Neutral Kaon mixing beyond the Standard Model

We compute the hadronic matrix elements of the four-quark operators needed for the study of $K^0-{\bar{K}}^0$ mixing beyond the Standard Model. We have used $n_f=2+1$ flavours of domain wall fermion (DWF) at two values of the lattice spacing ($a\approx 0.08$ and $a\approx 0.11\text{fm}$) and with lightest unitary pion mass of $\approx 300\text{MeV}$. Renormalisation is performed non-perturbatively and the impact of different intermediate momentum schemes is investigated.