Photon-hadron jet correlations in p+p and Au+Au collisions at {radical}(s{sub NN})=200 GeV
Abstract
We report the observation at the Relativistic Heavy Ion Collider of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers with associated hadrons are obtained by statistical subtraction of the decay photon-hadron ({gamma}-h) background. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair exactly balance in momentum at leading order in perturbative quantum chromodynamics, making such correlations a powerful probe of the in-medium parton energy loss. The away-side nuclear suppression factor, I{sub AA}, in central Au+Au collisions, is 0.32{+-}0.12{sup stat}{+-}0.09{sup syst} for hadrons of 3<p{sub T}{sup h}<5 in coincidence with photons of 5<p{sub T}{sup {gamma}}<15 GeV/c. The suppression is comparable to that observed for high-p{sub T} single hadrons and dihadrons. The direct photon associated yields in p+p collisions scale approximately with the momentum balance, z{sub T}{identical_to}p{sub T}{sup h}/p{sub T}{sup {gamma}}, as expected for a measurement of the away-side parton fragmentation function. We compare to Au+Au collisions for which the momentum balance dependence of the nuclear modification should be sensitive to the path-length dependence of parton energy loss.
- Authors:
-
- University of Colorado, Boulder, Colorado 80309 (United States)
- Joint Institute for Nuclear Research, RU-141980 Dubna, Moscow Region (Russian Federation)
- Columbia University, New York, NY 10027 and Nevis Laboratories, Irvington, New York 10533 (United States)
- Chemistry Department, Stony Brook University, Stony Brook, SUNY, New York 11794-3400 (United States)
- Publication Date:
- OSTI Identifier:
- 21290077
- Resource Type:
- Journal Article
- Journal Name:
- Physical Review. C, Nuclear Physics
- Additional Journal Information:
- Journal Volume: 80; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevC.80.024908; (c) 2009 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; BALANCES; BROOKHAVEN RHIC; COLLISIONS; COMPARATIVE EVALUATIONS; CORRELATIONS; ENERGY LOSSES; FRAGMENTATION; GEV RANGE; GOLD; HADRONS; MODIFICATIONS; NUCLEAR DECAY; PHOTONS; PROTON-PROTON INTERACTIONS; QUANTUM CHROMODYNAMICS
Citation Formats
Adare, A, Bickley, A A, Ellinghaus, F, Kelly, S, Kinney, E, Kiriluk, K, Nagle, J L, Seele, J, Wysocki, M, Afanasiev, S, Isupov, A, Litvinenko, A, Malakhov, A, Peresedov, V, Rukoyatkin, P, Zolin, L, Aidala, C, Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337, Ajitanand, N N, Alexander, J, and Chung, P. Photon-hadron jet correlations in p+p and Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States: N. p., 2009.
Web. doi:10.1103/PHYSREVC.80.024908.
Adare, A, Bickley, A A, Ellinghaus, F, Kelly, S, Kinney, E, Kiriluk, K, Nagle, J L, Seele, J, Wysocki, M, Afanasiev, S, Isupov, A, Litvinenko, A, Malakhov, A, Peresedov, V, Rukoyatkin, P, Zolin, L, Aidala, C, Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337, Ajitanand, N N, Alexander, J, & Chung, P. Photon-hadron jet correlations in p+p and Au+Au collisions at {radical}(s{sub NN})=200 GeV. United States. https://doi.org/10.1103/PHYSREVC.80.024908
Adare, A, Bickley, A A, Ellinghaus, F, Kelly, S, Kinney, E, Kiriluk, K, Nagle, J L, Seele, J, Wysocki, M, Afanasiev, S, Isupov, A, Litvinenko, A, Malakhov, A, Peresedov, V, Rukoyatkin, P, Zolin, L, Aidala, C, Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337, Ajitanand, N N, Alexander, J, and Chung, P. Sat .
"Photon-hadron jet correlations in p+p and Au+Au collisions at {radical}(s{sub NN})=200 GeV". United States. https://doi.org/10.1103/PHYSREVC.80.024908.
@article{osti_21290077,
title = {Photon-hadron jet correlations in p+p and 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 Kiriluk, K 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 Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337 and Ajitanand, N N and Alexander, J and Chung, P},
abstractNote = {We report the observation at the Relativistic Heavy Ion Collider of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers with associated hadrons are obtained by statistical subtraction of the decay photon-hadron ({gamma}-h) background. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair exactly balance in momentum at leading order in perturbative quantum chromodynamics, making such correlations a powerful probe of the in-medium parton energy loss. The away-side nuclear suppression factor, I{sub AA}, in central Au+Au collisions, is 0.32{+-}0.12{sup stat}{+-}0.09{sup syst} for hadrons of 3<p{sub T}{sup h}<5 in coincidence with photons of 5<p{sub T}{sup {gamma}}<15 GeV/c. The suppression is comparable to that observed for high-p{sub T} single hadrons and dihadrons. The direct photon associated yields in p+p collisions scale approximately with the momentum balance, z{sub T}{identical_to}p{sub T}{sup h}/p{sub T}{sup {gamma}}, as expected for a measurement of the away-side parton fragmentation function. We compare to Au+Au collisions for which the momentum balance dependence of the nuclear modification should be sensitive to the path-length dependence of parton energy loss.},
doi = {10.1103/PHYSREVC.80.024908},
url = {https://www.osti.gov/biblio/21290077},
journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 2,
volume = 80,
place = {United States},
year = {2009},
month = {8}
}