Tag Archives: Evento scientifico

Speaker: Davide Giusti With the advancement of precision physics in the Flavor sector, tests of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix are playing an increasingly significant and impactful role in understanding the limits of the Standard Model of particle physics. Achieving exquisite precision in current and future experiments requires theoretical predictions to better control low-energy hadronic effects, which, thanks to the growing potential of supercomputing and advances in non-perturbative techniques, can now be achieved by the most modern numerical simulations of lattice QCD, including the effects of long-range electromagnetic interaction. After a review of the state of the art in the field for the accurate extraction of the elements of the CKM matrix, in this seminar I will illustrate some new lattice results, using domain wall chiral fermions, on the form factors contributing to the amplitudes of radiative leptonic decays of light and heavy mesons, $H \to \ell \nu_\ell \gamma$, including multiple virtualities of the emitted photon for the study of rare four-lepton decays, such as $H \to \ell^{\prime +} \ell^{\prime -} \ell \nu_\ell$ or $H \to \ell^{\prime +} \ell^{\prime -} \ell^+ \ell^-$. In addition, I will present some recent efforts and the new program of the BMW collaboration in the study of the unitarity of the first row of the CKM matrix. This activity is part of the Theoretical Phenomenology Visiting Institute@LNF, running from 23 March to 27 March 2026, and supported by CSN4 to promote the participation of early-career scientists.

This workshop aims to bring together theorists and experimentalists working on various aspects of kaon decays, with a focus on fostering interdisciplinary collaboration and advancing precision studies in flavor physics. Topics will include radiative kaon decays, rare processes, multi-lepton final states, and future prospects in K​ measurements. Special attention will be given to novel lattice QCD approaches and their phenomenological implications. The program will feature a hands-on session on Monte Carlo generators and radiative corrections, aimed at clarifying current methodologies and enhancing analysis tools. Contributions from major experimental collaborations—including NA62, KLOE/KLOE-2, E36, and LHCb—will be complemented by theoretical insights from lattice groups such as BMW, ETMC, RBC, and UKQCD. This activity is part of the Theoretical Phenomenology Visiting Institute @ LNF, running from 23 March to 27 March 2026, and supported by CSN4 to promote the participation of early-career scientists across three scientific events. The Theoretical Phenomenology Visiting Institute @ LNF initiative is chaired by Federico Mescia. The workshop will take place in the Salvini Auditorium (Building 36, access via the LNF secondary entrance at Via E. Fermi, 60 – see map). (Talks by invitation only)

The recent result published by the PADME Collaboration at LNF, has strengthened the interest in the searches for the hypothetical X17 particle, whose existence has been firstly suggested by nuclear physics experiments performed at ATOMKI. The aim of the Workshop is to provide a comprehensive review of the current experimental activities, and of the possible future developments in this field. Emphasis will be given to searches at particle’s accelerators.  

(Advanced LinEar collider study GROup) Workshop

Speaker: Cristina Lazzeroni (University of Birmingham) The main aim of the proposed KOTO II experiment at JPARC is the measurement of the ultra-rare decay KL to pi0 nu nu. This decay is heavily suppressed and its branching is very well predicted by the SM (3x 10-11 with about 2% uncertainty), thereby exhibiting an exceptional sensitivity to new physics. The design includes a new beamline with a 5-degree extraction angle, and a new detector with a 12-meter-long signal decay region and a 3-meter diameter calorimeter. A discovery of the KL to pi0 nu nu decay with 5σ significance is achievable for the SM value of the branching ratio. The design, expected performance, and current status of the KOTO II experiment will be presented.

Speaker: Alfredo Stanzione (La Sapienza Univ., Roma) An interesting feature of a cosmological phase transition can be a stage of exponential expansion (supercooling). The modified expansion history and the entropy injection at reheating, can affect the final energy fraction of dark matter. In this paper, we revisit the calculation of the freeze-out and freeze-in dynamics, showing additional effects on top of the standard dilution factor if the dark matter production is completed during the supercooling stage. We show for the first time how these effects can be particularly interesting for direct detection, as the parameter space for WIMP-like candidates shifts from excluded to allowed regions, and freeze-in candidates get closer to experimental reach. A phenomenological motivation to consider supercooling is the associated gravitational wave background. The implications of a finite-duration reheating stage, when the equation of state is close to matter-domination, are a peculiar low-frequency spectrum, and its shift to lower frequencies. These effects are a complementary test of the dynamics that we study for dark matter production, and remarkably can link direct detection of dark matter and gravitational wave astronomy.

The Theoretical Phenomenology Visiting Institute@LNF will host a two-day workshop titled ‘The Semileptonic B Frontier: LHC, B-factories, Lattice QCD & the Hunt for Precision’ from February” 16 to 18, 2026, as part of its activities scheduled for February 16–20. The aim of the workshop is to bring together theorists and experimentalists working on various aspects of semileptonic b-hadron decays for both charged and neutral flavour changing current processes. Topics will include recent developments, open questions, and future directions, including novel lattice approaches for inclusive B decays, CKM determinations, hadronic form factors, and potential signals of New Physics. Participants will review the latest B-physics experimental results and the theoretical inputs, will discuss new observables and tools to enhance the future analyses. The aim of the workshop is to foster the collaboration across different communities, to improve the understanding of experimental systematic uncertainties and theoretical calculations in this crucial area of flavor physics.

Speaker: Alessandro Paoloni (Istituto Nazionale di Fisica Nucleare) JUNO is an experiment located in the GuangDong province of People’s Republic of China and dedicated to the measurement of the neutrino mass hierarchy through the detection of antineutrinos produced by two nuclear power plants. The experiment is based on 20 kton of liquid scintillator read out by 17596 20″ photomultipliers and 25587 3″ photomultipliers. JUNO mass is one order of magnitude higher than previous experiments on solar neutrinos (Borexino) and reactor antineutrinos (KamLAND). The unprecedented mass posed previously unknown complexities in the design and the realization of the experiment, which finally started data taking during August 2025. In the seminar the experiment will be described and its performances reported. Given the optimal baseline and the large mass of the experiment, two months of data taking have been sufficient for the best up-to-date measurement of the solar neutrino oscillation parameters, entering the era of high precision in neutrino physics.

Speaker: Emanuele Rosi The detection of gravitational waves (GW) after several decades from their formulation opened a new window to observe the universe. The new generation of GW detectors is expected to span a large parameter space, requiring theoretical physicist to develop different approaches to face the two body problem in General Relativity, each of them based on some perturbative expansion, e.g. Post Newtonian, Post Minkowskian (PM), Self Force. Among these, Effective Field Theories (EFTs) and quantum amplitudes are used together to extract scattering observables which also have a meaningful classical limit, both in the PM and Self Force frameworks. We analyse the high energy (Regge) regime of spinless two body scattering within this approach, by the prospect of isolating universal effects and to give insights on the resummation of the PM observables at higher orders, made possible by the simplicity of the calculations in the Regge limit. A sequence of classical Feynman diagrams is recognised to contribute to the leading power and leading log(s/t) in the high energy expansion. We compute them up to four loops (5PM) and use analyticity properties of the S Matrix to maximise the information that we can extract at any PM order.

Alessandro Pilloni (UniME & INFN CT) In the last 20 years, the discoveries of tenths of exotic candidates has challenged the simplistic quark model predictions, most notably in the charmonium sector. While no consensus on their nature has been reached in the community, it is time to have a critical review of our understanding of the sector, to see what developments can be expected in the near future. I will review the most relevant experimental observations of the last few years, and discuss the theoretical and phenomenological tools that will help us to move forward in understanding this complicate sector of QCD.