Majorana-Raychaudhuri Seminars
Welcome to Majorana-Raychaudhuri Seminars. We organise seminars in the field of Quantum Field Theory, Gravitation, Cosmology and Particle Physics on Fridays at 16.30 - 18.00 (IST*) / 12.00 - 13.00 (CET*) as a joint venture of INFN & University Salerno, Italy & PAMU, Indian Statistical Institute, Kolkata, India.
Please use this link to join the seminar.
Seminars This Week:
December 20, 2024: (12:00 - 12:45 CET/ 16:30 - 17:15 IST)
Title: BelleII excess & Muon g-2 illuminating Light DM with Higgs Portal
Abstract: The Belle II collaboration recently announced that they observed the B→ Kνν decay process for the first time. However, their result encounters a 2.7σ deviation from the Standard Model calculation. Additionally, Fermilab released new data on muon g -2 away from the SM expectation with 5.1σ. In this talk, I would like to talk about the simplest UV-complete U(1)Lµ−Lτ-charged complex scalar Dark Matter model. Thanks to the existence of light dark Higgs boson and light dark photon, I can explain the observed relic density of DM and resolve the results reported by both Belle II and Fermilab experiments simultaneously. As a byproduct, the Hubble tension can be alleviated.
December 20, 2024: (12:45 - 13:30 CET/ 17:15 - 18:00 IST)
Title: Origin of cosmic rays in our galaxy
Abstract: The origin of cosmic rays remains unclear, with particles up to the second knee or ankle of cosmic ray energy spectra believed to be of galactic origin. As cosmic rays are charged particles, they are deflected by galactic/intergalactic magnetic field and hence are not directly point back to their sources. An alternate approach to searching for cosmic ray origin is through the detection of gamma-rays and neutrinos which are produced in the interaction of cosmic rays with the ambient matter/radiation in the vicinity of the sources. Supernova remnants are potential galactic objects capable of accelerating cosmic rays up to the knee or ankle energy, but key issues in the SNR origin model remain unresolved. Supernova explosions, on the other hand, tend to cluster in space and time because big OB stars develop in clusters and have limited lifetimes. As a result, overlapping shocks from SNRs and huge star winds created by OB associations can accelerate cosmic rays to PeV energy. In this presentation, our understanding on these issues will be addressed. Possibility of cosmic ray acceleration at star atmosphere to high energies will be explored.
December 20, 2024: (13:30 - 14:15 CET/ 18:00 - 18:45 IST)
Title: The interactions and detection of neutrinos from sub-TeV to beyond EeV
Abstract: High-energy (HE; ~100 GeV to 100 PeV) and ultrahigh-energy (UHE; >~ 100 PeV) neutrinos are essential for advancing both particle physics and astrophysics, offering significant opportunities to study neutrino interactions and test the Standard Model and beyond. On the other hand, neutrino interactions are the cornerstone of all neutrino measurements, as neutrinos are always detected via particles from their interactions. Studying neutrino interactions also reveals new event classes (e.g., dimuons), offering novel measurement opportunities. Neutrino interaction theory is both interesting and challenging: although neutrinos only participate in gravitational and weak interactions, neutrino interaction studies relevant to neutrino experiments also significantly involve strong interactions and quantum electrodynamics. For sub-TeV–EeV neutrinos, while the dominant interaction, deep-inelastic scattering (DIS), is well understood, the increasing data from current and future experiments demands studying subdominant interactions, which remain poorly understood.
In this talk, I will talk about the studies of the sub-TeV--EeV neutrino interactions and detection, including W-boson and trident production, dimuons, and final state radiation (a QED radiative correction as large as 25% while completely overlooked by current experiments).
Organisers:
Gaetano Lambiase (University & INFN Salerno, Italy)
Supratik Pal (PAMU - ISI, Kolkata, India)
Anish Ghoshal (University of Warsaw, Poland)
Arnab Paul (Indian Institute of Technology Madras, India)
Shiladitya Porey (Novosibirsk State University, Russia)
