$K^{\ast 0}$ and ${\Sigma }^{\ast }$ production in Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeV and 62.4 GeV

Abstract

Applying a quark combination model for the hadronization of Quark Gluon Plasma (QGP) and A Relativistic Transport (ART) model for the subsequent hadronic rescattering process, we investigate the production of $K^{\ast 0}$ and ${\Sigma }^{\ast }$ resonances in central Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeV and 62.4 GeV. The initial $K^{\ast 0}$ produced via hadronization is higher than the experimental data in the low $p_T$ region and is close to the data at 2-3 GeV/c. We take into account the hadronic rescattering effects which lead to a strong suppression of $K^{\ast 0}$ with low $p_T$, and find that the $p_T$ spectrum of $K^{\ast 0}$ can be well described. According to the suppressed magnitude of $K^{\ast 0}$ yield, the time span of hadronic rescattering stage is estimated to be about 13 fm/c at 200 GeV and 5 fm/c at 62.4 GeV. The $p_T$ spectrum of ${\Sigma }^{\ast }$ directly obtained by quark combination hadronization in central Au+Au collisions at 200 GeV is in well agreement with the experimental data, which shows a weak hadronic rescattering effects. The elliptic flow v2 of ${\Sigma }^{\ast }$ in minimum bias Au+Au collisions at 200 GeV and $p_T$ spectrum of ${\Sigma }^{\ast }$ at lower 62.4 GeV are predicted.

Comments: 12 pages, 6 figures