Traditional Korean music and dancing marked the start of the International Conference on High Energy Physics (ICHEP) in Seoul, South Korea. (Image: Marcos Dracos)
This year’s International Conference on High Energy Physics (ICHEP) — the “biggie” of conferences in high-energy physics — took place in Seoul, South Korea, on 4–11 July.
For a taste of the important scientific findings presented at the conference by the collaborations behind the main experiments at the Large Hadron Collider (LHC), read this related update for scientists.
PARK INNOVAARE in Switzerland is now home to the newest CERN business incubation centre. (Image: Daniel Erne)
CERN is behind a network of ten BICs, hosted in ten of its Member States, to assist entrepreneurs and small businesses in taking CERN technologies and expertise to the market. In practice, CERN supports the selected companies through technical visits to CERN, technical consultancy and services, and preferential rate licensing of CERN intellectual property. The incubated start-ups have access to CERN’s expertise, as well as to CERN’s international BIC network.
PARK INNOVAARE is a unique innovation centre that operates with partners PSI (Paul Scherrer Institute) and FHNW (University of Applied Sciences and Arts in Northwestern Switzerland). These partners will support start-ups by providing office-space, technological expertise, business coaching programmes, access to local and national networks, and support in accessing finance. Start-ups entering the PARK INNOVAARE BIC will also receive funding for the realisation of their projects.
Swiss technology start-ups are invited to apply before 17 September 2018, and a jury will select the first incubatee. The selected start-ups will be presented at the Start-up Forum in Aargau in November.
Speakers from PARK INNOVAARE, CERN, PSI and FHNW at the launch of the Swiss Business Incubation Centre of CERN Technologies. (Image: PARK INNOVAARE)
There are currently 23 start-ups worldwide using CERN technology and know-how. These have applications in domains as diverse as medtech, digital preservation and material science.
For details about the BIC of CERN Technologies at PARK INNOVAARE and more details about the programme, please visit www.parkinnovaare.ch/cern-bic
Timepix3, one of the read-out chips of Medipix (Image: CERN)
What if, instead of a black and white X-ray picture, a doctor of a cancer patient had access to colour images identifying the tissues being scanned? This colour X-ray imaging technique could produce clearer and more accurate pictures and help doctors give their patients more accurate diagnoses.
This is now a reality, thanks to a New-Zealand company that scanned, for the first time, a human body using a breakthrough colour medical scanner based on the Medipix3 technology developed at CERN. Father and son scientists Professors Phil and Anthony Butler from Canterbury and Otago Universities spent a decade building and refining their product.
Medipix is a family of read-out chips for particle imaging and detection. The original concept of Medipix is that it works like a camera, detecting and counting each individual particle hitting the pixels when its electronic shutter is open. This enables high-resolution, high-contrast, very reliable images, making it unique for imaging applications in particular in the medical field.
Hybrid pixel-detector technology was initially developed to address the needs of particle tracking at the Large Hadron Collider, and successive generations of Medipix chips have demonstrated over 20 years the great potential of the technology outside of high-energy physics.
MARS Bioimaging Ltd, which is commercialising the 3D scanner, is linked to the University of Otago and Canterbury. The latter together with more than 20 research institutes forms the third generation of Medipix collaboration. The Medipix3 chip is the most advanced chip available today and Professor Phil Butler recognises that “this technology sets the machine apart diagnostically because its small pixels and accurate energy resolution mean that this new imaging tool is able to get images that no other imaging tool can achieve.”
MARS’ solution couples the spectroscopic information generated by the Medipix3 enabled detector with powerful algorithms to generate 3D images. The colours represent different energy levels of the X-ray photons as recorded by the detector hence identifying different components of body parts such as fat, water, calcium, and disease markers.
A 3D image of a wrist with a watch showing part of the finger bones in white and soft tissue in red. (Image: MARS Bioimaging Ltd)
So far, researchers have been using a small version of the MARS scanner to study cancer, bone and joint health, and vascular diseases that cause heart attacks and strokes. “In all of these studies, promising early results suggest that when spectral imaging is routinely used in clinics it will enable more accurate diagnosis and personalisation of treatment,” Professor Anthony Butler says.
CERN's Knowledge Transfer group has a long-standing expertise in transferring CERN technologies, in particular for medical applications. In the case of the 3D scanner, a license agreement has been established between CERN, on behalf of Medipix3 collaboration and MARS Bioimaging Ltd. As Aurélie Pezous, CERN Knowledge Transfer Officer states, “It is always satisfying to see our work leveraging benefits for patients around the world. Real-life applications such as this one fuels our efforts to reach even further.”
In the coming months, orthopaedic and rheumatology patients in New Zealand will be scanned by the revolutionary MARS scanner in a clinical trial that is a world first, paving the way to a potentially routine use of this new generation equipment.
ISOLDE’s resonant ionization laser ion source (RILIS) provided the first beams of neutron-rich chromium isotopes to the ISOLTRAP precision balance. (Image: Noemí Carabán González/CERN)
CERN’s nuclear physics facility, ISOLDE, has minted a new coin in its impressive collection of isotopes. The facility has forged neutron-rich isotopes of the element chromium for the first time, and in prodigious quantities. These isotopes were measured by the precision balance ISOLTRAP, which has been performing mass measurements at ISOLDE for the last 30 years. The new mass values, reported in Physical Review Letters, are up to 300 times more precise than previous results, offering new insight into the nuclear structure of chromium isotopes.
The fact that atoms weigh less than the sum of the masses of their constituent protons, neutrons and electrons gives access to their nuclear binding energy –theminimum energy required to disassemble an atom’s nucleus. Therefore, the nuclear binding energy provides information about an atom’s nuclear structure. Certain configurations of protons and neutrons are more strongly bound than others, revealing “magic numbers” of protons or neutrons that are arranged into filled shells within the nucleus. One of the main goals of modern nuclear physics is to produce systems at the extremes of nuclear stability to check whether these magic numbers are still valid (see CERN Courier), providing a tough test for nuclear models.
