Nuclear deformation at finite temperature

TL;DR

This paper introduces a rotationally invariant method using auxiliary-field Monte Carlo to analyze nuclear deformation at finite temperature, revealing persistent deformation effects beyond mean-field predictions.

Contribution

The authors develop a novel approach combining Monte Carlo techniques with rotational invariance to study nuclear deformation at finite temperature.

Findings

Deformation signatures are model-independent.

Deformation persists above mean-field phase transition temperature.

Method successfully applied to rare-earth nuclei.

Abstract

Deformation, a key concept in our understanding of heavy nuclei, is based on a mean-field description that breaks the rotational invariance of the nuclear many-body Hamiltonian. We present a method to analyze nuclear deformations at finite temperature in a framework that preserves rotational invariance. The auxiliary-field Monte-Carlo method is used to generate the statistical ensemble and calculate the probability distribution associated with the quadrupole operator. Applying the technique to nuclei in the rare-earth region, we identify model-independent signatures of deformation and find that deformation effects persist to higher temperatures than the spherical-to-deformed shape phase-transition temperature of mean-field theory.