2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/183861We present results on lattice QCD at finite temperature (T) and chemical potential (μ). We apply the overlap-improving multi-parameter reweighting technique for n_f=4 and 2+1 staggered QCD. We use semi-realistic masses on L_t=4 lattices. The critical endpoint (E) of 2+1 flavour QCD on the μ-T plane is located. Our results are based on {\cal{O}}(10^3-10^4) configurations.7 pages, 4 figures, talk given at Finite Density QCD at Nara, Nara, Japan, 10-12 July 2003High Energy Physics - Latticetext