Evidence of Final-State Suppression of High-p_T Hadrons in Au + Au Collisions Using d + Au Measurements at RHIC

Abstract

Transverse momentum spectra of charged hadrons with $p_T<$ 6 GeV/c have been measured near mid-rapidity (0.2 $<\eta <$ 1.4) by the PHOBOS experiment at RHIC in Au + Au and d + Au collisions at $\sqrt{s_{{}_{NN}}}=200GeV$. The spectra for different collision centralities are compared to $p+\bar{p}$ collisions at the same energy. The resulting nuclear modification factor for central Au + Au collisions shows evidence of strong suppression of charged hadrons in the high-$p_T$ region ($>2$ GeV/c). In contrast, the d + Au nuclear modification factor exhibits no suppression of the high-$p_T$ yields. These measurements suggest a large energy loss of the high-$p_T$ particles in the highly interacting medium created in the central Au + Au collisions. The lack of suppression in d + Au collisions suggests that it is unlikely that initial state effects can explain the suppression in the central Au + Au collisions.

arXiv comment3 pages, 4 figures, International Europhysics Conference on High Energy Physics EPS (July 17th-23rd 2003) in Aachen, Germany

References in corpus (4)

• Parton saturation and N_part scaling of semi--hard processes in QCD
• Centrality dependence of charged hadron transverse momentum spectra in d+Au collisions at sqrt(s_NN) = 200 GeV
• Jet Quenching and Radiative Energy Loss in Dense Nuclear Matter
• Charged hadron transverse momentum distributions in Au+Au collisions at sqrt(s_NN) = 200 GeV

Cited by in corpus (1)

• New State of Nuclear Matter: Nearly Perfect Fluid of Quarks and Gluons in Heavy Ion Collisions at RHIC Energies