From 6 to 13 July 2022, Bologna hosts, for the first time in Italy, the 41st edition of ICHEP – International Conference on High Energy Physics, the scientific reference event in particle physics for over 70 years,
in which, every two years, the most relevant results produced by the scientific community are presented about particle physics, astrophysics, cosmology and technology of accelerators and strategies and plans for the future of research in these fields are discussed.
Six days of work – with a break on Sunday – at the Bologna Congress Center, which will involve over a thousand physicists from all over the world, with more than 900 presentations in parallel sessions (from 6 to 9 July) and plenary (from 11 to 13 July): after the forced break of the health emergency, the event returns therefore inpresence, also proposing the streaming mode to allow remote participation.
The first results of the XENONnT Dark Matter experiment, installed underground at the INFN Laboratori Nazionali del Gran Sasso, has been presented on July 22 at the IDM2022 conference in Vienna.
XENONnT presents the lowest background ever achieved in a direct dark matter experiment, 5 times lower than its predecessor XENON1T.
We observe no excess above known backgrounds, so we can attribute the excess observed two years ago in the XENON1T experiment as due to trace amount of tritium, which was one of the hypothesis at the time. We can now set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and axion-like particles as bosonic dark matter.
The XENON-Bologna group is responsible of the MonteCarlo simulations and background predictions oft the experiment (crucial in the current analysis), and of the design, installation and operation of the neutron veto, one of the novel subsystems of XENONnT, already used also in this work thanks to its very good performances in removing part of the gamma background from detector materials.
The XENON-Bologna group is led by Gabriella Sartorelli, and composed by Marco Selvi, Lorenzo Bellagamba, Franco Semeria, Graziano Bruni, Pietro Di Gangi, Federica Agostini, Andrea Mancuso e Federico Casadei.
Other colleagues and INFN Services have been instrumental for the detector construction: Antonio Chiarini, Marco Guerzoni, Roberto Michinelli, the Mechanical Workshop, together with the Direction&Administration.
Black holes are objects so compact that not even light can escape them and they are described by solutions of Einstein’s equations characterized by very few physical parameters, such as mass, angular momentum and electric charge. The American physicist John Wheeler, to whom we might owe the paternity of the term “black hole”, summed up this extreme simplicity by saying that “black holes have no hair”, which contrasts sharply with the enormous complexity of those stars which, having run out of nuclear fuel, can collapse and form black holes. This contrast, between the simplicity of black holes and the complexity of stars, is at the origin of the “paradox of information loss” formulated by Stephen Hawking. The famous British physicist, in the early 1970s, showed that black holes can “evaporate” by emitting a radiation that depends only on the quantities (mass, angular momentum and charge) that characterize the outside of the black hole. The information on the very complex structure of the original star would therefore be lost if the black hole evaporated completely. The “paradox” is based on the description of the star that forms the black hole and its gravitational field using classical physics on the one hand, while the radiation in which the black hole evaporates is described using quantum physics on the other. An international research group involving Roberto Casadio of the INFN Section of Bologna and of the Department of Physics and Astronomy “A. Righi ”of the University of Bologna has obtained results that significantly modify this theoretical framework. In an article written together with Professor Xavier Calmet and PhD student Folkert Kuipers of the University of Sussex (UK) and Professor Stephen Hsu of Michigan State University (USA), recently published in the journal Physical Review Letters, it was shown that the gravitational field instead depends on the internal structure of the source according to quantum physics. Hence, we can say that both around a star and outside a black hole there are “quantum hair” which, although very weak, can contain the information necessary to resolve the paradox. This result has a historical parallel in the quantum description of atoms which, at the beginning of the last century, explained their stability and does not require any drastic revolution of the quantum field theories used today to describe nature in a unified way.
Sushanta Tripathy, a post-doc INFN fellow at INFN Bologna Unit, was appointed by the Phsyics Coordination of the ALICE Experiment convener of the Physics Working Group “Monte Carlo generators and minimum-bias physics”. The appointment has been endorsed officially from the ALICE Collaboration Board last 10th June.
Sushanta graduated at Pondicherry Central University, in India and obtained his Ph.D. at the prestigious Indian Institute of Technology at Indore in 2019. Before joining INFN Bologna in January 2020, he had positions as visiting researcher at Lund University in Sweden and at UNAM in Mexico City as post-doc.
