We study the $S_3$-symmetric two Higgs doublet model by adding generations of vector like leptons (VLL) which are odd under a discrete $Z_2$ symmetry. The lightest neutral component VLL acts as dark matter (DM) whereas full set belongs to sector with no mixings allowed standard fermions. analyse in light and collider searches. show that DM is compatible current relic density data well satisfyin...

If signals suggesting supersymmetry (SUSY) are discovered at the LHC then it will be vital to measure the spins of the new particles to demonstrate that they are indeed the predicted super-partners. A method is discussed by which the spins of some of the SUSY particles can be determined. Angular distributions in sparticle decays lead to charge asymmetry in lepton-jet invariant mass distribution...

The topic of lepton universality is directly related to the structure of the fundamental fermion elds and the dynamics generating it. It can be investigated independently for the charged and the neutral weak interactions. The precise measurements of the neutral couplings achieved at LEP and SLC are the key ingredients for the investigation of electroweak radiative corrections and the indirect i...

A final state consisting of one charged lepton, at least jet, and little missing transverse energy can be a very promising signature new physics the LHC across wide range models. However, it has received only limited attention so far. In this work we discuss potential sensitivity channel to various scenarios. To demonstrate our point, consider its application lepton parton distribution function...

Lepton flavor violating processes are obtained from the mixing between ordinary leptons and vector like SU(2)L doublet leptons in the 27 of E6. The effects of this lepton mixing are, however, suppressed naturally by the hierarchy of charged lepton masses. In the supersymmetric model, significant effects of lepton flavor violation may rather appear through the slepton mixing, which is in the pre...

It is found from discovery of the neutrino oscillation that the lepton-flavor symmetries are not exact in nature, while the charged lepton-flavor violation (cLFV) has not been observed yet. The cLFV is suppressed even if the tiny neutrino masses observed in the experiments are introduced in the standard model (SM). The cLFV processes are proportional to the fourth power of the neutrino masses d...