In this work, a search for heavy pseudoscalar and scalar (A/H) Higgs bosons decaying to top-anti-top quark pairs (t ̄t) and a measurement of top quark polarization and t ̄t spin correlation are presented, performed using 35.9 /fb of data recorded by the CMS experiment in 2016. The dileptonic t ̄t final state is investigated in both analyses.The A/H Higgs boson search exploits the 2-dimensional spectrum of t ̄t invariant mass and an angular observable sensitive to both the spin and parity of the t ̄t system. [...]

With recent advances in the generation of ultrashort laser pulses, electron and nuclear dynamics in molecules can be investigated on their natural, atto- to femtosecond timescale. This opens up the investigation of many interesting phenomena, including primary events in chemistry and biology. [...]

This work considers the phase-space evolution of an externally injectedelectron beam under various plasma-based acceleration scenariosusing numerical methods.Plasma wakefield acceleration, an exceptional technology with thepotential to drive the next generation of particle accelerators, uses aparticle driver to excite a wakefield carrying gradients in the rangeof10 GV m−1to100 GV m−1, orders of magnitude higher than theconventional cavities currently available. However, the plasma envi-ronment has stringent requirements with respect to acceptable beamparameters which need to be carefully analyzed to enable stable beamtransport and acceleration. [...]

This thesis is focused on the search for pair production of the supersymmetric $\tau$ lepton partners within the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). The search is performed using the data collected at a center-of-mass-energy $\sqrt{s} = 13$ TeV with the CMS detector in the years 2016-2017.One of the most popular extensions of the Standard Model (SM) is supersymmetry (SUSY). [...]

The development of tools and techniques such as free-electron lasers (FELs) and pumpprobeexperiments has advanced the field of femtochemistry and made it possible tofollow the real-time dynamics of photo-excited molecular species on the femtosecondtime scale. Advances in femtochemistry experiments present new challenges and opportunitiesin the field of theoretical/computational femtochemistry for describing theultrafast molecular dynamics on the potential energy surfaces of electronically excitedmolecules.This thesis presents a series of theoretical studies on ultrafast dynamics of molecularsystems after excitation/ionization by laser pulses in the VUV to XUV regime, whichis highly relevant for pump-probe experiments [...]

Several tools for quench localization at Superconducting Radio Frequency cavities exist. One of these techniques uses the excitation of temperature waves in liquid Helium below the lambda point. [...]

This work addresses the measurements and phenomenology of the azimuthal separation $\Delta\phi_{12}$ between the jets with the largest transverse momenta $(p_T)$ in multi-jet event topologies. The measurements are based on proton-proton collision data at the center-of-mass energy of 13 TeV recorded by the Compact Muon Solenoid (CMS) experiment in 2016, and correspond to an integrated luminosity of 35.9 fb$^{−1}$ [...]

Das Hauptziel dieser Arbeit ist die Charakterisierung extrem starker Quellen, die höchstwahrscheinlich die kosmische Strahlung beschleunigen. In dieser Arbeit wurden VHE-Gammastrahlenbeobachtungen mit den MAGIC-Teleskopen verwendet, um die Eigenschaften von Blazaren zu untersuchen. [...]

Der Ursprung ultra-hochenergetischer kosmischer Strahlung (UHECRs) ist eine der wichtigsten offenen Fragen der Astrophysik. Gammastrahlenblitze (GRBs) galten als potentielle Quellen, da sie zu den energetischsten Ereignissen im Universum zählen. [...]

Exclusive photoproduction ofρ0vector mesons is studied with the H1 detectorat HERA. A sample of over 900 000π+π−photoproduction events was collectedin the years 2006-2007 using the H1 Fast Track Trigger. [...]

A large class of four dimensional N=1 theories can be obtained by twisted compactification along a Riemann surface C of six dimensional theories with N=(1,0) supersymmetry. When the (1,0) theory is that of the theory on M5-branes on a transverse C_2/Z_k singularity the resulting four dimensional theories are said to be of class S_k . [...]

The work in this thesis deals with two functional medical imaging methods, i.e. positron emission tomography (PET) and X-ray uorescence imaging (XFI). [...]

