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Your search keyword '"Y S, Iwata"' showing total 8 results
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8 results on '"Y S, Iwata"'

1. First observation of the ΣN decay of the S = - 2 system

Author

Kenichi Imai, S. Torikai, N. Yasuda, M. Yosoi, Hiroyuki Noumi, H. Hayata, S. Ogawa, D.H. Davis, T. Kouketsu, J. Y. Kim, I. G. Park, H. Tanaka, Y. L. Lee, K. Tanida, Y. S. Iwata, Takayoshi Kawai, C. Nagoshi, Michiko Sekimoto, K. M. Baik, Y. Kakita, K. S. Sim, H. Okabe, M. Kaneko, Koji Yamamoto, Adam Rusek, C. O. Kim, Kazuma Nakazawa, B. Bassalleck, J. H. Chung, Shigeki Aoki, Y. S. Ra, Saewoong Bahk, Masaharu Ieiri, M. Mitsuhara, J. S. Song, Tomokazu Fukuda, H. Akikawa, L. H. Zhu, J. K. Ahn, M. S. Chung, D. Seki, T. Tsunemi, M. Kawasaki, J. W C McNabb, Y. Kondo, K. Hoshino, Toshiyuki Takahashi, H. Kanda, J. T. Yang, K. Oyama, Hirotaka Takahashi, J. T. Rhee, P.K. Saha, Junji Tojo, Y. Nagase, S. J. Kim, H. M. Park, N. Ushida, H. Torii, K. Arai, Y. H. Iwata, H. Shibuya, A. K. Ichikawa, J. Parker, C. S. Yoon, Tomoko Yoshida, Fujio Takeutchi, Seok Kim, T. Watanabe, C.J. Yoon, and D.N. Tovee

Subjects
Rest (physics), Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Event (relativity), Hadron, Hyperon, Nuclear fusion
Abstract

An event emitting a Σ- -hyperon from a Ξ- -hyperon nuclear capture at rest has been observed in a hybrid-emulsion experiment. The event has been analyzed as the first observation of the weak decay of the S = - 2 system.

Published
2007
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2. Study of double-strangeness nuclei with hybrid-emulsion method (KEK-PS E373)

Author

K. Oyama, T. Kouketsu, B. Bassalleck, J. Parker, I. G. Park, C. O. Kim, H. Takahashi, Tomoko Yoshida, J. S. Song, N. Ushida, S. Ogawa, K. Hoshino, H. Akikawa, Toshiyuki Takahashi, K. Arai, H. Kanda, J.T. Yang, L. H. Zhu, J. K. Ahn, Michiko Sekimoto, Shigeki Aoki, Y. S. Iwata, Junji Tojo, Y. Nagase, S. J. Kim, Y. H. Iwata, J. Y. Kim, J. H. Chung, H. M. Park, H. Torii, Y. L. Lee, H. Okabe, J. W C McNabb, Atsushi Ichikawa, N. Yasuda, M. Mitsuhara, A. Rusek, Kwang Souk Sim, Y. S. Ra, T. Kawai, K. Imai, H. Tanaka, Saewoong Bahk, K. M. Baik, Fujio Takeutchi, M. Kaneko, Kazuhiro Yamamoto, Seok Kim, P. K. Saha, C.J. Yoon, D. Seki, C. S. Yoon, H. Shibuya, Y. Kondo, K. Tanida, J. T. Rhee, Masaharu Ieiri, M. S. Chung, S. Torikai, M. Yosoi, Hiroyuki Noumi, Kazuma Nakazawa, and C. Nagoshi

Subjects
Physics, Nuclear and High Energy Physics, Optics, Scintillating fiber, Spectrometer, business.industry, Track (disk drive), Detector, Emulsion, Nuclear emulsion, Strangeness, business
Abstract

An experiment to search for double-strangeness nuclei in nuclear emulsion is now being carried on as KEK-PS E373. Preliminary results of the data analysis for the K + spectrometer and the scintillating fiber detectors are presented. Status of the automatic track finding method for the emulsion is reported.

