Distributions of Charged Hadrons Associated with High Transverse Momentum Particles inppandAu+AuCollisions atsNN=200 GeV

Charged hadrons in 0.15 4 GeV/c are reconstructed in pp and Au+Au collisions at {radical}(s{sub NN})=200 GeV. The associated multiplicity and p{sub perpendicular} magnitude sum are found to increase from pp to central Au+Au collisions. The associated p{sub perpendicular} distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.