The K-meson form factor and charge radius: linking low-energy data to future high-energy Jefferson Laboratory results

Understand

Starting from a successful model of the pi-meson electromagnetic form factor, we calculate the similar form factor, f_K(Q^2), of the charged K meson for a wide range of the momentum transfer squared, Q^2.

• The only remaining free parameter is to be determined from the measurements of the K-meson charge radius, r_K.
• We fit this single parameter to the published data of the NA-7 experiment which measured f_K(Q^2) at Q^2->0 and determine our preferred range of r_K, which happens to be close to recent lattice results.
• Still, the accuracy in the determination of r_K is poor.