Lattice-motivated holomorphic nearly perturbative QCD

Ayala, César; Cvetič, Gorazd; Kögerler, Reinhart

doi:10.1088/1361-6471/aa6fdf

Cited by 19 publications

(60 citation statements)

References 178 publications

(355 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This property was noted earlier, for different observables, in Refs. [24,25,71]. In this context, it appears to be important that in 2δ and 3δ AQCD the coupling practically merges with the underlying pQCD coupling a(Q 2 ) at higher values of Q 2 Λ 2 QCD .…”

Section: Discussionmentioning

confidence: 95%

“…This type of QCD variants [22,24,25] with coupling A(Q 2 ) holomorphic in Q 2 ∈ C\(−∞, −M 2 thr ] are constructed on the idea that: (a) the coupling A(Q 2 ) at high |Q 2 | > 1 GeV 2 should practically coincide with the underlying pQCD 13 coupling a(Q 2 ); (b) and at moderate and low |Q 2 | 1GeV 2 the coupling should reproduce the well measured semihadronic τ -lepton decay physics and possibly some other experimental indicators. We note that (F)APT does not fulfill these requirements.…”

Section: δ and 3δ Aqcdmentioning

confidence: 99%

“…In this work we fit the theoretical OPE expressions to the experimental BSR results in pQCD, in (F)APT, and two additional extensions of QCD to low Q 2 , namely the 2δ [22,23] and 3δ [24,25] AQCD. The latter two extensions have the coupling A(Q 2 ) [the analog of the pQCD coupling a(Q 2 )] which is free of Landau singularities and physically motivated in the entire relevant regime of Q 2 in the complex plane, Q 2 ∈ C\(−∞, −M 2 thr ], where M 2 thr 1 GeV 2 is a positive threshold scale.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Bjorken polarized sum rule and infrared-safe QCD couplings

et al. 2018

Self Cite

View full text Add to dashboard Cite

Experimental data obtained for the polarized Bjorken sum rule (BSR) Γ p−n 1 (Q 2 ) are fitted by using predictions derived within a truncated operator product expansion (OPE) approach to QCD. Four QCD versions are considered: perturbative QCD (pQCD) in the MS scheme, Analytic Perturbation Theory (APT), and 2δ and 3δ analytic QCD versions. In contrast to pQCD, these QCD variants do not have Landau singularities at low positive Q 2 , which facilitates the fitting procedure significantly. The fitting procedure is applied first to the experimental data of the inelastic part of BSR, and the known elastic contributions are added after the fitting. In general, when 2δ and 3δ QCD coupling is used the fitted curves give the best results, within the Q 2 -range of the fit as well as in extended Q 2intervals. When the fitting procedure is applied to the total BSR, i.e., to the sum of the experimental data and the elastic contribution, the quality of the results deteriorates significantly.

show abstract

Section: Discussionmentioning

confidence: 95%

Section: δ and 3δ Aqcdmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bjorken polarized sum rule and infrared-safe QCD couplings

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…[70]. It is widely used in different QCDoriented studies [49,[93][94][95][96][97][98][99][100]. In this section we will use this mMOM-scheme in the SU(N c ) theory to find out the constraints imposed by its gauge-dependence on the conditions of existence of the fundamental property of the β-function factorization in the GCR.…”

Section: The Qed Generalized Crewther Relation In the Ms Mom And Os mentioning

confidence: 99%

Renormalization scheme and gauge (in)dependence of the generalized Crewther relation: what are the real grounds of the β-factorization property?

Garkusha

Kataev

Molokoedov

2018

J. High Energ. Phys.

View full text Add to dashboard Cite

The problem of scheme and gauge dependence of the factorization property of the renormalization group β-function in the SU(N c ) QCD generalized Crewther relation (GCR), which connects the flavor non-singlet contributions to the Adler and Bjorken polarized sum rule functions, is investigated at the O(a 4 s ) level of perturbation theory. It is known that in the gauge-invariant renormalization MS-scheme this property holds in the QCD GCR at least at this order. To study whether this factorization property is true in all gauge-invariant schemes, we consider the MS-like schemes in QCD and the QED-limit of the GCR in the MS-scheme and in two other gauge-independent subtraction schemes, namely in the momentum MOM and the on-shell OS schemes. In these schemes we confirm the existence of the β-function factorization in the QCD and QED variants of the GCR. The problem of the possible β-factorization in the gauge-dependent renormalization schemes in QCD is studied. To investigate this problem we consider the gauge non-invariant mMOM and MOMgggg-schemes. We demonstrate that in the mMOM scheme at the O(a 3 s ) level the β-factorization is valid for three values of the gauge parameter ξ only, namely for ξ = −3, −1 and ξ = 0. In the O(a 4 s ) order of PT it remains valid only for case of the Landau gauge ξ = 0. The consideration of these two gauge-dependent schemes for the QCD GCR allows us to conclude that the factorization of RG β-function will always be implemented in any MOM-like renormalization schemes with linear covariant gauge at ξ = 0 and ξ = −3 at the O(a 3 s ) approximation. It is demonstrated that if factorization property for the MS-like 1 Affiliation from 2011 till 2015.Open Access, c The Authors. Article funded by SCOAP 3 .https://doi.org/10.1007/JHEP02(2018)161 JHEP02(2018)161schemes is true in all orders of PT, as theoretically indicated in the several works on the subject, then the factorization will also occur in the arbitrary MOM-like scheme in the Landau gauge in all orders of perturbation theory as well.

show abstract

“…(20) can be found in, e.g., Refs. [38][39][40][41] and [42,43]. 5 Note that the "timelike" effective couplant a…”

Section: Various Ways To Handle R(s)mentioning

confidence: 99%

Explicit form of the R-ratio of electron–positron annihilation into hadrons

Нестеренко

2019

J. Phys. G: Nucl. Part. Phys.

View full text Add to dashboard Cite

The explicit expression for the R-ratio of electron-positron annihilation into hadrons, which properly accounts for all the effects due to continuation of the spacelike perturbative results into the timelike domain, is obtained at an arbitrary loop level. Several equivalent ways to derive a commonly employed approximation of the R-ratio are recapped and the impact of discarded in the latter higher-order π 2 -terms on the evaluation of the strong running coupling is elucidated. The obtained results substantially facilitate the theoretical study of electron-positron annihilation into hadrons and the related strong interaction processes.

show abstract

Lattice-motivated holomorphic nearly perturbative QCD

Cited by 19 publications

References 178 publications

Bjorken polarized sum rule and infrared-safe QCD couplings

Bjorken polarized sum rule and infrared-safe QCD couplings

Renormalization scheme and gauge (in)dependence of the generalized Crewther relation: what are the real grounds of the β-factorization property?

Explicit form of the R-ratio of electron–positron annihilation into hadrons

Contact Info

Product

Resources

About