Gauge Symmetry in the Large-amplitude Collective Motion of Superfluid Nuclei

TL;DR

This paper explores the gauge symmetry properties of the ASCC method, used for modeling large-amplitude collective motion in superfluid nuclei, focusing on how constraints and approximations affect this symmetry.

Contribution

It analyzes the gauge symmetry in the ASCC method and discusses how adiabatic expansion influences this symmetry within the framework of constrained systems.

Findings

Gauge symmetry originates from particle number constraints.

Adiabatic expansion partially breaks the gauge symmetry.

The validity of adiabatic expansion under gauge transformations is examined.

Abstract

The adiabatic self-consistent collective coordinate (ASCC) method is a practical method for the description of large-amplitude collective motion in atomic nuclei with superfluidity and an advanced version of the adiabatic time-dependent Hartree-Fock-Bogoliubov theory. We investigate the gauge symmetry in the ASCC method on the basis of the theory of constrained systems. The gauge symmetry in the ASCC method is originated from the constraint on the particle number in the collective Hamiltonian, and it is partially broken by the adiabatic expansion. The validity of the adiabatic expansion under the general gauge transformation is also discussed.