Anatomy of Roper Resonance

Abstract

Sixty years ago, the first excited state of a proton/neutron was ``born.'' During this time, we learned a lot about it, specifically - how unique this case is: a single resonance with two pole positions on different Riemann sheets. Let me present a brief history to remind readers how development progressed. Sure, history is sometimes something that never happened, described by those who were never there...

Comments: 6 pages, 3 figures, 1 table; It is a great pleasure to dedicate this article to Dave Roper on his ninetieth birthday