It is widely believed that the top loop corrections to the Higgs effective potential destabilize the electroweak vacuum and that, imposing stability, lower bounds on the Higgs mass can be derived. With the help of a scalar-Yukawa model, we show that this apparent instability is due to the extrapolation of the potential into a region where it is no longer valid. Stability turns out to be an intrinsic property of the theory (rather than an additional constraint to be imposed on it). However, lower bounds for the Higgs mass can still be derived with the help of a criterion dictated by the properties of the potential itself. If the scale of new physics lies in the TeV region, sizable differences with the usual bounds are found. Finally, our results exclude the alternative metastability scenario, according to which we might be living in a sufficiently long lived metastable electroweak vacuum.
|Titolo:||Effective potential (in)stability and lower bounds on the scalar (Higgs) mass|
|Data di pubblicazione:||2005|
|Appare nelle tipologie:||1.1 Articolo in rivista|