Related papers: Testing lepton number violation with the reaction …
Lepton number violation may arise via the spontaneous breakdown of a global symmetry. In extra dimensions, spontaneous lepton number violation in the bulk implies the existence of a Goldstone boson, the majoron J^(0), as well as an…
In this work, we investigate the prospects of future $e^{+}e^{-}$ colliders in testing a Higgs triplet model with a scalar triplet and a scalar singlet under $SU(2)$. The parameters of the model are fixed so that the lightest $CP-$even…
We derive new constraints on the quantities delta_{XY}^{ij}, X,Y=L,R, which parametrise the flavour-off-diagonal terms of the charged slepton mass matrix in the MSSM. Considering mass and anomalous magnetic moment of the electron we obtain…
A sequential fourth generation of quarks and leptons is allowed by precision electroweak constraints if the mass splitting between the heavy quarks is between 50 and 80 GeV. Although heavy quarks can be easily detected at the LHC, it is…
We explore signatures of Lepton Number Violation (LNV) from decays of the discovered Higgs ($h$) and Z bosons into a pair of Right-Handed Neutrinos (RHNs). Due to the Majorana nature of RHNs, the final state can be the same-sign dilepton…
We study the one-loop induced muon number processes when the standard model is minimally extended to include a $\rm SU(2)$ singlet of a charged scalar $h^+$ and a neutral fermion $N$. We find that $\mu \rightarrow e \gamma$ is more…
Using the ZEUS detector at the HERA electron-proton collider, we have searched for lepton flavor violation in ep collisions at a center-of-mass energy s^1/2 of 300 GeV. Events of the type e + p -> lepton + X with a final-state lepton (mu or…
In supersymmetric extensions of the Standard Model, the lepton flavour violation (LFV) is closely related to the structure of slepton masses and mixing. Allowing for the most general flavour structure of the slepton sector, consistent with…
We consider the most general supersymmetric model with minimal particle content and an additional discrete Z_3 symmetry (instead of R-parity), which allows lepton number violating terms and results in non-zero Majorana neutrino masses. We…
Compared to $\mu \to e \gamma$ and $\mu \to e e e$, the process $\mu \to e$ conversion in nuclei receives enhanced contributions from Higgs-induced lepton flavor violation. Upcoming $\mu \to e$ conversion experiments with drastically…
The process of top-quark pair production at future high-energy $e^+ e^-$ linear colliders has been investigated as a possible test of physics beyond the Standard Model. Non-standard interactions have been assumed both for the production and…
In lepton-number-violating supersymmetric models, there is no natural choice of basis to distinguish the down-type Higgs and lepton superfields. We employ basis-independent techniques to identify the massless majoron and associated light…
We analyze neutrino masses and Lepton Flavor Violation (LFV) in charged leptons with a minimal ansatz about the breaking of the U(3)^5 flavor symmetry, consistent with the U(2)^3 breaking pattern of quark Yukawa couplings, in the context of…
In the minimal extension of the standard electroweak theory with ultra massive Majorana neutrinos, the process e- + e- -> mu- + mu- could be observable, in sharp contrast with the reaction e- + e- -> W- + W- which is entirely controlled by…
In the absence of a fundamental principle preventing charged lepton flavour violation, one expects that extensions of the Standard Model accommodating neutrino masses and mixings should also allow for charged lepton flavour violating…
Many scenarios of physics beyond the Standard Model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional scalars with masses in the MeV to GeV…
We have investigated the three vector boson production in electron-electron collisions in the framework of the left-right symmetric electroweak model. The process occurs due to lepton number violating interactions mediated by Majorana…
We analyse the $Z$ and Higgs boson decays $Z\to \ell^+ \ell^- $ ($\ell = e, \mu,\tau$), $H\to \gamma\gamma$ and $H\to Z\gamma$ that are induced at one-loop level in models with a doubly-charged isosinglet scalar. After discussing current…
We have derived new upper limits on several products (two at a time) of lepton number violating $\lambda'$-type couplings from the consideration of $\Delta S = 2$ and $\Delta B = 2$ box graphs. Each box contains one scalar lepton and one…
A search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5 inverse femtobarns of proton-proton collisions with center-of-mass energy…