1
|
Hiyama E, Sasaki K, Miyamoto T, Doi T, Hatsuda T, Yamamoto Y, Rijken TA. Possible Lightest Ξ Hypernucleus with Modern ΞN Interactions. PHYSICAL REVIEW LETTERS 2020; 124:092501. [PMID: 32202898 DOI: 10.1103/physrevlett.124.092501] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 01/18/2020] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Experimental evidence exists that the Ξ-nucleus interaction is attractive. We search for NNΞ and NNNΞ bound systems on the basis of the AV8 NN potential combined with either a phenomenological Nijmegen ΞN potential or a first principles HAL QCD ΞN potential. The binding energies of the three-body and four-body systems (below the d+Ξ and ^{3}H/^{3}He+Ξ thresholds, respectively) are calculated by a high precision variational approach, the Gaussian expansion method. Although the two ΞN potentials have significantly different isospin (T) and spin (S) dependence, the NNNΞ system with quantum numbers (T=0, J^{π}=1^{+}) appears to be bound (one deep for Nijmegen and one shallow for HAL QCD) below the ^{3}H/^{3}He+Ξ threshold. Experimental implications for such a state are discussed.
Collapse
Affiliation(s)
- E Hiyama
- Department of Physics, Kyushu University, Fukuoka, Japan, 819-0395 and Strangeness Nuclear Physics Laboratory, RIKEN Nishina Center, Wako 351-0198, Japan
| | - K Sasaki
- Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Miyamoto
- Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan and Quantum Hadron Physics Laboratory, RIKEN Nishina Center, Wako 351-0198, Japan
| | - T Doi
- Quantum Hadron Physics Laboratory, RIKEN Nishina Center, Wako 351-0198, Japan and Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), RIKEN, Wako 351-0198, Japan
| | - T Hatsuda
- Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), RIKEN, Wako 351-0198, Japan and Quantum Hadron Physics Laboratory, RIKEN Nishina Center, Wako 351-0198, Japan
| | - Y Yamamoto
- Physics Section, Tsuru University, Tsuru, Yamanashi 402-8555, Japan and Strangeness Nuclear Physics Laboratory, RIKEN Nishina Center, Wako 351-0198, Japan
| | - Th A Rijken
- Institute for Theoretical Physics, University of Nijmegen, Njjmegen, Netherlands
| |
Collapse
|
2
|
Yang SB, Ahn JK, Akazawa Y, Aoki K, Chiga N, Ekawa H, Evtoukhovitch P, Feliciello A, Fujita M, Hasegawa S, Hayakawa S, Hayakawa T, Honda R, Hosomi K, Hwang SH, Ichige N, Ichikawa Y, Ikeda M, Imai K, Ishimoto S, Kanatsuki S, Kim SH, Kinbara S, Kobayashi K, Koike T, Lee JY, Miwa K, Moon TJ, Nagae T, Nakada Y, Nakagawa M, Ogura Y, Sakaguchi A, Sako H, Sasaki Y, Sato S, Shirotori K, Sugimura H, Suto S, Suzuki S, Takahashi T, Tamura H, Tanida K, Togawa Y, Tsamalaidze Z, Ukai M, Wang TF, Yamamoto TO. First Determination of the Level Structure of an sd-Shell Hypernucleus, _{Λ}^{19}F. PHYSICAL REVIEW LETTERS 2018; 120:132505. [PMID: 29694189 DOI: 10.1103/physrevlett.120.132505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/15/2018] [Indexed: 06/08/2023]
Abstract
We report on the first observation of γ rays emitted from an sd-shell hypernucleus, _{Λ}^{19}F. The energy spacing between the ground state doublet, 1/2^{+} and 3/2^{+} states, of _{Λ}^{19}F is determined to be 315.5±0.4(stat)_{-0.5}^{+0.6}(syst) keV by measuring the γ-ray energy of the M1(3/2^{+}→1/2^{+}) transition. In addition, three γ-ray peaks are observed and assigned as E2(5/2^{+}→1/2^{+}), E1(1/2^{-}→1/2^{+}), and E1(1/2^{-}→3/2^{+}) transitions. The excitation energies of the 5/2^{+} and 1/2^{-} states are determined to be 895.2±0.3(stat)±0.5(syst) and 1265.6±1.2(stat)_{-0.5}^{+0.7}(syst) keV, respectively. It is found that the ground state doublet spacing is well described by theoretical models based on existing s- and p-shell hypernuclear data.
