arXiv:0707.2030·v1·High Energy Physics — Phenomenology
On the definition of the \Delta mass and width
D. Djukanovic🇩🇪 · J. Gegelia🇩🇪 · S. Scherer🇩🇪
Abstract
In the framework of effective field theory we show that, at two-loop order, the mass and width of the \Delta resonance defined via the (relativistic) Breit-Wigner parametrization both depend on the choice of field variables. In contrast, the complex-valued position of the pole of the propagator is independent of this choice.
Comments: 3 pages, 1 figure, REVTeX 4