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

by Arnd Behring (CERN)

Thursday Mar 14, 2024, 2:00 PM → 3:00 PM Europe/Zurich

Aula Caldirola (Università degli Studi di Milano)

Abstract:
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 DIS
 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!