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  • richardmitnick 4:10 pm on February 17, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From AAAS: “Five things scientists could learn with their new, improved particle accelerator” 

    AAAS

    AAAS

    15 February
    Emily Conover

    1
    CMS

    The Large Hadron Collider (LHC) is back, and it’s better than ever.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC

    The particle accelerator, located at CERN, the European particle physics lab near Geneva, Switzerland, shut down in February 2013, and since then scientists have been upgrading and repairing it and its particle detectors. The LHC will be back up to full speed this May. Yesterday, scientists discussed the new prospects for the LHC at the annual meeting of AAAS (which publishes Science).

    The LHC is the world’s most powerful particle accelerator. Protons blast along its 17-mile (27-kilometer) ring at nearly light speed, colliding at the sites of several particle detectors, which sift through the resulting particle debris. In 2012, LHC’s ATLAS and CMS experiments discovered the Higgs boson with data from the LHC’s first run, thereby explaining how particles get mass.

    CERN ATLAS New
    ATLAS

    CERN CMS New
    CMS

    The revamped LHC will run at a 60% higher energy, with more sensitive detectors, and a higher collision rate. What might we find with the new-and-improved machine? Here are five questions scientists hope to answer:

    1. Does the Higgs boson hold any surprises?

    Now that we’ve found the Higgs boson, there’s still a lot we can learn from it. Thanks to the LHC’s energy boost, it will produce Higgs bosons at a rate five times higher, and scientists will be using the resulting abundance of Higgs to understand the particle in detail. How does it decay? Does it match the theoretical predictions? Anything out of the ordinary would be a boon to physicists, who are looking for evidence of new phenomena that can explain some of the unsolved mysteries of physics.

    2. What is “dark matter”?

    Only 15% of the matter in the universe is the kind we are familiar with. The rest is dark matter, which is invisible to us except for subtle hints, like its gravitational effects on the cosmos. Physicists are clamoring to know what it is. One likely dark matter culprit is a WIMP, or weakly interacting massive particle, which could show up in the LHC. Dark matter’s fingerprints could even be found on the Higgs boson, which may sometimes decay to dark matter. You can bet that scientists will be sifting through their data for any trace.

    3. Will we ever find supersymmetry?

    Supersymmetry, or SUSY, is a hugely popular theory of particle physics that would solve many unanswered questions about physics, including why the mass of the Higgs boson is lighter than naively expected—if only it were true. This theory proposes a slew of exotic elementary particles that are heavier twins of known ones, but with different spin—a type of intrinsic rotational momentum. Higher energies at the new LHC could boost the production of hypothetical supersymmetric particles called gluinos by a factor of 60, increasing the odds of finding it.

    Supersymmetry standard model
    Standard Model of Supersymmetric particles

    4. Where did all the antimatter go?

    Physicists don’t know why we exist. According to theory, after the big bang the universe was equal parts matter and antimatter, which annihilate one another when they meet. This should have eventually resulted in a lifeless universe devoid of matter. But instead, our universe is full of matter, and antimatter is rare—somehow, the balance between matter and antimatter tipped. With the upgraded LHC, experiments will be able to precisely test how matter might differ from antimatter, and how our universe came to be.

    5. What was our infant universe like?

    Just after the big bang, our universe was so hot and dense that protons and neutrons couldn’t form, and the particles that make them up—quarks and gluons—floated in a soup known as the quark-gluon plasma. To study this type of matter, the LHC produces extra-violent collisions using lead nuclei instead of protons, recreating the fireball of the primordial universe. Aided by the new LHC’s higher rate of collisions, scientists will be able to take more baby photos of our universe than ever before.

    See the full article here.

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

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  • richardmitnick 6:42 am on February 17, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From CERN: “CERN accelerators boost argon into action” 

    CERN New Masthead

    16 Feb 2015
    Corinne Pralavorio

    1
    Argon ions collide with scandium in the NA61/SHINE experiment at CERN (Image: NA61)

    CERN Shine
    SPS
    The experiment is located in the North Area of CERN and the particles are accelerated by SPS

    CERN’s accelerators supply a raft of experiments with all sorts of different particles. Now the accelerator complex is performing a new trick: supplying argon ions to an experimental programme for the first time. The argon ions are produced at a special source and made to circulate around four accelerators before being sent to a target.

    Preparations for this beam of argon ions have been in progress at the CERN accelerator chain for two years. Controlling these particles, which have a much greater mass than protons and are sent at six different energies, is no mean feat. The machine operators had to adapt the acceleration system of the Super Proton Synchrotron (SPS), a 7-kilometre-circumference accelerator that represents the last loop on the ions’ journey before they are ejected.

    The SPS is the last accelerator in the chain before the 27-kilometre-circumference Large Hadron Collider (LHC). To allow eight weeks of physics with argon ions while also sending protons to the LHC experiments, the accelerators will alternate between these two types of particles. In each cycle of 21.6 seconds, the SPS will deliver two beams of protons and one beam of argon ions.

    The argon ions are destined for the NA61/Shine experiment, which is studying the phenomenon of quark-gluon plasma, a state that is thought to have existed at the very beginning of the universe and in which quarks moved around freely, unconfined by the strong force in protons and neutrons. More specifically, the experiment is studying the transitions between the phase in which quarks are confined and the phase in which they are free. Last Thursday, the NA61/SHINE team recorded first collisions with argon: the argon ions, travelling with a momentum of 150 GeV/c per nucleon, collided with scandium nuclei.

