Related papers: Leptobaryons as Majorana Dark Matter
The leptonic mixing angle $\theta_{13}$ is known to be small. If it is indeed tiny, the simplest explanation is that charged leptons mix only in the $\mu-\tau$ sector and neutrinos only in the 1-2 sector. We show that this pattern may be…
We present a comprehensive study of Majorana dark matter in a $U(1)_{B-L}$ gauge extension of the standard model, where three exotic fermions with $B-L$ charges as $-4, -4, +5$ are added to make the model free from the triangle gauge…
In the $SO(5) \times U(1)$ gauge-Higgs unification the lightest, neutral component of $n_F$ $SO(5)$-spinor fermions (dark fermions), which are relevant for having the observed unstable Higgs boson, becomes the dark matter of the universe.…
We study constraints on the hidden sector model mediated by an additional SU(2) Higgs doublet from the phenomenology of Higgs bosons. The hidden sector is assumed to contain a hidden U(1) gauge symmetry and the hidden U(1) gauge boson gets…
Cosmic ray anomalies observed by PAMELA and Fermi-LAT experiments may be interpreted by heavy (TeV-scale) dark matter annihilation enhanced by Sommerfeld effects mediated by a very light (sub-GeV) U(1)_X gauge boson, while the recent direct…
The classical conservation of the lepton number is an accidental symmetry present in the Standard Model (SM). Thus, we consider here a scenario where the SM is extended with a U(1) gauge group, promoting the lepton number to a local…
We are considering a minimal $U(1)_B$ extension of the Standard Model (SM) by promoting the baryon number as a local gauge symmetry to accommodate a stable dark matter (DM) candidate. The gauge theory of baryons induces non-trivial triangle…
We study an effective theory beyond the standard model (SM) where either of two additional gauge singlets, a Majorana fermion and a real scalar, constitutes all or some fraction of dark matter. In particular, we focus on the masses of the…
The LHCb collaboration has recently reported on some anomalies in $b\to s$ transitions. In addition to discrepancies with the Standard Model (SM) predictions in some angular observables and branching ratios, an intriguing hint for lepton…
We study classically scale invariant models in which the Standard Model Higgs mass term is replaced in the Lagrangian by a Higgs portal coupling to a complex scalar field of a dark sector. We focus on models that are weakly coupled with the…
We study the 2010 specific version of the 2002 proposed $U(1)_X$ extension of the supersymmetric standard model, which has no $\mu$ term and conserves baryon number and lepton number separately and automatically. We consider in detail the…
The extension of the Standard model (SM) with three heavy right handed neutrinos, a complex scalar and the gauged $U(1)_{\rm B-L}$ symmetry (the minimal $B-L$ model) is considered the most compelling minimal one: the presence and the…
We propose a minimal extension of the standard model (SM) by including a scalar triplet with hypercharge 2 and two vector-like leptons: one doublet and a singlet, to explain simulatenously the non-zero neutrino mass and dark matter (DM)…
A weighted average weak mixing angle theta_W derived from relatively low Q^2 experiments is compared with the Standard Model prediction obtained from precision measurements. The approximate 1.8 sigma discrepancy is fit with an intermediate…
We discuss neutrino masses and mixing in the framework of a supersymmetric model with an $U(1)_{R}$ symmetry, consisting of a single right handed neutrino superfield with an appropriate R charge. The lepton number ($L$) of the standard…
We discuss the interplay between dark matter, leptogenesis and a new gauge boson $Z^\prime$ in the $B-L$ model. A fermion dark matter $\chi$ carrying $U(1)_{B-L}$ charge is introduced to the model but not coupling with other particles. We…
We investigate the dark matter and the cosmological baryon asymmetry in a simple theory where baryon (B) and lepton (L) number are local gauge symmetries that are spontaneously broken. In this model, the cold dark matter candidate is the…
Minimal scenarios with light (sub-GeV) dark matter whose relic density is obtained from thermal freeze-out must include new light mediators. In particular, a very well-motivated case is that of a new "dark" massive vector gauge boson…
We consider the collider phenomenology of a singlet Majoron model with softly broken lepton number. Lepton number is spontaneously broken when the real part of a new singlet scalar develops vacuum expectation value. With the additional soft…
Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly freedom, only combinations of B-L are viable. In this spirit, we…