Coupled-channels analysis of pion and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>η</mml:mi></mml:math> electroproduction within the Jülich-Bonn-Washington model

Abstract

Pion and $\ensuremath{\eta}$ electroproduction data are jointly analyzed for the first time, up to a center-of-mass energy of 1.6 GeV. The framework is a dynamical coupled-channels model, based on the recent J\"ulich-Bonn-Washington analysis of pion electroproduction data for the same energy range. Comparisons are made to a number of single-channel $\ensuremath{\eta}$ electroproduction fits. By comparing multipoles of comparable fit quality, we find some of these amplitudes are well determined over the near-threshold region, while others will require fits over an extended energy range.