Exclusive decay of J/Ψ into a lepton pair combined with light hadrons

We study the exclusive decay of J/Psi into a lepton pair combined with light hadrons in the kinematic region, specified by that the total energy of the light hadrons is much smaller than m(c), the mass of the c-quark. In this region, the nonperturbative effect related to J/Psi and that related to the light hadrons can be separated, the former is represented by a NRQCD matrix element, while the later is represented by a matrix element of a correlator of electric chromofields. The results are obtained in a axial gauge by assuming that contributions from two-gluon emission are dominant, But we can show that these results can be obtained without the assumption in arbitrary gauges. A discussion of the results are presented, (C) 2001 Elsevier Science B.V, All rights reserved.