1998/12/16 by Maxim V. Polyakov, M. V. Polyakov, Andreas Schäfer +3 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.60.051502
published as Phys.Rev.D60:051502,1999 · LATEX, 6 pages
arxiv created 1998/12/16 · openalex publication_date 1999/08/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The charm quark contribution to the first moment of g1(x,Q 2) is calculated using a heavy mass expansion of the divergence of the singlet axial current. It is shown to be small. 1 The size of a possible intrinsic charm contribution in the proton has been the topic of intensive discussions [1, 2, 3, 4] for many years. It is therefore a natural question to investigate the polarized intrinsic charm distribution in the nucleon [5]. Recently one of us and collaborators argued [6] that earlier treatments of the polarized charm contribution to the η and η ′ [7, 8] were incorrect. In this contribution we extent and adopt that analysis to the nucleon. More precisely we shall focus on the intrinsic charm contribution to the first moment of the spin structure function g1(x, Q2). This is known to be intimately related to the gluonic axial anomaly [9, 10, 11, 12]. It may be expressed as forward limit of G (0) A (t), the form factor in the proton matrix element of the singlet axial current 〈N(p2, λ2)|j (0) 5µ (0)|N(p1, λ1)〉 = ū (λ2)