Transverse momentum dependence of the quark helicity distributions and the Cahn effect in double-spin asymmetry A{sub LL} in semiinclusive DIS

Journal Article · Sun Oct 01 04:00:00 EDT 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.74.074015· OSTI ID:20871314

Anselmino, M ^[1]; Efremov, A ^[2]; Kotzinian, A ^[2]; Parsamyan, B ^[3]

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1. Dipartimento di Fisica Teorica, Universita di Torino, and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Turin (Italy)
2. JINR, 141980 Dubna (Russian Federation)
3. Dipartimento di Fisica Generale, Universita di Torino, and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Turin (Italy)

Within the LO QCD parton model of Semi-Inclusive Deep Inelastic Scattering, lN{yields}lhX, with unintegrated quark distribution and fragmentation functions, we study the P{sub hT} dependence of the double longitudinal-spin asymmetry A{sub LL}. We include 1/Q kinematic corrections, which induce an azimuthal modulation of the asymmetry, analogous to the Cahn effect in unpolarized SIDIS. We show that a study of A{sub LL} and of the weighted DSA A{sub LL}{sup cos{phi}{sub h}} allows to extract the transverse momentum dependence of the unintegrated helicity distribution function g{sub 1L}{sup q}(x,k{sub perpendicular}) [or {delta}q(x,k{sub perpendicular})]. Predictions, based on some models for the unknown functions, are given for ongoing COMPASS, HERMES and JLab experiments.

• OSTI ID: 20871314
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 74; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
CEBAF ACCELERATOR
CORRECTIONS
DEEP INELASTIC SCATTERING
DISTRIBUTION
DISTRIBUTION FUNCTIONS
GLUON MODEL
HELICITY
MODULATION
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
QUANTUM CHROMODYNAMICS
QUARK MODEL
QUARKS
SEMI-EXCLUSIVE INTERACTIONS
SPIN
TRANSVERSE MOMENTUM