Chromium (Cr) has 24 protons, situating it midway between the magic calcium (with 20 protons) and the magic nickel (with 28). Its isotopes with a large number of neutrons, around 63Cr, are interesting for the study of nuclear structure. This is because these isotopes are located midway between the magic neutron numbers 28 and 50, where different nuclear models predict different deformed nuclear shapes and in some cases a new magic number at neutron number 40.
In this new study, the ISOLDE researchers have used a chemically selective ion source called resonant ionization laser ion source (RILIS) to deliver beams of neutron-rich chromium isotopes to the ISOLTRAP weigh station, allowing it to venture as far in neutron number as63Cr, whose half-life is only 130 ms.
The filled shells of nuclei with magic numbers favour spherical nuclear shapes. By contrast, the nuclei of the chromium isotopes weighed by ISOLTRAP are deformed. However, contrary to previous conclusions, the ISOLDE measurements show that the deformation sets in gradually with the addition of a further neutron. Comparison between the ISOLDE measurements and improved models to describe unfilled-shell nuclei is expected to shed more light on the nuclear structure of chromium isotopes.
François Englert (left) and Peter Higgs at CERN on 4 July 2012, on the occasion of the announcement of the discovery of a Higgs boson (Image: Maximilien Brice/CERN)
It is six years ago that the discovery of the Higgs boson was announced, to great fanfare in the world’s media, as a crowning success of CERN’s Large Hadron Collider (LHC). The excitement of those days now seems a distant memory, replaced by a growing sense of disappointment at the lack of any major discovery thereafter.
While there are valid reasons to feel less than delighted by the null results of searches for physics beyond the Standard Model (SM), this does not justify a mood of despondency. A particular concern is that, in today’s hyper-connected world, apparently harmless academic discussions risk evolving into a negative outlook for the field in broader society. For example, a recent news article in Natureled on the LHC’s “failure to detect new particles beyond the Higgs”, while The Economistreported that “Fundamental physics is frustrating physicists”. Equally worryingly, the situation in particle physics is sometimes negatively contrasted with that for gravitational waves: while the latter is, quite rightly, heralded as the start of a new era of exploration, the discovery of the Higgs is often described as the end of a long effort to complete the SM.
Let’s look at things more positively. The Higgs boson is a totally new type of fundamental particle that allows unprecedented tests of electroweak symmetry breaking. It thus provides us with a novel microscope with which to probe the universe at the smallest scales, in analogy with the prospects for new gravitational-wave telescopes that will study the largest scales. There is a clear need to measure its couplings to other particles – especially its coupling with itself – and to explore potential connections between the Higgs and hidden or dark sectors. These arguments alone provide ample motivation for the next generation of colliders including and beyond the high-luminosity LHC upgrade.
So far the Higgs boson indeed looks SM-like, but some perspective is necessary. It took more than 40 years from the discovery of the neutrino to the realisation that it is not massless and therefore not SM-like; addressing this mystery is now a key component of the global particle-physics programme. Turning to my own main research area, the beauty quark – which reached its 40th birthday last year – is another example of a long-established particle that is now providing exciting hints of new phenomena (see Beauty quarks test lepton universality). One thrilling scenario, if these deviations from the SM are confirmed, is that the new physics landscape can be explored through both the b and Higgs microscopes. Let’s call it “multi-messenger particle physics”.
How the results of our research are communicated to the public has never been more important. We must be honest about the lack of new physics that we all hoped would be found in early LHC data, yet to characterise this as a “failure” is absurd. If anything, the LHC has been more successful than expected, leaving its experiments struggling to keep up with the astonishing rates of delivered data. Particle physics is, after all, about exploring the unknown; the analysis of LHC data has led to thousands of publications and a wealth of new knowledge, and there is every possibility that there are big discoveries waiting to be made with further data and more innovative analyses. We also should not overlook the returns to society that the LHC has brought, from technology developments with associated spin-offs to the training of thousands of highly skilled young researchers.
The level of expectation that has been heaped on the LHC seems unprecedented in the history of physics. Has any other facility been considered to have produced disappointing results because only one Nobel-prize winning discovery was made in its first few years of operation? Perhaps this reflects that the LHC is simply the right machine at the right time, but that time is not over: our new microscope is set to run for the next two decades and bring physics at the TeV scale into clear focus. The more we talk about that, the better our long-term chances of success.
This text first appeared in the March 2018 issue of the CERN Courier.
X-band technology at the CLEAR test facility at CERN (Image : Julien Ordan/CERN)
The Large Hadron Collider (LHC) collides protons at an energy of 13 TeV and is expected to operate until the mid-2030s. Looking beyond, one possible path for particle physics is a high-energy linear electron–positron collider. The Compact Linear Collider (CLIC) project at CERN envisions an initial-energy 380 GeV centre-of-mass facility focused on precision measurements of the Higgs boson and the top quark, which are promising targets to search for deviations from the Standard Model.
The accelerator technology required by CLIC has been under development for around 30 years. During the past decade, this technology has matured to the point where it is being transferred to applications beyond high-energy physics. Specifically, the unique requirements for CLIC have led to a new “X-band” accelerator technology that is attracting the interest of light-source and medical communities, and which would have been difficult for those communities to advance themselves due to their diverse nature.
Perhaps the most significant X-band application is for “X-ray free-electron laser” (XFEL) facilities that produce intense and short X-ray bursts by passing a very low-emittance electron beam through an undulator magnet. CLIC technology, both the high-frequency and high-gradient aspects, has the potential to significantly reduce the cost of such X-ray facilities, allowing them to be funded at the regional scale.
Linear-accelerator technology is also working its way beyond electron linacs, particularly in the treatment of cancer. The most common accelerator-based cancer treatment is X-rays, but protons and heavy ions offer many potential advantages. A new generation of linacs offer the potential for smaller, lower-cost facilities for hadron therapy with additional flexibility.
While CLIC’s primary objective is to provide technology for a particle-physics facility in the multi-TeV range, an application requiring a mere 45 MeV beam finds itself benefiting from the same technology. Called Smart*Light, this small-scale project is developing a compact X-ray source for a wide range of applications including cultural heritage, metallurgy, geology and medical. It aims to make the equipment small and inexpensive enough to be able to integrate it in a museum or university setting.
