Comment on "Mass and Width of the Lowest Resonance in QCD"

Abstract

I. Caprini's, G. Colangelo's, and H. Leutwyler's (CCL) article "Mass and Width of the Lowest Resonance in QCD", Phys. Rev. Lett. 96, 132001 (2006) [hep-ph/0512364], is critically reviewed. The present comment is devoted to complement a recent experimental discussion (D.V. Bugg, J. Phys. G 34, 151 (2007) [hep-ph/0608081]) of short-comings in the CCL analysis, by presenting theoretical arguments pointing at a serious flaw in the theoretical formalism used by CCL, and also at the unlikeliness of their tiny error bars in the sigma-meson mass and width. The criticism made in the comment applies analogously to the analysis on the kappa-meson mass performed in the article "The K0*(800) scalar resonance from Roy-Steiner representations of pi K scattering" published as S. Descotes-Genon and B. Moussallam, Eur. Phys. J. C 48, 553 (2006) [hep-ph/0607133].