Stephen Baumgart

Stephen Baumgart's picture
Systems Engineer Physicist
Varian Medical Systems
Research Areas: 
Nuclear Physics
Research Type: 
Experimentalist
Education: 
Ph.D. 2009, Yale University
Advisor: 
Helen Caines
Dissertation Title: 
A Study of Open Charm Production in 200 GeV Heavy Ion Collisons
Dissertation Abstract: 

A hot and dense form of matter is produced in Au+Au and Cu+Cu collisions at [special characters omitted] = 200 GeV at the Relativistic Heavy-Ion Collider. This matter exhibits the features of a new deconfined state of matter, the Quark-Gluon Plasma. This thesis reports on the production of open charm mesons, the D 0 + D¯0 in Cu+Cu collisions and the [special characters omitted] in Au+Au collisions as a probe of the properties of this matter and its formation.

D0(D¯0) mesons are measured in [special characters omitted] = 200 GeV Cu+Cu collisions via their K-π +(K+π-) decay channel. Their mid-rapidity yield is then used to extract a total inclusive charm cross-section per nucleon-nucleon collision. This charm cross-section is compared with experimental results from other collision systems as well as pQCD predictions.

D_s^\pm mesons are reconstructed through their &phis;π± decay channel in [special characters omitted] = 200 GeV Au+Au collisions using a secondary-vertexing reconstruction technique. The mid-rapidity Ds yield in [special characters omitted] = 200 GeV Au+Au collisions is reported and compared with experimental results from e+e - collisions at [special characters omitted] = 91 GeV, Pythia simulation, as well as the predictions of the Statistical Hadronization Model for a Quark-Gluon Plasma.