The hybrid design of the Pierre Auger Observatory allows one to measure the longitudinal profile of ultra-high energy air showers and the depth at which the shower reaches its maximum size (Xmax). It also provides a record of the shower front by sampling the secondary particles at ground level. These measurements give a variety of independent experimental observables with information about the nature of the primary particle and its interactions. In this contribution we present a comparison of our mass sensitive observables with the prediction of different hadronic interaction models. Furthermore we show how the analysis of the tail of the distribution of Xmax allows one to estimate the proton-air cross-section for particle production at center-of-mass energies of 57 TeV.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 2549243The Pierre Auger Observatory measures extensive air showers (EAS) up to the highest energies. One of the biggest challenges in current data analyses is to interpret these data in terms of the primary mass composition. Due to the insufficient constraint of interactions in EAS this is afflicted with large uncertainties. On the other hand, this high sensitivity of EAS to interaction features can be exploited to determine or constrain properties of interactions up to of 450 TeV. We demonstrate how specific EAS observations are suited for this task and thus may contribute to limit the uncertainties in the interpretation of air showers. These are the estimation of the muon number at ground level and the study of the hadronic cross section for particle production via EAS fluctuations.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 2466299The Pierre Auger Observatory detects the secondary particles generated when an Ultra High Energy Cosmic Ray (UHECR) interacts at the top of the atmosphere. The number of particles involved in are at these energies (EeV range) is of the order of billions and the generation of a single simulated extensive air shower requires many hours of computing time with current processors. In addition, the storage space consumed by the output of one simulated EAS is, in average, of the order of hundreds of MB. To complete the task we make use of Grid resources to be able to generate sufficient quantities of showers for our physics studies in reasonable time periods. We have developed a set of highly automated scripts written in common software scripting languages in order to deal with the high number of jobs which we have to submit regularly to the Grid.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 2504443The thesis outlines the results of a setting up two state of the art lidar systems; an elastic lidar and a water vapor Raman lidar. These lidars include both an analog channel and a photon counting channel; a sophisticated, seldom found combination that provides exceptional capabilities. The examination of the response of these two lidar systems is done in considerable detail and shows remarkable agreement between theory and actual capability. The thesis then describes the application of these two lidar systems to an examination of boundary layer physics in complex transition from the ocean to the mountainous region in the interior of Slovenia and an examination of particulates from the volcano eruption in Iceland.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 2216187This Report summarises the results of the activities of the LHC Higgs Cross Section Working Group. The main goal of the working group was to provide realistic predictions upon providing results on cross sections with benchmark cuts, differential distributions, details of specific decay channels, and further recent developments.
D.06 Final report on a foreign/international project
COBISS.SI-ID: 2587131