Cosmological lithium problem solution in accelerator experiment

Abstract

The cosmological lithium problem is a serious problem for understanding the early Universe, which casts doubt on the Big Bang nucleosynthesis (BBN) model. The problem is that the data on the abundance of ⁶Li and ⁷Li elements obtained from astronomic observations and in the BBN model are too different, based on the data on all nuclear reactions in which these elements produce (or destroy). Astronomy continues to improve the optical instrumentation in order to achieve better resolution and efficiency. In nuclear physics, cross sections of all reactions resulting in the lithium nucleus production (or destruction) are being clarified. This work presents a brief review of related theoretical calculations and experimental data. Experimental results are presented in the laboratory coordinate system for ³H(³He, γ)⁶Li reaction at an energy of 38 keV, first obtained using the Hall ion accelerator in National Research Tomsk Polytechnic University, Tomsk, Russia. S-factor calculated for ³H(³He, γ)⁶Li S = 0.15 ± 0.03 keV·b reaction is inconsistent either with approximation of the experimental data obtained at high energies, or theoretical calculations. It is also inconsistent with assumptions about a new physics hidden in this reaction. Our work discusses the possibility of solving the cosmological lithium problem via reactions with light neutron clusters.