θ dependence in SU(3) Yang-Mills theory from analytic continuation

الأصل · EN

We investigate the topological properties of the SU(3) pure gauge theory by performing numerical simulations at imaginary values of the θ parameter. By monitoring the dependence of various cumulants of the topological charge distribution on the imaginary part of θ and exploiting analytic continuation, we determine the free energy density up to the sixth order order in θ, f(θ,T) = f(0,T) + 1 2 χ(T) θ² (1 + b₂(T) θ² + b₄(T) θ⁴ + O(θ⁶)). That permits us to achieve determinations with improved accuracy, in particular for the higher order terms, with control over the continuum and the infinite volume extrapolations. We obtain b₂=-0.0216(15) and |b₄| 4× 10⁻⁴.