the secrets of this incredibly lightweight, incredibly rarely interacting particle that somehow shaped the universe,” Parno says.

    The optimism of neutrino mass researchers is infectious. They continue, with tangible passion, to push the limits of human ingenuity.

    And there’s always room for newcomers.

    “You have to have young people because they’re the people who actually can get stuff done,” Robertson says. “There’s this huge group of people. I’m just wandering along jumping from the shoulder of one giant to another. That’s part of what makes science fun.”

    The latest: The DOE’s Fermi National Accelerator Laboratory LBNF/DUNE experiment.



    Nature Physics
    See the science paper for instructive material with images.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.


    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 11:07 pm on January 5, 2023 Permalink | Reply
    Tags: "Unraveling the neutrino’s mysteries at the Deep Underground Neutrino Experiment", , At Sudbury scientists found the reason for the missing neutrinos: Neutrinos change type-or “flavour” as they fly through space., At the Virginia Tech Center for Neutrino Physics Camillo Mariani and Patrick Huber have woven theoretical and experimental physics together in contributing to the DUNE project., , , , , John Bahcall calculated the amount of solar neutrinos he predicted the experiment would collect from the nuclear reactions that took place inside its large underground tank filled with cleaning fluid., Neutrino physics, , , , Raymond Davis Jr. and John Bahcall in the 1960s attempted to count solar neutrinos at an experiment at the Homestake Mine in South Dakota the current Dune far detector site., Sanford Underground Research Laboratory, , The Homestake Experiment which ran from 1970-92 only collected one-third of the neutrinos Bahcall had predicted., , This phenomenon of changing flavours-known as “neutrino oscillation”-directly contradicts the Standard Model which had predicted neutrinos to be massless.   

    From The Virginia Polytechnic Institute and State University: “Unraveling the neutrino’s mysteries at the Deep Underground Neutrino Experiment” 

    From The Virginia Polytechnic Institute and State University

    1.4.23
    Suzanne Irby

    At the Virginia Tech Center for Neutrino Physics Camillo Mariani and Patrick Huber have woven theoretical and experimental physics together in contributing to the DUNE project.

    1
    A look inside the ProtoDune Cyrostat Final structure inside a mine in South Dakota. Photo courtesy of The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organización Europea para la Investigación Nuclear][Organization européenne pour la recherche nucléaire] [Europäische Organization für Kernforschung](CH) [CERN].

    Neutrinos mind their own business. Each second, billions of these fundamental particles will pass through stars, planets, buildings, and human bodies and will rarely ever be stopped by them, like a subatomic subway crowd. It’s why they’re often described as “ghostly” or “elusive.”

    If scientists could create and capture the rare instances when these tiny and weakly interactive particles run into something, they could step into the gray area that all physicists ultimately hope to explore, said theoretical physicist Patrick Huber: that of facts that exist outside the Standard Model of Particle Physics, beyond its explanation.

    Neutrinos live there, and so does dark matter.

    Neutrino behavior, if accurately measured, could hold the evidence for how we — and our bodies and buildings and planets and stars, all made of matter — have been able to exist since the Big Bang. “There are certain things that the Standard Model does not explain, like why there’s more matter than antimatter in the universe,” said Huber, a professor in the Department of Physics and a Roger Moore and Mojdeh Khatam-Moore Faculty Fellow in the Virginia Tech College of Science. “But we never have found the ingredients which make these known facts outside of the Standard Model really work. If there is to be a large contribution of new physics, it can only really manifest itself in neutrinos.”

    To find out what neutrinos are up to, physicists will need to shoot them from the most powerful beam ever made at a distant, massive, subterranean, and painstakingly precise particle detector. More than a thousand scientists have come together to create that kind of experiment in a decades-long project called the Deep Underground Neutrino Experiment (DUNE), hosted by the DOE’s Fermi National Accelerator Laboratory.

    __________________________________________________
    Fermilab LBNF/DUNE Neutrino Experiment


    __________________________________________________

    1
    Camillo Mariani (at left) and Patrick Huber. Photo by Steven Mackay for Virginia Tech.

    For the past decade and in the buildup to DUNE’s development, Huber has collaborated with experimental physicist Camillo Mariani at Virginia Tech’s Center for Neutrino Physics, where they’ve looked at ways to achieve the unprecedented precision an experiment like DUNE will need to measure neutrino behavior and discover the “new physics” sought by the field.

    Mariani has brought what they’ve learned to his work on DUNE’s international team as they develop the facility. Their pursuit of precision is one piece of a puzzle that Raymond Davis Jr. and John Bahcall started in the 1960s, with attempts to count solar neutrinos.

    When two physicists stared up at the sun

    Raymond Davis Jr. led one of the first experiments to measure neutrinos coming from one of nature’s abundant sources: the sun. As Davis built the experiment at the Homestake Mine in Lead, South Dakota, Bahcall calculated the amount of solar neutrinos he predicted the experiment would collect from the nuclear reactions that took place inside its large, underground tank filled with cleaning fluid. But the Homestake Experiment which ran from 1970-92 only collected one-third of the neutrinos Bahcall had predicted.

    Most physicists at the time figured that either Davis had done something wrong with the experiment or that Bahcall’s calculations were off. The issue of the missing neutrinos became known as the “solar neutrino problem” that physicists would try to solve for years. Scientists at the Sudbury Neutrino Observatory finally solved it in a 2002 experiment at a Canadian mine.

    Using a giant sphere full of heavy water, they measured neutrinos via the light produced inside by nuclear reactions. They found the reason for the missing neutrinos: Neutrinos change type-or “flavour” as they fly through space.

    There are three known neutrino flavours: electron, muon, and tau. The Sudbury experiment was sensitive to all three, unlike Davis’s, which only picked up electron neutrinos. It’s this phenomenon of changing flavours-known as “neutrino oscillation”-that directly contradicts the Standard Model which had predicted neutrinos to be massless.

    Camillo Mariani breaks down neutrino oscillations using ice cream flavors. “You can imagine that you go to an ice cream shop, and you get your favorite: banana,” Mariani said. “And then you step out, and your ice cream flavor now becomes strawberry. You take another two steps, and the strawberry becomes vanilla. Another three steps, and the vanilla becomes coconut. This is what people call an oscillation. And it can be a function of distance traveled over a function of time. And these only happen if the mass of the particle is not zero.”

    With the problem of missing solar neutrinos solved, physicists have since moved on to probing how neutrino oscillations work. The big, underlying science question today is whether these flavour changes in neutrinos and antineutrinos happen at the same rate or not, Huber said. If they oscillate differently, that difference — a physical process known as CP violation — could help to explain why our universe consists of us and our surroundings, over light and light alone.

    Physicists believe that 14 billion years ago, there were exactly the same amounts of matter and antimatter in the universe. “If that were true, and it always remained like that, then eventually, all matter and antimatter would have met and annihilated each other and become light (energy),” Huber said. “The universe would then contain only light (energy) and nothing else. Obviously, that’s not how it happened.”

    Because we exist, it’s clear that matter dominated over antimatter during the Big Bang, in a break of symmetry. Neutrino oscillations could show how this was possible by demonstrating their own asymmetry. DUNE provides a way to catch that asymmetry in the act — or not.

    The difference in oscillation rate between neutrinos and antineutrinos — or lack thereof — is not going to be glaring, Huber said, which is why physicists like him and Mariani are so fixated on precision. It could come down to tenths or hundredths of a number in DUNE’s measurements. Though it’s a feat, DUNE is the minimum needed to get it done, Huber said, because in the case of precisely measuring neutrino oscillations, “you need a Saturn rocket to fly to the moon.”

    “Physics in the last two decades has gone from a field where we’re happy just saying, ‘Oh, we’ve seen neutrinos, hooray,’ to the point where we’re trying to do very precise measurements,” Huber said. “DUNE is the epitome of that. That really is the end of a decades-long evolution where neutrino physics became more and more precise. DUNE is trying to do one of the most precise measurements ever attempted with neutrinos.”

    A Saturn rocket to fly to the moon

    There are some musts in measuring neutrino oscillations: creating enough neutrino events, only a handful of which will be snatched up by an experiment; putting enough distance between the neutrinos’ source and their endpoint for them to exhibit their oscillations; and establishing a setup that’s massive and highly-resolved enough to capture the energy the events leave behind.

    DUNE’s answer to this starts with a powerful neutrino beam based at Fermilab in Batavia, Illinois. Here, physicists will shoot neutrinos underground across 1,300 kilometers of underground distance at a 40,000-ton particle detector filled with liquid argon. The detector will be located at the same mining area used by the [Davis-Bahcall] Homestake Experiment in South Dakota.

    As neutrinos bump into the argon inside the detector and leave behind trails of energy, that material will offer unmatched precision in measuring them, Mariani said. “Essentially, it’s like taking a photo camera from the 1980s and comparing that with your phone camera that has millions of pixels,” he said.

    The College of Science has another DUNE connection, quite close, too. Kevin Pitts, who started his tenure as dean of the college this past June and who is an affiliated faculty member of the Department of Physics, last year was named the chief research officer at Fermilab. There, he oversaw the lab’s science program, which includes the multibillion-dollar DUNE project.

    “The DUNE experiment will be a truly remarkable technological achievement that will lead to truly remarkable scientific insights,” Pitts said. “This experiment will feature 40,000 tons of liquid argon a mile underground in an abandoned gold mine in the Black Hills. Scientists from around the world are contributing to this effort because they are excited by the transformational science that will be performed at this facility.”

    For years, Mariani and Huber have worked at ensuring that this part of the DUNE project doesn’t fail. Because scientists don’t actually see neutrinos themselves as the particles hit a detector, they must reconstruct the interaction that took place with the energy left behind.

    Getting that right depends on the microphysics of what happens within the interaction, Huber said. Reconstructing the interaction is as complex as tracing the effects of shooting a bullet at a clock, he said: “Depending on how you may hit the clock, you may have gears flying out, you may have the numerals fly off. To really reconstruct the clock, or the whole interaction, from that, I need to know the probability for the bullet to eject each given subpart of the system.”

