Above And Beyond The Standard Model: On Phenomenology Of Lee-Wick Theory And Massive Vector Color-Octet

TL;DR

This thesis explores extensions of the Standard Model, focusing on the Lee-Wick theory to address the Hierarchy problem and on massive vector color-octets (colorons) in the strong sector, providing new insights into their phenomenology and theoretical consistency.

Contribution

It offers a detailed analysis of the Lee-Wick Standard Model's naturalness issues and presents the first complete QCD correction calculations for coloron production, advancing understanding of these beyond Standard Model theories.

Findings

Identified tension between naturalness and isospin violation in LW SM.

Analyzed global symmetries and renormalizability of LW scalar QED.

Performed first complete QCD correction calculation for coloron production.

Abstract

The present Thesis is dedicated to a formal and phenomenological investigation of extensions to two separate sectors of the Standard Model of particle physics (SM): the electroweak sector and the strong sector. The Thesis is divided into two main parts: Part I focuses on the Lee-Wick Standard Model (LW SM), which, by providing a solution to the Hierarchy problem, forms a natural extension of the electroweak sector, while Part II studies the coloron theory, arising from extending the strong sector gauge group. Providing a general introduction about the current state of the SM and the associated challenges in Chapter 1, we proceed in Chapter 2 to analyze the tension between naturalness and isospin violation in the LW SM. Chapter 3 discusses the global symmetries and the renormalizability of LW scalar QED. A first complete calculation of QCD corrections to the production of a massive color-octet vector boson (colorons) is reported in Chapter 4. Finally, we conclude the Thesis in Chapter 5 by summarizing the discussed results and presenting an outlook for future research in the surveyed areas.