arXiv subjects

A. L. Kataev

Publications and source records attributed to A. L. Kataev.

At least 19 recordsLinked to original sources

arXiv2026

Perturbative QCD fitting of KEDR and BESIII $e^+e^-$ data for R(s) and $α_s$ determination

The experimental data collected by KEDR and BESIII collaborations at the energies below charm quark thresholds are compared with the massless QCD expressions for the $e^+e^-$ annihilation R-ratio truncated at different orders of perturbation theory. The fits demonstrate the dependence of the extracted $α_s(M_Z)$ values on the orders of truncation of the corresponding approximations. The next-to-leading order, next-to-next-to-leading order and next-to-next-to-next-to-leading order fits of the combined KEDR data and BESIII data , truncated at the scale of mass of $J/Ψ$ meson, give the following results $α_s(M_Z)=0.1151_{-0.0069}^{+0.0052}$, $α_s(M_Z)=0.1190_{-0.0081}^{+0.0064}$and $α_s(M_Z)=0.1283_{-0.0075}^{+0.0028}$. The increasing tendency of fitted $α_s(M_Z)$ value is associated with the effects of not totally controlled within asymptotic perturbation theory expansions kinematical $π^2$ contributions to R-ratio coefficients due to analytical continuation from the space-like to time-like energy regions. The applications of the fixed orders of perturbation theory expansions and careful treatment of the analytical continuation effects are commented.

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arXiv2026

On the link between finite QFT and standard RG approaches

A finite formulation of quantum field theory based on a system of differential equations reminiscent of the Callan-Symanzik equations is discussed. This system of equations was previously formulated in the bare language. We rederive it in a fully renormalized language. For the latter, within a simple $ϕ^4$ toy model, it is shown that with a specific choice of renormalization conditions - namely, the on-shell scheme for the renormalized mass - this class of finite renormalization prescriptions is equivalent to the standard renormalization-group equation written in the Callan-Symanzik-Ovsyannikov form.

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arXiv2025

Exact relations between running of $α_s$ and $α$ in ${\cal N}=1$ SQCD+SQED

In ${\cal N}=1$ supersymmetric QCD-like theories we derive the (all-order) exact equations relating the renormalization group behaviour of the strong and electromagnetic couplings and prove that they are valid in the HD+MSL renormalization prescription. In particular, the $β$-function of ${\cal N}=1$ SQCD can be expressed in terms of the Adler $D$-function. If all favors have the same absolute value of the electromagnetic charges, it is also possible to write a simple relation between the $β$-functions for the strong and electromagnetic coupling constants. In this particular case there is a special renormalization group invariant relation.

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arXiv2023

The decomposed photon anomalous dimension in QCD and the $\{β\}$-expanded representations for the Adler function

This work is devoted to the study of the $\{β\}$-expansion of the perturbative expressions for the $e^+e^-$ annihilation Adler function $D(Q^2)$ and for the related renormalization group functions, namely for the photon vacuum polarization function and its anomalous dimension $γ(α_s)$ in QCD at the $\mathcal{O}(α^4_s)$ order. We emphasize that $γ(α_s)$ is not a conformal-invariant contribution to $D(Q^2)$ and, therefore, for a consistent analysis it is necessary to decompose its higher-order PT coefficients in powers of the $β$-function coefficients in the same way as for the Adler function. The arguments in favor of this statement are given. The comparison of the $\overline{MS}$ and PMC/BLM approximants are demonstrated.Theoretical and phenomenologically related consequences of this comparison are briefly commented.

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arXiv2023

The generalized Crewther relation and V-scheme: analytic $O(α^4_s)$ results in QCD and QED

Using the analytical $\rm{\overline{MS}}$-scheme three-loop contribution to the perturbative Coulomb-like part of the static color potential of heavy quark-antiquark system, we obtain the analytical expression for the fourth-order $β$-function in the gauge-invariant effective V-scheme in the case of the generic simple gauge group. Also we present the Adler function of electron-positron annihilation into hadrons and the coefficient function of the Bjorken polarized sum rule in the V-scheme up to $α^4_s$ terms. We demonstrate that at this level of PT in this effective scheme the $β$-function is factorized in the conformal symmetry breaking term of the generalized Crewther relation, which connects the flavor non-singlet contributions to the Adler and Bjorken polarized sum rule functions. We prove why this relation will be true in other gauge-invariant renormalization schemes as well. The obtained results enable to reveal the difference between the V-scheme $β$-function in QED and the Gell-Man--Low $Ψ$-function. This distinction arises due to the presence of the light-by-light type scattering corrections first appearing in the static potential at the three-loop level.

