Low-energy positron-H2 collisions in the distributed positron model

A new treatment of short-range correlation effects (the distributed positron model) is used to calculate a variety of scattering results for low-energy positrons on H2. The new treatment of correlation is based on a physically motivated approximation that mimics the effect of virtual positronium formation, but requires no semiempirical parameters or non-physical assumptions. Our total, integrated cross sections are found to be in excellent agreement with measured values. The differential cross sections and eigenphase sums are compared with the results of several recent ab initio calculations. (author)