Electroweak Symmetry Breaking in the Era of the Higgs Boson Discovery

Electroweak Symmetry Breaking in the Era of the Higgs Boson Discovery PDF Author: Daniele Bertolini (Ph. D.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 125

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Book Description
In this thesis we study possible deviations from the electroweak symmetry breaking mechanism as predicted by the Standard Model (SM), and we introduce a new framework to analyze hadronic final states at colliders. In the first part, we begin by considering supersymmetric extensions of the SM and by studying the connection between electroweak symmetry breaking and supersymmetry breaking. Contrary to the common lore, we show that a visible dynamics in the Higgs sector can contribute to supersymmetry breaking, as long as soft masses receive contributions also from one or more hidden sectors. A striking feature is the presence of a light pseudo-goldstino in the spectrum. We study potential collider signatures of visible supersymmetry breaking in Higgs and neutralino decays. Then, we move to a study of the Higgs data collected at the Large Hadron Collider (LHC). By using both measurements of the Higgs boson couplings, and limits on Higgs-like states at higher masses, we investigate whether the data support the possibility that the SM Higgs is mixed with another scalar. We consider fits to simplified models and we find that mixing angles with sin 2 6 > 0.2 are disfavored at 95% CL over a scalar mass range 200 - 1000 GeV. In the second part, we propose a new way to define inclusive jet (and subject) based observables at colliders. We introduce a new class of event shapes that characterize the jet-like structure of the event by using only information in the neighborhood of each particle. We show that conventional jet-based observables such as jet multiplicity, summed scalar transverse momentum, and missing transverse momentum can be recovered within this approach. We show that in this framework trimming can be recast as a particle weight assignment, without explicit jet identification. Finally, we comment on potential applications of the method both at trigger and analysis level.

Electroweak Symmetry Breaking in the Era of the Higgs Boson Discovery

Electroweak Symmetry Breaking in the Era of the Higgs Boson Discovery PDF Author: Daniele Bertolini (Ph. D.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 125

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Book Description
In this thesis we study possible deviations from the electroweak symmetry breaking mechanism as predicted by the Standard Model (SM), and we introduce a new framework to analyze hadronic final states at colliders. In the first part, we begin by considering supersymmetric extensions of the SM and by studying the connection between electroweak symmetry breaking and supersymmetry breaking. Contrary to the common lore, we show that a visible dynamics in the Higgs sector can contribute to supersymmetry breaking, as long as soft masses receive contributions also from one or more hidden sectors. A striking feature is the presence of a light pseudo-goldstino in the spectrum. We study potential collider signatures of visible supersymmetry breaking in Higgs and neutralino decays. Then, we move to a study of the Higgs data collected at the Large Hadron Collider (LHC). By using both measurements of the Higgs boson couplings, and limits on Higgs-like states at higher masses, we investigate whether the data support the possibility that the SM Higgs is mixed with another scalar. We consider fits to simplified models and we find that mixing angles with sin 2 6 > 0.2 are disfavored at 95% CL over a scalar mass range 200 - 1000 GeV. In the second part, we propose a new way to define inclusive jet (and subject) based observables at colliders. We introduce a new class of event shapes that characterize the jet-like structure of the event by using only information in the neighborhood of each particle. We show that conventional jet-based observables such as jet multiplicity, summed scalar transverse momentum, and missing transverse momentum can be recovered within this approach. We show that in this framework trimming can be recast as a particle weight assignment, without explicit jet identification. Finally, we comment on potential applications of the method both at trigger and analysis level.

Electroweak Symmetry Breaking - Proceedings Of The Budapest Workshop

Electroweak Symmetry Breaking - Proceedings Of The Budapest Workshop PDF Author: Ferenc Csikor
Publisher: World Scientific
ISBN: 9814549894
Category : Broken symmetry (Physics)
Languages : en
Pages : 254

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Book Description
This volume contains the talks given at the above workshop which was devoted to discussing the newest developments in various models of electroweak symmetry breaking forming the basis of modern particle physics. It includes various aspects of Higgs physics and condensate models embodying dynamical symmetry breaking.

Strong Electroweak Symmetry Breaking in the Large Hadron Collider Era

Strong Electroweak Symmetry Breaking in the Large Hadron Collider Era PDF Author: Jared Andrew Evans
Publisher:
ISBN: 9781267023438
Category :
Languages : en
Pages :

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Book Description
With the Large Hadron Collider collecting data, both the pursuit of novel detection techniques and the exploration of new ideas are more important than ever. Novel detection techniques are essential in order for the community to garner the most worth from the machine. New ideas are needed both to expand the boundaries of what could be observed and to foster the creative mindset of the community that moves particle physics into fascinating, and often unexpected, directions. Discovering whether electroweak symmetry is broken strongly or weakly is one of the most pressing questions to be answered. Exploring the possibility of strong electroweak symmetry breaking is the topic of this work. The first of two major sectors in this work concerns the theory of conformal technicolor. We present the low energy minimal model for conformal technicolor and verify that it can satisfy current constraints from experiment. We will also provide a UV completion for this model, which realistically extends the sector with high-energy supersymmetry. Two complete models of flavor are presented. This is the first example of a complete, consistent model of strong electroweak symmetry breaking. The second of the two sectors discusses experimental signatures arising in a large class of general technicolor models at the Large Hadron Collider. The possible existence of narrow scalar states that can be produced via gluon-gluon fusion is first discussed. These states can decay into exotic final states of multiple electroweak gauge bosons, third generation particles and even light composite Higgs particles. A two Higgs doublet model is proposed as an effective way to model these exciting states. Lastly, we discuss the array of possible final states and their possible discovery.