Published
2001
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3. Production of twin Λ-hypernuclei from Ξ− hyperon capture at rest

Author

M. Ieiri, Y. S. Ra, Hirotaka Takahashi, C.J. Yoon, K. Tanida, Y. S. Iwata, J. Parker, Y. L. Lee, M. Sekimoto, H. M. Park, C. S. Yoon, Sanghoon Kim, A. Rusek, B. Bassalleck, S. Torikai, Saewoong Bahk, H. Shibuya, M. Yosoi, K. Nakazawa, P. K. Saha, A. K. Ichikawa, K. Hoshino, N. Yasuda, L. H. Zhu, N. Ushida, H. Akikawa, J.H. Chung, Junji Tojo, J.W.C. McNabb, J. K. Ahn, Y. Kondo, K. M. Baik, J. T. Yang, J. S. Song, Tomohiro Takahashi, M. Kaneko, M.S. Chung, C. Nagoshi, Y. H. Iwata, S. Ogawa, H. Noumi, J.Y. Kim, H. Kanda, C. O. Kim, T. Kawai, Shigeki Aoki, M. Mitsuhara, D. Seki, T. Yoshida, F. Takeutchi, S.J. Kim, K. Oyama, Koji Yamamoto, Y. Nagase, H. Torii, J.T. Rhee, K. Arai, Kwang Souk Sim, T. Kouketsu, I. G. Park, H. Tanaka, H. Okabe, and K. Imai

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Atomic system, Hyperon, Neutron, Nuclear emulsion, Hypernucleus
Abstract

A hybrid emulsion experiment was carried out to study double-strangeness nuclei produced via Ξ− hyperon capture at rest with the expectation of ten times larger statistics than previous experiments. We have analyzed 5% of the total emulsion and found one “twin-hypernuclei” event involving the emission of two single-Λ hypernuclei and a nuclear fragment from a Ξ− hyperon stopping point. The event is interpreted as the decay of a Ξ − + 14 N atomic system to 5 Λ He + 5 Λ He + 4 He + neutron . The species of the Ξ−-atom and the fragmentation products are uniquely identified for the first time for twin-hypernuclei events. Combined with the results from a past hybrid-emulsion experiment, one double-Λ hypernucleus and three twin-hypernuclei events have been found from Ξ− captures on light emulsion nuclei. The ratio of the detected rate of double-Λ hypernuclei to that of twin-hypernuclei is compared with theoretical estimates.

Published
2001
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4. Double-Λhypernuclei observed in a hybrid emulsion experiment

Author

A. K. Ichikawa, M. Sekimoto, M. Kawasaki, K. Hoshino, Seok Kim, Toshiyuki Takahashi, H. Kanda, Koji Yamamoto, B. Bassalleck, I. G. Park, N. Ushida, K. S. Sim, P. K. Saha, Kenichi Imai, C. S. Yoon, M. S. Chung, H. Okabe, H. N. Kyaw, D. Seki, T. Kouketsu, T. Wint, Hirotaka Takahashi, D.N. Tovee, Y. S. Ra, Junji Tojo, Y. Nagase, Fujio Takeutchi, J. Y. Kim, J. W C McNabb, A. Sawa, S. J. Kim, Saewoong Bahk, H. Shibuya, Tomokazu Fukuda, C. J. Yoon, H. M. Park, H. Akikawa, K. Oyama, Takayoshi Kawai, C. Nagoshi, N. Yasuda, Adam Rusek, Y. Kondo, M. Kaneko, J. K. Ahn, S. Ogawa, Y. Nakanishi, J. S. Song, Masaharu Ieiri, J. T. Yang, K. Miwa, K. Itonaga, D. H. Davis, L. H. Zhu, J. T. Rhee, H. Tanaka, Shigeki Aoki, K. Tanida, T. Tsunemi, Kazuma Nakazawa, K. T. Tint, C. O. Kim, Y. S. Iwata, B. D. Park, K. M. Baik, J. H. Chung, J. Parker, M. Mitsuhara, Tomoko Yoshida, Y. L. Lee, S. Torikai, M. Yosoi, Hiroyuki Noumi, H. Torii, K. Arai, Y. H. Iwata, A. A. Min, and M. Ukai

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Binding energy, Hyperon, Particle Data Group, Lambda
Abstract

