Quark-Mass Dependence of Elastic $πK$ Scattering from QCD

Journal Article · 23 July 2019 · Physical Review Letters

DOI: https://doi.org/10.1103/PhysRevLett.123.042002 · OSTI ID:1545442

Wilson, David J. ; Briceño, Raúl A.; Dudek, Jozef J.; Edwards, Robert G.; Thomas, Christopher E.

We present a determination of the isospin-½ elastic $πK$ scattering amplitudes in $$S$$ and $$P$$ partial waves using lattice quantum chromodynamics. The amplitudes, constrained for a large number of real-valued energy points, are obtained as a function of light-quark mass, corresponding to four pion masses between 200 and 400 MeV, at a single lattice spacing. Below the first inelastic threshold, the $$P$$-wave scattering amplitude is dominated by a single pole singularity that evolves from being a stable bound state at the highest quark mass into a narrow resonance that broadens as the pion and kaon masses are reduced. As in experiment, the $$S$$-wave amplitude does not exhibit an obviously resonant behavior, but instead shows a slow rise from threshold, which is not inconsistent with the presence of a $$κ/K_{0}^{*}$$(700)-like resonance at the considered quark masses. As has been found in analyses of experimental scattering data, simple analytic continuations into the complex energy plane of precisely determined lattice QCD amplitudes on the real energy axis are not sufficient to model-independently determine the existence and properties of this state. The spectra and amplitudes we present will serve as an input for increasingly elaborate amplitude analysis techniques that implement more of the analytic structure expected at complex energies.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: National Science Foundation (NSF); Royal Society–Science Foundation Ireland University; Science and Technology Facilities Council (STFC); State of Illinois; USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21). Scientific Discovery through Advanced Computing (SciDAC); USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• Contributing Organization: Hadron Spectrum Collaboration
• Grant/Contract Number: AC02-05CH11231; AC05-00OR22725; AC05-06OR23177; SC0018416; SC0019229
• OSTI ID: 1545442
• Report Number(s): DOE/OR/23177--4665; JLAB-THY--19-2911; arXiv:1904.03188; 042002
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 123; ISSN 0031-9007; ISSN PRLTAO
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English