Gravity-mediated (or composite) dark matter

Abstract

Dark matter could have an electroweak origin, yet communicate with the visible sector exclusively through gravitational interactions. In a set-up addressing the hierarchy problem, we propose a new dark matter scenario where gravitational mediators, arising from the compactification of extra-dimensions, are responsible for dark matter interactions and its relic abundance in the Universe. We write an explicit example of this mechanism in warped extradimensions and work out its constraints. We also develop a dual picture of the model, based on a four-dimensional scenario with partial compositeness. We show that Gravity-mediated Dark Matter is equivalent to a mechanism of generating viable dark matter scenarios in a strongly-coupled, near-conformal theory, such as in composite Higgs models. *

See-saw composite Higgs model at the LHC: Linking naturalness to the 750 GeV diphoton resonance

“…The neutral heavy fermions in our model can play the role of DM, with the resonance φ playing the role of a DM mediator. Similar scenarios have been discussed in the literature in the context of radion/dilaton and axion mediators, for the CP-even [12] and CP-odd [13] cases. In our case, the DM mediator should be a CP-odd η, since then the annihilation cross section is s-wave unsuppressed.…”

“…The cross section σðpp → H → γγÞ needed to accommodate the diphoton excess, its best-fit value given by (21), can be related to the fermion parameters responsible for the production and decay. The production cross section σ XS ðgg → HÞ is only dependent on g H G in (12), and its value at 13 TeV LHC is (see e.g. [10])…”

Benchmarks for Higgs effective theory: extended Higgs sectors

“…The b i are the β function coefficients leading to anomalous scale-invariance violations (dilaton) or, equivalently, contributions from fields localized near the IR brane or bulk running (radion) [125][126][127]. The values of b i depend on the degree of compositeness of fermions in the SM and possible new CFT contributions.…”

Diboson excesses demystified in effective field theory approach

“…4 We assumed that the spin-2 resonance couples dominantly to the transverse modes of SM gauge bosons [54,55] while the terms proportional to the metric g µν in the energymomentum tensor vanish under the traceless condition. For a heavy spin-2 resonance with m G m W,Z , the gauge boson mass terms can be ignored, even if the spin-2 resonance couples to the longitudinal modes of gauge bosons as well [54,55]. The partial decay widths of the spin-2 resonance with CP-even interactions into γγ, Zγ, ZZ, W + W − , and gg [54,55] are…”

“…For a heavy spin-2 resonance with m G m W,Z , the gauge boson mass terms can be ignored, even if the spin-2 resonance couples to the longitudinal modes of gauge bosons as well [54,55]. The partial decay widths of the spin-2 resonance with CP-even interactions into γγ, Zγ, ZZ, W + W − , and gg [54,55] are…”