$B_c$ meson exclusive decays to a $P$-wave charmonium and a pion at NLO accuracy

Abstract

In this paper, we calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to the exclusive processes $B_c^{+}\to {\chi }_{cJ}(h_c){\pi }^{+}$ in the framework of the nonrelativistic QCD (NRQCD) factorization formalism. The results show that NLO QCD corrections markedly enhance the branching ratios with $K$ factors of about 2.5. In combination with the study of $B_c^{+}\to J/\psi {\pi }^{+}$, we find that the NLO NRQCD prediction for the ratio of branching fractions $\frac{\mathcal{B}(B_c^{+}\to {\chi }_{c0}{\pi }^{+})}{\mathcal{B}(B_c^{+}\to J/\psi {\pi }^{+})}$ is then compatible with the experimental measurement.

Comments: Version accepted by PRD