2018/12/18 by Tom van Daal, van Daal, Tom
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.1812.07336
PhD thesis, successfully defended at University of Groningen on December 13, 2018. Note that some figures have shifted a bit due to the fact that the original thesis format is 17 by 24 cm. This thesis has been published by the University of Groningen and can be found here in the original format: https://www.rug.nl/research/portal/files/67440087/Complete_thesis.pdf
arxiv created 2018/12/18 · openalex publication_date 2018/12/18 · arxiv updated 2018/12/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Originally it was thought that the proton is not divisible into smaller particles. However, from collision experiments it follows that it consists of a 'soup' of countless 'colored' elementary particles such as quarks and gluons that are kept together by the strong nuclear force. The particles constituting the proton are also referred to as partons and their distributions are described by parton distribution functions (PDFs). As these functions cannot be calculated, they must be extracted from experiment. More knowledge on PDFs teaches us more about the inner workings of protons and enables us to more accurately describe collisions between protons at the Large Hadron Collider (LHC). In this thesis we have studied quantities that depend on various types of PDFs. We have investigated one particular PDF called the Boer-Mulders function that describes correlations between the spin and transverse momentum of quarks inside the proton. This function gives rise to a very specific asymmetry in the directions of produced particles. In contrast to earlier expectations, we have shown that this PDF does not suffer from quantum effects related to color entanglement. Furthermore, we have introduced various new gluon PDFs that contain interesting information on the behavior of gluons. As it turns out, the description of the gluon content of particles such as protons simplifies tremendously in certain collisions at very high energies. Finally, we have derived how certain asymmetries that have been observed in collisions between protons and lead nuclei at the LHC can be related to quantum correlations between gluons.