Structure near the K- + p + p threshold in the in-flight 3He(K-, Λp)n reaction

Y. Sada, S. Ajimura, M. Bazzi, G. Beer, H. Bhang, M. Bragadireanu, P. Buehler, L. Busso, M. Cargnelli, S. Choi, C. Curceanu, S. Enomoto, D. Faso, H. Fujioka, Y. Fujiwara, T. Fukuda, C. Guaraldo, T. Hashimoto, R. S. Hayano, T. HiraiwaM. Iio, M. Iliescu, K. Inoue, Y. Ishiguro, T. Ishikawa, S. Ishimoto, T. Ishiwatari, K. Itahashi, M. Iwai, M. Iwasaki, Y. Kato, S. Kawasaki, P. Kienle, H. Kou, Y. Ma, J. Marton, Y. Matsuda, Y. Mizoi, O. Morra, T. Nagae, H. Noumi, H. Ohnishi, S. Okada, H. Outa, K. Piscicchia, A. Romero Vidal, A. Sakaguchi, F. Sakuma, M. Sato, A. Scordo, M. Sekimoto, H. Shi, D. Sirghi, F. Sirghi, K. Suzuki, S. Suzuki, T. Suzuki, K. Tanida, H. Tatsuno, M. Tokuda, D. Tomono, A. Toyoda, K. Tsukada, O. Vazquez Doce, E. Widmann, B. K. Wuenschek, T. Yamaga, T. Yamazaki, H. Yim, Q. Zhang, J. Zmeskal

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47 Citations (Scopus)


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.

Original languageEnglish
Article number051D01
JournalProgress of Theoretical and Experimental Physics
Issue number5
Publication statusPublished - 2016 May

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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