Semileptonic $B_q$ decays to heavy tensor mesons

The semileptonic decays of $B_q$ mesons ($q=u,d,s$) to $J^P=2^+$ charmed mesons are investigated. The form factors parametrising the hadronic matrix elements of the weak vector and axial-vector quark currents are evaluated using light-cone QCD sum rules with external $B_q$ state, including the 3-particle contributions. The form factors of pseudoscalar and tensor quark currents occurring in extensions of the Standard Model are also determined. The relations expected in the heavy quark limit are tested and the size of finite heavy quark mass corrections are determined for the various form factors. Results are presented for the semileptonic $B_q$ to heavy tensor meson decay rates in the Standard Model, and for the ratios testing Lepton Flavour Universality.