Notes

Outline

Measurement of the Centrality Dependence of Charged Particle Pseudorapidity Density with the PHOBOS Detector Michael Reuter University of Illinois at Chicago for the                         Collaboration APS Spring Meeting:  Washington, DC    April 29, 2001

The PHOBOS Detector

The BIG Picture

Selecting Collisions

Determining Centrality

Uncertainty on Npart Measurement sensitive to trigger bias “Minimum-bias” still has bias Affects most peripheral events

Detector Geometry

Vertex Finding

Tracklet Analysis

Tracklet Systematic Error

Measured dNch/dh

Centrality Dependence of dNch/dh

Comparison to SPS

Summary