Related papers: Dark sector portal with vector-like leptons and fl…
A mechanism for leptogenesis at the electroweak scale was investigated in a model of dark energy and dark matter proposed by one of us (PQH). This model involves an asymptotically free gauge group SU(2)Z and an axion-like particle with an…
Flavor symmetries that explain masses and mixings of the standard model fermions dictate flavor patterns for the couplings of scalar and vector leptoquarks to the standard model fermions. A generic feature is that couplings to…
We study renormalizable extensions of the standard model that contain vector-like fermions in a (single) complex representation of the standard model gauge group. There are 11 models where the vector-like fermions Yukawa couple to the…
The lepton sector of the Standard Model is at present haunted by several intriguing anomalies, including an emerging pattern of deviations in $b \to s \ell \ell$ processes, with hints of lepton flavor universality violation, and a…
It is appealing to stabilize dark matter by the same discrete symmetry that is used to explain the structure of quark and lepton mass matrices. However, to generate the observed fermion mixing patterns, any flavor symmetry must necessarily…
Phenomenological studies of Flavored Dark Matter (FDM) models often have to assume a near-diagonal flavor structure in the coupling matrix in order to remain consistent with bounds from flavor violating processes. In this paper we show that…
We propose the existence of a hidden or dark sector besides the standard model (SM) of particle physics, whose members (both fermionic and bosonic) obey a local SU(2)$_{\rm H}$ gauge symmetry while behaving like a singlet under the SM gauge…
We propose that the flavor structure of the standard model is based on a horizontal $SU(2)$ symmetry. It generically predicts (i) a parametrically small mass for the lightest charged fermions, (ii) small mixings in the quark sector, and…
Light dark matter with flavor-violating couplings to fermions may be copiously produced in the laboratory as missing energy from decays of SM particles. Here we study the effective Lagrangian of a light dark vector with generic dipole or…
The kinetic mixing (KM) portal, by which the Standard Model (SM) photon mixes with a light dark photon arising from a new $U(1)_D$ gauge group, allows for the possibility of viable scenarios of sub-GeV thermal dark matter (DM) with…
All pieces of concrete evidence for phenomena outside the standard model (SM) - neutrino masses and dark matter - are consistent with the existence of new degrees of freedom that interact very weakly, if at all, with those in the SM. We…
We propose a theory in which the Standard Model gauge symmetry is extended by a new $SU(2)_\ell$ group acting nontrivially on the lepton sector which is spontaneously broken at the TeV scale. Under this $SU(2)_\ell$ the ordinary leptons…
The inert Zee model is an extension of the Zee model for neutrino masses. This new model explains the dark matter relic abundance, generates a one-loop neutrino masses and forbids tree-level Higgs-mediated flavor changing neutral currents.…
We revisit the dark matter phenomenology of a flavor-dependent $U(1)_X$ gauge extension of the Standard Model, where anomaly cancellation predicts the existence of exactly three fermion generations and requires the presence of three…
We propose a flavor symmetric approach to unify the origin of dark matter (DM) with the non-zero $\theta_{13}$ in the lepton sector. In this framework, breaking of a $U(1)$ flavor symmetry to a remnant $Z_2$ ensures the stability of the DM…
The Lepton Portal Dark Matter model, in which dark matter states only coupling to the charged leptons, can explain the excess of the muon anomalous magnetic moment measured by the Muon $g - 2$ experiment. In this paper, we demonstrate that…
We explore the potential for detecting the inelastic dark model (DM) with an additional $U(1)_D$ gauge symmetry at various types of lepton colliders. The new gauge boson $Z'$ resulting from the spontaneous breaking of $U(1)_D$ can act as a…
We construct a model based on an extra gauge symmetry, SU(2)_X x U(1)_{B-L}, which can provide gauge bosons to serve as weakly-interacting massive particle dark matter. The stability of the dark matter is naturally guaranteed by a discrete…
In this paper, we summarize phenomenology in lepton portal dark matter (DM) models, where DM couples to leptons and extra leptons/sleptons. There are several possible setups: complex/real scalar DM and Dirac/Majorana fermion DM. In…
Apparent regularities in fermion masses and mixings are often associated with physics at a high flavor scale, especially in the context of discrete flavor symmetries. One of the main reasons for that is that the correct vacuum alignment…