English
Related papers

Related papers: The Master Differential Equations for the 2-loop S…

200 papers

For a large class of two-loop selfenergy- and vertex-type diagrams with only one non-zero mass ($M$) and the vertices also with only one non-zero external momentum squared ($q^2$) the first few expansion coefficients are calculated by the…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Fleischer , A. V. Kotikov , O. L. Veretin

In this paper we calculate at high-precision the expansions in e=(4-D)/2 of the master integrals of 4-loop vacuum bubble diagrams with equal masses, using a method based on the solution of systems of difference equations. We also show that…

High Energy Physics - Phenomenology · Physics 2009-11-07 Stefano Laporta

We describe the calculation of all planar master integrals that are needed for the computation of NNLO QCD corrections to the production of two off-shell vector bosons in hadron collisions. The most complicated representatives of integrals…

High Energy Physics - Phenomenology · Physics 2015-06-18 Johannes M. Henn , Kirill Melnikov , Vladimir A. Smirnov

We compute the master integrals for massless two-loop vertex graphs with three off-shell legs. These master integrals are relevant for the QCD corrections to H to V*V* (where V = W, Z) and for two-loop studies of the triple gluon (and…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. G. Birthwright , E. W. N. Glover , P. Marquard

We present the calculation of massless two-loop Master Integrals relevant to five-point amplitudes with one off-shell external leg and derive the complete set of planar Master Integrals with five on-mass-shell legs, that contribute to many…

High Energy Physics - Phenomenology · Physics 2016-05-04 Costas G. Papadopoulos , Damiano Tommasini , Christopher Wever

The method of the large mass expansion (LME) is investigated for selfenergy and vertex functions in two-loop order. It has the technical advantage that in many cases the expansion coefficients can be expressed analytically. As long as only…

High Energy Physics - Phenomenology · Physics 2009-09-25 J. Fleischer , A. V. Kotikov , O. L. Veretin

The two-loop box contributions to massive Bhabha scattering may be reduced to two-loop box master integrals (MIs) with five, six, and seven internal lines, plus vertices and self energies. The self-energy and vertex MIs may be solved…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Czakon , J. Gluza , K. Kajda , T. Riemann

We describe a strategy to solve differential equations for Feynman integrals by powers series expansions near singular points and to obtain high precision results for the corresponding master integrals. We consider Feynman integrals with…

High Energy Physics - Phenomenology · Physics 2018-04-04 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov

Generalized-unitarity calculations of two-loop amplitudes are performed by expanding the amplitude in a basis of master integrals and then determining the coefficients by taking a number of generalized cuts. In this paper, we present a…

High Energy Physics - Phenomenology · Physics 2025-05-08 Simon Caron-Huot , Kasper J. Larsen

The techniques of integration by parts and differential reduction differ in the counting of master integrals. This is illustrated using as an example the two-loop sunset diagram with on-shell kinematics. A new algebraic relation between the…

Mathematical Physics · Physics 2011-08-09 Mikhail Yu. Kalmykov , Bernd A. Kniehl

We obtain a second order differential equation on moduli space satisfied by certain modular graph functions at genus two, each of which has two links. This eigenvalue equation is obtained by analyzing the variations of these graphs under…

High Energy Physics - Theory · Physics 2019-02-20 Anirban Basu

A set of recurrence relations for on-shell two-loop self-energy diagrams with one mass is presented, which allows to reduce the diagrams with arbitrary indices (powers of scalar propagators) to a set of the master integrals. The SHELL2…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Fleischer , M. Yu. Kalmykov , A. V. Kotikov

An algorithm is constructed to derive a small momentum expansion for two-loop two-point diagrams in all cases where, due to the presence of physical thresholds, there are singularities at zero external momentum. The coefficients of this…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. A. Berends , A. I. Davydychev , V. A. Smirnov , J. B. Tausk

We evaluate the maxcut of the two loops sunrise amplitude with three different masses by using the Minkoskean (as opposed to the usual Euclidean) continuous dimension regularisation, obtaining in that way six related but different functions…

High Energy Physics - Theory · Physics 2024-07-19 Filippo Caleca , Ettore Remiddi

The computation of master integrals from their differential equations requires boundary values to be supplied by an independent method. These boundary values are often desired at singular kinematical points. We demonstrate how the auxiliary…

High Energy Physics - Phenomenology · Physics 2024-04-23 Gaia Fontana , Thomas Gehrmann , Kay Schönwald

We compute the master integrals for two-loop QCD corrections to quasi parton distribution functions (PDFs) in large momentum effective theory. Analytical results of the master integrals are derived using the method of differential…

High Energy Physics - Phenomenology · Physics 2020-10-28 Long-Bin Chen , Wei Wang , Ruilin Zhu

Motivated by the precision results in the electroweak theory studies of two-loopFeynman diagrams are performed. Specifically this paper gives a contribution to the knowledge of massive two-loop self-energy diagrams in arbitrary and…

High Energy Physics - Phenomenology · Physics 2011-09-30 S. Bauberger , F. A. Berends , M. Boehm , M. Buza

We present the computation of a full set of planar five-point two-loop master integrals with one external mass. These integrals are an important ingredient for two-loop scattering amplitudes for two-jet-associated W-boson production at…

High Energy Physics - Phenomenology · Physics 2020-12-30 S. Abreu , H. Ita , F. Moriello , B. Page , W. Tschernow , M. Zeng

In this talk, we discuss our recent computation of the two-loop sunrise integral with arbitrary non-zero particle masses. In two space-time dimensions, we arrive at a result in terms of elliptic dilogarithms. Near four space-time…

High Energy Physics - Phenomenology · Physics 2015-10-15 Luise Adams , Christian Bogner , Stefan Weinzierl

We show how to compute the two-loop sunset integrals at finite volume, for non-degenerate masses and non-zero momentum. We present results for all integrals that appear in the Chiral Perturbation Therory ($\chi$PT) calculation of the…

High Energy Physics - Lattice · Physics 2014-12-03 Johan Bijnens , Emil Boström , Timo A. Lähde