Cross section and polarization observables for the reaction e{sup +}+e{sup -}{yields}a{sub 1}(1260)+{pi}

A model independent formalism for the electron positron annihilation reaction e{sup +}+e{sup -}{yields}a{sub 1}(1260)+{pi} has been derived. The differential and total cross sections and the elements of the spin-density matrix of the a{sub 1}-meson were calculated in terms of the electromagnetic form factors of the corresponding {gamma}*a{sub 1}{pi} current. Simple models of a{sub 1} form factors have been fitted to the available cross section data and they allow to give numerical predictions for the different observables.