Partition-function zeros and the SU(3) deconfining phase transition

Using new methods to analyze Monte Carlo data, we have calculated the leading partition-function zero for Su(3) lattice gauge theory on various Lₜ{L}³$ lattices. For ${L}ₜ$=4 lattices we find in the range L=4--16 the scaling behavior of a second-order transition with {ν}=0.468(6). However, for larger lattices (L=14--24), the scaling behavior is consistent with a first-order transition: {ν}=0.35(2). The first-order nature of the transition is further substantiated by the fact that the finite-size scaling analysis of the specific heat yields a nonvanishing infinite-volume latent heat.