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  • richardmitnick 12:46 pm on September 23, 2018 Permalink | Reply
    Tags: , At CERN-The hunt for leptoquarks is on, , Particle Accelerators, ,   

    From CERN: “The hunt for leptoquarks is on” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    19 Sep 2018
    Achintya Rao

    1
    A collision event recorded by CMS at the start of the data-taking run of 2018. CMS sifts through such collisions up to 40 million times per second looking for signs of hypothetical particles like leptoquarks (Image: Thomas McCauley/Tai Sakuma/CMS/CERN)

    Matter is made of elementary particles, and the Standard Model of particle physics states that these particles occur in two families: leptons (such as electrons and neutrinos) and quarks (which make up protons and neutrons).

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    Under the Standard Model, these two families are totally distinct, with different electric charges and quantum numbers, but have the same number of generations (see image below).

    However, some theories that go beyond the Standard Model, including certain “grand unified theories”, predict that leptons and quarks merge at high energies to become leptoquarks. These leptoquarks are proposed in theories attempting to unify the strong, weak and electromagnetic forces.

    Such “unifications” are not unusual in physics. Electricity and magnetism were famously unified in the 19th century into a single force known as electromagnetism, via Maxwell’s elegant mathematical formulae. In the case of leptoquarks, these hybrid particles are thought to have the properties of both leptons and quarks, as well as the same number of generations. This would not only allow them to “split” into the two types of particles but would also allow leptons to change into quarks and vice versa. Indeed, anomalies detected by the LHCb experiment as well as by Belle and Babar in measurements of the properties of B mesons could be also explained by the existence of these hypothesised particles.

    Standard Model Image by Daniel Dominguez-CERN

    KEK Belle 2 detector, in Tsukuba, Ibaraki Prefecture, Japan


    SLAC/Babar

    If leptoquarks exist, they would be very heavy and quickly transform, or “decay”, into more stable leptons or quarks. Previous experiments at the SPS and LEP at CERN, HERA at DESY and the Tevatron at Fermilab have looked at decays to first- and second-generation particles. Searches for third-generation leptoquarks (LQ3) were first performed at the Tevatron, and are now being explored at the Large Hadron Collider (LHC).

    The Super Proton Synchrotron (SPS), CERN’s second-largest accelerator.


    CERN LEP Collider

    DESY HERA , 1992 to 2007

    FNAL/Tevatron map


    FNAL/Tevatron

    Since leptoquarks would transform into a lepton and a quark, LHC searchers look for telltale signatures in the distributions of these “decay products”. In the case of third-generation leptoquarks, the lepton could be a tau or a tau neutrino while the quark could be a top or bottom.

    In a recent paper [The European Physical Journal C], using data collected in 2016 at a collision energy of 13 TeV, the Compact Muon Solenoid (CMS) collaboration at the LHC presented the results of searches for third-generation leptoquarks, where every LQ3 produced in the collisions initially transformed into a tau-top pair.

    CERN/CMS Detector

    Because colliders produce particles and antiparticles at the same time, CMS specifically searched for the presence of leptoquark-antileptoquark pairs in collision events containing the remnants of a top quark, an antitop quark, a tau lepton and an antitau lepton. Further, because leptoquarks have never been seen before and their properties remain a mystery, physicists rely on sophisticated calculations based on known parameters to look for them. These parameters include the energy of the collisions and expected background levels, constrained by the possible values for the mass and spin of the hypothetical particle. Through these calculations, the scientists can estimate how many leptoquarks might have been produced in a particular data set of proton-proton collisions and how many might have been transformed into the end products their detectors can look for.

    “Leptoquarks have became one of the most tantalising ideas for extending our calculations, as they make it possible to explain several observed anomalies. At the LHC we are making every effort to either prove or exclude their existence,” says Roman Kogler, a physicist on CMS who worked on this search.

    After sifting through collision events looking for specific characteristics, CMS saw no excess in the data that might point to the existence of third-generation leptoquarks. The scientists were therefore able to conclude that any LQ3 that transform exclusively to a top-tau pair would need to be at least 900 GeV in mass, or around five times heavier than the top quark, the heaviest particle we have observed.

    The limits placed by CMS on the mass of third-generation leptoquarks are the tightest so far. CMS has also searched for third-generation leptoquarks that transform into a tau lepton and a bottom quark, concluding that such leptoquarks would need to be at least 740 GeV in mass. However, it is important to note that this result comes from the examination of only a fraction of LHC data at 13 TeV, from 2016. Further searches from CMS and ATLAS that take into account data from 2017 as well as the forthcoming run of 2018 will ensure that the LHC can continue to test theories about the fundamental nature of our universe.

    CERN/ATLAS detector

    See the full article here.


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

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

    OTHER PROJECTS AT CERN

    CERN AEGIS

    CERN ALPHA

    CERN ALPHA

    CERN AMS

    CERN ACACUSA

    CERN ASACUSA

    CERN ATRAP

    CERN ATRAP

    CERN AWAKE

    CERN AWAKE

    CERN CAST

    CERN CAST Axion Solar Telescope

    CERN CLOUD

    CERN CLOUD

    CERN COMPASS

    CERN COMPASS

    CERN DIRAC

    CERN DIRAC

    CERN ISOLDE

    CERN ISOLDE

    CERN LHCf

    CERN LHCf

    CERN NA62

    CERN NA62

    CERN NTOF

    CERN TOTEM

    CERN UA9

    CERN Proto Dune

    CERN Proto Dune

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  • richardmitnick 1:53 pm on September 14, 2018 Permalink | Reply
    Tags: , , , , Particle Accelerators, ,   

    From CERN: “The LHC prepares for the future” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    14 Sep 2018
    Corinne Pralavorio

    1
    View of the CERN Control Centre where the operators control the LHC (Image: Maximilien Brice/CERN)

    The Large Hadron Collider is stopping proton collisions for five days this week to undergo numerous tests.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    Accelerator specialists need to test the LHC when it is not in production mode and there are only several weeks left in which they can do it. At the end of the year, CERN’s accelerators will be shut down for a major two-year upgrade programme that will result in a renovated accelerator complex using more intense beams and higher energy. Scientists are conducting research to prepare for this new stage and the next, the High-Luminosity LHC.

