  In the past years many possible extensions of the Standard Model (SM) have
been investigated. If one of this model is revealed at the LHC, we will need
tools to distinguish it among the many others studied. One possibility to
achieve this goal is to utilize the forward-backward asymmetry. In this paper
we calculate the asymmetry for a model in which there is an extra U(1)
anomalous symmetry. Furthermore, we show that the asymmetry can be used to
impose constraints on the free parameters of the model.
