  We simulate K pi scattering in s-wave and p-wave for both isospins I=1/2, 3/2
using quark-antiquark and meson-meson interpolating fields. We extract the
elastic phase shifts delta at several values of the K-pi relative momenta. The
resulting phases exhibit qualitative agreement with the experimental phases in
all four channels. We express the s-wave phase shifts near threshold in terms
of the scattering length and the effective range. Our K pi system has zero
total momentum and is simulated on a single ensemble with two dynamical quarks,
so results apply for mpi=266 MeV and mK=552 MeV in our simulation. The
backtracking contractions in both I=1/2 channels are handled by the use of
Laplacian-Heavyside smeared quarks within the distillation method. Elastic
phases are extracted from the energy levels using Luscher's relations. In all
four channels we observe the expected K(n)pi(-n) scattering states, which are
shifted due to the interaction. In both attractive I=1/2 channels we observe
additional states that are related to resonances; we attribute them to
K_0^*(1430) in s-wave and K*(892), K*(1410) and K*(1680) in p-wave.

High Energy Physics - Lattice;High Energy Physics - Phenomenology