  In the paper we discuss the angular correlation present in hadron-hadron
collisions at large rapidity difference ($\bas\,y_{12}\,\gg\,1$). We find that
in the CGC/saturation approach the largest contribution stems from the density
variation mechanism. Our principal results are that the odd Fourier
harmonics($v_{2n+1}$), decrease substantially as function of $y_{12}$, while
the even harmonics ($v_{2n}$ ), increase considerably with a growth of
$y_{12}$.
