Further study on the production of P-wave doubly heavy baryons from Z-boson decays

Abstract

In this paper, we carried out a systematic investigation for the excited doubly heavy baryons production in Z-boson decays within the NRQCD factorization approach. Our investigation accounts for all the P-wave intermediate diquark states, i.e.〈cc〉[P11]3¯, 〈cc〉[PJ3]6, 〈bc〉[P11]3¯/6, 〈bc〉[PJ3]3¯/6, 〈bb〉[P11]3¯, and 〈bb〉[PJ3]6 with J=(0,1,2). The results show that contributions from all diquark states in P-wave were 7%, 8%, and 3% in comparing with S-wave for the production of Ξcc, Ξbc and Ξbb via Z-boson decay, respectively. Based on these results, we predicted about 0.539×103(106) events for Ξcc, 1.827×103(106) events for Ξbc, and 0.036×103(106) events for Ξbb can be produced annually at the LHC (CEPC). Additionally, we plot the differential decay widths of Ξcc, Ξbc and Ξbb as a function of the invariant mass s23 and energy function z distributions, and analyze the theoretical uncertainties in decay width arising from the mass parameters of heavy quark.