Abstract
The Crystal Ball detector has been used at the DORIS II storage ring at DESY to study the reactionγγ→π 0 π 0 π 0 in theπ 0 π 0 π 0 invariant mass range from 850 MeV/c2 to 2600 MeV/c2. An enhancement around 1750 MeV/c2 is attributed to theπ 2(1670) resonance. The observedπ 0 π 0 invariant mass distribution and theπ 0 angular distributions are consistent with those expected for the decay chainπ 2→π 0 f 2(1270)→π 0 π 0 π 0. From our measurements we find the following resonance parameters: two photon partial width\(\Gamma _{\pi _2 }^{\gamma \gamma } = (1.41 \pm 0.23 \pm 0.28)keV\), massM(π 2)=(1742±31±49)MeV/c2. and total width\(\Gamma _{\pi _2 }^{tot} = (236 \pm 49 \pm 36)MeV\).
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Supported by the U.S. Department of Energy, contract No. DE-AC03-81ER40050 and by the National Science Foundation, grant No. PHY75-22980
Supported by the National Science Foundation, grant No.-PHY85-12145
Supported by the U.S. Department of Energy, contract No. DE-AC02-76ER03066
Supported by the German Bundesministerium für Forschung und Technologie, contract No. 054 ER 11P(5)
Supported by the German Bundesministerium für Forschung und Technologie, contract No. 054 HH 11P(7) and by the Deutsche Forschungsgemeinschaft
Supported by the U.S. Department of Energy, contract No. DE-AC02-76ER03064
Supported by FOM-NWO
Supported by the U.S. Department of Energy, contract No. DE-AC02-76ER03072 and by the National Science Foundation, grant No. PHY82-08761
Supported by the U.S. Department of Energy, contract No. DE-AC03-76SF00326 and by the National Science Foundation, grant No. PHY81-07396
Supported by the U.S. Department of Energy, contract No. DE-AC03-76SF00515
Supported by the German Bundesministerium für Forschung und Technologie, contract No. 054 WU 11P(1)
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Crystal Ball Collaboration., Antreasyan, D., Bartels, H.W. et al. First observation of the reactionγγ→π 2→π 0 π 0 π 0 . Z. Phys. C - Particles and Fields 48, 561–568 (1990). https://doi.org/10.1007/BF01614689
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DOI: https://doi.org/10.1007/BF01614689