    “We have many requests from CERN’s teams because these periods of machine development allow components to be tested in real conditions and the results of simulations to be checked,” says Jan Uythoven, the head of the machine development programme. No fewer than twenty-four tests are scheduled for what will be this year’s third testing period.

    One of the major areas of research focuses on beam stability : perturbations are systematically tracked and corrected by the LHC operators. When instabilities arise, the operators stop the beams and dump them. “To keep high-intensity beams stable, we have to improve the fine-tuning of the LHC,” Jan Uythoven adds. Extensive research is therefore being carried out to better understand these instabilities, with operators causing them deliberately in order to study how the beams behave.

    The operators are also testing new optics for the High-Luminosity LHC or, in other words, a new way of adjusting the magnets to increase the beam concentration at the collision points. Another subject of the study concerns the heat generated by more intense future beams, which raises the temperature in the magnet’s core to the limit of what is needed to maintain the superconducting state. Lastly, tests are also being carried out on new components. In particular, innovative collimators were implemented at the start of the year. Collimators are protective items of equipment that stop the particles that deviate from the trajectory to prevent them from damaging the accelerator.

    After this five-day test period, the LHC will stop running completely for a technical stop lasting another five days, during which teams will carry out repairs and maintenance. The technical stop will be followed by five weeks of proton collisions before the next period of machine development and the lead-ion run.

    See the full article here.


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

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

    OTHER PROJECTS AT CERN

    CERN AEGIS

    CERN ALPHA

    CERN ALPHA

    CERN AMS

    CERN ACACUSA

    CERN ASACUSA

    CERN ATRAP

    CERN ATRAP

    CERN AWAKE

    CERN AWAKE

    CERN CAST

    CERN CAST Axion Solar Telescope

    CERN CLOUD

    CERN CLOUD

    CERN COMPASS

    CERN COMPASS

    CERN DIRAC

    CERN DIRAC

    CERN ISOLDE

    CERN ISOLDE

    CERN LHCf

    CERN LHCf

    CERN NA62

    CERN NA62

    CERN NTOF

    CERN TOTEM

    CERN UA9

    CERN Proto Dune

    CERN Proto Dune

     
  • richardmitnick 9:26 pm on September 13, 2018 Permalink | Reply
    Tags: , , Because we only looked at one-millionth of the data that's out there. Perhaps the nightmare is one we've brought upon ourselves, , , Every 25 nanoseconds there's a chance of a collision, Has The Large Hadron Collider Accidentally Thrown Away The Evidence For New Physics?, , Most of CERN's data from the LHC has been lost forever., Only 0.0001% of the total data can be saved for analysis, Out of every one million collisions that occurs at the LHC only one of them has all of its data written down and recorded., Particle Accelerators, , , We think we're doing the smart thing by choosing to save what we're saving but we can't be sure   

    From Ethan Siegel: “Has The Large Hadron Collider Accidentally Thrown Away The Evidence For New Physics?” 

    From Ethan Siegel
    Sep 13, 2018

    The Universe is out there, waiting for you to discover it.

    1
    The ATLAS particle detector of the Large Hadron Collider (LHC) at the European Nuclear Research Center (CERN) in Geneva, Switzerland. Built inside an underground tunnel of 27km (17miles) in circumference, CERN’s LHC is the world’s largest and most powerful particle collider and the largest single machine in the world. It can only record a tiny fraction of the data it collects. No image credit.

    Over at the Large Hadron Collider, protons simultaneously circle clockwise and counterclockwise, smashing into one another while moving at 99.9999991% the speed of light apiece. At two specific points designed to have the greatest numbers of collisions, enormous particle detectors were constructed and installed: the CMS and ATLAS detectors. After billions upon billions of collisions at these enormous energies, the LHC has brought us further in our hunt for the fundamental nature of the Universe and our understanding of the elementary building blocks of matter.

    Earlier this month, the LHC celebrated 10 years of operation, with the discovery of the Higgs boson marking its crowning achievement. Yet despite these successes, no new particles, interactions, decays, or fundamental physics has been found. Worst of all is this: most of CERN’s data from the LHC has been lost forever.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    2
    The CMS Collaboration, whose detector is shown prior to final assembly here, has released their latest, most comprehensive results ever. There is no indication of physics beyond the Standard Model in the results.CERN/Maximlien Brice.

    This is one of the least well-understood pieces of the high-energy physics puzzle, at least among the general public. The LHC hasn’t just lost most of its data: it’s lost a whopping 99.9999% of it. That’s right; out of every one million collisions that occurs at the LHC, only one of them has all of its data written down and recorded.

    It’s something that happened out of necessity, due to the limitations imposed by the laws of nature themselves, as well as what technology can presently do. But in making that decision, there’s a tremendous fear made all the more palpable by the fact that, other than the much-anticipated Higgs, nothing new has been discovered. The fear is this: that there is new physics waiting to be discovered, but we’ve missed it by throwing this data away.

