(Astro)-Particles Physics, Photo Conversion Materials, Student Lab and Education
المصدر:
Physical review / D 75(1), 012007 (2007). doi:10.1103/PhysRevD.75.012007 Physical Review D, 75(1). American Physical Society Airapetian, A, Blok, H P, Hesselink, W H A, van der Nat, P B & Wang, S 2007, ' Precise determination of the spin structure function g(1) of the proton, deuteron, and neutron ', Physical Review D, vol. 75, no. 1 . https://doi.org/10.1103/PhysRevD.75.012007
Precise measurements of the spin structure functions of the proton $g_1^p(x,Q^2)$ and deuteron $g_1^d(x,Q^2)$ are presented over the kinematic range $0.0041 \leq x \leq 0.9$ and $0.18 $ GeV$^2$ $\leq Q^2 \leq 20$ GeV$^2$. 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 $g_1^n$ is extracted by combining proton and deuteron data. The integrals of $g_1^{p,d}$ at $Q^2=5$ GeV$^2$ are evaluated over the measured $x$ range. Neglecting any possible contribution to the $g_1^d$ integral from the region $x \leq 0.021$, a value of $0.330 \pm 0.011\mathrm{(theo.)}\pm0.025\mathrm{(exp.)}\pm 0.028$(evol.) is obtained for the flavor-singlet axial charge $a_0$ in a leading-twist NNLO analysis.
