Measurement of Quarkonium Polarization to Probe QCD at the LHC

This thesis discusses in detail the measurement of the polarizations of all S-wave vector quarkonium states in LHC proton-proton collisions with the CMS detector. Heavy quarkonium states constitute an ideal laboratory to study non-perturbative effects of quantum chromodynamics and to understand how quarks bind into hadrons. The experimental results are interpreted through an original phenomenological approach, which leads to a coherent picture of quarkonium production cross sections and polarizations within a simple model, dominated by one single color-octet production mechanism. These findings provide new insights into the dynamics of heavy quarkonium production at the LHC, an important step towards a satisfactory understanding of hadron formation within the standard model of particle physics.

Autorentext
Valentin Knünz completed his undergraduate and PhD studies at the University of Technology Vienna, performing experimental particle physics research at the Institute of High Energy Physics of the Austrian Academy of Sciences, participating in the CMS experiment at the LHC. Upon graduation he was accepted as a fellow at CERN, continuing his research within the CMS collaboration.

Inhalt
Introduction.- Quarkonium Physics.- Experimental Setup.- Data Analysis.- Discussion of Results.- Conclusions.