Model Independent Extraction of S-Matrix Poles from Experimental Data

TL;DR

This paper introduces a model-independent method for extracting resonance pole positions from experimental data by fitting data intervals to simple poles and statistically analyzing the results, providing more accurate resonance parameters.

Contribution

It presents a novel approach that separates data into intervals and fits them to simple poles, improving the accuracy of resonance pole extraction without relying on specific models.

Findings

Successfully extracted pole positions for Z and N(1440) resonances.

Resolved discrepancies in Upsilon(11020) mass measurements.

Demonstrated the method's effectiveness on experimental data.

Abstract

By separating data points close to a resonance into intervals, and fitting all possible intervals to a simple pole with constant coherently added background, we obtained a substantial number of convergent fits. After a carefully chosen set of statistical constraints was imposed, we calculated the average of a resonance pole position from the statistically acceptable results. We used this method to find pole positions of Z and N(1440) resonances, and to show that the strong discrepancy between the old and new measurements of the Upsilon(11020) mass stems from specious comparison of the Upsilon(11020) pole with its Breit-Wigner mass.