Search for medium effects with jet-like hadron correlations at ALICE at the LHC

[摘要] We present an analysis of the properties of jets in proton-proton and lead-lead collisions at the ALICE experiment at the CERN Large Hadron Collider. The jet width and transverse momentum imbalance were studied in minimum bias proton collisions. The width was found to be independent of hadron transverse momentum and to have a larger value than measurements from earlier experiments at lower beam energies, consistent with theoretical expectations. The imbalance was found to increase with collision energy and also with the transverse momentum of the hadrons in the jet. The dependence of jet yield on the produced multiplicity was studied in proton and ion collisions, with a view to identifying suppression through interaction with a quark-gluon plasma. This suppression was identified in lead collisions as expected, but no suppression was observed in high multiplicity proton collisions. The jet width and tranverse momentum imbalance were also studied as a function of multiplicity. In proton collisions, the jet width was measured to be independent of multiplicity and hadron transverse momentum and consistent with minimum bias measurements. The width was observed to decrease in lead collisions of increasing centrality; this was interpreted as a suppression of the high momentum hadrons in the jet.

[发布机构] University:University of Birmingham;Department:School of Physics and Astronomy

[关键词] Q Science;QC Physics