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  • richardmitnick 10:05 am on October 31, 2013 Permalink | Reply
    Tags: , , , Matter/Antimatter   

    From Fermilab- “Frontier Science Result: DZero Muons, matter and mystery” 


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

    Thursday, Oct. 31, 2013
    Mark Williams

    Experiments at particle colliders are often described as “recreating the big bang”: making new particles out of energy, and then watching to see what happens. In almost all such experiments, we find that matter and antimatter are produced in equal amounts, and this is consistent with our current model. However, if the big bang followed the same rules, all the matter and antimatter would have mutually annihilated, with nothing left to form stars, planets and life. The very fact that we exist, and observe a matter-dominated universe, shows that our picture of the particle interactions is not complete.

    At the DZero experiment, scientists have spent a decade studying this matter-antimatter asymmetry using muons produced in their detector, and last week they released their final results. The measurement counts the number of observed muons (negatively charged) and antimuons (positively charged) to compare the amount of matter and antimatter resulting from the originally symmetric proton-antiproton collisions.

    As an analogy, this is much like weighing the matter and antimatter with a set of scales. The challenge is that the scales themselves introduce their own asymmetry into the measurement. Because the detector is built out of matter, it responds slightly differently to matter and antimatter particles as they are detected. These “detector effects” must be precisely determined before the measurement can be made. Luckily, the DZero detector has some clever attributes that make it uniquely suited for this kind of analysis.

    scale
    The new measurement uses the DZero detector like a set of scales, weighing the amount of matter and antimatter. However, the scales are themselves asymmetric, and the main challenge is to understand and quantify the effect of this behavior.

    Intriguingly, after correcting for the detector effects, the results indicate a statistically significant asymmetry in the number of same-charge muon pairs, with around one part in 400 more pairs of negative muons than positive muons. This is much larger than can be accounted for by current theories, suggesting the presence of additional as-yet unknown processes that favor the production of matter over antimatter. Now, assuming that this isn’t a very unlikely statistical fluctuation, the big question is: What could be causing this asymmetry, and could it be the same process that helped shape the early universe? Future precision measurements of specific asymmetries, as well as theoretical developments, are needed to help understand this puzzle.

    See the full article here.

    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.


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  • richardmitnick 6:12 am on September 28, 2013 Permalink | Reply
    Tags: , , , Matter/Antimatter   

    From Brookhaven Lab: “Supercomputers Help Solve a 50-Year Homework Assignment” 

    Brookhaven Lab

    Calculation related to question of why the universe is made of matter.

    September 26, 2013
    Karen McNulty Walsh

    Kids everywhere grumble about homework. But their complaints will hold no water with a group of theoretical physicists who’ve spent almost 50 years solving one homework problem—a calculation of one type of subatomic particle decay aimed at helping to answer the question of why the early universe ended up with an excess of matter.

    Without that excess, the matter and antimatter created in equal amounts in the Big Bang would have completely annihilated one another. Our universe would contain nothing but light—no homework, no schools…but also no people, or planets, or stars!

    bbe
    According to the Big Bang model, the Universe expanded from an extremely dense and hot state and continues to expand today. A common analogy explains that space itself is expanding, carrying galaxies with it, like spots on an inflating balloon. The graphic scheme above is an artist’s concept illustrating the expansion of a portion of a flat universe.

    Physicists long ago figured out something must have happened to explain the imbalance—and our very existence.

