Wrapping up a two-day state visit to Switzerland, president of the French Republic, Emmanuel Macron (right) came to CERN on 16 November accompanied by the president of the Swiss Confederation Alain Berset (left). CERN Director-General Fabiola Gianotti took the host-state leaders on a tour of the ATLAS cavern and to the recently inaugurated Science Gateway. Speaking to journalists during the visit, Macron said: “If I came here today, it is to reiterate my confidence in the scientific community and our ambition to maintain our leadership in this domain.” (translated)
While it is believed that each galaxy, including our own, contains a supermassive black hole (SMBH) at its centre, much remains unknown about the origin of these extreme objects. The seeds for SMBHs are thought to have existed as early as 200 million years after the Big Bang, after which they accreted mass for 13 billion years to turn into black holes with sizes of up to tens of billions of solar masses. But what were the seeds of these massive black holes? Some theories state that they were formed after the collapse of the first generation of stars, thereby making them tens to hundreds of solar masses, while other theories attribute their origin to the collapse of massive gas clouds that could produce seeds with masses of 104–105 solar masses.
The recent joint detection of a SMBH dating from 500 million years after the Big Bang by the James Webb Space Telescope (JWST) and the Chandra X-ray Observatory provides new insights into this debate. The JWST, sensitive to highly redshifted emission from the early universe, observed a gravitationally lensed area to provide images of some of the oldest galaxies. One such galaxy, called UHZ1, has a redshift corresponding to 13.2 billion years ago, or 500 million years after the Big Bang. Apart from its age, the observations allow an estimate of its stellar mass, while the SMBH expected to be at its centre remains hidden in these wavelengths. This is where Chandra, which is sensitive in the 0.2 to 10 keV energy range, came in.
Observations by Chandra of the area of the cluster lens, Abell 2744, which magnifies UHZ1, shows an excess at energies of 2–7 keV. The measured emission spectrum and luminosity correspond to that from an accreting black hole with a mass of 107 to 108 solar masses, which is about half of the total mass of the galaxy. This can be compared to our own galaxy where the SMBH is estimated to make up only 0.1% of the total mass.
Such a mass can be explained by a seed black-hole of 104 to 105 solar masses accreting matter for 300 million years. A small seed is more difficult to explain, however, because such sources would have to continuously accrete matter at twice their Eddington limit (the point at which the gravitational pull of the object is cancelled by the radiation pressure it applies through the accretion to the surrounding matter). Although super-Eddington accretion is possible, as this limit assumes for example spherical emission of the radiation, which is not necessarily correct, the accretion rates required for light seeds are difficult to explain.
The measurements of a single early galaxy already provide strong hints regarding the source of SMBHs. As JWST continues to observe the early universe, more such sources will likely be revealed. This will allow us to better understand the masses of the seeds, as well as how they grew over a period of 13 billion years.
CERN’s third environment report, published on 4 December, chronicles progress made in various high-priority environmental domains during the years 2021 and 2022, and reflects a proactive approach to environmental protection across the laboratory.
CERN’s strategy with respect to the environment is based on three pillars: minimise the lab’s impact on the environment, reduce energy consumption and increase energy reuse, and develop technologies that can help society to preserve the planet. For a large part of the latest reporting period, CERN’s accelerator complex was undergoing a long shutdown that ended in July 2022 with the start of Run 3 (scheduled to end in 2025). The report charts progress made in domains such as waste, noise, ionising radiation and biodiversity, land use and landscape change. It specifically covers measures taken to reach objectives set out in the first report published in 2020: limiting the rise in electricity and water consumption and reducing direct emissions (“Scope 1”) of fluorinated gases from large experiments.
CERN is committed to limiting the rise in electricity consumption to 5% up to the end of Run 3 compared to the 2018 baseline year (which corresponds to a maximum target of 1314 GWh), while delivering significantly increased performance of its facilities. It is also committed to increasing energy reuse. A total of 1215 GWh was consumed in 2022, and the accelerator complex is now more efficient, delivering more data per unit of energy consumed (CERN Courier May/June 2022 p55). In light of the energy crisis, CERN implemented additional energy-saving measures as a mark of social responsibility, and further explored diversification of energy sources and heat-recovery projects. The process to obtain the internationally recognised ISO 50001 energy-management certification was also undertaken in the reporting period, and has since been awarded.
