  Starting with the most general effective Hamiltonian comprising scalar and
vector operators beyond the standard model, we discuss the impact of various
operators on the zero of the forward--backward asymmetry in the dileptonic B
decay B -> K^\ast \mu^+ \mu^-. We find that, zero of the asymmetry is highly
sensitive to the sign and size of the vector--vector operators and opposite
chirality counterparts of the usual operators. The scalar--scalar four--fermion
operators, on the other hand, have mild effect on the zero of the asymmetry.
Our results are expected to be checked in the near future experiments.
