Ph.D. Theses

The topic of this thesis is a new approach to solve the DGLAP evolution equation to obtain not only the collinear Parton Distribution Functions (PDFs) but also the Transverse Momentum Dependent (TMD) PDFs (TMDs). The DGLAP equation is solved with the Parton Branching (PB) method, which allows a determination of kinematic variables at every branching and a construction of the TMDs in a large range in longitudinal momentum fraction $x$ and evolution scale $\mu^2$. [...]

This thesis presents the study of the time development of hadronic showers in a highly granular hadron calorimeter using data collected by the CALICE Analog Hadron Calorimeter (AHCAL) technological prototype at the Super Proton Synchrotron (SPS) at CERN in July 2015 in μ−, e− and hadron beams up to 90 GeV.Highly granular calorimeters are designed for the concept of Particle Flow Algorithm which aims to mea- sure each individual particle in a jet using the best sub-detector measurement. The Particle Flow approach is a key aspect of the detectors for the International Linear Collider (ILC) which is a future linear lepton collider designed for precision physics studies at a center of mass energy up to 500 GeV.The CALICE Collaboration is developing highly granular calorimeters for future colliders. [...]

Recent studies show that scar-free surgery is possible with picosecondlaser pulses tuned to the strong absorption band of water in the Mid-IR. Away to generate these pulses is with an optical parametric amplifier (OPA)pumped by a picosecond infrared laser (PIRL). [...]

This work presents measurements of the normalized and absolute differential top-quark pair ($t\bar{t}$) production cross sections in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data were collected by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{-1}$. [...]

The discovery of the Higgs boson culminates a 40-year long hunt and completes a theoretical framework under which almost all collider data can be consistently explained. At the same time, paradoxically, the confirmation of an apparent mass gap above the electroweak scale exacerbates the problem of the electroweak hierarchy [...]

Mode-locked lasers can provide a stable source of optical pulses with intrinsically low timing jitter, and as such have a broad range of important applications, both as sources of low-noise microwave signals and as the key enabling technology for optical frequency combs. Integrating such laser systems onto a chip using silicon photonics will dramatically reduce size and cost, thus increasing the accessibility of this technology for widespread deployment. [...]

The European X-ray Free-Electron Laser is currently under construction at theDeutsches ElektronenSynchrotron in Hamburg, Germany. This linear accelerator, with a length of 3.4 km,will generate extremely intense and short X-ray laser light pulses with a duration in the femtosecondrange and wavelengths down to 0.05 nm. [...]

Non-perturbative aspects of N = 2 supersymmetric field theories of class S are deeply encoded in the algebra of functions on moduli spaces M-flat of flat SL(N)-connections on Riemann surfaces. Expectation values of Wilson and ’t Hooft supersymmetric line operators are related to holonomies of flat connections, while expectation values of line operators in the low energy effective theory are related to Fock-Goncharov coordinates on M-flat. [...]

The International Linear Collider (ILC) is a proposed linear electron positron collider with a center-of-mass energy of 250 GeV in its first stage. After the discovery of the Higgs boson at the Large Hadron Collider (LHC) at CERN in 2012, the physics goals of the ILC include the measurements of the Higgs boson properties and its interactions, but also measurements of the top quark and searches beyond the Standard Model are part of the ILC program in the different ILC stages. [...]