Measurement of the nuclear modification factor of b-jets in 5.02 TeV Pb+Pb collisions with the ATLAS detector

ATLAS Publications, T.M. Carter, R.Y. Gonzalez Andana, A. Hasib, M.P. Heath, S. Palazzo, V.A. Parrish, E.P. Takeva, N. Themistokleous, E.M. Villhauer, E. Zaid

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

This paper presents a measurement of b-jet production in Pb+Pb and pp collisions at √sNN = 5.02 TeV with the ATLAS detector at the LHC. The measurement uses 260 pb−1 of pp collisions collected in 2017 and 1.4 nb−1
of Pb+Pb collisions collected in 2018. In both collision systems, jets are reconstructed via the anti-k t algorithm. The b-jets are identified from a sample of jets containing muons from the semileptonic decay of b-quarks using template fits of the muon momentum relative to the jet axis. In pp collisions, b-jets are reconstructed for radius parameters R = 0.2 and R = 0.4, and only R = 0.2 jets are used in Pb+Pb collisions. For comparison, inclusive R = 0.2 jets are also measured using 1.7 nb−1 of Pb+Pb collisions collected in 2018
and the same pp collision data as the b-jet measurement. The nuclear modification factor, RAA , is calculated for both b-jets and inclusive jets with R = 0.2 over the transverse momentum range of 80–290 GeV. The nuclear modification factor for b-jets decreases from peripheral to central collisions. The
ratio of the b-jet RAA to inclusive jet RAA is also presented and suggests that the RAA for b-jets is larger than that for inclusive jets in central Pb+Pb collisions. The measurements are compared with theoretical calculations and suggest a role for mass and colour-charge effects in partonic energy loss in
heavy-ion collisions.
Original languageEnglish
Article number438
Pages (from-to)1-32
Number of pages32
JournalThe European Physical Journal C
Issue number5
Publication statusPublished - 25 May 2023


Dive into the research topics of 'Measurement of the nuclear modification factor of b-jets in 5.02 TeV Pb+Pb collisions with the ATLAS detector'. Together they form a unique fingerprint.

Cite this