Microscopic description of nuclear collective states by symmetry conserving mean field theory

Symmetries in Science II

“…Although there have been intense efforts in recent years ( Otsuka, 1984, Barrett, 1984, Pittel, 1984, Moszkowski, 1984, Yang et. aI., 1984, Arima, 1984, P. Ring, 1984, Wu and Feng,1984, Xu, 1984 to provide a better way of mapping a fermion system to a boson system so that a microscopic understanding of the IBM may emerge, such efforts have so far not bear fruit in the understanding of the origins of these dynamical symmetries. In our view, the dynamical symmetries unraveled by the IBM constitute the fundamental behavior of nuclei and therefore should, and must, manifest themselves directly from the fermion degrees of freedom without introducing bosons.Therefore it seems to us that the question one needs to ask at this point is: Suppose one begins with the same input physics as the IBM, namely nucleons in the valence shells tend to couple to the coherent S (1=0) and D (1=2) pairs, can one still find the dynamical symmetries which seem to manifest in the IBM.…”