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  • richardmitnick 2:16 pm on April 22, 2017 Permalink | Reply
    Tags: , CERN CMS, , , , Videos   

    From CMS at CERN: Fantastic Videos 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    CERN

    These incredible videos are presented in no particular order.,


    An introduction to the CMS Experiment at CERN


    Welcome to LHC season 2: new frontiers in physics at #13TeV


    LHC animation: The path of the protons


    The Large Hadron Collider Returns in the Hunt for New Physics


    Physics Run 2016


    Back to the Big Bang: Inside the Large Hadron Collider – From the World Science Festival


    Higgs boson: what’s next? #13TeV

    Please help promote STEM in your local schools.

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    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    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 12:09 pm on April 13, 2017 Permalink | Reply
    Tags: CERN CMS, ,   

    From Rice: “Proton-nuclei smashups yield clues about ‘quark gluon plasma’ “ 

    Rice U bloc

    Rice University

    April 10, 2017
    Jade Boyd

    Rice University physicists probe exotic state of nuclear matter at Europe’s LHC

    1
    A visual of data collected by the Compact Muon Solenoid detector during a proton-lead collision at the Large Hadron Collider in 2016. (Image courtesy of Thomas McCauley/CERN)

    Findings from Rice University physicists working at Europe’s Large Hadron Collider (LHC) are providing new insight about an exotic state of matter called the “quark-gluon plasma” that occurs when protons and neutrons melt.

    As the most powerful particle accelerator on Earth, the LHC is able to smash together the nuclei of atoms at nearly the speed of the light. The energy released in these collisions is vast and allows physicists to recreate the hot, dense conditions that existed in the early universe. Quark-gluon plasma, or QGP, is a high-energy soup of particles that’s formed when protons and neutrons melt at temperatures approaching several trillion kelvins.

    In a recent paper in Physical Review Letters written on behalf of more than 2,000 scientists working on the LHC’s Compact Muon Solenoid (CMS) experiment, Rice physicists Wei Li and Zhoudunming (Kong) Tu proposed a new approach for studying a characteristic magnetic property of QGP called the “chiral magnetic effect” (CME).

    CERN/CMS Detector

    Their approach uses collisions between protons and lead nuclei. CME is an electromagnetic phenomenon that arises as a consequence of quantum mechanics and is also related to so-called topological phases of matter, an area of condensed matter physics that has drawn increased worldwide attention since capturing the Nobel Prize in physics in 2016.

    “To find evidence for the chiral magnetic effect and thus topological phases in hot QGP matter has been a major goal in the field of high-energy nuclear physics for some time,” Li said. “Early findings, although indicative of the CME, still remain inconclusive, mainly because of other background processes that are difficult to control and quantify.”

    QGP was first produced around 2000 at the Relativistic Heavy Ion Collider in New York and later at the LHC in 2010.

    BNL/RHIC

    CERN/LHC Map

    In those experiments, physicists smashed together two fast-moving lead nuclei, each of containing 82 protons and 126 neutrons, the two building blocks of all atomic nuclei. Because the melting protons in these collisions each carries a positive electric charge, the QGPs from these experiments contained enormously strong magnetic fields, which are estimated to be about a trillion times stronger than the strongest magnetic field ever created in a laboratory.

    The chiral magnetic effect is an exotic asymmetric electromagnetic effect that only arises due to the combination of quantum mechanics and the extreme physical conditions in a QGP. The laws of classical electrodynamics would forbid the existence of such a state, and indeed, Li’s inspiration for the new experiments arose from thinking about the problem in classical terms.

    “I was inspired by a problem in an undergraduate course I was teaching on classical electrodynamics,” Li said.

    Two years ago Li discovered that head-on collisions at LHC between a lead nucleus and a single proton created small amounts of particles that appeared to behave as a liquid. On closer analysis, he and colleagues at CMS found the collisions were creating small amounts of QGP.

    In a 2015 Rice News report about the discovery, Rice alumnus Don Lincoln, a particle physicist and physics communicator at Fermilab, wrote, “This result was surprising because when the proton hits the lead nucleus, it punches a hole through much of the nucleus, like shooting a rifle at a watermelon (as opposed to colliding two lead nuclei, which is like slamming two watermelons together).”

    Li said, “One unusual thing about the droplets of QGP created in proton-lead collisions is the configuration of their magnetic fields. The QGP is formed near the center of the initial lead nucleus, which makes it easy to tell that the strength of the magnetic field is rather negligible in comparison with the QGP created in lead-lead collisions. As a result, proton-lead collisions provide us a means to switch off the magnetic field — and the CME signal — in a QGP in a well-controlled way.”

