CP Violation in B Decays and the CKM Matrix

TL;DR

This paper reports on measurements of CP violation in B meson decays from BaBar and Belle experiments, confirming CP violation within B decays and exploring discrepancies and constraints on the CKM matrix elements and unitarity angles.

Contribution

It provides new measurements of CP violation parameters and CKM matrix elements, highlighting agreements and discrepancies between different experimental results.

Findings

BaBar and Belle results for $eta$ agree, confirming CP violation.

Discrepancy of 3.5 sigma between BaBar and Belle in $eta$ measurements.

Evidence of CP violation in $B^0 o ho^+ ho^-$ decays.

Abstract

Results by the BaBar and Belle experiments of the measurements $\sin 2\alpha$, $\sin 2\beta$ and $\sin (2\beta + \gamma)$ along with the CKM matrix elements $V_{cb}$ and $V_{ub}$ are presented. The BaBar and Belle experiments $b \to sc\bar{c}$ results for $\sin 2\beta$ are in good agreement with each other, comfortably establishing CP violation within B decays. However, there is a 3.5 standard deviation between this result and $\sin 2\beta$ measured by the Belle experiment using $B^0 \to \phi K^0_S$ decays. Belle also find evidence for CP violation through time dependent measurements of the decay $B^0 \to \pi^+ \pi^-$, whilst a tighter constraint has been placed on the unitarity angle $\alpha$ by BaBar, using time dependent studies of the decay $B^0 \to \rho^+\rho^-$ .