Poles, the only true resonant-state signals, are extracted from a worldwide collection of partial wave amplitudes using only one, well controlled pole-extraction method

TL;DR

This paper introduces a single, well-controlled pole-extraction method to identify true resonant states from worldwide partial wave data, reducing model dependence and establishing more reliable resonance existence confidence.

Contribution

The study presents a unified, analytic, coupled-channel approach for pole extraction that minimizes model assumptions, providing a more robust identification of resonant states.

Findings

Successfully applied to the S11 partial wave.

Reduces model dependence in pole extraction.

Establishes confidence limits for resonance existence.

Abstract

Each and every energy dependent partial-wave analysis is parameterizing the pole positions in a procedure defined by the way how the continuous energy dependence is implemented. These pole positions are, henceforth, inherently model dependent. To reduce this model dependence, we use only one, coupled-channel, unitary, fully analytic method based on the isobar approximation to extract the pole positions from the each available member of the worldwide collection of partial wave amplitudes which are understood as nothing more but a good energy dependent representation of genuine experimental numbers assembled in a form of partial-wave data. In that way, the model dependence related to the different assumptions on the analytic form of the partial-wave amplitudes is avoided, and the true confidence limit for the existence of a particular resonant state, at least in one model, is established. The way how the method works, and first results are demonstrated for the S11 partial wave.