Search for rare B meson decays at the BaBar experiment

TL;DR

This paper reports on BaBar experiment searches for rare B meson decays involving flavor-changing neutral currents, measuring branching fractions, angular asymmetries, and CP asymmetries to probe physics beyond the Standard Model.

Contribution

First search for B to K tau tau decay and detailed measurements of angular and CP asymmetries in B meson decays using BaBar data.

Findings

First search for B to K tau tau decay.

Measurement of angular asymmetries in B to Kstar l l decays.

Measurement of CP asymmetry in B to KS0 rho gamma decay.

Abstract

b to s transitions are flavour-changing neutral current (FCNC) processes that play an important role in the search for physics beyond the Standard Model (SM). Contributions from virtual particles in the loop are predicted to deviate observables, such as the branching fraction, from their SM expectations. Using data from the BaBar experiment, we present the first search for the rare decay B to K tau tau. The BABAR results on the measurement of the angular asymmetries of B to Kstar l l, where l is an electron or muon, are also reported. In addition, using a time-dependent analysis of B to KS0 pi pi gamma, the mixing induced CP-asymmetry for the radiative FCNC decay, B to KS0 rho gamma, is measured, along with an amplitude analysis of the m (K pi) and m (K pi pi) spectrum.