Speaker
Description
The abundances of the light elements can be spectroscopically determined by observing the low-metallicity stars. Usually, those measurements are in agreement with the Big Bang Nucleosynthesis predictions. In particular, the measured abundance of Li7 is 3-4 times lower than expected, discrepancy known as the “cosmological Li problem”.
The reaction 3H(α,γ)7Li contributes to the production of Li-7 in Universe and can be studied through its inverse reaction, according to the reciprocity theorem. In consequence, the Li-7 photodisintegration has been measured by our team at the High Intensity γ-ray Source (HIγS)
at Duke University (USA) using a silicon detector array (SIDAR) to observe the coincidences between the alpha particles and the tritons. The final number of coincidences has been determined and the preliminary astrophysical S-factor has been extracted. A preliminary R-Matrix fit has been performed over the data from 2023 together with the data from 2017 and from 1994, covering an energy range between 2.5 and 10 MeV.
