Article
Physics, Particles & Fields
Stefano Frixione, Bryan R. Webber
Summary: This article discusses how color flows can simplify the computation of matrix elements and enable parton shower Monte Carlos to achieve accuracy beyond leading color. By systematically employing these color flows, tree-level matrix elements and their soft limits can be given in a closed form that does not require any color algebra. Additionally, the study examines how color loops and dipole graphs can help extend the accuracy of Monte Carlos by including subleading-color effects.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Daniel de Florian, Ignacio Fabre, Gudrun Heinrich, Javier Mazzitelli, Ludovic Scyboz
Summary: This study combines NLO predictions with full top-quark mass dependence with approximate NNLO predictions for Higgs-boson pair production in gluon fusion. It examines the impact of anomalous couplings on various observables and provides numerical coefficients for the approximate NNLO cross section as a function of the anomalous couplings at root s = 14TeV.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Dhimiter D. Canko, Costas G. Papadopoulos, Nikolaos Syrrakos
Summary: Analytic expressions for three families of planar two-loop five-point Master Integrals with one off-shell leg are presented in terms of polylogarithmic functions, using the Simplified Differential Equations approach. The results are relevant for studying various 2 -> 3 scattering processes at the LHC, particularly for leading-color W + 2 jets production.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Bakul Agarwal, Stephen P. Jones, Andreas von Manteuffel
Summary: This study calculates the two-loop QCD corrections to gg -> ZZ involving a closed top-quark loop using a new method, with the amplitude expressed in terms of finite integrals derived by employing syzygies. Numerical integration results show agreement with previous expansions in asymptotic limits and provide ab initio results for intermediate partonic energies and non-central scattering at higher energies.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Luca Buonocore, Paolo Nason, Francesco Tramontano, Giulia Zanderighi
Summary: This study examines several basic photon and lepton-initiated processes at the LHC, utilizing recently developed photon and lepton parton densities for computation. The comparison of different calculation methods and their application in searching for exotic particles and observing Standard-Model processes are discussed.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Matthias Heller, Andreas von Manteuffel, Robert M. Schabinger, Hubert Spiesberger
Summary: The study focuses on the qq-initiated two-loop electroweak-QCD Drell-Yan scattering amplitude with vanishing light quark and lepton masses using dimensional regularization schemes. It is found that the infrared pole terms of the mixed two-loop amplitude are controlled by a known generalization of the dipole formula, and that exactly the same two-loop polarized hard scattering functions are obtained in both the standard 't Hooft-Veltman-Breitenlohner-Maison gamma(5) scheme and Kreimer's anticommuting gamma(5) scheme.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Fabrizio Caola, Silvia Ferrario Ravasio, Giovanni Limatola, Kirill Melnikov, Paolo Nason
Summary: In this study, we investigate the impact of linear power corrections related to QCD on certain collider observables. By presenting arguments, we conclude that such corrections do not appear in inclusive observables with respect to QCD radiation. Although our study is conducted in a simplified framework, the results can be applied, to some extent, to processes in both lepton and hadron colliders.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Simone Alioli, Alessandro Broggio, Matthew A. Lim
Summary: We study the resummation of the 0-jettiness resolution variable tau(0) for the top-quark pair production process in hadronic collisions. Starting from an effective theory framework, we derive a factorisation formula for this observable and calculate its corrections. By matching with fixed order calculations, we obtain the most accurate prediction for the process.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Jeffrey R. Forshaw, Jack Holguin
Summary: In QCD, coherence violation is an interesting and counter-intuitive phenomenon, almost all observables sensitive to soft radiation at hadron colliders will violate coherence to some degree.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Anatoly Radyushkin, Shuai Zhao
