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  • richardmitnick 3:56 pm on February 17, 2017 Permalink | Reply
    Tags: , Bjorken x variable, , , HERA collider, How strange is the proton?, , Particle Physics, , , , Strong interactions   

    From CERN ATLAS: “How strange is the proton?” 

    CERN ATLAS Higgs Event

    CERN/ATLAS
    ATLAS

    25th January 2017
    ATLAS Collaboration

    1
    Figure 1: The data ellipses illustrate the 68% CL coverage for the total uncertainties (full green) and total excluding the luminosity uncertainty (open black). Theoretical predictions based on various PDF sets are shown with open symbols of different colours. (Image: ATLAS Collaboration/CERN)

    The protons collided by the LHC are not elementary particles, but are instead made up of quarks, antiquarks and gluons. The theory of the strong interactions – quantum chromodynamics (QCD) – does not allow physicists to calculate the composition of protons from first principles. However, QCD can connect measurements made in different processes and at different energy scales such that universal “parton density functions” (PDFs) can be extracted. These determine the dynamic substructure of the proton.

    The discovery of quarks as the elements of the partonic structure of the proton dates about 50 years. Soon after QCD was born and the existence of gluons inside the proton was established. Much has since been learned through a combination of new experimental data and theoretical advances. At the LHC, reactions involve quarks or gluons that carry a certain fraction x of the proton’s momentum, expressed through the Bjorken x variable. Below x of 0.01, the proton constituents are mainly gluons and a sea of quark-antiquark pairs.

    Electron-proton scattering data from the HERA collider has constrained the gluon and the sum of all quarks weighted by the square of their electric charge.

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    Data from the HERA collider live on (Image: DESY Hamburg)

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    DESY map

    But the low x sea-quark composition – expressed in terms of the lighter quarks named up, down and strange quarks – is still not well understood. New data from the ATLAS experiment shows, with unprecedented precision, the production of W and Z bosons through the weak interaction. This sheds new light on the question: how “strange” the proton is at small x?

    The W production is detected through its decay into a charged lepton (electron or muon) and a neutrino, while the Z boson produces an electron-positron (or muon-antimuon) pair. The experimental detection of electrons and muons poses different challenges and thus the simultaneous measurement in both channels provides an important cross-check of the results, thus improving the final precision achieved. The integrated cross sections for Z boson and W boson production are measured with a precision of 0.3% and 0.6%, respectively, and with an additional common normalisation uncertainty from the luminosity determination of 1.8%. Differential cross sections are also measured in a variety of kinematic regions and about half of the measurement points have a precision of 1% or better.

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    Figure 2: Determination of the relative strange-to-light quark fraction R_s. Bands: Present result and its uncertainty contributions from experimental data, QCD fit, and theoretical uncertainties. Closed symbols with horizontal error bars: predictions from different NNLO PDF sets. Open square: previous ATLAS result. (Image: ATLAS Collaboration/CERN)

    The measurements are then compared to state-of-the-art QCD expectations using different PDF sets. Because the production of W and Z bosons through the weak interaction has a different dependence on the specific quark flavours compared to the electromagnetic interaction seen in electron-positron scattering at HERA, analysing both data sets gives new access to the strange quark content of the proton.

    As is shown in Figure 1, the measured production rate of W bosons is very similar for all PDF sets, in good agreement with the data. In contrast, the rate for Z boson production is underestimated significantly for most PDF sets. A dedicated analysis enables this deficit to be attributed to a too small strange quark contribution in most PDF sets. The new PDF set, which this paper presents, requires the strange quark sea to be of a similar size as the up and down quark sea. This is summarised by the quantity RS, which is the ratio of the strange quark sea to the up and down quark sea, and which is found to be close to one, as shown in Figure 2. This result is a striking confirmation of the hypothesis of a light-flavour symmetry of proton structure at low x. This result will generate many further studies, because hitherto there had been indications from low energy neutrino-scattering data that favoured a suppressed strange-quark contribution with respect to the up and down quark parts, leading to an RS close to 0.5.

    The analysis also shows that the potential to which precise W and Z cross sections can provide useful constraints on PDFs is not limited by the now very high experimental precision, but rather by the uncertainty of the currently available theory calculations. The salient results of this paper are thus of fundamental importance for forthcoming high-precision measurements, such as the mass of the W boson, and also represent a strong incentive for further improving the theory of Drell-Yan scattering in proton-proton collisions.

    Links:

    Precision measurement and interpretation of inclusive W+, W− and Z/γ∗ production cross sections with the ATLAS detector, https://arxiv.org/abs/1612.03016

    See the full article here .

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

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  • richardmitnick 10:17 am on February 16, 2017 Permalink | Reply
    Tags: , , , , , , Particle Physics, SCOAP³,   

    From The Conversation: “How the insights of the Large Hadron Collider are being made open to everyone” 

    Conversation
    The Conversation

    January 12, 2017 [Just appeared in social media.]
    Virginia Barbour

    CERN CMS Higgs Event
    CERN CMS Higgs Event

    If you visit the Large Hadron Collider (LHC) exhibition, now at the Queensland Museum, you’ll see the recreation of a moment when the scientist who saw the first results indicating discovery of the Higgs boson laments she can’t yet tell anyone.

    It’s a transitory problem for her, lasting as long as it takes for the result to be thoroughly cross-checked. But it illustrates a key concept in science: it’s not enough to do it; it must be communicated.

    That’s what is behind one of the lesser known initiatives of CERN (European Organization for Nuclear Research): an ambitious plan to make all its research in particle physics available to everyone, with a big global collaboration inspired by the way scientists came together to make discoveries at the LHC.

    This initiative is called SCOAP³, the Sponsoring Consortium for Open Access in Particle Physics Publishing, and is now about to enter its fourth year of operation. It’s a worldwide collaboration of more than 3,000 libraries (including six in Australia), key funding agencies and research centres in 44 countries, together with three intergovernmental organisations.

    It aims to make work previously only available to paying subscribers of academic journals freely and immediately available to everyone. In its first three years it has made more than 13,000 articles available.

