Baryon anomaly and strong color fields in Pb + Pb collisions at 2.76ATeV at the CERN Large Hadron Collider

Abstract

With the HIJING/B$\ifmmode\bar\else\textasciimacron\fi{}B$ v2.0 heavy ion event generator, we explore the phenomenological consequences of several high parton density dynamical effects predicted in central Pb+Pb collisions at the Large Hadron Collider (LHC) energies. These include (1) jet quenching due to parton energy loss ($dE/dx$), (2) strangeness and hyperon enhancement due to strong longitudinal color field (SCF), and (3) enhancement of baryon-to-meson ratios due to baryon-antibaryon junction (J$\ifmmode\bar\else\textasciimacron\fi{}J$) loops and SCF effects. The saturation/minijet cutoff scale ${p}_{0}(s,A)$ and effective string tension $\ensuremath{\kappa}(s,A)$ are constrained by our previous analysis of LHC $p+p$ data and recent data on the charged multiplicity for Pb+Pb collisions reported by the ALICE collaboration. We predict the hadron flavor dependence (mesons and baryons) of the nuclear modification factor ${R}_{AA}({p}_{T})$ and emphasize the possibility that the baryon anomaly could persist at the LHC up to ${p}_{T}\ensuremath{\sim}10$ GeV, well beyond the range observed in central Au+Au collisions at RHIC energies.