Gluon Polarisation in the Nucleon from High Transverse Momentum Hadron Pairs at COMPASS

Journal Article · Tue Aug 04 04:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3215658· OSTI ID:21316922

Kurek, Krzysztof ^[1]

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1. A. Soltan Institute for Nuclear Studies, Hoza 69, 00-681 (Poland)

The main goal of the COMPASS spin physics programme is the measurement of the helicity contribution of the gluons, {delta}G/G, to the nucleon spin. It is determined from the longitudinal spin asymmetry in the scattering of 160 GeV polarised muons off a polarised LiD target. The new analysis and new COMPASS {delta}G/G result obtained from high transverse momentum hadron pairs for Q{sup 2}>1(GeV/c){sup 2} is presented. The weighted method based on a Neural Network approach is discussed. The result of {delta}G/G 0.08{+-}0.10(stat){+-}0.05(syst)disfavors a large positive contribution to the nucleon spin for a gluon momentum fraction around 0.08 and agrees with the previously obtained result from the analysis for the small Q{sup 2} kinematical region (Q{sup 2}<1(GeV/c){sup 2})

• OSTI ID: 21316922
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1149; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
DEUTERIUM TARGET
FOUR MOMENTUM TRANSFER
GEV RANGE
GLUONS
HELICITY
MULTIPARTICLE SPECTROMETERS
MUON BEAMS
MUON REACTIONS
MUON-NUCLEON INTERACTIONS
NEURAL NETWORKS
PARTICLE IDENTIFICATION
POLARIZATION
POLARIZED BEAMS
POLARIZED TARGETS
QUANTUM CHROMODYNAMICS
SPIN
TRANSVERSE MOMENTUM