String Inspired QCD and $E_6$ Models

174 Pages·1996·1.366 MB·English

by  Boyce, M M

STRING INSPIRED QCD AND E MODELS
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MICHAEL M. BOYCE
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PH.D. THESIS
1996
String Inspired QCD and E Models
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by
Michael M. Boyce, B.Sc., M.Sc.
A thesis submitted to
the Faculty of Graduate Studies and Research
in partial fulfillment of
the requirements for the degree of
Doctor of Philosophy
Ottawa-Carleton Institute for Physics
Department of Physics
Carleton University
Ottawa, Ontario, Canada
June 10, 1996
c copyright
(cid:13)
1996, Michael M. Boyce
The undersigned recommend to
the Faculty of Graduate Studies and Research
acceptance of the thesis
String Inspired QCD and E Models
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submitted by Michael M. Boyce, B.Sc., M.Sc.
in partial fulfilment of the requirements for
the degree of Doctor of Philosophy
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Abstract
The work in this thesis consists of two distinct parts:
A class of models called, “String-flip potential models,” (SFP’s) are studied as
a possible candidate for modeling nuclear matter in terms of constituent quarks.
These models are inspired from lattice quantum-chromodynamics (QCD) and are
nonperturbative in nature. It is shown that they are viable candidates for modeling
nuclear matter since they reproduce most of the bulk properties except for nuclear
binding. Their properties are studied in nuclear and mesonic matter. A new class
of models is developed, called “flux-bubble potential models,” which allows for the
SFP’s to be extended to include perturbative QCD interactions. Attempts to obtain
nuclear binding is not successful, but valuable insight was gained towards possible
future directions to pursue.
ThepossibilityofstudyingSuperstringinspiredE phenomenologyathighenergy
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hadron colliders is investigated. The production of heavy lepton pairs via a gluon-
gluon fusion mechanism is discussed. An enhancement in the parton level cross-
section is expected due to the heavy (s)fermion loops which couple to the gluons.
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TO MY PARENTS
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Acknowledgements
The size of this thesis represents only a small part of the mountain of work,
with its multitude of crevices, that went into its making. Herein are the remnants
of literally thousands of lines of computer code and many thick binders of hand
computations.
I would like to thank my supervisor Dr. P.J.S. Watson for giving me the opportu-
nity to see what real research is like. Real in the sense of being innovative and trying
to come up with original ideas, as opposed to just grinding out some calculations.
I would like to thank Drs. M.A. Doncheski and H. K¨onig for giving me the
opportunity to collaborate with them on some E work, contained in chapter 4 of
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this thesis — OK this is grinding! :) RL
I would like to thank my Ph.D.examination committee DeanR.Blockley (chair),
Dr. F. Dehne, Dr. S. Godfrey, Dr. G. Karl, Dr. G. Oakham, Dr. A. Song, and
Dr. P.J.S. Watson for giving me an enjoyable but challenging thesis defense. I would
especially like to thank Dr. S. Godfrey who served double duty by filling in on
Dr. G. Karl’s behalf, who was ill at time of the defense and therefore unable to
attend (I sincerely hope all went well). I would also like to thank Dr. S. Godfrey
for filling in after the defense as acting supervisor, as mine was away at this time,
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making sure that all of the corrections were made to my thesis, and for carefully
re-reading it for any minor errors.
IwouldliketothankmyPh.D.committeemembers, pastandpresent, Dr.S.God-
frey, Dr. W. Romo, Dr. G. Slater, Dr. P.J.S. Watson for a job well done.
I would like to thank S. Nicholson for taking time out of her very busy sched-
ule to proofread my thesis. Also, I would like to thank H. Blundell, A. Dekok,
Dr. M.A. Doncheski, and Dr. H. K¨onig, for proofreading various documents of mine,
such as parts of this thesis, papers, conference proceedings, etc.
I would like to thank Dr. M.A. Doncheski, Dr. H. K¨onig, H. Blundell, M. Jones,
I. Melo, Dr. S. Sanghera, Dr. M.K. Sundaresan, and Dr. G. Oakham for their very