CERN’s objective is to reduce direct greenhouse-gas emissions by 28% by the end of Run 3 compared to 2018, which corresponds to a maximum target of 138,300 tCO2e. In 2022, 184,300 tCO2e direct emissions were generated, with a comprehensive programme to ensure progress towards the objective. For example, the experiments have increased efforts to repair leaks in gas systems and worked towards replacing current gases with more environmentally friendly ones. With respect to indirect greenhouse-gas emissions (“Scope 3”), CERN first reported these in the second environment report (2019–2020) spanning catering, commuting and duty travel. This third report now includes scope 3 emissions arising from procurement, which represent 92% of this total, and details the main sources of related emissions.
Regarding water consumption, CERN is committed to keeping the increase in its water consumption below 5% up to the end of Run 3 compared to 2018 (which corresponds to a maximum target of 3651 ML) despite a growing demand for water cooling at the upgraded facilities. Since 2000, CERN has radically decreased its water consumption by about 80%. The report also explores how waste is managed. CERN’s aim over the reporting period has been to increase its recycling rate for non-hazardous waste, which represents over 70% of the total waste generated. In 2022 this recycling rate was 69% compared to 56% in 2018.
Biodiversity, land use and landscape change are another important focus of the report, as is the latest on how CERN’s technology and knowledge benefit society, notably with the new CERN Innovation Programme on Environmental Applications launched in March 2022.
Benoît Delille, head of the CERN Occupational Health and Safety and Environmental Protection unit, concludes: “Over the years since we embarked on our first environment report, we have learned a great deal about our footprint, implemented mechanisms to better understand and control it, and increased our efforts to identify and develop technologies stemming from our core research that have the potential to benefit the environment.”
On 8 December, the high-energy physics advisory panel to the US Department of Energy and National Science Foundation released a 10-year strategic plan for US particle physics. The Particle Physics Project Prioritization Panel (P5) report recommends projects across high-energy physics for different budget scenarios. Extensive input from the 2021 Snowmass exercise and other community efforts was distilled into three overarching themes: decipher the quantum realm; explore new paradigms in physics; and illuminate the hidden universe, each of which has been linked to science drivers that represent the most promising avenues of investigation for the next 10 years and beyond.
“The Higgs boson had just been discovered before the previous P5 process, and now our continued study of the particle has greatly informed what we think may lie beyond the standard model of particle physics,” said panel chair Hitoshi Murayama (UCB). “Our thinking about what dark matter might be has also changed, forcing the community to look elsewhere – to the cosmos. And in 2015, the discovery of gravitational waves was reported. Accelerator technology is changing too, which has shifted the discussion to the technology R&D needed to build the next-generation particle collider.”
Independent of the budget scenario, realising the full scientific potential of existing projects is the highest P5 priority, including the High-Luminosity LHC, DUNE and PIP-II, and the Vera C Rubin Observatory. In addition, the panel recommends continued support for the medium-scale experiments NOvA, SBN, T2K and IceCube; DarkSide-20k, LZ, SuperCDMS and XENONnT; DESI; Belle II and LHCb; and Mu2e.
On the hot topic of future colliders, the P5 report endorses an off-shore Higgs factory, naming FCC-ee and ILC, to advance studies of the Higgs boson following the HL-LHC. The US should actively engage in design studies to establish the technical feasibility and cost of Higgs factories and convene a targeted panel to make decisions in US accelerator physics at the time when major decisions concerning an off-shore Higgs factory are expected, at which point the US should commit funds commensurate with its involvement in the LHC and HL-LHC. Looking further into the future “and ultimately aim to bring an unparalleled global facility to US soil”, the P5 report supports vigorous R&D toward a 10 TeV parton-centre-of-momentum collider, including a targeted programme to establish the feasibility of a 10 TeV muon collider at Fermilab – dubbed “our Muon Shot”.
