The properties of nuclear matter are fairly well understood near normal density. Nuclear matter is made of point-like quarks and gluons, which seem to be confined inside hadrons such as protons and neutrons. According to the Quantum Chromodynamics (QCD), the theory of the strong interactions, when nuclear matter become compressed or heated, it must undergo a change of phase to a new state of matter, the quark-gluon plasma, in which quarks and gluons are free to move about within a confinement volume much larger than hadronic sizes.

Quark Gluon Plasma has also a connection to astrophysics. Due to the enormous densities and temperatures prevailing during the first microseconds after Big Bang, quarks and gluons should, in the early universe, have moved around freely. During the expansion temperatures and densities decreased and the matter today found in the universe was created.

A new major accelerator, the Relativistic Heavy Ion Collider (RHIC) has recently come online at Brookhaven National Laboratory (BNL) in Long Island about 65 miles East of New York City. RHIC will provide the capability of colliding heavy nuclei (with masses up to Gold) at very high energy, up to 200~GeV/c. These collisions will produce extended volumes of hadronic matter with high energy densities and will provide the opportunity for observing directly the parameters of the predicted phase transition, and the mechanisms of quark confinement. This will improve our understanding of the strong force in a regime where theoretical calculations are most difficult. Currently my research effort is focused on the the PHENIX experiment, one of the two large experiment currently taking data at RHIC.

In order to understand the interaction of relativistic heavy ions with nuclear matter it is necessary to understand the simpler interactions of protons with matter. I am also studying hot hadronic matter produced at lower excitation energies using proton beam on a nuclear target in experiment E910 at the Alternating Gradient Synchrotron (AGS) accelerator at Brookhaven National Laboratory.