New numerical results and novel effective string predictions for Wilson loops

Understand

We compute the prediction of the Nambu-Goto effective string model for a rectangular Wilson loop up to three loops.

• This is done through the use of an operatorial, first order formulation and of the open string analogues of boundary states.
• This result is interesting since there are universality theorems stating that the predictions up to three loops are common to all effective string models.
• To test the effective string prediction, we set up the Montecarlo evaluation, in the 3d Ising gauge model, of an observable (the ratio of two Wilson loops with the same perimeter) for which boundary effects are relatively small.