Medium-induced modification of groomed and ungroomed jet mass and angularities in Pb–Pb collisions at sNN=5.02 [Figure presented]

ALICE Collaboration

doi:10.1016/j.physletb.2025.139409

Medium-induced modification of groomed and ungroomed jet mass and angularities in Pb–Pb collisions at s_NN=5.02 [Figure presented]

ALICE Collaboration

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

The ALICE Collaboration presents a new suite of jet substructure measurements in Pb–Pb and pp collisions at a center-of-mass energy per nucleon pair s_NN=5.02 [Figure presented]. These measurements provide access to the internal structure of jets via the momentum and angle of their constituents, probing how the quark–gluon plasma modifies jets, an effect known as jet quenching. Jet grooming additionally removes soft wide-angle radiation to enhance perturbative accuracy and reduce experimental uncertainties. We report the groomed and ungroomed jet mass m_jet and jet angularities λ_α^κ using κ=1 and α>0. Charged-particle jets are reconstructed at midrapidity using the anti-k_T algorithm with resolution parameter R=0.2. A narrowing of the jet mass and angularity distributions in Pb–Pb collisions with respect to pp is observed and is enhanced for groomed results, confirming modification of the jet core. By using consistent jet definitions and kinematic cuts between the mass and angularities for the first time, previous inconsistencies in the interpretation of quenching measurements are resolved, rectifying a hurdle for understanding how jet quenching arises from first principles and highlighting the importance of a well-controlled baseline. These results are compared with a variety of theoretical models of jet quenching, providing constraints on jet energy-loss mechanisms in the quark–gluon plasma.

Original language	English
Article number	139409
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	864
DOIs	https://doi.org/10.1016/j.physletb.2025.139409
Publication status	Published - May 2025

Bibliographical note

Publisher Copyright:
© 2025 CERN for the benefit of the ALICE Collaboration

Funding

The ALICE Collaboration would like to thank all its engineers and technicians for their invaluable contributions to the construction of the experiment and the CERN accelerator teams for the outstanding performance of the LHC complex. The ALICE Collaboration gratefully acknowledges the resources and support provided by all Grid centres and the Worldwide LHC Computing Grid (WLCG) collaboration. The ALICE Collaboration acknowledges the following funding agencies for their support in building and running the ALICE detector: A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation (ANSL), State Committee of Science and World Federation of Scientists (WFS), Armenia; Austrian Academy of Sciences, Austrian Science Fund (FWF): [M 2467-N36] and Nationalstiftung fur Forschung, Technologie und Entwicklung, Austria; Ministry of Communications and High Technologies, National Nuclear Research Center, Azerbaijan; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Financiadora de Estudos e Projetos (Finep), Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) and Universidade Federal do Rio Grande do Sul (UFRGS), Brazil; Bulgarian Ministry of Education and Science, within the National Roadmap for Research Infrastructures 2020-2027 (object CERN), Bulgaria; Ministry of Education of China (MOEC), Ministry of Science & Technology of China (MSTC) and National Natural Science Foundation of China (NSFC), China; Ministry of Science and Education and Croatian Science Foundation, Croatia; Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Cubaenergia, Cuba; Ministry of Education, Youth and Sports of the Czech Republic, Czech Republic; The Danish Council for Independent Research and Natural Sciences, the Villum Fonden and Danish National Research Foundation (DNRF), Denmark; Helsinki Institute of Physics (HIP), Finland; Commissariat a l'Energie Atomique (CEA) and Institut National de Physique Nucleaire et de Physique des Particules (IN2P3) and Centre National de la Recherche Scientifique (CNRS), France; Bundesministerium fur Bildung und Forschung (BMBF) and GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Germany; General Secretariat for Research and Technology, Ministry of Education, Research and Religions, Greece; National Research, Development and Innovation Office, Hungary; Department of Atomic Energy, Government of India (DAE), Department of Science and Technology, Government of India (DST), University Grants Commission, Government of India (UGC) and Council of Scientific and Industrial Research (CSIR), India; National Research and Innovation Agency - BRIN, Indonesia; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Japan Society for the Promotion of Science (JSPS) KAKENHI, Japan; Consejo Nacional de Ciencia (CONACYT) y Tecnologia, through Fondo de Cooperacion Internacional en Ciencia y Tecnologia (FONCICYT) and Direccion General de Asuntos del Personal Academico (DGAPA), Mexico; Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)), Netherlands; The Research Council of Norway, Norway; Pontificia Universidad Catolica del Peru, Peru; Ministry of Science and Higher Education, National Science Centre and WUT ID-UB, Poland; Korea Institute of Science and Technology Information and National Research Foundation of Korea (NRF), Republic of Korea; Ministry of Education and Scientific Research, Institute of Atomic Physics, Ministry of Research and Innovation and Institute of Atomic Physics and Universitatea Nationala de Stiinta si Tehnologie Politehnica Bucuresti, Romania; Ministry of Education, Science, Research and Sport of the Slovak Republic, Slovakia; National Research Foundation of South Africa, South Africa; Swedish Research Council (VR) and Knut & Alice Wallenberg Foundation (KAW), Sweden; European Organization for Nuclear Research, Switzerland; Suranaree University of Technology (SUT), National Science and Technology Development Agency (NSTDA) and National Science, Research and Innovation Fund (NSRF via PMU-B B05 F650021), Thailand; Turkish Energy, Nuclear and Mineral Research Agency (TENMAK), Turkey; National Academy of Sciences of Ukraine, Ukraine; Science and Technology Facilities Council (STFC), United Kingdom; National Science Foundation of the United States of America (NSF) and United States Department of Energy, Office of Nuclear Physics (DOE NP), United States of America. In addition, individual groups or members have received support from: Czech Science Foundation (grant no. 23-07499S), Czech Republic; FORTE project, reg. no. CZ.02.01.01/00/22_008/0004632, Czech Republic, co-funded by the European Union, Czech Republic; European Research Council (grant no. 950692), European Union; ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data and Quantum Computing, European Union - NextGenerationEU; Academy of Finland (Center of Excellence in Quark Matter) (grant nos. 346327, 346328), Finland; Deutsche Forschungs Gemeinschaft (DFG, German Research Foundation) "Neutrinos and Dark Matter in Astro-and Particle Physics'' (grant no. SFB 1258), Germany.

