Conservation Properties in the Time-Dependent Hartree Fock Theory

TL;DR

This paper examines how angular momentum conservation is maintained in 3D time-dependent Hartree-Fock nuclear simulations, highlighting issues with nucleon emission and numerical artifacts affecting angular momentum.

Contribution

It analyzes conservation properties in TDHF calculations, proposing strategies to differentiate physical effects from numerical artifacts in angular momentum loss.

Findings

Free rotation of deformed nuclei is well-preserved on coarse grids.

Nucleon emission during collisions affects angular momentum conservation.

Numerical artifacts can mimic physical angular momentum loss.

Abstract

We discuss the conservation of angular momentum in nuclear time-dependent Hartree-Fock calculations for a numerical representation of wave functions and potentials on a three-dimensional cartesian grid. Free rotation of a deformed nucleus performs extremely well even for relatively coarse spatial grids. Heavy ion collisions produce a highly excited compound system associated with substantial nucleon emission. These emitted nucleons reach the bounds of the numerical box which leads to a decrease of angular momentum. We discuss strategies to distinguish the physically justified loss from numerical artifacts.