Collapse
Affiliation(s)
- S B Yang
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
- Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - J K Ahn
- Department of Physics, Korea University, Seoul 02841, Korea
| | - Y Akazawa
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - K Aoki
- Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
| | - N Chiga
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - H Ekawa
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - P Evtoukhovitch
- Joint Institute for Nuclear Research, Dubna, Moscow Region 141980, Russia
| | - A Feliciello
- INFN, Sezione di Torino, via P. Giuria 1, 10125 Torino, Italy
| | - M Fujita
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - S Hasegawa
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - S Hayakawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Hayakawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - R Honda
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - K Hosomi
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - S H Hwang
- Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea
| | - N Ichige
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - Y Ichikawa
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - M Ikeda
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - K Imai
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - S Ishimoto
- Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
| | - S Kanatsuki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - S H Kim
- Department of Physics, Korea University, Seoul 02841, Korea
| | - S Kinbara
- Faculty of Education, Gifu University, Gifu 501-1193, Japan
| | - K Kobayashi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - T Koike
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - J Y Lee
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - K Miwa
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - T J Moon
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - T Nagae
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - Y Nakada
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - M Nakagawa
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Y Ogura
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - A Sakaguchi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - H Sako
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - Y Sasaki
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - S Sato
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - K Shirotori
- Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - H Sugimura
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - S Suto
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - S Suzuki
- Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
| | - T Takahashi
- Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
| | - H Tamura
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - K Tanida
- Advanced Science Research Center (ASRC), Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - Y Togawa
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - Z Tsamalaidze
- Joint Institute for Nuclear Research, Dubna, Moscow Region 141980, Russia
| | - M Ukai
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - T F Wang
- Research Center of Nuclear Science and Technology (RCNST) and School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
| | - T O Yamamoto
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| |
Collapse
|
3
|
Feliciello A, Nagae T. Experimental review of hypernuclear physics: recent achievements and future perspectives. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2015; 78:096301. [PMID: 26317857 DOI: 10.1088/0034-4885/78/9/096301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Since the shutdown of several old proton synchrotrons, which played a fundamental role in the second generation experiments in hypernuclear physics performed in Europe, USA and Japan, some new experimental setups aiming to achieve sub-MeV energy resolution have been operating for a long time. Over the last decade the hypernuclear physics community has been committed to carrying out several third generation experiments by exploiting the potential offered by new accelerators, such as a continuous electron beam machine and a ϕ-factory. Large data samples were collected on specific items thanks to dedicated facilities and experimental apparatuses. The attention was mainly focused on both high-resolution spectroscopy and the decay mode study of single Λ-hypernuclei. Nowadays this phase is over but, until recently, important and, to some extent, unexpected results were achieved. An updated review of selected experimental results is presented, as well as a survey of perspectives for future studies.
Collapse
Affiliation(s)
- A Feliciello
- Istituto Nazionale di Fisica Nucleare-Sezione di Torino, Via P. Giuria 1, I-10125 Torino, Italy
| | | |
Collapse
|
4
|
|
5
|
Nakamura SN, Matsumura A, Okayasu Y, Seva T, Rodriguez VM, Baturin P, Yuan L, Acha A, Ahmidouch A, Androic D, Asaturyan A, Asaturyan R, Baker OK, Benmokhtar F, Bosted P, Carlini R, Chen C, Christy M, Cole L, Danagoulian S, Daniel A, Dharmawardane V, Egiyan K, Elaasar M, Ent R, Fenker H, Fujii Y, Furic M, Gan L, Gaskell D, Gasparian A, Gibson EF, Gogami T, Gueye P, Han Y, Hashimoto O, Hiyama E, Honda D, Horn T, Hu B, Hungerford EV, Jayalath C, Jones M, Johnston K, Kalantarians N, Kanda H, Kaneta M, Kato F, Kato S, Kawama D, Keppel C, Lan KJ, Luo W, Mack D, Maeda K, Malace S, Margaryan A, Marikyan G, Markowitz P, Maruta T, Maruyama N, Miyoshi T, Mkrtchyan A, Mkrtchyan H, Nagao S, Navasardyan T, Niculescu G, Niculescu MI, Nomura H, Nonaka K, Ohtani A, Oyamada M, Perez N, Petkovic T, Randeniya S, Reinhold J, Roche J, Sato Y, Segbefia EK, Simicevic N, Smith G, Song Y, Sumihama M, Tadevosyan V, Takahashi T, Tang L, Tsukada K, Tvaskis V, Vulcan W, Wells S, Wood SA, Yan C, Zhamkochyan S. Observation of the (Λ)(7)He hypernucleus by the (e, e'K+) reaction. PHYSICAL REVIEW LETTERS 2013; 110:012502. [PMID: 23383783 DOI: 10.1103/physrevlett.110.012502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Indexed: 06/01/2023]
Abstract
An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, (Λ)(7)He, was observed for the first time with the (e, e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The (Λ)(7)He binding energy supplies the last missing information of the A = 7, T = 1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.
