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


Bray, Bruce D. (1998) A Determination of the Neutron Spin Structure Function gⁿ₁ with the 1995 HERMES Data. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/pr7a-ed83.


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 gn110(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.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Physics
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Filippone, Bradley W.
Thesis Committee:
  • Filippone, Bradley W. (chair)
  • Hughes, Emlyn Willard
  • Politzer, Hugh David
  • Weinstein, Alan Jay
Defense Date:23 July 1997
Record Number:CaltechTHESIS:02222021-234525490
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14092
Deposited By: Kristofer Jolley
Deposited On:23 Feb 2021 23:00
Last Modified:26 Oct 2021 18:43

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