A high-sensitivity seismic-acoustic station built by a multidisciplinary team of researchers from the National Institute for Geophysics and Volcanology (INGV) and the National Institute for Nuclear Physics (INFN) has just been laid 3,500 metres deep in the abyssal plain of the Ionian Sea, 80 kilometres Southeast of Portopalo di Capo Passero (Siracusa, Sicily).

Thanks to the work of the research team involved, the station, built as part of the Marine Hazard National Operational Programme - "Development and Cohesion Fund" related to the 2014-2020 schedule, which envisaged the implementation of a working prototype, has exceeded its initial objectives and has already been successfully connected to the large KM3NeT/ARCA submarine infrastructure, the largest abyssal neutrino telescope in the Mediterranean Sea.

The station is already capturing the sounds and noises that propagate in the depths of the sea, providing valuable information on the environmental impact these acoustic waves produce. The acquired data is sent in real time to INGV's processing servers housed at the Data Processing Center at INFN's operational headquarters in Portopalo di Capo Passero, via a submarine electro-optical cable approximately 100 kilometres long.

The locations involved in the project are, for INFN, the Southern National Laboratories, the Bari Division and the Rome Division), while, for INGV, the Palermo Division. 

In order to implement this sophisticated scientific observatory, INGV researchers in Palermo installed a sensor on the station capable of detecting both the conductivity and temperature of water masses and the pressure of the water column above, as well as a hydrophone oriented to the study of low frequencies of acoustic waves and a high-sensitivity marine seismometer. 

Researchers at INFN Southern National Laboratories, on the other hand, designed and built the station structure, along with the control and data transmission electronics, as well as watertight enclosures to house the electronics, which are resistant to high pressures. Thanks to the use of advanced technologies and expertise, this instrumentation propels research toward the long-term study of the deepest areas of seas and oceans that are otherwise poorly observed.

The ultracold atoms lab of the Pitaevskii Center for Bose-Einstein Condensation in Trento reports for the first time the observation of phenomena related to the stability of our universe. The results arise from the collaboration among the National Institute of Optics of Cnr, the Physics Department of the University of Trento, Tifpa-Infn and the University of Newcastle and it has been published in Nature Physics.

In which kind of vacuum is our universe? Modern physics describes our universe as an intricate outcome of the interactions between particles and fields (the electromagnetic one, for example). From a general point of view, our universe could be in a not so stable configuration, known as false vacuum, which has an energy higher than the absolute minimum. So, in principle it could decay to the lowest energy state, the true vacuum, triggered by quantum or thermal fluctuations.

False vacuum decay could take place on very different time scales, depending on the system parameters and it manifests with the appearance of bubbles of true vacuum, similarly to the formation of liquid drops in a gas cooled below the condensation point. This process is strongly related to cosmological phenomena and the research community has dedicated great effort to understand in which kind of vacuum our universe is. Several research groups have developed sophisticated theories to describe this process, and, in the absence of a direct access to the conditions of the Big Bang, table top experimental platforms for testing and simulating these models have been devised.

 Today the first observation of this decay is reported in a study published on Nature Physics and with Alessandro Zenesini (Pitaevskii BEC Center, Istituto nazionale di ottica del Consiglio nazionale delle ricerche e Dipartimento di Fisica dell’Università di Trento, Tifpa Trento Institute for Fundamental Physics and Applications, INFN as first author. Researchers prepared a cloud of sodium atoms in an initial state which looks like a false vacuum. They then measured the time it takes to the system to decay to the real vacuum, under different experimental conditions. After a first comparison with numerical simulations of the system, the authors joined the theory group of Ian Moss, well known cosmologist which has also collaborated with Stephen Hawking, to verify that the most reliable theory of false vacuum decay is compatible with the observations.

Once again, ultracold atoms prove to be an ideal platform for quantum simulation both of the extremely small and the extremely large. “We used the magnetic properties of atoms to create artificial false and true vacuum in an ultra-stable and controllable environment. This exquisite control of the degenerate atomic cloud allows us to study false vacuum decay in different experimental conditions and to compare our results with theoretical predictions.” reports Alessandro Zenesini, Cnr-Ino researcher who collaborated for this research with Giacomo Lamporesi and Alessio Recati from the same institute. 

“False vacuum decay theories were developed more than fifty years ago having in mind processes typical of high-energy and subnuclear physics and cosmology.” says Gabriele Ferrari (UniTrento). “The results are a first step toward the validation of theories which were only on paper, and pave the road to new lines of experimental research on the different aspects of the birth and dynamics of the true vacuum bubble, with also effects on biochemistry and quantum computation.”

This research was funded by Provincia Autonoma di Trento, INFN, MUR, Q@TN, UK Quantum Technologies programme and European Union.

