A numerical study of lattice QED with dynamical fermions

Using the pseudo-fermion method U(1) lattice gauge theory with dynamical staggered fermions is studied. The plaqette energy, the chiral order parameter and the Polyakov line have been measured. With fermions of mass 0.20 and 0.25 a phase transition is observed, separating the strong coupling regime from a phase where chiral symmetry is restored.     

Study of compact QED with light fermions

We present a numerical study of compact QED including dynamical fermions of mass = 0.10 (lattice units) on a 6⁴ lattice. Staggered lattice fermions and the Wilson action and mixed gauge actions were studied. The simulations used two modified hybrid methods: one with stochastic fields and the other with deterministic ones. Working with a variable number of flavors we found that the chiral transition which separates the strong and weak coupling phases is of first order in all cases. The strength of these discontinuous transitions increase with the number of flavors.     

QCD thermodynamics with dynamical overlap fermions

We study QCD thermodynamics using two flavors of dynamical overlap fermions with quark masses corresponding to a pion mass of 350 MeV. We determine several observables on _Nt=6$N_t=6$ and 8 lattices. All our runs are performed with fixed global topology. Our results are compared with staggered ones and a nice agreement is found.     

The hadronic spectrum with dynamical fermions

Results are presented of a numerical calculation of the hadronic spectrum on a 12³×24 lattice, which incorporates the effects due to virtual quark-antiquark pairs.