Nucleon-nucleon partial-wave analysis to 1100 MeV

Comprehensive analyses of nucleon-nucleon elastic-scattering data below 1100 MeV laboratory kinetic energy are presented. The data base from which an energy-dependent solution and 22 single-energy solutions are obtained consists of 7223 pp and 5474 np data. A resonancelike structure is found to occur in the ${}_{}{}^1{}_{}{}^{}\mathrm{D}_2^{}{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}\mathrm{F}_3^{}{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}\mathrm{P}_2^{}{}_{}{}^{}$ ${\mathrm{-}}^3$ ${\mathrm{F}}_2$, and ${}_{}{}^3{}_{}{}^{}\mathrm{F}_4^{}{}_{}{}^{}$ ${\mathrm{-}}^3$ ${\mathrm{H}}_4$ partial waves; this behavior is associated with poles in the complex energy plane. The pole positions and residues are obtained by analytic continuation of the ‘‘production’’ piece of the T matrix obtained in the energy-dependent solution. The new phases differ somewhat from previously published VPI&SU solutions, especially in I=0 waves above 500 MeV, where np data are very sparse. The partial waves are, however, based upon a significantly larger data base and reflect correspondingly smaller errors. The full data base and solution files can be obtained through a computer scattering analysis interactive dial-in (SAID) system at VPI&SU, which also exists at many institutions around the world and which can be transferred to any site with a suitable computer system. The SAID system can be used to modify solutions, plan experiments, and obtain any of the multitude of predictions which derive from partial-wave analyses of the world data base.