Speaker
Description
The physics of bottom hadrons plays a fundamental role both in the precision tests of the Standard Model (SM) and in searches of possible New Physics (NP). Rare B-meson decays, which are induced by the Flavor-Changing Neutral Currents (FCNCs) $b \to s (d)$ transitions, provide a stringent test of the SM in flavor physics. Being loop-induced in the SM, these transitions are suppressed and NP effects can increase substantially their decay widths. In this talk we discuss the extremely rare decay $B^+ \to \pi^+ \tau^+ \tau^-$. We present its dilepton invariant-mass spectrum and decay rate calculated in the effective electroweak Hamiltonian approach for the $b \to d \ell^+ \ell^-$ transitions in the SM, accounting long-distance contributions, for different types of the $B \to \pi$ formfactor parameterizations.
This research is supported by the RSF Grant № 22-22-00877, https://rcsf.ru/project/22-22-00877/.
