The effect of fluctuations of the vortex core size on the static   potentials evaluated by the thick center vortex model
  By varying the vortex core size of the thick center vortex model, we have studied the short distance potentials between static sources. It has been found that fluctuations of the vortex core size lead to Coulombic behavior. Furthermore, we discuss the influence of such fluctuations on Casimir scaling for both the Coulombic and the linear part of the potential. 
Sedigheh Deldar, Shahnoosh Rafibakhsh