NLO QCD corrections to B c(B*c) production around the Z pole at an e + e - collider

Abstract

The production of $B_c$ and $B_c^*$ mesons at a $Z$-factory (an $e^+e^-$ collider operating at energies around the $Z$ pole) is calculatedup to the next-to-leading order (NLO) QCD accuracy. The results show that the dependence of the total cross sections on the renormalization scale $\mu$ is suppressed by the corrections, and the NLO corrections enhance the total cross sections of $B_c$ by $52%$ and of $B_c^*$ by $33%$ when the renormalization scale is taken at $\mu=2m_b$. To observe the various behaviors of the production of the mesons $B_c$ and $B_c^*$, such as the differential cross section vs. the out-going angle, the forward-backward asymmetry, and the distribution vs. the energy fraction $z$ up to NLO QCD accuracy as well as the relevant $K$-factor (NLO to LO) for the production, are calculated, and it is pointed out that some of the observables obtained in the present work may be used as a specific precision test of the standard model.