Towards completing the standard model: Vacuum stability, electroweak symmetry breaking, and dark matter

Abstract

We study the standard model (SM) in its full perturbative validity range between ΛQCD and the U (1)Y Landau pole, assuming that a yet unknown gravitational theory in the UV does not introduce additional particle thresholds, as suggested by the tiny cosmological constant and the absence of new stabilising physics at the EW scale. We find that, due to dimensional transmutation, the SM Higgs potential has a global minimum at 10 26 GeV, invalidating the SM as a phenomenologically acceptable model in this energy range. We show that extending the classically scale invariant SM with one complex singlet scalar S allows us to: (i) stabilise the SM Higgs potential; (ii) induce a scale in the singlet sector via dimensional transmutation that generates the negative SM Higgs mass term via the Higgs portal; (iii) provide a stable CP-odd singlet as the thermal relic dark matter due to CP-conservation of the scalar potential; (iv) provide a degree of freedom that can act as an inflaton in the form of the CP-even singlet. The logarithmic behaviour of dimensional transmutation allows one to accommodate the large hierarchy between the electroweak scale and the Landau pole, while understanding the latter requires a new non-perturbative view on the SM.

Minimal conformal extensions of the Higgs sector

“…The description of one additional complex singlet with zero hypercharge is equivalent to the description of two additional real singlets and will be covered in section 2.2 (see also e.g. [46]). If χ is an SU(2) L doublet with Y = 1/2 it is a second Higgs boson and -…”

Constraining dark sectors at colliders: Beyond the effective theory approach

“…These models provide a direct link with Higgs physics and also include theoretical scenarios which manifest a common origin of the electroweak and the DM scales in nature as was recently explored in Refs. [44][45][46][47][48][49][50][51][52][53]. More specifically, consider the case where the mediator is a complex scalar Φ which is a singlet of the SM and interacts with it only via the portal interactions with the Higgs:…”

The Higgs of the Higgs and the diphoton channel

“…They can be divided into two main categories, depending on which correction renormalises a quartic coupling λ down to negative values at low energy, such that the dimension-less potential λ 4 develops a minimum: either λ) corrections due to other scalar quartics [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]; or g) corrections due to a gauge coupling [12,[33][34][35][36][37][38]. 2 1 Furthermore [71] also contain some explicit mass term.…”