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

Abstract

We calculate the baryon magnetic moments using covariant Chiral Perturbation Theory ($χ$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) $χ$PT and covariant Infrared (IR) $χ$PT. We also analyze the source of this improvement with particular attention on the comparison between the covariant results.

4 pages, 2 figures, accepted for publication in PRL