Eur. Phys. J. C (2011) 71: 1563
https://doi.org/10.1140/epjc/s10052-011-1563-z

Regular Article - Theoretical Physics

Production of the P-wave excited B _c -states through the Z ⁰ boson decays

Department of Physics, Chongqing University, Chongqing, 400044, People’s Republic of China

^* e-mail: wuxg@cqu.edu.cn

Received: 27 November 2010
Revised: 13 January 2011
Published online: 1 March 2011

Abstract

In Deng et al. (Eur. Phys. J. C 70:113, 2010), we have dealt with the production of the two color-singlet S-wave -quarkonium states and through the Z ⁰ boson decays. As an important sequential work, we make a further discussion on the production of the more complicated P-wave excited -quarkonium states, i.e. and (with J=(1,2,3)). More over, we also calculate the channel with the two color-octet quarkonium states and , whose contributions to the decay width maybe at the same order of magnitude as that of the color-singlet P-wave states according to the naive nonrelativistic quantum chromodynamics scaling rules. The P-wave states shall provide sizable contributions to the B _c production, whose decay width is about 20% of the total decay width . After summing up all the mentioned -quarkonium states’ contributions, we obtain KeV, where the errors are caused by the main sources of uncertainty.