    CERN’s accelerators accelerate protons most of the time, but occasionally juggle with other particles. Aside from lead ions and now argon ions, the complex has also accelerated electrons, positrons, antiprotons, deuterons and a particles, as well as oxygen, sulphur and indium ions. These particles are either collided with each other or sent to targets to create beams of secondary particles, such as neutrinos. The accelerator complex supplies around twenty experiments studying a wide range of physics phenomena, such as antimatter, exotic nuclei, neutrinos, cosmic rays, the strong interaction and the Higgs boson. Some are looking for signs of physics beyond the current theories or for as yet unknown particles that might help to account for dark matter. They include the four main LHC experiments ALICE, ATLAS, CMS and LHCb, which are the best known and which will be back in action as of the spring. In addition, several dozen experiments are carried out each year at the ISOLDE and n_TOF nuclear physics facilities.

    See the full article here.

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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

    LHC

    CERN LHC New

    LHC particles

    Quantum Diaries

     
  • richardmitnick 6:54 am on February 15, 2015 Permalink | Reply
    Tags: , ATLAS Canada, , , Particle Accelerators,   

    From TRIUMF Lab: “ATLAS-Canada Prepares for Next Run of the Large Hadron Collider; Higher Intensity Predicted to Generate More Data” 

    WestGrid Canada
    Compute Calcul Canada

    Feb 15, 2015

    Reda Tafirout
    ATLAS-Canada, TRIUMF

    1
    The eight torodial magnets can be seen on the huge ATLAS detector with the calorimeter before it is moved into the middle of the detector. This calorimeter will measure the energies of particles produced when protons collide in the centre of the detector. ATLAS will work along side the CMS experiment to search for new physics at the 14 TeV level. Image Courtesy of CERN.

    CERN CMS New
    CMS

    In March 2015, the world’s largest particle accelerator, the Large Hadron Collider (LHC), will end a two-year shutdown and begin its second running phase, this time at a significantly higher collision energy level than before.

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

    Run 2, which will last three years, will restart at a record collision energy of 13 TeV, nearly double the beam intensity of the LHC’s initial running phase (2010-2013). One electron volt, or 1 eV is the energy generated from a single electron moving through a potential of 1 Volt. With the doubling of the LHC collision energy, the potential exists for new opportunities to find physics beyond the Standard Model and to broaden the Higgs physics program.

    2
    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.

    ATLAS-Canada, a partner in the international ATLAS experiment, has worked with Compute Canada since its inception to fully integrate Compute Canada computing facilities into the Worldwide LHC Computing Grid (WLCG). Since 2011, Compute Canada resource allocations have been instrumental in supporting ATLAS scientists’ work, including their major and historical discovery of a Higgs particle in July 2012.

    This January, ATLAS-Canada was one of a handful of research groups in the country who received an allocation through Compute Canada’s inaugural RPP competition. In 2015, ATLAS Canada will have access to 3,378 core years of computational power and 3,164 TB of storage capacity on Compute Canada systems. This storage allication is expected to nearly double in 2017.

    “The availability of Compute Canada resources is crucial to our continued contribution to the groundbreaking discoveries coming from the Large Hadron Collider,” says Reda Tafirout, a TRIUMF Research Scientist and ATLAS-Canada Computing Coordinator. “The computational needs for 2015-2017 remain very high as a much larger volume of data will be collected and generated during LHC Run 2 phase. The proton-proton collisions will occur at a much higher beam energy and intensity making analysis more complex. Significant computing resources will be required to analyze the data and to produce large-scale simulation samples in a timely fashion.”

    Each year, the ATLAS experiment collects several Petabytes of raw data during LHC operations, and it produces numerous derived and simulated datasets that are of similar scale effectively on a continuous basis. The nature of ATLAS computing and its scale require the resources to be distributed across multiple sites so productivity does not come to a halt for a sustained period during either a scheduled maintenance, site expansion/consolidation, or other issues such as a security breach or service vulnerability.

    As part of WLCG, there are two ATLAS Tier-2 federations based at Compute Canada facilities: one in the east and one in the west. SciNet (University of Toronto) and CLUMEQ (McGill University) facilities are used in the east, while in the west, WestGrid facilities at Simon Fraser University and the University of Victoria are used. Distributing Compute Canada resources for ATLAS across a few sites allows load balancing across sites and also leverages the knowledge accumulatedby the local technical experts.

    “These resources allow us to meet our increasing commitments to ATLAS as more data are being generated, and allows Canadians to remain competitive on the world stage,” says Tafirout.

    One of the priorities of the LHC Run 2 physics program is to determine whether the new boson discovered in 2012 is precisely the Higgs boson of the Standard Model, or possibly the lightest boson of several in an extended Higgs sector.

    In addition, Canadian scientists will continue to lead a number of other important research investigations at ATLAS. These include the search for quantum black holes and strong gravity effects; the search for massive long-lived highly ionizing particle or a particle with a large electric charge; leading several important measurements in various collision event topologies and models; and preparing to measure the scattering of two massive vector bosons (VBS), which is a key process to probe the nature of electroweak symmetry breaking and allows to test if the Higgs sector is fully responsible to unitarize this amplitude.

    “The coming years will provide access to the design energy and increased luminosity of the LHC and therefore mark a crucial time in the search for new physics,” says Tafirout. “The extra Canadian-only computing resources will have a high impact and will keep Canadians highly competitive in these exciting times for particle physics.”

