Testing the Standard Model and searching for New Physics with $B_d \to \pi \pi$ and $B_s \to K K$ decays

TL;DR

This paper presents a combined analysis of specific B meson decays to test the Standard Model and search for new physics, utilizing recent LHCb measurements within a global CKM fit framework.

Contribution

It introduces a method to optimize the use of B decay modes for constraining new physics contributions and the B_s mixing phase in a global fit approach.

Findings

Constraints on new physics contributions to penguin amplitudes.

Limits on the B_s mixing phase derived from decay data.

Demonstration of the method with recent LHCb measurements.

Abstract

We propose to perform a combined analysis of $B \to \pi\pi$ and $B_s \to K^+ K^-$ modes, in the framework of a global CKM fit. The method optimizes the constraining power of these decays and allows to derive constraints on NP contributions to penguin amplitudes or on the $B_s$ mixing phase. We illustrate these capabilities with a simplified analysis using the recent measurements by the LHCb Collaboration, neglecting correlations with other SM observables.