CP asymmetries in $B$ meson two-body baryonic decays

TL;DR

This paper investigates CP asymmetries in B meson decays to baryon-antibaryon pairs using theoretical models, providing predictions for decay rates and CP asymmetries, and suggesting promising channels for experimental observation.

Contribution

It introduces a detailed analysis of CP asymmetries in baryonic B decays using the $^3P_0$ model and chiral selection rules, with specific predictions for decay rates and asymmetries.

Findings

Predicted decay branching ratios align with current experimental data.

Estimated large CP-odd observables in specific $B_s^0$ decay channels.

Calculated significant direct CP asymmetries for certain decay modes.

Abstract

We study the CP-odd and CP-even observables of the $B$ mesons decaying into a baryon and antibaryon. We estimate these observables through the $^3P_0$ model and chiral selection rule. The decay branching ratios of $ B^+ \to p \overline{\Lambda}$ and $ B^0 \to p \overline{p}$ are calculated to be $2.31 \times 10^{-7}$ and $1.27 \times 10^{ -8} $, which are consistent with the current experiments, respectively. The effects of the $B-\overline{B}$ oscillations are considered, which largely suppress the direct CP asymmetries in the $B_s^0$ decays. We suggest the experiments to visit $B_s^0 \to \Lambda(\to p \pi^-) \overline{\Lambda} (\to \overline{ p} \pi^+) $, where the time-averaged CP-odd observables are estimated to be large. The direct CP asymmetries of $B^+ \to p \overline{\Lambda}$ and $B^0 \to p\overline{p}$ are found to be $26.2\%$ and $-3.1\%$ for a positive strong phase and $-36.9\%$ and $4.2\%$ for a negative strong phase, respectively.