    In the new paper, Li, Tu and their CMS colleagues showed evidence from proton-lead collision data that helps shed light on the electromagnetic behaviors that arise from the chiral magnetic effect in lead-lead QGPs.

    Li said more details still need to be worked out before a definitive conclusion can be drawn, but he said the results bode well for future QGP discoveries at the LHC.

    “This is just a first step in a new avenue opened up by proton-nucleus collisions for the search of exotic topological phases in QGP,” Li said. “We are working hard on accumulating more data and performing a series of new studies. Hopefully, in coming years, we will see the first direct evidence for the chiral magnetic effect.”

    The research is supported by the Department of Energy, the Robert Welch Foundation and Alfred Sloan Foundation.

    See the full article here .

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    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 11:33 am on March 24, 2017 Permalink | Reply
    Tags: A new gem inside the CMS detector, , , CERN CMS, , , , ,   

    From Symmetry: “A new gem inside the CMS detector” 

    Symmetry Mag

    Symmetry

    03/24/17
    Sarah Charley

    1
    Photo by Maximilien Brice, CERN

    This month scientists embedded sophisticated new instruments in the heart of a Large Hadron Collider experiment.

    Sometimes big questions require big tools. That’s why a global community of scientists designed and built gigantic detectors to monitor the high-energy particle collisions generated by CERN’s Large Hadron Collider in Geneva, Switzerland. From these collisions, scientists can retrace the footsteps of the Big Bang and search for new properties of nature.

    The CMS experiment is one such detector. In 2012, it co-discovered the elusive Higgs boson with its sister experiment, ATLAS. Now, scientists want CMS to push beyond the known laws of physics and search for new phenomena that could help answer fundamental questions about our universe. But to do this, the CMS detector needed an upgrade.

    “Just like any other electronic device, over time parts of our detector wear down,” says Steve Nahn, a researcher in the US Department of Energy’s Fermi National Accelerator Laboratory and the US project manager for the CMS detector upgrades. “We’ve been planning and designing this upgrade since shortly after our experiment first started collecting data in 2010.”

    The CMS detector is built like a giant onion. It contains layers of instruments that track the trajectory, energy and momentum of particles produced in the LHC’s collisions. The vast majority of the sensors in the massive detector are packed into its center, within what is called the pixel detector. The CMS pixel detector uses sensors like those inside digital cameras but with a lightning fast shutter speed: In three dimensions, they take 40 million pictures every second.

    For the last several years, scientists and engineers at Fermilab and 21 US universities have been assembling and testing a new pixel detector to replace the current one as part of the CMS upgrade, with funding provided by the Department of Energy Office of Science and National Science Foundation.

    2
    Maral Alyari of SUNY Buffalo and Stephanie Timpone of Fermilab measure the thermal properties of a forward pixel detector disk at Fermilab. Almost all of the construction and testing of the forward pixel detectors occurred in the United States before the components were shipped to CERN for installation inside the CMS detector. Photo by Reidar Hahn, Fermilab

    3
    Stephanie Timpone consults a cabling map while fellow engineers Greg Derylo and Otto Alvarez inspect a completed forward pixel disk. The cabling map guides their task of routing the the thin, flexible cables that connect the disk’s 672 silicon sensors to electronics boards. Maximilien Brice, CERN

    4
    The CMS detector, located in a cavern 100 meters underground, is open for the pixel detector installation. Photo by Maximilien Brice, CERN

    5
    Postdoctoral researcher Stefanos Leontsinis and colleague Roland Horisberger work with a mock-up of one side of the barrel pixel detector next to the LHC’s beampipe.
    Photo by Maximilien Brice, CERN

    6
    Leontsinis watches the clearance as engineers slide the first part of the barrel pixel just millimeters from the LHC’s beampipe. Photo by Maximilien Brice, CERN

    7
    Scientists and engineers lift and guide the components by hand as they prepare to insert them into the CMS detector. Photo by Maximilien Brice, CERN

    8
    Scientists and engineers connect the cooling pipes of the forward pixel detector. The pixel detector is flushed with liquid carbon dioxide to keep the silicon sensors protected from the LHC’s high-energy collisions. Photo by Maximilien Brice, CERN

    The pixel detector consists of three sections: the innermost barrel section and two end caps called the forward pixel detectors. The tiered and can-like structure gives scientists a near-complete sphere of coverage around the collision point. Because the three pixel detectors fit on the beam pipe like three bulky bracelets, engineers designed each component as two half-moons, which latch together to form a ring around the beam pipe during the insertion process.