    When shooting neutrinos at argon atoms, argon nuclei can eject all sorts of particles: neutrons, protons, and new particles like pions, which are easy for detectors to miss and which all need to be counted for an accurate measurement of the total energy produced by the neutrino event. “In our work with Dr. Mariani, I think we were the first group who really tried to look into the details of that and quantify what kind of systematic uncertainties would arise from that,” Huber said. “I think that work had a huge impact on how people think about designing the whole experiment.”

    Huber and Mariani see the Center for Neutrino Physics as one of the few places where that degree of collaboration between theorists and experimentalists could happen. Since its founding in 2010, the center has built up both its theoretical and experimental programs with the sense that as neutrino physics evolved, theorists and experimentalists would always need each other.

    When an experimentalist and a theorist go for coffee

    In physics, theory and experiments tend to go back and forth in a feedback cycle: the theorists put forward a question, the experimentalists figure out a way to build an experiment to try to answer the question, and once they have the data, the theorists try to figure out what it means.

    When theorists and experimentalists have trouble understanding each other, this back and forth won’t go smoothly. It’s becoming easier and easier for that to happen, Huber said, as carving out a career path in physics tends to push scientists to self-identify as either a theorist or an experimentalist. “By the time you’re a grown researcher, you often lose this ability to effectively communicate with each other,” Huber said. “I think the only way around this is regular social interaction, where in the end, you learn to understand the language of the other side.”

    Huber, the center’s director, said it’s important to look for ways to keep theorists and experimentalists talking, in theory-experiment joint seminars or in something as simple as a shared cup of coffee. “Dr. Mariani happens to have a nice coffee machine,” he said. “It’s really that you have this casual social interaction and a relationship where nobody feels embarrassed to ask stupid questions. I can go down the hallway and ask any of my experimental colleagues, ‘Hey, what happens if you did X?’ And mostly they will tell me, ‘Well, X will blow up,’ or something like that. But sometimes you find you have some genuinely interesting new things you can do.”

    So it will go with DUNE. The project’s ability to surface new insights on neutrinos will depend in part on how its scientists can center their different talents on the same question, Huber said.

    DUNE is planned to collect data on neutrino oscillations for 20 years, starting in 2029. It’ll be another 10 to 15 years before physicists can find meaning in the results. They may or may not find evidence answering the question of matter’s dominance over antimatter in the universe. But DUNE’s potential goes beyond that, Huber said.

    DUNE represents a facility with technologies physicists will be able to use in ways they haven’t yet dreamed up. “This is where it gets really interesting,” Huber said. “Once you have this new facility and technical capability, people become very creative and find thousands of other ways to extract new science from that. In reality, what we do in science is driven by curiosity. That’s the reason we’re doing this.”

    See the full article here.

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Virginia Polytechnic Institute and State University is a public, land-grant, research university with its main campus in Blacksburg, Virginia. It also has educational facilities in six regions statewide and a study-abroad site in Riva San Vitale, Switzerland. Through its Corps of Cadets ROTC program, Virginia Tech is also designated as one of six senior military colleges in the United States.

    Virginia Tech offers 280 undergraduate and graduate degree programs to some 34,400 students and manages a research portfolio of $522 million, placing it 46th among universities in the U.S. for research expenditures and the only Virginia school listed among the top 50. Virginia Tech is the state’s second-largest public university by enrollment. The deadliest mass shooting on an American college campus occurred on campus in 2007, during which a student fatally shot 32 other students and faculty members and wounded 23 other people.

     
  • richardmitnick 10:59 pm on December 19, 2022 Permalink | Reply
    Tags: "A New Day Awaits Solar Neutrinos", , Deep Underground Neutrino Experiment (DUNE) at Fermilab and SURF, In South Dakota’s Homestake gold mine [now SURF-Sanford Underground Research Facility] physicist Raymond Davis and his colleagues observed the first neutrino signal from the Sun., Jiangmen Underground Neutrino Observatory (JUNO)-a large neutrino detector in China, Neutrino oscillations—a phenomenon that is difficult to reconcile with established theories., Neutrino physics, , , , Scientists say a new generation of solar-neutrino experiments may help in solving outstanding questions about both neutrinos and solar physics., , The number of neutrinos was one third of what models predicted—a mystery that led to many new experiments staking claims to different energy and length scales related to the neutrino behavior., The study of solar neutrinos began in the late 1960s.   

    From “Physics” : “A New Day Awaits Solar Neutrinos” 

    About Physics

    From “Physics”

    12.13.22

    Solar neutrinos are no longer the “stars” of neutrino research, but next-generation experiments characterizing these neutrinos may deepen our understanding of solar and neutrino physics.

    1
    Neutrino experiments, such as the Borexino detector depicted on the right, have illuminated many details about the Sun and the neutrinos it produces. Credit: Borexino Collaboration.

    Measurements of solar neutrinos proved that our star is powered by nuclear reactions while also bringing to light many other details about the Sun’s inner workings. They also led to the discovery of neutrino oscillations—a phenomenon that is difficult to reconcile with established theories.

    [Three flavours: tau and Muon and electron]

    Current neutrino research mostly relies on neutrinos generated on Earth by reactors and accelerators. But some physicists argue that there is still a lot to be done with neutrinos generated in the Sun. A new generation of solar-neutrino experiments may help in solving outstanding questions about both neutrinos and solar physics, these scientists say.

    The study of solar neutrinos began in the late 1960s. Using a detector filled with dry-cleaning fluid and placed in South Dakota’s Homestake gold mine physicist Raymond Davis and his colleagues observed the first neutrino signal from the Sun. They were surprised, however, to find that the number of neutrinos was one third of what models predicted—a mystery that led to a “neutrino gold rush,” with many new experiments staking claims to different energy and length scales related to the neutrino behavior. Eventually, physicists explained the missing neutrinos as resulting from oscillations between neutrino flavors (see Nobel Focus: Neutrino and X-ray Vision). These oscillations implied that neutrinos have mass, in tension with the standard model of particle physics.

    The study of neutrino oscillations continues with efforts to pin down the neutrino masses and mixing parameters that determine the oscillating behavior. The main target, however, is no longer solar neutrinos. “The majority of the community, by a large margin, is focused on accelerator neutrinos,” says Michael Smy from the University of California- Irvine. The reason for this shift, he says, is that an accelerator experiment can explore higher-energy neutrinos and control the source-detector distance over which oscillations may occur. Researchers can also switch the accelerator on and off, which helps remove certain backgrounds.

    On the flip side, there are advantages to using solar neutrinos. For one, the interactions between neutrinos and detector materials are generally better understood at the low energies that characterize solar neutrinos, Smy says. Solar neutrinos also come to us for “free,” so the experiments can be less expensive, says Wick Haxton from University of California, Berkeley.

    Many experiments have focused on solar neutrinos. The Borexino experiment in Italy, for example, was built with the main purpose of collecting low energy (sub-MeV) neutrinos from the Sun.

    Since the project’s start in 2007, the team has taken several steps to remove large radioactive backgrounds. “Over the years, they’ve actually mapped the whole spectrum of solar neutrinos,” Haxton says. “They were unique in that regard.” This week, the Borexino Collaboration reported observations of the neutrinos from the carbon-nitrogen-oxygen (CNO) cycle (see Viewpoint: Elemental Accounting of the Solar Interior).

    Borexino shut down in October 2021, leaving a gap in the detection capability of solar-neutrino studies. “We do not have more data to be analyzed, and therefore the CNO result is the last major output from our experiment,” says Borexino spokesperson Gioacchino Ranucci. The observations of the solar-neutrino spectrum have agreed well with solar-model predictions, and the data have placed important constraints on oscillation parameters. “But there are still questions to be solved” regarding both the Sun’s chemical makeup and “tensions” in the neutrino oscillation picture, says Ranucci.

    Haxton sees a missed opportunity in the closing of Borexino without a clear replacement. “There’s some fascinating questions about the Sun that we haven’t answered very well,” he says. Borexino demonstrated, for example, that solar-neutrino observations could help resolve uncertainties about the elemental abundances in the interior of the Sun. But more precise measurements will be needed to determine the initial ingredients out of which the Sun formed, Haxton says. He also would like to see a better accounting of the total energy in solar neutrinos, which might reveal exotic physics going on inside the Sun. Current neutrino detectors cannot provide these measurements, as they are only sensitive to the high-energy end of the solar-neutrino spectrum.

    Still, there are several solar-neutrino problems that current and planned detectors can tackle. Smy works on Japan’s Super-Kamiokande (Super-K) experiment, which has been instrumental in understanding neutrinos since it began taking data in 1996.

    It continues to be a workhorse in neutrino physics, observing neutrinos from the Sun and other sources. Smy says that Super-K’s current solar-neutrino research focuses on the matter effect—a neutrino flavor conversion that occurs in highly dense regions, such as the interior of the Sun and of Earth. The matter effect has already been observed, but Smy and his colleagues continue to analyze Super-K data in the energy region where the matter effect turns on, as this transition may contain signs of nonstandard interactions between neutrinos and other particles.

    Another focus of ongoing solar-neutrino research is pinpointing the values for the neutrino oscillation parameters. “There are interesting discrepancies in the data that we very much want to resolve,” says Shirley Li from The DOE’s Fermi National Accelerator Laboratory.. She is especially interested in an apparent disagreement between solar-neutrino observations and reactor-neutrino observations. She has looked at whether this problem could be resolved by the Deep Underground Neutrino Experiment (DUNE)—a planned neutrino detector in the Sanford Underground Research Facility (located in the former Homestake Mine where Davis performed his neutrino experiment).

    DUNE’s main goal is to observe high-energy neutrinos coming from the Fermilab accelerator. But the detector should also be able to detect solar neutrinos at the high-energy end of the solar spectrum, according to an analysis by Li and her colleagues.

    In addition to DUNE, other planned neutrino projects could provide new solar-neutrino results. Smy mentions Jiangmen Underground Neutrino Observatory (JUNO)-a large neutrino detector in China that is expected to start taking data next year.

