Mass and width of the $\Delta (1232)$ resonance using complex-mass renormalization

Abstract

We discuss the pole mass and the width of the $\Delta (1232)$ resonance to third order in chiral effective field theory. In our calculation we choose the complex-mass renormalization scheme (CMS) and show that the CMS provides a consistent power-counting scheme. In terms of the pion-mass dependence, we compare the convergence behavior of the CMS with the small-scale expansion (SSE).

Comments: 15 pages, 6 figures