Microscopic analysis ofK+-nucleus elastic scattering based onK+-nucleon phase shifts

Abstract

We investigate K + -nucleus elastic scattering at intermediate energies within a microscopic optical model approach. To this effect we use the current K + -nucleon (KN) phase shifts from the Center for Nuclear Studies of the George Washington University as primary input. First, the KN phase shifts are used to generate Gel'fand-Levitan-Marchenko real and local inversion potentials. Secondly, these potentials are supplemented with a short range complex separable term in such a way that the corresponding unitary and non-unitary KN S matrices are exactly reproduced. These KN potentials allow to calculate all needed on-and off-shell contributions of the t matrix, the driving effective interaction in the full-folding K + -nucleus optical model potentials reported here. Elastic scattering of positive kaons from 6 Li, 12 C, 28 Si and 40 Ca are studied at beam momenta in the range 400-1000 MeV/c, leading to a fair description of most differential and total cross section data. To complete the analysis the full-folding model, three kinds of simpler tρ calculations are considered and results discussed. We conclude that conventional medium effects, in conjunction with a proper representation of the basic KN interaction are essential for the description of K + -nucleus phenomena.

In-medium nuclear interactions of low-energy hadrons

“…By the late 1990s, experimentation in K + -nuclear physics had subsided, and with it died out also theoretical interest although the problems with medium modifications of the interaction remained, as is shown below. Theoretical interest in K + -nuclear physics to some extent has been revived recently [171,172,173,174], particularly in connection with possible contributions due to Θ + pentaquark degrees of free- Eq. ( 54) was replaced by the following ansatz [171,172]:…”

Phase variation of hadronic amplitudes

“…Of course, one is not restricted to nucleons in regard to determining the strong phase from multiple scattering. The scattering of K + from nuclei, as recently treated by Arellano and von Geramb [26], provides such an opportunity. They used inverse scattering theory, starting from phase shifts, to find potentials that represent the basic K + N data.…”