Transition form factors and light-cone distribution amplitudes of pseudoscalar mesons in the chiral quark model

It is shown that a chiral quark model of the Nambu–Jona-Lasinio type can be used to describe “soft”-momenta parts of the amplitudes with large momentum transfer. As a sample, the processes \gamma^* --> \gamma (\pi,\eta,\eta’) where one of the photons, \gamma^, has large space-like virtuality is investigated. The \gamma^ --> \gamma (\pi,\eta,\eta’)$ transition form factors are calculated for a wide region of transferred momenta. The results are consistent with the calculations performed in the instanton-induced chiral quark model and agree with experimental data. The distribution amplitudes of pseudoscalar mesons are derived.