Measurement of the ω→π0e+e- and η→e+e-γ Dalitz decays with the A2 setup at the Mainz Microtron

A2 Collaboration at MAMI

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The Dalitz decays η→e+e-γ and ω→π0e+e- have been measured in the γp→ηp and γp→ωp reactions, respectively, with the A2 tagged-photon facility at the Mainz Microtron. The value obtained for the slope parameter of the electromagnetic transition form factor of η, Λη-2=(1.97±0.11tot)GeV-2, is in good agreement with previous measurements of the η→e+e-γ and η→μ+μ-γ decays. The uncertainty obtained in the value of Λη-2 is lower than in previous results based on the η→e+e-γ decay. The value obtained for the ω slope parameter, Λωπ0-2=(1.99±0.21tot)GeV-2, is somewhat lower than previous measurements based on ω→π0μ+μ-, but the results for the ω transition form factor are in better agreement with theoretical calculations, compared to earlier experiments.

Original languageAmerican English
Article number035208
JournalPhysical Review C
Issue number3
StatePublished - 22 Mar 2017

Bibliographical note

Funding Information:
This work was supported by the Deutsche Forschungsgemeinschaft (SFB443, SFB/TR16, and SFB1044), DFG-RFBR (Grant No. 09-02-91330), the European Community-Research Infrastructure Activity under the FP6 Structuring the European Research Area program (Hadron Physics, Contract No. RII3-CT-2004-506078), Schweizerischer Nationalfonds (Contracts No. 200020-156983, No. 132799, No. 121781, No. 117601, and No. 113511), the U.K. Science and Technology Facilities Council (STFC 57071/1, 50727/1), the U.S. Department of Energy (Offices of Science and Nuclear Physics, Awards No. DE-FG02-99-ER41110, No. DE-FG02-88ER40415, and No. DE-FG02-01-ER41194) and National Science Foundation (Grants No. PHY-1039130 and No. IIA-1358175), INFN (Italy), and NSERC (Canada). We thank the undergraduate students of Mount Allison University and The George Washington University for their assistance.

Publisher Copyright:
© 2017 American Physical Society.


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