Published April 2, 2010 | Version v1
Journal article

Indication of a Deeply Bound and Compact K-pp State Formed in the pp→pΛK+ Reaction at 2.85 GeV

  • 1. RIKEN Nishina Center, Wako, Saitama, 351-0198 Japan (Japan)
  • 2. Department of Physics, University of Tokyo, Tokyo, 116-0033 Japan (Japan)
  • 3. Dipartimento di Fisica Generale ''A. Avogadro'' and INFN, Torino (Italy)
  • 4. Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany)
  • 5. Stefan Meyer Institute for Subatomic Physics, Austrian Academy of Sciences, Vienna (Austria)
  • 6. Laboratoire National Saturne, CEA Saclay (France)
  • 7. Dipartimento di Fisica Generale 'A. Avogadro' and INFN, Torino (Italy)
  • 8. Indiana University Cyclotron Facility, Bloomington, Indiana (United States)

Description

We have analyzed data of the DISTO experiment on the exclusive pp→pΛK+ reaction at 2.85 GeV to search for a strongly bound compact K-pp(≡X) state to be formed in the pp→K++X reaction. The observed spectra of the K+ missing mass and the pΛ invariant-mass with high transverse momenta of p and K+ revealed a broad distinct peak of 26-σ confidence with a mass MX=2267±3(stat)±5(syst) MeV/c2 and a width ΓX=118±8(stat)±10(syst) MeV. The enormously large cross section indicates formation of a compact K-pp with a large binding energy of BK=103 MeV, which can be a possible gateway toward cold and dense kaonic nuclear matter.

Additional details

Publishing Information

Journal Title
Physical Review Letters
Journal Volume
104
Journal Issue
13
Journal Page Range
p. 132502-132502.5
ISSN
0031-9007
CODEN
PRLTAO

Optional Information

Notes
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