Description
Why and how the strong interaction forms the matter we are made of, is one of the most challenging questions in contemporary physics. The PANDA experiment at FAIR will be a uniquely versatile facility to answer this question. The stored high-precision antiproton beam from the HESR will be the only one in this energy region and will offer access to hitherto unexplored territory in the physics landscape. The energy of the antiproton beam corresponds to the confinement domain where quarks and gluons form bound systems such as mesons (quark-antiquark pairs) and baryons (quark triplets). This energy range is the very region where the strong interaction is the most difficult to describe. Although the theory of Quantum ChromoDynamics (QCD) has been meticulously and successfully tested at high energies / short distances, it is still difficult to describe the properties of hadrons from first principles. Special methods like Lattice QCD or Effective Field Theories have made tremendous progress during the past decade, but are in general are computationally heavy and require guidance from experimental data.
To this day, many of the hadron properties are not fully understood though they influence a broad spectrum of problems in contemporary physics ranging from astrophysics and cosmology to strongly coupled complex systems in condensed matter physics [1]. Furthermore, non-perturbative effects often constitute the major part of the systematic uncertainties in various tests of the Standard Model (SM) at the LHC and in e.g. calculations of the muon g-2 [2]. In addition to its multi-facet approach to understand the strong interaction, PANDA can provide precision tests of fundamental symmetries. These tests constitute a key ingredient in the search for physics beyond the SM.
The PANDA physics program is organised into four pillars as shown in Figure 1: nucleon structure, strangeness, charm and exotics, and hadrons in nuclei.