In this talk, I will present our recent Lattice calculation about spin decomposition of charmonium using overlap fermion on 2+1 flavor RBC/UKQCD domain-wall gauge configurations at 0.083 fm. It is found that the contribution of quark spin to 1S, 1P charmonium spin is comparable with the prediction of quark model. On the other hand, the gluon total angular momentum contributes 10-20% to the total spin of different charmonium states. We also investigate the quark spin component in the exotic state
Nobuyuki Matsumoto