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

Anders, J. K.; Beck, H. P.; Chatterjee, M.; Ereditato, A.; Franconi, L.; Halser, L.; Haug, S.; Ilg, A.; Müller, R.; O'Neill, A. P.; Weber, M. S. (2023). Measurement of the nuclear modification factor of b-jets in 5.02 TeV Pb+Pb collisions with the ATLAS detector. The European physical journal. C, Particles and fields, 83(5) Springer 10.1140/epjc/s10052-023-11427-9

s10052-023-11427-9.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (6MB) | Preview

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.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP)
10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)

UniBE Contributor:

Anders, John Kenneth, Beck, Hans Peter, Chatterjee, Meghranjana, Ereditato, Antonio, Franconi, Laura, Halser, Lea, Haug, Sigve, Ilg, Armin, Müller, Roman, O'Neill, Aaron Paul, Weber, Michele


500 Science > 530 Physics









Date Deposited:

23 Feb 2024 13:50

Last Modified:

23 Feb 2024 13:56

Publisher DOI:


Additional Information:

Kollaboration - Es sind nur die Berner Autor*innen namentlich erwaehnt; the ATLAS collaboration




Actions (login required)

Edit item Edit item
Provide Feedback