Watch the recording of a recent seminar at CERN about the use of Smart*Light for the investigation of art objects.
Collaboration has driven the wider adoption of CLIC’s technology, which is extremely important for CLIC itself. It enlarges the commercial base, driving costs down and reliability up, and making firms more likely to invest. Another benefit is the improved understanding of the technology and its operability by accelerator experts, with a broadened user base bringing new ideas.
Despite having started in large linear colliders, the use of the technology now starts to be dominated by a proliferation of small-scale applications. Few of these were envisaged when CLIC was formulated in the late 1980s – XFELs were in their infancy at the time. As the technology is applied further, its performance will rise even more, perhaps even leading to the use of smaller applications to build a higher-energy collider.
Read the full article on the CERN Courier.
ISOLDE researcher Magdalena Kowalska is leading the study into DNA molecules using isotopes.
Though known for particle physics, CERN’s facilities also dip their toes into other fields. For example, researchers at CERN’s nuclear physics facility, ISOLDE, have been investigating DNA molecules. The researchers have applied an ultrasensitive variant of nuclear magnetic resonance (NMR) spectroscopy, called beta-NMR, to these molecules in both solid and cell-like liquid environments. Beta-NMR has been used widely to study exotic nuclei and solid materials, but this is the first time the technique has been applied to biological matter.
The data, recorded in May, show that the NMR signal produced by a sodium isotope changes and disappears much more slowly in the presence of DNA than without it. This points to the expected interaction between this vital element and DNA. Future work should shed more light on this interaction and uncover the binding site of sodium in the DNA.
NMR spectroscopy is one of the go-to techniques for visualising the structure of biological molecules, such as proteins and DNA, and their interaction with essential metal ions such as sodium and potassium. It does so by placing a few micrograms of a sample of biological molecules in a strong magnetic field and analysing how the magnetic nuclei within the sample absorb radio waves. The magnetic field causes these nuclei, or spins, to line up either parallel or antiparallel to the magnetic field, and the radio waves cause the spins to change between different spin directions. The radio frequency that triggers this change depends on the strength of the magnetic field and the identity and environment of the atoms of the nuclei. The spin flip, or NMR signal, is detected through the electric current it induces in a radiofrequency coil.
However, the technique is relatively insensitive; to produce a useful NMR signal, it requires a large number of magnetic nuclei. By contrast, beta-NMR spectroscopy requires far fewer magnetic nuclei inside the sample. In this variant of NMR, which is up to a billion times more sensitive than conventional NMR, the magnetic nuclei can be neatly oriented using lasers and the NMR signal is detected through the emission of beta particles (electrons or positrons) from magnetic short-lived nuclei that are implanted into the sample.
In their study, the ISOLDE researchers, led by Magdalena Kowalska, took short-livedsodium ions produced at the ISOLDE facility, placed them into samples containing DNA molecules – both solid and cell-like liquid samples – and applied the beta-NMR technique. They studied DNA G-quadruplex structures, which are a variation of the well-known double-helix structure.
The researchers found that the NMR signal emitted by sodium disappears much more slowly, on a timescale of the order of a second, when DNA G-quadruplex structuresare present in the samples. The result is in agreement with classical NMR studies on other DNA structures, which showed that the same can happen when “free” sodium moves towards DNA. Future work involving a detailed comparison between the NMR spectra and chemical calculations is expected to reveal the location of sodium in the DNA samples.
In the long run, the researchers also hope to use other isotopes, such as copper and zinc, which, for reasons that are not yet fully clear, tend to be found in large and small quantities respectively, in the brains of patients with Alzheimer’s or Parkinson’s disease.
Screenshot of the application video of one of the winning teams (Image: Cryptic Ontics)
High-school students from the International School of Manila, Philippines, and R.N. Podar School in Mumbai, India, are the winners of the 2018 Beamline for Schools competition. In September, they will carry out their proposed experiments at CERN together with professional researchers.
This CERN initiative is open to high-school students from all over the world who want to get a taste of the life of a scientist. This year, 195 teams took part, an increase on the 180 teams participating in 2017. Overall, the competition involved more than 1500 students from 42 countries. The teams submitted a written proposal to address a physics question using a particle beam at CERN and a video to explain how they would do so.
Taking into consideration creativity, motivation, feasibility and scientific method, CERN experts shortlisted thirty teams. All these teams will receive a cosmic ray detector known as Cosmic Pi. The judges had a hard time choosing the winners but finally selected “Beamcats” from the Philippines and “Cryptic Ontics” from India. Among the shortlisted teams the following were exceptionally good and came close to winning: Club de Física “Enrico Fermi” (Spain), Dubai College Raiders of the Lost Quark (United Arab Emirates), ITU Bee (Turkey), Lahore Grammar School Johar Town (Pakistan), PAPRAD - Plastic Absorption of Proton Radiation (Sweden), Relativity Clock (Iran), Stalking Particles (Bangladesh) and The Strong Force (South Africa).
The Filipino team consists of three boys and three girls, who proposed to use particles known as pions for cancer therapy. They will simulate human tissues using materials that are similar in composition to the human body, and measure the energy lost by the beam while travelling through it, technically known as the Bragg peak. The use of subatomic particles instead of X-rays in anti-cancer radiation therapy is gaining increasing interest as it is potentially less harmful to the healthy tissues surrounding tumours. For example, CERN was actively involved in a collaborative design study that laid the foundations for two of Europe’s proton and carbon-ion therapy centres: CNAO in Italy and MedAustron in Austria.
The application video from the team “Beamcats”, from the International school of Manila, Philippines
“Hard work and perseverance is the foundation on which we measure our success, and the fact that our CERN mentors identified this quality within us and our proposal was truly amazing,” enthused Charvie Yadav from the Beamcats team. “This is such a valuable experience for me. I hope this inspires young students all around the world.”
