Prerequisites for studying relativistic quantum dynamics in experiments at the GSI and FAIR facilities

• Applicants: Dr. Alexandre Gumberidze; Professor Dr. Thomas Stöhlker
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2017 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 323411814

The present proposal aims at implementing a strong collaboration working on the theory of quantum dynamics of electrons (including electron-positron pair creation) and radiation processes in presence of strong electromagnetic fields. These studies are needed for experiments that are planned to be performed at the GSI and FAIR facilities. The teams will work on development of relativistic methods for calculations of the electron-excitation, charge-transfer, and pair-creation processes in low-energy ion-atom collisions. The previously developed approach will be extended to the time-dependent density functional theory that will allow us to properly account for interelectronic-interaction effects and describe relativistic many-electron processes in (quasi) symmetric low-energy ion-atom collisions. The study of quasimolecular radiation spectra at low-energy heavy-ion collisions is of special interest. Indeed, the coherent superposition of the transition amplitudes with the photon emission in the incoming and outgoing part of the ion trajectories leads to an interference structure of radiation, which allows a detailed comparison between theory and experiment. The analysis of the intensity and shape of the spectra will be a powerful tool for studying various processes and searching for new physics in low-energy heavy ion-atom collisions at the supercritical regime. Thus, a technique for calculations of the quasimolecular radiation spectra at low-energy heavy-ion collision will be developed. With these extensions, the probabilities of various processes in low-energy heavy ion-atom collisions, that are planned to be investigated at the CRYRING (Darmstadt), will be calculated. Also the calculations of the charge-transfer, ionization, and pair-creation probabilities in ion-atom (-ion) collisions at the projectile energies near the Coulomb barrier will be performed including into consideration all occupied negative-energy states of the Dirac continuum. The teams will also work on the development of a relativistic technique for describing of highly charged ions exposed to strong laser fields. The role of non-dipole effects, the influence of the negative-energy Dirac continuum and spin-asymmetry effects in these processes will be investigated. A relativistic approach for describing the interaction of twisted electrons with various ionic and atomic systems will be also developed. Relativistic calculations of the radiative and dielectronic recombinations of the vortex electron beams with heavy highly charged ions will be performed. All the work will be done in close collaboration with the experimentalists from GSI/FAIR (part of the German team in this project), thus ensuring an optimal planning and preparation of the corresponding upcoming experiments to allow for addressing the most interesting physics phenomena in the realm of low-energy ion collisions.

• DFG Programme: Research Grants
• International Connection: Russia
• Co-Investigators: Dr. Angela Bräuning-Demian; Dr. Michael Lestinsky
• Cooperation Partner: Professor Dr. Vladimir M. Shabaev