Related papers: Isosinglet vectorlike leptons at $e^+e^-$ collider…
A search for high-mass resonances decaying into $\tau^{+}\tau^{-}$ final states using proton-proton collisions at $\sqrt{s}= 8$ TeV produced by the Large Hadron Collider is presented. The data were recorded with the ATLAS detector and…
We study the impact that a heavy generation of vector-like leptons can have on the value of the electric dipole moment of the electron, and the rates for the flavor violating processes mu --> e gamma and mu --> 3e. The smallness of the…
The tau lepton plays important role in the correlation between the low-energy neutrino oscillation data and the lepton flavor structure in heavy neutrino decay. We investigate the lepton flavor signatures with tau lepton at hadron collider…
We describe current and future hadron collider limits on new vector-like leptons with exotic decays. We consider the possibility that, besides standard decays, the new leptons can also decay into a Standard Model charged lepton and a stable…
The tau lepton can be more composite than naively expected in models of strong electroweak symmetry breaking with tri-bimaximal lepton mixing. New leptonic resonances required by custodial symmetry, the tau custodians, can then be the first…
In bilinear R-Parity violating models where a term \epsilon_3L_3H_2 is introduced in the superpotential, the tau lepton can mix with charginos. We show that this mixing is fully compatible with LEP1 precision measurements of the Z\tau\tau…
A search for high-mass resonances decaying into tau-lepton pairs is performed using a data sample of pp collisions at sqrt(s) = 7 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of…
A spin-1 weakly interacting vector boson, Z', is predicted by many new physics theories. Searches at colliders for such a Z' resonance typically focus on lepton-antilepton or top-antitop events. Here we present a novel channel with a Z'…
A search for heavy resonances that decay to tau lepton pairs is performed using proton-proton collisions at sqrt(s) = 13 TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 2.2…
A search for pair-production of vector-like leptons is presented, considering their decays into a third-generation Standard Model (SM) quark and a vector leptoquark ($U_1$) as predicted by an ultraviolet-complete extension of the SM,…
There are two strong arguments in favor of vector-like leptons and quarks: Flavor Democracy call for them, and E6 GUT predicts existence of iso-singlet quarks and iso-doublet leptons. Vector-like quarks (VLQ) are extensively searched by…
The performance of tau-lepton reconstruction and identification algorithms is studied using a data sample of proton-proton collisions at sqrt(s)=7 TeV, corresponding to an integrated luminosity of 36 inverse picobarns collected with the CMS…
The electric and magnetic dipole moments of the electron and of the muon provide stringent tests of the Standard Model and sensitive probes of new physics. By contrast, the corresponding dipole moments of the $\tau$ lepton remain weakly…
New Physics models with either an elementary or composite origin are often associated with a similar imprint in a direct search at colliders, case in point being the production of a light pseudoscalar in association with a monochromatic…
We study the processes $W_L W_L \to t \bar t$ and $W_L Z_L \to t\bar b (\bar t b)$ at future lepton colliders as probes of the couplings of the top quark to resonances at the TeV scale. We consider the cases in which the dominant low energy…
We discuss sensitivities to lepton flavor violating (and conserving) interactions at future muon colliders, especially at $\mu^+\mu^+$ colliders. Compared with the searches for rare decays of $\mu$ and $\tau$, we find that the TeV-scale…
Vector-like leptons (VLLs) as one kind of interesting new particles can produce rich phenomenology at low- and high-energy experiments. In the framework of the singlet vector-like leptons with scalar (VLS) model, we investigate the…
This Letter presents a search for a heavy neutral particle decaying into an opposite-sign different-flavor dilepton pair, $e^\pm \mu^\mp$, $e^\pm \tau^\mp$, or $\mu^\pm \tau^\mp$ using 20.3 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} = 8$…
Oblique contributions from vector particles that are strongly coupled to the known gauge bosons are calculated for the case of various observables at a 1 TeV $e^+e^-$ collider. Constraints provided by LEP 1 results are taken into account in…
Searches for new low-mass matter and mediator particles have actively been pursued at fixed target experiments and at $e^+e^-$ colliders. It is challenging at the CERN LHC, but they have been searched for in Higgs boson decays and in $B$…