The “Cryptic Ontics” team consists of nine boys and nine girls. A core team of nine students will visit CERN to study the deflection of protons and electrons in a magnetic field. By studying the interaction between charged particles and a magnetic ﬁeld in the lab, the team hopes to learn about the anomalies in the Earth's magnetic ﬁeld as a function of the variance of the cosmic-ray detection rate.
The application video from the team “Cryptic Ontics”, R.N. Podar School in Mumbai, India
“Winning this competition will not just help us practically in our studies and work, but will also teach us more about other people and working together. Altogether, I look forward to visiting CERN and to learning and growing along the way,” said Satchit Chatterji from the Cryptic Ontics team.
This is the first time that Asian high schools have won the competition. Previously, students from the Netherlands, Greece, Italy (twice), South Africa, Poland, the United Kingdom and Canada were selected to perform their proposed experiments at CERN.
The first Beamline for Schools competition was held in 2014 on the occasion of CERN’s 60th anniversary. “This year it was even harder than before to select two winning teams. Many of the participating teams would have well deserved to be invited to CERN to carry out their experiments. We are grateful for the work and effort of all the teams who entered the competition and hope that even more teachers will encourage their students in the future to take part in this amazing experience,”said Sarah Aretz, Beamline for Schools project leader.
Beamline for Schools is an education and outreach project funded by the CERN & Society Foundation, supported by individual donors, foundations and companies. In 2018, the project is partially funded by the Arconic Foundation; additional contributions have been received from the Motorola Solutions Foundation, Amgen, as well as from the Ernest Solvay Fund, which is managed by the King Baudouin Foundation.
CERN’s accelerators will enter a two-year maintenance and upgrade shutdown at the end of this year, which means that there will be no beams serving the beamlines. CERN has therefore teamed up with the DESY research centre in Hamburg, Germany's national laboratory for particle physics, accelerators and photon science, to continue the Beamline for Schools project during the upgrade, and the 2019 winners will perform their experiments there.
European hadron therapy facilities in operation or under construction in 2016 (Image: CERN Courier)
From 19 to 21 June, sixty experts from all over the world are meeting at the European Scientific Institute (ESI) in Archamps, France, to explore future medical accelerators for treating cancer with ions. Ion therapy, also known as hadron therapy, is an advanced form of radiotherapy that uses protons and other ions to precisely target tumour cells while sparing the surrounding healthy tissues. While commercial solutions for proton therapy are now available, there are only a few bespoke facilities providing heavier ions such as carbon. The cost, complexity and size of these facilities are hampering the widespread adoption of this treatment (read more in the CERN Courier features “Therapeutic Particles” and “The changing landscape of cancer therapy”).
The workshop, jointly organised by CERN and GSI, allows scientists to exchange ideas, share current experiences and explore future possibilities towards the design for a next-generation medical research and therapy facility with ions in Europe. It is the second workshop in the series “Ions for cancer therapy, space research and material science”, initiated by GSI to highlight the increasingly important interface between physics and its applications.
CERN’s Maurizio Vretenar, one of the workshop co-organisers, presented “Accelerators for Medicine” last week at CERN. He reviewed the different applications of particle accelerators to the medical field, from cancer treatment with beams of accelerator-produced particles (photons, electrons, protons, ions and neutrons) to the generation of radioactive isotopes used in medical diagnostics, cancer therapy and the new domain of theragnostics. He outlined the status, the potential, and the challenges of meeting the increasing demand for therapeutic procedures based on accelerators.
Watch the recording of the “Accelerators for Medicine” Academic Training Lecture here.
Civil works have begun on the ATLAS and CMS sites to build new underground structures for the High-Luminosity LHC. (Image: Julien Ordan / CERN)
The Large Hadron Collider (LHC) is officially entering a new stage. Today, a ground-breaking ceremony at CERN celebrates the start of the civil-engineering work for the High-Luminosity LHC (HL-LHC): a new milestone in CERN’s history. By 2026 this major upgrade will have considerably improved the performance of the LHC, by increasing the number of collisions in the large experiments and thus boosting the probability of the discovery of new physics phenomena.
The LHC started colliding particles in 2010. Inside the 27-km LHC ring, bunches of protons travel at almost the speed of light and collide at four interaction points. These collisions generate new particles, which are measured by detectors surrounding the interaction points. By analysing these collisions, physicists from all over the world are deepening our understanding of the laws of nature.
While the LHC is able to produce up to 1 billion proton-proton collisions per second, the HL-LHC will increase this number, referred to by physicists as “luminosity”, by a factor of between five and seven, allowing about 10 times more data to be accumulated between 2026 and 2036. This means that physicists will be able to investigate rare phenomena and make more accurate measurements. For example, the LHC allowed physicists to unearth the Higgs boson in 2012, thereby making great progress in understanding how particles acquire their mass. The HL-LHC upgrade will allow the Higgs boson’s properties to be defined more accurately, and to measure with increased precision how it is produced, how it decays and how it interacts with other particles. In addition, scenarios beyond the Standard Model will be investigated, including supersymmetry (SUSY), theories about extra dimensions and quark substructure (compositeness).
“The High-Luminosity LHC will extend the LHC’s reach beyond its initial mission, bringing new opportunities for discovery, measuring the properties of particles such as the Higgs boson with greater precision, and exploring the fundamental constituents of the universe ever more profoundly,” said CERN Director-General Fabiola Gianotti.
The HL-LHC project started as an international endeavour involving 29 institutes from 13 countries. It began in November 2011 and two years later was identified as one of the main priorities of the European Strategy for Particle Physics, before the project was formally approved by the CERN Council in June 2016. After successful prototyping, many new hardware elements will be constructed and installed in the years to come. Overall, more than 1.2 km of the current machine will need to be replaced with many new high-technology components such as magnets, collimators and radiofrequency cavities.
The secret to increasing the collision rate is to squeeze the particle beam at the interaction points so that the probability of proton-proton collisions increases. To achieve this, the HL-LHC requires about 130 new magnets, in particular 24 new superconducting focusing quadrupoles to focus the beam and four superconducting dipoles. Both the quadrupoles and dipoles reach a field of about 11.5 tesla, as compared to the 8.3 tesla dipoles currently in use in the LHC. Sixteen brand-new “crab cavities” will also be installed to maximise the overlap of the proton bunches at the collision points. Their function is to tilt the bunches so that they appear to move sideways – just like a crab.
