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

• Published in: The journal of high energy physics 2020-11, Vol.2020 (11), p.1-74, Article 17
• Main Authors: Molina, R., de Elvira, J. Ruiz
• Format: Article
• Language: English
• Subjects: Chiral dynamics; Chiral Lagrangians; Classical and Quantum Gravitation; Decay rate; Dependence; Elementary Particles; High energy physics; Lattice QCD; Perturbation theory; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Regular Article - Theoretical Physics; Relativity Theory; Strangeness; String Theory
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP11(2020)017

A bstract 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.