Excited doubly heavy baryon production via W+ boson decays

Abstract

In this paper, decay widths of the doubly heavy baryons (${\mathrm{\ensuremath{\Xi}}}_{cc}$ and ${\mathrm{\ensuremath{\Xi}}}_{bc}$) production are theoretically calculated in the whole phase space through ${W}^{+}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}_{cc}+\overline{c}+\overline{s}$ and ${W}^{+}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}_{bc}+\overline{b}+\overline{s}$, within the framework of nonrelativistic QCD (NRQCD). Differential widths $d\mathrm{\ensuremath{\Gamma}}/d{s}_{12}$, $d\mathrm{\ensuremath{\Gamma}}/d{s}_{23}$, $d\mathrm{\ensuremath{\Gamma}}/d\mathrm{cos}{\ensuremath{\theta}}_{12}$, and $d\mathrm{\ensuremath{\Gamma}}/d\mathrm{cos}{\ensuremath{\theta}}_{13}$ are also given. In addition to the ordinary S-wave contributions for the baryons, we specifically calculate P-wave contributions as a comparison, namely the high excited states of the intermediate diquark, including $[{^{1}P}_{1}]$ and $[{^{1}P}_{J}]$ (with $J=0,1,2$) in both color antitriplet state $\overline{\mathbf{3}}$ and color sextuplet state $\mathbf{6}$. It shows that the contribution from the P-wave is about one order lower than the S-wave. According to the results, we can expect plentiful events produced at the LHC, i.e., $3.69\ifmmode\times\else\texttimes\fi{}{10}^{5}\text{ }\text{ }{\mathrm{\ensuremath{\Xi}}}_{cc}$ events and $4.91\ifmmode\times\else\texttimes\fi{}{10}^{4}\text{ }\text{ }{\mathrm{\ensuremath{\Xi}}}_{bc}$ events per year.