In this Letter, we propose a new possible connection between dark matter relic density and baryon asymmetry of the universe. The portal between standard model sector and dark matter not only controls the relic density and detections of dark matter, but also allows the dark matter to trigger the first order electroweak phase transition. We discuss systematically possible scalar dark matter candidates, starting from a real singlet to arbitrary high representations. We show that the simplest realization is provided by a doublet, and that strong first-order electroweak phase transition implies a lower bound on the dark matter direct detection rate. The mass of dark matter lies between 45 and 80 GeV, allowing for an appreciable invisible decay width of the Standard Model Higgs boson, which is constrained to be lighter than 130 GeV for the sake of the strong phase transition.Introduction. The existence of dark matter (DM) has now been well established in astrophysical and cosmological observations, and it is known to constitute around twenty percent of the total energy density in the universe. Many experiments have been setup underground or in the sky in order to probe DM interactions.The most popular DM candidate is a stable weaklyinteracting massive particle (WIMP) [1]. The correct thermal relic density is obtained if its mass lies near the electroweak scale, thus possible connections to electroweak symmetry breaking could be conjectured. Another possibility is the asymmetric dark matter [2] whose origin can be related to the baryogenesis processes in the universe. This scenario has been revived recently in different incarnations [3], due to the observation that DM and baryon relic densities are of the same order of magnitude, and also partly inspired by the hints of a light GeV scale DM from direct detection experiments. One of the common features of the above listed work is, they all resort to baryon/lepton number violations beyond the SM. However, baryon number is known not to be exact in the SM [4] and it is possible to have baryon number violating process happening efficiently at a high temperature [5,6] if the minimal Higgs sector is extended.In this Letter, we propose a scenario, where the portal between the standard model (SM) and dark sectors not only gives correct relic density and facilitates direct/indirect detections of DM, but also allows the DM to play an important role in the electroweak baryogenesis. Based on this picture, a new connection could be built between symmetric dark matter and asymmetric baryonic matter.An essential ingredient for successful electroweak baryogenesis is the existence of a strong enough first order phase transition. The finite temperature Higgs potential should contain a term proportional to φ 3 T . Such a term exists in the SM but is not large enough. If the DM were to do the job, it would have to be a scalar particle. Namely, fermions never contribute to the cubic

The extension of the standard model's minimal Higgs sector with an inert SU (2) L scalar doublet can provide light dark matter candidate and simultaneously induce a strong phase transition for explaining Baryogenesis. There is however no symmetry reasons to prevent the extension using scalars with higher SU (2) L representations. By making random scans over the models' parameters, we show that in the light of electroweak physics constraints, strong first order electroweak phase transition and the possibility of having sub-TeV cold dark matter candidate the higher representations are rather disfavored compared to the inert doublet. This is done by computing generic perturbativity behavior and impact on electroweak phase transitions of higher representations in comparison with the inert doublet model. Explicit phase transition and cold dark matter phenomenology within the context of the inert triplet and quartet representations are used for detailed illustrations.1 Scalar singlet can also be a force carrier between SM and dark matter sector inducing strong EWPhT [58,59] or trigger EWPhT independent of being DM [60].

In this work we investigate the sphaleron solution in a SU(2) × U(1) X gauge theory, which also encompasses the Standard Model, with higher scalar representation(s) (J (i) , X (i) ). We show that the field profiles describing the sphaleron in higher scalar multiplet, have similar trends like the doublet case with respect to the radial distance. We compute the sphaleron energy and find that it scales linearly with the vacuum expectation value of the scalar field and its slope depends on the representation. We also investigate the effect of U(1) gauge field and find that it is small for the physical value of the mixing angle, θ W and resembles the case for the doublet. For higher representations, we show that the criterion for strong first order phase transition, v c /T c > η, is relaxed with respect to the doublet case, i.e. η < 1.

We study various properties of a Proca field coupled to gravity through minimal and quadrupole interactions, described by a two-parameter family of Lagrangians. Stückelberg decomposition of the effective theory spells out its model-dependent ultraviolet cutoff, parametrically larger than the Proca mass. We present pp-wave solutions that the model admits, consider linear fluctuations on such backgrounds, and thereby constrain the parameter space of the theory by requiring null-energy condition and the absence of negative time delays in high-energy scattering. We briefly discuss the positivity constraints−derived from unitarity and analyticity of scattering amplitudes−that become ineffective in this regard.

Abstract:We investigate the lepton flavor violation (LFV) in the inert scalar model with higher representations. We generalize the inert doublet model with right handed neutrino by using higher scalar and fermion representation of SU(2) L . As the generalized model and the inert doublet model have the same parameter space, we compare the rates of µ → eγ, µ → eee and µ − e conversion in nuclei in the doublet and its immediate extension, the quartet model. We show that the corresponding rates are larger in the case of higher representation compared to the Inert doublet for the same region of parameter space. This implies that such extended models are more constrained by current LFV bounds and will have better prospects in future experiments.

The mystery of dark matter remains an unsettled problem of particle physics. On top of that, experiments show a persistent contention of the muon anomalous magnetic moment (AMM) relative to the Standard Model (SM) prediction. In this work, we consider the possibility of extending the SM with a non-Abelian gauge symmetry SU(2) X , under which SM leptons transform non-trivially. SM leptons receive corrections to their AMMs of right order via one-loop processes mediated by beyond SM (BSM) fermions required to cancel anomalies, and BSM gauge bosons that play the role of dark matter. We show that simultaneous explanation of the muon AMM along with reproducing correct relic abundance allows rather a narrow range of 0.5–2 TeV dark matter mass, consistent with current experimental constraints. However, a concurrent description that also includes electron AMM is challenging in this set-up.

We investigate the Sommerfeld enhancement (SE) in the generalized scotogenic model with large electroweak multiplets. We focus on scalar dark matter (DM) candidate of the model and compare DM annihilation cross sections to W W , ZZ, γγ and γZ at present day in the galactic halo for scalar doublet and its immediate generalization, the quartet in their respective viable regions of parameter space. We find that larger multiplet has sizable Sommerfeld enhanced annihilation cross section compared to the doublet and because of that it is more likely to be constrained by the current H.E.S.S. results and future CTA sensitivity limits. The ModelThe scalar sector of the generalized scotogenic model has been presented in [55,61]. Here we briefly present the potential and the particle states for setting up our notations.

Very recently, a substantial 7σ deviation of the W -boson mass from the Standard Model (SM) prediction has been reported by the CDF collaboration. Furthermore, the Muon g-2 Experiment recently confirmed the longstanding tension in (g − 2)µ. Besides, the updated result from the LHCb collaboration found evidence for the breaking of lepton universality in beauty-quark decays, which shows a 3.1σ discrepancy and is consistent with their previous measurements. Motivated by several of these drawbacks of the SM, in this work, we propose a model consisting of two scalar leptoquarks and a vectorlike quark to simultaneously address the W -boson mass shift, the (g−2)µ, and anomalies in the neutral current transitions of the B-meson decays. The proposed model also sheds light on the origin of neutrino mass and can be tested at the LHC and B meson factories.