Measurement of jet radial profiles in Pb–Pb collisions at √sNN = 2.76 TeV
MetadataShow full item record
The jet radial structure and particle transverse momentum (pT) composition within jets are presented in centrality-selected Pb–Pb collisions at √sNN = 2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of R = 0.3 at midrapidity |ηch jet| < 0.6 for transverse momenta pT, ch jet = 30–120 GeV/c. Jet–hadron correlations in relative azimuth and pseudorapidity space ( ϕ, η) are measured to study the distribution of the associated particles around the jet axis for different pT,assoc-ranges between 1 and 20 GeV/c. The data in Pb–Pb collisions are compared to reference distributions for pp collisions, obtained using embedded PYTHIA simulations. The number of high-pT associate particles (4 < pT,assoc < 20 GeV/c) in Pb–Pb collisions is found to be suppressed compared to the reference by 30 to 10%, depending on centrality. The radial particle distribution relative to the jet axis shows a moderate modification in Pb–Pb collisions with respect to PYTHIA. High-pT associate particles are slightly more collimated in Pb–Pb collisions compared to the reference, while low-pT associate particles tend to be broadened. The results, which are presented for the first time down to pT, ch jet = 30 GeV/c in Pb–Pb collisions, are compatible with both previous jet–hadron-related measurements from the CMS Collaboration and jet shape measurements from the ALICE Collaboration at higher pT, and add further support for the established picture of in-medium parton energy loss.
CitationAcharya S, Adamová D, Adhya SP, Adler C, Adolfsson J, Aggarwal MM, Aglieri Rinella G, Agnello M, Agrawal N, Ahammed Z, Alme J, Altenkaemper L, Djuvsland Ø, Ersdal MR, Fionda FMC, Grøttvik OS, Lofnes IM, Nystrand J, Rehman Au, Røhrich D, Tambave GJ, Ullaland K, Wagner B, Yang S, Yuan S, Zhou Z, Arsene IC, Bätzing P, Dordic O, Lardeux A, Lindal S, Mahmood SM, Malik QW, Richter M, Røed K, Skaali TB, Tveter TS, Wikne JC, Zhao C, Helstrup H, Hetland KF, Kileng B, Nesbø SV, Storetvedt M, Langøy R, Lien JA, Ahmad SF, Ahn SU, Aiola S, Akindinov A, ALICE C. Measurement of jet radial profiles in Pb–Pb collisions at √sNN = 2.76 TeV. Physics Letters B. 2019;796:204-219
Copyright 2019 The Author(s)