Suppression of high transverse momentum hadrons at RHIC by (pre-) hadronic final state interactions

摘要

We investigate transverse hadron spectra from proton + proton, deuteron + An and An + An collisions at roots = 200 GeV and roots = 17.3 GeV within the Hadron-String Dynamics (HSD) approach which is based on quark, diquark, string and hadronic degrees of freedom as well as PYTHIA calculations for the high-p(perpendicular to) spectra. The comparison to experimental data on transverse mass spectra from p + p, d + An and An + An reactions shows that pre-hadronic effects are responsible for both the hardening of the spectra for low transverse momenta (Cronin effect) as well as the suppression of high-p(perpendicular to) hadrons. The interactions of formed hadrons are found to be negligible in central An + An collisions at roots = 200 GeV for p(perpendicular to) greater than or equal to 6 GeV/c, but have some importance for the shape of the ratio R-AA at lower pperpendicular to values (less than or equal to6 GeV/c). The large suppression seen experimentally is attributed to the inelastic interactions of 'leading' pre-hadrons with the dense environment, which could be partly of colored partonic nature in order to explain the large attenuation seen in most central An + Au collisions. (C) 2004 Elsevier B.V. All rights reserved.