PRINCIPAL QUANTUM NUMBER DEPENDENCE FOR POSITRON-HYDROGEN SCATTERING

Over the last two decades, there has been considerable interest in the electron-atom and positron-atom scattering problems. Most of this wor k has concentrated on elastic scattering and excitation of the lowest energy states. However, due to recent technological advances, it is no w becoming possible to examine the excitation of higher lying states e xperimentally. The important question then concerns whether these high er states contain new information. Earlier, we have examined this issu e for electron-hydrogen scattering. The purpose of this work is to exa mine the N dependence for positron-hydrogen scattering. The second-ord er distorted-wave method has been used to calculate scattering amplitu des for excitation of s- and p-states of hydrogen for N = 2, 3, 4, 5 a nd 6. The N dependence of the integrated cross sections, differential cross sections and polarization fractions will be discussed for energi es up to 1 keV and the results will be compared with those for electro n-hydrogen scattering.