Signatures of generalized ALP interactions in SM decays of mesons

In addition to giving rise to spectacular new physics signals in the final states of meson decays, Axion-like-particles also induce modifications in the standard model decays of mesons. These indirect' signatures can be parametrized as the modifications of the hadronic form factors and can be probed using meson decay width and decay distribution measurements. Starting with a generalized ALP Lagrangian, we demonstrate these effects for semileptonic Kaon decays and derived bounds using NA48/2 data. We also briefly discuss other indirect signatures such as modification of meson mass spectrum and sum rules’ comprised of meson decay amplitudes which show deviation in presence of ALP.