Ph.D. Theses

In the last twenty years, a variety of unexpected resonances had been observed within thecharmonium mass region. Although the existence of unconventional states has been predictedby the quantum chromodynamics (QCD), a quantum field theory describing the strong force,a clear evidence was missing. [...]

The study of strongly interacting matter under extreme conditions in terms of temperature and pressure has moved more and more in the focus of high energy physics over the last decades. These conditions can be created in the collision of heavy-ions at various facilities around the world, together covering a broad range of collision energies starting in the GeV region and ranging up to energies of several TeV. [...]

Die Entstehung der Elemente im Universum wird auf eine Vielzahl von Prozessen zurückgeführt, die sowohl in Urknall - als auch in stellaren Szenarien angesiedelt werden. Die Kenntnis der dort ablaufenden Reaktionen und deren Raten ermöglicht es die zugrundeliegenden Modelle einzugrenzen und somit genauere Aussagen über die Plausibilität der Szenarien zu treffen. [...]

The main subject of this thesis is the study of hadron and photon production in relativistic heavy-ion collisions by means of hydrodynamics+transport approaches. Two different kinds of such hybrid approaches are employed in this work, the SMASH-vHLLE-hybrid and a MUSIC+SMASH hybrid. [...]

Sensors for high rate charge particle tracking have to withstand the harsh radiation doses deposited by the particles to be sensed. This holds particularly for the novel CMOS Monolithic Active Pixel Sensors, which are considered a promising sensor technology for future vertex detectors due to their very light material budget and excellent spatial resolution. [...]

The relevant field of interest in High Energy Physics experiments is shifting to searching and studying extremely rare particles and phenomena. The search for rare probes requires an increase in the number of available statistics by increasing the particle interaction rate. [...]

Das Feld der Hochenergie-Schwerionenforschung hat sich der Untersuchung des Quark-Gluon-Plasmas (QGP) gewidmet. Ein QGP ist ein sehr heißer und dichter Materiezustand, der kurz nach dem Urknall für einige Mikrosekunden das Universum füllte. [...]

Das Projekt anan ist ein Werkzeug zur Fehlersuche in verteilten Hochleistungsrechnern. Die Neuheit des Beitrags besteht darin, dass die bekannten Methoden, die bereits erfolgreich zum Debuggen von Soft- und Hardware eingesetzt werden, auf Hochleistungs-Rechnen übertragen worden sind. [...]

The multipass regenerative multibunch beam breakup instability is specific to recirculating linacs (linear accelerators) and energy recovery linacs operating in continuous wave mode where particle bunches pass multiple times through the same superconducting RF cavities with extremely high quality factor. Parasitic electromagnetic modes excited in the cavities can affect bunch dynamics in such a way, that on its subsequent passes it excites the modes further and a positive feedback loop is formed. [...]