Sushanta’s extensive research work covers the study of hadronic resonances from proton-proton to heavy-ion collisions, including the \phi meson and the debated f0(980) state, and the study of global observables as event shapes, multiplicity and spherocity. As INFN fellow, besides leading several ALICE publications, he authored on his own several papers with few collaborators, including a review in Scientific Reports on event topology and global observables in heavy-ion collisions and a study published on Physical Review D estimating the impact parameter and transverse spherocity using machine learning (Artificial Intelligence) techniques. Since 2021, Sushanta has also joined the ERC-CosmicAntiNuclei project at the University of Bologna, working on the development of an afterburner model for antinuclei formation using Monte Carlo event generators.
In this new role, Sushanta will be a member of the ALICE Physics Board and will coordinate analyses on luminosity measurements, multiplicity, underlying event and supervision of Monte Carlo generators used in ALICE analyses. He will take service effective since September 1st.
The award ceremony for the competition reserved for INFN employees and associates took place on Saturday afternoon, May 14, at the Acacia Theater in Naples, “Adesso tocca a noi: il mondo della fisica racconta la scienza con l’arte”. The competition between professionals, in its first edition, is part of the European project “Art & Sciences across Italy” curated by INFN and aimed at Italian high school students to promote scientific dissemination through the language of art .
It was precisely the students participating in the project who, at first challenged each other with art containing scientific content to win an internship at CERN in Geneva and then voted for those created by the INFN employee and associated staff, determining the 12 works winners.
Award ceremony at the Acacia Theater in Naples
Over 220 students expressed their opinion on the 60 works presented by the researchers and technicians and, among the 12 winning works, that of our colleague Donato Di Ferdinando was also selected.
“The Opera Selfie” is the title of the photo presented by Donato, obtained from a nuclear emulsion of the OPERA experiment, exposed through a pinhole, on which the image of the entire OPERA detector was later impressed. The concept of a part of the detector that reveals all of itself and the imperfections of the emulsion that gave a retro flavor to the photo really appealed to the jury made up of students.
In the Svalbard archipelago, beyond the Arctic Circle, the permanent station of the EEE project for cosmic rays (PolarqEEEst) has picked up signals related to the recent eruption of the volcano in the Tonga archipelago. Twelve hours after the eruption, the barometric sensors, installed together with the three EEE detectors in Ny-Ålesund with the purpose of correcting the pressure dependence of the muon rate, observed an anomalous oscillation of the atmospheric pressure, with an amplitude of 1.3 hPa. Further oscillations, detected about 12, 24, 36 and 48 hours after the event, are compatible with the arrival of the shock wave from the opposite direction, and with successive passages of the two waves, after completing further revolutions around the Earth. The detectors have been assembled and installed with the fundamental contribution of the technical services of the Bologna Section, and are operational in the international research base in Ny-Ålesund since 2019. The PolarqEEEst experiment is the result of a collaboration between the INFN Sections and Universities of Bologna and Bari and the Centro Fermi in Rome, with the important support of the Italian CNR for the permanent installation in Ny-Ålesund. This result underlines the reliability of the detectors, which can operate for long periods of time, providing useful measurements for cross-disciplinary scientific studies.
The researchers of the CUORE experiment (Cryogenic Underground Observatory for Rare Events), located at the Gran Sasso National Laboratories of the National Institute of Nuclear Physics (INFN), have published the new results of the investigation on the nature of the neutrino in Nature.
The results obtained and published in Nature are based on a amount of data, collected in the last three years, ten times greater than any other research with similar experimental technique. Despite its phenomenal sensitivity, the experiment has not yet observed evidence of double beta decay without neutrino emission. From these results, however, it is possible to establish that a tellurium atom takes more than 22 million billion billion years to decay: these new CUORE limits on the behavior of neutrinos are crucial for the search for a possible new discovery in particle physics which would be revolutionary because it would help to understand our own origins.
But CUORE is a true scientific and technological triumph, not only for its new results, but also for having successfully demonstrated the operation of its cryostat in truly extreme conditions. Cuore cryostat has been operating continuously for almost three years at a temperature of 10 thousandths of a degree. above absolute zero (10 milliKelvin).
The Bologna research group has participated in the CUORE experiment since 2008 and took part in the assembly of the over nine hundred tellurium oxide crystals (130TeO2) and provided a significant contribution during the delicate assembly phase of the cryostat that, as highlighted in the Nature article, is today the state of the art in the context of cryogenic instruments of this size.
Personnel of the General Technical Service of the INFN Section of Bologna during an intervention on the cryostat
The Bologna research group has participated in the CUORE experiment since 2008 and took part in the assembly of the over nine hundred tellurium oxide crystals (130TeO2) and provided a significant contribution during the delicate assembly phase of the cryostat that, as highlighted in the Nature article, is today the state of the art in the context of cryogenic instruments of this size.
