Cross section and transverse single-spin asymmetry of η mesons in p↑+p collisions at s=200 GeV at forward rapidity

Le résumé fourni par la source

We present a measurement of the cross section and transverse single-spin asymmetry (${A}_{N}$) for $\ensuremath{\eta}$ mesons at large pseudorapidity from $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$ ${p}^{\ensuremath{\uparrow}}+p$ collisions. The measured cross section for $0.5<{p}_{T}<5.0\text{ }\text{ }\mathrm{GeV}/c$ and $3.0<|\ensuremath{\eta}|<3.8$ is well described by a next-to-leading-order perturbative-quantum-chromodynamics calculation. The asymmetries ${A}_{N}$ have been measured as a function of Feynman-$x$ (${x}_{F}$) from $0.2<|{x}_{F}|<0.7$, as well as transverse momentum (${p}_{T}$) from $1.0<{p}_{T}<4.5\text{ }\text{ }\mathrm{GeV}/c$. The asymmetry averaged over positive ${x}_{F}$ is $⟨{A}_{N}⟩=0.061\ifmmode\pm\else\textpm\fi{}0.014$. The results are consistent with prior transverse single-spin measurements of forward $\ensuremath{\eta}$ and ${\ensuremath{\pi}}^{0}$ mesons at various energies in overlapping ${x}_{F}$ ranges. Comparison of different particle species can help to determine the origin of the large observed asymmetries in ${p}^{\ensuremath{\uparrow}}+p$ collisions.

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