    “Our results will serve as a tough test for our current understanding of particle physics.”
    — Brookhaven theoretical physicist Taku Izubuchi

    “The fact that we have a universe made of matter strongly suggests that there is some violation of symmetry,” said Taku Izubuchi, a theoretical physicist at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory.

    team
    Members of Brookhaven Lab’s high-energy physics theory group who were involved in the kaon decay calculations Sitting, left to right: Christoph Lehner, Amarjit Soni, Taku Izubuchi, Christopher Kelly, Chulwoo Jung. Standing, left to right: Eigo Shintani, Hyung-Jin Kim, Ethan Neil, Taichi Kawanai, Tomomi Ishikawa

    The physicists call it charge conjugation-parity (CP) violation. Instead of everything in the universe behaving perfectly symmetrically, certain subatomic interactions happen differently if viewed in a mirror (violating parity) or when particles and their oppositely charged antiparticles swap each other (violating charge conjugation symmetry). Scientists at Brookhaven—James Cronin and Val Fitch—were the first to find evidence of such a symmetry “switch-up” in experiments conducted in 1964 at the Alternating Gradient Synchrotron, with additional evidence coming from experiments at CERN, the European Laboratory for Nuclear Research. Cronin and Fitch received the 1980 Nobel Prize in physics for this work.

    rack
    Theoretical physicists and kaon-decay calculators Norman Christ, Robert Mawhinney (both of Columbia University), and Taku Izubuchi (of Brookhaven), holding one rack of the QCDOC supercomputer at Brookhaven, which was used for many of the earlier kaon calculations. It was replaced by QCDCQ in 2012.

    What was observed was the decay of a subatomic particle known as a kaon into two other particles called pions. Kaons and pions (and many other particles as well) are composed of quarks. Understanding kaon decay in terms of its quark composition has posed a difficult problem for theoretical physicists.

    “That was the homework assignment handed to theoretical physicists, to develop a theory to explain this kaon decay process—a mathematical description we could use to calculate how frequently it happens and whether or how much it could account for the matter-antimatter imbalance in the universe. Our results will serve as a tough test for our current understanding of particle physics,” Izubuchi said.

    The mathematical equations of Quantum Chromodynamics, or QCD—the theory that describes how quarks and gluons interact—have a multitude of variables and possible values for those variables. So the scientists needed to wait for supercomputing capabilities to evolve before they could actually solve them. The physicists invented the complex algorithms and wrote nifty software packages that some of the world’s most powerful supercomputers used to describe the quarks’ behavior and solve the problem.

    The supercomputing resources used for this research included: QCDCQ, a pre-commercial version of the IBM Blue Gene supercomputers, located at the RIKEN/BNL Research Center—a center funded by the Japanese RIKEN laboratory in a cooperative agreement with Brookhaven Lab; a Blue Gene/Q supercomputer of the New York State Center for Computational Science, hosted by Brookhaven; half a rack of an additional Blue Gene/Q funded by DOE through the US based lattice QCD consortium, USQCD; a Blue Gene/Q machine at the Edinburgh Parallel Computing Centre; the large installation of BlueGene/P (Intrepid) and Blue Gene/Q (Mira) machines at Argonne National Laboratory funded by the DOE Office of Science; and PC cluster machines at Fermi National Accelerator Laboratory and at RIKEN.

    See the full article here.

    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


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  • richardmitnick 3:50 pm on August 16, 2013 Permalink | Reply
    Tags: , , Matter/Antimatter,   

    From Symmetry: "Antimatter experiment seeks help from the crowd" 

    After a successful trial run, a CERN antimatter experiment plans to use crowdsourcing to analyze its data.

    August 16, 2013
    Ashley WennersHerron and Kathryn Jepsen

    “Scientists investigating the effect of gravity on animatter recently conducted a different kind of experiment: They asked members of the public to help them analyze their data. Anyone with access to a computer and the Internet was welcome to take part in the trial run, which went off without a hitch. The scientists plan to do it again in the coming months.

    The AEgIS experiment at CERN examines beams of antimatter particles, recording the points at which they begin to deviate from their normal trajectories and the points at which they come into contact with matter and annihilate. Seeing how quickly—and in what direction—the particles fall will offer insight into just how the antimatter feels gravity’s pull.

    CERN AEGIA New
    AEgIS

    The experiment requires the scientists to match up pairs of dots to trace each particle’s path. They have a lot of dots to connect. ‘We have so much data that automation or many volunteers are the only options at this point,’ says CERN physicist Michael Doser, who leads the experiment. The scientists could try to create a program to do this job, Doser says, but people are just better than machines at this kind of pattern recognition. ‘So we brought the data to the people.’