Summary: This study presents one-loop corrections for the newly introduced gluon condensate PDF F(x) and provides the expression for the gg-part of its evolution kernel. By strictly adhering to gauge invariance requirements and utilizing on-shell states, it was discovered that there were terms such as q^2δ(x) found for the ξ = 0 GPD F(x, q^2) at nonzero momentum transfer q. The results did not align with the original attempt of one-loop calculations for gluon states, indicating caution for calculations using matrix elements with virtual external gluons.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Daniele Lombardi, Marius Wiesemann, Giulia Zanderighi
Summary: This study computes the NNLO+PS predictions for W+W- production in hadronic collisions, matching them consistently with parton showers using the MINNLOPS method. By including spin correlations, interferences, and off-shell effects, the evaluation time of the two-loop contribution has been significantly reduced. The results show good agreement with experimental measurements from ATLAS and CMS, highlighting the importance of NNLO corrections and matching to parton showers for an accurate simulation of W+W- events.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Martin Beneke, Philipp Boer, Jan-Niklas Toelstede, K. Keri Vos
Summary: This paper discusses the generalization of the leading-twist light-cone distribution amplitude for light mesons including QED effects and its renormalization group evolution at the strong-interaction scale Lambda(QCD). For charged mesons, there are qualitative differences in scale evolution between QCD and QED-generalized, especially regarding the endpoint behavior. The evolution equation is analytically solved to first order in the electromagnetic coupling alpha(em), which resums large logarithms in QCD while providing numerical estimates for QED corrections to Gegenbauer coefficients and inverse moments relevant to (QED-generalized) factorization theorems for hard exclusive processes.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
C. A. Flett, J. A. Gracey, S. P. Jones, T. Teubner
Summary: We calculate the exclusive electroproduction, gamma*p -> Vp, of heavy quarkonia V to NLO in the collinear factorisation scheme, which has been formally proven for this process, extending the photoproduction phase space of the exclusive heavy quarkonia observable to electroproduction kinematics with an off-shell virtuality Q(2) carried by the photon. This process is relevant for diffractive scattering at HERA and the upcoming EIC, as well as at the proposed LHeC and FCC.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Dhimiter D. Canko, Nikolaos Syrrakos
Summary: The article details two resummation methods derived from the Simplified Differential Equations approach applied to a canonical basis of master integrals. The first method facilitates determining boundary conditions by establishing relationships between basis elements, while the second method shows how solutions to a canonical basis with one mass less can be obtained through the x -> 1 limit. Both methods utilize residue matrices for the {0, 1} letters of the canonical differential equation, and are demonstrated through the application to a three-loop ladder-box canonical basis.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Piotr Bargiela, Fabrizio Caola, Andreas von Manteuffel, Lorenzo Tancredi
Summary: This study is of great importance for calculating the NNLO QCD corrections to diphoton production in gluon fusion. The researchers employed a new method to calculate scattering amplitudes, providing accurate and compact analytical results.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
A. Broggio, Ch. Gnendiger, A. Signer, D. Stoeckinger, A. Visconti
JOURNAL OF HIGH ENERGY PHYSICS
(2016)
Article
Physics, Particles & Fields
Alessandro Broggioa, Andrea Ferroglia, Ben D. Pecjak, Adrian Signer, Li Lin Yang
JOURNAL OF HIGH ENERGY PHYSICS
(2016)
Article
Physics, Particles & Fields
Alessandro Broggio, Andrea Ferroglia, Giovanni Ossola, Ben D. Pecjak
JOURNAL OF HIGH ENERGY PHYSICS
(2016)
Article
Physics, Particles & Fields
C. Gnendiger, A. Signer, D. Stoeckinger, A. Broggio, A. L. Cherchiglia, F. Driencourt-Mangin, A. R. Fazio, B. Hiller, P. Mastrolia, T. Peraro, R. Pittau, G. M. Pruna, G. Rodrigo, M. Sampaio, G. Sborlini, W. J. Torres Bobadilla, F. Tramontano, Y. Ulrich, A. Visconti
EUROPEAN PHYSICAL JOURNAL C
(2017)
Article
