Projects / Programmes
Experimental Particle Physics
January 1, 2015
- December 31, 2021
| 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 |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
experimental particle physics, CERN, KEK, LHC, Super KEKB, ATLAS, Belle II, leptons, quarks, interactions, symmetries, Standard model, Higgs boson, New Physics, exotics, heavy flavour, CP violation, particle detectors, Grid computing, medical imaging
Researchers (43)
Organisations (3)
Abstract
The research programme represents the only activity in the field of experimental particle physics in Slovenia. The research is carried out through participation in two major experiments at the energy and intensity frontier: ATLAS at LHC in CERN and the upcoming Belle II at Super KEKB in KEK. The group holds major responsibilities in all experimental aspects from detector R&D, construction, commissioning and operation, computing, and physics analysis of the data, in both collaborations.
Based on successes in the previous programme period, the proposed research focuses on exploitation of increased energy and luminosity with ATLAS at LHC, and the large statistics of e+e- collisions with Belle II at Super KEKB. The quest thus continues for signals of physics beyond the Standard Model.
Constant upgrades are required for both detectors as well as for the computing infrastructure of the Tier-2 centre in Ljubljana. Participating in several R&D endeavours we are pushing detector technology beyond current limitations. Applications to medicine offer improved detection methods in nuclear imaging.
Significance for science
The proposed research programme 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 proposed experiments have both been heavily scrutinized, approved, and now followed up 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 and hopefully beyond 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 show that the observed magnitude of violation is 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 at both, the energy and intensity frontier, posses also a more widespread importance. If existing, the New Physics processes would cause a large change in understanding the structure of the world we live in. Consider for example the supersymmetric extensions of the SM, based on string theories. One can draw similarities in the impact that a possible experimental evidence for these 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 Belle-II 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 yet a member state of CERN. The successful conclusion of ongoing negotiations for associate membership should remedy this, and significantly boost the socioeconomic return
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 in early 90's for the needs of LHC information exchange. To the present day it has become a new branch of information technology, with associated turnover counted in trillions. Similar predictions are also being made for the development of the distributed computing (Grid), which has been developed and is exploited for LHC computing.
Most important scientific results
Annual report
2015,
interim report
Most important socioeconomically and culturally relevant results
Annual report
2015,
interim report
