Extracting the resonance parameters from experimental data on scattering of charged particles

Abstract

A new parametrization of the multi-channel S-matrix is used to fit scattering data and then to locate the resonances as its poles. The S-matrix is written in terms of the corresponding "in" and "out" Jost matrices which are expanded in the Taylor series of the collision energy E around an appropriately chosen energy E0. In order to do this, the Jost matrices are written in a semi-analytic form where all the factors (involving the channel momenta and Sommerfeld parameters) responsible for their "bad behaviour" (i.e. responsible for the multi-valuedness of the Jost matrices and for branching of the Riemann surface of the energy) are given explicitly. The remaining unknown factors in the Jost matrices are analytic and single-valued functions of the variable E and are defined on a simple energy plane. The expansion is done for these analytic functions and the expansion coefficients are used as the fitting parameters. The method is tested on a two-channel model, using a set of artificially generated data points with typical error bars and a typical random noise in the positions of the points.

arXiv comment15 pages, 7 figures, 2 tables

References in corpus (5)

• Padé Approximants and Resonance Poles
• A METHOD OF CALCULATING THE JOST FUNCTION FOR ANALYTIC POTENTIALS
• Pade approximation of the S-matrix as a way of locating quantum resonances and bound states
• Analyzing the contribution of individual resonance poles of the S-matrix to the two-channel scattering
• A method for extracting the resonance parameters from experimental cross section

Cited by in corpus (3)

• Numerical calculation of the decay widths, the decay constants, and the decay energy spectra of the resonances of the delta-shell potential
• Jost-matrix analysis of the resonance 5He*(3/2+) near the dt-threshold
• $R$-matrix type parametrization of the Jost function for extracting the resonance parameters from scattering data