The Standard Model and Composite Higgs theory

• Grant number: 25/00161-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Gustavo Alberto Burdman
• Grantee: Murilo Martins Trevisan
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Standard Model (SM) of particle physics is an extremely successful description of the experimental data available today. However its limitations are apparent given the large number of arbitrary parameters it has. More importantly, the SM electroweak scale is unstable, giving rise for what is called the hierarchy problem. The solution to this problem requires new physics at the TeV scale, precisely the energy scale being explored at the Large Hadron Collider (LHC) at CERN. Motivated by this problem, we propose to study extensions of the Standard Model (SM) that describe new physics at the TeV scale.Since the discovery of the Higgs boson in 2012, the SM spectrum has been completed. The solution to the hierarchy problem mentioned above typically has two avenues of thought: if the Higgs boson is elementary, supersymmetry must be present at the TeV scale. Conversely, the Higgs is not an elementary state, i.e. it is composite. In this project we will concentrate on the latter case. Composite Higgs models in general require the existence of new particles at the TeV scale. Given that for those the Higgs is a (pseudo) Nambu-Goldstone boson (pNGB) resulting from the spontaneous breaking of a global symmetry, new states emerge from the new symmetry and appear inevitable. On the other hand, the absence of the discovery of those states, particularly at the LHC, is a problem for composite Higgs models. However, the phenomenology related to the Higgs boson, particularly the modification of its couplings, is well defined. This will be the focus of the project: to study the theoretical basis and phenomenology of these models,with particular focus on scenarios requiring high luminosity to be studied.