assumption, the initial lepton belongs to the weak isodoublet $(\nu,~e)$. The final lepton belongs to another doublet, e.g. $(\nu_{\mu},~\mu)$, and the final quarks are also from a doublet, e.g. $(u, ~d)$. The antilepton and the antiquark belong to the charge conjugate doublets. Obviously, the scattering amplitude $A$ for the annihilation can be written as follows: $$\label{A}
A = q^{k'}({p'}_1) \bar{q}_{i'}({p'}_2) A^{i i'}_{k'
  k}l^k(p_1)\bar{l}_i(p_2) ~ ,$$ where the $SU(2)$ matrix amplitude $A^{i i'}_{k' k}$ has to be calculated. We will consider it in DLA. The DL contributions to $A^{i i'}_{k' k}$ are different according to the kinematics of the process. The kinematics is defined by appropriate relations among the Mandelstam variables $s,~t,~u$, $$\label{studef}
s = (p_1 + p_2)^2,~t = (p_1 - {p'}_1)^2, ~u = (p_1 - {p'}_2)^2 ~.$$ Throughout this paper we assume that $\sqrt{s} \gg M_{W,Z}$.

The kinematical regime defined as $$\label{hard}
-t \sim -u \sim s$$ is called the hard kinematics and corresponds to large cm scattering angles $\theta \equiv \theta_{ \mathbf{p_1\,{p'}_1}} \sim 1$ . Radiative corrections to the annihilation in this kinematics yield DL contributions.

There are also two other Regge-type kinematical regimes where DL contributions appear. First, there is the configuration where $$\label{tkin}
 s \sim -u \gg 