Light- and strange-quark mass dependence of the ρ(770) meson revisited

• Main Authors: R. Molina, J. Ruiz de Elvira
• Format: Article
• Language: English
• Published: SpringerOpen 2020-11-01
• Series: Journal of High Energy Physics
• Subjects: Chiral Lagrangians; Lattice QCD
• Online Access: http://link.springer.com/article/10.1007/JHEP11(2020)017

Abstract Recent lattice data on ππ-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 ρ(770) 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 ρ(770) 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 ρ(770) meson is studied.