Heavy baryon/meson ratios in relativistic heavy ion collisions

Understand

Heavy baryon/meson ratios $\Lambda_c/D^0$ and $\Lambda_b/\bar{B}^0$ in relativistic heavy ion collisions are studied in the quark coalescence model.

• For heavy baryons, we include production from coalescence of heavy quarks with free light quarks as well as with bounded light diquarks that might exist in the strongly coupled quark-gluon plasma produced in these collisions.
• Including the contribution from decays of heavy hadron resonances and also that due to fragmentation of heavy quarks that are left in the system after coalescence, the resulting $\Lambda_c/D^0$ and $\Lambda_b/\bar{B}^0$ ratios in midrapidity ($|y|\le 0.5$) from central Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV are about a factor of five and ten, respectively, larger than those given by the thermal model, and about a factor of ten and twelve, respectively, larger than corresponding ratios in the PYTHIA model for $pp$ collisions.
• These ratios are reduced by a factor of about 1.6 if there are no diquarks in the quark-gluon plasma.