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arXiv · 1406.0433

Improved sphaleron decoupling condition and the Higgs coupling constants in the real singlet-extended SM

Kaori Fuyuto·Eibun Senaha
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Abstract

We improve the sphaleron decoupling condition in the real singlet-extended standard model. The sphaleron energy is obtained using the finite temperature one-loop effective potential with daisy resummation. For moderate values of the model parameters, the sphaleron decoupling condition is found to be $v_C/T_C>(1.1-1.2)$, where $T_C$ denotes a critical temperature and $v_C$ is the corresponding vacuum expectation value of the doublet Higgs field at $T_C$. We also investigate the deviation of the triple Higgs boson coupling from its standard model value in the region where the improved sphaleron decoupling condition is satisfied. As a result of the improvement, the deviation of the triple Higgs boson coupling gets more enhanced. In a typical case, if the Higgs couplings to the gauge bosons/fermions deviate from the SM values by about 3 (10)%, the deviation of the triple Higgs boson coupling can be as large as about 16 (50)%, which is about 4 (8)% larger than that based on the conventional criterion $v_C/T_C>1$.

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Kaori Fuyuto, Eibun Senaha. 2014-07-27. Improved sphaleron decoupling condition and the Higgs coupling constants in the real singlet-extended SM. https://doi.org/10.1103/physrevd.90.015015

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