Complex masses in the S-matrix
Abstract
Most excited hadrons have multiparticle strong decay modes, which can often be described as resulting from intermediate states containing one or two resonances. In a theoretical approach, such a description in terms of quasi-two-particle initial and final states leads to unitarity violations, because of the complex masses of the involved resonances. In the present paper, an empirical algebraic procedure is presented to restore unitarity of the S-matrix while preserving its symmetry. Preliminary results are presented in a first application to S-wave pion-pion scattering, in the framework of the Resonance-Spectrum Expansion.
Cite
@article{arxiv.1005.2490,
title = {Complex masses in the S-matrix},
author = {George Rupp and Susana Coito and Eef van Beveren},
journal= {arXiv preprint arXiv:1005.2490},
year = {2015}
}
Comments
6 pages, 2 figures, Acta Physica Polonica B style; plenary talk given by George Rupp at the workshop Excited QCD 2010, 31 Jan. - 6 Feb. 2010 in Stara Lesna, Slovakia