Speaker
Description
We consider the interaction potential between a static quark and an antiquark forming a singlet in the quenched approximation. For this purpose we work in the Landau-De-Witt gauge and exploit some properties of the Yang-Mills theory in the Landau gauge observed in Monte-Carlo simulations and previously obtained by various semi-analytical methods. In particular, the gluon propagator exhibits massive behavior with positivity violations, the ghost propagator shows a massless behavior and the coupling constant has no Landau pole and remains at moderate values even in the infrared. By means of these properties we show the existence of a solution of the equations of motion in the form of a flux tube in the case of a very distant quark-antiquark pair. The moderate value of the coupling constant allows us to obtain such a solution by a controlled semi-classical approximation which we compare successfully with Monte-Carlo simulations. This solution results in a string tension that also compares well with such simulations. For the purpose of concrete calculations we use the Curci-Ferrari model which has proven to be very efficient in reproducing the infrared behavior of the Yang-Mills theories, but the results obtained do not seem to depend on the details of the precise calculation method as long as it respects the main characteristics of the Yang-Mills correlation functions.
