关键词: 低能散射, 中心力场, 零能共振, 冉绍尔-汤森（Ramsauer-Townsend）效应, 零能解

Abstract: Four different results for low energy scattering by a short-range central potential are summarized： 1. The differential cross section is finite and isotropic; 2. The differential ross section is finite but significantly aniso- tropic; 3. Zero energy resonance; 4. Ramsauer-Townsend effect. The conditions for these results are analyzed in detail. They are closely related to the behavior of the zero energy solutions. The results for several simple potentials are presented and the general conclusions are verified.

Key words: low energy scattering, central potential, zero enegy resonance, Ramsauer-Townsend effect, zeroenergy solution