Production of exotic states in photon-induced processes at LHC and EIC.

• Grant number: 24/19103-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2025
• End date: July 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Fernando Silveira Navarra
• Grantee: Fernando César Silva Santos Sobrinho
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/04867-2 - High energy physics and instrumentation with the LHC-CERN, AP.ESP

Abstract

Twenty years ago, with the discovery of the X(3872) state in 2003, a new era in the study of hadronic spectroscopy was inaugurated. Since then, the BES, BABAR, BELLE, ATLAS, ALICE, CMS, and LHCb collaborations have observed dozens of mesonic states containing heavy quarks, which cannot be understood as conventional states formed by a quark and an antiquark. These states are now known as exotic states. This research project explores the study of these exotic states. The central aim of the research is to characterize the structure of these states, which can be either compact (tetraquarks) or more extended (mesonic molecules).The project investigates the production of exotic states in ultra-peripheral collisions (UPCs), where strong interaction is suppressed, and particle production is dominated by photon-induced processes. A key focus is the production of charmed mesonic molecules, such as the scalar state $D^+D^-$, whose initial cross-section calculations were carried out during the researcher's master's degree, with results already published. The work now seeks to extend these studies to electron-ion collisions at the Electron-Ion Collider, in order to avoid contamination from Pomeron-Pomeron interactions.Additionally, the project proposes a comparison between different definitions of ultra-peripheral collisions (geometric, kinematic, and dynamic) and aims to investigate form factors associated with the $D^* D \gamma$ and $D D \gamma$ vertices using QCD sum rules, with the goal of refining the calculations of radiative interactions. The research also intends to study charmed meson molecules using the Bethe-Salpeter equation to calculate masses, binding energies, and wave functions, in collaboration with experts in the field.