Parametrization of the Standard Model description of hadronic tau decays

• Grant number: 23/14556-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2023
• End date: July 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Diogo Rodrigues Boito
• Grantee: Rita Natieli de Oliveira
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 21/06756-6 - Testing the standard model: precision QCD and muon g-2, AP.JP2

Abstract

The determination of the strong coupling, alpha_s, from the theoretical description of inclusive hadronic tau decays in Quantum Chromodynamics (QCD) is one of the most precise alpha_s extractions from experimental data. The theoretical description is dominated by perturbation theory, but receives non-perturbative contributions from the Operator Product Expansion and duality violations. For several reasons, the QCD description is non-trivial: it involves an integration in the complex plane, the five-loop running of ±_s must be performed numerically, there are correlations among the different theoretical contributions, to name a few. It would be highly desirable to have a much simpler, but reliable, parametrization of the full QCD result, including all correlations, in order to provide a simple interface with precision Electroweak Fits and Monte Carlo simulations, especially those related with the FCC-e or other future facilities. It is the role of this Master's thesis to produce such parametrization.