Loopfest XXII

Session

Session 2

20 May 2024, 14:00

Fondren Science Building 123 (Dallas Texas USA)

Conveners

Session 2

• Joshua Isaacson
• Tobias Neumann (William & Mary)

4. Five Parton Scattering at Two Loops

Harald Ita (PSI)

20/05/2024, 14:00

We compute the two-loop helicity amplitudes for the scattering of five partons, including all contributions beyond the leading-color approximation. The analytic expressions are represented as linear combinations of transcendental functions with rational coefficients, which we reconstruct from finite-field samples obtained with the numerical unitarity method. Guided by the requirement of...

24. Recent progress in planar two–loop six–point Feynman integrals computation

Antonela Matijašić

20/05/2024, 14:35

The state-of-the-art in current two-loop QCD amplitude calculations is at five-particle scattering. In contrast, very little is known at present about two–loop six–particle scattering processes. In recent years, the results for one-loop hexagon integrals to higher order in the dimensional regulator become available as well as the results on the maximal cut of the planar two-loop six-point...

30. p-adic reconstruction of rational functions in multi-loop calculations

Herschel Chawdhry (Florida State University)

20/05/2024, 15:10

The calculation and manipulation of large multi-variable rational
functions is a key bottleneck in multi-loop calculations. In this talk I
will present work using p-adic numbers to reconstruct rational functions
in a compact form. I will apply this to examples such as rational
functions appearing in cutting-edge 2-loop 5-point amplitudes calculations.

17. Feynman integral reduction using Blade

Xin Guan (SLAC)

20/05/2024, 16:15

Feynman integral reduction is very challenging for state-of-the-art calculations. Blade represents the first implementation of the block-triangular form improved Feynman integral reduction method, typically resulting in a remarkable improvement of the IBP reduction efficiency by one to two orders of magnitude. In this talk, I will introduce the key ideas of Blade and present various benchmarks.

3. GRIFFIN: A C++ library for higher-order electroweak corrections

Ayres Freitas

20/05/2024, 16:50

This talk describes a modular framework for the description of electroweak scattering and decay processes, including but not limited to Z-resonance physics. The framework consistently combines a complex-pole expansion near a s-channel resonance with a regular fixed-order perturbative description away from the resonance, in a manifestly gauge-invariant scheme. This framework has been...

10. A Numerical Implementation of the LASS Subtraction Scheme

Adam Kardos

20/05/2024, 17:25

NNLO QCD corrections are indispensible for Today's and
tomorrow's colliders. Several schemes are available in
the literature. The LASS (Local Analytic Subtraction Scheme)
as it is developed in Turin gives one more solution to
the problem. Its simple analytical integrals make it tempting
to generalize even to hadron collisions. Before this
crucial step a proof-of-concept numerical...

2. Heavy Quark Production at High Precision

Prof. Fred Olness (Southern Methodist University (US))

20/05/2024, 18:00

We review improvements in precision heavy quark production including updates in the xFitter global analysis framework, and extensions of ACOT using fast grid techniques.