Measurement of the midrapidity transverse energy distribution from √s_NN = 130GeV Au+Au collisions at RHIC

Abstract

The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that <E_T>/<N_ch> remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at √s_NN = 130GeV is at least ε_Bj = 4.6GeV/fm³, which is a factor of 1.6 larger than found at √s_NN = 17.2GeV ( Pb+Pb at CERN).