The lifetime of the first excited 2~+ state in ~(18)C was measured using an upgraded recoil shadow method to determine the electric quadrupole transition.The measured mean lifetime is 18.9±0.9 (stat)±4.4 (syst) ps,which corresponds to a B(E2;2~+_1→0~+_(gs)) value of (4.3±0.2±1.0) e~2fm~4,or about 1.5 Weisskopf units.The mean lifetime of the first 2~+ state in ~(16)C was remeasured to be about 18 ps,about four times shorter than the value reported previously.This discrepancy was explained by incorporating the γ-ray angular distribution measured in this work into the previous measurement.The observed transition strengths in ~(16,18)C are hindered compared to the empirical transition strengths,indicating that the anomalous hindrance observed in ~(16)C persists in ~(18)C.
参考文献
| [1] | Bohr A,Mottelson B R.Mat Fys Medd Dan Vid Selsk,1953,27:16;Grodzins L.Phys Lett,1962,2:88;Raman S,Nestor Jr C W,Bhatt K H.Phys Rev,1988,C37:805. |
| [2] | Bohr A,Mottelson B R.Mat Fys Medd Dan Vid Selsk,1953,27:16;Grodzins L.Phys Lett,1962,2:88;Raman S,Nestor Jr C W,Bhatt K H.Phys Rev,1988,C37:805. |
| [3] | Bohr A,Mottelson B R.Mat Fys Medd Dan Vid Selsk,1953,27:16;Grodzins L.Phys Lett,1962,2:88;Raman S,Nestor Jr C W,Bhatt K H.Phys Rev,1988,C37:805. |
| [4] | ImaiN,Ong H J,Aoi N,et al.Phys Rev Lett,2004,92:O62 501. |
| [5] | Firestone R B,Shirley V S.Table of Isotopes.New Work:Wiley,1996,8th ed,Vol I. |
| [6] | Elekes Z,Dombradi Zs,Krasznahorkay A,et al.Phys Lett,2004,B586:34. |
| [7] | Ong H J,Imai N,Aoi N,et al.Phys Rev,2006,C73:024 610. |
| [8] | Ong H J,Imai N,Suzuki D,et al.Phys Rev,2008,C78:014 308. |
| [9] | Kubo T,Ishihara M,Inabe N,et al.Nucl Instr Meth,1992,B70:309. |
| [10] | Hisanaga I,Motobayashi T,Ando Y.RIKEN Aceel Prog Rep,1998,31:162. |
| [11] | Nishio T,Motobayashi T,Ieki K,et al.RIKEN Accel Prog Rep,1996,29:184. |
| [12] | Takeuchi S,Motobayashi T,Murakami H,et al.RIKEN Accel Prog Rep,2003,36:148. |
| [13] | Program Code GEANT.CERN Program Library. |
| [14] | Wiedeking M,Fallon P,Macehiavelli A O,et al.Phys Rev Lett,2008,100:152 601. |
| [15] | Raman S,Nestor Jr C W,Tikkanen P.At Data and Nucl Data Tables,2001,78:1. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%