Charge asymmetry in $e^{+}e^{-}\to B^{(*)}\bar{B}^{(*)}$ processes in the vicinity of $\Upsilon(4S)$

TL;DR

This paper investigates charge asymmetry in $e^{+}e^{-}$ annihilation into $B^{(*)}ar{B}^{(*)}$ pairs near the $$ resonance, highlighting the role of final-state interactions and multichannel interference effects.

Contribution

The study introduces a multichannel approach accounting for isotopic invariance violation and final-state interactions, aligning well with recent experimental data.

Findings

Good agreement with Belle-II results for cross section ratios near $$

Cross section ratios for neutral and charged $B^{(*)}$ pairs can differ significantly at higher energies

Interference effects in multichannel production amplitudes explain energy-dependent asymmetries

Abstract

The effects of isotopic invariance violation in the processes $e^{+}e^{-}\to B\bar{B}$, $e^{+}e^{-}\to B^{*}\bar{B}$, and $e^{+}e^{-}\to B^{*}\bar{B}^{*}$ are considered in the energy range between the thresholds of $B^{+}B^{-}$ and $B_{s}^{0}\bar{B}_{s}^{0}$ production. The analysis is based on taking into account the final-state interaction in a six-channel problem. Our approach allowed us to obtain good agreement with recent Belle-II results for the ratio of the $B^{0}\bar{B}^{0}$ and $B^{+}B^{-}$ production cross sections in $e^{+}e^{-}$ annihilation in the vicinity of $\Upsilon(4S)$. It is shown that at higher energies the ratios of the cross sections for pairs of neutral and charged $B^{(*)}$ mesons can differ significantly from unity. A detailed measurement of this effect will provide evidence that the nontrivial energy dependence of the $B^{(*)}\bar{B}^{(*)}$ production cross sections is a consequence of interference of the particle production amplitudes in the multichannel problem.