Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus

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

doi:10.1103/PhysRevLett.96.062301

Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus

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

SCI - Physics

Research output: Contribution to journal › Article › peer-review

57 Citations (Scopus)

Abstract

We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay of HeΛ5 formed via the Li6(π+,K+) reaction. The energies of the two nucleons and the pair number distributions in the opening angle between them were measured. In both np and nn pairs, we observed a clean back-to-back correlation coming from the two-body weak reactions of Λp→np and Λn→nn, respectively. The ratio of the nucleon pair numbers was Nnn/Nnp=0.45±0.11(stat)±0.03(syst) in the kinematic region of cosθNN<-0.8. Since each decay mode was exclusively detected, the measured ratio should be close to the ratio of Γ(Λp→np)/Γ(Λn→nn). The ratio is consistent with recent theoretical calculations based on the heavy meson and/or direct-quark exchange picture.

Original language	English
Article number	062301
Journal	Physical review letters
Volume	96
Issue number	6
DOIs	https://doi.org/10.1103/PhysRevLett.96.062301
Publication status	Published - 2006

ASJC Scopus subject areas

Physics and Astronomy(all)

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Kang, B. H., Bhang, H., Kim, E. H., Kim, J. H., Kim, M. J., Yim, H. J., Ajimura, S., Miyake, Y., Aoki, K., Nagae, T., Noumi, H., Outa, H., Saha, P. K., Sato, Y., Sekimoto, M., Toyoda, A., Banu, A., Fukuda, T., Hashimoto, O., ... Tanida, K. (2006). Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus. Physical review letters, 96(6), [062301]. https://doi.org/10.1103/PhysRevLett.96.062301

Kang, BH, Bhang, H, Kim, EH, Kim, JH, Kim, MJ, Yim, HJ, Ajimura, S, Miyake, Y, Aoki, K, Nagae, T, Noumi, H, Outa, H, Saha, PK, Sato, Y, Sekimoto, M, Toyoda, A, Banu, A, Fukuda, T, Hashimoto, O, Kameoka, S, Miura, Y, Nakamura, SN, Okayasu, Y, Takahashi, T, Tamura, H, Tsukada, K, Watanabe, T, Hwang, JI, Maruta, T, Nakamura, M, Okada, S, Park, H & Tanida, K 2006, 'Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus', Physical review letters, vol. 96, no. 6, 062301. https://doi.org/10.1103/PhysRevLett.96.062301

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title = "Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus",

abstract = "We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay of HeΛ5 formed via the Li6(π+,K+) reaction. The energies of the two nucleons and the pair number distributions in the opening angle between them were measured. In both np and nn pairs, we observed a clean back-to-back correlation coming from the two-body weak reactions of Λp→np and Λn→nn, respectively. The ratio of the nucleon pair numbers was Nnn/Nnp=0.45±0.11(stat)±0.03(syst) in the kinematic region of cosθNN<-0.8. Since each decay mode was exclusively detected, the measured ratio should be close to the ratio of Γ(Λp→np)/Γ(Λn→nn). The ratio is consistent with recent theoretical calculations based on the heavy meson and/or direct-quark exchange picture.",

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

year = "2006",

doi = "10.1103/PhysRevLett.96.062301",

language = "English",

volume = "96",

journal = "Physical Review Letters",

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T1 - Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus

AU - Kang, B. H.

AU - Bhang, H.

AU - Kim, E. H.

AU - Kim, J. H.

AU - Kim, M. J.

AU - Yim, H. J.

AU - Ajimura, S.

AU - Miyake, Y.

AU - Aoki, K.

AU - Nagae, T.

AU - Noumi, H.

AU - Outa, H.

AU - Saha, P. K.

AU - Sato, Y.

AU - Sekimoto, M.

AU - Toyoda, A.

AU - Banu, A.

AU - Fukuda, T.

AU - Hashimoto, O.

AU - Kameoka, S.

AU - Miura, Y.

AU - Nakamura, S. N.

AU - Okayasu, Y.

AU - Takahashi, T.

AU - Tamura, H.

AU - Tsukada, K.

AU - Watanabe, T.

AU - Hwang, J. I.

AU - Maruta, T.

AU - Nakamura, M.

AU - Okada, S.

AU - Park, H.

AU - Tanida, K.

PY - 2006

Y1 - 2006

N2 - We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay of HeΛ5 formed via the Li6(π+,K+) reaction. The energies of the two nucleons and the pair number distributions in the opening angle between them were measured. In both np and nn pairs, we observed a clean back-to-back correlation coming from the two-body weak reactions of Λp→np and Λn→nn, respectively. The ratio of the nucleon pair numbers was Nnn/Nnp=0.45±0.11(stat)±0.03(syst) in the kinematic region of cosθNN<-0.8. Since each decay mode was exclusively detected, the measured ratio should be close to the ratio of Γ(Λp→np)/Γ(Λn→nn). The ratio is consistent with recent theoretical calculations based on the heavy meson and/or direct-quark exchange picture.

AB - We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay of HeΛ5 formed via the Li6(π+,K+) reaction. The energies of the two nucleons and the pair number distributions in the opening angle between them were measured. In both np and nn pairs, we observed a clean back-to-back correlation coming from the two-body weak reactions of Λp→np and Λn→nn, respectively. The ratio of the nucleon pair numbers was Nnn/Nnp=0.45±0.11(stat)±0.03(syst) in the kinematic region of cosθNN<-0.8. Since each decay mode was exclusively detected, the measured ratio should be close to the ratio of Γ(Λp→np)/Γ(Λn→nn). The ratio is consistent with recent theoretical calculations based on the heavy meson and/or direct-quark exchange picture.

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Exclusive measurement of the nonmesonic weak decay of the heΛ5 hypernucleus

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