A communication resource from the world's particle physics laboratories.
Candidates for a Higgs produced with a Z. ATLAS (l): both decay ultimately to leptons, leaving two electrons (green) and four muons (red). CMS (r): the Higgs decays to two charm quarks forming jets (cones); the Z decays to electrons (green) (Image: ATLAS/CMS/CERN)
Among the highlights are the latest precision measurements involving the Higgs boson. In only seven years since its discovery, scientists have carefully studied several of the properties of this unique particle, which is increasingly becoming a powerful tool in the search for new physics.
The two-stage miniature accelerator is operated with terahertz radiation (shown here in red). In a first step (left) the electron bunches (shown in blue) are compressed, in a second step (right) they are accelerated. The two individual elements are each about two centimetres wide. Credit: DESY, Gesine Born
“The wavelength of terahertz radiation is about a hundred times shorter than the radio waves currently used to accelerate particles,” explained Kärtner. “This means that the components of the accelerator can also be built to be around a hundred times smaller.”
A multicolor mosaic image of the massive galaxy cluster, Abell 370, located in the constellation Cetus – named for a sea monster in Greek mythology. Galaxy clusters are the largest structures in the universe bound by gravity, and consist of thousands of galaxies and large amounts of dark matter. Abell 370 formed when two less massive galaxy clusters merged together billions of years ago. It is more than 6.5 billion light-years away from Earth. The mosaic is approximately 4.5 million light-years across and has been constructed from deep optical imaging in the Legacy Surveys’ eighth data release. (Credit: John Moustakas/Siena College; Legacy Surveys team)
“We are building a detailed map of the universe and measuring its expansion history over the last 10 to 12 billion years,” Dey said. “The DESI experiment represents the most detailed – and definitely the coolest – cosmic cartography experiment undertaken to date. Although the imaging was carried out for the DESI project, the data are publicly available so everyone can enjoy the sky and explore the cosmos.”
The 2019 CERN Beamline for Schools winners: (from left) Team from the West High School in Salt Lake City, USA (Image: Kara Budge) and team from the Praedinius Gymnasium in Groningen, Netherlands (Image: Martin Mug).
“We are all very excited to welcome this year’s winners to DESY. This is a new chapter in the history of this competition because, for the first time, we are taking the finals of the competition to another research laboratory. As always, the more then 60 voluntary experts from CERN and DESY evaluated all the proposals for their creativity, motivation, proposed methodology, feasibility and their overall ability to explore some of the concepts of modern particle physics” said Sarah Aretz, BL4S project manager.
From the colour difference of two slightly delayed laser flashes (left) a non-linear crystal generates an energetic terahertz pulse (right). Credit: DESY, Lucid Berlin
“The wavelength of terahertz radiation is about a thousand times shorter than the radio waves that are currently used to accelerate particles,” says Kärtner, who is a lead scientist at DESY. “This means that the components of the accelerator can also be built to be around a thousand times smaller.”
“The Granada symposium is an important step in the process of updating the European Strategy for Particle Physics and aims to prioritise our scientific goals and prepare for the upcoming generation of facilities and experiments,” said the President of the CERN Council, Ursula Bassler. “The discussions will focus on the scientific reach of potential new projects, the associated technological challenges and the resources required.”
The BESIII collaboration observed baryon polarization in baryon-antibaryon (matter-antimatter particle) events from J/ψ particles produced at the BEPCII collider.
Artistic view of the Science Gateway. (Image: RPBW)
“The Science Gateway will enable CERN to expand significantly its education and outreach offering for the general public, in particular the younger generations. We will be able to share with everybody the fascination of exploring and learning how matter and the universe work, the advanced technologies we need to develop in order to build our ambitious instruments and their impact on society, and how science can influence our daily life,” says CERN Director-General Fabiola Gianotti. “I am deeply grateful to the donors for their crucial support in the fulfilment of this beautiful project.”
