Robert Harlander

Institute for Theoretical Particle Physics and Cosmology
Faculty of Mathematics, Computer Science and Natural Sciences
RWTH Aachen University
52056 Aachen, Germany
phone: +49-241-80-27045
fax: +49-241-80-22187
Office: 28A414, Campus Melaten

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LHC and Philosophy



Master Topics for winter term 2022/2023

Click on the topic titles below to see more details. To apply, follow the instructions here, where you can also find topics from the other members of our institute. The slides of that presentation can be found here. In order to discuss the topics in more detail, visit this zoom-room on 30 June 2022 at 1pm.
The gradient-flow formulation of QCD

The gradient flow is a concept which provides a potential bridge between perturbative and non-perturbative physics. The crucial parameter switching between these two regimes is the flow time t.

In this project, you will learn the concepts of the gradient flow and develop methods to extrapolate the perturbative small-t region to the non-perturbative large-t regime. This will help to combine perturbative and lattice results for the determination of fundamental QCD parameters.

There are several topics that can be worked on during a master's thesis, among them the definition of QCD ghosts at finite flow time, or the asymptotic expansion in the limit of large flow times.

Related publications from our group: Examples for previous master's theses on this topic:
  • Janosch Borgulat (April 2022, RWTH Aachen)
    Towards the Full Energy-Momentum Tensor in the Gradient Flow Formalism
  • Yannick Kluth (September 2018, RWTH Aachen)
    Gradient Flow and the Energy-Momentum Tensor
  • Fabian Lange (September 2017, RWTH Aachen):
    The Perturbative Gradient Flow at Higher Orders
  • Johannes Artz (June 2017, RWTH Aachen):
    Automatic approach to the perturbative gradient flow

Effective Field Theories to arbitrary orders

Effective Field Theories can describe physics beyond the Standard Model in a generic way. Their construction is algorithmic, but very cumbersome.

In this project, you will develop an algorithm for transformations between different operator bases for EFTs. This will be useful for the interpretation of data collected at the LHC and future colliders, in particular in the light of possible new discoveries.

Previous master's theses on this topic:
  • Tim Kempkens (October 2021, RWTH Aachen)
    Automated Generation of EFT Operators
  • Joshua Rosaler (June 2020, RWTH Aachen)
    EFTGen: An Algorithm for Automatic Generation of Higher Dimensional Operators in Effective Field Theory
Some literature:

Renormalization of Effective Field Theories

Effective Field Theories are a way to parametrize unknown physics. A proper theoretical description requires the renormalization of the higher-dimensional operators at higher orders in perturbation theory.

In this project, you will learn the concepts of Effective Field Theories and operator renormalization. You will develop a method to systematically determine the renormalization matrix to higher orders in perturbation theory.

Previous master's theses on this topic:

  • Joshua Schophoven (November 2020, RWTH Aachen)
    Methods for Higher Order Renormalisation of Quantum Field Theories
Some literature:

Higgs production at the LHC

The Higgs mechanism of the Standard Model is the minimal implementation of spontaneous symmetry breaking. A careful study of the underlying phenomenology may shed light into regions beyond the Standard Model.

In this project, you will build on long experience of our group in this field. You will theoretically study the production mechanisms of Higgs bosons beyond the Standard Model, in particular supersymmetric models, 2-Higgs-doublet models, or effective field theories.

Related publications from our group: Examples for previous master's theses on this topic:
  • Sebastian Rhode (April 2019), Higgs Production in Gluon Fusion with Higher-Dimensional Operators
  • Lukas Simon (October 2018), CP-mixing effects in Higgs-Strahlung

last updated on Oct 29, 2022 by RH