Di-hadron correlations at ISR and RHIC energies

The structure of hadron-hadron correlations is investigated in proton-proton (pp) collisions. We focus on the transmission of the initial transverse momenta of partons (“intrinsic kT”) 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.