Flavor structure of the nucleon as revealed at HERMES.

Conference · Thu Sep 05 04:00:00 EDT 2002

DOI:https://doi.org/10.1007/978-94-010-0165-6_2· OSTI ID:801582

Jackson, H E

The flavor structure of the nucleon as revealed in parton distributions (PDF's) is central to understanding the partonic structure of the nucleon. Recent data on unpolarized PDF's and their implications for the flavor-dependent quark helicity distributions are discussed. Results are presented for spin asymmetries in inclusive and semi-inclusive cross sections for production of pions, and kaons measured by the HERMES experiment in deep-inelastic scattering of polarized positrons on proton and deuterium Targets. A full 5 component extraction of polarized quark distributions for u, d, {bar u}, {bar d}, and (s + {bar s}) is reported. Resulting valence quark distributions conform to results of earlier experiments. There is no evidence for a significant polarization of the light sea. In contrast to the conclusions inferred from studies of polarized inclusive scattering, a leading order analysis of the HERMES data suggests a zero or slightly positive polarization of the strange sea. There is no evidence for a measurable flavor asymmetry in the polarized distributions for the light sea.

• Research Organization: Argonne National Lab., IL (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 801582
• Report Number(s): ANL/PHY/CP-108601
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CROSS SECTIONS
DEUTERIUM TARGET
HELICITY
KAONS
NUCLEONS
PARTONS
PIONS
POLARIZATION
POSITRONS
PROTONS
QUARKS
SCATTERING
SPIN
VALENCE