Inclusive double-helicity asymmetries in neutral-pion and eta-meson production in p → + p → collisions at s =200GeV
Article
Adare, A, Aidala, C, Ajitanand, NN et al. (2014). Inclusive double-helicity asymmetries in neutral-pion and eta-meson production in p → + p → collisions at s =200GeV
. PHYSICAL REVIEW D, 90(1), 10.1103/PhysRevD.90.012007
Adare, A, Aidala, C, Ajitanand, NN et al. (2014). Inclusive double-helicity asymmetries in neutral-pion and eta-meson production in p → + p → collisions at s =200GeV
. PHYSICAL REVIEW D, 90(1), 10.1103/PhysRevD.90.012007
Results are presented from data recorded in 2009 by the PHENIX experiment at the Relativistic Heavy Ion Collider for the double-longitudinal spin asymmetry, ALL, for π0 and η production in s=200GeV polarized p+p collisions. Comparison of the π0 results with different theory expectations based on fits of other published data showed a preference for small positive values of gluon polarization, ΔG, in the proton in the probed Bjorken x range. The effect of adding the new 2009 π0 data to a recent global analysis of polarized scattering data is also shown, resulting in a best fit value ΔGDSSV[0.05,0.2]=0.06-0.15+0.11 in the range 0.05