2 papers
hep-ph2025
The impact of and $γ^* N$ interactions on our understanding of nucleon excitations
Volker Burkert, Gernot Eichmann, Eberhard Klempt
We review recent progress in our understanding of the nucleon excitation spectrum. Thanks to dedicated efforts at facilities such as ELSA, MAMI and Jefferson Lab, several new nucle…
nucl-ex2025
The Roper resonance and kin
Volker Burkert, Eberhard Klempt
The properties of the Roper resonance N(1440) are reviewed. Quark models have long struggled to reproduce its mass relative to its negative-parity partner N(1535). This discrepancy…