  Finite-volume lattice QCD calculations offer the possibility of extracting
resonance parameters from the energy-dependent elastic phase-shift computed
using the Luescher technique. In this letter, as a trial of the method, we
report on the extraction of the non-resonant phase-shift for S and D-wave pi-pi
isospin-2 scattering from dynamical lattice QCD computations. We define a
variational basis of operators resembling pairs of pions of definite relative
momentum and extract a spectrum of excited states that maps to phase-shifts at
a set of discrete scattering momenta. Computations are performed with pion
masses between 400 and 520 MeV on multiple spatial volumes. We observe no
significant quark mass dependence in the phase-shifts extracted which are in
reasonable agreement with the available experimental data at low momentum.
