Books

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%. [...]

Plasma wakefields are a promising approach for the acceleration of electrons with ultrahigh (10 to 100 GV/m) electric fields. Nowadays, high-intensity laser pulses are routinely utilized to excite these large-amplitude plasma waves. [...]

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. [...]

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 addresses the measurements and phenomenology of the azimuthal separation ∆φ12 between the jets with the largest transverse momenta (pT) in multi-jet event topolo-gies. The measurements are based on proton-proton collision data at the center-of-massenergy of 13 TeV recorded by the Compact Muon Solenoid (CMS) experiment in 2016, and correspond to an integrated luminosity of35.9fb−1. [...]

This thesis presents the measurement of 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 . The W^± bosons arereconstructed by the presence of a muon and a neutrino, with the latter indicated by the missing transverse momentum in an event. [...]

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. [...]

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 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 [...]