Neutral pion production in Au plus Au collisions at root s(NN)=200 GeV

The results of midrapidity (0<y<0.8) neutral pion spectra over an extended transverse momentum range (1<p[subscript T]<12 GeV/c) in √(s[subscript NN])=200 GeV Au+Au collisions, measured by the STAR experiment, are presented. The neutral pions are reconstructed from photons measured eith...

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Bibliographic Details
Main Authors: Walker, M., van Nieuwenhuizen, Gerrit Jan, Surrow, Bernd, Sakuma, Tai, Redwine, Robert P., Milner, Richard G., Leight, William Axel, Kocoloski, Adam Philip, Jones, Christopher LaDon, Hoffman, A. M., Corliss, Ross Cameron, Betancourt, Michael Joseph, Balewski, Jan T.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:en_US
Published: American Physical Society 2010
Online Access:http://hdl.handle.net/1721.1/52747
https://orcid.org/0000-0002-5515-4563
https://orcid.org/0000-0001-5839-707X
https://orcid.org/0000-0002-0031-1963
https://orcid.org/0000-0002-9107-6312
Description
Summary:The results of midrapidity (0<y<0.8) neutral pion spectra over an extended transverse momentum range (1<p[subscript T]<12 GeV/c) in √(s[subscript NN])=200 GeV Au+Au collisions, measured by the STAR experiment, are presented. The neutral pions are reconstructed from photons measured either by the STAR Barrel Electro-Magnetic Calorimeter or by the Time Projection Chamber via tracking of conversion electron-positron pairs. Our measurements are compared to previously published π[superscript ±] and π[superscript 0] results. The nuclear modification factors R[subscript CP] and R[subscript AA] of π[superscript 0] are also presented as a function of p[subscript T]. In the most central Au+Au collisions, the binary collision scaled π[superscript 0] yield at high p[subscript T] is suppressed by a factor of about 5 compared to the expectation from the yield of p+p collisions. Such a large suppression is in agreement with previous observations for light quark mesons and is consistent with the scenario that partons suffer considerable energy loss in the dense medium formed in central nucleus-nucleus collisions at the Relativistic Heavy Ion Collider.