Decipher gluons as (the) source of geometry & forces inside the smallest and hottest droplets formed on earth and in the most important building block of matter, the proton.
Protons and nuclei are the most important block of matters. Our today's knowledge of their internal structure at length scales below the size of the proton however remains mostly limited to one-dimensional information, the fraction of the momentum carried by their constituents, the so-called partons. The structure at very short distances, where the matter is dominated by gluonic fields, is even more elusive. The most direct probe of internal structure is the investigation with a electromagnetic probes: photon or electron- proton/nucleus scattering. Gluodynamics is contributing to the quest of proton and nucleus structure with new experimental measurements at JLAB, LHC and studies towards the future EIC and theoretical developments exploiting new observables.
Gluodynamics is scientifically based at the fruitful interface between the structure of nucleons and nuclei and Quark-Gluon Plasma structure. The study of hadron structure beyond one dimension is so far splitted in several research direction either investigated the transverse momentum or the transverse spatial position or the high-energy limit. In order to make a full differential picture of the proton and nuclei, these developments need to be connected together and the teams of Gluodynamics are in the position to make significant progress in this quest together. For Quark-Gluon Plasma studies, a theoretical rigorous understanding of the initial state and the availability for phenomenological studies is needed. This initial state studies arise natural from the hadron structure community and need to be brought up in easily accessible simulations to define the initial conditions of hydrodynamic evolution of heavy-ion collisions. Finally, the experimental and theoretical community needs to be supported by modern codes for the simulation of processes. Gluodynamics supports already existing world-leading efforts within the French community.
The study of the Quark-Gluon Plasma in high-energy heavy-ion collision has established the applicability of hydro dynamic modelling of very small droplets of strongly-interacting matter with the dimension of 10^-14 m. However, the microscopic structure of the underlying fluid remains not well understood. In order to illuminate the constituents of this matter created in the laboratory, heavy-quarkonium and jets are key observables. Heavy-quarkonium is studied within Gluodynamics both in the fixed target and the collider configuration of the LHC in close collaboration between the various experimental groups including ALICE, LHCb and CMS. The structure of jets, a unique multi-scale probe of the Quark-Gluon Plasma to resolve the structure, is investigated by the CMS group under the support of the theory community.
QCD research at large energies will see new unique facilities at the horizon at the future accelerators, the electron-ion collider and the HL-LHC. Both in terms of scientific questions, instrumental challenges, both endeavours are approaching each other and a close exchange between the community, even a merging will be beneficial for the understanding of the strong interaction. The world-leading strong interaction community of P2IO is prepare with Gluodynamics and this ambition in mind the future programms of hadron structure and dense QCD matter studies.