    JUNO has the capability to detect both neutrinos from the Sun and antineutrinos from nuclear reactors. As such, it could test so-called CPT symmetry that assumes a mirror-like relation between matter and antimatter. Further down the road, researchers are proposing to install a neutrino experiment in the China Jinping Underground Laboratory, the deepest scientific facility in the world. “They have the capability of building a Borexino-like detector that’s an order of magnitude larger,” Haxton says. He thinks such an experiment could potentially fill in some of the missing pieces to our understanding of the Sun.

    The current lull in solar-neutrino physics may be a product of the earlier excitement surrounding the missing neutrino problem. “Folks were so anxious to solve the general problem that—once it was solved—they moved on to something else,” Haxton says. But he is optimistic that solar-neutrino physics will have its day again. “Physics goes in cycles.”

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Physicists are drowning in a flood of research papers in their own fields and coping with an even larger deluge in other areas of physics. How can an active researcher stay informed about the most important developments in physics? Physics highlights a selection of papers from the Physical Review journals. In consultation with expert scientists, the editors choose these papers for their importance and/or intrinsic interest. To highlight these papers, Physics features three kinds of articles: Viewpoints are commentaries written by active researchers, who are asked to explain the results to physicists in other subfields. Focus stories are written by professional science writers in a journalistic style and are intended to be accessible to students and non-experts. Synopses are brief editor-written summaries. Physics provides a much-needed guide to the best in physics, and we welcome your comments.

     
  • richardmitnick 9:03 am on June 7, 2022 Permalink | Reply
    Tags: "Neutrinos from a Black Hole Snack", An event named AT2019fdr from November 2019., , , , , Neutrino physics, ,   

    From “Physics News” : “Neutrinos from a Black Hole Snack” 

    About Physics

    From “Physics News”

    June 3, 2022
    Mark Buchanan

    Researchers have found new evidence that high-energy neutrinos are emitted when a black hole gobbles up a hapless star.

    1

    Doomed star. When a star is torn apart by a black hole—as shown in this artist’s representation—high-energy neutrinos can be produced. An observatory at the South Pole has detected a neutrino that appears to have come from one of these events.
    Credit: NASA/CXC/M.Weiss.

    Neutrinos of extremely high energy routinely strike Earth. Physicists suspect these particles are created in cosmic processes involving black holes, but exactly which process dominates this production remains uncertain. Now astronomers report the detection of a high-energy neutrino linked directly to a tidal disruption event (TDE)—the violent shredding of a star by the intense gravity of a nearby black hole [1]. This observation is the second strong association of a high-energy neutrino with such a star-devouring event, allowing researchers to make a crude initial estimate of how many neutrinos are produced through this mechanism.

    High-energy neutrinos—roughly those in the TeV energy range and above—give physicists information on some of the most violent astrophysical events in the Universe, many occurring well outside our Galaxy. Because neutrinos interact with matter so weakly, they travel unaltered over immense distances from their original production sites. Theoretical models—backed by observations—have linked them to a wide variety of potential sources, including active galactic nuclei, which are supermassive black holes that produce beams of energetic particles as they devour surrounding gas. TDEs offer another possibility, as copious neutrinos should be generated if a black hole tears apart a nearby orbiting star (see Research News: “Revolution” for Alternative Black Hole Probe). Most generation scenarios involve large black holes.

    Currently, however, researchers remain unable to estimate the relative importance of these distinct processes. For example, active galactic nuclei are far more common than TDEs, but the latter could emit a very high percentage of their energy as neutrinos. As a result, “We don’t really know where the majority of high-energy cosmic neutrinos come from,” says physicist Marek Kowalski of Humboldt University in Germany. Knowing the neutrino origins would help researchers understand the extreme astrophysical events that generate some of the most energetic cosmic rays in the Universe.

    Last year, Kowalski and his colleagues reported the first coincidence detection of a neutrino and a TDE [2]. The neutrino was spotted by the IceCube Neutrino Observatory—an array of detectors buried deep within the ice near the South Pole.

    _____________________________________________________
    U Wisconsin IceCube neutrino observatory

    U Wisconsin IceCube Neutrino Observatory neutrino detector at the at the Amundsen-Scott South Pole Station in Antarctica South Pole, elevation of 2,835 metres (9,301 feet).
    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration.

    Lunar Icecube

    IceCube Gen-2 DeepCore PINGU annotated

    IceCube neutrino detector interior.

    IceCube DeepCore annotated.

    IceCube Gen-2 DeepCore PINGU annotated

    DM-Ice II at IceCube annotated.


    _____________________________________________________

    The researchers found that the neutrino’s location in the sky corresponded to a long-lived burst of radiation that exhibited TDE signatures in archived astronomical data.


    DESY, Science Communication Lab.
    The animation depicts a tidal disruption event of the kind believed to have produced a recently detected high-energy neutrino. The event begins when a star orbits too close to a supermassive black hole, causing it to stretch out into long noodle-like strands, in a process called “spaghettification.” The star’s torn-up remnants spiral into the black hole, driving reactions that create high-energy neutrinos and other particles.

    Adding to this earlier finding, Kowalski and colleagues now report finding a second TDE closely linked to a different neutrino, which was detected on 30 May 2020 by IceCube. The researchers discovered the association by using computers to sort through a database of astronomical observations collected by the Zwicky Transient Facility, California, which uses a wide-view, optical camera to scan the entire Northern Sky every two days.

    In their search, the team discovered an event named AT2019fdr from November 2019, which was closely associated with the most likely direction of the high-energy neutrino. Exploiting data from other telescopes, they also identified specific radiative signatures expected for a TDE.

    This association is strong evidence, the researchers argue, that this neutrino was created during a years-long radiative flare released by the black-hole–star interaction. Based on a preliminary statistical analysis, they estimate that there is only a 0.034% probability that the neutrino’s direction just happened by chance to match that of the TDE. But they say that further work on localizing the neutrino direction could change this estimate.

    “This is certainly a major result,” says astrophysicist Nicholas Stone of the Racah Institute of Physics in Israel. He says that the first observed association gave credence to TDEs being sources for high-energy neutrinos, but it was hard to be confident with just one event. “With a second neutrino-TDE association, we are now on much firmer footing.”

    This second detection does more than just bolster confidence in the earlier detection, says team member Simeon Reusch, a Ph.D. student of Kowalski’s. It also makes possible a crude estimate of the TDE contribution to high-energy neutrino production. Comparing these two observations with the full catalog of cosmic neutrinos detected by the IceCube observatory, the researchers conclude that at least 7.8% of high-energy neutrinos must be coming from TDEs. “Because tidal disruption events are so rare, our findings indicate that they are probably extremely efficient neutrino factories,” Kowalski says.

    References

    S. Reusch et al., “Candidate tidal disruption event AT2019fdr coincident with a high-energy neutrino,” Phys. Rev. Lett. 128, 221101 (2022).
    R. Stein et al., “A tidal disruption event coincident with a high-energy neutrino,” Nat. Astron. 5, 510 (2021).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Physicists are drowning in a flood of research papers in their own fields and coping with an even larger deluge in other areas of physics. How can an active researcher stay informed about the most important developments in physics? Physics News highlights a selection of papers from the Physical Review journals. In consultation with expert scientists, the editors choose these papers for their importance and/or intrinsic interest. To highlight these papers, Physics News features three kinds of articles: Viewpoints are commentaries written by active researchers, who are asked to explain the results to physicists in other subfields. Focus stories are written by professional science writers in a journalistic style and are intended to be accessible to students and non-experts. Synopses are brief editor-written summaries. Physics News provides a much-needed guide to the best in physics, and we welcome your comments.

     
  • richardmitnick 8:45 pm on May 31, 2022 Permalink | Reply
    Tags: "Physicists Announce First Results from Daya Bay’s Final Dataset", , , Data collection ended in December 2020., Daya Bay physicists made the world’s first conclusive measurement of theta13 in 2012 and subsequently improved upon the measurement's precision as the experiment continued taking data., Neutrino physics, , Only one of the three mixing angles remained unknown at the time Daya Bay was designed in 2007: theta13., Physicists calculated how many antineutrinos changed flavors and consequently the value of theta13., Physicists expect there might be some difference between neutrinos and antineutrinos., Physicists have now measured the value of theta13 with a precision two and a half times greater than the experiment’s design goal., Physicists may gain insight into the imbalance of matter and antimatter in the universe., , , The eight detectors at Daya Bay pick up light signals generated by antineutrinos streaming from nearby nuclear power plants., theta13 measurement, To determine the value of theta13 Daya Bay scientists detected neutrinos of a specific flavor—in this case electron antineutrinos.   

    From The DOE’s Brookhaven National Laboratory: “Physicists Announce First Results from Daya Bay’s Final Dataset” 

    From The DOE’s Brookhaven National Laboratory

    May 31, 2022
    Stephanie Kossman
    skossman@bnl.gov
    (631) 344-8671

    Peter Genzer
    genzer@bnl.gov
    (631) 344-3174

    1
    Bird’s-eye view of the underground Daya Bay far detector hall during installation. The four antineutrino detectors are immersed in a large pool filled with ultra-pure water. (Credit: Roy Kaltschmidt, Berkeley Lab)

    Over nearly nine years, the Daya Bay Reactor Neutrino Experiment captured an unprecedented five and a half million interactions from subatomic particles called neutrinos. Now, the international team of physicists of the Daya Bay collaboration has reported the first result from the experiment’s full dataset—the most precise measurement yet of theta13, a key parameter for understanding how neutrinos change their “flavor.”

    The result, announced today at the Neutrino 2022 conference in Seoul, South Korea, will help physicists explore some of the biggest mysteries surrounding the nature of matter and the universe.

    Neutrinos are subatomic particles that are both famously elusive and tremendously abundant. They endlessly bombard every inch of Earth’s surface at nearly the speed of light, but rarely interact with matter. They can travel through a lightyear’s worth of lead without ever disturbing a single atom.

    One of the defining characteristics of these ghost-like particles is their ability to oscillate between three distinct “flavors”: muon neutrino, tau neutrino, and electron neutrino. The Daya Bay Reactor Neutrino Experiment was designed to investigate the properties that dictate the probability of those oscillations, or what are known as mixing angles and mass splittings.

    Only one of the three mixing angles remained unknown at the time Daya Bay was designed in 2007: theta13. So, Daya Bay was built to measure theta13* with higher sensitivity than any other experiment.

