The semileptonic decays of B c (2 S)

The Bc(2S) meson cannot decay through the OZI-Allowed channels because its mass is below the BD threshold. The Bc(2S) meson also cannot decay to multi-light hadron states, since there is different quark in Bc(2S) meson. The decay modes of Bc(2S) include the strong decay Bc+2I , a few electromagnetic decays and many more weak decay channels. So the electromagnetic decays of Bc(2S) have been discussed in the previous work. In this letter, we study the semileptonic weak decays of Bc(2S) meson. The mass and wave functions of Bc(2S) meson are calculated by the improved Bethe-Salpeter(BS) method. According to the BS wave functions of Bc(2S) and final-state mesons, we get the hadronic matrix element, then the semileptonic decay channels of Bc(2S) to final-state mesons as pseudoscalar mesons and vector mesons are studied. Finally, the semileptonic weak decay widths of Bc(2S) are presented.