Details

Autor(en) / Beteiligte

• Cheng, P.
• Yu, Y.
• Xing, H.-Y.
• Chen, C.
• Cui, Z.-F.
• Roberts, C.D.

Titel

Perspective on polarised parton distribution functions and proton spin

Ist Teil von

• Physics letters. B, 2023-09, Vol.844, p.138074, Article 138074

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Quelle

Elsevier ScienceDirect Journals Collection

Beschreibungen/Notizen

• Supposing there exists an effective charge which defines an evolution scheme for both unpolarised and polarised parton distribution functions (DFs) that is all-orders exact and using Ansätze for hadron-scale proton polarised valence quark DFs, constrained by flavour-separated axial charges and insights from perturbative quantum chromodynamics, predictions are delivered for all proton polarised DFs at the scale ζC2=3 GeV2. The pointwise behaviour of the predicted DFs and, consequently, their moments, compare favourably with results inferred from data. Notably, flavour-separated singlet polarised DFs are small. On the other hand, the polarised gluon DF, ΔG(x;ζC), is large and positive. Using our result, we predict ∫0.051dxΔG(x;ζC)=0.214(4) and that experimental measurements of the proton flavour-singlet axial charge should return a0E(ζC)=0.33(2).