    Over time, scientists have increased the rate of particle collisions at the LHC. In 2016 alone, the LHC produced about as many collisions as it had in the three years of its first run together. To be able to differentiate between dozens of simultaneous collisions, CMS needed a brand new pixel detector.

    The upgrade packs even more sensors into the heart of the CMS detector. It’s as if CMS graduated from a 66-megapixel camera to a 124-megapixel camera.

    Each of the two forward pixel detectors is a mosaic of 672 silicon sensors, robust electronics and bundles of cables and optical fibers that feed electricity and instructions in and carry raw data out, according to Marco Verzocchi, a Fermilab researcher on the CMS experiment.

    The multipart, 6.5-meter-long pixel detector is as delicate as raw spaghetti. Installing the new components into a gap the size of a manhole required more than just finesse. It required months of planning and extreme coordination.

    “We practiced this installation on mock-ups of our detector many times,” says Greg Derylo, an engineer at Fermilab. “By the time we got to the actual installation, we knew exactly how we needed to slide this new component into the heart of CMS.”

    The most difficult part was maneuvering the delicate components around the pre-existing structures inside the CMS experiment.

    “In total, the full three-part pixel detector consists of six separate segments, which fit together like a three-dimensional cylindrical puzzle around the beam pipe,” says Stephanie Timpone, a Fermilab engineer. “Inserting the pieces in the right positions and right order without touching any of the pre-existing supports and protections was a well-choreographed dance.”

    For engineers like Timpone and Derylo, installing the pixel detector was the last step of a six-year process. But for the scientists working on the CMS experiment, it was just the beginning.

    “Now we have to make it work,” says Stefanos Leontsinis, a postdoctoral researcher at the University of Colorado, Boulder. “We’ll spend the next several weeks testing the components and preparing for the LHC restart.”

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 2:48 pm on January 5, 2017 Permalink | Reply
    Tags: , , CERN CMS, , , , , ,   

    From Symmetry: “Anything to declare?” A Really Cool Article by Sarah Charley 

    Symmetry Mag
    Symmetry

    01/05/17
    Sarah Charley

    1
    A scientist at CERN removes a delicate half-disk of pixels from its custom-made box. The box was designed to fit snugly in an airplane seat. Photo courtesy of John Conway

    John Conway knows the exact width of airplane aisles (15 inches). He also personally knows the Transportation Security Administration operations manager at Chicago’s O’Hare Airport. That’s because Conway has spent the last decade transporting extremely sensitive detector equipment in commercial airline cabins.

    “We have a long history of shipping particle detectors through commercial carriers and having them arrive broken,” says Conway, who is a physicist at the University of California, Davis. “So in 2007 we decided to start carrying them ourselves. Our equipment is our baby, so who better to transport it than the people whose work depends on it?”

    Their instrument isn’t musical, but it’s just as fragile and irreplaceable as a vintage Italian cello, and it travels the same way. Members of the collaboration for the CMS experiment at CERN research center tested different approaches for shipping the instrument by embedding accelerometers in the packages. Their best method for safety and cost-effectiveness? Reserving a seat on the plane for the delicate cargo.

    CERN CMS Higgs Event
    CERN/CMS Detector
    CMS at CERN

    In November Conway accompanied parts of the new CMS pixel detector from the Department of Energy’s Fermi National Accelerator Laboratory [FNAL] in Chicago to CERN in Geneva. The pixels are very thin silicon chips mounted inside a long cylindrical tube. This new part will sit in the heart of the CMS experiment and record data from the high-energy particle collisions generated by the Large Hadron Collider [LHC].

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

    “It functions like the sensor inside a digital camera,” Conway said, “except it has 45 megapixels and takes 40 million pictures every second.”

    Scientists and engineers assembled and tested these delicate silicon disks at Fermilab before Conway and two colleagues escorted them to Geneva. The development and construction of the component pieces took place at Fermilab and universities around the United States.

    Conway and his colleagues reserved each custom-made container its own economy seat and then accompanied these precious packages through check-in, security and all the way to their final destination at CERN. And although these packages did not leave Fermilab through the shipping department, each carried its own official paperwork.

    “We’d get a lot of weird looks when rolling them onto the airplane,” Conway says. “One time the flight crew kept joking that we were transporting dinosaur eggs.”

    After four trips by three people across the Atlantic, all 12 components of the US-built pixel detectors are at CERN and ready for integration with their European counterparts. This winter the completed new pixel detector will replace its time-worn predecessor currently inside the CMS detector.

