YOUNGST@RS - Loop-the-Loop: Feynman Calculus and its Applications to Gravity and Particle Physics

Session

Scattering Amplitudes in Particle Physics

14 Nov 2024, 10:30

21. Two-loop massive corrections for diphoton production in gluon fusion

Federico Coro

14/11/2024, 10:30

We consider the two-loop helicity amplitudes for photon pair
production in gluon fusion with a loop of heavy quark. We adopt a
procedure to obtain an $\epsilon$-factorised form for the full system of
MIs, also for those whose analytic structure involves elliptic functions. We discuss the
simplifications at amplitude and integrand level that can be achieved
by expressing the amplitude...

22. ε-form for Feynman integrals with Calabi-Yau geometry

Sara Maggio

14/11/2024, 11:00

ε-factorized differential equations are needed to solve Feynman integrals order by order in ε. In this talk, I will first introduce geometries beyond multiple polylogarithms, and then discuss how to derive an ε-factorized differential equation for integrals with an underlying Calabi-Yau geometry dependent on one or more parameters. I will show some examples where we tested our method and I...

23. Towards two-loop QCD corrections to pp → tt̄j

Colomba Brancaccio

14/11/2024, 11:30

I discuss the status of the computation of two-loop QCD corrections to top quark pair
production in association with a jet at hadron colliders, which represents a bottleneck
in achieving more precise predictions for this process. I briefly introduce cutting-edge
computational techniques that tackle the extreme algebraic and analytic complexities
of two-loop multi-scale helicity amplitudes...

24. A first computation of three-loop master integrals for the production of two off-shell vector bosons with different masses

Dhimiter Canko

14/11/2024, 13:30

In this talk, we present analytic results in terms of real-valued multiple polylogarithms up to order six in the expansion around the dimensional regulator and on physical kinematics for four integral families that are relevant to the production of two off-shell vector bosons with different masses. Our study consists of a ladder-box, a tennis-court, and two reducible ladder-box-like families.

25. Computing form factors in N=4 sYM for Higgs plus jet(s) production

Jungwon Lim

14/11/2024, 14:00

In high precision era of Higgs physics, it is crucial to compute the amplitudes in higher order so that we can test our Standard Model. The maximally supersymmetric Yang-Mills theory is a nice playground having more simplification while it still retains footprint of QCD. In this talk, I will discuss mainly about the techniques to compute the three-point three-loop form factors in N=4 sYM and...

26. Tackling Apparent Singularities in Calabi-Yau Feynman Integrals

Sebastian Pögel

14/11/2024, 14:30

It is well-known that Calabi-Yau geometries make a prominent appearance in the evaluation of Feynman integrals. Going beyond the simplest cases of Calabi-Yau integrals—-specifically the Banana integrals—-I will examine features that require extensions of established methods, particularly in the presence of apparent singularities. I will illustrate these methods through the derivation of an...

27. Subtracting IR singularities with a fully general analytic algorithm in massless QCD

Gloria Bertolotti

14/11/2024, 15:30

This talk presents the construction of the NNLO subtraction formula for the cancellation of IR singularities obtained within the framework of Local Analytic Sector Subtraction. Such general and automated program has been completed for the treatment of unresolved radiation in processes featuring any arbitrarily-populated massless final state. The final outcome is a compact and analytic...

28. Numerical Integration of the $N_f$ Virtual Corrections to Triboson Production at NNLO

Matilde Vicini

14/11/2024, 16:00

I will present our recent computation of previously inaccessible $N_f$
virtual contributions at NNLO for the production of three massive vector
bosons. We perform the numerical integration by simultaneously
addressing infrared, ultraviolet, and threshold singularities through
local subtractions in momentum space. I will outline the ongoing work
toward obtaining the complete NNLO...

29. Nested soft-collinear infrared subtraction

Federica Devoto

14/11/2024, 16:30

In this talk, I will present the nested soft-collinear approach to the long-standing issue of infrared subtraction at next-to-next-to-leading order in QCD. At this order in perturbation theory, the structure of infrared singularities is rather clear. However, a fully general method for combining virtual and real emission singularities yielding predictions for physical observables is only now...