Choose your own talk: Three tales in higher-order calculations

by Dr Arnd Behring (CERN)

Wednesday 10 Jan 2024, 10:45 → 11:45 Europe/Berlin

A.1.01/03 - Alps (New)

Higher-order calculations are the backbone of precision predictions in particle
physics. In this presentation, I want to offer three possible topics:

- The four-loop rho parameter and elliptic integrals
 The rho parameter is an important electroweak precision observable. At
 three-loop order, the QCD corrections have been shown to contain elliptic
 Feynman integrals. Let's explore what lies beyond!

- N-jettiness beam functions at N3LO in QCD
 The current frontier for differential distributions at the LHC are N3LO
 corrections. These predictions require intricate schemes to deal with
 singularities from soft and collinear radiation. Beam functions describe
 effects of collinear radiation along the incoming beams and constitute an
 important building block in these schemes. Let's see how to calculate them!

- Massive operator matrix elements for PDFs and deep-inelastic scattering
 When massless quarks become massive, many curious things happen. Massive
 operator matrix elements connect massless and massive descriptions of quarks
 in the context of parton distribution functions and deep-inelastic scattering.
 While calculating them, we discover three spaces, connected by Mellin
 transformations, generating functions and discontinuities and find an
 interesting connection to the optical theorem.

During the talk you, the audience, will have the opportunity to choose between
those topics and decide how the talk is going to go. Bring your smartphone (or
laptop) to vote!