Rotational states in deformed nuclei: An analytic approach

TL;DR

This paper develops an analytic field theory model to describe rotational states in deformed nuclei, highlighting the role of symmetry breaking and Goldstone modes, and connecting theoretical predictions with empirical data.

Contribution

It introduces an analytic approach based on symmetry breaking and Goldstone modes to derive rotational states and models in deformed nuclei, linking theory with experimental observations.

Findings

Rotor picture derived from isoscalar Goldstone modes

Two-rotor model from isovector scissors modes

Connection established between formalism and empirical M1 sum rules

Abstract

The consequences of the spontaneous breaking of rotational symmetry are investigated in a field theory model for deformed nuclei, based on simple separable interactions. The crucial role of the Ward-Takahashi identities to describe the rotational states is emphasized. We show explicitly how the rotor picture emerges from the isoscalar Goldstone modes, and how the two-rotor model emerges from the isovector scissors modes. As an application of the formalism, we discuss the M1 sum rules in deformed nuclei, and make connection to empirical information.