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

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 $J/\psi\to \gamma^*\to B\bar B$. 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.