    The scientists decided to release a small fraction of the data to the public as a test.

    dots
    The crowdsourcing software renders the particle tracks as a 3D image. Courtesy of: CERN

    Last month, a small group of students at CERN’s Summer Student Webfest designed a crowdsourcing program for AEgIS. Last week, the experiment put out the call for help. In the first hour, several hundred volunteers completed the task. ‘I expect a publication or two sometime in early 2014 on this analysis which directly benefits from help from the public,’ Doser says.

    Anyone interested in taking part in the next experiment in armchair physics can watch for the call on the AEgIS website. “

    See the full article here.

    Symmetry is a joint Fermilab/SLAC publication.



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  • richardmitnick 4:57 pm on April 30, 2013 Permalink | Reply
    Tags: , , , , , Matter/Antimatter   

    From Symmetry: “Matter, antimatter, we all fall down—right?” 

    April 30, 2013
    Ashley WennersHerron

    Scientists perform the first direct investigation into how antimatter interacts with gravity.

    What goes up must come down, the saying goes. But things might work a little differently with antimatter.
    A CERN-based experiment has taken the first step in investigating exactly how antimatter interacts with gravity.

    men
    Photo: CERN

    Atimatter particles should mimic those of matter particles. If it turns out that there is a difference, it will be a sign of dramatically new physics.
    CERN ALPHA NewSo far, no one has been able to test directly how antimatter interacts with gravity—but the ALPHA experiment has begun to try.

    The ALPHA experiment’s main purpose is to trap and study antihydrogen atoms, the antimatter partners of hydrogen atoms. The antihydrogen atoms are held in place inside a tube by magnetic forces. Physicists on ALPHA have trapped more than 500 antiatoms since 2010. They keep them in their trap for up to about 16 minutes. When they turn off their magnets, the antiatoms fall out of the trap. A highly sensitive detector tracks the antiatoms and records where they first come in contact with matter and annihilate.”

    See the full article here.

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 12:22 pm on April 18, 2013 Permalink | Reply
    Tags: , , , , , Matter/Antimatter, ,   

    From Fermilab- “Frontier Science Result: DZero Precise measure of matter preference 

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

    Thursday, April 18, 2013
    Mike Cooke

    “We live in a universe filled with matter, with no detectable pockets of antimatter, but don’t fully understand why. In the very early universe, matter and antimatter were created in equal abundance. As the universe cooled, the matter and antimatter annihilated each other, but left behind the small excess of matter that accounts for all of the stars, planets and galaxies in the universe today. This difference is thought to result from the slightly different ways the particles and antiparticles decayed. However, the decay rate difference predicted by the Standard Model is not nearly enough to account for the amount of matter in the universe. By precisely measuring processes that show a difference between matter and antimatter, physicists attempt to understand what caused the imbalance that led to the universe today.

    scene
    Most matter and antimatter annihilated each other in the very early universe, but a small excess of matter remained to form the universe we live in today. To attempt to understand this imbalance, scientists measure particle decay processes that show a difference between matter and antimatter.

    A recent result at DZero studied this asymmetry in the decay of a charged B meson, made of a bottom quark and an up quark, into a J/Ψ meson and a charged K meson, which involves the bottom quark decaying into a strange quark and two charm quarks. To reduce the uncertainty on the measurement, the analysis exploited the fact that the magnetic polarities of magnets in the DZero detector were systematically flipped during the decade of data collecting for Run II. Each possible source of bias in the measurement of asymmetry between matter and antimatter was carefully studied and accounted for.

    The final result is the world’s most precise measurement of matter-antimatter asymmetry in charged B meson decays to a J/Ψ meson and a charged K meson. The measured asymmetry is consistent with the Standard Model. While it does not indicate the presence of new physics and explain the matter-antimatter asymmetry in the universe, it is an important step in exploring this mystery.”

