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  • richardmitnick 12:58 pm on January 15, 2019 Permalink | Reply
    Tags: , , , , HEP, ,   

    From CERN: “International collaboration publishes concept design for a post-LHC future circular collider at CERN” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    15 January, 2019

    1
    The proposed layout of the future circular collider (Image: CERN)

    Today, the Future Circular Collider (FCC) collaboration submitted its Conceptual Design Report (CDR) for publication, a four-volume document that presents the different options for a large circular collider of the future. It showcases the great physics opportunities offered by machines of unprecedented energy and intensity and describes the technical challenges, cost and schedule for realisation.

    Over the next two years, the particle physics community will be updating the European Strategy for Particle Physics, outlining the future of the discipline beyond the horizon of the Large Hadron Collider (LHC). The roadmap for the future should, in particular, lead to crucial choices for research and development in the coming years, ultimately with a view to building the particle accelerator that will succeed the LHC and will be able to significantly expand our knowledge of matter and the universe. The new CDR contributes to the European Strategy. The possibility of a future circular collider will be examined during the strategy process, together with the other post-LHC collider option at CERN, the CLIC linear collider.

    The FCC study started in 2014 and stems directly from the previous update of the European Strategy, approved in May 2013, which recommended that design and feasibility studies be conducted in order for Europe “to be in a position to propose an ambitious post-LHC accelerator project at CERN by the time of the next Strategy update”. The FCC would provide electron-positron, proton-proton and ion-ion collisions at unprecedented energies and intensities, with the possibility of electron-proton and electron-ion collisions.

    “The FCC conceptual design report is a remarkable accomplishment. It shows the tremendous potential of the FCC to improve our knowledge of fundamental physics and to advance many technologies with a broad impact on society”, said CERN Director-General Fabiola Gianotti. “While presenting new, daunting challenges, the FCC would greatly benefit from CERN’s expertise, accelerator complex and infrastructures, which have been developed over more than half a century.”

    The discovery of the Higgs boson at the LHC opened a new path for research, as the Higgs boson could be a door into new physics. Detailed studies of its properties are therefore a priority for any future high-energy physics accelerator. The different options explored by the FCC study offer unique opportunities to study the nature of the Higgs boson. In addition, experimental evidence requires physics beyond the Standard Model to account for observations such as dark matter and the domination of matter over antimatter. The search for new physics, for which a future circular collider would have a vast discovery potential, is therefore of paramount importance to making significant progress in our understanding of the universe.

    The FCC design study was a huge effort, possible only thanks to a large international collaboration. Over five years and with the strong support of the European Commission through the Horizon 2020 programme, the FCC collaboration involved more than 1300 contributors from 150 universities, research institutes and industrial partners who actively participated in the design effort and the R&D of new technologies to prepare for the sustainable deployment and efficient operation of a possible future circular collider.


    (Video: CERN)

    “The FCC’s ultimate goal is to provide a 100-kilometre superconducting proton accelerator ring, with an energy of up to 100 TeV, meaning an order of magnitude more powerful than the LHC”, said CERN Director for Accelerators and Technology, Frédérick Bordry. “The FCC timeline foresees starting with an electron-positron machine, just as LEP preceded the LHC. This would enable a rich programme to benefit the particle physics community throughout the twenty-first century.”

    Using new-generation high-field superconducting magnets, the FCC proton collider would offer a wide range of new physics opportunities. Reaching energies of 100 TeV and beyond would allow precise studies of how a Higgs particle interacts with another Higgs particle, and thorough exploration of the role of the electroweak-symmetry breaking in the history of our universe. It would also allow us to access unprecedented energy scales, looking for new massive particles, with multiple opportunities for great discoveries. In addition, it would also collide heavy ions, sustaining a rich heavy-ion physics programme to study the state of matter in the early universe.

    “Proton colliders have been the tool-of-choice for generations to venture new physics at the smallest scale. A large proton collider would present a leap forward in this exploration and decisively extend the physics programme beyond results provided by the LHC and a possible electron-positron collider.” said CERN Director for Research and Computing, Eckhard Elsen.

    A 90-to-365-GeV electron-positron machine with high luminosity could be a first step. Such a collider would be a very powerful “Higgs factory”, making it possible to detect new, rare processes and measure the known particles with precisions never achieved before. These precise measurements would provide great sensitivity to possible tiny deviations from the Standard Model expectations, which would be a sign of new physics.

    The cost of a large circular electron-positron collider would be in the 9-billion-euro range, including 5 billion euros for the civil engineering work for a 100-kilometre tunnel. This collider would serve the worldwide physics community for 15 to 20 years. The physics programme could start by 2040 at the end of the High-Luminosity LHC. The cost estimate for a superconducting proton machine that would afterwards use the same tunnel is around 15 billion euros. This machine could start operation in the late 2050s.

    The complex instruments required for particle physics inspire new concepts, innovation and groundbreaking technologies, which benefit other research disciplines and eventually find their way into many applications that have a significant impact on the knowledge economy and society. A future circular collider would offer extraordinary opportunities for industry, helping to push the limits of technology further. It would also provide exceptional training for a new generation of researchers and engineers.

    CDR to be publicly available here: https://cern.ch/fcc-cdr
    Photos: https://cds.cern.ch/ record/2653532
    Background information: https://cern.ch/fcc-cdr/webkit
    More information: https://cern.ch/fcc

    See the full article here.


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    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New
    ALICE

    CERN/ALICE Detector


    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

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  • richardmitnick 1:01 pm on December 25, 2018 Permalink | Reply
    Tags: "United States and France express interest to collaborate on construction of superconducting particle accelerator at Fermilab and the Deep Underground Neutrino Experiment, , , , HEP, , ,   

    From Fermi National Accelerator Lab: “United States and France express interest to collaborate on construction of superconducting particle accelerator at Fermilab and the Deep Underground Neutrino Experiment” 

    FNAL II photo

    FNAL Art Image
    FNAL Art Image by Angela Gonzales

    From Fermi National Accelerator Lab , an enduring source of strength for the US contribution to scientific research world wide.

    December 19, 2018

    The U.S. Department of Energy (DOE), the French Atomic Energy Commission (CEA) and the French National Center for Scientific Research (CNRS) have signed statements this month expressing interest to collaborate on high-tech international particle physics projects that are planned to be hosted at DOE’s Fermi National Accelerator Laboratory.

    The three agencies indicated plans to work together on the development and production of technical components for PIP-II (Proton Improvement Plan-II), a major DOE particle accelerator project with substantial international contributions. In addition, CNRS and CEA also plan to collaborate on the construction of the Fermilab-hosted Deep Underground Neutrino Experiment (DUNE), an international flagship science project that will unlock the mysteries of neutrinos — subatomic particles that travel close to the speed of light and have almost no mass.

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    DOE Undersecretary for Science Paul Dabbar (left) and Vincent Berger, Director of Fundamental Research at the CEA, at the signing ceremony in France on Dec. 11. The signing with CNRS took place on Dec. 19.

    The construction of a 176-meter-long superconducting particle accelerator is the centerpiece of the PIP-II project. The new accelerator upgrade will become the heart of the Fermilab accelerator complex and provide the proton beam to power a broad program of accelerator-based particle physics research for many decades to come. In particular, PIP-II will enable the world’s most powerful high-energy neutrino beam to power DUNE. The experiment requires enormous quantities of neutrinos to discover the role these particles played in the formation of the early universe. The first delivery of particle beams to DUNE is scheduled for 2026.

