The Global Community of Particle Physics

This account brings you hot items from public particle physics news sources, including CERN,, and

  • Week 48 at the Pole

    2017-12-14T22:28:51Z via NavierStokesApp To: Public

    "Week 48 at the Pole"

    The many flight delays this season affected the arrival of not only personnel but cargo, too. It eventually showed up though, and last week IceCube’s winterovers were busy managing it all at the IceCube Lab. It was a lot of carrying and exhausting, but they were still smiling after it was all said and done

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  • Putting the breaks on driverless cars, and dolphins that can muffle their ears

    2017-12-14T20:28:47Z via NavierStokesApp To: Public

    "Putting the breaks on driverless cars, and dolphins that can muffle their ears"

    Whales and dolphins have incredibly sensitive hearing and are known to be harmed by loud underwater noises. David Grimm talks with Sarah Crespi about new research on captive cetaceans suggesting that some species can naturally muffle such sounds—perhaps opening a way to protect these marine mammals in the wild. Sarah also interviews Staff Writer Jeffrey Mervis about his story on the future of autonomous cars. Will they really reduce traffic and make our lives easier? What does the science say?    Listen to previous podcasts.    [Image: Laura Wolf/Flickr; Music: Jeffrey Cook]

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  • 25 years of Large Hadron Collider experimental programme

    2017-12-14T15:28:47Z via NavierStokesApp To: Public

    "25 years of Large Hadron Collider experimental programme"

    This week CERN marks 25 years since the meeting at Evian, where the first ideas for the LHC experimental programme were debuted (Image: Maximilien Brice/CERN)

    On Friday 15 December 2017, CERN is celebrating the 25th anniversary of the Large Hadron Collider (LHC) experimental programme. The occasion will be marked with a special scientific symposium looking at the LHC’s history, the physics landscape into which the LHC experiments were born, and the challenging path that led to the very successful LHC programme we know today.

    The anniversary is linked to a meeting that took place in 1992, in Evian, entitled Towards the LHC Experimental Programme, marking a crucial milestone in the design and development of the LHC experiments.

    The symposium, which will be live webcast, will also include a presentation of the latest results from the four large experiments, ATLAS, CMS, LHCb and ALICE.

    Join the live webcast from 11:00-16:00 CET.

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  • Breaking data records bit by bit

    2017-12-14T09:28:43Z via NavierStokesApp To: Public

    "Breaking data records bit by bit"

    Magnetic tapes, retrieved by robotic arms, are used for long-term storage (Image: Julian Ordan/CERN)

    This year CERN’s data centre broke its own record, when it collected more data than ever before.

    During October 2017, the data centre stored the colossal amount of 12.3 petabytes of data. To put this in context, one petabyte is equivalent to the storage capacity of around 15,000 64GB smartphones. Most of this data come from the Large Hadron Collider’s experiments, so this record is a direct result of the outstanding LHC performance, the rest is made up of data from other experiments and backups.

    “For the last ten years, the data volume stored on tape at CERN has been growing at an almost exponential rate. By the end of June we had already passed a data storage milestone, with a total of 200 petabytes of data permanently archived on tape,” explains German Cancio, who leads the tape, archive & backups storage section in CERN’s IT department.

    The CERN data centre is at the heart of the Organization’s infrastructure. Here data from every experiment at CERN is collected, the first stage in reconstructing that data is performed, and copies of all the experiments’ data are archived to long-term tape storage.

    Most of the data collected at CERN will be stored forever, the physics data is so valuable that it will never be deleted and needs to be preserved for future generations of physicists.

    “An important characteristic of the CERN data archive is its longevity,” Cancio adds. “Even after an experiment ends all recorded data has to remain available for at least 20 years, but usually longer. Some of the archive files produced by previous CERN experiments have been migrated across different hardware, software and media generations for over 30 years. For archives like CERN’s, that do not only preserve existing data but also continue to grow, our data preservation is particularly challenging.”

    While tapes may sound like an outdated mode of storage, they are actually the most reliable and cost-effective technology for large-scale archiving of data, and have always been used in this field. One copy of data on a tape is considered much more reliable than the same copy on a disk.

    CERN currently manages the largest scientific data archive in the High Energy Physics (HEP) domain and keeps innovating in data storage,” concludes Cancio.

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  • Explore CERN in the world of Minecraft

    2017-12-13T12:28:39Z via NavierStokesApp To: Public

    "Explore CERN in the world of Minecraft"

    Students have recreated CERN and the ATLAS laboratory in detail using Minecraft’s signature 3D blocks (Image: ATLAS)

    Now you can discover CERN and the ATLAS detector in incredible detail on the gaming platform Minecraft, through ATLAScraft, launched today.

    The virtual world recreates the Laboratory using Minecraft’s signature 3D blocks, in an interactive museum and map that includes striking images accompanied by detailed explanations and mini-games to explore the world of particle physics.

    The centrepiece of the game is a stunning scale model of the ATLAS experiment, complete with underground service caverns and tunnels for the Large Hadron Collider (LHC). Players can slice open the experiment to reveal layers of subdetectors, watch particles meet at the ATLAS collision point, and play minigames that explain how each subdetector works.

    This virtual world was created by UK secondary school students together with ATLAS physicists, in a project funded by the UK’s Science and Technology Facilities Council (STFC) and the ATLAS Experiment. With the help of experts, the students became the teachers in ATLAScraft, turning their new knowledge of the detector and particle physics into engaging activities for players.

    Explore CERN through the new ATLAScraft game (Video: ATLAScraft)

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    Stephen Sekula likes this.

    I once made my own home and surrounding streets as a Doom level. It was fun =)

    JanKusanagi at 2017-12-13T13:05:23Z

    George Standish, Stephen Sekula likes this.

  • New CERN facility can help medical research into cancer

    2017-12-12T14:28:22Z via NavierStokesApp To: Public

    "New CERN facility can help medical research into cancer"

    As in the ISOLDE facility, the targets at MEDICIS have to be handled by robots because they are radioactive (Image: Maximilien Brice/CERN)

    Today, the new CERN-MEDICIS facility has produced radioisotopes for medical research for the first time. MEDICIS (Medical Isotopes Collected from ISOLDE) aims to provide a wide range of radioisotopes, some of which can be produced only at CERN thanks to the unique ISOLDE facility. These radioisotopes are destined primarily for hospitals and research centres in Switzerland and across Europe. Great strides have been made recently in the use of radioisotopes for diagnosis and treatment, and MEDICIS will enable researchers to devise and test unconventional radioisotopes with a view to developing new approaches to fight cancer. 

