Sivers asymmetry for the proton and the neutron

Journal Article · Mon Oct 13 04:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3013030· OSTI ID:21251438

Scopetta, S ^[1]; Courtoy, A ^[2]; Fratini, F ^[1]; Vento, V ^[2]

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1. Dipartimento di Fisica, Universita degli Studi di Perugia, via A. Pascoli, 06100 Perugia (Italy)
2. Departament de Fisica Teorica, Universitat de Valencia and Institut de Fisica Corpuscular, Consejo Superior de Investigaciones Cientificas 46100 Burjassot (Valencia) (Spain)

A formalism is presented to evaluate the Sivers function in constituent quark models. A non-relativistic reduction of the scheme is performed and applied to the Isgur-Karl model. The results obtained are consistent with a sizable Sivers effect and the signs for the u and d flavor contributions turn out to be opposite. The Burkardt Sum Rule is fulfilled to a large extent. After the estimate of the QCD evolution of the results from the momentum scale of the model to the experimental one, a reasonable agreement with the available data is obtained. A calculation of nuclear effects in the extraction of neutron single spin asymmetries in semi-inclusive deep inelastic scattering off {sup 3}He is also described. In the kinematics of forth-coming experiments at JLab, it is found that the nuclear effects arising within an Impulse Approximation approach are under control.

• OSTI ID: 21251438
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1056; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
CHIRAL SYMMETRY
DEEP INELASTIC SCATTERING
FLAVOR MODEL
HELIUM 3 TARGET
IMPULSE APPROXIMATION
NEUTRONS
PROTONS
QUANTUM CHROMODYNAMICS
QUARK-GLUON INTERACTIONS
SEMI-INCLUSIVE INTERACTIONS
SPIN
SUM RULES