Speaker
Description
We will present new PHENIX measurements of charmonium production in
p+Au collisions at \sqrt{s}=200 GeV and discuss their implications for
QCD dynamics in small collision systems. These results probe the
possible roles of multi-parton interactions, long-range partonic correlations, and novel final-state effects in asymmetric p+Au
collisions at RHIC energies, while carefully accounting for potential
auto-correlation biases identified in previous p+p studies. PHENIX
offers a unique experimental configuration with spectrometers spanning
forward, mid-, and backward rapidities. In particular, the muon arm
spectrometers enable studies of multiplicity dependence in both small-
and large-Bjorken-x regions of p+Au collisions. Using this broad
rapidity coverage, we study the local event-activity dependence of
J/\psi production with a rapidity separation between the charmonium
signal and the event-activity estimator. This approach suppresses
auto-correlation effects and provides a cleaner handle on the
interplay between hard and soft QCD processes in p+Au collisions. The
observed trends offer new insight into the mechanisms governing
charmonium production and event activity in cold/hot nuclear matter at RHIC.