    Presently, the ATLAS-Canada collaboration consists of 39 faculty members at nine universities (plus ATLAS TRIUMF, Canada’s National Laboratory for Particle and Nuclear Physics), as well as 25 postdoctoral fellows, and 66 graduate students. This represents about half of the experimental particle physics community in Canada. The Canadian universities are University of Alberta, University of British Columbia, Carleton University, McGill University, Université de Montréal, Simon Fraser University, University of Toronto, University of Victoria, and York University. The overall ATLAS collaboration consists of about 3,000 researchers from 177 institutions in 38 countries (see http://atlas.ch).

    “The next three years will be very exciting for the ATLAS collaboration and it is important for Canada to remain a key player and contributor to the scientific output of the ATLAS experiment,” says Tafirout. “Canadians plan to build on the expertise and leadership that they demonstrated during Run 1 and are well equipped to make key contributions to ATLAS during Run 2.”

    See the full article here.

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    Triumf Campus
    Triumf Campus
    World Class Science at Triumf Lab, British Columbia, Canada
    Canada’s national laboratory for particle and nuclear physics
    Member Universities:
    University of Alberta, University of British Columbia, Carleton University, University of Guelph, University of Manitoba, Université de Montréal, Simon Fraser University,
    Queen’s University, University of Toronto, University of Victoria, York University. Not too shabby, eh?

    Associate Members:
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  • richardmitnick 5:56 am on February 15, 2015 Permalink | Reply
    Tags: , , , , , Particle Accelerators,   

    From NBC: “After the Higgs, LHC Rounds Up the Unusual Suspects in Particle Physics” 

    NBC News

    NBC News

    February 14th 2015
    Alan Boyle

    Supersymmetry and dark matter, neutralinos, gravitinos and gluinos … you can expect exotic topics like these to be spinning around as the Large Hadron Collider ramps up to smash subatomic particles again over the next couple of months.

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

    Physicists say the first hints of unconventional physics, such as evidence for the existence of those weird-sounding gluinos, could emerge within the next few months. Or not.

    It’s been almost three years since scientists at Europe’s CERN particle physics lab announced that the world’s most powerful collider had found the Higgs boson, a mysterious particle whose existence was predicted almost a half-century earlier. It’s been two years since the LHC was shut down for repairs and upgrades. Now thousands of physicists are getting ready to send beams of protons through the machine for the first time since 2013.

    “The beam is knocking at the door,” Frederick Bordry, CERN’s director for accelerators and technology, said Saturday during a preview of the LHC’s second experimental run at the annual meeting of the American Association for the Advancement of Science, here in San Jose.

    Bordry said the LHC’s supercooled magnets are being prepared for the first proton beams to start circulating around the end of March. Scientific observations would begin after a two-month conditioning period, or by the end of May, he said.

    “Don’t kill me if we are taking three or four days more,” he joked.

    LHC gets an energy boost

    It has taken decades to plan and build the $10 billion Large Hadron Collider and its four main detectors, housed in tunnels that run 300 feet (100 meters) beneath the countryside at the French-Swiss border. Now Bordry and others at CERN have mapped out a schedule of experimental runs and maintenance periods to keep the LHC on the frontier of physics until at least 2035.

    The upcoming run is scheduled to last until 2017. During that time, the LHC will ramp up to smash protons together at 60 percent higher energies than it did at the end of its initial run: 13 trillion electron volts, or 13 TeV, as opposed to 8 TeV. Moreover, the beam luminosity will be three times higher.

    That means the collider’s detectors should be detecting Higgs bosons — particles that are associated with the process that imparts mass to other subatomic particles — at five times the frequency, said Beate Heinemann, a physicist at the University of California at Berkeley and the Berkeley Lab who’s part of the LHC’s ATLAS experimental group.

    CERN ATLAS New
    ATLAS

    Heinemann said the boost in the LHC’s capabilities should also improve scientists’ chances of detecting gluinos, a theoretical particle predicted by supersymmetry theory, by a factor of 60.

    Hints of weirdness

    Heinemann and her colleagues said the collider’s initial three-year run has already pointed to some apparent discrepancies with the Standard Model, the theory that currently holds sway in particle physics. However, those discrepancies have not yet shown up at a confidence level that would persuade scientists that something weird was really going on.

    3
    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.

    If the weirdness is real, the LHC could provide evidence for it during the upcoming run, perhaps as soon as August or September, Heinemann told reporters.

    The new phenomena could take the form of supersymmetric particles, as-yet-undetected bits of matter that would add an elegant twist to the Standard Model. One such particle could be a gluino, the supersymmetric partner of a known particle called the gluon.

    Other hypothesized supersymmetric particles include neutralinos, which could account for the universe’s mysterious dark matter; and gravitinos, which could help explain dark matter as well as some of the mysteries surrounding gravity. The discrepancies also could be caused by a new breed of fourth-generation quark, Heinemann said.

    2
    Supersymmetry theory, or SUSY, suggests that each fundamental subatomic particle we’ve detected to date has a yet-to-be-discovered partner with complementary characteristics. The red box highlights the gluino, a particle that physicists believe could be detected at the Large Hadron Collider. If it exists, that is.

    However, there’s also a chance that the apparent discrepancies are nothing more than statistical glitches. That’s what happened a couple of years ago, when physicists saw hints pointing to the existence of a second kind of Higgs boson — only to watch those hints fade away as more readings were taken.

