Investigation of γ*γ* → η' at the BESIII Experiment

In this analysis, the production of pseudoscalar eta' mesons via two virtual spacelike photons is studied (gamma*gamma*-> eta'). Double-tagged measurements are conducted at the BESIII experiment in Beijing, China, in which both virtual photons possess nonzero virtualities Q(1)(2) and Q(1)(2). The Monte Carlo generator Ekhara 3.0 is used to simulate the expected signal event distribution. By measuring the double differential cross section at BESIII, the transition form factor (TFF) can be determined for Q(1)(2), Q(1)(2) < 2 GeV2. The TFF of pseudoscalar mesons serves as essential input for calculating the hadronic light-by-light contribution to the theoretical Standard Model prediction of the anomalous magnetic moment of the muon a(mu) = (g(mu) - 2)/2.