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  • richardmitnick 3:34 pm on May 22, 2016 Permalink | Reply
    Tags: , , CERN LHC, , , ,   

    From HuffPost: “Meet The Most Powerful Woman In Particle Physics” Women in Science 

    Huffington Post
    The Huffington Post

    05/18/2016
    David Freeman

    1
    Fabiola Gianotti, CERN’s new director-general. Christian Beutler

    Fabiola Gianotti isn’t new to CERN, the Geneva, Switzerland-based research organization that operates the Large Hadron Collider (LHC), the world’s biggest particle collider.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    In fact, the Italian particle physicist was among the CERN scientists who made history in 2012 with the discovery of the Higgs boson.

    CERN CMS Higgs Event
    CERN CMS Higgs Event

    CERN/CMS Detector
    CERN/CMS Detector

    But now Gianotti isn’t just working at CERN. As the organization’s new director-general — the first woman ever to hold the position — she’s running the show. And though expanding our knowledge of the subatomic realm remains her main focus, she’s acutely aware that she is now a high-visibility role model for women around the world.

    “Physics is widely regarding as a male-dominated field, and it’s true that there are more men in our community than women,” Gianotti told The Huffington Post in an email. “So I am glad if in my new role I can contribute to encourage young women to undertake a job in scientific research with the certitude that they have the same opportunities as men.”

    Recently, HuffPost Science posed a few questions to Gianotti via email. Here, lightly edited, are her answers.

    How will things be different for you in your new role?

    My new role is very interesting and stimulating, and I feel very honored to have been offered it. The range of issues I have to deal with is much broader than before and includes scientific strategy and planning, budget, personnel aspects, relations with a large variety of stakeholders, etc. Days are long and full, and I am learning many new things. And there is nothing more enriching and gratifying than learning.

    What’s a typical day like for you?

    Super-hectic, super-speedy and … atypical!

    What do you think explains the gender gap in science generally and in physics particularly?

    There are many factors. There’s no difference in ability between men and women, that’s for sure. And in my experience, the more diverse a team is, the stronger it is. There is the baggage of history, of course, which takes a long time to overcome. There is the question of the lack of role models, and there is the question of making workplaces more family friendly. We need to enable parents, men or women, to take breaks to raise families and we need to support parents with infrastructure and facilities.

    2
    The Large Hadron Collider, Geneva, Switzerland.

    Your term as CERN’s director-general is scheduled to last five years. What are your goals for CERN during this period?

    The second run of the LHC is the top priority for CERN in the coming years. We got off to a very good start in 2015, and have three years of data-taking ahead of us before we go into the accelerator’s second long shutdown. The experiments are expected to record at least three times more data than in Run 1 at an energy almost twice as large. It will be a long time before another such step in energy will be made in the future.

    So, the coming years are going to be an exciting period for high-energy physics. But CERN is not just the LHC. We have a variety of experiments and facilities, including precise measurements of rare decays and detailed studies of antimatter, to mention just a couple of them. In parallel with the ongoing program, we will be working to ensure a healthy long-term future for CERN, at first with the high-luminosity LHC upgrade scheduled to come on stream in the middle of the next decade, and also through a range of design studies looking at the post-LHC era — from 2035 onwards.

    CERN HL-LHC bloc

    What discoveries can we reasonably expect from CERN during your term?

    I’m afraid that I don’t have a crystal ball to hand. There will be a wealth of excellent physics results from the LHC Run 2 and from other CERN experiments. We’ll certainly get to know the Higgs boson much better and expand our exploration of physics beyond the Standard Model.

    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.
    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.

    Whether we find any hints of the new physics everyone is so eagerly waiting for, however, I don’t know. We know there’s new physics to be found. Good as it is, the Standard Model explains only the 5 percent of the universe that is visible. There are so many exciting questions still waiting to be answered.

    What are the biggest opportunities at CERN? The biggest challenges?

    These two questions have a single answer. Over the coming years, the greatest opportunities and challenges, not only for CERN but for the global particle physics community as a whole, come from the changing nature of the field. Collaboration between regions is growing. CERN recently signed a set of agreements with the U.S. outlining U.S. participation in the upgrade of the LHC and CERN participation in neutrino projects at Fermilab in the U.S.

    FNAL LBNF/DUNE
    FNAL LBNF/DUNE

    There are also emerging players in the field, notably China, whose scientific community has expressed ambitious goals for a potential future facility. All this represents a great opportunity for particle physics. The challenge for all of us in the field is to advance in a globally coordinated manner, so as to be able to carry out as many exciting and complementary projects as possible.

    Were you always interested in being a scientist? If you couldn’t be a scientist, what would you be/do?

    I was always interested in science, and I was always interested in music. I pursued both for as long as I could, but when the time came to make a choice, I chose science. I suppose that as a professional physicist, it is still possible to enjoy music — I still play the piano from time to time. But as a professional musician, it would be harder to engage in science.

    What do you do in your spare time?

    I spend my little spare time with family and friends. I do some sport, I listen to music, I read.

    What do you think is the biggest misconception nonscientists have about particle physics?

    That it’s hard to understand! Of course, if you want to be a particle physicist, you have to master the language of mathematics and be trained to quite a high level. But if you want to understand the field conceptually, it’s almost child’s play. All children are natural scientists. They are curious, and they want to take things apart to see how they work.

    Particle physics is just like that. We study the fundamental building blocks of matter from which everything is made, and the forces at work between them. And the equations that describe the building blocks and their interactions are simple and elegant. They can be written on a small piece of paper.

    See the full article here .

    Please help promote STEM in your local schools.

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  • richardmitnick 8:28 am on May 22, 2016 Permalink | Reply
    Tags: , , CERN LHC, , , ,   

    From livescience: “LHC [Particle] Smasher Opens Quantum Physics Floodgates” 

    Livescience

    May 20, 2016
    Ian O’Neill, Discovery News

    1
    A display of a proton-proton collision taken in the LHCb detector in the early hours of May 9.
    Credit: CERN/LHCB

    CERN/LHCb
    CERN/LHCb

    A display of a proton-proton collision taken in the LHCb detector in the early hours of May 9. Credit: CERN/LHCb

    The Large Hadron Collider is the most complex machine ever built by humankind and it is probing into deep quantum unknown, revealing never-before-seen detail in the matter and forces that underpin the foundations of our universe.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    In its most basic sense, the LHC is a time machine; with each relativistic proton-on-proton collision, the particle accelerator is revealing energy densities and states of matter that haven’t existed in our universe since the moment after the Big Bang, nearly 14 billion years ago.

    The collider, which is managed by the European Organization for Nuclear Research (CERN) is located near Geneva, Switzerland.

    With the countless billions of collisions between ions inside the LHC’s detectors comes a firehose of data that needs to be recorded, deciphered and stored. Since the 27 kilometer (17 mile) circumference ring of supercooled electromagnets started smashing protons together once more after its winter break, LHC scientists are expecting a lot more data this year than what the experiment produced in 2015.

    “The LHC is running extremely well,” said CERN Director for Accelerators and Technology Frédérick Bordry in a statement. “We now have an ambitious goal for 2016, as we plan to deliver around six times more data than in 2015.”

    And this data will contain ever more detailed information about the elusive Higgs boson that was discovered in 2012 and possibly even details of “new” or “exotic” physics that physicists could spend decades trying to understand. Key to the LHC’s aims is to attempt to understand what dark matter is and why the universe is composed of matter and not antimatter.

    In fact, there was already a buzz surrounding an unexpected signal that was recorded in 2015 that could represent something amazing, but as is the mantra of any scientist: more data is needed. And it looks like LHC physicists are about to be flooded with the stuff.

    Central to the LHC’s recent upgrades is the sheer density of accelerated “beams” of protons that are accelerated to close to the speed of light. The more concentrated or focused the beams, the more collisions can be achieved. More collisions means more data and the more likelihood of revealing new and exciting things about our universe. This year, LHC engineers hope to magnetically squeeze the beams of protons when they collide inside the detectors, generating up to one billion proton collisions per second.

