Properties of Full Jet in High-Energy Heavy-Ion Collisions from Parton Scatterings

The properties of fully reconstructed jet are investigated in p + p and Pb + Pb collisions atsNN= 2.76 TeV within a multiphase transport (AMPT) model with both partonic scatterings and hadronic rescatterings. A large transverse momentum (pT) asymmetry of dijet or photon-jet arises from the strong interactions between jet and partonic matter. Theξ-dependent jet fragmentation function in Pb + Pb collisions is decomposed into two contributions from different jet hadronization mechanisms, that is, fragmentation versus coalescence. The medium modification of differential jet shape displays that the jet energy is redistributed towards a larger radius owing to jet-medium interactions in heavy-ion collisions. Jet triangular azimuthal anisotropy coefficient,v3jet, which shows a smaller magnitude than the elliptic coefficientv2jet, decreases more quickly with increasing jetpT, which can be attributed to a path-length effect of jet energy loss. All of these properties of full jet are consistent with the jet energy loss mechanism in a stronglyinteracting partonic matter in high-energy heavy-ion collisions.

New results from fluctuation analysis in NA49 at the CERN SPS

The exploration of the phase diagram of strongly interacting matter, particularly the study of the phase transition from hadronic to partonic matter and the search for a hypothetical critical endpoint of the first order transition line, is one of the most challenging tasks in present heavy ion physics.New results on chemical (particle ratio), transverse momentum, multiplicity and azimuthal angle fluctuations are presented. We also discuss their connection to the onset of deconfinement and to the critical endpoint.

HOW DOES PARTON CASCADE PRODUCE A DOUBLE-PEAK STRUCTURE IN AMPT MODEL?

In order to search for the origin of double-peak structure in di-hadron azimuthal correlation at RHIC, a γ-jet with known production point and momentum is triggered in a multi-phase transport model. Partonic medium presents different shapes of responses to different geometry configurations of triggered γ-jet. The key of the double-peak structure is found to be a strong shadowing effect of dense core, which is related to transverse expansion and radial flow of partonic matter.