How to define physical properties of unstable particles
High Energy Physics - Phenomenology
2014-11-20 v1
Abstract
In the framework of effective quantum field theory we address the definition of physical quantities characterizing unstable particles. With the aid of a one-loop calculation, we study this issue in terms of the charge and the magnetic moment of a spin-1/2 resonance. By appealing to the invariance of physical observables under field redefinitions we demonstrate that physical properties of unstable particles should be extracted from the residues at complex (double) poles of the corresponding S-matrix.
Keywords
Cite
@article{arxiv.0910.4280,
title = {How to define physical properties of unstable particles},
author = {J. Gegelia and S. Scherer},
journal= {arXiv preprint arXiv:0910.4280},
year = {2014}
}
Comments
11 pages, 3 figures, REVTeX 4