Quark structure of the pion and pion form factor

We consider the pion structure in the region of low and moderately high momentum transfers: at low Q², the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, Q²=10--25 GeV², the pion form factor is calculated within perturbative QCD taking into account one-gluon hard exchange. Using the data on the pion form factor at Q²3 GeV² and the pion axial-vector decay constant, we reconstruct the pion wave function in the soft and intermediate regions. This very wave function combined with the one-gluon hard scattering amplitude allows a calculation of the pion form factor in the hard region Q²=10--25 GeV². A specific feature of the reconstructed pion wave function is a quasizone character of the qq{} excitations. On the basis of the obtained pion wave function and the data on deep inelastic scattering off the pion, the valence quark distribution in a constitutent quark is determined.