Modification of the Effective-Range Formula for Nucleon-Nucleon Scattering

Abstract

The effective-range formula is welt known to be a usefal description of low-energy scattering phase shifts. However, except at the limit of zero kinetic energy, the effective-range formula is, in general, not exact. A studv is reported of the deviation from the effectiverange formula in light of the analytic structure of pantial-wave amplitudes as suggested by Mandelstam (Phys. Rev. 112, 1344(1958)). Consideration is given to the s-wave N-N scattering in both the singlet and the triplet states. (W.D.M.)