Projects / Programmes
Experimental Elementary Particle Physics
January 1, 2004
- December 31, 2008
| 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 |
experimental physics, particle physics, accelerators, detectors, CERN, DESY, KEK, ATLAS, Belle, DELPHI, HERA-B, leptons, quarks, interactions, Standard model, super-symmetry, Higgs boson, CP symmetry, mesons, semiconductor detectors, Cherenkov detectors, medical imaging
Researchers (34)
Organisations (4)
Abstract
The research is devoted to measurements in the field of elementary particles, to reveal the ultimate building blocks of matter and the nature of interactions between them. Experiments are carried out at international centres for particle physics within four collaborations: ATLAS and DELPHI at CERN near Geneva, HERA-B at DESY in Hamburg and Belle at KEK in Tsukuba. The aim of the experiments for the next five year period is to complete the remaining analyses of data at DELPHI and HERA-B, to pin down with precision the parameters of CP violation and rare decays of B mesons at Belle and to open up the 1 TeV energy range with ATLAS at the Large Hadron Collider in search for the Higgs particle and the appearance of super-symmetric particles or other extensions of the Standard model. These data should resolve the remaining open questions of the Standard model such as the origin of mass and should set firm directions to a unified theory beyond. Advanced technology employed in the experiments will be exploited to build novel cameras for medical imaging. Our participation in the first large-scale deployment of the GRID technology for LHC computing by setting up a GRID node should provide the seed application of this all-promising computer paradigm in Slovenia.
Significance for science
The described research represents a challenging task at the very frontier of contemporary scientific endeavour, utilizing vast human and financial resources and stretching or even extending existing technologies to render the experiments possible. The experiments have both been heavily scrutinized and finally approved by research committees, composed of leading experts from the field and beyond. They represent a joint effort of the global scientific community, and are constantly monitored by scientists as well as by the authorities that are funding them. Their task is to deepen our insight into constituents of matter and the forces acting between them. In this quest accelerators of highest energies or with special properties are used, to probe high energy densities as they existed a glimpse after the Big Bang that created the Universe. The Standard model of electroweak and strong interactions is one of the most celebrated theories of our time, a theory that will be probed to its limits by the experiments proposed in this research programme. These experiments have, each in their own, complimentary way, a good chance of finding signatures of physics beyond the Standard model, be it the predicted and long awaited supersymmety or some more exotic realization of physics at a larger energy scale. One of important unsolved questions of contemporary science is why we live in a universe in which the matter (particles) completely dominates over the antimatter (antiparticles). Already in 1967 the Russian physicist A. Saharov suggested three necessary conditions for such an asymmetric universe evolution. One of those is the violation of the CP symmetry, which can be measured in the world of subatomic particles. Another condition, the violation of the baryon number conservation, also belongs to that area of research. Measurements with the Belle detector in the past period of this research programme offered very precise determinations of the CP violation in the system of B mesons and represent another achieved milestone in the field. However, the measured values of the Cabbibo-Kobayashi-Maskawa matrix elements which within the SM parameterize the CP violation prove the observed magnitude of violation to be significantly too small to describe the asymmetric universe. Unknown sources of the CP violation must exist, related to new particles and processes, commonly grouped under the term New Physics. A discovery of those may bring an answer to the question of the universe asymmetry as observed nowadays. The measurements with the Belle detector have also a more widespread importance. If existing, the New Physics processes would cause a large change in understanding of the structure of the world we live in. Considering an example of the supersymmetric extensions of the SM, based on the string theories, one can draw similarities in the impact that a possible experimental evidence for this models would have to the one of the relativistic theory. As the latter changed the reasoning about the world by introducing a time dimension as an equivalent to the three spatial dimensions, also the supersymmetric theories would introduce ten spatial dimensions instead of only three (additional dimensions would not be infinite as is the case with the familiar ones but rather shrunk to the sizes many orders of magnitude smaller than the size of the hadrons). While the LHC collider could enable experimental evidence for the existence of new particles (confirming the qualitative correctness of many beyond the SM theories) the precision measurements to be performed with the Super Belle detector will differentiate among these models and by that enable determination of the so far unknown particle properties.
Significance for the country
Participation of Slovenian science in big collaborative international projects, exploring the frontiers of science, is of vital importance for the development of Slovenia. Carrying out research under equal terms with their colleagues from all over the world enables Slovenia and its researchers to: - participate in top research projects in one of the most propulsive fields of science, - publish in the most renowned scientific journals and take part in top-class international conferences, - ease formation of young researchers in international collaboration and competition with their fellow scientists from all around the world, - transfer research knowledge and experience into education at university and post-graduate level, - access and provide hands-on experience with the ultimate technology in the fields of detectors, electronics and computing, - transfer the applied technologies to Slovenia, - apply know-how to other fields of science and technology, - provoke participation of Slovenian industry in development, production and supply of high-tech products. The access to technology programmes at CERN as well as tendering for high-tech orders for the accelerator programme are severely hindered by the fact that Slovenia, in contrast to the remaining Middle-European states, is not a member state of CERN. Exposure to top-level technology, many times even in the phase of its development are crucial in the formation of young researchers with a high innovation potential, as well as for senior scientists to keep up with the development of the technology and transfer this knowledge to their younger colleagues and students. The contacts established in collaborations often lead to participation in technology projects beyond the scope of the original scientific goal. The development of new computational methods in combination with distributed data processing is expected to stimulate the development of other branches of science where large computing capacities and/or computing simulations are needed (computing, informatics, meteorology, statistics) and in the final instance also significantly contribute to the development of the informatics infrastructure. As an example one can stress, that the world wide web (WWW) was developed at CERN for the needs of the LHC project. To the present day it has become a totally new branch of information technology. Similar predictions are also being made for the development of the distributed computing (Grid), which is being developed for the needs of the LHC project.
Most important scientific results
Final report,
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Most important socioeconomically and culturally relevant results
Final report,
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