Constraining the Higgs-dilaton with LHC and dark matter searches

Abstract

We study a scenario in which the dilaton, a pseudo-Goldstone boson of the spontaneous breaking of conformal symmetry, provides a portal between dark matter and the visible sector. We consider the low-energy description of the theory in which the dilaton mixes with the Standard Model Higgs boson, thereby predicting a second scalar at or above the weak scale. We derive the collider and dark matter constraints on the corresponding parameter space and find that existing experimental data point towards the decoupling limit in which the CFT scale is well above the electroweak scale. Moreover, the thermal production of dark matter implies its mass is likely above the TeV scale. Upcoming direct detection experiments may allow for the discovery of the dilaton-mediated thermal dark matter while future collider studies will also be sensitive to the available parameter space.

Electroweak phase transition and baryogenesis in composite Higgs models

“…Let us now briefly discuss the possible ways to test these couplings. The dilaton phenomenology is in many respects similar to the phenomenology of the SM Higgs, with differences mainly caused by the different masses, and the different couplings which are reduced roughly by a factor of v/χ 0 for the dilaton [57,58] (a more precise estimate of the couplings in our case is given by the expressions above). The dilaton couplings to the massive SM gauge bosons (7.7) control the vector boson fusion channel for dilaton production, which can be tagged by forward jets and thus be well tested even if the dominant χ production channel is different, i.e.…”

Interpreting a 750 GeV diphoton resonance

“…We consider a generalization of the dilaton scenario of ref. [30], taking the full SM, including the Higgs doublet, to be part of a conformal sector (see also [36]). The dilaton is the PNGB of the spontaneously broken scale invariance.…”

Heavy dark matter through the dilaton portal

“…Models of dilaton portal dark matter have also been well studied in the literature [9,[15][16][17][18]. In this paper, we will study both the fermionic and vector dark matter cases in detail, pointing out along the way the connection between the dilaton portal and models of vector dark matter based on effective field theory.…”