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Title: Flavor decomposition of the polarized quark distributions in the nucleon from inclusive and semi-inclusive deep-inelastic scattering.

Abstract

Spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons have been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and {sup 3}He targets, in the kinematic range 0.023<x<0.6 and 1 GeV{sup 2}<Q{sup 2}<10 GeV{sup 2}. Polarized quark distributions are extracted as a function of x for up (u + {ovr u}) and down (d + {ovr d} ) flavors. The up quark polarization is positive and the down quark polarization is negative in the measured range. The polarization of the sea is compatible with zero. The first moments of the polarized quark distributions are presented. The isospin non-singlet combination {Delta}q{sub 3} is consistent with the prediction based on the Bjorken sum rule. The moments of the polarized quark distributions are compared to predictions based on SU(3){sub f} flavor symmetry and to a prediction from lattice QCD.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); FOR
OSTI Identifier:
943120
Report Number(s):
ANL/PHY/JA-37662
Journal ID: ISSN 0370-2693; PYLBAJ; TRN: US201002%%607
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Phys. Lett. B
Additional Journal Information:
Journal Volume: B; Journal Issue: 464 ; Oct. 7, 1999; Journal ID: ISSN 0370-2693
Country of Publication:
United States
Language:
ENGLISH
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CROSS SECTIONS; DECOMPOSITION; DEEP INELASTIC SCATTERING; FLAVOR MODEL; HADRONS; HELIUM; HYDROGEN; ISOSPIN; NUCLEONS; POLARIZATION; POLARIZED TARGETS; POSITRONS; PRODUCTION; QUANTUM CHROMODYNAMICS; QUARKS; SPIN; SUM RULES; SYMMETRY

Citation Formats

Ackerstaff, K, Airapetian, A, Akopov, N, Akushevich, I, Amarian, M, De Schepper, D, Gao, H, Hansen, J -O, Jackson, H E, Jones, C, Makins, N C. R., O'Neill, T G, Potterveld, D H, HERMES Collaboration, Physics, DESY,, Yerevan Physics Inst., Zeuthen, DESY, National Inst. voor Kernfysica en Hoge-Energiefysica, Inst. Superiore di Sanita, Massachusetts Inst. of Tech., and Univ. of Illinois. Flavor decomposition of the polarized quark distributions in the nucleon from inclusive and semi-inclusive deep-inelastic scattering.. United States: N. p., 1999. Web. doi:10.1016/S0370-2693(99)00964-8.
Ackerstaff, K, Airapetian, A, Akopov, N, Akushevich, I, Amarian, M, De Schepper, D, Gao, H, Hansen, J -O, Jackson, H E, Jones, C, Makins, N C. R., O'Neill, T G, Potterveld, D H, HERMES Collaboration, Physics, DESY,, Yerevan Physics Inst., Zeuthen, DESY, National Inst. voor Kernfysica en Hoge-Energiefysica, Inst. Superiore di Sanita, Massachusetts Inst. of Tech., & Univ. of Illinois. Flavor decomposition of the polarized quark distributions in the nucleon from inclusive and semi-inclusive deep-inelastic scattering.. United States. https://doi.org/10.1016/S0370-2693(99)00964-8
Ackerstaff, K, Airapetian, A, Akopov, N, Akushevich, I, Amarian, M, De Schepper, D, Gao, H, Hansen, J -O, Jackson, H E, Jones, C, Makins, N C. R., O'Neill, T G, Potterveld, D H, HERMES Collaboration, Physics, DESY,, Yerevan Physics Inst., Zeuthen, DESY, National Inst. voor Kernfysica en Hoge-Energiefysica, Inst. Superiore di Sanita, Massachusetts Inst. of Tech., and Univ. of Illinois. 1999. "Flavor decomposition of the polarized quark distributions in the nucleon from inclusive and semi-inclusive deep-inelastic scattering.". United States. https://doi.org/10.1016/S0370-2693(99)00964-8.
@article{osti_943120,
title = {Flavor decomposition of the polarized quark distributions in the nucleon from inclusive and semi-inclusive deep-inelastic scattering.},
author = {Ackerstaff, K and Airapetian, A and Akopov, N and Akushevich, I and Amarian, M and De Schepper, D and Gao, H and Hansen, J -O and Jackson, H E and Jones, C and Makins, N C. R. and O'Neill, T G and Potterveld, D H and HERMES Collaboration and Physics and DESY, and Yerevan Physics Inst. and Zeuthen, DESY and National Inst. voor Kernfysica en Hoge-Energiefysica and Inst. Superiore di Sanita and Massachusetts Inst. of Tech. and Univ. of Illinois},
abstractNote = {Spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons have been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and {sup 3}He targets, in the kinematic range 0.023<x<0.6 and 1 GeV{sup 2}<Q{sup 2}<10 GeV{sup 2}. Polarized quark distributions are extracted as a function of x for up (u + {ovr u}) and down (d + {ovr d} ) flavors. The up quark polarization is positive and the down quark polarization is negative in the measured range. The polarization of the sea is compatible with zero. The first moments of the polarized quark distributions are presented. The isospin non-singlet combination {Delta}q{sub 3} is consistent with the prediction based on the Bjorken sum rule. The moments of the polarized quark distributions are compared to predictions based on SU(3){sub f} flavor symmetry and to a prediction from lattice QCD.},
doi = {10.1016/S0370-2693(99)00964-8},
url = {https://www.osti.gov/biblio/943120}, journal = {Phys. Lett. B},
issn = {0370-2693},
number = 464 ; Oct. 7, 1999,
volume = B,
place = {United States},
year = {Thu Oct 07 00:00:00 EDT 1999},
month = {Thu Oct 07 00:00:00 EDT 1999}
}