Another key ingredient in increasing the overall luminosity in the LHC is to enhance the machine’s availability and efficiency. For this, the HL-LHC project includes the relocation of some equipment to make it more accessible for maintenance. The power converters of the magnets will thus be moved into separate galleries, connected by new innovative superconducting cables capable of carrying up to 100 kA with almost zero energy dissipation.
“Audacity underpins the history of CERN and the High-Luminosity LHC writes a new chapter, building a bridge to the future,” said CERN’s Director for Accelerators and Technology, Frédérick Bordry. “It will allow new research and with its new innovative technologies, it is also a window to the accelerators of the future and to new applications for society.”
To allow all these improvements to be carried out, major civil-engineering work at two main sites is needed, in Switzerland and in France. This includes the construction of new buildings, shafts, caverns and underground galleries. Tunnels and underground halls will house new cryogenic equipment, the electrical power supply systems and various plants for electricity, cooling and ventilation.
During the civil engineering work, the LHC will continue to operate, with two long technical stop periods that will allow preparations and installations to be made for high luminosity alongside yearly regular maintenance activities. After completion of this major upgrade, the LHC is expected to produce data in high-luminosity mode from 2026 onwards. By pushing the frontiers of accelerator and detector technology, it will also pave the way for future higher-energy accelerators.
The LHC will receive a major upgrade and transform into the High-Luminosity LHC over the coming years. But what does this mean and how will its goals be achieved? Find out in this video featuring several people involved in the project. (Video: Polar Media/CERN.)
HALO, the immersive art installation at Art Basel (Image: Claudia Marcelloni/CERN)
The Semiconductor duo, Ruth Jarman and Joe Gerhardt, were CERN artists-in-residence in 2015. (Image: Claudia Marcelloni/CERN)
Merging particle physics and art, a CERN-inspired artwork is being featured for the first time at Art Basel, the international art fair in Basel, Switzerland from 13 to 17 June. A large-scale immersive art installation entitled HALO is the artistic interpretation of the Large Hadron Collider’s ATLAS experiment and celebrates the links between art, science and technology.
Inspired by raw data generated by ATLAS, the artwork has been conceived and executed by CERN’s former artists-in-residence, the “Semiconductor” duo Ruth Jarman and Joe Gerhardt, in collaboration with Mónica Bello, curator and head of Arts at CERN. During their three-month Arts at CERN residency in 2015, Semiconductor had the chance to explore particle-collision data in collaboration with scientists from the University of Sussex ATLAS group and work with them on the data later used in the artwork.
HALO is a cylindrical structure, measuring ten metres in diameter and surrounded by 4-metre-long vertical piano wires. On the inside, an enormous 360-degree screen creates an immersive visual experience. Using kaleidoscopic images of slowed-down particle collisions, which trigger piano wires to create sound, the experience takes the visitors into the realm of subatomic matter through the multiple patterns generated in the space. HALO is conceived as an experiential reworking of the ATLAS experiment. Its data sets and its complex assemblage is suggestive of the technology associated with scientific endeavour.
“Ruth and Joe have created an immersive installation that conveys fundamental research with innovative ideas and artistic creativity in an extraordinary artwork. HALO is an opportunity for visitors to see how scientists and artists work together, inspiring each other and bringing to life unique visions of our world.” - Mónica Bello, head of Arts at CERN.
The artwork is part of the 4th Audemars Piguet Art Commission. Every year, an artist-curator duo is selected to realise a new artwork that explores complexity and precision, while enlisting contemporary creative practice, complex mechanics, technology, and science. HALO is a collaboration between Audemars Piguet and CERN through its arts office, Arts at CERN.
HALO can be viewed and experienced from 13 to 17 June, at Messeplatz Basel, at Hall 4U during the public opening hours (10:00 to 21:00). Entry to the installation is free and suitable for all audiences.
Vint Cerf's slides included this visualisation of inbound traffic on the NSFNET T1 backbone in September 1991 (purple for zero bytes to white for 100 billion bytes). (Image: Donna Cox and Robert Patterson, Merit Network, Inc., NCSA and NSF)
“It’s not a surprise that networking produces social effects” stated Vint Cerf when he spoke at CERN on 6 June. As an American Internet pioneer, often referred to as one of the fathers of the Internet, Cerf shared his thoughts on big data and social media, as well as acknowledging the birth of the World Wide Web at CERN. His talk not only looked back at the history of the Internet but also at its future and the challenges ahead.
He recounted the pre-Internet days of 1969, when, as a graduate student, he wrote software for the ARPANET project. After the project’s success, he and Robert Kahn worked on the Internet design before publishing a paper in 1974. The team they assembled built a fully distributed system with no central control that was international from the beginning.
He reminisced too about the early days of email, developed on the ARPANET in 1971 as an experiment that instantly caught on. Rather than decreasing travel budgets, it did the opposite; projects became bigger and more international, and people travelled from further afield to attend meetings. Mailing lists quickly sprang up from “Sci-fi lovers” to the “Yum-Yum” reviews of local restaurants. It was clear that the technological development had social characteristics.
Indeed from early email, to web pages, to today’s social media, people have wanted to share knowledge and feel that it was useful to others. This quest for positive feedback, however, runs into issues when sharing personal information. Now, with the prevalence of e-commerce and the Internet of things, the amount of information that companies have about a person over time becomes concerning, hence the recent EU data protection changes to protect people’s privacy.
People need to be aware of both the benefits and the hazards of being online. Misinformation, whether malicious or unintentional, has entered the system and the challenge is to distinguish good and bad quality content. Now more than ever, thinking critically is important. Yet it takes time and effort.
