DOCSLIB.ORG

New Insights Into Modified Scalar Sectors and Exotic Higgs Decays

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
New Insights Into Modified Scalar Sectors and Exotic Higgs Decays Dissertation submitted to the Combined Faculties for the Natural Sciences and Mathematics of the Ruperto-Carola University of Heidelberg, Germany for the degree of Doctor of Natural Sciences Put forward by Alexander Helmboldt Born in Mannheim, Germany Oral examination: 19.07.2018 New insights into modified scalar sectors and exotic Higgs decays Referees: Prof. Dr. Dr. h.c. Manfred Lindner Prof. Dr. Tilman Plehn New insights into modified scalar sectors and exotic Higgs decays In the context of models with modified Higgs sectors, we examine different possible causes for a systematic absence of new physics from current searches at the Large Hadron Collider (LHC). First, having in mind the lack of clear signs for supersymmetry, we consider theo- ries based on classical scale invariance as an alternative approach towards addressing the gauge hierarchy problem. Within the aforementioned framework, we present a systematic analysis of simple Standard Model (SM) extensions. As a result, we identify the minimal model, which allows for radiative electroweak symmetry breaking, is consistent with all current experimental constraints and does not reintroduce any fine-tuning issues. Next, given that very light scalar particles as predicted by several well-motivated beyond-the- SM theories have not yet been detected either, we propose a novel search strategy based on exotic Higgs decays into three of these light scalars. We show that said processes can be abundant enough to be observable at the LHC or future lepton colliders in exciting new signatures containing six SM fermions in the final state. In particular, we demon- strate the three-body channel's capabilities in probing scenarios which are inaccessible to existing searches exclusively relying on the related two-body Higgs decay. Our last study is motivated by the fact that new physics may manifest itself only through effects which are out of the LHC's reach due to the large amounts of hadronic background. As an example, we consider quark-flavor-violating Higgs decays involving bottom quarks and evaluate the expected sensitivity of direct searches at the proposed International Linear Collider (ILC). In doing so, we identify hadronic SM Higgs decays with mistagged jets as the dominant background processes and find that a dedicated analysis is anticipated to explore branching ratios down to the per-mill level. Neue Erkenntnisse uber¨ modifizierte Higgs-Sektoren und exotische Higgs Zerf¨alle Im Rahmen von Modellen mit modifizierten Higgs-Sektoren untersuchen wir verschiedene m¨ogliche Ursachen fur¨ eine systematische Abwesenheit neuer Physik von entsprechenden Suchen am Large Hadron Collider (LHC). Angesichts des Fehlens klarer Hinweise auf Su- persymmetrie betrachten wir als Erstes klassisch skaleninvariante Theorien, die einen al- ternativen Zugang zur L¨osung des Hierarchieproblems darstellen. Innerhalb solcher Theo- rien fuhren¨ wir eine systematische Studie einfacher Standardmodell (SM) Erweiterungen durch. Somit k¨onnen wir das minimale Modell identifizieren, welches radiative elektro- schwache Symmetriebrechung erlaubt und vereinbar mit allen experimentellen Schranken ist, ohne dabei ein Feinabstimmungsproblem wiedereinzufuhren.¨ Auch leichte skalare Teil- chen, deren Existenz von etlichen gut motivierten Modellen jenseits des SM vorhergesagt wird, konnten bisher nicht gefunden werden. Daher schlagen wir als N¨achstes eine neue Suchstrategie vor, die auf exotischen Higgszerf¨allen in drei dieser leichten Skalare ba- siert. Wir finden, dass besagte Prozesse h¨aufig genug vorkommen k¨onnen, um am LHC oder zukunftigen¨ Leptonbeschleunigern in neuen, spektakul¨aren Signaturen mit sechs SM Fermionen im Endzustand beobachtet zu werden. Insbesondere zeigen wir, dass der Drei- K¨orper-Zerfall Szenarien testen kann, die fur¨ bestehende Suchen, welche ausschließlich auf dem verwandten