Measurement of the 3He spin-structure functions and of neutron (3He) spin-dependent sum rules at 0.035 ≤ Q2 ≤ 0.24 GeV2 (original) (raw)
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Phys. Rev. C 108, 035203, 2023
In this study, we performed calculations and analyses of the structure functions of polarized nucleons and light nuclei, specifically 3 He and 3 H, using second-order Feynman diagrams. Our investigation focused on two main aspects: First, we examined the symmetry properties of polarized light sea quarks. Second, we conducted a detailed investigation into the impacts of symmetry breaking on the structure functions of both nucleons and nuclei. To achieve this, we utilized the existing polarized parton distribution functions (polarized PDFs) available in the literature. These PDFs were used to calculate and compare the polarized structure functions g 1 and g 2 of the nuclei. Additionally, we examined and analyzed the Bjorken and Efremov-Leader-Teryaev sum rules by utilizing the moments of the polarized structure functions. The Lorentz color force components, namely F y,n E and F y,n B , were determined using the twist-2, twist-3, and twist-4 matrix elements. When symmetry breaking is applied, it is observed that they have similar magnitudes but opposite signs. Our theoretical predictions for the polarized structure functions of nucleons and light nuclei, taking into account the symmetry breaking of light sea quarks, exhibit better agreement with experimental data.
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2000
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Measurements of the Q 2 dependence of the proton and neutron spin structure functions g p _1 and g n _1
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The correction arising from the three-gluon condensate to the QCD sum rules of the nucleon coupling constant to the axial isoscalar current, g~t, is calculated. It is found that the contribution of the three-gluon condensate can make the sum rules more stable. The resultant theoretical value, g] = 0.58 + 0.20, agrees with the phenomenological estimate. The first moments of the spin structure functions for proton, neutron and deuteron are found to be consistent with the improved Ellis-Jaffe sum rules.
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