“Everyone, especially young people, should think critically about the information they encounter. Where did this come from? Is there any corroborating evidence? What was the motivation for putting this information into the system? Could there possibly have been some ulterior motive in placing that information into a social-networking environment or on a webpage?” – Vint Cerf
In the age of big data, there are challenges ahead not only in processing such vast quantities of information but also in digital preservation. The digital content created today may not be readable in 50 years’ time. The media may not be available, the reader may no longer exist, or even if it does, the software may be unmaintained and no longer run on the then available hardware. To preserve digital information means building emulators and keeping software updated among other things. Perhaps making programmers feel an ethical responsibility for the code that they produce could help them to fix and update the code, avoiding bugs and vulnerabilities.
Though his talk focused on the technical challenges, he acknowledged that there are also legal and business challenges of big data and social media. Yet despite highlighting the risks, Cerf’s presentation was both entertaining and optimistic. As he leapt nimbly around the auditorium for the questions and answers, microphone in hand, he provided the audience not only with a feast of anecdotes but also food for thought for the Internet of tomorrow.
Watch the CERN Academic Training Lecture recording of “Big data and social media” by Vint Cerf.
Artist’s impression of the merger of two neutron stars (Image: University of Warwick/Mark Garlick)
Quark matter – an extremely dense phase of matter made up of subatomic particles called quarks – may exist at the heart of neutron stars. It can also be created for brief moments in particle colliders on Earth, such as CERN’s Large Hadron Collider. But the collective behaviour of quark matter isn’t easy to pin down. In a colloquium this week at CERN, Aleksi Kurkela from CERN’s Theory department and the University of Stavanger, Norway, explained how neutron-star data have allowed him and his colleagues to place tight bounds on the collective behaviour of this extreme form of matter.
Kurkela and colleagues used a neutron-star property deduced from the first observation by the LIGO and Virgo scientific collaborations of gravitational waves – ripples in the fabric of spacetime – emitted by the merger of two neutron stars. This property describes the stiffness of a star in response to stresses caused by the gravitational pull of a companion star, and is known technically as tidal deformability.
To describe the collective behaviour of quark matter, physicists generally employ equations of state, which relate the pressure of a state of matter to other state properties. But they have yet to come up with a unique equation of state for quark matter; they have derived only families of such equations. By plugging tidal-deformability values of the neutron stars observed by LIGO and Virgo into a derivation of a family of equations of state for neutron-star quark matter, Kurkela and colleagues were able to dramatically reduce the size of that equation family. Such a reduced family provides more stringent limits on the collective properties of quark matter, and more generally on nuclear matter at high densities, than were previously available.
Armed with these results, the researchers then flipped the problem around and used the quark-matter limits to deduce neutron-star properties. Using this approach, the team obtained the relationship between the radius and mass of a neutron star, and found that the maximum radius of a neutron star that is 1.4 times more massive than the Sun should be between about 10 and 14 km.
Want to find out more? Read the paper describing the research.
Artistic view of the Brout-Englert-Higgs Field (Image: Daniel Dominguez/CERN)
The Higgs boson interacts only with massive particles, yet it was initially discovered in its decay to two massless photons. Quantum mechanics allows the Higgs to fluctuate for a very short time into a top quark and a top anti-quark, which promptly annihilate each other into a photon pair. The probability of this process occurring varies with the strength of the interaction (known as coupling) between the Higgs boson and top quarks. Its measurement allows researchers to indirectly infer the value of the Higgs-top coupling. A more direct manifestation of the Higgs-top coupling is the emission of a Higgs boson by a top-antitop quark pair.
An event candidate for the production of a top quark and top antiquark pair in conjunction with a Higgs boson in CMS. The Higgs decays into a tau+ lepton, which in turn decays into hadrons and a tau-, which decays into an electron. The decay product symbols are in blue. The top quark decays into three jets (sprays of lighter particles) whose names are given in purple. One of these is initiated by a b-quark. The top antiquark decays into a muon and b-jet, whose names appear in red. (Image: CMS/CERN)
Results presented today, at the LHCP conference in Bologna, describe the observation of this so-called "ttH production" process. Results from the CMS collaboration, with a significance exceeding five standard deviations (considered the gold standard) for the first time, have just been published in the journal Physical Review Letters; including more data from the ongoing LHC-run, the ATLAS collaboration just submitted new results for publication, with a larger significance. The findings of the two experiments are consistent with one another and with the Standard Model. They tell scientists more about the properties of the Higgs boson and give clues for where to look for new physics.
Visualisation of an event from the tt̄H(γγ) analysis. The event contains two photon candidates displayed as green towers in the electromagnetic calorimeter, and six jets (b-jet) shown as yellow (blue) cones. (Image: ATLAS/CERN)
Measuring the ttH production process is challenging, as it is rare: only 1% of Higgs bosons are produced in association with two top quarks and, in addition, the Higgs and the top quarks decay into other particles in many complex ways, or modes. Using data from proton–proton collisions collected at energies of 7, 8, and 13 TeV, the ATLAS and CMS teams performed several independent searches for ttH production, each targeting different Higgs-decay modes (to W bosons, Z bosons, photons, τ leptons, and bottom-quark jets). To maximise the sensitivity to the experimentally challenging ttH signal, each experiment then combined the results from all of its searches.
"The superb performance of the LHC and the improved experimental tools in mastering this complex analysis led to this beautiful result,” added CERN Director for Research and Computing Eckhard Elsen. “It also shows that we are on the right track with our plans for the High-Luminosity LHC and the physics results it promises.”
Scientists from ATLAS, CMS and the CERN theory department explain the significance of today's results. (Video: CERN)
The FRESCA2 cryostat before the insertion of the magnet. (Image: Sophia Bennett)
In its quest for knowledge, CERN pushes technologies to the limits. In the Laboratory’s workshops, scientists are inventing magnets that will equip the accelerators of the future. The latest performance record has been established by the FRESCA2 magnet, a superconducting dipole magnet 1.5 metres long, 1 metre in diameter and with an aperture of 10 centimetres. FRESCA2 has recently reached a magnetic field of 14.6 teslas, a record for a magnet with a “free” aperture. To put this in context, the LHC magnets generate fields of 8.34 teslas in the centre of a 5-cm aperture, and the previous record of this type of magnet was held by the Lawrence Berkeley Laboratory’s (LBNL) HD2 magnet, which reached 13.8 teslas in 2008.
