Hunting new animalcula with rare K and B decays

¹ TUM Institute for Advanced Study, Lichtenbergstr. 2a, D-85748 Garching, Germany
² Physik Department, TUM School of Natural Sciences, TU München, James-Franck-Straße, D-85748 Garching, Germany

^* Talk given at QCD@Work 2024, Trani, June 2024.

Published online: 10 December 2024

Abstract

We summarize the recent strategy for an efficient hunting of new animalcula with the help of rare K and B decays that avoids the use of the |V_cb| and |V_ub| parameters that are subject to tensions between their determinations from inclusive and exclusive decays. In particular we update the values of the |V_cb|-independent ratios of various K and B decay branching ratios predicted by the Standard Model. We also stress the usefulness of the |V_cb|–γ plots in the search for new physics. We select the magnificant seven among rare K and B decays that should play a leading role in the search for new physics due to their theoretical cleanness: B⁺ → K⁺(K*)vv^- and K⁺ → π⁺vv^- measured recently by Belle II and NA62, respectively, K_L → π⁰vv^- investigated by KOTO and also B_s,d → μ⁺μ⁻ and K_S → μ⁺μ⁻ measured by the LHCb, CMS and ATLAS experiments at CERN.