Longitudinal double-spin asymmetry and cross section for inclusive neutral pion productionat midrapidity in polarized proton collisions at sqrt s = 200 GeV

Journal Article · Wed Dec 30 00:00:00 EST 2009 · Physical Review. D, Particles, Fields, Gravitation and Cosmology

DOI:https://doi.org/10.1103/PhysRevD.80.111108· OSTI ID:1041143

Abelev, B I; Dunlop, J

We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive {pi}{sup 0} production at midrapidity in polarized proton collisions at {radical}s = 200 GeV. The cross section was measured over a transverse momentum range of 1 < p{sub T} < 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p{sub T} < 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of {pi}{sup 0}'s in their parent jets was found to be around 0.7 for electromagnetically triggered events.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: DE-AC02-98CH10886
• OSTI ID: 1041143
• Report Number(s): BNL-91208-2010-JA; R&D Project: PO-003; KB0202012; TRN: US1202611
• Journal Information: Physical Review. D, Particles, Fields, Gravitation and Cosmology, Vol. 80, Issue 11; ISSN 1550-7998
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASYMMETRY
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
GLUONS
INCLUSIVE INTERACTIONS
PIONS
POLARIZATION
PARTICLE PRODUCTION
PARTICLE RAPIDITY
PIONS NEUTRAL
PROTONS
QUANTUM CHROMODYNAMICS
SPIN
TRANSVERSE MOMENTUM
relativistic heavy ion collider