Isomeric 0+ state in 12Be

doi:10.1016/S0370-2693(03)00341-1

Physics Letters B

Volume 560, Issues 1–2, 8 May 2003, Pages 31-36

https://doi.org/10.1016/S0370-2693(03)00341-1 Get rights and content

Abstract

An isomeric 0⁺ state in ¹²Be was found at E_x=2.24 MeV. The isomer was identified by measuring coincident two γ-rays from in-flight ¹²Be nuclei, ^12mBe→¹² $Be^{∗}$ (2⁺₁)→¹²Be_g.s., produced by the projectile fragmentation of ¹⁸O at 100 A MeV on a beryllium target. Its spin was determined to be 0⁺ by the angular correlation of the two γ-rays. The low excitation energy of the 0⁺ state is a strong evidence of the break of the N=8 shell closure in the ¹²Be nucleus.

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Acknowledgements

We would like to thank the RIKEN Ring Cyclotron staff members for their operation during the experiment. We acknowledge valuable discussions on shell-model calculations with T. Otsuka. The present work was partially supported by the Grant-in-Aid for Scientific Research (No. 11440081) by the Ministry of Education, Culture, Sports, Science and Technology.

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Citation Excerpt :
Discussion on other final state effects is given in [1991CA09,1994IR02,1994JE04,1994RY04,1995BI07,1995BI19,1995NI02,1996BI01,1996BI21,1996JE04,1999KE04,2002DE07,2004BA99,2004BB15,2005BA07,2005BA23,2005PR02,2007AL14,2007PI05], and discussion on the reaction mechanism is found in [1990LO09,1991VA05,1992DR02,1993CI05,1993OF01,1994IR01,1994RY03,1994TA11,1994WE06,1999MO02,2002ME17,2004FR27,2004MU29,2004RO35,2004TA18,2011RY03]. See also [1993KE02,1993KO12,1994BI05,1994VE08,1994WA19,1995RY02,1996JO15,1997BI06,1997GI13,1998HO20,1999JO06,2000DE38,2000UD01,2005KE04,2009TA34,2014MO25,2014TO14]. Angular distributions of the elastic and inelastically scattered pions have been measured at many energies: see Table 12.27.

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Physics Letters B

Abstract

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Acknowledgements

References (23)

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Phys. Lett. B

Phys. Lett. B

Nucl. Phys. A

Nucl. Phys. A

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Phys. Rev. Lett.

J. Phys. G

Cited by (123)

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A new measurement of the intruder configuration in <sup>12</sup>Be

Energy levels of light nuclei A = 12