useful physics consultations.
I would like to thank OPAL, CRPP, and THEORY groups, as well as the Depart-
ment of Physics for usage of their computing facilities. Also, I would like to thank
A. Barney, J. Carleton, Dr. F. Dehne, A. Dekok, W. Hong, B. Jack, M. Jones, and
M. Sperling, for their general computer and computational related consultations.
I would like to the lab and tech. guys D. Paterson, G. Curley, G. Findlay, and
J. Sliwka, well...for just being lab and tech. guys!
I would like to thank R. Tighe for her warm hearted nature towards graduate
students, especially to those in need. Also, I would like to thank the graduate
advisors, past and present, Drs. P. Kalyniak and W. Romo, who also kept a caring
eye on their flocks.
I would like to thank the secretaries, past and present, R. Tighe, T. Buckley, and
E. Lacelle for generally being helpful and always bringing a shaft of light into the
department for those especially gloomy days.
Finally, I would like to thank all of my friends, past and present, the bar go-ers,
the sports players, the movie go-ers, the pool players, etc., Dr. G. Bhattacharya,
H. Bundell, G. Cron, F. Dalnok-Veress, A. Dekok, Dr. M.A. Doncheski, V. Dragon,
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Dr. D.J. Dumas, L. Gates, M. Gintner, Dr. I. Ivanovi´c, M. Jones, D. Kaytar,
Dr. H. K¨onig, G. Laberge, E.P. Lawrence, Dr. I. Melo, S. Nicholson, J.K. Older,
Dr. K.A. Peterson, B.F. Phelps, Dr. A. Pouladdej, Dr. P. Rapley, M. Richardson,
S. Sail, Dr. S. Sanghera, D. Sheikh-Baheri, V. Silalahi, Dr. R. Sinha, A. Turcotte,
S. Towers, Dr. P.M. Wort, Y. Xue, and G. Zhang, for making my stay in Ottawa
and the Carleton University Department of Physics a pleasant one.
A thousands pardons to those whom I may have missed.
MAY YOU ALL LIVE LONG AND PROSPER!
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Contents
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
1 Introduction 1
1.1 The String-Flip Potential Model . . . . . . . . . . . . . . . . . . . . . 2
1.1.1 Possible Phases of Nuclear Matter . . . . . . . . . . . . . . . . 4
1.1.2 A Crude Model of Nuclear Matter . . . . . . . . . . . . . . . . 8
1.2 Superstring Inspired E Models . . . . . . . . . . . . . . . . . . . . . 9
6
1.2.1 E Phenomenology . . . . . . . . . . . . . . . . . . . . . . . . 12
6
1.2.2 Heavy Lepton Production . . . . . . . . . . . . . . . . . . . . 15
1.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2 The SU(3) String-Flip Potential Model 18
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2 The General String-Flip Potential Model . . . . . . . . . . . . . . . . 19
2.3 SU(3) String-Flip Model . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.4 Monte Carlo Calculation . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
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3 Flux-Bubble Models and Mesonic Molecules 39
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.2 Flux-Bubble Models . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.3 In Search of a Wave Function . . . . . . . . . . . . . . . . . . . . . . 41
3.4 Mesonic Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.4.1 The Distributed Minimization Algorithm . . . . . . . . . . . . 44
3.4.2 A General Survey of Extensions to SU (2) . . . . . . . . . . . 49
ℓ
3.4.3 Back to the SU (2) String-Flip Potential Model . . . . . . . . 64
ℓ
3.4.4 A New Wave Function . . . . . . . . . . . . . . . . . . . . . . 68
3.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
3.6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4 L+L Production in E 85
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4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.2 A Low Energy E Model . . . . . . . . . . . . . . . . . . . . . . . . . 86
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4.3 L+L Production Cross-Section . . . . . . . . . . . . . . . . . . . . . 98
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4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
4.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
5 Conclusions 122
5.1 Summary Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
5.1.1 String-Flip and Flux-Bubble Models . . . . . . . . . . . . . . 122
5.1.2 L+L Production . . . . . . . . . . . . . . . . . . . . . . . . . 125
−
5.2 Closing Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
A Three-quark K.E. Computations 127
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