    “Radioisotopes are used in precision medicine to diagnose cancers, as well as other diseases such as heart irregularities, and to deliver very small radiation doses exactly where they are needed to avoid destroying the surrounding healthy tissue,” said Thierry Stora, MEDICIS project coordinator. “With the start of MEDICIS, we can now produce unconventional isotopes and help to expand the range of applications.”

    A chemical element can exist in several variants or isotopes, depending on how many neutrons its nucleus has. Some isotopes are naturally radioactive and are known as radioisotopes. They can be found almost everywhere, for example in rocks or even in drinking water. Other radioisotopes are not naturally available, but can be produced using particle accelerators. MEDICIS uses a proton beam from ISOLDE – the Isotope Mass Separator Online facility at CERN – to produce radioisotopes for medical research. The first batch produced was Terbium 155Tb, which is considered a promising radioisotope for diagnosing prostate cancer, as early results have recently shown.

    Innovative ideas and technologies from physics have contributed to great advances in the field of medicine over the last 100 years, since the advent of radiation-based medical diagnosis and treatment and following the discovery of X-rays and radioactivity. Radioisotopes are thus already widely used by the medical community for imaging, diagnosis and radiation therapy. However, many isotopes currently used do not combine the most appropriate physical and chemical properties and, in some cases, a different type of radiation could be better suited. MEDICIS can help to look for radioisotopes with the right properties to enhance precision for both imaging and treatment.

    “CERN-MEDICIS demonstrates again how CERN technologies can benefit society beyond their use for our fundamental research. With its unique facilities and expertise, CERN is committed to maximising the impact of CERN technologies in our everyday lives,” said CERN’s Director for Accelerators and Technology, Frédérick Bordry.  

    At ISOLDE, the high-intensity proton beam from CERN’s Proton Synchrotron Booster (PSB) is directed onto specially developed thick targets, yielding a large variety of atomic fragments. Different devices are used to ionise, extract and separate nuclei according to their mass, forming a low-energy beam that is delivered to various experimental stations. MEDICIS works by placing a second target behind ISOLDE’s. Once the isotopes have been produced at the MEDICIS target, an automated conveyor belt carries them to the MEDICIS facility, where the radioisotopes of interest are extracted through mass separation and implanted in a metallic foil. They are then delivered to research facilities including the Paul Scherrer Institut (PSI), the University Hospital of Vaud (CHUV) and the Geneva University Hospitals (HUG).

    Once at the facility, researchers dissolve the isotope and attach it to a molecule, such as a protein or sugar, chosen to target the tumour precisely. This makes the isotope injectable, and the molecule can then adhere to the tumour or organ that needs imaging or treating.

    ISOLDE has been running for 50 years, and 1300 isotopes from 73 chemicals have been produced at CERN for research in many areas, including fundamental nuclear research, astrophysics and life sciences. Although ISOLDE already produces isotopes for medical research, the new MEDICIS facility will allow it to provide radioisotopes meeting the requirements of the medical research community as a matter of course.

    CERN-MEDICIS is an effort led by CERN with contributions from its dedicated Knowledge Transfer Fund, private foundations and partner institutes. It also benefits from a European Commission Marie Skłodowska-Curie training grant, which has been helping to shape a pan-European medical and scientific collaboration since 2014.


    The robot arm at MEDICIS. (Video: Noemi Caraban/CERN)

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  • Week 47 at the Pole

    2017-12-09T05:28:29Z via NavierStokesApp To: Public

    "Week 47 at the Pole"

    It was a busy week for IceCube’s newest winterovers. A plane arrived after a long hiatus, bringing some new folks to the station and taking away last year’s winterovers, finally. But much of the excitement came from alarms going off—the ones for fire were false alarms thankfully. But it gave the new winterovers a chance to apply their training to emergency response operations.

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  • Folding DNA into teddy bears and getting creative about gun violence research

    2017-12-09T04:28:26Z via NavierStokesApp To: Public

    "Folding DNA into teddy bears and getting creative about gun violence research"

    This week, three papers came out describing new approaches to folding DNA into large complex shapes—20 times bigger than previous DNA sculptures. Staff Writer Bob Service talks with Sarah Crespi about building microscopic teddy bears, doughnuts, and more from genetic material, and using these techniques to push forward fields from materials science to drug delivery. Sarah also interviews Philip Cook of Duke University in Durham, North Carolina, about his Policy Forum on gun regulation research. It’s long been hard to collect data on gun violence in the United States, and Cook talks about how some researchers are getting funding and hard data. He also discusses some strong early results on open-carry laws and links between gun control and intimate partner homicide. Listen to previous podcasts. [Image: : K. WAGENBAUER ET AL., NATURE, VOL. 551, 2017; Music: Jeffrey Cook]

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  • Crab cavities: colliding protons head-on

    2017-12-09T04:28:26Z via NavierStokesApp To: Public

    "Crab cavities: colliding protons head-on"

    One of the first two crab cavities during construction in a clean room at CERN. (Image: Ulysse Fichet/CERN)

    They won’t pinch you and you won’t find them on the beach. The name of the new radio-frequency crab cavities has nothing to do with their appearance and is merely illustrative of the effect they will have on circulating proton bunches.

    Crab cavities will help increase the luminosity of collisions in the High-Luminosity LHC (HL-LHC) – the future upgrade of the LHC planned for after 2025. The luminosity of a collider is proportional to the number of collisions that occur in a given amount of time. The higher the luminosity, the more collisions, and the more data the experiments can gather to allow them to observe rare processes.

    At present, two superconducting crab cavities have been manufactured at CERN and inserted into a specially designed cryostat, which will keep them at their operating temperature of two kelvin. Currently in their final stages of testing, they will be installed in the Super Proton Synchrotron (SPS) during this year’s winter technical stop. In 2018, they will be tested with a proton beam for the first time. 

    The assembly of the crab cavity housing, a cryostat that will serve as a high-performance thermos flask, reducing the heat load and keeping the cavities at their operating temperature. (Image: Maximilien Brice/CERN)

    The beams in the LHC are made of bunches, each containing billions of protons. They are similar to trains with carriages full of billions of passengers. In the LHC, the two counter-circulating proton beams meet at a small crossing angle at the collision point of the experiments.

