title: Change of θ dependence in 4D SU(N) gauge theories across the deconfinement transition.
abstract: We study the dependence of 4D SU(N) gauge theories on the topological θ term at finite temperature T. We exploit the lattice formulation of the theory, presenting numerical results for the expansion of the free energy up to O(θ6), for N=3 and N=6. Our analysis shows that the θ dependence drastically changes across the deconfinement transition: the low-T phase is characterized by a large-N scaling with θ/N as relevant variable, while in the high-T phase the scaling variable is just θ and the free energy is essentially determined by the instanton-gas approximation.
authors.affiliation: Dipartimento Fisica dell'Università di Pisa and INFN, Largo Pontecorvo 3, I-56127 Pisa, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bonati
authors.forename: Massimo
authors.initials: M
authors.lastname: D'Elia
authors.forename: Haralambos
authors.initials: H
authors.lastname: Panagopoulos
authors.forename: Ettore
authors.initials: E
authors.lastname: Vicari