Two-Proton Radioactivity of ^{67}Kr

T Goigoux; P Ascher; B Blank; M Gerbaux; J Giovinazzo; S Grévy; T Kurtukian Nieto; C Magron; P Doornenbal; G G Kiss; S Nishimura; P-A Söderström; V H Phong; J Wu; D S Ahn; N Fukuda; N Inabe; T Kubo; S Kubono; H Sakurai; Y Shimizu; T Sumikama; H Suzuki; H Takeda; J Agramunt; A Algora; V Guadilla; A Montaner-Piza; A I Morales; S E A Orrigo; B Rubio; Y Fujita; M Tanaka; W Gelletly; P Aguilera; F Molina; F Diel; D Lubos; G de Angelis; D Napoli; C Borcea; A Boso; R B Cakirli; E Ganioglu; J Chiba; D Nishimura; H Oikawa; Y Takei; S Yagi; K Wimmer; G de France; S Go; B A Brown

doi:10.1103/PhysRevLett.117.162501

Two-Proton Radioactivity of ^{67}Kr

Phys Rev Lett. 2016 Oct 14;117(16):162501. doi: 10.1103/PhysRevLett.117.162501. Epub 2016 Oct 14.

Authors

T Goigoux¹, P Ascher¹, B Blank¹, M Gerbaux¹, J Giovinazzo¹, S Grévy¹, T Kurtukian Nieto¹, C Magron¹, P Doornenbal², G G Kiss², S Nishimura², P-A Söderström², V H Phong², J Wu², D S Ahn², N Fukuda², N Inabe², T Kubo², S Kubono², H Sakurai^{2

3}, Y Shimizu², T Sumikama², H Suzuki², H Takeda², J Agramunt⁴, A Algora^{4

5}, V Guadilla⁴, A Montaner-Piza⁴, A I Morales⁴, S E A Orrigo⁴, B Rubio⁴, Y Fujita^{6

7}, M Tanaka⁶, W Gelletly^{4

8}, P Aguilera⁹, F Molina⁹, F Diel¹⁰, D Lubos¹¹, G de Angelis¹², D Napoli¹², C Borcea¹³, A Boso¹⁴, R B Cakirli¹⁵, E Ganioglu¹⁵, J Chiba¹⁶, D Nishimura¹⁶, H Oikawa¹⁶, Y Takei¹⁶, S Yagi¹⁶, K Wimmer³, G de France¹⁷, S Go¹⁸, B A Brown¹⁹

Affiliations

¹ Centre d'Études Nucléaires de Bordeaux Gradignan, Université de Bordeaux-UMR 5797 CNRS/IN2P3, Chemin du Solarium, 33175 Gradignan, France.
² RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
³ Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
⁴ Instituto de Física Corpuscular, CSIC-Universidad de Valencia, E-46071 Valencia, Spain.
⁵ Institute of Nuclear Research of the Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen, Hungary.
⁶ Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
⁷ Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan.
⁸ Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
⁹ Comisión Chilena de Energía Nuclear, Casilla 188-D, Amunátegui 95, Santiago Centro, Santiago, Chile.
¹⁰ Institute of Nuclear Physics, University of Cologne, D-50937 Cologne, Germany.
¹¹ Physik Department E12, Technische Universität München, D-85748 Garching, Germany.
¹² Laboratori Nazionali di Legnaro dell'INFN, I-35020 Legnaro (Padova), Italy.
¹³ National Institute for Physics and Nuclear Engineering IFIN-HH, P.O. Box MG-6, Bucharest-Magurele, Romania.
¹⁴ INFN Sezione di Padova and Dipartimento di Fisica, Università di Padova, I-35131 Padova, Italy.
¹⁵ Department of Physics, Istanbul University, Istanbul 34134, Turkey.
¹⁶ Department of Physics, Tokyo University of Science, Noda, Chiba 278-8510, Japan.
¹⁷ Grand Accélérateur National d'Ions Lourds, B.P. 55027, F-14076 Caen Cedex 05, France.
¹⁸ Department of Physics and Astronomy, University of Tennessee, 401 Nielsen Physics Building, 1408 Circle Drive, Knoxville, Tennessee 37996-1200, USA.
¹⁹ Department of Physics and Astronomy, and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA.

PMID: 27792367
DOI: 10.1103/PhysRevLett.117.162501

Abstract

In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from ^{67}Kr. At the same time, no evidence for 2p emission of ^{59}Ge and ^{63}Se, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to ^{67}Kr as being the best new candidate among the three for two-proton radioactivity. ^{67}Kr is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of ^{67}Kr is 7.4(30) ms.