Disentangling phase transitions and critical points in the proton-neutron interacting boson model by catastrophe theory

TL;DR

This paper uses catastrophe theory to analytically derive the phase diagram and transition orders in the proton-neutron interacting boson model, improving upon previous numerical approaches.

Contribution

It provides an analytical derivation of the IBM-2 phase diagram using catastrophe theory, clarifying phase transition orders.

Findings

Analytical phase diagram of IBM-2 derived

Identification of phase transition orders

Application of cusp catastrophe to nuclear models

Abstract

We introduce the basic concepts of catastrophe theory needed to derive analytically the phase diagram of the proton-neutron interacting boson model (IBM-2). Previous studies [1,2,3] were based on numerical solutions. We here explain the whole IBM-2 phase diagram including the precise order of the phase transitions in terms of the cusp catastrophe.