Testing AdS/CFT Deviations from pQCD Heavy Quark Energy Loss with Pb+Pb at LHC

TL;DR

This paper compares heavy quark energy loss predictions from AdS/CFT and pQCD models in LHC collisions, proposing a new observable to detect deviations from perturbative QCD.

Contribution

It introduces a novel observable based on the double ratio of nuclear modification factors of charm and bottom jets to identify strong coupling effects.

Findings

AdS/CFT predicts momentum-independent drag coefficient.

pQCD predicts a characteristic log(pT/M)/pT variation.

Proposed observable can distinguish between strong and weak coupling regimes.

Abstract

Heavy quark jet quenching in nuclear collisions at LHC is predicted and compared using the classical gravity AdS/CFT correspondence and Standard Model perturbative QCD. The momentum independence and inverse quark mass dependence of the drag coefficient in AdS/CFT differs substantially from the characteristic log(pT/M)/pT variation of the drag in QCD. We propose that the measurement of the momentum dependence of the double ratio of the nuclear modification factors of charm and bottom jets is a robust observable that can be used to search for strong coupling deviations from perturbative QCD predictions.