Article
Astronomy & Astrophysics
B. Ananthanarayan, Sumit Banik, Samuel Friot, Shayan Ghosh
Summary: The computational technique of N-fold Mellin-Barnes integrals is utilized to derive series representations of the massive one-loop conformal three-point Feynman integral, confirming certain existing results and providing new ones. This work also proves recent conjectures regarding the representation of the massive one-loop conformal n-point integral in terms of multiple hypergeometric series, and explores the relationships among these conjectures and new transformations in hypergeometric functions theory. Additionally, the study identifies spurious contributions that can arise in the Yangian approach.
Article
Astronomy & Astrophysics
Matteo Becchetti, Roberto Bonciani, Vittorio Del Duca, Valentin Hirschi, Francesco Moriello, Armin Schweitzer
Summary: This study presents the exact next-to-leading-order QCD corrections to the light-quark part of the mixed QCD-EW contributions to Higgs production via gluon fusion at the Large Hadron Collider for a center-of-mass energy of 13 TeV. The choice of renormalization and factorization scales has a significant impact on the final result.
Article
Multidisciplinary Sciences
Ievgen Dubovyk, Johann Usovitsch, Krzysztof Grzanka
Summary: This paper focuses on studying Z-boson decay in e(+)e(-) collisions as a method to search for new physics in particle physics. Improving the precision of calculations of Standard Model electroweak pseudo-observables related to the Z-boson is crucial for meeting experimental requirements and increasing the chance of detecting non-standard effects. Calculating three-loop Feynman integrals is necessary to achieve this goal, and methods like sector decomposition, Mellin-Barnes, and differential equations are used for numerical solutions.
Article
Astronomy & Astrophysics
Ansgar Denner, Jean-Nicolas Lang, Mathieu Pellen
Summary: This article presents the computation of next-to-leading-order (NLO) QCD corrections for a specific physics process at the LHC, marking the first public release of a full NLO computation for a 2 -> 8 process with 6 external strongly interacting partons. By comparing results with and without a double-pole approximation for the top quarks, it is found that the difference between the full calculation and the approximation is generally below 5%, but can reach up to 10% in certain phase space regions.
Article
Astronomy & Astrophysics
Arnd Behring, Federico Buccioni, Fabrizio Caola, Maximilian Delto, Matthieu Jaquier, Kirill Melnikov, Raoul Rontsch
Summary: Mixed QCD-electroweak corrections to fully differential production of an on-shell W boson, including decays of W bosons to lepton pairs in the leading order approximation, are computed analytically for arbitrary electroweak gauge boson masses. Analytic results for integrated subtraction terms are obtained within a soft-collinear subtraction scheme tailored to handle the structural simplicity of infrared singularities of mixed QCD-electroweak contributions, with numerical results presented for mixed corrections to the fiducial cross section of pp -> W+ -> l(+)nu and selected kinematic distributions in this process.
Article
Mathematics, Interdisciplinary Applications
Gerd Baumann, Norbert Sudland
Summary: The purpose of this study is to provide a systematic and unified approach to Mellin-Barnes integrals and associated special functions, encompassing their fundamental features and important conclusions. The method uses Mellin-Barnes integrals and numerical approximation techniques to achieve fast convergence and handle endpoint singularities.
FRACTAL AND FRACTIONAL
(2022)
Article
Astronomy & Astrophysics
Matteo Fael, Kay Schoenwald, Matthias Steinhauser
Summary: The study calculates the relation between the pole mass and the kinetic mass of a heavy quark, providing precise conversion relations between the (MS) over bar and kinetic masses. The computation involves moments of the spectral function for scattering near threshold, reaching up to three-loop order. The results have important implications for experimental extractions of fundamental matrix elements.
