Spectral functions of confined particles

Binosi, Daniele; Tripolt, Ralf-Arno

doi:10.1016/j.physletb.2019.135171

Cited by 125 publications

(138 citation statements)

References 87 publications

Supporting

Mentioning

134

Contrasting

Order By: Relevance

“…Evidently, the large-x exponent is β(ζ 5 ) = 2.66 (12) . Working with results obtained in an exploratory lQCD calculation [33], one finds β lQCD (ζ 5 ) = 2.45 (58); and also the following comparison between low-order moments:…”

Section: Evolution Of Pion Distribution Functions -The Pionmentioning

confidence: 92%

Drawing insights from pion parton distributions *

et al. 2020

Self Cite

View full text Add to dashboard Cite

A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition form factors. The analysis reveals the following momentum fractions at the scale ζ2 := 2 GeV: x valence = 0.48(3), x glue = 0.41(2), xsea = 0.11(2); and despite hardening induced by the emergent phenomenon of dynamical chiral symmetry breaking, the valence-quark distribution function, q π (x), exhibits the x 1 behaviour predicted by quantum chromodynamics (QCD). After evolution to ζ = 5.2 GeV, the prediction for q π (x) matches that obtained using lattice-regularised QCD. This confluence should both stimulate improved analyses of existing data and aid in planning efforts to obtain new data on the pion distribution functions.

show abstract

Section: Evolution Of Pion Distribution Functions -The Pionmentioning

confidence: 92%

Drawing insights from pion parton distributions *

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…We therefore persist with a straightforward RL truncation, computing all form factors on the accessible domain and then extrapolating to larger Q 2 -values using the Schlessinger point method (SPM), whose properties and accuracy are explained elsewhere [38,[97][98][99][100][101]. We note only that the SPM is based on the Padé approximant.…”

Section: B Focus: Electric Form Factormentioning

confidence: 99%

Elastic electromagnetic form factors of vector mesons

Binosi

Cui

et al. 2019

Phys. Rev. D

View full text Add to dashboard Cite

A symmetry-preserving approach to the two valence-body continuum bound-state problem is used to calculate the elastic electromagnetic form factors of the ρ-meson and subsequently to study the evolution of vector-meson form factors with current-quark mass. To facilitate a range of additional comparisons, K * form factors are also computed. The analysis reveals that: vector mesons are larger than pseudoscalar mesons; composite vector mesons are non-spherical, with magnetic and quadrupole moments that deviate ∼ 30% from point-particle values; in many ways, vector-meson properties are as much influenced by emergent mass as those of pseudoscalars; and vector meson electric form factors possess a zero at spacelike momentum transfer. Qualitative similarities between the electric form factors of the ρ and the proton, G p E , are used to argue that the character of emergent mass in the Standard Model can force a zero in G p E . Morover, the existence of a zero in vector meson electric form factors entails that a single-pole vector meson dominance model can only be of limited use in estimating properties of off-shell vector mesons, providing poor guidance for systems in which the Higgs-mechanism of mass generation is dominant. *

show abstract

“…The gluon propagator obtained by solving the truncated Dyson-Schwinger equation on the complex momentum plane in pure Yang-Mills theory is shown to have no complex poles [43]. A recent reconstruction technique indicates complex poles in the gluon propagator [42]. Pursuing the rich analytic structure of the QCD propagators deserves further investigations because QFT describing confined particles is not yet well understood.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

“…Considerable efforts have been devoted to reconstructing the spectral functions from the Euclidean data based on the Källén-Lehmann spectral representation, e.g., [31,32]. On the other hand, several models of Yang-Mills theory [14,[33][34][35][36][37][38][39], including the (pure) massive Yang-Mills model [40,41], and a way of the reconstruction from the Euclidean data [42] predict complex poles in the gluon propagator that invalidate the Källén-Lehmann spectral representation. The existence of complex poles of the propagators of the confined particles is a controversial issue, e.g., [43].…”

Section: Introductionmentioning

confidence: 99%

Complex poles and spectral functions of Landau gauge QCD and QCD-like theories

Hayashi

Kondo

2020

Phys. Rev. D

View full text Add to dashboard Cite

In view of the expectation that the existence of complex poles is a signal of confinement, we investigate the analytic structure of gluon, quark, and ghost propagators in the Landau gauge QCD and QCD-like theories by employing an effective model of Yang-Mills theory with a gluon mass term, which we call the massive Yang-Mills model. In this model, we particularly investigate the number of complex poles in the parameter space of the model consisting of gauge coupling constant, gluon mass, and quark mass for the gauge group SU (3) and various numbers of quark flavors NF within the asymptotic free region. This investigation extends the previous result obtained for the pure Yang-Mills theory with no flavor of quarks NF = 0 that the gluon propagator has a pair of complex conjugate poles and the negative spectral function while the ghost propagator has no complex pole. The gluon and quark propagators at the best-fit parameters for NF = 2 QCD have one pair of complex conjugate poles as in the zero flavor case. By increasing quark flavors, we find a new region in which the gluon propagator has two pairs of complex conjugate poles for light quarks with the intermediate number of flavors 4 N f < 10. However, the gluon propagator has no complex poles if very light quarks have many flavors N f ≥ 10 or both of the gauge coupling and quark mass are small. In the other regions, the gluon propagator has one pair of complex conjugate poles. Moreover, as a general feature, we argue that the gluon spectral function of this model with nonzero quark mass is negative in the infrared limit. In sharp contrast to gluons, the quark and ghost propagators are insensitive to the number of quark flavors within the current approximations adopted in this paper. These results suggest that details of the confinement mechanism may depend on the number of quark flavors and quark mass.

show abstract

Spectral functions of confined particles

Cited by 125 publications

References 87 publications

Drawing insights from pion parton distributions *

Drawing insights from pion parton distributions *

Elastic electromagnetic form factors of vector mesons

Complex poles and spectral functions of Landau gauge QCD and QCD-like theories

Contact Info

Product

Resources

About