Speaker
Dr
Mickey Chiu
(Brookhaven National Lab)
Description
RHIC experiments have observed that inclusive hadron yields in
the forward rapidity (deuteron) direction for $\sqrt{s_{NN}} = 200$
GeV d+Au collisions are suppressed relative to p+p collisions.
The mechanism for the suppression has not been firmly established;
theoretical descriptions include nuclear shadowing, initial-state parton energy loss, and gluon saturation. We present measurements by the PHENIX experiment at RHIC of di-hadron pair production in d+Au
collisions where the particles in the pair are varied across a wide
range of rapidity out to $|\eta| = 3.8$ using a new forward electromagnetic calorimeter, the MPC. These di-hadron measurements probe down to parton momentum fractions x ~ $10^{-3}$ in the gold nucleus, where the interesting possibility of observing gluon saturation effects at RHIC is the greatest. Our measurements show that the correlated yield of back-to-back pairs in d+Au collisions is suppressed by up to an order of magnitude relative to p+p collisions, and increases with greater nuclear path thickness and with decreasing parton x in the Au nucleus.
Primary author
Dr
Mickey Chiu
(Brookhaven National Lab)