Article
Astronomy & Astrophysics
Oleksandr Tomalak, Kaushik Borah, Richard J. Hill, Kevin S. McFarland, Daniel Ruterbories
Summary: Inverse muon decay is a promising tool to constrain neutrino fluxes. In this paper, we calculate radiative corrections to the scattering processes and provide analytic expressions for observable distributions. Our results clarify and extend the applicability of previous results in the literature.
Article
Physics, Particles & Fields
Tai-Fu Feng, Hai-Bin Zhang, Yan-Qing Dong, Yang Zhou
Summary: By applying the Mellin-Barnes representation and the Miller transformation, we derive a system of linear partial differential equations known as the GKZ-system for the 2-loop self energy diagram with 4 propagators. The codimension of the derived GKZ-system is determined by the number of independent dimensionless ratios involving the external momentum squared and virtual mass squared. We obtain a total of 536 hypergeometric functions in the neighborhoods of the origin and infinity, with 30 linearly independent hypergeometric functions forming a fundamental solution system with nonempty intersection in a proper subset of the parameter space.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Multidisciplinary
Simon Badger, Heribertus Bayu Hartanto, Simone Zoia
Summary: An analytic computation of two-loop QCD corrections to u (d) over bar -> W(+)b (b) over bar for an on-shell W boson was presented using leading color and massless bottom quark approximations. Integration-by-parts reduction of the unpolarized squared matrix element was achieved through finite field reconstruction techniques, leading to the identification of an independent basis of special functions allowing for analytic subtraction of infrared and ultraviolet poles. This basis is applicable to all planar topologies for five-particle scattering with an off-shell leg.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Matteo Fael, Fabian Lange, Kay Schoenwald, Matthias Steinhauser
Summary: This paper computes the three-loop corrections to singlet form factors for massive quarks using a semianalytic method, providing precise results across all kinematic regions. The anomaly contribution from an external axial-vector current is particularly emphasized, and the contribution for a pseudoscalar current is discussed in detail, along with the verification of the chiral Ward identity to three-loop order. Explicit results are presented for the low- and high-energy regions, as well as the expansions around threshold.
Article
Physics, Particles & Fields
Marco Bonetti, Erik Panzer, Lorenzo Tancredi
Summary: In this study, we calculate the two-loop mixed QCD-Electroweak corrections to important reactions, specifically focusing on the contribution of virtual light quarks. We compute the independent helicity amplitudes and form factors for this process, expressing them in terms of hyperlogarithms with algebraic arguments. The Feynman integrals are calculated through direct integration over Feynman parameters, and the results are presented using a basis of rational prefactors.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Tommaso Armadillo, Roberto Bonciani, Simone Devoto, Narayan Rana, Alessandro Vicini
Summary: We present an algorithm to evaluate multiloop Feynman integrals with an arbitrary number of internal massive lines, with the masses being in general complex-valued, and its implementation in the Mathematica package SeaSyde. The implementation solves by series expansions the system of differential equations satisfied by the Master Integrals. At variance with respect to other existing codes, the analytical continuation of the solution is performed in the complex plane associated to each kinematical invariant. We present the results of the evaluation of the Master Integrals relevant for the NNLO QCD-EW corrections to the neutral-current Drell-Yan processes.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Mathematics, Applied
Showkat Ahmad Dar, Mohammad Kamarujjama, Richard Bruce Paris, Mohammad Idris Qureshi
Summary: In this paper, the authors investigate and evaluate analytical expressions for certain definite integrals originally derived by Srinivasa Ramanujan. The expressions are represented in terms of Meijer's G-function and are obtained using Laplace transforms. Additionally, the authors explore infinite summation formulas involving Meijer's G-function and closed-form evaluations of related infinite series.
ANALYSIS-INTERNATIONAL MATHEMATICAL JOURNAL OF ANALYSIS AND ITS APPLICATIONS
(2023)
Correction
Physics, Multidisciplinary
S. G. Bondarenko, L. V. Kalinovskaya, L. A. Rumyantsev, V. L. Yermolchyk
Summary: An erratum for this paper has been published.