    What makes the crab cavities special is their ability to “tilt” the proton bunches in each beam, maximising their overlap at the collision point. Тhis way every single proton in the bunch is forced to pass through the whole length of the opposite bunch, which increases the probability that it will collide with another particle. After being tilted, the motion of the proton bunches appears to be sideways – just like a crab.

    An illustration of the effect of the crab cavities on the proton bunches. (Image: CERN)

    Find out more about the crab cavities in the video below.

    Rama Calaga, the radio-frequency physicist behind the technology, Ofelia Capatina, deputy leader of the crab cavities project, and Lucio Rossi, leader of the High-Luminosity LHC project, explain the principle of the crab cavities. (Video: Polar Media and CERN Audiovisual Productions)

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  • At the LHC, tomorrow is already here

    2017-12-09T03:28:41Z via NavierStokesApp To: Public

    "At the LHC, tomorrow is already here"

    The CERN Control Centre in 2017, from where all the Laboratory's accelerators and technical infrastructure are controlled. The accelerator complex and the LHC produced a record amount of data in 2017. (Image: Julien Ordan/CERN)

    On Monday, 4 December at 4.00 a.m., the accelerator operators hit the stop button on the accelerator complex and the Large Hadron Collider for their usual winter break. But while the machines are hibernating, there’s no rest for the humans, as CERN teams will be busy with all the maintenance and upgrade work required before the machines are restarted in the spring. 

    The LHC has ended the year with yet another luminosity record, having produced 50 inverse femtobarns of data, i.e. 5 million billion collisions, in 2017. But the accelerator hasn’t just produced lots of data for the physics programmes. 

    Before the technical stop, a number of new techniques for increasing the luminosity of the machine were tested. These techniques are mostly being developed for the LHC’s successor, the High-Luminosity LHC. With a planned start-up date of 2026, the High-Luminosity LHC will produce five to ten times as many collisions as the current LHC. To do this, it will be kitted out with new equipment and will use a new optics scheme, based on ATS (Achromatic Telescopic Squeezing), a configuration that was tested this year at the LHC. 

    Handling beams of particles is a bit like handling beams of light. In an accelerator, dipole magnets act like mirrors, guiding the beams around the bends. Quadrupole magnets act alternately like concave or convex lenses, keeping the beams in line transversally, but also and above all focusing them as much as possible at the interaction points of the experiments. Corrector magnets (hexapoles) correct chromatic aberrations (a bit like corrective lenses for astigmatism). Configuring the optics of an accelerator is all about combining the strengths of these different magnets.

    One particularly efficient approach to increasing luminosity, and therefore the number of collisions, is to reduce the size of the beam at the interaction points, or in other words to compress the bunches of particles as much as possible. In the High-Luminosity LHC, more powerful quadrupole magnets with larger apertures, installed either side of the experiments, will focus the bunches before collision. However, for these magnets to be as effective as possible, the beam must first be considerably expanded: a bit like a stretching a spring as much as possible so that it retracts as much as possible. And this is where the new configuration comes in. Instead of just using the quadrupole magnets either side of the collision points, the ATS system also makes use of magnets situated further away from the experiments in the machine, transforming seven kilometres of the accelerator into a giant focusing system. 

    Graph showing the integrated luminosity over the various runs of the LHC. In 2017, the LHC produced 50 inverse femtobarns of data, the equivalent of 5 million billion collisions. (Image: CERN)

    These techniques have been used in part this year at the LHC and will be used even more during future runs. “The heart of the High-Luminosity LHC is already beating in the LHC,” explains Stéphane Fartoukh, the physicist who came up with the new concept.  “The latest tests, carried out last week, have once again proved the reliability of the scheme and demonstrated other potential applications, sometimes beyond our initial expectations.

    For further information:

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  • GRAVITY - Immaginare l’Universo dopo Einstein

    2017-12-09T03:28:41Z via NavierStokesApp To: Public

    "GRAVITY - Immaginare l’Universo dopo Einstein"

    l Pensiero creativo di artisti e scienziati alla prova dei grandi interrogativi posti dal Cosmo. Una mostra di MAXXI, Agenzia Spaziale Italiana e Istituto Nazionale di Fisica Nucleare - 2 dicembre 2017- 29 aprile 2018

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  • New study: Scientists narrow down the search for dark photons using decade-old particle collider data

    2017-11-10T18:29:23Z via NavierStokesApp To: Public

    "New study: Scientists narrow down the search for dark photons using decade-old particle collider data"

    New study: Scientists narrow down the search for dark photons using decade-old particle collider dataPress ReleaseDanielle Wed, 11/08/2017 - 08:033417

    Analysis of data from the BaBar experiment rules out theorized particle’s explanation for muon mystery

    In its final years of operation, a particle collider in Northern California was refocused to search for signs of new particles that might help fill in some big blanks in our understanding of the universe.

    A fresh analysis of this data, co-led by physicists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), limits some of the hiding places for one type of theorized particle – the dark photon, also known as the heavy photon – that was proposed to help explain the mystery of dark matter.

    The latest result, published in the journal Physical Review Letters by the roughly 240-member BaBar Collaboration, adds to results from a collection of previous experiments seeking, but not yet finding, the theorized dark photons.

    “Although it does not rule out the existence of dark photons, the BaBar results do limit where they can hide, and definitively rule out their explanation for another intriguing mystery associated with the property of the subatomic particle known as the muon,” said Michael Roney, BaBar spokesperson and University of Victoria professor.

    Dark matter, which accounts for an estimated 85 percent of the total mass of the universe, has only been observed by its gravitational interactions with normal matter. For example, the rotation rate of galaxies is much faster than expected based on their visible matter, suggesting there is “missing” mass that has so far remained invisible to us.

    So physicists have been working on theories and experiments to help explain what dark matter is made of – whether it is composed of undiscovered particles, for example, and whether there may be a hidden or “dark” force that governs the interactions of such particles among themselves and with visible matter. The dark photon, if it exists, has been put forward as a possible carrier of this dark force.

    Using data collected from 2006 to 2008 at SLAC National Accelerator Laboratory in Menlo Park, California, the analysis team scanned the recorded byproducts of particle collisions for signs of a single particle of light – a photon – devoid of associated particle processes.

