Limits...
Propagators and topology.

Maas A - Eur Phys J C Part Fields (2015)

Bottom Line: The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives.However, the mid-momentum behavior is significantly affected.These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

View Article: PubMed Central - PubMed

Affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.

ABSTRACT

Two popular perspectives on the non-perturbative domain of Yang-Mills theories are either in terms of the gluons themselves or in terms of collective gluonic excitations, i.e. topological excitations. If both views are correct, then they are only two different representations of the same underlying physics. One possibility to investigate this connection is by the determination of gluon correlation functions in topological background fields, as created by the smearing of lattice configurations. This is performed here for the minimal Landau gauge gluon propagator, ghost propagator, and running coupling, both in momentum and position space for SU(2) Yang-Mills theory. The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives. However, the mid-momentum behavior is significantly affected. These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

No MeSH data available.


The ghost dressing function for different volumes at fixed lattice spacing (left panels) and different lattice spacing at fixed physical volumes (1.7 fm) (right panels) for different number of APE sweeps, being slightly smeared, moderately smeared, or strongly smeared
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Fig14: The ghost dressing function for different volumes at fixed lattice spacing (left panels) and different lattice spacing at fixed physical volumes (1.7 fm) (right panels) for different number of APE sweeps, being slightly smeared, moderately smeared, or strongly smeared

Mentions: Besides the gluon propagator, the ghost propagator plays an important role as it contributes to the infrared dynamics in Landau gauge, for both Yang–Mills theory and QCD [1, 3]. Especially, it will be important for the running coupling in the next section [2]. Before analyzing it, the first step is once more to assess the importance of lattice artifacts. The influence of both the lattice volume and the discretization for a smeared ghost dressing function is shown in Fig. 14, for the same suppression factors as in Figs. 3 and 4. In comparison to the effects on the gluon dressing function in Figs. 3 and 4, the impact for the ghost dressing function is different. The volume artifacts are very similar to the case without smearing [1]. Changing the discretization has more effect. One is on the renormalization, which is performed in Fig. 14 with the same renormalization constants as for the unsmeared case. These factors yield even for the smallest suppression no longer coinciding values. At the strongest suppression, the effect is more pronounced as it suppressed the ghost dressing function for the coarsest lattice stronger than it is on the finest lattice. Hence, the results discussed below may be bigger on a finer lattice. Also comparing the values of and , they move closer together in the far infrared with increasing smearing. Thus, the impact of smearing seems to increase with increasing lattice spacing.Fig. 14


Propagators and topology.

Maas A - Eur Phys J C Part Fields (2015)

The ghost dressing function for different volumes at fixed lattice spacing (left panels) and different lattice spacing at fixed physical volumes (1.7 fm) (right panels) for different number of APE sweeps, being slightly smeared, moderately smeared, or strongly smeared
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4376381&req=5

Fig14: The ghost dressing function for different volumes at fixed lattice spacing (left panels) and different lattice spacing at fixed physical volumes (1.7 fm) (right panels) for different number of APE sweeps, being slightly smeared, moderately smeared, or strongly smeared
Mentions: Besides the gluon propagator, the ghost propagator plays an important role as it contributes to the infrared dynamics in Landau gauge, for both Yang–Mills theory and QCD [1, 3]. Especially, it will be important for the running coupling in the next section [2]. Before analyzing it, the first step is once more to assess the importance of lattice artifacts. The influence of both the lattice volume and the discretization for a smeared ghost dressing function is shown in Fig. 14, for the same suppression factors as in Figs. 3 and 4. In comparison to the effects on the gluon dressing function in Figs. 3 and 4, the impact for the ghost dressing function is different. The volume artifacts are very similar to the case without smearing [1]. Changing the discretization has more effect. One is on the renormalization, which is performed in Fig. 14 with the same renormalization constants as for the unsmeared case. These factors yield even for the smallest suppression no longer coinciding values. At the strongest suppression, the effect is more pronounced as it suppressed the ghost dressing function for the coarsest lattice stronger than it is on the finest lattice. Hence, the results discussed below may be bigger on a finer lattice. Also comparing the values of and , they move closer together in the far infrared with increasing smearing. Thus, the impact of smearing seems to increase with increasing lattice spacing.Fig. 14

Bottom Line: The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives.However, the mid-momentum behavior is significantly affected.These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

View Article: PubMed Central - PubMed

Affiliation: Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria.

ABSTRACT

Two popular perspectives on the non-perturbative domain of Yang-Mills theories are either in terms of the gluons themselves or in terms of collective gluonic excitations, i.e. topological excitations. If both views are correct, then they are only two different representations of the same underlying physics. One possibility to investigate this connection is by the determination of gluon correlation functions in topological background fields, as created by the smearing of lattice configurations. This is performed here for the minimal Landau gauge gluon propagator, ghost propagator, and running coupling, both in momentum and position space for SU(2) Yang-Mills theory. The results show that the salient low-momentum features of the propagators are qualitatively retained under smearing at sufficiently small momenta, in agreement with an equivalence of both perspectives. However, the mid-momentum behavior is significantly affected. These results are also relevant for the construction of truncations in functional methods, as they provide hints on necessary properties to be retained in truncations.

No MeSH data available.