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Related papers: Two-loop Resummation in Fractional Analytic Pertur…

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We give a short introduction to the Analytic Perturbation Theory (APT) and its generalization to Fractional powers -- FAPT. We describe how to treat heavy-quark thresholds in FAPT and then show how to resum perturbative series in both the…

High Energy Physics - Phenomenology · Physics 2014-11-18 Alexander P. Bakulev

We present new results on the summation of nonpower-series expansions in QCD Analytic Perturbation Theory (APT) in the one-loop approximation. We show how to generalize the approach suggested by one of us earlier to the cases of APT and…

High Energy Physics - Phenomenology · Physics 2008-03-27 A. P. Bakulev , S. V. Mikhailov

We discuss the resummation approach in QCD Analytic Perturbation Theory (APT). We start with a simple example of asymptotic power series for a zero-dimensional analog of the scalar $g\,\phi^4$ model. Then we give a short historic preamble…

High Energy Physics - Phenomenology · Physics 2012-01-10 Alexander P. Bakulev , Irina V. Potapova

We describe the generalization of Analytic Perturbation Theory (APT) for QCD observables, initiated by Radyushkin, Krasnikov, Pivovarov, Shirkov and Solovtsov, to fractional powers of coupling -- Fractional APT (FAPT). The basic aspects of…

High Energy Physics - Phenomenology · Physics 2015-05-14 Alexander P. Bakulev

We give a short introduction to the Analytic Perturbation Theory (APT) in QCD, discuss its problems and how they can be resolved in Fractional APT (FAPT), and give a brief report about taking into account heavy-quark thresholds in FAPT.…

High Energy Physics - Phenomenology · Physics 2008-10-22 Alexander P. Bakulev

Results on the resummation of non-power-series expansions of the Adler function of a scalar, $D_S$, and a vector, $D_V$, correlator are presented within fractional analytic perturbation theory (FAPT). The first observable can be used to…

High Energy Physics - Phenomenology · Physics 2010-11-02 A. P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We give the generalization of Fractional Analytic Perturbation Theory (FAPT) for QCD observables, recently developed both for the Euclidean and Minkowski regions of squared momentum transfer q^2, which takes into account heavy-quark…

High Energy Physics - Phenomenology · Physics 2010-12-30 Alexander P. Bakulev

We work out and discuss the Minkowski version of Fractional Analytic Perturbation Theory (FAPT) for QCD observables, recently developed and presented by us for the Euclidean region. The original analytic approach to QCD, initiated by…

High Energy Physics - Phenomenology · Physics 2014-11-18 A. P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We give a short introduction to the Analytic Perturbation Theory (APT) in QCD, describe its problems and suggest as a tool for their resolution the Fractional APT (FAPT). We also describe shortly how to treat heavy-quark thresholds in FAPT.…

High Energy Physics - Phenomenology · Physics 2008-10-21 Alexander P. Bakulev

The subject of the first section-lecture is concerned with the strength and the weakness of the perturbation theory (PT) approach, that is expansion in powers of a small parameter $\alpha$, in Quantum Theory. We start with outlining a…

High Energy Physics - Phenomenology · Physics 2012-03-05 Alexander P. Bakulev , Dmitry V. Shirkov

The aim of this topical article is to outline the fundamental ideas underlying the recently developed Fractional Analytic Perturbation Theory (FAPT) of QCD and present its main calculational tools together with key applications. For this,…

High Energy Physics - Phenomenology · Physics 2016-02-11 N. G. Stefanis

We describe the development of Analytic Perturbation Theory (APT) in QCD, called Fractional APT (FAPT), which has been suggested to apply the renormalization group evolution and QCD factorization technique in the framework of APT.

High Energy Physics - Phenomenology · Physics 2007-10-10 Alexander P. Bakulev

The paper is devoted to application of recently devised ghost-free Analytic Perturbation Theory (APT) for analysis of some QCD observables. We start with the discussion of the main problem of the perturbative QCD -- ghost singularities and…

High Energy Physics - Phenomenology · Physics 2011-09-13 D. V. Shirkov

We provide here all the procedures in \texttt{Mathematica} which are needed for the computation of the analytic images of the strong coupling constant powers in Minkowski (${\bar{\mathfrak A}_{\nu}(s;n_f)}$ and ${\mathfrak…

High Energy Physics - Phenomenology · Physics 2012-08-27 Alexander P. Bakulev , Vyacheslav L. Khandramai

This is part two in a series of papers in which we investigate an approach based on Lagrangian perturbation theory (LPT) to study the non-linear evolution of the large-scale structure distribution in the universe. Firstly, we compute the…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-15 Cornelius Rampf , Yvonne Y. Y. Wong

We present the elements of three applications of resummation methods in non-Abelian gauge theories: (1), QED X QCD exponentiation and shower/ME matching for LHC physics; (2), IR improvement of DGLAP theory; (3), resummed quantum gravity and…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. F. L. Ward

Within the ghost-free Analytic Perturbation Theory (APT), devised in the last decade for low energy QCD, simple approximations are proposed for 3-loop analytic couplings and their effective powers, in both the space-like (Euclidean) and…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. V. Shirkov , A. V. Zayakin

The decay of the Higgs boson into two photons is discussed. Using Sudakov technicue, we study a new type of double logarithms in the case of the light quark loop. First, we examine the origin of such logarithms at the one loop level. Then…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. I. Kotsky , O. I. Yakovlev

Modeling the large-scale structure of the universe on nonlinear scales has the potential to substantially increase the science return of upcoming surveys by increasing the number of modes available for model comparisons. One way to achieve…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-30 Marcel Schmittfull , Zvonimir Vlah

We perform a two-loop calculation in Light Cone Perturbation Theory (LCPT) to evaluate the next-to-leading order nonsinglet splitting function. Our calculation demonstrates the methodology and feasibility of performing higher order…

High Energy Physics - Phenomenology · Physics 2026-01-16 Tuomas Lappi , Risto Paatelainen , Mikko Seppälä
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