出版社:SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要:Bosonic string formation in gauge theories is reviewed with focus on the confining flux in lattice
QCD and its string theory description. Recent results on the Casimir energy of the flux ground
state and the string excitation spectrum are analyzed in the Dirichlet string limit of large separation
between static sources. The closed string-soliton (torelon) with electric flux winding around a
compact dimension and the three-string with a Y-junction created by three static sources are also
reviewed. It is shown that string spectra from lattice simulations are consistent with universal
predictions of the leading operators from the derivative expansion of a Poincare invariant effective
string Lagrangian with reparameterization symmetry. Important characterisitics of the confining
flux, like stiffness and the related massive breather modes, are coded in operators with higher
derivatives and their determination remains a difficult challenge for lattice gauge theory.