*Review* **Excited States in Isobaric Multiplets—Experimental Advances and the Shell-Model Approach**

**Michael A Bentley**

School of Physics, Engineering and Technology, University of York, York YO10 5DD, UK; michael.bentley@york.ac.uk

**Abstract:** A review of recent advances in the study of the energy splitting between excited isobaric analogue states is presented. Some of the experimental developments, and new approaches, associated with spectroscopy of the most proton-rich members of isobaric multiplets, are discussed. The review focuses on the immense impact of the shell-model in the analysis of energy differences and their interpretation in terms of nuclear structure phenomena.

**Keywords:** isospin symmetry; nuclear shell model; charge symmetry; charge independence; *γ*-ray spectroscopy; knockout reactions
