Decays of an exotic 1-+ hybrid meson resonance in QCD
Abstract
We present the first determination of the hadronic decays of the lightest exotic JP C=1-+ resonance in lattice QCD. Working with SU(3) flavor symmetry, where the up, down and strange-quark masses approximately match the physical strange-quark mass giving mπ∼700 MeV , we compute finite-volume spectra on six lattice volumes which constrain a scattering system featuring eight coupled channels. Analytically continuing the scattering amplitudes into the complex-energy plane, we find a pole singularity corresponding to a narrow resonance which shows relatively weak coupling to the open pseudoscalar-pseudoscalar, vector-pseudoscalar and vector-vector decay channels, but large couplings to at least one kinematically closed axial-vector-pseudoscalar channel. Attempting a simple extrapolation of the couplings to physical light-quark mass suggests a broad π1 resonance decaying dominantly through the b1π mode with much smaller decays into f1π , ρ π , η′π and η π . A large total width is potentially in agreement with the experimental π1(1564 ) candidate state observed in η π , η′π , which we suggest may be heavily suppressed decay channels.
- Publication:
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Physical Review D
- Pub Date:
- March 2021
- DOI:
- 10.1103/PhysRevD.103.054502
- arXiv:
- arXiv:2009.10034
- Bibcode:
- 2021PhRvD.103e4502W
- Keywords:
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- High Energy Physics - Lattice;
- High Energy Physics - Phenomenology
- E-Print:
- 33 pages, 20 figures, small changes to match published version