Seminario «Stars as laboratory of fundamental physics»

Seminario del Máster en Física: Radiaciones, Nanotecnología, Partículas y Astrofísica, impartido por Oscar Straniero, INAF-Osservatorio Astronomico d’Abruzzo (Italia).

Resumen: Understanding stellar structures implies understanding the fundamental interactions: strong, weak, electromagnetic as well as gravity. In particular, the high temperatures that develop in stellar interiors allow the activation of nuclear process, such as the fusion of charge nuclei, and thermal processes, such as Compton scattering of photons on electrons or ions, capable to produce weak interactive small particles (WISPs), like neutrinos. Until now, only solar neutrinos have been revealed, probing early hypothesis about the chain of nuclear reactions which are the main energy source in the Sun, and also valuable hints for the comprehension of neutrino physics, such as neutrino masses and flavour mixing. Even if the direct observation of WISPs from stars is, in general, a challenging task, the fundamental interactions that produce these particles also affect stellar macroscopic features, such as their luminosity. Thus, observations of these stellar properties can be used to constrain the fundamental interactions and even provide hints for new physics. For instance, red giant stars may constrain the neutrino magnetic moment or the coupling of non-standard particles, such as Axions, with standard particles, such as electrons. These studies require reliable stellar models and, in turn, reliable input physics, among which accurate cross sections of nuclear reactions. So the theoretical development is strictly connected to the experimental effort done to measure these cross sections at the thermal energy experienced in stellar interiors. These lectures will introduce the students to the synergy between theory and experiments. The basic concepts of stellar modelling will be discussed first, also by means of practical exercises. Then, current nuclear physics experiments devoted to obtain stellar nuclear cross sections will be illustrated. Finally, I will show how to constrain new physics by comparing theoretical predictions to astronomical measurements of macroscopic stellar parameters.

• Fecha: 12, 13 y 14 de marzo de 2024
• Lugar: Facultad de Ciencias. Día 12 en aula C43. Días 13 y 14 en aula C33.
• Horario: de 11:00 a 12:00 h.
• Organiza: Máster en Física: Radiaciones, Nanotecnología, Partículas y Astrofísica:
• Más información: fvereda@ugr.es