Improved Measurements of Partial Rate Asymmetry in B -> h h Decays

TL;DR

This paper presents improved measurements of partial rate asymmetry in various B meson decays using a larger data set, providing more precise results that contribute to understanding CP violation.

Contribution

The study offers the most precise measurements to date of partial rate asymmetries in multiple B decay modes with an expanded data sample.

Findings

Acp(K-+ pi+-) = -0.088 ± 0.035 ± 0.013, 2.4 sigma from zero

Results for other decay modes are also reported

Enhanced data sample improves measurement accuracy

Abstract

We report improved measurements of the partial rate asymmetry (Acp) in B -> h h decays with 140fb^-1 of data collected with the Belle detector at the KEKB e+e- collider. Here h stands for a charged or neutral pion or kaon and in total five decay modes are included: K-+ pi+-, K0s pi-+, K-+ pi0, pi-+ pi0 and K0s pi0. The flavor of the last decay mode is determined from the accompanying B meson. Using a data sample 4.7 times larger than that of our previous measurement, we find Acp(K-+ pi+-) -0.088+-0.035+-0.013, 2.4 sigma from zero. Results for other decay modes are also presented.