Measurements of jet quenching with semi-inclusive hadron plus jet distributions in Au plus Au collisions at root s(NN)=200 GeV

0477479 - ÚJF 2018 RIV US eng J - Journal Article
Adamczyk, L. - Adkins, J. K. - Agakishiev, G. - Bielčík, J. - Bielčíková, Jana - Chaloupka, P. - Federič, Pavol - Federičová, P. - Harlenderová, A. - Kocmánek, Martin - Kvapil, J. - Lidrych, J. - Rusňák, Jan - Rusňáková, O. - Šaur, Miroslav - Šimko, Miroslav - Šumbera, Michal - Trzeciak, B. A. … Total 348 authors
Measurements of jet quenching with semi-inclusive hadron plus jet distributions in Au plus Au collisions at root s(NN)=200 GeV.
Physical Review C. Roč. 96, č. 2 (2017), č. článku 024905. ISSN 2469-9985. E-ISSN 2469-9993
R&D Projects: GA MŠMT LG15001; GA MŠMT LM2015054
Institutional support: RVO:61389005
Keywords : STAR collaboration * heavy ion collisions * centrality dependence
OECD category: Nuclear physics
Impact factor: 3.304, year: 2017

The STAR Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum hadron trigger, in central and peripheral Au + Au collisions at root s(NN) = 200 GeV. Charged jets are reconstructed with the anti-kT algorithm for jet radii R between 0.2 and 0.5 and with low infrared cutoff of track constituents (p(T) > 0.2 GeV/c). A novel mixed-event technique is used to correct the large uncorrelated background present in heavy ion collisions. Corrected recoil jet distributions are reported at midrapidity, for charged-jet transverse momentum p(T,jet)(ch) < 30 GeV/c. Comparison is made to similar measurements for Pb + Pb collisions at root s = 2.76 TeV, to calculations for p + p collisions at root s = 200 GeV based on the PYTHIA Monte Carlo generator and on a next-to-leading order perturbative QCD approach, and to theoretical calculations incorporating jet quenching. The recoil jet yield is suppressed in central relative to peripheral collisions, with the magnitude of the suppression corresponding to medium-induced charged energy transport out of the jet cone of 2.8 +/- 0.2(stat) +/- 1.5(sys) GeV/c, for 10 < p(T,jet)(ch) < 20 GeV/c and R = 0.5. No medium-induced change in jet shape is observed for R < 0.5. The azimuthal distribution of low-p(T,jet)(ch) recoil jets may be enhanced at large azimuthal angles to the trigger axis, due to scattering off quasiparticles in the hot QCD medium. Measurement of this distribution gives a 90% statistical confidence upper limit to the yield enhancement at large deflection angles in central Au + Au collisions of 50 +/- 30( sys)% of the large-angle yield in p + p collisions predicted by PYTHIA.
Permanent Link: http://hdl.handle.net/11104/0273827