Anatomy of the ρ resonance from lattice QCD at the physical point

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12 Scopus citations

Abstract

We propose a strategy to access the qq component of the resonance in lattice QCD. Through a mixed action formalism (overlap valence on domain wall sea), the energy of the qq component is derived at dierent valence quark masses, and shows a linear dependence on m2π. The slope is determined to be c1=0:505(3)GeV-1, from which the valence πρ sigma term is extracted to be δ(val) πρ = 9:82(6) MeV using the Feynman-Hellman theorem. At the physical pion mass, the mass of the qq component is interpolated to be mρ=775:9±6:0±1:8 MeV, which is close to the ρ resonance mass. We also obtain the leptonic decay constant of the qq component to be fρ- =208:5±5:5±0:9 MeV, which can be compared with the experimental value f exp ρ ≈221 MeV through the relation fexp ρ = p Zρfρ ±, with Zρ≈1:13 being the on-shell wavefunction renormalization ofρ owing to the ρ-π interaction. We emphasize that mρ and fρ of the qq component, which are obtained for the first time from QCD, can be taken as the input parameters of ρ in eective field theory studies where ρ acts as a fundamental degree of freedom.

Original languageEnglish
Article number063102
JournalChinese Physics C
Volume42
Issue number6
DOIs
StatePublished - May 2018

Bibliographical note

Publisher Copyright:
© 2018 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Keywords

  • leptonic decay constant
  • renormalization
  • ρ resonance

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation
  • Astronomy and Astrophysics

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