    Add these advances in extreme beam control with the fact the LHC will be running at a record-breaking collision energy of 13 TeV and we have the unprecedented opportunity to make some groundbreaking discoveries.

    “In 2015, we opened the doors to a completely new landscape with unprecedented energy. Now we can begin to explore this landscape in depth,” said CERN Director for Research and Computing, Eckhard Elsen.

    The current plan is to continue proton-proton collisions for six months and then carry out a four-week run using much heavier lead ions.

    So the message is clear: Hold onto your hats. We’re in for an incredible year of discovery that could confirm or deny certain models of our universe and revel something completely unexpected and, possibly, something very exotic.

    See the full article here .

    Please help promote STEM in your local schools.

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  • richardmitnick 11:07 am on May 19, 2016 Permalink | Reply
    Tags: , , CERN LHC, , The Biggest Hopes Of What A New Particle At The LHC Might Reveal   

    From Ethan Siegel: “The Biggest Hopes Of What A New Particle At The LHC Might Reveal” 

    Starts with a Bang

    May 18, 2016
    Ethan Siegel

    1
    Inside the magnet upgrades on the LHC, that have it running at nearly double the energies of the first (2010-2013) run. Image credit: Richard Juilliart/AFP/Getty Images.

    Built over an 11-year period from 1998 to 2008, the Large Hadron Collider was designed with one goal in mind: to create the greatest numbers of the highest-energy collisions ever, in the hopes of finding new fundamental particles and of revealing new secrets of nature.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Over a three year period from 2010 to 2013, the LHC collided protons together at energies nearly four times the previous record, with an upgrade nearly doubling that in 2015: to a record 13 TeV, or approximately 14,000 times the energy inherent to a proton via Einstein’s E = mc^2. The largest, most advanced detectors of all — CMS and ATLAS — were built around the main two collision points, collecting as precise and accurate data about all the debris that emerges each time two protons smash together.

    CERN/CMS Detector
    CERN/CMS detector

    CERN/ATLAS detector
    CERN/ATLAS detector

    July 2012 was a watershed moment for particle physics, as enough high-energy collisions were reconstructed to definitively announce, in both detectors, the first concrete, direct evidence for the Higgs Boson: the last undiscovered particle in the Standard Model of particle physics.

    CERN ATLAS Higgs Event
    CERN ATLAS Higgs Event

    CERN CMS Higgs Event
    CERN CMS Higgs Event

    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.
    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

    3
    Image credit: The CMS Collaboration, “Observation of the diphoton decay of the Higgs boson and measurement of its properties”, (2014). This was the first “5-sigma” detection of the Higgs.

    But that was expected. The problem is, there are a whole host of questions about the Universe that the Standard Model of particle physics doesn’t answer at a fundamental level, including:

    Why is there more matter than antimatter in the Universe?
    What is dark matter, and what particle(s) beyond the Standard Model (which cannot account for it) explains it?
    Why does our Universe have dark energy, and what is its nature?
    Why don’t the strong interactions in the Standard Model exhibit CP-violation in the strong decays?

    Why do neutrinos have such small but non-zero masses compared to all the other particles?
    And why do the Standard Model particles have the properties and masses that they do, and not any others?

    And the great hope of the LHC, the real hope, is that we’ll learn something extra, beyond the Standard Model, that helps answer one or more of these questions.

    4
    The particles of the Standard Model, all of which have been detected. Image credit: E. Siegel, from his new book, Beyond The Galaxy.

    With the possible exception of dark energy, all of these problems pretty much require new fundamental particles to explain them. And many of them — the dark matter problem, the matter/antimatter problem, and the mass-of-the-particles problem (a.k.a. the Hierarchy problem) — may actually be within reach at the LHC. One way to look for this new physics is to look for deviations from the expected (and well-calculated) behavior in the decays and other properties of the known, detectable Standard Model particles. So far, to the best of our abilities, everything falls within the “normal” range, where things are perfectly consistent with the Standard Model.

    6
    Image credit: The ATLAS collaboration, 2015, of the various decay channels of the Higgs. The parameter mu = 1 corresponds to a Standard Model Higgs only. Via https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2015-007/.

    But the second way is even better: to discover, directly, evidence for a new particle beyond the Standard Model. As the LHC begins collecting even higher-energy data and with even greater numbers of collisions-per-second, it’s in the best position it’s ever going to be to find new fundamental particles; particles it never expected to find. Of course, it doesn’t exactly find particles; it finds the decay products of particles! Fortunately, because of how physics works, we can reconstruct what energy (and hence, what mass) those particles were created at, and whether we’ve got a new particle after all. At the end of the LHC’s initial run, there’s an intriguing (but not certain) hint of what might be a new particle. This “750 GeV diphoton bump” might not be real, but if it is, it could mean the world to physicists everywhere.

    7
    The ATLAS and CMS diphoton bumps, displayed together, clearly correlating at ~750 GeV. Image credit: CERN, CMS/ATLAS collaborations, image generated by Matt Strassler at https://profmattstrassler.com/2015/12/16/is-this-the-beginning-of-the-end-of-the-standard-model/.

    The preliminary signal is discernible in both the CMS and the ATLAS detectors so far, and that makes the possibility extra tantalizing. Within about 6 more months, we should know whether this signal is strengthening — and hence likely real — or whether it shows itself to be spurious. If it’s real, here are some of the top possibilities:

    1. It’s a second Higgs boson! Many extensions to the Standard Model — like supersymmetry — predict additional Higgs particles that are heavier than the current (126 GeV) one we know. If so, this could be a window into a whole world of physics beyond the Standard Model, including into the matter/antimatter asymmetry and the Hierarchy problem.
    2. It’s dark matter-related. Could this new particle be a window into the dark sector? Is there some energy non-conservation happening here that means we’re making something that the detectors can’t see? This is one of the “dare-to-dream” possibilities of particle physics: that the LHC could create dark matter. There’s even a fun little correlation here with something most people haven’t put together: there’s an excess in cosmic ray energies seen in this exact same energy range from the balloon-borne Advanced Thin Ionization Calorimeter (ATIC) experiment!

    8
    Image credit: J. Chang et al. (2008), Nature, from the Advanced Thin Ionization Calorimeter (ATIC).

    3.It’s a window into extra dimensions. If there are more than the three spatial dimensions we’re used to, especially at smaller scales, new particles can arise in our three dimensions as a result. These Kaluza-Klein particles could show up at the LHC, and might decay to two photons. Studying how they decay could tell us whether this is true.

    4.It’s a new part of the neutrino sector. This would be a little unusual — since neutrinos don’t normally decay to two photons; they’ve got the wrong spin — but a scalar neutrino could create two photons, which is actually a thing in Standard Model extensions. The couplings and decay pathways, if it’s real, could show us this.

    5. It’s a composite particle. The first particle we ever saw decay into two photons was the lightest quark-antiquark combination of all: the neutral pion. Perhaps these Standard Model particles are combining in ways we don’t yet understand, and what we’ve found is nothing new.
    Or, most excitingly, none of the above. The most exciting discoveries are the ones you never anticipated, and perhaps it isn’t any of the speculative scenarios we know to look for. Perhaps nature is more surprising than even our wildest theoretical dreams.

    6. Or, most excitingly, none of the above. The most exciting discoveries are the ones you never anticipated, and perhaps it isn’t any of the speculative scenarios we know to look for. Perhaps nature is more surprising than even our wildest theoretical dreams.

    The answers, believe it or not, are locked inside of the smallest particles in nature. All we need are the highest energies we can get to in order to find out.

    Of course, this could simply turn out to be a statistically insignificant bump that goes away with more data; it may be nothing at all. This has already happened once before, at about three times the energy. There was hint of an extra “bump” at just over 2 TeV in both detectors, as you can see for yourself.

