TY - JOUR
T1 - Measurement of angular and momentum distributions of charged particles within and around jets in Pb plus Pb and pp collisions at root s(NN)=5.02 TeV with the ATLAS detector
AU - Aad, G.
AU - Abbott, B.
AU - Abbott, DC
AU - Abud, AA
AU - Abeling, K.
AU - Abhayasinghe, DK
AU - Abidi, S.H.
AU - AbouZeid, Ossama Sherif Alexander
AU - Abraham, NL
AU - Abramowicz, H.
AU - Besjes, Geert-Jan
AU - Alonso Diaz, Alejandro
AU - Camplani, Alessandra
AU - Dam, Mogens
AU - de Almeida Dias, Flavia
AU - Bajic, Milena
AU - Hansen, Jørgen Beck
AU - Hansen, Peter Henrik
AU - Hansen, Jørn Dines
AU - Galster, Gorm Aske Gram Krohn
AU - Ignazzi, Rosanna
AU - Monk, James William
AU - hqz214, hqz214
AU - Stark, Simon Holm
AU - Petersen, Troels Christian
AU - Wiglesworth, Graig
AU - Xella, Stefania
AU - ATLAS
PY - 2019/12/2
Y1 - 2019/12/2
N2 - Studies of the fragmentation of jets into charged particles in heavy-ion collisions can provide information about the mechanism of jet quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. This paper presents a measurement of the angular distribution of charged particles around the jet axis in sNN=5.02 TeV Pb+Pb and pp collisions, using the ATLAS detector at the LHC. The Pb+Pb and pp data sets have integrated luminosities of 0.49nb-1 and 25pb-1, respectively. The measurement is performed for jets reconstructed with the anti-kt algorithm with radius parameter R=0.4 and is extended to an angular distance of r=0.8 from the jet axis. Results are presented as a function of Pb+Pb collision centrality and distance from the jet axis for charged particles with transverse momenta in the 1- to 63-GeV range, matched to jets with transverse momenta in the 126- to 316-GeV range and an absolute value of jet rapidity of less than 1.7. Modifications to the measured distributions are quantified by taking a ratio to the measurements in pp collisions. Yields of charged particles with transverse momenta below 4 GeV are observed to be increasingly enhanced as a function of angular distance from the jet axis, reaching a maximum at r=0.6. Charged particles with transverse momenta above 4 GeV have an enhanced yield in Pb+Pb collisions in the jet core for angular distances up to r=0.05 from the jet axis, with a suppression at larger distances.
AB - Studies of the fragmentation of jets into charged particles in heavy-ion collisions can provide information about the mechanism of jet quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. This paper presents a measurement of the angular distribution of charged particles around the jet axis in sNN=5.02 TeV Pb+Pb and pp collisions, using the ATLAS detector at the LHC. The Pb+Pb and pp data sets have integrated luminosities of 0.49nb-1 and 25pb-1, respectively. The measurement is performed for jets reconstructed with the anti-kt algorithm with radius parameter R=0.4 and is extended to an angular distance of r=0.8 from the jet axis. Results are presented as a function of Pb+Pb collision centrality and distance from the jet axis for charged particles with transverse momenta in the 1- to 63-GeV range, matched to jets with transverse momenta in the 126- to 316-GeV range and an absolute value of jet rapidity of less than 1.7. Modifications to the measured distributions are quantified by taking a ratio to the measurements in pp collisions. Yields of charged particles with transverse momenta below 4 GeV are observed to be increasingly enhanced as a function of angular distance from the jet axis, reaching a maximum at r=0.6. Charged particles with transverse momenta above 4 GeV have an enhanced yield in Pb+Pb collisions in the jet core for angular distances up to r=0.05 from the jet axis, with a suppression at larger distances.
U2 - 10.1103/PhysRevC.100.064901
DO - 10.1103/PhysRevC.100.064901
M3 - Journal article
SN - 2469-9985
VL - 100
JO - Physical Review C
JF - Physical Review C
IS - 6
M1 - 064901
ER -