    The BaBar experiment, which ran from 1999 to 2008 at SLAC, collected data from collisions of electrons with positrons, their positively charged antiparticles. The collider driving BaBar, called PEP-II, was built through a collaboration that included SLAC, Berkeley Lab, and Lawrence Livermore National Laboratory. At its peak, the BaBar Collaboration involved over 630 physicists from 13 countries.

    BaBar was originally designed to study the differences in the behavior between matter and antimatter involving a b-quark. Simultaneously with a competing experiment in Japan called Belle, BaBar confirmed the predictions of theorists and paved the way for the 2008 Nobel Prize. Berkeley Lab physicist Pier Oddone proposed the idea for BaBar and Belle in 1987 while he was the Lab’s Physics division director.

    The latest analysis used about 10 percent of BaBar’s data – recorded in its final two years of operation. Its data collection was refocused on finding particles not accounted for in physics’ Standard Model – a sort of rulebook for what particles and forces make up the known universe.

    “BaBar performed an extensive campaign searching for dark sector particles, and this result will further constrain their existence,” said Bertrand Echenard, a research professor at Caltech who was instrumental in this effort.

    Yury Kolomensky, a physicist in the Nuclear Science Division at Berkeley Lab and a faculty member in the Department of Physics at UC Berkeley, said, “The signature (of a dark photon) in the detector would be extremely simple: one high-energy photon, without any other activity.”

    A number of the dark photon theories predict that the associated dark matter particles would be invisible to the detector. The single photon, radiated from a beam particle, signals that an electron-positron collision has occurred and that the invisible dark photon decayed to the dark matter particles, revealing itself in the absence of any other accompanying energy.

    When physicists had proposed dark photons in 2009, it excited new interest in the physics community, and prompted a fresh look at BaBar’s data. Kolomensky supervised the data analysis, performed by UC Berkeley undergraduates Mark Derdzinski and Alexander Giuffrida.

    “Dark photons could bridge this hidden divide between dark matter and our world, so it would be exciting if we had seen it,” Kolomensky said.

    The dark photon has also been postulated to explain a discrepancy between the observation of a property of the muon spin and the value predicted for it in the Standard Model. Measuring this property with unprecedented precision is the goal of the Muon g-2 (pronounced gee-minus-two) Experiment at Fermi National Accelerator Laboratory.

    Earlier measurements at Brookhaven National Laboratory had found that this property of muons – like a spinning top with a wobble that is ever-slightly off the norm – is off by about 0.0002 percent from what is expected. Dark photons were suggested as one possible particle candidate to explain this mystery, and a new round of experiments begun earlier this year should help to determine whether the anomaly is actually a discovery.

    The latest BaBar result, Kolomensky said, largely “rules out these dark photon theories as an explanation for the g-2 anomaly, effectively closing this particular window, but it also means there is something else driving the g-2 anomaly if it’s a real effect.”

    It’s a common and constant interplay between theory and experiments, with theory adjusting to new constraints set by experiments, and experiments seeking inspiration from new and adjusted theories to find the next proving grounds for testing out those theories.

    Scientists have been actively mining BaBar’s data, Roney said, to take advantage of the well-understood experimental conditions and detector to test new theoretical ideas.

    “Finding an explanation for dark matter is one of the most important challenges in physics today, and looking for dark photons was a natural way for BaBar to contribute,” Roney said, adding that many experiments in operation or planned around the world are seeking to address this problem.

    An upgrade of an experiment in Japan that is similar to BaBar, called Belle II,  turns on next year. “Eventually, Belle II will produce 100 times more statistics compared to BaBar,” Kolomensky said. “Experiments like this can probe new theories and more states, effectively opening new possibilities for additional tests and measurements.”

    “Until Belle II has accumulated significant amounts of data, BaBar will continue for the next several years to yield new impactful results like this one,” Roney said.

    The study featured participation by the international BaBar collaboration, which includes researchers from about 66 institutions in the U.S., Canada, France, Spain, Italy, Norway, Germany, Russia, India, Saudi Arabia, U.K., the Netherlands, and Israel. The work was supported by the U.S. Department of Energy’s Office of Science and the National Science Foundation; the Natural Sciences and Engineering Research Council in Canada; CEA and CNRS-IN2P3 in France; BMBF and DFG in Germany; INFN in Italy; FOM in the Netherlands; NFR in Norway; MES in Russia; MINECO in Spain; STFC in the U.K.; and BSF in Israel and the U.S. Individuals involved with this study have received support from the Marie Curie EIF in the European Union, and the Alfred P. Sloan Foundation in the U.S.


    Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel Prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit



    This chart shows the search area (green) explored in an analysis of BaBar data where dark photon particles have not been found, compared with other experiments’ search areas. The red band shows the favored search area  to show whether dark photons are causing the so-called “g-2 anomaly,” and the white areas are among the unexplored territories for dark photons. (Credit: Muon g-2 Collaboration) 

    The BaBar detector at SLAC National Accelerator Laboratory. (Credit: SLAC)

    Lawrence Berkeley National Laboratory

    Shielding blocks removed exposing the Bevatron. (Courtesy: Lawrence Berkeley National Lab)

    Shielding blocks removed exposing the Bevatron. (Courtesy: Lawrence Berkeley National Lab)

    In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

    Berkeley Lab is a multidisciplinary national laboratory located in Berkeley, California on a hillside directly above the campus of the University of California at Berkeley. The site consists of 76 buildings located on 183 acres, which overlook both the campus and the San Francisco Bay.