    7
    Images credit: ATLAS collaboration (L), via http://arxiv.org/abs/1506.00962; CMS collaboration (R), via http://arxiv.org/abs/1405.3447.

    A reanalysis of the data shows there’s no significance to this signal, and that might be what we have in the 750 GeV case, too. But the possibility that it’s real is too big to ignore, and the data will come in to tell us by the end of this year. The biggest unanswered, fundamental questions in theoretical physics will get a run for the money, and all it takes is for a bump in the data to hold up a little bit longer.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    “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 4:33 pm on May 17, 2016 Permalink | Reply
    Tags: , , CERN LHC,   

    From CERN: “How to help CERN to run more simulations” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    CERN

    16 May 2016
    by The LHC@home team

    With LHC@Home you can actively contribute to the computing capacity of the Laboratory!

    LHC Sixtrack

    You may think that CERN’s large Data Centre and the Worldwide LHC Computing Grid have enough computing capacity for all the Laboratory’s users. However, given the massive amount of data coming from LHC experiments and other sources, additional computing resources are always needed, notably for simulations of physics events, or accelerator and detector upgrades.

    This is an area where you can help, by installing BOINC and running simulations from LHC@home on your office PC or laptop. These background simulations will not disturb your work, as BOINC can be configured to automatically stop computing when your PC is in use.

    BOINC WallPaper

    BOINCLarge

    As mentioned in earlier editions of the Bulletin (see here and here), contributions from LHC@home volunteers have played a major role in LHC beam simulation studies.

    LHC@Home Classic Users 133,627 Hosts (computers) 359,237 Teams 5,079 Countries 205 Total BOINC credit 4,797,971,717
    Last day 205,687
    (Statistics from BOINCStats)

    The computing capacity they made available corresponds to about half the capacity of the CERN batch system! Thanks to this precious contribution, detailed studies of subtle effects related with non-linear beam dynamics have been performed using the SixTrack code. This proved extremely useful not only for the LHC, but also for its upgrade, the HL-LHC.

    More recently, thanks to virtualisation, the use of LHC@home has been expanded to other applications. Full physics simulations are run in a small CernVM virtual machine on all types of volunteer computers. Monte-Carlo simulations for theorists were first included in a project called Test4Theory. Results are submitted to a database called MCPLots, based in the Theory department at CERN. Since 2011, about 2.7 trillion events have been simulated.

    Following this success, ATLAS became the first experiment to join, and the number of volunteers engaged in ATLAS physics events simulation has been steadily ramping up for the last 18 months. The production rate is now equivalent to that of a large WLCG Tier 2 site! These events are fully integrated into the experiment data management system and are already being used for the physics analysis of Run 2. Now applications for the other LHC experiments are also being tested under LHC@home.

    We encourage you to help to produce more results. It is really easy to join! On a standard CERN NICE PC, you can install BOINC with CMF, and then connect to LHC@home as indicated on the LHC@home web-site and in the CMF instructions. If you use a Macintosh or Linux desktop, please refer to the instructions for your platform on the website, which also includes a video tutorial.

    Help our accelerator and research community and join LHC@home!

    [This subject is near and dear to my heart. For about six years I was a “cruncher”. I worked on Six Track and Test4Theory for CERN. In total, all projects I amassed 37,000,000 credits before I had to quit. I still believe in Public Distributed Computing. I support BOINC and World Community Grid on this blog when something is published.]

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

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    Meet CERN in a variety of places:

    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 LHC Map
    CERN LHC Grand Tunnel

    CERN LHC particles

    Quantum Diaries

     
  • richardmitnick 9:07 am on May 14, 2016 Permalink | Reply
    Tags: , Boston U, Boston U Bump Hunters, CERN LHC, , , ,   

    From BU: “Bump Hunters” 

    Boston University Bloc

    Boston University

    5.14.16
    Elizabeth Dougherty

    Boston U Bump Hunters Steve Ahlen, Kenneth Lane, Tulika Bose, Kevin Black, Sheldon Glashow
    Bump Hunters Steve Ahlen, Kenneth Lane, Tulika Bose, Kevin Black, Sheldon Glashow

    Tulika Bose stands guard over the printer.

    She’s carried her laptop down the hall and submitted her print job on arrival to be certain that she will intercept her papers before anyone else has a chance to see them. Her documents contain secrets.

    Bose is a physicist working at the Large Hadron Collider (LHC) in Switzerland.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Her work has nothing to do with weapons or national defense or space exploration or any of the usual top-secret stuff physicists work on. What her files contain are ideas about what we—everything under the sun and beyond it—are made of. Her documents could contain the secrets of the universe.


    Access mp4 video here .
    When Protons Collide: A proton collision is like a car accident—except when it isn’t. Physicist Kevin Black explains why. (Watch out for the kitchen sink!) Video by Joe Chan

    An associate professor of physics at Boston University, Bose is part of a cadre of physicists at BU committed to understanding matter down to its smallest particles and most intricate interactions. BU is unusual, one of only a small handful of US universities with researchers working on multiple experiments at the LHC.

    These experiments are looking for signs of particles that have never been seen before. The particles familiar from high school physics—electrons, protons, and neutrons—were just the beginning. Over the past several decades, physicists have confirmed that there are six kinds of quarks; three types of leptons; and assorted bosons, including photons, gluons, and the famed Higgs. These particles only exist in high-energy environments, such as the LHC, where protons are sent hurtling around a ring at speeds very close to the speed of light, colliding together spectacularly. All of the particles that are predicted to exist by the accepted theory of particle physics, called the Standard Model, have been found through experiments like those done at the LHC.

    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.
    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.

    2
    A theoretical physicist since the 1960s and a Nobel Laureate, Glashow came to BU in 2000 because of the physics department’s emphasis on experiments like those at the LHC. Photo by Gina Manning

    U also happens to have on its faculty Sheldon Glashow, a BU College of Arts & Sciences physics professor, who won the Nobel Prize in Physics in 1979 for his work developing the foundations of the Standard Model. Theorists like Glashow and Kenneth Lane, also a BU professor of physics, and experimental physicists like Bose have become masters of the Standard Model and are spending their careers trying to figure out one thing: Is there more to the universe than what we know right now?

    The answer, almost surely, is yes.

    When physicists look for new particles, they are really looking for “bumps” in the data produced by their experiments. A bump indicates that something appeared with energy or mass that was different than expected. “We call it ‘bump hunting,’” says Steve Ahlen, BU professor of physics, who represents yet another flavor of physicist. A hardware physicist, Ahlen has built muon detector chambers with his own hands and led their construction in Boston. Those built in Boston were auspiciously placed at the LHC and captured a good portion of the particles that allowed researchers to confirm the existence of the Higgs boson in 2012.

    The hunt is on, at a time like no other in physics. The quest reached a pinnacle with the Higgs boson, but finding it wasn’t the end. It was just the beginning.

    “Before the Higgs was discovered, people were absolutely convinced that it was there. The challenge was finding it,” says Glashow. “The trouble now is that we theorists don’t know what else is out there. We are no longer so confident that we know what to look for. But we hope that something interesting will show up.”

    On Colliders and Detectors

    The Large Hadron Collider is currently the world’s highest energy particle collider. It is also the largest machine ever built. The circular tunnel around which proton beams fly is 17 miles wide and buried 574 feet underground in a rural area on the border of France and Switzerland at the European Organization for Nuclear Research (CERN). The collider’s job is to smash particles together at high speeds and record the spray of shrapnel that results, so that physicists can look for signs of new particles. If they find something that looks interesting, they piece the data back together again, retracing the paths of all the particles in the spray back to the collision that caused them.

    “I think of it as if a murder has happened, and you have all these clues,” says Bose. “The detective comes in and uses all these clues to reconstruct the scene and figure out who committed the crime.”

