Hybrid exotic meson with J^{PC}=1^{-+} in AdS/QCD

We investigate the hybrid exotic meson with $J^{PC}=1^{-+}$ within the framework of an AdS/QCD model. Introducing a holographic field dual to the operator for hybrid exotic meson, we obtain the eigen-value equation for its mass. Fixing all free parameters by QCD observables such as the $rho$-meson mass, we predict the masses of the hybrid exotic meson. The results turn out to be $1476 mathrm{MeV}$ for the ground state, and $2611 mathrm{MeV}$ for the first excited one. Being compared with the existing experimental data for the $pi_1(1400)$, which is known to be $m_{pi_1} = 1351pm30 mathrm{MeV}$, the present result seems to be qualitative in agreement with it. We also predict the decay constant of $pi_1$(1400): $F_{pi_1}= 10.6$ MeV.