    See the full article here.

    The final result is the world’s most precise measurement of matter-antimatter asymmetry in charged B meson decays to a J/Ψ meson and a charged K meson. The measured asymmetry is consistent with the Standard Model. While it does not indicate the presence of new physics and explain the matter-antimatter asymmetry in the universe, it is an important step in exploring this mystery.

    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.


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  • richardmitnick 1:03 pm on March 25, 2013 Permalink | Reply
    Tags: , , CERN ATRAP, , Matter/Antimatter,   

    From CERN: “ATRAP: Never a dull moment for the antiproton” 

    CERN New Masthead

    March 25, 2013
    Katarina Anthony

    “In results published today in Physical Review Letters, the Antihydrogen TRAP (ATRAP) experiment at CERN’s Antiproton Decelerator reveals a new measurement of the antiproton magnetic moment made with an unprecedented uncertainty of only 4.4 parts per million. This is not just an impressive feat for the ATRAP team, but is also an important attempt to understand the matter-antimatter imbalance of the universe, one of the great mysteries of modern physics.

    apt
    Antihydrogen TRAP

    apd
    The Antiproton Decelerator

    ‘Precise comparisons of the properties of the antiproton and proton are intriguing and important,’ says ATRAP spokesperson Gerald Gabrielse of Harvard University, ‘given that the fundamental cause of the dramatic imbalance of antimatter and matter in the universe has yet to be discovered. By comparing the antiproton’s tiny magnet to that of the proton, we probe one of nature’s most fundamental symmetries, known as CPT, at a high precision.’

    The ATRAP team found that the magnets of the antiproton and proton are ‘exactly opposite’ – equal in strength but opposite in direction, consistent with the prediction of the Standard Model and its CPT theorem to 5 parts per million. However, the potential for much greater measurement precision puts ATRAP in position to test the Standard Model prediction much more stringently still.”

    Standard Model New

    See the full article here.

    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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  • richardmitnick 7:40 am on February 19, 2013 Permalink | Reply
    Tags: , , , , Matter/Antimatter, ,   

    From CERN: “Proton-lead run brings new physics reach to LHCb” 

    CERN New Masthead

    19 Feb 2013
    Antonella del Rosso

    During the recent lead-proton run at the Large Hadron Collider (LHC), the Large Hadron Collider beauty (LHCb) experiment took data from collisions between protons and ions for the first time.

    lhcb
    A proton-lead ion collision, as observed by the LHCb detector during the 2013 data-taking period (Image: LHCb/CERN)

    LHCb is an asymmetric detector designed to study matter-antimatter asymmetries and rare decays involving heavy quarks. Though LHCb is small compared to the multipurpose detectors CMS and ATLAS and the specialized heavy-ion detector ALICE, it has something special: the location of LHCb close to the collision point allows it to identify particles that scatter at very small angles from collisions.

    ‘The detector’s unique angular coverage will enable us to study strange, charm and also beauty quark production in regions not accessible to the other experiments,’ says LHCb spokesperson Pierluigi Campana.

    See the full article here.

    Read all about LHCb here.

    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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  • richardmitnick 11:38 am on February 12, 2013 Permalink | Reply
    Tags: , , , , Matter/Antimatter,   

    From CERN: “Fat antiatoms, laser beams and matter-antimatter asymmetry” 

    CERN New Masthead

    CERN

    Stephanie Hills
    12 Feb 2013

    Imagine being able to ‘inflate’ an atom with a laser, then slow it down, catch it or bend it around corners. At the AEGIS experiment at the Antiproton Decelerator, Stephen Hogan of University College London and an international team of collaborators are trying to do just that.