But more generally and even more so in searches for rare events, the reduction of background noise is fundamental. In this context, the Bologna group has started a campaign to identify noise sources by focusing on disturbances at frequencies below one hertz. These disturbances constitute an unwanted and uncontrollable background noise that could significantly limit the energy resolution at very low energies as in the case of the search for dark matter or axions. This is an original study that made use of the expertise of colleagues of the Geophysics and of the Oceanography and atmospheric sector of DIFA, in addition to the contributions of colleagues from the INGV of Bologna and the INGV of l’ Aquila, and to the contribution of SARA Electronic Instruments of Perugia.
CUORE will benefit from this ongoing study, but the results obtained will be extremely useful in mitigating the effects of these disturbances in next-generation bolometric experiments which aim to significantly increase the potential for discovery of neutrino-less double beta decay. These include the CUPID experiment which is scheduled to take place again at the Gran Sasso underground laboratories and reuse the cryogenic infrastructure of CUORE, currently in the design phase. With reference to this project, the Bologna group participates, in collaboration with the Bologna unit of the IMM Institute for Microelectronics and Microsystems of the CNR and with the IMEM of Parma, in a research and development of cryogenic thermal transducers.
DUNE is the new generation experiment under construction in the United States on the most intense neutrino beam. It has over 1400 participants, 217 institutions (including CERN) from 37 countries. DUNE will make use of two detectors placed on the beam line: a “near” detector located at the Fermi National Accelerator Laboratory in Batavia, Illinois will record the neutrino interactions in the vicinity of the beam producing area, while the “far” detector, composed of four large Time Projection Chambers (~ 80,000 t of liquid Argon) will be located at the Sanford Underground Research Facility in Lead, South Dakota, 1,300 km from the point of production and 1.5 km deep. The Long-Baseline Neutrino Facility (LBNF) will provide the neutrino beam and supporting infrastructure.
In his role as Director of Research at CERN (2009-2015), Prof. Bertolucci played a decisive role in the launch of the LBNF-DUNE program which for the first time sees the adoption in the United States of a flagship program managed according to the CERN model (infrastructures held by the host institution, experiments owned by an international community), enlarging the scientific scope of CERN beyond the Geneva laboratory.
The DUNE experiment has a broad experimental program, including:
-the physics of neutrino oscillations: the main objective of the experiment is to determine the mass ordering of neutrinos and the possible violation of the CP symmetry in the lepton sector. These measurements could provide insight into the origin of matter-antimatter asymmetry, one of the fundamental issues in particle physics and cosmology.
– the decay of the proton: its observation would be a sensational discovery in particle physics and provide a key point for grand unification theories.
– the observation of stellar collapse neutrinos in our galaxy: the measurement of the neutrino flux from this source would provide unique information on the first stage of the nucleus collapse and on the formation of a neutron star.
Moreover, in consideration of the large statistics, DUNE will provide the most comprehensive set of measurements of neutrino induced reactions and will be sensitive to several signatures of physics beyond the Standard Model.
Since his arrival in Bologna in 2016 as Extraordinary Professor at the University of Bologna, prof. Bertolucci promoted the participation in DUNE of a large research group at the local INFN Division, and coordinated the Italian effort on the neutrino program in the USA, which sees the participation of a constantly growing national community.
The Governing of AIDAinnova, the largest European project on R&D for particle physics, financed within the Horizon-2020 programme with 10 million euros for a duration of 4 years, has unanimously endorsed the nomination of Paolo Giacomelli of INFN Bologna, as the next Scientific Coordinator of the project from the 1st of April 2022 until the end of the project on 30th March 2025.
ICHEP, the International Conference on High Energy Physics, is coming to Italy for the first time from 6-13 July 2022. It will gather in Bologna theoretical and experimental physicists from around the world who are engaged in the field of particle physics. On the occasion of this big event, the conference organising committee has launched, in collaboration with AIAP, the Italian Association for Visual Communication, a competition for designing a brand or logotype and poster that define the visual identity of the 2022 edition of the prestigious conference, with a prize of €3,000. The competition is aimed at students in design, graphic design, and communication design courses as well as graphic designers and designers – both individually or organised in groups – who will have up to 15 December to send in their work. The brand or logotype will need to constitute the distinctive, identifying element of the event, synthesising, in a single image, both regional aspects, linked to the peculiarities of the host city, and scientific ones, i.e. those pertaining to the conference theme. The poster will, on the other hand, be the essential tool for presenting the event: it will need to be visually coherent with the brand or logotype and will need to contain text and institutional logos. The organisation of the 41st edition of the conference, was entrusted to the INFN divisions of Bologna and Ferrara.