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 4:25 pm on December 6, 2016 Permalink | Reply
    Tags: 2016: an exceptional year for the LHC, , , , , CERN CMS, ,   

    From CERN: “2016: an exceptional year for the LHC” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    CERN

    6 Dec 2016
    Corinne Pralavorio

    1
    This proton-lead ion collision in the ATLAS detector produced a top quark – the heaviest quark – and its antiquark (Image: ATLAS)

    It’s the particles’ last lap of the ring. On 5 December 2016, protons and lead ions circulated in the Large Hadron Collider (LHC) for the last time. At exactly 6.02am, the experiments recorded their last collisions (also known as ‘events’).

    When the machines are turned off, the LHC operators take stock, and the resulting figures are astonishing.

    The number of collisions recorded by ATLAS and CMS during the proton run from April to the end of October was 60% higher than anticipated. Overall, all of the LHC experiments observed more than 6.5 million billion (6.5 x 1015) collisions, at an energy of 13 TeV. That equates to more data than had been collected in the previous three runs combined.

    3
    One of the first proton-lead ion collisions at 8.16 TeV recorded by the ALICE experiment. (Image: ALICE/CERN)

    In technical terms, the integrated luminosity received by ATLAS and CMS reached 40 inverse femtobarns (fb−1), compared with the 25fb−1 originally planned. Luminosity, which measures the number of potential collisions in a given time, is a crucial indicator of an accelerator’s performance.

    “One of the key factors contributing to this success was the remarkable availability of the LHC and its injectors,” explains Mike Lamont, who leads the team that operates the accelerators. The LHC’s overall availability in 2016 was just shy of 50%, which means the accelerator was in ‘collision mode’ 50% of the time: a very impressive achievement for the operators. “It’s the result of an ongoing programme of work over the last few years to consolidate and upgrade the machines and procedures,” Lamont continues.

    4
    An event recorded by the CMS experiment during the LHC’s proton-lead ion run for which no fewer than 449 particles tracks were reconstructed. (Image: CMS/CERN)

    For the last four weeks, the machine has turned to a different type of collision, where lead ions have been colliding with protons. “This is a new and complex operating mode, but the excellent functioning of the accelerators and the competence of the teams involved has allowed us to surpass our performance expectations,” says John Jowett, who is in charge of heavy-ion runs.

    With the machine running at an energy of 8.16 TeV, a record for this assymetric type of collision, the experiments have recorded more than 380 billion collisions. The machine achieved a peak luminosity over seven times higher than initially expected, as well as exceptional beam lifetimes. The performance is even more remarkable considering that colliding protons with lead ions, which have a mass 206 times greater and a charge 82 times higher, requires numerous painstaking adjustments to the machine.

    The physicists are now analysing the enormous amounts of data that have been collected, in preparation for presenting their results at the winter conferences.

    6
    A proton-lead ion collision recorded by the LHCb experiment in the last few days of the LHC’s 2016 run. (Image: LHCb)

    Meanwhile, CERN’s accelerators will take a long break, called the Extended Year End Technical Stop (EYETS) until the end of March 2017. But, while the accelerators might be on holiday, the technical teams certainly aren’t. The winter stop is an opportunity to carry out maintenance on these extremely complex machines, which are made up of thousands of components. The annual stop for the LHC is being extended by two months in 2017 to allow more major renovation work on the accelerator complex and its 35 kilometres of machines to take place. Particles will return to the LHC in spring 2017.

    7
    The integrated luminosity of the LHC with proton-proton collisions in 2016 compared to previous years. Luminosity is a measure of a collider’s efficiency and is proportional to the number of collisions. The integrated luminosity achieved by the LHC in 2016 far surpassed expectations and is double that achieved at a lower energy in 2012. (Image : CERN)

    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 II

    LHC

    CERN LHC Map
    CERN LHC Grand Tunnel

    CERN LHC particles

    Quantum Diaries

     
  • richardmitnick 10:59 am on November 4, 2016 Permalink | Reply
    Tags: , CERN CMS, , , The buzz from CMS   

    From FNAL: “The buzz from CMS” 

    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.

    November 4, 2016
    Vivan O’Dell

    CERN/CMS Detector
    CERN/CMS Detector

    The CMS experiment at CERN’s Large Hadron Collider is buzzing with activity.

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

    The first year of Run 2 is ending, and as we near the end of 2016, we have our work cut out for us.

    CMS is upgrading its inner tracking detector over the winter during a 21-week temporary halt of beams. We’re preparing for more upgrades during the second LHC long shutdown in 2018-19. We’re also finalizing designs for a major upgrade, targeting the 10-year running period from 2026-3035. CMS is like three experiments at once: one collecting and analyzing data, one in the final stages of building and installing, and one in the early design phase.

