Physics and Astronomy
Journal or Book Title
Physical Review D
We present an improved measurement of the double helicity asymmetry for pi(0) production in polarized proton-proton scattering at root s=200 GeV employing the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The improvements to our previous measurement come from two main factors: Inclusion of a new data set from the 2004 RHIC run with higher beam polarizations than the earlier run and a recalibration of the beam polarization measurements for the earlier run, which resulted in reduced uncertainties and increased beam polarizations. The results are compared to a Next to Leading Order (NLO) perturbative Quantum Chromodynamics (pQCD) calculation with a range of polarized gluon distributions.
American Physical Society
Adler, S. S.; Belikov, Sergey; Constantin, Paul; Grau, Nathan C.; Hill, John C.; Lajoie, John G.; Lebedev, Alexandre; Ogilvie, Craig; Pei, H.; Rak, Jan; Rosati, Marzia; Skutnik, S.; Wohn, F. K.; Zong, X.; et al.; and PHENIX Collaboration, "Improved measurement of double helicity asymmetry in inclusive midrapidity pi(0) production for polarized p+p collisions at root s=200 GeV" (2006). Physics and Astronomy Publications. 357.