Theoretical uncertainties within the Duflo-Zuker mass model

TL;DR

This paper evaluates the uncertainties in the Duflo-Zuker nuclear mass model, analyzing how parameter uncertainties affect extrapolations to driplines, and proposes a simplified version with smaller uncertainties.

Contribution

It introduces a simplified DZ19 model with reduced uncertainties and systematically analyzes uncertainty propagation and dripline predictions in the Duflo-Zuker mass model.

Findings

DZ mass models have good extrapolation properties.

Large deviations occur in superheavy nuclei extrapolations.

Simplified DZ19 model reduces uncertainties significantly.

Abstract

It is becoming increasingly important to understand the uncertainties of nuclear mass model calculations and their limitations when extrapolating to driplines. In this paper we evaluate the parameter uncertainties the Duflo-Zuker (DZ) shell model mass formulae by fitting to the latest experimental mass compilation AME2012 and analyze the propagation of the uncertainties in binding energy calculations when extrapolated to driplines. The parameter uncertainties and uncertain propagations are evaluated with the help of the covariance matrix thus derived. Large deviations from the extrapolations of AME2012 are seen in superheavy nuclei. A simplified version of the DZ model (DZ19) with much smaller uncertainties than that of DZ33 is proposed. Calculations are compared with results from other mass formulae. Systematics on the uncertainty propagation as well as the positions of the driplines are also presented. The DZ mass formulae are shown to be well defined with good extrapolation properties and rather small uncertainties, even though some of the parameters of the full DZ33 model cannot be fully determined by fitting to available experimental data.