Speaker
Description
Nuclear astrophysics is going to play a pivotal role in understanding the evolution of our Universe. In the multimessenger era, the need of completing the cosmological framework of the standard Big Bang Nucleosynthesis is surely one of the most hot topics. For such a reason, recent studies have been focused on the deep comprehension of some unsolved issues such as the so-called ”lithium-problem”. Although lithium is mainly produced by the $^3$He$(\alpha,\gamma){}^7$Be reaction, the role of the unstable beryllium-7 in the next steps of the reaction network needs to be studied [1]. For such a reason, neutron induced reactions on such isotope have been the central argument of recent Trojan Horse (THM) investigations. The Trojan Horse Method (THM) [2] have been applied for measuring the cross section of the $(n,\alpha )$ reaction channel on $^7$Be by means of charge-symmetry hypothesis applied to the previous $^7$Li$(p,\alpha ){}^4$He THM data corrected for Coulomb effects. The deduced $^7$Be$(n,\alpha ){}^4$He data overlap with the Big Bang nucleosynthesis energies and the deduced reaction rate allows us to evaluate the corresponding cosmological implications [3]. Additionally, a devoted measurement has been performed in INFN-LNL by means of the in-flight produced $^7$Be beam impinging onto a deuterated target for investigating the quasi-free $^2$H($^7$Be,$\alpha \alpha)p$ reaction suitable for measuring the $^7$Be$(n,\alpha){}^4$He cross section in the energy domain of BBN. The data analysis and the cosmological consequences will be shown and discussed [3].
[1] C. Bertulani & T. Kajino, Progress in Particle and Nuclear Physics 89,
56 (2016)
[2] R.E. Tribble et al., Report on Progress Physics 77, 106901 (2014)
[3] L. Lamia et al., The Astrophysical Journal 850, 175 (2017)
