Photoproduction of eta-mesic 3He.
The photoproduction of eta-mesic 3He has been investigated using the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI. The total inclusive cross section for the reaction gamma3He-->etaX has been measured for photon energies from threshold to 820 MeV. The total and angular differential coherent eta cross sections have been extracted up to energies of 745 MeV. A resonancelike structure just above the eta production threshold with an isotropic angular distribution suggests the existence of a resonant quasibound state. This is supported by studies of a competing decay channel of such a quasibound eta-mesic nucleus into pi(0)pX. A binding energy of (-4.4+/-4.2) MeV and a width of (25.6+/-6.1) MeV is deduced for the quasibound eta-mesic state in 3He.
Pfeiffer
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II. Physikalisches Institut, Universität Giessen, D-35392 Giessen, Germany.
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Beck
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Caselotti
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Cherepnya
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Föhl
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Hornidge
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Janssen
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Kashevarov
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Kondratiev
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Kotulla
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Krusche
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McGeorge
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MacGregor
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Mengel
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Messchendorp
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Metag
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Novotny
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Rost
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Sack
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Sanderson
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Schadmand
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Thomas
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