    Operating in Guangdong, China, the Daya Bay Reactor Neutrino Experiment [above] consists of large, cylindrical particle detectors immersed in pools of water in three underground caverns. The eight detectors pick up light signals generated by antineutrinos streaming from nearby nuclear power plants. Antineutrinos are the antiparticles of neutrinos, and they are produced in abundance by nuclear reactors. Daya Bay was built through an international effort and a first-of-its-kind partnership for a major physics project between China and the United States. The Beijing-based Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences leads China’s role in the collaboration, while the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory and Brookhaven National Laboratory co-lead U.S. participation.

    2
    Sensitive photomultiplier tubes lining the Daya Bay detector walls are designed to amplify and record the faint flashes that signify an antineutrino interaction. (Credit: Roy Kaltschmidt, Berkeley Lab)

    To determine the value of theta13 Daya Bay scientists detected neutrinos of a specific flavor—in this case electron antineutrinos—in each of the underground caverns. Two caverns are near the nuclear reactors and the third cavern is farther away, providing ample distance for the antineutrinos to oscillate. By comparing the number of electron antineutrinos picked up by the near and far detectors, physicists calculated how many changed flavors and, consequently, the value of theta13.

    Daya Bay physicists made the world’s first conclusive measurement of theta13 in 2012 and subsequently improved upon the measurement’s precision as the experiment continued taking data. Now, after nine years of operation and the end of data collection in December 2020, excellent detector performance, and dedicated data analysis, Daya Bay has far exceeded expectations. Working with the complete dataset, physicists have now measured the value of theta13 with a precision two and a half times greater than the experiment’s design goal. No other existing or planned experiment is expected to reach such an exquisite level of precision.

    “We had multiple analysis teams that painstakingly scrutinized the entire dataset, carefully taking into account the evolution of detector performance over the nine years of operation,” said Daya Bay co-spokesperson Jun Cao of IHEP. “The teams took advantage of the large dataset not only to refine the selection of antineutrino events but also to improve the determination of backgrounds. This dedicated effort allowed us to reach an unrivaled level of precision.”

    The precision measurement of theta13 will enable physicists to more easily measure other parameters in neutrino physics, as well as develop more accurate models of subatomic particles and how they interact.

    By investigating the properties and interactions of antineutrinos, physicists may gain insight into the imbalance of matter and antimatter in the universe. Physicists believe that matter and antimatter were created in equal amounts at the time of the Big Bang. But if that were the case, these two opposites should have annihilated, leaving behind only light. Some difference between the two must have tipped the balance to explain the preponderance of matter (and lack of antimatter) in the universe today.

    “We expect there might be some difference between neutrinos and antineutrinos,” said Berkeley physicist and Daya Bay co-spokesperson Kam-Biu Luk. “We’ve never detected differences between particles and antiparticles for leptons, the type of particles that includes neutrinos. We’ve only detected differences between particles and antiparticles for quarks. But the differences we see with the quarks aren’t enough to explain why there’s more matter than antimatter in the universe. It’s possible that neutrinos might be the smoking gun.”

    3
    The Daya Bay experiment measures the antineutrinos produced by the reactors of the Daya Bay Nuclear Power Plant and the Ling Ao Nuclear Power Plant in mainland China. The photo shows a panoramic view of the Daya Bay reactor complex. (Credit: Roy Kaltschmidt, Berkeley Lab)

    The latest analysis of Daya Bay’s final dataset also provided physicists with a precise measurement of the mass splitting. This property dictates the frequency of neutrino oscillations.

    “The measurement of mass splitting was not one of Daya Bay’s original design goals, but it became accessible thanks to the relatively large value of theta13,” Luk said. “We measured the mass splitting to 2.3% with the final Daya Bay dataset, an improvement over the 2.8% precision of the previous Daya Bay measurement.”

    Moving forward, the international Daya Bay collaboration expects to report additional findings from the final dataset, including updates to previous measurements.

    Next-generation neutrino experiments, such as the Deep Underground Neutrino Experiment (DUNE), will leverage the Daya Bay results to precisely measure and compare properties of neutrinos and antineutrinos.

    Currently under construction, DUNE will provide physicists with the world’s most intense neutrino beam, underground detectors separated by 800 miles, and the opportunity to study the behavior of neutrinos like never before.

    “As one of many physics goals, DUNE expects to eventually measure theta13 almost as precisely as Daya Bay,” said Brookhaven experimental physicist and Daya Bay collaborator Elizabeth Worcester. “This is exciting because we will then have precise theta13 measurements from different oscillation channels, which will rigorously test the three-neutrino model. Until DUNE reaches that high precision, we can use Daya Bay’s precise theta13 measurement as a constraint to enable the search for differences between neutrino and antineutrino properties.”

    Scientists will also leverage the large theta13 value and reactor neutrinos to determine which of the three neutrinos is the lightest. “The precise theta13 measurement of Daya Bay improves the mass-ordering sensitivity of the Jiangmen Underground Neutrino Observatory (JUNO), which will complete construction in China next year,” said Yifang Wang, JUNO spokesperson and IHEP director. “Furthermore, JUNO will achieve sub-percent level precision on the mass splitting measured by Daya Bay in several years.”

    The Daya Bay Reactor Neutrino experiment is supported by the Ministry of Science and Technology of China, the DOE Office of Science High Energy Physics program, the Chinese Academy of Sciences, the National Natural Science Foundation of China, and other funding agencies. The Daya Bay collaboration has 237 participants at 42 institutions in Asia, Europe, and North America.

    *Physicists measure theta13 in terms of its oscillation amplitude, or what is mathematically written as sin22q13.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Brookhaven Campus

    One of ten national laboratories overseen and primarily funded by the The DOE Office of Science, The DOE’s Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

    Research at BNL specializes in nuclear and high energy physics, energy science and technology, environmental and bioscience, nanoscience and national security. The 5,300 acre campus contains several large research facilities, including the Relativistic Heavy Ion Collider [below] and National Synchrotron Light Source II [below]. Seven Nobel prizes have been awarded for work conducted at Brookhaven lab.

    BNL is staffed by approximately 2,750 scientists, engineers, technicians, and support personnel, and hosts 4,000 guest investigators every year. The laboratory has its own police station, fire department, and ZIP code (11973). In total, the lab spans a 5,265-acre (21 km^2) area that is mostly coterminous with the hamlet of Upton, New York. BNL is served by a rail spur operated as-needed by the New York and Atlantic Railway. Co-located with the laboratory is the Upton, New York, forecast office of the National Weather Service.

    Major programs

    Although originally conceived as a nuclear research facility, Brookhaven Lab’s mission has greatly expanded. Its foci are now:

    Nuclear and high-energy physics
    Physics and chemistry of materials
    Environmental and climate research
    Nanomaterials
    Energy research
    Nonproliferation
    Structural biology
    Accelerator physics

    Operation

    Brookhaven National Lab was originally owned by the Atomic Energy Commission(US) and is now owned by that agency’s successor, the United States Department of Energy (DOE). DOE subcontracts the research and operation to universities and research organizations. It is currently operated by Brookhaven Science Associates LLC, which is an equal partnership of Stony Brook University and Battelle Memorial Institute. From 1947 to 1998, it was operated by Associated Universities, Inc.(AUI), but AUI lost its contract in the wake of two incidents: a 1994 fire at the facility’s high-beam flux reactor that exposed several workers to radiation and reports in 1997 of a tritium leak into the groundwater of the Long Island Central Pine Barrens on which the facility sits.

    Foundations

    Following World War II, the US Atomic Energy Commission was created to support government-sponsored peacetime research on atomic energy. The effort to build a nuclear reactor in the American northeast was fostered largely by physicists Isidor Isaac Rabi and Norman Foster Ramsey Jr., who during the war witnessed many of their colleagues at Columbia University leave for new remote research sites following the departure of the Manhattan Project from its campus. Their effort to house this reactor near New York City was rivalled by a similar effort at the Massachusetts Institute of Technology to have a facility near Boston, Massachusetts. Involvement was quickly solicited from representatives of northeastern universities to the south and west of New York City such that this city would be at their geographic center. In March 1946 a nonprofit corporation was established that consisted of representatives from nine major research universities — Columbia University, Cornell University, Harvard University, Johns Hopkins University, Massachusetts Institute of Technology, Princeton University, University of Pennsylvania, University of Rochester, and Yale University.

    Out of 17 considered sites in the Boston-Washington corridor, Camp Upton on Long Island was eventually chosen as the most suitable in consideration of space, transportation, and availability. The camp had been a training center from the US Army during both World War I and World War II. After the latter war, Camp Upton was deemed no longer necessary and became available for reuse. A plan was conceived to convert the military camp into a research facility.

    On March 21, 1947, the Camp Upton site was officially transferred from the U.S. War Department to the new U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE).

    Research and facilities

    Reactor history

    In 1947 construction began on the first nuclear reactor at Brookhaven, the Brookhaven Graphite Research Reactor. This reactor, which opened in 1950, was the first reactor to be constructed in the United States after World War II. The High Flux Beam Reactor operated from 1965 to 1999. In 1959 Brookhaven built the first US reactor specifically tailored to medical research, the Brookhaven Medical Research Reactor, which operated until 2000.

    Accelerator history

    In 1952 Brookhaven began using its first particle accelerator, the Cosmotron. At the time the Cosmotron was the world’s highest energy accelerator, being the first to impart more than 1 GeV of energy to a particle.

    BNL Cosmotron 1952-1966.

    The Cosmotron was retired in 1966, after it was superseded in 1960 by the new Alternating Gradient Synchrotron (AGS).

    BNL Alternating Gradient Synchrotron (AGS).

    The AGS was used in research that resulted in 3 Nobel prizes, including the discovery of the muon neutrino, the charm quark, and CP violation.

    In 1970 in BNL started the ISABELLE project to develop and build two proton intersecting storage rings.

    The groundbreaking for the project was in October 1978. In 1981, with the tunnel for the accelerator already excavated, problems with the superconducting magnets needed for the ISABELLE accelerator brought the project to a halt, and the project was eventually cancelled in 1983.