    The major upgrade, the High-Luminosity LHC upgrades, targets the detectors as well as the accelerator, and Fermilab has major responsibilities in both of these areas. Fermilab is the host lab for U.S. contributions to CMS and is home to the CMS HL-LHC upgrade project office. We are also a major player in the upgrades of tracking, calorimetry and trigger. These upgrades will allow CMS to run efficiently in a high-collision-rate and high-radiation environment.

    Last year, CERN officially approved the CMS and ATLAS detector upgrades to move from proposal phase to detailed technical designs, which is similar to a project “baselining” phase. This was followed in April with both NSF and DOE officially recognizing the U.S. contributions to the HL-LHC CMS upgrades: We received CD-0 approval for the detector upgrades from DOE and the official approval to move into the preliminary-design phase from NSF. The U.S. contributions to the accelerator also achieved CD-0 in April.

    The next year will be a busy year for the CMS HL-LHC upgrades: In the United States we are planning for DOE CD-1 in the fall and the NSF Preliminary Design Review at the end of the year. Internationally, CMS is working on delivering four detailed technical design reports, which cover all aspects of the upgrades, their costs, and the planned international contributions to build and maintain them. Luckily the sun never sets on the CMS collaboration, and the CMS Center at Fermilab offers unlimited espresso.

    Both upgrades, which will be installed over the next couple of years, will enable CMS to collect nearly 100 times more data at its current center-of-mass collision energy, which is roughly 14 TeV. That boost in data volume increases the potential for making significant discoveries of new phenomena to complete our understanding of particle physics and allows more precise measurements of Higgs boson properties and other tests of Standard Model processes.

    Vivian O’Dell is the U.S. CMS Phase II upgrade project manager.

    See the full article here .

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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 11:47 am on October 17, 2016 Permalink | Reply
    Tags: , , CERN CMS, Dr Michel Della Negra, Dr Peter Jenni, , Sir Tejinder (Jim) Virdee, W.K.H. Panofsky Prize   

    From ICL: “Fathers of Higgs boson detectors awarded particle physics prize” 

    Imperial College London
    Imperial College London

    17 October 2016
    Hayley Dunning

    1
    Professor Sir Tejinder Virdee (L) and Dr Michel DellaNegra (R)

    2
    Dr Peter Jenni

    Two Imperial physicists share in a prize for experimental physics for their work masterminding the CMS and ATLAS experiments

    The W.K.H. Panofsky Prize in Experimental Particle Physics, awarded by the American Physical Society, has this year been given to three scientists, “For distinguished leadership in the conception, design, and construction of the ATLAS and CMS detectors, which were instrumental in the discovery of the Higgs boson.”

    Receiving the honours are Professor Sir Tejinder (Jim) Virdee FRS from the Department of Physics at Imperial, Dr Michel Della Negra from CERN, who is also a Distinguished Research Fellow at Imperial, and Dr Peter Jenni from CERN and Albert-Ludwigs-University Freiburg.

    In July 2012, scientists using the Compact Muon Solenoid (CMS) and A Toroidal LHC Apparatus (ATLAS) experiments operating at the Large Hadron Collider (LHC) at CERN announced the discovery of the Higgs boson.

    CERN/CMS Detector
    CERN/CMS Detector

    CERN CMS Higgs Event
    CERN CMS Higgs Event

    CERN/ATLAS detector
    CERN/ATLAS detector

    CERN ATLAS Higgs Event
    CERN ATLAS Higgs Event

    This new particle, whose associated field gives mass to the fundamental particles, is the last missing link of the Standard Model of particle physics.

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

    Professor Jordan Nash, head of the Department of Physics at Imperial, said: “I’m delighted to see that Jim and Michel have been awarded this year’s Panofsky prize. Their dedication for more than two decades to the design, construction, and operation of the CMS detector has been essential to enabling the wonderful science and discoveries we have seen at the LHC.”

    Hayley Dunning talked to Professor Virdee about his latest award, chasing the Higgs and the future of the Large Hadron Collider.

    You’ve won a few prizes for your work – how does it feel to win the W.K.H. Panofsky Prize?

    It is a great honour to receive this prize and it is particularly pleasing to get this recognition from our peers. Even though the past 25 years have been long and not without many difficulties, it has nevertheless led to a fantastic result for all of us at the LHC – the discovery of the Higgs boson.

