Indirect methods in nuclear astrophysics with relativistic radioactive beams

TL;DR

This paper reviews how relativistic radioactive beams are used in nuclear astrophysics to study stellar processes and reactions that are difficult to measure directly, combining experimental and theoretical approaches.

Contribution

It provides a comprehensive overview of experimental methods and theoretical models involving relativistic radioactive beams to address key astrophysical questions.

Findings

Relativistic radioactive beams help study low-energy nuclear reactions indirectly.

Experimental methods have advanced understanding of the equation of state of nuclear matter.

Theoretical models are crucial for interpreting experimental results in astrophysics.

Abstract

Reactions with radioactive nuclear beams at relativistic energies have opened new doors to clarify the mechanisms of stellar evolution and cataclysmic events involving stars and during the big bang epoch. Numerous nuclear reactions of astrophysical interest cannot be assessed directly in laboratory experiments. Ironically, some of the information needed to describe such reactions, at extremely low energies (e.g., keVs), can only be studied on Earth by using relativistic collisions between heavy ions at GeV energies. In this contribution, we make a short review of experiments with relativistic radioactive beams and of the theoretical methods needed to understand the physics of stars, adding to the knowledge inferred from astronomical observations. We continue by introducing a more detailed description of how the use of relativistic radioactive beams can help to solve astrophysical puzzles and several successful experimental methods. State-of-the-art theories are discussed at some length with the purpose of helping us understand the experimental results reported. The review is not complete and we have focused most of it to traditional methods aiming at the determination of the equation of state of symmetric and asymmetric nuclear matter and the role of the symmetry energy. Whenever possible, under the limitations of our present understanding of experimental data and theory, we try to pinpoint the information still missing to further understand how stars evolve, explode, and how their internal structure might be.