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Quark-Mass Dependence of Elastic πK Scattering from QCD.

Published version
Peer-reviewed

Type

Article

Change log

Authors

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

Abstract

We present a determination of the isospin-1/2 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.

Description

Keywords

Hadron Spectrum Collaboration

Journal Title

Phys Rev Lett

Conference Name

Journal ISSN

0031-9007
1079-7114

Volume Title

123

Publisher

American Physical Society (APS)
Sponsorship
Science and Technology Facilities Council (ST/P000681/1)