Perturbative limit of the two-pion light-cone distribution amplitude - art. no. 074029

We consider pion pair production in two-photon collisions gamma* gamma --> pi(+) pi(-) at large photon virtuality Q(2) and center-of-mass energy root s in the hard-scattering picture. in the limit where s is large but s << Q( 2) we derive an expression for the two-pion light-cone distribution in term s of the conventional pion distribution amplitudes. Our result reproduces t he well-known scaling behavior, helicity selection rule and symmetry relati ons in this regime.