    “The collaboration on PIP-II and DUNE is a win-win situation for France and the U.S. Department of Energy,” said DOE Undersecretary for Science Paul Dabbar. “Scientists in France and the United States have a wealth of experience building components for superconducting particle accelerators and are contributing substantially to developing key technologies for DUNE. France’s expression of interest brings into the fold for the projects a partnership that has already seen great interest and contributions from across the globe.”

    Two French institutions — the departments of the Institute of Research into the Fundamental Laws of the Universe (Irfu), part of the French Atomic Energy Commission, and the CNRS IN2P3 laboratories: Institute of Nuclear Physics (IPN) and Linear Accelerator Laboratory (LAL) — are expected to build components for PIP-II. They both have extensive experience in the development of superconducting radio-frequency acceleration, which is the enabling technology for PIP-II, and are contributors to two major superconducting particle accelerator projects in Europe: the X-ray Free Electron Laser (XFEL) and the (ESS).


    European XFEL campus

    ESS European Spallation Source, currently under construction in Lund, Sweden.

    “For IN2P3, the DUNE experiment is of major scientific interest for the next decade, and this interest naturally extends to the PIP-II project, which actually aligns perfectly well with our experience on superconducting linac technologies,” said IN2P3 Director Reynald Pain. “Our scientific and technical teams are very excited to start this collaboration.”

    At the heart of the PIP-II project is the construction of an 800-million-electronvolt superconducting linear accelerator. The new accelerator will feature acceleration cavities made of niobium and double the beam energy of its predecessor. That boost will enable the Fermilab accelerator complex to achieve megawatt-scale proton beam power.

    “Irfu physicists are strongly involved in neutrino physics,” said Vincent Berger, Director of Fundamental Research at the CEA. “In this field, the DUNE experiment is particularly promising. In that context, contributing to the PIP-II project would be very interesting for our accelerator teams, who have strong experience in superconducting linacs. Our first discussions with Fermilab staff have been very stimulating.”

    In addition to France, other international partners are making significant contributions to PIP-II: India, the United Kingdom and Italy. DOE’s Argonne and Lawrence Berkeley National laboratories are also contributing key components to the project.

    France brings world-leading expertise and capabilities to the PIP-II project,” said PIP-II Project Director Lia Merminga. “It is a tremendous opportunity and honor to work with them and apply their demonstrated excellence to our project.”

    French scientists also plan to contribute to building the DUNE detector, a massive stadium-sized neutrino detector that will be located 1.5 kilometers underground at Sanford Underground Research Facility in South Dakota. Construction of prototype detectors are currently under way at the European Organization for Nuclear Research (CERN), the European particle physics laboratory located near the French-Swiss border. These prototypes include key contributions from French institutions in developing the dual-phase technology for one of the two ProtoDUNE detectors.

    “French scientists were among the founders of the DUNE experiment,” said Ed Blucher, DUNE collaboration co-spokesperson and professor at the University of Chicago. “Their enormous experience in detector and electronics development will be crucial to successful construction of the DUNE detectors.”

    See the full article here .


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    FNAL Icon

    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.


    FNAL/MINERvA

    FNAL DAMIC

    FNAL Muon g-2 studio

    FNAL Short-Baseline Near Detector under construction

    FNAL Mu2e solenoid

    Dark Energy Camera [DECam], built at FNAL

    FNAL DUNE Argon tank at SURF

    FNAL/MicrobooNE

    FNAL Don Lincoln

    FNAL/MINOS

    FNAL Cryomodule Testing Facility

    FNAL Minos Far Detector

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

    FNAL/NOvA experiment map

    FNAL NOvA Near Detector

    FNAL ICARUS

    FNAL Holometer

     
  • richardmitnick 12:43 pm on December 25, 2018 Permalink | Reply
    Tags: A primer on neutrinoless double-beta decay, , HEP, , , , Particles and antiparticles, , The matter-antimatter conudrum   

    From Sanford Underground Research Facility: “A primer on neutrinoless double-beta decay” 

    SURF logo
    Sanford Underground levels

    From Sanford Underground Research Facility

    December 21, 2018
    Erin Broberg

    We asked Vincente Guiseppe about this theorized phenomenon and what it means for our understanding of the universe.

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    Vince Guiseppe points to the center of the shield that houses Majorana’s detectors. Credit Matthew Kapust

    At Sanford Underground Research Facility, we often talk about the Majorana Demonstrator’s search for “neutrinoless double-beta decay.”

    U Washington Majorana Demonstrator Experiment at SURF

    We say that this process could be incredibly important to understanding the imbalance of matter and anti-matter in the early universe. We explain how it is difficult to detect, demanding a miniscule background. We show photos of germanium detectors and ultra-pure copper shields, then describe immaculate cleanrooms and show off stylish Tyvek garb.

    But what exactly is neutrinoless double-beta decay?

    To find out, we went directly to the source. Dr. Vincente Guiseppe is the co-spokesperson for the Majorana Demonstrator collaboration and an assistant professor of physics and astronomy at the University of South Carolina.

    The best way to explain this mysterious process, Guiseppe said, is to work backward, defining one word at a time. So, let’s start at the end.

    Decay

    “There are two types of isotopes,” Guiseppe explains, “stable and radioactive.”

    The nuclei of a stable isotope are relaxed, meaning, they have a very low energy state. The nuclei of a radioactive isotope, on the other hand, are in a high energy state—they are very excited. But objects in nature prefer to be relaxed, Guiseppe said.

    So how do nuclei achieve a lower energy state? Through radioactive decay.

    “In nuclear physics, decay means a relaxation or a change of an atomic nucleus,” Guiseppe explained. “Nature allows protons and neutrons to change their makeup to achieve a desirable equilibrium. Once a nucleus is at the lowest energy state, we call it a stable isotope.”

    A lot of times, the words “radioactive decay” sound threatening. That’s because they often are used in the context of radiation you don’twant—radiation that is dangerous or destructive. In reality, though, radioactive decays are taking place all the time.

    “Potassium 40 is an isotope in our bodies,” said Guiseppe. “These isotopes decay 200,000 times per minute.”

    Radioactive decay is simply a nucleus reconfiguring itself through an interplay of matter and energy. Researchers with Majorana are looking for a natural process in which nuclei undergo such a change.

    Double-beta

    Every time an isotope decays, it loses a bit of energy in the form of a particle. Scientists classify types of decays by defining what type of particle comes out of the decay. In the case of beta decay, the particle emitted is an electron, or a beta particle.

    While there are multiple types of decays that could occur within the detector, Majorana researchers are looking specifically for a decay in which a beta particle is emitted.

    “And by ‘double-beta,’ we just mean we are looking for two of these decays simultaneously,” Guiseppe said.

    Neutrino(less)

    All reactions in nature, including beta decays, require symmetry, or a balance. Because of this symmetry, scientists originally assumed that every time an isotope underwent beta decay, it would emit an electron with a uniform energy. The problem was, it didn’t.

    “Electrons emitted from beta decays have a range of energies,” Guiseppe said. “Sometimes it is low, sometimes it is high, but it has this average value that was more or less half of what the scientists thought it should be.”

    This inconsistency lead researchers to realize that there must be another particle emitted—one that could not easily be detected, having no charge and very little mass. That missing particle was a neutrino.

    “When neutrinos were discovered in 1956, their addition to the beta-decay equation was confirmed,” said Guiseppe. “The neutrino balances this fundamental symmetry. With beta decay, there has to be both an electron and a neutrino produced.”

    Hold on a second. By definition, a beta decay must have an electron. By the laws of physics, it must have a neutrino. So why is Majorana looking for neutrinoless double-beta decay?

