Differential cross section for n-p elastic scattering in the angular region 50° * <180° at 459 MeV

The differential cross section for n-p elastic scattering at 459 MeV in the c.m. angular region 50\ifmmode^\circ\else\textdegree\fi{}${\mathrm{\ensuremath{\theta}}}^{\mathrm{*}}$180\ifmmode^\circ\else\textdegree\fi{} has been measured with high statistical precision and good relative accuracy. The uncertainty in the absolute normalization (based on the simultaneously measured yield of deuterons from the np\ensuremath{\rightarrow}d${\mathrm{\ensuremath{\pi}}}^{0}$ reaction) was initially estimated to be \ensuremath{\sim}7%. The results agree well with back-angle data obtained independently at LAMPF but less well with results from Saclay and the Princeton-Pennsylvania Accelerator and, except for a normalization difference of 10%, are fairly well represented by a phase-shift fit. The pole-extrapolation method of Chew was used to extract the pion-nucleon coupling constant ${\mathit{f}}^{2}$ from the back-angle portion of the data. The value obtained, ${\mathit{f}}^{2}$=0.069, is somewhat smaller than the values 0.0735--0.0790 obtained from analyses of pion-nucleon scattering, tending to confirm the need for an upward renormalization of the angular distribution by \ensuremath{\sim}10%.