Baryon magnetic moments: Symmetries and relations

Magnetic moments of the octet baryons are computed using lattice QCD in background magnetic fields, including the first treatment of the magnetically coupled ∑ 0 - ⋀ system. Although the computations are performed for relatively large values of the up and down quark masses, we gain new insight into the symmetries and relations between magnetic moments by working at a three-flavor mass-symmetric point. While the spinflavor symmetry in the large N c limit of QCD is shared by the naive constituent quark model, we find instances where quark model predictions are considerably favored over those emerging in the large N c limit. We suggest further calculations that would shed light on the curious patterns of baryon magnetic moments.