Branching ratios and $CP$ asymmetries of $B\rightarrow \chi_{c1}K(\pi)$ decays

TL;DR

This paper calculates branching ratios and $CP$ asymmetries for specific $B$ meson decays using perturbative QCD, providing predictions that align well with data and suggesting new ways to measure CKM angles.

Contribution

It offers detailed PQCD-based predictions for $B ightarrow ext{chic}_1 K( ext{pi})$ decays, improving upon earlier analyses and proposing experimental tests.

Findings

Branching ratios for $B ightarrow ext{chic}_1 K$ match experimental data.

$CP$ asymmetries are predicted to be small.

The $B^0 ightarrow ext{chic}_1 K_S$ channel can measure $eta$.

Abstract

We investigate the exclusive nonleptonic decays $B\rightarrow \chi_{c1}K(\pi)$ in the conventional perturbative QCD (PQCD) formalism. The predictions of branching ratios and $CP$ asymmetries are given in detail. We compare our results with available experimental data as well as predictions of other theoretical studies existing in the literature. It seems that the branching ratios of $B\rightarrow \chi_{c1} K$ are more consistent with data than the earlier analyses. For the Cabibbo-suppressed $B_s$ decay, the branching ratio can reach the order of $10^{-5}$, which would be straight forward for experimental observations. The numerical results show that the direct $CP$ asymmetries of the concerned decays are rather small. The mixing-induced $CP$ asymmetry in the $B^0\rightarrow \chi_{c1}K_S$ is very close to $\sin{2\beta}$, which suggests that this channel offer an alternative method for measuring the Cabbibo-Kobayashi-Maskawa (CKM) angle $\beta$. The obtained results in the present work could be tested by further experiments in the LHCb and forthcoming Belle II.