Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 2001 Measurement of Bottom Quark Production in Two -Photon Collisions. Sepehr Saremi Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: http://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Saremi, Sepehr, "Measurement of Bottom Quark Production in Two -Photon Collisions." (2001). LSU Historical Dissertations and Theses. 433. http://digitalcommons.lsu.edu/gradschool_disstheses/433 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with smalt overlaps. Photographs included in the original manuscript have been reproduced xerographicaliy in this copy. Higher quality 6” x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. ProQuest Information and Learning 300 North Zeeb Road. Ann Arbor, Ml 48106-1346 USA 800-521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. MEASUREMENT OF BOTTOM QUARK PRODUCTION IN TWO-PHOTON COLLISIONS A Dissertation Submitted to the Graduate Faculty o f the Louisiana State University and Agricultural and Mechanical College in partial fulfillment o f the requirements for the degree o f Doctor o f Philosophy in The Department o f Physics and Astronomy by Sepehr Saremi B.S., Louisiana State University, 1995 M.S., Louisiana State University, 1997 December 2001 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number 3042649 UMI’ UMI Microform 3042649 Copyright 2002 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. To my dear parents Fatemeh and Majid Saremi, who have given me encouragement and support. ii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENTS I feel very indebted to my parents for the support that I have received from them throughout my education. As a child they always encouraged me to pursue the highest levels of knowledge. Their financial support for my education was by all means exceptional. I would not have reached this point without them. At LSU, I was fortunate to meet my thesis advisor, Professor Roger Mc­ Neil. He provided me the opportunity to work on the L3 experiment at CERN and introduced me to the field of two-photon physics. It was a pleasure for me to work under his direction and I am grateful to him for his guidance. I would like to thank all of my other physics professors. Unfortunately I will not be able to name them one by one since the list will be long. However, I like to mention Professor William Metcalf, the chairman of the Physics and Astronomy department at LSU. I enjoyed Professor Metcalf’s classes as an undergraduate and benefited from his support as a graduate student. It was a great experience for me to work at CERN. Over there, I had the opportunity to work with many particle physicists. Most notable among them is Dr. Valery Andreev, LSU’s post doctoral researcher at CERN. I spent a lot of time working with Dr. Andreev. He was very patient in guiding me and always helped me whenever I needed it. I do not know how to thank him. I also like to express my gratitude to Professor Maria Kienzle and Dr. John Field. I had valuable discussions with these individuals in our weekly two-photon analysis meeting. Their suggestions gave me useful insights regarding my research. In addition, I want to thank all my other iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. colleagues in the L3 collaboration. The L3 experiment was very successful as a result of the dedicated effort of many excellent physicists and technical staff members. I thank the spokesman, Professor Samuel C. C. Ting for his leadership of the 2 0 year long experiment. Finally, I am grateful to all the family members and relatives who gave me emotional support and enthusiasm for reaching my goals. I would like to especially thank my sister and brother-in-law, Setareh and Ali, for the year that I spent with them in Los Angeles. IV Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS ACKNOWLEDGEMENTS ..................................................................... iii LIST OF TABLES ..........................................................................................vii LIST OF FIGURES ..................................................................................... viii ABSTRACT ....................................................................................................xii CHAPTER 1 INTRODUCTION ................................................................................... 1 1.1 Photon As A P a r ti c le ............................................................... 1 1.2 Two Photon Interactions ........................................................ 4 2 QCD AND HEAVY FLAVOR PRODUCTION .............................. 14 2.1 Quantum C hrom odynam ics ..................................................... 14 2.2 Two Photon Production In Storage R ings ........................... 18 2.3 QCD And Two Photon Interactions .................................... 19 2.4 Heavy Flavor Production In Two Photon Collisions .... 21 3 THE L3 DETECTOR AT LEP ................................................................29 3.1 LEP C o llid e r ....................................................................................29 3.2 Particle Detectors At e+e" Co llid ers...........................................33 3.3 L3 D etector .......................................................................................39 3.3.1 Time Expansion C h a m b e r .................................................. 42 3.3.2 Electromagnetic Calorim eter ............................................... 44 3.3.3 Hadron Calorimeter ................................................................46 3.3.4 Muon C ham ber ...................................................................... 48 3.3.5 Luminosity M onitor ................................................................52 4 DATA AQUISITION AND SIMULATION ...................................... 54 4.1 Trigger S y ste m ................................................................................ 54 4.1.1 Level 1 Trigger .......................................................................... 55 4.1.2 Level 2 Trigger ..................................................................... 59 4.1.3 Level 3 Trigger ..........................................................................60 4.2 Event Reconstruction ...................................................................60 4.2.1 Tracks In The T E C ................................................................61 4.2.2 Clusters In The Calorimeters ............................................... 61 4.2.3 Muons In The MUCH ............................................................ 62 4.3 Monte Carlo Simulation ................................................................62 4.3.1 Event G e n e ra tio n ...................................................................63 4.3.2 Detector Simulation ................................................................64 4.4 Final Data Structure ...................................................................... 65 5 EVENT SELECTION ................................................................................ 67 5.1 Hadronic Two-Photon E v e n ts ....................................................67 5.2 Electron Selection ..................................................................... 75 v Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 5.3 Muon Selection .............................................................................