The DePFET is a sensor amplifier structure first proposed in 1987. In recent years, DeFPET
based sensors have been deployed for particle tracking at Belle II experiment and been …

The world of photon science experiences significant advancements since the advent of
synchrotron light sources with unprecedented brilliance, intensity and pulse repetition rates …

We report the successful operation of a functional pixel detector with gaseous helium
cooling. Using an accurate mock-up beforehand, the cooling was validated. We use a …

We perform the first search for $ C\! P $ violation in ${D_ {(s)}^{+}\to {} K_ {S}^{0} K^{-
}\pi^{+}\pi^{+}} $ decays. We use a combined data set from the Belle and Belle II …

Present and future high-energy physics experiments pose challenging demands on the
detector systems and analysis methods. This dissertation addresses both aspects by …

Charged particle tracking has played a key role in the development of particle physics,
particularly for understanding phenomena involving short-lived particles precisely. As a …

Phenomena such as dark matter can be connected to the standard model via additional spin-
0 mediators. This doctoral thesis describes a search for a long-lived spin-0 particle S in rare …

Flavour physics offers some of the most promising hints of physics beyond the Standard
Model (BSM). Precision measurements in the last decade have shown significant deviations …

This thesis presents two searches for the rare B→ K (∗) νν decays at the Belle II experiment,
operating at the SuperKEKB asymmetric-energy electron-positron collider, at the KEK …

The Belle II experiment aims to study the standard model (SM) of particle physics and to
search for new physics (NP) beyond the standard model with unprecedented precision. This …