Ablikim, M.Achasov, M. N.Adlarson, P.Ai, X. C.Aliberti, R.Amoroso, A.Çetin, Serkant Ali2024-05-192024-05-1920242470-00102470-0029https://doi.org10.1103/PhysRevD.109.012007https://hdl.handle.net/20.500.12713/5844Using a data sample of (10087 +/- 44) x 106 J=psi events collected by the BESIII detector in 2009, 2012, 2018 and 2019, the electromagnetic Dalitz process J=psi -> e+e-eta(1405) is observed via the decay eta(1405) -> pi 0f0(980), f0(980) -> pi+pi-, with a significance of about 9.8 sigma. The branching fraction of this decay is measured to be B(J=psi -> e+e-eta(1405)-> e+e- pi 0f0(980) -> e+e- pi 0 pi+ pi-)=(2.04 +/- 0.20(stat)+/- 0.08(syst))x 10-7. The branching fraction ratio B(J=psi -> e+e- eta(1405))=B(J=psi -> gamma eta(1405)) is determined to be (1.36 +/- 0.17(stat) +/- 0.06(syst)) x 10-2. Furthermore, an e+e- invariant mass dependent transition form factor of J=psi -> e+e-eta(1405) is presented for the first time. The obtained result provides input for different theoretical models and is valuable for the improved understanding the intrinsic structure of the eta(1405) meson.eninfo:eu-repo/semantics/openAccessGaseous-HydrogenFinal-StatesAnnihilationsE(+)E(-)RestTofArticle1091WOS:0011832351000062-s2.0-85182556273N/A10.1103/PhysRevD.109.012007Q1