engleski

Fixed-t analyticity as a constraint in single- energy partial-wave analyses of meson photoproduction reactions

Partial-wave amplitudes of meson photoproduction reactions are an important source of information in baryon spectroscopy.We investigate a new approach in single-energy partial-wave analyses of these reactions. Instead of using a constraint to theoretical models in order to achieve solutions which are continuous in energy, we enforce the analyticity of the amplitudes at fixed values of the Mandelstam variable t . We present an iterative procedure with successive fixed-t amplitude analyses which constrain the single-energy partial-wave analyses and apply this method to the γp → ηp reaction. We use pseudodata, generated by the EtaMAID model, to test the method and to analyze ambiguities. Finally, we present an analytically constrained partial-wave analysis using experimental data for four polarization observables recently measured at MAMI and GRAAL in the energy range from threshold to √s = 1.85 GeV.

fixed-t analyticity ; partial wave analysis ; meson photoproduction

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