    3
    A four-muon candidate event in the ATLAS detector at the Large Hadron Collider. The muon/anti-muon tracks are highlighted in red, as the long-lived muons travel farther than any other unstable particle. This is an interesting event, but for every event we record, a million others get discarded.ATLAS Collaboration/CERN

    We didn’t have a choice in the matter, really. Something had to be thrown away. The way the LHC works is by accelerating protons as close to the speed of light as possible in opposite directions and smashing them together. This is how particle accelerators have worked best for generations. According to Einstein, a particle’s energy is a combination of its rest mass (which you may recognize as E = mc2) and the energy of its motion, also known as its kinetic energy. The faster you go — or more accurately, the closer you get to the speed of light — the higher energy-per-particle you can achieve.

    At the LHC, we collide protons together at 299,792,455 m/s, just 3 m/s shy of the speed of light itself. By smashing them together at such high speeds, moving in opposite directions, we make it possible for otherwise impossible particles to exist.

    The reason is this: all particle (and antiparticles) that we can create have a certain amount of energy inherent to them, in the form of their mass-at-rest. When you smash two particles together, some of that energy has to go into the individual components of those particles, both their rest energy and their kinetic energy (i.e., their energy-of-motion).

    But if you have enough energy, some of that energy can also go into the production of new particles! This is where E = mc2 gets really interesting: not only do all particles with a mass (m) have an energy (E) inherent to their existence, but if you have enough available energy, you can create new particles. At the LHC, humanity has achieved collisions with more available energy for the creation of new particles than in any other laboratory in history.

    The energy-per-particle is around 7 TeV, meaning each proton achieves approximately 7,000 times its rest-mass energy in the form of kinetic energy. But collisions are rare and protons aren’t just tiny, they’re mostly empty space. In order to get a large probability of a collision, you need to put more than one proton in at a time; you inject your protons in bunches instead.

    At full intensity, this means that there are many tiny bunches of protons going clockwise and counterclockwise inside the LHC whenever it’s running. The LHC tunnels are approximately 26 kilometers long, with only 7.5 meters (or around 25 feet) separating each bunch. As these bunches of beams go around, they get squeezed as they interact at the mid-point of each detector. Every 25 nanoseconds, there’s a chance of a collision.

    So what do you do? Do you have a small number of collisions and record every one? That’s a waste of energy and potential data.

    Instead, you pump in enough protons in each bunch to ensure you have a good collision every time two bunches pass through. And every time you have a collision, particles rip through the detector in all directions, triggering the complex electronics and circuitry that allow us to reconstruct what was created, when, and where in the detector. It’s like a giant explosion, and only by measuring all the pieces of shrapnel that come out can we reconstruct what happened (and what new things were created) at the point of ignition.

    CERN CMS Higgs Event

    The problem that then arises, however, is in taking all of that data and recording it. The detectors themselves are big: 22 meters for CMS and 46 meters long for ATLAS. At any given time, there are particles arising from three different collisions in CMS and six separate collisions in ATLAS. In order to record data, there are two steps that must occur:

    The data has to be moved into the detector’s memory, which is limited by the speed of your electronics. Even at the speed of light, we can only “remember” about 1-in-1,000 collisions.
    The data in memory has to be written to disk (or some other permanent device), and that’s a much slower process than storing data in memory. Only about 1-in-1,000 collisions that the memory stores can be written to disk.

    That’s why, with the necessity of taking both of these steps, only 0.0001% of the total data can be saved for analysis.

    How do we know we’re saving the right pieces of data? The ones where it’s most likely we’re creating new particles, seeing the importance of new interactions, or observing new physics?

    When you have proton-proton collisions, most of what comes out are normal particles, in the sense that they’re made up almost exclusively of up-and-down quarks. (This means particles like protons, neutrons, and pions.) And most collisions are glancing collisions, meaning that most of the particles wind up hitting the detector in the forwards or backwards direction.

    So, to take that first step, we try and look for particle tracks of relatively high-energies that go in the transverse direction, rather than forwards or backwards. We try and put into the detector’s memory the events that we think had the most available energy (E) for creating new particles, of the highest mass (m) possible. Then, we quickly perform a computational scan of what’s in the detector’s memory to see if it’s worth writing to disk or not. If we choose to do so, that’s the only thing that detector will be writing for approximately the next 1/40th of a second or so.

    1/40th of a second might not seem like much, but it’s approximately 25,000,000 nanoseconds: enough time for about a million bunches to collide.

    5
    The particle tracks emanating from a high energy collision at the LHC in 2014. Only 1-in-1,000,000 such collisions have been written down and saved; the majority have been lost.

    We think we’re doing the smart thing by choosing to save what we’re saving, but we can’t be sure. In 2010, the CERN Data Centre passed an enormous data milestone: 10 Petabytes of data. By the end of 2013, they had passed 100 Petabytes of data; in 2017, they passed the 200 Petabyte milestone. Yet for all of it, we know that we’ve thrown away — or failed to record — about 1,000,000 times that amount. We may have collected hundreds of Petabytes, but we’ve discarded, and lost forever, hundreds of Zettabytes: more than the total amount of internet data created in a year.

    6
    The total amount of data that’s been collected by the LHC far outstrips the total amount of data sent-and-received over the internet over the last 10 years. But only 0.0001% of that data has been written down and saved; the rest is gone for good. No image credit.

