The partonic structure of hadrons
PT-CERN Call 2021/2
Instituto Superior Técnico (Universidade de Lisboa)
Laboratório de Instrumentação e Física Experimental de Partículas
Almost all mass of visible matter rests in atomic nuclei and therefore in nucleons, which are complicated bound states of “partons”, namely quarks and gluons, the fundamental degrees of freedom in QCD. However, the structure of mesons and baryons is much more complicated than the naïve quark model suggests and their internal composition is still largely unknown territory. The distribution of quarks and gluons inside hadrons and nuclei, the decomposition of spin and orbital angular momentum, and the role of gluons in the dynamical generation of a hadron’s mass are all urgent questions that need to be answered. The experimental landscape in the forthcoming decades will be shaped by the COMPASS++/AMBER experiments at CERN and the Electron-Ion-Collider (EIC) at Brookhaven, which aim to map out the partonic structure of mesons, nucleons and nuclei and reveal the origin of the glue that binds their constituents. The central quantities of interest are parton correlation functions such as PDFs (Parton Distribution Functions), GPDs (Generalized Parton Distributions) and TMDs (Transverse Momentum Distributions), which encode the spatial and momentum distributions of partons and their spin and orbital angular momentum correlations inside hadrons. The goal of this project is to compute PDFs, GPDs and TMDs with nonperturbative continuum calculations by employing a new technique that has been recently established. This will deliver new insights on the internal structure of hadrons and provide much needed theory support for upcoming experiments at CERN and other facilities.