Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p+p collisions at SQUARE ROOTs=62.4 GeV
Abstrakt
Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from p+p collisions at SQUARE ROOTs=62.4 GeV are presented. The PHENIX measurement of the cross sections for 1.0<pT<4.5 GeV/c are consistent with perturbative QCD calculations at next-to-leading order in the strong-coupling constant, αs.
Resummed pQCD calculations including terms with next-to-leading-log accuracy, yielding reduced theoretical uncertainties, also agree with the data. The double-helicity asymmetry, sensitive at leading order to the gluon polarization in a momentum-fraction range of 0.05LESS-THAN OR EQUIVALENT TOxgluonLESS-THAN OR EQUIVALENT TO0.2, is consistent with recent global parametrizations disfavoring large gluon polarization.