Narrow Results

We calculate the exclusive semileptonic and nonleptonic decays of B_c meson to heavy-light orbitally excited states in the framework of the improved Bethe–Salpeter method. The hadronic matrix elements are calculated and expressed as overlap integrals of the relativistic Salpeter wave functions of corresponding mesons, decay rates of the semileptonic and nonleptonic B_c decays to , and are obtained. Some channels provide us sizable ratios, for examples, and , with such ratios, the missing scalar B_s0 may be detected though its cascade strong decays in the forthcoming LHC experiment.

We present a next-to-leading order (NLO) relativistic correction to $B_c\to J/\psi$ tensor form factors within nonrelativistic QCD (NRQCD). We also consider complete Dirac bilinears $\bar{c}\mathrm{\Gamma }b$ with $4\times 4$ matrices $\mathrm{\Gamma }=1,{\gamma }^5,{\gamma }^{\mu },{\gamma }^{\mu }{\gamma }^5,{\sigma }^{\mu \nu }$ in the $b\to c$ transition. The relation among different current form factors is given and it shows that symmetries emerge in the heavy bottom quark limit. For a phenomenological extension, we propose to extract the long-distance matrix elements (LDMEs) for $B_c$ meson from the recent HPQCD lattice data and the NLO form factors at large momentum recoil.