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Threshold Effects in Two--Photon Decays of Higgs Particles

Kirill Melnikov·Michael Spira·Oleg Yakovlev
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Abstract

The couplings of Higgs particles to two photons are analyzed in the threshold region, where the Higgs mass is about twice the loop--particle mass leading to possible bound state formation. The amplitude of the pseudoscalar decay $A\to γγ$ for pseudoscalar masses in the range of $(t\bar t)$--bound state masses is calculated in leading and next--to--leading order in $α_s$. It is shown that the real and imaginary parts of the form factor are significantly different from the lowest order perturbative one.

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Kirill Melnikov, Michael Spira, Oleg Yakovlev. 1994-05-16. Threshold Effects in Two--Photon Decays of Higgs Particles. https://doi.org/10.1007/bf01560100

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