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.
ASJC Scopus subject areas
- Nuclear and High Energy Physics