In recent years, research has been carried out on soft matter in order to improve the abilityto control and manipulate its structural and thermodynamic properties at the nanoscale.Among these materials are normal alkanes (n-alkanes), a class of soft matter that hasalready been thoroughly researched in the bulk state. The aim of this master thesis isto investigate the behavior of n-alkanes under nanoconfinement. [...]

Shape resonances are a ubiquitous phenomenon in electron–molecule scattering, in which the impinging electron is resonantly captured in a pseudo-bound state that is supported by the molecular potential. To study the electron scattering dynamics, we use time- and angle- resolved photoelectron spectroscopy here. [...]

Despite its outstanding phenomenological successes, the Standard Model of particle physicshas a number of severe shortcomings. In this thesis, I address some of the most strikingof these. [...]

The influence of the composition within multilayered heterostructure oxide semiconductors has a critical impact on the performance of thin-film transistor (TFT) devices. The heterostructures, comprising alternating polycrystalline indium oxide, tin(IV) oxide and aluminium oxide layers, are fabricated by a facile atomic layer deposition (ALD) process, enabling the tuning of its electrical properties by precisely controlling the thickness of the individual layers. [...]

Photoionization is one of the most possible processes that can happen when light interacts with anelectronic system. This seemingly simple phenomenon has expanded into a rich playground thanksto the rapid development of ultraintense and ultrashort light-source technology.In this doctoral dissertation, we investigate photoionization dynamics that can be measured ortriggered by advanced light sources. [...]

The time scale of the dynamics in atoms and molecules varies from attoseconds (10-18) to picoseconds (10-12) depending on the size of the particles. To study such dynamics, ultrafast light pulses are needed to trigger and capture the reaction. [...]

In this thesis we discuss modern mathematical tools for the perturbative analysis of supersymmetric Yang–Mills theories (abbreviated SYM). We apply contemporary and traditional computational techniques to two kind of problems. [...]

The free-electron laser in Hamburg (FLASH) is a soft X-ray user facility, delivering radiation for photon science since 2005. Since 2014, a second beam line for user operation, FLASH2, has been in operation. [...]

In this thesis we propose intensity correlation enhanced imaging techniques in two major areas of imaging with light. The first area is diffractive imaging. [...]

Der Ursprung ultra-hochenergetischer kosmischer Strahlung (UHECRs) ist immer noch unbekannt. Neutrinoteleskope wie IceCube messen einen Fluss hochenergetischer astrophysikalischer Neutrinos, dessen erwarteter Ursprung Wechselwirkungen kosmischer Strahlung (CR) ist. [...]

Now-a-days displays have become a field of tremendous importance as they provide the best means for interface between man and machine. Large numbers of displays are presently available in the market, but among all these displays about 90% are controlled by the liquid crystal display (LCD) technology. [...]

The subject of this thesis was the development of a thin-disk laser with a continuous waveintracavity intensity of more than $10^{10} {W}{cm^{-2}}$ for the adiabatic alignment ofmolecules. In particular, this necessitates an intracavity power of more than 100 kW, aninternal focus with a radius of 20 µm, a well-defined and stable polarization, and benefitsfrom fundamental transverse mode operation. [...]

The transport and acceleration of positron beams is a crucial challengeon the path towards plasma-based particle colliders. This work pro-poses to use a finite radius plasma in a plasma wakefield acceleratoras a way to reduce the restoring force acting on the plasma electrons,resulting in an elongation of their on-axis return point and, hence,creating a long, high-density electron filament. [...]

In dieser Arbeit wird die Messung des normalisierten differentiellen Wechselwirkungsquerschnitts von Top Quark Produktionen mit zusätzlichen Jets präsentiert. Es werden Proton-Proton Kollisionsdaten des ATLAS Experiments am Large Hadron Collider bei einer Schwerpunktsenergie von 13 TeV mit einer Luminosität von 3.2 fb-1 verwendet. [...]

For the International Large Detector (ILD) at the planned International Linear Collider (ILC) a Time Projection Chamber (TPC) is foreseen as the main tracking detector. The TPC will have a single-point resolution of 100 µm in Rphi and 0.4-1.4 mm along the Z axis. [...]

