1. The K* 0(800) scalar resonance from Roy–Steiner representations of πK scattering
- Author
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B. Moussallam, S. Descotes-Genon, Laboratoire de Physique Théorique d'Orsay [Orsay] (LPT), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
- Subjects
Particle physics ,Physics and Astronomy (miscellaneous) ,Scalar (mathematics) ,FOS: Physical sciences ,Strangeness ,01 natural sciences ,Resonance (particle physics) ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,symbols.namesake ,High Energy Physics - Phenomenology (hep-ph) ,High Energy Physics - Lattice ,0103 physical sciences ,010306 general physics ,Scalar meson ,Engineering (miscellaneous) ,Mathematical physics ,Physics ,010308 nuclear & particles physics ,Plane (geometry) ,High Energy Physics - Lattice (hep-lat) ,High Energy Physics - Phenomenology ,Riemann hypothesis ,Amplitude ,[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] ,symbols ,Complex plane - Abstract
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: E_kappa = 658 \pm 13 MeV and Gamma_kappa = 557 \pm 24 MeV., 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
- Published
- 2006
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