New measurement of the rare decay η→π0γγ with the Crystal Ball/TAPS detectors at the Mainz Microtron

B. M K Nefkens, S. Prakhov, P. Aguar-Bartolomé, J. R M Annand, H. J. Arends, K. Bantawa, R. Beck, V. Bekrenev, H. Berghäuser, A. Braghieri, W. J. Briscoe, J. Brudvik, S. Cherepnya, R. F B Codling, C. Collicott, S. Costanza, I. V. Danilkin, A. Denig, B. Demissie, M. DieterleE. J. Downie, P. Drexler, L. V. Fil'Kov, A. Fix, S. Garni, D. I. Glazier, R. Gregor, D. Hamilton, E. Heid, D. Hornidge, D. Howdle, O. Jahn, T. C. Jude, V. L. Kashevarov, A. Käser, I. Keshelashvili, R. Kondratiev, M. Korolija, M. Kotulla, A. Koulbardis, S. Kruglov, B. Krusche, V. Lisin, K. Livingston, I. J D Macgregor, Y. Maghrbi, J. Mancel, D. M. Manley, E. F. McNicoll, D. Mekterovic, V. Metag, A. Mushkarenkov, A. Nikolaev, R. Novotny, M. Oberle, H. Ortega, M. Ostrick, P. Ott, P. B. Otte, B. Oussena, P. Pedroni, A. Polonski, J. Robinson, G. Rosner, T. Rostomyan, S. Schumann, M. H. Sikora, A. Starostin, I. I. Strakovsky, T. Strub, I. M. Suarez, I. Supek, C. M. Tarbert, M. Thiel, A. Thomas, M. Unverzagt, D. P. Watts, D. Werthmüller, L. Witthauer

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A new measurement of the rare, doubly radiative decay η→π 0γγ was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Γ(η→π0γγ), on the two-photon invariant-mass squared, m2(γγ), as well as a new, more precise value for the decay width, Γ(η→π0γγ)=(0.33±0.03tot) eV, are based on analysis of 1.2×103η→π0γγ decays from a total of 6×107η mesons produced in the γp→ηp reaction. The present results for dΓ(η→π0γγ)/ dm2(γγ) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

Original languageEnglish
Article number025206
JournalPhysical Review C - Nuclear Physics
Issue number2
Publication statusPublished - 14 Aug 2014


ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Nefkens, B. M. K., Prakhov, S., Aguar-Bartolomé, P., Annand, J. R. M., Arends, H. J., Bantawa, K., ... Witthauer, L. (2014). New measurement of the rare decay η→π0γγ with the Crystal Ball/TAPS detectors at the Mainz Microtron. Physical Review C - Nuclear Physics, 90(2), [025206].