    “When you put a thousand physicists in a room to do data analysis, and each one of them makes 100 or 1,000 data plots, you’re likely to get statistical anomalies now and then — just like monkeys in the room typing out Shakespeare plays. Things happen,” said UCLA physicist Jay Hauser, a member of the LHC’s CMS collaboration.

    CERN CMS New
    CMS

    He said the data anomalies will provide a focus for future observations.

    “If it’s statistics, they’ll probably go away or diminish,” Hauser said. “If it’s real and interesting, then the effect will grow, and we get really excited.”

    Fermilab physicist Don Lincoln discussed the upcoming restart of the Large Hadron Collider — and the discoveries that may lie ahead — with NBC News’ Alan Boyle earlier this month on “Virtually Speaking Science.”

    5

    Read the pre-show interview, and listen to the hourlong podcast via BlogTalkRadio or iTunes.

    See the full article here.

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  • richardmitnick 2:04 pm on February 13, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From BNL: “Smashing Polarized Protons to Uncover Spin and Other Secrets” 

    Brookhaven Lab

    February 11, 2015
    Karen McNulty Walsh, (631) 344-8350 or Peter Genzer, (631) 344-3174

    1
    The Relativistic Heavy Ion Collider at Brookhaven National Laboratory is the only facility in the world capable of colliding beams of spin-polarized protons—either with one another or with a range of heavier ions.
    BNL RHIC
    RHIC

    If you want to unravel the secrets of proton spin, put a “twist” in your colliding proton beams. This technique, tried and perfected at the Relativistic Heavy Ion Collider (RHIC)—a particle collider and U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory—orients the colliding protons’ spins in a particular direction, somewhat like tiny bar magnets with their North poles all pointing up.

    Changing that direction and colliding different combinations of these spin-polarized proton beams gives scientists a way to decipher how the protons’ internal building blocks—quarks and gluons—contribute to their overall spin. RHIC is the only facility in the world with the ability to collide such polarized protons. The latest round of these collisions has just begun and will continue for approximately the next nine weeks.

    Run 15 will produce higher collision rates than in previous years, thanks to a number of machine upgrades at RHIC.

    For example, recently installed electron lenses will help keep proton beams tightly bunched to maximize the chances of the particles colliding.

    “When protons pass by each other, their positive charges make the protons in one beam repel those in the other,” explained Wolfram Fischer Accelerator Division Head for Brookhaven’s Collider-Accelerator Department. “Electron lenses use the attractive force of negatively charged electrons to compensate for this repulsive tendency and thereby allow more protons to be packed into the beams.”

    Deconstructing proton spin

    2
    RHIC’s polarized proton collisions are offering insight into how the spins of the internal building blocks of a proton — the quarks and antiquarks (balls with arrows) and gluons (yellow “springs”) — contribute to the overall proton spin, as well as whether and how much the orbital and transverse “bouncing” motions of these individual particles also contribute to spin.

    The mystery of the source of proton spin has puzzled nuclear physicists ever since experiments in the 1980s showed that the spins of quarks and antiquarks could account for, at most, a third of the proton’s total spin. “One main goal of RHIC’s energetic polarized-proton collisions is to increase the precision of our measurements so we can better tease out the contribution from the gluons’ spin,” said Jamie Dunlop, Associate Chair for Nuclear Physics in Brookhaven’s Physics Department.

    By sending the protons through spiral-cut magnets called Siberian snakes —which regularly flip the protons’ spin direction from up to down and vice versa to correct for depolarizing effects—and spin rotator magnets located on either side of RHIC’s two particle detectors, the scientists can twist and turn the beam to orient the proton’s spins pretty much any way they like. So far, these experiments at RHIC have revealed that gluon spins play a crucial role in proton spin, nearly equal to that of the quark and anti-quark spins. The new precision measurements will help clarify just how big that contribution is.

    3
    Spiraling magnets called Siberian snakes, placed at strategic locations along the chain of magnets that make up the RHIC accelerator, regularly flip the protons’ spin direction from up to down and vice versa to correct for depolarizing effects.

    Another key goal is to define and determine why, in transversely polarized proton-proton collisions, there is an imbalance in the way certain particles are deflected in one direction rather than another.

    “When you collide an unpolarized proton beam (where the proton spins can be pointing in any direction) with a proton polarized transverse to its direction of travel (say, with its polarization axis facing up), there is a net deflection—an imbalance in the probability for a particle to go to the left versus to go to the right —just like when a ball hits a spinning fan,” said Dunlop. “The effect at RHIC is huge,” he said, with up to twice as many particles going to one side as opposed to the other.

    The source of this phenomenon is still unclear, despite its strength and despite more than a decade of measurements.

    4
    At RHIC, collisions of protons polarized transverse to their direction of travel (say, with the polarization axis facing up) with an unpolarized proton beam (where the proton spins can be pointing in any direction) result in an imbalance in the probability for a particle created in the collision to go to the left versus to the right. Run 15 will help physicists explore the source of this phenomenon, which could be connected to the transverse momentum of the quarks and gluons inside the proton.

    “Some scientists think it could be connected to the transverse momentum of the quarks and gluons inside the proton—a bouncing kind of motion of these subcomponents that is perpendicular to the protons’ direction of travel,” said Brookhaven physicist Elke Aschenauer, a leader in the spin program at RHIC. “The polarization of RHIC’s beams makes it possible to visualize this motion by measuring the tendency of particles to come out to the left versus right.”

