Related papers: Charged Leptons With Nanosecond Lifetimes
A first search is presented for vector-like leptons (VLLs) decaying into a light long-lived pseudoscalar boson and a standard model $\tau$ lepton. The pseudoscalar boson is assumed to have a mass below the $\tau^+\tau^-$ threshold, so that…
In this note we discuss a characteristic collider signature of models of gauge mediated supersymmetry breaking in which the selectron and smuon are mass-degenerate co-NLSP. In these models, all processes involving superpartners give rise to…
We propose $S_4$ symmetric four-generation models for charged leptons. Although an $S_4$ symmetric four-generation model has been already proposed, there are some additional symmetries in the model. We construct four-generation models for…
The zero neutrino mode of the double beta decay in heavy deformed nuclei is investigated in the framework of the pseudo SU(3) model, which has provided an accurate description of collective nuclear structure and predicted half-lives for the…
We study previously unconsidered 3-3-1 models which are characterized by each lepton generation having a different representation under the gauge group. Flavor-changing neutral currents in the lepton sector occur in these models. To satisfy…
A new Majoron model is presented within the framework of the seesaw mechanism. Its Higgs sector consists of only doublet representations and the lepton-number violation takes place at the same scale of the electroweak symmetry breaking.…
The production and decay of exotic leptons are discussed in the context of the vector singlet, vector doublet and fer\-mion mirror-fer\-mion models, at c.m. energies $\sqrt{s}=190GeV$ (LEP II) and $\sqrt{s}=500GeV$ (NLC). The model…
The experimental rate of neutrinoless double beta decay can be saturated by the exchange of virtual sterile neutrinos, that mix with the ordinary neutrinos and are heavier than 200 MeV. Interestingly, this hypothesis is subject only to…
Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions…
The lepton flavour violating charged lepton decays mu to e + gamma and thermal leptogenesis are analysed in the minimal supersymmetric standard model with see-saw mechanism of neutrino mass generation and soft supersymmetry breaking terms…
Electrons and electron neutrinos in the inner core of the core-collapse supernova are highly degenerate and therefore numerous during a few seconds of explosion. In contrast, leptons of other flavors are non-degenerate and therefore…
The leptons are viewed as composite objects, exhibiting anomalous magnetic moments and anomalous flavor-changing transition moments. The decay \mu \to e \gamma is expected to occur with a branching ratio of the same order as the present…
This is a review of new results on the Tau lepton. The lifetime has been measured with improved precision, allowing the test of lepton universality to 0.2% level. There are several new measurements of the branching ratios for the hadronic…
All supersymmetric generalizations of the Standard Model allow for stable non-topological solitons of the Q-ball type which may have non-zero baryon and lepton numbers, as well as the electric charge. These solitons can be produced in the…
We propose a radiative neutrino-mass model by introducing 3 generations of fermion pairs $E^{-(N+1)/2} E^{+(N+1)/2}$ and a couple of multi-charged bosonic doublet fields $\Phi_{N/2}, \Phi_{N/2+1}$, where $N=1,3,5,7,9$. We show that the…
We propose a new mechanism producing a non-vanishing lepton number asymmetry, based on decays of heavy Majorana neutrinos. If they are produced out of equilibrium, as occurs in preheating scenario, and are superpositions of mass eigenstates…
We show that when the unparticle sector is coupled to the Standard Model, unparticle excitations can decay to Standard Model particles. This radically modifies the signals of unparticle production. We present a method for the calculation of…
Seesaw models with a slightly broken lepton number symmetry can explain small neutrino masses, and allow for low-scale leptogenesis. We make a thorough analysis of leptogenesis within the simplest model with two right-handed (RH) neutrinos…
Traditional analysis of $g=2(1+\kappa )$ experiments for charged leptons use a classical spin vector picture. For muons, we here employ a more exact Dirac quantum four component spinor theory. Survival probabilities (including wave packet…
Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori…