Weakness or Strength in the Golden Years of RHIC and LHC?

TL;DR

Recent LHC data support perturbative QCD models of jet quenching, with some discrepancies in strongly-coupled AdS/CFT predictions, highlighting the need for more heavy meson data and jet measurements at RHIC.

Contribution

The paper compares perturbative QCD and AdS/CFT predictions of jet quenching against RHIC and LHC data, emphasizing the importance of heavy meson measurements.

Findings

pQCD predictions agree with LHC data for certain observables

AdS/CFT models tend to oversuppress D mesons compared to data

Heavy meson data, especially B mesons, are crucial for understanding quark-gluon plasma

Abstract

Recent LHC data suggest that perturbative QCD provides a qualitatively consistent picture of jet quenching. Constrained to RHIC pi0 suppression, zero parameter WHDG energy loss predictions agree quantitatively with the charged hadron v2 and D meson RAA measured at LHC and qualitatively with the charged hadron RAA. On the other hand, RHIC-constrained LHC predictions from fully strongly-coupled AdS/CFT qualitatively oversuppress D mesons compared to data; light meson predictions are on less firm theoretical ground but also suggest oversuppression. More detailed data from heavy, especially B, mesons will continue to help clarify our picture of the physics of the quark-gluon plasma. Since the approach of pQCD predictions to LHC data occurs at momenta >~ 15 GeV/c, a robust consistency check between pQCD and both RHIC and LHC data requires RHIC jet measurements.