Deconfining phase transition on lattices with boundaries at low temperature

In lattice gauge theory (LGT) equilibrium simulations of QCD are usually performed with periodic boundary conditions (BCs). In contrast, deconfined regions created in heavy ion collisions are bordered by the confined phase. Here we discuss BCs in LGT with respect to their suitability to model a cold exterior of the lattice volume. Subsequently, we perform Monte Carlo (MC) simulations of pure SU(3) LGT with a thus inspired simple change of BCs using volumes of a size comparable to those typically encountered in the BNL relativistic heavy ion collider (RHIC) experiment. Corrections to the usual LGT results survive in the finite volume continuum limit. We estimate them as a function of the volume size for the temporal extensions N-tau=4 and 6 of the lattice and find that the results collapse to one curve when the previously established SU(3) scaling relation for the Wilson action is used. In magnitude the corrections found are comparable to those of including quarks. As observables we use a pseudocritical temperature, which rises opposite to the effect of quarks, and the width of the transition, which broadens similar to the effect of quarks.