Modified Analysis of Nucleon-Nucleon Scattering. IV.p−pScattering between 9.68 and 98 Mev

Abstract

Proton-proton scattering experiments at 9. 68, 18.2, 19.8, 25.63, 39.4, 46, 66, 68.3, 95, and 98 Mev are analyzed under the assumption that the higher partial waves are correctly represented by the one-pion exchange contribution (OPEC). Although the data do not determine a unique phase shift set at any energy, the theoretically reasonable requirement that the l D 2 phase be positive and the 3 P 2 -^2 coupling parameter be negative at 68 and 98 Mev singles out the following solutions (nuclear-bar phase shifts in degrees):This solution type can be qualitatively followed to both lower and higher energies. Such an extension (a) has been shown by Riazuddin to be required by triplet nucleon-nucleon dispersion relations at 4 Mev, (b) is consistent with the best solutions at both 210 and 310 Mev, (c) is qualitatively similar to the requirements of the best phenomenological and semiphenomenological potential models, and (d) carries the signature of the P phases required for consistency with the final-state interaction in the photodisintegration of the deuteron. An attempt to tie solutions at 9.68, 25.63, and 39.4 Mev together using a three-parameter P-phase energy dependence derived by Fubini and Stanghellini, with two of the parameters determined by single pion exchange, was qualitatively consistent but quantitatively unsuccessful. Although on the above grounds, we believe that this is the physically correct solution type in this energy range, the reader is warned that the solution is experimentally not unique, and that the phase shifts can be varied by a few degrees in a correlated way without doing undue violence to the data. On both counts, it is highly desirable that the triple scattering experiments needed for refining these values be carried through. That only two such experiments at a single angle are needed has recently been shown by Iwadare.