skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Dihadron azimuthal correlations in Au+Au collisions at {radical}(s{sub NN})=200 GeV

Abstract

Azimuthal angle ({delta}{phi}) correlations are presented for a broad range of transverse momentum (0.4<p{sub T}<10 GeV/c) and centrality (0-92%) selections for charged hadrons from dijets in Au+Au collisions at {radical}(s{sub NN})=200 GeV. With increasing p{sub T}, the away-side {delta}{phi} distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons with p+p data suggest that the away-side distribution can be divided into a partially suppressed 'head' region centered at {delta}{phi}{approx}{pi}, and an enhanced 'shoulder' region centered at {delta}{phi}{approx}{pi}{+-}1.1. The p{sub T} spectrum for the associated hadrons in the head region softens toward central collisions. The spectral slope for the shoulder region is independent of centrality and trigger p{sub T}. The properties of the near-side distributions are also modified relative to those in p+p collisions, reflected by the broadening of the jet shape in {delta}{phi} and {delta}{eta}, and an enhancement of the per-trigger yield. However, these modifications seem to be limited to p{sub T} < or approx. 4 GeV/c, above which both the hadron pair shape and per-trigger yield become similar to p+p collisions. These observations suggest that both the away- and near-side distributions contain a jet fragmentation component which dominates for p{submore » T} > or approx. 5 GeV/c and a medium-induced component which is important for p{sub T} < or approx. 4 GeV/c. We also quantify the role of jets at intermediate and low p{sub T} through the yield of jet-induced pairs in comparison with binary scaled p+p pair yield. The yield of jet-induced pairs is suppressed at high pair proxy energy (sum of the p{sub T} magnitudes of the two hadrons) and is enhanced at low pair proxy energy. The former is consistent with jet quenching; the latter is consistent with the enhancement of soft hadron pairs due to transport of lost energy to lower p{sub T}.« less

Authors:
; ; ; ; ; ; ;  [1]; ; ; ; ; ; ;  [2]; ; ; ; ;  [3]
  1. University of Colorado, Boulder, Colorado 80309 (United States)
  2. Joint Institute for Nuclear Research, RU-141980 Dubna, Moscow Region (Russian Federation)
  3. Columbia University, New York, New York 10027 (United States) and Nevis Laboratories, Irvington, New York 10533 (United States)
Publication Date:
OSTI Identifier:
21192046
Resource Type:
Journal Article
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 78; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevC.78.014901; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2813
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ATOM-ATOM COLLISIONS; COLLISIONS; COMPARATIVE EVALUATIONS; CORRELATIONS; DISTRIBUTION; FRAGMENTATION; GEV RANGE; GOLD; HADRONS; MODIFICATIONS; QUENCHING; SPECTRA; TRANSVERSE MOMENTUM

Citation Formats

Adare, A, Bickley, A A, Ellinghaus, F, Kelly, S, Kinney, E, Nagle, J L, Seele, J, Wysocki, M, Afanasiev, S, Isupov, A, Litvinenko, A, Malakhov, A, Peresedov, V, Rukoyatkin, P, Zolin, L, Aidala, C, Bjorndal, M T, Chi, C Y, Cole, B A, and D'Enterria, D. Dihadron azimuthal correlations in Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States: N. p., 2008. Web. doi:10.1103/PHYSREVC.78.014901.
Adare, A, Bickley, A A, Ellinghaus, F, Kelly, S, Kinney, E, Nagle, J L, Seele, J, Wysocki, M, Afanasiev, S, Isupov, A, Litvinenko, A, Malakhov, A, Peresedov, V, Rukoyatkin, P, Zolin, L, Aidala, C, Bjorndal, M T, Chi, C Y, Cole, B A, & D'Enterria, D. Dihadron azimuthal correlations in Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States. https://doi.org/10.1103/PHYSREVC.78.014901
Adare, A, Bickley, A A, Ellinghaus, F, Kelly, S, Kinney, E, Nagle, J L, Seele, J, Wysocki, M, Afanasiev, S, Isupov, A, Litvinenko, A, Malakhov, A, Peresedov, V, Rukoyatkin, P, Zolin, L, Aidala, C, Bjorndal, M T, Chi, C Y, Cole, B A, and D'Enterria, D. Tue . "Dihadron azimuthal correlations in Au+Au collisions at {radical}(s{sub NN})=200 GeV". United States. https://doi.org/10.1103/PHYSREVC.78.014901.
@article{osti_21192046,
title = {Dihadron azimuthal correlations in Au+Au collisions at {radical}(s{sub NN})=200 GeV},
author = {Adare, A and Bickley, A A and Ellinghaus, F and Kelly, S and Kinney, E and Nagle, J L and Seele, J and Wysocki, M and Afanasiev, S and Isupov, A and Litvinenko, A and Malakhov, A and Peresedov, V and Rukoyatkin, P and Zolin, L and Aidala, C and Bjorndal, M T and Chi, C Y and Cole, B A and D'Enterria, D},
abstractNote = {Azimuthal angle ({delta}{phi}) correlations are presented for a broad range of transverse momentum (0.4<p{sub T}<10 GeV/c) and centrality (0-92%) selections for charged hadrons from dijets in Au+Au collisions at {radical}(s{sub NN})=200 GeV. With increasing p{sub T}, the away-side {delta}{phi} distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons with p+p data suggest that the away-side distribution can be divided into a partially suppressed 'head' region centered at {delta}{phi}{approx}{pi}, and an enhanced 'shoulder' region centered at {delta}{phi}{approx}{pi}{+-}1.1. The p{sub T} spectrum for the associated hadrons in the head region softens toward central collisions. The spectral slope for the shoulder region is independent of centrality and trigger p{sub T}. The properties of the near-side distributions are also modified relative to those in p+p collisions, reflected by the broadening of the jet shape in {delta}{phi} and {delta}{eta}, and an enhancement of the per-trigger yield. However, these modifications seem to be limited to p{sub T} < or approx. 4 GeV/c, above which both the hadron pair shape and per-trigger yield become similar to p+p collisions. These observations suggest that both the away- and near-side distributions contain a jet fragmentation component which dominates for p{sub T} > or approx. 5 GeV/c and a medium-induced component which is important for p{sub T} < or approx. 4 GeV/c. We also quantify the role of jets at intermediate and low p{sub T} through the yield of jet-induced pairs in comparison with binary scaled p+p pair yield. The yield of jet-induced pairs is suppressed at high pair proxy energy (sum of the p{sub T} magnitudes of the two hadrons) and is enhanced at low pair proxy energy. The former is consistent with jet quenching; the latter is consistent with the enhancement of soft hadron pairs due to transport of lost energy to lower p{sub T}.},
doi = {10.1103/PHYSREVC.78.014901},
url = {https://www.osti.gov/biblio/21192046}, journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 1,
volume = 78,
place = {United States},
year = {2008},
month = {7}
}