Configuration mixing in the interacting boson model

The geometry and phase transition behavior of configuration mixing in the interacting boson model

In the last 20 years there has been much interest in the study of nuclear coexistence phenomena, understood as the possibility of a simultaneous excitation of nuclear configurations which may lead to shape phase transitions [1]. The structural changes in the properties of physical systems are called phase transitions. These changes have long been studied in systems such as water in its gaseous,...

Criticality in the configuration - mixed interacting boson model : ( 1 ) U ( 5 ) – Q̂ ( χ ) · Q̂ ( χ ) mixing

The case of U(5)–Q̂(χ) · Q̂(χ) mixing in the configuration-mixed Interacting Boson Model is studied in its mean-field approximation. Phase diagrams with analytical and numerical solutions are constructed and discussed. Indications for first-order and second-order shape phase transitions can be obtained from binding energies and from critical exponents, respectively.

Criticality in the configuration-mixed Interacting Boson Model: (2) Q̂(χ1)Q̂(χ1)-Q̂(χ2)Q̂(χ2) mixing

The case of Q̂(χ1) · Q̂(χ1)-Q̂(χ2) · Q̂(χ2) mixing in the interacting boson model is studied within its mean-field approximation. It is shown that the criticality conditions lead to two classes of solutions and that χ1 and χ2 need to have an opposite sign to allow for prolate-oblate shape coexistence. No evidence for a stable triaxial minimum is found. Phase diagrams for selected cases have been co...

Symmetries in the Interacting Boson Model

We study the energy level statistics of the states in U(5) and O(6) dynamical symmetries of the interacting boson model and the high spin states with backbending in U(5) symmetry. In the calculations, the degeneracy resulting from the additional quantum number is eliminated manually. The calculated results indicate that the finite boson number N effect is prominent. When N has a value close to ...

The Interacting Boson Approximation Model and Applications