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 (RAA). The jet RAA is measured as a function of jet pT, the charged kt splitting scale (d12‾‾‾√), and the angular separation (ΔR12) of two leading sub-jets. The jet RAA gradually decreases with increasing d12‾‾‾√, implying significantly stronger suppression of large-radius jets with larger kt splitting scale. The jet RAA gradually decreases for ΔR12 in the range 0.01−0.2 and then remains consistent with a constant for ΔR12≳0.2. The observed significant dependence of jet suppression on the jet substructure will provide new insights into its role in the quenching process.

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

Longo, R.;
2025-01-01

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 (RAA). The jet RAA is measured as a function of jet pT, the charged kt splitting scale (d12‾‾‾√), and the angular separation (ΔR12) of two leading sub-jets. The jet RAA gradually decreases with increasing d12‾‾‾√, implying significantly stronger suppression of large-radius jets with larger kt splitting scale. The jet RAA gradually decreases for ΔR12 in the range 0.01−0.2 and then remains consistent with a constant for ΔR12≳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
871
N/A
N/A
https://arxiv.org/abs/2504.04805
Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N.J.; Abidi, S.H.; Aboelela, M.; Aboulhorma, A.; Abramowicz, H.; Abulaiti, Y.;...espandi
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/2111580
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact