Covariant spectator theory ofnpscattering: Effective range expansions and relativistic deuteron wave functions

Abstract

We present the effective range expansions for the ${}^{1}{S}_{0}$ and ${}^{3}{S}_{1}$ scattering phase shifts, and the relativistic deuteron wave functions that accompany our recent high precision fits (with ${\ensuremath{\chi}}^{2}/{N}_{\mathrm{data}}\ensuremath{\simeq}1$) to the 2007 world $\mathit{np}$ data below 350 MeV. The wave functions are expanded in a series of analytical functions (with the correct asymptotic behavior at both large and small arguments) that can be Fourier-transformed from momentum to coordinate space and are convenient to use in any application. A fortran subroutine to compute these wave functions can be obtained from the authors.