Neutrino oscillations, the phenomenon that neutrinos can change their flavor after propagation through space, is proof of their non-zero masses and, therefore, a sign of new physics beyondthe Standard Model. IceCube is a cubic kilometer Cherenkov neutrino detector buried in the Antarctic glacial ice at the geographic South Pole. [...]

In this thesis, the structure and dynamics of highly concentrated core-shell nanogel particlescomposed of a silica core and a poly(N-isoproylacrylamide) (PNIPAm) shell suspendedin water are studied. The particles were synthesised with dierent core-to-shell size ratiosand prepared at various concentrations with volume fractions e between approximately0:004 and 2. [...]

Die vorliegende Arbeit beschäftigt sich mit der Untersuchung des Ionenspeichermechanismus in V2O5-Kathodenmaterial. Insbesondere wurde die Speicherung von Mg2+, K+ und Zn2+ mit in operando-Synchrotronbeugung und in operando Röntgenabsorptionsspektroskopie in Kombination mit ex situ Raman und Röntgenphotoelektronenspektroskopie (XPS) oder Transmissionselektronenmikroskopie (TEM) untersucht. [...]

Within this work a wholesome approach to the characterization of FEL based THz radiationis made on the example of the THz radiation provided at the THz beamline at Flash thefree electron laser at DESY in Hamburg. A SRW based model of the THz generation froma free electron and the corresponding transport is developed and used to gain insight intothe complex intensity profile created by the interplay of the THz undulator and variousmagnetic edges. [...]

Phase-change materials (e. g. [...]

Nowadays, the lithium-rich layered 3d-transition-metal (TM) oxides (LLOs) are regarded as one of the most attractive cathode materials for next-generation lithium-ion batteries (LIBs), because they can exhibit a discharge capacity (approaching 300 mAh g$^{-1}$ at 0.1 C) much higher than that of the currently used materials(~ 180 mAh g$^{-1}$at 0.1 C). However, the formation mechanism of LLOs has not been fully understood on a fundamental level yet.One of the most interesting and still open questionsis aboutlithium and oxygen atoms are incorporatedinto the precursor’s crystal structure during the synthesisoffinal LLO products.Asystematic exploration of this subject was conducted in this PhD work. [...]

The recording of structural dynamics of individual large biomolecules requires efficient delivery of these biomolecules, which are usually thermally labile or non-volatile, to the X-ray or electron beam interaction point. Laser-induced acoustic desorption (LIAD) is a promising technique for gentle and efficient preparation of large intact neutral molecules into the gas-phase. [...]

The aim for size and cost reduction of particle accelerators has generated great interest in thedevelopment of novel acceleration techniques beyond the current radio frequency based technology.Those techniques are, for example, dielectric laser accelerators (DLAs) and have thepotential to reduce the size and costs, due to their high field gradients and small acceleration periods.DLAs consist of structures which are characterized by apertures in the µm range, leadingto electron-bunch charges in the pC range. At the SINBAD (Short and INnovative Bunches andAccelerators at DESY) facility at DESY, various techniques are foreseen to be investigated usingthe ARES (Accelerator Research Experiment at SINBAD) linear accelerator. [...]

X-rays allow to non-destructively investigate biological, chemical or physical processes at the nano-scale. Their high penetration depth in matter allows to investigate samples even inside sample environments, which would be difficult with complementary methods such as transmission electron microscopy (TEM). [...]

One of the big technical and scientific challenges today is to accomplish the ultimate dreamof filming chemical reactions with atomic spatial and temporal resolution and recording themolecular movie. Important prerequisites toward this goal are, on the one hand, methodsto create cold, controlled molecular samples and, on the other hand, imaging techniquesthat combine the required spatial and temporal resolution. [...]

The International Linear Collider (ILC) is a planned electron-positron collider with a first stage at a center-of-mass energy of 250 GeV. The electron beam will be polarized to 80% and the positron beam to 30%. [...]

Colliding wind binaries (CWBs) are unique acceleration sites of cosmicray particles and are known emitters of non-thermal photons. Out of morethan 40 known Galactic CWBs, two have been detected in γ-ray energies, ηCar and γ2 Vel. [...]

