- deconfined interface tension , wetting , and the spectrum of the transfer matrix

The reduced tension σ cd of the interface between the confined and the deconfined phase of SU (3) pure gauge theory is determined from numerical simulations of the first transfer matrix eigenvalues. At Tc = 1/Lt we find σ cd = 0.139(4)T 2 c for Lt = 2. The interfaces show universal behavior because the deconfined-deconfined interfaces are completely wet by the confined phase. The critical exponents of complete wetting follow from the analytic interface solutions of a Z Z(3)-symmetric Φ 4 model in three dimensions. We find numerical evidence that the confined-deconfined interface is rough. The tension of the interface between the low temperature hadron phase and the high temperature quark-gluon plasma phase is an important parameter of the QCD phase transition. In the early universe the interface tension determines the nucleation rate of hadronic bubbles from the high temperature plasma. Thus, it sets the scale for spatial inhomogeneities in the baryon density, which may influence the primordial nucleosynthe-sis of light elements. To obtain an estimate for the interface tension in QCD we neglect the quarks and we concentrate on an SU (3) pure glue theory. Then the phase transition is first order, i.e. the confined and the deconfined phase coexist at the critical temperature T c , and the interface tension is nonzero. It is convenient to define the reduced interface tension σ cd = F AT c , (1) where F is the free energy of the interface and A is its area. In the pure glue theory the deconfinement phase transition is associated with the spontaneous breakdown of the Z Z(3) center symmetry. Hence, as opposed to full QCD, there * Speaker at the conference, supported by Schweizer Nationalfond are three distinct high temperature phases, which coexist at temperatures T > T c. Two different deconfined phases are separated by deconfined-deconfined interfaces with a reduced interface tension σ dd (T). At T c all four phases (three deconfined and one confined) coexist with each other. Thermodynamical stability requires σ dd (T c) ≤ 2σ cd. Frei and Patkós [1] have suggested that σ dd (T c) = 2σ cd. (2) Then a deconfined-deconfined interface consists of two confined-deconfined interfaces with a macro-scopic layer of confined phase in between. One says that the deconfined-deconfined interfaces are completely wet by the confined phase. Complete wetting is a critical phenomenon of interfaces (hence T c is really a critical …