Exclusive decays $χ_{cJ}\to K^*(892)K$ within the effective field theory framework

Nikolay Kivel

Published 2018-04-30Version 1

We study hadronic decays $\chi_{cJ}\rightarrow K^*(892)\bar{K} $ within the effective field theory framework. We consider colour-singlet and colour-octet contributions using (p)NRQCD effective theory and study their properties. We show that infrared singularities in collinear integrals of the colour-singlet amplitudes can be absorbed into the colour-octet matrix element. The heavy quark spin symmetry allows us to establish a relation between the colour-octet matrix elements and to compute hard spin symmetry breaking corrections which are free from any infrared divergencies. We apply obtained corrections for a phenomenological description of the measured branching fractions.