Fostering and encouraging young female researchers in theoretical physics: this is the goal of the INFN Milla Baldo Ceolin Prize, which, now in its fourth year, was awarded to ten brilliant recent female graduates, on October 8^th.
The young female students who wrote the best master's theses in theoretical physics in 2023 are: Matilde Barberi Squarotti (University of Turin), Marta Cocco (University of Perugia), Beatrice Costeri (University of Pavia), Alessandra Grieco (University of Padua), Nanako Kato (University of Cagliari), Giulia Muco (Sapienza University of Rome), Miriam Patricolo (University of Pisa), Laura Pezzella (Sapienza University of Rome), Agnese Tolino (University of Turin) and Alison Warman (University of Genoa).
The prize is named after a great scientist, a researcher of international fame, for a long time the director of the INFN Padua Division and the first woman to hold a chair at the University of Padua: Milla Baldo Ceolin conducted research in the field of particle physics, working on the Berkeley and Argonne accelerators in the United States, the ITEP accelerator in Moscow and the ILL reactor in Grenoble, France, in addition to the CERN accelerator machines.
The ceremony was attended by Galileo Galilei Institute Director Stefania De Curtis, INFN National Commission for Theoretical Physics Chairman Fulvio Piccinini, and INFN President Antonio Zoccoli. It was followed by the screening of the documentary "Galileo (R)evolution - The Path of Science", which proposes a dialogue between Galileo's life and that of the new generation of scientists.

It is the most precise measurement ever obtained at CERN’s Large Hadron Collider (LHC) accelerator of the mass of the W boson, and determines its value to be 80360.2 MeV with an uncertainty of 9.9 MeV. The measurement was made by the CMS experiment by analysing data produced in proton-proton collisions of the second LHC data-acquisition period (run2). The result, much awaited by the international particle physics scientific community, was presented by the CMS Scientific Collaboration at a seminar held today, 17 September, at CERN.
“The measurement of the mass of the W boson was obtained by CMS through a state-of-the-art analysis of the data produced at the LHC”, underlines Giacomo Sguazzoni, INFN researcher and national manager of CMS. “The precision achieved was unimaginable when the LHC and CMS were conceived, and is the result of the dogged and passionate work of many colleagues engaged in research activities that, over the years, have enabled CMS, a very complex and sophisticated detector, to achieve performance far beyond that originally envisioned by the project”, concludes Sguazzoni.
“This measurement is the result of many years of capillary work during which we faced and solved numerous experimental problems”, explains Lorenzo Bianchini, Professor of physics at the University of Pisa, INFN associate, and coordinator of the ERC ASYMOW project dedicated to this very measurement. “We built on the experience acquired from similar measurements at the LHC and the Tevatron, addressing critical issues with recent advances in theoretical precision calculations and new data analysis paradigms. What emerged was a modern and innovative measurement in many respects, the result of international collaborative effort in which the Italian contribution was extremely important, also thanks to the opportunities offered by European research funding. All this using only a tenth of the run2 data, thus leaving ample room for improvement of the measurement in the coming years”, concludes Bianchini.
Since its discovery, the W boson has been measured with increasing precision by various experiments, at CERN and other laboratories. The result now presented by CMS agrees with theoretical predictions and with all previous measurements, except that obtained by the CDF experiment at Fermilab’s Tevatron accelerator in the United States.
In 2022, the CDF Scientific Collaboration had, in fact, measured a surprisingly high value of the W boson mass of 80434.0 MeV with an uncertainty of 9.4 MeV: a value that differs significantly from the theoretical prediction of the Standard Model and other experimental results, requiring further study. In 2023, the ATLAS collaboration, which had provided its first measurement of the mass of the W boson in 2017, published a new improved measurement based on a reanalysis of proton-proton collision data from the first LHC data-acquisition period (run1). The new value of the W mass determined by ATLAS - 80366.5 MeV with an uncertainty of 15.9 MeV - was in line with all previous measurements except that of CDF, which still remains the most precise measurement obtained to date. Now, the CMS experiment, with its first measurement of the mass of the W boson, also brings its contribution to these studies, and its result is confirmed to be in line with all previous measurements except, as already mentioned, that of CDF.
Together with the Z boson, the W boson is the elementary particle mediating the weak force and was first observed in 1983, by the UA1 and UA2 experiments at CERN’s Super Proton Synchrotron (SPS) accelerator. For this discovery, Carlo Rubbia, who led the UA1 experiment, and Simon van deer Meer, were awarded the Nobel Prize in Physics the following year. The Standard Model puts the mass of the W boson in close relation to the force of the interaction unifying the electromagnetic and weak forces, and to the masses of the Higgs boson and the top quark, constraining its value to 80353 million electron volts (MeV) with an uncertainty of 6 MeV. Determining the value of the mass of the W boson with high precision is therefore very important because it allows us to verify whether these properties are all consistent with the Standard Model. If they are not, the cause would lie in new physical phenomena, such as new particles or interactions.
“The value of the mass of the W boson derives, in the Standard Model, from two fundamental ingredients: the strength of the weak interaction – of which it is a mediator – and the value of the Higgs field, which is responsible for generating the mass of all elementary particles observed to date”, explains Stefania De Curtis, director of INFN’s Galileo Galilei Institute. “Thus, this new measurement represents a further success of our theory because, given its precision, which exceeds all expectations, it confirms the prediction at the level of the quantum corrections that contribute to its value. The alignment at the quantum level with theoretical predictions indicates that, at least for the W mass, no new phenomena or particles are needed to explain its nature. This does not rule out that they are not lurking around the corner and that LHC experiments may ‘discover’ them in the near future in order to shed light on the still open problems of the Standard Model”, concludes De Curtis.