A Search For The Sm Higgs Boson In The Process Zhllbb In 4.1/fb Of Cdf Ii Data

Author

Shalhout Zaki Shalhout, Wayne State UniversityFollow

Access Type

Open Access Dissertation

Date of Award

1-1-2010

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Physics and Astronomy

First Advisor

Robert Harr

Abstract

This dissertation presents a search for the standard model (SM) Higgs boson in the associated production process ZH → l⁺l_- bb using 4.1fb^-1 of Tevatron collision data collected with the CDF II detector.

To increase the sensitivity to a ZH signal over previous CDF searches, we implement new electron and expanded b-jet identification algorithms.

We utilize neural network classifiers enhanced with matrix element probabilities, a b-jet identifying neural network, and multivariate jet energy corrections to maximize the separation of signal from SM backgrounds.

We employ three neural network classifiers separately optimized for each of our three b-tag categories.

We find good agreement between the observed data and the predicted SM backgrounds.

The neural network output for data is compared to the output for the expected SM background to set 95% confidence level upper limits on the ZH production cross section times the branching ratio for H→ bb.

We consider Higgs boson masses between 100 and 150 GeV/c² in 5 GeV steps.

For a Higgs boson mass of 115 GeV/c² we observe (expect) a 95% confidence level upper limit of 5.9(6.8).

Recommended Citation

Shalhout, Shalhout Zaki, "A Search For The Sm Higgs Boson In The Process Zhllbb In 4.1/fb Of Cdf Ii Data" (2010). Wayne State University Dissertations. 29.
https://digitalcommons.wayne.edu/oa_dissertations/29