    It’s eminently possible that the LHC created new particles, saw evidence of new interactions, and observed and recorded all the signs of new physics. And it’s also possible, due to our ignorance of what we were looking for, we’ve thrown it all away, and will continue to do so. The nightmare scenario — of no new physics beyond the Standard Model — appears to be coming true. But the real nightmare is the very real possibility that the new physics is there, we’ve built the perfect machine to find it, we’ve found it, and we’ll never realize it because of the decisions and assumptions we’ve made. The real nightmare is that we’ve fooled ourselves into believing the Standard Model is right, because we only looked at one-millionth of the data that’s out there. Perhaps the nightmare is one we’ve brought upon ourselves.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    See the full article here .

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

     
  • richardmitnick 12:08 pm on September 9, 2018 Permalink | Reply
    Tags: , , , , First successful test of a proton-driven plasma wakefield accelerator, , ILC-International Linear Collider, Particle Accelerators, ,   

    From Sanford Underground Research Facility via SingularityHub: “This Breakthrough New Particle Accelerator Is Small But Mighty” 

    SURF logo
    Sanford Underground levels

    From Sanford Underground Research Facility

    via

    SingularityHub

    Sep 04, 2018
    Edd Gent

    CERN AWAKE

    Particle accelerators have become crucial tools for understanding the fundamental nature of our universe, but they are incredibly big and expensive. That could change, though, after scientists validated a new approach that could usher in a generation of smaller, more powerful accelerators.

    The discovery of the Higgs Boson in 2012 was a scientific triumph that helped validate decades of theoretical research. But finding it required us to build the 17-mile–long Large Hadron Collider (LHC) beneath Switzerland and France, which cost about $13.25 billion.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    Now scientists at CERN, the organization that runs the LHC, have published results of the first successful test of a proton-driven plasma wakefield accelerator in Nature. The machine is the first successful demonstration of an idea only dreamt up in 2009, which could achieve considerably higher energies over shorter distances than older approaches.

    The idea of using wakefields to accelerate particles has been around since the 1970s. By firing a high–energy beam into a plasma—the fourth state of matter that is essentially a gas whose electrons have come loose from their atoms or molecules—it’s possible to get its soup of electrons to oscillate.

    This creates something akin to the wake formed as a ship passes through water, and by shooting another beam of electrons into the plasma at a specific angle, you can get the electrons to effectively ride this plasma wave, accelerating them to much higher speeds.

    Previous approaches have relied on lasers or electron beams to create these wakefields, but their energy dissipates quickly, so they can only accelerate particles over short distances. That means reaching higher energies would likely require multiple stages [Nature]. Protons, on the other hand, are easy to accelerate and can maintain high energies over very long distances, so a wakefield accelerator driven by them is able to accelerate particles to much higher speeds in a single stage.

    In its first demonstration, the AWAKE experiment boosted electrons to 2 GeV, or 2 billion electronvolts (a measure of energy also commonly used as a unit of momentum in particle physics) over 10 meters. In theory, the same approach could achieve 1 TeV (1,000 GeV) if scaled up to 1 kilometer long (0.6 miles).

    CERN AWAKE schematic


    CERN AWAKE

    That pales in significance compared to the energies reached by the LHC, which smashes protons together to reach peak energies of 13TeV. But proton collisions are messy, because they are made up of lots of smaller fundamental particles, so analyzing the results is a time-consuming and tricky task.

    That’s why most designs for future accelerators plan to use lighter particles like electrons, which will create cleaner collisions [PhysicsWorld]. Current theories also consider electrons to be fundamental particles (i.e., they don’t break into smaller parts), but smashing them into other particles at higher speeds may prove that wrong [New Scientist].

    These particles lose energy far quicker than protons in circular accelerators like the LHC, so most proposals are for linear accelerators. That means that unlike the LHC, where particles can be boosted repeatedly as they circulate around the ring multiple times, all the acceleration has to be done in a single go. The proposed International Linear Collider (ILC) is expected to cost $7 billion [Science] and will require a 20– to 40–kilometer-long tunnel to reach 0.25 TeV.

    ILC schematic, being planned for the Kitakami highland, in the Iwate prefecture of northern Japan

    That’s because, like the LHC, it will rely on radio frequency cavities, which bounce high-intensity radio waves around inside a metallic chamber to create an electric field that accelerates the particles. Reaching higher energies requires many such RF cavities and therefore long and costly tunnels. That makes the promise of reaching TeVs over just a few kilometers with proton-driven wakefield accelerators very promising.

    But it’s probably a bit early to rip up the ILC’s designs quite yet. Building devices that can generate useful experimental results will require substantial improvements in the beam quality, which is currently somewhat lacking. The current approach also requires a powerful proton source—in this case, CERN’s Super Proton Synchrotron—so it’s more complicated than just building the accelerator.

    The Super Proton Synchrotron (SPS), CERN’s second-largest accelerator.

    Nonetheless, AWAKE deputy spokesperson Matthew Wing told Science that they could be doing practical experiments within five years, and within 20 years the technology could be used to convert the LHC into an electron-proton collider at roughly a 10th of the cost of a more conventional radio frequency cavity design.

    5
    Last year, physicists working on the Advanced Wakefield collaboration at CERN added an electron source and beamline (pictured) to their plasma wakefield accelerator. Maximilien Brice, Julien Ordan/CERN

    That could make it possible to determine whether electrons truly are fundamental particles, potentially opening up entirely new frontiers in physics and rewriting our understanding of the universe.

    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 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.
    LUX/Dark matter experiment at SURFLUX/Dark matter experiment at SURF

    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 Majorana Demonstrator experiment, 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.

