Shape transition and fluctuation in neutron-rich Cr isotopes around N = 40

TL;DR

This paper investigates the shape transition and fluctuations in neutron-rich Cr isotopes near N=40 using a microscopic collective Hamiltonian approach, revealing a prolately deformed but transitional character with significant shape fluctuations.

Contribution

It introduces a microscopic method to study shape transitions in neutron-rich isotopes, combining collective Schrödinger equation solutions with microscopic potential and inertial functions.

Findings

Cr isotopes around 64Cr are prolately deformed.

Low-lying states exhibit large-amplitude shape fluctuations.

The shape transition shows transitional character with shape coexistence.

Abstract

The spherical-to-prolate shape transition in neutron-rich Cr isotopes from N = 34 to 42 is studied by solving the collective Schr\"odinger equation for the five-dimensional quadrupole collective Hamiltonian. The collective potential and inertial functions are microscopically derived with use of the constrained Hartree-Fock-Bogoliubov plus local quasiparticle random-phase approximation method. Nature of the quadrupole collectivity of low-lying states is discussed by evaluating excitation spectra and electric quadrupole moments and transition strengths. The result of calculation indicates that Cr isotopes around 64Cr are prolately deformed but still possess transitional character; large-amplitude shape fluctuations dominate in their low-lying states.