The present work is devoted to the phenomenon of redox-isomerism in Langmuir monolayers of europium bis-tetra-15-crown-5-phthalocyaninate - (Eu[(15C5)4Pc]2). It is found that the intramolecular electron transfer from the electronic system of the phthalocyanine ligand to the 4f-orbital of europium atom occurs during the spreading of the Eu[(15C5)4Pc]2 solution in chloroform onto the air-water interface. [...]

In this thesis we study the astrophysical implication of self-interacting dark matter. Observations on different scales suggest the existence of an additional form of matter which interacts gravitationally. [...]

The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. [...]

The exceptional binary star Eta Carinae has been fascinating scientists and the people in the Southern hemisphere alike for hundreds of years. It survived an enormous outbreak, comparable to a supernova energy-wise, and for a short period became the brightest star of the night sky. [...]

The acceleration of electron beams in plasma wakefields driven by charged particlebeams is among the most promising candidates for future TeV-scale compact electronaccelerators. Currently available high energy proton beams that could serve as driverbeams in a plasma wakefeld accelerator (PWFA) are much longer than what is requiredfor efficient excitation of high-amplitude wakefields and thus for generating the desiredhigh acceleration gradients. [...]

Because of their ultrashort pulse duration and extremely high peak power, interest in ultrashort pulse lasers for strong-field experiments has been rapidly increasing over the past decades. After the invention of passively mode-locked lasers, further developments of ultrashort pulses in achieving ultrashort pulse duration, extremely high peak power and phase stabilization enable scientists to do frontier research such as bio-imaging, astronomical spectroscopy, solid-state high-harmonic generation, optical-field-driven electron emission from nanostructures, light-matter interaction in new materials, etc. [...]

In this work, plasma wakefield acceleration with high transformer ratios, i.e. highratios between acceleration of witness particles to deceleration of driver particles, is investigated experimentally.Particle-beam-driven plasma wakefield acceleration (PWFA) is one of the primecandidates for future compact accelerator technologies. [...]

The generation of ultrashort electron bunches is an active area of research in accelerator physics. A key application of such bunches is the injection into novel accelerators with high-frequency accelerating fields, such as laser-wakefield plasma accelerators or dielectric laser accelerators. [...]

The amorphous material compound AlYB14 exhibits interesting properties due to anicosahedral B network but lacks oxidation resistance at high temperatures, as Boxide forms corrosive boric acid. Therefore, it was attempted to improve the stabilitywith a higher Al content up an Al/Y ratio of 2.4, as it is know to form a protective Aloxide layer preventing further oxidation. [...]

This thesis is about simulations, proof-of-principle experimental setups and first test experiments for new ultra-compact particle accelerators based on dielectric structures. Due to the high damage threshold of nano- and micrometer-scale dielectrics in the optical regime, accelerating fields on the order of GV/m can be achieved. [...]

The ALPS II experiment at DESY is searching for new particles beyond the standardmodel of particle physics in a laboratory-based Light-Shining-through-a-Wall experiment,using high nesse optical resonators to reach the required sensitivity. The inputand output mirrors on the optical tables have extremely accurate positioning and alignmentrequirements, for which the analysis of ground vibration and seismic noise is essential.This thesis, therefore, focuses on this analysis, its evaluation, and the developmentof future seismic isolations for the ALPS II and JURA experiments.This work describes mechanical vibrations, seismic noise sources, seismic isolationprinciples, and also the seismic devices used to perform seismic noise analysis with theirmethods of measuring, calibrating, and analysing the acquired data. [...]

In the first part of this thesis we investigate the viability of a class of models for de Sitter (dS) vacua in string theory, due to Kachru, Kallosh, Linde and Trivedi (KKLT). We start by explaining why the success or failure of such models is sensitive to a large number of Planck suppressed operators, and collect circumstantial evidence that this UV sensitivity cannot be evaded with delicately engineered models such as the Kallosh-Linde (KL) racetrack due to a generic conflict with the weak gravity conjecture (WGC) for axions. [...]