    The National Synchrotron Light Source operated from 1982 to 2014 and was involved with two Nobel Prize-winning discoveries. It has since been replaced by the National Synchrotron Light Source II. [below].

    BNL National Synchrotron Light Source.

    After ISABELLE’S cancellation, physicist at BNL proposed that the excavated tunnel and parts of the magnet assembly be used in another accelerator. In 1984 the first proposal for the accelerator now known as the Relativistic Heavy Ion Collider (RHIC)[below] was put forward. The construction got funded in 1991 and RHIC has been operational since 2000. One of the world’s only two operating heavy-ion colliders, RHIC is as of 2010 the second-highest-energy collider after the Large Hadron Collider(CH). RHIC is housed in a tunnel 2.4 miles (3.9 km) long and is visible from space.

    On January 9, 2020, It was announced by Paul Dabbar, undersecretary of the US Department of Energy Office of Science, that the BNL eRHIC design has been selected over the conceptual design put forward by DOE’s Thomas Jefferson National Accelerator Facility [Jlab] (US) as the future Electron–ion collider (EIC) in the United States.

    Brookhaven Lab Electron-Ion Collider (EIC) to be built inside the tunnel that currently houses the RHIC.

    In addition to the site selection, it was announced that the BNL EIC had acquired CD-0 from the Department of Energy. BNL’s eRHIC design proposes upgrading the existing Relativistic Heavy Ion Collider, which collides beams light to heavy ions including polarized protons, with a polarized electron facility, to be housed in the same tunnel.

    Other discoveries

    In 1958, Brookhaven scientists created one of the world’s first video games, Tennis for Two. In 1968 Brookhaven scientists patented Maglev, a transportation technology that utilizes magnetic levitation.

    Major facilities

    Relativistic Heavy Ion Collider (RHIC), which was designed to research quark–gluon plasma and the sources of proton spin. Until 2009 it was the world’s most powerful heavy ion collider. It is the only collider of spin-polarized protons.

    Center for Functional Nanomaterials (CFN), used for the study of nanoscale materials.

    BNL National Synchrotron Light Source II, Brookhaven’s newest user facility, opened in 2015 to replace the National Synchrotron Light Source (NSLS), which had operated for 30 years. NSLS was involved in the work that won the 2003 and 2009 Nobel Prize in Chemistry.

    Alternating Gradient Synchrotron, a particle accelerator that was used in three of the lab’s Nobel prizes.
    Accelerator Test Facility, generates, accelerates and monitors particle beams.
    Tandem Van de Graaff, once the world’s largest electrostatic accelerator.

    Computational Science resources, including access to a massively parallel Blue Gene series supercomputer that is among the fastest in the world for scientific research, run jointly by Brookhaven National Laboratory and Stony Brook University-SUNY.

    Interdisciplinary Science Building, with unique laboratories for studying high-temperature superconductors and other materials important for addressing energy challenges.
    NASA Space Radiation Laboratory, where scientists use beams of ions to simulate cosmic rays and assess the risks of space radiation to human space travelers and equipment.

    Off-site contributions

    It is a contributing partner to the ATLAS experiment, one of the four detectors located at the The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH)[CERN] Large Hadron Collider(LHC).

    The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH)[CERN] map.

    Iconic view of the European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear] [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] ATLAS detector.

    It is currently operating at The European Organization for Nuclear Research [La Organización Europea para la Investigación Nuclear][Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN] near Geneva, Switzerland.

    Brookhaven was also responsible for the design of the Spallation Neutron Source at DOE’s Oak Ridge National Laboratory, Tennessee.

    DOE’s Oak Ridge National Laboratory Spallation Neutron Source annotated.

    Brookhaven plays a role in a range of neutrino research projects around the world, including the Daya Bay Neutrino Experiment (CN) nuclear power plant, approximately 52 kilometers northeast of Hong Kong and 45 kilometers east of Shenzhen, China.

    Daya Bay Neutrino Experiment (CN) nuclear power plant, approximately 52 kilometers northeast of Hong Kong and 45 kilometers east of Shenzhen, China .


    BNL Center for Functional Nanomaterials.

    BNL National Synchrotron Light Source II.

    BNL NSLS II.

    BNL Relative Heavy Ion Collider Campus.

    BNL/RHIC Star Detector.

    BNL/RHIC Phenix detector.

     
  • richardmitnick 8:12 pm on May 26, 2022 Permalink | Reply
    Tags: "Researchers hunt for one-pole magnets by combining cosmic rays and particle accelerators", , , , By re-analyzing data from a wide range of experimental monopole searches the researchers identified novel limits on monopoles across a wide range of masses., , Neutrino physics, Paul Dirac theorized the existence of one-pole “magnetic monopoles" – particles comparable to electrons but with a magnetic charge., , The interdisciplinary research required bringing together expertise from several distinct corners of science - including accelerator physics; neutrino interactions and cosmic rays., , These results and source of monopoles studied by the researchers will serve as a useful benchmark for interpreting subsequent future monopole searches at terrestrial laboratories.   

    From The Kavli Institute for the Physics and Mathematics of the Universe (IPMU) [カブリ数物連携宇宙研](JP) at The University of Tokyo [東京大学](JP): “Researchers hunt for one-pole magnets by combining cosmic rays and particle accelerators” 

    KavliFoundation

    From The Kavli Institute for the Physics and Mathematics of the Universe (IPMU) [カブリ数物連携宇宙研](JP) at The University of Tokyo [東京大学](JP)

    Kavli IPMU

    May 26, 2022

    Research contact
    Volodymyr Takhistov
    Project Researcher / Kavli IPMU Fellow
    Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), The University of Tokyo
    E-mail:volodymyr.takhistov@ipmu.jp

    Media contact
    Motoko Kakubayashi
    Press officer
    Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), The University of Tokyo
    E-mail:press@ipmu.jp

    Some of the world’s most powerful particle accelerators have helped researchers draw new leading limits on the existence of long theorized magnetic monopoles from the collisions of energetic cosmic rays bombarding the Earth’s atmosphere, reports a new study published in Physical Review Letters.

    1
    Figure 1. Schematic illustration of magnetic compass and hypothetical magnetic monopole (Credit: Kavli IPMU)

    Magnets are intimately familiar to everyone, with wide-ranging applications within daily life, from TVs and computers to kids toys. However, breaking any magnet, such as a navigation compass needle consisting of north and south poles in half, will result in just two smaller two-pole magnets. This mystery has eluded researchers for decades since 1931, when physicist Paul Dirac theorized the existence of one-pole “magnetic monopoles” – particles comparable to electrons but with a magnetic charge.

    To explore whether magnetic monopoles exist, an international team of researchers, including the University of Tokyo’s Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Fellow Volodymyr Takhistov, studied available data from a variety of terrestrial experiments and have carried out the most sensitive searches to date for monopoles over a broad range of possible masses. The researchers focused on an unusual source of monopoles – atmospheric collisions of cosmic rays that have been occurring for eons.

    The interdisciplinary research required bringing together expertise from several distinct corners of science – including accelerator physics, neutrino interactions and cosmic rays.

    Cosmic ray collisions with the atmosphere have already played a central role in advancing science, especially the exploration of ghostly neutrinos. This lead to Kavli IPMU Senior Fellow Takaaki Kajita’s 2015 Nobel Prize in Physics for the discovery by the Super-Kamiokande experiment that neutrinos oscillate in flight, implying that they have mass.

    Partially inspired by the results of Super-Kamiokande, the team set to work on monopoles. Particularly intriguing were light monopoles with masses around the electroweak scale, which can be readily accessible to conventional particle accelerators.

    By carrying out simulations of cosmic ray collisions, analogously to particle collisions at the LHC at CERN, the researchers obtained a persistent beam of light monopoles raining down upon different terrestrial experiments.

    2
    Figure 2. A schematic illustration of magnetic monopole (M) production from collisions of cosmic rays with the Earth’s atmosphere. (Credit: Volodymyr Takhistov)

    This unique source of monopoles is especially interesting, as it is independent of any pre-existing monopoles such as those potentially left over as relics from the early Universe, and covers a broad range of energies.

    By re-analyzing data from a wide range of previous experimental monopole searches, the researchers identified novel limits on monopoles across a wide range of masses, including those beyond the reach of conventional collider monopole searches.

    These results and source of monopoles studied by the researchers will serve as a useful benchmark for interpreting subsequent future monopole searches at terrestrial laboratories.

    Details of their study were published in Physical Review Letters on 17 May, 2022.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Kavli Institute for the Physics and Mathematics of the Universe (IPMU) [カブリ数物連携宇宙研](JP) at The University of Tokyo [東京大学](JP) is an international research institute with English as its official language. The goal of the institute is to discover the fundamental laws of nature and to understand the Universe from the synergistic perspectives of mathematics, astronomy, and theoretical and experimental physics. The Institute for the Physics and Mathematics of the Universe (IPMU) was established in October 2007 under the World Premier International Research Center Initiative (WPI) of the Ministry of Education, Sports, Science and Technology in Japan with the University of Tokyo as the host institution. IPMU was designated as the first research institute within the University of Tokyo Institutes for Advanced Study (UTIAS) in January 2011. It received an endowment from The Kavli Foundation and was renamed the “Kavli Institute for the Physics and Mathematics of the Universe” in April 2012. Kavli IPMU is located on the Kashiwa campus of the University of Tokyo, and more than half of its full-time scientific members come from outside Japan.

    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 8:43 am on February 28, 2022 Permalink | Reply
    Tags: "Local nuclear reactor helps UChicago scientists catch and study neutrinos", , , Neutrino physics, ,   

    From The University of Chicago (US): “Local nuclear reactor helps UChicago scientists catch and study neutrinos” 

    U Chicago bloc

    From The University of Chicago (US)

    Feb 24, 2022
    Louise Lerner

    1
    University of Chicago graduate student Mark Lewis observes the compact neutrino detector (visible as the black cube on top of a silver platform) next to the containment wall of a reactor at Constellation’s Dresden Generating Station. Photo courtesy Collar lab.

    ‘Ghost particles’ research could bolster physics, nuclear nonproliferation.

    A nuclear reactor at an Illinois energy plant is helping University of Chicago scientists learn how to catch and understand the tiny, elusive particles known as neutrinos.