Astro-matters
Looking outward, the panel identified several critical areas in cosmic evolution, neutrinos and dark matter where next-generation facilities could make a dramatic impact. Topping the list are: CMB-S4, which will use telescopes in Chile and Antarctica to study the cosmic microwave background (CERN Courier March/April 2022 p34); early implementation of a planned accelerator upgrade at Fermilab to advance the timeline of DUNE (in addition to a re-envisioned second phase of DUNE and R&D towards an advanced fourth detector); and a comprehensive Generation-3 dark-matter experiment to be coordinated with international partners and preferably sited in the US. Here, states the report, the impact of the more constrained budget scenario is severe, and could force the US to cede leadership in Generation-3 and to descope or delay elements of DUNE: “Limiting of DUNE’s physics reach would negatively impact the reputation of the US as an international host, and more limited contributions to an off-shore Higgs factory would tarnish our standing as a partner for future global facilities.”
Multi-messenger observatories with dark-matter sensitivity, including IceCube Gen-2 for the study of neutrino properties, and small-scale dark-matter experiments employing innovative technologies, are singled out for support. In addition, the panel recommends that the Department of Energy create a new competitive programme to support a portfolio of smaller, more agile experiments in high-energy physics.
The P5 report supports vigorous R&D toward a 10 TeV parton-centre-of-momentum collider
Investing in the scientific workforce and enhancing computational and technological infrastructure are described as “crucial”, with increased support for theory, general accelerator R&D, instrumentation and computing needed to bolster areas where US leadership has begun to erode. The report also urges broader engagement with and support for the workforce, suggesting that all projects, workshops, conferences and collaborations incorporate ethics agreements that detail expectations for professional conduct and establish mechanisms for transparent reporting, response and training.
“In the P5 exercise, it’s really important that we take this broad look at where the field of particle physics is headed, to deliver a report that amounts to a strategic plan for the US community with a 10-year budgetary timeline and a 20-year context,” said P5 panel deputy chair Karsten Heeger (Yale). “The panel thought about where the next big discoveries might lie and how we could maximise impact within budget, to support future discoveries and the next generation of researchers and technical workers who will be needed to achieve them.”
Polish industry has been collaborating with CERN for years and has been very successful in various technical domains, such as cryogenics, mechanical engineering, electrical engineering and IT. The contracts and orders entrusted to Polish companies have been carried out with good quality. Polish companies proves that they are solid business partners and demonstrate a high level of specialisation.
Industrial supplies for CERN were provided by KrioSystem in Wrocław and Turbotech in Płock, CHEMAR in Kielce and RAFAKO in Racibórz. CERN also operates devices manufactured by the ZPAS company in Wolibórz, while Polish company ZEC Service has been awarded CMS Gold awards for the delivery and assembly of cooling installations. Creotech Instruments – a company established by a physicist and two engineers who met at CERN – is a regular manufacturer of electronics for CERN and enjoys a strong collaboration with CERN’s engineering teams. Polish companies also transfer technology from CERN to industry, such as TECHTRA in Wrocław, which obtained a license from CERN for the production and commercialisation of GEM (Gas Electron Multiplier) foil. Deliveries to CERN are also carried out, inter alia, by FORMAT, Softcom or Zakład Produkcji Doświadczalnej CEBEA from Bochnia. FIBRAIN, a manufacturer in the photonics and fiber optics sector, supplied CERN with launchers, which are used during measurement work in the CERN Tunnel.
These are just a few examples of companies from Poland that are successfully supplying products to CERN and other Big Science centers.
Among the scientific institutes, the National Center for Nuclear Research in Otwock near Warsaw and the Institute of Nuclear Physics of the Polish Academy of Sciences in Krakow are particularly active.
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The Świerk Science and Technology Park, at the National Center for Nuclear Research is the point of contact with Big Science centers for Polish industry and houses an ILO office for CERN, ITER and XFEL.
