New Model ofb-Quark Interactions: A Superstring Alternative

Inspired by the possible particle content of the heterotic superstring at low energies, a model is proposed where the $b$ quark is not paired with the $t$ quark. Instead, the $b$ quark couples to the $c$ quark through a second $W$ boson. This model is consistent with all established experimental and phenomenological constraints, and predicts the mass of the second $W$ boson to be just beyond the experimental limit of about 400 GeV.