    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.

    Fermilab LBNE
    LBNE

     
  • richardmitnick 11:59 am on September 8, 2018 Permalink | Reply
    Tags: , , , Particle Accelerators, , , Ten years of Large Hadron Collider discoveries are just the start of decoding the universe,   

    From The Conversation: “Ten years of Large Hadron Collider discoveries are just the start of decoding the universe” 

    Conversation
    From The Conversation


    The activity during a high-energy collision at the CMS control room of the European Organization for Nuclear Research, CERN, at their headquarters outside Geneva, Switzerland. AP Photo

    “Ten years! Ten years since the start of operations for the Large Hadron Collider (LHC), one of the most complex machines ever created. The LHC is the world’s largest particle accelerator, buried 100 meters under the French and Swiss countryside with a 17-mile circumference.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    On Sept. 10, 2008, protons, the center of a hydrogen atom, were circulated around the LHC accelerator for the first time. However, the excitement was short-lived because on Sept. 22 an incident occurred that damaged more than 50 of the LHC’s more than 6,000 magnets – which are critical for keeping the protons traveling on their circular path. Repairs took more than a year, but in March 2010 the LHC began colliding protons. The LHC is the crown jewel of CERN, the European particle physics laboratory that was founded after World War II as a way to reunite and rebuild science in war-torn Europe. Now scientists from six continents and 100 countries conduct experiments there.

    You might be wondering what the LHC does and why it is a big deal. Great questions. The LHC collides two beams of protons together at the highest energies ever achieved in a laboratory. Six experiments located around the 17-mile ring study the results of these collisions with massive detectors built in underground caverns. That’s the what, but why? The goal is to understand the nature of the most basic building blocks of universe and how they interact with each other. This is fundamental science at its most basic.

    3
    View of the LHC in its tunnel at CERN (European particle physics laboratory) near Geneva, Switzerland. The LHC is a 27-kilometer-long underground ring of superconducting magnets housed in this pipe-like structure, or cryostat. The cryostat is cooled by liquid helium to keep it at an operating temperature just above absolute zero. It will accelerate two counterrotating beam of protons to an energy of 7 tera-electron volts (TeV) and then bring them to collide head-on. Several detectors are being built around the LHC to detect the various particles produced by the collision. Martial Trezzini/KEYSTONE/AP Photo.

    The LHC has not disappointed. One of the discoveries made with the LHC includes the long sought-after Higgs boson, which gives mass to all of the protons and neutrons in the quark gluon plasma, predicted in 1964 by scientists working to combine theories of two of the fundamental forces of nature.

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    I work on one of the six LHC experiments – the Compact Muon Solenoid experiment designed to discover the Higgs boson and search for signs of previously unknown particles or forces.

    CERN/CMS Detector

    My institution, Florida State University, joined the Compact Muon Solenoid collaboration in 1994 when I was a young graduate student at another school working on a different experiment at a different laboratory. Planning for the LHC dates back to 1984. The LHC was hard to build and expensive – 10 billion euros – and took 24 years to come to fruition. Now we are celebrating 10 years since the LHC began operating.

    Discoveries from the LHC

    The most significant discovery to come from the LHC so far is the discovery of the Higgs boson on July 4, 2012. The announcement was made at CERN and captivated a worldwide audience. In fact, my wife and I watched it via webcast on our big screen TV in our living room. Since the announcement was at 3 a.m. Florida time, we went for pancakes at IHOP to celebrate afterwards.

    The Higgs boson was the last remaining piece of what we call the standard model of particle physics.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    This theory covers all of the known fundamental particles – 17 of them – and three of the four forces through which they interact, although gravity is not yet included. The standard model is an incredibly well-tested theory. Two of the six scientists who developed the part of the standard model that predicts the Higgs boson won the Nobel Prize in 2013.

    3
    The Higgs boson, sometimes refered to as the ‘God particle,’ was first seen during by experiments at the Large Hadron Collider. Designua/Shutterstock.com

    I am often asked, why do we continue to run experiments, smashing together protons, if we’ve already discovered the Higgs boson? Aren’t we done? Well, there is still lots to be understood. There are a number of questions that the standard model does not answer. For example, studies of galaxies and other large-scale structures in the universe indicate that there is a lot more matter out there than we observe. We call this dark matter since we can’t see it. The most common explanation to date is that dark matter is made of an unknown particle. Physicists hope that the LHC may be able to produce this mystery particle and study it. That would be an amazing discovery.

    Just last week, the ATLAS and Compact Muon Solenoid collaborations announced the first observation of the Higgs boson decaying, or breaking apart, into bottom quarks. The Higgs boson decays in many different ways – some rare, some common. The standard model makes predictions about how often each type of decay happens. To fully test the model, we need to observe all of the predicted decays. Our recent observation is in agreement with the standard model – another success.

    More questions, more answers to come

    There are lots of other puzzles in the universe and we may require new theories of physics to explain such phenomena – such as matter/anti-matter asymmetry to explain why the universe has more matter than anti-matter, or the hierarchy problem to understand why gravity is so much weaker than the other forces.

    But for me, the quest for new, unexplained data is important because every time that physicists think we have it all figured out, nature provides a surprise that leads to a deeper understanding of our world.

    The LHC continues to test the standard model of particle physics. Scientists love when theory matches data. But we usually learn more when they don’t. This means we don’t fully understand what is happening. And that, for many of us, is the future goal of the LHC: to discover evidence of something we don’t understand. There are thousands of theories that predict new physics that we have not observed. Which are right? We need a discovery to learn if any are correct.

