There has been a great deal of attention to the low lying energy spectum in a nucleus because of the abundance of experimetal data. Likewise ,perhaps to a lesser extent but still significant the high end for a given configuration has been examined. Here ,using single j shell calculations as a guide we examine the middle part of the spectum resulting form single j shell calculations. Seniority a...

Finite spin models, applicable to investigations of mesoscopic rings, give rise to eigenproblems of very large dimensions. Efficient, and as exact as possible, solutions of such eigenproblems are very difficult. A method leading to block diagonalization of Hamiltonian matrix is proposed in this paper. For a given symmetry group of a Heisenberg Hamiltonian commuting with the total spin projectio...

A physically meaningful analogy is drawn between the ordering and dynamical behavior of molecular rotations in solid hydrogen and the ordering and dynamical behavior of magnetic spin systems. In solid hydrogen the magnitude J of the rotational angular momentum is a good quantum number. Molecules having J = 1 resemble spin one magnetic moments, whereas those with J = 0 are "non‐magnetic." Solid ...

The discovery of the baryonic states P c (4380) and P + c (4450) by the LHCb collaboration in the process pp → bb̄ → ΛbX, followed by the decay Λ 0 b → J/ψ p K− has evoked a lot of theoretical interest. These states have the minimal quark content cc̄uud, as suggested by their discovery mode J/ψ p, and the preferred J assignments are 52 + for the P c (4450) and 3 2 − for the P c (4380). In the com...

We discuss a microscopic framework for phenomenological boson-fermion models of nuclear structure based on the U(n/m) type of superalgebras. The generalized Dyson mapping of fermion collective superalgebras provides a basis to do so and to understand how collectivity selects the required preservation of boson plus fermion number as a good quantum number. We also consider the difference between ...