Scalar Phantoms

In view of the measured Higgs mass of 125 GeV, the perturbative renormalization group evolution of the Standard Model suggests that our Higgs vacuum might not be stable. We connect the usual perturbative approach and the functional renormalization group which allows for a straightforward inclusion of higher-dimensional operators in the presence of an ultraviolet cutoff. In the latter framework we study vacuum stability in the presence of higher-dimensional operators. We find that their presence can have a sizable influence on the maximum ultraviolet scale of the Standard Model and the existence of instabilities. Finally, we discuss how such operators can be generated in specific models and study the relation between the instability scale of the potential and the scale of new physics required to avoid instabilities.

Section: Jhep04(2015)022mentioning

confidence: 99%

The Higgs mass and the scale of new physics

Eichhorn

Gies

Jaeckel

et al. 2015

“…ref. [1][2][3][4][5][6][7][8]), consists in adding to the SM a gauge singlet real scalar η, and assuming that it is stable due to a parity η → −η. The model is quite predictive since it only depends on two extra parameters: the singlet mass m η and its "portal" coupling to the Higgs boson, λ.…”

Section: Motivationmentioning

confidence: 99%

“…To recover the predictions of the renormalizable model [1][2][3][4][5][6][7][8], that we will refer to as the 'non-composite case', we can take the limit f → ∞. In this case only λ controls the interactions of η with the SM fields.…”

Section: Jhep07(2012)015mentioning

confidence: 99%

“…To understand the behavior of the relic density with m η , one should keep in mind that each annihilation channel ηη ↔ XX opens only for η masses above the threshold value m X 1 − v 2 rel /4, with v rel ∼ 2/3 at freeze-out. In order to analyze the effect of the composite interactions, let us recall that in the non-composite 1 An alternative mechanism to generate the DM relic density is freeze-in, that is realized when the DM interactions with the SM are so weak that the DM species was never in equilibrium. In this case SM particles can slowly annihilate (or decay) into DM generating the required relic density.…”

Section: Relic Density Of the Composite Dark Mattermentioning

confidence: 99%

See 1 more Smart Citation

Composite scalar dark matter

Frigerio

Pomarol

Riva

et al. 2012

156

227

We show that the dark matter (DM) could be a light composite scalar η, emerging from a TeV-scale strongly-coupled sector as a pseudo Nambu-Goldstone boson (pNGB). Such state arises naturally in scenarios where the Higgs is also a composite pNGB, as in O(6)/O(5) models, which are particularly predictive, since the low-energy interactions of η are determined by symmetry considerations. We identify the region of parameters where η has the required DM relic density, satisfying at the same time the constraints from Higgs searches at the LHC, as well as DM direct searches. Compositeness, in addition to justify the lightness of the scalars, can enhance the DM scattering rates and lead to an excellent discovery prospect for the near future. For a Higgs mass m h 125 GeV and a pNGB characteristic scale f 1 TeV, we find that the DM mass is either m η 50−70 GeV, with DM annihilations driven by the Higgs resonance, or in the range 100−500 GeV, where the DM derivative interaction with the Higgs becomes dominant. In the former case the invisible Higgs decay to two DM particles could weaken the LHC Higgs signal.

“…The lowest order Higgs portal operators mediating interactions between the DM and the SM states then read H † H|χ| 2 or H † HV µ V µ , with χ and V µ being a scalar and a vector DM candidate, respectively, see e.g. [2][3][4][5][6][7][8][9]. 1 These 1 An analogous fermionic Higgs portal interaction [10,11] is dimension-5.…”

Section: Introductionmentioning

confidence: 99%

Multicomponent Dark Matter from gauge symmetry

Arcadi

Groß

Lebedev

et al. 2016

The composition of Dark Matter (DM) remains an important open question. The current data do not distinguish between single-and multi-component DM, while in theory constructions it is often assumed that DM is composed of a single field. In this work, we study a hidden sector which naturally entails multicomponent DM consisting of spin-1 and spin-0 states. This UV complete set-up is based on SU(3) hidden gauge symmetry with the minimal scalar field content to break it spontaneously. The presence of multiple DM components is a result of a residual Z 2 × Z 2 symmetry which is part of an unbroken global U(1) × Z 2 inherent in the Yang-Mills systems. We find that the model exhibits various parametric regimes with drastically different DM detection prospects. In particular, we find that the direct detection cross section is much suppressed in large regions of parameter space as long as the Standard Model Higgs mixes predominantly with a single scalar from the hidden sector. The resulting scattering rate is often beyond the level of sensitivity of XENON1T, while still being consistent with the thermal WIMP paradigm.