    Using polarized protons to probe heavier ions

    After the initial nine-week part of the run, RHIC physicists will begin a series of experiments they’ve never done before—collisions of polarized protons in one beam with a beam of heavier ions (first gold, for about five weeks, then a shorter two-week run with aluminum). These collisions will help the scientists search for indications of gluon saturation—dense gluon fields predicted by theorists to exist in the nuclei and hinted at in results from early deuteron-gold collisions at RHIC and, more recently, proton-lead collisions at the Large Hadron Collider (LHC).

    6
    Colliding polarized protons with heavier nuclei will offer insight into gluon walls postulated to exist within the nuclei. Analysis of jets of particles streaming out of these collisions with a preference for one direction over another will help scientists tease out how the gluons’ density is distributed inside the nucleus.

    These gluon fields could play an important role in proton spin and also in the formation of quark-gluon plasma—where the protons and neutrons in two colliding ion beams melt to form a seething soup of quark and gluon building blocks no longer confined within individual nuclei. Recent data at RHIC and the LHC have given hints that tiny droplets of quark-gluon plasma may even be formed in collisions of protons (or deuterons) with larger nuclei.

    “A crucial test to see whether this is the case would be to engineer the formation of one, two, or three droplets via collisions of protons, deuterons, or helium-3 projectiles with larger nuclei,” said University of Colorado physicist Jamie Nagle, a co-spokesperson for the PHENIX collaboration at RHIC. “With deuteron and helium results already in hand, data from proton-heavy ion collisions in Run 15 will complete the set of these initial tests.”

    BNL Phenix
    PHENIX

    In addition, said Aschenauer, “RHIC’s unique ability to collide polarized protons with heavy nuclei provides the only opportunity in the world to get a first look at the orbital momentum of gluons inside the proton.” Orbital momentum describes how the gluons move around within the proton—a separate characteristic from their spin, which is more analogous to rotation around an internal axis. These collisions therefore provide a window through which physicists can view another possible contribution to the proton spin puzzle.

    “We do this,” she explained, “by looking at the production of rare J/psi particles, which are produced when two gluons merge. If these particles emerge with a preference for the left or right direction with respect to the polarization direction of the proton beam, it tells something about how the gluons were moving around inside the proton.”

    RHIC scientists will also make improved measurements of “direct photons,” particles of light that emerge directly from the collisions without any interactions with the rest of the particles created in the particle smashups. These particles give the most direct insight into the conditions created within the collision zone, including the orbital motion of quarks (in proton-proton collisions) and the role of gluon fields (in collisions of protons with larger nuclei).

    Detector upgrades

    Many of these measurements will be made possible by upgrades designed specifically for this purpose at RHIC’s two sophisticated particle detectors, PHENIX and STAR.

    BNL Star
    STAR

    For example, STAR and PHENIX have both installed novel detector technologies to help analyze particles that emerge from RHIC collisions in the forward direction—close to and along the direction of the beamline.

    “PHENIX has pushed the boundaries of photon detection with a compact tungsten-silicon hybrid detector called the MPC-EX,” said PHENIX Deputy Spokesperson John Lajoie, a professor at Iowa State University. “This detector combines the high density of tungsten with the fine spatial resolution of silicon to separate very closely spaced particles. With this novel new detector, PHENIX will be able to separate direct photons from sources of background that would otherwise overwhelm the signal.”

    STAR has a preshower detector installed in front of the forward meson spectrometer. “This is the first large-scale implementation at RHIC using next-generation silicon photomultipliers for the detection of scintillator light emitted by plastic scintillators, which create light when charged particles pass through them,” Dunlop said. “It replaces a technology much like vacuum tubes that has been used for decades to precisely detect small amounts of light. Only recently has solid-state technology gotten to this point,” he said. The silicon photomultiplier technology may also be incorporated into a future upgrade to PHENIX, which will further expand RHIC’s capabilities.

    “All of these advances to the collider and its detectors showcase the value of RHIC as a testing ground for new technologies that may prove to be useful for other colliders and future research projects at and beyond Brookhaven Lab,” Dunlop said.

    Research at RHIC is funded primarily by the DOE Office of Science, and also by these agencies and organizations.

    See the full article here.

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    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.
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  • richardmitnick 11:45 am on February 13, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From Symmetry: “What’s new for LHC Run II” 

    Symmetry

    February 13, 2015
    Sarah Charley

    1

    The most powerful particle accelerator on Earth has been asleep for the past two years. Soon it will reawaken for its second run.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC

    Since shutting down in early 2013, the LHC and its detectors have undergone a multitude of upgrades and repairs. When the particle accelerator restarts, it will collide protons at an unprecedented energy: 13 trillion electron volts. Scaled up into our macroscopic world, the force of these proton-proton collisions is roughly equivalent to an apple hitting the moon hard enough to create a crater 6 miles across.

    The upgraded capabilities of the ATLAS, CMS, ALICE and LHCb detectors—plus the LHC’s extra boost of power—will give scientists access to a previously inaccessible realm of physics.

    CERN ATLAS New
    ATLAS

    CERN CMS New
    CMS

    CERN ALICE New
    ALICE

    CERN LHCb New
    LHCb

    To the Higgs boson …and beyond!

    In the first run of the LHC, the ATLAS and CMS experiments ended the 50-year hunt for the Higgs boson, which was predicted the Standard Model of particles and forces. Now scientists want to know if the Higgs they found is hiding any surprises.

    1
    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.

