Covariances from model variation: Application to quantities for astrophysics

¹ Reactor Physics and Thermal Hydraulic Laboratory, Paul Scherrer Institut, Villigen, Switzerland
² Nuclear Data Section, International Atomic Energy Agency, Vienna, Austria
³ Institut d’Astronomie et d’Astrophysique, Université Libre de Bruxelles Brussels, Belgium

^* e-mail: dimitri-alexandre.rochman@psi.ch
^** e-mail: a.koning@iaea.org
^*** e-mail: stephane.goriely@ulb.be

Published online: 29 March 2023

Abstract

In this work, covariance matrices coming from model variations, in contrast to the usual parameter variations, are presented. The considered phenomenological and microscopic models are included in the code TALYS, and concern level densities, gamma strength functions, optical potentials and masses. A total of 288 model sets for each isotope is used to estimate both uncertainties and correlations from systematical origin. The calculated quantities are of interest for astrophysical applications, such as capture cross sections, and reaction rates. The isotopes (3 ≤ Z ≤ 100) are from the proton to neutron drip lines, covering about 8800 cases, and are included in the TENDL-2021 library.