2006/07/31 by S. Descotes-Genon, Sébastien Descotes–Genon, B. Moussallam · 5 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-lat #hep-ph
paper · pdf · doi:10.1140/epjc/s10052-006-0036-2
published as Eur.Phys.J.C48:553,2006 · 16 pages, 8 figures. Domain of validity of a Roy-Steiner representation corrected and enlarged, and features of the K^*_0(800) pole discussed in more details. Conclusions unchanged
arxiv created 2006/08/25 · openalex publication_date 2006/11/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We discuss the existence of the light scalar meson K^*0(800) (also called kappa) in a rigorous way, by showing the presence of a pole in the pi K --> pi K amplitude on the second Riemann sheet. For this purpose, we study the domain of validity of two classes of Roy-Steiner representations in the complex energy plane. We prove that one of them is valid in a region sufficiently broad in the imaginary direction. From this representation, we compute the l=0 partial wave in the complex plane with neither additional approximation nor model dependence, relying only on experimental data. A scalar resonance with strangeness S=1 is found with the following mass and width: Ekappa = 658 ± 13 MeV and Gammakappa = 557 ± 24 MeV.