    Not only are these articles free for anyone to read, but because they are published under a Creative Commons attribution license (CCBY), they are also available for anyone to use in anyway they wish, such as to illustrate a talk, pass onto a class of school children, or feed to an artificial intelligence program to extract information from. And these usage rights are enshrined forever.

    The concept of sharing research is not new in physics. Open access to research is now a growing worldwide initiative, including in Australasia. CERN, which runs the LHC, was also where the world wide web was invented in 1989 by Tim Berners-Lee, a British computer scientist at CERN.

    The main purpose of the web was to enable researchers contributing to CERN from all over the world share documents, including scientific drafts, no matter what computer systems they were using.

    Before the web, physicists had been sharing paper drafts by post for decades, so they were one of the first groups to really embrace the new online opportunities for sharing early research. Today, the pre-press site arxiv.org has more than a million free article drafts covering physics, mathematics, astronomy and more.

    But, with such a specialised field, do these “open access” papers really matter? The short answer is “yes”. Downloads have doubled to journals participating in SCOAP³.

    With millions of open access articles now being downloaded across all specialities, there is enormous opportunity for new ideas and collaborations to spring from chance readership. This is an important trend: the concept of serendipity enabled by open access was explored in 2015 in an episode of ABC RN’s Future Tense program.

    Greater than the sum of the parts

    There’s also a bigger picture to SCOAP³’s open access model. Not long ago, the research literature was fragmented. Individual papers and the connections between them were only as good as the physical library, with its paper journals, that academics had access to.

    Now we can do searches in much less time than we spend thinking of the search question, and the results we are presented with are crucially dependent on how easily available the findings themselves are. And availability is not just a function of whether an article is free or not but whether it is truly open, i.e. connected and reusable.

    One concept is whether research is “FAIR”, or Findable, Accessible, Interoperable and Reusable. In short, can anyone find, read, use and reuse the work?

    The principle is most advanced for data, but in Australia work is ongoing to apply it to all research outputs. This approach was also proposed at the November 2016 meeting of the G20 Science, Technology and Innovation Ministers Meeting. Research findings that are not FAIR can, effectively, be invisible. It’s a huge waste of millions of taxpayer dollars to fund research that won’t be seen.

    There is an even bigger picture that research and research publications have to fit into: that of science in society.

    Across the world we see politicians challenging accepted scientific norms. Is the fact that most academic research remains available only to those who can pay to see it contributing to an acceptance of such misinformed views?

    If one role for science is to inform public debate, then restricting access to that science will necessarily hinder any informed public debate. Although no one suggests that most readers of news sites will regularly want to delve into the details of papers in high energy physics, open access papers are 47% more likely to end up being cited in Wikipedia, which is a source that many non-scientists do turn to.

    Even worse, work that is not available openly now may not even be available in perpetuity, something that is being discussed by scientists in the USA.

    So in the same way that CERN itself is an example of the power of international collaboration to ask some of the fundamental scientific questions of our time, SCOAP³ provides a way to ensure that the answers, whatever they are, are available to everyone, forever.

    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 2:36 pm on February 10, 2017 Permalink | Reply
    Tags: , , , , Electron-Ion Collider possibly opening a new frontier in nuclear physics., Exploring the Matter that Filled the Early Universe, , , Particle Physics, Quark Matter 2017 conference (QM17), , Ultrarelativistic heavy-ion collisions   

    From BNL: “Exploring the Matter that Filled the Early Universe” 

    Brookhaven Lab

    February 6, 2017
    Karen McNulty Walsh
    kmcnulty@bnl.gov

    (631) 344-8350
    Peter Genzer
    (631) 344-3174
    genzer@bnl.gov

    1
    Credit for conference logo design: Anjali Chandrashekar, student, Pratt Institute

    Theorists and scientists conducting experiments that recreate matter as it existed in the very early universe are gathered in Chicago this week to present and discuss their latest results. These experiments, conducted at the world’s premier particle colliders — the Relativistic Heavy Ion Collider (RHIC) at the U.S. Department of Energy’s Brookhaven National Laboratory, and the Large Hadron Collider (LHC) at the European Center for Nuclear Research (CERN) — are revealing intriguing information about the building blocks of visible matter and the force that holds them together in the universe today.

    BNL RHIC Campus
    BNL/RHIC Star Detector
    RHIC map and STAR detector

    CERN/LHC Map
    CERN LHC Grand TunnelCERN LHC particles
    LHC at CERN

    The Quark Matter 2017 conference (QM17) will feature new results describing the particles created as atomic nuclei smash into one another at nearly the speed of light at RHIC and the LHC. These “ultrarelativistic heavy-ion collisions” melt ordinary protons and neutrons, momentarily setting free their inner constituents — quarks and gluons — so scientists can study their behavior and interactions. The physicists want to sort out the detailed properties of the hot “quark-gluon plasma” (QGP), and understand what happens as this primordial soup cools and coalesces to form the more familiar matter of today’s world.

    The two scientific collaborations conducting nuclear physics research at RHIC—STAR and PHENIX, named for their house-sized detectors—will present findings that build on earlier discoveries at this DOE Office of Science User Facility.

    Brookhaven Phenix
    Brookhaven Phenix

    The two collaborations perform cross-checking analyses to verify results, while also exploiting each detector’s unique capabilities and strengths for independent explorations. The QM17 presentations will showcase precision measurements made possible by recent detector upgrades.

    “These results illustrate how a global community of dedicated scientists is taking full advantage of RHIC’s remarkable versatility to explore in depth the structure of nuclear matter over a wide range of temperatures and densities to better understand the dynamic behavior of quarks and gluons and the strong nuclear force,” said Berndt Mueller, Associate Laboratory Director for Nuclear and Particle Physics at Brookhaven Lab. “The latest RHIC findings indicate that RHIC sits at the ‘sweet spot’ for probing the most interesting questions about the quark-gluon plasma and its transition to matter as we know it.”

    The meeting will also feature talks on the planned upgrade of the PHENIX experiment to a new RHIC detector known as sPHENIX, which will have greatly increased capabilities for tracking subatomic interactions.

