Nuclear Physics Colloquium

Venue: Physics Building, Max-von-Laue-Str. 1, Seminar Room PHYS 2.116
Time: Thursday, July 07, 4:30 pm (s.t.)
Contact: hees@fias.uni-frankfurt.de

Phase diagram of an asymptotically free model through lattice dualization

Falk Bruckmann (University Regensburg)

The 2d O(3) $\sigma$ model shares asymptotic freedom, mass generation and other nonperturbative features with 4d QCD. Likewise, a sign problem at nonzero chemical potential hampers numerical simulations of its thermodynamics. I demonstrate how mapping the corresponding lattice fields to dual degrees of freedom solves the sign problem. At small volume and temperatures this can be used to extract the phase shifts governing the particles' interaction. Moreover, I discuss the phase diagram of this model including a quantum phase transition and a comparison to a solvable model.