Diese Arbeit beschäftigt sich mit den grundlegenden Prozessen, die hochintensive und kurze Lichtpulse in Nanopartikeln auslösen. Als Modellsystem werden Xenoncluster im Größenbereich von 20 bis 90\,nm im Radius verwendet. [...]

The underlying theme on which this Thesis develops is double parton scattering (DPS), which is a nucleon-nucleon scattering process in which two partons from each nucleon collide individually with one another to undergo two independent hard interactions. While these types of processes are usually suppressed with respect to theclassic single parton scattering (SPS), there are some circumstances in which DPS can give sizeable contributionsto the overall cross section, making DPS an important competitor to its SPS counterpart. [...]

The astronomical evidence for Dark Matter has sparked a large interest in Dark Matter searches at the LHC. Final states involving top quarks are interesting, because many models predict the Dark Matter to have larger couplings to more massive particles. [...]

This thesis presents the measurement of associated production of a W$^±$ boson and a charm quark (W + c) in proton-proton collisions at a center-of-mass energy of 13 TeV. The data used in this analysis has been recorded by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 35.7 fb$^{-1}$ . [...]

In this work, the dynamics of low-energy photoelectrons, generated by multiphoton ionization from near-infrared (NIR) laser pulses, in the presence of intense near single-cycle carrier-envelope phase stable Terahertz (THz) pulses, were experimentally investigated. For certain time delays between the NIR and THz pulses, a strong modulation of the photoelectron momentum distribution was observed and attributed to rescattering from the ionic core. [...]

We investigate an early Universe inflationary phase driven by a pseudo Nambu-Goldstone boson. The setup is not only naturally protected in the sense of t’Hooft, but such particles are also ubiquitous in quantum and string theories. [...]

The coherent synthesis of pulses from Optical Parametric Amplifiers (OPAs) offers the possibility to realize field-controlled electromagnetic waveforms with sub-cycle durations, widely scalable in energy and spectral bandwidth.Here we demonstrate a fully functional prototype of a mJ-level two channel parametric waveform synthesizer, which is ready to be upgraded to three channels. The synthesized field, whose bandwidth covers more than 2 octaves, from ~500 nm to ~2200 nm, can be compressed to a non-sinusoidal sub-cycle waveform close to the transform-limit.The long term stable operation of such a complex laser source is achieved, for the first time, by means of a sophisticated optical and mechanical design of the whole OPA system, along with targeted improvements made to the commercial pump laser.A new seeding scheme based on multiple supercontinua, further scalable to the mid-IR, leads to excellent phase stability among the different OPA channels and to a simplified dispersion management scheme.A detailed study, both theoretical and experimental, of the couplings among different pulse parameters during the parametric amplification, unveiled novel details of the Carrier-Envelope-Phase (CEP) stabilization process via OPA, and guided the design of the CEP-controlled seeding front-end.A simplified two-dimensional spectral shearing interferometry setup, where the ancillary pulses are obtained by spectral filtering the pump pulses, has been developed to easily characterize the spectral phase of the ultrabroadband pulses from each channel, overcoming the limitation of second-harmonic-based methods.Furthermore, ad-hoc nonlinear optical techniques have been deployed to observe the most relevant synthesis parameters such as the CEP of the seeding pulses and the relative phase among the different channels outputs. [...]

As no sign of physics beyond the Standard Model has emerged at the Large Hadron Collider sofar, high precision measurements of particle properties and couplings become increasingly interesting.A commonly used language to interpret these measurements is effective field theory, inwhich higher-dimensional operators are added to the Standard Model. Traditional approachesmost commonly set constraints on anomalous couplings by employing and combining unfoldedmeasurements. [...]

This bachelor thesis aims to develop and optimize a method to analyse the energyof electron bunches accelerated by a laser-plasma wakefield accelerator (LPWA).An electron spectrometer is used, which consists of a magnet do disperse electronsof different energies, and a luminescence screen, on which the electrons are madevisible. Due to the high energy spread of electrons accelerated by a LPWA, awide screen is used, which can only be observed by using a fisheye lens. [...]