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    The solenoid magnet that will form the core of the sPHENIX detector. No image credit

    In addition, at least one talk will focus on the scientific rationale for building an Electron-Ion Collider, a proposed future facility that would enable an in-depth exploration of gluons in protons and other nuclei, opening a new frontier in nuclear physics.

    In addition, at least one talk will focus on the scientific rationale for building an Electron-Ion Collider, a proposed future facility that would enable an in-depth exploration of gluons in protons and other nuclei, opening a new frontier in nuclear physics.

    Select QM 2017 Highlights from RHIC

    Does size really matter?

    Before RHIC began operations in 2000, nuclear physicists suspected it would take collisions of large nuclei such as gold to produce enough heat to create quark-gluon plasma. Since then, RHIC’s gold-gold smashups (and later collisions of lead nuclei at the LHC) have reliably recreated a soup of quarks and gluons that flows like a nearly “perfect” liquid with extraordinarily low viscosity. Scientists detect the flow by observing correlations in certain characteristics of particles streaming from the collisions even when they are relatively far apart. More recently, smashups of smaller nuclei such as helium and even single protons with the large nuclei have produced correlation patterns that suggest that smaller drops of QGP might be possible. The latest results, to be presented by PHENIX, come from collisions of protons with aluminum nuclei, and also from deuteron-gold collisions over a range of collision energies. Lowering the energy changes how long the QGP phase lasts, which should change the strength of the correlations. The new results also include the first analysis of particles emerging closest to the colliding beams in the forward and rearward directions, as tracked by the recently installed Forward Silicon Vertex Tracker. Adding this tracker to detector components picking up particles emerging more centrally, perpendicular to the colliding beams, gives the physicists a way to test in three dimensions how the correlations vary with the pressure gradients created by the asymmetrical collisions.

    Discerning differences among heavy quarks


    A virtual tour of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC).

    PHENIX’s Central Barrel and Forward Silicon Vertex Tracker and STAR’s high precision Heavy Flavor Tracker (HFT) give RHIC physicists access to studying the behavior of so-called heavy quarks, which go by the exotic names of “charm” and “bottom.” These particles, produced in the QGP, start to decay into other particles a short distance from the collision zone, but those decay products eventually strike the trackers. By tracing their tracks, scientists can identify precisely where the decay took place. And since charm and bottom quarks have slightly different lifetimes before decaying, and therefore different travel distances, this method gives the scientists a way to tell them apart.

    Going with the flow

    One way scientists will use this data is to see how heavy quarks are affected by the QGP, and whether there are differences among them. Earlier indirect findings by PHENIX, later confirmed by STAR, already indicated that heavy quarks get swept up in the flow of the QGP, somewhat like a rock getting pulled along by a stream instead of sinking to the bottom. These observations formed part of the motivation for the construction of the STAR HFT. New data from the HFT to be presented by STAR provide the first direct evidence of heavy quark flow, and show that the interactions of these heavy particles with the QGP medium are strong. STAR’s HFT is the first application of the silicon based Monolithic Active Pixel Sensor technology in a collider environment. The measurements show that the flow of a type of heavy particles called D0s, which contain a charm quark, follows the same trend as seen for lighter particles and can be described by the same viscous hydrodynamics. The unprecedented precision in this measurement will pave the path towards precisely determining one of the intrinsic transport properties of the QGP and tell us how quarks interact with it.

    PHENIX will present precision results from its Central Barrel Vertex Detector showing that some heavy quarks are more affected by the QGP than others. The results show that charm quarks lose more energy in the QGP than heavier bottom quarks. With this high statistics data set, PHENIX will now be able to study how the energy-loss is affected by how central, or head-on, the collisions are. PHENIX will also present its first heavy-quark result from the Forward Silicon Vertex Tracker, measuring the total cross section of bottom quarks emerging in the forward and rearward directions in collisions between copper and gold ions.

    Learning how particles grow


    A virtual tour of the STAR detector at the Relativistic Heavy Ion Collider (RHIC).

    The STAR HFT has also made it possible to make the first measurements of a particle called Lambda c emerging from RHIC collisions. Lambda c is made of three quarks—just like protons and neutrons—but with one of the three being a heavy quark. These Lambda c particles are extremely difficult to tease out from the data. But because they can only be created in energetic particle collisions, they carry unique information about the conditions within. Studying this “sentry” information carried by the Lambda c should help scientists learn how relatively “free” quarks that populate the early-stage QGP eventually coalesce and combine to form the more familiar composite particles of ordinary matter.

    Tracking high-momentum jets

    Observing how jets of particles springing from individual quarks or gluons lose energy, or get “quenched,” as they interact with the medium has been one major sign that RHIC’s energetic collisions of gold on gold were forming QGP. STAR will present several new jet studies that provide further insights into both how this quenching occurs and how the lost energy re-emerges, In addition, PHENIX will present new results exploring the question of whether collisions of smaller particles with gold, which appear to create the flow patterns of QGP, also show evidence of jet quenching. Their results include data on jet energy loss in a variety of collision systems, both large and small. The method uses photons emitted opposite the jet to calibrate how much energy the jet should have to determine whether or not there was quenching. The data show some modifications to the jet structure and the yield of high-momentum particles inside the jets, but it is not yet clear how to interpret these results.

    Taking the QGP’s temperature

    Tracking heavy quarks and particles made from them gives RHIC physicists a new way to zero in on a more precise temperature of the QGP—already known to be more than 250,000 times hotter than the center of the sun. The new precision comes from measuring how different bound states of heavy quark-antiquark pairs, held together with different amounts of energy, melt in the plasma. STAR counts up different types of these particles (for example, Upsilons, pairs of bottom and anti-bottom quarks, that come in several binding varieties) using another recently upgraded detector component called the Muon Telescope Detector. Muons are the decay products of the Upsilons. STAR uses these counts to look for a deficit of one type of Upsilon relative to another to set boundaries on the QGP temperature. The physicists are eager to compare their results with those from the LHC, where with higher collision energies, they expect to see higher temperatures.

