Theory of strong interaction

The institute "Theory of Strong Interaction" (IAS-4/IKP-3) deals with strong interactions in the non-perturbative arena, in particular with the structure and dynamics of hadrons and atomic nuclei. Of particular interest is the spectrum of quantum chromodynamics, such as the calculation of the properties of unstable hadrons and nuclear reactions which play an important role in the synthesis of elements in stars. Fundamental tools are Monte Carlo simulations of the QCD path integral and the development of effective field theories for nuclear structure in the continuum as well as on the lattice. With the nuclear lattice simulation method developed at IAS-4, a completely new approach to the calculation of strongly interacting quantum systems has been created. These stochastic methods are also successfully applied to strongly correlated electronic systems such as graphene or carbon nano-structures.

Our research


Baryon spectroscopy

The spectrum of resonances is key to the understanding of the strong interaction. The Jülich-Bonn model including dynamically-coupled channels allows for a better understanding of experimental data.Baryon spectroscopy

Exotic hadrons

Exotic hadrons

Many experimentally found hadrons do not fit into the traditional scheme of 2- and 3-quark states. We systematically investigate such states.Exotic hadrons

Phase diagram of nuclear matter

Nuclear Lattice Effective Field Theory

Nuclear Lattice Effective Field Theory is a new tool for simulations of structure and dynamics of atomic nuclei.NLEFT

Excitation spectrum of 6-Li and 7-Lambda Li

Strangeness & Hypernuclei

Baryon-baryon interaction are important for the understanding neutron stars and reveal the impact of strangeness in nuclear physics. Hypernuclei are an important source of information on their properties.Strangeness & Hypernuclei

Geometries with strongly correlated electrons

Strongly correlated electrons

Lattice stochastic methods are used to investigate the electronic properties of strongly correlated electrons in low dimensional geometries.Strongly correlated electrons

Excluded regions of electric dipole moments (EDMs).

Electric dipole moments of hadrons and light nuclei

A non-zero permanent electric dipole moment of any subatomic particle is a clear signal for CP violation beyond the Kobayashi-Maskawa mechanism of the Standard Model of particle physics.Electric dipole moments

Schematic drawing of a BSM particle in a nucleon

Lattice Quantum Chromodynamics

Lattice Quantum Chromodynamics (LQCD) is used as a numerical tool to calculate non-perturbative hadronic processes in particle and nuclear physics.  Our LQCD calculations utilize the large high-performance computing (HPC) resources within JSC/FZJ to compute beyond the standard model (BSM) processes and properties of exotic hadrons.LQCD


Prof. Dr. Dr. h.c. Ulf-G. Meißner vom Helmholtz-Institut für Strahlen- und Kernphysik der Universität Bonn erhält einen ERC Advanced Grant.

Ulf-G. Meißner Awarded an ERC Advanced Grant

What happens when strange quarks are inserted into atomic nuclei? What “habitable” universes are theoretically possible? Prof. Ulf-G. Meißner from the Institute for Advanced Simulation – Theory of the Strong Interactions (IAS-4) aims to find the answers to these and other questions through research.

Fit to Mainz cross sections

High-precision determination of the electric and magnetic radius of the proton

Based on dispersion theory and new data, the most precise determination of the proton's electromagnetic radii was obtained.