    CERN plans to continue LHC operations for a long time. We are planning upgrades to the accelerator and detectors to allow it to run through 2035.

    It is not clear who will retire first, me or the LHC. Ten years ago, we anxiously awaited the first beams of protons. Now we are busy studying a wealth of data and hope for a surprise that leads us down a new path. Here’s to looking forward to the next 20 years.”

    See the full article here .

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    The Conversation US 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 3:18 pm on September 7, 2018 Permalink | Reply
    Tags: , , , , Particle Accelerators, , , The incredible lightness of the Higgs   

    From CERN: “The incredible lightness of the Higgs” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    7 Sep 2018
    Ana Lopes

    CERN ATLAS another view Image Claudia Marcelloni ATLAS CERN


    View of the ATLAS detector. The ATLAS collaboration reports results of a combination of searches for a new particle – dubbed a vector-like top quark – that could be the culprit behind the Higgs lightness.

    Why is the Higgs boson so light? That’s one of the questions that has been bothering particle physicists since the famous particle was discovered in 2012.

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    This is because the theory of how the particle interacts with the most massive of all observed elementary particles, the top quark, involves corrections at a fundamental (quantum) level that could result in a Higgs mass much larger than the measured value of 125 GeV. How large? Perhaps as much as sixteen orders of magnitude larger than the measured Higgs mass. Since the Higgs mass is so light, this suggests more particles could exist that cancel the quantum corrections from the top quark (and other heavy particles).

    In a paper posted online and submitted to the journal Physical Review Letters, the ATLAS collaboration reports results of a combination of searches for a new particle – dubbed a vector-like top quark – that could help keep the Higgs boson light.

    Various proposals attempt to cancel out the large quantum corrections to the Higgs boson mass. Many of them involve vector-like top quarks, which are hypothetical particles not predicted by the Standard Model of particle physics.

    Standard Model of Particle Physics from Symmetry Magazine


    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    Unlike the Standard Model top quark, which always decays to a bottom quark and a W boson, vector-like top quarks would decay in one of three different ways, if they decayed to Standard Model particles. Specifically, a vector-like top quark would decay to a bottom quark and a W boson, or to a Z boson and a top quark, or still to a Higgs boson and a top quark.

    To maximise the chances of finding vector-like top quarks, the ATLAS collaboration conducted several different types of search using data from proton–proton collisions collected at the Large Hadron Collider (LHC) in 2015 and 2016 at an energy of 13 TeV; each individual search is sensitive to a particular set of particle decays. They then combined the results to increase the sensitivity to vector-like top quarks, yet found no sign of them.

    Despite this, their analysis allowed them to expand the reach of individual searches and place the most stringent lower bounds on the mass of vector-like top quarks to date. The analysis excludes vector-like top quarks with masses below about 1300 GeV for any combination of the three top-quark decays into Standard Model particles. The previous best lower limit from an individual search was 1190 GeV.

    It will now get more challenging: for masses heavier than 1300 GeV a single vector-like top quark is created more often than a pair. But with a wealth of data coming from the LHC, the search continues.

    See the full article here.


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    Please help promote STEM in your local schools.

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    Meet CERN in a variety of places:

    Quantum Diaries
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    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

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  • richardmitnick 1:17 pm on September 5, 2018 Permalink | Reply
    Tags: , , , , Particle Accelerators, ,   

    From CERN ATLAS: “ATLAS searches for double Higgs production” 

    CERN ATLAS Higgs Event

    CERN/ATLAS
    From CERN ATLAS

    5th September 2018

    1
    Upper limits at 95% confidence level on the cross-section of the non-resonant Higgs boson pair production as a function of κλ. The allowed range of κλ is derived from the interval where the theoretical prediction is found below the experimental upper limits on the cross-section. (Image: ATLAS Collaboration/CERN)

    The Brout-Englert-Higgs (BEH) mechanism is at the core of the Standard Model, the theory that describes the fundamental constituents of matter and their interactions. It introduces a new field, the Higgs field, through which the weak bosons (W+/- and Z) become massive while the photon remains massless. The excitation of this field is a physical particle, the Higgs boson, which was discovered by the ATLAS and CMS collaborations in 2012.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    The BEH mechanism also predicts that the Higgs field can interact with itself; in other words, a single (virtual) Higgs boson can decay into two Higgs bosons. Observing and measuring this self-interaction, or “Higgs self-coupling”, would be the ultimate validation of the theory of mass generation, while any deviation from Standard Model predictions would open a window on new physics.

    Unfortunately, Higgs boson pairs are predicted to be very rare in proton–proton collisions, with a production rate roughly a thousand times smaller than the single Higgs boson. To make matters worse, not all di-Higgs boson production occurs through Higgs self-coupling. Vast amounts of data are therefore needed for this to be probed, making it a flagship analysis for the high-luminosity upgrade of the LHC (HL-LHC).

    It is nevertheless important to explore di-Higgs production also with smaller datasets as new physics beyond the Standard Model might enhance the production rate.

    The ATLAS collaboration has searched for Higgs boson pairs (HH) in the dataset collected in 2015 and 2016 using various decay channels. The most sensitive of these involve one Higgs boson decaying into a pair of b-quarks and one decaying into either another pair of b-quarks (HH→bbbb), two tau-leptons (HH→bbττ) or two photons (HH→bbγγ). These three searches were recently statistically combined and, as a result, the production rate of HH pairs could be excluded beyond 6.7 times the Standard Model prediction, at a 95% confidence level.

