Forward neutral-pion transverse single-spin asymmetries in p+p collisions at {radical}{ovr s}=200 GeV.

Journal Article · Tue Jan 01 00:00:00 EST 2008 · Phys. Rev. Lett.

DOI:https://doi.org/10.1103/PhysRevLett.101.222001· OSTI ID:963643

Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Krueger, K; Spinka, H M; Underwood, D G

We report precision measurements of the Feynman x (x{sub F}) dependence, and first measurements of the transverse momentum (p{sub T}) dependence, of transverse single-spin asymmetries for the production of {pi}{sup 0} mesons from polarized proton collisions at {radical}s = 200 GeV. The x{sub F} dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p{sub T} dependence at fixed x{sub F} are not consistent with these same perturbative QCD-based calculations.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF); Swiss NSF
• DOE Contract Number: DE-AC02-06CH11357
• OSTI ID: 963643
• Report Number(s): ANL-HEP-PR-09-79; PRLTAO; TRN: US0903230
• Journal Information: Phys. Rev. Lett., Vol. 101, Issue 2008; ISSN 0031-9007
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
GLUONS
MESONS
ORIGIN
PRODUCTION
PROTONS
QUANTUM CHROMODYNAMICS
QUARKS
SPIN
TRANSVERSE MOMENTUM