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arXiv2022

Representation of the RG-invariant quantities in perturbative QCD through powers of the conformal anomaly

In this work we consider the possibility of representing the perturbative series for renormalization group invariant quantities in QCD in the form of their decomposition in powers of the conformal anomaly $β(α_s)/α_s$ in the ${\rm{\overline{MS}}}$-scheme. We remind that such expansion is possible for the Adler function of the process of $e^+e^-$ annihilation into hadrons and the coefficient function of the Bjorken polarized sum rule for the deep-inelastic electron-nucleon scattering, which are both related by the Crewther-Broadhurst-Kataev relation. In addition, we study the discussed decomposition for the static quark-antiquark Coulomb-like potential, its relation with the quantity defined by the cusp anomalous dimension and the coefficient function of the Bjorken unpolarized sum rule of neutrino-nucleon scattering. In conclusion we also present the formal results of applying this approach to the non-renormalization invariant ratio between the pole and ${\rm{\overline{MS}}}$-scheme running mass of heavy quark in QCD and compare them with those already known in the literature. The arguments in favor of the validity of the considered representation in powers of $β(α_s)/α_s$ for all mentioned perturbative quantities are discussed.

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arXiv2022

Notes on interplay of the QCD and EW perturbative corrections to the pole-running top-quark mass ratio

A specific representation of the known one-loop EW correction to the relation between the pole and running $\msbar$-scheme masses of the top-quark through particle masses of the Standard Model is given within the Fleischer-Jegerlehner tadpole scheme, where the vacuum expectation value of the Higgs field is renormalized. The importance of taking into account both the EW and QCD effects in this relation in the considered case is emphasized. It is noted that the discard of the EW corrections leads to over $10\;{\rm{GeV}}$ shift in the difference between the pole and running $t$-quark masses. This magnitude exceeds essentially the modern uncertainties of the considered relation, following from the treatment of the Tevatron and LHC data where both pole and running $t$-quark masses are defined in the widespread approach when only the QCD corrections are kept in mind between them.

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arXiv2022

The ${\rm{\bar{MS}}}$-scheme $α_s^5$ QCD contributions to the Adler function and Bjorken polarized sum rule in the Crewther-type two-fold $\{β\}$-expanded representation

We consider the two-fold expansion in powers of the conformal anomaly and of the strong coupling $α_s$ for the non-singlet contributions to Adler $D$-function and Bjorken polarized sum rule calculated previously in the $\MSbar$-scheme at the four-loop level. This representation provides relations between definite terms of different loop orders appearing within the $\{β\}$-expansion of these quantities. Supposing the validity of this two-fold representation at the five-loop order and using these relations, we obtain some $\mathcal{O}(α_s^5)$ corrections to the $D$-function, to the $R$-ratio of $e^+e^-$-annihilation into hadrons and to Bjorken polarized sum rule. These corrections are presented both analytically in the case of the generic simple gauge group and numerically for the $SU(3)$ color group. The arguments in the favor of validity of the two-fold representation are given at least at the four-loop level. Within the $\{β\}$-expansion procedure the analytical Riemann $ζ_4$-contributions to the five-loop expressions for the Adler function and Bjorken polarized sum rule are also fixed for the case of the generic simple gauge group.

