ar X iv : n uc l - th / 9 30 30 26 v 1 3 1 M ar 1 99 3 Boson - fermion mappings for odd systems from supercoherent states

ar X iv : n uc l - th / 9 30 90 09 v 1 8 S ep 1 99 3 MESON - EXCHANGE CURRENTS AND THE STRANGENESS RADIUS OF 4

Meson-exchange current contributions to the strangeness radius of He are computed in the one-boson exchange approximation. It is found that these contributions introduce a ∼10% correction to the one-body contribution. They should not, therefore, hamper the extraction of the nucleon strangeness radius from the parity-violating electron-He asymmetry.

ar X iv : n uc l - th / 9 50 30 19 v 1 2 1 M ar 1 99 5 OFF SHELL πN AMPLITUDE AND THE pp → ppπ 0 REACTION NEAR THRESHOLD

Boson-fermion mappings for odd systems from supercoherent states.

We extend the formalism whereby boson mappings can be derived from generalized coherent states to boson-fermion mappings for systems with an odd number of fermions. This is accomplished by constructing supercoherent states in terms of both complex and Grassmann variables. In addition to a known mapping for the full so(2N+1) algebra, we also uncover some other formal mappings, together with mapp...

ar X iv : n uc l - th / 9 90 60 29 v 3 1 5 Ju l 1 99 9 1 Quark Matter ’ 99 — Theoretical Summary : What Next ?

X iv : n uc l - th / 9 81 10 30 v 4 2 5 M ar 1 99 9 Anharmonic collective excitation in a solvable model

We apply the time-dependent variational principle, the nuclear field theory, and the boson expansion method to the Lipkin model to discuss anharmonicities of collective vibrational excitations. It is shown that all of these approaches lead to the same anharmonicity to leading order in the number of particles. Comparison with the exact solution of the Lipkin model shows that these theories repro...