    New physics could be indicated by a Higgs self-coupling which differs from the Standard Model prediction by a factor κλ. This would affect the production rate and the kinematic distributions of the Higgs boson pairs and, as such, is an excellent probe for new physics. The recent statistical combination of the HH searches in ATLAS constrains the value of κλ to be between –5.0 and +12.1, at a 95% confidence level (see figure). It is the world’s most stringent constraint on the anomalous Higgs self-coupling to date.

    Higgs boson pairs are also a key signature of heavy new particle decays in several scenarios beyond the Standard Model. These might include an additional Higgs boson in models that extend the Higgs sector of the Standard Model, or the excitation of a graviton in models with extra spatial dimensions. The combined HH searches performed by ATLAS with the 2015-2016 dataset impose stringent constraints on the production rates of such resonances at the LHC.

    See the full article here .


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    Please help promote STEM in your local schools.

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    CERN map


    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN


    CERN Courier

    QuantumDiaries


    Quantum Diaries

     
  • richardmitnick 3:00 pm on September 4, 2018 Permalink | Reply
    Tags: , , , , , , , Particle Accelerators, , ,   

    From University at Buffalo: “UB physicists awarded $1.45 million to study inner workings of the universe” 

    U Buffalo bloc.

    From University at Buffalo

    September 4, 2018
    Charlotte Hsu

    1
    Photo illustration: Left to right: University at Buffalo physicists Avto Kharchilava, Ia Iashvili and Salvatore Rappoccio. Credit: Douglas Levere / University at Buffalo / CERN

    Funding comes as the field marks its latest big discovery — the observation of the Higgs boson’s most common mode of decay.

    University at Buffalo scientists have received $1.45 million from the National Science Foundation (NSF) for research in high-energy physics, a field that uses particle accelerators to smash beams of protons into one another at near-light speeds, generating data that illuminates the fundamental laws of nature.

    The grant was awarded to Salvatore Rappoccio, PhD, associate professor of physics in the UB College of Arts and Sciences, and UB physics professors Ia Iashvili, PhD, and Avto Kharchilava, PhD.

    The funding began Sept. 1, just days after the latest big discovery in high-energy physics.

    On Aug. 28, an international team of thousands of researchers — including Iashvili, Kharchilava and Rappoccio — announced that they had observed the Higgs boson, a subatomic particle, decaying into a pair of lighter particles called a bottom quark and antibottom quark.

    The sighting took place at the world’s most powerful particle accelerator, the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN).

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    The finding deepens our understanding of why objects have mass. It also validates the Standard Model, a set of equations that physicists use to describe elementary particles and the way they behave (in essence, the way the universe works).

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    For Kharchilava, the discovery was over a decade in the making. He and his UB students had been searching for evidence of the Higgs boson transforming into bottom quarks since around 2005.

    “I was looking for this decay for almost 15 years, when we began the search at Fermilab, which operated the Tevatron collider,” he says. “We did not succeed back then because we did not have enough data and precision, so now we have more data and better precision and we have finally made the discovery.”


    FNAL/Tevatron map



    FNAL/Tevatron CDF detector


    FNAL/Tevatron DZero detector

    The new NSF funding will enable the UB scientists to continue their work on the Higgs boson, the Standard Model and the hunt for new phenomena in physics.

    The finding deepens our understanding of why objects have mass. It also validates the Standard Model, a set of equations that physicists use to describe elementary particles and the way they behave (in essence, the way the universe works).

    For Kharchilava, the discovery was over a decade in the making. He and his UB students had been searching for evidence of the Higgs boson transforming into bottom quarks since around 2005.

    “I was looking for this decay for almost 15 years, when we began the search at Fermilab, which operated the Tevatron collider,” he says. “We did not succeed back then because we did not have enough data and precision, so now we have more data and better precision and we have finally made the discovery.”

    See the full article here .

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

    Please help promote STEM in your local schools.

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    U Buffalo Campus

    UB is a premier, research-intensive public university and a member of the Association of American Universities. As the largest, most comprehensive institution in the 64-campus State University of New York system, our research, creative activity and people positively impact the world.

     
  • richardmitnick 1:10 pm on August 31, 2018 Permalink | Reply
    Tags: , , , , , Hunting for dark quarks, Particle Accelerators, ,   

    From CERN: “Hunting for dark quarks” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    31 Aug 2018
    Ana Lopes

    1
    A proton–proton collision event with two emerging-jet candidates. (Image: CMS/CERN)

    Quarks are the smallest particles that we know of. In fact, according to the Standard Model of particle physics, which describes all known particles and their interactions, quarks should be infinitely small.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    If that’s not mind-boggling enough, enter dark quarks – hypothetical particles that have been proposed to explain dark matter, an invisible form of matter that fills the universe and holds the Milky Way and other galaxies together.

    In a recent study, the CMS collaboration describes how it has sifted through data from the Large Hadron Collider (LHC) to try and spot dark quarks. Although the search came up empty-handed, it allowed the team to inch closer to the parent particles from which dark quarks may originate.

    One compelling theory extends the Standard Model to explain why the observed mass densities of normal matter and dark matter are similar. It does so by invoking the existence of dark quarks that interact with ordinary quarks via a mediator particle. If such mediator particles were produced in pairs in a proton–proton collision, each mediator particle of the pair would transform into a normal quark and a dark quark, both of which would produce a spray, or “jet”, of particles called hadrons, composed of quarks or dark quarks. In total, there would be two jets of regular hadrons originating from the collision point, and two “emerging” jets that would emerge a distance away from the collision point because dark hadrons would take some time to decay into visible particles.

