Viscous hydrodynamics description of $\varphi$ meson production in Au+Au and Cu+Cu collisions

Abstract

In the Israel-Stewart's theory of 2nd order dissipative hydrodynamics, we have simulated $\varphi$ production in Au+Au and Cu+Cu collisions at ${\sqrt{s}}_{NN}$=200 GeV. Evolution of QGP fluid with viscosity over the entropy ratio $\eta /s$=0.25, thermalised at ${\tau }_i$=0.2 fm, with initial energy density ${ϵ}_i$=5.1 $GeV/f{m}^3$ explains the experimental data on $\varphi$ multiplicity, integrated $v_2$, mean $p_T$, $p_T$ spectra and elliptic flow in central and mid-central Au+Au collisions. $\eta /s$=0.25 is also consistent with centrality dependence of $\varphi$ $p_T$ spectra in Cu+Cu collisions. The central energy density in Cu+Cu collisions is ${ϵ}_i$=3.48 $GeV/f{m}^3$.

Comments: 8 pages, 10 figures. Recent STAR data on $\varphi$ production in Au+Au and Cu+Cu are analysed in viscous hydrodynamics