Utilising $B \to \pi K$ Decays at the High-Precision Frontier

TL;DR

This paper investigates anomalies in $B o ext{pi}K$ decays suggesting potential New Physics, introduces a new method to determine electroweak penguin parameters, and discusses prospects for high-precision CP violation measurements to confirm these effects.

Contribution

It presents a novel method to extract electroweak penguin parameters using isospin relations with minimal $SU(3)$ input, aiming to identify New Physics in $B$-decays.

Findings

Correlation between CP asymmetries indicates tension with the Standard Model.

New method successfully applies to current data for $B o ext{pi}K$ decays.

Potential to establish New Physics in the electroweak penguin sector.

Abstract

For about twenty years, $B\to\pi K$ decays are in the focus of $B$-decay studies. We show that a correlation between the CP asymmetries of $B^0_d\to\pi^0K_{\rm S}$ reveals a tension with the Standard Model. Should it be due to New Physics, a modified electroweak penguin sector provides particularly interesting possibilities. We present a new method to determine the electroweak penguin parameters, which uses an isospin relation and requires only minimal $SU(3)$ input. We apply it to the current data for $B\to\pi K$ decays and discuss the prospects for utilizing CP violation in $B^0_d\to\pi^0K_{\rm S}$. The strategy has the exciting potential to establish New Physics in the electroweak penguin sector in the high-precision era of $B$-physics.