PHOBICS physics capabilities

PHOBOS is the name of a detector and of a research program to study systematically the physics of relativistic heavy-ion collisions over a large range of impact parameters and nuclear species. Collisions with a center of mass energy of 200 A GeV at RHIC are expected to produce the highest energy densities ever accessible in the laboratory. In this writeup, we outline the physics capabilities of the PHOBOS detector and describe the detector design in terms of the general philosophy behind the PHOBOS research program. In order to make the discussion concrete, we then focus on two specific examples of physics measurements that we plan to make at RHIC: dN/dζ for charged particles and the mass spectrum from φ→ K+K- decays