Generation non-universality and flavor changing neutral currents in the 331 model

Abstract

The 331 model, an extension of the standard electroweak theory to $SU(3)_L\times U(1)_X$, naturally predicts three families of quarks and leptons via the requirement of anomaly cancellation. This is accomplished by making one of the quark families transform differently from the other two, thus leading to flavor changing neutral currents. Using experimental input on neutral meson mixing, we show that the third family must be the one that is singled out, at least up to small family mixing. We additionally describe a convenient way to parametrize the new mixing matrix that plays a role in the gauge interactions of the ordinary quarks with the new 331 quarks.