    In their study, the CMS researchers looked through data from proton–proton collisions collected at the LHC at an energy of 13 TeV to search for instances, or “events”, in which such mediator particles and associated emerging jets might occur. They used two distinguishing features to identify emerging jets and pick them out from a background of events that are expected to mimic their traits.

    The team found no strong evidence for the existence of such emerging jets, but the data allowed them to exclude masses for the hypothetical mediator particle of 400–1250 GeV for dark pions that travel for lengths between 5 and 225 mm before they decay. The results are the first from a dedicated search for such mediator particles and jets.

    See the full article here.


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

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

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  • richardmitnick 12:37 pm on August 31, 2018 Permalink | Reply
    Tags: A particle called a beauty meson was breaking down in ways that just weren't line up with predictions, , Anomalies in The Large Hadron Collider's Data Are Still Stubbornly Pointing to New Physics, , , Particle Accelerators, , ,   

    From CERN via Science Alert: “Anomalies in The Large Hadron Collider’s Data Are Still Stubbornly Pointing to New Physics” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    via

    Science Alert

    31 AUG 2018
    MIKE MCRAE

    1
    (CERN) [CMS?]

    Past experiments using CERN’s super-sized particle-smasher, the Large Hadron Collider (LHC), hinted at something unexpected. A particle called a beauty meson was breaking down in ways that just weren’t line up with predictions.

    That means one of two things – our predictions are wrong, or the numbers are out. And a new approach makes it less likely that the observations are a mere coincidence, making it’s nearly enough for scientists to start getting excited.

    3
    (CERN / ALICE event)

    A small group of physicists took the collider’s data on beauty meson (or b meson for short) disintegration, and investigated what might happen if they swapped one assumption regarding its decay for another that assumed interactions were still occurring after they transformed.

    The results were more than a little surprising. The alternative approach doubles down on the take that something strange really is going on.

    In physics, anomalies are usually viewed as good things. Fantastic things. Unexpected numbers could be the window to a whole new way of seeing physics.

    Physicists are quite a conservative bunch. You have to be when the fundamental laws of the Universe are at stake.

    So when experimental results don’t quite match up with the theory, it’s first presumed to be a random blip in the statistical chaos of a complicated test. If a follow-up experiment shows the same thing, it’s still presumed to be ‘one of those things’.

    But after enough experiments, sufficient data can be collected to compare the chances of errors with the likelihood that something truly interesting is going on.

    If an unexpected result differs from the predicted outcome by at least three standard deviations it’s called a 3 sigma [σ], and physicists are allowed to look at the results while nodding enthusiastically with their eyebrows raised. It becomes an observation.

    To really attract attention, the anomaly should persist when there’s enough data to push that difference to five standard deviations. A 5σ event is cause to break out the champagne.

    Over the years, the LHC has been used to create particles called mesons, with the purpose of watching what happens in the moments after they’re born.

    Mesons are a type of hadron, somewhat like the proton. Only instead of consisting of three quarks in a stable formation under strong interactions, they’re made of only two – a quark and an antiquark.

    Even the most stable of mesons fall apart after hundredths of a second. The framework we use to describe the construction and decay of particles – the Standard Model – describes what we should see when different mesons split up.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.


    Standard Model of Particle Physics from Symmetry Magazine

    The beauty meson is a down quark connected to a bottom anti-quark. When the particle’s properties are plugged into the Standard Model, b-meson decay should produce pairs of electrons and positrons, or electron-like muons and their opposites, anti-muons.

    This electron or muon outcome should be 50-50. But that’s not what we’re seeing. Results are showing far more of the electron-positron products than muon-anti-muons.

    This is worth paying attention to. But when the sum of the results are held up next to the Standard Model’s prediction, the difference is a mere 3.4 sigma. Interesting, but nothing to go wild over.

    The Standard Model is a fine piece of work. Built over decades on the foundations of the field theories first laid out by the brilliant Scottish theorist James Clerk Maxwell, it’s served as a map for the unseen realms of many new particles.

    But it’s not perfect. There’s things we’ve seen in nature – from dark matter to the masses of neutrinos – that currently seem to be out of reach of the Standard Model’s framework.

    In moments like this, physicists tweak basic assumptions on the model and see if they do a better job of explaining what we’re seeing.

    “In previous calculations, it was assumed that when the meson disintegrates, there are no more interactions between its products,” says physicist Danny van Dyk from the University of Zurich.

    “In our latest calculations we have included the additional effect: long-distance effects called the charm-loop.”

    The details of this effect aren’t for the amateur, and aren’t quite Standard Model material.

    In short, they involve complicated interactions of virtual particles – particles that don’t persist long enough to go anywhere, but arise in principle in the fluctuations of quantum uncertainty – and an interaction between the decay products after they’ve split up.

    What is interesting is that by explaining the meson’s breakdown through this speculative charm loop the anomaly’s significance jumps to a convincing 6.1σ.

    In spite of the leap, it’s still not a champagne affair. More work needs to be done, which includes piling up the observations in light of this new process.

    “We will probably have a sufficient amount within two or three years to confirm the existence of an anomaly with a credibility entitling us to talk about a discovery,” says Marcin Chrzaszcz from the University of Zurich.

    If confirmed it would show enough flexibility in the Standard Model to stretch its boundaries, potentially revealing pathways to new areas of physics.

    It’s a tiny crack, and still might turn up nothing. But nobody said solving the biggest mysteries in the Universe would be easy.

    This research was published in European Physical Journal C.

    See the full article here.


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

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

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    CERN UA9

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