Di-hadron correlations at ISR and RHIC energies

Abstract The structure of hadron–hadron correlations is investigated in proton–proton ( p p ) collisions. We focus on the transmission of the initial transverse momenta of partons (“intrinsic k T ”) to the hadron–hadron correlations. Values of the intrinsic transverse-momentum obtained from experimental correlations are compared to the results of a model with partially randomized parton transverse momenta at ISR and RHIC energies. Procedures for extracting the correlations from data are discussed.