  We consider a holographic QCD model for light mesons beyond the leading order
in the context of 5-dim gauged linear sigma model on the interval in the
AdS$_5$ space. We include two dimension-6 operators in addition to the
canonical bulk kinetic terms, and study chiral dynamics of $\pi$, $\rho$, $a_1$
and some of their KK modes. As novel features of dim-6 operators, we get
non-vanishing Br$(a_1 \to \pi \gamma)$, the electromagnetic form factor and the
charge radius of a charged pion, which improve the leading order results
significantly and agree well with the experimental results.
