Lifetimes of Λ hypernuclei up to ΛFe

H. C. Bhang; S. Ajimura; K. Aoki; T. Hasegawa; O. Hashimoto; H. Hotchi; Y. D. Kim; T. Kishimoto; K. Maeda; H. Noumi; Y. Ohta; K. Omata; H. Outa; H. Park; Y. Sato; M. Sekimoto; T. Shibata; T. Takahashi; M. Youn

doi:10.1016/S0375-9474(98)00283-8

Lifetimes of Λ hypernuclei up to _ΛFe

H. C. Bhang, S. Ajimura, K. Aoki, T. Hasegawa, O. Hashimoto, H. Hotchi, Y. D. Kim, T. Kishimoto, K. Maeda, H. Noumi, Y. Ohta, K. Omata, H. Outa, H. Park, Y. Sato, M. Sekimoto, T. Shibata, T. Takahashi, M. Youn

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

13 Citations (Scopus)

Abstract

We have observed that the global behavior of the lifetime of a Λ hyperon in nuclear matter is almost mass independent. Its lifetime decreases slightly from that of a free Λ and quickly saturates at ∼80% of τΛ in free space as the mass number increases. We have determined the lifetimes of three Λ hypernuclei as τ(¹²_ΛC_g.s.) = 231 ± 15 ps, τ(²⁸_ΛSi_g.s.) = 206 ± 12 ps and τ({⁵⁶_ΛFe}) = 215⁺¹⁴_-13ps. The hypernuclei were produced by the (π⁺, K⁺) reaction and identified by the SKS spectrometer at the KEK 12 GeV PS. The lifetimes were obtained by a direct measurement of the production time of a hypernucleus and its decay time with two sets of timing/range counters. These are the first lifetime results of Λ hypernuclei over this broad mass range with the explicit identification of the produced hypernuclei.

Original language	English
Pages (from-to)	269c-278c
Journal	Nuclear Physics A
Volume	639
Issue number	1-2
DOIs	https://doi.org/10.1016/S0375-9474(98)00283-8
Publication status	Published - 1998 Aug 24
Externally published	Yes

ASJC Scopus subject areas

Nuclear and High Energy Physics

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10.1016/S0375-9474(98)00283-8

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@article{ca263281f7744f33a6ee68c03cc91552,

title = "Lifetimes of Λ hypernuclei up to ΛFe",

abstract = "We have observed that the global behavior of the lifetime of a Λ hyperon in nuclear matter is almost mass independent. Its lifetime decreases slightly from that of a free Λ and quickly saturates at ∼80% of τΛ in free space as the mass number increases. We have determined the lifetimes of three Λ hypernuclei as τ(12ΛCg.s.) = 231 ± 15 ps, τ(28ΛSig.s.) = 206 ± 12 ps and τ({56ΛFe}) = 215+14-13ps. The hypernuclei were produced by the (π+, K+) reaction and identified by the SKS spectrometer at the KEK 12 GeV PS. The lifetimes were obtained by a direct measurement of the production time of a hypernucleus and its decay time with two sets of timing/range counters. These are the first lifetime results of Λ hypernuclei over this broad mass range with the explicit identification of the produced hypernuclei.",

author = "Bhang, {H. C.} and S. Ajimura and K. Aoki and T. Hasegawa and O. Hashimoto and H. Hotchi and Kim, {Y. D.} and T. Kishimoto and K. Maeda and H. Noumi and Y. Ohta and K. Omata and H. Outa and H. Park and Y. Sato and M. Sekimoto and T. Shibata and T. Takahashi and M. Youn",

note = "Funding Information: We are grateful for the generous support from the staff members of KEK and INS. We also deeply appreciate the continuous encouragement by Prof. K. Nakai and Prof. T. Yamazaki throughout this experiment. We very much benefitted from discussions with Prof. Fukuda and Prof. Nagae. H.B. acknowledges partial support from the Korea-Japan collaborative research program of KOSEF and the Ministry of Education through the Research Institute of Basic Science of Seoul National University.",

year = "1998",

month = aug,

day = "24",

doi = "10.1016/S0375-9474(98)00283-8",

language = "English",

volume = "639",

pages = "269c--278c",

journal = "Nuclear Physics A",

issn = "0375-9474",

publisher = "Elsevier",

number = "1-2",

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TY - JOUR

T1 - Lifetimes of Λ hypernuclei up to ΛFe

AU - Bhang, H. C.

AU - Ajimura, S.

AU - Aoki, K.

AU - Hasegawa, T.

AU - Hashimoto, O.

AU - Hotchi, H.

AU - Kim, Y. D.

AU - Kishimoto, T.

AU - Maeda, K.

AU - Noumi, H.

AU - Ohta, Y.

AU - Omata, K.

AU - Outa, H.

AU - Park, H.

AU - Sato, Y.

AU - Sekimoto, M.

AU - Shibata, T.

AU - Takahashi, T.

AU - Youn, M.

N1 - Funding Information: We are grateful for the generous support from the staff members of KEK and INS. We also deeply appreciate the continuous encouragement by Prof. K. Nakai and Prof. T. Yamazaki throughout this experiment. We very much benefitted from discussions with Prof. Fukuda and Prof. Nagae. H.B. acknowledges partial support from the Korea-Japan collaborative research program of KOSEF and the Ministry of Education through the Research Institute of Basic Science of Seoul National University.

PY - 1998/8/24

Y1 - 1998/8/24

N2 - We have observed that the global behavior of the lifetime of a Λ hyperon in nuclear matter is almost mass independent. Its lifetime decreases slightly from that of a free Λ and quickly saturates at ∼80% of τΛ in free space as the mass number increases. We have determined the lifetimes of three Λ hypernuclei as τ(12ΛCg.s.) = 231 ± 15 ps, τ(28ΛSig.s.) = 206 ± 12 ps and τ({56ΛFe}) = 215+14-13ps. The hypernuclei were produced by the (π+, K+) reaction and identified by the SKS spectrometer at the KEK 12 GeV PS. The lifetimes were obtained by a direct measurement of the production time of a hypernucleus and its decay time with two sets of timing/range counters. These are the first lifetime results of Λ hypernuclei over this broad mass range with the explicit identification of the produced hypernuclei.

AB - We have observed that the global behavior of the lifetime of a Λ hyperon in nuclear matter is almost mass independent. Its lifetime decreases slightly from that of a free Λ and quickly saturates at ∼80% of τΛ in free space as the mass number increases. We have determined the lifetimes of three Λ hypernuclei as τ(12ΛCg.s.) = 231 ± 15 ps, τ(28ΛSig.s.) = 206 ± 12 ps and τ({56ΛFe}) = 215+14-13ps. The hypernuclei were produced by the (π+, K+) reaction and identified by the SKS spectrometer at the KEK 12 GeV PS. The lifetimes were obtained by a direct measurement of the production time of a hypernucleus and its decay time with two sets of timing/range counters. These are the first lifetime results of Λ hypernuclei over this broad mass range with the explicit identification of the produced hypernuclei.

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U2 - 10.1016/S0375-9474(98)00283-8

DO - 10.1016/S0375-9474(98)00283-8

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VL - 639

SP - 269c-278c

JO - Nuclear Physics A

JF - Nuclear Physics A

IS - 1-2

ER -

Lifetimes of Λ hypernuclei up to _ΛFe

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