Electromagnetic form factors of octet baryons with the nonlocal chiral effective theory

Abstract

The electromagnetic form factors of octet baryons are investigated with the nonlocal chiral effective theory. The nonlocal interaction generates both the regulator, which makes the loop integral convergent, and the Q 2 dependence of form factors at tree level. Both octet and decuplet intermediate states are included in the oneloop calculation. The momentum dependence of baryon form factors is studied up to 1 GeV 2 with the same number of parameters as for the nucleon form factors. The obtained magnetic moments of all the octet baryons as well as the radii are in good agreement with the experimental data and/or lattice simulation.

The $Σ$ and $Ξ$ electromagnetic form factors in the extended vector meson dominance model

“…[2] it was attracted from the elastic scattering of high energy Σ − off electrons from carbon and copper targets using the CERN hyperon beam, where these events are identified using a maximum likelihood technique exploring the kinematical relations of the scattered particles. Theoretical calculations with chiral perturbation theory (ChPT) [40,56] and the nonlocal chiral effective theory (ChET) [57], and chiral constituent quark model (ChCQM) [58] are also listed for comparison. On can see that the orderings of the most charge radii calculated by other works are in agreement with our results.…”

Sea quark contributions to the electromagnetic form factors of $Σ$ hyperons

“…Besides, the physical masses are employed, for mesons, octet and decuplet baryons. The covariant regulator is chosen to be a dipole form [34,35]…”

“…In recent years, we proposed a nonlocal chiral effective theory, which makes it possible to study the form factors at relatively large Q 2 [33][34][35]. With the introduction of the gauge links, the nonlocal Lagrangians are locally gauge invariant.…”

Generalized parton distributions of sea quarks in the proton from nonlocal chiral effective theory

“…( 1), to compute the effects of meson loops on the magnetic GPD E requires an additional contribution to the Lagrangian for the magnetic interaction, which enters at a higher order. The magnetic Lagrangian for the octet, decuplet and octet-decuplet transition interaction is given by [41,42,[63][64][65]]…”

“…where we adopt the notation c 1 , c 2 and c 3 for the octet baryon interaction from Ref. [63] and c 4 for the octet-decuplet transition, which corresponds to the constant µ T in Refs. [41,42],…”