Charge-exchange reactions and the quest for resolution

Abstract

Hadronic charge-exchange reactions of the type (n, p) and (p, n) at intermediate energies between roughly 100 and 300MeV per nucleon have gained in importance over the last 25 year. This is because these reactions can be employed as a powerful tool in numerous fields of nuclear and particle physics alike. Charge-exchange experiments have significantly contributed to the understanding of the dynamics of spin and isospin excitation, to the structure of particle-hole states in light- and medium-mass nuclei and even to elucidating nucleon-nucleon and halo-nuclei properties. However, the most significant advancements have been made --and are still being made-- towards the understanding of weak interaction processes in nuclei, especially those where neutrinos play a pivotal role. This is foremost due to the high level of resolution, which was experimentally achieved over the course of time. This review focuses on the power of charge-exchange reactions, whereby particular emphasis will be placed on resolution. At the center will be the (n, p)-type $(d,{}^{2}{\rm He})$ reaction and the (p, n)-type $({}^{3}{\rm He},t)$ reaction.