Baryon excitation through meson hadro- and photoproduction in a coupled-channels framework

In this dissertation, we investigate all nucleon resonances in the energy region below W = 2.0 GeV with spin up to 52 through meson hadro- and photoproduction within a coupled-channels framework. We include the six asymptotic states of gammaN, pi N, 2piN, etaN, KΛ, and KSigma. We construct background contributions by including the standard s-, u-, and t-channel diagrams with couplings consistent with chiral symmetry. In addition, we include two sets of contact terms, motivated by chiral symmetry and implemented in elastic piN scattering and pion photoproduction for the first time. Spin 1/2, 32 , and 52 baryon resonance states are implemented by means of the consistent hadronic and electromagnetic resonance couplings as introduced by Pascalutsa.; In simultaneous fits, we successfully describe piN → pi N, piN → 2piN and gamma N → piN partial-wave amplitudes, and the observables of etaN, KΛ, and KSigma photoproduction obtained from experiments performed by CLAS and other labs. We confirm all of the PDG 2-, 3-, and 4-star N* and Delta* states, but find none of the 1-star resonances below W = 2.1 GeV, such as the P31(1750). We find a third D13 state around 1980 MeV but inconclusive evidence for fourth state in this partial wave. We search for missing states in all partial waves, and find no "missing" resonances.