Dynamically-coupled partial-waves in ρπ isospin-2 scattering from lattice QCD


Type
Article
Change log
Authors
Dudek, JJ 
Edwards, RG 
Wilson, DJ 
Abstract

We present the first determination of ρπ scattering, incorporating dynamically-coupled partial-waves, using lattice QCD, a first-principles numerical approach to QCD. Considering the case of isospin-2 ρπ, we calculate partial-wave amplitudes with J≤3 and determine the degree of dynamical mixing between the coupled S and D-wave channels with JP=1+. The analysis makes use of the relationship between scattering amplitudes and the discrete spectrum of states in the finite volume lattice. Constraints on the scattering amplitudes are provided by over one hundred energy levels computed on two lattice volumes at various overall momenta and in several irreducible representations of the relevant symmetry groups. The spectra follow from variational analyses of matrices of correlations functions computed with large bases of meson-meson operators. Calculations are performed with degenerate light and strange quarks tuned to the physical strange quark mass so that mπ∼700 MeV, ensuring that the ρ is stable against strong decay. This work demonstrates the successful application of techniques, opening the door to calculations of scattering processes that incorporate the effects of dynamically-coupled partial-waves, including those involving resonances or bound states.

Description
Keywords
Lattice field theory simulation, QCD Phenomenology
Journal Title
Journal of High Energy Physics
Conference Name
Journal ISSN
1126-6708
1029-8479
Volume Title
2018
Publisher
Springer Science and Business Media LLC
Sponsorship
Science and Technology Facilities Council (ST/P000681/1)
STFC (1628534)