If you are looking for partners from Poland, in the area of R&D, come to us. We will help you establish valuable business contacts.
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If you need support in the area of materials research, computer science, or dosimetry measurements our labs stand open. Our scientists will help you improve your offer.
The Materials Research Laboratory at the National Center for Nuclear Research conducts scientific research, rheatesting and diagnostics of structural materials using destructive and non-destructive methods.
Non-irradiated and irradiated materials are tested in the following laboratories:
• Laboratory of Structural, Chemical and Corrosion;
• Laboratory of Mechanical Testing;
• Non-Destructive Testing Laboratory;
• Hot Cell Laboratory.
The Materials Research Laboratory has been recognised as an accredited testing laboratory granted by the Polish Center for Accreditation.
Świerk IT Center provides the highest quality modern IT services to entities involved in the development of the nuclear sector in the territory of the Republic of Poland, state administration units and scientific research institutions.
A supercomputer with the necessary accompanying infrastructure, it is one of several high-power computers in Poland. It ensures effective processing of large data sets (including for the Large Hadron Collider at CERN).
Companies from Poland and abroad successfully cooperate with us.
Experimental particle physicist Lawrence W Jones, a well-respected mentor and educator who contributed to important developments in accelerators and detectors, passed away on 30 June 2023.
Born in Evanston, Illinois on 16 November 1925, he enrolled at Northwestern University in autumn 1943 but was drafted into the US army a few months later. He served in Europe during World War II in 1944 and 1945, returning to Northwestern to complete a BSc in zoology and physics in 1948, followed by an MSc in 1949. After completing a PhD from the University of California, Berkeley in 1952, Jones went to the University of Michigan to begin a lifetime career in the physics faculty. In 1962 he acted as dissertation adviser to future Nobel laureate Samuel Ting and was promoted to full professor in 1963. He served as the physics department chair from 1982 to 1987 and was named professor emeritus in 1998.
Jones collaborated in the 1950s in the Midwestern Universities Research Association, a collaboration of US universities that developed key concepts for colliding beams, and built the first fixed-focus alternating gradient accelerator. Over the course of his career, Jones also contributed to the development of scintillation counters, optical spark chambers and hadron calorimeters. He participated in experiments designed to measure inelastic and elastic scattering, particle production, dimuon events, neutrino physics and charm production.
Jones came to CERN as a Ford Foundation Fellow (1961–1962) and as a Guggenheim Fellow (1964–1965), and then contributed to cosmic-ray experiments on Mount Evans, Colorado and nearby Echo Lake. In 1983 he joined the L3 experiment at LEP, which was led by his former student Ting. The Michigan team, led by Byron Roe, helped to design, construct and install the experiment’s hadron calorimeter – a key component used to determine the number of elementary neutrino families. Jones also contributed to the construction of L3 cosmics, a programme to trigger on and measure cosmic rays using the detector’s precision muon detector and surrounding solenoidal magnet.
Jones’ interest in entomology led to a species of beetle (Cryptorhinula jonsi) being named after him. On the first Earth Day, in 1970, Jones introduced the term “liquid hydrogen fuel economy” and, in 1976, he joined the advisory board of the International Association for Hydrogen Energy. He had a long involvement with the Ann Arbor Ecology Center, which he led in 1974–1975, and became co-chair of the Michigan Environmental Council’s Science Advisory Committee in 2000.
Celebrating the 1973 discovery of weak neutral currents by the Gargamelle experiment and the 1983 discoveries of the W and Z bosons by the UA1 and UA2 experiments at the SppS, a highly memorable scientific symposium in the new CERN Science Gateway on 31 October brought the past, present and future of electroweak exploration into vivid focus. “Weak neutral currents were the foundation, the W and Z bosons the pillars, and the Higgs boson the crown of the 50 year-long journey that paved the electroweak way,” said former Gargamelle member Dieter Haidt (DESY) in his opening presentation.
