Projects / Programmes
January 1, 2009
- December 31, 2014
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P211 |
Natural sciences and mathematics |
High energy interactions, cosmic rays |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
osmic rays, astrophysics, elementary paticles, cosmology, symmetries, LIDAR
Researchers (19)
Organisations (2)
Abstract
Pierre Auger collaboration is currently building the world largest observatory for detection of cosmic-ray induced air-shower. Since the flux of cosmic rays with energies above 10 on 20 eV is rather minute (1 event/km2/century) and since the spatial dimensions of the shower at the ground level is around 10 km, the detector should cover as much of the atmospheric volume as possible. There are two types of sub-detectors comprising the Pierre Auger Observatory. Čerenkov surface detector array is covering an area of 3.000 km2, sampling showers at 1.400 m a.s.l. Above the surface array four fluorescence detectors are gathering information from fluorescence light produced by the electromagnetic part of the shower cascade in the atmosphere. At the time of the completion of the Pierre Auger Observatory, it will be at least 10 times larger as any other existing experiment. Next to that, it will be the only detector ever built which will operate in hybrid mode.
Research effort of the Slovenian team within the Pierre Auger collaboration is covering the following fields: development and deployment of the LIDAR systems for on-line acquisition of optical properties of the atmosphere, development of remote control and data acquisition for the detectors, fluorescence detector calibration, Monte Carlo simulations of air-shower development and simulations of detectors response, on-line and off-line hybrid data analysis, analysis of cosmic-ray spectrum and determination of possible astronomical sources, modeling of cosmic-ray propagation trough the Universe.
Understanding of the cosmic-ray spectrum will certainly be the focal point of the air-shower analysis. Special attention will be given to events detected in the hybrid mode. These events, in contrast to other existing experiments, provide detailed information on systematic errors. We beleive that by comparing simulations based on standard models, and measurements of events with center of mass energies up to 1.000 TeV, new insights in primary interactions will be gained at energies which can not be achieved by existing colliders.
Since inter- and intra-galactic magnetic fields only minutely affect the travel direction of cosmic rays at extreme energies, a detailed study of cosmic-ray sources, acceleration mechanisms, and differentiation between isotropic and point-like sources will become possible.
BELLE experiment is operated by an international collaboration at KEK in Tsukuba, Japan. Since 1973 the CP symmetry is as an intrinsic property of the electro-weak interaction included in the Standard model. This symmetry should manifest itself not only in the decays of K mesons, where it was discovered, but also in other processes in nature. Due to the complexity of the experiments, the experimental verification of CP non-invariance outside the neutral kaon system has been achieved only as late as 2001. BELLE experiment was one of two detectors which observed CP symmetry breaking in decays of B mesons. Their results are within experimental accuracy in agreement with the predictions of the Standard model. Nevertheless, many physicists doubt that Standard model is the ultimate theory. Precise measurements of CP symmetry violation are indirectly sensitive to the existence of new physical processes and physics beyond the Standard model. In the next five years, the BELLE experiment will be conducting intensive data taking. Our research activities will be mainly focused on the data analysis and study of the influence of symmetries on the evolution of the Universe.
DELPHI collaboration at CERN in Geneva, Switzerland, is finalizing its data analysis. In the next two years we will continue to for possible new particles and study their conection with the existence of ultra-high energy cosmic rays.
