Nuclear Astrophysics at the Low-Energy Frontiers: Updates from underground laboratories

Abstract

Nuclear fusion reactions are the heart of nuclear astrophysics: they sensitively influence the nucleosynthesis of the elements in the earliest stages of the Universe and in all the objects formed thereafter; control the associated energy generation and neutrino luminosity; influence the evolution of stars. Unfortunately, measuring reaction cross sections at astrophysically relevant energies is exceptionally challenging due to Coulomb repulsion between nuclei, resulting in cross section values as low as fbar. Laboratorial measurements of these cross sections are often unfeasible due to overwhelming cosmic-ray-induced backgrounds. One effective solution to this problem is to conduct experiments in underground laboratories. The Laboratory for Underground Nuclear Astrophysics (LUNA) is an experimental approach based on an underground accelerator focusing on studying nuclear fusion reactions. Its primary objective is to accomplish direct measurement of cross sections for nuclear reactions that have significance in stellar and primordial nucleosynthesis. This article will present the latest findings and future objectives.