    At Constellation’s (formerly Exelon) Dresden Generating Station in Morris, Illinois, the team took the first measurements of neutrinos coming off a nuclear reactor with a tiny detector. These particles are extremely hard to catch because they interact so rarely with matter, but power reactors are one of the few places on Earth with a high concentration of them.

    “This was an exciting opportunity to benefit from the enormous neutrino production from a reactor, but also a challenge in the noisy industrial environment right next to a reactor,” said Prof. Juan Collar, a particle physicist who led the research. “This is the closest that neutrino physicists have been able to get to a commercial reactor core. We gained unique experience in operating a detector under these conditions, thanks to Constellation’s generosity in accommodating our experiment.”

    With this knowledge, the group is planning to take more measurements that may be able to tease out answers to questions about the fundamental laws governing particle and nuclear interactions.

    The technique may also be useful in nuclear nonproliferation, because the neutrinos can tell scientists about what’s going on in the core of the reactor. Detectors could be placed next to reactors as a safeguard to monitor whether the reactor is being used for energy production or to make weapons.

    “Orders of magnitude”

    Neutrinos are sometimes called “ghost particles” because they pass invisibly through almost all matter.

    (Billions have already zipped through your body today without your notice, en route from elsewhere in outer space.) But if you can catch them, they can tell you about what’s happening where they came from, and about the fundamental properties of the universe.

    In particular, scientists would like to learn about specific aspects of neutrino behavior—whether they have electromagnetic properties (for instance, a “magnetic moment”), and whether they interact with as yet unknown particles hiding from our notice, or in new ways with known particles. Taking extensive measurements of as many neutrinos as possible can help narrow down these possibilities.

    The need for many neutrinos is what drew Collar’s team to nuclear reactors. “Commercial reactors are the largest source of neutrinos on Earth by orders of magnitude,” he said. In the normal course of operation, nuclear reactors produce astronomical numbers of neutrinos per second. They occur when atoms inside the reactor break up into lighter elements, and release some of the energy in the form of neutrinos.

    However, there’s a problem. Because neutrinos are so lightweight, and interact so rarely, scientists normally have to find them by filling an enormous tank with detecting fluids and then search for the telltale signal that a passing particle has produced one of a number of known reactions in it.

    But there’s no room inside a commercial nuclear reactor for a multi-ton detector. The researchers needed something much, much smaller. Luckily, Collar is an expert in building such devices; he previously lead a team that built the world’s smallest neutrino detector.

    2
    The international COHERENT Collaboration, which includes physicists at UChicago use a detector that’s small and lightweight enough for a researcher to carry. Their findings, which confirm the theory of The DOE’s Fermi National Accelerator Laboratory (US)’s Daniel Freedman, were reported Aug. 3 in the journal Science.

    In a second stroke of luck, Illinois is one of the leading nuclear energy states—about half the state’s electricity is generated at nuclear reactors. Constellation granted Collar permission to test the detector at Dresden Generating Station, one of the first-ever commercial nuclear plants in the nation.

    4
    An exterior view of Commonwealth Edison Company’s Dresden nuclear power station near Morris, Illinois.
    Credit: The Department of Energy (US).

    Previously, Collar and his team had tested their tiny detectors at a particle accelerator in The DOE’s Oak Ridge National Laboratory in Tennessee, where they were able to carefully control much of the environment in order to get a good signal. But in order for the detector to work at Dresden, they had to build a new version adapted to deal with the much noisier environment of an operating commercial reactor.

    “You’re getting radiation, heat, vibration from the turbines, radiofrequency noise from the pumps and other machinery,” Collar said. “But we managed to work around all the challenges that were thrown our way.”

    They designed the detector with a complex multi-layered shielding to protect it from other stray particles that would contaminate the data. Eventually, they were able to leave the detector in place to function unattended for several months, taking data all the while.

    The team next hopes to take data at another reactor down the road at Constellation’s Braidwood Generating Station, or at the Vandellòs nuclear plant in coastal Spain. “This method can really contribute to our understanding of neutrino properties,” Collar said. “A lot of theoretical knowledge can be extracted from our data.”

    The knowledge about operating small detectors in such noisy environments is also in high demand. “There is an interest in the nuclear nonproliferation community to set detectors next to reactors, because they can tell you what’s going on in the core—revealing any deviations from the declared use,” Collar said.

    The output of neutrinos changes according to what kind of fuel the reactor is burning and what it’s producing, so detectors should be able to monitor for warning signs of weapons production, or whether fuel is being secretly diverted elsewhere. But to make this goal a reality, such detectors would have to be small, robust and easy to use; Collar said the Dresden work helps gather valuable data to make such detectors possible.

    There may also be many other uses for neutrino detectors. “For example, once we have sufficiently sensitive neutrino detectors, you could use them to map the interior of the Earth—perhaps even detect oil or other useful deposits,” Collar said. “A lot of thinking along these lines has been done, but it is still in the future.”

    While working on the design, Collar was reminded that his laboratory on campus continues a line of work initiated by Prof. Willard Libby in the 1950s to discover how to use carbon-dating to tell the age of an object.

    “These pioneers had to come up with techniques that we still use today to find a relatively small signal amongst a great deal of background noise,” he said. “It’s rewarding to think our work is part of a long local tradition. And Illinois is a special place for nuclear power generation, for similar reasons.”

    Science papers:

    Physical Review D

    Suggestive evidence for Coherent Elastic Neutrino-Nucleus Scattering from reactor antineutrinos

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Chicago Campus

    The University of Chicago (US) is an urban research university that has driven new ways of thinking since 1890. Our commitment to free and open inquiry draws inspired scholars to our global campuses, where ideas are born that challenge and change the world.

    We empower individuals to challenge conventional thinking in pursuit of original ideas. Students in the College develop critical, analytic, and writing skills in our rigorous, interdisciplinary core curriculum. Through graduate programs, students test their ideas with University of Chicago scholars, and become the next generation of leaders in academia, industry, nonprofits, and government.

    University of Chicago research has led to such breakthroughs as discovering the link between cancer and genetics, establishing revolutionary theories of economics, and developing tools to produce reliably excellent urban schooling. We generate new insights for the benefit of present and future generations with our national and affiliated laboratories: DOE’s Argonne National Laboratory (US), DOE’s Fermi National Accelerator Laboratory (US), and the Marine Biological Laboratory in Woods Hole, Massachusetts.
    The University of Chicago is enriched by the city we call home. In partnership with our neighbors, we invest in Chicago’s mid-South Side across such areas as health, education, economic growth, and the arts. Together with our medical center, we are the largest private employer on the South Side.

    In all we do, we are driven to dig deeper, push further, and ask bigger questions—and to leverage our knowledge to enrich all human life. Our diverse and creative students and alumni drive innovation, lead international conversations, and make masterpieces. Alumni and faculty, lecturers and postdocs go on to become Nobel laureates, CEOs, university presidents, attorneys general, literary giants, and astronauts. The University of Chicago is a private research university in Chicago, Illinois. Founded in 1890, its main campus is located in Chicago’s Hyde Park neighborhood. It enrolled 16,445 students in Fall 2019, including 6,286 undergraduates and 10,159 graduate students. The University of Chicago is ranked among the top universities in the world by major education publications, and it is among the most selective in the United States.

    The university is composed of one undergraduate college and five graduate research divisions, which contain all of the university’s graduate programs and interdisciplinary committees. Chicago has eight professional schools: the Law School, the Booth School of Business, the Pritzker School of Medicine, the School of Social Service Administration, the Harris School of Public Policy, the Divinity School, the Graham School of Continuing Liberal and Professional Studies, and the Pritzker School of Molecular Engineering. The university has additional campuses and centers in London, Paris, Beijing, Delhi, and Hong Kong, as well as in downtown Chicago.

    University of Chicago scholars have played a major role in the development of many academic disciplines, including economics, law, literary criticism, mathematics, religion, sociology, and the behavioralism school of political science, establishing the Chicago schools in various fields. Chicago’s Metallurgical Laboratory produced the world’s first man-made, self-sustaining nuclear reaction in Chicago Pile-1 beneath the viewing stands of the university’s Stagg Field. Advances in chemistry led to the “radiocarbon revolution” in the carbon-14 dating of ancient life and objects. The university research efforts include administration of DOE’s Fermi National Accelerator Laboratory(US) and DOE’s Argonne National Laboratory(US), as well as the U Chicago Marine Biological Laboratory in Woods Hole, Massachusetts (MBL)(US). The university is also home to the University of Chicago Press, the largest university press in the United States. The Barack Obama Presidential Center is expected to be housed at the university and will include both the Obama presidential library and offices of the Obama Foundation.

    The University of Chicago’s students, faculty, and staff have included 100 Nobel laureates as of 2020, giving it the fourth-most affiliated Nobel laureates of any university in the world. The university’s faculty members and alumni also include 10 Fields Medalists, 4 Turing Award winners, 52 MacArthur Fellows, 26 Marshall Scholars, 27 Pulitzer Prize winners, 20 National Humanities Medalists, 29 living billionaire graduates, and have won eight Olympic medals.

    The University of Chicago is enriched by the city we call home. In partnership with our neighbors, we invest in Chicago’s mid-South Side across such areas as health, education, economic growth, and the arts. Together with our medical center, we are the largest private employer on the South Side.

    In all we do, we are driven to dig deeper, push further, and ask bigger questions—and to leverage our knowledge to enrich all human life. Our diverse and creative students and alumni drive innovation, lead international conversations, and make masterpieces. Alumni and faculty, lecturers and postdocs go on to become Nobel laureates, CEOs, university presidents, attorneys general, literary giants, and astronauts.

    Research

    According to the National Science Foundation (US), University of Chicago spent $423.9 million on research and development in 2018, ranking it 60th in the nation. It is classified among “R1: Doctoral Universities – Very high research activity” and is a founding member of the Association of American Universities (US) and was a member of the Committee on Institutional Cooperation from 1946 through June 29, 2016, when the group’s name was changed to the Big Ten Academic Alliance. The University of Chicago is not a member of the rebranded consortium, but will continue to be a collaborator.