DESI "first light" image of the Whirlpool Galaxy, also known as Messier 51. This image was obtained the first night of observing with the DESI Commissioning Instrument on the Mayall Telescope at the Kitt Peak National Observatory in Tucson, Arizona; an r-band filter was used to capture the red light from the galaxy. (Credit: DESI Collaboration)
”It was an incredible moment to see those first images on the control room monitors,” said Connie Rockosi, who is leading this early commissioning of the DESI lenses. “A whole lot of people have worked really hard on this, and it’s really exciting to show how much has come together already.”
This year, results from the main experiments at the Large Hadron Collider (ALICE, ATLAS, CMS and LHCb) included new pentaquarks, new charmed beauty particles, a more precise measurement of matter–antimatter asymmetry in strange beauty particles, and new results from heavy-ion collisions.
The first hadronic event in the Belle II Phase3 physics run
On March 25 19:44 (JST), 2019, electron-positron collisions have restarted at the SuperKEKB collider, and the Belle II experiment has now kicked off its physics data taking. Belle II is now fully instrumented with a state-of-the-art vertex detector, just in time for the start of the cherry blossom season in Japan.
(From left) Mladen Šarčević, Serbian Minister of Education, Science and Technological Development, Ana Brnabić, Prime Minister of the Republic of Serbia, Fabiola Gianotti, CERN Director-General, and Charlotte Warakaulle, CERN Director for International Relations.
(Image: CERN)
“Serbia has a longstanding relationship with CERN, with the continuous involvement of Serbian scientists in CERN’s major experiments. I’m very happy to see that Serbia’s initiative to seek membership status of CERN has now converged and that we can welcome Serbia as a Member State,”said Ursula Bassler, President of the CERN Council.
“The result is a milestone in the history of particle physics. Ever since the discovery of the D meson more than 40 years ago, particle physicists have suspected that CP violation also occurs in this system, but it was only now, using essentially the full data sample collected by the experiment, that the LHCb collaboration has finally been able to observe the effect,” said CERN Director for Research and Computing, Eckhard Elsen.
The interior vacuum "tank" of TRIUMF's main cyclotron, the largest in the world. (Courtesy of TRIUMF)
“This investment from the federal government will allow TRIUMF to realize its full potential,” said Dr. Digvir Jayas, Chair of the TRIUMF Board of Management. “By leveraging ARIEL, IAMI, and TRIUMF Innovations, TRIUMF will continue to be a global leader in translating science and technology into innovation and commercialization. Today’s announcement represents a major milestone for the lab’s community of university members, researchers, students, users, industry partners and collaborators, and for all the people the lab serves.”
This new complex of buildings, located near Fermilab’s Wilson Hall, will host the 215-meter-long (700-foot-long) PIP-II particle accelerator, the new heart of the Fermilab accelerator complex. Credit: Fermilab
“The PIP-II accelerator project will fuel discovery at Fermilab for decades to come, facilitating new innovations and new insights into our universe. I’m excited for the further cooperation between America’s premier particle physics and accelerator laboratory and its international partners, and the resulting better understanding of the universe.”
Under Secretary for Science Paul Dabbar
The proton spin puzzle: Scientists want to know how different constituents of the proton contribute to its spin, a fundamental property that plays a role in how these building blocks give rise to nearly all visible matter in the universe. Pieces of the puzzle include the orbital angular momentum of quarks and gluons (top left), gluon spin (top right) and quark and antiquark spin (bottom). The latest data from RHIC reveal that the antiquarks' contribution is more complex than previously thought.
“This measurement shows that the quark piece of the proton spin puzzle is made of several pieces,” said James Drachenberg, a deputy spokesperson for STAR from Abilene Christian University. “It’s not a boring puzzle; it’s not evenly divided. There’s a more complicated picture and this result is giving us the first glimpse of what that picture looks like.”
Belle II and SuperKEKB are poised to become the world’s first Super B factory facility. Belle II aims to accumulate 50 times more data than its predecessor, Belle, and to seek out new physics hidden in subatomic particles that could shed light on mysteries of the early universe.
A 3D picture of the planned FASER detector as seen in the TI12 tunnel. The detector is precisely aligned with the collision axis in ATLAS, 480 m away from the collision point (Image: FASER/CERN)
“FASER is a neat physics proposal that addresses a particular aspect in the search for physics beyond the Standard Model and I am pleased to see it being implemented so efficiently,” adds Eckhard Elsen, CERN’s Director for Research and Computing.
