The pion is a key particle for understanding Quantum Chromodynamics (QCD), the theory of the strong interaction. However, its gluon content, remains poorly understood. This thesis will explore a novel way to investigate the gluon content of the pion, combining vector meson production and the Sullivan process, which allows the pion to be studied in electron-proton collisions without requiring a dedicated pion target.
The student will analyse existing data from the CLAS12 experiment at Jefferson Lab to study exclusive phi-meson production near threshold on the pion. The goal is to establish the feasibility of isolating the Sullivan process and accessing the pion’s gluon gravitational form factors, which provide insight into its internal mass and pressure distributions. The analysis will involve particle identification, event reconstruction and background suppression and development of a dedicated event generator.
The project will also include feasibility studies for future measurements at the Electron-Ion Collider (EIC), where higher collision energies could open new opportunities to investigate the pion’s gluon structure, including through J/psi production.