# Improved Measurement of Double Helicity Asymmetry in Inclusive Midrapidity $\pi^0$ Production for Polarized p+p Collisions at $\sqrt S$=200 GeV

Abstract : We present an improved measurement of the double helicity asymmetry for $\pi^0$ production in polarized proton-proton scattering at $\sqrt S$= 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, 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.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00025579
Contributor : Suzanne Robert Connect in order to contact the contributor
Submitted on : Tuesday, February 7, 2006 - 4:41:05 PM
Last modification on : Tuesday, April 20, 2021 - 12:00:12 PM

### Citation

S.S. Adler, S. Afanasiev, C. Aidala, N.N. Ajitanand, Y. Akiba, et al.. Improved Measurement of Double Helicity Asymmetry in Inclusive Midrapidity $\pi^0$ Production for Polarized p+p Collisions at $\sqrt S$=200 GeV. Physical Review D, American Physical Society, 2006, 73, pp.091102. ⟨10.1103/PhysRevD.73.091102⟩. ⟨in2p3-00025579⟩

Record views