Chronicle of the discovery of the back-bending phenomenon in atomic nuclei: a personal recollection 50 years on

TL;DR

This paper recounts the historical discovery of the back-bending phenomenon in atomic nuclei, emphasizing the experimental and theoretical collaboration that led to understanding nuclear structure changes at high rotational frequencies.

Contribution

It provides a detailed personal account of the discovery process, highlighting the importance of systematic surveys and precise measurements in nuclear physics.

Findings

Identification of anomalous increase in moment of inertia

Revelation of back-bending as a key nuclear structure phenomenon

Historical insight into experimental-theoretical collaboration

Abstract

A chronicle describing the historical context and the development of ideas and experiments leading to the discovery of the back-bending phenomenon in rapidly rotating atomic nuclei some 50 years ago is presented. The moment of inertia of some atomic nuclei increases anomalously at a certain rotational frequency, revealing important clues to our understanding of nuclear structure. I highlight the decisive interactions and contacts between experimentalists and theorists, which created the right environment, allowing for the revelation of an undetected phenomenon in Nature. Finally, I reflect on the key points allowing for the discovery and particularly point to the importance of systematic surveys, which in this case investigated the energy levels in heavy nuclei of a large sample of elements, as well as to the accuracy of the measurements of the ground state levels made at the time.