    PHENIX’s measurements of temperature have relied on tracking photons, particles of light, emitted from the hot matter (think of the glow of an iron bar in a blacksmith’s fire, where the color of the light is related to how hot the iron is). But PHENIX’s photon data have uncovered something unusual: While collisions initially emit photons equally in all directions, fractions of a second later the emitted photons appear to have a directional preference that resembles the elliptical flow pattern of the perfect liquid QGP. This is intriguing because photons shouldn’t interact with the matter—or even be produced in such measurable quantities as the matter produced in the collisions cools and expands. To explore this mystery, PHENIX measured thermal direct photons at different gold-gold collision energies (39, 62, and 200 billion electron volts, or GeV), as well as in the smaller collision system. The results they present will shed light on the sources of these direct photons.

    Disentangling the effects of cold nuclear matter

    RHIC physicists are also learning more about “cold” nuclear matter—the state of the nucleus, filled with a field of gluons, before it collides—and how to account for its effects when studying the hot QGP. In order to disentangle the effects of cold nuclear matter, PHENIX is comparing the suppression of the excited state of the bound charm-anti-charm particle known as Psi to its ground state. They are studying collisions of protons and helium with gold or aluminum—small systems where cold nuclear matter predominates—and will use these as a baseline for better understanding the sequential melting of the bound states in the hot QGP. Their findings indicate that the less tightly bound version of the Psi is more than twice as susceptible to the effects of cold nuclear matter than the more tightly bound version. This effect must be accounted for in analyzing the data from QGP-creating collisions where the presence of both cold and hot nuclear matter influences the results.

    New way to turn down the energy

    STAR has exploited RHIC’s ability to collide nuclei over a wide range of collision energies, conducting a Beam Energy Scan to explore the creation of QGP and its transition to ordinary nuclear matter over a wide range of conditions. At QM17 they’ll present data from collisions at the lowest energy yet. Instead of colliding one beam into the beam coming into the detector from the opposite direction, as occurs in most RHIC experiments, STAR placed a stationary target (a foil of gold) within the beam pipe inside STAR and aimed just one beam at the target. Like a collision in which one moving car crashes into one that is parked, this fixed-target collision lowered the impact compared to what would occur if both beams (or cars) were moving and colliding head on. Data from these low energy collisions will be an integral part of phase two of the Beam Energy Scan, which is enabled by improvements to the RHIC accelerator complex that allow for higher collision rates.

    Research at RHIC is funded primarily by the U.S. Department of Energy’s Office of Science and by these agencies and organizations.

    See the full article here .

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    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 2:31 pm on February 5, 2017 Permalink | Reply
    Tags: , , , , , , , Particle Physics   

    From CERN via futurism: “Scientists May Have Solved the Biggest Mystery of the Big Bang” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    CERN

    1

    futurism

    February 2, 2017
    Chelsea Gohd

    The Unanswered Question

    The European Council for Nuclear Research (CERN) works to help us better understand what comprises the fabric of our universe. At this French association, engineers and physicists use particle accelerators and detectors to gain insight into the fundamental properties of matter and the laws of nature. Now, CERN scientists may have found an answer to one of the most pressing mysteries in the Standard Model of Physics, and their research can be found in Nature Physics.

    According to the Big Bang Theory, the universe began with the production of equal amounts of matter and antimatter. Since matter and antimatter cancel each other out, releasing light as they destroy each other, only a minuscule number of particles (mostly just radiation) should exist in the universe. But, clearly, we have more than just a few particles in our universe. So, what is the missing piece? Why is the amount of matter and the amount of antimatter so unbalanced?


    Access mp4 video here .

    The Standard Model of particle physics does account for a small percentage of this asymmetry, but the majority of the matter produced during the Big Bang remains unexplained.

    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.

    Noticing this serious gap in information, scientists theorized that the laws of physics are not the same for matter and antimatter (or particles and antiparticles). But how do they differ? Where do these laws separate?

    This separation, known as charge-parity (CP) violation, has been seen in hadronic subatomic particles (mesons), but the particles in question are baryons. Finding evidence of CP violation in these particles would allow scientists to calculate the amount of matter in the universe, and answer the question of why we have an asymmetric universe. After decades of effort, the scientists at CERN think they’ve done just that.

    Using a Large Hadron Collider (LHC) detector, CERN scientists were able to witness CP violation in baryon particles. When smashed together, the matter (Λb0) and antimatter (Λb0-bar) versions of the particles decayed into different components with a significant difference in the quantities of the matter and antimatter baryons. According to the team’s report, “The LHCb data revealed a significant level of asymmetries in those CP-violation-sensitive quantities for the Λb0 and Λb0-bar baryon decays, with differences in some cases as large as 20 percent.”


    Access mp4 video here .

    What Does This Mean?

    This discovery isn’t yet statistically significant enough to claim that it is definitive proof of a CP variation, but most believe that it is only a matter of time. “Particle physics results are dragged, kicking and screaming, out of the noise via careful statistical analysis; no discovery is complete until the chance of it being a fluke is below one in a million. This result isn’t there yet (it’s at about the one-in-a-thousand level),” says scientist Chris Lee. “The asymmetry will either be quickly strengthened or it will disappear entirely. However, given that the result for mesons is well and truly confirmed, it would be really strange for this result to turn out to be wrong.”

    This borderline discovery is one huge leap forward in fully understanding what happened before, during, and after the Big Bang. While developments in physics like this may seem, from the outside, to be technical achievements exciting only to scientists, this new information could be the key to unlocking one of the biggest mysteries in modern physics. If the scientists at CERN are able to prove that matter and antimatter do, in fact, obey separate laws of physics, science as we know it would change and we’ll need to reevaluate our understanding of our physical world.

    See the full article here.

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    Meet CERN in a variety of places:

    Cern Courier
    CernCourier
    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 1:12 pm on January 31, 2017 Permalink | Reply
    Tags: , , , , , Particle Physics, ,   

    From Symmetry: “Sign of a long-sought asymmetry” 

    Symmetry Mag
    Symmetry

    01/30/17
    Sarah Charley

    A result from the LHCb experiment shows what could be the first evidence of matter and antimatter baryons behaving differently.

    1
    Simona Lippi

    CERN LHC LHCb
    LHCb

    A new result from the LHCb experiment at CERN could help explain why our universe is made of matter and not antimatter.

