Lessons from LHCb and Belle II measurements of $B\to J/\psi \pi$ and $B\to J/\psi K$ decays

TL;DR

This paper analyzes recent CP asymmetry measurements in B meson decays from LHCb and Belle II, using flavor symmetry relations to predict CP violation effects in related decay modes within the Standard Model.

Contribution

It introduces new predictions for CP violation in B meson decays based on recent experimental data and flavor-$SU(3)$ symmetry analysis, including first-order breaking corrections.

Findings

Predictions for CP violation in $B^+ o J/ ho K^+$ and $B_s o J/ ho ar{K}^0$ decays.

Estimates of the difference between $S_{ ho K_S}$ and $ ext{sin}2eta$.

Predictions for rate and CP asymmetries in $B_s o J/ ho ext{pi}^0$ decay.

Abstract

The LHCb collaboration has recently measured the CP asymmetry in $B^+\to J/\psi\pi^+$ decay, while the Belle II collaboration has recently measured the CP asymmetries in $B^0\to J/\psi\pi^0$ decay. Within the Standard Model, and using flavor-$SU(3)$ relations including first-order breaking corrections, these measurements lead to new predictions with regard to CP violation in $B^+\to J/\psi K^+$ and $B_s\to J/\psi\overline{K}{}^0$ decays, the difference between $S_{\psi K_S}$ and $\sin2\beta$, and the rate and CP asymmetries in $B_s\to J/\psi\pi^0$ decay.