# Research Group of Prof. Steinhauser

Currently our working group studies the following topics:

• Higgs boson production at the LHC

 We consider both single and double Higgs boson production. The latter is a promising candidate in order to obtain information about the triple Higgs boson coupling and thus about the scalar potential in the Standard Model.
• Rare decays of $B$ mesons

 Rare $B$ meson decays like $\bar{B}\to X_s\gamma$ and $B_s\to\mu^+\mu^-$ are sensitive probes for physics beyond the Standard Model. For example, one obtains the most sensitive bound of the mass of a charged Higgs boson in the 2HDM II model, see plot [Eur.Phys.J. C77 (2017) no.3, 201]
• Non-relativistic QCD and QED

• Massive and massless form factors

 Form factors enter as building blocks a number of physical quantities. Among them are massive fermion production in electron positron collisions, deacay rates scalar and pseudo-scalar Higgs bosons, virtual corrections of the Drell-Yan process for the production of lepton pairs at hadron colliders, and virtual corrections to Higgs boson production at the LHC. Furthermore, form factors constitute important toys, which help to investigate the structure of high-order quantum corrections. Form factors are also an indispensable tools to investigate the infrared structure of scattering amplitudes to high orders in perturbation theory. In particular, it is possible to extract universal process-independent quantities like the cusp anomalous dimension.
• Supersymmetric Higgs boson masses
• Determination of Standard Model parameters

 The most precise values for for the charm and bottom quark masses are obtained with the help of low-moment sum rules. The figure shows the $\overline{\rm MS}$ charm quark mass at the renormalization scale $\mu=3$ GeV. [Phys.Rev. D96 (2017) no.11, 116007]
• Automation of multi-loop calculations