6 papers
Getting a handle on correlation functions
Gernot Eichmann
The central objects in a quantum field theory are its n-point correlation functions and matrix elements. Their structure is determined by Lorentz invariance and leads to tensor dec…
Timelike form factor for the anomalous process $γ^\ast Ï\rightarrow ÏÏ$
Angel S. Miramontes, Gernot Eichmann, Reinhard Alkofer
The form factor for the anomalous process $γ^\ast Ï\rightarrow ÏÏ$ is calculated in the isospin limit for several values of the light current-quark mass (i.e.,…
Structure of open-flavour four-quark states in the charm and bottom region
Joshua Hoffer, Gernot Eichmann, Christian S. Fischer
We present quantitative results for masses and the internal structure of four-quark states with two heavy quarks, i.e. with and $q,q' \in \{u…
Functional methods for hadron spectroscopy
Gernot Eichmann, Christian S. Fischer, Joshua Hoffer
We summarize recent results for four-quark states with hidden and open flavor obtained from a four-quark Bethe-Salpeter/Faddeev-Yakubowsky equation. The approach dynamically predic…
Hadron physics with functional methods
Gernot Eichmann
We give a pedagogical introduction to hadron spectroscopy and structure studies using functional methods. We explain the basic features of Dyson-Schwinger, Bethe-Salpeter and Fadde…
Axial-vector and scalar contributions to hadronic light-by-light scattering
Gernot Eichmann, Christian S. Fischer, Tim Haeuser +1
We present results for single axial-vector and scalar meson pole contributions to the hadronic light-by-light scattering (HLbL) part of the muon's anomalous magnetic moment. In the…