    1 Cyclotron Road
    Berkeley, CA94720
    United States


    Glenn Roberts Jr.,
    Public Affairs, Lawrence Berkeley National Laboratory

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  • Inauguration of Next-generation Neutrino Science Organization for the Hyper-Kamiokande Nucleon Decay and Neutrino Experiment

    2017-11-10T17:29:22Z via NavierStokesApp To: Public

    "Inauguration of Next-generation Neutrino Science Organization for the Hyper-Kamiokande Nucleon Decay and Neutrino Experiment"

    Inauguration of Next-generation Neutrino Science Organization for the Hyper-Kamiokande Nucleon Decay and Neutrino ExperimentPress ReleaseLauren Fri, 11/10/2017 - 09:433617

    The Hyper-Kamiokande project aims to address the mysteries of the origin and evolution of the Universe’s matter as well as to confront theories of elementary particle unification. To realize these goals it will combine a high intensity neutrino beam from J-PARC with a new detector based upon precision neutrino experimental techniques developed in Japan and built to be approximately 10 times larger than the running Super-Kamiokande.
    On October 1st, 2017, The University of Tokyo launched its “Next-generation Neutrino Science Organization (NNSO),” in cooperation with the Institute for Cosmic Ray Research (ICRR), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), and the University of Tokyo’s School of Science. The NNSO is a means of pioneering the future of neutrino physics through the development of neutrino research techniques and detector technologies. In particular, it aims to advance what will become its flagship facility, the Hyper-Kamiokande project. To mark the occasion, an inaugural ceremony was held on November 8th, 2017, at the Kamioka Observatory in Japan.
    Professor Takaaki Kajita, director of NNSO and a Nobel laureate for the discovery of neutrino oscillations demonstrating that neutrinos have mass, started the ceremony with opening remarks: “Understanding the neutrino, whose mass is extremely small, is not only important to particle physics, but is also thought to have deep connections to the origins of matter. Indeed, by observing neutrinos created with the high intensity proton accelerator J-PARC at Hyper-Kamiokande and testing whether or not neutrino and antineutrino oscillations are the same, we expect to close in on the mysteries of our matter-dominated universe. Further, we would like to discover the decay of the proton and thereby verify the unification of the three forces that act between elementary particles. Through the research represented by these goals, I would like to greatly expand our knowledge of elementary particles and the universe.” 
    Professor Masashi Haneda, Executive Vice President of The University of Tokyo and Director of The University of Tokyo Institutes for Advanced Study, greeted attendees with these words: “Through the cooperation of these three important institutions, I’m sure that a world-class center for neutrino research will be established. Further, it will contribute much to cultivate talented young researchers. Succeeding Kamiokande and Super-Kamiokande, the Hyper-Kamiokande project will lead the world’s neutrino research. I would like to underline that the University of Tokyo will do our best to support this newly established organization.” 
    Professor Hiroyuki Takeda, Dean of the School of Science, also gave an address: “The School of Science has a long and intimate relationship to the research in Kamioka, because Professor Koshiba started the original Kamiokande experiment when he was a faculty member of the School of Science. It is our great pleasure that we can further deepen the relationship with ICRR and Kavli IPMU through this organization to promote neutrino physics and the Hyper-Kamiokande project.”
    Professor Hitoshi Murayama, director of the Kavli Institute for the Physics and Mathematics of the Universe, delivered this message: “I firmly believe that the Hyper-Kamiokande experiment will be one of the most important experiments in the foreseeable future to study the Universe. Kavli IPMU would like to contribute to the Hyper-Kamiokande experiment with experimental expertise, theoretical support, and international networking. I'm very excited. Let's make the Hyper-Kamiokande experiment happen!”
    Tomonori Nishii, Director of Scientific Research Institutes Division, Ministry of Education, Culture, Science and Technology (MEXT), Japan, presented congratulations: “In July of this year, the MEXT Roadmap 2017, which outlines the basic plan for pursuing large-scale projects, has been compiled by the Council for Science and Technology. It made the implementation priority of such projects clear. “Nucleon Decay and Neutrino Oscillation Experiment with a Large Advanced Detector”, that is Hyper-Kamiokande, is highly evaluated and listed in the roadmap with six other projects. MEXT, together with you, looks forward to seeing this new organization thrive as an international collaborative research hub and produce excellent scientific research achievements.”
    The ceremony was attended by about 100 people from MEXT, the University of Tokyo, KEK, local government and community, the Kamioka Mining and Smelting Company, and collaborating scientists. At the end, all attendees got together to take a group photo and celebrated the start of the new organization for promotion of neutrino physics and the Hyper-Kamiokande project.


    Hyper-Kamiokande, or Hyper-K, is a straightforward extension of the successful water Cherenkov detector experiment Super-Kamiokande.  It employs well-proven and high-performance water Cherenkov detector technology with established capabilities of neutrino oscillation studies by accelerator and atmospheric neutrinos, proton decay searches, and precision measurements of solar and supernova neutrinos.  Hyper-Kamiokande will provide major new capabilities to make new discoveries in particle and astroparticle physics thanks to an order of magnitude increase in detector mass and improvements in photon detection, along with the envisioned J-PARC Megawatt-class neutrino beam.
    An international Hyper-Kamiokande proto-collaboration has been formed to carry out the experiment; it consists of about 300 researchers from 15 countries as of April 2017. The Hyper-Kamiokande member states are Armenia, Brazil, Canada, Ecuador, France, Italy, Japan, Korea, Poland, Russia, Spain, Switzerland, UK, Ukraine, and USA. The Institute for Cosmic Ray Research of the University of Tokyo and the Institute of Particle and Nuclear Studies of the High Energy Accelerator Research Organization KEK have signed a MoU affirming cooperation in the Hyper-K project to review and develop the program.
    Hyper-K is to be built as a tank with a 187 kiloton fiducial volume containing about 40,000 50-cm photo-multiplier tubes (PMTs), providing 40% photo cathode coverage. The proto-collaboration has succeeded in developing new PMTs with double the single-photon-sensitivity of those in Super-K.   
    The Hyper-K and J-PARC neutrino beam measurement of neutrino oscillation is more likely to provide a 5-sigma discovery of CP violation than any other existing or proposed experiment.  Hyper-K will also be the world leader for nucleon decays.  The sensitivity to the partial lifetime of protons for the decay modes of p→e+π0 is expected to exceed 1035 years.  This is the only known, realistic detector option capable of reaching such a sensitivity for the p→e+π0 mode.  Finally, the astrophysical neutrino program involves precision measurement of solar neutrinos and their matter effects, as well as high-statistics supernova burst and supernova relic neutrinos.

