Expectations for dihadron correlation measurements at the LHC

TL;DR

This paper discusses how dihadron correlation measurements at the LHC can provide more detailed insights into parton energy loss in the quark-gluon plasma, building on RHIC results and extrapolating to higher energies.

Contribution

It presents an extrapolation of RHIC dihadron correlation results to LHC energies and analyzes the potential of these measurements to reveal medium properties.

Findings

Extrapolated back-to-back yields from RHIC to LHC energies.

Highlighted differences and similarities between RHIC and LHC measurements.

Suggested dihadron correlations as a more differential probe of medium effects.

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.