Year: 2025
Type: preprint
Abstract: We investigate the structure of the nucleon in the presence of a uniform external magnetic field within the framework of light-front holographic QCD (LFHQCD). Starting from the light-front Schrödinger equation for the quark–diquark system, we incorporate the magnetic field through minimal coupling in the transverse holographic variable. This yields additional diamagnetic and Zeeman contributions that effectively renormalize the confining scale and split spin and orbital projections. We derive analytic small-field expressions for the nucleon mass shift, magnetic polarizability, and radius modification, and we provide numerical solutions for the full \(B\)-dependent spectrum. The formalism extends naturally to nucleon electromagnetic form factors, Sachs radii, and transverse charge and magnetization densities, allowing us to predict how these distributions are squeezed by the external field. Our results show that magnetic fields act to compress the nucleon’s transverse profile while inducing characteristic Zeeman splittings for excited states. This work offers the first systematic light-front holographic treatment of nucleon structure in background fields, bridging lattice QCD calculations and forthcoming measurements of hadronic structure in magnetized environments such as heavy-ion collisions and astrophysical systems.
Source: Qeios
DOI: 10.32388/rdx192
Author: Fidele Twagirayezu
Institution: University of California, Los Angeles
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4414088331