First Measurement of the Running of the Top Quark Mass

Download First Measurement of the Running of the Top Quark Mass PDF Online Free

Author :
Publisher : Springer Nature
ISBN 13 : 3030903761
Total Pages : 170 pages
Book Rating : 4.0/5 (39 download)

DOWNLOAD NOW!


Book Synopsis First Measurement of the Running of the Top Quark Mass by : Matteo M. Defranchis

Download or read book First Measurement of the Running of the Top Quark Mass written by Matteo M. Defranchis and published by Springer Nature. This book was released on 2022-01-03 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, the first measurement of the running of the top quark mass is presented. This is a fundamental quantum effect that had never been studied before. Any deviation from the expected behaviour can be interpreted as a hint of the presence of physics beyond the Standard Model. All relevant aspects of the analysis are extensively described and documented. This thesis also describes a simultaneous measurement of the inclusive top quark-antiquark production cross section and the top quark mass in the simulation. The measured cross section is also used to precisely determine the values of the top quark mass and the strong coupling constant by comparing to state-of-the-art theoretical predictions. All the theoretical and experimental aspects relevant to the results presented in this thesis are discussed in the initial chapters in a concise but complete way, which makes the material accessible to a wider audience.

LHC Physics

Download LHC Physics PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 1439837708
Total Pages : 415 pages
Book Rating : 4.4/5 (398 download)

DOWNLOAD NOW!


Book Synopsis LHC Physics by : T. Binoth

Download or read book LHC Physics written by T. Binoth and published by CRC Press. This book was released on 2012-04-25 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the phenomenology of the Large Hadron Collider (LHC) at CERN, LHC Physics focuses on the first years of data collected at the LHC as well as the experimental and theoretical tools involved. It discusses a broad spectrum of experimental and theoretical activity in particle physics, from the searches for the Higgs boson and physics beyond the Standard Model to studies of quantum chromodynamics, the B-physics sector, and the properties of dense hadronic matter in heavy-ion collisions. Covering the topics in a pedagogical manner, the book introduces the theoretical and phenomenological framework of hadron collisions and presents the current theoretical models of frontier physics. It offers overviews of the main detector components, the initial calibration procedures, and search strategies. The authors also provide explicit examples of physics analyses drawn from the recently shut down Tevatron. In the coming years, or perhaps even sooner, the LHC experiments may reveal the Higgs boson and offer insight beyond the Standard Model. Written by some of the most prominent and active researchers in particle physics, this volume equips new physicists with the theory and tools needed to understand the various LHC experiments and prepares them to make future contributions to the field.

Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass

Download Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319400053
Total Pages : 172 pages
Book Rating : 4.3/5 (194 download)

DOWNLOAD NOW!


Book Synopsis Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass by : Jan Kieseler

Download or read book Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass written by Jan Kieseler and published by Springer. This book was released on 2016-06-15 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the first experimental calibration of the top-quark Monte-Carlo mass. It also provides the top-quark mass-independent and most precise top-quark pair production cross-section measurement to date. The most precise measurements of the top-quark mass obtain the top-quark mass parameter (Monte-Carlo mass) used in simulations, which are partially based on heuristic models. Its interpretation in terms of mass parameters used in theoretical calculations, e.g. a running or a pole mass, has been a long-standing open problem with far-reaching implications beyond particle physics, even affecting conclusions on the stability of the vacuum state of our universe. In this thesis, this problem is solved experimentally in three steps using data obtained with the compact muon solenoid (CMS) detector. The most precise top-quark pair production cross-section measurements to date are performed. The Monte-Carlo mass is determined and a new method for extracting the top-quark mass from theoretical calculations is presented. Lastly, the top-quark production cross-sections are obtained – for the first time – without residual dependence on the top-quark mass, are interpreted using theoretical calculations to determine the top-quark running- and pole mass with unprecedented precision, and are fully consistently compared with the simultaneously obtained top-quark Monte-Carlo mass.

Top Quark Physics at Hadron Colliders

Download Top Quark Physics at Hadron Colliders PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 3540710604
Total Pages : 166 pages
Book Rating : 4.5/5 (47 download)

DOWNLOAD NOW!


Book Synopsis Top Quark Physics at Hadron Colliders by : Arnulf Quadt

Download or read book Top Quark Physics at Hadron Colliders written by Arnulf Quadt and published by Springer Science & Business Media. This book was released on 2007-08-16 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.

CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination

Download CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 331958880X
Total Pages : 286 pages
Book Rating : 4.3/5 (195 download)

DOWNLOAD NOW!


Book Synopsis CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination by : Simon Spannagel

Download or read book CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination written by Simon Spannagel and published by Springer. This book was released on 2017-08-01 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses two different topics, both vital for implementing modern high-energy physics experiments: detector development and data analysis. Providing a concise introduction to both the standard model of particle physics and the basic principles of semiconductor tracking detectors, it presents the first measurement of the top quark pole mass from the differential cross-section of tt+J events in the dileptonic tt decay channel. The first part focuses on the development and characterization of silicon pixel detectors. To account for the expected increase in luminosity of the Large Hadron Collider (LHC), the pixel detector of the compact muon solenoid (CMS) experiment is replaced by an upgraded detector with new front-end electronics. It presents comprehensive test beam studies conducted to verify the design and quantify the performance of the new front-end in terms of tracking efficiency and spatial resolution. Furthermore, it proposes a new cluster interpolation method, which utilizes the third central moment of the cluster charge distribution to improve the position resolution. The second part of the thesis introduces an alternative measurement of the top quark mass from the normalized differential production cross-sections of dileptonic top quark pair events with an additional jet. The energy measurement is 8TeV. Using theoretical predictions at next-to-leading order in perturbative Quantum Chromodynamics (QCD), the top quark pole mass is determined using a template fit method.

Measurement of the Top Quark Mass

Download Measurement of the Top Quark Mass PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 292 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!


Book Synopsis Measurement of the Top Quark Mass by : Tzu-Chung Frank Hsieh

Download or read book Measurement of the Top Quark Mass written by Tzu-Chung Frank Hsieh and published by . This book was released on 1998 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Top Quark Pair Production

Download Top Quark Pair Production PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 3319014870
Total Pages : 231 pages
Book Rating : 4.3/5 (19 download)

DOWNLOAD NOW!


Book Synopsis Top Quark Pair Production by : Anna Christine Henrichs

Download or read book Top Quark Pair Production written by Anna Christine Henrichs and published by Springer Science & Business Media. This book was released on 2013-10-04 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Before any kind of new physics discovery could be made at the LHC, a precise understanding and measurement of the Standard Model of particle physics' processes was necessary. The book provides an introduction to top quark production in the context of the Standard Model and presents two such precise measurements of the production of top quark pairs in proton-proton collisions at a center-of-mass energy of 7 TeV that were observed with the ATLAS Experiment at the LHC. The presented measurements focus on events with one charged lepton, missing transverse energy and jets. Using novel and advanced analysis techniques as well as a good understanding of the detector, they constitute the most precise measurements of the quantity at that time.

Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method

Download Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 364214070X
Total Pages : 155 pages
Book Rating : 4.6/5 (421 download)

DOWNLOAD NOW!


Book Synopsis Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method by : Alexander Grohsjean

Download or read book Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method written by Alexander Grohsjean and published by Springer Science & Business Media. This book was released on 2010-10-01 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main pacemakers of scienti?c research are curiosity, ingenuity, and a pinch of persistence. Equipped with these characteristics a young researcher will be s- cessful in pushing scienti?c discoveries. And there is still a lot to discover and to understand. In the course of understanding the origin and structure of matter it is now known that all matter is made up of six types of quarks. Each of these carry a different mass. But neither are the particular mass values understood nor is it known why elementary particles carry mass at all. One could perhaps accept some small generic mass value for every quark, but nature has decided differently. Two quarks are extremely light, three more have a somewhat typical mass value, but one quark is extremely massive. It is the top quark, the heaviest quark and even the heaviest elementary particle that we know, carrying a mass as large as the mass of three iron nuclei. Even though there exists no explanation of why different particle types carry certain masses, the internal consistency of the currently best theory—the standard model of particle physics—yields a relation between the masses of the top quark, the so-called W boson, and the yet unobserved Higgs particle. Therefore, when one assumes validity of the model, it is even possible to take precise measurements of the top quark mass to predict the mass of the Higgs (and potentially other yet unobserved) particles.

Strings, Branes And Extra Dimensions (Tasi 2001)

Download Strings, Branes And Extra Dimensions (Tasi 2001) PDF Online Free

Author :
Publisher : World Scientific
ISBN 13 : 981448301X
Total Pages : 867 pages
Book Rating : 4.8/5 (144 download)

DOWNLOAD NOW!