Physics, Particles & Fields
Alessandro Broggio, Andrea Ferroglia, Ben D. Pecjak, Li Lin Yang
JOURNAL OF HIGH ENERGY PHYSICS
(2017)
Article
Physics, Particles & Fields
Roberto Bonciani, Alessandro Broggio, Leandro Cieri, Andrea Ferroglia
EUROPEAN PHYSICAL JOURNAL C
(2018)
Article
Physics, Particles & Fields
Martin Beneke, Alessandro Broggio, Mathias Garny, Sebastian Jaskiewicz, Robert Szafron, Leonardo Vernazza, Jian Wang
JOURNAL OF HIGH ENERGY PHYSICS
(2019)
Article
Physics, Multidisciplinary
R. Bonciani, A. Broggio, S. Di Vita, A. Ferroglia, M. K. Mandal, P. Mastrolia, L. Mattiazzi, A. Primo, J. Ronca, U. Schubert, W. J. Torres Bobadilla, F. Tramontano
Summary: We present the first fully analytic evaluation of the transition amplitude for the scattering of a massless into a massive pair of fermions at the two-loop level in quantum electrodynamics. Our result has crucial implications for the determination of the electromagnetic coupling in scattering reactions and its impact on the anomalous magnetic moment of the muon.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
A. Broggio, T. Engel, A. Ferroglia, M. K. Mandal, P. Mastrolia, M. Rocco, J. Ronca, A. Signer, W. J. Torres Bobadilla, Y. Ulrich, M. Zoller
Summary: We have calculated the complete set of NNLO QED corrections for muon-electron scattering, including leptonic, non-perturbative hadronic, and photonic contributions. Our calculation takes into account all fermionic corrections as well as the photonic subset that only corrects the electron or the muon line with full mass dependence. By expanding the genuine four-point two-loop topologies in the small electron mass, considering logarithmically enhanced as well as constant mass effects using massification, we were able to achieve a fast and stable implementation of the real-virtual contribution. All matrix elements are implemented in the McMule framework, allowing for the fully-differential calculation of any infrared-safe observable. Our results are a significant milestone towards the ambitious precision goal required by the MUonE experiment, which demands a background prediction at the level of 10 ppm.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Simone Alioli, Georgios Billis, Alessandro Broggio, Alessandro Gavardi, Stefan Kallweit, Matthew A. Lim, Giulia Marinelli, Riccardo Nagar, Davide Napoletano
Summary: We have made several improvements to the Geneva method for matching NNLO calculations to parton shower programs. These include changes to the resummed calculation used in the matching procedure, modifications in the implementation of the splitting functions, and an improved treatment of timelike logarithms. These improvements have increased the stability of the numerical cancellation and showed good agreement with experimental data.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Particles & Fields
Simone Alioli, Georgios Billis, Alessandro Broggio, Alessandro Gavardi, Stefan Kallweit, Matthew A. Lim, Giulia Marinelli, Riccardo Nagar, Davide Napoletano
Summary: In this study, the production of Higgs boson pairs at next-to-next-to leading order in QCD matched to parton showers is investigated using the GENEVA framework and heavy-top-limit approximation. The resummation of large logarithms of the zero-jettiness T-0 up to next-to-next-to-next-to-leading-log accuracy is included. The study is important for matching schemes like that employed in GENEVA, where a different variable is used for resummation compared to the ordering of the parton shower. To further investigate this effect, the original shower interface designed for PYTHIA8 is extended to include other parton showers such as DIRE and SHERPA.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Review
Astronomy & Astrophysics
Simone Alioli, Alessandro Broggio, Alessandro Gavardi, Stefan Kallweit, Matthew A. Lim, Riccardo Nagar, Davide Napoletano, Christian W. Bauer, Luca Rottoli
Summary: Researchers extended the GENEVA Monte Carlo framework using the transverse momentum of a color-singlet system as the resolution variable, allowing for precise predictions through N3LL resummation. They presented satisfactory results for Drell-Yan lepton-pair production and assessed the impact of two different resolution variables on differential observables.
Article
Astronomy & Astrophysics
Simone Alioli, Alessandro Broggio, Stefan Kallweit, Matthew A. Lim, Luca Rottoli
Article
Astronomy & Astrophysics
Alessandro Broggio, Andrea Ferroglia, Miguel C. N. Fiolhais, Antonio Onofre