    Matter particles, such as protons and electrons, all have an antimatter twin. These antimatter twins appear identical in nearly every respect except that their electric and magnetic properties are opposite.

    Cosmologists predict that the Big Bang produced an equal amount of matter and antimatter, which is a conundrum because matter and antimatter annihilate into pure energy when they come into contact. Particle physicists are looking for any minuscule differences between matter and antimatter, which might explain why our universe contains planets and stars and not a sizzling broth of light and energy instead.

    The Large Hadron Collider doesn’t just generate Higgs bosons during its high-energy proton collisions—it also produces antimatter. By comparing the decay patterns of matter particles with their antimatter twins, the LHCb experiment is looking for miniscule differences in how these rival particles behave.

    “Many antimatter experiments study particles in a very confined and controlled environment,” says Nicola Neri, a researcher at Italian research institute INFN and one of the leaders of the study. “In our experiment, the antiparticles flow and decay, so we can examine other properties, such as the momenta and trajectories of their decay products.”

    The result, published today in Nature Physics, examined the decay products of matter and antimatter baryons (a particles containing three quarks) and looked at the spatial distribution of the resulting daughter particles within the detector. Specifically, Neri and his colleagues looked for a very rare decay of the lambda-b particle (which contains an up quark, down quark and bottom quark) into a proton and three pions (which contain an up quark and anti-down quark).

    Based on data from 6000 decays, Neri and his team found a difference in the spatial orientation of the daughter particles of the matter and antimatter lambda-bs.

    “This is the first time we’ve seen evidence of matter and antimatter baryons behaving differently,” Neri says. “But we need more data before we can make a definitive claim.”

    Statistically, the result has a significant of 3.3 sigma, which means its chances of being a just a statistical fluctuation (and not a new property of nature) is one out of a thousand. The traditional threshold for discovery is 5 sigma, which equates to odds of one out of more than a million.

    For Neri, this result is more than early evidence of a never before seen process—it is a key that opens new research opportunities for LHCb physicists.

    “We proved that we are there,” Neri says, “Our experiment is so sensitive that we can start systematically looking for this matter-antimatter asymmetry in heavy baryons at LHCb. We have this capability, and we will be able to do even more after the detector is upgraded next year.”

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 9:29 am on January 30, 2017 Permalink | Reply
    Tags: , , Particle Physics, ,   

    From The Conversation: “Giant atoms could help unveil ‘dark matter’ and other cosmic secrets” 

    Conversation
    The Conversation

    January 5, 2017
    Diego A. Quiñones

    1
    Composite image showing the galaxy cluster 1E 0657-56. Chandra X-Ray Observatory/NASA

    The universe is an astonishingly secretive place. Mysterious substances known as dark matter and dark energy account for some 95% of it. Despite huge effort to find out what they are, we simply don’t know.

    We know dark matter exists because of the gravitational pull of galaxy clusters – the matter we can see in a cluster just isn’t enough to hold it together by gravity. So there must be some extra material there, made up by unknown particles that simply aren’t visible to us. Several candidate particles have already been proposed.

    Scientists are trying to work out what these unknown particles are by looking at how they affect the ordinary matter we see around us. But so far it has proven difficult, so we know it interacts only weakly with normal matter at best. Now my colleague Benjamin Varcoe and I have come up with a new way to probe dark matter that may just prove successful: by using atoms that have been stretched to be 4,000 times larger than usual.

    Advantageous atoms

    We have come a long way from the Greeks’ vision of atoms as the indivisible components of all matter. The first evidence-based argument for the existence of atoms was presented in the early 1800s by John Dalton. But it wasn’t until the beginning of the 20th century that JJ Thomson and Ernest Rutherford discovered that atoms consist of electrons and a nucleus. Soon after, Erwin Schrödinger described the atom mathematically using what is today called quantum theory.

    Modern experiments have been able to trap and manipulate individual atoms with outstanding precision. This knowledge has been used to create new technologies, like lasers and atomic clocks, and future computers may use single atoms as their primary components.

    Individual atoms are hard to study and control because they are very sensitive to external perturbations. This sensitivity is usually an inconvenience, but our study suggests that it makes some atoms ideal as probes for the detection of particles that don’t interact strongly with regular matter – such as dark matter.

    Our model is based on the fact that weakly interacting particles must bounce from the nucleus of the atom it collides with and exchange a small amount of energy with it – similar to the collision between two pool balls. The energy exchange will produce a sudden displacement of the nucleus that will eventually be felt by the electron. This means the entire energy of the atom changes, which can be analysed to obtain information about the properties of the colliding particle.

    However the amount of transferred energy is very small, so a special kind of atom is necessary to make the interaction relevant. We worked out that the so-called “Rydberg atom” would do the trick. These are atoms with long distances between the electron and the nucleus, meaning they possess high potential energy. Potential energy is a form of stored energy. For example, a ball on a high shelf has potential energy because this could be converted to kinetic energy if it falls off the shelf.

    In the lab, it is possible to trap atoms and prepare them in a Rydberg state – making them as big as 4,000 times their original size. This is done by illuminating the atoms with a laser with light at a very specific frequency.

    This prepared atom is likely much heavier than the dark matter particles. So rather than a pool ball striking another, a more appropriate description will be a marble hitting a bowling ball. It seems strange that big atoms are more perturbed by collisions than small ones – one may expect the opposite (smaller things are usually more affected when a collision occurs).

    The explanation is related to two features of Rydberg atoms: they are highly unstable because of their elevated energy, so minor perturbations would disturb them more. Also, due to their big area, the probability of the atoms interacting with particles is increased, so they will suffer more collisions.

    Spotting the tiniest of particles

    Current experiments typically look for dark matter particles by trying to detect their scattering off atomic nuclei or electrons on Earth. They do this by looking for light or free electrons in big tanks of liquid noble gases that are generated by energy transfer between the dark matter particle and the atoms of the liquid.