Zwei-K¨orper-Zerfall beruhen, unzug¨anglich sind. Unsere letzte Stu- die ist dadurch motiviert, dass neue Physik sich m¨oglicherweise nur durch solche Signa- turen manifestiert, welche wegen des vielen hadronischen Untergrundes am LHC nicht nachweisbar sind. Als Beispiel betrachten wir Quark-Flavor-verletzende Higgszerf¨alle mit Bottom-Quarks und bestimmen die erwartete Sensitivit¨at direkter Suchen am geplanten International Linear Collider (ILC). Dabei erkennen wir hadronische SM Higgszerf¨alle mit falsch identifizierten Jets als die dominanten Untergrundprozesse und finden, dass eine ge- eignete Analyse es erlauben wird, Verzweigungsverh¨altnisse im Promillebereich zu prufen.¨ v Contents 1 Introduction and motivation 1 2 The Standard Model and beyond 7 2.1 The Standard Model in a nutshell ............... 8 2.2 Electroweak symmetry breaking . 13 2.3 The gauge hierarchy problem . 17 3 Minimal conformal extensions of the Higgs sector 21 3.1 Basics of scale-invariant model building . 24 3.2 The Gildener-Weinberg formalism . 27 3.3 Finding the minimal conformal model . 30 3.3.1 SM + one scalar representation . 30 A Real multiplet with vanishing vev . 31 B Real multiplet with finite vev . 36 C Complex multiplet with vanishing vev . 42 D Complex multiplet with finite vev . 46 3.3.2 SM + one scalar and one fermionic representation . 49 3.3.3 SM + two scalar representations . 49 A Two real multiplets with vanishing vev . 50 B The minimal conformal model . 53 C Non-minimal conformal models . 59 3.4 Summary and conclusion .................... 61 4 Three-body Higgs boson decays into extra light scalars 63 4.1 Higgs decays into scalars { a model-independent analysis . 66 4.1.1 Model-independent constraints . 68 A Experimental constraints . 68 B Theoretical constraints . 70 4.1.2 Model-independent results . 72 4.2 Scalar singlet-extension of the Standard Model . 75 4.2.1 Constraints on the parameter space . 79 A Experimental constraints . 79 B Theoretical constraints . 80 4.2.2 Decay properties of the light scalar . 81 vii viii Contents 4.3 Scalar Higgs decays at colliders . 84 4.3.1 Low-mass regime ..................... 84 4.3.2 Intermediate-mass regime . 90 4.3.3 High-mass regime ..................... 91 4.4 Summary and conclusion .................... 95 5 Quark-flavor-violating Higgs boson decays at the ILC 99 5.1 The ILC and Higgs physics . 101 5.2 Theoretical framework and indirect constraints . 105 5.3 Analysis and results . 109 5.3.1 General aspects of the analyses . 109 5.3.2 Hadronic channel at 250 GeV . 112 5.3.3 Leptonic channels . 116 A Estimated performance . 116 B Charged lepton channel at 250 GeV . 119 C Neutrino channel at 250 GeV and 500 GeV . 122 5.4 Summary and conclusion . 128 6 Final conclusion and outlook 131 Appendix A Calculating the Gildener-Weinberg scale 137 B One-loop renormalization group equations 141 B.1 SM + real scalar representation(s) . 142 B.2 SM + one complex scalar representation . 143 C Phase space threshold functions 145 D Tree-level perturbative unitarity 147 E Statistical methods 151 E.1 Setting upper limits . 151 E.2 Discovering signals . 154 List of Abbreviations 157 List of Figures 159 List of Tables 161 Bibliography 163 Chapter 1 Introduction and motivation July 4th 2012 will go down in history as one of the most memorable days for particle physicists during the last decades. The seminal discovery of the Higgs boson at the Large Hadron Collider (LHC) [1, 2], which was announced on that Wednesday, marked the long-awaited experimental ob- servation of the last missing piece of the Standard Model (SM) of particle physics, and thus the culmination of years of extensive effort to track down a particle which was already predicted in the 1960s, and which is of immense importance for high-energy physics. Whereas, for instance, a third genera- tion of quarks and leptons seems expendable from a purely formal point of view, the existence of the Higgs field is absolutely crucial for writing down a consistent quantum field theory describing the fundamental interactions of Nature, barring gravity [3{5]. Although the minimal SM has thus been completed from a theoretical perspective, it still leaves many fundamental questions of modern physics unanswered. For example, while the Standard Model as it stands accurately captures phenomena related to the electromagnetic, weak and strong forces, a con- sistent quantum theory of gravity could not be incorporated so far. It is furthermore still unclear if and how dark matter and dark energy, which after all make up more than 95 % of the universe's energy density [6, 7], may be accounted for within the framework of particle physics. But also the origins of phenomena whose ties to elementary particles are more obvious remain unresolved. Thus, for instance, the actual mechanisms behind mas- sive neutrinos or the baryon asymmetry of the universe are yet unknown. Driven by this large variety of open problems, the field of beyond-the-SM (BSM) model building has long pursued, and still pursues, a plethora of different and ever new directions with the aim of including one or several of the aforementioned phenomena in a consistent theory of particle physics. Interestingly, many of the existing approaches involve postulating further scalar bosons, or otherwise modifying the Higgs sector of the minimal SM 1 2 Chapter 1. Introduction and motivation (see e.g. [8] for a recent comprehensive review).a The question of whether or not the particle found by the ATLAS and CMS experiments is indeed precisely that predicted by the Standard Model is therefore one of the most pressing questions of contemporary high-energy physics. One additional reason to believe that the SM scalar sector is incomplete and requires modification stems from the very nature of said sector itself. Specifically, the SM Higgs being an elementary spinless boson implies the emergence of the infamous gauge hierarchy problem [9{14] as soon as the Standard Model is embedded in a more fundamental quantum field theory involving additional heavy particles. Although as a question about natu- ralness the hierarchy problem poses more of an aesthetic issue rather than a theoretical inconsistency, the quest for its solution has crucially shaped model building and the search for new physics over the last decades.
Load more

Recommended publications
  • LD2668T41961L36.Pdf
    CARBC^IA-CONTAINIMG CGHFOUKDS PRODUCED BI THE PILE-SEOTRQH IRRADIATIGH OP CYAHOGUANIDIIE THOMAS WILLIAM LAPP * B.A., Co* College, 1959 A MAS TBI'S THESIS . submitted in partial fulfillment of the requirements for the degree MASTER 07 SCIENCE Department of Chemistry KANSAS STATE UNIVERSITY Manhattan, Kansas 1%1 TABLE OP COHTKHTS INTRODUCTIOU 1 Theoretical Considerations 3 Previous llH(n,p)cU studies 10 EXPERIMENTAL 21 Sample Preparation. 21 Irradiation of the Cyanoguanidine Sample. • 21 Analysis of the Irradiated Sample 23 Total Carbon-U Activity 25 Chemical Separations 25 Radiochemical Counting Techniques 31 RESULTS AND DISCUSSION 37 Distribution of the Carbon-14 Recoil Atom 40 Radiocarbon Product Distribution 46 SUMMARY 50 ACKNOWLEDGMENTS 51 REFERENCES 52 t nmtCLXTroi In a flux of thermal neutrons, nitrogen atone undergo the nuclear trine- formation NH(n>p)cH. in normal pile-neutron irradiations, the compound to be Irradiated is also subjected to gamma radiation. Both the gamma radia- tion and the nuclear reactions initiated by the neutrons are capable of supplying energy to promote chemical reactions which normally would occur only at elevated temperatures. Collins and Calkins (6) have estimated the average energy of the gamma rays in the Oak Ridge graphite reactor to be approximately 1 Mev. Few nuclear reactions are initiated by the absorption of gamma rays at this photon energy and thus, the important nuclear reactions are those produced by the neutrons. The eyanoguanidine molecule is interesting for studying the chemical consequences produced by the nuclear transformation NU( n ,p)cH for two reasons (1) Within the eyanoguanidine molecule, the nitrogen atoms are bound to carbon atoms by three different types of bonding: single, double and triple bonds.