    “I just spent all this time explaining why you need a neutrino for a beta decay,” Guiseppe said with a smile. “And now, I’m going to say, no, you might not need a neutrino every time.”

    Scientists, Guiseppe said, have good reason to believe that neutrinos have the ability to do something very interesting—the ability to act like anti-neutrinos.

    Neutrinos — the maverick of the early universe

    To better understand the theory, we must first examine what is called the matter and antimatter asymmetry problem.

    According to the Big Bang theory, when the universe first formed, it had equal parts of matter and antimatter. This is a conundrum because, when matter and antimatter meet, they annihilate, leaving a universe filled with pure energy—no planets, stars or comets. And, most certainly, no life.

    So, what happened? Why did matter win out in the cosmic battle? Scientists are seeking an answer to how matter became the dominant form of matter in the universe.

    Many scientists believe there must have been a particle—very much like a neutrino—that acted very inconsistently with our current understanding of the laws of physics. This inconsistency, if detected, could answer the matter and anti-matter asymmetry puzzle. If just one particle acted differently, it could have upset the balance and allowed a remnant of matter to survive.

    For most particles, there exists matter and anti-matter. These types of matter are mirror images of each other—100 percent different. In the early 1930s, however, physicist Ettore Majorana theorized that neutrinos could be their own anti-particle—or what we call today, a Majorana particle.

    3
    Ettore Majorana

    “The claim is that maybe there’s no difference between neutrinos and what we call anti-neutrinos. They may be indistinguishable from each other,” said Guiseppe. “If they have that quality, it could help explain matter and antimatter asymmetry.”

    Neutrinoless double-beta decay — putting it all together

    If neutrinos have this property, it could answer a lot of questions for scientists; for example, how matter became the dominant form of matter in the universe, allowing for the creation of everything we see. But how might Majorana help discover it?

    Researchers are waiting for a double-beta decay to occur inside the Majorana Demonstrator. If it does, and if neutrinos can indeed act like their own antiparticle, then the two neutrinos necessary may interact, possibly being absorbed, making the double-beta decay seem neutrinoless.

    “If two beta decays occur in the Majorana Demonstrator, in close proximity to each other, and neutrinos do have this property, then we will detect the absence of neutrinos,” Guiseppe said.

    Should this rare event be detected, it will require rewriting the Standard Model of Particles and Interactions, our basic understanding of the physical world.

    “What isn’t up for debate,” Guiseppe concluded, “is that if neutrinos are indistinguishable from their anti-particle, then they will allow this neutrinoless double-beta decay process to take place. If they have this property, we will see the decay in Majorana. This is the best type of experiment we have to learn that.”

    See the full article here .


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    About us.
    The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.
    LUX/Dark matter experiment at SURFLUX/Dark matter experiment at SURF

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

    Fermilab LBNE
    LBNE

    U Washington Majorana Demonstrator Experiment at SURF

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

    LBNL LZ project at SURF, Lead, SD, USA

    CASPAR at SURF


    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 11:06 am on December 25, 2018 Permalink | Reply
    Tags: , , , HEP, , , , ,   

    From The New York Times: “It’s Intermission for the Large Hadron Collider” 

    New York Times

    From The New York Times

    This is a special Augmented reality production of the NYT. Please view the original full article to take advantage of the 360 degree images inside the LHC.

    DEC. 21, 2018
    Dennis Overbye

    The largest machine ever built is shutting down for two years of upgrades. Take an immersive tour of the collider and study the remnants of a Higgs particle in augmented reality.

    4

    CERN Control Center

    MEYRIN, Switzerland — There is silence on the subatomic firing range.

    A quarter-century ago, the physicists of CERN, the European Center for Nuclear Research, bet their careers and their political capital on the biggest and most expensive science experiment ever built, the Large Hadron Collider.

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New

    ALICE

    CERN/ALICE Detector

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    The collider is a kind of microscope that works by flinging subatomic particles around a 17-mile electromagnetic racetrack beneath the French-Swiss countryside, smashing them together 600 million times a second and sifting through the debris for new particles and forces of nature. The instrument is also a time machine, providing a glimpse of the physics that prevailed in the early moments of the universe and laid the foundation for the cosmos as we see it today.

    The reward came in 2012 with the discovery of the Higgs boson, a long-sought particle that helps explain why there is mass, diversity and life in the cosmos.

    CERN CMS Higgs Event

    CERN ATLAS Higgs Event

    The discovery was celebrated with champagne and a Nobel prize.

    The collider will continue smashing particles and expectations for another 20 years. But first, an intermission. On December 3rd, the particle beams stopped humming. The giant magnets that guide the whizzing protons sighed and released their grip. The underground detectors that ring the tunnel stood down from their watch.

    Over the next two years, during the first of what will be a series of shutdowns, engineers will upgrade the collider to make its beams more intense and its instruments more sensitive and discerning. And theoretical physicists will pause to make sense of the tantalizing, bewildering mysteries that the Large Hadron Collider has generated so far.

    When protons collide

    The collider gets its mojo from Einstein’s dictum that mass and energy are the same. The more energy that the collider can produce, the more massive are the particles created by the collisions. With every increase in the energy of their collider, CERN physicists are able to edge farther and farther back in time, closer to the physics of the Big Bang, when the universe was much hotter than today.

    Inside CERN’s subterranean ring, some 10,000 superconducting electromagnets, powered by a small city’s worth of electricity, guide two beams of protons in opposite directions around the tunnel at 99.99999 percent of the speed of light, or an energy of 7 trillion electron volts. Those protons make the 17-mile circuit 11,000 times a second. (In physics, mass and energy are both expressed in terms of units called electron volts. A single proton, the building block of ordinary atoms, weighs about a billion electron volts.)

    The protons enter the collider as atoms in a puff of hydrogen gas squirted from a bottle. As the atoms travel, electrical fields strip them of electrons, leaving bare, positively charged protons. These are sped up by a series of increasingly larger and more energetic electromagnets, until they are ready to enter the main ring of the collider.

    When protons finally enter the main ring, they have been boosted into flying bombs of primordial energy, primed to smash apart — and recombine — when they strike their opposite numbers head-on, coming from the other direction.

    The protons circulate inside vacuum pipes – one running clockwise, the other counterclockwise – and these are surrounded by superconducting electromagnets strung together around the tunnel like sausages. To generate enough force to bend the speeding protons, the magnets must be uncommonly strong: 8.3 Tesla, or more than a hundred thousand times stronger than Earth’s magnetic field — and more than strong enough to wreck a fancy Swiss watch.

    Such a field in turn requires an electrical current of 12,000 amperes. That’s only feasible if the magnets are superconducting, meaning that electricity flows without expensive resistance. For that to happen, the magnets must be supercold; they are bathed in 150 tons of superfluid helium at a temperature of 1.9 Kelvin, making the Large Hadron Collider literally one of the coldest places in the universe.

    If things go wrong down here, they can go very wrong. In 2008, as the collider was still being tuned up, the link between a pair of magnets exploded, delaying operations for almost two years.

    The energy stored in the magnetic fields is equivalent to a fully loaded jumbo jet going 500 miles per hour; if a magnet loses its cool and heats up, all that energy must go someplace. And the proton beam itself can cut through many feet of steel.

    A tale of four detectors

    The beams cross at four points around the racetrack.

    At each juncture, gigantic detectors — underground mountains of electronics, cables, computers, pipes, magnets and even more magnets — have been erected. The two biggest and most expensive experiments, CMS (the Compact Muon Solenoid) and Atlas (A Toroidal L.H.C. Apparatus) sit, respectively, at the noon and 6 o’clock positions of the circular track.