    1
    The Large Underground Xenon experiment installed 4,850 ft underground inside a 70,000-gallon water tank shield. Gigaparsec at English Wikipedia, CC BY-SA

    But, according to the laws of quantum mechanics, there needs to be a certain a minimum energy transfer for the light to be produced. An analogy would be a particle colliding with a guitar string: it will produce a note that we can hear, but if the particle is too small the string will not vibrate at all.

    So the problem with these methods is that the dark matter particle has to be big enough if we are to detect it in this way. However, our calculations show that the Rydberg atoms will be disturbed in a significant way even by low-mass particles – meaning they can be applied to search for candidates of dark matter that other experiments miss. One of such particles is the Axion, a hypothetical particle which is a strong candidate for dark matter.

    Experiments would require for the atoms to be treated with extreme care, but they will not require to be done in a deep underground facility like other experiments, as the Rydberg atoms are expected to be less susceptible to cosmic rays compared to dark matter.

    We are working to further improve the sensitivity of the system, aiming to extend the range of particles that it may be able to perceive.

    Beyond dark matter we are also aiming to one day apply it for the detection of gravitational waves, the ripples in the fabric of space predicted by Einstein long time ago. These perturbations of the space-time continuum have been recently discovered, but we believe that by using atoms we may be able to detect gravitational waves with a different frequency to the ones already observed.

    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.

     
    • gregoriobaquero 9:46 am on January 30, 2017 Permalink | Reply

      Precisely to the point of my paper. If I am right nothing is going to be found. No new particles. The density of neutrinos”hot Dark Matter”) we can measure in our frame of reference does not tell the whole picture since we have the same local time with neutrinos passing by. What had not been taken into account is that gravitational time dilation is accumulating neutrinos when compared to neutrinos passing far away from the galaxy. Sent from my iPhone

      >

      Like

    • gregoriobaquero 9:48 am on January 30, 2017 Permalink | Reply

      Also, this phenomenon is similar to how relativity explains electromagnetism. Veritasium has a good video about it.

      Sent from my iPhone

      >

      Like

    • gregoriobaquero 9:54 am on January 30, 2017 Permalink | Reply

      Precisely to the point of my paper. If I am right nothing is going to be found. No new particles. The density of neutrinos”hot Dark Matter”) we can measure in our frame of reference does not tell the whole picture since we have the same local time with neutrinos passing by. What had not been taken into account is that gravitational time dilation is accumulating neutrinos when compared to neutrinos passing far away from the galaxy.

      Also, this phenomenon is similar to how relativity explains electromagnetism. Veritasium has a good video about it.

      Like

    • richardmitnick 10:19 am on January 30, 2017 Permalink | Reply

      Thank you so much for coming on to comment. I appreciate it very much.

      Like

  • richardmitnick 1:58 pm on January 27, 2017 Permalink | Reply
    Tags: , Fermilab achieves milestone beam power for neutrino experiments, , , Main Injector, , , Particle Physics,   

    From FNAL: “Fermilab achieves milestone beam power for neutrino experiments” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

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

    January 26, 2017
    Ricarda Laasch

    1
    Thanks to recent upgrades to the Main Injector, Fermilab’s flagship accelerator, Fermilab scientists have produced 700-kilowatt proton beams for the lab’s experiments. Photo: Peter Ginter

    Fermilab’s accelerator is now delivering more neutrinos to experiments than ever before.

    The U.S. Department of Energy’s Fermi National Accelerator Laboratory has achieved a significant milestone for proton beam power. On Jan. 24, the laboratory’s flagship particle accelerator delivered a 700-kilowatt proton beam over one hour at an energy of 120 billion electronvolts.

    The Main Injector accelerator provides a massive number of protons to create particles called neutrinos, elusive particles that influence how our universe has evolved. Neutrinos are the second-most abundant matter particles in our universe. Trillions pass through us every second without leaving a trace.

    Because they are so abundant, neutrinos can influence all kinds of processes, such as the formation of galaxies or supernovae. Neutrinos might also be the key to uncovering why there is more matter than antimatter in our universe. They might be one of the most valuable players in the history of our universe, but they are hard to capture and this makes them difficult to study.

    “We push always for higher and higher beam powers at accelerators, and we are lucky our accelerator colleagues live for a challenge,” said Steve Brice, head of Fermilab’s Neutrino Division. “Every neutrino is an opportunity to study our universe further.”

    With more beam power, scientists can provide more neutrinos in a given amount of time. At Fermilab, that means more opportunities to study these subtle particles at the lab’s three major neutrino experiments: MicroBooNE, MINERvA and NOvA.

    FNAL/MicrobooNE
    FNAL/MicrobooNE

    FNAL/MINERvA
    FNAL/MINERvA

    FNAL/NOvA experiment
    FNAL/NOvA map

    FNAL NOvA Near Detector
    FNAL NOvA Near Detector

    “Neutrino experiments ask for the world, if they can get it. And they should,” said Dave Capista, accelerator scientist at Fermilab. Even higher beam powers will be needed for the future international Deep Underground Neutrino Experiment, to be hosted by Fermilab. DUNE, along with its supporting Long-Baseline Neutrino Facility, is the largest new project being undertaken in particle physics anywhere in the world since the Large Hadron Collider.

    FNAL DUNE Argon tank at SURF
    FNAL DUNE Argon tank at SURF
    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA
    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    “It’s a negotiation process: What is the highest beam power we can reasonably achieve while keeping the machine stable, and how much would that benefit the neutrino researcher compared to what they had before?” said Fermilab accelerator scientist Mary Convery.

    “This step-by-step journey was a technical challenge and also tested our understanding of the physics of high-intensity beams,” said Fermilab Chief Accelerator Officer Sergei Nagaitsev. “But by reaching this ambitious goal, we show how great the team of physicists, engineers, technicians and everyone else involved is.” The 700-kilowatt beam power was the goal declared for 2017 for Fermilab’s accelerator-based experimental program.

    Particle accelerators are complex machines with many different parts that change and influence the particle beam constantly. One challenge with high-intensity beams is that they are relatively large and hard to handle. Particles in accelerators travel in groups referred to as bunches.

    Roughly one hundred billion protons are in one bunch, and they need their space. The beam pipes – through which particles travel inside the accelerator – need to be big enough for the bunches to fit. Otherwise particles will scrape the inner surface of the pipes and get lost in the equipment.