History could have turned out differently, said Haidt, since both CERN and Brookhaven National Laboratory (BNL) were competing in the new era of high-energy neutrino physics: “The CERN beam was a flop initially, allowing BNL to snatch the muon-neutrino discovery in 1962, but a second attempt at CERN was better.” This led André Lagarrigue to dream of a giant bubble chamber, Gargamelle, financed and built by French institutes and operated by CERN with beams from the Proton Synchrotron (PS) from 1970 to 1976. Picking out the neutral-current signal from the neutron-cascade background was a major challenge, and a solution seemed hopeless until Haidt and his collaborators made a breakthrough regarding the meson component of the cascade.
The ten years between the discovery of neutral currents and the W and Z bosons are what took CERN from competent mediocrity to world leader
Lyn Evans
By early July 1973, it was realised that Gargamelle had seen a new effect. Paul Musset presented the results in the CERN auditorium on 19 July, yet by that autumn Gargamelle was “treated with derision” due to conflicting results from a competitor experiment in the US. ‘The Gargamelle claim is the worst thing to happen to CERN,’ Director-General John Adams was said to have remarked. Jack Steinberger even wagered his cellar that it was wrong. Following further cross checks by bombarding the detector with protons, the Gargamelle result stood firm. At the end of Haidt’s presentation, collaboration members who were present in the audience were recognised with a warm round of applause.
From the PS to the SPS The neutral-current discovery and the subsequent Gargamelle measurement of the weak mixing angle made it clear not only that the electroweak theory was right but that the W and Z were within reach of the technology of the day. Moving from the PS to the SPS, Jean-Pierre Revol (Yonsei University) took the audience to the UA1 and UA2 experiments ten years later. Again, history could have taken a different turn. While CERN was working towards a e+e– collider to find the W and Z, said Revol, Carlo Rubbia proposed the radically different concept of a hadron collider — first to Fermilab, which, luckily for CERN, declined. All the ingredients were presented by Rubbia, Peter McIntyre and David Cline in 1976; the UA1 detector was proposed in 1978 and a second detector, UA2, was proposed by CERN six months later. UA1 was huge by the standards of the day, said Revol. “I was advised not to join, as there were too many people! It was a truly innovative project: the largest wire chamber ever built, with 4π coverage. The central tracker, which allowed online event displays, made UA1 the crucial stepping stone from bubble chambers to modern electronic ones. The DAQ was also revolutionary. It was the beginning of computer clusters, with same power as IBM mainframes.”
First SppS collisions took place on 10 July 1981, and by mid-January 1983 ten candidate W events had been spotted by the two experiments. The W discovery was officially announced at CERN on 25 January 1983. The search for the Z then started to ramp up, with the UA1 team monitoring the “express line” event display around the clock. On 30 April, Marie Noelle Minard called Revol to say she had seen the first Z. Rubbia announced the result at a seminar on 27 May, and UA2 confirmed the discovery on 7 June. “The SppS was a most unlikely project but was a game changer,” said Haidt. “It gave CERN tremendous recognition and paved the way for future collaborations, at LEP then LHC.”
Former UA2 member Pierre Darriulat (Vietnam National Space Centre) concurred: “It was not clear at all at that time if the collider would work, but the machine worked better than expected and the detectors better than we could dream of.” He also spoke powerfully about the competition between UA1 and UA2: “We were happy, but it was spoiled in a way because there was all this talk of who would be ‘first’ to discover. It was so childish, so ridiculous, so unscientific. Our competition with UA1 was intense, but friendly and somewhat fun. We were deeply conscious of our debt toward Carlo and Simon [van der Meer], so we shared their joy when they were awarded the Nobel prize two years later.” Darriulat emphasised the major role of the Intersecting Storage Rings and the input of theorists such as John Ellis and Mary K Gaillard, reserving particular praise for Rubbia. “Carlo did the hard work. We joined at the last moment. We regarded him as the King, even if we were not all in his court, and we enjoyed the rare times when we saw the King naked!”
