Effective Lagrangian for strong and electromagnetic interactions of high-spin resonances

Abstract

Recent experiments of photon-nucleon and meson-nucleon scatterings have accumulated a lot of data for various meson production processes. One of the purposes of those experiments is to search for the missing resonances which were not discovered until now but whose existence was predicted by hadron models. The analyses of the data requires the development of dynamical coupled-channel models. Since several missing resonances are expected to have spin higher than 3/2, we need to include higher-spin resonances in dynamical coupled-channel models, which enable us to determine the couplings of effective Lagrangians of higher-spin baryons with pseudoscalar mesons or vector mesons. However, hadron models, such as quark models, give predictions only of the decay amplitudes of such baryons. Here we demonstrate the formalism of high-spin resonances and construct the relation between the coupling constants of effective Lagrangians and the partial decay widths that can be predicted by hadron models. This allows us to compare the coupling constants to the hadron model predictions not only in magnitude but in sign as well. Published by the American Physical Society 2025