PhD Thesis
Daniel Patrick Cronin-Hennessy


Institution: Duke University, Durham, N.C.
Thesis supervisor: Thomas J. Phillips
Submitted: August 1997

Title
-----
Tests of Perturbative QCD in W + Jets Events Produced in 
sqrt(s) = 1.8 TeV p-pbar Collisions.


Abstract
--------

We have analysed 108 pb^-1 of data from sqrt(s) = 1.8 TeV p-pbar
collisions. The data were collected at the Collider Detector at
Fermilab during the 1992-93 and 1994-95 runs.  We have selected the W
bosons in these data in order to test predictions of perturbative QCD.
Standard model contributions to W + jet events include top production,
diboson production and direct single W boson production with
associated hadronic jets.  The largest contribution to the W + jets is
direct single W production.  We isolated this contribution in order to
measure the cross sections for direct single W boson production as a
function of jet multiplicity, the jet energy spectra, and jet-jet
correlations.  The high luminosity during data collection has provided
51431 inclusive W to e nu events which allow precision tests of
perturbative QCD. The cross sections and hadronic jet properties
predicted by perturbative QCD are compared to our data measurements.
Leading order QCD calculations from VECBOS have been processed through
the HERWIG fragmentation program and fully simulated with the CDF
detector simulation program (QFL).  HERWIG provides added gluon
radiation which represent partial higher order corrections to the
tree-level diagrams and we refer to this calculation as enhanced
leading order. The theory calculation is sensitive to several scales:
renormalization, factorization and the cut-off used for the
fragmentation.  We find that the theory predicts the main qualitative
features of the data.


Posted to /cdf/pub/thesis/cdf4981_cronin_thesis.ps
    http://www-cdf.fnal.gov/thesis/cdf4981_cronin_thesis.ps

Posted by groer@cdfsga