A hybrid experiment with nuclear emulsion and scintillating-fiber detectors (KEK-E373) has been performed to search for double-strangeness systems. Among about 10${}^{3}$ events of ${\ensuremath{\Xi}}^{\ensuremath{-}}$ hyperons captured at rest by emulsion nuclei, we have observed four events which clearly show the topology of cascade weak decays of double-$\ensuremath{\Lambda}$ hypernuclei including the ``Nagara'' event. Regarding the Nagara event, values of the two-$\ensuremath{\Lambda}$ binding energy (${B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$) and the $\ensuremath{\Lambda}$-$\ensuremath{\Lambda}$ interaction energy ($\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$) of ${}_{\ensuremath{\Lambda}}^{}{}_{\ensuremath{\Lambda}}^{6}\mathrm{He}$ have been revised to 6.91 $\ifmmode\pm\else\textpm\fi{}$ 0.16 and 0.67 $\ifmmode\pm\else\textpm\fi{}$ 0.17 MeV, respectively, due to the recent change of the ${\ensuremath{\Xi}}^{\ensuremath{-}}$ mass value (Particle Data Group). For another three events, we have determined possible species of double-$\ensuremath{\Lambda}$ hypernuclei together with their binding energies.

Published
2013
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5. First observation of the ΣN decay of the S = −2 system

Author

T. Watanabe, J. K. Ahn, H. Akikawa, S. Aoki, K. Arai, S. Y. Bahk, K. M. Baik, B. Bassalleck, J. H. Chung, M. S. Chung, D. H. Davis, T. Fukuda, H. Hayata, K. Hoshino, A. Ichikawa, M. Ieiri, K. Imai, Y. H. Iwata, Y. S. Iwata, Y. Kakita, H. Kanda, M. Kaneko, T. Kawai, M. Kawasaki, C. O. Kim, J. Y. Kim, S. J. Kim, S. H. Kim, Y. Kondo, T. Kouketsu, Y. L. Lee, J. W. C. McNabb, M. Mitsuhara, Y. Nagase, C. Nagoshi, K. Nakazawa, H. Noumi, S. Ogawa, H. Okabe, K. Oyama, H. M. Park, I. G. Park, J. Parker, Y. S. Ra, J. T. Rhee, A. Rusek, H. Shibuya, K. S. Sim, P. K. Saha, D. Seki, M. Sekimoto, J. S. Song, H. Takahashi, T. Takahashi, F. Takeutchi, H. Tanaka, K. Tanida, J. Tojo, H. Torii, S. Torikai, T. Tsunemi, D. N. Tovee, N. Ushida, K. Yamamoto, N. Yasuda, J. T. Yang, C. J. Yoon, C. S. Yoon, M. Yosoi, T. Yoshida, and L. Zhu

Published
2008
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6. Observation of aHΛΛ6eDouble Hypernucleus

Author

S. Torikai, J. Parker, M. Yosoi, J. H. Chung, N. Ushida, Hiroyuki Noumi, D.H. Davis, M. Mitsuhara, Tomoko Yoshida, Y. S. Iwata, Y. S. Ra, Fujio Takeutchi, Kazuma Nakazawa, Y. L. Lee, H. Torii, H. Shibuya, M. Sekimoto, K. S. Sim, C. O. Kim, Junji Tojo, Y. Nagase, K. M. Baik, Adam Rusek, H. Okabe, K. Oyama, S. J. Kim, Tomokazu Fukuda, Kazunuki Yamamoto, H. Akikawa, K. Imai, K. Arai, J. S. Song, J. K. Ahn, H. Tanaka, L. H. Zhu, T. Takahashi, B. Bassalleck, C. S. Yoon, T. Kouketsu, Shigeki Aoki, M. S. Chung, D.N. Tovee, Saewoong Bahk, Takayoshi Kawai, C. Nagoshi, Seok Kim, J. Y. Kim, J. W C McNabb, H. M. Park, N. Yasuda, K. Hoshino, H. Kanda, Masaharu Ieiri, K. Tanida, I. G. Park, Y. H. Iwata, Hirotaka Takahashi, J. T. Rhee, M. Kawasaki, M. Kaneko, S. Ogawa, P. K. Saha, D. Seki, C. J. Yoon, Y. Kondo, J. T. Yang, and A. K. Ichikawa

Subjects
Physics, Particle physics, Excited state, Hyperon, General Physics and Astronomy, Lambda, Hypernucleus
Abstract

A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ${}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}^{6}\mathrm{He}$ emitted from a ${\ensuremath{\Xi}}^{\ensuremath{-}}$ hyperon nuclear capture at rest. The mass of ${}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}^{6}\mathrm{He}$ and the $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\Lambda}$ interaction energy $\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$ have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of $\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$ is $1.01\ifmmode\pm\else\textpm\fi{}{0.20}_{\ensuremath{-}0.11}^{+0.18}\phantom{\rule{0ex}{0ex}}\mathrm{MeV}$. This demonstrates that the $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\Lambda}$ interaction is weakly attractive.

