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Image: ion42/FAIR

09.03.2021 | 

Each year, the European Research Council (ERC) awards several extremely prestigious research funding prizes for cutting-edge research. The outstanding quality of scientific research at GSI and FAIR was directly recognized last year with two "ERC Advanced Grants" for GSI physicists Marco Durante and Gabriel Martínez-Pinedo. In addition, GSI and FAIR also attract ERC grant laureates from other research institutions who are closely connected to GSI/FAIR through their specialist topics or who realize the experimental part of their project here. The most recent examples of this: Professor Evgeny Epelbaum from Ruhr University Bochum and Dr. Kathrin Wimmer from the Spanish National Research Council (CSIC).

Dr. Kathrin Wimmer from the Institute for Structure of Matter (IEM-CSIC) coordinates the project LISA (Lifetime measurements with Solid Active targets), which aims to measure rare atomic nuclei with innovative detectors and high-resolution gamma-ray spectroscopy. For the practical research part, she will also use the GSI/FAIR facilities in the framework of her just awarded "ERC Consolidator Grant".

The aim of the LISA project is to develop a novel method for lifetime measurements in atomic nuclei. Lifetimes probe the collectivity of a nucleus through its electromagnetic transition properties. The experimental approach is based on active solid targets employing novel diamond detectors and will dramatically enhance the scope of measurements in exotic nuclei. Coupled to the state-of-the-art gamma-ray tracking detector AGATA, LISA will overcome the present challenges of lifetime measurements with low-intensity beams of unstable nuclei.

LISA will exploit the unique capabilities of the FAIR accelerator center, being built at GSI. The future fragmentation facility will deliver the most exotic and highest intensity radioactive ion beams. LISA will greatly expand the nuclear structure program of HISPEC, a prominent project within the NUSTAR science pillar at FAIR. The results will have significant impact on the theoretical descriptions and modelling of atomic nuclei making their predictions more reliable.

The award winner Dr. Kathrin Wimmer, currently working at CSIC Madrid, and Dr. Jürgen Gerl, NUSTAR coordinator and head of the nuclear structure department at GSI, are very much looking forward to working together on the exciting LISA project at GSI.

Professor Evgeny Epelbaum is thematically closely connected to GSI/FAIR via his project "Nuclear Theory from First Principles", which is funded by an ERC Advanced Grant. In the project, the holder of the Chair of Theoretical Physics at Ruhr-Universität Bochum (RUB) wants to use theoretical methods to describe the forces between three nuclear particles.

Pairwise interactions between two nucleons are already relatively well understood. This enables physicists to describe what is going on inside the simplest atomic nucleus, i.e. one that consists of two nucleons. The opposite is true for more complicated atomic nuclei consisting of three or more nucleons. Here, the interactions are still a mystery. This is where Evgeny Epelbaum's research project comes in. He and his team hope to describe the forces acting in a system of three or more nucleons. To this end, the researchers are using a theoretical method known as effective field theory, which is widely used in particle physics. With this approach, the Bochum-based group already described precisely the interactions between two nucleons in the past. Now, they intend to extend the approach to three-particle forces.

Based on the theory developed under the ERC Grant, the team also wants to analyse the existing experimental data for the three-nucleon system. Experiments to understand multi-nucleon systems are an essential part of the FAIR research program in nuclear structure. The team's goal is to resolve discrepancies between theory and experiment. Moreover, numerical simulations are planned for more complex nuclear systems, which consist of even more particles, in order to explore relationships between the nuclear forces and their properties. Such simulations also provide insights into areas that are not accessible to experimental research. For example, it is possible to explore how the properties of atomic nuclei or processes in the stars depend on the constants of nature  – such as the masses of quarks.

Another example from 2020 of outstanding researchers honored with an ERC grant is Professor Beatriz Jurado from the Centre Etudes Nucléaires de Bordeaux Gradignan (CENBG), who received an ERC Advanced Grant at the same time as GSI physicists Professor Marco Durante and Professor Gabriel Martínez-Pinedo. She will also use the research facilities of GSI/FAIR to conduct the experimental part of her ERC Grant project.

Her project aims to develop a new methodology to indirectly infer neutron-induced cross sections of unstable nuclei. These cross sections are essential for nuclear astrophysics. The experimental part of Beatriz Jurado´s project will be realized at the accelerator facility on the GSI/FAIR campus as part of FAIR Phase 0, using the storage rings ESR and CRYRING.

The Scientific Managing Director of GSI and FAIR, Professor Paolo Giubellino, expressed his enthusiasm that in addition to GSI/FAIR’s own scientists, several EU award-winning researchers are closely associated with GSI/FAIR: "I am very happy that the research community demonstrates its interest in the GSI/FAIR research facilities and the science conducted here, and that the world-class value of these themes is recognized by the ERC grant committees." (BP)