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A modeling methodology and matrix formalism is presented that permits analysis of arbitrarily complex interferometric waveguide systems, including polarization and backreflection effects. Considerable improvement results from separation of…

Mathematical Physics · Physics 2015-05-20 Robert P. Dahlgren

We compute the master integrals relevant for the two-loop corrections to pseudo-scalar quarkonium and leptonium production and decay. We present both analytic and high-precision numerical results. The analytic expressions are given in terms…

High Energy Physics - Phenomenology · Physics 2022-11-18 Samuel Abreu , Matteo Becchetti , Claude Duhr , Melih A. Ozcelik

We present an analytical method to calculate the three-loop massive Feynman integral in arbitrary dimensions. The method is based on the Mellin-Barnes representation of the Feynman integral. The Meijer theorem and its corollary are used to…

High Energy Physics - Phenomenology · Physics 2024-08-06 Jian Wang , Dongyu Yang

We propose that the height-angle ray vector in matrix optics should be complex, based on a geometric algebra analysis. We also propose that the ray's 2x2 matrix operators should be right-acting, so that the matrix product succession would…

Optics · Physics 2008-12-04 Quirino M. Sugon , Daniel J. McNamara

A recently proposed method of calculating scalar two-loop propagator and vertex functions with massive particles is illustrated with simple examples. A double integral representation is derived with the example of a propagator function. An…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrzej Czarnecki

We present a new method for the numerical evaluation of arbitrary loop integrals in dimensional regularization. We first derive Mellin-Barnes integral representations and apply an algorithmic technique, based on the Cauchy theorem, to…

High Energy Physics - Phenomenology · Physics 2009-11-11 Charalampos Anastasiou , Alejandro Daleo

We discuss the determination of the infrared singularities of massive one-loop 5-point functions with Mellin-Barnes (MB) representations. Massless internal lines may lead to poles in the $\eps$ expansion of the Feynman diagram, while…

High Energy Physics - Phenomenology · Physics 2009-04-14 Janusz Gluza , Tord Riemann

Motivated by recent work on the utility of Mellin space for representing conformal correlators in $AdS$/CFT, we study its suitability for representing dual conformal integrals of the type which appear in perturbative scattering amplitudes…

High Energy Physics - Theory · Physics 2015-06-04 Miguel F. Paulos , Marcus Spradlin , Anastasia Volovich

The two-loop massive operator matrix elements for the fermionic local twist--2 operators with external massive fermion lines in Quantum Electrodynamics (QED) are calculated up to the constant terms in the dimensional parameter $\epsilon = D…

High Energy Physics - Phenomenology · Physics 2011-11-02 Johannes Blümlein , Abilio De Freitas , Wilhelmus van Neerven

We present analytic expressions in terms of polylogarithmic functions for all three families of planar two-loop five-point Master Integrals with one off-shell leg. The calculation is based on the Simplified Differential Equations approach.…

High Energy Physics - Phenomenology · Physics 2021-05-12 Dhimiter D. Canko , Costas G. Papadopoulos , Nikolaos Syrrakos

This paper is devoted to the calculation by Mellin-Barnes transform of a especial class of integrals. It contains double integrals in the position space in d = 4-2e dimensions, where e is parameter of dimensional regularization. These…

High Energy Physics - Theory · Physics 2010-06-01 Pedro Allendes , Natanael Guerrero , Igor Kondrashuk , Eduardo A. Notte Cuello

We compute the Mellin amplitude of the planar four-point correlator of weight-two half-BPS operators in $\mathcal{N}=4$ SYM at one and two-loop orders in the small 't Hooft coupling expansion. The two-loop Mellin amplitude has an infinite…

High Energy Physics - Theory · Physics 2024-01-01 Faizan Bhat , Pronobesh Maity

We present the results for two-loop massive kite master integrals with elliptics in terms of iterated integrals with algebraic kernels. The key ingredients are new integral representations for sunset subgraphs in $d=4-2\epsilon$ and…

High Energy Physics - Phenomenology · Physics 2021-02-24 M. A. Bezuglov , A. I. Onishchenko , O. L. Veretin

We present the two-mass QCD contributions to the pure singlet operator matrix element at three loop order in x-space. These terms are relevant for calculating the structure function $F_2(x,Q^2)$ at $O(\alpha_s^3)$ as well as for the…

High Energy Physics - Phenomenology · Physics 2018-02-01 J. Ablinger , J. Blümlein , A. De Freitas , C. Schneider , K. Schönwald

We present the analytic calculation of the Master Integrals necessary to compute the planar massive QCD corrections to Di-photon (and Di-jet) production at hadron colliders. The masters are evaluated by means of the differential equations…

High Energy Physics - Phenomenology · Physics 2018-02-14 Matteo Becchetti , Roberto Bonciani

Virtual two-loop corrections to scattering amplitudes are a key ingredient to precision physics at collider experiments. We compute the full set of planar master integrals relevant to five-point functions in massless QCD, and use these to…

High Energy Physics - Phenomenology · Physics 2016-04-18 T. Gehrmann , J. M. Henn , N. A. Lo Presti

We derive a compact expression for the three-point MHV form factors of half-BPS operators in N=4 super Yang-Mills at two loops. The main tools of our calculation are generalised unitarity applied at the form factor level, and the compact…

High Energy Physics - Theory · Physics 2015-06-03 Andreas Brandhuber , Gabriele Travaglini , Gang Yang

We study in QCD the $\overline{\mathrm{MS}}$ renormalization of three-quark operators with up to two covariant derivatives, which are related to $N=0,1,2$ Mellin moments of baryonic light-cone distributions amplitudes. Apart from general…

High Energy Physics - Phenomenology · Physics 2026-04-14 Kniehl B. A. , Veretin O. L

We present in detail the calculation of the $O(\a_s)$ virtual corrections to the matrix element for $b \to s \g$. Besides the one-loop virtual corrections of the electromagnetic and color dipole operators $O_7$ and $O_8$, we include the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christoph Greub , Tobias Hurth , D. Wyler

We compute the two-loop renormalization functions, in the RI' scheme, of local bilinear quark operators $\bar{\psi}\Gamma\psi$, where $\Gamma$ corresponds to the Vector, Axial-Vector and Tensor Dirac operators, in the lattice formulation of…

High Energy Physics - Lattice · Physics 2009-07-30 A. Skouroupathis , H. Panagopoulos
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