2001/05/19 by A. Hasenfratz, Hasenfratz, A., F. Knechtli +1
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #hep-lat
paper · pdf · doi:10.48550/arxiv.hep-lat/0105022
21 pages, 9 figures; We have added new data to Section III. and a new analysis of the finite temperature phase diagram. We find agreement with the prediction of instanton models
arxiv created 2001/06/20 · arxiv updated 2009/11/30
We study the finite temperature phase transition of four flavor staggered fermions with hypercubic fat link actions on Nt=4 and Nt=6 temporal lattices. Our fat links are constructed with hypercubic blocking (HYP) and therefore are very compact. We present a new algorithm for simulating fermions coupled to HYP fat links. The algorithm has a simple form based on the standard overrelaxation and heatbath updatings for the pure gauge action. We observe that as we increase the smoothness of the gauge fields by changing the parameters of the blocking the very pronounced first order phase transition of the thin link action becomes weaker and moves to physically uninteresting values of the gauge coupling. With our smoothest HYP action we do not find any indication of a phase transition in the accessible temperature range on the Nt=4 or 6 lattices even at quark masses close to the physical light quark mass. We argue that the observed difference in the phase diagram is due to the improved flavor symmetry of the smeared link actions.