Resonances in coupled {\pi}K,{\eta}K scattering from quantum chromodynamics

Abstract

Using first-principles calculation within Quantum Chromodynamics, we are able to determine a pattern of strangeness=1 resonances which appear as complex singularities within coupled $\pi K$, $\eta K$ scattering amplitudes. We make use of numerical computation in the lattice discretized approach to the quantum field theory with light quark masses corresponding to $m_{\pi }\sim 400\text{MeV}$ and at a single lattice spacing. The energy dependence of scattering amplitudes is extracted through their relationship to the discrete spectrum in a finite-volume, which we map out in unprecedented detail.

Comments: V3: version accepted for publication in PRL. A code bug which led to incorrect normalization of certain correlation functions is corrected - qualitative features of the results remain unchanged