Publications (36)
Constructing Compact Ansätze for Scattering Amplitudes
Giuseppe De Laurentis, Ben Page
In these proceedings, we discuss the recent approach of Ref. [1] for the construction of compact Ansätze for scattering amplitudes. The method builds powerful constraints on the a…
Chebyshev Approximations of Feynman Integrals for Collider Physics
Samuel Abreu, Afonso Guerreiro, Ben Page
We present a novel approach for solving canonical differential equations for Feynman integrals based on an approximation of the integrals with Chebyshev polynomials. By exploiting…
The NRQCD spectrum at non-zero temperature using Backus-Gilbert regularisations
Antonio Smecca, Gert Aarts, Chris Allton +10
Understanding how the properties of heavy mesons change as temperature increases is crucial for gaining valuable insights into the quark-gluon plasma. Information about meson masse…
Ansätze for Scattering Amplitudes from -adic Numbers and Algebraic Geometry
Giuseppe De Laurentis, Ben Page
Rational coefficients of special functions in scattering amplitudes are known to simplify on singular surfaces, often diverging less strongly than the naïve expectation. To system…
All Two-Loop Feynman Integrals for Five-Point One-Mass Scattering
Samuel Abreu, Dmitry Chicherin, Harald Ita +4
We compute the complete set of two-loop master integrals for the scattering of four massless particles and a massive one. Our results are ready for phenomenological applications, r…
Critical Points and Syzygies for Feynman Integrals
Ben Page, Qian Song
We investigate a novel theoretical structure underlying the computation of integration-by-parts relations between Feynman integrals via syzygy-based methods. Building on insights f…
Four-loop two-mass tadpoles and the parameter
Samuel Abreu, Arnd Behring, Andrew McLeod +1
We calculate four-loop QCD corrections to the electroweak parameter with a non-vanishing quark mass. At three loops, it was observed that elliptic integrals contribute to…
Higgs characterisation at NLO in QCD: CP properties of the top-quark Yukawa interaction
Federico Demartin, Fabio Maltoni, Kentarou Mawatari +2
At the LHC the CP properties of the top-quark Yukawa interaction can be probed through Higgs production in gluon fusion or in association with top quarks. We consider the possibili…
The two-loop five-point amplitude in super-Yang-Mills theory
Samuel Abreu, Lance J. Dixon, Enrico Herrmann +2
We compute the symbol of the two-loop five-point scattering amplitude in = 4 super-Yang-Mills theory, including its full color dependence. This requires constructing…
Planar Six-Point Feynman Integrals for Four-Dimensional Gauge Theories
Samuel Abreu, Pier Francesco Monni, Ben Page +1
We compute all planar two-loop six-point Feynman integrals entering scattering observables in massless gauge theories such as QCD. A central result of this paper is the formulation…
Recent Results from the FASTSUM Collaboration
Chris Allton, Gert Aarts, Ryan Bignell +10
The FASTSUM Collaboration has developed a comprehensive research programme in thermal QCD using 2+1 flavour, anisotropic ensembles. In this talk, we summarise some of our recent re…
Spectral properties of bottomonium at high temperature: a systematic investigation
Jon-Ivar Skullerud, Gert Aarts, Chris Allton +11
We investigate spectral features of bottomonium at high temperature, in particular the thermal mass shift and width of ground state S-wave and P-wave state. We employ and compare a…
Recent developments from Feynman integrals
Robin Marzucca, Andrew J. McLeod, Ben Page +3
This talk reviews recent developments in the field of analytical Feynman integral calculations. The central theme is the geometry associated to a given Feynman integral. In the sim…
Compact Syzygies for Feynman Integrals from Landau Singularities
Federico Coro, Pavel P. Novichkov, Ben Page +1
We discuss a recent proposal for constructing ``syzygy solutions'', which play a crucial role in integration-by-parts reductions for multi-loop scattering amplitudes. We highlight…
Five-Point Two-Loop Amplitudes from Numerical Unitarity
Samuel Abreu, Fernando Febres Cordero, Harald Ita +2
We present advances in the development of the numerical unitarity method for the computation of multi-loop amplitudes in QCD. As an application, we show results for all the leading…
Heavy quark thermodynamics with anisotropic lattices
Jon-Ivar Skullerud, Rachel Horohan D'Arcy, Gert Aarts +11
We present recent results from the FASTSUM collaboration, using anisotropic lattice QCD to study spectral properties of heavy quarkonia and open heavy flavour systems at high tempe…
R2 vertices for the effective ggH theory
Ben Page, Roberto Pittau
We list all possible R2 Feynman rules needed in NLO computations involving couplings of Higgs and gluons mediated by an infinitely heavy top loop. They provide the rational contrib…
Universal Decomposition of Phase-Space Integrands
David A. Kosower, Ben Page
One-loop integrands can be written in terms of a simple, process-independent basis. We show that a similar basis exists for integrands of phase-space integrals for the real-emissio…
