QCD status of factorization ansatz for double parton distributions

This article brings attention to what is knowable from perturbative QCD theory on two-parton distribution functions in the light of recent CDF measurements [Phys. Rev. D 56, 3811 (1997)] of the inclusive cross section for double parton scattering. It is shown that the solution of generalized Lipatov-Altarelli-Parisi-Dokshitzer equations for the two-parton distributions is not at all the product of two single-parton distributions, which is usually applied to the current analysis as an ansatz.