PUB - Publikationen an der Universität Bielefeld

This thesis investigates the chiral phase transition in Quantum Chromodynamics (QCD) with five mass degenerate quark flavors. After performing lattice QCD simulations, I discuss measurements of the chiral condensate at small masses and classify the chiral phase transition. The data analysis is done via established approaches, as well as state-of-the-art machine learning means. That way, I introduce the Masked Autoregressive Flow (MAF) and the Vision Transformer (ViT) to QCD data analysis. This approach is used to identify a critical mass marking the boundary between first-order and crossover regions. Another part of this thesis analyzes scaling functions in the 3-d, Z(2), O(2) and O(4) universality classes and their finite size dependence using Monte Carlo simulations of improved ϕ⁴ models. We extract parametrizations of the Z(2) and O(2) scaling functions to high precisions by fitting data from simulations of the respective spin models.