The study of condensed matter dynamics on ultrafast timescales is one of the key topics in modern material science research. Hard X-ray free-electron laser sources with extreme peak brightness and ultra short pulses provide excellent conditions for studying ultrafast dynamics in the time domain by employing such techniques as X-ray pump-probe spectroscopy or X-ray photon correlation spectroscopy. [...]

In this thesis, the Drell-Yan production is described in next-to-leading order (NLO)with transverse momentum dependent parton densities (TMDs). The NLO method MC@NLOis applied for the hard process calculation and is combined with TMDs obtained within theparton branching (PB) method (PB-TMDs). [...]

Matrix Product States can efficiently approximate ground states. Based on the Matrix Product formalism we use variational optimization methods to calculate ground state energies of the spin-1/2 critical Heisenberg and the spin-/2 transverse Ising model in one spatial dimension. [...]

This thesis is devoted to the study of mass effects in higher order radiative corrections within QED and QCD. The first part of the thesis deals with the process of deep-inelastic scattering. [...]

This thesis presents developments and results of an experimental setup which combines soft X-ray spectroscopy methods for electronic structure analysis and imaging capabilities with the goal to gain detailed understanding of quantum materials, which exhibit spatial electronic inhomogeneities. The setup features a combination of two Fresnel zone plates which are about 1mm long and sub-μm wide: Firstly, a linear illumination zone plate creates a vertical X-ray focus line on the sample. [...]

This dissertation addresses two applications of silicon pixel detectors as tracking devices, namely the applications in high energy physics experiments and in a novel tomographic technique termed material budget imaging.For current and future experiments in high energy physics, one of the main challenges for the development of silicon detectors is the immense radiation fluence received over the years of operation.In this thesis, the performance of silicon pixel detectors for the tracking detector of the Compact Muon Solenoid (CMS) experiment is investigated for fluences of up to $\Phi_{eq}= 1.39\times10^{15}$n/cm$^2$ close to the expected lifetime fluence of the innermost layer of the barrel pixel detector. Measurements conducted at the DESY II Test Beam Facility show, that the maximum collected charge is reduced significantly by the high radiation fluences, but that an efficiency of above 99 % can be maintained when applying reasonable bias voltages.The voltage required to fully deplete the sensor rises up to around 600 V.The effective Lorentz angle of unirradiated detector modules and a module irradiated to a fluence of $\Phi_{eq}= 4\times10^{14}$n/cm$^2$ was determined for various bias voltages using a 1.34 T magnetic field.The findings imply that the high bias voltages required for an efficient operation of radiation damaged pixel detectors will impair the resolution of the detector modules significantly.The second application investigated is the use of silicon pixel detectors for an imaging technique aiming to reconstruct the three-dimensional material distribution of arbitrary samples.Using the high-resolution EUDET-type Beam Telescopes available at the DESY II Test Beam Facility to measure the scattering angle of relativistic particles when traversing a sample allows for the determination of its projected material budget in two dimensions.A rotation of the sample and an inverse Radon transform facilitates a reconstruction of the sample's internal structure.Simulations of this technique are presented as well as the first acquired three-dimensional material budget images.The simulations and an evaluation of the underlying two-dimensional images indicate a possible resolution of this method of less than 20 $\mu$m at a sufficiently high contrast-to-noise ratio.The potential and the limits of material budget imaging as well as possible future applications and developments are discussed..

A search for high mass Higgs bosons produced in association with at least one $b$-quark and decaying into a pair of $b$-quarks using the LHC Run 2 data collected by the CMS detector is presented. The corresponding data sample was accumulated during the proton-proton collisions in 2016 at a centre-of-mass energy of $\sqrt{s} = 13$ TeV, corresponding to an integrated luminosity of 35.7 fb$^{-1}$.An extended Higgs sector containing high mass Higgs states is predicted by many theories beyond the Standard Model, such as a general two Higgs doublet model (2HDM) and its realization in the Minimal Supersymmetric extension of the Standard Model (MSSM).In many scenarios within these models Higgs couplings to $b$-quarks are significantly enhanced and therefore the final state exploited in this work is of particular interest.From the experimental point of view this final state leads to at least three highly energetic $b$-jets in the event, of which the two with the highest transverse momentum, are assumed to originate from the Higgs boson decay and another one comes from the associated production mechanism. [...]