    Wrapped around them, like the layers of an onion, are instruments designed to measure every last spark of energy or matter that might spew from the collision. Silicon detectors track the paths of lightweight, charged particles such as electrons. Scintillation crystals capture the energies of gamma rays. Chambers of electrified gas track more far-flung particles. And powerful magnets bend the paths of these particles so that their charges and masses can be determined.

    The proton beams cross 40 million times per second in each of the four detectors, resulting in about a billion actual collisions every second.

    What’s the antimatter?

    Why is there something instead of nothing in the universe?

    Answering that question is the mission of the detector known as LHCb, which sits at about 4 o’clock on the collider dial. The “b” stands for beauty — and for the B meson, a subatomic particle that is crucial to the experiment.

    When matter is created — in a collider, in the Big Bang — equal amounts of matter and its opposite, antimatter, should be formed, according to the laws of physics As We Know Them. When matter and antimatter meet, they annihilate each other, producing energy.

    By that logic, when matter and antimatter formed in the Big Bang, they should have cancelled out each other, leaving behind an empty universe. But it’s not empty: We are here, and our antimatter is not.

    Why not? Physicists suspect that some subtle imbalance between matter and antimatter is responsible. The LHCb experiment looks for that imbalance in the behavior of B mesons, which are often sprayed from the proton collisions.

    B mesons have an exotic property: They flicker back and forth between being matter and antimatter. Sensors record their passage through the LHCb room, seeking differences between the particles and their antimatter twins. Any discrepancy between the two could be a clue to why matter flourished billions of years ago and antimatter perished.

    Turning back the cosmic clock

    At about 8 o’clock on the collider dial is Alice, another detector with a special purpose. It, too, is fixed on the distant past: the brief moment a couple of microseconds after the Big Bang, before the first protons and neutrons congealed out of a “primordial soup” of quarks and gluons.

    Alice’s job is to study tiny droplets of that distant past that are created when the collider bangs together lead ions instead of protons. Researchers expected this material, known in the lingo as a quark-gluon plasma, to behave like a gas, but it turns out to behave more like a liquid.

    Sifting the data

    The collider’s enormous detectors are like 100 megapixel cameras that take 40 million pictures a second. Most of the data from that deluge is immediately thrown away. Triggers, programmed to pick out events that physicists thought might be interesting, save only about a thousand collision events per second. Even still, an enormous pool of data winds up in the CERN computer banks.

    CERN DATA Center

    According to the casino rules of modern quantum physics, anything that can happen will happen eventually. Before a single proton is fired through the collider, computers have calculated all the possible outcomes of a collision according to known physics. Any unexpected bump in the real data at some energy could be a signal of unknown physics, a new particle.

    That was how the Higgs was discovered, emerging from the statistical noise in the autumn of 2011. Only one of every 10 billion collisions creates a Higgs boson. The Higgs vanishes instantly and can’t be observed directly, but it decays into fragments that can be measured and identified.

    What eventually stood out from the data was evidence for a particle that weighs all by itself as much as an iodine atom: a flake of an invisible force field that permeates space like molasses, impeding motion and assigning mass to objects that pass through it.

    And so in 2012, after half a century and billions of dollars, thousands of physicists toasted over champagne. Peter Higgs, for whom the elusive boson was named, shared the Nobel prize with François Englert, who had independently predicted the particle’s existence.

    Peter Higgs

    François Englert

    An intermission underground

    The current shutdown is the first of a pair of billion-dollar upgrades intended to boost the productivity of the Large Hadron Collider tenfold by the end of the decade.

    The first shutdown will last for two years, until 2021; during that time, engineers will improve the series of smaller racetracks that speed up protons and inject them into the main collider. The collider then will run for two years and shut down again, in 2024, for two more years, so that engineers can install new magnets to intensify the proton beams and collisions.

    Reincarnated in 2026 as the High Luminosity L.H.C., the collider is scheduled to run for another decade, until 2035 or so, which means its career probing the edge of human knowledge is still beginning.

    Judging by the collider’s productivity, measured in terms of trillions of subatomic smashups, more than 95 percent of its scientific potential lies ahead.

    Both the Atlas and CMS experiments will receive major upgrades during the next two shutdowns, including new silicon trackers, to replace the olds ones burned out by radiation.

    To keep up with the increased collision rate, both Atlas and CMS have had to upgrade the finicky trigger systems that decide which collision events to keep and study. Currently, of a billion events per second, they can keep 1,500; the upgrade will raise that figure to 10,000.

    And what a flow of collisions it will be. Physicists measure the productivity, or luminosity, of their colliders in terms of collisions. It took about 3,000 trillion collisions to confirm the Higgs boson. As of the December shutdown the collider had logged about 20,000 trillion collisions. But those were, and are, early days.

    By 2037, the Large Hadron Collider should have produced roughly 4 million trillion primordial fireballs, bristling with who knows what. The whole universe is still up for grabs.

    After the Higgs

    Discovering the Higgs was an auspicious start. But the champagne came with a mystery.

    Over the last century, physicists have learned to explain some of the grandest and subtlest phenomena in nature — the arc of a rainbow, the scent of a gardenia, the twitch of a cat’s whiskers — as a handful of elementary particles interacting through four basic forces, playing a game of catch with force-carrying particles called bosons according to a set of equations called the Standard Model.

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

    But why these particles and these forces? Why is the universe made of matter but not antimatter? What happens at the center of a black hole, or happened at the first instant of the Big Bang? If the Higgs boson determines the masses of particles, what determines the mass of the Higgs?

    Who, in other words, watches the watchman?

    The Standard Model, for all its brilliance and elegance, does not say. Particles that might answer these questions have not shown up yet in the collider. Fabiola Gianotti, the director-general of CERN, expressed surprise. “I would have expected new physics to manifest itself at the energy scale of the Large Hadron Collider,” she said.

    Some physicists have responded by speculating about multiple universes and other exotic phenomena. Some clues, Dr. Gianotti said, might come from studying the new particle on the block, the Higgs.

    “We physicists are happy when we understand things, but we are even happier when we don’t understand,” she said. “And today we know that we don’t understand everything. We know that we are missing something important and fundamental. And this is very exciting.”

    Colliders of tomorrow

    Humans soon must decide which machines, if any, will be built to augment or replace the Large Hadron Collider. That collider had a “killer app” of sorts: it was designed to achieve an energy at which, according to the prediction of the Standard Model, the Higgs or something like it would become evident and provide an explanation for particle masses.

    But the Standard Model doesn’t predict a new keystone particle in the next higher energy range. Luckily, nobody believes the Standard Model is the last word about the universe, but as the machines increase in energy, particle physicists will be shooting in the dark.

    For a long time, the leading candidate for Next Big Physics Machine has been the International Linear Collider, which would fire electrons and their antimatter opposites, positrons, at each other.

    ILC schematic, being planned for the Kitakami highland, in the Iwate prefecture of northern Japan

    The collisions would produce showers of Higgs bosons. The experiment would be built in Japan, if it is built at all, but Japan has yet to commit to hosting the project, which would require them to pay for about half of the $5.5 billion cost- see https://sciencesprings.wordpress.com/2018/12/21/from-nature-via-ilc-plans-for-worlds-next-major-particle-collider-dealt-big-blow.

