  A scenario is investigated in which the leading-twist pion distribution
amplitude phi_pi (x) is approximated by the pion decay constant f_pi for all
essential values of the light-cone fraction x. A model for the light-front wave
function Psi(x,k_perp) is proposed that produces such a distribution amplitude
and has a rapidly decreasing (exponential for definiteness) dependence on the
light-front energy combination k_perp^2/x(1-x). It is shown that this model
easily reproduces the fit of recent large-Q^2 BaBar data on the photon-pion
transition form factor. Some aspects of scenario with flat pion distribution
amplitude are discussed.
