Neutrino production ine+e−collisions in a left-right-symmetric model

The production of light and heavy ($\nu N$) and two heavy neutrinos ($\mathrm{NN}$) in $e^{+}{e}^{-}$ collisions is investigated. The heavy neutrinos which appear naturally in the left-right-symmetric models are considered. The correlation between heavy gauge boson masses, masses of heavy neutrinos, and elements of the mixing matrices in the charged and neutral currents are taken into account. For comparison, two cases where the neutrinos are either Majorana or Dirac particles are studied. However, only Majorana neutrinos appear naturally in the studied version of a $L-R$-symmetric model. New bounds on the mass of heavy neutrinos from CERN LEP I, and the correlation between masses of the charged gauge bosons and heavy Majorana neutrinos which follows from the lack of neutrinoless double-$\beta$ decay, are included. The conclusion about production of heavy Majorana neutrinos from the $L-R$ model in future $e^{+}{e}^{-}$ colliders (LEP II, NLC) is less optimistic compared with previous investigations. In the case of two Dirac neutrino production ($\mathrm{NN}$) the cross section is larger than in the Majorana case.