Collapse
Affiliation(s)
- S N Nakamura
- Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
|
7
|
Saha PK, Fukuda T, Imoto W, Ahn JK, Ajimura S, Aoki K, Bhang HC, Fujioka H, Hotchi H, Hwang JI, Itabashi T, Kang BH, Kim HD, Kim MJ, Kishimoto T, Krutenkova A, Maruta T, Miura Y, Miwa K, Nagae T, Noumi H, Outa H, Ohtaki T, Sakaguchi A, Sato Y, Sekimoto M, Shimizu Y, Tamura H, Tanida K, Toyoda A, Ukai M, Yim HJ. Production of the neutron-rich hypernucleus 10LambdaLi in the (pi-,K+) double charge-exchange reaction. PHYSICAL REVIEW LETTERS 2005; 94:052502. [PMID: 15783631 DOI: 10.1103/physrevlett.94.052502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Indexed: 05/24/2023]
Abstract
In order to produce a neutron-rich Lambda hypernucleus for the first time, we carried out an experiment by utilizing the (pi-,K+) double charge-exchange reaction on a 10B target. We observed the production of a 10LambdaLi hypernucleus. The cross section for the Lambda bound region was found to be 11.3+/-1.9 nb/sr with the 1.2 GeV/c incident momentum, which is compared with the 10LambdaB hypernucleus production cross section, 7.8+/-0.3 microb/sr, in the (pi+,K+) reaction with a 1.05 GeV/c incident momentum beam.
Collapse
Affiliation(s)
- P K Saha
- Osaka Electro-Communication University, Neyagawa, Osaka 572-8530, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ukai M, Ajimura S, Akikawa H, Alburger DE, Banu A, Chrien RE, Franklin GB, Franz J, Hashimoto O, Hayakawa T, Hotchi H, Imai K, Kishimoto T, May M, Millener DJ, Minami S, Miura Y, Miyoshi T, Mizunuma K, Nagae T, Nakamura SN, Nakazawa K, Okayasu Y, Pile P, Quinn BP, Rusek A, Sato Y, Sutter R, Takahashi H, Tang L, Tamura H, Tanida K, Yuan L, Zhou SH. Hypernuclear fine structure in (16)(Lambda)O and the LambdaN tensor interaction. PHYSICAL REVIEW LETTERS 2004; 93:232501. [PMID: 15601150 DOI: 10.1103/physrevlett.93.232501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Indexed: 05/24/2023]
Abstract
We have observed two gamma-ray transitions in (16)(Lambda)O from the 6.6 MeV excited 1(-)(2) state to both ground-state spin-doublet members (1(-)(1),0(-)) by the (K-,pi(-)gamma) reaction. We have obtained the ground-state doublet spacing to be 26.4+/-1.6(stat)+/-0.5(syst) keV and the excitation energy of the 1(-)(2) state to be 6561.7+/-1.1(stat)+/-1.7(syst) keV. The ground-state doublet spacing provides a small but nonzero strength of the tensor interaction between a Lambda and a nucleon. This is the first experimental result on the LambdaN tensor interaction.
