Single-spin asymmetry of J/ψ production in p+p , p+Al , and p+Au collisions with transversely polarized proton beams at sNN=200 GeV

Le résumé fourni par la source

We report the transverse single-spin asymmetries of $J/\ensuremath{\psi}$ production at forward and backward rapidity, $1.2<|y|<2.2$, as a function of $J/\ensuremath{\psi}$ transverse momentum (${p}_{T}$) and Feynman-$x$ (${x}_{F}$). The data analyzed were recorded by the PHENIX experiment at the Relativistic Heavy Ion Collider in 2015 from $p+p$, $p+\mathrm{Al}$, and $p+\mathrm{Au}$ collisions with transversely polarized proton beams at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$. At this collision energy, single-spin asymmetries for heavy-flavor particle production of $p+p$ collisions provide access to the spin-dependent gluon distribution and higher-twist correlation functions inside the nucleon, such as the gluon Qiu-Sterman and trigluon correlation functions. $\mathrm{Proton}+\mathrm{nucleus}$ collisions offer an excellent opportunity to study nuclear effects on the correlation functions. The data indicate a positive asymmetry at the two-standard-deviation level in the $p+p$ data for $2\text{ }\text{ }\mathrm{GeV}/c<{p}_{T}<10\text{ }\text{ }\mathrm{GeV}/c$ at backward rapidity and negative asymmetries at the two-standard-deviation level in the $p+\mathrm{Au}$ data for ${p}_{T}<2\text{ }\text{ }\mathrm{GeV}/c$ at both forward and backward rapidity, while in $p+\mathrm{Al}$ collisions the asymmetries are consistent with zero within the range of experimental uncertainties.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.