Hadrons in Strong Electric and Magnetic Fields

TL;DR

This paper uses chiral perturbation theory to analyze how strong electric and magnetic fields affect hadrons, revealing non-perturbative effects like hadron decay and proton beta-decay in extreme conditions.

Contribution

It extends chiral perturbation theory to strong fields, deriving new relations and analyzing non-perturbative phenomena such as hadron decay and the inversion of nucleon hierarchy.

Findings

Non-perturbative effects cause hadron decay in strong electric fields.

Strong magnetic fields invert the nucleon hierarchy, enabling proton beta-decay.

First-order perturbation aligns well with non-perturbative results in certain regimes.

Abstract

We use chiral perturbation theory to investigate hadronic properties in strong electric and magnetic fields. A strong-field power counting is employed, and results for pions and nucleons are obtained using Schwinger's proper-time method. In the limit of weak fields, we accordingly recover the well known one-loop chiral perturbation theory results for the electric and magnetic polarizabilities of pions and nucleons. In strong constant fields, we extend the Gell-Mann-Oakes-Renner relation. For the case of electric fields, we find that non-perturbative effects result in hadron decay. For sufficiently strong magnetic fields, the chiral analysis confirms that the nucleon hierarchy becomes inverted giving rise to proton beta-decay. Properties of asymptotic expansions are explored by considering weak field limits. In the regime where the perturbative expansion breaks down, the first-order term gives the best agreement with the non perturbative result.