Related papers: An optimized basis for hadronic light-by-light sca…
The contributions to the muon anomalous magnetic moment from hadronic vacuum polarization and from hadronic light-by-light scattering are reexamined within the frame work of chiral perturbation theory; the $1/N_c$-expansion; and the…
We present our model-independent and data-driven method to describe pseudoscalar meson transition form factors in the space- and (low-energy) time-like regions. The method is general and conforms a toolkit applicable to any other form…
We develop a method to compute the pion transition form factor directly at arbitrary space-like photon momenta and use it to determine the $\pi^0$-pole contribution to the hadronic light-by-light scattering in the anomalous magnetic moment…
We summarise recent results for the quark loop part of the light-by-light scattering contribution to the muons anomalous magnetic moment. In particular we focus on the impact of a momentum dependent quark and quark-photon vertex. We compare…
We summarize our recent results for the quark loop part of the light-by-light scattering contribution as well as the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon. In particular we focus on the role…
We present preliminary results from our calculation of the pseudoscalar transition form factors of the $\eta$ and $\eta'$ mesons using staggered quarks on $N_f=2+1+1$ gauge ensembles generated by the Budapest-Marseille-Wuppertal…
We review the status of the hadronic light-by-light contribution to the muon anomalous magnetic moment and critically compare recent calculations. We also study in detail which momentum regions the pi^0 exchange main contribution…
Whereas the theoretical results for the dominant contributions to hadronic light-by-light scattering coming from pseudoscalar meson exchange have converged over the past years, the various published estimates of the contribution due to…
We calculate the hadronic light-by-light contributions to the muon $g-2$. We use both $1/N_c$ and chiral counting to organize the calculation. Then we calculate the leading and next-to-leading order in the $1/N_c$ expansion low energy…
The precision measurements of well-known light-by-light reactions lead to important insights of nonlinear quantum electrodynamics (QED) vacuum polarization. The laser of an intense electromagnetic field strength provides an essential tool…
We have studied the $P\to\gamma^\star\gamma^\star$ form factor in Resonance Chiral Theory, with $P = \pi^0,\eta,\eta'$, to compute the contribution of the pseudoscalar pole to the hadronic light-by-light piece of the anomalous magnetic…
In recent years, the anomalous magnetic moment of the muon has triggered a lot of activity in the lattice QCD community because a persistent tension of about $3.5~\sigma$ is observed between the phenomenological estimate and the Brookhaven…
We think that phenomenological resonance Lagrangian models, constrained by global fits from low energy hadron reaction data, can help to improve muon g-2 predictions. The main issue are those contributions which cannot be calculated by…
In this thesis, I present dispersive treatments of two hadronic processes: the semileptonic kaon decay $K_{\ell4}$ and hadronic light-by-light scattering. The $K_{\ell4}$ decay is one of the best sources of information on some of the…
The hadronic light-by-light scattering contribution to the muon g-2 is the most troublesome component of its theoretical prediction; (1) it cannot be determined from the other measurable quantities, (2) the dimensional argument and the…
The calculation of the hadronic light-by-light scattering contribution to the muon g-2 currently relies entirely on models. Measurements of the form factors which describe the interactions of hadrons with photons can help to constrain the…
Short-distance constraints from the operator product expansion in QCD play an important role in the evaluation of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. While conventional hadronic…
We employ Hamiltonian light-front quantum field theory in a basis function approach to solve the non-perturbative problem of an electron in a strong scalar transverse confining potential. We evaluate both the invariant mass spectra and the…
The neutral pion generates the leading pole contribution to the hadronic light-by-light tensor, which is given in terms of the nonperturbative transition form factor $\mathcal{F}_{\pi^0\gamma\gamma}(q_1^2,q_2^2)$. Here we present an…
We present our recent results on the hadronic light-by-light pseudoscalar-exchange contribution to the anomalous magnetic moment of the muon using rational approximants. Our work provides a generalization of Pad\'e approximants to the…