Related papers: Updated Constraints and Future Prospects on Majoro…
An interesting possibility for dark matter is a scalar particle of mass of order 10 MeV-1 GeV, interacting with a U(1) gauge boson (dark photon) which mixes with the photon. We present a simple and natural model realizing this possibility.…
We discuss spontaneous Leptogenesis in the Type II Seesaw model of neutrino masses featuring an electroweak triplet scalar $T$ in a coherent pseudo Nambu-Goldstone boson (pNGB) background. In the "wash-in" scenario the inverse decays of…
We study a simple extension of the Standard Model featuring a dark sector with an ultralight pseudo Nambu-Goldstone boson as dark matter candidate. We focus on the mass range $\mathcal{O}(10^{-20} - 10^{-10})$ eV, relevant for strong…
In this work, we revisit pseudo Nambu Goldstone boson (pNGB) DM model where global $U(1)$ dark symmetry is spontaneously broken as well as explicitly with broken by with linear symmetry breaking, focusing on the dark matter mass range in…
It is often said that neutrino mass is a window to a new physics beyond the standard model (SM). This is certainly true if neutrinos are Majorana particles since the SM with Majorana neutrino mass is not a complete theory. The classical…
If the neutrino is Majorana type and the electroweak phase transition is second or weak first order, neutrino-induced interactions together with sphaleron transitions have the potential to erase a previously generated baryon asymmetry of…
Persistent excesses in the spectra of gamma rays from the galactic center and cosmic ray antiprotons can be explained by dark matter of mass $50\sim 65$\,GeV annihilating into $b$ quarks, but this is typically hard to reconcile with direct…
A singlet majoron can arise from the seesaw framework as a pseudo-Goldstone boson when the heavy Majorana neutrinos acquire masses via the spontaneous breaking of global ${\rm U}(1)_L$ symmetry. The resulting cosmological impacts are…
We discuss the possibility to find an upper bound on the seesaw scale using the cosmological bound on the cold dark matter relic density. We investigate a simple relation between the origin of neutrino masses and the properties of a dark…
Majorana properties of neutrinos have long been a focus in the pursuit of possible new physics beyond the standard model, which has motivated lots of dedicated theoretical and experimental studies. A future same-sign muon collider is an…
Lepton number violation plays an essential role in many scenarios of neutrino mass generation and also provides new clues to search new physics beyond the standard model. We consider the neutrinophilic two-Higgs-doublet model ($\nu$-2HDM)…
The family of Dirac Seesaw models offers an intriguing alternative explanation for the smallness of neutrino masses without necessarily requiring microscopic lepton number violation, when compared to the more familiar class of Majorana…
We investigate Majorana dark matter in a new variant of $U(1)_{L_{\mu}-L_{\tau}}$ gauge extension of Standard Model, where the scalar sector is enriched with an inert doublet and a $(\bar{3},1,1/3)$ scalar leptoquark. We compute the…
We study the possibility of testing a dark matter (DM) scenario embedded in a global lepton number symmetry $U(1)_L$ via gravitational waves (GW) and cosmic microwave background (CMB) observations. The spontaneous breaking of $U(1)_L$…
The Majorana nature of neutrinos can be experimentally verified only via {\it lepton-number} violating processes involving charged leptons. We study 36 lepton-number violating ($\lv$) processes from the decays of tau leptons and…
We present a predictive framework for neutrino mass generation based on the spontaneous breaking of a leptonic $U(1)_{L_\mu-L_\tau}$ symmetry within a supersymmetric setting. The breaking of the global symmetry gives rise to a Majoron-like…
The possibility that the accurately known value of the Z width might furnish information about the coupling of two neutrinos to the Majoron (Nambu-Goldstone boson of spontaneous lepton number violation) is proposed and investigated in…
We discuss singlet fermion dark matter within a left-right symmetric model promoting baryon and lepton numbers as separate gauge symmetries. We add a simple Dirac fermionic dark matter singlet under $SU(2)_{L,R}$ with nonzero and equal…
In this letter we address the issue of generating appropriate tiny neutrino masses within the framework of a particular $SU(3)_{c}\otimes SU(3)_{L}\otimes U(1)_{X}$ gauge model by adding three singlet exotic Majorana neutrinos to the ones…
The idea that dark-matter interactions with Standard-Model particles may be mediated by new bosons with masses in the MeV-to-GeV range took off several years ago. Constraints on such models were soon calculated based on older measurements.…