Expectations for dihadron correlation measurements at the LHC

Abstract

The suppression of high transverse momentum (P_T) inclusive hadron spectra in heavy-ion collisions as compared to the scaled expectation of high P_T hadron production in p-p collisions is the most direct manifestation of the interaction of hard partons with the soft bulk medium produced in heavy-ion collisions which is absent in p-p collisions. Yet the measured nuclear suppression factor R_AA is a very averaged quantity and hence only a limited amount of information about the medium evolution and the nature of the interaction with the medium can be deduced from R_AA. Measurements of hard back-to-back hadron correlations in 200 AGeV Au-Au collisions at RHIC have opened a new window to study the energy loss of partons in a medium in a more differential way and for a different distribution of in-medium pathlengths than in the case of R_AA. In this work, we present an extrapolation of our results for back-to-back yields at RHIC energies to 5.5 TeV Pb-Pb collisions at the CERN LHC. We also discuss differences and similarities between the measurement at RHIC.