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collaborations:
LHC and Philosophy
DFG RTG
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Research interests:
My research interests are in the field of theoretical particle physics.
The focus of my research is centered around the physics of the Higgs boson.
A list of conferences can be found here.
Details
Gradient Flow
What started as a small side project with my student Tobias Neumann in 2016
has now become one of my main fields of research.
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R.V. Harlander and T. Neumann,
The perturbative QCD gradient flow to three loops
JHEP 06 (2016) 161
[arXiv:1606.03756]
67 citations
This is my first paper on the gradient flow. It is also the first three-loop calculation within the gradient flow ever. We calculated the flowed action density in perturbation theory, which provides the conversion of the strong coupling from the MSbar scheme to the GF scheme. Given a sufficiently precise lattice calculation of that quantity, one would be able to derive the strong coupling in the MSbar scheme to high precision.
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J. Artz, R.V. Harlander, F. Lange, T. Neumann, and M. Prausa,
Results and techniques for higher order calculations within the gradient flow formalism
JHEP 06 (2019) 121
[err. ibid. 10 (2019) 032]
[arXiv:1905.00882]
48 citations
This paper describes the technical details behind our calculations within the gradient-flow formalism. It gives a complete list of the Feynman rules for flowed QCD, it describes their implementation into QGRAF, the algebraic manipulations when calculating the Feynman diagrams with FORM, the reduction of the integrals to master integrals using Kira+Firefly, and the numerical evaluation of the master integrals. It also includes a number of applications.
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Effective Field Theories
The fact that the Large Hadron Collider has not found any particles besides
those described by the Standard Model has pretty much
put our quest for understanding
fundamental physics on hold. All of the plethora of models developed as
possible extension of the Standard Model in order to describe phenomena
such as Dark Matter or Dark Energy have somewhat lost their initial attractivity.
Instead, particle physics has turned to a more agnostic description of possible
physics beyond the Standard Model, going by the name of
Effective Field Theories (EFTs).
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R.V. Harlander and M.C. Schaaf,
AutoEFT: Automated Operator Construction for Effective Field Theories
Comput. Phys. Commun. 300 (2024) 109198
[arXiv:2309.15783]
13 citations
The construction of EFTs is extremely cumbersome. For example, the first approximation for an EFT based on the Standard Model involves 2500 different terms. With AutoEFT, we have developed a tool which constructs EFTs automatically, given the field content and the symmetries of the theory.
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R.V. Harlander, T. Kempkens, M.C. Schaaf,
Standard Model Effective Field Theory up to Mass Dimension 12
Phys. Rev. D 108 (2023) 055020
[arXiv:2305.06832]
37 citations
We used our program AutoEFT to derive, for the time ever, the operators of the SMEFT basis up to mass dimension 10, 11, and 12. Note that it took almost 25 years to take the step from mass dimension 6 to 8.
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Higgs physics
This used to be my main research field around the time of the Higgs discovery
in the year 2012. I have contributed to the prediction of the Higgs production
rate at the Large Hadron Collider, I have studied how
last updated on
Jul 10, 2025 by RH
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