    [Show full text]
  • The New Look in Oil-Mud Technology
    DISPERSIBLE COLLOIDS The New Look in Oil-Mud Technology JAY P. SIMPSON MEMBER AIME BAROID DIV., NATIONAL LEAD CO. Downloaded from http://onepetro.org/jpt/article-pdf/13/12/1177/2213517/spe-150-pa.pdf by guest on 27 September 2021 J. C. COWAN HOUSTON, TEX. A. E. BEASLEY, JR. Abstract tributed to the general inflexibility of the systems. This inflexibility resulted primarily because one basic component Liquids having oil as the continuous phase long have was used in an attempt to arrive at all mud properties. been recognized as desirable for drilling and completing These oil systems can be compared with the early water­ under certain conditions. Performance limitations, high base muds. costs and inconvenience of handling, however, have kept these oil muds from becoming accepted for widespread, Water-base mlfds in the early years of drilling depended general use. upon bentonite for rheological properties, suspension of solids and filtration control. As was learned with these As previously used, the muds consisted of a bodying earlier clay-water systems, one basic component cannot agent for oil, or primary emulsifier of water in the oil, and by itself provide all of ideal drilling-fluid properties. Today a series of supplementary additives to modify that principal each water-base drilling-fluid property can be controlled component. In recent years a new approach to oil muds with an exactness that was not believed possible even 10 has been taken. Oil-dispersible colloids have been developed years ago. Water-base muds are prepared to have certain to perform specific functions in oil without dependence properties to serve specific purposes, some examples of upon thickening of the oil or emulsification of water.
    [Show full text]
  • Download Author Version (PDF)
    PCCP Accepted Manuscript This is an Accepted Manuscript, which has been through the Royal Society of Chemistry peer review process and has been accepted for publication. Accepted Manuscripts are published online shortly after acceptance, before technical editing, formatting and proof reading. Using this free service, authors can make their results available to the community, in citable form, before we publish the edited article. We will replace this Accepted Manuscript with the edited and formatted Advance Article as soon as it is available. You can find more information about Accepted Manuscripts in the Information for Authors. Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. The journal’s standard Terms & Conditions and the Ethical guidelines still apply. In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains. www.rsc.org/pccp Page 1 of 12Journal Name Physical Chemistry Chemical Physics Dynamic Article Links ► Cite this: DOI: 10.1039/c0xx00000x www.rsc.org/xxxxxx ARTICLE TYPE Estimating the Binding Ability of Onium Ions with CO 2 and π Systems: A Computational Investigation M. Althaf Hussain, A. Subha Mahadevi and G. Narahari Sastry* Manuscript Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX 5 DOI: 10.1039/b000000x Density functional theory (DFT) calculations have been employed on 165 complexes of onium ions + + + + (NH 4 , PH 4 , OH 3 ,SH 3 ) and methylated onium ions with CO 2, aromatic (C 6H6) and heteroaromatic (C 5H5X, X = N, P; C 4H5Y, Y = N, P; C 4H4Z, Z = O, S) systems.
