Physics beyond the standard model with kaons at NA62

Also a search for an invisible dark photon A′ has been performed, exploiting the efficient photon-veto capability and high resolution tracking of the NA62. The signal stems from the chain $\mathit{K}$+ → $\pi ^{+} \pi^{0}$ followed by $ \pi^{0}$ → $\mathit{A}$′γ. No significant statistical excess has been identified. Upper limits on the dark photon coupling to the ordinary photon as a function of the dark photon mass have been set, improving on the previous limits over the mass range 60 - 110 MeV/c2.