The R(s) observable in perturbative QCD.

• Grant number: 24/22469-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: December 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Diogo Rodrigues Boito
• Grantee: Maria Eduarda Cavini Garbossa
• 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 observable R(s), built from the inclusive cross-section for the process e+e to (hadrons), plays a central role in QCD. Apart from its intrinsic importance for testing the theory, it is directly related to the contribution of quarks and gluons to the anomalous magnetic moment of the muon. In this work, the student will develop the description of this observable in the context of perturbative QCD, for sufficiently high energies. She will study the consequences of perturbative corrections to R(s) and how the one-loop correction is calculated from Feynman diagrams, as well as compare the results with recent experiments.