    [Show full text]
  • A Probabilistic QCD Picture of Diffractive Dissociation and Predictions for Future Eics
    A probabilistic QCD picture of diffractive dissociation and predictions for future EICs Anh Dung Le Based on: ADL, Mueller & Munier, PRD 103 (2021) 054031 ADL, Mueller & Munier, ar iv:2103"100## ADL, arXi!:2103"0$$24 Presen%ed at RPP2021 MO I!A ION + A QCD pi.%ure for diffra.%ion and partonic le!el + Predic%ions a% /u%ure ele.%ron-ion colliders (EICs) 4'ser!a'le of interes%: Rapidity-gap distribution! Diffraction at #ERA$ A large angular ga& obser!ed( Large ra&idity ga& (LRG) 2 CON E" ) 3" DIS in dipole 6odel and diffra.%ion 33" Diffra.%i!e disso.ia%ion of oniu6: a proba'ilis%ic ,CD &ic%ure 333" Diffra.%ive disso.ia%ion a% /u%ure EICs 3 QCD dipole *odel for DI) 7ir%ual photon probes nu.leus !ia a quark-an%iquar9 .olor single% dipole (oniu6) Dipole /a.%oriza%ion: Proba. of the splitting virtual photon → dipole :;: momen%um frac%ion of &hoton carried b) quar9 (or an%i8uark)] 4 Diffractive dissociation of virtual p+oton 2!ol!ed s%a%e 'y Q-D radiati!e e6issions Photon disso.iated to a se% o/ &arti.les (X) > angular gap in de%e.%ors =u.leus ke&% in%ac% 5 Diffractive dissociation of onium 6 Color dipole evolution: )oft-gluon e*issions I0 I0 r Large N 1 ?igh-ra&idi%) e!olu%ion I . I 2 r 2 Transverse position rk r2 space I1 I1 Large nu6'er o/ colors (N.) li6i%: gluon ≃ ;ero1si;e quar91an%i8uark pair @ one1gluon e6ission ≃ (1A 2) di&ole bran.hing (L4; soH1gluon a&&roI.) Boos%ing to high rapidi%y B: 1 Bran.hing re&ea%ed (and inde&enden%) → 'ran.hing &ro.ess 1 Coc9 s%ate of oniu6 is a se% of di&oles wi%h random si;es {r9F A random num'er densi%) n(r9) Each event recorded in a detector corresp.
    [Show full text]
  • SANTA CRUZ INSTITUTE for PARTICLE PHYSICS LIST of PREPRINTS SCIPP # 1. Finite Size Scaling and Asymptotic Freedom of the SU(2)
    SANTA CRUZ INSTITUTE FOR PARTICLE PHYSICS LIST OF PREPRINTS SCIPP # 1. Finite Size Scaling and Asymptotic Freedom of the SU(2) Lattice Gauge Model, M. Nauenberg, T. Schalk and R. Brower, Phys. Rev. D24:548 (1981) 81/1 2. Cosmic Ray Trigger Circuit for Large Solenoidal Particle Detectors, A. Seiden, P. Shaffer and J. Warner, NIM 193:597 (1982) 81/2 3. Elastic Photon-Photon Scattering in the 50-130 GeV Range, A.M. Breakstone et al., Phys. Rev. Lett. 47:1778 (1981) 81/3 4. Quasi-Elastic Omega Photoproduction at 50-130 GeV, A.M. Breakstone et al., Phys. Rev. Lett. 47:1782 (1981) 81/4 5. Large Drift Chambers with a Multi-Wire Cell Design, F. Grancagnolo and A. Seiden 81/5 6. A Large-Solid-Angle Spectrometer for High Energy Electrons and Photons, A.M. Breakstone, C.A. Heusch and A. Seiden, NIM 211:209 (1983) 81/6 7. The SU(2) Adjoint Higgs Model, R.C. Brower et al., Phys. Rev. D25:3319 (1982) 81/7 8. Some Ideas on a Central Tracking Chamber for the SLAC Linear Collider, A. Seiden, Proceedings of the 2nd 81/8 TRISTAN Physics Workshop, KEK, Tsukuba, Japan; Ed. Y. Unno, KEK 82-1, p.466 (May 1982) 9. Heavy Flavor Production from Photons and Hadrons, C. Heusch, Presented at the SLAC Summer Institute 82/9 on Particle Physics, 1981. 10. Wide Angle Secondaries Produced by `Beamstrahlung' Interactions, D.B. Smith (SLC Report). 82/10 11. Central Tracking Chamber for SLC, A. Seiden (SLC Report) 82/11 12. Tradeoffs in Drift Chamber Design, A.
