LUNA: Nuclear Astrophysics Deep Underground

TL;DR

LUNA has significantly advanced nuclear astrophysics by measuring key reaction cross sections underground, improving our understanding of stellar processes, neutrinos, and the universe, with future plans to explore additional stellar reactions.

Contribution

This paper reviews two decades of LUNA's underground measurements of nuclear reaction cross sections crucial for astrophysics, highlighting their impact and future research directions.

Findings

Precise measurements of proton-proton and CNO cycle reactions.

Enhanced understanding of solar neutrinos and stellar evolution.

Future plans for studying helium, carbon burning, and stellar neutron sources.

Abstract

Nuclear astrophysics strives for a comprehensive picture of the nuclear reactions responsible for synthesizing the chemical elements and for powering the stellar evolution engine. Deep underground in the Gran Sasso laboratory the cross sections of the key reactions of the proton-proton chain and of the Carbon-Nitrogen-Oxygen (CNO) cycle have been measured right down to the energies of astrophysical interest. The salient features of underground nuclear astrophysics are summarized here. The main results obtained by LUNA in the last twenty years are reviewed, and their influence on the comprehension of the properties of the neutrino, of the Sun and of the Universe itself are discussed. Future directions of underground nuclear astrophysics towards the study of helium and carbon burning and of stellar neutron sources in stars are pointed out.