Elsevier

Physics Letters B

Volume 725, Issues 1–3, 9 August 2013, Pages 60-78
Physics Letters B

Measurement with the ATLAS detector of multi-particle azimuthal correlations in p+Pb collisions at sNN=5.02TeV

https://doi.org/10.1016/j.physletb.2013.06.057Get rights and content
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open access

Abstract

In order to study further the long-range correlations (“ridge”) observed recently in p+Pb collisions at sNN=5.02TeV, the second-order azimuthal anisotropy parameter of charged particles, v2, has been measured with the cumulant method using the ATLAS detector at the LHC. In a data sample corresponding to an integrated luminosity of approximately 1μb1, the parameter v2 has been obtained using two- and four-particle cumulants over the pseudorapidity range |η|<2.5. The results are presented as a function of transverse momentum and the event activity, defined in terms of the transverse energy summed over 3.1<η<4.9 in the direction of the Pb beam. They show features characteristic of collective anisotropic flow, similar to that observed in Pb+Pb collisions. A comparison is made to results obtained using two-particle correlation methods, and to predictions from hydrodynamic models of p+Pb collisions. Despite the small transverse spatial extent of the p+Pb collision system, the large magnitude of v2 and its similarity to hydrodynamic predictions provide additional evidence for the importance of final-state effects in p+Pb reactions.

Cited by (0)

© CERN for the benefit of the ATLAS Collaboration.

a

Also at Department of Physics, Kingʼs College London, London, United Kingdom.

b

Also at Laboratorio de Instrumentacao e Fisica Experimental de Particulas — LIP, Lisboa, Portugal.

c

Also at Faculdade de Ciencias and CFNUL, Universidade de Lisboa, Lisboa, Portugal.

d

Also at Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom.

e

Also at TRIUMF, Vancouver, BC, Canada.

f

Also at Department of Physics, California State University, Fresno, CA, United States.

g

Also at Novosibirsk State University, Novosibirsk, Russia.

h

Also at Department of Physics, University of Coimbra, Coimbra, Portugal.

i

Also at Università di Napoli Parthenope, Napoli, Italy.

j

Also at Institute of Particle Physics (IPP), Canada.

k

Also at Department of Physics, Middle East Technical University, Ankara, Turkey.

l

Also at Louisiana Tech University, Ruston, LA, United States.

m

Also at Dep Fisica and CEFITEC of Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal.

n

Also at Department of Physics and Astronomy, Michigan State University, East Lansing, MI, United States.

o

Also at Department of Financial and Management Engineering, University of the Aegean, Chios, Greece.

p

Also at Department of Physics, University of Cape Town, Cape Town, South Africa.

q

Also at Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan.

r

Also at Institut für Experimentalphysik, Universität Hamburg, Hamburg, Germany.

s

Also at Manhattan College, New York, NY, United States.

t

Also at CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France.

u

Also at School of Physics and Engineering, Sun Yat-sen University, Guanzhou, China.

v

Also at Academia Sinica Grid Computing, Institute of Physics, Academia Sinica, Taipei, Taiwan.

w

Also at Laboratoire de Physique Nucléaire et de Hautes Energies, UPMC and Université Paris-Diderot and CNRS/IN2P3, Paris, France.

x

Also at School of Physical Sciences, National Institute of Science Education and Research, Bhubaneswar, India.

y

Also at Dipartimento di Fisica, Università La Sapienza, Roma, Italy.

z

Also at DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de lʼUnivers), CEA Saclay (Commissariat à lʼEnergie Atomique et aux Energies Alternatives), Gif-sur-Yvette, France.

aa

Also at Section de Physique, Université de Genève, Geneva, Switzerland.

ab

Also at Departamento de Fisica, Universidade de Minho, Braga, Portugal.

ac

Also at Department of Physics, The University of Texas at Austin, Austin, TX, United States.

ad

Also at Department of Physics and Astronomy, University of South Carolina, Columbia, SC, United States.

ae

Also at Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Budapest, Hungary.

af

Also at DESY, Hamburg and Zeuthen, Germany.

ag

Also at International School for Advanced Studies (SISSA), Trieste, Italy.

ah

Also at LAL, Université Paris-Sud and CNRS/IN2P3, Orsay, France.

ai

Also at Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russia.

aj

Also at Nevis Laboratory, Columbia University, Irvington, NY, United States.

ak

Also at Department of Physics, Oxford University, Oxford, United Kingdom.

al

Also at Discipline of Physics, University of KwaZulu-Natal, Durban, South Africa.

Deceased.

E-mail address: [email protected].