The s process in stars is one of the most important mechanisms for producing the heavier elements such as Cadmium, Tungsten or Lead. The most important neutron source to activate this process inside the stars is represented by alpha capture on 13C: 13C + α -> 16O + n. After a long experimental campaign, which lasted about 4 years, the international collaboration LUNA (Laboratory for Underground Nuclear Astrophysics) has studied this process down to the energies of interest in stars, providing invaluable information for the construction of models that reproduce the stellar evolution. The results of this work have been published in the prestigious Physical Review Letters of the American Physical Society: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.152701.

About 50 scientists from universities and research institutes from Italy, Germany, Hungary and the United Kingdom collaborate with LUNA. Padua contributes to this result thanks to the work of the researchers of the Physics and Astronomy Department and the INFN Section.

The paper is in the framework of the Physics of the Universe excellence project of our Department.

For more information: antonio.caciolli (at) unipd (dot) it