Internal Seminars WS 19/20

Tue 01.10.2019 14:00 (Glassbox MBP1)

Annika Reinert (Bonn University)

Dark photons and plasma effects


Mon 07.10.2019 10:00 (MBP1 015)

3 Master Thesis Presentations:

10:00: Jasmina Nasufi (RWTH)
Beam functions in transverse momentum factorisation
10:40: Marco Niggetiedt (RWTH)
Quark mass effects in Higgs boson processes
11:20: Marcel Wald (RWTH)
Top-quark pair production in electron-positron collisions


Tue 08.10.2019 10:15 (MBP1 026)

Master Thesis Presentation:

Markus Schmidt (RWTH)
The Fermi Bubbles within a Stochastic Differential Equation Approach


Wed 16.10.2019 11:00 (26C 402)

Master Thesis Presentation:

Lucius Bsuhnaq (RWTH)
Calculational methods in the Gradient Flow Formalism


Thu 17.10.2019 14:00 (26C 402)

Master Thesis Midterm Presentation:

Thorben Finke (RWTH)
Deep neural networks for new physics searches at the LHC



Thu 17.10.2019 14:45 (26C 402)

Master Thesis Presentation:

Fabian Esser (RWTH)
Effects of higher-dimensional operators to the Higgs sector in a split-SUSY model



Tue 29.10.2019 10:15 (MBP110)

Master Thesis Midterm Presentation:

Juliana Carrasco (RWTH)
Long-lived particles in strongly interacting dark sectors



Wed 30.10.2019 10:00 (26C 402)

Master Thesis Midterm Presentation:

Juliana Carrasco (RWTH)
Feynman Rules with massive and massless spinor-helicity variables



Tue 12.11.2019 11:00 (26C 402)

Master Thesis Presentation:

Pattara Angkinun (RWTH)
Reinterpretation of Supersymmetry Searches in a Simplified Flavor Violation Model



Thu 05.12.2019 10:00 (26C 401)

Master Thesis Midterm Presentation:

Jonas Rongen (RWTH)
Scalar QCD/QED in the gradient flow formalism



Wed 11.12.2019 11:00 (MBP1 026)

Master Thesis Presentation:

Marc Klinger (RWTH)
Blazar variability in the context of magnetic reconnection and the plasmoid instability



Tue 14.01.2020 9:15 (MBP1 026)

Master Thesis Midterm Presentation:

Parth Bhargava (RWTH)
Beyond the single-stream treatment of cosmological structure formation with the Schrödinger Method

The Schrödinger method (ScM) for large scale structure formation is a phase-space based description of collisionless Cold Dark Matter (CDM). It involves modelling the dynamics of dark matter with the Vlasov - Poisson equation. So far it has been only applied to CDM, i.e. with a single phase-space sheet where it is able to resolve the shell-crossing singularity. The topic of my mid-term talk is to discuss how one can also model cosmological initial conditions with a finite velocity dispersion within ScM. I shall motivate the necessary theory and show some results with warm initial conditions which can be used to model Warm Dark Matter (WDM) and neutrinos.



Wed 12.02.2020 11:00 (26C 402)

Bachelor Thesis Presentation:

Nils Felten (RWTH)
Die Entwicklung des Higgs-Mechanismus



Wed 04.03.2020 11:15 (MBP1 026)

Andrew Robertson (Durham)

Probing the nature of dark matter - from dwarf galaxies to galaxy clusters

I will begin with a discussion of dwarf galaxy rotation curves, outlining a number of proposed mechanisms for producing their ‘puzzling diversity’ (the fact that some appear to have constant density dark matter ‘cores', while others have centrally-concentrated ‘cusps') and highlighting the strengths and weaknesses of these different mechanisms in matching the observational data. One of these possibilities is that dark matter is more complicated than CDM, with self-interacting dark matter (SIDM) able to modify the distribution of dark matter in the centres of galaxies. SIDM would not only affect dwarf galaxies, but more massive systems as well. I will present the first large-volume, cosmological simulations including both SIDM and baryonic physics. SIDM has little effect on the distribution of gas and stars within massive galaxies and galaxy clusters. However, gravitational lensing observables can discriminate between dark matter models, and I will show how the distribution of Einstein radii can be used to constrain the SIDM cross-section. Finally, I will discuss using these simulations to test analytic methods for modelling SIDM density profiles in the presence of baryons.



Thu 05.03.2020 11:00 (26C 402)

Long Chen (MPI Munich)

Some issues in the computation of two-loop QCD amplitudes of ZH production from quark-antiquark annihilation

In this talk, I will discuss some technically interesting observation made in a recent calculation of the two-loop QCD corrections to the amplitude of the Higgs production associated with a Z boson via the quark-antiquark annihilation channel with a non-vanishing bottom-quark Yukawa coupling, which is a necessary ingredient of the full next-to-next-to-leading-order QCD corrections to the ZH process in the five-flavour scheme. The computation is performed by projecting the D-dimensional scattering amplitude directly onto a set of Lorentz structures related to the linear polarisation states of the Z boson. The Ward identity for this amplitude in the presence of Yukawa interactions is derived and subsequently verified to the two-loop order in QCD. In particular, I will comment on an interesting subtlety appearing in the conventional form factor decomposition of amplitudes involving axial currents regularised in D dimensions, as well as some related intriguing issues.