Semileptonic and nonleptonic weak decays of (1S,2S)and _c(1S,2S) to D_(s)in the covariant light-front approach

In addition to the strong and electromagnetic decay modes, the psi(1S,2S) and eta c(1S,2S) can also decay via the weak interaction. Such weak decays can be detected by the high-luminosity heavy-flavor experiments. At present, some of the semileptonic and nonleptonic J/Psi weak decays have been measured at BESIII. Researching for these charmonium weak decays to D(s) meson can provide a platform to check of the standard model (SM) and probe new physics (NP). So we investigate the semileptonic and nonleptonic weak decays of psi(1S,2S) and eta c(1S,2S) to D(s) within the covariant light-front quark model (CLFQM). With form factors of the transitions psi (1S,2S) -> D(s) and eta c (1S,2S) -> D(s) calculated under the CLFQM, we predict and discuss some physical observables, such as the branching ratios, the longitudinal polarizations fL and the forward-backward asymmetries AFB. One can find that the Cabibbo-favored semi-leptonic decay channels psi(1S,2S) -> D-s & ell;+nu & ell; with & ell;=e,mu and the nonleptonic decay modes psi(1S,2S) -> D -s rho+ have relatively large branching ratios of the order O(10-9), which are most likely to be accessible at the future high-luminosity experiments.