    In the meantime, Europe has convened meetings and workshops to decide on a plan for the future of particle physics there. “If there is no word from Japan by the end of the year, then the I.L.C. will not figure in the next five-year plan for Europe,” Lyn Evans, a CERN physicist who was in charge of building the Large Hadron Collider, said in an email.

    CERN has proposed its own version of a linear collider, the Compact Linear Collider, that could be scaled up gradually from Higgs bosons to higher energies. Also being considered is a humongous collider, 100 kilometers around, that would lie under Lake Geneva and would reach energies of 100 trillion electron volts — seven times the power of the Large Hadron Collider.

    Cern Compact Linear Collider

    CLC map

    CLC TWO-BEAM ACCELERATION TEST STAND

    And in November the Chinese Academy of Sciences released the design for a next-generation collider of similar size, called the Circular Electron Positron Collider.

    China Circular Electron Positron Collider (CEPC) map

    China Circular Electron-Positron collider depiction

    The machine could be the precursor for a still more powerful machine that has been dubbed the Great Collider. Politics and economics, as well as physics, will decide which, if any, of these machines will see a shovel.

    “If we want a new machine, nothing is possible before 2035,” Frederick Bordry, CERN’s director of accelerators, said of European plans. Building such a machine is a true human adventure, he said: “Twenty-five years to build and another 25 to operate.”

    Noting that he himself is 64, he added, “I’m working for the young people.”

    See the full article here .

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  • richardmitnick 10:22 am on December 21, 2018 Permalink | Reply
    Tags: , , HEP, , ,   

    From Nature via ILC: “Plans for world’s next major particle collider dealt big blow” 

    From ILC.

    19 December 2018
    Elizabeth Gibney

    Nature

    Plans to build a particle smasher in Japan to succeed the Large Hadron Collider have suffered a significant setback. An influential report by Japanese scientists concluded that they could not support plans to build the International Linear Collider (ILC) in the country.

    ILC schematic, being planned for the Kitakami highland, in the Iwate prefecture of northern Japan

    The facility has been decades in design and would study the Higgs boson, which was discovered in 2012 and is the last puzzle piece in particle physicists’ ‘standard model’.

    The discoveries predicted to come out of the ILC would not fully warrant its nearly US$7-billion cost, said a committee of the Science Council of Japan in a report released on 19 December, according to press reports. As host, Japan might be expected to pay as much as half of the total. The committee, which advises the government, added that uncertainty about whether international partners would share the project’s costs increased its concerns.

    The proposed accelerator — which would be more than 20 kilometres long — would enable physicists to detect the products of precise collisions between electrons and their antimatter counterparts, positrons.

    Government advice

    The government will now use the report, which reflects the views of the academic community in Japan and not just those of high-energy physicists, to guide its decision on whether to host the facility. A decision is expected by 7 March, when the international group overseeing the ILC’s development, the Linear Collider Board, meets in Tokyo.

    Physicists expressed concern at the committee’s conclusions. “This is very bad news, as this makes it very unlikely that the #ILC will be build in Japan — and probably at all,” tweeted Axel Maas, a theoretical physicist at the University of Graz in Austria.

    However, the committee did state that the scientific case for building the ILC was sound, says Hitoshi Yamamoto, a physicist at Tohoku University in Sendai and a member of the ILC collaboration. It also acknowledged that the collider is seen in the particle-physics community as the top priority among possible future projects, he adds.

    The project now needs some good news, says Yamamoto. With funding tight around the world, “the situation for the ILC is getting worse rapidly”, he says. “A positive announcement by the Japanese government will reverse the trend and suddenly bring the ILC as the top item on the table,” says Yamamoto.

    Any concern that other areas of science in Japan could suffer if the costly project goes ahead is understandable, says Brian Foster, a physicist at the University of Oxford, UK, and part of the team designing the facility. But he says the council’s pessimistic take does not necessarily mean the government will not support the project. “If the government wants to do it, it will,” he says.

    Sole nation

    Japan is the only nation so far to show interest in the collider, and a decision on whether it will host the facility is long overdue. Japanese physicists pitched to the international community to build the facility in Japan in 2012, after scientists at the LHC — based at CERN, Europe’s particle-physics lab near Geneva — discovered the Higgs boson, a particle involved in the mechanism by which all others get mass.

    Physicists wanted to use the new facility to study any phenomena that the LHC might discover. They know that the standard model is incomplete and hope that unknown higher-energy particles could help explain long-standing mysteries such as the nature of dark matter.

    But plans for the collider have stagnated because no nations have offered funding, and because of the LHC’s failure to find any new phenomena beyond the Higgs. In 2017 physicists scaled back their ambitions for the ILC, proposing a shorter, lower-energy design that would focus on the Higgs alone.

    To physicists, a ‘Higgs factory’ would still be hugely valuable. As electron and positrons are fundamental particles, their collisions would be cleaner than the proton–proton collisions at the LHC. By targeting collisions at the right energy, the planned collider would produce millions of Higgs bosons for studies that could reveal new physics indirectly, by exploring how the Higgs boson interacts with other known particles.

    Researchers in China, who recently proposed to build a 100-kilometre ring-shaped Higgs factory, will also examine the report carefully. They need funding from both Chinese and foreign governments to build the facility. Although particle physicists would like to see both experiments built, international partners are likely to fund only one Higgs factory. If the ILC receives the backing of the high energy physics community, that may shorten the odds on the Chinese collider being built, although the country could also go it alone.

    See the full article here .

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    The International Linear Collider (ILC) is a proposed linear particle accelerator.It is planned to have a collision energy of 500 GeV initially, with the possibility for a later upgrade to 1000 GeV (1 TeV). The host country for the accelerator has not yet been chosen and proposed locations are Japan, Europe (CERN) and the USA (Fermilab). Japan is considered the most likely candidate, as the Japanese government is willing to contribute half of the costs, according to a representative for the European Commission on Future Accelerators.Construction could begin in 2015 or 2016 and will not be completed before 2026.

     
  • richardmitnick 2:53 pm on December 20, 2018 Permalink | Reply
    Tags: , , HEP, , , , Preparing ATLAS for the future   

    From CERN ATLAS: “Preparing ATLAS for the future” 

    CERN ATLAS Higgs Event

    CERN/ATLAS
    From CERN ATLAS

    20th December 2018
    Katarina Anthony

    Long Shutdown 2 (LS2) of the Large Hadron Collider commenced last week, as the accelerator powered down and the entry to the ATLAS cavern opened wide. Over the next two years, teams from across the ATLAS Collaboration will be upgrading and consolidating their experiment. On the agenda: the refurbishments of key electronics, the maintenance of various detector components and – critically – the installation of new detectors.

    “We are at an important moment for the ATLAS experiment,” says Karl Jakobs, Spokesperson of the ATLAS collaboration. “On the one hand, we continue to maintain and consolidate detector elements that have served us well since the beginning of data taking in 2009. On the other, we are installing new electronics, trigger and detector components as a first step to prepare ATLAS for the High-Luminosity LHC (HL-LHC) in 2026.”

    The HL-LHC will collide beams at up to seven times the luminosity for which the ATLAS detector was designed, resulting in about 200 simultaneous collisions per beam crossing. This will greatly increase ATLAS’ potential to spot new or rare physics processes – but necessitates the development and installation of new detectors with radiation-hard elements, finer granularity and faster readout. In preparation of this, ATLAS has published six Technical Design Reports and one Technical Proposal over 2017-2018, describing the new designs and technologies needed to handle HL-LHC data. While most of these new systems will be installed during the next long shutdown (LS3, scheduled for 2024) – some will already see service in Run 3!

