Forward Neutral Pion Transverse Single Spin Asymmetries in p+p Collisions at sqrt s = 200 GeV

Journal Article · Wed Nov 26 00:00:00 EST 2008 · Physical Review Letter

OSTI ID:963332

Coll, STAR

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 are in fair agreement with perturbative QCD (pQCD) 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 pQCD-based calculations.

• Research Organization: ErnestOrlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Nuclear Science Division
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 963332
• Report Number(s): LBNL-2105E; TRN: US0903172
• Journal Information: Physical Review Letter, Journal Name: Physical Review Letter
• Country of Publication: United States
• Language: English

Related Subjects

73
ACCURACY
GLUONS
MESONS
ORIGIN
PIONS
PRODUCTION
PROTONS
QUANTUM CHROMODYNAMICS
QUARKS
SPIN
TRANSVERSE MOMENTUM