Measurement of transverse single-spin asymmetries for J/psi production in polarized p plus p collisions at root s=200 GeV

Adare, Andrew
Ogilvie, Craig
Dion, Alan
Hill, John
Kempel, Todd
Lajoie, John
Lebedev, Alexandre
Ogilvie, Craig
Pei, H.
Rosati, Marzia
Semenov, Alexey
Silva, C.
Vale, Carla
Wei, Feng
et al.
Journal Title
Journal ISSN
Volume Title
Source URI
Research Projects
Organizational Units
Physics and Astronomy
Organizational Unit
Journal Issue

We report the first measurement of transverse single-spin asymmetries in J/psi production from transversely polarized p + p collisions at root s = 200 GeV with data taken by the PHENIX experiment in 2006 and 2008. The measurement was performed over the rapidity ranges 1.2 < vertical bar y vertical bar < 2.2 and vertical bar y vertical bar < 0.35 for transverse momenta up to 6 GeV/c. J/psi production at the Relativistic Heavy Ion Collider is dominated by processes involving initial-state gluons, and transverse single-spin asymmetries of the J/psi can provide access to gluon dynamics within the nucleon. Such asymmetries may also shed light on the long-standing question in QCD of the J/psi production mechanism. Asymmetries were obtained as a function of J/psi transverse momentum and Feynman-x, with a value of -0.086 +/- 0.026(stat) +/- 0.003(syst) in the forward region. This result suggests possible nonzero trigluon correlation functions in transversely polarized protons and, if well defined in this reaction, a nonzero gluon Sivers distribution function.

<p>This article is published as Adare, A., S. Afanasiev, C. Aidala, N. N. Ajitanand, Yasuyuki Akiba, H. Al-Bataineh, J. Alexander et al. "Measurement of transverse single-spin asymmetries for J/ψ production in polarized p+ p collisions at s= 200 GeV." <em>Physical Review D</em> 82, no. 11 (2010): 112008. DOI:<a href="" target="_blank">10.1103/PhysRevD.82.112008</a>. Posted with permission.</p>