  We study evolution equations describing jet propagation through quark--gluon
plasma (QGP). In particular we investigate the contribution of momentum
transfer during branching and find that such a contribution is sizeable.
Furthermore, we study various approximations, such as the Gaussian
approximation and the diffusive approximation to the jet-broadening term. We
notice that in order to reproduce the BDIM equation (without the momentum
transfer in the branching) the diffusive approximation requires a very large
value of the jet-quenching parameter $\hat q$.
