Köln 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HK: Fachverband Physik der Hadronen und Kerne
HK 34: Hadron Structure and Spectroscopy IV
HK 34.3: Vortrag
Mittwoch, 12. März 2025, 18:00–18:15, HS 3 Physik
Partial Wave Analysis of the process γ*γ→ f1(1285)→ηπ+π− at BESIII — •Jan Muskalla, Achim Denig, Chistoph Redmer, and Max Lellmann — Johannes Gutenberg-Universität Mainz
The anomalous magnetic moment of the muon aµ is one of the most precisely measured observables of the Standard Model (SM). However, large discrepancies persist between SM predictions and experiment. The uncertainties of the SM prediction are currently dominated by hadronic contributions. Improving the precision requires more accurate measurements of transition form factors (TFFs) for axial-vector mesons contributing to hadronic light-by-light scattering (HLbL). These TFFs serve as experimental input to theoretical calculations and can be accessed from the cross section of meson production in γγ collisions at e+e− machines.
The BESIII experiment at the Beijing Electron Positron Collider (BEPCII) is collecting data in the τ-charm energy region and offers large datasets ideally suited for studying γγ interactions. With a data set of 20 fb−1 at √s=3.77 GeV, the process γ*γ→ f1(1285) is investigated in a single tag configuration, where only one of the scattered electrons is detected. This allows the measurement of the momentum dependence of the TFF. To study the interference effects in the decay f1(1285)→ηπ+π−, a partial wave analysis (PWA) is performed. This talk will discuss the data analysis, amplitudes for the PWA and techniques to extract the TFFs for the different helicity configurations of the f1(1285).
Keywords: BESIII; PWA; HLbL; TFF; g-2