ﻻ يوجد ملخص باللغة العربية
Results are presented from data recorded in 2009 by the PHENIX experiment at the Relativistic Heavy Ion Collider for the double-longitudinal spin asymmetry, $A_{LL}$, for $pi^0$ and $eta$ production in $sqrt{s} = 200$ GeV polarized $p$$+$$p$ collisions. Comparison of the $pi^0$ results with different theory expectations based on fits of other published data showed a preference for small positive values of gluon polarization, $Delta G$, in the proton in the probed Bjorken $x$ range. The effect of adding the new 2009 pz data to a recent global analysis of polarized scattering data is also shown, resulting in a best fit value $Delta G^{[0.05,0.2]}_{mbox{DSSV}} = 0.06^{+0.11}_{-0.15}$ in the range $0.05<x<0.2$, with the uncertainty at $Delta chi^2 = 9$ when considering only statistical experimental uncertainties. Shifting the PHENIX data points by their systematic uncertainty leads to a variation of the best-fit value of $Delta G^{[0.05,0.2]}_{mbox{DSSV}}$ between $0.02$ and $0.12$, demonstrating the need for full treatment of the experimental systematic uncertainties in future global analyses.
We present the midrapidity charged pion invariant cross sections and the ratio of $pi^-$-to-$pi^+$ production ($5<p_T<13$ GeV/$c$), together with the double-helicity asymmetries ($5<p_T<12$ GeV/$c$) in polarized $p$$+$$p$ collisions at $sqrt{s} = 200
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 $sqrt{s}=510$ GeV longitudinally polariz
Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from p+p collisions at sqrt(s)=62.4 GeV are presented. The PHENIX measurements for 1.0 < p_T < 4.5 GeV/c are consisten
Measurements of double-helicity asymmetries for inclusive hadron production in polarized p+p collisions are sensitive to helicity--dependent parton distribution functions, in particular to the gluon helicity distribution, Delta(g). This study focuses
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured low mass vector meson, $omega$, $rho$, and $phi$, production through the dimuon decay channel at forward rapidity ($1.2<|y|<2.2$) in $p$$+$$p$ collisions at $sqrt{s}=200$ GeV.