T-even transverse momentum dependent gluon fragmentation functions in a spectator model

Abstract

We present a model calculation of transverse momentum dependent (TMD) gluon fragmentation functions in both spin-1/2 and spin-0 hadrons. Our approach is based on the postulation that a time-like off-shell gluon can fragment into a hadron and a single spectator particle. So far, such spectator models have been restricted to TMD distribution functions of quarks and gluon as well TMD fragmentation function of quarks. The effective coupling between the gluon-hadron-spectator system is described by a vertex composed of two form factors. We obtain analytical expressions for the four T-even TMD fragmentation functions of the gluon. We also provide numerical results on the z-dependence and kT-dependence of the fragmentation functions. Our analysis reveals the non-negligible impact of these fragmentation functions, which could potentially be explored in forthcoming experimental measurements.