Measurement of Transverse Single-Spin Asymmetries for J/psi Production in Polarized p+p Collisions at sqrt(s) = 200 GeV

We report the first measurement of transverse single-spin asymmetries in $J\mathrm{/}\psi$ production from transversely polarized $p+p$ collisions at $\sqrt{s} = 200$ GeV with data taken by the PHENIX experiment in 2006 and 2008. The measurement was performed over the rapidity ranges $1.2<\mathrm{\mid }y\mathrm{\mid }<2.2$ and $ |y| < 0.35$fortransversemomentaupto6GeV\mathrm{/}$c$\mathrm{.}$J/\psi$ production at RHIC is dominated by processes involving initial-state gluons, and transverse single-spin asymmetries of the $J\mathrm{/}\psi$ can provide access to gluon dynamics within the nucleon. Such asymmetries may also shed light on the long-standing question in QCD of the $J\mathrm{/}\psi$ production mechanism. Asymmetries were obtained as a function of $J\mathrm{/}\psi$ transverse momentum and Feynman-$x$, with a value of $-0.086\pm {0.026}^{\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}}\pm {0.003}^{\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t}}$ 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.