    In 2015, the LHC operated at 13 tera-electron-volts (TeV), the highest energy level yet. One TeV is a trillion electron-volts, which sounds like a lot. It is, but it is small compared to the energy consumed by light bulbs and laptops and other things of daily life. A tera-electron-volt is approximately equal to the energy of a single flying mosquito. What the LHC does, beyond multiplying that energy by 13, is compress it into the space of a proton beam, a million million times smaller than a mosquito.

    At this energy level, the LHC can accelerate protons to speeds extremely close to the speed of light. Further, it bundles those protons, with each beam containing a thousand bunches of about a hundred billion protons per bunch. Packing far more punch than a mosquito, the total energy of a beam is more like a 17-ton plane flying over 460 miles per hour.

    In March 2016, the collider began running again, this time with more intense beams. This increased brightness will make for more collisions per second, so the LHC will produce approximately six times more data than in 2015. “We’re just beginning to tap its potential,” says Kevin Black, an associate professor of physics at BU, and also Bose’s husband. Bose and her students work on an experiment called CMS at LHC. Black works on a different experiment there called ATLAS.

    The CMS and ATLAS experiments are, at their core, two different pieces of hardware that detect particles.

    CERN/CMS Detector
    CERN CMS Higgs Event
    CERN/CMS and Higgs event at CMS

    CERN/ATLAS
    CERN ATLAS Higgs Event
    CERN/ATLAS andHiggs event at ATLAS

    They sit at opposite sides of the beam ring surrounding two separate beam intersections, where they capture all of the shrapnel from the proton-proton collisions that occur at their centers.

    The ATLAS detector, which Ahlen helped build, is a 75-foot-high, 140-foot-long machine in which five layers of detection hardware measure the momentum and mass of particles produced when protons smash together. CMS, for Compact Muon Solenoid, is considerably smaller and more dense. It captures the same types of particles as ATLAS, just in a different way.

    2
    A hands-on physicist, Ahlen likes to build things. He is currently building dark energy detectors and climbing mountains to install them on telescopes. Photo by Gina Manning

    These machines can detect all of the particles defined in the Standard Model. Take muons as an example. A muon is a tiny particle, even by the standards of particle physicists, that is produced inside colliders and also when cosmic rays strike the atmosphere. When Ahlen got involved with the development of detectors for particle colliders in the 1990s, it wasn’t clear how to detect muons affordably. He came up with a simple solution: A twelve-foot-long, two-inch-diameter aluminum tube, crimped at both ends and filled with gas, with a wire stretched under tension from end to end. “If you pressurize it, it can localize the trajectory of a particle that passes through the tube,” he says, waving around a spare tube he keeps behind the door in his office.

    The ATLAS detector, which has several layers of specialized particle detectors, contains about 500,000 of these tubes. They were built all over the world to exacting standards, many in Boston by Ahlen, who borrowed and bartered equipment and materials to get the job done.

    While the tubes themselves might not seem so special, keep in mind that each tube in the ATLAS detector must be precisely placed. “We know where each wire is to less than the width of a human hair,” says Ahlen.

    Not only that, every particle that whizzes by must be recorded, along with the exact time it flew through. So every tube and every other sensor in the detector—tens of millions of them in total—is connected to a clock. The clocks are set to the beam crossing, which occurs every 25 nanoseconds. The first crossing is one. “The second, two, the third, three,” says Ahlen. “Every 25 nanoseconds, boom, boom.”

    There were 40 million beam crossings per second, and about a billion proton-proton collisions per second, in the last run of the LHC.

    The time-stamped data flows from each detector down an electrical pipe to join with others in a raging river of data. Carefully coded computer algorithms determine which events to keep and which to throw away. Bose, who is the “trigger” in charge of this gatekeeping for CMS, saves only about a thousand events per second. A lot, but still just a tiny fraction of the data produced.

    Secret Keepers

    CMS and ATLAS produce and save independent sets of data and have independent teams analyzing it. Bose, for example, is one of nearly 4,000 people working on the CMS experiment, while Black is part of a team of 3,000 people working on ATLAS.

    The teams sift through their data in secret, without sharing early results. At a time when data sharing in science is all the rage, secrecy seems to go against the grain, but it is a necessity in physics. In the past, there have been cases where rumors about the early sightings of new particles lead to false discoveries. In one case, physicists started looking for signs of a new particle people were buzzing about. “Any run that had a little bump in the rumored location, they kept,” says Black. “Anything that didn’t, they found a reason to throw out the data. Inadvertently, they self-selected the particle into existence.” In the end, an unbiased look at the data proved that the particle did not exist.

    3
    For Black (PhD ’05), who is currently stationed at the LHC in Switzerland, patience is a virtue. The phenomena he studies occur so rarely that even with millions of collisions per second, he might not see them. Photo by Darrin Vanselow

    So experimentalists like Bose and Black try not to share data. In fact, they try extra hard, since the two are married. “We don’t talk about the details,” says Black. “I think we actually have more of a dividing line there because we are worried that if there is any leak, people might look to us first.”

    In practice, though, that line is a bit murky. The thousands of scientists at the LHC work side-by-side. The offices of scientists on different experiments are intermeshed. They share cafeterias and printers and hold open-door seminars to discuss ideas. Despite all this openness, no one wants to undermine the credibility of the science they are doing. “From a pure science point of view, the result is much stronger when two independent experiments come up with the same answer without biasing each other,” says Bose. “We try to keep an open mind. You look everywhere and you see what you see.”

    In the end, it isn’t just secrecy that keeps the science pure. Particle physicists have also set a very high bar for discovery. For a new particle to be accepted, scientists must be confident that it is not a statistical fluctuation. They’ve agreed on a number, 5-sigma, which means that the chance of the data being a statistical fluctuation is 1 in 3.5 million.

    The concept of sigma might be familiar from basic statistics—or from tests graded on a curve. One standard deviation from the mean on a bell curve is called one-sigma. Students scoring two- or three-sigma above (or below) are rare and end up with the grades to prove it.

    But the LHC doesn’t make its findings based on a single test. A bump at the LHC stands out against the bell curves of all the tests ever run. This mass of data all taken together, says Bose, is called “background.” It forms a landscape that has become familiar to physicists. A bump like the Higgs appears as a blot on this predictable landscape, a little like the unexpected genius who shows up for test after test and busts the curve.

    The bump that physicists recognized as the first sign of the Higgs boson was produced by data from about 10 collisions. Even with such scant data, the confidence level was about 4-sigma because the Higgs stood out so starkly against the familiar background. Later, when all of the data came together, about 40 events produced a more pronounced bump with a confidence level of 8-sigma. “That’s a very clean discovery,” says Ahlen.

    From Old Physics, New

    The LHC fired up its proton beams again in March 2016, and saw its first collisions on April 23. The hope is that at the planned higher energy level, it will produce more dramatic collisions that will allow physicists to discover something new.

    “The best thing that could happen is that we’ll discover a whole set of new particles that don’t make any sense at all,” says Black. “I’m hopeful that sort of thing will happen, that we’ll discover something that truly doesn’t make sense and we’ll really learn something from it.”

    Physicists refer to their quest as a search for “new physics,” begging the question: What’s wrong with the old physics? It’s not so much that the old physics doesn’t work—it does, amazingly well—but ask any particle physicist, and they will tell you there’s something about it that just isn’t satisfying. Parameters have to line up in very specific ways for some calculations to work out. If something is off by a smidgen, everything falls apart.

    “This kind of special balancing out of parameters in the current theory gives us the impression that there has to be some underlying principle that we’re missing,” says Black.

    So it is and so it has always been in physics. It all started back when the Greeks came up with the solid but incomplete idea of the atom. Centuries later, Newton’s experiments resulted in Newtonian mechanics, which brilliantly explain the day-to-day physics of the movements of planets in space and objects on Earth. Things got heady in the late 1800s when scientists started to understand electrical currents and magnetic fields. The early 20th century gave rise to quantum theory, which explains the world of tiny, energetic things, like photons. According to Lane, every successful theory has engulfed its predecessor. “Quantum mechanics ate the physics of the 18th and 19th centuries alive,” he says.

