On interference effects in top-philic decay chains

Sizeable exotic Higgs boson production through gluon fusion via top quark loops is correlated with large Higgs decay probabilities into top quark final states, if these are kinematically accessible. It is known that gg -> S -> t (t) over bar over line is particularly susceptible to signal-background interference effects that can significantly impact discovery sensitivities. In such an instance, identifying more robust signatures to enhance the discovery sensitivity becomes necessary, shifting phenomenological focus to final states that show a reduced destructive signal-background interference. In this work, we discuss the phenomenological relevance of signal-signal and signal-background interference effects for decay chains. In particular, we identify asymmetric cascade decays in models of scalar extensions of the SM Higgs sector as new promising candidates. In parallel, characteristic interference patterns can provide a formidable tool for indirect CP spectroscopy of BSM sectors if a discovery is made in the future. This motivates associated searches at present and future colliders as robust discovery modes of new physics, in addition to serving as a sensitive tool for the reconstruction of the underlying UV electroweak potential. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The study discusses the phenomenological relevance of signal-signal and signal-background interference effects for decay chains, highlighting the potential of asymmetric cascade decays in models of scalar extensions of the SM Higgs sector. Additionally, characteristic interference patterns can serve as a powerful tool for indirect CP spectroscopy of BSM sectors if discoveries are made in the future, motivating associated searches at present and future colliders for robust discovery of new physics and reconstruction of the underlying UV electroweak potential.