Pseudorapidity asymmetry at high $p_{T}$ in $p(d)A$ collisions*

We calculate pseudorapity ($\eta$) asymmetry in $pBe$ and $dAu$ collisions in the framework of a next-to-leading order (NLO) pQCD-improved parton model. Our calculations are applicable in a wide range of kinematically accessible transverse momenta, $p_{T}$. The calculations [1,2] are tuned to describe existing spectra from pp collisions and asymmetric systems at midrapidity and large rapidities at FNAL and RHIC energies. We investigate the roles of nuclear shadowing and multiple scattering on the observed pseudorapity asymmetry [3]. Using this framework, we make predictions for pseudorapidity asymmetries at high $p_{T}$ and high $\eta$ at a wide range of energies up to LHC. [1] A. Adeluyi and G. Fai, Phys.\ Rev.\ C {\bf 76}, 054904 (2007) [2] G.G. Barnafoldi, P. Levai, G. Papp and G. Fai, Nucl.\ Phys.\ A {\bf 749}, 291 (2005) [3] B.I. Abelev {\it et al.} [STAR Collaboration], Phys.\ Rev. C {\bf 76}, 054903 (2007)