A description of charmonia decays $J/\psi \to B\bar{B}$ within the QCD factorisation framework

Abstract

Decays $J/\psi \to B\bar{B}$ into octet baryon-antibaryons pairs are studied within the QCD factorisation framework. The next-to-leading power correction to the leading-order decay amplitude is calculated for the first time. The phenomenological analysis also includes the interference with the electromagnetic decay $J/\psi \to {\gamma }^{\ast }\to B\bar{B}$. The branching fractions and the angular coefficients ${\alpha }_B$ are described with an accuracy of about $20\%$. The obtained results allow us to conclude that the calculated amplitudes provide a dominant contribution and therefore QCD factorisation provides a suitable basis for understanding of these decays.

Comments: 46 pages, 2 figures