| 1. |
- Sada, Y., et al.
(författare)
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Structure near the K- + p + p threshold in the in-flight 3He(K-, Λp)n reaction
- 2016
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Ingår i: Progress of Theoretical and Experimental Physics. - : Oxford University Press (OUP). - 2050-3911. ; 2016:5
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Tidskriftsartikel (refereegranskat)abstract
- To search for an S = -1 di-baryonic state which decays toΛp, the 3He(K-,Λp)nmissing reaction was studied at 1.0 GeV/c. Unobserved neutrons were kinematically identified from the missing mass MX of the 3He (K-,Λp) X reaction in order to have a large acceptance for the Λpn final state. The observed Λpn events, distributed widely over the kinematically allowed region of the Dalitz plot, establish that the major component comes from a three-nucleon absorption process. A concentration of events at a specific neutron kinetic energy was observed in a region of low momentum transfer to the Λp. To account for the observed peak structure, the simplest S-wave polewas assumed to exist in the reaction channel, having a Breit-Wigner formin energy and with a Gaussian form factor. A minimum X2 method was applied to deduce its mass, MX = 2355+6 -8 (stat.) ±12 (syst.)MeV/c2, and decay width, γX = 110+19 -17 (stat.) ±27 (syst.)MeV/c2, respectively. The form factor parameter QX ∼ 400MeV/c implies that the range of the interaction is about 0.5 fm.
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| 2. |
- Yamaga, Takumi, et al.
(författare)
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Study of the elementary (K -, n) reactions to search for the K NN bound state via the 3He (K -, n) reaction at J-PARC
- 2016
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Ingår i: XVIth International Conference on Hadron Spectroscopy, Hadron 2015. - : Author(s). - 9780735413894 ; 1735
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Konferensbidrag (refereegranskat)abstract
- We have searched for the simplest kaonic nuclear state, K̄NN, using the in-flight 3He (K-, n) reaction at the J-PARC hadron experimental facility. In the semi-inclusive neutron missing-mass spectrum at θnlab=0°, an excess of yield was observed just below the K- pp mass-threshold, which cannot be explained by any elementary reactions [PTEP 2015, 061D01]. To understand the missing-mass spectrum of 3He (K-, n) X, we investigated the elementary (K-, n) reactions using hydrogen and deuterium targets. The p (K-, n) X missing-mass spectrum was well described by the charge-exchange reaction. However, in the d (K-, n) X spectrum, we observed an excess of yield just below the K- p mass-threshold, which was similar to that in the 3He (K-, n) X spectrum.
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| 3. |
- Tatsuno, H., et al.
(författare)
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Future projects of light kaonic atom X-ray spectroscopy
- 2016
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 130
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Tidskriftsartikel (refereegranskat)abstract
- X-ray spectroscopy of light kaonic atoms is a unique tool to provide precise information on the fundamental KN interaction at the low-energy limit and the in-medium nuclear interaction of K-. The future experiments of kaonic deuterium strong-interaction shift and width (SIDDHARTA-2 and J-PARC E57) can extract the isospin dependent K-N interaction at threshold. The high-resolution X-ray spectroscopy of kaonic helium with microcalorimeters (J-PARC E62) has the possibility to solve the long-standing potential-strength problem of the attractive K--nucleus interaction. Here, the recent experimental results and the future projects of X-ray spectroscopy of light kaonic atoms are presented.
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