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200 papers

We study one dimensional dipole cascade models in the high-energy limit of QCD. Motivated by data on hadron multiplicities in the LHCb kinematical range, we generalize existing cascade models for splitting and recombination to account also…

High Energy Physics - Phenomenology · Physics 2025-11-05 Krzysztof Kutak , Michał Praszałowicz

We obtain finite parts (as well as $\epsilon$-pole parts) of massive three-loop vacuum diagrams with three-point and/or four-point interaction vertices by reducing them to tetrahedron diagrams with both massive and massless lines, whose…

High Energy Physics - Theory · Physics 2014-11-18 J. -M. Chung , B. K. Chung

Three--loop contributions to massive QED vacuum polarization are evaluated by a combination of analytical and numerical techniques. The first three Taylor coefficients, at small $q^2$, are obtained analytically, using $d$\/--dimensional…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. A. Baikov , D. J. Broadhurst

We present an optimization of the reduction algorithm of one-loop amplitudes in terms of master integrals. It is based on the exploitation of the polynomial structure of the integrand when evaluated at values of the loop-momentum fulfilling…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. Mastrolia , G. Ossola , C. G. Papadopoulos , R. Pittau

The two-loop QCD corrections to vector boson pair production at hadron colliders involve a new class of Feynman integrals: two-loop four-point functions with two off-shell external legs. We describe their reduction to a small set of master…

High Energy Physics - Phenomenology · Physics 2013-08-26 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

We propose a general scheme for dissipatively preparing arbitrary pure quantum states on a multipartite qubit register in a finite number of basic control blocks. Our "splitting-subspace" approach relies on control resources that are…

Quantum Physics · Physics 2013-11-19 Giacomo Baggio , Francesco Ticozzi , Lorenza Viola

We derive analytic results for scalar massless bosonic vacuum sum-integrals at two loops. Building upon a recent factorization proof of massive two-loop vacuum integrals, we are able to solve the corresponding Matsubara sums and map the…

High Energy Physics - Phenomenology · Physics 2026-03-24 Andrei I. Davydychev , Pablo Navarrete , York Schröder

We present the calculation of the master integrals needed for the two-loop QCDxEW corrections to $ q + \bar{q} \to l^- + l^+$ and $ q + \bar{q}' \to l^- + \overline{\nu} \, , $ for massless external particles. We treat W and Z bosons as…

High Energy Physics - Phenomenology · Physics 2016-10-12 Roberto Bonciani , Stefano Di Vita , Pierpaolo Mastrolia , Ulrich Schubert

We present the Master Integrals needed for the calculation of the two-loop QCD corrections to the forward-backward asymmetry of a quark-antiquark pair produced in electron-positron annihilation events. The abelian diagrams entering in the…

High Energy Physics - Phenomenology · Physics 2009-11-10 R. Bonciani , P. Mastrolia , E. Remiddi

We compute the leading colour contributions to five-gluon scattering at two loops in massless QCD. The integrands of all independent helicity amplitudes are evaluated using d-dimensional generalised unitarity cuts and finite field…

High Energy Physics - Phenomenology · Physics 2018-03-07 Simon Badger , Christian Brønnum-Hansen , Heribertus Bayu Hartanto , Tiziano Peraro

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

We evaluate analytically the master integrals for one of two types of planar families contributing to massive two-loop Bhabha scattering in QED. As in our previous paper, we apply a recently suggested new strategy to solve differential…

High Energy Physics - Theory · Physics 2015-06-16 Johannes M. Henn , Vladimir A. Smirnov

We present recent advancements in the computation of three-loop four-particle helicity amplitudes in full-color massless QCD. In this contribution, we focus on the $gg \to \gamma\gamma$ process. We show how to obtain compact analytic…

High Energy Physics - Phenomenology · Physics 2024-10-04 Piotr Bargiela

Some of the tools and techniques that have recently been used to compute Higgs boson pair production at NLO in QCD are discussed. The calculation relies on the use of integral reduction, to reduce the number of integrals which must be…

High Energy Physics - Phenomenology · Physics 2016-08-15 S. P. Jones

In this talk we review the status concerning vacuum integrals needed in perturbative expansions of QCD at non-zero temperature. We will focus on the differences as compared to familiar zero-temperature techniques, and provide a list of…

High Energy Physics - Phenomenology · Physics 2011-08-05 Y. Schroder

The scalar two-loop self-energy master diagram is studied in the case of arbitrary masses. Analytical results in terms of Lauricella- and Appell-functions are presented for the imaginary part. By using the dispersion relation a…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Bauberger , M. Boehm

We present a set of scalar master integrals (MIs) needed for a complete treatment of massive two-loop corrections to Bhabha scattering in QED, including integrals with arbitrary fermionic loops. The status of analytical solutions for the…

High Energy Physics - Phenomenology · Physics 2009-11-10 M. Czakon , J. Gluza , T. Riemann

In this thesis, we study the three-loop QCD form factors. After an introduction and a discussion of the physics motivation, we generate the quark form factor using Qgraf. We then show how to bring the Feynman integrals into a unique form by…

High Energy Physics - Phenomenology · Physics 2009-03-04 Beat Toedtli

We describe a new method of calculation of generic multi-loop master integrals based on the numerical solution of systems of difference equations in one variable. We show algorithms for the construction of the systems using…

High Energy Physics - Phenomenology · Physics 2009-07-09 S. Laporta

We consider the scalar sector of a general renormalizable theory and evaluate the effective potential through three loops analytically. We encounter three-loop vacuum bubble diagrams with up to two masses and six lines, which we solve using…

High Energy Physics - Theory · Physics 2018-11-13 Bernd A. Kniehl , Andrey F. Pikelner , Oleg L. Veretin