    2
    The Main Injector, a 2-mile-circumference racetrack for protons, is the most powerful particle accelerator in operation at Fermilab. It provides proton beams for various particle physics experiments as well as Fermilab Test Beam Facility. Photo: Reidar Hahn

    Such losses, as they’re called, need to be controlled, so while working on creating the conditions to generate a high-power beam, scientists also study where particles get lost and how it happens. They perform a number of engineering feats that allow them to catch the wandering particles before they damage something important in the accelerator tunnel.

    To generate high-power beams, the scientists and engineers at Fermilab use two accelerators in parallel. The Main Injector is the driver: It accelerates protons and subsequently smashes them into a target to create neutrinos. Even before the protons enter the Main Injector, they are prepared in the Recycler.

    The Fermilab accelerator complex can’t create big bunches from the get-go, so scientists create the big bunches by merging two smaller bunches in the Recycler. A small bunch of protons is sent into the Recycler, where it waits until the next small bunch is sent in to join it. Imagine a small herd of cattle, and then acquiring a new herd of the same size. Rather than caring for them separately, you allow the two herds to join each other on the big meadow to form a big herd. Now you can handle them as one herd instead of two.

    In this way Fermilab scientists double the number of particles in one bunch. The big bunches then go into the Main Injector for acceleration. This technique to increase the number of protons in each bunch had been used before in the Main Injector, but now the Recycler has been upgraded to be able to handle the process as well.

    “The real bonus is having two machines doing the job,” said Ioanis Kourbanis, who led the upgrade effort. “Before we had the Recycler merging the bunches, the Main Injector handled the merging process, and this was time consuming. Now, we can accelerate the already merged bunches in the Main Injector and meanwhile prepare the next group in the Recycler. This is the key to higher beam powers and more neutrinos.”

    Fermilab scientists and engineers were able to marry two advantages of the proton acceleration technique to generate the desired truckloads of neutrinos: increase the numbers of protons in each bunch and decrease the delivery time of those proton to create neutrinos.

    “Attaining this promised power is an achievement of the whole laboratory,” Nagaitsev said. “It is shared with all who have supported this journey.”

    The new heights will open many doors for the experiments, but no one will rest long on their laurels. The journey for high beam power continues, and new plans for even more beam power are already under way.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    FNAL Icon
    Fermilab Campus

    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 1:53 pm on January 19, 2017 Permalink | Reply
    Tags: , , , , Particle Physics, ,   

    From Symmetry: “Matter-antimatter mystery remains unsolved” 

    Symmetry Mag
    Symmetry

    01/19/17
    Sarah Charley

    1
    Maximilien Brice, CERN

    Measuring with high precision, physicists at CERN found a property of antiprotons perfectly mirrored that of protons.

    There is little wiggle room for disparities between matter and antimatter protons, according to a new study published by the BASE experiment at CERN.

    cern-base-collaboartion-bloc

    Charged matter particles, such as protons and electrons, all have an antimatter counterpart. These antiparticles appear identical in every respect to their matter siblings, but they have an opposite charge and an opposite magnetic property. This recalcitrant parity is a head-scratcher for cosmologists who want to know why matter triumphed over antimatter in the early universe.

    “We’re looking for hints,” says Stefan Ulmer, spokesperson of the BASE collaboration. “If we find a slight difference between matter and antimatter particles, it won’t tell us why the universe is made of matter and not antimatter, but it would be an important clue.”

    Ulmer and his colleagues working on the BASE experiment at CERN closely scrutinize the properties of antiprotons to look for any miniscule divergences from protons. In a paper published today in the journal Nature Communications, the BASE collaboration at CERN reports the most precise measurement ever made of the magnetic moment of the antiproton.

    “Each spin-carrying charged particle is like a small magnet,” Ulmer says. “The magnetic moment is a fundamental property which tells us the strength of that magnet.”

    The BASE measurement shows that the magnetic moments of the proton and antiproton are identical, apart from their opposite signs, within the experimental uncertainty of 0.8 parts per million. The result improves the precision of the previous best measurement by the ATRAP collaboration in 2013, also at CERN, by a factor of six. This new measurement shows an almost perfect symmetry between matter and antimatter particles, thus further constricting leeway for incongruencies which might have explained the cosmic asymmetry between matter and antimatter.

    The measurement was made at the Antimatter Factory at CERN, which generates antiprotons by first crashing normal protons into a target and then focusing and slowing the resulting antimatter particles using the Antiproton Decelerator. Because matter and antimatter annihilate upon contact, the BASE experiment first traps antiprotons in a vacuum using sophisticated electromagnetics and then cools them to about 1 degree Celsius above absolute zero. These electromagnetic reservoirs can store antiparticles for long periods of time; in some cases, over a year. Once in the reservoir, the antiprotons are fed one-by-one into a trap with a superimposed magnetic bottle, in which the antiprotons oscillate along the magnetic field lines. Depending on their North-South alignment in the magnetic bottle, the antiprotons will vibrate at two slightly different rates. From these oscillations (combined with nuclear magnetic resonance methods), physicists can determine the magnetic moment.

    The challenge with this new measurement was developing a technique sensitive to the miniscule differences between antiprotons aligned with the magnetic field versus those anti-aligned.

    “It’s the equivalent of determining if a particle has vibrated 5 million times or 5 million-plus-one times over the course of a second,” Ulmer says. “Because this measurement is so sensitive, we stored antiprotons in the reservoir and performed the measurement when the antiproton decelerator was off and the lab was quiet.”

    BASE now plans to measure the antiproton magnetic moment using a new trapping technique that should enable a precision at the level of a few parts per billion—that is, a factor of 200 to 800 improvement.

    Members of the BASE experiment hope that a higher level of precision might provide clues as to why matter flourishes while cosmic antimatter lingers on the brink of extinction.

    “Every new precision measurement helps us complete the framework and further refine our understanding of antimatter’s relationship with matter,” Ulmer says.

