The T2K Collaboration published new results showing the strongest constraint yet on the parameter that governs the breaking of the symmetry between matter and antimatter in neutrino oscillations. The parameter governing the matter/antimatter symmetry breaking in neutrino oscillation, called δcp phase can take a value from -180º to 180º. For the first time, T2K has disfavored almost half of the possible values at the 99.7% (3σ) confidence level, and is starting to reveal a basic property of neutrinos that has not been measured until now. This is an important step on the way to knowing whether or not neutrinos and antineutrinos behave differently. These results, using data collected through 2018, were published in Nature.

After 20 years of operations, the Sloan Digital Sky Survey (SDSS) published in 2020 its final cosmological analysis, a publication co-led by Andreu Font-Ribera (IFAE).

The 3D maps of over two million galaxies and quasars from SDSS have been used to provide exquisite measurements of the expansion rate of the universe over the last 11 billion years, using a technique known as Baryon Acoustic Oscillations (BAO). These BAO measurements provide by themselve a confirmation of the existence of dark energy (detected at 8-sigma), and improve by an order of magnitude the constraints on the curvature of the Universe.

The IFAE QCT lab was accommodated during 2020, hosting two dilution refrigerators with capacity to reach temperatures in the 10-20 millikelvin regime needed to operate superconducting qubits. The lab was already tested with the first measurements of a single superconducting qubit.

The MAGIC telescopes detected the first Gamma Ray Burst at very high energies. This was the most intense gamma-radiation ever obtained from such a cosmic object. But the GRB data have more to offer:“with further analysis, the MAGIC scientists could now confirm that the observation is consistent with the hypothesis that the speed of light in vacuum is constant – no evidence of a dependence with energy was found. So, like many other tests, GRB data also corroborate Einstein’s theory of General Relativity. The study was published in Physical Review Letters.

One of the main goals of the ATLAS experiment at the Large Hadron Collider (LHC) is to challenge the predictions of the Standard Model (SM), our most successful theory of elementary particles. To this end, a promising direction is the study of the top quark, the heaviest elementary particle known, with a mass close to that of a gold atom. The production of two top quarks and two antitop quarks (“four-top-quark” production) is a very rare process in the SM, happening only once every 1012 collisions. However, new particles beyond the SM can significantly enhance this rate.

In July 2019 the ATLAS Collaboration reported strong evidence for the production of four top quarks, a milestone reached by studying events with two same-charge leptons or three leptons, plus additional jets originating from the bottom quarks. The signal significance amounts to 4.3 standard deviations (s.d.), for an expected significance of 2.4 s.d. in the SM. This means that the measured rate is somewhat above the SM prediction, although still consistent with it within 1.7 s.d. The IFAE-ATLAS team has not only contributed to this result, but is also completing a search for this process in a complementary channel featuring only one lepton or two opposite-charge leptons. Additional data from the next LHC run, to start in 2022, along with further developments in the analysis techniques, will improve the precision of this challenging measurement, and hopefully allow drawing definite conclusions on whether the breakdown of the SM is finally in sight.

The anomalous magnetic moment of the muon, is among the most precise measured quantities in particle physics. Its nonzero value emerges purely out of quantum effects and tests our knowledge of particle physics. In particular, the current experimental value has reached a precision that requires accounting for all the known sectors of the Standard Model of particle physics when computing its theoretical value. In the past years, such an observable has attracted great attention due to the current discrepancy among the measured value and its theoretical prediction, that might point to the presence of new physics around the corner.

Scientists at IFAE have actively contributed to improving the current theory estimate of the muon’s magnetic moment, as part of the “Muon g-2 Theory Initiative". In particular, S. Peris has contributed to the current estimate of the lattice determination for the hadronic vacuum polarization contribution to (gμ−2)(g_{\mu}-2)(gμ​−2), while P. Masjuan and P. Sanchez-Puertas contributed to the current estimate of the hadronic light-by-light contribution. The global effort has crystallized in the publication of a whitepaper “The anomalous magnetic moment of the muon in the Standard Model” in 2020, where the people at IFAE also played an important role in the writing and coordination of the document.

In September 2020 PIC joined the Spanish Supercomputing Network (RES) as one of the nine nodes of the new Data Service. RES was created in March 2007 by the Spanish Ministry of Education and Science and it is recognized as a Singular Scientific and Technical Infrastructure (ICTS)” since 2014, as it is a unique infrastructure in its field, with public ownership and open to competitive access. The first RES call for Data projects opened at the end of 2020 and further calls are expected annually.

In December 2020 the LIDAR was shipped to La Palma for a one-year pathfinder testing period at the ORM within the LST1 site. The commissioning of the LIDAR in Barcelona was deemed completed after being able to re-aluminize its 1.8m mirror. This one-year test during 2021 shall demonstrate that the LIDAR on-site performance and endurance do fulfil the CTA requirements.

In 2020 the project became a truly international endeavour with the start of the participation of the LIDAR group from University of Nova Gorizia in Slovenia, in addition to the long-standing participation of Padova University in Italy.

In November 2020, IFAE became a partner of the company Deep Detection S.L. Deep Detection offers new industrial inspection solutions combining X-ray detection and artificial intelligence thanks to a multispectral X-ray camera that includes a photon-counting technology capable of detecting hitherto undetectable foreign bodies, such as plastics, wood or bones. Its first applications focus on the food security sector

After IFAE demonstrated the radiation hardness capabilities of 3D sensors (which surpass any other sensing technology), ATLAS selected these sensors for the innermost layer of the pixel tracker for the high-luminosity LHC era.
IFAE is now in the process of qualifying its assembly line to produce 3D modules for the first barrel layer of the ITk pixel detector. The first step will be the fabrication of RD53A mock modules to be used in demonstrator tests.

Qilimanjaro Quantum Tech SL, a spin-off of the University of Barcelona (UB), the Barcelona Supercomputing Center (BSC), and IFAE, was presented in 2020. Qilimanjaro’s integrated hardware & software team focuses on coherent quantum annealing high-quality qubit architectures to deliver scalable app-specific fully quantum processors and algorithmic services in a short timeframe

The classification and definitive analysis of the 39 events detected by Virgo and LIGO in the third observation period was published in 2020. Events included: 36 mergers of black holes; a likely merger of a binary system of neutron stars; and two systems that were most likely composed of a black hole and a neutron star. The catalogue provided, for the first time, a complete picture of the zextraordinarily large number of recorded gravitational-wave signals and their sources. It represents a wealth of observations and data on the physics of black holes, barely imaginable until only a few years ago.

In 2020, the project Simulating the expansion of the COVID-19 outbreak: a risk forecast tool considering socioeconomic and gender inequalities in Barcelona was awarded a “Premi de Recerca Científica Fons COVID de l’Ajuntament de Barcelona” grant with 72KEUR. Pere Masjuan is leading this project with the aim to develop a software tool to simulate COVID-19 spread by leveraging newly available demographic, mobility, and health data based on group theory techniques. Its main deliverable will consist of a user-friendly web interface for researchers to explore the determinants of the COVID-19 expansion with respect to socioeconomic and gender inequalities in Barcelona.