    “All the properties of the Higgs boson are already predicted by the Standard Model, so it’s our job to go out and measure those properties and see if they agree,” says Jay Hauser, a UCLA physicist working on the CMS experiment. “If anything disagrees, it could be a window to new physics.”

    Because the Higgs boson loves mass, scientists suspect that it might interact with a range of hidden, massive particles that we cannot see, such as dark matter. If the Higgs boson is dancing with any undiscovered physics, scientists should see evidence of this in the way the Higgs behaves.

    But even if the Higgs agrees with all predictions, something about it still seems a bit strange.

    “The Higgs mass doesn’t make any sense,” says Beate Heinemann, a Berkeley physicist and the deputy head of the ATLAS experiment. “It would make much more sense if it was much heavier, which is why we think there must be something that protects the Higgs boson and gives it a lower mass.”

    This Higgs bodyguard could be anything from supersymmetric particles to dark matter to extra dimensions.

    Supersymmetry standard model
    Standard Model of Supersymmetry

    “We have quite a few puzzles,” Heinemann says. “We think that there should be new physics at this energy scale, but we don’t know what it is yet.”

    Bringing it back to the big bang

    Scientists on the ALICE experiment have their sights on something else.

    In the beginning, the entire universe—all the stars, planets and galaxies—were part of a hot soup of matter called quark gluon plasma. The LHC can recreate those conditions in miniature by colliding beams of heavy atomic nuclei, which it does for four weeks per year. The ALICE detector specializes in investigating the properties of this primordial material.

    “The quark gluon plasma is so hot that ordinary protons and neutrons cannot exist in it,” says Peter Jacobs, a Berkeley physicist working on the ALICE experiment. “Quarks and gluons move around in it and interact in new ways that we haven’t seen before. It’s a new form of matter and we want to know how it behaves and what its properties are—like its structure and how it acts at different temperatures.”

    In the first run of the LHC, the ALICE experiment was able to characterize many aspects of this weird semi-liquid plasma, such as its viscosity.

    “The quarks and gluons interact more than we originally thought, indicating that the quark-qluon plasma is more like a liquid than a gas; indeed, almost as “perfect” a liquid as nature allows,” Jacobs says.

    But there is still more to investigate.

    “Run I was a discovery run, and we were able to explore many new things and developed a lot of curiosities,” Jacobs says. “During Run II, we will be able to explore these curiosities more deeply and give them quantitative values instead of just being able to describe them qualitatively.”

    The case of the missing antimatter

    Scientists suspect that the big bang acted like a universe-sized supercollider that brought equal parts of matter and antimatter into existence. But where did all of the antimatter go?

    The LHCb experiment is one of the world’s best early-universe detectives and looks for clues in the case of the disappearing antimatter.

    “We should have started with equivalent amount of matter and antimatter in the universe,” says Michael Williams, an MIT physicist working on the LHCb experiment. “But now, all we see is matter, and there is no way the Standard Model can explain this huge discrepancy. There must be some other way matter and antimatter behave differently.”

    To uncover the root of this huge discrepancy, the LHCb experiment does precision measurements of subatomic processes. LHCb scientists then compare the Standard Model predictions with these experimental observations to see how well they match up.

    Thus far, the Standard Model has been hard to break. But Williams thinks that increasing the precision of these measurements could start to show where the cracks are.

    “You never know if you’re on the cusp of making a discovery,” Williams says. “In Run II, we will measure lots of processes with a much higher precision, and this might reveal something that the Standard Model is not explaining.”

    See the full article here.

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 3:59 pm on February 6, 2015 Permalink | Reply
    Tags: , , , , , Particle Accelerators,   

    Amazing CERN Photo Essay From NBC News: “World’s Biggest Particle Smasher Gears Up for Next Run” 

    1

    CERN New Masthead

    After the discovery of the Higgs boson, or “God Particle,” in 2012, Europe’s giant particle accelerator at CERN has been getting an overhaul.

    1
    1. Scientists at the CERN particle physics center at the French-Swiss borders are preparing to restart the Large Hadron Collider (LHC), the world’s most powerful particle-smasher. Photographer Luca Locatelli was given access to maintenance work in November, providing a unique view into this vast underground laboratory. Engineers work on equipment for the LHC in the main workshop at CERN shown here.

    2
    2. A model of the Large Hadron Collider is displayed inside the LHC Magnet facility building, where components for the particle accelerator are built. The LHC was first started up in 2008 and is resuming high-energy collisions in March.

    3
    3. The LHC’s 17-mile-round underground tunnel directs particles through ATLAS, one of the facility’s two general-purpose detectors. ATLAS and the other detector, the Compact Muon Solenoid [CMS], probe a wide range of scientific mysteries, from the successful search for the Higgs boson to the hunt for extra dimensions and particles that could make up dark matter.

    4
    4. A scientist works inside one of the underground rooms of the Compact Muon Solenoid, another of LHC’s general-purpose detectors. The CMS experiment is one of the largest international scientific collaborations in history, involving 4,300 particle physicists, engineers, technicians, students and support staff from 182 institutes in 42 countries.

    5
    5. Maintenance work continues inside the CMS. The CMS detector is built around a huge solenoid magnet. This takes the form of a cylindrical coil of superconducting cable that generates a field of 4 tesla, about 100,000 times the strength of Earth’s magnetic field.

    6
    6. A unusual feature of the CMS detector is that instead of being built in place like the LHC’s other detectors, it was constructed in 15 sections at ground level before being lowered into an underground cavern and assembled. The complete detector is 70 feet long, 50 feet wide and 50 feet high (21 by 15 by 15 meters).

