Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at sNN = 5.02 TeV

The ALICE collaboration alice-publications@cern.ch

doi:10.1007/JHEP01(2024)199

Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at sNN = 5.02 TeV

The ALICE collaboration [email protected]

Relativistic Nuclear Physics

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

3 Scopus citations

Abstract

Correlations in azimuthal angle extending over a long range in pseudorapidity between particles, usually called the “ridge” phenomenon, were discovered in heavy-ion collisions, and later found in pp and p–Pb collisions. In large systems, they are thought to arise from the expansion (collective flow) of the produced particles. Extending these measurements over a wider range in pseudorapidity and final-state particle multiplicity is important to understand better the origin of these long-range correlations in small collision systems. In this Letter, measurements of the long-range correlations in p–Pb collisions at s_NN = 5.02 TeV are extended to a pseudorapidity gap of ∆η ~ 8 between particles using the ALICE forward multiplicity detectors. After suppressing non-flow correlations, e.g., from jet and resonance decays, the ridge structure is observed to persist up to a very large gap of ∆η ~ 8 for the first time in p–Pb collisions. This shows that the collective flow-like correlations extend over an extensive pseudorapidity range also in small collision systems such as p–Pb collisions. The pseudorapidity dependence of the second-order anisotropic flow coefficient, v₂(η), is extracted from the long-range correlations. The v₂(η) results are presented for a wide pseudorapidity range of –3.1 < η < 4.8 in various centrality classes in p–Pb collisions. To gain a comprehensive understanding of the source of anisotropic flow in small collision systems, the v₂(η) measurements are compared with hydrodynamic and transport model calculations. The comparison suggests that the final-state interactions play a dominant role in developing the anisotropic flow in small collision systems.

Original language	English
Article number	199
Journal	Journal of High Energy Physics
Volume	2024
Issue number	1
DOIs	https://doi.org/10.1007/JHEP01(2024)199
State	Published - Jan 2024

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 f\u00FCr Forschung, Technologie und Entwicklung, Austria; Ministry of Communications and High Technologies, National Nuclear Research Center, Azerbaijan; Conselho Nacional de Desen-volvimento Cient\u00EDfico e Tecnol\u00F3gico (CNPq), Financiadora de Estudos e Projetos (Finep), Funda\u00E7\u00E3o de Amparo \u00E0 Pesquisa do Estado de S\u00E3o 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\u20132027 (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 Tecnol\u00F3gicas y Desarrollo Nuclear (CEADEN), Cubaenerg\u00EDa, Cuba; Ministry of Education, Youth and Sports of the Czech Republic, Czech Republic; The Danish Council for Independent Research | Natural Sciences, the VILLUM FONDEN and Danish National Research Foundation (DNRF), Denmark; Helsinki Institute of Physics (HIP), Finland; Commissariat \u00E0 l\u2019Energie Atomique (CEA) and Institut National de Physique Nucl\u00E9aire et de Physique des Particules (IN2P3) and Centre National de la Recherche Scientifique (CNRS), France; Bundesministerium f\u00FCr Bildung und Forschung (BMBF) and GSI Helmholtzzentrum f\u00FCr 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 Tecnolog\u00EDa, through Fondo de Cooperaci\u00F3n Internacional en Ciencia y Tecnolog\u00EDa (FONCICYT) and Direcci\u00F3n General de Asuntos del Personal Academico (DGAPA), Mexico; Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands; The Research Council of Norway, Norway; Commission on Science and Technology for Sustainable Development in the South (COMSATS), Pakistan; Pontificia Universidad Cat\u00F3lica del Per\u00FA, Peru; Ministry of Education and Science, 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 University Politehnica of Bucharest, 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 B05F650021), 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: European Research Council, Strong 2020 - Horizon 2020 (grant nos. 950692, 824093), European Union; Academy of Finland (Center of Excellence in Quark Matter) (grant nos. 346327, 346328), Finland.

Keywords

Collective Flow
Heavy Ion Experiments
Particle Correlations and Fluctuations

Access to Document

10.1007/JHEP01(2024)199

Cite this

@article{2325ad5cad1446d6b61c66127e0ef640,

title = "Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at sNN = 5.02 TeV",

abstract = "Correlations in azimuthal angle extending over a long range in pseudorapidity between particles, usually called the “ridge” phenomenon, were discovered in heavy-ion collisions, and later found in pp and p–Pb collisions. In large systems, they are thought to arise from the expansion (collective flow) of the produced particles. Extending these measurements over a wider range in pseudorapidity and final-state particle multiplicity is important to understand better the origin of these long-range correlations in small collision systems. In this Letter, measurements of the long-range correlations in p–Pb collisions at sNN = 5.02 TeV are extended to a pseudorapidity gap of ∆η ~ 8 between particles using the ALICE forward multiplicity detectors. After suppressing non-flow correlations, e.g., from jet and resonance decays, the ridge structure is observed to persist up to a very large gap of ∆η ~ 8 for the first time in p–Pb collisions. This shows that the collective flow-like correlations extend over an extensive pseudorapidity range also in small collision systems such as p–Pb collisions. The pseudorapidity dependence of the second-order anisotropic flow coefficient, v2(η), is extracted from the long-range correlations. The v2(η) results are presented for a wide pseudorapidity range of –3.1 < η < 4.8 in various centrality classes in p–Pb collisions. To gain a comprehensive understanding of the source of anisotropic flow in small collision systems, the v2(η) measurements are compared with hydrodynamic and transport model calculations. The comparison suggests that the final-state interactions play a dominant role in developing the anisotropic flow in small collision systems.",

keywords = "Collective Flow, Heavy Ion Experiments, Particle Correlations and Fluctuations",

