Ratios of heavy baryons to heavy mesons in relativistic nucleus-nucleus collisions

Abstract

Heavy baryon/meson ratios c /D 0 and b /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 c /D 0 and b /B 0 ratios in midrapidity (|y| 0.5) from central Au + Au collisions at √ 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. The transverse momentum dependence of the heavy baryon/meson ratios is found to be sensitive to the heavy quark mass, with the b /B 0 ratio being much flatter than the c /D 0 ratio. The latter peaks at the transverse momentum p T

Strange and heavy hadrons production from coalescence plus fragmentation in AA collisions at RHIC and LHC

“…We have found that the Λ c /D 0 1.5 at the peaks at p T 2.5 GeV at RHIC energies and Λ c /D 0 0.8 in the p T 0 region. Similar results have been predicted in [2]. We observe that at LHC energies due to the fact that fragmentation start to be the dominant hadronization mechanism for the D meson production this ratio is predicted to be smaller at higher energies.…”

“…The inclusion of fragmentation reduce the ratio and we can see that in the peak region we get a quite good agreement with the only experimental data. Notice that in our calculation we obtain similar baryon/meson ratio to the one predicted in [2]. Compared with measured light baryon/meson ratios likep/π − and Λ/K 0 S ratios (see [18][19][20] heavy quarks.…”

“…In particular this can manifests in a baryon-to-meson enhancement for charmed hadrons. The Λ C /D 0 enhancement due to coalescence was first suggested in [2] where based on di-quark or three-quark coalescence mechanism with a full thermalized charm quarks and the predicted Λ c /D 0 ratio is found to be comparable to the recent experimental data. Other recent calculations on the Λ c /D 0 can be found in [3,4].…”

Hidden-charm and bottom meson-baryon molecules coupled with five-quark states

“…For the heavy meson [103], we obtain ΛD = 1.35Λ N and Λ B = 1.29Λ N for theD ( * ) meson and the B meson, respectively. For the heavy baryon [106], we obtain Λ Λc ∼ Λ Σc ∼ Λ N for the charmed baryon, and Λ Λ b ∼ Λ Σ b ∼ Λ N for the bottom baryon. We note that values of these cutoffs are smaller than those used in other studies, e.g.…”

“…The nucleon cutoff is determined to reproduce the deuteronbinding energy by the OPEP as Λ N = 837 MeV [103][104][105]. The ratios are computed by the means of constituent quark model with the harmonic oscillator potential [106], where the frequency is evaluated by the hadron charge radii in Refs. [107,108].…”