Related papers: Generation-changing interaction of sneutrinos in $…
We investigate a 5d gauge theory on $S^1$ with point interactions. The point interactions describe extra boundary conditions and provide three generations, the charged lepton mass hierarchy, the lepton flavor mixing and tiny degenerated…
Production and decay of gaugino-like charginos are crucially determined by sneutrino exchange. Therefore we study the pair production of charginos e^+ e^- -> chi^+_1 chi^-_1 with polarized beams and the subsequent decay chi^-_1 -> chi^0_1…
We examine various aspects of supersymmetric particle production at linear $e^+e^-$ colliders operating at a centre of mass energy of $\sqrt{s}=500$ GeV, and integrated luminosity of $\int {\cal L}dt=20-50$ fb$^{-1}$. Working within the…
The Large Hadron Collider could be a discovery machine for the neutrino mass pattern and its Majorana nature in the context of a well-motivated TeV scale Type II seesaw model. This is achieved by identifying the flavor structure of the…
A correlated analysis of observables arising from loop induced effects from a vectorlike generation is given. The observables include flavor changing radiative decays $\mu\to e \gamma, \tau\to \mu \gamma, \tau\to e \gamma$, electric dipole…
Pseudoscalar meson decay leads to an entangled state of charged leptons ($\mu,e$) and massive neutrinos. Tracing out the neutrino degrees of freedom leads to a reduced density matrix for the charged leptons whose off-diagonal elements…
We study the perspective to observe lepton number violating signatures from heavy Majorana neutrino decays at colliders in view of the requirement to explain the light neutrino masses via the seesaw mechanism. In the minimal model with only…
Despite the enormous achievements, the Standard model of Particle physics can not be consider as complete theory of fundamental interactions. Among other things, it can not describe the gravitational interaction and it depends on 19…
New physics close to the electroweak scale is well motivated by a number of theoretical arguments. However, colliders, most notably the Large Hadron Collider (LHC), have failed to deliver evidence for physics beyond the Standard Model. One…
There are three observables related to neutrino mass, namely the kinematic mass in direct searches, the effective mass in neutrino-less double beta decay, and the sum of neutrino masses in cosmology. In the limit of exactly degenerate…
We use a boost-invariant one-dimensional (cylindrically symmetric) fluid dynamics code to calculate $e^+e^-$ production from $\rho^0$ and $\omega$ decay in the central rapidity region of a central S+Au collision at $\sqrt{s}=20$…
Sleptons can easily be found at future linear e+e- colliders if kinematically accessible. Measurements of their masses and decay distributions would then determine MSSM parameters. This paper presents a detailed MC study of the production…
Electron positron collisions are a very promising environment to search for new physics, and in particular for dark sector related observables. The most challenging experimental problem in detecting dark sector candidates is the very high…
We study the production of the lightest neutralinos in the radiative process $e^+e^- \to \tilde\chi^0_1 \tilde\chi^0_1\gamma$ in low energy supersymmetric models for the International Linear Collider energies. This includes the minimal…
We study the lepton-flavor-violating reaction $\mu^+ e^- \to e^+ e^-$ within two extensions of the standard model that include heavy neutrinos. The reaction is studied in the low energy limit in the form of muonium decay $M\to e^+ e^-$ and…
We review the collider phenomenology of neutrino physics and the synergetic aspects at energy, intensity and cosmic frontiers to test the new physics behind the neutrino mass mechanism. In particular, we focus on seesaw models within the…
We discuss the process $e^-e^- \to W^- W^-$ mediated by heavy Majorana neutrino exchange in the t- and u channel. In our model the cross section for this reaction is a function of the masses (m_N) of the heavy Majorana neutrinos and mixing…
Cross-sections and angular distributions for hadronic and lepton pair final states in e+e- collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the…
In gauge models with bigger number of Higgs particles their couplings to fermions are more complicated then in the standard model (SM). The influence of the Higgs bosons exchange on the neutrino production cross section in $e^-e^+$…
The small neutrino mass observed in neutrino oscillations is nicely explained by the seesaw mechanism. Rich phenomenology is generally expected if the heavy neutrinos are not much heavier than the electroweak scale. A model with this…