Pencil beam scanning (PBS) proton therapy is due to its steep dose gradients a promising treatment option for many cancer patients, particularly if the tumour is surrounded by critical organs. Currently, organ motion often poses an obstacle for the irradiation of tumours in the thorax or abdomen since the interference of pencil beam and tumour motion can lead to distortions of the intended dose distribution and requires dedicated motion mitigation techniques. A technique which has been recomm...

The work presented in this thesis comprises two individual topics: While the first part presents a branching ratio measurement of the decay 𝐵0𝑠→ 𝐾0S𝐾0S, the second part discusses the author’s contribution to the simulation of the upgraded LHCb detector. To reduce systematic uncertainties, the branching ratio is measured normalised to the branching ratio ℬ(𝐵0 → 𝜙𝐾0S). The analysed data sample corresponds to an integrated luminosity of 3 fb−1 of 𝑝𝑝 collisions recorded at centre-of...

In this thesis, an approach is presented to probe the locations of track-like high energy starting events (HESE) for an additional clustering of neutrino events within six years of IceCube neutrino data at these positions. Two unbinned Likelihood stacking analyses using both a time-dependent, per-burst and a steady-state neutrino emission scenario are performed. This is done to be sensitive to a collection of weak fluxes, undetectable on their own and to test a rather broad regime of emi...

In this thesis corrections to the energy loss cross sections of high-energy muons are calculated. Over a large part of the energy range investigated by very large volume neutrino telescopes such as IceCube, pair production and bremsstrahlung dominate the energy loss. The theoretical uncertainties on the energy loss cross sections influence the experimental results as systematic uncertainties. These corrections are important for the energy reconstruction of high-energy muons which are ob...

In order to meet the requirements of the High Luminosity-LHC (HL-LHC), it will be necessary to replace the current tracker of the ATLAS experiment. Therefore, a new all-silicon tracking detector is being developed, the so-called Inner Tracker (ITk). The use of quad chip modules is intended in its pixel region. These quad modules consist of four read-out chips, bump-bonded to one large silicon pixel sensor. In this thesis, first prototypes of quad modules are investigated, which were asse...

Fading influences are a crucial point in dosimetry using thermoluminescence dosemeters. Due to thermal fading, the thermoluminescence signal decreases over time resulting in a potential underestimation of the irradiation dose. This thesis presents two techniques for a fading time independent irradiation dose estimation. Both methods are based on glow curve deconvolution. In the first approach, the fraction of signal photons of two peaks in the glow curve is used to estimate fading time an...

In dieser Arbeit wird eine Messung der CP-Asymmetrien Sf und S-f in B0→D^∓ π^±-Zerfällen präsentiert. Der analysierte Datensatz enthält dabei Ereignisse aus Proton-Proton-Kollisionen bei Schwerpunktsenergien von 7 und 8 TeV, die in den Jahren 2011 und 2012 vom LHCb-Detektor aufgenommen wurden und entspricht einer integrierten Luminosität von 3 fb-1. Die CP-Asymmetrien sind gemessen als Sf=0.058±0.020(stat.)±0.011(syst.), S-f =0.038±0.020(stat.)±0.007(syst.). Diese Ergebnisse sind präzise...

Diese Arbeit beschreibt eine Messung von zerfallszeitabhängiger 𝐶𝑃-Verletzung in den Zerfällen 𝐵0 → 𝐽/𝜓𝐾S0 und 𝐵0 → 𝜓(2𝑆)𝐾S0, in welchen das 𝐽/𝜓 aus zwei Elektronen und das 𝜓(2𝑆) aus zwei Muonen rekonstruiert wird. Der verwendete Datensatz entspricht einer integrierten Luminosität von 3fb^{−1} 𝑝𝑝-Kollisionen und wurde mit dem LHCb- Experiment bei Schwerpunktsenergien von 7 und 8 TeV aufgenommen. Die gemessenen 𝐶𝑃-Observablen sind 𝐶(𝐵0 → 𝐽/𝜓𝐾S0) = 0.12 ± 0.07 (stat...

