  To understand the difference between the value of the nn and Lambda-Lambda
two-body matrix elements, we examine the role of the coupling between the
Lambda-Lambda and Xi-N channels, first within the framework of SU(3), and
second in the numerical results for the binding energy of Lambda-Lambda 6He. We
find that it is essential to include the coupled channel nature of the BB
interaction as we proceed from strangeness zero to the strangeness -1 and -2
channels if we are to understand the relative magnitude of the two-body matrix
elements in the different strangeness channels.
