Baryon decays $$J/\psi \rightarrow B{\bar{B}}$$ within the QCD factorisation framework

Abstract

AbstractWe investigate $$J/\psi $$ J / ψ decays into octet baryon–antibaryons pairs. The decay amplitudes are computed within the collinear QCD factorisation framework. The subleading amplitude, which describes the decay of longitudinally polarised charmonium, is computed using twist-4 three-quark distribution amplitudes. The obtained results are used for a qualitative analysis of the experimental data. It is found that the polarisation parameter $$\alpha _B$$ α B can be described with an accuracy 10–30%, which may indicate that the pQCD contribution dominates this observable.