Asymmetries in $e^{+}$$e^{\mathrm{-}}$ collisions at the $Z^0$ pole from ${\mathrm{E}}_6$ grand unified theories

The effects of an extra neutral gauge boson predicted by ${\mathrm{E}}_6$ grand unified theories are studied in $e^{+}$ $e^{\mathrm{-}}$ collisions at &. We find that measurements of the left-right and forward-backward asymmetries are a sensitive test of the mixing between the $Z^0$ and Z’ bosons and can be used to constrain the mass of the Z’.