ar X iv : n uc l - th / 9 50 80 19 v 1 1 0 A ug 1 99 5 Instabilities in nuclei

ar X iv : n uc l - th / 0 10 80 18 v 1 8 A ug 2 00 1 1 Photon and Electron induced Particle Production on Nuclei ∗

ar X iv : n uc l - th / 9 50 80 11 v 2 1 1 A ug 1 99 5 THE d ’ - DIBARYON IN THE NONRELATIVISTIC QUARK MODEL

The narrow peak recently found in various pionic double charge exchange (DCX) cross sections can be explained by the assumption of a universal resonance at 2065 MeV, called d ′. We calculate the mass of a six-quark system with J P = 0 − , T = 0 quantum numbers employing a cluster model and a shell model basis to diagonalize the nonrelativistic quark model Hamiltonian.

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

ar X iv : n uc l - th / 0 50 80 60 v 1 2 9 A ug 2 00 5 Spin observables in p̄p → ΛΛ and density - matrix constraints

The positivity conditions of the spin density matrix constrain the spin observables of the reaction p̄p → ΛΛ, leading to model-independent, non-trivial inequalities. The formalism is briefly presented and examples of inequalities are provided.

ar X iv : n uc l - th / 0 10 80 54 v 1 2 3 A ug 2 00 1 RANDOMLY INTERACTING BOSONS , MEAN - FIELDS AND L = 0 GROUND STATES

Random interactions are used to investigate to what extent the low-lying behavior of even-even nuclei depend on particular nucleon-nucleon interactions. The surprising results that were obtained for the interacting boson model, i.e. the dominance of ground states with L = 0 and the occurrence of both vibrational and rotational structure, are interpreted and explained in terms of a mean-field an...