TY - JOUR
T1 - Measurement of long-range pseudorapidity correlations and azimuthal harmonics in √sNN =5.02 TeV proton-lead collisions with the ATLAS detector
AU - ATLAS Collaboration
AU - Aad, G.
AU - Abbott, B.
AU - Abdallah, J.
AU - Abdel Khalek, S.
AU - Abdinov, O.
AU - Aben, R.
AU - Abi, B.
AU - Abolins, M.
AU - Abouzeid, O. S.
AU - Abramowicz, H.
AU - Abreu, H.
AU - Abreu, R.
AU - Abulaiti, Y.
AU - Acharya, B. S.
AU - Adamczyk, L.
AU - Adams, D. L.
AU - Adelman, J.
AU - Adomeit, S.
AU - Adye, T.
AU - Agatonovic-Jovin, T.
AU - Aguilar-Saavedra, J. A.
AU - Agustoni, M.
AU - Ahlen, S. P.
AU - Ahmadov, F.
AU - Aielli, G.
AU - Akerstedt, H.
AU - Åkesson, T. P.A.
AU - Akimoto, G.
AU - Akimov, A. V.
AU - Alberghi, G. L.
AU - Albert, J.
AU - Albrand, S.
AU - Alconada Verzini, M. J.
AU - Aleksa, M.
AU - Aleksandrov, I. N.
AU - Alexa, C.
AU - Alexander, G.
AU - Alexandre, G.
AU - Alexopoulos, T.
AU - Alhroob, M.
AU - Alimonti, G.
AU - Alio, L.
AU - Alison, J.
AU - Arnold, H.
AU - Da Via, C.
AU - Dao, V.
AU - Hobbs, J.
AU - Jia, J.
AU - Piacquadio, G.
AU - Tsybychev, D.
N1 - Publisher Copyright:
© 2014 CERN, for the ATLAS Collaboration.
PY - 2014/10/9
Y1 - 2014/10/9
N2 - Measurements of two-particle correlation functions and the first five azimuthal harmonics, v1 to v5, are presented, using 28 nb-1 of p+Pb collisions at a nucleon-nucleon center-of-mass energy of √sNN=5.02 TeV measured with the ATLAS detector at the LHC. Significant long-range "ridgelike" correlations are observed for pairs with small (|Δϕ|<π/3) and back-to-back pairs (|Δφ|>2π/3) over the transverse momentum range 0.4T<12 GeV and in different intervals of event activity. The event activity is defined by either the number of reconstructed tracks or the total transverse energy on the Pb-fragmentation side. The azimuthal structure of such long-range correlations is Fourier decomposed to obtain the harmonics νn as a function of pT and event activity. The extracted νn values for n=2 to 5 decrease with n. The ν2 and ν3 values are found to be positive in the measured pT range. The ν1 is also measured as a function of pT and is observed to change sign around pT≈1.5-2.0 GeV and then increase to about 0.1 for pT>4 GeV. The ν2 (pT), ν3 (pT), and ν4 (pT) are compared to the νn coefficients in Pb+Pb collisions at √sNN=2.76 TeV with similar event multiplicities. Reasonable agreement is observed after accounting for the difference in the average pT of particles produced in the two collision systems.
AB - Measurements of two-particle correlation functions and the first five azimuthal harmonics, v1 to v5, are presented, using 28 nb-1 of p+Pb collisions at a nucleon-nucleon center-of-mass energy of √sNN=5.02 TeV measured with the ATLAS detector at the LHC. Significant long-range "ridgelike" correlations are observed for pairs with small (|Δϕ|<π/3) and back-to-back pairs (|Δφ|>2π/3) over the transverse momentum range 0.4T<12 GeV and in different intervals of event activity. The event activity is defined by either the number of reconstructed tracks or the total transverse energy on the Pb-fragmentation side. The azimuthal structure of such long-range correlations is Fourier decomposed to obtain the harmonics νn as a function of pT and event activity. The extracted νn values for n=2 to 5 decrease with n. The ν2 and ν3 values are found to be positive in the measured pT range. The ν1 is also measured as a function of pT and is observed to change sign around pT≈1.5-2.0 GeV and then increase to about 0.1 for pT>4 GeV. The ν2 (pT), ν3 (pT), and ν4 (pT) are compared to the νn coefficients in Pb+Pb collisions at √sNN=2.76 TeV with similar event multiplicities. Reasonable agreement is observed after accounting for the difference in the average pT of particles produced in the two collision systems.
UR - https://www.scopus.com/pages/publications/84908431471
U2 - 10.1103/PhysRevC.90.044906
DO - 10.1103/PhysRevC.90.044906
M3 - Article
AN - SCOPUS:84908431471
SN - 0556-2813
VL - 90
JO - Physical Review C - Nuclear Physics
JF - Physical Review C - Nuclear Physics
IS - 4
M1 - 044906
ER -