The topic Cosmic Matter in the Laboratory aims at cutting edge research for a precise and quantitative understanding of strongly interacting matter in terms of the relevant degrees of freedom at all length scales. New facilities, in particular the construction of the accelerator complex FAIR at Darmstadt and the recent advances in the theory of the strong interaction, render this possible.
The strong force played and still plays an essential role in the evolution of the Universe, in the early stage where the quark gluon plasma prevailed, in the synthesis of chemical elements as well as in the formation and development of stars. The strong interaction acts between the 'colour' charges carried by the fundamental degrees of freedom, the quarks and gluons. The dynamics of colour is described by quantum chromo dynamics (QCD). At small distances, below a fraction of a femtometer, QCD is perturbative and the strong interaction is characterised by the exchange of gluons between colour charges. Conversely, at large distances the interaction between colour charges is strong and leads to confinement of colour charges. Thus, quarks and gluons are bound in colour-neutral objects: baryons, mesons and as predicted by QCD possibly more exotic objects. At large distances these are the relevant degrees of freedom. The residual strong interaction between colour-neutral hadrons is analogous to the electromagnetic force that arises between electrically neutral molecules due to polarisation effects and binds hadrons to nuclei. In addition to the confinement of colour, another basic feature of QCD is of particular importance for the topic Cosmic Matter in the Laboratory, the spontaneous breaking of the chiral symmetry in vacuum. Both play decisive but so far not fully unravelled roles in the non-perturbative regime of QCD, which determines some of the intrinsic features of sub-atomic physics, like the hadron mass spectrum, the structure of nucleons and nuclei and the phase diagram of hot and dense strongly interacting matter.
The role of the strong interaction in the standard model of physics renders close connections to the two other topics Fundamental Particles and Forces and Matter and Radiation from the Universe in this research programme, ranging from the creation of mass, the strong interaction of particles to the element synthesis. But also outside this research programme, the search for New Physics in many cases is limited by our insufficient knowledge of strong interactions at low energies. Precision observables, such as the anomalous magnetic moment of the muon, the running coupling constant of QED, or the electroweak mixing angle offer unique opportunities for precise tests of the Standard Model, however, are limited by hadronic uncertainties. Progress in the experimental as well as theoretical understanding of low-energy quantities therefore play a crucial role in improving or eventually overcoming these hadronic limitations.
Forefront research into the physics of hadrons and nuclei requires a complex and technically advanced research infrastructure. The cooler synchrotron COSY at FZJ and the heavy-ion accelerator facilities at UNILAC, SIS18 and ESR at GSI represent a worldwide unique combination of accelerator facilities which allow the acceleration, storing and cooling of polarised proton and deuteron beams and of all ions in virtually any charge state from very low energies of several MeV per nucleon up to relativistic energies of 1-2 GeV per nucleon. The Helmholtz Association with its research centers FZJ and GSI is the key player realizing the new international accelerator facility FAIR in Darmstadt, which extends the existing research capabilities at GSI Darmstadt on different frontiers: higher energy of ions (factor 20), higher intensity of produced rare isotopes (factor 100 - 10,000) and the new extension to stored beams of cooled antiprotons at momenta up to 15 GeV/c.
This research topic Cosmic Matter in the Laboratory will focus on the following:
- Study of quark-gluon dynamics and phases in very dense and/or very hot nuclear matter with the ALICE experiment at LHC of CERN, the HADES and CBM experiment at the SIS100 synchrotron at the future FAIR facility. The many particle aspects of the strong force at small distances can be studied by investigation of the phase diagram of QCD at different temperatures and densities.
- The dynamics, structure and stability of hadrons, the mechanism of hadronisation, and strong CP-violation. Antiproton beams are one of the main new features of the FAIR facility and will be exploited at the future PANDA-experiment at FAIR. The PAX collaboration develops a method for polarising antiproton beams at a later stage of FAIR. The search for an electric dipole moment within the JEDI collaboration addresses directly the strong CP problem. The direct comparison between matter and antimatter properties will be studied with low energy antiproton beams at FAIR by the FLAIR collaboration.
- The creation of light and heavy exotic isotopes up to the limits of stability and the subsequent investigation of their structure and chemistry will drive the research at the super fragment separator (S-FRS) in the experiments of the NuSTAR collaboration at FAIR. The storage rings will be used for studying highly charged ions, exotic decay modes, nuclear masses, isomers, and for the detection of low momentum transfer reactions with very thin internal targets.
- The research activities of the two Helmholtz Institutes (HI) in Jena and Mainz associated to GSI are closely embedded in the strategy of GSI towards FAIR. They have both been founded in 2009 and are now entering into the PoF evaluation. HI Mainz will participate in this topic Cosmic Matter in the Laboratory and HI Jena will contribute to the programme From Matter to Materials and Life.
- Furthermore, the FZJ activity for an experiment to search for an electric dipole moment (EDM) of charged particles using storage rings (JEDI) will be evaluated in the framework of this topic.
- In addition, an important part of the strategy of GSI is a sustained funding for an extended networking and talent management program both at the national as well as the international level. This will be evaluated here also.
Research platforms are an important asset for a collaborative effort to increase synergies and to strengthen the scientific community for maximum output. As part of the strategic alignment, research platforms like the Hessian Helmholtz International Center for FAIR (HIC4FAIR), the Helmholtz Alliance Cosmic Matter in the Laboratory, the Helmholtz-Institute Jena and the Helmholtz-Institute Mainz have been established in recent years in order to foster joint R&D- activities for FAIR. The Helmholtz Graduate School HIRe for FAIR brings together about 380 doctoral students in a structured PhD-curriculum, working on topics essential for the design and construction of FAIR. Here research centers and universities cooperate very closely with matching funds and joint positions. FAIR, FZJ and GSI are embedded in an international multifaceted frame- work of research platforms, networks, and funding schemes with different scopes, relationships, and time lines.
The Helmholtz topic Cosmic Matter in the Laboratory with the upcoming world leading FAIR facility will be a central player in the field of nuclear physics and the study of strong interactions. It will shape the field of nuclear structure research, hadron physics, dense nuclear matter and the test of fundamental symmetries.