    [Show full text]
  • Deep-Inelastic Onium Scattering
    DAPNIA/SPP 95-15 SPhT-T95-090 Deep-Inelastic Onium Scattering H.Navelet1, R.P eschanski1,Ch.Royon2 1- Service de Physique Th´eorique, Centre d’Etudes de Saclay F-91191 Gif-sur-Yvette Cedex (France) 2- DAPNIA - SPP, Centre d’Etudes de Saclay F-91191 Gif-sur-Yvette Cedex (France) Abstract: Using the colour dipole approach of the QCD per- turbative (BFKL) Pomeron exchange in onium-onium scattering, we compute the cross section for small but hierarchically different onium sizes. A specific term dependent on the size-ratio is gener- ated. In deep inelastic onium scattering it appears as a scaling- violation contribution to the quark structure function near the BFKL singularity. We find that the extension of the formalism for deep inelastic onium scattering to the proton structure func- tion provides a remarkably good 3-parameter fit to HERA data at small x with a simple physical interpretation in terms of the dipole formulation. 1 Recently, a dipole model approach to the QCD computation of onium- onium scattering from the perturbative resummation of leading logarithms has been proposed[1, 2, 3]. In this framework, each onium state describes a small (i.e. massive) colour-singlet quark-antiquark pair whose infinite mo- mentum wavefuntion is itself composed of colour dipoles at the moment of the interaction. These onia interact locally in impact-parameter space via 2-gluon exchange between the component dipoles. The overall total cross-section has been shown to reproduce the well-known[4] QCD Pomeron exchange (BFKL) due to leading log 1/x resummation. It is thus tempting to try and apply this formalism to the deep-inelastic scattering off protons and more specifically to the proton structure function measured at HERA[5].
    [Show full text]
  • Diffractive Dissociation in Future Electron-Ion Colliders
    1 INTRODUCTION Diffractive dissociation in future electron-ion colliders Anh Dung Le?, CPHT, CNRS, École polytechnique, IP Paris, F-91128 Palaiseau, France * [email protected] August 2, 2021 Proceedings for the XXVIII International Workshop on Deep-Inelastic Scattering and Related Subjects, Stony Brook University, New York, USA, 12-16 April 2021 doi:10.21468/SciPostPhysProc.? Abstract We study diffractive scattering cross sections, focusing on the rapidity gap distribution in realistic kinematics at future electron-ion colliders. Our study consists in numerical solu- tions of the QCD evolution equations in both fixed and running coupling frameworks. The fixed and the running coupling equations are shown to lead to different shapes for the rapid- ity gap distribution. The obtained distribution when the coupling is fixed exhibits a shape characteristic of a recently developed model for diffractive dissociation, which indicates the relevance of the study of that diffractive observable for the partonic-level understanding of diffraction. 1 Introduction Single diffractive dissociation in electron-hadron collisions is defined to be the scattering process in which the virtual photon mediating the interaction fluctuates into a set of partons part of which goes in the final state while the hadron remains intact, leaving a large rapidity gap between the latter and the slowest produced particle. The rapidity gap characterization of diffractive events is manifested in collision experiments by the existence of a large angular sector in the detector arXiv:2107.14511v1 [hep-ph] 30 Jul 2021 with no measured particle. Such events were first observed in electron-proton collisions at DESY HERA [1,2 ], and their detailed analysis is one of goals of the construction of future electron-ion colliders [3–5].
