5,661 research outputs found
Light- and strange-quark mass dependence of the meson revisited
Recent lattice data on -scattering phase shifts in the
vector-isovector channel, pseudoscalar meson masses and decay constants for
strange-quark masses smaller or equal to the physical value allow us to study
the strangeness dependence of these observables for the first time. We perform
a global analysis on two kind of lattice trajectories depending on whether the
sum of quark masses or the strange-quark mass is kept fixed to the physical
point. The quark mass dependence of these observables is extracted from
unitarized coupled-channel one-loop Chiral Perturbation Theory. This analysis
guides new predictions on the meson properties over trajectories
where the strange-quark mass is lighter than the physical mass, as well as on
the SU(3) symmetric line. As a result, the light- and strange-quark mass
dependence of the meson parameters are discussed and precise values
of the Low Energy Constants present in unitarized one-loop Chiral Perturbation
Theory are given. Finally, the current discrepancy between two- and
three-flavor lattice results for the meson is studied.Comment: 44 pages, 41 figures, 11 table
Strange resonance poles from scattering below 1.8 GeV
In this work we present a determination of the mass, width and coupling of
the resonances that appear in kaon-pion scattering below 1.8 GeV. These are:
the much debated scalar -meson, nowdays known as , the
scalar , the and vectors, the spin-two
as well as the spin-three . The parameters will be
determined from the pole associated to each resonance by means of an analytic
continuation of the scattering amplitudes obtained in a recent and
precise data analysis constrained with dispersion relations, which were not
well satisfied in previous analyses. This analytic continuation will be
performed by means of Pad\'e approximants, thus avoiding a particular model for
the pole parameterization. We also pay particular attention to the evaluation
of uncertainties.Comment: 13 pages, 12 figures. Accepted version to appear in Eur. Phys. J. C.
Clarifications and references added, minor typos correcte
- …