Study of background and transmission properties of the KATRIN spectrometers

The KATRIN experiment will determine the effective mass of the electron anti-neutrino with a sensitivity of 200 meV. This thesis focuses on the detailed description and optimization of background and transmission properties of the spectrometers. Various physics models have been implemented into the simulation software Kassiopeia to study experimental observations by Monte-Carlo simulations. A measurement strategy has been worked out to determine the main spectrometer transmission properties

Kassiopeia: A Modern, Extensible C++ Particle Tracking Package

The Kassiopeia particle tracking framework is an object-oriented software package using modern C++ techniques, written originally to meet the needs of the KATRIN collaboration. Kassiopeia features a new algorithmic paradigm for particle tracking simulations which targets experiments containing complex geometries and electromagnetic fields, with high priority put on calculation efficiency, customizability, extensibility, and ease of use for novice programmers. To solve Kassiopeia's target physics problem the software is capable of simulating particle trajectories governed by arbitrarily complex differential equations of motion, continuous physics processes that may in part be modeled as terms perturbing that equation of motion, stochastic processes that occur in flight such as bulk scattering and decay, and stochastic surface processes occuring at interfaces, including transmission and reflection effects. This entire set of computations takes place against the backdrop of a rich geometry package which serves a variety of roles, including initialization of electromagnetic field simulations and the support of state-dependent algorithm-swapping and behavioral changes as a particle's state evolves. Thanks to the very general approach taken by Kassiopeia it can be used by other experiments facing similar challenges when calculating particle trajectories in electromagnetic fields. It is publicly available at https://github.com/KATRIN-Experiment/Kassiopei

Latest results on astrophysical neutrinos using high-energy events with contained vertices

<p>The IceCube Neutrino Observatory, a cubic kilometer scale detector in the deep Antarctic ice, has detected an astrophysical neutrino flux above 100 TeV. In this poster we present the results of seven years of data using a sample of high-energy events with contained vertices. Compared to previous iterations of this analysis, the treatment of systematics and calibration has been improved and new reconstructions have been employed. The analysis studies an extended set of astrophysical scenarios, such as a double power-law and a high-energy cutoff. Additionally, searches for galactic and extra-galactic point sources have been performed and the results will be presented.</p

Kassiopeia: a modern, extensible C++ particle tracking package

The Kassiopeia particle tracking framework is an object-oriented software package using modern C++ techniques, written originally to meet the needs of the KATRIN collaboration. Kassiopeia features a new algorithmic paradigm for particle tracking simulations which targets experiments containing complex geometries and electromagnetic fields, with high priority put on calculation efficiency, customizability, extensibility, and ease-of-use for novice programmers. To solve Kassiopeia's target physics problem the software is capable of simulating particle trajectories governed by arbitrarily complex differential equations of motion, continuous physics processes that may in part be modeled as terms perturbing that equation of motion, stochastic processes that occur in flight such as bulk scattering and decay, and stochastic surface processes occurring at interfaces, including transmission and reflection effects. This entire set of computations takes place against the backdrop of a rich geometry package which serves a variety of roles, including initialization of electromagnetic field simulations and the support of state-dependent algorithm-swapping and behavioral changes as a particle's state evolves. Thanks to the very general approach taken by Kassiopeia it can be used by other experiments facing similar challenges when calculating particle trajectories in electromagnetic fields. It is publicly available at https://github.com/KATRIN-Experiment/Kassiopeia.United States. Department of Energy. Office of Nuclear Physics (Award FG02-97ER41041)United States. Department of Energy. Office of Nuclear Physics (Award DE-FG02-06ER-41420

High-energy neutrino follow-up search of gravitational wave event GW150914 with ANTARES and IceCube

We present the high-energy-neutrino follow-up observations of the first gravitational wave transient GW150914 observed by the Advanced LIGO detectors on September 14, 2015. We search for coincident neutrino candidates within the data recorded by the IceCube and Antares neutrino detectors. A possible joint detection could be used in targeted electromagnetic follow-up observations, given the significantly better angular resolution of neutrino events compared to gravitational waves. We find no neutrino candidates in both temporal and spatial coincidence with the gravitational wave event. Within ±500  s of the gravitational wave event, the number of neutrino candidates detected by IceCube and Antares were three and zero, respectively. This is consistent with the expected atmospheric background, and none of the neutrino candidates were directionally coincident with GW150914. We use this nondetection to constrain neutrino emission from the gravitational-wave event.by Anand Sengupta et al