    This award is also acknowledgement of the huge experimental effort that led to the discovery of the Higgs boson. This wouldn’t have been possible without the contributions of thousands of scientists and engineers from around the world. On a personal note, I have enjoyed the enormous support of my exceptional colleagues at Imperial as well as the many others in the CMS Collaboration.

    What attracted you to particle physics and big experiments like the LHC?

    Particle physics is a modern-day name for the centuries-old effort to understand the fundamental laws of nature. I was intrigued to find out more: how nature really works at the most fundamental level, and I’ve always felt that this has to be one of the most exciting of human endeavours.

    Particle physicists didn’t really set out to do ‘big’ experiments. I, like my colleagues, were not attracted by the magnitude of the experiment, but by the magnitude and importance of the questions for which we were searching answers. CMS has the size it has due to the huge power of its ‘microscope’ to examine physics at the smallest distance scales offered for study by the highest accelerator energy so far achieved.

    And this can be seen in the history of this endeavour: twenty-five years ago, we started CMS with a handful of physicists and engineers. The enormity of the detectors that were necessary to answer these enormous questions meant that the collective talents and resources of a worldwide effort would be necessary. Now, CMS has over 3,000 scientists and engineers and involves 40 countries.

    Did you always believe you would be able to find the Higgs boson with CMS and ATLAS?

    In retrospect, and not overlooking the open mind that we all physicists have to have, I did believe, that if the Higgs boson were a true constituent particle of nature, we would find it sooner or later at the LHC. It has to be remembered that mass is a fundamental attribute of fundamental particles and is what gives our universe substance.

    At the time of conception of the CMS detector, a few of us paid particular attention to conjectures that suggested the mass of the Higgs boson could lie in the range where, years later, in 2012, it was eventually found. In this range the electromagnetic calorimeter, which I pioneered, played a vital role. Similarly, other parts of CMS were conceived, designed and constructed so as to ensure that the Higgs boson would be found if it were at other masses.

    Luckily, it turned out that the Higgs boson is a choice of nature. What was less of a stroke of luck is that we found it – given that it is a real element of nature.

    What are you working on now, and what do you hope for the future of the LHC experiments?

    My current work involves the in-depth study of the properties of the newly found Higgs boson, the search for widely anticipated physics beyond the Standard Model, and the design of the upgrades to the CMS detector for very high luminosity (implying very high proton-proton interaction rate) LHC running, due to start in the mid-2020s.

    In the context of this upgrade, a year or so ago I began another exciting project to develop a novel technique to replace a part of CMS. The goal is to increase the physics reach of the next phase of the LHC and take us into the 2030s. In 2015 I was awarded an EU-ERC Advanced grant to carry out the research, development and prototyping of this novel project.

    See the full article here .

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    Imperial College London

    Imperial College London is a science-based university with an international reputation for excellence in teaching and research. Consistently rated amongst the world’s best universities, Imperial is committed to developing the next generation of researchers, scientists and academics through collaboration across disciplines. Located in the heart of London, Imperial is a multidisciplinary space for education, research, translation and commercialisation, harnessing science and innovation to tackle global challenges.

     
  • richardmitnick 8:00 am on October 8, 2016 Permalink | Reply
    Tags: , CERN CMS, , , , ,   

    From Don Lincoln at FNAL: “Eight is enough” 

    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.

    October 7, 2016

    FNAL Don Lincoln
    Don Lincoln

    1
    In the search for new physics, no stone can be left unturned. In this analysis, scientists looked for a new particle that underwent a cascade of decays, resulting in eight distinct particles. No image credit.

    While the LHC was built for many purposes, one of the key reasons it was created was to investigate the most energetic collisions possible. The basic idea is that high-energy collisions have the best chance of unveiling phenomena never before observed.

    In particle physics, low-energy things happen all the time, while high-energy things are extremely rare. To give a sense of scale, the lowest-energy collisions that we study occur about a billion times more often than the highest-energy collisions we can create.

    Now if you want to study very high-energy things, you want to use the strongest force available to you. That’s because a strong force makes many collisions, and if you make many collisions, you are more likely to see the rare and very high-energy type of event you are looking for. In particle physics terminology, that means that you need to use events that use the strong nuclear force.

    That works out as a good strategy at the LHC because the LHC collides protons together, and protons are full of quarks and gluons, both of which interact via the strong force. The basic idea is that a quark or gluon from one proton will interact with a quark or gluon from the other proton, merge into some new and undiscovered particle, and then decay and be observed in the detector. Now the CMS experiment has already looked into the case where this new particle decayed directly into two ordinary particles.