Collapse
Affiliation(s)
- M Ukai
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Miyoshi T, Sarsour M, Yuan L, Zhu X, Ahmidouch A, Ambrozewicz P, Androic D, Angelescu T, Asaturyan R, Avery S, Baker OK, Bertovic I, Breuer H, Carlini R, Cha J, Chrien R, Christy M, Cole L, Danagoulian S, Dehnhard D, Elaasar M, Empl A, Ent R, Fenker H, Fujii Y, Furic M, Gan L, Garrow K, Gasparian A, Gueye P, Harvey M, Hashimoto O, Hinton W, Hu B, Hungerford E, Jackson C, Johnston K, Juengst H, Keppel C, Lan K, Liang Y, Likhachev VP, Liu JH, Mack D, Margaryan A, Markowitz P, Martoff J, Mkrtchyan H, Nakamura SN, Petkovic T, Reinhold J, Roche J, Sato Y, Sawafta R, Simicevic N, Smith G, Stepanyan S, Tadevosyan V, Takahashi T, Tanida K, Tang L, Ukai M, Uzzle A, Vulcan W, Wells S, Wood S, Xu G, Yamaguchi H, Yan C. High resolution spectroscopy of the 12Lambda B hypernucleus produced by the (e,e'K+) reaction. PHYSICAL REVIEW LETTERS 2003; 90:232502. [PMID: 12857252 DOI: 10.1103/physrevlett.90.232502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2002] [Indexed: 05/24/2023]
Abstract
High-energy, cw electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the potential of the (e,e'K+) reaction for hypernuclear spectroscopy. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed energy resolution was found to be approximately 900 keV for the (12)(Lambda)B spectrum, and is substantially better than any previous hypernuclear experiment using magnetic spectrometers. The positions of the major excitations are found to be in agreement with a theoretical prediction and with a previous binding energy measurement, but additional structure is also observed in the core excited region, underlining the future promise of this technique.
Collapse
Affiliation(s)
- T Miyoshi
- Tohoku University, Sendai 980-8578, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Akikawa H, Ajimura S, Chrien RE, Eugenio PM, Franklin GB, Franz J, Gang L, Imai K, Khaustov P, May M, Pile PH, Quinn B, Rusek A, Sasao J, Sawafta RI, Schmitt H, Tamura H, Tang L, Tanida K, Yuan L, Zhou SH, Zhu LH, Zhu XF. Hypernuclear fine structure in (9)(lambda)Be. PHYSICAL REVIEW LETTERS 2002; 88:082501. [PMID: 11863952 DOI: 10.1103/physrevlett.88.082501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2001] [Indexed: 05/23/2023]
Abstract
With a germanium detector array (Hyperball), we observed two gamma-ray peaks corresponding to the two transitions (5/2(+)-->1/2(+) and 3/2(+)-->1/2(+)) in the (9)(Lambda)Be hypernucleus which was produced by the 9Be(K-,pi(-)) reaction. The energies of the gamma rays are 3029 +/- 2 +/- 1 keV and 3060 +/- 2 +/- 1 keV. The energy difference was measured to be 31.4(+2.5)(-3.6) keV, which indicates a very small Lambda-spin-dependent spin-orbit force between a Lambda and a nucleon. This is the smallest level splitting by far ever measured in a hypernucleus.
Collapse
Affiliation(s)
- H Akikawa
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Tanida K, Tamura H, Abe D, Akikawa H, Araki K, Bhang H, Endo T, Fujii Y, Fukuda T, Hashimoto O, Imai K, Hotchi H, Kakiguchi Y, Kim JH, Kim YD, Miyoshi T, Murakami T, Nagae T, Noumi H, Outa H, Ozawa K, Saito T, Sasao J, Sato Y, Satoh S, Sawafta RI, Sekimoto M, Takahashi T, Tang L, Xia HH, Zhou SH, Zhu LH. Measurement of the B(e2) of (7)(lambda)Li and shrinkage of the hypernuclear size. PHYSICAL REVIEW LETTERS 2001; 86:1982-1985. [PMID: 11289835 DOI: 10.1103/physrevlett.86.1982] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2000] [Indexed: 05/23/2023]
Abstract
We report on the first measurement of a hypernuclear gamma-transition probability. gamma rays emitted in the E2(5/2(+)-->1/2(+)) transition of (7)(Lambda)Li were detected by a large-acceptance germanium detector array (Hyperball), and the lifetime of the parent state ( 5/2(+)) was determined by the Doppler shift attenuation method. The obtained result, 5.8(+0.9)(-0.7)+/-0.7 ps, was then converted into the reduced transition probability [ B(E2)] to be B(E2;5/2(+)-->1/2(+)) = 3.6+/-0.5(+0.5)(-0.4) e(2) fm(4). Compared with the B(E2) of the corresponding E2(3(+)-->1(+)) transition in the 6Li nucleus, our result gives evidence that the size of the 6Li core in (7)(Lambda)Li is smaller than the 6Li nucleus in the free space.
Collapse
Affiliation(s)
- K Tanida
- Department of Physics, University of Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|