Two-Proton Emission from the Ground State of <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">O</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>12</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math></span>

R. A. Kryger; A. Azhari; M. Hellström; J. H. Kelley; T. Kubo; R. Pfaff; E. Ramakrishnan; B. M. Sherrill; M. Thoennessen; S. Yokoyama; R. J. Charity; J. Dempsey; A. Kirov; N. Robertson; D. G. Sarantites; L. G. Sobotka; J. A. Winger

doi:10.1103/PhysRevLett.74.860

Two-Proton Emission from the Ground State of ${}^{12}O$

R. A. Kryger, A. Azhari, M. Hellström, J. H. Kelley, T. Kubo, R. Pfaff, E. Ramakrishnan, B. M. Sherrill, M. Thoennessen, S. Yokoyama, R. J. Charity, J. Dempsey, A. Kirov, N. Robertson, D. G. Sarantites, L. G. Sobotka, and J. A. Winger

Phys. Rev. Lett. 74, 860 – Published 6 February 1995

Abstract

The three-body decay ${}^{12}O \to 2 p + {}^{10}C$ was studied following production via single-neutron stripping from a radioactive ${}^{13}O$ projectile. This is the first observation of two-proton emission from an unbound ground state where the one-proton emission channel is energetically closed beyond the lightest case of ${}^{6}{Be}$ . No evidence for ${}^{2}{He}$ emission is seen, despite predictions for a large diproton branching ratio. An upper limit of 7% (95% C.L.) is established for this decay branch. The implications of the small diproton branching ratio observed here and seen previously in ${}^{6}{Be}$ are discussed.

Received 17 August 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.860

Authors & Affiliations

R. A. Kryger¹, A. Azhari^1,2, M. Hellström¹, J. H. Kelley^1,2, T. Kubo^1,*, R. Pfaff¹, E. Ramakrishnan^1,2, B. M. Sherrill^1,2, M. Thoennessen^1,2, S. Yokoyama^1,2, R. J. Charity³, J. Dempsey³, A. Kirov³, N. Robertson⁴, D. G. Sarantites³, L. G. Sobotka^3,4, and J. A. Winger^5,†

¹National Superconducting Cyclotron Laboratory, East Lansing, Michigan 48824-1321
²Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824-1321
³Department of Chemistry, Washington University, St. Louis, Missouri 63130
⁴Department of Physics, Washington University, St. Louis, Missouri 63130
⁵Cyclotron Institute, Texas A & M University, College Station, Texas 77843

^*Present address: RIKEN, Hirosawa, Wako, Saitama 351-01 Japan.
^†Present address: Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS 39762.