    CERN/CMS Detector
    CERN/CMS Detector

    It has also looked into the case where the new particle decayed into two new (but different) particles that then each decayed into two ordinary particles. In this scenario, there would be four ordinary particles hitting the detector. Neither of these analyses led to the discovery of new physics.

    However, there is no reason that these should be the only two possible scenarios. It could be that LHC collisions would make one new particle, which then decayed into two new but lower-mass particles, each of which subsequently decayed into two more new and even lighter particles, resulting in four, which each finally decayed into two ordinary particles, producing eight. Thus the CMS experiment went looking for events in which eight ordinary particles simultaneously hit the detector.

    CMS was searching for particles called “jets,” which are actually collections of even more particles, but we can use algorithms to reduce a jet to looking like a single particle. So they were looking for events that produced eight jets.

    So far so good. The problem with this analysis arises because, even without new physics, the strong nuclear force makes lots of events in which there are eight or more jets, so it is pretty hard to identify events with eight jets that are made by new physics. But there is one saving grace. The collisions in which eight jets are made by ordinary physics have the same basic distribution of total energy as the ones in which only two jets are made. So they use the well-understood two-jet data to make predictions of eight-jet data and then compare it to the measurements all eight-jet data. If too many eight-jet events are found, then maybe they’ve made a discovery.

    Sadly, no excess was found. But this was a clever technique and one that might well be worth pursuing in the future. The most recent paper was for data recorded at a collision energy of eight trillion electronvolts of energy (back in 2012), and we’ve recorded data with 13 trillion electronvolts. Maybe with the new data, this technique will lead to a different result.

    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 5:31 pm on September 15, 2016 Permalink | Reply
    Tags: , CERN CMS, , Pixel detector, U.S. CMS FPIX team   

    From FNAL: “The world’s latest (and greatest) pixel detector” 

    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.

    September 14, 2016
    Steve Nahn

    This article, and the work it represents, is dedicated to our dear friend and colleague Gino Bolla.

    There’s a new pixel detector in the world, and it’s one of our own.

    1
    This close-up shows three disks in one half cylinder, a quarter of the full FPIX detector.

    The Forward Pixel detector, part of the CMS Phase 1 upgrade, is taking shape out at SiDet. The new device lies at the heart of the CMS detector, providing micron-scale resolution on charged particle trajectories, which in turn provides precision position measurements of the proton-proton collisions. This detector is composed of 672 modules, each of which has 16 readout chips. Each chip reads out the signal from charge deposited on one of an array of 52×80 pixels.

    That means nearly 45 million pixels to sample at 100 kHz, the nominal trigger rate of CMS. The modules are mounted onto inner and outer custom carbon fiber “half-disks,” and three inner-outer pairs are mounted in the custom carbon fiber support structure, called a “half-cylinder.” The half-cylinder also brings the innovative dual-phase carbon dioxide cooling fluid and power to the half-disks and carries the data away via optical fibers.

    In addition to the physical detector, there are also the external components, such as the power supply and interlock system and the Data Acquisition system. To say it is a complex apparatus is a rather gross understatement. Though it is based on the original detector, this version supplies an extra layer of tracking with less mass and is more capable of handling the increased instantaneous luminosity expected in LHC Run 2 and Run 3, which will bring us up to 2023.

    Over the last three years, the U.S. CMS FPIX team, including contributions from 21 institutions, has designed, prototyped, extensively tested, and fabricated the detector components. They are in the last stages of assembly and on time for installation during the upcoming winter technical stop of the LHC. The entire enterprise exploited the unique strengths of this dispersed team. For example, the sensors were procured by the University of Kansas; the data-concentrator ASIC was designed by Rutgers University; the modules were assembled at Purdue University and the University of Nebraska and tested by x-ray exposure at Kansas State University and the University of Illinois-Chicago.

    Kansas State, Vanderbilt University, the University of Mississippi and Cornell University are developing data acquisition and control systems, while Fermilab has focused on mechanical structure, microelectronics and integration. And right now it is all coming together at SiDet.

    Over the past six months, modules have been arriving at SiDet, where a small army of students, postdocs, faculty (and even a project manager, when they let him) have been testing the modules at 17 degrees and at -20 degrees Celsius. In parallel a team of talented technicians and engineers has been assembling the mechanical structure. It hasn’t been without hiccups, notably the initially low yield of modules due to splinters (from cutting up wafers) damaging readout chips and the discovery of a whole new (to us, anyway) potential failure mode. This mode, known as “hot cracking,” is when impurities in the small stainless steel tubing spread out around stress lines during the molten cooling phase of laser welding, forming cracks only a handful of microns wide but several hundred long, which initially withstand pressure testing but may fail after extended thermal cycling.

