Selected topics on parton distribution functions

Journal Article · Wed Dec 14 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3667318· OSTI ID:22003994

Hirai, M; Saito, K ^[1]; Kawamura, H ^[2]; Kumano, S ^[2]

---

1. Department of Physics, Faculty of Science and Technology, Tokyo University of Science 2641, Yamazaki, Noda, Chiba, 278-8510 (Japan)
2. KEK Theory Center, Institute of Particle and Nuclear Studies, KEK 1-1, Ooho, Tsukuba, Ibaraki, 305-0801 (Japan)

We report recent studies on structure functions of the nucleon and nuclei. First, clustering effects are investigated in the structure function F{sub 2} of {sup 9}Be for explaining an unusual nuclear correction found in a JLab experiment. We propose that high densities created by formation of clustering structure like 2{alpha}+neutron in {sup 9}Be is the origin of the unexpected JLab result by using the antisymmetrized molecular dynamics (AMD). There is an approved proposal at JLab to investigate the structure functions of light nuclei including the cluster structure, so that much details will become clear in a few years. Second, tensor-polarized quark and antiquark distributions are obtained by analyzing HERMES measurements on the structure function b{sub 1} for the deuteron. The result suggests a finite tensor polarization for antiquark distributions, which is an interesting topic for further theoretical and experimental investigations. An experimental proposal exists at JLab for measuring b{sub 1} of the deuteron as a new tensor-structure study in 2010's. Furthermore, the antiquark tensor polarization could be measured by polarized deuteron Drell-Yan processes at hadron facilities such as J-PARC and GSI-FAIR. Third, the recent CDF dijet anomaly is investigated within the standard model by considering possible modifications of the strange-quark distribution. We find that the shape of a dijet-mass spectrum changes depending on the strange-quark distribution. It indicates that the CDF excess could be partially explained as a PDF effect, particularly by the strangeness in the nucleon, within the standard model if the excess at m{sub jj}{approx_equal}140 GeV is not a sharp peak.

• OSTI ID: 22003994
• Journal Information: AIP Conference Proceedings, Vol. 1418, Issue 1; Conference: PacSPIN2011: 8. Circum-Pan-Pacific symposium on high energy spin physics, Cairns, QLD (Australia), 20-24 Jun 2011; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIQUARKS
BERYLLIUM 9
CEBAF ACCELERATOR
DEUTERONS
DISTRIBUTION FUNCTIONS
DRELL MODEL
GEV RANGE
GLUONS
J-PARC
MOLECULAR DYNAMICS METHOD
NEUTRONS
NUCLEAR STRUCTURE
PARTICLE PRODUCTION
PARTICLE STRUCTURE
POLARIZATION
S QUARKS
SHELL MODELS
STANDARD MODEL
STRUCTURE FUNCTIONS