Large transverse momentum suppression at RHIC: Shadowing and absorption

We propose a model of suppression of $\pi^0$'s based on two different effects: at low $p_T$ we take into account the shadowing corrections, which are non-linear and essential for the description of the inclusive spectra, while at large $p_T$ the suppression is produced through the interaction of the large $p_T$ pion with the dense medium created in the collision. The main features of the data on $AuAu$ and $dAu$ collisions at RHIC energies are reproduced both at mid and at forward rapidities.