Candidate Resonant Tetraneutron State Populated by the ^{4}He(^{8}He,^{8}Be) Reaction

K Kisamori; S Shimoura; H Miya; S Michimasa; S Ota; M Assie; H Baba; T Baba; D Beaumel; M Dozono; T Fujii; N Fukuda; S Go; F Hammache; E Ideguchi; N Inabe; M Itoh; D Kameda; S Kawase; T Kawabata; M Kobayashi; Y Kondo; T Kubo; Y Kubota; M Kurata-Nishimura; C S Lee; Y Maeda; H Matsubara; K Miki; T Nishi; S Noji; S Sakaguchi; H Sakai; Y Sasamoto; M Sasano; H Sato; Y Shimizu; A Stolz; H Suzuki; M Takaki; H Takeda; S Takeuchi; A Tamii; L Tang; H Tokieda; M Tsumura; T Uesaka; K Yako; Y Yanagisawa; R Yokoyama; K Yoshida

doi:10.1103/PhysRevLett.116.052501

Candidate Resonant Tetraneutron State Populated by the ^{4}He(^{8}He,^{8}Be) Reaction

Phys Rev Lett. 2016 Feb 5;116(5):052501. doi: 10.1103/PhysRevLett.116.052501. Epub 2016 Feb 3.

Authors

K Kisamori^{1

2}, S Shimoura¹, H Miya^{1

2}, S Michimasa¹, S Ota¹, M Assie³, H Baba², T Baba⁴, D Beaumel^{2

3}, M Dozono², T Fujii^{1

2}, N Fukuda², S Go^{1

2}, F Hammache³, E Ideguchi⁵, N Inabe², M Itoh⁶, D Kameda², S Kawase¹, T Kawabata⁴, M Kobayashi¹, Y Kondo^{2

7}, T Kubo², Y Kubota^{1

2}, M Kurata-Nishimura², C S Lee^{1

2}, Y Maeda⁸, H Matsubara⁹, K Miki⁵, T Nishi^{2

10}, S Noji¹¹, S Sakaguchi^{2

12}, H Sakai², Y Sasamoto¹, M Sasano², H Sato², Y Shimizu², A Stolz¹¹, H Suzuki², M Takaki¹, H Takeda², S Takeuchi², A Tamii⁵, L Tang¹, H Tokieda¹, M Tsumura⁴, T Uesaka², K Yako¹, Y Yanagisawa², R Yokoyama¹, K Yoshida²

Affiliations

¹ Center for Nuclear Study, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
² RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
³ IPN Orsay, 15 Rue, Georges, Clemenceau 91400 Orsay, France.
⁴ Department of Physics, Kyoto University, Yoshida-Honcho, Sakyo, Kyoto 606-8501, Japan.
⁵ Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
⁶ Cyclotron and Radioisotope Center, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
⁷ Department of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo 152-8550, Japan.
⁸ Faculty of Engineering, University of Miyazaki, 1-1 Gakuen, Kibanadai-nishi, Miyazaki 889-2192, Japan.
⁹ National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba, Japan.
¹⁰ Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
¹¹ National Superconducting Cyclotron Laboratory, Michigan State University, 640 S Shaw Lane, East Lansing, Michigan 48824, USA.
¹² Department of Physics, Kyushu University, 6-10-1 Hakozaki, Higashi, Fukuoka 812-8581, Japan.

PMID: 26894705
DOI: 10.1103/PhysRevLett.116.052501

Abstract

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.