Correlations and Fluctuations over a Broad Range in Pseudorapidity using the PHOBOS Detector Original Research Article

The PHOBOS apparatus includes a charged particle multiplicity detector covering almost all of 4π in solid angle. The broad coverage in pseudorapidity, η, which is unique at RHIC, combined with the ability to collect a large sample of events with minimal bias, makes possible a study of correlations and fluctuations over most of the pseudorapidity range, even at the highest beam energy. Long range correlations, short range correlations at large |η|, event-by-event fluctuations in the total number of charged particles, and event-by-event variation in the full shape of the pseudorapidity distribution can all be studied. Preliminary results for the first exploration of these capabilities of the PHOBOS detector, along with some average properties of the pseudorapidity distributions, are presented.