Published
2001
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7. Observation of a (6)(LambdaLambda)He double hypernucleus

Author

H, Takahashi, J K, Ahn, H, Akikawa, S, Aoki, K, Arai, S Y, Bahk, K M, Baik, B, Bassalleck, J H, Chung, M S, Chung, D H, Davis, T, Fukuda, K, Hoshino, A, Ichikawa, M, Ieiri, K, Imai, Y H, Iwata, Y S, Iwata, H, Kanda, M, Kaneko, T, Kawai, M, Kawasaki, C O, Kim, J Y, Kim, S J, Kim, S H, Kim, Y, Kondo, T, Kouketsu, Y L, Lee, J W, McNabb, M, Mitsuhara, Y, Nagase, C, Nagoshi, K, Nakazawa, H, Noumi, S, Ogawa, H, Okabe, K, Oyama, H M, Park, I G, Park, J, Parker, Y S, Ra, J T, Rhee, A, Rusek, H, Shibuya, K S, Sim, P K, Saha, D, Seki, M, Sekimoto, J S, Song, T, Takahashi, F, Takeutchi, H, Tanaka, K, Tanida, J, Tojo, H, Torii, S, Torikai, D N, Tovee, N, Ushida, K, Yamamoto, N, Yasuda, J T, Yang, C J, Yoon, C S, Yoon, M, Yosoi, T, Yoshida, and L, Zhu

Abstract

A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.

Published
2001

8. Doubly strange nuclei by a hybrid-emulsion experiment E373 at KEK

Author

Masaharu Ieiri, M. Sekimoto, Y. S. Ra, G. B. Franklin, M. S. Chung, Y. Akaishi, Fujio Takeutchi, Kensuke Arai, P. K. Saha, T. Takahashi, C. Nagoshi, Adam Rusek, Hirotaka Takahashi, Y. S. Iwata, S. Torikai, N. Yasuda, Takayoshi Kawai, C. S. Yoon, H. Shibuya, Shigeki Aoki, Saewoong Bahk, Y. Yamamoto, Y. Kondo, D.N. Tovee, J. H. Chung, A. K. Ichikawa, J. T. Rhee, M. Yosoi, K. M. Baik, Kazuma Nakazawa, B. Bassalleck, Jinhu Yang, Hiroyuki Noumi, K. S. Sim, D. H. Davis, I. G. Park, Sanghoon Kim, Hajime Tanaka, H. Okabe, T. Yoshida, M. Kaneko, C. O. Kim, D. Seki, K. Imai, S. Ogawa, J. S. Song, C. J. Yoon, H. Torii, L. H. Zhu, Tomokazu Fukuda, H. Akikawa, J. K. Ahn, K. Tanida, M. Mitsuhara, T. Kouketsu, Y. H. Iwata, Toshio Motoba, Kazunuki Yamamoto, J. Y. Kim, Y. L. Lee, J. Parker, N. Ushida, K. Oyama, Junji Tojo, Y. Nagase, S. J. Kim, H. M. Park, J. W C McNabb, K. Hoshino, and H. Kanda

Subjects
Physics, Nuclear physics, Particle physics, Pion, Meson, Hyperon, Lambda baryon, Isotopes of beryllium, Hypernucleus, Isotopes of helium, Xi baryon
Abstract

A hybrid emulsion experiment E373 at KEK has been carried out to study doubly strange nuclear system. By the 8% data analysis of all, one twin single-Λ hypernuclei event and two events of double-Λ hypernucleus have been successfully detected. The twin single-Λ event is uniquely interpreted as Ⅺ−+14N→Λ5He+Λ5He+4He+n for the first time. In the first double-Λ hypernucleus event, “Demachi-Yanagi,” it is interpreted as Ⅺ−+12C→ΛΛ10Be* (or ΛΛ10Be*)+t. The second double-Λ hypernucleus event, “NAGARA,” shows a clearly recognized topology and the interpretation is unique as Ⅺ−+12C→ΛΛ6He+4He+t, ΛΛ6He→Λ5He+π−+p, Λ5He→p+d+2n etc. By the preliminary result of the ΛΛ6He, the attractive ΛΛ interaction has been confirmed with the ΔBΛΛ∼1 MeV.

Published
2001
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