Magnetic Strings as Part of Yang–mills Plasma

Magnetic strings are defined as infinitely thin surfaces which are closed in the vacuum and can be open on an external monopole trajectory (that is, defined by 't Hooft loop). We review briefly lattice data on the magnetic strings which refer mostly to SU(2) and SU(3) pure Yang-Mills theories and concentrate on implications of the strings for the Yang-Mills plasma. We argue that magnetic strings might be a liquid component of the Yang-Mills plasma and suggest tests of this hypothesis. 1. Generalities 1.1. Definition of magnetic strings There are two fundamental probes of Yang-Mills vacuum, Wilson and 't Hooft loops, related to the heavy-quark and heavy-monopole potentials: W ∼ exp (−V Q ¯ Q (r) T) , H ∼ exp (−V M ¯ M (r) T). (1) In the string picture, one postulates that the Wilson and 't Hooft loops are given by sums over all surfaces which can be spanned on the loops,