K\bar{K}-Continuum and Isoscalar Nucleon Form Factors

Abstract

We analyse the isoscalar vector current form factors of the nucleon using dispersion relations. In addition to the usual vector meson poles, we account for the K\bar{K}-continuum contribution by drawing upon a recent analytic continuation of KN scattering amplitudes. For the Pauli form factor all strength in the ϕregion is already given by the continuum contribution, whereas for the Dirac form factor additional strength in the ϕregion is required. The pertinent implications for the leading strangeness moments are demonstrated as well. We derive a reasonable range for the leading moments which is free of assumptions about the asymptotic behavior of the form factors. We also determine the \phiNN coupling constants from the form factor fits and directly from the K\bar{K} -> N\bar{N} partial waves and compare the resulting values.