2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/192920We propose a method to probe the nature of phase transitions in lattice QCD at finite temperature and density, which is based on the investigation of an effective potential as a function of the average plaquette. We analyze data obtained in a simulation of two-flavor QCD using p4-improved staggered quarks with bare quark mass $m/T = 0.4$, and find that a first order phase transition line appears in the high density regime for $μ_q/T \simge 2.5$. We also discuss the difference between the phase structures of QCD with non-zero quark chemical potential and non-zero isospin chemical potential.17 pages, 9 figuresHigh Energy Physics - LatticeHigh Energy Physics - Phenomenologytext