Early Experimental Studies of the Roper Resonance at the Los Alamos Meson Physics Facility — LAMPF

The Roper resonance (\(P_{11}(1440)\) or \(N_{\scriptstyle \frac {1}{2}}^{\scriptstyle +}(1440))\) has been and continues to be the subject of experimental studies at both hadronic and electromagnetic facilities. This year, we celebrate and honor its discoverer, L. David Roper, on the occasion of his \(90^{\rm th}\) birthday. Recent studies and publications have emphasized the role of electromagnetic beams in studying the properties of the Roper resonance. In this article, we review the role of early experiments using hadronic beams that were sparked by the discovery of the “Roper”, and also motivated and encouraged the design and construction of the early meson factories such as LAMPF (Los Alamos Meson Physics Facility), TRIUMF (TRI University Meson Facility), PSI (Paul Scherrer Institute, formerly SIN), and INR (Institute for Nuclear Research). Abstract Published by the Jagiellonian University 2026 authors