Constraining nucleosythesis in neutrino-driven winds using the impact of (α, xn) reaction rates

¹ Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstr. 2, Darmstadt 64289, Germany
² GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, Darmstadt 64291, Germany
³ Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
⁴ Institute for Applied Physics, Goethe University Frankfurt, Max-von-Laue-Str. 12, Frankfurt am Main 60438, Germany
⁵ GEPI, Observatoire de Paris, Université PSL, CNRS, 5 place Jules Janssen, 92195 Meudon, France
⁶ Institute of Nuclear & Particle Physics, Department of Physics & Astronomy, Ohio University, Athens, OH, 45701 USA
⁷ Institute for Nuclear Research (ATOMKI), H-4001 Debrecen, Bem tér 18/c, Hungary
⁸ National Superconducting Cyclotron Laboratory, East Lansing, MI, 48824, USA
⁹ Joint Institute for Nuclear Astrophysics – Center for the Evolution of the Elements, Michigan State University, East Lansing, Michigan 48824, USA
¹⁰ Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore CA USA 94550

^* e-mail: psaltis@theorie.ikp.physik.tu-darmstadt.de

Published online: 22 March 2023

Abstract

The lighter heavy elements of the first r-process peak, between strontium and silver, can be synthesized in the moderately neutron-rich neutrino–driven ejecta of either core–collapse supernovae or neutron star mergers via the weak r–process. This nucleosynthesis scenario exhibits uncertainties from the absence of experimental data from (α, xn) reactions on neutron–rich nuclei, which are currently based on statistical model estimates. We have performed a new impact study to identify the most important (α, xn) reactions that can affect the production of the lighter heavy elements under different astrophysical conditions using new, constrained (α, xn) reaction rates based on the Atomki-V2 αOMP. Our results show how when reducing the nuclear physics uncertainties, we can use abundance ratios to constrain the astrophysical conditions/environment. This can be achieved in the near future, when the key (α, xn) reaction rates will be measured experimentally in radioactive beam facilities.