Right-Handed Neutrinos as the Origin of the Electroweak Scale

The insular nature of the Standard Model may be explained if the Higgs mass parameter is only sensitive to quantum corrections from physical states. Starting from a scale-free electroweak sector at tree-level, we postulate that quantum effects of heavy right-handed neutrinos induce a mass term for a scalar weak doublet that contains the dark matter particle. In turn, below the scale of heavy neutrinos, the dark matter sector sets the scale of the Higgs potential. We show that this framework can lead to a Higgs mass that respects physical naturalness, while also providing a viable scalar dark matter candidate, realistic light neutrino masses, and the baryon asymmetry of the Universe via leptogenesis. The proposed scenario can remain perturbative and stable up to the Planck scale, thereby accommodating simple extensions to include a high scale (2\times 10^{16} GeV) inflationary sector, implied by recent measurements. In that case, our model typically predicts that the dark matter scalar is close to 1 TeV in mass and could be accessible in near future direct detection experiments.Comment: Revtex4, 10 pages, 6 figures. An appendix on a classically scale invariant scenario for right-handed neutrino masses, as well as new references added. Version accepted for publication in PR

Dark Matter from Hidden Forces

We examine the possibility that dark matter may be the manifestation of dark forces of a hidden sector, i.e. "Dark Force = Dark Matter." As an illustrative and minimal example we consider the hidden SU(2)_h x U(1)_h gauge group. The hidden dynamics is indirectly coupled to the Standard Model (SM) through kinetic mixing of U(1)_h with the U(1)_Y of hypercharge. We assume a hidden symmetry breaking pattern analogous to that of the SM electroweak symmetry, augmented with an extra scalar that allows both the "hidden Z boson" Z_h and the "hidden photon" \gamma_h to be massive. The "hidden W" bosons W_h are dark matter in this scenario. This setup can readily accommodate a potential direct detection signal for dark matter at ~10 GeV from CDMSII-Si data. For some choices of parameters, the model can lead to signals both in "dark matter beam" experiments, from Z_h\to W_h W_h, as well as in experiments that look for visible signals of dark photons, mediated by \gamma_h. Other possible phenomenological consequences are also briefly discussed.Comment: 11 pages, 4 figures; References and additional comments added. Results unchange

Editorial overview: recent innovations in the metabolomics revolution

No abstract available

Invariant random subgroups of semidirect products

We study invariant random subgroups (IRSs) of semidirect products $G = A \rtimes \Gamma$. In particular, we characterize all IRSs of parabolic subgroups of $\mathrm{SL}_d(\mathbb{R})$, and show that all ergodic IRSs of $\mathbb{R}^d \rtimes \mathrm{SL}_d(\mathbb{R})$ are either of the form $\mathbb{R}^d \rtimes K$ for some IRS of $\mathrm{SL}_d(\mathbb{R})$, or are induced from IRSs of $\Lambda \rtimes \mathrm{SL}(\Lambda)$, where $\Lambda < \mathbb{R}^d$ is a lattice.Comment: 16 page

Electroweak Phase Transition, Higgs Diphoton Rate, and New Heavy Fermions

We show that weak scale vector-like fermions with order one couplings to the Higgs can lead to a novel mechanism for a strongly first-order electroweak phase transition (EWPhT), through their tendency to drive the Higgs quartic coupling negative. These same fermions could also enhance the loop-induced branching fraction of the Higgs into two photons, as suggested by the recent discovery of a ~125 GeV Higgs-like state at the CERN Large Hadron Collider (LHC). Our results suggest that measurements of the diphoton decay rate of the Higgs and its self coupling, at the LHC or perhaps at a future lepton collider, could probe the EWPhT in the early Universe, with significant implications for the viability of electroweak baryogenesis scenarios.Comment: 6 pages, 1 figure. Revised version shows that the original conclusions hold in a distinct region of parameter space. New discussion on collider probes adde