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arXiv2020

Multiloop contributions to the on-shell-$ \overline{\rm{MS}}$ heavy quark mass relation in QCD and the asymptotic structure of the corresponding series: the updated consideration

The asymptotic structure of the QCD perturbative relation between the on-shell and $\overline{\rm{MS}}$ heavy quark masses is studied. We estimate the five and six-loop contributions to this relation by three different techniques. First, the effective charges motivated approach in two variants is used. Second, the results following from the large-$β_0$ approximation are analyzed. Finally, the consequences of applying the asymptotic renormalon-based formula are investigated. We show that all approaches lead to corrections which are qualitatively consistent in order of magnitude. Their sign-alternating character in powers of the number of massless quarks is demonstrated. We emphasize that there is no contradiction in the behavior of the fine structure of the renormalon-based estimates with other approaches if one use the detailed information about the normalization factor included in the renormalon asymptotic formula. The obtained five- and six-loop estimates indicate that in the case of the $b$-quark the asymptotic character of the studied relation manifests itself above the fourth order of PT, whereas for the $t$-quark it starts to reveal itself after the seventh order. This allows to conclude that like the running masses, the pole masses of the $b$ and especially $t$-quark in principle may be used in the phenomenologically-oriented studies.

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arXiv2020

Riemann $ζ(4)$ function contributions to $O\left({α_s}^5\right)$ terms of Adler D-function and Bjorken polarized sum rule in $SU\left(N_c\right)$ QCD: results and consequences

Two renormalization group invariant quantities in quantum chromodinamics (QCD), defined in Euclidean space,namely, Adler D-function of electron-positron annihilation to hadrons and Bjorken polarized deep-inelastic scattering sum rule, are considered. It is shown, that the 5-th order corrections to them in $\overline{MS}$-like renormalization prescriptions, proportional to Riemann $ζ$-function $ζ\left(4\right)$, can be restored by the transition to the C-scheme, with the $β$-function, analogous to Novikov, Shifman, Vainshtein and Zakharov exact $β$-function in $\mathcal{N}=1$ supersymmetric gauge theories. The general analytical expression for these corrections in $SU\left(N_c\right)$ QCD is deduced and their scale invariance is shown. The $β$-expansion procedure for these contributions is performed and mutual cancellation of them in the 5-th order of the generalized Crewther identity are discussed.

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arXiv2020

Exact $β$-function in Abelian and non-Abelian $\mathcal{N}=1$ supersymmetric gauge models and its analogy with QCD $β$-function in C-scheme

For $\mathcal{N}=1$ supersymmetric Yang-Mills theory without matter it is demonstrated that there is a class of renormalization schemes, in which the exact Novikov, Shifman, Vainshtein, and Zakharov (NSVZ) formula for the renormalization group $β$-function, defined in terms of the renormalized coupling constant, is valid. These schemes are related with each other by finite renormalizations forming a one-parameter commutative subgroup of general renormalization group transformations. The analogy between the exact $β$-function in $\mathcal{N}=1$ supersymmetric Yang-Mills theory without matter and the $β$-function of quantum chromodynamics in the C-scheme is discussed.

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arXiv2020

The three-loop Adler $D$-function for ${\cal N}=1$ SQCD with various renormalization prescriptions

The three-loop Adler $D$-function for ${\cal N}=1$ SQCD in the $\overline{\mbox{DR}}$ scheme is calculated. It appears that the result does not satisfy NSVZ-like equation which relates the $D$-function to the anomalous dimension of the matter superfields. However this NSVZ-like equation can be restored by a special tuning of the renormalization scheme. Also we demonstrate that the $D$-function defined in terms of the bare coupling does not satisfy the NSVZ-like equation in the case of using the regularization by dimensional reduction. The scheme-dependence of the $D$-function written in the form of the $β$-expansion is briefly discussed.

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arXiv2019

Subgroup Of Finite Renormalizations, Conserving The NSVZ Relation In $\mathcal{N} = 1$ SQED

In supersymmetric quantum electrodynamics there is the exact relation between the expressed through the unrenormalized coupling gauge beta-function and the anomalous dimension of matter superfields. In the present report we describe the subgroup of general renormalization group transformations, conserving this relation exactly in all orders of the perturbation theory in terms of the renormalized coupling constant.