    7
    7. The last bit of maintenance work is perfomed inside the ALICE (A Large Ion Collider Experiment) before it resumes operation in 2015. ALICE is a heavy-ion detector that’s designed to study the physics of strongly interacting matter at extreme energy densities.

    8
    8. The ALICE detector sits in a vast cavern almost 200 feet (56 meters) below ground, close to the village of St Genis-Pouilly in France. When ALICE is in operation, the engineers in charge of the LHC switch from using beams of protons to beams of lead ions.

    9
    9. The ALICE collaboration uses a 10,000-ton detector – 85 feet long, 50 feet high and 50 feet wide (26 by 16 by 16 meters) – to study quark-gluon plasma, the “Big Bang soup” that existed when the universe was a trillionth of a second old.

    10
    10. In addition to the experiments at the LHC, scientists at the CERN particle physics center conduct huge numbers of smaller experiments. A bird’s-eye view shows one of the experiments in progress.

    11
    11. The Antiproton Decelerator provides low-energy antiprotons, mainly for studies of antimatter. Previously, “antiparticle factories” at CERN and elsewhere consisted of chains of accelerators, each performing one of the steps needed to provide antiparticles for experiments. Now the Antiproton Decelerator performs all the necessary steps, from making the antiprotons to delivering them to experiments. At CERN, scientists have used the antiprotons to create atoms of antihydrogen for a fraction of a second.

    12
    12.The 7,000-ton ATLAS detector is the largest particle detector ever constructed in terms of volume. ATLAS and the Compact Muon Solenoid, or CMS, were instrumental in the successful search for the Higgs boson at the Large Hadron Collider.

    And, for good measure, the 2008 video The Big Bang Machine from BBC. This video is from before the LHC started up. But, in my view, it is the best teaching video on both the LHC and
    particle physics involved in its experiments. This video features Sir Dr. Brian Cox, University of Manchester. Brian worked or works on the ATLAS project. He spent some time at FNAL’s Tevatron and does not leave it out as has been done by others. There are more recent videos. They simply do not do as well in communicating this story.


    Watch, enjoy, learn.

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  • richardmitnick 1:40 pm on February 6, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From CERN: “Everything is illuminated” 

    CERN New Masthead

    Feb 2, 2015
    Katarina Anthony

    On Monday, 26 January, CMS installed one of the final pieces in its complex puzzle: the new Pixel Luminosity Telescope. This latest addition will augment the experiment’s luminosity measurements, recording the bunch-by-bunch luminosity at the CMS collision point and delivering high-precision measurements of the integrated luminosity.

    2

    Installing the PLT in the heart of the CMS experiment.

    No matter the analysis, there’s one factor that every experimentalist needs to know perfectly: the luminosity. Its error bars can make or break a result, so its high precision measurement is vital for success. With this in mind, the CMS collaboration tasked the BRIL (Beam Radiation Instrumentation and Luminosity) project with developing a new detector to record luminosity for Run 2. Working with experimentalists from across the CMS collaboration and CERN, BRIL designed, created and installed the small – but mighty – Pixel Luminosity Telescope (PLT).

    “During Run 1, our primary online luminosity measurements came from the forward hadron calorimeter, which we compared to the offline luminosity measurement using the pixel detector,” says Anne Dabrowski, BRIL deputy project leader and technical coordinator (CERN). “But as we move to higher and higher luminosities and pile-ups in Run 2, extracting the luminosity gets harder to do.” That’s where the PLT comes in. Designed with the new LHC Run 2 in mind, the PLT uses radiation-hard CMS pixel sensors to provide near-instantaneous readings of the per-bunch luminosity – thus helping LHC operators provide the maximum useful luminosity to CMS. The PLT is unconnected to the CMS trigger and reads out at 40 MHz (every 25 ns) with no dead-time.

    The BRIL team includes collaborators from CERN, Germany, New Zealand, the USA, Italy and Russia.

    Research and development on the PLT began ten years ago, with diamonds first considered for the pixel telescope planes. A PLT prototype was even installed along the LHC beam line during Run 1. “Diamond sensors would have been an excellent choice, as they do not need to be run at low temperatures to have an acceptable radiation damage signal loss,” says David Stickland, BRIL project leader (Princeton University). However – while the potential for a diamond PLT remains – the prototype results led the team to use a more tested and reliable material for Run 2: silicon.

    However, this practical decision would create new issues for the BRIL team to resolve: “Suddenly, heat was a real concern,” explains Anne. “If we wanted to get a good signal out of silicon sensors, we had to bring the telescopes down in temperature.” With only 18 months to go until installation, the BRIL team had to go back to the drawing board to try and fit a cooling structure into an already-constrained space.

    The PLT is comprised of two arrays of eight small-angle telescopes situated on either side of the CMS interaction point. Each telescope hovers only 1 cm away from the CMS beam pipe, where it uses three planes of pixel sensors to take separate, unique measurements of luminosity. (Image: A. Rao)

    “We were successful thanks to the ingenuity of the CMS engineering integration office and PH-DT engineers, in particular Robert Loos,” says David. “Rob designed an extraordinary 3D-printed cooling structure using a titanium alloy, using the ‘selective laser melting (SLM)’ technique in order to ‘grow’ the cooling structure we needed.” Despite the internal diameter of the cooling channels being less than 3 mm, the cooling structure can make right-angle turns at the drop of a dime and withstand pressure up to 15 bar. “It’s tremendously strong, light and compact. I don’t know how it could have been made without this technique,” David adds.

