Medium effects on high particle production measured with the PHENIX experiment
Revised: 20 May 2005
Published online: 8 July 2005
Transverse momentum () spectra measured by the PHENIX experiment at RHIC in Au + Au, d + Au and pp collisions at and in Au + Au collisions at are presented. A suppression of the yield of high hadrons in central Au + Au collisions by a factor 4-5 at is found relative to the pp reference scaled by the nuclear overlap function . In contrast, direct photons are not suppressed in central Au + Au collisions and no suppression of high particles can be seen in d + Au collisions. This leads to the conclusion that the dense medium formed in central Au + Au collisions is responsible for the suppression.
© Springer-Verlag, 2005