PHENIX Measurement of High-$p_T$ Hadron-hadron and Photon-hadron Azimuthal Correlations

Understand

High-$p_T$ hadron-hadron correlations have been measured with the PHENIX experiment in $\Cu$ and $\pp$ collisions at $\sqrt{s_{NN}}=200$ GeV.

• A comparison of the jet widths and yields between the two colliding systems allows us to study the medium effect on jets.
• We also present a first measurement of direct photon-hadron correlations in $\Au$ and $\pp$ collisions.
• We find that the near-side yields are consistent with zero in both systems.