Type

Text

Type

Dissertation

Advisor

Sterman, George | Meade, Patrick. | Meade, Patrick | Tsybychev, Dmitri | Izaguirre, Eder.

Date

2017-08-01

Keywords

Physics

Department

Department of Physics.

Language

en_US

Source

This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree

Identifier

http://hdl.handle.net/11401/78179

Publisher

The Graduate School, Stony Brook University: Stony Brook, NY.

Format

application/pdf

Abstract

The Higgs boson discovered in 2012, might be the portal to new physics. With the Higgs as the common theme we present the following research arcs. In order to study the Higgs, it is important to have a very good handle on Standard model(SM) backgrounds. One such background process is SM WW production, which reported routine 3 sigma excesses in early run 1 of the LHC. However, experiments use Parton Showers for theoretical prediction and this might be inadequate for exclusive cross-sections. We show that taking into account higher order Sudakov logarithms through transverse momentum and jet-veto resummation predicts a larger cross-section than parton showers and reduces the theory-experiment disagreement. Next, improvements are suggested to the state-of-the-art finite temperature field theory calculations that can predict the nature of the electroweak phase transitions in beyond-the-standard model scenarios. We find that relaxing the high-temperature approximation and resumming logs of temperature to super-daisy order can have significant changes in the order of the phase transition. This in turn can have important consequences for the possibility of creating the baryon anti-baryon asymmetry across this phase transition. Our improved calculation in general predicts weaker phase transitions, and hence smaller baryon-anti baryon asymmetry. This strengthens the case for building future colliders in the form of a no-lose theorem; absence of deviation from the Standard model in Higgs precision physics can falsify the possibility of Electroweak Baryogenesis. Finally, we present another consequence of Higgs precision studies, constraining new physics invented to ameliorate the hierarchy problem. These theories generically predict top partners at the electroweak scale, which are connected with the top quark through a symmetry. However these top partners have not been detected at colliders making the electroweak scale severely fine-tuned. We find that generically, top-partner mass limits will reach a TeV just from Higgs precision at future colliders. | 245 pages

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