1997/08/05 by Th. Wilbois, T. Wilbois, P. Wilhelm +2 · 1 citation
Engineering · Physics and Astronomy · #Atomic physics #Dipole #Excitation #Multipole expansion #Particle Accelerators and Free-Electron Lasers #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quadrupole #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Resonance (particle physics) #nucl-th
paper · pdf · doi:10.1103/physrevc.57.295
published as Phys.Rev.C57:295-304,1998 · 22 pages revtex including 7 postscript figures
arxiv created 1997/08/05 · openalex publication_date 1998/01/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Several methods for the treatment of pion photoproduction in the region of the \ensuremathΔ(1232) resonance are discussed, in particular the effective Lagrangian approach and the speed plot analysis are compared to a dynamical treatment. As a main topic, we discuss the extraction of the genuine resonance parts of the magnetic dipole and electric quadrupole multipoles of the electromagnetic excitation of the resonance. To this end, we try to relate the various values for the ratio REM of the E2 to M1 multipole excitation strengths for the \ensuremathΔ(1232) resonance as extracted by the different methods to corresponding ratios of a dynamical model. Moreover, it is confirmed that all methods for extracting resonance properties suffer from an unitary ambiguity which is due to some phenomenological contributions entering the models.