FRESCA2 was developed since 2009 through a collaboration between CERN and CEA-Saclay (France) in the framework of the European project EuCARD and the development of the High Luminosity LHC. Formed by the superconducting niobium-tin compound and cooled to 1.9 kelvin (-271°C), it had already reached a field of 13.3 teslas in August 2017. Then, with a modification of the mechanical pre-stressing, it started a new series of tests in April before reaching its record intensity.
"This is a crucial step in the development of magnets with very high magnetic fields," says Gijs de Rijk, head of the FRESCA2 programme. “FRESCA2 has already played an important role in the development of the new magnets for the High Luminosity LHC and will soon help develop the next generation of magnets."
FRESCA2 is indeed intended to test new superconducting cables in real situation, i.e. in an high magnetic field. Its free aperture provides a space in the centre of the magnet to accommodate samples of cables.
CERN and its partners are working on the development of magnets that could generate fields of 16 Tesla and beyond, as part of the Future Collider Study. To achieve this, the performance of the niobium-tin superconducting cables, which are already used for the new High Luminosity LHC magnets, must be increased. Coils formed of high-temperature superconductors are also under study.
The FRESCA2 magnet, before being inserted into its cryostat for intensity tests. (Image: CERN)
Timepix3, one of the read-out chips of Medipix.
Medipix – a family of read-out chips for particle imaging and detection developed at CERN – has proved its credentials outside the field of high-energy physics, including in art authentication and restoration. At a seminar at 11:00 CEST today at CERN, broadcast via a webcast, Ron M. A. Heeren from Maastricht University in the Netherlands now describes how one such chip, the Timepix chip, might in the future be found in surgery rooms and pathology departments.
The idea is to use the Timepix chip as a component of the detector in mass spectrometry imaging – a technique that maps the molecular composition of cells and tissues, and is used in many clinical research areas. In his talk, Ron Heeren will describe how Timepix enables the imaging throughput needed for intraoperative molecular pathology. This could help surgeons diagnose cancers and evaluate surgical margins, the rim of tissue around a tumour that has been surgically removed.
For more information, visit the event page.
Test bench of the first two prototype crab cavities in the Super Proton Synchrotron (SPS) accelerator. The cryomodule containing the cavities is installed on a mobile table that allows it to be moved into the beam line as needed. (Image: M. Brice/CERN)
CERN has successfully tested “crab cavities” to rotate a beam of protons – a world first. The test took place on 23 May using a beam from CERN’s Super Proton Synchrotron (SPS) accelerator and showed that bunches of protons could be tilted using these superconducting transverse radiofrequency cavities. These cavities are a key component of the High-Luminosity Large Hadron Collider (HL-LHC), the future upgrade of the LHC.
The HL-LHC, which will be commissioned after 2025, will increase the luminosity of the LHC by a factor of five to ten. Luminosity is a crucial indicator of a collider’s performance: it gives the number of potential collisions per surface unit over a given period of time. In other words, the higher the luminosity, the higher the number of collisions and the more data the experiments can gather. This will allow researchers to observe rare processes that occur beyond the LHC’s present sensitivity level. Physicists will also be able to perform precise studies of the new particles observed at the LHC, such as the Higgs boson. The newly developed crab cavities will play an important role to increase the luminosity.
In the LHC, the two counter-rotating beams are not a continuous stream of particles but are made up of “bunches” of protons a few centimetres long, each containing billions of protons. These bunches meet at a small angle at each collision point of the experiments. When installed at each side of the ATLAS and CMS experiments, the crab cavities will “tilt” bunches of protons in each beam to maximise their overlap at the collision point. Тhis way every proton in the bunch will be forced to pass through the whole length of the opposite bunch, increasing the probability of collisions and hence more luminosity. After being tilted, the motion of the proton bunches appears to be sideways – just like a crab. Crab cavities were already used in the KEKB collider in Japan for electrons and positrons, but never with protons, which are more massive and at significantly higher energies. “The crab cavities are expected to increase the overall luminosity by 15 to 20%,” explains Rama Calaga, leader of the crab cavity project.
The two first crab cavity prototypes were manufactured at CERN in 2017 in collaboration with Lancaster University and the Science and Technology Facilities Council (STFC) in the United Kingdom, as well as the U.S. LHC Accelerator Research Program (USLARP). The cavities were assembled in a cryostat and tested at CERN. They are made of high-purity niobium superconducting material, operating at 2 kelvins (-271°C), in order to generate very high transverse voltage of 3-4 million volts. The cavities were installed in the SPS accelerator during the last winter technical stop to undergo validation tests with proton beams.
The first beam tests on 23 May lasted for more than 5 hours at a temperature of 4.2 K with a single proton bunch accelerated to 26 GeV and containing between 20 and 80 billion protons, almost the intensity of the LHC bunches. The crab cavities were powered to about 10% of their nominal voltage. The “crabbing” was observed using a special monitor to observe the tilt along the length of the bunch. “These tests mark the start-up of a unique facility for testing superconducting cavities on a high-current, high-energy proton beam,” explains Lucio Rossi, leader of the HL-LHC project. “The results are impressive and crucial to prove the feasibility of using such cavities for increasing the luminosity in the LHC.”
In the coming months, the cavities will be commissioned to their nominal voltage of 3.4 million volts and will undergo a series of tests to fully validate their operation for the HL-LHC era. A total of 16 such cavities will be installed in the HL-LHC – eight near ATLAS and eight near CMS.
Watch this short video to learn more about how the crab cavities work. (Video: Polar Media/CERN)
The LHCb detector seen in 2018 in its underground cavern. The excellent precision of this detector allowed LHCb physicists to perform detailed measurements on the doubly charmed particle they discovered only last year. (Image: M. Brice, J. Ordan/CERN)
Finding a new particle is always a nice surprise, but measuring its characteristics is another story and just as important. Less than a year after announcing the discovery of the particle going by the snappy name of Ξcc++ (Xicc++), this week the LHCb collaboration announced the first measurement of its lifetime. The announcement was made during the CHARM 2018 international workshop in Novosibirsk in Russia: a charming moment for this doubly charmed particle.