    Key among these is the installation of ATLAS’ 10-metre diametre New Small Wheels (NSW) – the largest and most critical project to be carried out during LS2, and the first major HL-LHC addition to the detector. Teams are currently finalising the construction of the new wheels, the first of which will be installed in 2020.

    3
    The mechanical structure of the New Small Wheel (Image: CERN)

    Meet Jamie, a Mechanical Engineering Technician at CERN who’s working on the ATLAS experiment.

    “The New Small Wheels employ two detector technologies: small-strip Thin Gap Chambers (sTGC) and Micromegas. Both are able to withstand the higher flux of neutrons and photons expected in future LHC interactions, which will produce counting rates as high as 20,000 per second per square centimetre in the inner part of the NSW,” says Ludovico Pontecorvo, ATLAS Technical Coordinator. “Furthermore, these new technologies will greatly improve the ATLAS muon trigger capabilities, allowing for refined event selection.”

    Additional improvements to ATLAS’ muon system include 16 new chambers featuring Small Monitored Drift Tubes (sMDT) and Resistive Plate Chambers (RPCs) to be installed in the barrel of the experiment, thus improving the overall trigger coverage of the detector. The smaller diameter tubes of the sMDTs provide an order of magnitude higher rate capability.

    LS2 will also see the enhancement of the ATLAS Liquid Argon (LAr) calorimeter with new front-end electronics and optical-fibre cabling. This will greatly improve the resolution of the detector at trigger level, providing four-times higher granularity to allow “jets” of particles to be better differentiated from electrons and photons, thus refining the first decision level where collision events are accepted for offline storage or dismissed. ATLAS’ trigger and data-acquisition systems will also be upgraded during LS2 with new electronics boards, further improving the overall resolution of the experiment, and preparing for the HL-LHC.

    “The organisation of LS2 activities is particularly complex, as the maintenance needs of the detectors have to be combined with tight installation schedules,” says Pontecorvo. On the long list of planned maintenance tasks: the complete overhaul of the Tile Calorimeter’s cooling connectors; repairs to the Transition Radiation Tracker (TRT), LAr and RPC detectors; the completion of the ATLAS Forward Proton (AFP) detector; and preparations for a new, all-silicon inner tracker scheduled for installation during LS3.

    “Each improvement we make to the experiment aims to maximise its performance, taking advantage of the ever-improving operation of the machine,” concludes Jakobs. “While these works are ongoing, we will continue to analyse the wealth of data collected during Run 2 – it will be a very busy time for the entire collaboration!”

    See the full article here .


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    CERN map


    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN


    CERN Courier

    QuantumDiaries


    Quantum Diaries

     
  • richardmitnick 8:48 am on December 3, 2018 Permalink | Reply
    Tags: , CERN LHC prepares for new achievements, HEP, , ,   

    From CERN: “LHC prepares for new achievements” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    3 December, 2018

    After an outstanding performance, the Large Hadron Collider (LHC), the accelerator complex and the experiments are now stopping for two years for major improvements and upgrading.

    1
    The Superconducting Magnets and Circuits Consolidation project which took place during the first Long Shutdown (LS1) (Image: Maximilien Brice/CERN)

    Early this morning, operators of the CERN Control Centre turned off the Large Hadron Collider (LHC), ending the very successful second run of the world’s most powerful particle accelerator. CERN’s accelerator complex will be stopped for about two years to enable major upgrade and renovation works.

    During this second run (2015–2018), the LHC performed beyond expectations, achieving approximately 16 million billion proton-proton collisions at an energy of 13 TeV and large datasets for lead-lead collisions at an energy of 5.02 TeV. These collisions produced an enormous amount of data, with more than 300 petabytes (300 million gigabytes) now permanently archived in CERN’s data centre tape libraries. This is the equivalent of 1000 years of 24/7 video streaming! By analysing these data, the LHC experiments have already produced a large amount of results, extending our knowledge of fundamental physics and of the Universe.

    “The second run of the LHC has been impressive, as we could deliver well beyond our objectives and expectations, producing five times more data than during the first run, at the unprecedented energy of 13 TeV,” says Frédérick Bordry, CERN Director for Accelerators and Technology. “With this second long shutdown starting now, we will prepare the machine for even more collisions at the design energy of 14 TeV.”

    “In addition to many other beautiful results, over the past few years the LHC experiments have made tremendous progress in the understanding of the properties of the Higgs boson,” adds Fabiola Gianotti, CERN Director-General. “The Higgs boson is a special particle, very different from the other elementary particles observed so far; its properties may give us useful indications about physics beyond the Standard Model.”

    A cornerstone of the Standard Model of particle physics – the theory that best describes the elementary particles and the forces that binds them together – the Higgs boson was discovered at CERN in 2012 and has been studied ever since. In particular, physicists are analysing the way it decays or transforms into other particles, to check the Standard Model’s predictions. Over the last three years, the LHC experiments extended the measurements of rates of Higgs boson decays, including the most common, but hard-to-detect, decay into bottom quarks, and the rare production of a Higgs boson in association with top quarks. The ATLAS and CMS experiments also presented updated measurement of the Higgs boson mass with the best precision to date.

    Beside the Higgs boson, the LHC experiments produced a wide range of results and hundreds of scientific publications, including the discovery of exotic new particles such as Ξcc++ and pentaquarks with the LHCb experiment, and the unveiling of so-far unobserved phenomena in proton–proton and proton-lead collisions at ALICE.

    During the two-year break, Long Shutdown 2 (LS2), the whole accelerator complex and detectors will be reinforced and upgraded for the next LHC run, starting in 2021, and the High-Luminosity LHC (HL-LHC) project, which will start operation after 2025. Increasing the luminosity of the LHC means producing far more data.

    “The rich harvest of the second run enables the researchers to look for very rare processes,” explains Eckhard Elsen, Director for Research and Computing at CERN. “They will be busy throughout the shutdown examining the huge data sample for possible signatures of new physics that haven’t had the chance to emerge from the dominant contribution of the Standard Model processes. This will guide us into the HL-LHC when the data sample will increase by yet another order of magnitude.”

    Several components of the accelerator chain (injectors) that feed the LHC with protons will be renewed to produce more intense beams. The first link in this chain, the linear accelerator Linac2, will leave the floor to Linac4.

    CERN Linac2

    CERN Linac 4

    The new linear accelerator will accelerate H- ions, which are later stripped to protons, allowing the preparation of brighter beams. The second accelerator in the chain, the Proton Synchrotron Booster, will be equipped with completely new injection and acceleration systems. The Super Proton Synchrotron (SPS), the last injector before the LHC, will have new radio frequency power to accelerate higher beam intensities, and will be connected to upgraded transfer lines.

    CERN The Proton Synchrotron Booster

    The Super Proton Synchrotron (SPS), CERN’s second-largest accelerator. (Image: Julien Ordan/CERN

    Some improvements of the LHC are also planned during LS2. The bypass diodes – the electrical components that protect the magnets in case of quench – will be shielded, as prerequisite for extending the LHC beam energy to 7 TeV after the LS2, and more than 20 main superconducting magnets will be replaced. Moreover, civil engineering works for the HL-LHC that started in June 2018 will continue, new galleries will be connected to the LHC tunnel, and new powerful magnet and superconducting technologies will be tested for the first time.

    All the LHC experiments will upgrade important parts of their detectors in the next two years. Almost the entire LHCb experiment will be replaced with faster detector components that will enable the collaboration to record events at full proton-proton rate. Similarly, ALICE will upgrade the technology of its tracking detectors. ATLAS and CMS will undergo improvements and start to prepare for the big experiments’ upgrade for HL-LHC.