Our competition with UA1 was intense, but friendly and somewhat fun
Pierre Darriulat
The ten years between the discovery of neutral currents and the W and Z bosons are what took CERN “from competent mediocrity to world leader”, said Lyn Evans in his account of the SppS feat. Simon van der Meer deserved special recognition, not just for his 1972 paper on stochastic cooling, but also his earlier invention of the magnetic horn, which was pivotal in increasing the neutrino flux in Gargamelle. Evans explained the crucial roles of the Initial Cooling Experiment and the Antiproton Accumulator, and the many modifications needed to turn the SPS into a proton-antiproton collider. “All of this knowledge was put into the LHC, which worked from the beginning extremely well and continues to do so. One example was intrabeam scattering. Understanding this is what gives us the very long beam lifetimes at the LHC.”
Long journey The electroweak adventure began long before CERN existed, pointed out Wolfgang Hollik, with 2023 also marking the 90th anniversary of Fermi’s four-fermion model. The incorporation of parity violation came in 1957 and the theory itself was constructed in the 1960s by Glashow, Salam, Weinberg and others. But it wasn’t until ‘t Hooft and Veltman showed that the theory is renormalizable in the early 1970s that it became a fully-fledged quantum field theory. This opened the door to precision electroweak physics and the ability to search for new particles, in particular the top quark and Higgs boson, that were not directly accessible to experiments. Electroweak theory also drove a new approach in theoretical particle physics based around working groups and common codes, noted Hollik.
The afternoon session of the symposium took participants deep into the myriad of electroweak measurements at LEP and SLD (Guy Wilkinson, University of Oxford), Tevatron and HERA (Bo Jayatilaka, Fermilab), and finally the LHC (Maarten Boonekamp, Université Paris-Saclay and Elisabetta Manca, UCLA). The challenges of such measurements at a hadron collider, especially of the W-boson mass, were emphasised, as were their synergies with QCD in measurements in improving the precision of parton distribution functions.
The electroweak journey is far from over, however, with the Higgs boson offering the newest exploration tool. Rounding off a day of excellent presentations and personal reflections, Rebeca Gonzalez Suarez (Uppsala University) imagined a symposium 40 years from now when the proposed collider FCC-ee at CERN has been operating for 16 years and physicists have reconstructed nearly 1013 W and Z bosons. Such a machine would take the precision of electroweak physics into the keV realm and translate to a factor of seven increase in energy scale. “All of this brings exciting challenges: accelerator R&D, machine-detector interface, detector design, software development, theory calculations,” she said. “If we want to make it happen, now is the time to join and contribute!”
Only two experiments worldwide are dedicated to the study of rare kaon decays: NA62 at CERN and KOTO at J-PARC in Japan. NA62 plans to conclude its efforts in 2025, and both experiments are aiming to reach important milestones on this timescale. The future experimental landscape for kaon physics beyond this date is by no means clear, however. With proposals for next-generation facilities such as HIKE at CERN and KOTO-II at J-PARC currently under scrutiny, more than 100 kaon experts met at CERN from 11 to 14 September for a hybrid workshop to take stock of the experimental and theoretical opportunities in kaon physics in the coming decades.
Kaons, which contain one strange and either a lighter up or down quark, have played a central role in the development of the Standard Model (SM). Augusto Ceccucci (CERN) pointed out that many of the SM’s salient features – including flavour mixing, parity violation, the charm quark and CP violation – were discovered through the study of kaons, leading to the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix. The full particle content of the SM was finally experimentally established at CERN with the Higgs-boson discovery in 2012, but many open questions remain.
The kaon’s special role in this context was the central topic of the workshop. The study of rare kaon decays provides a unique sensitivity to new physics, up to scales higher than those at collider experiments. In the SM, the rare decay of a charged or neutral kaon into a pion plus a pair of charged or neutral leptons is strongly suppressed, even more so than the similar rare B-meson decays. This is due to the absence at tree-level of flavour-changing neutral current interactions (e.g. s → d) in the SM. Such a transition can only proceed at loop level involving the creation of at least one very heavy (virtual) electroweak gauge boson (figure “Decayed”, left). While experimentally this suppression constitutes a formidable challenge in identifying the decay products amongst a variety of background signals, new-physics contributions could leave a significantly measurable imprint through tree-level or virtual contributions. In contrast to rare B decays, the “gold-plated” rare kaon decay channels K+→π+νν and KL→π0νν do not suffer from large hadronic uncertainties and are experimentally clean due to the limited number of possible decay channels.
