K* production in Heavy Ion Collisions at RHIC

Abstract

Study of resonances with their short life-times provides useful tools to probe the properties of hot and dense matter produced in relativistic heavy ion collisions. The high density and/or high temperature of the medium can modify resonance properties such as mass and width. Therefore, measurement of these properties can reveal important information about the evolution dynamics in heavy ion collisions. We report the measurements of $K^{*}$ transverse momentum($p_T$) spectra at mid-rapidity via its hadronic decay channel up to intermediate $p_{T}$ of 2.9 GeV/c using the STAR detector in Au+Au and Cu+Cu collisions at $\sqrt{s_{\mathrm{NN}}}$= 62.4 GeV and 200 GeV. These results are compared to previously reported $K^{*}$ results from Au+Au collisions at RHIC. Integrated yield ratios of $K^{*}/K$ and $K^{*}/\phi$ are used to understand the rescattering and regeneration effects on $K^{*}$ production.