    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 1:20 pm on January 17, 2017 Permalink | Reply
    Tags: , Fermions and Bosons, , Particle Physics,   

    From Don Lincoln at FNAL: “Fermions and Bosons” Video 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

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

    FNAL Don Lincoln
    From Don Lincoln

    In particle physics, there are many different types of particles, mostly ending with the phrase “-on.” In this video, Fermilab’s Dr. Don Lincoln talks about fermions and bosons and what is the key difference between these two particles.


    Access mp4 video here .

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    FNAL Icon
    Fermilab Campus

    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 2:46 pm on January 14, 2017 Permalink | Reply
    Tags: , , , , Julia Thom-Levy, , Particle Physics, Thom-Levy research group,   

    From Cornell: Women in STEM – “In Search of New Physics Phenomena” Julia Thom-Levy 

    Cornell Bloc

    Cornell University

    1.13.17
    Alexandra Chang

    1
    Julia Thom-Levy
    Associate Professor
    Physics, College of Arts and Sciences
    Expertise
    Experimental high energy physics; experimental particle physics; Large Hadron Collider, solid state detectors for particle physics

    More than 3,800 miles away and across the Atlantic Ocean from Cornell’s Physical Sciences Building is Geneva, Switzerland, the home of the European Organization for Nuclear Research (CERN) laboratory and the highest-energy particle accelerator on earth.

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

    Cornell at CERN

    Despite the distance, Cornell researchers are actively involved in the cutting-edge particle physics experiments taking place at CERN. Julia Thom-Levy, Physics, is one such professor. Thom-Levy has worked on the Compact Muon Solenoid (CMS) experiment at CERN’s Large Hadron Collider (LHC) since 2005.

    CERN/CMS Detector
    CERN/CMS Detector

    Specifically, Thom-Levy is on a collaborative team of Cornell researchers who are responsible for developing software for the CMS detector, designing upgrades to the detector, and analyzing data collected by the CMS—all in search of new physics phenomena.

    CMS is one of the two LHC detectors that led to the discovery of the Higgs boson (an elementary particle in the Standard Model of particle physics) in 2012 during the most recent LHC run. Since then, the LHC has been undergoing repairs. A second run took place during June 2015, with the LHC running at twice the energy, a major improvement that could lead to further discoveries.

    “We are in an interesting situation here: a mathematical model—The Standard Model—explains all particle observations very well,” says Thom-Levy, who played a role in confirming the Standard Model to better precision over the past 15 years.

    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.

    “It’s a very precise model. We know, however, that it doesn’t hold water, because we cannot explain certain important things like dark matter, or how exactly the Higgs boson ends up with the mass that we measure. There is a strange tension: on the one hand, we know what these particles do; we can predict it, but we don’t know why.”

    Supersymmetry

    Thom-Levy says that the second run of the LHC could reveal new particles, or inconsistencies in the data—“smoking guns” that will point scientists in the right direction. For example, they could find particles that might be consistent with supersymmetry, a proposed extension of the Standard Model, which could explain such mysteries as dark matter.

    Dark matter in our universe has been elusive so far to detection—it does not emit or absorb light. Thom-Levy says that the LHC might, however, be able to produce dark matter, and that it is possible to observe it through its distinctive signature in the detector, which is the signature of nothing. One possibility is that dark matter consists of the lightest supersymmetric particles, and discovering it in the next run would be a huge boon to the researchers.

    That said, Thom-Levy is cautious in her predictions. “I’m being very hypothetical,” she says. “The big glaring signature for supersymmetry did not appear in the first run. That was one of the surprises. It’s such a beautiful theory and we joke that it would be a shame if nature didn’t work that way. It’s something we will continue to look for.”

    The Big Data Element

    The Cornell CMS group—James Alexander, Richie Patterson, Anders Ryd, Peter Wittich, and Thom-Levy along with their students and postdocs—play a critical role in developing software to record and interpret the incredible amounts of data collected by the CMS.

    2
    Members of the Thom-Levy research group

    When the detector is running, it records terabytes of data every day, and that data needs to be stored and distributed to various research institutions across the world for analysis. Researchers write programs to filter through trillions of proton interactions to get to the ones that are really interesting—ones that produce a Higgs or a top quark, for example.

    “The most interesting interactions are often the most rare; they are the highest energy, highest masses, and very unlikely to be produced,” says Thom-Levy. “A lot of our field is like needle-in-the-haystack research.” Because of this, Thom-Levy says her students are exposed to “big-data,” and they learn how to handle and analyze huge volumes of data.

    Students also spend time at CERN and learn how to make the detector work. Many of the group’s students are currently in Geneva, writing software for and testing electronics on the CMS detector.

    Next-Generation Detectors

    Thom-Levy is also developing better detectors, using the latest cutting-edge materials and technologies. One challenge is that the particle’s high energies result in extremely high radiation levels, which damage the detector. As energy levels and particle density increase, the detectors need to become better at withstanding radiation, while still providing high precision measurements.

    To address that and other problems, Thom-Levy is involved in a collaborative project testing the use of three-dimensional integrated circuitry for silicon detectors. She says that it could make detectors much thinner, use less power, and make them potentially stronger against radiation. So far, her group has simulated detectors and prototyped components at the Cornell NanoScale Science and Technology Facility (CNF). The next steps would be to work with more industry and university partners to hopefully build the next generation of detectors to be used at CERN’s CMS.

    Pursuing the Universe’s Mysteries

    Thom-Levy describes her journey to CERN as a sort of odyssey following the most interesting particle physics to various places. She started at Germany’s national accelerator lab, moved on to Stanford’s Linear Accelerator Center, off to Fermilab in Illinois, until finally landing at CERN. “With each move, the energy went up,” she says with a laugh.

    When asked why she was drawn to particle physics in the first place, she gives credit to the local accelerator in her hometown. “I always knew I wanted to do sub-nuclear physics,” she says. “How does the nucleus work? What does it consist of? Can you break its constituents down, down, down? What’s the most fundamental unit in the universe?”

    These are questions that are both scientific and philosophical to Thom-Levy. “We want to get to the very essence. It’s nothing we can touch, but the shadows of the mysterious workings of tiny particles may tell us about the most fundamental truth of the world.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
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