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Related papers: QCD evolution equations from conformal symmetry

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We construct the evolution equations for the twist-3 chiral-odd spin independent fracture functions in QCD. The Gribov-Lipatov reciprocity relation is fulfilled at the one-loop level for the quasi-partonic two-particle cut vertices only. It…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. V. Belitsky , E. A. Kuraev

We calculate the second-order QCD corrections to the forward-backward asymmetry in $e^+e^-$ annihilation. Using the quark axis definition, we do not agree with either existing calculation, but the difference relative to one of them is small…

High Energy Physics - Phenomenology · Physics 2010-02-03 Stefano Catani , Michael H. Seymour

The widely used nonperturbative wave functions and distribution functions of QCD are determined as matrix elements of light-ray operators. These operators appear as large momentum limit of nonlocal hadron operators or as summed up local…

High Energy Physics - Phenomenology · Physics 2015-06-25 D. Müller , D. Robaschik , B. Geyer , F. -M. Dittes , J. Hořejši

We carry out a three-loop computation that establishes the existence of scale without conformal invariance in dimensional regularization with the MS scheme in d=4-epsilon spacetime dimensions. We also comment on the effects of scheme…

High Energy Physics - Theory · Physics 2015-09-14 Jean-François Fortin , Benjamín Grinstein , Andreas Stergiou

We explore several models of QCD evolution equations simplified by considering only the rapidity dependence of dipole scattering amplitudes, while provisionally neglecting their dependence on transverse coordinates. Our main focus is on the…

High Energy Physics - Phenomenology · Physics 2009-11-11 P. Rembiesa , A. M. Stasto

We revisit the Next-to-Leading Order (two-loop) contributions to the Anomalous Dimensions of $\Delta F = 1$ four-quark operators in QCD. We devise a test for anomalous dimensions, that we regard as of general interest, and by means of which…

High Energy Physics - Phenomenology · Physics 2025-06-19 Pol Morell , Javier Virto

The Lange-Neubert evolution equation describes the scale dependence of the wave function of a meson built of an infinitely heavy quark and light antiquark at light-like separations, which is the hydrogen atom problem of QCD. It has numerous…

High Energy Physics - Phenomenology · Physics 2015-06-18 V. M. Braun , A. N. Manashov

We prove a set of identities for the anomalous dimensions of the quark and gluon conformal operators in the flavour singlet channel in QCD. These relations arise from the graded commutator algebra of the N=1 superconformal group. We…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Muller , A. Schafer

We formulate a consistent 1/N_c^2 expansion of the QCD evolution equations for the twist-three quark distributions g_2(x,Q^2), h_L(x,Q^2) and e(x,Q^2) based on the interpretation of the evolution as a three-particle quantum-mechanical…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. M. Braun , G. P. Korchemsky , A. N. Manashov

We study the scale dependence of twist-3 distributions defined with chirality-odd quark-gluon operators. To derive the scale dependence we explicitly calculate these distributions of multi-parton states instead of a hadron. Taking one-loop…

High Energy Physics - Phenomenology · Physics 2015-06-11 J. P. Ma , Q. Wang , G. P. Zhang

Parton recombination is reconsidered in perturbation theory without using the AGK cutting rules in the leading order of the recombination. We use time-ordered perturbation theory to sum the cut diagrams, which are neglected in the GLR…

High Energy Physics - Phenomenology · Physics 2014-11-17 Wei Zhu

We extend and develop a method for perturbative calculations of anomalous dimensions and mixing matrices of leading twist conformal primary operators in conformal field theories. Such operators lie on the unitarity bound and hence are…

High Energy Physics - Theory · Physics 2008-11-26 A. V. Belitsky , J. Henn , C. Jarczak , D. Müller , E. Sokatchev

We compute the two-loop QCD corrections to the heavy quark form factors in case of the vector, axial-vector, scalar and pseudo-scalar currents up to second order in the dimensional parameter $\epsilon = (4-D)/2$. These terms are required in…

High Energy Physics - Phenomenology · Physics 2018-05-30 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , P. Marquard , N. Rana , C. Schneider

We analytically compute the four-loop QCD corrections for the colour structure $(d_F^{abcd})^2$ to the massless non-singlet quark form factor. The computation involves non-trivial non-planar integral families which have master integrals in…

High Energy Physics - Phenomenology · Physics 2019-03-27 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We complete the construction of the non-forward evolution kernels in next-to-leading order responsible for the scale dependence of e.g. parity even singlet distribution amplitudes. Our formalism is designed to avoid any explicit two-loop…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Müller

Anomalous superconformal Ward identities and commutator algebra in N = 1 super-Yang-Mills theory give rise to constraints between the QCD special conformal anomalies of conformal composite operators. We evaluate the superconformal anomalies…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Müller

Linear and non-linear QCD evolutions at high energy suffer from severe issues related to convergence, due to higher order corrections enhanced by large double and single transverse logarithms. We resum double logarithms to all orders by…

High Energy Physics - Phenomenology · Physics 2015-09-29 E. Iancu , J. D. Madrigal , A. H. Mueller , G. Soyez , D. N. Triantafyllopoulos

We evaluate the complete leading-order evolution kernels for the chiral-odd twist-3 distributions $e(x)$ and $\widetilde h_L(x)$ of the nucleon. We establish the connection between the evolution equations in light-cone position and…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. V. Belitsky , D. Muller

We review some recent results about the computation of mixed QCD-QED corrections beyond the leading order in perturbation theory. We start by considering the effects induced in the Altarelli-Parisi equations and the partonic distributions.…

High Energy Physics - Phenomenology · Physics 2018-05-17 German F. R. Sborlini

An effective non-local quantum field theory is constructed, which describes interaction of pomerons in the high-coloured QCD. The theory includes both splitting and merging triple pomeron vertexes and diagrams with pomeronic loops. The…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. A. Braun