Abstract
AbstractUsing dispersion theory, the electromagnetic Sigma-to-Lambda transition form factors are expressed as the product of the pion electromagnetic form factor and the $$\Sigma {\bar{\varLambda }}\rightarrow \pi \pi $$
Σ
Λ
¯
→
π
π
scattering amplitudes with the latter estimated from SU(3) chiral perturbation theory including the baryon decuplet as explicit degrees of freedom. The contribution of the $$K{\bar{K}}$$
K
K
¯
channel is also taken into account and the $$\pi \pi $$
π
π
–$$K{\bar{K}}$$
K
K
¯
coupled-channel effect is included by means of a two-channel Muskhelishvili–Omnès representation. It is found that the electric transition form factor shows a significant shift after the inclusion of the $$K{\bar{K}}$$
K
K
¯
channel, while the magnetic transition form factor is only weakly affected. However, the $$K{\bar{K}}$$
K
K
¯
effect on the electric form factor is obscured by the undetermined coupling $$h_A$$
h
A
in the three-flavor chiral Lagrangian. The error bands of the Sigma-to-Lambda transition form factors from the uncertainties of the couplings and low-energy constant in three-flavor chiral perturbation theory are estimated by a bootstrap sampling method.
Funder
National Natural Science Foundation of China
Deutsche Forschungsgemeinschaft
Bundesministerium für Bildung und Forschung
Volkswagen Foundation
Publisher
Springer Science and Business Media LLC
Subject
Nuclear and High Energy Physics