Tag Archives: Evento scientifico

Speaker: Stefano Morisi (Università Federico II Napoli) I propose two alternatives to the axion mechanism for addressing the strong CP problem. The first approach involves imposing CP as an inherent symmetry of the Lagrangian, which is then spontaneously broken. To generate the correct texture for the Yukawa matrices, is assumed a discrete Z2 symmetry that is softly broken by the scalar potential. By identifying a benchmark point for the Yukawa couplings that aligns with the measured quark masses, the CKM matrix, and low-energy flavor-changing constraints, our findings suggest that this model offers a viable solution to the CP problem I also mention a second approach based on SO(10) GUT model.

Speaker: Pablo Figueroa (Valencia Univ.) Low-threshold direct-detection experiments are rapidly expanding their physics reach beyond conventional weak-scale DM searches. First, I will present new constraints on sub-GeV DM derived from the PandaX-4T S2-only search for CEvNS. These limits are competitive with the recent DAMIC-M bounds and provide leading constraints on scalar and asymmetric thermal dark matter models for masses between 20 and 200 MeV. Second, I will discuss the possibility of probing keV-scale thermal solar neutrinos produced by electroweak processes in the solar plasma. Using XENONnT S2-only data, one can place an upper limit on this flux at the level of (\eta \lesssim 1.2\times 10^{8}) times the Standard Model prediction, while paired searches from XENONnT, LZ, and PandaX give slightly weaker limits. Looking ahead, future experiments such as XLZD could improve these sensitivities by several orders of magnitude. Together, these results illustrate how low-threshold direct-detection experiments can probe both dark-sectors and low-energy astrophysical neutrinos

Speaker: Vishakha Lingadahally (Royal Holloway, University of London) The process of top-quark pair production through the decay of scalars in the One-Higgs Singlet extension of the Standard Model is associated with large interference effects between loop-induced ‘SM-like’ Higgs and heavy Higgs amplitudes, as well as QCD continuum background. In this seminar, I will talk about attaching leptonic decays to the di-top final state at NLO and studying the effects of spin correlations. I present NLO phenomenological predictions for the leptonic decays of top pairs produced in the decay of a CP-odd pseudoscalar at the LHC, with full spin correlation effects preserved in the decayed products. I also aim at attaching parton showers and performing analyses of differential cross sections as functions of various parameters to study the significance in searches for new scalars and pseudoscalars beyond the Standard Model.  

Speaker: Sungwoo Youn (IBS, Daejeon) Axions are a well-motivated dark matter candidate arising from the Peccei–Quinn solution to the strong CP problem. The IBS Dark Matter Axion Group (DMAG) is pursuing a comprehensive experimental program to search for axion dark matter using cavity haloscopes, which exploit the axion–photon coupling in strong magnetic fields. In particular, IBS-DMAG has achieved world-leading sensitivity in the GHz frequency range, significantly advancing the exploration of QCD axion parameter space. In this seminar, I will discuss the key experimental techniques underlying these efforts, including high-Q resonant cavities, ultra-low-noise microwave detection, and high-frequency search strategies. I will also present our recent results from the past few years and outline future directions to extend sensitivity and mass coverage.

Speaker: Prisco Lo Chiatto (Max Planck Für Physik, Weizmann Institute of Science) We study scenarios in which ultralight dark matter (ULDM) causes oscillations of the Cabibbo–Kobayashi—Maskawa (CKM) matrix elements, considering two frameworks. The first, previously proposed in the literature, employs the Nelson–Barr mechanism to solve the strong CP problem and the CKM phase is identified with a pseudo-Nambu– Goldstone boson. The second, inspired by Froggatt–Nielsen flavor models, relies on quadratic couplings of the ULDM to the Standard Model while naturally suppressing linear couplings. On the experimental side, we outline a strategy to search for such oscillations at flavor factories using meson decays, focusing on the NA62 experiment as the most promising candidate for discovery thanks to its large kaon statistics. We show that the sensitivity of lifetime-based observables is parametrically degraded when the total particle flux is not known exactly, leading to a substantial loss of sensitivity compared to naive estimates. We therefore advocate alternative observables based on direct counting of events, which retain the expected 1/N1/N scaling and provide a robust probe of oscillating CKM elements. Our results highlight flavor experiments as a novel probe of ULDM through time-dependent signatures.

Speaker: Konstantin Schmid (University and INFN Padova) In searches for beyond the Standard Model (BSM) Physics, bottom-up effective field theories (EFTs), such as the Standard Model EFT (SMEFT) and Higgs EFT (HEFT), have become crucial theoretical tools. Especially the di-Higgs production process offers the opportunity to probe correlations among the couplings of one or two Higgs bosons to fermions and gauge bosons and this context, it serves as a powerful test of the underlying EFT framework. In this talk, we study Higgs pair production via gluon fusion within the HEFT and SMEFT, also including NLO QCD corrections and sub-leading operators. In particular, we focus on the effect of the Wilson coefficients on the invariant mass shapes and assess the sensitivity of angular observables to the contribution of sub-leading operators.

Speaker: Vindy Prasad (Jilin Univ.) The Standard Model (SM) successfully describes fundamental particles and their interactions but fails to explain several outstanding issues, including the nature of dark matter (DM). DM constitutes approximately one quarter of the total matter density of the universe and is invisible across the electromagnetic spectrum. It may account for observed anomalies such as galaxy rotation curves and other fundamental characteristics of our universe. DM may couple to SM particles via portals. These portals introduce several new physics particles, such as light Higgs boson, dark photon, axion-like particle, and sterile neutrinos. These new physics scenarios may also appear in several baryon- and lepton-number-violating processes. Furthermore, the origin of DM and the observed asymmetry between visible matter and antimatter may be connected through the introduction of a dark baryon. The new physics particles can be accessible at high-intensity electron-positron collider experiments, such as the BESIII experiment, if their masses are in the MeV-GeV range. BESIII has recently explored the possibilities of these new physics scenarios using large data samples collected at several energy points, including the J/psi, psi(2S) and psi(3770) resonances. This talk will review the recent BESIII results related to searches for new physics.

Il Convegno Nazionale SIRR, che ha una cadenza biennale, rappresenta il più importante momento di aggregazione sia per gli iscritti alla Società che per potenziali futuri soci interessati a condividere il loro lavoro e a discuterne le prospettive nei vari ambiti di ricerca coperti dalla SIRR. Il Convegno Nazionale SIRR 2026 è organizzato in collaborazione con l’Istituto Nazionale di Fisica Nucleare (INFN), grazie al recente accordo INFN–SIRR che formalizza e rafforza la sinergia tra le due comunità scientifiche. Sito web: https://web.infn.it/convegnonazionalesirr2026/