6533b7d8fe1ef96bd126acce

RESEARCH PRODUCT

form factor at order of chiral perturbation theory

P. PostKarl Schilcher

subject

PhysicsCouplingNuclear and High Energy PhysicsChiral perturbation theoryMesonCharge radiusHigh Energy Physics::LatticeForm factor (quantum field theory)Order (group theory)Direct couplingMathematical physicsElectromagnetic tensor

description

Abstract This paper describes the calculation of the electromagnetic form factor of the K 0 meson at order p 6 of chiral perturbation theory which is the next-to-leading order correction to the well-known p 4 result achieved by Gasser and Leutwyler. On the one hand, at order p 6 the chiral expansion contains 1- and 2-loop diagrams which are discussed in detail. Especially, a numerical procedure for calculating the irreducible 2-loop graphs of the sunset topology is presented. On the other hand, the chiral Lagrangian L (6) produces a direct coupling of the K 0 current with the electromagnetic field tensor. Due to this coupling one of the unknown parameters of L (6) occurs in the contribution to the K 0 charge radius.

https://doi.org/10.1016/s0550-3213(00)00769-0