Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HK: Fachverband Physik der Hadronen und Kerne
HK 37: Hadron Structure and Spectroscopy VII
HK 37.1: Gruppenbericht
Donnerstag, 19. März 2026, 16:15–16:45, PHIL C 301
Measurements of two-photon scattering reactions at the BESIII experiment as inputs to the Hadronic Light-by-Light contribution to (g−2)µ — Achim Denig, Max Lellmann, Jan Muskalla, and •Christoph Florian Redmer for the BESIII collaboration — Institut für Kernphysik, Johannes Gutenberg-Universität Mainz
While recently agreement between the direct measurements and the Standard Model prediction of the anomalous magnetic moment of the muon was reported, further improvement of the prediction is required to match the precision of the measurement. The prediction is limited by the knowledge of the hadronic contributions, which can be calculated from data-driven approaches. One of these contributions is the hadronic Light-by-Light scattering. It depends on the knowledge of transition form factors of light pseudoscalar, scalar, axial, and tensor mesons as well as the coupling of multi-meson systems to two photons, which are accessible in e+e− collisions.
The BESIII experiment, operated at the BEPCII accelerator in Beijing, China, has collected the world’s largest data sets of e+e− collisions in the τ-charm region between 2 GeV and 5 GeV. The recently completed 20 fb−1 data set at 3.773 GeV is ideally suited to study the momentum-transfer dependence of transition form factors at space-like momentum transfers of Q2≈ 1 GeV2, which is of special relevance in the context of aµ. In this presentation we discuss recent results, ongoing projects, and future prospects of the measurements at the BESIII experiment. — Supported by DFG FOR5327
Keywords: anomalous magnetic moment of the muon; two-photon scattering; transition form factors