  The measurement of the forward-backward asymmetry at LHC could be an
important instrument to pinpoint the features of extra neutral gauge particles
obtained by an extension of the gauge symmetry group of the standard model. For
definitiveness, in this work we consider an extension of the gauge group of the
Minimal Supersymmetric Standard Model by an extra anomalous U(1) gauge symmetry
(MiAUMSSM). We focus on pp -> e+e- at LHC and use four different definitions of
the asymmetry obtained implementing four different cuts on the directions and
momenta of the final states of our process of interest. The calculations are
performed without imposing constraints on the charges of the extra Z's of our
model, since the anomaly is cancelled by a Green-Schwarz type mechanism. Our
final result is a fit of our data with a polynomial in the charges from which
to extract the values of the charges given the experimental result.