Funders	Funder number
A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation (ANSL), State Committee of Science and World Federation of Scientists (WFS), Armenia
Austrian Academy of Sciences, Austrian Science Fund (FWF)	M 2467-N36
Nationalstiftung fur Forschung, Technologie und Entwicklung, Austria
Ministry of Communications and High Technologies, National Nuclear Research Center, Azerbaijan
Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil
Financiadora de Estudos e Projetos (Finep), Brazil
Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Brazil
Universidade Federal do Rio Grande do Sul (UFRGS), Brazil
Bulgarian Ministry of Education and Science, within the National Roadmap for Research Infrastructures 2020-2027 (object CERN), Bulgaria
Ministry of Education of China (MOEC), China
Ministry of Science & Technology of China (MSTC), China
National Natural Science Foundation of China (NSFC), China
Ministry of Science and Education, Croatia
Croatian Science Foundation, Croatia
Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Cubaenergia, Cuba
Ministry of Education, Youth and Sports of the Czech Republic, Czech Republic
Danish Council for Independent Research and Natural Sciences, Denmark
VILLUM FONDEN, Denmark
Danish National Research Foundation (DNRF), Denmark
Helsinki Institute of Physics (HIP), Finland
Commissariat a l'Energie Atomique (CEA), France
Institut National de Physique Nucleaire et de Physique des Particules (IN2P3), France
Centre National de la Recherche Scientifique (CNRS), France
Bundesministerium fur Bildung und Forschung (BMBF), Germany
GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Germany
General Secretariat for Research and Technology, Ministry of Education, Research and Religions, Greece
National Research, Development and Innovation Office, Hungary
Department of Atomic Energy, Government of India (DAE)
Department of Science and Technology, Government of India (DST)
University Grants Commission, Government of India (UGC)
Council of Scientific and Industrial Research (CSIR), India
National Research and Innovation Agency - BRIN, Indonesia
Istituto Nazionale di Fisica Nucleare (INFN), Italy
Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) , Japan
Japan Society for the Promotion of Science (JSPS) KAKENHI, Japan
Consejo Nacional de Ciencia (CONACYT) y Tecnologia, through Fondo de Cooperacion Internacional en Ciencia y Tecnologia (FONCICYT), Mexico
Direccion General de Asuntos del Personal Academico (DGAPA), Mexico
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)), Netherlands
Research Council of Norway, Norway
Pontificia Universidad Catolica del Peru, Peru
Ministry of Science and Higher Education, Poland
National Science Centre , Poland
WUT ID-UB, Poland
Korea Institute of Science and Technology Information, Republic of Korea
National Research Foundation of Korea (NRF), Republic of Korea
Ministry of Education and Scientific Research, Romania
Institute of Atomic Physics, Romania
Ministry of Research and Innovation, Romania
Universitatea Nationala de Stiinta si Tehnologie Politehnica Bucuresti, Romania
Ministry of Education, Science, Research and Sport of the Slovak Republic, Slovakia
National Research Foundation of South Africa, South Africa
Swedish Research Council (VR), Sweden
Knut & Alice Wallenberg Foundation (KAW), Sweden
European Organization for Nuclear Research, Switzerland
Suranaree University of Technology (SUT), Thailand
National Science and Technology Development Agency (NSTDA), Thailand
National Science, Research and Innovation Fund (NSRF), Thailand	PMU-B B05F650021
Turkish Energy, Nuclear and Mineral Research Agency (TENMAK), Turkey
National Academy of Sciences of Ukraine, Ukraine
Science and Technology Facilities Council (STFC), United Kingdom
National Science Foundation of the United States of America (NSF), United States of America
United States Department of Energy, Office of Nuclear Physics (DOE NP), United States of America
Czech Science Foundation, Czech Republic	23-07499S
FORTE project, Czech Republic	CZ.02.01.01/00/22_008/0004632
European Union, Czech Republic
European Research Council, European Union	950692
ICSC - Centro Nazionale di Ricerca in High Performance Computing, Big Data and Quantum Computing, European Union - NextGenerationEU
Academy of Finland (Center of Excellence in Quark Matter) , Finland	346327, 346328
Deutsche Forschungs Gemeinschaft (DFG, German Research Foundation) "Neutrinos and Dark Matter in Astro-and Particle Physics", Germany	SFB 1258

