Properties of particle production at large transverse momentum in Au+Au and Cu+Cu collisions at RHIC

Abstract

Abstract.We present the incident energy and system size dependence of the p T spectra for π ± , p, andp using Au+Au and Cu+Cu collisions at √ s NN = 62.4 and 200GeV in STAR experiment at RHIC. Through these measurements in the p T range of 0.2 < p T < 10 GeV/c we conduct a systematic study of the beam energy, system size and particle species dependence of nuclear modification factors and address specific predictions from the quark coalescence models regarding the beam energy dependence of baryon enhancement in the intermediate p T (2 < p T < 6 GeV/c) region.

Phase-space coalescence for heavy and light quarks at RHIC

“…At lower energy, Au+Au at 62 AGeV, a direct extrapolation with the same model predicts [66] an enhancement of the p/π ratio and a decrease ofp/π respect to 200 AGeV. Such a trend is again in reasonable agreement with experimental data [28,29].…”

Spectra of identified high-pTπ±andpAbelev1, Aggarwal2, Ahammed3 et al. 2010Phys. Rev. C283190View full textAdd to dashboardCite

“…Identified proton and pion measurements from pp collisions concur with this picture [1,9], as well as direct measurements of baryon and meson production in quark and gluon jets [10]. Thus, identified particle measurements at high-p T can then be used to analyze gluon and quark propagation through the medium and to probe the color-charge differences of energy loss [2,9,11,12].…”

Physics with identified particles at STAR

“…Coalescence models predict a higher (lower) p/π + ( p/π − ) ratio at 62 GeV compared to 200 GeV at intermediate p T [25]. Figure 6 shows the K 0 S , p/π + and p/π − ratios as a function of p T in central Au+Au collisions at 62 and 200 GeV [30]. At intermediate p T , we observe: p/π + (62 GeV) > p/π + (200 GeV),…”