Frontiers and Careers in Nuclear and Hadronic Physics 2023

Study of Neutral-Pion Pair Production in Two-Photon Scattering at BESIII

30 Oct 2023, 11:30

20m

Student and Postdoc Talks Research Talks

Speaker

Max Lellmann (JGU Mainz)

Description

The anomalous magnetic moment of the muon, $a_{\mu }=(g-2{)}_{\mu }/2$, is one of the most precisely measured observables of the Standard Model. However, its value shows a sizeable discrepancy to the Standard Model prediction. It is still under discussion whether this discrepancy is a hint for New Physics or a proof for the limited understanding of strong interaction at low energies. To get a better understanding of this discrepancy, one needs to reduce the uncertainty of both, the Standard Model prediction and the direct measurement.

Information on the production of pion pairs in two-photon fusion processes plays an important role in the dispersive calculation of the hadronic light-by-light scattering contribution to $a_{\mu }$, which is one of the two large contributions to the Standard Model predictions uncertainty. The BESIII experiment, located at the institute of high energy physics in Beijing/China, offers a perfect testbed for the investigation of two-photon processes at small momentum transfers. The process $e^{+}{e}^{-}\to e^{+}{e}^{-}{\pi }^0{\pi }^0$ is measured at the BESIII experiment at centre-of-mass energies between 3.68 and 4.7$$GeV with a total integrated luminosity of more than 20$$fb${}^{-1}$, with more data being available in future. This presentation will discuss the current status of the analysis.