    The most recent meal, so to speak, was devoured in the 1960s and 70s by the Standard Model. By 1960, physicists knew about weak nuclear forces, which govern how particles decay into other particles. But no one knew how this force was related to existing theories of electromagnetism. Glashow worked out a new model for weak nuclear forces that relied on three new particles.

    “No one cared,” he says, until 1967, when Glashow’s idea morphed, in a confluence of other ideas, into a theory that made sense: The Standard Model. “Experimenters went out of their way to verify the predictions of the theory,” says Glashow, who won the Nobel Prize alongside Steven Weinberg and Abdus Salam for their work. “Lo and behold, the theory was right.”

    For theorists like Glashow and Lane, the observations of experiments lend credence to theory, and theory provides a rationale for understanding and deciphering what is seen in experiments. “Physics is an experimental science,” says Lane. “It’s not mathematics or philosophy. If it can’t be tested by experiment, it ain’t physics.”

    The most recent piece of experimental data confirming the Standard Model was the discovery of the Higgs boson in 2012. For Lane, the Higgs was a bit of a disappointment. “It’s kind of a simple-minded solution to a big problem,” he says. “Some people still feel burned by this discovery. Me, for example.”

    But ultimately, Lane is interested in figuring out what the most basic, fundamental particles are and how they interact with one another. “Right now, we have a story for that, but there’s always been a story for that,” he says.

    As long as people have been curious about the world they live in, they’ve been coming up with theories, testing them, and making them better. “This,” says Lane, “is an enterprise that need have no end.”

    See the full article here .

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  • richardmitnick 12:21 pm on May 9, 2016 Permalink | Reply
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    From FNAL: “Large Hadron Collider prepares to deliver six times the data” 

    FNAL II photo

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    May 9, 2016

    Media contact

    Andre Salles, Fermilab Office of Communication, asalles@fnal.gov, 630-840-6733
    Ivy F. Kupec, National Science Foundation, ikupec@nsf.gov, 703-292-8796
    Rick Borchelt, U.S. Department of Energy Office of Communications and Public Affairs, rick.borchelt@science.doe.gov, 202-586-4477
    Sarah Charley, US LHC, scharley@fnal.gov, 630-338-3034 (cell)

    1
    Collisions recorded on May 7, 2016, by the CMS detector on the Large Hadron Collider. After a winter break, the LHC is now taking data again at extraordinary energies. Image: CERN

    Experiments at the LHC are once again recording collisions at extraordinary energies

    Editor’s note: The following news release about the restart of the Large Hadron Collider is being issued by the U.S. Department of Energy’s Fermi National Accelerator Laboratory on behalf of the U.S. scientists working on the LHC. Fermilab serves as the U.S. hub for the CMS experiment at the LHC and the roughly 1,000 U.S. scientists who work on that experiment, including about 100 Fermilab employees. Fermilab is a Tier 1 computing center for LHC data and hosts a Remote Operations Center to process and analyze that data. Read more information about Fermilab’s role in the CMS experiment and the LHC. Fermilab scientists are available for interviews upon request, including Joel Butler, recently elected next spokesperson of the CMS experiment.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    After months of winter hibernation, the Large Hadron Collider is once again smashing protons and taking data. The LHC will run around the clock for the next six months and produce roughly 2 quadrillion high-quality proton collisions, six times more than in 2015 and just shy of the total number of collisions recorded during the nearly three years of the collider’s first run.

    “2015 was a recommissioning year. 2016 will be a year of full data production during which we will focus on delivering the maximum number of data to the experiments,” said Fabiola Gianotti, CERN director general.

    CERN Fabiola Gianotti
    Fabiola Gianotti

    The LHC is the world’s most powerful particle accelerator. Its collisions produce subatomic fireballs of energy, which morph into the fundamental building blocks of matter. The four particle detectors located on the LHC’s ring allow scientists to record and study the properties of these building blocks and look for new fundamental particles and forces.

    “We’re proud to support more than a thousand U.S. scientists and engineers who play integral parts in operating the detectors, analyzing the data and developing tools and technologies to upgrade the LHC’s performance in this international endeavor,” said Jim Siegrist, associate director of science for high-energy physics in the U.S. Department of Energy’s Office of Science. “The LHC is the only place in the world where this kind of research can be performed, and we are a fully committed partner on the LHC experiments and the future development of the collider itself.”

    [Never should it be forgotten that this work could have proceeded i the US had the US Congress followed through with funding for the Superconducting Super Collider which had begun construction in Texas. In 1993, our congress decided to stop this project and leave this research to others.]

    Between 2010 and 2013 the LHC produced proton-proton collisions with 8 teraelectronvolts of energy. In the spring of 2015, after a two-year shutdown, LHC operators ramped up the collision energy to 13 TeV. This increase in energy enables scientists to explore a new realm of physics that was previously inaccessible. Run II collisions also produce Higgs bosons — the groundbreaking particle discovered in LHC Run I — 25 percent faster than Run I collisions and increase the chances of finding new massive particles by more than 40 percent.

    Almost everything we know about matter is summed up in the Standard Model of particle physics, an elegant map of the subatomic world.

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

    During the first run of the LHC, scientists on the ATLAS and CMS experiments discovered the Higgs boson, the cornerstone of the Standard Model that helps explain the origins of mass.

    CERN/ATLAS
    CERN ATLAS Higgs Event
    ATLAS

    CERN/CMS Detector
    CERN CMS Higgs Event
    CMS

    The LHCb experiment also discovered never-before-seen five-quark particles, and the ALICE experiment studied the near-perfect liquid that existed immediately after the Big Bang. All these observations are in line with the predictions of the Standard Model.

    CERN/LHCb
    LHCb

    AliceDetectorLarge
    ALICE

    “So far the Standard Model seems to explain matter, but we know there has to be something beyond the Standard Model,” said Denise Caldwell, director of the Physics Division of the National Science Foundation. “This potential new physics can only be uncovered with more data that will come with the next LHC run.”

    For example, the Standard Model contains no explanation of gravity, which is one of the four fundamental forces in the universe. It also does not explain astronomical observations of dark matter, a type of matter that interacts with our visible universe only through gravity, nor does it explain why matter prevailed over antimatter during the formation of the early universe. The small mass of the Higgs boson also suggests that matter is fundamentally unstable.

    The new LHC data will help scientists verify the Standard Model’s predictions and push beyond its boundaries. Many predicted and theoretical subatomic processes are so rare that scientists need billions of collisions to find just a small handful of events that are clean and scientifically interesting. Scientists also need an enormous amount of data to precisely measure well-known Standard Model processes. Any significant deviations from the Standard Model’s predictions could be the first step towards new physics.

    The United States is the largest national contributor to both the ATLAS and CMS experiments, with 45 U.S. universities and laboratories working on ATLAS and 49 working on CMS.

    CERN, the European Organization for Nuclear Research, is the world’s leading laboratory for particle physics. It has its headquarters in Geneva. At present, its member states are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a candidate for accession. Cyprus and Serbia are associate members in the pre-stage to membership. Turkey and Pakistan are associate members. India, Japan, the Russian Federation, the United States of America, Turkey, the European Union, JINR and UNESCO have observer status.

    See the full from FNAL article here .
    See the Symmetry article here .

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    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 10:43 am on May 2, 2016 Permalink | Reply
    Tags: , , CERN LHC, , ,   

    From phys.org: “Physicists abuzz about possible new particle as CERN revs up” 

    physdotorg
    phys.org

    May 2, 2016
    Jamey Keaten And Frank Jordans

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Scientists around the globe are revved up with excitement as the world’s biggest atom smasher—best known for revealing the Higgs boson four years ago—starts whirring again to churn out data that may confirm cautious hints of an entirely new particle.

    Higgs Boson Event
    Higgs Boson Event

    Such a discovery would all but upend the most basic understanding of physics, experts say.