Book Synopsis Strings, Branes And Extra Dimensions (Tasi 2001) by : Steven S Gubser

Download or read book Strings, Branes And Extra Dimensions (Tasi 2001) written by Steven S Gubser and published by World Scientific. This book was released on 2004-03-23 with total page 867 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers some recent advances in string theory and extra dimensions. Intended mainly for advanced graduate students in theoretical physics, it presents a rare combination of formal and phenomenological topics, based on the annual lectures given at the School of the Theoretical Advanced Study Institute (2001) — a traditional event that brings together graduate students in high energy physics for an intensive course of advanced learning. The lecturers in the School are leaders in their fields.The first lecture, by E D'Hoker and D Freedman, is a systematic introduction to the gauge-gravity correspondence, focusing in particular on correlation functions in the conformal case. The second, by L Dolan, provides an introduction to perturbative string theory, including recent advances on backgrounds involving Ramond-Ramond fluxes. The third, by S Gubser, explains some of the basic facts about special holonomy and its uses in string theory and M-theory. The fourth, by J Hewett, surveys the TeV phenomenology of theories with large extra dimensions. The fifth, by G Kane, presents the case for supersymmetry at the weak scale and some of its likely experimental consequences. The sixth, by A Liddle, surveys recent developments in cosmology, particularly with regard to recent measurements of the CMB and constraints on inflation. The seventh, by B Ovrut, presents the basic features of heterotic M-theory, including constructions that contain the Standard Model. The eighth, by K Rajagopal, explains the recent advances in understanding QCD at low temperatures and high densities in terms of color superconductivity. The ninth, by M Sher, summarizes grand unified theories and baryogenesis, including discussions of supersymmetry breaking and the Standard Model Higgs mechanism. The tenth, by M Spiropulu, describes collider physics, from a survey of current and future machines to examples of data analyses relevant to theories beyond the Standard Model. The eleventh, by M Strassler, is an introduction to supersymmetric gauge theory, focusing on Wilsonian renormalization and analogies between three- and four-dimensional theories. The twelfth, by W Taylor and B Zwiebach, introduces string field theory and discusses recent advances in understanding open string tachyon condensation. The thirteenth, by D Waldram, discusses explicit model building in heterotic M-theory, emphasizing the role of the E8 gauge fields.The written presentation of these lectures is detailed yet straightforward, and they will be of use to both students and experienced researchers in high-energy theoretical physics for years to come.The proceedings have been selected for coverage in:• Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)• CC Proceedings — Engineering & Physical Sciences

Low-Energy Electrons

Download Low-Energy Electrons PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 0429602766
Total Pages : 254 pages
Book Rating : 4.4/5 (296 download)

DOWNLOAD NOW!


Book Synopsis Low-Energy Electrons by : Oddur Ingólfsson

Download or read book Low-Energy Electrons written by Oddur Ingólfsson and published by CRC Press. This book was released on 2019-04-23 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-energy electrons are ubiquitous in nature and play an important role in natural phenomena as well as many potential and current industrial processes. Authored by 16 active researchers, this book describes the fundamental characteristics of low-energy electron–molecule interactions and their role in different fields of science and technology, including plasma processing, nanotechnology, and health care, as well as astro- and atmospheric physics and chemistry. The book is packed with illustrative examples, from both fundamental and application sides, features about 130 figures, and lists over 800 references. It may serve as an advanced graduate-level study course material where selected chapters can be used either individually or in combination as a basis to highlight and study specific aspects of low-energy electron–molecule interactions. It is also directed at researchers in the fields of plasma physics, nanotechnology, and radiation damage to biologically relevant material (such as in cancer therapy), especially those with an interest in high-energy-radiation-induced processes, from both an experimental and a theoretical point of view.

LA GRAVEDAD DE LOS ASUNTOS

Download LA GRAVEDAD DE LOS ASUNTOS PDF Online Free

Author :
Publisher :
ISBN 13 : 9788416714438
Total Pages : 0 pages
Book Rating : 4.7/5 (144 download)

DOWNLOAD NOW!


Book Synopsis LA GRAVEDAD DE LOS ASUNTOS by :

Download or read book LA GRAVEDAD DE LOS ASUNTOS written by and published by . This book was released on 2017-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Featuring the work of nine Mexican artists in video, performance, sculpture, drawing and installation, Matters of Gravityreflects on the force of gravity through its absence. Artists are Tania Candiani, Ale de la Puente, Ivan Puig, Arcangel Constantini, Fabiola Torres-Alzaga, Gilberto Esparza, Juan José Díaz Infante, Nahum and Marcela Armas.

