The ATLAS detector at the Large Hadron Collider has been used to measure jet substructure modification and suppression in Pb + Pb collisions at a nucleon–nucleon center-of-mass energy $$\sqrt{{^S}_{NN}}$$ = 5.02 TeV in comparison with proton–proton (pp) collisions at $$\sqrt{{^S}}$$ = 5.02 TeV. The Pb + Pb data, collected in 2018, have an integrated luminosity of 1.72 nb-1, while the pp data, collected in 2017, have an integrated luminosity of 260 pb-1. Jets used in this analysis are clustered using the anti-kt algorithm with a radius parameter R = 0.4. The jet constituents, defined by both tracking and calorimeter information, are used to determine the angular scale rg of the first hard splitting inside the jet by reclustering them using the Cambridge–Aachen algorithm and employing the soft-drop grooming technique. The nuclear modification factor, RAA, used to characterize jet suppression in Pb + Pb collisions, is presented differentially in rg, jet transverse momentum, and in intervals of collision centrality. The RAA value is observed to depend significantly on jet rg. Jets produced with the largest measured rg are found to be twice as suppressed as those with the smallest rg in central Pb + Pb collisions. The RAA values do not exhibit a strong variation with jet pT in any of the rg intervals. The rg and pT dependence of jet RAA is qualitatively consistent with a picture of jet quenching arising from coherence and provides the most direct evidence in support of this approach.
Aad, G., et al. "Measurement of substructure-dependent jet suppression in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Pb</mml:mi><mml:mo>+</mml:mo><mml:mi>Pb</mml:mi></mml:mrow></mml:math> collisions at 5.02 TeV with the ATLAS detector." Physical Review. C, vol. 107, no. 5, May. 2023. https://doi.org/10.1103/physrevc.107.054909
Aad, G., Abbott, B., Abbott, D. C., Abeling, K., Abidi, S. H., Aboulhorma, A., Abramowicz, H., Abreu, H., Abulaiti, Y., Abusleme Hoffman, A. C., Acharya, B. S., Achkar, B., Adam, L., Adam Bourdarios, C., Adamczyk, L., Adamek, L., Addepalli, S. V., Adelman, J., ... Zwalinski, L. (2023). Measurement of substructure-dependent jet suppression in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Pb</mml:mi><mml:mo>+</mml:mo><mml:mi>Pb</mml:mi></mml:mrow></mml:math> collisions at 5.02 TeV with the ATLAS detector. Physical Review. C, 107(5). https://doi.org/10.1103/physrevc.107.054909
Aad, G., Abbott, B., Abbott, D. C., et al., "Measurement of substructure-dependent jet suppression in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Pb</mml:mi><mml:mo>+</mml:mo><mml:mi>Pb</mml:mi></mml:mrow></mml:math> collisions at 5.02 TeV with the ATLAS detector," Physical Review. C 107, no. 5 (2023), https://doi.org/10.1103/physrevc.107.054909
@article{osti_1996475,
author = {Aad, G. and Abbott, B. and Abbott, D. C. and Abeling, K. and Abidi, S. H. and Aboulhorma, A. and Abramowicz, H. and Abreu, H. and Abulaiti, Y. and Abusleme Hoffman, A. C. and others},
title = {Measurement of substructure-dependent jet suppression in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Pb</mml:mi><mml:mo>+</mml:mo><mml:mi>Pb</mml:mi></mml:mrow></mml:math> collisions at 5.02 TeV with the ATLAS detector},
annote = {The ATLAS detector at the Large Hadron Collider has been used to measure jet substructure modification and suppression in Pb + Pb collisions at a nucleon–nucleon center-of-mass energy $\sqrt{{^S}_{NN}}$ = 5.02 TeV in comparison with proton–proton (pp) collisions at $\sqrt{{^S}}$ = 5.02 TeV. The Pb + Pb data, collected in 2018, have an integrated luminosity of 1.72 nb-1, while the pp data, collected in 2017, have an integrated luminosity of 260 pb-1. Jets used in this analysis are clustered using the anti-kt algorithm with a radius parameter R = 0.4. The jet constituents, defined by both tracking and calorimeter information, are used to determine the angular scale rg of the first hard splitting inside the jet by reclustering them using the Cambridge–Aachen algorithm and employing the soft-drop grooming technique. The nuclear modification factor, RAA, used to characterize jet suppression in Pb + Pb collisions, is presented differentially in rg, jet transverse momentum, and in intervals of collision centrality. The RAA value is observed to depend significantly on jet rg. Jets produced with the largest measured rg are found to be twice as suppressed as those with the smallest rg in central Pb + Pb collisions. The RAA values do not exhibit a strong variation with jet pT in any of the rg intervals. The rg and pT dependence of jet RAA is qualitatively consistent with a picture of jet quenching arising from coherence and provides the most direct evidence in support of this approach.},
doi = {10.1103/physrevc.107.054909},
url = {https://www.osti.gov/biblio/1996475},
journal = {Physical Review. C},
issn = {ISSN 2469-9985},
number = {5},
volume = {107},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2023},
month = {05}}
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), High Energy Physics (HEP)
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 362, Issue 2-3https://doi.org/10.1016/0168-9002(95)00274-X
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3https://doi.org/10.1016/S0168-9002(03)01368-8