    The European Center for Nuclear Research, or CERN by its French-language acronym, has in recent months given more oomph to the machinery in a 27-kilometer (17-mile) underground circuit along the French-Swiss border known as the Large Hadron Collider.

    In a surprise development in December, two separate LHC detectors each turned up faint signs that could indicate a new particle, and since then theorizing has been rife.

    “It’s a hint at a possible discovery,” said theoretical physicist Csaba Csaki, who isn’t involved in the experiments. “If this is really true, then it would possibly be the most exciting thing that I have seen in particle physics in my career—more exciting than the discovery of the Higgs itself.”

    After a wintertime break, the Large Hadron Collider, or LHC, reopened on March 25 to prepare for a restart in early May. CERN scientists are doing safety tests and scrubbing clean the pipes before slamming together large bundles of particles in hopes of producing enough data to clear up that mystery. Firm answers aren’t expected for weeks, if not until an August conference of physicists in Chicago known as ICHEP.

    On Friday, the LHC was temporarily immobilized by a weasel, which invaded a transformer that helps power the machine and set off an electrical outage. CERN says it was one of a few small glitches that will delay by a few days plans to start the data collection at the $4.4 billion collider.

    The 2012 confirmation of the Higgs boson, dubbed the “God particle” by some laypeople, culminated a theory first floated decades earlier. The “Higgs” rounded out the Standard Model of physics, which aims to explain how the universe is structured at the infinitesimal level.

    The LHC’s Atlas and Compact Muon Solenoid particle detectors in December turned up preliminary readings that suggested a particle not accounted for by the Standard Model might exist at 750 Giga electron Volts. This mystery particle would be nearly four times more massive than the top quark, the most massive particle in the model, and six times more massive than the Higgs, CERN officials say.

    CERN/ATLAS
    CERN/ATLAS

    CERN/CMS Detector
    CERN/CMS Detector

    The Standard Model has worked well, but has gaps notably about dark matter, which is believed to make up one-quarter of the mass of the universe.

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

    Theorists say the December results, if confirmed, could help elucidate that enigma; or it could signal a graviton—a theorized first particle with gravity—or another boson, even hint of a new dimension.

    More data is needed to iron those possibilities out, and even then, the December results could just be a blip. But with so much still unexplained, physicists say discoveries of new particles—whether this year or later—may be inevitable as colliders get more and more powerful.

    Dave Charlton, who heads the Atlas team, said the December results could just be a “fluctuation” and “in that case, really for science, there’s not really any consequence … At this point, you won’t find any experimentalist who will put any weight on this: We are all very largely expecting it to go away again.”

    “But if it stays around, it’s almost a new ball game,” said Charlton, an experimental physicist at the University of Birmingham in Britain.

    The unprecedented power of the LHC has turned physics on its head in recent years. Whereas theorists once predicted behaviors that experimentalists would test in the lab, the vast energy being pumped into CERN’s collider means scientists are now seeing results for which there isn’t yet a theoretical explanation.

    “This particle—if it’s real—it would be something totally unexpected that tells us we’re missing something interesting,” he said.

    Whatever happens, experimentalists and theorists agree that 2016 promises to be exciting because of the sheer amount of data pumped out from the high-intensity collisions at record-high energy of 13 Tera electron Volts, a level first reached on a smaller scale last year, and up from 8 TeVs previously. (CERN likens 1 TeV to the energy generated by a flying mosquito: That may not sound like much, but it’s being generated at a scale a trillion times smaller.)

    In energy, the LHC will be nearly at full throttle—its maximum is 14 TeV—and over 2,700 bunches of particles will be in beams that collide at the speed of light, which is “nearly the maximum,” CERN spokesman Arnaud Marsollier said. He said the aim is to produce six times more collisions this year than in 2015.

    “When you open up the energies, you open up possibilities to find new particles,” he said. “The window that we’re opening at 13 TeV is very significant. If something exists between 8 and 13 TeV, we’re going to find it.”

    Still, both branches of physics are trying to stay skeptical despite the buzz that’s been growing since December.

    Csaki, a theorist at Cornell University in Ithaca, New York, stressed that the preliminary results don’t qualify as a discovery yet and there’s a good chance they may turn out not to be true. The Higgs boson had been predicted by physicists for a long time before it was finally confirmed, he noted.

    “Right now it’s a statistical game, but the good thing is that there will be a lot of new data coming in this year and hopefully by this summer we will know if this is real or not,” Csaki said, alluding to the Chicago conference. “No vacation in August.”

    See the full article here .

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    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 7:57 am on April 14, 2016 Permalink | Reply
    Tags: , , CERN LHC, ,   

    From FNAL’s Don Lincoln on livescience: “Collider Unleashed! The LHC Will Soon Hit Its Stride” 

    Livescience

    April 12, 2016

    FNAL Don Lincoln
    Don Lincoln, Senior Scientist, Fermi National Accelerator Laboratory; Adjunct Professor of Physics, University of Notre Dame

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    If you’re a science groupie and would love nothing better than for a cornerstone scientific theory to be overthrown and replaced with something newer and better, then 2016 might well be your year. The world’s largest particle accelerator, the Large Hadron Collider (LHC), is resuming operations after a pause during the winter months, when the cost for electricity in France is highest.

    So why is it such a big deal that LHC coming back on line? It’s because this is the year the accelerator will operate at something approaching its design specifications. Scientists will smash the gas pedal to the floor, crank the fire hose wide open, spin the amplifier button to eleven or enact whatever metaphor you like. This year is the first real year of full-scale LHC operations.

    A particle smasher reborn

    Now if you actually are a science groupie, you know what the LHC is and have probably heard about some of its accomplishments. You know it smashes together two beams of protons traveling at nearly the speed of light. You know scientists using the LHC found the Higgs boson.

    CERN ATLAS Higgs Event
    CERN ATLAS Higgs Event

    CERN CMS Higgs Event
    CERN CMS Higgs Event

    You know that this marvel is the largest scientific device ever built.

    So what’s different now? Well, let’s go back in time to 2008, when the LHC circulated its first beams. At the time, the world’s premier particle accelerator was the U.S. Department of Energy’s Fermilab Tevatron, which collided beams at a whopping 2 trillion electron volts (TeV) of energy and with a beam brightness of about 2 × 1032 cm-2 s-1.

    FNAL/Tevatron map
    FNAL/Tevatron map

    FNAL/Tevatron CDF
    FNAL/Tevatron CDF detectorFNAL/DZero detector
    FNAL/DZero detector

    The technical term for beam brightness is “instantaneous luminosity,” and basically it’s a density. More precisely, when a beam passes through a target, the instantaneous luminosity (L) is the number of particles per second in a beam that pass a location (ΔNB/Δt) divided by the area of the beam (A), multiplied by the number of targets (NT), L = ΔNB/Δt × (1/A) × NT. (And the target can be another beam.)

    The simplest analogy that will help you understand this quantity is a light source and a magnifying glass. You can increase the “luminosity” of the light by turning up the brightness of the light source or by focusing the light more tightly. It is the same way with a beam. You can increase the instantaneous luminosity by increasing the number of beam or target particles, or by concentrating the beam into a smaller area.

    The LHC was built to replace the Tevatron and trounce that machine’s already-impressive performance numbers.

    [If our USA Congress was not filled with idiots, we would have built in Texas the Superconducting Super Collider and not lost this HEP race.]

    The new accelerator was designed to collide beams at a collision energy of 14 TeV and to have a beam brightness — instantaneous luminosity — of at least 100 × 1032 cm-2 s-1. So the beam energy was to be seven times higher, and the beam brightness would increase 50- to 100-fold.

    Sadly, in 2008, a design flaw was uncovered in the LHC when an electrical short caused severe damage, requiring two years to repair . Further, when the LHC actually did run, in 2010, it operated at half the design energy (7 TeV) and at a beam brightness basically the same as that of the Fermilab Tevatron. The lower energy was to give a large safety margin, as the design flaw had been only patched, not completely reengineered.

