Measurement of substructure-dependent suppression of large-radius jets with charged particles in Pb+Pb collisions with ATLAS
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol.871, 2025 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 871
- Publication Date: 2025
- Doi Number: 10.1016/j.physletb.2025.139929
- Journal Name: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, INSPEC, MathSciNet, zbMATH, Directory of Open Access Journals
- Keywords: Jet quenching, Jets & heavy flavor physics, Quark-gluon plasma, Relativistic heavy-ion collisions
- Ankara University Affiliated: Yes
Abstract
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.