Coincidence exclusive measurement of the nonmesonic weak decay of Λ12C

M. J. Kim, S. Ajimura, K. Aoki, A. Banu, H. Bhang, T. Fukuda, O. Hashimoto, J. I. Hwang, S. Kameoka, B. H. Kang, E. H. Kim, J. H. Kim, T. Maruta, Y. Miura, Y. Miyake, T. Nagae, M. Nakamura, S. N. Nakamura, H. Noumi, S. OkadaY. Okayasu, H. Outa, H. Park, P. K. Saha, Y. Sato, M. Sekimoto, S. Shin, T. Takahashi, H. Tamura, K. Tanida, A. Toyota, K. Tsukada, T. Watanabe, H. J. Yim

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We have measured the angular correlation of the pair nucleons np and nn emitted from the nonmesonic weak decay (NMWD) of Λ 12C produced via the (π+,K+) reaction in coincidence measurement. The Λp → np and Λn → nn modes were clearly identified by measuring the back-to-back correlation of the emitted nucleon pairs which is the characteristic of two-body kinematics. From the measured nucleon pair numbers Nnn and Nnp, the ratio Γnp of the partial decay widths Γn(Λn → nn) and Γp(Λp → np) of Λ12C was extracted to be 0.51 ± 0.13(stat)±0.04(syst); this result is almost free from the ambiguity due to the nuclear final state interaction and 3-body decay process, which were inherent in the previous results. The obtained Γn/ Γp ratio of Λ12C (p-shell) is close to that of Λ5He (s-shell). The results are consistent with those of recent theoretical calculations.

Original languageEnglish
Title of host publicationPARTICLES AND NUCLEI
Subtitle of host publicationSeventeenth Internatinal Conference on Particles and Nuclei
Number of pages3
Publication statusPublished - 2006
Externally publishedYes
EventPARTICLES AND NUCLEI: Seventeenth Internatinal Conference on Particles and Nuclei - Santa Fe, NM, United States
Duration: 2005 Oct 232005 Oct 30

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherPARTICLES AND NUCLEI: Seventeenth Internatinal Conference on Particles and Nuclei
Country/TerritoryUnited States
CitySanta Fe, NM


  • Nonmesonic weak decay
  • Γ/Γ ratio

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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