author = "{The ALICE collaboration [email protected]} and S. Acharya and D. Adamov{\'a} and {Aglieri Rinella}, G. and M. Agnello and N. Agrawal and Z. Ahammed and S. Ahmad and Ahn, {S. U.} and I. Ahuja and A. Akindinov 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 T. Alt and Altamura, {A. R.} and I. Altsybeev and Anaam, {M. N.} and C. Andrei and N. Andreou and A. Andronic and V. Anguelov and F. Antinori and P. Antonioli and N. Apadula and L. Aphecetche and H. Appelsh{\"a}user and C. Arata and S. Arcelli and M. Aresti and R. Arnaldi and Arneiro, {J. G.M.C.A.} and Arsene, {I. C.} and M. Arslandok and A. Augustinus and R. Averbeck and Azmi, {M. D.} and H. Baba and A. Badal{\`a} and J. Bae and F. Bock and Read, {K. F.} and Schmidt, {N. V.}",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2024.",

year = "2024",

month = jan,

doi = "10.1007/JHEP01(2024)199",

language = "English",

volume = "2024",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

publisher = "Springer",

number = "1",

}

TY - JOUR

T1 - Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at sNN = 5.02 TeV

AU - The ALICE collaboration [email protected]

AU - Acharya, S.

AU - Adamová, D.

AU - Aglieri Rinella, G.

AU - Agnello, M.

AU - Agrawal, N.

AU - Ahammed, Z.

AU - Ahmad, S.

AU - Ahn, S. U.

AU - Ahuja, I.

AU - Akindinov, A.

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 - Alt, T.

AU - Altamura, A. R.

AU - Altsybeev, I.

AU - Anaam, M. N.

AU - Andrei, C.

AU - Andreou, N.

AU - Andronic, A.

AU - Anguelov, V.

AU - Antinori, F.

AU - Antonioli, P.

AU - Apadula, N.

AU - Aphecetche, L.

AU - Appelshäuser, H.

AU - Arata, C.

AU - Arcelli, S.

AU - Aresti, M.

AU - Arnaldi, R.

AU - Arneiro, J. G.M.C.A.

AU - Arsene, I. C.

AU - Arslandok, M.

AU - Augustinus, A.

AU - Averbeck, R.

AU - Azmi, M. D.

AU - Baba, H.

AU - Badalà, A.

AU - Bae, J.

AU - Bock, F.

AU - Read, K. F.

AU - Schmidt, N. V.

PY - 2024/1

Y1 - 2024/1

N2 - Correlations in azimuthal angle extending over a long range in pseudorapidity between particles, usually called the “ridge” phenomenon, were discovered in heavy-ion collisions, and later found in pp and p–Pb collisions. In large systems, they are thought to arise from the expansion (collective flow) of the produced particles. Extending these measurements over a wider range in pseudorapidity and final-state particle multiplicity is important to understand better the origin of these long-range correlations in small collision systems. In this Letter, measurements of the long-range correlations in p–Pb collisions at sNN = 5.02 TeV are extended to a pseudorapidity gap of ∆η ~ 8 between particles using the ALICE forward multiplicity detectors. After suppressing non-flow correlations, e.g., from jet and resonance decays, the ridge structure is observed to persist up to a very large gap of ∆η ~ 8 for the first time in p–Pb collisions. This shows that the collective flow-like correlations extend over an extensive pseudorapidity range also in small collision systems such as p–Pb collisions. The pseudorapidity dependence of the second-order anisotropic flow coefficient, v2(η), is extracted from the long-range correlations. The v2(η) results are presented for a wide pseudorapidity range of –3.1 < η < 4.8 in various centrality classes in p–Pb collisions. To gain a comprehensive understanding of the source of anisotropic flow in small collision systems, the v2(η) measurements are compared with hydrodynamic and transport model calculations. The comparison suggests that the final-state interactions play a dominant role in developing the anisotropic flow in small collision systems.

AB - Correlations in azimuthal angle extending over a long range in pseudorapidity between particles, usually called the “ridge” phenomenon, were discovered in heavy-ion collisions, and later found in pp and p–Pb collisions. In large systems, they are thought to arise from the expansion (collective flow) of the produced particles. Extending these measurements over a wider range in pseudorapidity and final-state particle multiplicity is important to understand better the origin of these long-range correlations in small collision systems. In this Letter, measurements of the long-range correlations in p–Pb collisions at sNN = 5.02 TeV are extended to a pseudorapidity gap of ∆η ~ 8 between particles using the ALICE forward multiplicity detectors. After suppressing non-flow correlations, e.g., from jet and resonance decays, the ridge structure is observed to persist up to a very large gap of ∆η ~ 8 for the first time in p–Pb collisions. This shows that the collective flow-like correlations extend over an extensive pseudorapidity range also in small collision systems such as p–Pb collisions. The pseudorapidity dependence of the second-order anisotropic flow coefficient, v2(η), is extracted from the long-range correlations. The v2(η) results are presented for a wide pseudorapidity range of –3.1 < η < 4.8 in various centrality classes in p–Pb collisions. To gain a comprehensive understanding of the source of anisotropic flow in small collision systems, the v2(η) measurements are compared with hydrodynamic and transport model calculations. The comparison suggests that the final-state interactions play a dominant role in developing the anisotropic flow in small collision systems.

KW - Collective Flow

KW - Heavy Ion Experiments

KW - Particle Correlations and Fluctuations

UR - http://www.scopus.com/inward/record.url?scp=85188751771&partnerID=8YFLogxK

U2 - 10.1007/JHEP01(2024)199

DO - 10.1007/JHEP01(2024)199

M3 - Article

AN - SCOPUS:85188751771

SN - 1126-6708

VL - 2024

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 1

M1 - 199

ER -

Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at sNN = 5.02 TeV

Abstract

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this