Penguin-mediated B_(d,s)->VV decays and the Bs - anti-Bs mixing angle

TL;DR

This paper proposes three strategies to determine the Bs mixing angle phi_s using penguin-mediated vector decays and predicts related branching ratios and CP asymmetries by combining QCD factorisation with flavour symmetries.

Contribution

It introduces novel methods for extracting the Bs mixing angle using specific decay channels and provides theoretical predictions for observables in these decays.

Findings

Predicted longitudinal branching ratios for Bs->K*K* decays

Estimated CP asymmetries in Bs->K*K* decays

Proposed strategies improve precision in measuring phi_s

Abstract

In this letter, we propose three different strategies to extract the weak mixing angle phi_s of the Bs system using penguin-mediated decays into vectors, mainly Bs->K*K*, Bs->phi K* and Bs->phi phi. We also provide predictions for the longitudinal branching ratio and CP-asymmetries of Bs->K*K* using a method that combines QCD factorisation with flavour symmetries to relate this decay to its Bd counterpart.