Electromagnetic structure of charmed baryons in Lattice QCD

Abstract

As a continuation of our recent work on the electromagnetic properties of the doubly charmed Ξ cc baryon, we compute the charge radii and the magnetic moments of the singly charmed Σ c , Ω c and the doubly charmed Ω cc baryons in 2+1 flavor Lattice QCD. In general, the charmed baryons are found to be compact as compared to the proton. The charm quark acts to decrease the size of the baryons to smaller values. We discuss the mechanism behind the dependence of the charge radii on the light valence-and sea-quark masses. The magnetic moments are found to be almost stable with respect to changing quark mass. We investigate the individual quark sector contributions to the charge radii and the magnetic moments. The magnetic moments of the singly charmed baryons are found to be dominantly determined by the light quark and the role of the charm quark is significantly enhanced for the doubly charmed baryons.

Magnetic moments of the spin- 1/2 doubly charmed baryons in covariant baryon chiral perturbation theory

“…Clearly, the lattice QCD results of Ref. [20] and the present BChPT results (based on the same lattice QCD data) are not consistent with the quark model results. This is somehow surprising because one naively expects that the quark model becomes a better approximation of QCD with increasing quark masses as realized in lattice QCD simulations.…”

“…[20], which are given in Table IV. The LEC g a will be determined by three ways: (case 1) by fitting to the lattice QCD simulations, (case 2) by the heavy antiquark diquark symmetry (HADS), or (case 3) by the quark model.…”

“…This indicates that there is a considerable discrepancy between the quark model (the HADS) and the lattice QCD simulations of Ref. [20]. 1 Note that we have used all of the eight sets of lattice QCD data and some of them are obtained with pion masses as large as 700 MeV.…”

“…For m B , we use the SU(3) average of the lattice QCD results, i.e., m B ¼ 3722 MeV [20]. The Ξ cc baryons are contained in a column H, which reads…”

“…In the present work, we will contrast the ChPT results with the lattice QCD data of Ref. [20] to determine the unknown low energy constants (LECs). In many recent studies (see, e.g., Refs.…”