Production of doubly heavy baryon at the Muon-Ion Collider

Abstract

This study forecasts the production of doubly heavy baryons, ${\Xi }_{cc}$, ${\Xi }_{bc}$, and ${\Xi }_{bb}$, within the nonrelativistic QCD framework at the Muon-Ion Collider (MuIC). It examines two production mechanisms: photon-gluon fusion ($\gamma +g\to (Q{Q}^{\prime })[n]+\bar{Q}+\overline{Q^{\prime }}$) and extrinsic heavy quark channels ($\gamma +Q\to (Q{Q}^{\prime })[n]+\overline{Q^{\prime }}$), where $Q$ and $Q^{\prime }$ denote heavy quarks ($c$ or $b$) and $(Q{Q}^{\prime })[n]$ represents a diquark in specific spin-color configurations. The diquark fragments into ${\Xi }_{Q{Q}^{\prime }}$ baryons with high probability. For ${\Xi }_{cc}$ and ${\Xi }_{bb}$, the relevant configurations are ${[}^1{S}_0{]}_{\text{6}}$ (spin-singlet and color-sextuplet) and ${[}^3{S}_1{]}_{\bar{\text{3}}}$ (spin-triplet and color-antitriplet). For ${\Xi }_{bc}$, the configurations are ${[}^1{S}_0{]}_{\bar{\text{3}}}$, ${[}^1{S}_0{]}_{\text{6}}$, ${[}^3{S}_1{]}_{\bar{\text{3}}}$, and ${[}^3{S}_1{]}_{\text{6}}$. The study compares total and differential cross-sections for these channels, highlighting their uncertainties. The results indicate that the extrinsic heavy quark channel, particularly the ${[}^3{S}_1{]}_{\bar{\text{3}}}$ configuration, dominates ${\Xi }_{Q{Q}^{\prime }}$ production, though other diquark states also contribute significantly. Using quark masses $m_c=1.80\pm 0.10$ GeV and $m_b=5.1\pm 0.20$ GeV, the study estimates annual event yields at MuIC ($\sqrt{s}=1$ TeV, luminosity $\mathcal{L}\simeq 40$ ${\mathrm{fb}}^{-1}$) of $(3.67_{-0.91}^{+1.29})\times 10^9$ for ${\Xi }_{cc}$, $(2.24_{-0.20}^{+0.28})\times 10^8$ for ${\Xi }_{bc}$, and $(3.00_{-0.56}^{+0.64})\times 10^6$ for ${\Xi }_{bb}$. These findings suggest that MuIC will significantly enhance our understanding of doubly heavy baryons.

Comments: 11 pages, 3 figures, 7 tables, accepted by Chinese physics C