Confinement of quarks and valence gluons in SU(N) Yang-Mills-Higgs models

Abstract

In this work, we analyze a class of Yang-Mills models containing adjoint Higgs fields, with SU (N ) symmetry spontaneously broken down to Z(N ), showing they contain center vortices, Y-junctions formed by them, and junctions where different center vortices are smoothly interpolated by monopole-like configurations. In the context of dual superconductors, these objects represent different states of the gluon field. Center vortices confine quarks to form normal hadron states. The interpolating monopole, which in our model cannot exist as an isolated configuration, is identified with a confined valence gluon. A junction containing a monopole can bind quarks in a color nonsinglet state to form an overall neutral object, identified with a hybrid hadron. These states, formed by quarks bound to a valence gluon, are allowed by QCD, and current experimental collaborations are aimed at identifying them. Finally, considering the general version of the model, based on a compact simple gauge group G, the picture is completed with a heuristic discussion about why it would be natural using as G the dual of the chromoelectric gauge group G e , and external pointlike monopoles to represent the mesonic and baryonic Wilson loops.

4D ensembles of percolating center vortices and monopole defects: The emergence of flux tubes withN-ality and gluon confinement

“…The simplest case corresponds to the fundamental representation ⃗w ¼ ⃗w i , i ¼ 1; …; N [44], which will be considered from now on. In chains, pairs of center vortex branches are matched by monopoles [16,52,57]. In this case, we can writeS…”

“…In that case, the difference is that the effective description (52), which includes the normal phase, can be derived from the microscopic one [70]. …”

“…Therefore, in the presence of the source 2πs μν ⃗ β e · ⃗ T, a flux tube with N-ality is induced. These models are also well known to possess flux tube solutions with confined dual monopoles [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56]. In particular, as the distance between a pair of adjoint quarks is increased, the saddle point will eventually favor string-breaking by screening the external sources with induced dual monopoles, which get identified with valence gluons.…”

“…[51]. A color-flavor locking phase could also be present in SUðNÞ YMH models with N 2 − 1 (real) adjoint Higgs fields [52][53][54]. Confined dual monopoles were interpreted as gluons in Refs.…”

“…The relation between four-dimensional ensembles of monopoles that carry adjoint charges and models based on a set of adjoint Higgs fields was suggested in Ref. [52]. This idea was further elaborated in Ref.…”