The K+K+ scattering length is calculated in fully-dynamical lattice QCD with domain-wall valence quarks on the MILC asqtad-improved gauge configurations with rooted staggered sea quarks. Three-flavor mixed-action chiral perturbation theory at next-to-leading order, which includes the leading effects of the finite lattice spacing, is used to extrapolate the results of the lattice calculation to the physical value of m_{ K+}/f_{ K+}. We find m_{ K+} a_{ K+K+} = -0.352 +- 0.016, where the statistical and systematic errors have been combined in quadrature.
Categories: hep-lat hep-ph nucl-th