Recent Results from PHENIX

Abstract

I report on results from the PHENIX collaboration for the first RHIC run, where gold ions were collided at $\sqrt{s_{NN}}=130 GeV$. In order to study initial conditions, PHENIX has measured the ratio between anti-protons and protons, the transverse energy, and charged multiplicity as a function of collision centrality. These measurements allows us to extract some information on the initial density of created partons, the baryon density, the energy density, and particle production. In order to probe the formation of a possible new state of matter, PHENIX has measured the neutral pion and unidentified hadron transverse momentum spectra. We find a deficit compared to the the expectations from simple nucleon-nucleon scaling. These novel results are consistent with expectations that high $p_T$ leading particles will be suppressed in the presence of the formation of a plasma.