    However, due to the dedication and talents of the teams involved, these problems have been overcome. We are well on the way to sending this new detector to CERN. If you have time, you should head out to SiDet to see it before it goes and gets buried deep in the heart of CMS, but you’ll have to hurry! The first of four half-cylinders complete with modules has been tested and is at CERN already, with the second one following this week, and the third and fourth within the next few weeks. Look for one of the people in the photo above, who will be happy to show you the fruits of their labor.

    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 4:00 pm on June 29, 2016 Permalink | Reply
    Tags: , CERN CMS, , , , , , Tetraquarks? For real?   

    From Symmetry: “LHCb discovers family of tetraquarks” 

    Symmetry Mag

    Symmetry

    06/29/16
    Sarah Charley

    1
    LHCb. Courtesy of CERN

    Researchers found four new particles made of the same four building blocks.

    It’s quadruplets! Syracuse University researchers on the LHCb experiment confirmed the existence of a new four-quark particle and serendipitously discovered three of its siblings.

    Quarks are the solid scaffolding inside composite particles like protons and neutrons. Normally quarks come in pairs of two or three, but in 2014 LHCb researchers confirmed the existence four-quark particles and, one year later, five-quark particles.

    The particles in this new family were named based on their respective masses, denoted in mega-electronvolts: X(4140), X(4274), X(4500) and X(4700). Each particle contains two charm quarks and two strange quarks arranged in a unique way, making them the first four-quark particles composed entirely of heavy quarks. Researchers also measured each particle’s quantum numbers, which describe their subatomic properties. Theorists will use these new measurements to enhance their understanding of the formation of particles and the fundamental structures of matter.

    “What we have discovered is a unique system,” says Tomasz Skwarnicki, a physics professor at Syracuse University. “We have four exotic particles of the same type; it’s the first time we have seen this and this discovery is already helping us distinguish between the theoretical models.”

    Evidence of the lightest particle in this family of four and a hint of another were first seen by the CDF experiment at the US Department of Energy’s Fermi National Accelerator Lab in 2009.

    FNAL/Tevatron CDF detector
    FNAL/Tevatron machine
    FNAL/Tevatron map
    CDF; Tevatron; Tevtron map

    However, other experiments were unable to confirm this observation until 2012, when the CMS experiment at CERN reported seeing the same particle-like bumps with a much greater statistical certainty.

    CERN/CMS Detector
    CERN/CMS Detector

    Later, the D0 collaboration at Fermilab also reported another observation of this particle.

    FNAL/Tevatron DZero detector
    D0/FNAL

    “It was a long road to get here,” says University of Iowa physicist Kai Yi, who works on both the CDF and CMS experiments. “This has been a collective effort by many complementary experiments. I’m very happy that LHCb has now reconfirmed this particle’s existence and measured its quantum numbers.”

    The US contribution to the LHCb experiment is funded by the National Science Foundation.

    LHCb researcher Thomas Britton performed this analysis as his PhD thesis at Syracuse University.

    “When I first saw the structures jumping out of the data, little did I know this analysis would be such an aporetic saga,” Britton says. “We looked at every known particle and process to make sure these four structures couldn’t be explained by any pre-existing physics. It was like baking a six-dimensional cake with 98 ingredients and no recipe—just a picture of a cake.”

    Even though the four new particles all contain the same quark composition, they each have a unique internal structure, mass and their own sets of quantum numbers. These characteristics are determined by the internal spatial configurations of the quarks.

    “The quarks inside these particles behave like electrons inside atoms,” Skwarnicki says. “They can be ‘excited’ and jump into higher energy orbitals. The energy configuration of the quarks gives each particle its unique mass and identity.”

    According to theoretical predictions, the quarks inside could be tightly bound (like three quarks packed inside a single proton) or loosely bound (like two atoms forming a molecule.) By closely examining each particle’s quantum numbers, scientists were able to narrow down the possible structures.

    “The molecular explanation does not fit with the data,” Skwarnicki says. “But I personally would not conclude that these are definitely tightly bound states of four quarks. It could be possible that these are not even particles. The result could show the complex interplays of known particle pairs flippantly changing their identities.”

    Theorists are currently working on models to explain these new results—be it a family of four new particles or bizarre ripple effects from known particles. Either way, this study will help shape our understanding of the subatomic universe.

    “The huge amount of data generated by the LHC is enabling a resurgence in searches for exotic particles and rare physical phenomena,” Britton says. “There’s so many possible things for us to find and I’m happy to be a part of it.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
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