Higgs Discovery

Download Higgs Discovery PDF Online Free

Author :
Publisher : Harper Collins
ISBN 13 : 0062245317
Total Pages : 94 pages
Book Rating : 4.0/5 (622 download)

DOWNLOAD NOW!


Book Synopsis Higgs Discovery by : Lisa Randall

Download or read book Higgs Discovery written by Lisa Randall and published by Harper Collins. This book was released on 2012-07-24 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: On July 4, 2012, physicists at the Large Hadron Collider in Geneva madehistory when they discovered an entirely new type of subatomic particle that many scientists believe is the Higgs boson. For forty years, physicists searched for this capstone to the Standard Model of particle physics—the theory that describes both the most elementary components that are known in matter and the forces through which they interact. This particle points to the Higgs field, which provides the key to understanding why elementary particles have mass. In Higgs Discovery, Lisa Randall explains the science behind this monumental discovery, its exhilarating implications, and the power of empty space.

Two Lectures

Download Two Lectures PDF Online Free

Author :
Publisher : CUP Archive
ISBN 13 :
Total Pages : 64 pages
Book Rating : 4.:/5 (89 download)

DOWNLOAD NOW!


Book Synopsis Two Lectures by : Werner Heisenberg

Download or read book Two Lectures written by Werner Heisenberg and published by CUP Archive. This book was released on 1949 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of the TtH Production Cross-section with a Collimated H -> Bb Decay in Pp Collisions at Sqrt(s)

Download Measurement of the TtH Production Cross-section with a Collimated H -> Bb Decay in Pp Collisions at Sqrt(s) PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)

DOWNLOAD NOW!


Book Synopsis Measurement of the TtH Production Cross-section with a Collimated H -> Bb Decay in Pp Collisions at Sqrt(s) by : Eftychia Tzovara

Download or read book Measurement of the TtH Production Cross-section with a Collimated H -> Bb Decay in Pp Collisions at Sqrt(s) written by Eftychia Tzovara and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The predictions of the Standard Model (SM) of particle physics have been probed with remarkable accuracy, so far. The Large Hadron Collider (LHC) at CERN has significantly contributed to this quest. A remarkable achievement of the ATLAS and CMS experiments at the LHC was the discovery of the Higgs boson in 2012, the last missing piece of the SM. With the increasing amount of proton-proton collisions delivered by the LHC, more precise measurements of the Higgs boson are now possible, while rare processes are accessible as well. A property of the Higgs boson that is of particular importance is its coupling to the top quark, which is expected to be the strongest in the SM due to the high mass of the top quark. Therefore, its precise measurement is a stringent test of the SM. A direct measurement of the top-quark Yukawa coupling can be assessed through the Higgs-boson production in association with a pair of top quarks (ttH). This thesis presents the measurement of the ttH process with a subsequent Higgs-boson decay to a pair of b-quarks (H -> bb), the decay mode with the largest branching ratio. The measurement is performed with data collected by the ATLAS detector, corresponding to an integrated luminosity of 139 fb^-1 at a center-of-mass energy of 13 TeV. Events with one or two charged leptons from the tt decay in the final state are considered to the measurement. The main challenge of the ttH(H -> bb) channel emerges from the large SM backgrounds from the production of top-quark pairs with additional jets (tt+jets). Also the many jets coming from b-hadrons (b-jets) in the final state cause combinatorial ambiguities. Thus, the identification of such jets is decisive in order to determine the signal and reject many background processes. The ttH events are split into exclusive analysis regions, based on the number of leptons, jets, and jets tagged as b-jets, providing regions enhanced in signal, or in the main background components. Specifically in the single-lepton channel, a boosted category is defined by selecting events in which the Higgs boson and possibly also the hadronically decaying top quark are produced with high transverse momentum (pT), with their decay products being collimated in large-radius jets. The single-lepton boosted channel targets events with Higgs-boson candidate pT >= 300 GeV and is the main scope of this thesis. To identify the reconstructed objects with the underlying particles and to maximise the discrimination of the ttH signal from the overwhelming tt+jets background events in the signal-enriched regions, machine-learning algorithms are employed. The background is dominated by a tt process with an additional gluon in the final state which further splits into a pair of b-quarks (tt+bb). Besides, a large number of heavy-flavour jets in the final state is not well modelled, thus many systematic uncertainties have to be considered, decreasing the sensitivity of the measurement. All the defined analysis regions are analysed together in a combined profile likelihood fit to test for the presence of signal. The fit simultaneously determines the event yields for the signal and the most important background component, while constraining the overall background model within the assigned systematic uncertainties. Eventually, the ratio of the measured ttH cross section to the SM expectation in the inclusive cross-section measurement is found to be 0.35 +0.36,-0.34}, corresponding to an observed (expected) significance of 1.0 (2.7) standard deviations. A ttH signal strength larger than the SM prediction is excluded at 95% confidence level. The measurement uncertainty is dominated by systematic uncertainties, mainly regarding the theoretical knowledge of the tt +>= 1b background process. Finally, to further test the SM, the cross-section is measured differentially as a function of the generator-level Higgs-boson pT, taking advantage of the reconstruction of the Higgs-boson kinematics.