Access to Document

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1-s2.0-S0370269325001698-mainFinal published version, 2.97 MBLicence: CC BY

Cite this

@article{da332c56c33c49e0b9a8d6b2d998ed23,

title = "Medium-induced modification of groomed and ungroomed jet mass and angularities in Pb–Pb collisions at sNN=5.02 [Figure presented]",

abstract = "The ALICE Collaboration presents a new suite of jet substructure measurements in Pb–Pb and pp collisions at a center-of-mass energy per nucleon pair sNN=5.02 [Figure presented]. These measurements provide access to the internal structure of jets via the momentum and angle of their constituents, probing how the quark–gluon plasma modifies jets, an effect known as jet quenching. Jet grooming additionally removes soft wide-angle radiation to enhance perturbative accuracy and reduce experimental uncertainties. We report the groomed and ungroomed jet mass mjet and jet angularities λακ using κ=1 and α>0. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameter R=0.2. A narrowing of the jet mass and angularity distributions in Pb–Pb collisions with respect to pp is observed and is enhanced for groomed results, confirming modification of the jet core. By using consistent jet definitions and kinematic cuts between the mass and angularities for the first time, previous inconsistencies in the interpretation of quenching measurements are resolved, rectifying a hurdle for understanding how jet quenching arises from first principles and highlighting the importance of a well-controlled baseline. These results are compared with a variety of theoretical models of jet quenching, providing constraints on jet energy-loss mechanisms in the quark–gluon plasma.",

author = "ALICE Collaboration and S. Acharya and A. Agarwal and {Aglieri Rinella}, G. and L. Aglietta and M. Agnello and N. Agrawal and Z. Ahammed and S. Ahmad and Ahn, {S. U.} and I. Ahuja and A. Akindinov and V. Akishina and M. Al-Turany and D. Aleksandrov and B. Alessandro and Alfanda, {H. M.} and {Alfaro Molina}, R. and B. Ali and A. Alici and N. Alizadehvandchali and A. Alkin and J. Alme and G. Alocco and S. Basu and A. Caliva and P. Christakoglou and T. Chujo and A. Dobrin and L. Fabbietti and A. Grelli and Jacobs, {P. M.} and S. Jaelani and J. Klein and C. Kuhn and Kuijer, {P. G.} and {La Pointe}, {S. L.} and G. Luparello and S. Muhuri and T. Peitzmann and N. Poljak and S. Qiu and Sas, {M. H.P.} and Snellings, {R. J.M.} and D. Thomas and {van Doremalen}, {L. V.R.} and M. Verweij and Y. Wang and Wessels, {J. P.} and Z. Yin and D. Zhou and Johanna L{\"o}mker and Bas Hofman and Olaf Massen",

note = "Publisher Copyright: {\textcopyright} 2025 CERN for the benefit of the ALICE Collaboration",

year = "2025",

month = may,

doi = "10.1016/j.physletb.2025.139409",

language = "English",

volume = "864",

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

issn = "0370-2693",

publisher = "Elsevier",

}

TY - JOUR

T1 - Medium-induced modification of groomed and ungroomed jet mass and angularities in Pb–Pb collisions at sNN=5.02 [Figure presented]

AU - ALICE Collaboration

AU - Acharya, S.

