DEEP-INELASTIC SCATTERING OF POLARIZED ELECTRONS BY POLARIZED HE-3 AND THE STUDY OF THE NEUTRON SPIN STRUCTURE
Citation
Pl. Anthony et al., DEEP-INELASTIC SCATTERING OF POLARIZED ELECTRONS BY POLARIZED HE-3 AND THE STUDY OF THE NEUTRON SPIN STRUCTURE, Physical review. D. Particles and fields, 54(11), 1996, pp. 6620-6650
Categorie Soggetti
Physics, Particles & Fields
SICI code
0556-2821(1996)54:11<6620:DSOPEB>2.0.ZU;2-N
Abstract
The neutron longitudinal and transverse asymmetries A(1)(n) and A(2)(n
) have been extracted from deep inelastic scattering of polarized elec
trons by a polarized He-3 target at incident energies of 19.42, 22.66,
and 25.51 GeV. The measurement allows for the determination of the ne
utron spin structure functions g(1)(n)(x,Q(2)) and g(2)(x,Q(2)) over
the range 0.03<x<0.6 at an average Q(2) of 2 (GeV/c)(2). The data are
used for the evaluation of the Ellis-Jaffe and Bjorken sum rules. The
neutron spin structure function g(1)(n)(x,Q(2)) is small and negative
within the range of our measurement, yielding an integral f(0.03)(0.6)
g(1)(n)(x)dx = -0.028 +/- 0.006 (stat) +/- 0.006 (syst). Assuming Regg
ae behavior at low x, we extract Gamma(1)(n) = f(0)(1)g(1)(n)(x)dx = -
0.031 +/- 0.006 (stat) +/- 0.009 (syst). Combined with previous proton
integral results from SLAC experiment E143, we find Gamma(1)(p) - Gam
ma(1)(n) = 0.160 +/- 0.015 in agreement with the Bjorken sum rule pred
iction Gamma(1)(p) - Gamma(1)(n) = 0.176 +/- 0.008 at a Q(2) value of
3 (GeV/c)(2) evaluated using alpha(s) = 0.32 +/- 0.05.