Hypernuclear States in Finite Nuclei with the Nijmegen OBE Interaction

Abstract

Recently indications for the formation of .E-hypemuclear states have been observed in the (K, 7r) reactions.!) The.E single particle (s.p.) potential UE is of fundamental interest on the structure of L.:-hypemuclei and/ or the property of the .E-nucleon(N) interaction. Though nothing definite can be said, the peak positions of the pion spectrum suggest that the .E S.p. potential is somewhat shallower than the corresponding A one. The unexpectedly narrow width of .E-states r E -;S8 Me V is worth noting. Several reasons ).3) have been pointed out why the strong conversion process N.E-'>NA be suppressed in nuclei, though their mutual relation is not clear enough. The A s.p. potential has been systematically reproduced in finite nuclei4) and nuclear matter 5) by use of the one-boson-exchange (OBE) hyperon-nucleon (Y-N) interaction given by the Nijmegen group.) In this short note we calculate the s.p. potential and conversion width of a .E-particle in finite closed nuclei, !60 and 40Ca, using the Nijmegen YoN interaction (model D, unless otherwise noted) in parallel with the S.p. potential of a A-particle. A similar calculation in the case of nuclear matter was performed by Dabrowski and Rozynek. 3) They showed that the Pauli exclusion principle and dispersive effects suppress the N1: -'> NA process and reduce rEo It is noted, however, that their treatments are not necessarily the same for A and.E. In order to test the employed YoN interaction, we apply a consistent many-body treatment to both A and .E. The Nijmegen YoN interaction if is the 2X2 matrix