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Sten is a caucasian male with cropped red hair and beard.

Sten Åstrand

Doctoral student

Sten is a caucasian male with cropped red hair and beard.

Measurement of substructure-dependent suppression of large-radius jets with charged particles in Pb+Pb collisions with ATLAS

Author

  • G. Aad
  • T.P.A. åkesson
  • K.S.V. Astrand
  • C. Doglioni
  • P.A. Ekman
  • V. Hedberg
  • H. Herde
  • B. Konya
  • E. Lytken
  • R. Poettgen
  • O. Smirnova
  • N. Sur
  • E.J. Wallin
  • L. Zwalinski

Summary, in English

Measurements of jet substructure in Pb+Pb collisions provide key insights into the mechanism of jet quenching in the hot and dense QCD medium created in these collisions.This Letter presents a measurement of the suppression of large-radius jets with a radius parameter of R=1.0 and its dependence on the jet substructure. The measurement uses 1.72 nb-1 of Pb+Pb data and 255 pb-1 of pp data, both at sNN=5.02 TeV, recorded with the ATLAS detector at the Large Hadron Collider. Large-radius jets are reconstructed by reclustering R=0.2 calorimetric jets and are measured for transverse momentum above 200 GeV. Jet substructure is evaluated using charged-particle tracks, and the overall level of jet suppression is quantified using the jet nuclear modification factor ( R AA). The jet R AA is measured as a function of jet p T, the charged kt splitting scale (d12), and the angular separation (? R 12) of two leading sub-jets. The jet R AA gradually decreases with increasing d12, implying significantly stronger suppression of large-radius jets with larger kt splitting scale. The jet R AA gradually decreases for ? R 12 in the range 0.01-0.2 and then remains consistent with a constant for ? R 12 ? 0.2. The observed significant dependence of jet suppression on the jet substructure will provide new insights into its role in the quenching process. © 2025 The Authors.

Department/s

  • Particle and nuclear physics
  • eSSENCE: The e-Science Collaboration
  • Department of Physics

Publishing year

2025

Language

English

Publication/Series

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

Volume

871

Document type

Journal article

Publisher

Elsevier

Topic

  • Subatomic Physics

Keywords

  • Jet quenching
  • Jets & heavy flavor physics
  • Quark-gluon plasma
  • Relativistic heavy-ion collisions

Status

Published

ISBN/ISSN/Other

  • ISSN: 0370-2693