Speaker
Description
The Casimir energy and profile of the QCD flux-tube are discussed within the framework of Lüscher-Weisz (LW) string action with two boundary terms. We perform our numerical simulations on the 4-dim pure SU(3) Yang-Mills lattice gauge theory at finite temperature. The static quark-antiquark ($Q\bar{Q}$) potential is calculated using link-integrated Polyakov loop correlators. In general, we detect signatures of the two boundary terms of the string action. Near the QCD Plateau, the L\"uscher-Weisz string is yielding a static potential which is in a good agreement with the lattice data for source separations $R \ge 0.3$ fm. At higher temperature, near to the deconfinement point $T/T_{c}=0.9$, the fits to the potential data improve compared to the pure Nambu-Goto string. Good match with the numerical data are retrieved at color source separation $R > 0.6$ fm; however, deviations from the string tension $\sigma_{0} a^{2}$ parameter persist. The mean-square width of the energy profile at $T/T_{c}=0.9$ is well fitted to the width of the L\"uscher-Weisz string at leading or next-to-leading order over distance scales $R \ge 0.5$ fm provided considering either two or one boundary term corrections for each order, respectively.
