Quark propagator

The overlapping of the quark zero-modes provides the propagation of the quarks by jumping from one instanton to another one. So, Diow was reduced to the determinant of the finite matrix in the space of... 

A- Also we define quark propagator in the field of single instanton A and external fields V ... 

Then, the quark propagator S can be expanded with respect to a single instanton ... 

The main assumption of previous works (D. Diakonov et.al., 1986 D.I. Diakonov et.al., 1996) (see also review (T. Schafer et.al., 1998)) was that at very small m the quark propagator in the single instanton field A may t>e approximated as ... 

Pobylitsa, P. Quarks in the instanton vacuuml. Quark propagator. Phys.Lett. B, 226 387, 1989 LINP, preprint 1598, 1990. 

We see indeed that in HDET the quarks near the Fermi surface or ip+ modes are the propagating modes, while ip- are not. 

Recently, the possible formation of diquark condensates in QCD at finite density has been re-investigated in a series of papers following Refs. [1, 2], It has been shown that in chiral quark models with nonperturbatrive 4-point interaction motivated from instantons [3] or nonperturbative gluon propagators [4, 5], the anomalous quark pair amplitudes can be very large - of the order of 100 MeV. The diquark pairs that are formed as a result of the attractive inter-... 

One might think that the electroweak theory can explain the baryon asymmetry. The 3rd out-of-equilibrium condition is met if the electroweak phase transition is of strongly 1st order. In this case the phase transition proceeds via bubble formation of the broken electroweak phase. Quarks propagating across the bubble wall may be reflected back, thereby producing the baryon asymmetry [17]. 

We have not done so for the following reason. The introduction of the new level of elementarity , the quarks and gluons, beyond the level of mesons and baryons, is, we believe, of a fundamentally new kind, both physically and philosophically in the modern history of science. For in all previous cases the ultimate proof of the existence of a hypothesized constituent was to produce and identify that constituent in the laboratory, for example, via a track in a bubble-chamber or, where a neutral particle was involved, like the A°, to have very obvious and incontrovertible evidence of its propagation and decay into charged tracks. 

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