Scalar and Axial mesons: From light to heavy

• Grant number: 24/22383-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: December 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Nuclear Physics
• Principal Investigator: Alberto Martinez Torres
• Grantee: Angelina Mascarini Serra
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The nature and properties of the scalar and axial mesons is a topic of great interest and in recent years has raised applications in various areas of particle physics, from topics related to strong interaction to applications in weak decays. For example, in the light sector, the formation of scalar mesons such as ¿(600), ¿(700), f0(980), a0(980) can be of great relevance when describing data related to the C-parity violations observed in the decays of D and Ds mesons in three pions, processes that are being studied by the LHCb collaboration. In the heavy sector, the formation of axial states such as X(3872), with hidden charm, or Tcc, which is a state with a mass similar to X(3872) but with charm +2, will play a relevant role when describing the cross section of proton-antiproton processes, which will be measured by the PANDA collaboration, whose main purpose is to determinethe properties of heavy mesons with charm (hidden and/or explicit). States like the previous ones are examples of so-called exotic hadrons, which are those whose properties cannot be understood in terms of the traditional quark model. In particular, mesons such as ¿(600), f0(980), a0(980), X(3872), Tcc can be understood as molecules of other hadrons. Recently, the study of exotic hadrons has experienced a colossal boom, becoming one of the main and most prolific lines of research in experimental facilities such as BES (China), LHC (Switzerland), and soon it will also be at FAIR (Germany). In this scientific initiation, the necessary methods to be able to determine the T matrices that describe the interaction between mesons, producing the dynamic generation of scalar and axial mesons, such as ¿(600), f0(980), X(3872), Tcc, will be presented. The results obtained for these T matrices could be used in more complex calculations, such as those related to the weak decay of a D meson into three pions, or the description of the proton-antiproton interaction producing mesons with charm.