Diquark and nucleons under strong magnetic fields in the NJL model

TL;DR

This paper investigates how strong magnetic fields affect nucleons and diquarks using the NJL model, providing numerical predictions for their masses and magnetic moments and comparing with other theoretical approaches.

Contribution

It introduces a detailed NJL model analysis of nucleons and diquarks under strong magnetic fields, including analytical and numerical methods for mass and magnetic moment calculations.

Findings

Numerical predictions for diquark and nucleon masses under strong magnetic fields.

Comparison of NJL model results with Chiral Perturbation Theory and Lattice QCD.

Estimated nucleon magnetic moments in strong magnetic environments.

Abstract

We study the description of nucleons and diquarks in the presence of a uniform strong magnetic field within the framework of the two-flavor Nambu-Jona--Lasinio (NJL) model. Diquarks are constructed through the resummation of quark loop chains using the random phase approximation, while nucleons are treated as bound quark-diquark states described by a relativistic Fadeev equation, using the static approximation for quark exchange interactions. For charged particles, analytical calculations are performed using the Ritus eigenfunction method, which properly takes into account the breakdown of translation invariance that arises from the presence of Schwinger phases. Within this scheme, for definite model parametrizations we obtain numerical predictions for diquark and nucleon masses, which are compared with Chiral Perturbation Theory and Lattice QCD results. In addition, numerical estimations for nucleon magnetic moments are obtained.