IGFAE contributes to a new technique for studying nuclear reactions in stellar explosions

Researcher Yassid Ayyad, from the Galician Institute of High Energy Physics (IGFAE), a joint centre of the University of Santiago de Compostela and a member of the CIGUS Network, an initiative launched by the regional government (Xunta de Galicia) that groups together centres of accredited scientific excellence within the Galician university system, has published an article in the journal Physical Review Letters describing a new technique to determine and study the nuclear reactions that take place in stellar explosions, such as supernovae.

The researcher was responsible for overseeing part of the analysis and the framework of simulations necessary to interpret the results. According to the team in charge of the project, these data open a new avenue for tackling a series of scientific challenges, including astrophysics and neutrino physics. As the authors explain, studying the nuclear reactions that occur in supernovae is essential for understanding the evolution of the universe. There is one type of supernovae – core-collapse supernovae – which affect stars larger than eight solar masses at the end of their life cycle. In this process, these giant stars generate a black hole or a very dense neutron star.
During this collapse, the atomic nuclei of the elements present in the core of the star capture electrons. These reactions reduce the pressure of the star and generate neutrinos that carry away energy. Modelling and obtaining a deeper insight into these reactions therefore helps to unravel the unknown aspects of such large-scale phenomena.

The team led by Yassid Ayyad is currently preparing a new project related to this technique. “We are working on a similar experiment that will be conducted in July this year, using the same experimental device, but this time we will be measuring the electromagnetic response of 11Li, a very exotic nucleus characterised by two neutrons orbiting far away from the nucleus. This is known as a halo nucleus,” added Ayyad. “This proposal is being led by our research group and will serve as a thesis topic for one of our students,” he concluded.