    [Show full text]
  • Investigating Extreme Ultraviolet Radiation Chemistry with First-Principles Quantum Chemistry Calculations
    Investigating extreme ultraviolet radiation chemistry with first-principles quantum chemistry calculations a,b c c Jonathan H. Ma, Han Wang, David Prendergast, a,d a, Andrew Neureuther, and Patrick Naulleau * a Lawrence Berkeley Laboratory, Materials Sciences Division, Center of X-Ray Optics, Berkeley, California, United States b University of California Berkeley, Department of Physics, Berkeley, California, United States c Lawrence Berkeley Laboratory, Molecular Foundry, Berkeley, California, United States d University of California Berkeley, Department of Electrical Engineering and Computer Science, Berkeley, California, United States Abstract. In extreme ultraviolet (EUV) lithography, chemistry is driven by secondary elec- trons. A deeper understanding of these processes is needed. However, electron-driven processes are inherently difficult to experimentally characterize for EUV materials, impeding targeted material engineering. A computational framework is needed to provide information for rational material engineering and identification at a molecular level. We demonstrate that density func- tional theory calculations can fulfill this purpose. We first demonstrate that primary electron energy spectrum can be predicted accurately. Second, the dynamics of a photoacid generator upon excitation or electron attachment are studied with ab-initio molecular dynamics calcula- tions. Third, we demonstrate that electron attachment affinity is a good predictor of reduction potential and dose to clear. The correlation between such calculations and experiments suggests that these methods can be applied to computationally screen and design molecular components of EUV material and speed up the development process. Keywords: extreme ultraviolet lithography; extreme ultraviolet exposure chemistry; photoacid generator chemistry; radiation chemistry; extreme ultraviolet fundamentals. 1 Introduction With the introduction of extreme ultraviolet (EUV), electron-driven processes in photoresists 1 become relevant.
    [Show full text]
  • Thesis, We Take Σψ Directly from Experimental Data
    QUARKONIUM TRANSPORT THEORY IN ULTRA-RELATIVISTIC HEAVY-ION COLLISIONS A Dissertation by XIAOJIAN DU Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, Ralf Rapp Committee Members, Siu Ah Chin Che-Ming Ko Saskia Mioduszewski Frank Sottile Head of Department, Grigory Rogachev August 2019 Major Subject: Physics Copyright 2019 Xiaojian Du ABSTRACT The study of the fundamental strong interaction is an important vehicle for advancing our understanding of nuclear physics. Quarkonia, bound states of heavy quark-antiquark pairs, are promising probes for studying the strong force, in particular its confining prop- erty which constrains quarks and gluons to hadrons. Ultrarelativistic heavy-ion collisions (URHICs) are the only experimental method that can screen the strong force by creating a hot and dense medium. The suppression of quarkonia observed in URHICs is believed to be due to the formation of a deconfined quark-gluon plasma (QGP), a medium with un- bound quarks and gluons. In order to study this phenomenon, we utilize a transport model to describe the evolution of quarkonium states in URHICs. This model calculates the sup- pression of heavy quarkonia, as well as recombination of heavy quark-antiquark pairs, in the medium. For charmonium, in particular, the recombination is essential for describing the momentum and energy dependencies of their spectra. Based on the fact that different binding energies lead to different dissociation temperatures, a “sequential regeneration” of excited and ground-state charmonia is proposed and implemented to compare to experi- mental data in nuclear collisions.
    [Show full text]
  • Quantum Phase Transition and Degeneracy of a Circuit-QED Vacuum Pierre Nataf, Cristiano Ciuti
    Quantum phase transition and degeneracy of a circuit-QED vacuum Pierre Nataf, Cristiano Ciuti To cite this version: Pierre Nataf, Cristiano Ciuti. Quantum phase transition and degeneracy of a circuit-QED vacuum. 2009. hal-00418515v1 HAL Id: hal-00418515 https://hal.archives-ouvertes.fr/hal-00418515v1 Preprint submitted on 18 Sep 2009 (v1), last revised 15 Jan 2010 (v3) HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Quantum phase transition and degeneracy of a circuit-QED vacuum 1 1, Pierre Nataf and Cristiano Ciuti ∗ 1Laboratoire Mat´eriaux et Ph´enom`enes Quantiques, Universit´eParis Diderot-Paris 7 and CNRS, Bˆatiment Condorcet, 10 rue Alice Domont et L´eonie Duquet, 75205 Paris Cedex 13, France We investigate theoretically the quantum vacuum properties of a transmission line resonator inductively coupled to a chain of N superconducting qubits. We derive the quantum Hamiltonian for such circuit-QED system, showing that, due to the type and strength of the interaction, a quantum phase transition occurs in the limit of large N, with a twice degenerate quantum vacuum above a critical coupling. The phase diagram can be fully explored thanks to the controllable ultrastrong coupling of the qubits with the modes of the transmission line resonator.
