Connecting B_d and B_s decays through QCD factorisation and flavour symmetries

TL;DR

This paper uses QCD factorisation and flavour symmetries to relate B_{d,s} decay modes, proposing sum rules to constrain CKM angles and strategies to determine the B_s mixing angle.

Contribution

It introduces a novel approach combining QCD factorisation and SU(3) symmetry to relate B_{d,s} decays and derive sum rules for CKM constraints.

Findings

Predicted B_s -> KK branching ratios and CP asymmetries

Proposed sum rules for penguin-mediated decays

Outlined strategies for measuring B_s mixing angle

Abstract

We analyse B_{d,s} -> K(*)0 K(*)0 modes within the SM, relating them in a controlled way through SU(3)-flavour symmetry and QCD-improved factorisation. We propose a set of sum rules for such penguin-mediated decays to constrain some CKM angles. We determine B_s -> KK branching ratios and CP-asymmetries as functions of A_{dir}(B_d -> K0 \bar{K}0). Applying the same techniques to B_{d,s}-> K*0 \bar{K}*0, we outline strategies to determine the B_s mixing angle.