Top mass determination, Higgs inflation, and vacuum stability

Abstract

The possibility that new physics beyond the Standard Model (SM) appears only at the Planck scale M P is often considered. However, it is usually assumed that new physics interactions at M P do not affect the electroweak vacuum lifetime, so the latter is obtained neglecting these terms. According to the resulting stability phase diagram, for the current experimental values of the top and Higgs masses, our universe lives in a metastable state (with very long lifetime), near the edge of stability. However, we show that the stability phase diagram strongly depends on new physics and that, despite claims to the contrary, a more precise determination of the top (as well as of the Higgs) mass will not allow to discriminate between stability, metastability or criticality of the electroweak vacuum. At the same time, we show that the conditions needed for the realization of Higgs inflation scenarios (all obtained neglecting new physics) are too sensitive to the presence of new interactions at M P . Therefore, Higgs inflation scenarios require very severe fine tunings that cast serious doubts on these models.

Triple Higgs boson production at a 100 TeV proton-proton collider

“…The so-called 'self-couplings' and their energy dependence are crucial in determining the stability of the vacuum. Current observations suggest that our Universe may be sitting at a metastable false vacuum [1][2][3][4][5][6][7][8] and measurements of these couplings will illuminate this fact further. At colliders, these terms, i.e.…”

“…5 The excellent resolution of the di-photon invariant mass, that has contributed to the Higgs boson discovery at the LHC's Run 1, can be exploited to facilitate background rejection. The present analysis follows a simple path, using the R = 0.4 anti-k t jets as described in section 3.…”

The Higgs mass and the scale of new physics

“…(2.9). The additional logarithmic contribution to the quartic potential term contributes to the Higgs mass as [54,[64][65][66] …”

“…In this appendix we briefly discuss estimates for the tunneling rates in the presence of a ∼ λ 6 ϕ 6 -term [64][65][66][67]. The tunnelling rate can be calculated by determining the Euclidean action of bubbles S E [ϕ bounce ], where ϕ bounce is the bounce solution of the Euclidean equations of motion for a real scalar field…”

“…[64][65][66] that the presence of higher-order operators could have a significant impact on the lifetime of the electroweak vacuum in a meta-stable situation, for example if λ 6 is negative. Estimates relying solely on λ 4 strictly only apply to a restricted set of UV-completions.…”