The charged-kaon decay is currently being studied at NA62, and a measurement of its branching ratio with a precision of 15% is expected by 2025. However, as highlighted by NA62 physics coordinator Karim Massri (Lancaster University), to improve this measurement and thus significantly increase the likelihood of a discovery, the experimental precision must be reduced to the level of the theoretical prediction, i.e. 5%. This can only be achieved with a next-generation experiment. The HIKE experiment, a proposed high-intensity kaon factory at CERN currently under approval, would reach the 5% precision goal on the measurement of K+→π+νν during its first phase of operation. experiment, a future high-intensity kaon factory at CERN currently under approval, will reach the 5% precision goal on the measurement of K+→π+νν during its first phase of operation. Afterwards, a second phase with a neutral KL beam aiming at the first observation of the very rare decays KL→π0ℓ+ℓ– is foreseen. With a setup and detectors optimised for the measurement of the most challenging processes, the HIKE programme would be able to achieve unprecedented precision on most K+ and KL decays.
For KOTO, Koji Shimi and Hashime Nanjo reported on the experimental progress on KL→π0ℓ+ℓ– and presented a new bound on its branching ratio. A planned phase two of KOTO, if funded, aims to measure the branching ratio with a precision of 20%. Although principally designed for the study of (rare) bottom-quark decays, LHCb can also provide information about the rare decay of the shorter-lived KS.Radoslav Marchevski (EPFL Lausanne) presented the status and the prospects for a proposed LHCb-Phase II upgrade.
From the theory perspective, underpinned by impressive new perturbative, lattice QCD and effective-field-theory calculations presented at the workshop, the planned measurement of K+→π+νν at HIKE clearly has discovery potential, remarked Gino Isidori (University of Zurich). Together with other rare decay channels such as KL→μ+μ–, KL→π0ℓ+ℓ– and K+→π+ℓ+ℓ– that would be measured by HIKE, added Giancarlo D’Ambrosio (INFN), the combined global theory analyses of experimental data will allow for discovering new physics if it exists within the reach of the experiment, and for providing solid constraints for new physics.
From 28 August to 1 September, the 18th International Conference on Topics in Astroparticle and Underground Physics took place at the University of Vienna, organised by HEPHY/Austrian Academy of Sciences (ÖAW), and attracting about 450 participants. An extensive offer of parallel sessions each afternoon spanned direct dark-matter detection, advances in gravitational-wave (GW) searches, neutrino physics, astrophysics and cosmology, cosmic rays and astroparticle physics, as well as intertrack sessions on two or more subjects. A broad stage was also given to outreach and education, featuring science-communication projects from around the world, open science and masterclasses.
The conference provided an excellent review of the status of scientific questions being addressed by experiments in underground labs, including the latest constraints on dark matter from PandaX, LUX-ZEPLIN, SuperCDMS, CRESST and XENONnT. The various techniques for studying dark matter indirectly, for example via cosmic radiation, were reviewed, as well as direct searches at accelerator facilities. The many and diverse efforts ongoing worldwide to understand the nature of neutrinos were covered comprehensively, including the parametrisation of their mixing properties, their absolute mass, whether neutrinos are their own antiparticle, and their role in the early and late universe and in supernova explosions. Two plenary presentations focused on recent highlights in the field: IceCube’s confirmation of neutrinos from the galactic plane, and evidence of a GW background at nanohertz frequencies measured with pulsar timing arrays (CERN Courier September/October 2023 p7). Others summarised the status of cosmology in theory and experiment, cosmic-ray physics and the detection of GWs.
