Study the contributions of S, P, and D-wave resonances to the quasi-two-body decays $B^{0}_{s} \rightarrow \psi(3686,3770)K\pi$ in perturbative QCD approach

TL;DR

This study uses perturbative QCD to analyze the contributions of various kaon-pion resonances to B_s meson decays into charmonium states and Kπ, providing predictions for branching ratios and polarization fractions.

Contribution

It introduces a detailed pQCD analysis of three-body B_s decays including multiple resonance contributions and predicts decay observables consistent with experimental data.

Findings

_s ecays dominated by ar{K}^*(892)^0 resonance.

ranching ratios for B_s ightarrow harmonium K extpi are around 10^{-5} and 10^{-6}.

ecay predictions align with current experimental measurements.

Abstract

Based on the perturbative quantum chromodynamics (pQCD) approach and the quasi-two-body approximation, we have studied the three-body decays B^{0}_{s}\rightarrow \psi(3686,3770)\emph{K}\pi, which include the contributions of the intermediate resonances \bar{\emph{K}}^{*}_{0}(1430)^{0}, \bar{\emph{K}}^{*}(892)^{0}, \bar{\emph{K}}^{*}(1410)^{0}, \bar{\emph{K}}^{*}(1680)^{0}, and \bar{\emph{K}}^{*}_{2}(1430)^{0}. The time-like form factors corresponding to the distribution amplitudes of the S, P, and D-wave of the kaon-pion pair have been adopted in the parameterized form, which describe the interactions between \emph{K} and \pi in the resonance region. First, the decays B^{0}_{s}\rightarrow \psi(2S,1D)\emph{K}^{-}\pi^{+} have been calculated followed by the calculation of the branching ratios of the decays B^{0}_{s}\rightarrow \psi(3686,3770)\emph{K}^{-}\pi^{+} using the 2S-1D mixing scheme. In addition, the pQCD predictions for the decays B^{0}_{s}\rightarrow \psi(2S,1D)\emph{K}\pi and B^{0}_{s}\rightarrow \psi(3686,3770)\emph{K}\pi have been obtained using the narrow-width approximation relation given by the Clebsch-Gorden coefficients. Our work shows that the \bar{\emph{K}}^{*}(892)^{0} resonance is the main contributor to the total decay, and the branching ratio and the longitudinal polarization fraction of the \psi(2S)\bar{\emph{K}}^{*}(892)^{0} decay mode agree well with the currently available data within errors. Furthermore, the theoretical predictions of the \psi(2S) and \psi(3686) decay modes are very close, indicating that they can be regarded as the same meson state. Finally, the pQCD predictions for branching ratios of decays B^{0}_{s}\rightarrow \psi(3686,3770)\emph{K}\pi are of the order of 10^{-5} and 10^{-6}, respectively, which can be verified using the ongoing LHCb and Belle II experiments.