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Related papers: Parametrization of the QCD coupling in the Evoluti…

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Closed expressions are presented for the contributions to QCD non-singlet forward evolution kernels $P(z)$ for the DGLAP equation and to $V(x,y)$ for non-forward (ER-BL) evolution equation for a certain class of diagrams which include…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. V. Mikhailov

A QCD model with an infinite number of vector mesons suggested by one of the authors is used to derive the value of the correction $\delta\alpha_{hadr}$ for $\alpha(m_{Z}^{2})$ due to the strong interactions. The result is…

High Energy Physics - Phenomenology · Physics 2009-10-28 B. V. Geshkenbein , V. L. Morgunov

Analytic QCD models are those where the QCD running coupling has the physically correct analytic behavior, i.e., no Landau singularities in the Euclidean regime. We present a simple analytic QCD model in which the discontinuity function of…

High Energy Physics - Phenomenology · Physics 2014-11-21 Carlos Contreras , Gorazd Cvetic , Olivier Espinosa , Hector E. Martinez

We show that already at the NLO level the DGLAP evolution kernel Pqq starts to depend on the choice of the evolution variable. We give an explicit example of such a variable, namely the maximum of transverse momenta of emitted partons and…

High Energy Physics - Phenomenology · Physics 2016-08-17 S. Jadach , A. Kusina , W. Placzek , M. Skrzypek

In the QCD the small~$x$ evolution of the interacting pomerons and odderons is studied with all angular momenta $l$ taken into account. The resulting system of coupled nonlinear evolution equations is formulated in the momentum space and…

High Energy Physics - Phenomenology · Physics 2020-05-25 M. A. Braun

We compute the Standard Model scalar coupling ($\lambda$) evolution in a particular QCD resummation scheme, where the QCD coupling becomes infrared finite due to the presence of a dynamically generated gluon mass, leading to the existence…

High Energy Physics - Phenomenology · Physics 2015-06-17 J. D. Gomez , A. A. Natale

The treatment of the running QCD coupling in evolution equations is discussed. It is shown that the use of the virtuality of ladder (vertical) partons as the scale for QCD coupling in every rung of ladder graphs is an approximation that…

High Energy Physics - Phenomenology · Physics 2010-03-25 B. I. Ermolaev , M. Greco , S. I. Troyan

The QCD evolution of both unpolarized and polarized generalized parton distributions (GPDs) to next-to-leading order (NLO) accuracy is presented, in both the DGLAP and ERBL regions, for two appropriately symmetrized input distributions…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Freund , M. F. McDermott

We consider a finite element approximation for a system consisting of the evolution of a closed planar curve by forced curve shortening flow coupled to a reaction-diffusion equation on the evolving curve. The scheme for the curve evolution…

Numerical Analysis · Mathematics 2016-07-07 John W. Barrett , Klaus Deckelnick , Vanessa Styles

We present a specific class of models for an infrared-finite analytic QCD coupling, such that at large space-like energy scales the coupling differs from the perturbative one by less than any inverse power of the energy scale. This…

High Energy Physics - Phenomenology · Physics 2008-11-26 Gorazd Cvetic , Cristian Valenzuela

QCD evolution equations in minimal subtraction schemes have a hidden symmetry: One can construct three operators that commute with the evolution kernel and form an $SL(2)$ algebra, i.e. they satisfy (exactly) the $SL(2)$ commutation…

High Energy Physics - Phenomenology · Physics 2016-04-20 V. M. Braun , A. N. Manashov , S. Moch , M. Strohmaier

We examine, in the `t Hooft renormalization scheme, the analytic running coupling $\bar\alpha_t(Q^2)$ in QCD, using the two-loop $\beta$-function with positive expansion parameters $\beta_0$ and $\beta_1$. An exact integral representation…

High Energy Physics - Theory · Physics 2022-07-27 F. T. Brandt , J. Frenkel , D. G. C. McKeon , G. S. S. Sakoda

We revisit constraints on the (pseudo)conformal Universe from the non-observation of statistical anisotropy in the Planck data. The quadratic maximal likelihood estimator is applied to the Planck temperature maps at frequencies 143 GHz and…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-05 G. I. Rubtsov , S. R. Ramazanov

The evolution of QCD coupling constant at finite temperature is considered by making use of the finite temperature renormalization group equation up to the one-loop order in the background field method with the Feynman gauge and the…

High Energy Physics - Theory · Physics 2007-05-23 M. Chaichian , M. Hayashi

We study deviations from the perturbative asymptotic behaviour in the running QCD coupling by analysing non-perturbative measurements of alpha_s (p) at low momenta as obtained from the lattice three-gluon vertex. Our exploratory study…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. Burgio , F. Di Renzo , C. Parrinello , C. Pittori

We start from the two existing QCD evolution equations for structure functions, the BFKL and DGLAP equations, and discuss the theoretical hints for a unifying picture of the evolution in $x$ and $Q^2.$ The main difficulty is due to the…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Peschanski

We study the consequences of including the running of the QCD coupling in the equation describing the evolution of the jet quenching parameter $\hat q$ in the double logarithmic approximation. To start with, we revisit the case of a fixed…

High Energy Physics - Phenomenology · Physics 2014-10-08 E. Iancu , D. N. Triantafyllopoulos

We investigate the occurrence of power terms in the running QCD coupling by analysing non-perturbative measurements of alpha_s (p) at low momenta obtained from the lattice three-gluon vertex. Our exploratory study provides some evidence for…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Burgio , F. Di Renzo , C. Parrinello , C. Pittori

The interplay of competing orders is relevant to high-temperature superconductivity known to emerge upon suppression of a parent antiferromagnetic order typically via charge doping. How such interplay evolves at low temperature---in…

Strongly Correlated Electrons · Physics 2017-07-14 Zuo-Dong Yu , Yuan Zhou , Wei-Guo Yin , Hai-Qing Lin , Chang-De Gong

We propose a model for the QCD running coupling constant based on the Analytical Inverse QCD Coupling Constant concept with an additional regularization in the low momentum region. Analyticity in the $q^2$-complex plane, where $q$ is the…

High Energy Physics - Phenomenology · Physics 2025-11-11 Malaspina R. , Pierini L. , Shekhovtsova O. , Pacetti S