@article{4018004105234074846c0bc8f04d101c,
title = "Observation of the dalitz decay η{\textquoteright}→γe+e−",
abstract = "We report the first observation of the Dalitz decay η{\textquoteright}→γe+e−, based on a data sample of 1.31 billion J/ψ events collected with the BESIII detector. The η{\textquoteright} mesons are produced via the J/ψ→γη{\textquoteright} decay process. The ratio Γ(η{\textquoteright}→γe+e−)/Γ(η{\textquoteright}→γγ) is measured to be (2.13±0.09(stat)±0.07(sys))×10−2. This corresponds to a branching fraction B(η{\textquoteright}→γe+e−)=(4.69±0.20(stat)±0.23(sys))×10−4. The transition form factor is extracted and different expressions are compared to the measured dependence on the e+e− invariant mass. The results are consistent with the prediction of the vector meson dominance model.",
author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and Ai, {X. C.} and O. Albayrak and M. Albrecht and Ambrose, {D. J.} and A. Amoroso and An, {F. F.} and Q. An and Bai, {J. Z.} and {Baldini Ferroli}, R. and Y. Ban and Bennett, {D. W.} and Bennett, {J. V.} and M. Bertani and D. Bettoni and Bian, {J. M.} and F. Bianchi and E. Boger and O. Bondarenko and I. Boyko and Briere, {R. A.} and H. Cai and X. Cai and O. Cakir and A. Calcaterra and Cao, {G. F.} and Cetin, {S. A.} and Chang, {J. F.} and G. Chelkov and G. Chen and Chen, {H. S.} and Chen, {H. Y.} and Chen, {J. C.} and Chen, {M. L.} and Chen, {S. J.} and X. Chen and Chen, {X. R.} and Chen, {Y. B.} and Cheng, {H. P.} and Chu, {X. K.} and G. Cibinetto and D. Cronin-Hennessy and Dai, {H. L.} and Dai, {J. P.} and A. Dbeyssi and D. Dedovich and Deng, {Z. Y.} and A. Denig and I. Denysenko",
note = "Publisher Copyright: {\textcopyright} 2015 American Physical Society.",
year = "2015",
month = jul,
day = "1",
doi = "10.1103/PhysRevD.92.012001",
language = "English",
volume = "92",
journal = "Physical Review D - Particles, Fields, Gravitation and Cosmology",
issn = "1550-7998",
number = "1",
}