Hyperfine Interactions

, 194:319 | Cite as

\({\boldsymbol N}\boldsymbol{\bar N}\) exotics and antiprotonic atoms



The BES Collaboration measurements of J/ψ radiative decays into \( p{\bar p}\) indicate a strong enhancement at \( p {\bar p}\) threshold. In a related experiment a peak in the invariant π  +  π − η′ mass is observed. It is shown that both structures may be related to a broad \( N{\bar N}\) quasi-bound state in the \(^{11}S_{0} \) wave. The existence of this state finds additional support from the antiprotonic atom level widths. It is also explained by a traditional model of \( N \bar{N} \) interactions based on G-parity transformation. The level widths in H, D and He antiprotonic atoms and the radiochemical studies of \( {\bar p}\) capture in nuclei indicate the existence of another near-threshold quasi-bound state in a P wave.


\(N\bar N\) exotics Antiprotonic atoms 


13.60.Le 14.65.Dw 13.20.Gd 13.75.Cs 12.39.Pn 


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© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Andrzej Soltan Institute for Nuclear StudiesWarsawPoland
  2. 2.Laboratoire de Physique Nucléaire et de Hautes Énergies, Groupe Théorie, IN2P3-CNRSUniversités Pierre & Marie Curie et Paris DiderotParis, CedexFrance

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