Work

Nucleon axial radius

Year: 2024

Type: article

Abstract: We present the first systematic study of the relativistic axial-vector four-current distributions inside a nucleon. We show in particular that the slope of the axial form factor G A ( Q 2 ) in the forward limit—conventionally denoted as R A 2 in the literature—does not represent the three-dimensional mean-square axial radius in the Breit frame, but corresponds instead to a contribution to the mean-square spin radius. We derive explicit expressions for the latter in different frames and find in general additional contributions that depend on both the nucleon mass and the forward values of the axial-vector form factors G A ( 0 ) and G P ( 0 ) . This provides an additional key motivation for ongoing lattice quantum chromodynamics (QCD) calculations and future experimental measurements of the induced pseudoscalar form factor G P ( Q 2 ) . Published by the American Physical Society 2024

Source: Physical review. D/Physical review. D.

DOI: 10.1103/physrevd.110.l091503

Authors: Yi Chen, Yang Li, Cédric Lorcé, Qun Wang

Institutions: University of Science and Technology of China, École Polytechnique, Centre de Physique Théorique, Institut Polytechnique de Paris, Anhui University of Science and Technology

Language: English

Topic: Quantum Chromodynamics and Particle Interactions

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Natural Science Foundation of China, Chinese Academy of Sciences

Awards: G1094733649, G2747052105, G328816031, G6851651439