    Proton beams will resume in spring 2021 with the LHC’s third run.

    See the full article here.


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    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New
    ALICE

    CERN/ALICE Detector


    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

    OTHER PROJECTS AT CERN

    CERN AEGIS

    CERN ALPHA

    CERN ALPHA


    CERN ALPHA-g Detector

    CERN ALPHA-g Detector


    CERN AMS

    CERN ACACUSA

    CERN ASACUSA

    CERN ATRAP

    CERN ATRAP

    CERN AWAKE

    CERN AWAKE

    CERN CAST

    CERN CAST Axion Solar Telescope

    CERN CLOUD

    CERN CLOUD

    CERN COMPASS

    CERN COMPASS

    CERN DIRAC

    CERN DIRAC

    CERN GBAR

    CERN GBAR

    CERN ISOLDE

    CERN ISOLDE

    CERN LHCf

    CERN LHCf

    CERN NA62

    CERN NA62

    CERN NTOF

    CERN TOTEM

    CERN UA9

    CERN Proto Dune

    CERN Proto Dune

     
  • richardmitnick 6:35 pm on November 17, 2018 Permalink | Reply
    Tags: , , , HEP, ILC-International Linear Collider plans in Japan, , , Studying the Higgs   

    From Science Magazine: “China unveils design for $5 billion particle smasher” 

    AAAS
    From Science Magazine

    1
    China’s Circular Electron Positron Collider would be built underground in a 100-kilometer-circumference tunnel at an as-yet-undetermined site.
    IHEP

    Nov. 16, 2018
    Dennis Normile

    BEIJING—The center of gravity in high energy physics could move to Asia if either of two grand plans is realized. At a workshop here last week, Chinese scientists unveiled the full conceptual design for the proposed Circular Electron Positron Collider (CEPC), a $5 billion machine to tackle the next big challenge in particle physics: studying the Higgs boson. (Part of the design was published in the summer.) Now, they’re ready to develop detailed plans, start construction in 2022, and launch operations around 2030—if the Chinese government agrees to fund it.

    Meanwhile, Japan’s government is due to decide by the end of December whether to host an equally costly machine to study the Higgs, the International Linear Collider (ILC).

    ILC schematic, being planned for the Kitakami highland, in the Iwate prefecture of northern Japan

    How Japan’s decision might affect China’s, which is a few years away, is unclear. But it seems increasingly likely that most of the future action around the Higgs will be in Asia. Proposed “Higgs factories” in Europe are decades away and the United States has no serious plans [remember the superconducting supercollider intended for Texas and killed by our idiot Congress in 1993 for having “no immediate economic value”?].

    The Higgs boson, key to explaining how other particles gain mass, was discovered at CERN, the European particle physics laboratory near Geneva, Switzerland, in 2012—more than 40 years after being theoretically predicted.

    CERN CMS Higgs Event


    CERN ATLAS Higgs Event

    LHC

    CERN map


    CERN LHC Tunnel

    CERN LHC particles

    Now, scientists want to confirm the particle’s properties, how it interacts with other particles, and whether it contributes to dark matter. Having only mass but no spin and no charge, the Higgs is really a “new kind of elementary particle” that is both “a special part of the standard model” and a “harbinger of some profound new principles,” says Nima Arkani-Hamed, a theorist at the Institute for Advanced Study in Princeton, New Jersey.

    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.


    Standard Model of Particle Physics from Symmetry Magazine

    Answering the most important questions in particle physics today “involves studying the Higgs to death,” he says.

    “Physicists want at least one machine,” says Joao Guimaraes da Costa, a physicist at the Chinese Academy of Sciences’s Institute of High Energy Physics (IHEP) here, which put together the Chinese proposal. “Ideally, both should be built,” because each has its scientific merits, adds Hitoshi Murayama, a theoretical physicist at the University of California, Berkeley, and the University of Tokyo’s Kavli Institute for the Physics and Mathematics of the Universe in Kashiwa, Japan.

    The CERN discovery relied on the Large Hadron Collider, a 27-kilometer ring [map is above] in which high-energy protons traveling in opposite directions are steered into head-on collisions. This produces showers of many types of particles, forcing physicists to sift through billions of events to spot the telltale signal of a Higgs. It’s a bit like smashing together cherry pies, Murayama says: “A lot of goo flies out when what you are really looking for is the little clinks between pits.”

    Smashing electrons into their antimatter counterparts, positrons, results in cleaner collisions that typically produce one Z particle and one Higgs boson at a time, says Bill Murray of The University of Warwick in Coventry, U.K. How Z particles decay is well understood, so other signals can be attributed to the Higgs “and we can watch what it does,” Murray says.

    Japan’s plan to build an electron-positron collider grew from international investigations in the 1990s. Physicists favored a linear arrangement [see schematic above], in which the particles are sent down two straight opposing raceways, colliding like bullets in rifles put muzzle to muzzle. That design promises higher energies, because it avoids the losses that result when charged particles are sent in a circle, causing them to shed energy in the form of x-rays. Its disadvantage is that particles that don’t collide are lost; in a circular design they continue around the ring for another chance at colliding.

    Along the way, Japan signaled it might host the machine and shoulder the lion’s share of the cost, with other countries contributing detectors, other components, and expertise. A 2013 basic design envisioned a 500-giga-electronvolt (GeV) linear collider in a 31-kilometer tunnel costing almost $8 billion, not counting labor. But by then, the CERN team had already pegged the Higgs mass at 125 GeV, making the ILC design “overkill,” Murayama says. The group has since revised the plan, aiming for a 250-GeV accelerator housed in a 20-kilometer-long tunnel and costing $5 billion, says Murayama, who is also deputy director of the Linear Collider Collaboration, which coordinates global R&D work on several future colliders.

    IHEP scientists made their own proposal just 2 months after the Higgs was announced. They recognized the energy required for a Higgs factory “is still in a range where circular is better,” Murray says. With its beamlines buried in a 100-kilometer-circumference tunnel at a site yet to be chosen, the CEPC would collide electrons and positrons at up to 240 GeV.

    Both approaches have their advantages. The CEPC will produce Higgs at roughly five times the rate of ILC, allowing research to move faster. But Murayama notes that the ILC could easily be upgraded to higher energies by extending the tunnel by another couple of kilometers. Most physicists don’t want to choose. The two colliders “are quite complementary,” Murray says.

    Whether politicians and funding agencies agree remains to be seen. Construction of the CEPC hinges on funding under China’s next 5-year plan, which starts in 2021, says IHEP Director Wang Yifang. IHEP would then also seek international contributors. Murayama says Japan needs to say yes to the ILC in time to negotiate support from the European Union under a particle physics strategy to be hammered out in 2019. Missing that opportunity could mean delaying the collider by 20 years, he says—and perhaps ceding the field to China.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 8:42 am on November 2, 2018 Permalink | Reply
    Tags: , , CERN ALPHA-g, HEP, , ,   

    From CERN: “New antimatter gravity experiments begin at CERN” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    2 Nov 2018
    Ana Lopes

    CERN ALPHA-g experiment being installed at CERN_s Antiproton Decelerator hall. (Image CERN)

    CERN ALPHA-g Detector

    We learn it at high school: Release two objects of different mass in the absence of friction forces and they fall down at the same rate in Earth’s gravity. What we haven’t learned, because it hasn’t been directly measured in experiments, is whether antimatter falls down at the same rate as ordinary matter or if it might behave differently. Two new experiments at CERN, ALPHA-g and GBAR, have now started their journey towards answering this question.