    The situation improved in 2011 when the beam brightness got as high as 30 × 1032 cm-2 s-1, although with the same beam energy. In 2012, the beam energy was raised to 8 TeV, and the beam brightness was higher still, peaking at about 65 × 1032 cm-2 s-1.

    The LHC was shut down during 2013 and 2014 to retrofit the accelerator to make it safe to run at closer to design specifications. The retrofits consisted mostly of additional industrial safety measures that allowed for better monitoring of the electrical currents in the LHC. This helps ensure there are no electrical shorts and that there is sufficient venting. The venting guarantees no catastrophic ruptures of the LHC magnets (which steer the beams) in the event that cryogenic liquids — helium and nitrogen — in the magnets warm up and turn into a gas. In 2015, the LHC resumed operations, this time at 13 TeV and with a beam brightness of 40 × 1032 cm-2 s-1.

    So what’s expected in 2016?

    The LHC will run at 13 TeV and with a beam brightness that is expected to approach 100 × 1032 cm-2 s-1 and possibly even slightly exceed that mark. Essentially, the LHC will be running at design specifications.

    In addition, there is a technical change in 2016. The protons in the LHC beams will be spread more uniformly around the ring, thus reducing the number of protons colliding simultaneously, resulting in better data that is easier to interpret.

    At a technical level, this is kind of interesting. A particle beam isn’t continuous like a laser beam or water coming out of a hose. Instead, the beam comes in a couple of thousand distinct “bunches.” A bunch looks a little bit like a stick of uncooked spaghetti, except it is about a foot long and much thinner — about 0.3 millimeters, most of the time. These bunches travel in the huge 16-mile-long (27 kilometers) circle that is the LHC, with each bunch separated from the other bunches by a distance that (until now) has been about 50 feet (15 meters).

    The technical change in 2016 is to take the same number of beam protons (roughly 3 × 1014 protons) and split them up into 2,808 bunches, each separated not by 50 feet, but by 25 feet (7.6 m). This doubles the number of bunches, but cuts the number of protons in each bunch in half. (Each bunch contains about 1011 protons.)

    Because the LHC has the same number of protons but separated into more bunches, that means when two bunches cross and collide in the center of the detector, there are fewer collisions per crossing. Since most collisions are boring and low-energy affairs, having a lot of them at the same time that an interesting collision occurs just clutters up the data.

    Ideally, you’d like to have only an interesting collision and no simultaneous boring ones. This change of bunch separation distance from 50 feet to 25 feet brings the data collection closer to ideal.

    Luminous beams

    Another crucial design element is the integrated beam. Beam brightness (instantaneous luminosity) is related to the number of proton collisions per second, while integrated beam (integrated luminosity) is related to the total number of collisions that occur as the two counter-rotating beams continually pass through the detector. Integrated luminosity is something that adds up over the days, months and years.

    The unit of integrated luminosity is a pb-1. This unit is a bit confusing, but not so bad. The “b” in “pb” stands for a barn (more on that in a moment). A barn is 10-24 cm2. A picobarn (pb) is 10-36 cm2. The term “barn” is a unit of area and comes from another particle physics term called a cross section, which is related to how likely it is that two particles will interact and generate a specific outcome. Two objects that have large effective area will interact easily, while objects with a small effective area will interact rarely.

    An object with an area of a barn is a square with a length of 10-12 cm. That’s about the size of the nucleus of a uranium atom.

    During World War II, physicists at Purdue University in Indiana were working with uranium and needed to mask their work for security reasons. So they invented the term “barn,” defining it as an area about the size of a uranium nucleus. Given how big this area is in the eyes of nuclear and particle physicists, the Purdue scientists were co-opting the phrase “as big as a barn.” In the luminosity world, with its units of (1/barn), small numbers mean more luminosity.

    This trend is evident in the integrated luminosity seen in the LHC each year as scientists improved their ability to operate the accelerator. The integrated luminosity in 2010 was 45 pb-1. In 2011 and 2012, it was 6,100 pb-1 and 23,300 pb-1, respectively. As time went on, the accelerator ran more reliably, resulting in far higher numbers of recorded collisions.

    Because the accelerator had been re-configured during the 2013 to 2014 shutdown, the luminosity was lower in 2015, coming in at 4,200 pb-1, although, of course, at the much higher beam energy. The 2016 projection could be as high as 35,000 pb-1. The predicted increase merely reflects the accelerator operators’ increased confidence in their ability to operate the facility.

    This means in 2016, we could actually record eight times as much data as we did in 2015. And it is expected that 2017 will bring even higher performance.

    Illuminating new science

    Let’s think about what these improvements mean. When LHC first collided beams, in 2010, the Higgs boson was still to be observed.

    Higgs Boson Event
    Higgs Boson Event

    On the other hand, the particle was already predicted, and there was good circumstantial evidence to expect that the Higgs would be discovered. And, without a doubt, it must be admitted that the discovery of the Higgs boson was an enormous scientific triumph.

    But confirming previously predicted particles, no matter how impressive, is not why the LHC was built.

    Scientists’ current theory of the particle world is called the Standard Model, and it was developed in the late 1960s, half a century ago.

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

    While it is an incredibly successful theory, it is known to have holes. Although it explains why particles have mass, it doesn’t explain why some particles have more mass than others. It doesn’t explain why there are so many fundamental particles, given that only a handful of them are needed to constitute the ordinary matter of atoms and puppies and pizzas. It doesn’t explain why the universe is composed solely of matter, when the theory predicts that matter and antimatter should exist in equal quantities. It doesn’t identify dark matter, which is five times more prevalent than ordinary matter and is necessary to explain why galaxies rotate in a stately manner and don’t rip themselves apart.

    When you get right down to it, there is a lot the Standard Model doesn’t explain. And while there are tons of ideas about new and improved theories that could replace it, ideas are cheap. The trick is to find out which idea is right.

    That’s where the LHC comes in. The LHC can explore what happens if we expose matter to more and more severe conditions. Using Einstein’s equation E = mc2, we can see how the high-collision energies only achievable in the LHC are converted into forms of matter never before seen. We can sift through the LHC data to find clues that point us in the right direction to hopefully figure out the next bigger and more effective theory. We can take another step toward our ultimate goal of finding a theory of everything.

    With the LHC now operating at essentially design spec, we can finally use the machine to do what we built it for: to explore new realms, to investigate phenomena never before seen and, stealing a line from my favorite television show, “to boldly go where no one has gone before.” We scientists are excited. We’re giddy. We’re pumped. In fact, there can be but one way to express how we view this upcoming year:

    See the full article here .

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  • richardmitnick 3:23 pm on April 7, 2016 Permalink | Reply
    Tags: , , , CERN LHC, , , , , ,   

    From Symmetry: “Physicists build ultra-powerful accelerator magnet” 

    Symmetry Mag

    Symmetry

    04/07/16
    Sarah Charley

    Magnet built for LHC

    The next generation of cutting-edge accelerator magnets is no longer just an idea. Recent tests revealed that the United States and CERN have successfully co-created a prototype superconducting accelerator magnet that is much more powerful than those currently inside the Large Hadron Collider.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    CERN/LHC

    Engineers will incorporate more than 20 magnets similar to this model into the next iteration of the LHC, which will take the stage in 2026 and increase the LHC’s luminosity by a factor of ten. That translates into a ten-fold increase in the data rate.

    “Building this magnet prototype was truly an international effort,” says Lucio Rossi, the head of the High-Luminosity (HighLumi) LHC project at CERN. “Half the magnetic coils inside the prototype were produced at CERN, and half at laboratories in the United States.”

    During the original construction of the Large Hadron Collider, US Department of Energy national laboratories foresaw the future need for stronger LHC magnets and created the LHC Accelerator Research Program (LARP): an R&D program committed to developing new accelerator technology for future LHC upgrades.

