Measurement of Branching Fractions for $B\to \eta_c K^{(*)}$ Decays

TL;DR

This paper reports precise measurements of branching fractions for various $B o a_c K^{(*)}$ decays, including the first observation of $B^0 o a_c K^{*0}$, using data from the Belle detector to enhance understanding of CP violation.

Contribution

It provides the first observation of the $B^0 o a_c K^{*0}$ decay mode and measures branching fractions for multiple $B o a_c K^{(*)}$ channels, advancing knowledge of $B$ meson decays.

Findings

First observation of $B^0 o a_c K^{*0}$ decay.

Measured branching fractions for multiple $B o a_c K^{(*)}$ channels.

Data collected from 29.1 fb$^{-1}$ at Belle detector.

Abstract

We report measurements of branching fractions for charged and neutral $B\to \eta_c K$ decays where the $\eta_c$ meson is reconstructed in the $K_S^0 K^{\pm}\pi^{\mp}, K^+ K^- \pi^0, K^{*0} K^-\pi^+$ and $p \bar{p}$ decay channels. The neutral $B^0$ channel is a CP eigenstate and can be used to measure the CP violation parameter $\sin 2\phi_1$. We also report the first observation of the $B^0\to \eta_c K^{*0}$ mode. The results are based on an analysis of 29.1 fb$^{-1}$ of data collected by the Belle detector at KEKB.