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Title: Precise determination of the spin structure function g{sub 1} of the proton, deuteron, and neutron.

Abstract

Precise measurements of the spin structure functions of the proton g{sub 1}{sup p}x,Q{sup 2} and deuteron g{sub 1}{sup d}x,Q{sup 2} are presented over the kinematic range 0.0041 <= x <= 0.9 and 0.18 GeV{sup 2} <= Q{sup 2} <= 20 GeV{sup 2}. The data were collected at the HERMES experiment at DESY, in deep-inelastic scattering of 27.6 GeV longitudinally polarized positrons off longitudinally polarized hydrogen and deuterium gas targets internal to the HERA storage ring. The neutron spin structure function g{sub 1}{sup n} is extracted by combining proton and deuteron data. The integrals of g{sub 1}{sup p,d} at Q{sup 2} = 5 GeV{sup 2} are evaluated over the measured x range. Neglecting any possible contribution to the g{sub 1}{sup d} integral from the region x <= 0.021, a value of 0.330 {+-} 0.011(theo) {+-} 0.025(exp) {+-} 0.028(evol) is obtained for the flavor-singlet axial charge a{sub 0} in a leading-twist next-to-next-to-leading-order analysis.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE; FOR; National Science Foundation (NSF)
OSTI Identifier:
940204
Report Number(s):
ANL/PHY/JA-57155
Journal ID: ISSN 1550-7998; TRN: US0807047
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Rev. D; Journal Volume: 75; Journal Issue: Jan. 1, 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
08 HYDROGEN; 43 PARTICLE ACCELERATORS; DEUTERIUM; DEUTERONS; HERA STORAGE RING; HYDROGEN; NEUTRONS; POSITRONS; PROTONS; SCATTERING; SPIN; STRUCTURE FUNCTIONS; TARGETS

Citation Formats

Airapetian, A., Akopov, N., Akopov, Z., Andrus, A., Aschenauer, E. C., El Alaoui, M. A., Jackson, H. E., Reimer, P. E., Sanjiev, I., The HERMES Collaboration, Physics, Univ. of Michigan, Yerevan Physics Inst., Univ. of Illinois, and DESY Lab. Precise determination of the spin structure function g{sub 1} of the proton, deuteron, and neutron.. United States: N. p., 2007. Web. doi:10.1103/PhysRevD.75.012007.
Airapetian, A., Akopov, N., Akopov, Z., Andrus, A., Aschenauer, E. C., El Alaoui, M. A., Jackson, H. E., Reimer, P. E., Sanjiev, I., The HERMES Collaboration, Physics, Univ. of Michigan, Yerevan Physics Inst., Univ. of Illinois, & DESY Lab. Precise determination of the spin structure function g{sub 1} of the proton, deuteron, and neutron.. United States. doi:10.1103/PhysRevD.75.012007.
Airapetian, A., Akopov, N., Akopov, Z., Andrus, A., Aschenauer, E. C., El Alaoui, M. A., Jackson, H. E., Reimer, P. E., Sanjiev, I., The HERMES Collaboration, Physics, Univ. of Michigan, Yerevan Physics Inst., Univ. of Illinois, and DESY Lab. Mon . "Precise determination of the spin structure function g{sub 1} of the proton, deuteron, and neutron.". United States. doi:10.1103/PhysRevD.75.012007.
@article{osti_940204,
title = {Precise determination of the spin structure function g{sub 1} of the proton, deuteron, and neutron.},
author = {Airapetian, A. and Akopov, N. and Akopov, Z. and Andrus, A. and Aschenauer, E. C. and El Alaoui, M. A. and Jackson, H. E. and Reimer, P. E. and Sanjiev, I. and The HERMES Collaboration and Physics and Univ. of Michigan and Yerevan Physics Inst. and Univ. of Illinois and DESY Lab.},
abstractNote = {Precise measurements of the spin structure functions of the proton g{sub 1}{sup p}x,Q{sup 2} and deuteron g{sub 1}{sup d}x,Q{sup 2} are presented over the kinematic range 0.0041 <= x <= 0.9 and 0.18 GeV{sup 2} <= Q{sup 2} <= 20 GeV{sup 2}. The data were collected at the HERMES experiment at DESY, in deep-inelastic scattering of 27.6 GeV longitudinally polarized positrons off longitudinally polarized hydrogen and deuterium gas targets internal to the HERA storage ring. The neutron spin structure function g{sub 1}{sup n} is extracted by combining proton and deuteron data. The integrals of g{sub 1}{sup p,d} at Q{sup 2} = 5 GeV{sup 2} are evaluated over the measured x range. Neglecting any possible contribution to the g{sub 1}{sup d} integral from the region x <= 0.021, a value of 0.330 {+-} 0.011(theo) {+-} 0.025(exp) {+-} 0.028(evol) is obtained for the flavor-singlet axial charge a{sub 0} in a leading-twist next-to-next-to-leading-order analysis.},
doi = {10.1103/PhysRevD.75.012007},
journal = {Phys. Rev. D},
number = Jan. 1, 2007,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}