S-WaveΛ−ΛInteraction for OddΣ−ΛParity

Abstract

The x 5o A-A zero-energy scattering length is calculated by solving the Schrodinger equation for the coupled A-A and 2-2 channels, using pionic exchange potentials (with hard core of radius xo) derived for the case of odd A-2 parity. Using the value of xo and the coupling constants /ss and gAS which fit the lowenergy A-N scattering data, the A-A interaction is found to be so strongly attractive as to bind in the ^So A -A state. Since the A-A interaction deduced phenomenologically from the analysis of A-A hypernuclei is not strong enough to bind, we conclude that the assumption of odd A-2 parity leads to contradictory results in the calculation of the low-energy A-N and A-A scattering.