    Related Links


    Media Inquiries

    Concerning the ceremony and the Next-generation Neutrino Science Organization
    Yumiko Takenaga
    Public Relations Officer
    The University of Tokyo Institute for Cosmic Ray Research 
    Tel: 0578-85-9704
    Concerning Hyper-Kamiokande
    Professor Masato Shiozawa 
    The University of Tokyo Institute for Cosmic Ray Research, and Next-generation Neutrino Science Organization

    Kavli Institute for the Physics and Mathematics of the Universe

    Hitoshi Murayama: Kavli IPMU Director (Credit:Kavli IPMU)

    Hitoshi Murayama: Kavli IPMU Director (Credit:Kavli IPMU)

    Kavli IPMU is founded as an international research institution addressing fundamental questions about the universe. What is the universe made of? How did it begin, and what is its fate? What are the laws that govern it, and why do we exist in it? These are basic questions for all humanity, as reflected in the thoroughly international and interdisciplinary character of Kavli IPMU. It aspires to become a truly world class institution, and more than half of its members are already international. With generous support from the Japanese government, Kavli IPMU has been off to a great start from scratch into a world-class research center with about eighty on-site scientific staff. Many exciting papers have been written by our members through collaborations with excellent visitors from abroad.

    5-1-5 Kashiwanoha
    Kashiwa, Chiba


    John Amari
    Public Relations Office
    The University of Tokyo International Institute for Advanced Studies
    Kavli Institute for the Physics and Mathematics of the Universe
    Tel: 04-7136-5977

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  • Week 44 at the Pole

    2017-11-10T16:28:47Z via NavierStokesApp To: Public

    "Week 44 at the Pole"

    Lots of firsts as a new summer season begins at the South Pole. Last week saw the first LC-30 to arrive, seen here as it’s being marshaled in and later after landing and releasing a group of red parkas onto the ice, the first group of many to come. The changing-of-the-guard period at the Pole has begun.

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  • Randomizing the news for science, transplanting genetically engineered skin, and the ethics of experimental brain implants

    2017-11-09T21:28:45Z via NavierStokesApp To: Public

    "Randomizing the news for science, transplanting genetically engineered skin, and the ethics of experimental brain implants"

    This week we hear stories on what to do with experimental brain implants after a study is over, how gene therapy gave a second skin to a boy with a rare epidermal disease, and how bone markings thought to be evidence for early hominid tool use may have been crocodile bites instead, with Online News Editor Catherine Matacic. Sarah Crespi interviews Gary King about his new experiment to bring fresh data to the age-old question of how the news media influences the public. Are journalists setting the agenda or following the crowd? How can you know if a news story makes a ripple in a sea of online information? In a powerful study, King’s group was able to publish randomized stories on 48 small and medium sized news sites in the United States and then track the results.  Listen to previous podcasts. [Image: Chad Sparkes/Flickr; Music: Jeffrey Cook]

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  • ICFA supports 250-GeV International Linear Collider and encourages its realization

    2017-11-09T17:28:40Z via NavierStokesApp To: Public

    "ICFA supports 250-GeV International Linear Collider and encourages its realization"

    ICFA supports 250-GeV International Linear Collider and encourages its realizationPress ReleaseDanielle Thu, 11/09/2017 - 10:453517

    The International Committee for Future Accelerators (ICFA) issued a statement to support the construction of the International Linear Collider (ILC) operating at 250 giga electron volts (GeV) as a so-called “Higgs factory. ICFA also stated its continuing support for the ILC and its encouragement of the collider’s timely realization as an international project led by Japanese initiative.

    The statement was issued at the 12th ICFA seminar held in Ottawa, Canada from 6 to 9 November 2017.

    “It is great to see so much congruency among all major particle physics players in the world,” said Joachim Mnich, Director of Particle Physics and Astroparticle Physics at DESY, Germany, and current chair of ICFA. “Particle physics has produced major discoveries that have attracted the attention of people around the globe like the Higgs particle. The next steps will be even more global as we further explore open fundamental questions using more powerful accelerators. The world’s scientists are coming together to chart this exciting future.”

    The full text of the ICFA statement (issued 8 November 2017):

    ICFA Statement on the ILC Operating at 250 GeV as a Higgs Boson Factory

    The discovery of a Higgs boson in 2012 at the Large Hadron Collider (LHC) at CERN is one of the most significant recent breakthroughs in science and marks a major step forward in fundamental physics. Precision studies of the Higgs boson will further deepen our understanding of the most fundamental laws of matter and its interactions.

    The International Linear Collider (ILC) operating at 250 GeV center-of-mass energy will provide excellent science from precision studies of the Higgs boson. Therefore, ICFA considers the ILC a key science project complementary to the LHC and its upgrade.

    ICFA welcomes the efforts by the Linear Collider Collaboration on cost reductions for the ILC, which indicate that up to 40% cost reduction relative to the 2013 Technical Design Report (500 GeV ILC) is possible for a 250 GeV collider.

    ICFA emphasizes the extendibility of the ILC to higher energies and notes that there is large discovery potential with important additional measurements accessible at energies beyond 250 GeV.

    ICFA thus supports the conclusions of the Linear Collider Board (LCB) in their report presented at this meeting and very strongly encourages Japan to realize the ILC in a timely fashion as a Higgs boson factory with a center-of-mass energy of 250 GeV as an international project1, led by Japanese initiative.

    1 In the LCB report the European XFEL and FAIR are mentioned as recent examples for international projects.

    Ottawa, November 2017

    About ICFA

    ICFA, the International Committee for Future Accelerators, was created to facilitate international collaboration in the construction and use of accelerators for high energy physics. The Committee has 16 members, selected primarily from the regions most deeply involved in high-energy physics.

    About the ILC

    The Linear Collider Collaboration (LCC) is an international endeavour that brings together about 2400 scientists and engineers from more than 300 universities and laboratories in 49 countries and regions. Consisting of two linear accelerators that face each other, the ILC will accelerate and collide electrons and their anti-particles, positrons. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they collide in the detectors at the centre of the machine.

    At the height of operation, bunches of electrons and positrons will collide roughly 7,000 times per second at a total collision energy of 250 GeV, creating a surge of new particles that are tracked and registered in the ILC’s detectors. Each bunch will contain 20 billion electrons or positrons concentrated into an area much smaller than that of a human hair.

    This means a very high rate of collisions. This high “luminosity”, when combined with the very precise interaction of two point-like colliding particles that annihilate each other, will allow the ILC to deliver a wealth of data to scientists that will allow the properties of particles, such as the Higgs boson, recently discovered at the Large Hadron Collider at CERN, to be measured precisely. It could also shed light on new areas of physics such as dark matter.

    The ILC had originally been designed with a collision energy on 500 GeV. The new version of the collider makes it less costly and faster to realise.

