Hidden Local Symmetry at One Loop

Abstract

We show that one-loop corrections with the hidden gauge boson loop preserve in the low energy limit all the successful tree level predictions of the hidden local symmetry in the SU(2)${}_L$$\times$SU(2)${}_R$$/$SU(2)${}_V$ chiral Lagrangian. Most amazingly, the $ρ$ meson dominance of the pion electromagnetic form factor survives the one-loop corrections at any momentum, if and only if we take the parameter choice $a=2$. For the choice $a=1$ (``vector limit"), $a$ is not renormalized ($Z_a=1$) and no deviation from $a=1$ is induced by the loop effects of the hidden gauge bosons. Actually, $a=1$ is a nontrivial ultraviolet fixed point.