    The university operates more than 140 research centers and institutes on campus. Among these are the Oriental Institute—a museum and research center for Near Eastern studies owned and operated by the university—and a number of National Resource Centers, including the Center for Middle Eastern Studies. Chicago also operates or is affiliated with several research institutions apart from the university proper. The university manages DOE’s Argonne National Laboratory(US), part of the United States Department of Energy’s national laboratory system, and co-manages DOE’s Fermi National Accelerator Laboratory (US), a nearby particle physics laboratory, as well as a stake in the Apache Point Observatory (US) in Sunspot, New Mexico.
    _____________________________________________________________________________________

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft).

    Apache Point Observatory (US), near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft).
    _____________________________________________________________________________________

    Faculty and students at the adjacent Toyota Technological Institute at Chicago collaborate with the university. In 2013, the university formed an affiliation with the formerly independent Marine Biological Laboratory in Woods Hole, Mass. Although formally unrelated, the National Opinion Research Center (US) is located on Chicago’s campus.

     
  • richardmitnick 10:25 am on December 26, 2021 Permalink | Reply
    Tags: "2021 A year physicists asked 'What lies beyond the Standard Model?'", , , , , , , Neutrino physics, Neutrinos [tau;muon;electron] represent three of the 17 fundamental particles in the Standard Model., , , ,   

    From The Conversation (AU) via phys.org : “2021 A year physicists asked ‘What lies beyond the Standard Model?'” 

    From The Conversation (AU)

    via

    phys.org

    December 23, 2021
    Aaron McGowan, The Conversation

    1
    Experiments at the Large Hadron Collider in Europe, like the ATLAS calorimeter seen here, are providing more accurate measurements of fundamental particles. Credit: Maximilien Brice, CC BY-NC.

    European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) [CERN].

    “If you ask a physicist like me to explain how the world works, my lazy answer might be: ‘It follows the Standard Model.’

    Standard Model of Particle Physics, Quantum Diaries

    The Standard Model explains the fundamental physics of how the universe works. It has endured over 50 trips around the Sun despite experimental physicists constantly probing for cracks in the model’s foundations.

    With few exceptions, it has stood up to this scrutiny, passing experimental test after experimental test with flying colors. But this wildly successful model has conceptual gaps that suggest there is a bit more to be learned about how the universe works.

    I am a neutrino physicist. Neutrinos represent three of the 17 fundamental particles in the Standard Model. They zip through every person on Earth at all times of day. I study the properties of interactions between neutrinos and normal matter particles.

    In 2021, physicists around the world ran a number of experiments that probed the Standard Model. Teams measured basic parameters of the model more precisely than ever before. Others investigated the fringes of knowledge where the best experimental measurements don’t quite match the predictions made by the Standard Model. And finally, groups built more powerful technologies designed to push the model to its limits and potentially discover new particles and fields. If these efforts pan out, they could lead to a more complete theory of the universe in the future.

    Filling holes in Standard Model

    In 1897, J.J. Thomson discovered the first fundamental particle, the electron, using nothing more than glass vacuum tubes and wires. More than 100 years later, physicists are still discovering new pieces of the Standard Model.

    2
    The Standard Model of physics allows scientists to make incredibly accurate predictions about how the world works, but it doesn’t explain everything. Credit: CERN, CC BY-NC.

    The Standard Model is a predictive framework that does two things. First, it explains what the basic particles of matter are. These are things like electrons and the quarks that make up protons and neutrons. Second, it predicts how these matter particles interact with each other using “messenger particles.” These are called bosons—they include photons and the famous Higgs boson—and they communicate the basic forces of nature. The Higgs boson wasn’t discovered until 2012 after decades of work at The European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire](CH), the huge particle collider in Europe.

    European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) CMS Higgs Event May 27, 2012.

    European Organization for Nuclear Research [Organisation européenne pour la recherche nucléaire] [Europäische Organisation für Kernforschung](CH) ATLAS Higgs Event June 18, 2012.

    Peter Higgs – University of Edinburgh [Oilthigh Dhùn Èideann] (SCT).

    The Standard Model is incredibly good at predicting many aspects of how the world works, but it does have some holes.

    Notably, it does not include any description of gravity. While Albert Einstein’s Theory of General Relativity describes how gravity works, physicists have not yet discovered a particle that conveys the force of gravity [Quantum Mechanics’ ‘graviton’]. A proper “Theory of Everything” would do everything the Standard Model can, but also include the messenger particles that communicate how gravity interacts with other particles.

    Another thing the Standard Model can’t do is explain why any particle has a certain mass—physicists must measure the mass of particles directly using experiments. Only after experiments give physicists these exact masses can they be used for predictions. The better the measurements, the better the predictions that can be made.

    Recently, physicists on a team at CERN measured how strongly the Higgs boson feels itself.

    4
    Twice the Higgs, twice the challenge
    ATLAS searches for pairs of Higgs bosons in the rare bbɣɣ decay channel, 29 March 2021.

    Another CERN team also measured the Higgs boson’s mass more precisely than ever before.

    4
    A new result by the CMS Collaboration narrows down the mass of the Higgs boson to a precision of 0.1%.

    And finally, there was also progress on measuring the mass of neutrinos.

    KATRIN experiment aims to measure the mass of the neutrino using a huge device called a spectrometer (interior shown)KIT Karlsruhe Institute of Technology [Karlsruher Institut für Technologie] (DE).

    Physicists know neutrinos have more than zero mass but less than the amount currently detectable. A team in Germany has continued to refine the techniques that could allow them to directly measure the mass of neutrinos.

    Hints of new forces or particles

    In April 2021, members of the Muon g-2 experiment at Fermilab announced their first measurement of the magnetic moment of the muon.

    DOE’s Fermi National Accelerator Laboratory(US) Muon g-2 studio. As muons race around a ring at the Muon g-2 studio, their spin axes twirl, reflecting the influence of unseen particles.

    The muon is one of the fundamental particles in the Standard Model, and this measurement of one of its properties is the most accurate to date. The reason this experiment was important was because the measurement didn’t perfectly match the Standard Model prediction of the magnetic moment. Basically, muons don’t behave as they should. This finding could point to undiscovered particles that interact with muons.

    But simultaneously, in April 2021, physicist Zoltan Fodor and his colleagues showed how they used a mathematical method called Lattice QCD to precisely calculate the muon’s magnetic moment. Their theoretical prediction is different from old predictions, still works within the Standard Model and, importantly, matches experimental measurements of the muon.

    The disagreement between the previously accepted predictions, this new result and the new prediction must be reconciled before physicists will know if the experimental result is truly beyond the Standard Model.

    Upgrading the tools of physics

    Physicists must swing between crafting the mind-bending ideas about reality that make up theories and advancing technologies to the point where new experiments can test those theories. 2021 was a big year for advancing the experimental tools of physics.

    First, the world’s largest particle accelerator, the Large Hadron Collider at CERN, was shut down and underwent some substantial upgrades. Physicists just restarted the facility in October, and they plan to begin the next data collection run in May 2022. The upgrades have boosted the power of the collider so that it can produce collisions at 14 TeV, up from the previous limit of 13 TeV. This means the batches of tiny protons that travel in beams around the circular accelerator together carry the same amount of energy as an 800,000-pound (360,000-kilogram) passenger train traveling at 100 mph (160 kph). At these incredible energies, physicists may discover new particles that were too heavy to see at lower energies.

    SixTRack CERN LHC particles.

    Some other technological advancements were made to help the search for dark matter. Many astrophysicists believe that dark matter particles, which don’t currently fit into the Standard Model, could answer some outstanding questions regarding the way gravity bends around stars—called gravitational lensing—as well as the speed at which stars rotate in spiral galaxies. Projects like the Cryogenic Dark Matter Search have yet to find dark matter particles, but the teams are developing larger and more sensitive detectors to be deployed in the near future.

    Gravitational Lensing Gravitational Lensing National Aeronautics Space Agency (US) and European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU).


    Super Cryogenic Dark Matter Search at DOE’s SLAC National Accelerator Laboratory (US) at Stanford University (US) at SNOLAB (Vale Inco Mine, Sudbury, Canada).

    Particularly relevant to my work with neutrinos is the development of immense new detectors like Hyper-Kamiokande and DUNE.

    Hyper-Kamiokande [(神岡宇宙素粒子研究施設](JP) a neutrino physics laboratory to be located underground in the Mozumi Mine of the Kamioka Mining and Smelting Co. near the Kamioka section of the city of Hida in Gifu Prefecture, Japan.

    DOE’s Fermi National Accelerator Laboratory(US) DUNE LBNF (US) from FNAL to Sanford Underground Research Facility, Lead, South Dakota, USA.

    DOE’s Fermi National Accelerator Laboratory(US) DUNE LBNF (US) Caverns at Sanford Underground Research Facility.

    Using these detectors, scientists will hopefully be able to answer questions about a fundamental asymmetry in how neutrinos oscillate. They will also be used to watch for proton decay, a proposed phenomenon that certain theories predict should occur.

    2021 highlighted some of the ways the Standard Model fails to explain every mystery of the universe. But new measurements and new technology are helping physicists move forward in the search for the Theory of Everything.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation (AU) launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 8:57 am on August 31, 2021 Permalink | Reply
    Tags: , , , Neutrino oscillation, Neutrino physics, , , , Solar Neutrino Problem   

    From Sanford Underground Research Facility-SURF: “The neutrino puzzle” 

    SURF-Sanford Underground Research Facility, Lead, South Dakota, USA.

    From Sanford Underground Research Facility-SURF

    Homestake Mining, Lead, South Dakota, USA.


    Homestake Mining Company

    August 30, 2021
    Constance Walter

    Researchers continue to piece together information about the ghostly particle.

    Imagine trying to put together a jigsaw puzzle that has no picture for reference, is missing several pieces and, of the pieces you do have, some don’t quite fit together.

    Welcome to the life of a neutrino researcher.