    [Show full text]
  • The University of Chicago Quantum Computing with Distributed Modules a Dissertation Submitted to the Faculty of the Division Of
    THE UNIVERSITY OF CHICAGO QUANTUM COMPUTING WITH DISTRIBUTED MODULES A DISSERTATION SUBMITTED TO THE FACULTY OF THE DIVISION OF THE PHYSICAL SCIENCES IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHYSICS BY NELSON LEUNG CHICAGO, ILLINOIS MARCH 2019 Copyright c 2019 by Nelson Leung All Rights Reserved TABLE OF CONTENTS LIST OF FIGURES . vi LIST OF TABLES . viii ACKNOWLEDGMENTS . ix ABSTRACT . x PREFACE............................................ 1 1 QUANTUM COMPUTING . 2 1.1 Introduction to Quantum Computing . .2 1.2 High-Level Description of Some Quantum Algorithms . .3 1.2.1 Grover’s algorithm . .3 1.2.2 Shor’s algorithm . .3 1.2.3 Variational Quantum Eigensolver (VQE) . .4 1.3 Quantum Architectures . .4 1.3.1 Trapped Ions . .4 1.3.2 Silicon . .5 1.3.3 Superconducting qubits . .5 1.4 Thesis Overview . .6 2 CIRCUIT QUANTUM ELECTRODYNAMICS . 7 2.1 Quantization of Quantum Harmonic Oscillator . .7 2.2 Circuit Quantum Harmonic Oscillator . 10 2.3 Josephson Junction . 12 2.4 Quantization of Transmon Qubit . 13 2.5 Quantization of Split Junction Transmon Qubit with External Flux . 16 2.6 Coupling between Resonators . 18 2.7 Dispersive Shift between Transmon and Resonator . 21 3 CONTROLLING SUPERCONDUCTING QUBITS . 23 3.1 Charge Control . 23 3.2 Flux Control . 25 3.3 Transmon State Measurement . 25 3.4 Cryogenic Environment . 26 3.5 Microwave Control Electronics . 26 3.5.1 Oscillator . 26 3.5.2 Arbitrary waveform generator . 27 3.5.3 IQ mixer . 27 3.6 Other Electronics . 28 3.7 Microwave Components . 28 3.7.1 Attenuator .
    [Show full text]
  • Lawrence Berkeley Laboratory UNIVERSITY of CALIFORNIA
    t.,t(> ~Yd LBL- 2 0 7 4 7 ~ I Lawrence Berkeley Laboratory UNIVERSITY OF CALIFORNIA 1 . '' r, ·) t· Physics Division ·• ... ' ;..; ;] 1986 :BRARY AND -"'TS S'=r..,...f('" • Lectures given at the Summer School on 'Architecture of Fundamental Interactions', Les Houches, France, July-August 1985 THE QUEST FOR SUPERSYMMETRY I. Hinchliffe December 1985 - Prepared for the U.S. Department of Energy under Contract DE-AC03-76SF00098 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of California. "") •.~ t ~ -- December 1985 LBL-20747 Table of Contents 1. Introduction THE QUEST FOR SUPERSYMMETRY* 2. Cosmological Bounds 3. Supersymmetry in e+ e- Annihilation Lectures given at the Summer School on 'Architecture of Fundamental 4.
    [Show full text]