    The research and development work that is being done for accelerators and detectors around the world and to take the linear collider project to the next step is coordinated by the Linear Collider Collaboration headed by former LHC Project Manager Lyn Evans. The Linear Collider Board(LCB), representing ICFA, will provide oversight to the LCC, chaired by Tatsuya Nakada, Ecole Polytechnique Fédérale de Lausanne, Switzerland.


    • Linear Collider Communicators (
    • Perrine Royole-Degieux, CNRS/IN2P3, France +33 4 73 40 54 59,
    • Rika Takahashi, KEK, Japan, +81 29 979 6292,
    • Barbara Warmbein, DESY, Germany, +49 40 8998 1847,
    • KEK Press Office, KEK, Japan,

    International Committee for Future Accelerators

    • Linear Collider Communicators (
    • Perrine Royole-Degieux, CNRS/IN2P3, France +33 4 73 40 54 59,
    • Rika Takahashi, KEK, Japan, +81 29 979 6292,
    • Barbara Warmbein, DESY, Germany, +49 40 8998 1847,
    • KEK Press Office, KEK, Japan,

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  • Combatting cancer in challenging environments

    2017-11-09T15:28:32Z via NavierStokesApp To: Public

    "Combatting cancer in challenging environments"

    World map showing access to radiotherapy treatment centres and the shortfall of more than 5000 radiotherapy machines in low- to middle-income countries. (Image: IAEA, AGaRT)

    If you live in a low- or middle-income country, your chances of surviving cancer are significantly lower than if you live in a wealthier economy, and that’s largely due to the availability of radiation therapy.

    A group of international experts in the fields of accelerator design, medical physics and oncology recently met at CERN to try to solve the technical problem of designing a robust linear accelerator (linac) that can be used in more challenging environments. 

    Between 2015 and 2035, the number of cancer diagnoses worldwide is expected to increase by 10 million, with around 65% of those cases in poorer economies. 

    It’s estimated that 12 600 new radiotherapy treatment machines will be needed to treat those patients. 

    “We need to develop a machine that provides state-of-the-art radiation therapy in situations where the power supply is unreliable, the climate is harsh or communications are poor,” explains Manjit Dosanjh, senior advisor for CERN medical applications. “We need to avoid a linac of sub-standard quality that would not only provide lower-quality treatment but would be a disincentive for the recruitment and retention of high-quality staff.”

    Limiting factors to the development and implementation of radiotherapy in lower-resourced nations don’t just include the cost of equipment and infrastructure, but also a shortage of trained personnel to properly calibrate and maintain the equipment and to deliver high-quality treatment. The plan is to design a medical accelerator that is affordable, easy to operate and maintain, and robust enough to be used in areas where these operational challenges might occur.

    “I grew up in Australia, where the distances to hospitals can be vast, the climate can be harsh and local access to medical experts can quite literally be the difference between life and death,” explains accelerator physicist Suzie Sheehy from the University of Oxford and the Science and Technology Facilities Council (STFC). “In this project, the challenges in different environments will be extremely varied, but it seems obvious to me that those of us on the cutting-edge of research in particle accelerators should rise to the challenge of re-designing systems to make them more available to those who need them. I see this as a challenge and an opportunity to take my research into spaces where it is most needed.”

    Jointly organised by CERN, the International Cancer Expert Corps (ICEC) and STFC, the workshop at CERN from 26 to 27 October was funded through the UK’s Global Challenges Research Fund, enabling key participants from Botswana, Ghana, Jordan, Nigeria and Tanzania to share their grass-roots perspectives. Understanding the in-country challenges will improve the effectiveness of the technology under design. Zubi Zubizaretta of the International Atomic Energy Agency (IAEA) also presented the results of the 2017 IAEA Radiation Therapy survey.

    This workshop followed on from the inaugural workshop in November 2016, and a future ICEC workshop will look at the education and training requirements for the estimated 130 000 local staff (oncologists, medical physicists and technicians) who will be needed to operate the treatment machines and deliver patient care.

    This ambitious project aims to have facilities and staff available to treat patients in low- and middle-income countries within 10 years.

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  • Week 43 at the Pole

    2017-11-07T15:28:25Z via NavierStokesApp To: Public

    "Week 43 at the Pole"

    Shoveling snow might not be that much fun, but at least at the South Pole, afterward you can walk away with a pretty “epic” beard, as the winterovers recently put it. Well, if you have a beard to begin with, that is.

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  • Marie Skłodowska-Curie: more alive today than ever!

    2017-11-07T08:28:30Z via NavierStokesApp To: Public

    "Marie Skłodowska-Curie: more alive today than ever!"

    Exactly 150 years ago, on 7 November 1867, Marie Skłodowska was born in Warsaw in Poland. A century and a half later, the name Marie Skłodowska-Curie is associated not only with this double-Nobel-prizewinning scientific luminary, but also with a whole community of European scientists: the Marie Skłodowska-Curie fellows.

    Since the programme was introduced by the European Commission in 1990, the Marie Skłodowska-Curie fellowships have benefitted more than 100 000 scientists at all stages of their careers (from doctoral students to experienced researchers). Above all, the programme aims to promote international and interdisciplinary mobility and excellence in research across all fields.

    Since 2004, the Marie Skłodowska-Curie programme has enabled more than 490 fellows to continue their studies at CERN, usually for a period of two years. At present, 134 participants in the programme are spread across various departments of the Laboratory.

    The aim of the Marie Skłodowska-Curie programme fits perfectly with CERN’s training mission. Several hundred undergraduate, doctoral and post-doctoral students have already benefited from CERN’s exceptional scientific environment and the know-how of its researchers, and the Marie Skłodowska-Curie programme has played a key role in making this happen. No doubt Marie Skłodowska-Curie herself would be proud of this success.



    The Marie Skłodowska-Curie programme through the eyes of its fellows


    Alessandra Gnecchi has been a Marie Skłodowska-Curie fellow in CERN’s Theoretical Physics department since April 2017. She is currently working on black holes in supersymmetric theories.

    Alessandra Gnecchi. (Image: Julien Ordan/CERN)


    “Marie Curie was the first female role model of the modern scientific era – I have a particular attachment to her. I was a young girl in the 1990s and read the book "Madame Curie", which made me decide to become a scientist.

    Today, the Marie Skłodowska-Curie Fellowship Programme allows scientists to study more than one research topic, which is very important. It demonstrates moreover that the recipient was able to write a challenging proposal. Because of these aspects, this fellowship could allow my career to become highly visible and productive, and it is up to me now to exploit this opportunity.”




