Campus Units
Physics and Astronomy
Document Type
Article
Publication Version
Published Version
Publication Date
12-29-2016
Journal or Book Title
Physical Review D
Volume
94
Issue
11
First Page
112008
DOI
10.1103/PhysRevD.94.112008
Abstract
We report the double-helicity asymmetry, A(LL)(J/Psi), in inclusive J/Psi production at forward rapidity as a function of transverse momentum p(T) and rapidity |y|. The data analyzed were taken during root s = 510 GeV longitudinally polarized p + p collisions at the Relativistic Heavy Ion Collider in the 2013 run using the PHENIX detector. At this collision energy, J/Psi particles are predominantly produced through gluon-gluon scatterings, thus A(LL)(J/Psi) is sensitive to the gluon polarization inside the proton. We measured A(LL)(J/Psi) by detecting the decay daughter muon pairs mu(+)mu(-) within the PHENIX muon spectrometers in the rapidity range 1.2 < |y| < 2.2. In this kinematic range, we measured the A(LL)(J/Psi) to be 0.012 +/- 0.010 (stat) +/- 0.003 (syst). The A(LL)(J.Psi) can be expressed to be proportional to the product of the gluon polarization distributions at two distinct ranges of Bjorken x: one at moderate range x approximate to 5 x 10(-2) where recent data of jet and pi(0) double helicity spin asymmetries have shown evidence for significant gluon polarization, and the other one covering the poorly known small-x region x approximate to 2 x 10(-3). Thus our new results could be used to further constrain the gluon polarization for x < 5 x 10(-2).
Copyright Owner
American Physical Society
Copyright Date
2016
Language
en
File Format
application/pdf
Recommended Citation
Adare, Andrew; Apadula, Nicole; Ding, Lei; Hill, John C.; Hotvedt, Nels J.; Lajoie, John G.; Lebedev, Alexandre; Ogilvie, Craig; Patel, Milap R.; Perry, Joshua; Rinn, Timothy T.; Rosati, Marzia; Sen, Abhisek; Shimomura, M.; Timilsina, Arbin; Whitaker, Shawn; et al.; and PHENIX Collaboration, "Measurements of double-helicity asymmetries in inclusive J/Psi production in longitudinally polarized p plus p collisions at root s=510 GeV" (2016). Physics and Astronomy Publications. 230.
https://lib.dr.iastate.edu/physastro_pubs/230
Comments
This article is from Physical Review D 94 (2016): 112008, doi:10.1103/PhysRevD.94.112008. Posted with permission.