    ad
    Antiproton Decelerator

    AEGIS is designed to test whether antimatter complies with the weak equivalence principle (WEP), a mathematical concept that states that the acceleration experienced by a particle in a gravitational field is independent of its mass and composition. The principle has been tested with very high precision for matter, but never for antimatter. If results from AEGIS show that the gravitational acceleration of antimatter in the Earth’s gravitational field is different to that of matter, this could provide clues to why our universe is now dominated by matter, even though matter and antimatter were created in equal amounts during the big bang.

    aegis
    The AEGIS experiment in the antimatter hall at CERN aims to make the first direct measurement of Earth’s gravitational effect on antimatter (Image: CERN)

    ‘We know that in our observable universe there is an asymmetry between matter and antimatter, but there is no consensus among the theorists as to why this is,’ says Hogan. ‘If gravity is different for antimatter, this might give us a clue. The results of our experiment will help guide us toward an appropriate theory.’”

    See the full article here.

    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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  • richardmitnick 10:05 am on January 7, 2013 Permalink | Reply
    Tags: , , Matter/Antimatter,   

    From Space.com: “Coldest Antimatter Yet Is Goal of New Technique” 

    SpacedotcomHeader
    Space.com

    This is copyright protected, so just a couple of hints to pique your interest.

    07 January 2013
    Clara Moskowitz

    “Scientists have devised a new method of cooling down antimatter to make it easier to experiment on than ever before. The new technique could help researchers probe the mysteries of antimatter, including why it’s so rare compared with matter in the universe.

    The new technique is focused on antihydrogen atoms, which contain one positron and one antiproton (regular hydrogen contains one electron and one proton).

    antimatter
    From StartsWithABang at ScienceBlogs

    ‘The ultimate goal of antihydrogen experiments is to compare its properties to those of hydrogen,’ physicist Francis Robicheaux of Auburn University in Alabama said in a statement. ‘Colder antihydrogen will be an important step for achieving this.’

    Robicheaux is the co-author of a paper describing the new cooling method published today (Jan. 6) in the Journal of Physics B: Atomic, Molecular and Optical Physics.”

    See the full article here.

    SPACE.com, launched in 1999, is the world’s No. 1 source for news of astronomy, skywatching, space exploration, commercial spaceflight and related technologies. Our team of experienced reporters, editors and video producers explore the latest discoveries, missions, trends and futuristic ideas, interviewing expert sources and offering up deep and broad analysis of the findings and issues that are fundamental to or understanding of the universe and our place in it. SPACE.com articles are regularly featured on the web sites of our media partners: MSNBC.com, Yahoo!, the Christian Science Monitor and others.

     
  • richardmitnick 1:17 pm on July 19, 2012 Permalink | Reply
    Tags: , , , , Matter/Antimatter, ,   

    From Fermilab Today: “Result of the Week – Puzzling new pieces in the antimatter mystery” 

    Fermilab continues to be a great source of strength in the U.S. Basic Research Community.

    Thursday, July 19, 2012
    Mike Cooke

    One of the most puzzling properties of matter in our universe is that there’s so much of it in the first place. When new matter is created during a particle collision, an equal amount of antimatter accompanies it nearly every time. The Standard Model allows only a very slight deviation from this symmetry, and not nearly enough difference between matter and antimatter to explain the abundance of matter in our universe today.

    am
    New measurements from DZero add pieces to the puzzle of matter-antimatter asymmetry.

    The DZero Collaboration has previously shown evidence for a greater matter-antimatter asymmetry than predicted by the Standard Model in the decays of neutral B mesons, particles that combine a bottom quark with either a down quark (Bd0) or strange quark (Bs0). Two new measurements, which focus separately on the Bd0 and Bs0, now add complementary pieces to this puzzling matter.

    The new measurements are consistent with the previous evidence for matter-antimatter asymmetry reported by the DZero collaboration, which measured a particular mixture of the Bd0 and Bs0 system asymmetries in an independent channel. In combination, these results differ from the Standard Model by about 3 standard deviations. These new pieces hint at a very interesting picture of the universe, but more precise measurements will be required to finally solve this puzzle.”

    See the full article here.

     
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