Positron scattering and transport in liquid helium

摘要: In previous papers we have proposed a method for the ab initio calculation of fully differential cross-sections electron scattering in liquids and applied it to liquid argon, xenon krypton. this paper, extend procedure consideration positron helium, which is complicated by annihilation process as well fact that definition region "owned" target atom used previously does not analogue. We explore several physically motivated definitions obtain effective dense fluid. find our calculations pure helium system cannot precisely match experimental measurements, however including small admixture (<0.1%) an impurity, can reasonable agreement gas phase. contrast, do phase measurements. This provides motivation further multiple effects theory.