Approximate BFKL kernel from DGLAP anomalous dimension

We have shown that, provided that the nonperturbative input is regular at the right of the ω=0 singularity of the dominant DGLAP anomalous dimension, the rise of F2 at small x, experimentally measured by the averaged observable [Formula: see text], is input-independent in the perturbative Q2 regime at small x. [Formula: see text] appears to be more input-dependent in the same range. The GRV-type parametrizations verify these properties. Other models, namely the BFKL kernel (QCD dipoles), DGLAP (with a nonperturbative input singular at the right of the ω=0) give different predictions for λ. At moderate Q2, there is a possibility of distinguishing these different perturbative QCD predictions in the near future.

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Electroproduction of two-light vector mesons from collinearly improved BFKL kernel

10.3360/dis.2008.74 ◽

2008 ◽

Author(s):

Alessandro Papa ◽

Francesco Caporale ◽

Augustin Sabio Vera

Keyword(s):

Vector Mesons ◽

Light Vector ◽

Bfkl Kernel

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Cwebs beyond three loops in multiparton amplitudes

Journal of High Energy Physics ◽

10.1007/jhep03(2021)188 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Neelima Agarwal ◽

Lorenzo Magnea ◽

Sourav Pal ◽

Anurag Tripathi

Keyword(s):

Gauge Theories ◽

Anomalous Dimension ◽

Wilson Line ◽

Building Blocks ◽

Feynman Diagrams ◽

Loop Order ◽

Abelian Gauge ◽

Sum Rule ◽

Combinatorial Properties ◽

Low Dimensional

Abstract Correlators of Wilson-line operators in non-abelian gauge theories are known to exponentiate, and their logarithms can be organised in terms of collections of Feynman diagrams called webs. In [1] we introduced the concept of Cweb, or correlator web, which is a set of skeleton diagrams built with connected gluon correlators, and we computed the mixing matrices for all Cwebs connecting four or five Wilson lines at four loops. Here we complete the evaluation of four-loop mixing matrices, presenting the results for all Cwebs connecting two and three Wilson lines. We observe that the conjuctured column sum rule is obeyed by all the mixing matrices that appear at four-loops. We also show how low-dimensional mixing matrices can be uniquely determined from their known combinatorial properties, and provide some all-order results for selected classes of mixing matrices. Our results complete the required colour building blocks for the calculation of the soft anomalous dimension matrix at four-loop order.

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Eigenvalue spectrum and scaling dimension of lattice $$ \mathcal{N} $$ = 4 supersymmetric Yang-Mills

Journal of High Energy Physics ◽

10.1007/jhep04(2021)260 ◽

2021 ◽

Vol 2021 (4) ◽

Author(s):

Georg Bergner ◽

David Schaich

Keyword(s):

Anomalous Dimension ◽

Finite Lattice ◽

Continuum Theory ◽

Lattice Volume ◽

Yang Mills ◽

Lattice Regularization ◽

Perturbative Renormalization ◽

Zero Values ◽

Definition Of ◽

Group Flow

Abstract We investigate the lattice regularization of $$ \mathcal{N} $$ N = 4 supersymmetric Yang-Mills theory, by stochastically computing the eigenvalue mode number of the fermion operator. This provides important insight into the non-perturbative renormalization group flow of the lattice theory, through the definition of a scale-dependent effective mass anomalous dimension. While this anomalous dimension is expected to vanish in the conformal continuum theory, the finite lattice volume and lattice spacing generically lead to non-zero values, which we use to study the approach to the continuum limit. Our numerical results, comparing multiple lattice volumes, ’t Hooft couplings, and numbers of colors, confirm convergence towards the expected continuum result, while quantifying the increasing significance of lattice artifacts at larger couplings.

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Chapter 10. Anomalous Dimension

Renormalization Group ◽

10.1515/9780691221694-011 ◽

1995 ◽

pp. 56-65

Keyword(s):

Anomalous Dimension

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Non-planar universal anomalous dimension of twist-two operators with general Lorentz spin at four loops in N=4 SYM theory

Nuclear Physics B ◽

10.1016/j.nuclphysb.2021.115429 ◽

2021 ◽

pp. 115429

Author(s):

B.A. Kniehl ◽

V.N. Velizhanin

Keyword(s):

Anomalous Dimension

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Electric dipole moment constraints on CP-violating heavy-quark Yukawas at next-to-leading order

Journal of High Energy Physics ◽

10.1007/jhep07(2021)080 ◽

2021 ◽

Vol 2021 (7) ◽

Author(s):

Joachim Brod ◽

Emmanuel Stamou

Keyword(s):

Electric Dipole ◽

Anomalous Dimension ◽

Phenomenological Study ◽

Dipole Moments ◽

Charm Quark ◽

Leading Order ◽

Logarithmic Order ◽

Electric Dipole Moments ◽

Yukawa Couplings ◽

Experimental Bound

Abstract Electric dipole moments are sensitive probes of new phases in the Higgs Yukawa couplings. We calculate the complete two-loop QCD anomalous dimension matrix for the mixing of CP-odd scalar and tensor operators and apply our results for a phenomenological study of CP violation in the bottom and charm Yukawa couplings. We find large shifts of the induced Wilson coefficients at next-to-leading-logarithmic order. Using the experimental bound on the electric dipole moments of the neutron and mercury, we update the constraints on CP-violating phases in the bottom and charm quark Yukawas.

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