Roberta Volpe on behalf of the Belle II Collaboration

08 July 2023

Abstract: We report on recent results obtained by the Belle II experiment related to searches for beyond the standard model physics. The B meson decay data sample used corresponds to an integrated luminosity of $L = 189$ fb$^{-1}$. In recent years, discrepancies from standard-model predictions, which suggest violation of lepton-flavor universality, have emerged in multiple measurements of B meson decays. In this document two analyses aimed to search for violation of the light lepton universality are reported: the inclusive $R(X_{e/\mu})$ measurement and an angular analysis of the $B^0 \to D^{*-} l^+ \nu_l$, with $l=e,\mu$, decays. New physics can manifests itself also with the production of new particles. The search for a long-lived spin-0 particle in $b\to s$ transitions, and its interpretation in two dark sector models, is reported as well.

Keyword(s): Proceedings of DIS2023. Light lepton universality, R(Xemu), angular asymmetries, dark sector, search for long-lived particles.
Note: proceedings of DIS2023: XXX International Workshop on Deep-Inelastic Scattering and Related Subjects, Michigan State University, USA, 27-31 March 2023