Universality of the topological susceptibility in the SU(3) gauge theory

Understand

The definition and computation of the topological susceptibility in non-abelian gauge theories is complicated by the presence of non-integrable short-distance singularities.

• Recently, alternative representations of the susceptibility were discovered, which are singularity-free and do not require renormalization.
• Such an expression is here studied quantitatively, using the lattice formulation of the SU(3) gauge theory and numerical simulations.
• The results confirm the expected scaling of the susceptibility with respect to the lattice spacing and they also agree, within errors, with computations of the susceptibility based on the use of a chiral lattice Dirac operator.