Pion form factor in the Kroll-Lee-Zumino model

Kroll-Lee-Zumino quantum field theory of pionic interactions: rho-meson propagator at two-loop level and electromagnetic pion form factor

The Kroll-Lee-Zumino renormalizable Abelian quantum field theory of pionic strong interactions is used to compute the rho-meson propagator at the two-loop level.

Scalar form factor of the pion in the Kroll-Lee-Zumino field theory

The renormalizable Kroll-Lee-Zumino field theory of pions and a neutral rho-meson is used to determine the scalar form factor of the pion in the space-like region at next-to-leading order. Perturbative calculations in this framework are parameter free, as the masses and the rho-pion-pion coupling are known from experiment. Results compare favourably with lattice QCD calculations.

Scalar radius of the pion in the Kroll-Lee-Zumino renormalizable theory

The Kroll-Lee-Zumino renormalizable Abelian quantum field theory of pions and a massive rho-meson is used to calculate the scalar radius of the pion at next to leading (one loop) order in perturbation theory. Due to renormalizability, this determination involves no free parameters. The result is $<r^2_π>_s = 0.40 {fm}^2$. This value gives for $\bar{\ell}_4$, the low energy constant of chiral perturbation theory, $\bar{\ell}_4 = 3.4$, and $F_π/F = 1.05$, where F is the pion decay constant in the chiral limit. Given the level of accuracy in the masses and the $ρππ$ coupling, the only sizable unc…

Electromagnetic and Scalar Pion form factor in the Kroll-Lee-Zumino model

The renormalizable Abelian quantum field theory model of Kroll, Lee, and Zumino is used at the one loop level to compute vertex corrections to the tree-level, Vector Meson Dominance (VMD) electromagnetic pion form factor. These corrections, together with the one-loop vacuum polarization contribution, imply a resulting electromagnetic pion form factor in excellent agreement with data in the whole range of accessible momentum transfers in the space-like region. The time-like form factor, which reproduces the Gounaris-Sakurai formula at and near the rho-meson peak, is unaffected by the vertex cor…

Electromagnetic Form Factors of Hadrons in Quantum Field Theories

In this talk, recent results are presented of calculations of electromagnetic form factors of hadrons in the framework of two quantum field theories (QFT), (a) Dual-Large $N_c$ QCD (Dual-$QCD_\infty$) for the pion, proton, and $Δ(1236)$, and (b) the Kroll-Lee-Zumino (KLZ) fully renormalizable Abelian QFT for the pion form factor. Both theories provide a QFT platform to improve on naive (tree-level) Vector Meson Dominance (VMD). Dual-$QCD_\infty$ provides a tree-level improvement by incorporating an infinite number of zero-width resonances, which can be subsequently shifted from the real axis t…

π介子与ρ介子相互作用的量子场论

A Quantum Field Theory for the interaction of pions and rhos

本文扩展Kroll-Lee-Zumino模型，引入带电ρ介子与中性π介子，利用SU(2)规范群与Higgs机制生成质量，计算π-π散射长度并与实验相符，重整化了一圈修正图。