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arXiv2019

On-shell renormalization scheme for ${\cal N}=1$ SQED and the NSVZ relation

In this paper we investigate the renormalization of ${\cal N}=1$ supersymmetric quantum electrodynamics, regularized by higher derivatives, in the on-shell scheme. It is demonstrated that in this scheme the exact Novikov, Shifman, Vainshtein, and Zakharov (NSVZ) equation relating the $β$-function to the anomalous dimension of the matter superfields is valid in all orders of the perturbation theory. This implies that the on-shell scheme enters the recently constructed continuous set of NSVZ subtraction schemes. To verify this statement, we compare the anomalous dimension of the matter superfields in the two-loop approximation and the $β$-function in the three-loop approximation, which are explicitly calculated in this scheme. The finite renormalizations relating the on-shell scheme to some other NSVZ subtraction schemes formulated previously are obtained.

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arXiv2019

The three-loop Adler $D$-function for ${\cal N}=1$ SQCD regularized by dimensional reduction

The three-loop Adler $D$-function for ${\cal N}=1$ SQCD in the $\overline{\mbox{DR}}$ scheme is calculated starting from the three-loop result recently obtained with the higher covariant derivative regularization. For this purpose, for the theory regularized by higher derivatives we find a subtraction scheme in which the Green functions coincide with the ones obtained with the dimensional reduction and the modified minimal subtraction prescription for the renormalization of the SQCD coupling constant and of the matter superfields. Also we calculate the $D$-function in the $\overline{\mbox{DR}}$ scheme for all renormalization constants (including the one for the electromagnetic coupling constant which appears due to the SQCD corrections). It is shown that the results do not satisfy the NSVZ-like equation relating the $D$-function to the anomalous dimension of the matter superfields. However, the NSVZ-like scheme can be constructed with the help of a properly tuned finite renormalization. It is also demonstrated that the three-loop $D$-function defined in terms of the bare couplings with the dimensional reduction does not satisfy the NSVZ-like equation for an arbitrary renormalization prescription. We also investigate a possibility to present the results in the form of the $β$-expansion and the scheme dependence of this expansion.

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arXiv2018

The least squares method: application to analysis of the flavor dependence of the QCD relation between pole and $\rm{\overline{MS}}$-scheme running heavy quark masses

The features of the ordinary least squares method, which gives a possible way to a solution of the overdetermined systems of algebraic equations and allows to estimate the uncertainties of the obtained solutions, are considered. As the important physical example we define four-loop QCD coefficients in the dependence of the relation between pole and running heavy quarks masses on the number of light flavors, using the existing results of numerical supercomputer based calculations of the corresponding four-loop contributions at different fixed numbers of light flavors. Stability of the found solutions to the number of the considered equations and unknowns is demonstrated and supported by the Pearsons's $χ$-squared test.

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arXiv2018

Dependence of five and six-loop estimated QCD corrections to the relation between pole and running masses of heavy quarks on the number of light flavours

In this paper various theoretical approaches are used to define the dependence of the estimated $\mathcal{O}(α^5_s)$ and $\mathcal{O}(α^6_s)$-corrections to the QCD relation between pole and $\rm{\overline{MS}}$ running masses of heavy quarks on the number of light flavours. It is found that recently studied asymptotic formula for the coefficients of this relation, based on the infared-renormalon method, does not reproduce sign-alternating structure in the flavour-dependence of the five and six-loop corrections, which holds in three other used by us approaches.

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arXiv2018

On the relation between pole and running heavy quark masses beyond the four-loop approximation

The effective charges motivated method is applied to the relation between pole and $\rm{\overline{MS}}$-scheme heavy quark masses to study high order perturbative QCD corrections in the observable quantities proportional to the running quark masses. The non-calculated five- and six-loop perturbative QCD coefficients are estimated. This approach predicts for these terms the sign-alternating expansion in powers of number of lighter flavors $n_l$, while the analyzed recently infrared renormalon asymptotic expressions do not reproduce the same behavior. We emphasize that coefficients of the quark mass relation contain proportional to $π^2$ effects, which result from analytical continuation from the Euclidean region, where the scales of the running masses and QCD coupling constant are initially fixed, to the Minkowskian region, where the pole masses and the running QCD parameters are determined. For the $t$-quark the asymptotic nature of the non-resummed PT mass relation does not manifest itself at six-loops, while for the $b$-quark the minimal PT term appears at the probed by direct calculations four-loop level. The recent infrared renormalon based studies support these conclusions.

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