Rational fibrations homogeneous spaces with positive Euler characteristics and Jacobians
We show that an orientable fibration whose fiber has a homotopy type of homogeneous space with rank is totally non homologous to zero for rational coefficients. The Jacobian formed by invariant polynomial under the Weyl group of plays a key role in the proof. We also show that it is valid for mod. coefficients if does not divide the order of the Weyl group of .