Gauge-invariant nonlocal quark condensates in QCD

We study, by numerical simulations on a lattice, the behaviour of the gauge-invariant nonlocal quark condensates in the QCD vacuum both in the quenched approximation and with four flavours of dynamical staggered fermions. The correlation length of the condensate is determined to be roughly twice as big as in the case of the gluon field strength correlators.Comment: LATTICE98(confine

A Strategy to Study Confinement in QCD

The order and the universality class of the deconfining phase transition can provide insight into the mechanism of color confinement, in particular for N_f=2. The mechanism of confinement by monopole condensation is reviewed.Comment: Presented at IRQCD '06 UERJ Rio de Janeiro (Brasil) 5-9 June 2006. 6 pages, 3 figure

Confinement of Color: Recent Progress

Recent progress done in Pisa on the subject is presented. It is shown that dual superconductivity of the vacuum or absence of it is an intrinsic property of QCD vacuum, independent of the choice of the abelian projection. The order of the deconfining phase transition in $N_f=2$ QCD is studied as a key to understand the mechanism of confinement.Comment: Talk at Confinement 2003, Tokyo, july 2003, to appear in the proceedings. 10 pages, 2 figure