An important tool to experimentally probe the nucleon excitation spectrum is the study
of meson photoproduction reactions. Partial wave analyses are used to extract the baryon resonances from the experimental data. For an unambiguous solution it is not enough to only measure the unpolarized cross section, but several single and carefully chosen double polarization observables are needed in...
One of the open challenges in subnuclear physics is to understand the
non-perturbative regime of Quantum Chromodynamics, including the world
of the nucleon and its excitations.
A necessary step towards this aim is a precise knowledge
of the experimental spectrum and the properties of baryon resonances.
Recently, large progress has been made based on photoproduction
Radiative transition of an excited baryon to a nucleon with emission of a virtual massive photon converting to dielectron pair (RNe+e- Dalitz decays) provides important information about baryon-photon coupling at low q2 =(me+e- )2 in time-like region. Enhancements in electromagnetic Transition Form-Factors (eTFF) at q2 close to vector mesons (/) poles have been predicted for N(1520/1535)...