In dieser Arbeit wird die Messung des Energiespektrums atmosphärischer Myonneutrinos in einem Energiebereich zwischen 125 GeV und 2 PeV mit Daten des IceCube-Detektors vorgestellt. Zur Durchführung der Messung wurde zunächst für die drei untersuchten Messjahre ein Myonneutrinodatensatz erzeugt. Für den Datensatz wurde eine Reinheit von 99.7±0.03% bei einer Ereignisrate von 3.47 mHz erreicht. Die Ereignisrate liegt circa 35% höher als bei vergleichbaren Datensätzen der selben Messjahre. Für d...

Für das Jahr 2019 ist ein Upgrade des LHCb Detektors geplant. Die Trackingstationen hinter dem Magneten sollen dabei durch einen Detektor aus szintillierenden Fasern mit Silizium-Photomultiplier-Auslese ersetzt werden. Um die gewünschte Ortsauflösung von unter 100 µm zu erreichen, werden Fasern mit einem Durchmesser von 250 µm präzise in mehreren Lagen positioniert und zu 2.4 m langen Matten verklebt. Qualitätskontrollen während der Produktion der Fasermatten sind zwingend notwendig, um eine ...

In this thesis a development and comparative study of a γ-Hadron separation for simulation and data measured by the First G-APD Cherenkov Telescope (FACT) is presented. The γ-Hadron separation uses a Random Forest algorithm in order to suppress the hadronic background and is evaluated on Monte Carlo simulations for the established analysis software MARS as well as for the newly developed software FACTTools. The results are applied to Crab Nebula data measured by FACT, whereas the separation ...

The LHCb detector will undergo a major upgrade during the Long Shutdown 2 of the LHC, which will take place from 2019 to 2020. As part of the upgrade, the main tracker will be replaced by a SciFi Tracker, based on scintillating fibres read out by SiPMs. Over 100000km of fibres are needed to build the SciFi Tracker, which will extend over an area of 360m2. It will provide a spatial resolution of better than 85 μm and a detection efficiency of 98:7%. This thesis presents a series of studies on ...

This thesis is concerned with the examination of Active Galactic Nuclei (AGN) within the field of gamma-ray and multi-wavelength astronomy in conjunction with data mining applications. The extension of the population of AGNs enables a tremendous refinement of our knowledge of gamma-ray emitting objects. For this purpose, the information about the class affiliation of a cataloged source and its corresponding counterparts is important. To possibly extend the AGN population, the multi-wavelengt...

In dieser Dissertation wird die erste Messung der b-tagging Effizienz eff(b) mit der pTrel-Methode am ATLAS Experiment unter Run 2 Bedingungen präsentiert. Die Messung wurde durchgeführt mit semileptonisch zerfallenden b-Hadronen mit einem Myon im Endzustand. Dies wurde erreicht durch Selektion von Myonen in einem Jet Kegel. Die pTrel-Variable is dabei sensitiv auf die Masse des schwach zerfallenden Teilchens und damit auf den Flavor des Jets. Dieser Zusammenhang lässt sich mit einem log-like...

Todays research in particle physics offers a wide field of opportunities for scientists from a variety of different subjects. Discoveries can only be made, with hundreds up to thousands of people working together in collaborations. Designing high precision detectors that can be up to several stories tall, followed by production, construction, commissioning and successful operation is only achievable with the combined effort of skilled and experienced detector physicists and engineers, while t...

In this thesis the analysis of data of the Crab Nebula obtained by the First G-APD Cherenkov Telescope (FACT) is presented. An analysis chain using modern machine learning methods for energy estimation and background suppression is developed. The generation and application of the machine learning models are validated using Monte Carlo simulated events. The Crab Nebula can be detected as a source of very high energy gamma rays with a significance of 39.89 σ. Its energy spectrum can be reconstr...