Loops and Legs in Quantum Field Theory

Session

Plenary 1

15 Apr 2024, 09:00

Martin Luther

Conveners

Plenary 1

• Peter Marquard (DESY)

Plenary 1

• Peter Marquard (DESY)

Presentation materials

welcome.pdf

48. NNLO corrections to Z+H production at lepton colliders

Ayres Freitas (University of Pittsburgh)

15/04/2024, 09:00

This contribution reports on a semi-numerical technique for the efficient calculation of electroweak NNLO corrections for 2->2 scattering processes. The method is based on dispersion relations and Feynman parameters, as well as suitable subtraction terms for the UV divergencies. As an important phenomenological application, the NNLO electroweak corrections with closed fermion loops to the...

26. Renormalization of the Dark Abelian Sector Model and Predictions for the W-boson mass

Heidi Rzehak (University of Tübingen)

15/04/2024, 09:30

The Dark Abelian Sector Model (DASM) is an extension of the Standard Model with an additional spontaneously broken $U_d(1)$ gauge symmetry connected to a dark sector, i.e. the SM particles do not carry the corresponding charge. In addition to the gauge boson resulting from the extra $U_d(1)$ gauge symmetry, the particle content is extended by a further Higgs boson, one Dirac fermion as well as...

47. Top-Bottom Interference Contribution to Fully-Inclusive Higgs Production

Marco Niggetiedt (Max-Planck-Institut für Physik)

15/04/2024, 10:00

LHC

We evaluate the top-bottom interference contribution to the fully-inclusive Higgs production cross section at next-to-next-to-leading order in QCD. To this end, we compute the relevant two-loop master integrals that enter the real-virtual contribution numerically using the method of differential equations. In addition, the Higgs-gluon form factor at three loops in QCD with two different...

54. Analytic third-order QCD corrections to top-quark and semileptonic b → u decays

Jian Wang (Shandong University in China)

15/04/2024, 11:00

We present the first analytic results of N3LO QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At NNLO, this dominant contribution accounts for 95% of the total correction. By utilizing the optical theorem, the N3LO corrections are related to the imaginary parts of the four-loop self-energy Feynman diagrams,...

56. Taming the N3LO correction to semileptonic $b \to u$ decay

Matteo Fael (CERN)

15/04/2024, 11:30

We present the QCD corrections of order $\alpha_s^3$ to the decay rate of $b \to u l \bar \nu_l$, originating from diagrams with closed fermion loops and neglecting the mass of the up quark. Our calculation relies on integration-by-parts reduction of Feynman integrals with one propagator raised to a symbolic power in Kira.
The five-loop master integrals are then evaluated with AMFlow...

70. Non-Planar Two-Loop Amplitudes for Five-Parton Scattering

Giuseppe De Laurentis (University of Edinburgh)

15/04/2024, 12:00

I present the recent calculation of the two-loop amplitudes required to obtain next-to-next-to-leading order predictions for three-jet production at the Large Hadron Collider. This calculation is performed in full color, that is including contributions from non-planar Feynman diagrams. I review the method of numerical generalized unitarity and the integrand decomposition technique employed to...