Signature of Pseudo Nambu-Goldstone Higgs boson in its Decay

Abstract

If the Higgs boson is a pseudo Nambu-Goldstone boson (PNGB), the $hZ\gamma$ contact interaction induced by the $\mathcal{O}(p^4)$ invariants of the non-linear sigma model is free from its nonlinearity effects. The process $h\to Z\gamma$ can be used to eliminate the universal effects of heavy particles, which can fake the nonlinearity effects of the PNGB Higgs boson in the process $h\to V^{\ast }V$ ($V=W^{\pm }$,\ $Z$). We demonstrate that the ratio of the signal strength of $h\to Z\gamma$ and $h\to V^{\ast }V$ is good to distinguish the signature of the PNGB Higgs boson from Higgs coupling deviations.