The Ξcc++ particle is composed of two charm quarks and one up quark, hence it is a member of the baryon family (particles composed of three quarks). The existence of the particle was predicted by the Standard Model, the theory which describes elementary particles and the forces that bind them together. LHCb’s observation came last year after several years of research. Its mass was measured to be around 3621 MeV, almost four times that of the proton (the best-known baryon), thanks to its two charm quarks.
The Ξcc++ particle is fleeting: it decays quickly into lighter particles. In fact it was through its decay into a Λc+ baryon and three lighter mesons, K-, π+ and π+, that it was discovered. Since then, LHCb physicists have been carrying on an analysis to determine its lifetime with a high level of precision. The value obtained is 0.256 picoseconds (0.000000000000256 seconds), with a small degree of uncertainty. Though very small in everyday life, such an amount of time is relatively large in the realm of subatomic particles. The measured value is within the range predicted by theoretical physicists on the basis of the Standard Model, namely between 0.20 and 1.05 picoseconds.
To achieve this precise result, LHCb physicists compared the measurement of the lifetime of the Ξcc++ with that of another particle whose lifetime is well-known. They based their measurements on the same sample of events that led to the discovery.
Measuring the lifetime of a particle is an important step in determining its characteristics. Thanks to the abundance of heavy quarks produced by the Large Hadron Collider (LHC) and the excellent precision of the LHCb detector, physicists will now continue their detailed measurements of the properties of this charming particle. With these types of measurements, they are gaining a better understanding of the interactions that govern the behaviour of particles containing heavy quarks.
More information on the new measurements of the Ξcc++ particle can be found on the LHCb website.
The AMS detector on the International Space Station (Image: NASA)
Join us via webcast at 16:30 CEST today to hear particle physicist and Nobel Prize winner Samuel Ting present the latest results from the Alpha Magnetic Spectrometer (AMS) collaboration in its pursuit to understand the origin of cosmic rays and dark matter.
The AMS detector, which measures 64 cubic metres and weighs 8.5 tonnes, was assembled at CERN. It was delivered by NASA’s space shuttle Endeavour on 16 May 2011 to the International Space Station – the largest structure in space ever built by humans.
In its seven years on board the Space Station, AMS has collected a huge amount of cosmic-ray data. NASA receives these data in Houston and then transmits them to the AMS Payload Operations Control Centre on the CERN site for analysis. In his talk today, Samuel Ting will describe the latest results from AMS and what they mean for our understanding of the Universe.
For more information, visit the event page.
The OPERA experiment at the Gran Sasso Laboratory in Italy (Image: INFN)
The OPERA experiment, located at the Gran Sasso Laboratory of the Italian National Institute for Nuclear Physics (INFN), was designed to conclusively prove that muon-neutrinos can convert to tau-neutrinos, through a process called neutrino oscillation, whose discovery was awarded the 2015 Nobel Physics Prize. In a paper published today in the journal Physical Review Letters, the OPERA collaboration reports the observation of a total of 10 candidate events for a muon to tau-neutrino conversion, in what are the very final results of the experiment. This demonstrates unambiguously that muon neutrinos oscillate into tau neutrinos on their way from CERN, where muon neutrinos were produced, to the Gran Sasso Laboratory 730 km away, where OPERA detected the ten tau neutrino candidates.
Today the OPERA collaboration has also made their data public through the CERN Open Data Portal. By releasing the data into the public domain, researchers outside the OPERA Collaboration have the opportunity to conduct novel research with them. The datasets provided come with rich context information to help interpret the data, also for educational use. A visualiser enables users to see the different events and download them. This is the first non-LHC data release through the CERN Open Data portal, a service launched in 2014.
There are three kinds of neutrinos in nature: electron, muon and tau neutrinos. They can be distinguished by the property that, when interacting with matter, they typically convert into the electrically charged lepton carrying their name: electron, muon and tau leptons. It is these leptons that are seen by detectors, such as the OPERA detector, unique in its capability of observing all three. Experiments carried out around the turn of the millennium showed that muon neutrinos, after travelling long distances, create fewer muons than expected, when interacting with a detector. This suggested that muon neutrinos were oscillating into other types of neutrinos. Since there was no change in the number of detected electrons, physicists suggested that muon neutrinos were primarily oscillating into tau neutrinos. This has now been unambiguously confirmed by OPERA, through the direct observation of tau neutrinos appearing hundreds of kilometres away from the muon neutrino source. The clarification of the oscillation patterns of neutrinos sheds light on some of the properties of these mysterious particles, such as their mass.
The OPERA collaboration observed the first tau-lepton event (evidence of muon-neutrino oscillation) in 2010, followed by four additional events reported between 2012 and 2015, when the discovery of tau neutrino appearance was first assessed. Thanks to a new analysis strategy applied to the full data sample collected between 2008 and 2012 – the period of neutrino production – a total of 10 candidate events have now been identified, with an extremely high level of significance.
“We have analysed everything with a completely new strategy, taking into account the peculiar features of the events,” said Giovanni De Lellis Spokesperson for the OPERA collaboration. “We also report the first direct observation of the tau neutrino lepton number, the parameter that discriminates neutrinos from their antimatter counterpart, antineutrinos. It is extremely gratifying to see today that our legacy results largely exceed the level of confidence we had envisaged in the experiment proposal.”
Beyond the contribution of the experiment to a better understanding of the way neutrinos behave, the development of new technologies is also part of the legacy of OPERA. The collaboration was the first to develop fully automated, high-speed readout technologies with sub-micrometric accuracy, which pioneered the large-scale use of the so-called nuclear emulsion films to record particle tracks. Nuclear emulsion technology finds applications in a wide range of other scientific areas from dark matter search to volcano and glacier investigation. It is also applied to optimise the hadron therapy for cancer treatment and was recently used to map out the interior of the Great Pyramid, one of the oldest and largest monuments on Earth, built during the dynasty of the pharaoh Khufu, also known as Cheops.