Electroweak Symmetry Breaking in Historical Perspective

Electroweak Symmetry Breaking in Historical Perspective PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

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Book Description
The discovery of the Higgs boson is a major milestone in our progress toward understanding the natural world. A particular aim of my review is to show how diverse ideas came together in the conception of electroweak symmetry breaking that led up to the discovery. Furthermore, I survey what we know now that we did not know before, what properties of the Higgs boson remain to be established, and what new questions we may now hope to address.

The Anatomy of Electroweak Symmetry Breaking

The Anatomy of Electroweak Symmetry Breaking PDF Author: Abdelhak Djouadi
Publisher:
ISBN:
Category :
Languages : en
Pages : 216

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Book Description


Electroweak Symmetry Breaking with a Nonstandard Higgs Boson

Electroweak Symmetry Breaking with a Nonstandard Higgs Boson PDF Author: Vassilios Koulovassilopoulos
Publisher:
ISBN:
Category : Electroweak interactions
Languages : en
Pages : 220

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Book Description


Electroweak Theory: Proceedings Of The Advanced School On Electweak Theory

Electroweak Theory: Proceedings Of The Advanced School On Electweak Theory PDF Author: Domenec Espriu
Publisher: World Scientific
ISBN: 9814545147
Category :
Languages : en
Pages : 238

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Book Description
Contents:Quark Mixing and CP Violation (F J Gilman)Heavy Quark Effective Theory (A V Manohar)Introduction to Low-Energy Supersymmetry (G F Giudice)An Introduction to Dynamical Electroweak Symmetry Breaking (R S Chivukula)Hadron Colliders, the Top Quark, and the Higgs Sector (C Quigg)Physics Potential of LEP2 and NLC (R Miquel)Precision Tests of the Electroweak Theory (P Langacker) Readership: High energy physicists. Keywords:

The God Particle

The God Particle PDF Author: Leon M. Lederman
Publisher: Houghton Mifflin Harcourt
ISBN: 9780618711680
Category : Science
Languages : en
Pages : 452

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Book Description
A fascinating tour of particle physics from Nobel Prize winner Leon Lederman. At the root of particle physics is an invincible sense of curiosity. Leon Lederman embraces this spirit of inquiry as he moves from the Greeks' earliest scientific observations to Einstein and beyond to chart this unique arm of scientific study. His survey concludes with the Higgs boson, nicknamed the God Particle, which scientists hypothesize will help unlock the last secrets of the subatomic universe, quarks and all--it's the dogged pursuit of this almost mystical entity that inspires Lederman's witty and accessible history.

Higgs Bosons, Electroweak Symmetry Breaking, and the Physics of the Large Hadron Collider

Higgs Bosons, Electroweak Symmetry Breaking, and the Physics of the Large Hadron Collider PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Book Description
The Large Hadron Collider, a 7 {circle_plus} 7 TeV proton-proton collider under construction at CERN (the European Laboratory for Particle Physics in Geneva), will take experiments squarely into a new energy domain where mysteries of the electroweak interaction will be unveiled. What marks the 1-TeV scale as an important target? Why is understanding how the electroweak symmetry is hidden important to our conception of the world around us? What expectations do we have for the agent that hides the electroweak symmetry? Why do particle physicists anticipate a great harvest of discoveries within reach of the LHC?

Electroweak Physics and Evidence for a Higgs Boson Decaying to a Pair of Tau Leptons with the CMS Detector

Electroweak Physics and Evidence for a Higgs Boson Decaying to a Pair of Tau Leptons with the CMS Detector PDF Author: Aram Apyan
Publisher:
ISBN:
Category :
Languages : en
Pages : 170

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Book Description
.Studies of the electroweak interactions using final states with leptons in proton-proton collisions at the Large Hadron Collider at [square root of] s = 7 TeV, [square root of] s = 8 TeV, and [square root of] s = 13 TeV center-of-mass energies are described. Measurements of total inclusive and fiducial W and Z boson production cross sections and their ratios are performed. The W and Z bosons are observed via their decays to electrons and muons. An indirect determination of the total width of the W boson and the B(W --> lv) from the measured cross section ratios is described. The discovery of a new boson with a mass of 125 GeV at the Large Hadron Collider in 2012 sheds a new light on understanding the nature of electroweak symmetry breaking. A question of great significance is whether the new field couples to fermions through a Yukawa coupling interaction predicted in the standard model of particles. Evidence of the 125 GeV Higgs boson decay to a pair of tau leptons with an observed significance of 3.1 standard deviations is established. The nature of the Higgs sector is probed through searches for neutral resonances decaying to a pair of tau leptons in gluon-fusion and b-quark associated production modes with no observation of a significant excess. In addition, the feasibility of measuring the standard model Higgs boson self-coupling with an expected data sample corresponding to an integrated luminosity of 3000 fb-1 is studied.