Particle Dark Matter

Download Particle Dark Matter PDF Online Free

Author :
Publisher : Cambridge University Press
ISBN 13 : 0521763681
Total Pages : 763 pages
Book Rating : 4.5/5 (217 download)

DOWNLOAD NOW!


Book Synopsis Particle Dark Matter by : Gianfranco Bertone

Download or read book Particle Dark Matter written by Gianfranco Bertone and published by Cambridge University Press. This book was released on 2010-01-07 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.

The Physics of the Quark-Gluon Plasma

Download The Physics of the Quark-Gluon Plasma PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 3642022855
Total Pages : 374 pages
Book Rating : 4.6/5 (42 download)

DOWNLOAD NOW!


Book Synopsis The Physics of the Quark-Gluon Plasma by : Sourav Sarkar

Download or read book The Physics of the Quark-Gluon Plasma written by Sourav Sarkar and published by Springer Science & Business Media. This book was released on 2009-12-16 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to offer to the next generation of young researchers a broad and largely self-contained introduction to the physics of heavy ion collisions and the quark-gluon plasma, providing material beyond that normally found in the available textbooks. For each of the main aspects - QCD thermodynamics and global features of the QGP, collision hydrodynamics, electromagnetic probes, jet and quarkonium production, color glass condensate, and the gravity connection - the present volume provides extensive and pedagogical lectures, surveying the present status of both theory and experiment. A particular feature of this volume is that all lectures have been written with the active assistance of selected students present at the course in order to ensure the adequate level and coverage for the intended readership.

Discovery of Single Top Quark Production

Download Discovery of Single Top Quark Production PDF Online Free

Author :
Publisher : Springer Science & Business Media
ISBN 13 : 1441977996
Total Pages : 149 pages
Book Rating : 4.4/5 (419 download)

DOWNLOAD NOW!


Book Synopsis Discovery of Single Top Quark Production by : Dag Gillberg

Download or read book Discovery of Single Top Quark Production written by Dag Gillberg and published by Springer Science & Business Media. This book was released on 2011-01-22 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark is by far the heaviest known fundamental particle with a mass nearing that of a gold atom. Because of this strikingly high mass, the top quark has several unique properties and might play an important role in electroweak symmetry breaking—the mechanism that gives all elementary particles mass. Creating top quarks requires access to very high energy collisions, and at present only the Tevatron collider at Fermilab is capable of reaching these energies. Until now, top quarks have only been observed produced in pairs via the strong interaction. At hadron colliders, it should also be possible to produce single top quarks via the electroweak interaction. Studies of single top quark production provide opportunities to measure the top quark spin, how top quarks mix with other quarks, and to look for new physics beyond the standard model. Because of these interesting properties, scientists have been looking for single top quarks for more than 15 years. This thesis presents the first discovery of single top quark production. It documents one of the flagship measurements of the D0 experiment, a collaboration of more than 600 physicists from around the world. It describes first observation of a physical process known as “single top quark production”, which had been sought for more than 10 years before its eventual discovery in 2009. Further, his thesis describes, in detail, the innovative approach Dr. Gillberg took to this analysis. Through the use of Boosted Decision Trees, a machine-learning technique, he observed the tiny single top signal within an otherwise overwhelming background. This Doctoral Thesis has been accepted by Simon Fraser University, Burnaby, BC, Canada.