Determination of the total width of the η' meson.
Taking advantage of both the low-emittance proton beam of the cooler synchrotron COSY and the high momentum precision of the COSY-11 detector system, the mass distribution of the η' meson was measured with a resolution of 0.33  MeV/c2 (FWHM), improving the experimental mass resolution by almost an order of magnitude with respect to previous results. Based on the sample of more than 2300 reconstructed pp → ppη' events, the total width of the η' meson was determined to be Γ(η') = 0.226 ± 0.017(stat) ± 0.014(syst)  MeV/c2.
Czerwiński
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E
Institute of Physics, Jagiellonian University, PL-30-059 Cracow, Poland. eryk.czerwinski@lnf.infn.it
Moskal
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Grzonka
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Czyzykiewicz
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R
Gil
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Kamys
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B
Khoukaz
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Klaja
J
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Klaja
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Krzemień
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Oelert
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Ritman
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Sefzick
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Siemaszko
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Silarski
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Smyrski
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Täschner
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Wolke
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Wüstner
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Zdebik
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Zieliński
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Zipper
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