Compact Two-Loop QCD Corrections for Production in Proton Collisions
Giuseppe De Laurentis, Harald Ita, Ben Page +1
We present compact two-loop QCD corrections in the leading-color approximation for the production of an electroweak vector boson, $V = \{W^{\pm}, Z,γ^\star\}$, in association with…
The two-loop five-point amplitude in supergravity
Samuel Abreu, Lance J. Dixon, Enrico Herrmann +2
We compute the symbol of the two-loop five-point amplitude in supergravity. We write an ansatz for the amplitude whose rational prefactors are based on not only 4-di…
LHAPDF6: parton density access in the LHC precision era
Andy Buckley, James Ferrando, Stephen Lloyd +5
The Fortran LHAPDF library has been a long-term workhorse in particle physics, providing standardised access to parton density functions for experimental and phenomenological purpo…
Two-Loop QCD Corrections for Three-Photon Production at Hadron Colliders
Samuel Abreu, Giuseppe De Laurentis, Harald Ita +3
We complete the computation of the two-loop helicity amplitudes for the production of three photons at hadron colliders, including all contributions beyond the leading-color approx…
Bottomonium spectral widths at nonzero temperature using maximum likelihood
Thomas Spriggs, Gert Aarts, Chris Allton +8
We present progress results from the Fastsum collaboration's programme to determine the spectrum of the bottomonium system as a function of temperature using a variety of approache…
Multi-Quark Colour Decompositions from Unitarity
Alexander Ochirov, Ben Page
Any loop QCD amplitude at full colour is constructed from kinematic and gauge-group building blocks. In a unitarity-based on-shell framework, both objects can be reconstructed from…
Differential equations from unitarity cuts: nonplanar hexa-box integrals
Samuel Abreu, Ben Page, Mao Zeng
We compute -factorized differential equations for all dimensionally-regularized integrals of the nonplanar hexa-box topology, which contribute for instance to 2-loop 5-point QC…
Full Colour for Loop Amplitudes in Yang-Mills Theory
Alexander Ochirov, Ben Page
We present a general method to account for full colour dependence Yang-Mills amplitudes at loop level. The method fits most naturally into the framework of multi-loop integrand red…
Genus Drop in Hyperelliptic Feynman Integrals
Robin Marzucca, Andrew J. McLeod, Ben Page +2
The maximal cut of the nonplanar crossed box diagram with all massive internal propagators was long ago shown to encode a hyperelliptic curve of genus 3 in momentum space. Surprisi…
Two-loop off-shell QCD amplitudes in FDR
Ben Page, Roberto Pittau
We link the FDR treatment of ultraviolet (UV) divergences to dimensional regularization up to two loops in QCD. This allows us to derive the one-loop and two-loop coupling constant…
Pseudo-Evanescent Feynman Integrals from Local Subtraction
Alessandro Georgoudis, Ben Page
We introduce a new approach for the computation of the class of Feynman integrals whose integrands vanish in strictly four-dimensions, so-called ''pseudo-evanescent'' integrals. We…
Novel Bottomonium Results
Ben Page, Chris Allton, Seyong Kim
We present the latest results from the use of the Backus-Gilbert method for reconstructing the spectra of NRQCD bottomonium mesons using anisotropic FASTSUM ensembles at non-zero t…
Two-Loop Hexa-Box Integrals for Non-Planar Five-Point One-Mass Processes
Samuel Abreu, Harald Ita, Ben Page +1
We present the calculation of the three distinct non-planar hexa-box topologies for five-point one-mass processes. These three topologies are required to obtain the two-loop virtua…
Hadrons at high temperature: an update from the FASTSUM collaboration
Jon-Ivar Skullerud, Gert Aarts, Chris Allton +16
We present the most recent results from the FASTSUM collaboration for hadron properties at high temperature. This includes the temperature dependence of the light and charmed meson…
A comparison of spectral reconstruction methods applied to non-zero temperature NRQCD meson correlation functions
Thomas Spriggs, Gert Aarts, Chris Allton +9
We present results from the fastsum collaboration's programme to determine the spectrum of the bottomonium system as a function of temperature. Three different methods of extractin…
NNLO final-state quark-pair corrections in four dimensions
Ben Page, Roberto Pittau
We describe how NNLO final state quark-pair corrections are computed in FDR by directly enforcing gauge invariance and unitarity in the definition of the regularized divergent inte…
Feynman Integral Reduction and Landau Singularities
Federico Coro, Pavel P. Novichkov, Ben Page +1
We propose that Feynman integral reduction is controlled by solutions of the Landau equations. We study integral relations with prescribed propagator powers using syzygy methods an…
Planar Two-Loop Five-Gluon Amplitudes from Numerical Unitarity
Samuel Abreu, Fernando Febres Cordero, Harald Ita +2
We present a calculation of the planar two-loop five-gluon amplitudes. The amplitudes are obtained in a variant of the generalized unitarity approach suitable for numerical computa…