Abstract: | Superstring theory in d = 10 dimensions after Calabi—Yau compactification yields a minimum low-energy gauge group SU(3)C × SU(2)L × U(1)Y × U(1)E. The low-energy theory includes particles with the quantum numbers of 27 representations of E6, each of which contains an extra neutrino νc conventionally called a “right-handed neutrino”. The contributions of ν and νc to
through Z0 and ZE mixing is calculated. Small contributions are found of the new right-handed neutrino and of the superstring boson ZE to σ(e+e− → γ + nothing). |