We propose a phenomenological Lagrangian for the decay of the $\mathrm{S}\mathrm{U}(3)$ nonets of the axial-vector mesons of $J^{PC}=1^{+-},1^{++}$ into a vector meson and a pseudoscalar constructed with tensor fields for the vector and axial-vector mesons. The formulation leads to a good reproduction of the different decay branching ratios and assuming vector meson dominance (VMD) it also leads to good results for the radiative decay of the $a_1$ into pion and photon, and in agreement with the structure proposed in the chiral tensor formulation of radiative decay of axial-vector mesons. The two $\mathrm{S}\mathrm{U}(3)$ parameters and the mixing angle of $K_{1A}$ and $K_{1B}$ needed to give the physical $K_1(1270)$ and $K_1(1400)$ resonances are also determined.

• Received 3 December 2003

DOI:https://doi.org/10.1103/PhysRevD.70.094006