Physics and Astronomy
Journal or Book Title
Physical Review C
The three gamma states, gamma (1S + 2S + 3S), are measured in d + Au and p + p collisions at root s(NN) = 200 GeV and rapidities 1.2 < vertical bar y vertical bar < 2.2 by the PHENIX experiment at the Relativistic Heavy Ion Collider. Cross sections for the inclusive gamma (1S + 2S + 3S) production are obtained. The inclusive yields per binary collision for d + Au collisions relative to those in p + p collisions (R-dAu) are found to be 0.62 +/- 0.26 (stat) +/- 0.13 (syst) in the gold-going direction and 0.91 +/- 0.33 (stat) +/- 0.16 (syst) in the deuteron-going direction. The measured results are compared to a nuclear-shadowing model, EPS09 [Eskola et al., J. High Energy Phys. 04 (2009) 065], combined with a final-state breakup cross section, sigma(br), and compared to lower energy p + A results. We also compare the results to the PHENIX J/psi results [Adare et al., Phys. Rev. Lett. 107, 142301 (2011)]. The rapidity dependence of the observed gamma suppression is consistent with lower energy p + A measurements.
American Physical Society
Adare, Andrew; Dion, Alan; Hill, John C.; Kempel, Todd; Lajoie, John G.; Lebedev, Alexandre; Ogilvie, Craig; Pei, H.; Rosati, Marzia; Semenov, Alexey Yu.; Silva, C. L.; Vale, Carla; Wei, Feng; et al.; and PHENIX Collaboration, "gamma (1S+2S+3S) production in d plus Au and p plus p collisions at root s(NN)=200 GeV and cold-nuclear-matter effects" (2013). Physics and Astronomy Publications. 251.