Stockholm university

Research project Exploring the strong interaction by using antiprotons – the PANDA project at FAIR

The aim of the PANDA experiment is to understand the strong force using very precise accelerated beam of antiprotons. The experiment is part of the research at the accelerator facility FAIR which is under construction in Darmstadt, Germany.

A major international accelerator facility for research with stable, radioactive and antiproton beams is being built at GSI (Gesellschaft ür Schwerionenforschung) in Darmstadt, Germany. The name of the facility is FAIR, which stands for Facility for Antiproton and Ion Research. The PANDA experiment is one out of four main research pillars at FAIR, where the aim is to produce and use very precise beams of antiprotons for the investigation of the strong interaction. The strong force is responsible for holding the atomic nucleus together. In one exciting study we plan to produces nuclei where one or two of the nuclear particles, neutrons and protons, are substituted by particles that carry the quantum number strangeness and investigate the strong forces inside the nucleus and thereby understanding important properties of neutrons stars.

Project description

A major international accelerator facility for research with stable, radioactive and antiproton beams is being built at GSI (Gesellschaft ür Schwerionenforschung) in Darmstadt, Germany. The name of the facility is FAIR, which stands for Facility for Antiproton and Ion Research.

The heart of the new facility is a superconducting synchrotron double ring facility with a circumference of about 1,100 meters. A system of cooler-storage rings for effective beam cooling at high energies and various experimental halls will be connected. Produced secondary beams of antiprotons and radioactive nuclei will be of unprecedented intensities and resolution.

The hadron and nuclear physics programmes at FAIR aim at the exploration of several fields. One out of four major projects is PANDA with the build-up of the PANDA detector and a programme of investigating the strong interaction in reactions induced by antiprotons. As one example, using accelerated and stored antiprotons with energies up to 15 GeV than annihilate with protons particles and states in the energy region of charmonium will be created. By measuring with precision the mass and lifetime, and the decay of conventional meson states, interpreted as consisting of a charm and anti-charm quark, as well as of states which are not explained in that simple way, the strong interaction will be studied in detail. In this energy region, which is a transition region between the high-energy region where QCD can be treated perturbatively (like the electromagnetic interaction) and the low-energy region, where the interaction is strong we will also search for, so called, glueballs – states comprising gluons alone. The energy precision and intensity in the experiment is an order of magnitude higher than at previous antiproton experiments, leading to a high discovery potential. As another example, at PANDA the structure of nuclei containing strangeness (neutrons exchanged by one or two hyperons) will also be explored, which will give information important for the understanding of properties of neutron stars where the hyperon content is believed to be significant.

The PANDA detector system is designed for experiments at the internal target of the high-energy antiproton storage ring HESR. It will allow detection and identification of neutral and charged particles produced in the interaction (annihilations) between high-energy antiprotons and nucleons or nuclei of a fixed target.

The PANDA collaboration consists of more than 420 researchers from 19 countries.
The nuclear physics group at Stockholm University, in collaboration with groups from Uppsala and Lund Universities, has been responsible for characterizing and improving the energy resolution of one of the major and technically most challenging parts of the detector, the electromagnetic calorimeter, as well as experimental and simulation studies of the front-end electronics connected to the calorimeters. At present the Stockholm group is involved in FAIR phase 0 (FAIR related research which takes place before the FAIR facility itself is operating) experiments at the HADES experiment at GSI, with the aim of studying hyperon-hyperon interactions.

According to the time schedule the FAIR facility will start operating towards the end of the present decade. The PANDA detector will, at least to certain parts, be assembled earlier in order for testing and research at other facilities.

Project members

Project managers

Per Erik Tegnér

Professor

Department of Physics
Per-Erik Tegner

Members

Gandharva Appagere

PhD Student

Department of Physics

Maria Doncel Monasterio

Researcher

Department of Physics

Publications