学术报告（2025年12月2日10:00）：Low-energy electroweak physics

主持人： 唐健 教授

报告人简介：Oleksandr (Sasha) Tomalak is an Associate Professor at the Institute of Theoretical Physics, Chinese Academy of Sciences in Beijing. His research spans nuclear and particle physics, with particular emphasis on high-precision studies of neutrino interactions, nucleon structure, and atomic energy levels. Tomalak has made seminal contributions to the theoretical foundations of next-generation neutrino oscillation experiments, developing effective field-theory frameworks to compute cross sections with percent and subpercent level of accuracy. His work on coherent elastic neutrino–nucleus scattering (CEνNS) has produced essential tools for dark-matter searches and low-energy neutrino experiments. In studies of neutron decay and the Cabibbo–Kobayashi–Maskawa (CKM) matrix, he has advanced methods for the precise determination of fundamental coupling constants. Tomalak has also addressed the proton-radius puzzle through innovative two-photon-exchange calculations and has contributed precise theoretical evaluations of energy-level shifts in hydrogen and muonic hydrogen.

报告简介：In this seminar, he will present recently developed effective field theory frameworks for computing radiative corrections to low-energy electroweak processes. Utilizing this approach, he will provide the most precise and accurate predictions for several observables: the cross sections for elastic (anti)neutrino-electron, (anti)neutrino-nucleon, and coherent elastic (anti)neutrino-nucleus scattering; as well as the neutrino energy spectra from neutron, pion, kaon, and muon decays. These predictions rigorously quantify uncertainties for the first time. New results are crucial for accurately normalizing (anti)neutrino fluxes in cross-section and oscillation experiments, extracting quark and lepton mixing matrices, refining models of solar and reactor neutrino physics, determining the nucleon axial-vector structure, and searching for new physics in low-energy electroweak interactions.