    CERN GBAR

    ALPHA-g is very similar to the ALPHA experiment [below], which makes neutral antihydrogen atoms by taking antiprotons from the Antiproton Decelerator (AD) and binding them with positrons from a sodium-22 source. ALPHA then confines the resulting neutral antihydrogen atoms in a magnetic trap and shines laser light or microwaves onto them to measure their internal structure. The ALPHA-g experiment has the same type of antiatom making and trapping apparatus except that it is oriented vertically. With this vertical set-up, researchers can measure precisely the vertical positions at which the antihydrogen atoms annihilate with normal matter once they switch off the trap’s magnetic field and the atoms are under the sole influence of gravity. The values of these positions will allow them to measure the effect of gravity on the antiatoms.

    The GBAR experiment, also located in the AD hall, takes a different tack. It plans to use antiprotons supplied by the ELENA deceleration ring and positrons produced by a small linear accelerator to make antihydrogen ions, consisting of one antiproton and two positrons. Next, after trapping the antihydrogen ions and chilling them to an ultralow temperature (about 10 microkelvin), it will use laser light to strip them of one positron, turning them into neutral antiatoms. At this point, the neutral antiatoms will be released from the trap and allowed to fall from a height of 20 centimetres, during which the researchers will monitor their behaviour.

    After months of round-the-clock work by researchers and engineers to put together the experiments, ALPHA-g and GBAR have received the first beams of antiprotons, marking the beginning of both experiments. ALPHA-g began taking beam on 30 October, after receiving the necessary safety approvals. ELENA sent its first beam to GBAR on 20 July, and since then the decelerator and GBAR researchers have been trying to perfect the delivery of the beam. The ALPHA-g and GBAR teams are now racing to commission their experiments before CERN’s accelerators shut down in a few weeks for a two-year period of maintenance work. Jeffrey Hangst, spokesperson of the ALPHA experiments, says: “We are hoping that we’ll get the chance to make the first gravity measurements with antimatter, but it’s a race against time.” Patrice Pérez, spokesperson of GBAR, says: “The GBAR experiment is using an entirely new apparatus and an antiproton beam still in its commissioning phase. We hope to produce antihydrogen this year and are working towards being ready to measure the gravitational effects on antimatter when the antiprotons are back in 2021.”

    Another experiment at the AD hall, AEgIS, which has been in operation for several years, is also working towards measuring the effect of gravity on antihydrogen using yet another approach. Like GBAR, AEgIS [below] is also hoping to produce its first antihydrogen atoms this year.

    Discovering any difference between the behaviour of antimatter and matter in connection with gravity could point to a quantum theory of gravity and perhaps cast light on why the universe seems to be made of matter rather than antimatter.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New
    ALICE

    CERN/ALICE Detector


    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

    OTHER PROJECTS AT CERN

    CERN AEGIS

    CERN ALPHA

    CERN ALPHA

    CERN AMS

    CERN ACACUSA

    CERN ASACUSA

    CERN ATRAP

    CERN ATRAP

    CERN AWAKE

    CERN AWAKE

    CERN CAST

    CERN CAST Axion Solar Telescope

    CERN CLOUD

    CERN CLOUD

    CERN COMPASS

    CERN COMPASS

    CERN DIRAC

    CERN DIRAC

    CERN GBAR

    CERN GBAR

    CERN ISOLDE

    CERN ISOLDE

    CERN LHCf

    CERN LHCf

    CERN NA62

    CERN NA62

    CERN NTOF

    CERN TOTEM

    CERN UA9

    CERN Proto Dune

    CERN Proto Dune

     
  • richardmitnick 8:08 am on November 2, 2018 Permalink | Reply
    Tags: , Antimatter particles, “Majorana” particles: particles that are indistinguishable from their antimatter counterparts, , , HEP, , , ,   

    From CERN: “Chasing a particle that is its own antiparticle” 

    Cern New Bloc

    Cern New Particle Event

    CERN New Masthead

    From CERN

    1 Nov 2018
    Ana Lopes

    1
    The ATLAS experiment at CERN. (Image: Maximilien Brice/CERN)

    Neutrinos weigh almost nothing: you need at least 250 000 of them to outweigh a single electron. But what if their lightness could be explained by a mechanism that needs neutrinos to be their own antiparticles? The ATLAS collaboration at CERN is looking into this, using data from high-energy proton collisions collected at the Large Hadron Collider (LHC).

    One way to explain neutrinos’ extreme lightness is the so-called seesaw mechanism, a popular extension 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.


    Standard Model of Particle Physics from Symmetry Magazine

    This mechanism involves pairing up the known light neutrinos with hypothetical heavy neutrinos. The heavier neutrino plays the part of a larger child on a seesaw, lifting the lighter neutrino to give it a small mass. But for this mechanism to work, both neutrinos need to be “Majorana” particles: particles that are indistinguishable from their antimatter counterparts.

    Antimatter particles have the same mass as their corresponding matter particles but have the opposite electric charge. So, for example, an electron has a negative electric charge and its antiparticle, the positron, is positive. But neutrinos have no electric charge, opening up the possibility that they could be their own antiparticles. Finding heavy Majorana neutrinos could not only help explain neutrino mass, it could also lead to a better understanding of why matter is much more abundant in the universe than antimatter.

    In an extended form of the seesaw model, these heavy Majorana neutrinos could potentially be light enough to be detected in LHC data. In a new paper, the ATLAS collaboration describes the results of its latest search for hints of these particles.

    ATLAS looked for instances in which both a heavy Majorana neutrino and a “right-handed” W boson, another hypothetical particle, could appear. They used LHC data from collision events that produce two “jets” of particles plus a pair of energetic electrons or a pair of their heavier cousins, muons.

    The researchers compared the observed number of such events with the number predicted by the Standard Model. They found no significant excess of events over the Standard Model expectation, indicating that no right-handed W bosons and heavy Majorana neutrinos took part in these collisions.

    However, the researchers were able to use their observations to excludepossible masses for these two particles. They excluded heavy Majorana neutrino masses up to about 3 TeV, for a right-handed W boson with a mass of 4.3 TeV. In addition, they explored for the first time the hypothesis that the Majorana neutrino is heavier than the right-handed W boson, placing a lower limit of 1.5 TeV on the mass of Majorana neutrinos. Further studies should be able to put tighter limits on the mass of heavy Majorana neutrinos in the hope of finding them – if, indeed, they exist.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Meet CERN in a variety of places:

    Quantum Diaries
    QuantumDiaries

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New
    ALICE

    CERN/ALICE Detector


    CMS
    CERN CMS New

    LHCb
    CERN LHCb New II

    LHC

    CERN map

    CERN LHC Grand Tunnel

    CERN LHC particles

    OTHER PROJECTS AT CERN

    CERN AEGIS

    CERN ALPHA

    CERN ALPHA

    CERN AMS

    CERN ACACUSA

    CERN ASACUSA

    CERN ATRAP

    CERN ATRAP

    CERN AWAKE

    CERN AWAKE

    CERN CAST

    CERN CAST Axion Solar Telescope

    CERN CLOUD

    CERN CLOUD

    CERN COMPASS

    CERN COMPASS

    CERN DIRAC

    CERN DIRAC

    CERN ISOLDE

    CERN ISOLDE

    CERN LHCf

    CERN LHCf

    CERN NA62

    CERN NA62

    CERN NTOF

    CERN TOTEM

    CERN UA9

    CERN Proto Dune

    CERN Proto Dune

     
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