Significance for science
The goal of the program was to investigate the phenomena related to extreme energy scales in nature. Its activities are embedded into the work of international research collaborations with competent partners, including among others the institutions from the EU, USA, Brazil, Argentina and Japan. Its results will be of fundamental nature and are expected to be relevant for science in general and in particular for the fields of astro- and elementary particle physics, astrophysics and cosmology. The research of ultra-high energy cosmic rays (UHECR) and their interactions in the Earth's atmosphere (at several 10's of times higher energies than the projected final energies of the LHC collider) is at the forefront of the global physics endeavors in fundamental science. It is a fact that ultra high energy cosmic rays are the most energetic particles in nature, and that collisions at those energies may, with present technologies, never be achievable in man-made particle colliders. Analysis and interpretation of UHECR data collected by the Pierre Auger Observatory may be more difficult than that for data collected at accelerators, but due to its uniqueness provides all the more a challenge to the research community. A related activity is the investigation of very-high energy (VHE) gamma-rays. As they travel in a straight line from their source to an observer, unscrambled by magnetic fields, they may provide the key to the identification of VHE gamma-ray and UHECR sources, which are expected to be related. Our involvement in the CTA project, an initiative to build the next generation ground-based very high energy gamma-ray instrument, is a step towards that goal. CTA is expected to provide a deep insight into the non-thermal high-energy universe. The above activities will be strongly supported and complemented by theoretic studies. The understanding of black holes and the early universe has undergone dramatic progress in recent years, especially due to results coming from various experiments such as Fermi-LAT. It is a very exciting moment for the study of quantum gravity, black holes and cosmology, as a result of these experiments. For the first time there is some real data that enables us to eliminate various inaccurate models and focus on the more promising ones. There is great hope that in the next few years dramatic progress will be made in this fundamental field of study, of great importance for the development of science. Recent experimental results in the field of elementary particle physics are rising new questions about the existence of new physics beyond the established Standard Model of elementary particles and interactions between them. We will pursue one of the ways to push the knowledge frontier through our activities in Belle2 collaboration, measuring the properties of B meson decays originating from electron-positron collisions at unprecedented luminosity, and, unlike the LHC, with a low level of background processes. Possible outcomes of these searches may, among others, include a discovery of a new mechanism at a higher energy scale, responsible for the observed CKM matrix hierarchy, and a better insight into the problem with the matter-antimatter asymmetry in the universe, which can not be explained solely by the CP violation within the Standard Model. Finally, the proposed research program was relevant for integration into research roadmap and research projects of EU, as the largest financial and manpower contributors for the foreseen Pierre Auger Observatory upgrade and the future Cherenkov Telescope Array are institutions from EU (Germany, France, Italy). For both observatories our activities within the group will be coordinated with these institutions and oriented towards applying for European projects in the framework of Horizon 2020 and other relevant European mechanisms.
Significance for the country
Direct impact of the proposed program on the economy and society arises through the possibility of a transfer of knowledge and state-of-the-art technologies, developed for use at international research collaborations (i.e. the Pierre Auger Observatory - PAO), to Slovenia for commerical use and public service, a task in which we have been actively pursuing since our initial involvement with PAO. As a direct spin-off of the basic research at PAO (characterization of the atmosphere as the main detector media using Lidar technology, timing of the ground detector array using GPS signals) the Laboratory for Astroparticle Physics of the University of Nova Gorica (together with its Center for Atmospheric Research and the Slovenian Environmental Agency) constructed the first lidar observatory site in Slovenia at Otlica, which among others successfully tracked and characterized Icelandic volcanic ash in 2010 Eyjafjallajökull eruption. We independently developed a Raman lidar system for the remote profiling of water vapor concentrations in the atmosphere, and in collaboration with the Slovenian companies Optotech and Fotona we have also developed a mobile lidar for aerosol tracking and identification. We are also investigating the impact of ionospheric perturbations on GPS and the posibilities of their mitigation, which were at low latitudes found to be of considerable importance in the times of the coming solar maximum. All these devices provide not only scientific results but also results with a broader impact on society. At the present we are in the negotiation phase with business partners to transfer this knowledge and technology into products for commercial use. These activities will be expanded and intensfied in the scope of the proposed project. As an indirect impact of the proposed program on society we highlight the active and competitive participation of Slovenian researchers and students in these leading-edge global research activities; success of this and other such projects will help ensure the recognition of Slovenia as a high technology oriented country, which would further stimulate and promote international scientific, economical and financial cooperation. The proposed program will facilitate the transfer of knowledge at the leading edge of current global research activities and state-of-the art technology into Slovenia, and in particular, it will provide a deeper insight into the description of fundamental interactions that govern our world, including gravity. The results are expected to bring indirect benefits on many levels of social activities, including on a cultural level and a technological level, as a profound understanding of nature inevitably leads to the development of tools beneficial to the society and the humankind as a whole.
Most important scientific results
Annual report
2009,
2010,
2011,
2012,
2013,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2009,
2010,
2011,
2012,
2013,
final report,
complete report on dLib.si
