J. A. Martins Simões

Signature for heavy Majorana neutrinos in hadronic collisions

The production and decay of new possible heavy Majorana neutrinos are analyzed in hadronic collisions. New bounds on the mixing of these particles with standard neutrinos are estimated according to a fundamental representation suggested by grand unified models. A clear signature for these Majorana neutrinos is given by same-sign dileptons plus a charged weak vector boson in the final state. We discuss the experimental possibilities for the future Large Hadron Collider (LHC) at CERN.

Same-sign dileptons as a signature for heavy Majorana neutrinos in hadron-hadron collisions

Abstract We discuss the possibility of same-sign dileptons as a signature for Majorana neutrinos. The production mechanism is given by a single heavy neutrino production and decay pp → l ± NX → l ± l ± X ′. Cross section and distributions are presented for the LHC energies.

Production and decay properties of possible spin 32 leptons

Abstract A systematic study of production and decay properties of hypothetical charged spin 3 2 leptons is presented. These particles are assumed to occur in each lepton family. The simplest V ± A currents constructed with these particle fields and the corresponding spin 1 2 neutrinos are assumed to be coupled to the familiar V − A lepton charged weak currents. Our results are independent from structure models and indicate ways for an experimental search for these particles.

Discriminating among the theoretical origins of new heavy Majorana neutrinos at CERN LHC

A study on the possibility of distinguishing new heavy Majorana neutrino models at LHC energies is presented. The experimental confirmation of standard neutrinos with nonzero mass and the theoretical possibility of lepton number violation find a natural explanation when new heavy Majorana neutrinos exist. These new neutrinos appear in models with new right-handed singlets, in new doublets of some grand unified theories and left-right symmetrical models. It is expected that signals of new particles can be found at the CERN high-energy hadron collider (LHC). We present signatures and distributions that can indicate the theoretical origin of these new particles. The single and pair production of heavy Majorana neutrinos are calculated and the model dependence is discussed. Same-sign dileptons in the final state provide a clear signal for the Majorana nature of heavy neutrinos, since there is lepton number violation. Mass bounds on heavy Majorana neutrinos allowing model discrimination are estimated for three different LHC luminosities.

New heavy charged leptons at future high energy electron-positron colliders

Abstract.New heavy charged lepton production and decay signatures at future electron-positron colliders are investigated at

Neutral heavy lepton production at next high energy e + e − linear colliders

\sqrt {s}=500

Minimal left-right symmetric models and new Z' properties at future electron-positron colliders

GeV. The consequences of model dependence for vector singlets and vector doublets are studied. Distributions are calculated including hadronization effects and experimental cuts that suppress the standard model background. The final state leptonic energy distributions are shown to give a very clear signature for heavy charged leptons.

Single heavy lepton production in high energy electron-positron collisions

The discovery potential for detecting new heavy Majorana and Dirac neutrinos at some recently proposed high energy

Spontaneous parity violation and minimal Higgs models

{e}^{+}{e}^{\ensuremath{-}}

Neutrino mixing in a left-right model

colliders is discussed. These new particles are suggested by grand unified theories and superstring-inspired models. For these models the production of a single heavy neutrino is shown to be more relevant than pair production when comparing cross sections and neutrino mass ranges. The process