    Vincente Guiseppe began his neutrino journey 15 years ago as a post-doc at DOE’s Los Alamos National Laboratory (US). He worked with germanium detectors and studied radon while a graduate student and followed the scientific community’s progress as the Solar Neutrino Problem was solved. The so-called Solar Neutrino Problem was created when Dr. Ray Davis Jr., who operated a solar neutrino experiment on the 4850 Level of the Homestake Gold Mine, discovered only one-third of the neutrinos that had been theorized. Nearly 30 years after Davis began his search, the problem was solved with the discovery of neutrino oscillation.

    “I began to understand that neutrinos had much more in store for us. That led me to move to neutrino physics and set me up to transition to the Majorana Demonstrator (Majorana) project,” said Guiseppe, who is now a co-spokesperson for Majorana, located nearly a mile underground at SURF, and a senior research staff member at DOE’s Oak Ridge National Lab (ORNL).

    Majorana uses germanium crystals in a search for the theorized Majorana particle—a neutrino that is believed to be its own antiparticle. Its discovery could help unravel mysteries about the origins of the universe and would add yet another piece to this baffling neutrino puzzle.

    We caught up with Guiseppe recently to talk about neutrinos—what scientists know (and don’t know), why neutrinos behave so strangely and why scientists keep searching for this ghost-like particle.

    SURF: What are neutrinos?

    Guiseppe: Let’s start with what we know. Of all the known fundamental particles that have mass, neutrinos are the most abundant—only the massless photon, which we see as light, is more abundant. We know their mass is quite small, but not zero—much lighter than their counterparts in the Standard Model of Physics—and we know there are three types and that they can change flavors. They also rarely interact with matter, which makes them difficult to study.

    All of these data points are pieces of that neutrino puzzle. But every piece is important if we want to complete the picture.

    SURF: Why should we care about the neutrino?

    Guiseppe: We care because they are so abundant. It’s almost embarrassing to have something that is so prevalent all around us and to not fully understand it. Think of it this way: You see a forest and the most abundant thing in that forest is a tree. But that’s all you know. You don’t know anything about how a tree operates. You don’t know how it grows, you don’t know why it’s green, you don’t know why it’s alive. It would be embarrassing to not know that. But that’s not the case with trees. Something so abundant as what we see in nature—animal species, trees, plants—we understand them completely, there’s nothing surprising. So, the fact that they are so abundant, and yet we know so little about them, brings a sort of duty to understand them.

    SURF: What intrigues you most about neutrino research?

    Guiseppe: Most? I would say the breadth of research and the big questions that can be answered by a single particle. While similar claims could be made about other particle research, the experimental approach is wide open. We look for neutrinos from nuclear reactors, particle accelerators, the earth, our atmosphere, the sun, from supernovae, and some experiments are only satisfied if we find no neutrinos, as in the case of neutrinoless double-beta decay searches. Neutrino research places detectors in underground caverns, at the South Pole, in the ocean, and even in a van for drive-by neutrino monitoring for nuclear safeguard applications. It’s a diverse field with big and unique questions.

    SURF: What is oscillation?

    Guiseppe: Oscillation is the idea that neutrinos can co-exist in a mixture of types or “flavors.” While they must start out as a particular flavor upon formation, they can evolve into a mixture of other flavors while traveling before falling into one flavor upon interaction with matter or detection. Hence, they are observed to oscillate between flavors from formation to detection.

    SURF: It’s a fundamental idea that a thing can’t become another thing unless acted upon by an outside force or material. How can something spontaneously become something it wasn’t a split second ago? And why are we OK with that?

    Guiseppe: Are people really okay with the idea of neutrinos changing flavors? I think we are, inasmuch as we are really okay with the implications of quantum mechanics? (As an aside, this reminds me of a question I asked my undergraduate quantum mechanics professor. I felt I was doing fine in the class and could work the problems but was worried that I really didn’t understand quantum mechanics. He responded with a slight grin: “Oh, no one really ‘understands’ quantum mechanics.”).

    It is quantum mechanics at work that makes this flavor change possible. Since neutrinos come in three separate flavors and three separate masses (and more importantly, each flavor does not come as a definite mass), they can exist in a quantum mechanical mixture of flavors. The root of your concern stems from the idea of its identify—what does it mean to change this identity?

    The comforting aspect is that neutrinos are not found to change speed, direction, mass, shape, or anything else that would require an outside force or energy in the usual sense. By changing flavor, the neutrino is only changing its personality and the rules by which it should follow at a given time.

    While this bit of personification is probably not comforting, it is only how the neutrino must interact with other particles that changes over time. You could think of the neutrino as being formed as one type, but then realizing it is not forced into that identity. It then remains in an indecisive state while being swayed to one type over another before finally making a decision upon detection or other interaction. In that sense, it is not a spontaneous change, but the result of a well thought-out (or predictable) decision process.

    SURF: What is a Majorana Particle and why is it important?

    Guiseppe: A Majorana particle is one that is indistinguishable from its antimatter partner. This sets it apart from all other particles. With the Majorana Demonstrator, we are looking for this particle in a process called neutrinoless double-beta decay.

    Neutrinoless double-beta decay is a nuclear process whereby two neutrons transform into two protons and electrons (aka, beta particles), but without the emission of two anti-neutrinos. This is in contrast to the two neutrino double-beta decay process where the two anti-neutrinos are emitted; a process that has been observed.

    SURF: Why neutrinoless double-beta decay?

    Guiseppe: Neutrinoless double-beta decay experiments offer the right mix of simplicity, experimental challenges, and the potential for a fascinating discovery. The signature for neutrinoless double-beta decay is simple: a measurement made at a specific energy and at a fixed point in the detector. But it’s a rare occurrence that is easily obscured so reducing all background (interferences) that can partially mimic this signature and foil the measurement is critical. Searching for this decay requires innovative detectors, as well as the ability to control the ubiquitous radiation found in everything around us.

    SURF: After so many years, how do you stay enthusiastic about neutrino research?

    Guiseppe: Its book isn’t finished yet. We have more to learn and more questions to answer—we only need the means to do so. I stay enthused due to the likelihood of some new surprises (or comforting discoveries) that await. Along the way, we can continue to make advances in detector technology and develop new (or cleaner) materials, which inevitably lead to applications outside of physics research. In the end, chasing down neutrino properties and the secrets they may hold remains exciting due to clever ideas that keep the next discovery within reach.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    About us: The Sanford Underground Research Facility-SURF in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The The U Washington MAJORANA Neutrinoless Double-beta Decay Experiment Demonstrator experiment (US), also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    The LUX Xenon dark matter detector | Sanford Underground Research Facility mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC National Accelerator Laboratory(US) physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.

    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”

    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

    FNAL DUNE LBNF (US) from FNAL to SURF, Lead, South Dakota, USA

    FNAL DUNE LBNF (US) Caverns at Sanford Lab.

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with Germanium Detector Array (or GERDA) experiment is searching for neutrinoless double beta decay (0νββ) in Ge-76 at the underground Laboratori Nazionali del Gran Sasso (LNGS) for a future tonne-scale 76Ge 0νββ search.

    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 11:54 am on February 1, 2021 Permalink | Reply
    Tags: "Andreas Ekström will explore the secrets of the strong force in atomic nuclei", , , Neutrino physics, , , , , ,   

    From Chalmers University of Technology [ tekniska högskola ](SE): “Andreas Ekström will explore the secrets of the strong force in atomic nuclei” 

    From Chalmers University of Technology [ tekniska högskola ](SE)

    25 Aug 2017 [Brought forward 1.31.21. Why now?]

    1
    For the next five years, Andreas Ekström will lead a research project funded with 1,5 M€ from the European Research Council (ERC). The goal is to establish new methods and theories to model atomic nuclei. Credit: Mia Halleröd Palmgren.

    All visible matter in the universe consists of atoms. The constituents of the atomic nucleus are held together by a force called the strong force. Despite its central importance, we do not yet know how it works. Researchers from Chalmers University of Technology will therefore try to reveal new information about atomic nuclei.

    “We need to create a solid theoretical framework to describe the strong force between protons and neutrons in atomic nuclei. Today’s theories form an incomplete patchwork”, says Andreas Ekström, researcher at the Department of Physics at Chalmers University of Technology.

    For the next five years, he will lead a research project funded with 1,5 M€ from the European Research Council (ERC). The goal is to establish new methods and theories to model atomic nuclei. He will focus on heavy, unstable, and exotic nuclei that so far have eluded researchers all over the world.

    ” To generate new knowledge about the strong force, I will investigate heavy atomic nuclei such as oxygen and calcium. A heavy nucleus typically contains more information than a light nucleus such as helium. However, it’s a greater challenge to analyze heavy nuclei”, says Andreas Ekström.

    1

    In his project, he will introduce new ways to exploit data from existing experiments and theoretically disassemble atomic nuclei to better understand the strong force. More or less laying the puzzle backwards. Since a heavy nucleus consists of considerably more neutrons and protons than a light one, it will be a tricky puzzle with many pieces to keep track of.

    But the research project is not only about describing the strong force in nuclei. It is also essential to work out methods for calculating the uncertainties in the models.

    “Many fields of research are based on input from fundamental . It is also very expensive and time consuming to conduct large experiments. Therefore, it is important that we can offer predictions with great precision.”

    The basic research that is conducted by Andreas Ekström is essential for understanding stellar physics and fusion processes in the sun as well as neutrino physics. The aim is to solve one of the great mysteries of our universe.

    “The strong force affects everything – from the smallest atomic nucleus to the biggest star – and a well-functioning society is based on understanding the world we live in. We need fundamental research as a pillar of society. Even though we will not have all the answers in five years, I hope that we can make important progress. My previous research has shown that the proposed method of laying the puzzle backwards is a possible way ahead”, says Andreas Ekström.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Chalmers University of Technology [tekniska högskola](SE) is a Swedish university located in Gothenburg that focuses on research and education in technology, natural science, architecture, maritime and other management areas

    The University was founded in 1829 following a donation by William Chalmers, a director of the Swedish East India Company. He donated part of his fortune for the establishment of an “industrial school”. Chalmers was run as a private institution until 1937, when the institute became a state-owned university. In 1994, the school was incorporated as an aktiebolag under the control of the Swedish Government, the faculty and the Student Union. Chalmers is one of only three universities in Sweden which are named after a person, the other two being Karolinska Institutet and Linnaeus University.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: