Resonances in coupled πK,ηK\pi K, \eta K scattering from lattice QCD

Nov 7, 2014
34 pages
Published in:
  • Phys.Rev.D 91 (2015) 5, 054008
  • Published: Mar 10, 2015
e-Print:
Report number:
  • JLAB-THY-14-1982,
  • DAMTP-2014-81,
  • JLAB-THY-14-1892

Citations per year

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Abstract: (APS)

Coupled-channel πK and ηK scattering amplitudes are determined by studying the finite-volume energy spectra obtained from dynamical lattice QCD calculations. Using a large basis of interpolating operators, including both those resembling a qq¯ construction and those resembling a pair of mesons with relative momentum, a reliable excited-state spectrum can be obtained. Working at mπ=391MeV, we find a gradual increase in the JP=0+ πK phase shift which may be identified with a broad scalar resonance that couples strongly to πK and weakly to ηK. The low-energy behavior of this amplitude suggests a virtual bound state that may be related to the κ resonance. A bound state with JP=1- is found very close to the πK threshold energy, whose coupling to the πK channel is compatible with that of the experimental K(892). Evidence is found for a narrow resonance in JP=2+. Isospin-3/2 πK scattering is also studied, and nonresonant phase shifts spanning the whole elastic scattering region are obtained.

Note:
  • 32 pages, 27 figures - replaced to better match version appearing in PRD. Previously incorrect JLab preprint number also corrected
  • 14.40.Be
  • 12.38.Gc
  • 13.75.Lb
  • resonance: scalar
  • excited state: spectrum
  • energy: threshold
  • pi K
  • lattice field theory
  • phase shift
  • bound state