Three-hadron angular correlations from perturbative QCD at the Relativistic Heavy Ion Collider and at the Large Hadron Collider

Abstract

We study three-hadron azimuthal angular correlations in high energy proton-proton and central nucleus-nucleus collisions at RHIC and LHC at mid-rapidity. We use the lowest order parton matrix elements for 2 to 3 processes and include the effect of parton energy loss in the quark-gluon plasma using the modified fragmentation function approach. For the case when the produced hadrons have comparable momenta, we observe two away side peaks at 2p=3 and 4p=3. We consider the dependence of the angular correlations with energy loss parameters that have been used in studies of single inclusive hadron production at RHIC. Our results on the angular dependence of the cross section agree well with the experimental data measured by the PHENIX collaboration. We comment on the possible contribution of 2 to 3 processes to di-hadron angular correlations and how a comparison of the two processes may help to further characterize the plasma.