Instrumentation of higher order modes (HOMs) excited in accelerating cavities for beam phase and position inference provides a noninvasive and economical beam diagnostic. The principles and techniques for this purpose are investigated for TESLA (TeV Energy Superconducting Linear Accelerator) cavities at the injector part of the newly built European XFEL and at FLASH, two free electron laser facilities based on the TESLA technology.I have designed and instrumented unconventional beam phase monitors based on monopole modes in TESLA cavities and demonstrated a routine resolution of 0.1° with a broadband setup [...]

The goal of this thesis was to characterize the properties of tetramyristoyl cardiolipin (TMCL) and several environmental influences on it. This included investigating the pH and temperature dependency of TMCL as well as the influences of ROS on TMCL and exam-ining the lipid-protein interactions between TMCL and cytc. [...]

Plasma wakefield accelerators are able to accelerate charged particles by using the electric fieldof the free electrons within a plasma. The electric field is about one magnitude bigger thanin conventional accelerators. [...]

This work presents several measurements of the inclusive top pair production cross sectionat a center of mass energy of√s = 13 TeV with the CMS detector. The cross section ismeasured using several data sets collected by the CMS detector in 2015 and 2016. [...]

Isolated few-cycle pulses are used as driving fields for high-harmonicgeneration (HHG) and in pump-probe experiments. In this work awave equation solver was developed, describing the propagation ofpulses with few- to sub-cycle duration in a nonlinear gas medium.The 1-D numerical model is used to investigate the behaviour insidehollow-core fibers. [...]

This thesis deals with the polymerization-induced self-assembly (PISA) of amphiphilic blockcopolymer nano-objects, which were synthesized using a controlled radical polymerization(CRP) method, in particular, the reversible addition-fragmentation chain-transfer (RAFT)aqueous polymerization in the presence of a poly(N,N-dimethylacrylamide) stabilizer agent(macro RAFT agent). Besides the use of N-isopropylacrylamide (NIPAm) as core-formingblock for thermo-responsive nanoparticle, the aqueous dispersion polymerization of 2-methoxyethyl acrylate (MEA) was pursued as a model to study hydrophilic-hydrophobic phasetransitions: as a monomer, MEA is water-soluble. [...]

The recent developments of several X-ray synchrotrons and (ultrabright) XFEL light sources with increasingly narrow and brilliant beams have allowed facilities to reduce both sample volume and data acquisition time. Moreover, this has created new opportunities for investigating versatile sample conditions while simultaneously increasing demands in terms of sample preparation. [...]

Diese Doktorarbeit behandelt die Messung des Wirkungsquerschnittes der Paarbildung von Top-Quarks mit zusätzlichen B-Jets (Teilchenschauer aus der Fragmentierung von B-Quarks) in Proton-Proton-Kollisionen bei einer Schwerpunktsenergie von √s =13 TeV am Large Hadron Collider. Der Datensatz wurde 2015/16 mit dem ATLAS-Detektor aufgezeichnet und entspricht einer integrierten Luminosität von 36,1/fb. [...]

This thesis deals with a systematic study of magnetic properties, i.e. saturation magnetization, exchange stiffness, anisotropy, interlayer exchange coupling, and average domains size, of ultrathin Co-based multilayer systems. [...]

This thesis presents a study of the Standard Model (SM) Higgs boson in the decay channelof ! eμ, as well as a search for neutral Minimal Supersymmetric Standard Model (MSSM)Higgs boson in the same decay channel, using data corresponding to an integrated luminosityof 35.9 fb−1 in proton-proton collisions with a center-of-mass energy of 13 TeV, collected bythe CMS detector at the Large Hadron Collider. The results of eμ channel in both analysesare combined with other channels of Higgs to decay: eh, μh and hh.An observation of the SM Higgs boson to is established with a significance of 4.9 standarddeviations, to be compared to an expected significance of 4.7 standard deviations [...]

We explore different scenarios of electroweak symmetry breaking by studying the phenomenology of several models that extend the scalar sector of the Standard Model (SM). We investigate resonant multiscalar production in a singlet extension of the SM. [...]