    Roberto Cardella. (Image: Julien Ordan/CERN)

    Roberto Cardella has been a Marie Skłodowska-Curie fellow in CERN’s Experimental Physics department since September 2016. He is currently working on the upgrade for the inner tracker of the ATLAS experiment.

    “My Marie Skłodowska-Curie Fellowship falls under an ITN (Innovation Training Network) called STREAM. In our consortium, there are currently 17 fellows, spread all over Europe, working on related topics. It is inspiring to work on an innovative topic and to collaborate with other students.

    This programme is a great opportunity for my career. Being part of a training network has already allowed me to get in touch with many institutes all over Europe. I am learning a lot from my colleagues here at CERN and the periodic meetings with the other students and partners in STREAM allow me to broaden my view of this field.”




    Anna Stakia. (Image: Sophia Bennett/CERN)

    Anna Stakia has been a Marie Skłodowska-Curie fellow in CERN’s Experimental Physics department since May 2016. She is currently working on New Physics searches and Machine Learning.

    “Marie Skłodowska-Curie is without a doubt one of the most eminent figures in physics, and in science in general. I feel honoured to be part of a programme that carries her name and I am personally incredibly inspired by it.

    To me, the strongest aspect of the Marie Skłodowska-Curie Programme is that it offers a broad variety of sub-academic and training options through which a fellow can navigate. In this way, any strict academic barriers are overcome. At the same time, the mobility opportunities enhance the fruitful interaction of students not only with researchers and working environments in foreign countries, but also among themselves, thus creating a fertile field for collaboration, which expands their research horizons, accelerates their progress and boosts their career potential.”



    Today, to mark 150 years since the birth of Marie Skłodowska-Curie, CERN, the University of Liverpool and the Ludwig Maximilian University of Munich are organising a series of events for the scientific community and the general public. For more information, visit the event website.

    From 3 pm (CET), watch the presentations at the University of Liverpool and at CERN.

    To go further, read the article published in July on Marie Curie's granddaughter's visit to CERN.

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  • How much does a kilogram weigh?

    2017-11-03T15:28:31Z via NavierStokesApp To: Public

    "How much does a kilogram weigh?"

    The National Institute of Standards and Technology (NIST)-4 Kibble balance measured Planck's constant to within 13 parts per billion in 2017, accurate enough to assist with the redefinition of the kilogram. (Image: J. L. Lee/NIST)

    The Kilogram doesn’t weigh a kilogram any more. This sad news was announced during a seminar at CERN on Thursday, 26 October by Professor Klaus von Klitzing, who was awarded the 1985 Nobel Prize in Physics for the discovery of the quantised Hall effect. “We are about to witness a revolutionary change in the way the kilogram is defined,” he declared.  

    Together with six other units – metre, second, ampere, kelvin, mole, and candela – the kilogram, a unit of mass, is part of the International System of Units (SI) that is used as a basis to express every measurable object or phenomenon in nature in numbers. This unit’s current definition is based on a small platinum and iridium cylinder, known as “le grand K”, that weighs exactly one kilogram. The cylinder was crafted in 1889 and, since then, has been kept safe under three glass bell jars in a high-security vault on the outskirts of Paris. There is one problem: the current standard kilogram is losing weight. About 50 micrograms, at the latest check. Enough to be different from its once-identical copies stored in laboratories around the world. 

    To solve this weight(y) problem, scientists have been looking for a new definition of the kilogram.

    At the quadrennial General Conference on Weights and Measures in 2014, the scientific metrology community formally agreed to redefine the kilogram in terms of the Planck constant (h), a quantum-mechanical quantity relating a particle’s energy to its frequency, and, through Einstein’s equation E = mc2, to its mass. Planck’s constant is one of the fundamental constants (physical quantities that are constants of natural phenomena, such as the speed of light or the electric charge of a proton).

    Planck’s constant will be assigned an exact fixed value based on the best measurements obtained worldwide. The kilogram will be redefined through the relationship between Planck’s constant and mass.

    “There’s nothing to be worried about,” says Klaus von Klitzing. “The new kilogram will be defined in such a way that (nearly) nothing will change in our daily life. It won’t make the kilogram more precise either, it will just make it more stable and more universal.”

    However, the redefinition process is not that simple. The International Committee for Weights and Measures, the governing body responsible for ensuring international agreement on measurements, has imposed strict requirements on the procedure to follow: three independent experiments measuring the Planck constant must agree on the derived value of the kilogram with uncertainties below 50 parts per billion, and at least one must achieve an uncertainty below 20 parts per billion. Fifty parts per billion in this case equals approximately 50 micrograms – about the weight of an eyelash.

    Two types of experiment have proved able to link the Planck constant to mass with such extraordinary precision. One method, led by an international team known as the Avogadro Project, entails counting the atoms in a silicon-28 sphere that weighs the same as the reference kilogram. The second method involves a sort of scale known as a watt (or Kibble) balance. Here, electromagnetic forces are counterbalanced by a test mass calibrated according to the reference kilogram.

    And that’s where the important discovery made by Klaus von Klitzing in 1980, which earned him the Nobel Prize in Physics, comes into play. In order to get extremely precise measurements of the current and voltage making up the electromagnetic forces in the watt balance, scientists use two different quantum-electrical universal constants. One of these is the von Klitzing constant, which is known with extreme precision, and can in turn be defined in terms of the Planck constant and the charge of the electron. The von Klitzing constant describes how resistance is quantised in a phenomenon called the “quantum Hall effect”, a quantum-mechanical phenomenon observed when electrons are confined in an extra-thin metallic layer subjected to low temperatures and strong magnetic fields.

    This is truly a big revolution,” von Klitzing says. “In fact, it has been dubbed the biggest revolution in metrology since the French Revolution, when the first global system of units was introduced by the French Academy of Sciences.”

    CERN is playing its part in this revolution. The Laboratory participated in a metrology project launched by the Swiss Metrology Office (METAS) to build a watt balance, which will be used to disseminate the definition of the new kilogram through extremely precise measurements of the Planck constant. CERN provided a crucial element of the watt balance: the magnetic circuit, which is needed to generate the electromagnetic forces balanced by the test mass. The magnet needs to be extremely stable during the measurement and provide a very homogenous magnetic field.

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