  Deuteron-gold collisions provide insights into the nuclear structure function
and a valuable baseline for Au+Au collisions. Measurement of the nuclear
modification factor, R_{dAu}, in d+Au in the PHENIX central arms for hadrons
and photons allows us to disentangle cold nuclear matter effects from the hot
medium effects that are important in Au+Au collisions. In addition, the d+Au
system can yield important insights into the gluonic structure of the Au
nucleus. RHIC experiments have previously measured suppression of forward
rapidity particle production relative to p+p scaled by the number of binary N-N
collisions, but a definitive explanation of these data is thus far elusive.
Correlations between hadrons with a large rapidity gap are a particularly
sensitive probe of gluon saturation. We will discuss probing this physics via
particle production in events tagged with high momentum particles at different
rapidities, along with R_{dAu} in new forward rapidity regions.
