Weak annihilation and new physics in charmless $B \to M M$ decays

TL;DR

This paper analyzes charmless B meson decays to explore weak annihilation effects and potential new physics contributions, using QCD factorization and current experimental data, and tests universality assumptions with implications for future measurements.

Contribution

It introduces a weak annihilation parameter for related decay modes, tests its universality, and assesses new physics effects in charmless B decays within a model-independent framework.

Findings

Data supports the universality of weak annihilation parameters except in specific cases.

The $A_{CP}$ puzzle persists in the $B o K\u03c0$ system.

Constraints on new physics scenarios are derived from current decay data.

Abstract

We use currently available data of nonleptonic charmless 2-body $B\to MM$ decays ($MM = PP, PV, VV$) that are mediated by $b\to (d, s)$ QCD- and QED-penguin operators to study weak annihilation and new-physics effects in the framework of QCD factorization. In particular we introduce one weak annihilation parameter for decays related by ($u \leftrightarrow d$) quark interchange and test this universality assumption. Within the standard model, the data supports this assumption with the only exceptions in the $B\to K \pi$ system, which exhibits the well-known "$\Delta A_{CP}$ puzzle", and some tensions in $B \to K^* \phi$. Beyond the standard model, we simultaneously determine weak-annihilation and new-physics parameters from data, employing model-independent scenarios that address the "$\Delta A_{CP}$ puzzle", such as QED-penguins and $b\to s \bar{u}u$ current-current operators. We discuss also possibilities that allow further tests of our assumption once improved measurements from LHCb and Belle II become available.