https://doi.org/10.1140/epja/s10050-023-00934-8
Regular Article - Theoretical Physics
Franz and his friends: 35-years of s-process studies by the Karlsruhe–Torino collaboration
1
Dipartimento di Fisica, Università di Torino, 10125, Torino, Italy
2
B2FH Association, Turin, Italy
Received:
28
July
2022
Accepted:
13
January
2023
Published online:
1
April
2023
This contribution is dedicated to Franz Käppeler and to the longstanding partnership between the Karlsruhe Group and the Torino Group. The Karlsruhe Group led by Franz from the Institute of Experimental Physics of the Karlsruhe Institute of Technology in Germany measured since the late 1980s a large set of Maxwellian-averaged neutron-capture cross sections with the aim of reaching uncertainties as low as 2%. The Torino Group, led by myself from the Department of Physics of the University of Turin in Italy and Maurizio Busso from the Turin Astronomical Observatory, worked on theoretical stellar predictions for neutron captures in low-mass stars during the Asymptotic Giant Branch phase. Thirty years of collaboration between these two groups produced 70 publications in major peer-reviewed journals, which involved hundreds of colleagues around the world. The two groups shared various students. For example, Claudio Arlandini from the Torino Group was appointed by Franz for a doctoral study in his group to measure the cross section of the s-only isotope 142Nd. The new value was found to support the Stellar Model prediction, which predicted perfect agreement with solar 142Nd, while Classical Analysis resulted in a deficit of 12%. The two Groups investigated together also branching points on the s-process path, where the competition between 
decay and neutron capture depends on the temperature, the local neutron density, or on both. Here, I briefly report on our collaborative work on the s-process-rich carbon stars and I include some personal memories.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
