Eur. Phys. J. A (2014) 50: 136
https://doi.org/10.1140/epja/i2014-14136-4

Regular Article - Experimental Physics

Excited states above the proton threshold in ²⁶Si

¹ Rare Isotope Science Project, Institute for Basic Science (IBS), 305-811, Yuseong-gu Daejeon, Republic of Korea
² RIKEN, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
³ Japan Atomic Energy Agency, Shirakata Shiran 2-4, 319-1106, Tokai, Ibaraki, Japan
⁴ Institute of Physics, University of Tsukuba, Tennodai 1-1-1, 305-8571, Tsukuba, Ibaraki, Japan
⁵ National Cerebral and Cardiovascular Center Research Institute, 565-8565, Suita, Osaka, Japan
⁶ Center for Nuclear Study (CNS), University of Tokyo, Wako Branch, 2-1 Hirosawa, 351-0198, Wako, Saitama, Japan
⁷ Laboratori Nazionali del Sud-INFN, Catania, Italy
⁸ Institute of Physics, Vietnamese Academy for Science and Technology, Hanoi, Vietnam
⁹ McMaster University, Hamilton, Ontario, L8S 4M1, Canada
¹⁰ Department of Physics, University of Notre Dame, Notre Dame, Indiana, 46556, USA
¹¹ National Astronomical Observatory, Osawa, Mitaka, 181-8588, Tokyo, Japan
¹² Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-0033, Tokyo, Japan

^* e-mail: komatsu@ibs.re.kr

Received: 30 April 2014
Revised: 24 July 2014
Accepted: 11 August 2014
Published online: 4 September 2014

Abstract

The level scheme above the proton threshold in ²⁶Si is crucial for evaluating the ²⁵Al(p, γ)²⁶Si stellar reaction, which is important for understanding the astrophysical origin of the long-lived cosmic radioactivity ²⁶Al(T _1/2 = 7.17 × 10⁵ y) in the Galaxy. The excited states in ²⁶Si have been studied using an in-beam γ-ray spectroscopy technique with the ²⁴Mg(³He, nγ)²⁶Si reaction. γ-rays with energies up to 4.6 MeV emitted from excited states in ²⁶Si have been measured using large volume HPGe detectors. The spin-parity of one of the most important states reported recently at 5890.0keV has been assigned as 0⁺ by γ-γ angular correlation measurements in this work.