AU - Agarwal, A.

AU - Aglieri Rinella, G.

AU - Aglietta, L.

AU - Agnello, M.

AU - Agrawal, N.

AU - Ahammed, Z.

AU - Ahmad, S.

AU - Ahn, S. U.

AU - Ahuja, I.

AU - Akindinov, A.

AU - Akishina, V.

AU - Al-Turany, M.

AU - Aleksandrov, D.

AU - Alessandro, B.

AU - Alfanda, H. M.

AU - Alfaro Molina, R.

AU - Ali, B.

AU - Alici, A.

AU - Alizadehvandchali, N.

AU - Alkin, A.

AU - Alme, J.

AU - Alocco, G.

AU - Basu, S.

AU - Caliva, A.

AU - Christakoglou, P.

AU - Chujo, T.

AU - Dobrin, A.

AU - Fabbietti, L.

AU - Grelli, A.

AU - Jacobs, P. M.

AU - Jaelani, S.

AU - Klein, J.

AU - Kuhn, C.

AU - Kuijer, P. G.

AU - La Pointe, S. L.

AU - Luparello, G.

AU - Muhuri, S.

AU - Peitzmann, T.

AU - Poljak, N.

AU - Qiu, S.

AU - Sas, M. H.P.

AU - Snellings, R. J.M.

AU - Thomas, D.

AU - van Doremalen, L. V.R.

AU - Verweij, M.

AU - Wang, Y.

AU - Wessels, J. P.

AU - Yin, Z.

AU - Zhou, D.

AU - Lömker, Johanna

AU - Hofman, Bas

AU - Massen, Olaf

PY - 2025/5

Y1 - 2025/5

N2 - The ALICE Collaboration presents a new suite of jet substructure measurements in Pb–Pb and pp collisions at a center-of-mass energy per nucleon pair sNN=5.02 [Figure presented]. These measurements provide access to the internal structure of jets via the momentum and angle of their constituents, probing how the quark–gluon plasma modifies jets, an effect known as jet quenching. Jet grooming additionally removes soft wide-angle radiation to enhance perturbative accuracy and reduce experimental uncertainties. We report the groomed and ungroomed jet mass mjet and jet angularities λακ using κ=1 and α>0. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameter R=0.2. A narrowing of the jet mass and angularity distributions in Pb–Pb collisions with respect to pp is observed and is enhanced for groomed results, confirming modification of the jet core. By using consistent jet definitions and kinematic cuts between the mass and angularities for the first time, previous inconsistencies in the interpretation of quenching measurements are resolved, rectifying a hurdle for understanding how jet quenching arises from first principles and highlighting the importance of a well-controlled baseline. These results are compared with a variety of theoretical models of jet quenching, providing constraints on jet energy-loss mechanisms in the quark–gluon plasma.

AB - The ALICE Collaboration presents a new suite of jet substructure measurements in Pb–Pb and pp collisions at a center-of-mass energy per nucleon pair sNN=5.02 [Figure presented]. These measurements provide access to the internal structure of jets via the momentum and angle of their constituents, probing how the quark–gluon plasma modifies jets, an effect known as jet quenching. Jet grooming additionally removes soft wide-angle radiation to enhance perturbative accuracy and reduce experimental uncertainties. We report the groomed and ungroomed jet mass mjet and jet angularities λακ using κ=1 and α>0. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with resolution parameter R=0.2. A narrowing of the jet mass and angularity distributions in Pb–Pb collisions with respect to pp is observed and is enhanced for groomed results, confirming modification of the jet core. By using consistent jet definitions and kinematic cuts between the mass and angularities for the first time, previous inconsistencies in the interpretation of quenching measurements are resolved, rectifying a hurdle for understanding how jet quenching arises from first principles and highlighting the importance of a well-controlled baseline. These results are compared with a variety of theoretical models of jet quenching, providing constraints on jet energy-loss mechanisms in the quark–gluon plasma.

UR - http://www.scopus.com/inward/record.url?scp=105001955005&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2025.139409

DO - 10.1016/j.physletb.2025.139409

M3 - Article

AN - SCOPUS:105001955005

SN - 0370-2693

VL - 864

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

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

M1 - 139409

ER -