Projects / Programmes
Fizika srednjih energij (Slovene)
January 1, 1999
- December 31, 2003
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P210 |
Natural sciences and mathematics |
Elementary particle physics, quantum field theory |
| P220 |
Natural sciences and mathematics |
Nuclear physics |
Researchers (7)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,753 |
Abstract
For very high energies, the predictions furnished by quantum chromodynamics (QCD) are based on the perturbation theory, which is possible due to a relatively weak coupling between the quarks and the gluons. For medium and low energies the strong nature of the interaction induces the so-called quark confinement. Recently, however, progress has been made in this area with theoretical physicists managing to develop a very promising approximate solution, a form of the effective field theory called the chiral perturbation theory. In addition, several hadronic systems are now more thoroughly understood within the framework of the existing knowledge about the strong interaction. The testing of these new approaches has been made possible by the recently developed electron accelerators, belonging to a new generation of such devices, which supply a continuous beam of electrons of the energy of a few GeV. This enables the coincidence experiments to be carried out and to measure the observable physical quantities, which can shed light on the theoretical progress.
Our group plans to take part in the experiments aimed at measuring the nucleon form factor, the cross-sections for the formation of nucleon resonances, the behaviour of nucleons in nuclear matter (especially with respect to the correlations between individual nucleons), the production of mesons and the excitation of nucleon resonances in the lightest nuclei.
As far as nuclear physics is concerned, we shall continue our research on the description of the excited states of nuclei in the vicinity of 100-Sn, applying the shell nuclear model.
We have already analysed the experimental results gathered with the NORDBALL system, and have identified for the first time the excited stated in 98-Cd and 102-Sn. The excited states of this latter nucleus were also studied in detail in the experiment performed at the Argonne National Laboratory in the USA. The measurements point to certain inadequacies of the shell nuclear model, with which the nuclei in the vicinity of doubly magic shells have been successfully described so far. Because of this discrepancy, the measurements should be repeated. If the validity of the current results is confirmed, the shell model will need to be amended. In this respect we have already established contacts with the Max Planck Institute in Heidelberg regarding our participation in the next generation of experiments in in-beam spectroscopy with the newly developed EUROBALL detection system.
We have also developed a computer simulation of the part of the new spectrometer responsible for charged particle detection and identification, which makes the determination of individual reaction channels in heavy ion fusion reactions possible. This identification, in turn, enables the assignment of gamma-ray lines to the nuclei created in the fusion and the subsequent particle evaporation process. Monte Carlo calculations have also been employed in the data processing for the experiments performed with the older NORDBALL spectrometer. On the basis of the expertise acquired in the process it will be possible to optimise the design and installation of individual components of the new detector system.
We have also established contacts with our American partners in the GAMASPHERE project, where we have proposed the study of the decay of superdeformed nuclei in collaboration with the Swedish group.
Regarding theoretical nuclear physics, work is in progress on the description of nuclear reaction mechanism where continuum states and complex states of the residual nucleus are of importance. The expertise gained in our research work on radiative capture reactions will be applied to the study of the corresponding simplified description of particle reactions.
Most important scientific results
Final report
Most important socioeconomically and culturally relevant results
Final report
