CP Violation in $B^0_s \to K^-\pi^+$, $B^0 \to K^+\pi^-$ Decays and Tests for SU(3) Flavor Symmetry Predictions

TL;DR

This paper analyzes CP violation measurements in B meson decays, confirming SU(3) flavor symmetry predictions and exploring potential SU(3) breaking effects using current experimental data.

Contribution

It provides the first confirmation of SU(3) symmetry predictions in B decay CP asymmetries and examines possible deviations due to symmetry breaking.

Findings

Confirmed the predicted relation between CP asymmetries and branching ratios in B decays.

Analyzed the consistency of SU(3) symmetry relations across different B decay modes.

Discussed potential SU(3) breaking effects on CP violation relations.

Abstract

The LHCb collaboration has recently measured the first direct CP violation in $B^0_s$ decays with a rate asymmetry $A_{CP}(B^0_s\to K^- \pi^+)$ given by $0.27 \pm 0.04(stat)\pm 0.01(syst)$. At the same time they also made the most precise measurement for $A_{CP}(B^0 \to K^+ \pi^-) = -0.080\pm 0.007(stat)\pm 0.003(syst)$. These data confirm the predicted relation, $A_{CP}(B^0 \to K^+ \pi^-)/A_{CP}(B^0_s \to K^- \pi^+) = - Br(B^0_s\to K^- \pi^+)\tau_{B^0}/Br(B^0 \to K^+ \pi^-)\tau_{B^0_s}$, in the standard model with SU(3) flavor symmetry. We discuss possible modifications due to SU(3) breaking effects to this relation. There are several other similar relations in B decays. Using current available data we study whether relevant relations hold in $B^0$ and $B^0_s$ to $PP$ and $PV$ decays. Here $P$ and $V$ indicate pesudoscalar and vector mesons in the flavor octet representations.