While working at CERN, Sir Tim Berners-Lee invented the World Wide Web.
“It is a great honour and a source of pride for CERN to host an event to mark the 30th anniversary of Tim Berners-Lee’s proposal for what would become the World Wide Web, and I am delighted that Sir Tim will be with us on the day,” said CERN Director-General, Fabiola Gianotti. "The Web's invention has transformed our world, and continues to show how fundamental research fuels innovation. CERN's culture of openness was a key factor in the Laboratory’s decision in 1993 to make the web available free to everybody, a key step in its development and subsequent spread.”
Figure 2: Schematic view of the detector system of the KOTO experiment. The neutral kaon beam enters from the left. The electromagnetic calorimeter in purple measures two gamma-rays from a neutral pion.
The KOTO collaboration set the upper limit of once in three hundred million on the rate of the neutral K-meson (kaon) decay into a neutral pi meson and a pair of neutrinos from the analysis of the data set collected in 2015, and improved the world’s best sensitivity by an order of magnitude.
Fabiola Gianotti, CERN Director-General, and Blaženka Divjak, Minister of Science and Education of the Republic of Croatia, signed an Agreement admitting Croatia as an Associate Member of CERN.
“It is a great pleasure to welcome Croatia into the CERN family as an Associate Member. Croatian scientists have made important contributions to a large variety of experiments at CERN for almost four decades and as an Associate Member, new opportunities open up for Croatia in scientific collaboration, technological development, education and training,” said Fabiola Gianotti.
A snapshot of a plasma channel’s electron density profile (blue) formed inside a sapphire tube (gray) with the combination of an electrical discharge and an 8-nanosecond laser pulse (red, orange, and yellow). This plasma channel was used to guide femtoseconds-long “driver” laser pulses from the BELLA petawatt laser system, which generated plasma waves and accelerated electrons to 8 billion electron volts in just 20 centimeters. (Credit: Gennadiy Bagdasarov/Keldysh Institute of Applied Mathematics; Anthony Gonsalves and Jean-Luc Vay/Berkeley Lab)
“In the future, multiple high-energy stages of electron acceleration could be coupled together to realize an electron-positron collider to explore fundamental physics with new precision,” said Eric Esarey, BELLA Center Director.
The BESIII detector finished accumulating a sample of 10 billion J/ψ events together with a continuum data sample on Feb. 11. The 10 billion J/ψ-event sample accumulated at BESIII is the world’s largest data sample produced directly from electron-positron annihilations.
The proposed layout of the future circular collider (Image: CERN)
“The FCC’s ultimate goal is to provide a 100-km 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.”
The National Science Foundation’s Cerro Tololo Inter-American Observatory in Chile houses the Dark Energy Camera. Photo: Fermilab
"Although the data-taking for DES is coming to an end, DECam will continue its exploration of the universe from the Blanco telescope and is expected remain a front-line engine of discovery for many years,” Heathcote said.
RHIC's STAR detector tracks the thousands of particles produced by each ion collision. It weighs 1,200 tons and is as large as a house.
Berndt Mueller, Brookhaven’s Associate Laboratory Director for Nuclear and Particle Physics, noted, “This 19th year of operations demonstrates once again how the RHIC team — both accelerator physicists and experimentalists — is continuing to explore innovative technologies and ways to stretch the physics capabilities of the most versatile particle accelerator in the world.”
-- Symmetry Magazine, Kathryn Jepsen
This year, October 31 was more than just Halloween. It was also the first global celebration of Dark Matter Day. In 25 countries, 11 US states and online, people interacted with scientists, watched demonstrations, viewed films, took in art exhibits and toured laboratories to learn about the ongoing search for dark matter.
Symmetry has collected a series of photos from participants around the world. Check out how people celebrated Dark Matter Day and download a commemorative dark matter poster (to be printed using visible matter).
This report distills the findings of a series of international peer reviews of the communications and outreach functions of large-scale multidisciplinary science laboratories around the world.