A Determination of the Neutron Spin Structure Function gⁿ₁ with the 1995 HERMES Data

Author: Bray, Bruce D.

Year: 1998

Degree: Dissertation (Ph.D.)

Advisor: Filippone, Bradley W.

Committee Members: Filippone, Bradley W.; Hughes, Emlyn Willard; Politzer, Hugh David; Weinstein, Alan Jay

Option: Physics

DOI: 10.7907/pr7a-ed83

Abstract

The internal spin structure of the neutron was studied in deep inelastic scattering of longitudinally polarized positrons from a polarized 3He target in the HERMES spectrometer at the DESY storage ring. The spin asymmetry was measured at an energy of 27.52 GeV in the range 0.023 ˂ x ˂ 0.8 at an average Q2 of 2.5 (GeV/c)2. The results are evolved to a constant Q2 of 2.5 (GeV /c)2 and arc in agreement with the world data for the spin dependent structure function gn 1. The integral of gn1 (ʃ10(x, Q2 = 2.5(Gev/c)2)dx) is found to he -0.036 ± 0.012(stat) ± 0.005(syst) ± 0.003(extrapolation) which is 2 standard deviations from the Ellis-Jaffe Sum Rule and, combined with the world data for the proton, is in good agreement with the Bjorken Sum Rule.

Combining this result with the weak coupling constants F and D implies the quarks carry (38 ± 11)% of the nucleon spin and the polarization of the strange sea represents (-7 ± 4)% of the nucleon spin.

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