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arXiv · hep-ph/9708286

Decay of Z into Three Pseudoscalar Bosons

E. Keith·Ernest Ma
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Abstract

We consider the decay of the $Z$ boson into three pseudoscalar bosons in a general two-Higgs-doublet model. Assuming $m_A$ to be very small, and that of the two physical neutral scalar bosons $h_1$ and $h_2$, $A$ only couples to $Z$ through $h_1$, we find the $Z \to A A A$ branching fraction to be negligible for moderate values of $\tan β\equiv v_2/v_1$, if there is no $λ_5 (Φ_1^\dagger Φ_2)^2 + h.c.$ term in the Higgs potential; otherwise there is no absolute bound but very large quartic couplings (beyond the validity of perturbation theory) are needed for it to be observable.

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E. Keith, Ernest Ma. 1997-08-08. Decay of Z into Three Pseudoscalar Bosons. https://doi.org/10.1103/physrevd.57.2017

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