281. Arrival directions of the highest-energy cosmic rays detected by the Pierre Auger ObservatoryUgo Giaccari, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Arrival directions, highest-energy cosmic rays, Pierre Auger Observatory Published in RUNG: 16.02.2018; Views: 3202; Downloads: 166 Full text (2,58 MB) |
282. A new method to determine the energy scale for high-energy cosmic rays using radio measurements at the Pierre Auger ObservatoryRaphael Krause, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: energy scale, cosmic rays, radio measurements, Pierre Auger Observatory Published in RUNG: 16.02.2018; Views: 3377; Downloads: 145 Full text (3,64 MB) |
283. Studies of the nature of the low-energy, gamma-like background for Cherenkov Telescope ArrayJulian Sitarek, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: CTA, low-energy, gamma-like background Published in RUNG: 16.02.2018; Views: 2946; Downloads: 130 Full text (203,13 KB) |
284. Observing the sky at extremely high energies with CTA: Status of the GCT projectHelene Sol, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: very high energy, CTA, GCT Published in RUNG: 16.02.2018; Views: 2829; Downloads: 163 Full text (916,79 KB) |
285. A Compact High Energy Camera (CHEC) for the Gamma-ray Cherenkov Telescope of the Cherenkov Telescope ArrayIain R. White, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Compact High Energy Camera, CTA, Gamma-ray Cherenkov Telescope Published in RUNG: 16.02.2018; Views: 3067; Downloads: 107 Full text (6,76 MB) |
286. Extragalactic source population studies at very high energies in the Cherenkov Telescope Array eraT. Hassan, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: very high energy, CTA, extragalactic source Published in RUNG: 16.02.2018; Views: 3391; Downloads: 138 Full text (651,65 KB) |
287. Astroparticle studies at the Pierre Auger ObservatoryLili Yang, invited lecture at foreign university Abstract: The Pierre Auger Observatory (PAO), the world’s largest cosmic ray detector combines a large surface detector (SD) with an air fluorescence detector (FD). It is designed to observe extensive air showers (EAS) of billions of secondary particles induced by the UHECRs in the earths’ atmosphere. The “hybrid” design (i.e., detected simultaneously by SD and FD) provides wealth of information about shower development and excellent event reconstruction. Together with observations of UHECRs, the Surface Detector (SD) of the PAO is sensitive to UHE neutrinos through the observation of deeply initiated inclined down-going showers produced by neutrino interactions in the atmosphere, which method has been well established. On the other hand, high-energy photons can also be discriminated from background of charged cosmic rays based on their characters of the shower front. In this talk, I will give a review on recent results from PAO and introduce the ultra-high energy multi-messenger studies from PAO. Keywords: Pierre Auger Observatory, cosmic rays, ultra-high energy Published in RUNG: 17.01.2018; Views: 3795; Downloads: 0 This document has many files! More... |
288. Search for Physics beyond the Standard Model with the CRESST Experiment2017, master's thesis Abstract: In spite of the successes of observational astro- and particle physics and cosmology very much of the universe remains unknown. The Standard Model of particle physics is a theory describing the electromagnetic, weak, and strong nuclear interactions, as well as classifying all the subatomic particles known. But there is overwhelming evidence, that all the known particles, the ordinary (baryonic) matter, the building blocks of planets, stars and ourselves, only make up about 4.9% of the energy content of the universe. The standard model of cosmology (CDM) indicates that the total mass-energy of the universe contains beside the 4.9% ordinary matter two other components: 26.8% dark matter and 68.3% dark energy. The accelerating expansion of the Universe is the result of the effect of the dark energy with its most simple form given by a cosmological constant in Einstein's Equation. Dark matter is an unidentified type of matter that is not accounted for by dark energy and neutrinos and is generally believed to be a non-relativistic, charge neutral and non-baryonic new form of matter. Although dark matter has not been directly observed yet, its existence and properties are inferred from its gravitational effects such as the motions of visible matter, gravitational lensing, its influence on the universe's large-scale structure, and its effects in the cosmic microwave background. Thus the search for Dark Matter is the search for physics beyond the standard model. Although the nature of dark matter is yet unknown, its presence is crucial to understanding the future of the universe. The CRESST experiment is searching for direct evidence in the form of a nuclear recoil induced on a scintillating CaWO4 crystal by a dark matter particle, and is installed and taking data underground at Laboratory Nazionali del Gran Sasso (LNGS) in Italy. While both, dark energy and dark matter, have not been detected directly, a class of dark matter particles that interact only via gravity and the weak force, referred to asWeakly Interacting Massive Particles (WIMPs), has been established as the leading candidate among the dark matter community. For this thesis a special model of dark matter was studied, namely the dark photon. This thesis provides a detailed description of the calculation of the 90% upper limit on the dark photon kinetic mixing based on data from the second phase of the CRESST experiment. The analysis was carried out in a frequentist approach based on the (unbinned) maximum-likelihood method and likelihood ratios. To make a statement about the calculated result and its quality, the used algorithm had to be tested, what was done with Monte Carlo simulations (pseudo data). Keywords: astro physics, particle physics, cosmology, universe, Standard Model of particle physics, standard model of cosmology, matter, ordinary matter, dark matter, dark energy, accelerating expansion of the Universe, non-baryonic, new form of matter, gravitational lensing, cosmic microwave background, search for physics beyond the standard model, CRESST experiment, direct detection, CaWO4 crystal, underground laboratory, Laboratory Nazionali del Gran Sasso, Weakly Interacting Massive Particles, WIMP, dark photon, 90% upper limit, upper limit, kinetic mixing, frequentist approach, unbinned, maximum likelihood Published in RUNG: 13.10.2017; Views: 4609; Downloads: 0 This document has many files! More... |
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290. Results from the Pierre Auger ObservatoryIvan De Mitri, Andrej Filipčič, Samo Stanič, Darko Veberič, Danilo Zavrtanik, Marko Zavrtanik, 2015, published scientific conference contribution Keywords: Pierre Auger Observatory, Ultra High Energy Cosmic Rays (UHECR), UHECR energy spectrum, UHECR mass composition Published in RUNG: 27.06.2017; Views: 4193; Downloads: 0 This document has many files! More... |