Heavy Majorana neutrino production at electron-muon colliders

Abstract Possibilities for detecting heavy Majorana neutrinos ( N 's) at future eμ colliders are investigated. In contrast to the e − e + colliders (LEP200 and NLC), the center-of-mass (CMS) energies achieved at eμ colliders can be much higher and the Z -mediated s channel is excluded automatically. This opens the attractive possibility of having high production cross sections for N 's and at the same time probing only the strength of charged current couplings of N 's ( NWe and NWμ ). The production cross sections and the expected numbers of events for the reaction e ∓ μ ± → NN → W ± l ∓ W ± l ′∓ are calculated for various masses M of the Majorana neutrinos and for the CMS energies s =0.5 –6.0 TeV. The values of the charged current coupling parameters are set equal to their present upper bounds. We obtain reasonably high production cross sections. Further, the effects of the off-shell intermediate N 's turn out to be large and they increase with increasing s .