    This is only the first example of the innovative design used by the BRIL group. So while the telescope’s installation may be complete, our coverage of their work is not yet over. Look out for an article in the next edition of the Bulletin to find out more…

    See the full article here.

    Please help promote STEM in your local schools.

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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

    LHC

    CERN LHC New

    LHC particles

    Quantum Diaries

     
  • richardmitnick 12:21 pm on January 29, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From FNAL: “Preserving the data and legacy of the Tevatron” 

    FNAL Home


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

    Thursday, Jan. 29, 2015
    The Run II Data Preservation Project Team: Joe Boyd, Project Technical Lead; Ken Herner, DZero; Bo Jayatilaka, CDF; Rob Kennedy, Project Manager; Willis Sakumoto, CDF

    The recently completed Tevatron Run II Data Preservation Project makes the reams of CDF and DZero data available for future analysis.

    Since the shutdown of the Tevatron in 2011, there has been a concerted effort to preserve the data and rich physics legacy from the CDF and DZero experiments.

    FNAL CDF
    FNAL DZero
    FNAL Tevatron machine
    Tevatron

    The Run II Data Preservation project, completed in December, enables scientists to perform publishable scientific analysis of Run II Tevatron data through at least 2020. Kenneth Herner and Bo Jayatilaka, co-leaders of the project for DZero and CDF respectively, point out that the Run II Data Preservation project enables scientists to revisit a measurement or to test new theoretical calculations long after the original experiments have ended.

    “These data sets can potentially verify discoveries made at the Large Hadron Collider,” Jayatilaka said.

    “The Tevatron’s unique proton-antiproton collision data set enables physics studies that are complementary to those at the LHC,” Herner added.

    In the world of digital science, “data preservation” means not only preservation of the data set itself, but also of the software to enable future access to that data. The Run II Data Preservation project also addressed documentation and adoption of the sustainable infrastructure needed to ensure that scientists will be able to analyze Run II data in future computing environments.

    The need for sustainable data preservation will continue to increase as science advances, experiments become less replicable and data sets become increasingly specialized. Projects such as the Data and Software Preservation for Open Science and the Study Group for Data Preservation in High Energy Physics are also working to expand and improve data preservation technology.

    Through the Run II Data Preservation project, both CDF and DZero have adapted their data analysis techniques with the long-term computing infrastructure supporting the Fermilab physics program going forward. Herner and Willis Sakumoto, co-leader of the effort at CDF, both emphasize that their users are now able to run their analyses in the long-term supported infrastructure without having to learn new tools.

    “The project has accomplished its goal of transitioning CDF analysis infrastructure support so that we can access the data and run the software into 2020 with minimal additional cost to the base program,” Sakumoto said.

    DZero users, too, are able to run their analysis using their familiar tools, Herner said.

    This two-year-long project was a collaborative effort of experts from CDF and DZero, as well as the Data Management and Applications Group, the Storage Services Group, and the Scientific Software Infrastructure Department of the Scientific Computing Division, to preserve the long-term value of the Tevatron Run II experiments.

    See the full article here.

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    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.

     
  • richardmitnick 12:05 pm on January 27, 2015 Permalink | Reply
    Tags: , , , , Particle Accelerators,   

    From CERN- “LHC Season 2: holding the key to new frontiers” 

    CERN New Masthead

    12 Jan 2015
    Cian O’Luanaigh

    This year, the Large Hadron Collider (LHC) will restart at the record collision energy of 13 TeV, following a two-year long shutdown (LS1) for planned maintenance. To mark this, today saw the LS1 activities coordinator symbolically handing over the LHC key to the operations team. The team will now perform tests on the machine in preparation for the restart this spring.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC

    After three years of highly successful running, the LHC was shut down for maintenance in 2013. Since then, engineers and technicians have been repairing and strengthening the 27-kilometre accelerator in preparation for its restart at 13 TeV. Some 18 of the 1232 dipole magnets that steer particle beams around the accelerator were replaced, and more than 10,000 electrical interconnections between the magnets were strengthened. The LHC’s vacuum, cryogenics and electronics systems were also consolidated.

    “It’s important to stress that after the long shutdown, the LHC is essentially a new machine,” said CERN Director-General Rolf Heuer in his New Year address at CERN last week.

    The collision energy of 13 TeV is a significant increase compared with the initial three-year LHC run, which began at 7 TeV and rose to 8 TeV. In addition, in the run that starts this year, bunches of protons in the accelerator will collide at briefer intervals – 25 nanoseconds(ns) between them instead of 50 ns – and the beams will be more tightly focused. All these factors are aimed at optimising the delivery of particle collisions for physics research.

    With collisions at energies never reached in a particle accelerator before, the LHC will open a new window for discovery, allowing further studies of the Higgs boson and the potential to address unsolved mysteries such as dark matter.

    The LHC is CERN’s flagship machine, but the accelerator complex also provides a broad programme of research that makes many contributions to fundamental physics. The long shutdown has allowed teams throughout CERN to upgrade experiments, detectors, accelerators and equipment.

    In addition, the laboratory has continued to nurture its collaborations around the world with involvements in future collider studies, showing CERN’s dedication to the future of particle physics at the very forefront of knowledge.

    It will be a busy year ahead, and with so much in store the laboratory looks forward to LHC Season 2 and more!

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    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

    LHC

    CERN LHC New

    LHC particles

    Quantum Diaries

     
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