Observation of an isoscalar meson ax(1565) in annihilation of the pp-atom from P states

Academic Article


  • A new isoscalar ππ resonance AX(1565) has been observed at a mass of 1565±10 MeV/c2 and a width of 170±20 MeV/c2. The resonance is produced in pp annihilation at rest into π+π-π0 from P states of antiprotonic hydrogen atoms formed b y stopping antiprotons in hydrogen gas at normal temperature and pressure. Annihilation from P states is identified by coincident observations of the LX-ray series emitted in the cascade of pp atoms. The resonance is seen as striking peak in the π+π- invariant mass spectrum. The phase of the π+π- D wave shows a resonance-like behaviour. Hence we assign the quantum numbers IG(JPC) = 0+(2++) to the resonance. © 1989.
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    Published In

  • Physics Letters B  Journal
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    Author List

  • May B; Duch KD; Heel M; Kalinowsky H; Kayser F; Klempt E; Reifenröther J; Schreiber O; Weidenauer P; Ziegler M
  • Start Page

  • 450
  • End Page

  • 458
  • Volume

  • 225
  • Issue

  • 4