Back-to-Back Correlations of Di-hadrons in dAu Collisions at RHIC

We perform a complete theoretical analysis of the azimuthal angular correlation of two-hadron productions in the forward $dAu$ collisions at RHIC in the saturation formalism, and obtain a very good agreement with the experimental data. It is demonstrated that the suppression and broadening of the away side peak provide a unique signal for the onset of the saturation mechanism at small-$x$ in a large nucleus. We emphasize that future experiments of di-hadron correlations in $pA$ collisions at both RHIC and LHC, and in $eA$ collisions at the planned electron-ion collider, shall provide us with a thorough study and understanding of the strong interaction dynamics in the saturation regime.