Monte Carlo analysis of non compact QED lattice theory with Higgs fields

We report the first results of a Monte Carlo analysis of the phase diagram of the non compact pure gauge U(1) lattice theory coupled to Higgs fields of unitary norm. We found evidence of second order transition lines in the phase space of the (β, γ) couplings, except for the large γ limit where the transition becomes of first order. We argue the existence of a tricritical point in the phase diagram. We conclude that this model exhibits a better behaviour than the usual compact QED with Higgs fields which manifest only first order transitions. © 1990.