Intertwined quantum phase transitions in the A ~ 100 region

Noam Gavrielov (GANIL, Caen, France)

Quantum phase transitions (QPTs) are a highly investigated phenomenon in nuclear physics, both theoretically and experimentally, where many rare isotope beam facilities investigate a plethora of nuclei as a function of nucleon number in order to understand their evolution in shape and shape coexistence that includes multiple shell model configurations. In this talk I will discuss my attempt to understand such phenomenon using algebraic frameworks. Specifically, I will present the interacting boson model (IBM) for even-even nuclei. This model allows one to investigate a vast array of phenomena, providing insight into the symmetry structure of the nucleus at a low computational cost. Using an extension of this framework to multiple configurations named the IBM with configuration mixing (IBM-CM), I will present my work on the chain of zirconium isotopes (Z = 40) with mass numbers A = 92-110 and the manifestation of the new notion of intertwined quantum phase transitions (IQPTs). IQPT is a situation involving two types of QPTs simultaneously, where one is a crossing of two configurations in the ground state, and one is a shape evolution within each configuration. Furthermore, I will introduce a novel model for configuration mixing in odd-mass nuclei, termed the interacting boson-fermion model with configuration mixing (IBFM-CM). Using this framework, I will present my work on the odd-mass niobium isotopes (Z = 41) with mass numbers A = 93-103 and the manifestation of IQPTs within this chain of isotopes. The occurrence of IQPTs in both chains of isotopes can set path for new investigations of this phenomenon in other chains, both even-even and odd-mass.