Perturbative width of open rigid strings

We present a perturbative calculation of the energy profile width of rigid strings up to two loops in D dimensions. The perturbative expansion of the extrinsic curvature term, signifying the rigidity/smoothness of the string in Polyakov-Kleinert action, is taken around the free Nambu-Goto string. The mean-square width of the string field is derived for open strings with the Dirichlet boundary condition. We compare the broadening of the smooth Polyakov-Kleinert string to the lattice Monte Carlo data of the QCD flux tube just before the deconfinement point and find a good match at the intermediate and large color source separation.

Automated summary

In this paper, we present a perturbative calculation of the energy profile width of rigid strings up to two loops in D dimensions. We use the perturbative expansion of the extrinsic curvature term to study the rigidity/smoothness of the string in the Polyakov-Kleinert action. By deriving the mean-square width of the string field for open strings with the Dirichlet boundary condition, we compare the broadening of the smooth Polyakov-Kleinert string to lattice Monte Carlo data of the QCD flux tube, finding a good match at intermediate and large color source separation.