Suppression of Upsilon Production in d+Au and Au+Au Collisions at sqrt(s_NN) = 200 GeV - Archive ouverte HAL Access content directly
Journal Articles Physics Letters B Year : 2014

Suppression of Upsilon Production in d+Au and Au+Au Collisions at sqrt(s_NN) = 200 GeV

, (1) , (1)
1
L. Adamczyk
  • Function : Author

Abstract

We report measurements of Upsilon meson production in p+p, d+Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p+p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon(1S+2S+3S) in the rapidity range |y|<1 in d+Au collisions of R_dAu = 0.67 +/- 0.12 (stat.) +/- 0.04 (sys.) +/- 0.08 (pp sys.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au+Au collisions, we measure a nuclear modification factor of R_AA=0.36 +/- 0.09 (stat.) +/- 0.01 (sys.) +/- 0.04 (pp sys.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au+Au collisions. The additional suppression in Au+Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark-Gluon Plasma. However, understanding the suppression seen in d+Au is still needed before any definitive statements about the nature of the suppression in Au+Au can be made.

Dates and versions

in2p3-00919581 , version 1 (17-12-2013)

Identifiers

Cite

L. Adamczyk, W. Borowski, S. Kabana. Suppression of Upsilon Production in d+Au and Au+Au Collisions at sqrt(s_NN) = 200 GeV. Physics Letters B, 2014, 735, pp.127-137. ⟨10.1016/j.physletb.2014.06.028⟩. ⟨in2p3-00919581⟩
46 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More