Spin physics with CLAS and CLAS12

Journal Article · Fri Oct 21 00:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3647350· OSTI ID:21611973

Biselli, Angela ^[1]

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1. Fairfield University, Fairfield, CT 06828 (United States)

An extensive experimental program to measure the spin structure of the nucleon has been conducted in Hall B at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) in the last decade. Using a longitudinally polarized beam scattering off longitudinally polarized NH{sub 3} and ND{sub 3} targets, inclusive Deep Inelastic Scattering (DIS), Semi-Inclusive DIS (SIDIS) and DVCS experiments were carried out that make a significant contributions to the existing data. The inclusive double spin asymmetry A{sub ||} was measured over a large range in Q{sup 2} and W, providing data of impressively high precision that give a better understanding of the structure of the nucleon in the DIS and the valence quarks regions. Using parameterizations A2 and F1 from world data, the virtual photon asymmetry A1 and the structure function g1 were extracted in a Q{sup 2} range from 0.05 to 5 GeV{sup 2} and a W range from 1.08 to 3.0 GeV. As a result of the extended kinematical range, first moments of structure functions were measured over a large range in Q{sup 2} and duality was tested. Furthermore, newly proposed experiments, using an upgraded accelerator at Jefferson Laboratory and an improved CLAS detector (CLAS12), are expected to increase the statistical precision of the current measurements and extend them to kinematic regions presently not accessible, such as high x. This will improve significantly our knowledge of the structure of the nucleon, including parton distribution functions, duality and higher twists contributions.

• OSTI ID: 21611973
• Journal Information: AIP Conference Proceedings, Vol. 1388, Issue 1; Conference: BARYONS' 10: International conference on the structure of baryons, Osaka (Japan), 7-11 Dec 2010; Other Information: DOI: 10.1063/1.3647350; (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

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMMONIA
CEBAF ACCELERATOR
CHIRAL SYMMETRY
DEEP INELASTIC SCATTERING
DISTRIBUTION FUNCTIONS
DUALITY
FOUR MOMENTUM TRANSFER
GEV RANGE
INCLUSIVE INTERACTIONS
MULTIPARTICLE SPECTROMETERS
NUCLEONS
PARTICLE IDENTIFICATION
PARTICLE KINEMATICS
PARTICLE STRUCTURE
POLARIZED BEAMS
POLARIZED TARGETS
QUARKS
SEMI-INCLUSIVE INTERACTIONS
SPIN
STRUCTURE FUNCTIONS
ACCELERATORS
ANGULAR MOMENTUM
BARYONS
BEAMS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FUNCTIONS
HADRONS
HYDRIDES
HYDROGEN COMPOUNDS
INELASTIC SCATTERING
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LINEAR ACCELERATORS
MEASURING INSTRUMENTS
MOMENTUM TRANSFER
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
SCATTERING
SPECTROMETERS
SYMMETRY
TARGETS