Casimir scaling inG2lattice gauge theory

Abstract

We computed potentials between static color sources from the six lowest representations of ${\mathrm{G}}_{2}$ lattice gauge theory, in numerical simulations with the Wilson action on asymmetric lattices with nonperturbatively estimated values of the bare anisotropy. We present evidence for (approximate) Casimir scaling of the obtained intermediate string tensions. The agreement with the Casimir-scaling prediction improves by increasing the coupling $\ensuremath{\beta}$ in the weak-coupling region above the crossover observed in ${\mathrm{G}}_{2}$ gauge theory. The result naturally fits into confinement models with magnetic disorder and vacuum domain structure, but may represent a challenge for other approaches.