The Probable Fate of the Standard Model
J. Ellis, J.R. Espinosa, G.F. Giudice, A. Hoecker, A. Riotto
(Submitted on 4 Jun 2009 (v1), last revised 22 Jul 2009 (this version, v2))
Extrapolating the Standard Model to high scales using the renormalisation group, three possibilities arise, depending on the mass of the Higgs boson: if the Higgs mass is large enough the Higgs self-coupling may blow up, entailing some new non-perturbative dynamics; if the Higgs mass is small the effective potential of the Standard Model may reveal an instability; or the Standard Model may survive all the way to the Planck scale for an intermediate range of Higgs masses. This latter case does not necessarily require stability at all times, but includes the possibility of a metastable vacuum which has not yet decayed. We evaluate the relative likelihoods of these possibilities, on the basis of a global fit to the Standard Model made using the Gfitter package. This uses the information about the Higgs mass available directly from Higgs searches at LEP and now the Tevatron, and indirectly from precision electroweak data. We find that the 'blow-up' scenario is disfavoured at the 99% confidence level (96% without the Tevatron exclusion), whereas the `survival' and possible 'metastable' scenarios remain plausible. A future measurement of the mass of the Higgs boson could reveal the fate of the Standard Model.
Comments: 16 pp, 7 figs
Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Theory (hep-th)
Journal reference: Phys.Lett.B679:369-375,2009
Report number: CERN-PH-TH/2009-058
Cite as: arXiv:0906.0954v2 [hep-ph]
[v1] Thu, 4 Jun 2009 18:25:10 GMT (151kb)
[v2] Wed, 22 Jul 2009 09:10:17 GMT (232kb)
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Uma mudança paradigmática à vista???
