José Miguel Arias Carrasco

U(5)-O(6) transition in the interacting boson model and the E(5) critical point symmetry

The relation of the recently proposed

Phase transitions and critical points in the rare-earth region

E(5)

Finite-size corrections in the bosonic algebraic approach to two-dimensional systems

critical point symmetry with the interacting boson model is investigated. The large-

Excited-state quantum phase transitions in a two-fluid Lipkin model

N

Boson-conserving one-nucleon transfer operator in the interacting boson model

limit of the interacting boson model at the critical point in the transition from U(5) to O(6) is obtained by solving the Richardson equations. It is shown explicitly that this algebraic calculation leads to the same results as the solution of the Bohr differential equation with a

Phase diagram of an extended Agassi model

{\ensuremath{\beta}}^{4}

A scalar two-level boson model to study the IBM phase diagram in the Casten triangle

potential.

Search for E(5) symmetry in nuclei: The Ru isotopes

A systematic study of isotope chains in the rare--earth region is presented. For the chains (144-154)Nd, (146-160)Sm, (148-162)Gd, and (150-166)Dy, energy levels, E2 transition rates, and two--neutron separation energies are described by using the most general (up to two--body terms) IBM Hamiltonian. For each isotope chain a general fit is performed in such a way that all parameters but one are kept fixed to describe the whole chain. In this region nuclei evolve from spherical to deformed shapes and a method based on catastrophe theory, in combination with a coherent state analysis to generate the IBM energy surfaces, is used to identify critical phase transition points.

β-decay rates of 121–131Cs in the microscopic interacting boson-fermion model

This work has been partially supported by the Spanish MEC, by the European regional development fund (FEDER) under Projects No. FIS2008-04189 and CPAN-Ingenio (No. CSD2007-00042), and by the Junta de Andalucia (Projects No. P07-FQM-02962, No. P07-FQM-03014, and No. P07-FQM-02894). P.P.F. acknowledges the Spanish MEC for an FPU grant. The authors thank Jorge Dukelsky, Francesco Iachello, Pieter van Isacker, Amiram Leviatan, and Armando Relano for valuable comments and suggestions.

Quantum Phase Transitions in Coupled Systems : an application of Catastrophe Theory

This work has been supported by the Spanish Ministerio de Econom ia y Competitividad and the European regional development fund (FEDER) under Project No. FIS2014-53448-C2-1-P and FIS2014-53448-C2-2-P