    MQXF1 quadrupole 1.5-meter prototype magnet sits at Fermilab before testing.
    MQXF1 quadrupole 1.5-meter prototype magnet sits at Fermilab before testing. G. Ambrosio (US-LARP and Fermilab), P. Ferracin and E. Todesco (CERN TE-MSC)

    This 1.5-meter-long model, which is a fully functioning accelerator magnet, was developed by scientists and engineers at Fermilab [FNAL], Brookhaven National Laboratory [BNL], Lawrence Berkeley National Laboratory [LBL], and CERN.

    FNAL II photo
    FNAL

    BNL Logo (2)
    BNL

    LBL Big
    LBL

    CERN
    CERN

    The magnet recently underwent an intense testing program at Fermilab, which it passed in March with flying colors. It will now undergo a rigorous series of endurance and stress tests to simulate the arduous conditions inside a particle accelerator.

    This new type of magnet will replace about 5 percent of the LHC’s focusing and steering magnets when the accelerator is converted into the High-Luminosity LHC, a planned upgrade which will increase the number and density of protons packed inside the accelerator. The HL-LHC upgrade will enable scientists to collect data at a much faster rate.

    The LHC’s magnets are made by repeatedly winding a superconducting cable into long coils. These coils are then installed on all sides of the beam pipe and encased inside a superfluid helium cryogenic system. When cooled to 1.9 Kelvin, the coils can carry a huge amount of electrical current with zero electrical resistance. By modulating the amount of current running through the coils, engineers can manipulate the strength and quality of the resulting magnetic field and control the particles inside the accelerator.

    The magnets currently inside the LHC are made from niobium titanium, a superconductor that can operate inside a magnetic field of up to 10 teslas before losing its superconducting properties. This new magnet is made from niobium-three tin (Nb3Sn), a superconductor capable of carrying current through a magnetic field of up to 20 teslas.

    “We’re dealing with a new technology that can achieve far beyond what was possible when the LHC was first constructed,” says Giorgio Apollinari, Fermilab scientist and Director of US LARP. “This new magnet technology will make the HL-LHC project possible and empower physicists to think about future applications of this technology in the field of accelerators.”

    High-Luminosity LHC coil
    High-Luminosity LHC coil similar to those incorporated into the successful magnet prototype shows the collaboration between CERN and the LHC Accelerator Research Program, LARP.
    Photo by Reidar Hahn, Fermilab

    This technology is powerful and versatile—like upgrading from a moped to a motorcycle. But this new super material doesn’t come without its drawbacks.

    “Niobium-three tin is much more complicated to work with than niobium titanium,” says Peter Wanderer, head of the Superconducting Magnet Division at Brookhaven National Lab. “It doesn’t become a superconductor until it is baked at 650 degrees Celsius. This heat-treatment changes the material’s atomic structure and it becomes almost as brittle as ceramic.”

    Building a moose-sized magnet from a material more fragile than a teacup is not an easy endeavor. Scientists and engineers at the US national laboratories spent 10 years designing and perfecting a new and internationally reproducible process to wind, form, bake and stabilize the coils.

    “The LARP-CERN collaboration works closely on all aspects of the design, fabrication and testing of the magnets,” says Soren Prestemon of the Berkeley Center for Magnet Technology at Berkeley Lab. “The success is a testament to the seamless nature of the collaboration, the level of expertise of the teams involved, and the ownership shown by the participating laboratories.”

    This model is a huge success for the engineers and scientists involved. But it is only the first step toward building the next big supercollider.

    “This test showed that it is possible,” Apollinari says. “The next step is it to apply everything we’ve learned moving from this prototype into bigger and bigger magnets.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 10:58 am on March 24, 2016 Permalink | Reply
    Tags: , CERN LHC, , New Software,   

    From Symmetry: “The next big LHC upgrade? Software.” 

    Symmetry Mag
    Symmetry

    03/24/16
    Sarah Charley

    Compatible and sustainable software could revolutionize high-energy physics research.

    1
    Eamonn Maguire / Antarctic Design

    The World Wide Web may have been invented at CERN, but it was raised and cultivated abroad. Now a group of Large Hadron Collider physicists are looking outside academia to solve one of the biggest challenges in physics—creating a software framework that is sophisticated, sustainable and more compatible with rest of the world.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    “The software we used to build the LHC and perform our analyses is 20 years old,” says Peter Elmer, a physicist at Princeton University. “Technology evolves, so we have to ask, does our software still make sense today? Will it still do what we need 20 or 30 years from now?”

    Elmer is part of a new initiative funded by the National Science Foundation called the DIANA/HEP project, or Data Intensive ANAlysis for High Energy Physics. The DIANA project has one main goal: improve high-energy physics software by incorporating best practices and algorithms from other disciplines.

    “We want to discourage physics from re-inventing the wheel,” says Kyle Cranmer, a physicist at New York University and co-founder of the DIANA project. “There has been an explosion of high-quality scientific software in recent years. We want to start incorporating the best products into our research so that we can perform better science more efficiently.”

    DIANA is the first project explicitly funded to work on sustainable software, but not alone in the endeavor to improve the way high energy physicists perform their analyses. In 2010 physicist Noel Dawe started the rootpy project, a community-driven initiative to improve the interface between ROOT and Python.

    “ROOT is the central tool that every physicist in my field uses,” says Dawe, who was a graduate student at Simon Fraser University when he started rootpy and is currently a fellow at the University of Melbourne. “It does quite a bit, but sometimes the best tool for the job is something else. I started rootpy as a side project when I was a graduate student because I wanted to find ways to interface ROOT code with other tools.”

    Physicists began developing ROOT in the 1990s in the computing language C++. This software has evolved a lot since then, but has slowly become outdated, cumbersome and difficult to interface with new scientific tools written in languages such as Python or Julia. C++ has also evolved over the course of the last twenty years, but physicists must maintain a level of backward compatibility in order to preserve some of their older code.

    “It’s in a bubble,” says Gilles Louppe, a machine learning expert working on the DIANA project. “It’s hard to get in and it’s hard to get out. It’s isolated from the rest of the world.”

    Before coming to CERN, Louppe was a core developer of the machine learning platform scikit-learn, an open source library of versatile data mining and data analysis tools. He is now a postdoctoral researcher at New York University and working closely with physicists to improve the interoperability between common LHC software products and the scientific python ecosystem. Improved interoperability will make it easier for physicists to benefit from global advancements in machine learning and data analysis.

    “Software and technology are changing so fast,” Cranmer says. “We can reap the rewards of industry and everything the world is coming up with.”

    One trend that is spreading rapidly in the data science community is the computational notebook: a hybrid of analysis code, plots and narrative text. Project Jupyter is developing the technology that enables these notebooks. Two developers from the Jupyter team recently visited CERN to work with the ROOT team and further develop the ROOT version, ROOTbook.

    “ROOTbooks represent a confluence of two communities and two technologies,” says Cranmer.

    Physics patterns

    To perform tasks such as identifying and tagging particles, physicists use machine learning. They essentially train their LHC software to identify certain patterns in the data by feeding it thousands of simulations. According to Elmer, this task is like one big “needle in a haystack” problem.

    “Imagine the book Where’s Waldo. But instead of just looking for one Waldo in one picture, there are many different kinds of Waldos and 100,000 pictures every second that need to be analyzed.”

    But what if these programs could learn to recognize patterns on their own with only minimal guidance? One small step outside the LHC is a thriving multi-billion dollar industry doing just that.

    “When I take a picture with my iPhone, it instantly interprets the thousands of pixels to identify people’s faces,” Elmer says. Companies like Facebook and Google are also incorporating more and more machine learning techniques to identify and catalogue information so that it is instantly accessible anywhere in the world.

    Organizations such as Google, Facebook and Russia’s Yandex are releasing more and more tools as open source. Scientists in other disciplines, such as astronomy, are incorporating these tools into the way they do science. Cranmer hopes that high-energy physics will move to a model that makes it easier to take advantage of these new offerings as well.

    “New software can expand the reach of what we can do at the LHC,” Cranmer says. “The potential is hard to guess.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
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