Extracting strange quark freeze-out information in Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV from $\ddot{I}•$ and $\hat{I}\text{c◯}$ production

Abstract

Using a covariant quark coalescence model combined with a blast-wave-like analytical parametrization for (anti-)strange quark phase-space freeze-out configuration, we extract information on strange quark freeze-out dynamics in Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV by fitting the measured transverse momentum spectra and elliptic flows ($v_2$) of $\ddot{I}•$ mesons and $\hat{I}\text{c◯}$ baryons. We find that although both the measured and calculated $v_2$ of $\ddot{I}•$ and $\hat{I}\text{c◯}$ satisfy the number-of-constituent-quark (NCQ) scaling, the NCQ-scaled $v_2$ is significantly smaller than the $v_2$ of strange quarks, implying that the NCQ-scaled $v_2$ of $\ddot{I}•$ and $\hat{I}\text{c◯}$ cannot be simply identified as the $v_2$ of strange quarks at hadronization. Meanwhile, our results indicate that the covariant quark coalescence model can nicely describe the spectra and elliptic flows of $\ddot{I}•$ and $\hat{I}\text{c◯}$ simultaneously, suggesting the coalescence mechanism is still valid for $\ddot{I}•$ and $\hat{I}\text{c◯}$ production in Pb+Pb collisions at LHC energies.

7 pages, 3 figures, 1 table. Some results updated and discussions added. Accepted version to appear in PRC