Leading SU(3)-breaking corrections to the baryon magnetic moments in Chiral Perturbation Theory

TL;DR

This paper computes baryon magnetic moments using covariant Chiral Perturbation Theory with SU(3) breaking effects, achieving improved agreement with experimental data compared to previous methods.

Contribution

It demonstrates that covariant $ ext{SU}(3)$-breaking corrections in $ ext{Chiral Perturbation Theory}$ significantly enhance the description of baryon magnetic moments.

Findings

Improved fit to experimental magnetic moments with covariant $ ext{ChPT}$.

Leading SU(3) breaking effects are crucial for accurate predictions.

Covariant $ ext{ChPT}$ outperforms Heavy Baryon and Infrared $ ext{ChPT}$ methods.

Abstract

We calculate the baryon magnetic moments using covariant Chiral Perturbation Theory ($\chi$PT) within the Extended-on-mass-shell (EOMS) renormalization scheme. By fitting the two available low-energy constants (LECs), we improve the Coleman-Glashow description of the data when we include the leading SU(3) breaking effects coming from the lowest-order loops. This success is in dramatic contrast with previous attempts at the same order using Heavy Baryon (HB) $\chi$PT and covariant Infrared (IR) $\chi$PT. We also analyze the source of this improvement with particular attention on the comparison between the covariant results.