Dr 雨 孟 (school of physics Peking Uniersity)
The charmonia decays present an ideal laboratory for testing the interplay between perturbative and nonperturbative QCD. In this talk, I focus on the all-photon decay and radiative decay of charmoina. Adopting a new method proposed recently, we perform the systematic lattice calculations on ηc/χc0→2γ and J/ψ→γηc. By using three Nf=2 twisted mass gauge ensembles with different lattice spacings, we obtain the final decay width for these processes. In the end, more interesting charmonia decays are looked forward.