Among participants was Arthur McDonald, co-recipient of the 2015 Nobel Prize in Physics for the discovery of neutrino oscillations, who gave a talk “Using messengers from outer space to understand our universe and its evolution” to a packed audience of all ages in the Festsaal ÖAW. He also celebrated his 80th birthday during the conference, earning a big round of applause.
A total of 110 posters were presented, more than half from early-career scientists. The five winners were: Korbinian Urban (TUM) for “TRISTAN: A novel detector for searching keV-sterile neutrinos at the KATRIN experiment”; Christoph Wiesinger (TUM) for “TAXO – Towards an ultra-low background semiconductor detector for IAXO”; Steffen Turkat (TU Dresden) for “Low-background radioactivity counting at the most sensitive HPGE detector in Germany”; Angelina Kinast (TUM) for “First results on 170 enrichment of CaWO4 crystals for spin-dependent DM search with CRESST”; and Krystal Alfonso (Virginia Tech) for “Analysis techniques for the search of neutrinoless double-beta decay of Te-130 with CUORE”.
The next edition of TAUP will take place in 2025 in Chengdu, China.
When Matteo Di Cosmo was 16 and listening to German electronic band Kraftwerk, he decided that he wanted to build his own synthesiser. “I fell in love with a track called ‘Radioactivity’, which starts with morse code of the word ‘radioactivity’, and I decided I wanted to build equipment to produce these sounds,” he explains. He had already built his own keyboards, but taking it to the next level pushed him to do a bachelor’s in electronics engineering at the University of Turin. Originally from Puglia in southern Italy, he went on to obtain two master’s degrees, one in mechatronics and one in electronics engineering.
Inspired by CERN
It was during this time that Matteo visited CERN. The experience left him with a strong desire to work there but he felt it was an unattainable ambition. Nevertheless, in 2011 he applied for a position through the “Volontaires Internationaux” programme and was successful. He joined the physics department in 2012 as a fellow, testing commercial equipment used in the backend electronics for CERN experiments. A year later he obtained a staff contract with increased responsibilities, including managing a team of around five and hiring people. Making use of CERN’s internal mobility programme, he then joined the electrical power converter group in the technology department and spent six years working with a multicultural team of 15 people. “CERN is the greatest example of a united Europe, as the incarnation of teamwork no matter what language or nationality,” he says, adding that his experience has undoubtedly affected his personality. “It left me with the sensation that I can no longer be in an environment that is not diverse.”
Finally, in 2018, the knowledge that Matteo had acquired at CERN enabled him to realise his teenage ambition, and he built his own synthesiser: the “tiny synth”, based on field programmable gate arrays (FPGAs). At the time, there were no other products on the market using this technology. Subsequently, he was contacted by the CEO of the organisation he works for today, who was looking for an engineer. Matteo was not ready to leave CERN so he asked the human resources department if he could work as a contractor alongside his job. The request was accepted as there was no conflict of interest.
Invest time in acquiring the skills relevant for your sector, but don’t forget to also spend some time thinking about where you are going
Four years into his dual role, however, Matteo began to reconsider his position. He wanted a job more centred on managing people, in the private sector and that was more focused on profitability. “I was very confident in my work, and I also appreciated my colleagues, but at the same time I think I had reached a ‘plateau’ of knowledge, so I felt I was not able to move forward.” Initially, he struggled with the decision whether to leave CERN. He turned to the CERN Alumni Network to find members who had held indefinite contracts at CERN but chose to pursue a career elsewhere. He met with three such people who took the time to listen and share their experiences, but it was a conversation with a colleague that brought him to the realisation that he needed a change. “One of my best friends asked me ‘are you happy?’ and I was not able to answer.”
Matteo left CERN in 2020 after eight enjoyable years, forever grateful of what it taught him. He is now based in Bari, Italy, where he works with people from around the world as an innovation leader at Music Tribe, delivering audio products for DJs and music producers.
As for his advice to others: “Invest time in acquiring the necessary skills relevant for your sector, but don’t forget to also spend some time thinking about where you are going. I was working all the time, developing electronics. But I forgot to ask myself if I am in the right place doing the right thing. We should all spend some time not only working, but on introspection.”
