PHOBOS

The Nuclear Chemistry (Heavy Ion) Group is creating and studying matter at the hottest temperatures accessible in the laboratory to date, more than 1 trillion degrees K (1,000,000,000,000 K or 2,000,000,000,000 F). This temperature far exceeds the temperatures at the surface (6000 K) or even the core (15,000,000 K) of the Sun. These temperatures are believed to recreate conditions similar to those occurring in the universe during the first microsecond (0.000001 s) after the big bang. Such matter is hard to describe in terms of hadronic degrees of freedom and is probably some form of "Quark Gluon Plasma" although the exact nature of this matter is still under active debate. We do this by hosting an international collaboration of about 60 scientists from 8 institutions in 3 countries and operating a multi-million-dollar detector. Both the collaboration and the detector are called PHOBOS. The detector is installed in the RHIC accelerator located here at BNL.

A picture of a single AuAu collision as seen by the PHOBOS detector at RHIC. Each collision creates a very small region of very hot matter in excess of 2,000,000,000,000 C.

The focus of the BNL group, as well as much of PHOBOS, is on characterizing the strongly interacting matter that we've created. In particular, we have discovered scaling laws which allow us to describe these rather complex collisions in terms of a few simple parameters or functions. They also allow us to relate head-on heavy-ion collisions to more glancing collisions and to more "elementary" collisions such as pp, pA/dA, eA and even e+e-. This approach should provide clear guidance on the important parameters and degrees of freedom in this high temperature matter.

Learn more about PHOBOS research.

The PHOBOS Collaboration at Brookhaven is supported by the the Heavy Ion Nuclear Physics Program of the Office of Nuclear Physics of the Office of Science under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

Last Modified: June 28, 2012