Production of the $B_c$ meson at the CEPC

Abstract

In this paper, we make a detailed study on the production of the Bc, B * c , Bc(2 1 S0), and B * c (2 3 S1) mesons via the three planned running modes (Z, W , and H) at the future Circular Electron-Positron Collider (CEPC). The fragmentation-function and full nonrelativistic QCD approaches are adopted to calculate the production cross sections. Considering the excited states shall decay to the ground Bc state (e.g. 1 1 S0-state) with almost 100% probability, our numerical results show that up to next-to-leading order QCD corrections, there are about 1.4 × 10 8 Bc events to be accumulated via the Z mode ( √ s = m Z ) of the CEPC, but only about 1.6 × 10 4 and 1.1 × 10 4 Bc events to be accumulated via the W ( √ s = 160 GeV) and H ( √ s = 240 GeV) modes, respectively. Since the Z mode is the best mode among the three planned modes of the CEPC for studying the production of the Bc, B * c , Bc(2 1 S0), and B * c (2 3 S1) mesons and the differential distributions of these mesons may be measured precisely at this mode, we further present the differential cross sections dσ/(dz dcosθ) and dσ/dz via the Z mode of the CEPC.