Doctoral Dissertations

Date of Award

8-2008

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Physics

Major Professor

Kenneth F. Read

Committee Members

Soren P. Sorensen, Vince Cianciolo, Ted Barnes, Robert Compton

Abstract

This dissertation presents the measurement of single muons from the semi-leptonic decay of heavy quark mesons (charm and bottom) in √s=200 GeV p+p collisions at the Relativistic Heavy Ion Collider at Brookhaven National Lab. The data were recorded in 2005 by the PHENIX experiment. The PHENIX muon spectrometer measures particles at forward angles from approximately 15º to 33º relative to the beam line in both forward and backward directions.

A new analysis technique was developed to estimate and subtract backgrounds from light hadrons in a statistical fashion to reveal the yield of heavy flavor single muons. The yield of single muons is measured as a function of transverse momentum and is used to estimate the charm quark production cross section over the measured region. As heavy quark production is a true prediction of perturbative quantum chromo-dynamic calculations, the measured single muon yield and estimated charm quark cross section are compared to theoretical calculations. These comparisons show that the measured yield of single muons exceeds the existing theoretical expectations by a varying degree, from a factor of four at the lowest measured transverse momentum to a factor of two at the largest measured transverse momentum. The integrated charm quark production estimate also exceeds existing theoretical estimates for charm at forward angles. However, the sizable uncertainties present in both the measured and calculated quantities prohibit a definitive statement concerning charm production at forward angles. In addition to theoretical comparisons, this measurement of single muons in p + p serves as a springboard to further heavy quark results in both the RHIC spin and heavy-ion programs.

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