Physics and Astronomy
Journal or Book Title
Physical Review D
Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from p + p collisions at root s = 62.4 GeV are presented. The PHENIX measurement of the cross sections for 1.0 < p(T) < 4.5 GeV/c are consistent with perturbative QCD calculations at next-to-leading order in the strong-coupling constant, alpha(s). 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 0.05 less than or similar to x(gluon) less than or similar to 0.2, is consistent with recent global parametrizations disfavoring large gluon polarization.
American Physical Society
Adare, Andrew; Hill, John C.; Kempel, Todd; Lajoie, John G.; Lebedev, Alexandre; Ogilvie, Craig; Pei, H.; Rosati, Marzia; Semenov, Alexey Yu.; Vale, Carla; Wei, Feng; et al.; and PHENIX Collaboration, "Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p plus p collisions at root s = 62.4 GeV" (2012). Physics and Astronomy Publications. 261.