| Recommended value (August, 2015): | 177.7 ± 0.6 ms | (Weighted Average) |
| Summary Table of Uncertainty Analysis: |  (PDF) |
|
| Measured values: | 178 ± 3 ms | (1999BE53) |
| 181.8 ± 0.4 ms | (1997SO34) (Excluded: insufficient experimental details) | |
| 178 ± 1 ms | (1992TE03) | |
| 178.1 ± 0.6 ms | (1994RE1R: see also 175.5 ± 7.6 ms in (1991RE02) and 178.1 ± 0.6 ms | |
| in the unpublished private communications of (2008REZZ)/(1995REZZ).) | ||
| 167 ± 20 ms | (1988SA04) | |
| 173 ± 14 ms | (1986CU01) | |
| 178.3 ± 0.4 ms | (1976AL02) | |
| 179 ± 16 ms | (1976FI03) | |
| 175 ± 1 ms | (1973AU1A, 1974RO31) | |
| 177 ± 3 ms | (1970CH1T, 1970CH07) | |
| 176 ± 1 ms | (1965DO13) | |
| 172 ± 25 ms | (1965SC17) | |
| 190 ± 30 ms | (1963AL18) | |
| 170 ± 10 ms | (1961HI01) | |
| 170 ± 5 ms | (1952HO25) | |
| 190 ± 50 ms | (1952SH44) | |
| 168 ± 4 ms | (1951GA30) | |
| Other Reviews: | 178.2 ± 0.4 ms | (2015BI05) |
| Decay to 9Be* (MeV) |
Jπ | Branching Ratio (%) | Log ft | B(GT) d | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| (1963AL18) | (1970CH1T, 1970CH07) | (1981LA11) | (1993CH06) a | (1963AL18) | (1969MA11) | (1970CH1T, 1970CH07) | b | c | |||
| 0 | 3/2- | 25 ± 15 | 65.0+2.7-2.4 | 50.5 ± 5 e | 49.2 ± 0.9 f | 5.5 ± 0.2 | 5.12+0.01-0.02 | 5.20+0.01-0.02 | 5.31 | 0.0292 ± 0.0009 | |
| 2.43 | 5/2- | 75 ± 15 | 32.0+2.7-3.7 g | 34 ± 4 | 29.7 ± 3.0 h | 4.7 ± 0.2 | 5.2 ± 0.2 | 5.00+0.04-0.28 | 5.10+0.04-0.05 | 5.07 | 0.046 ± 0.005 |
| 2.78 i | 1/2- | 3.0+2.7-0.3 g | 10 ± 2 | 15.8 ± 3.0 h | 5.97+0.05-0.28 | 6.06+0.05-0.28 | 5.54 | 0.011 ± 0.005 j | |||
| 7.94 | (5/2-) a,k | 1.5 ± 0.5 | < 2% l | 5.04 | 0.048 ± 0.018 j | ||||||
| 11.28 | (7/2-) m,n | 4 ± 0.5 | 1.1 ± 0.2 l | 2.87 o | 1.4 ± 0.5 j | ||||||
| 11.81 | 5/2- p | < 0.1 | 2.7 ± 0.2 l | > 4.0 | 8.9 ± 1.9 j | ||||||
| a) Based on Tables II and III of (1993CH06) taking into account the different value for Pn. |
| b) M.J. Martin, Nucl. Data Project, private communication to Fay Ajzenberg-Selove (1979AJ01). |
| c) M.J. Martin, private communication to Fay Ajzenberg-Selove (1984AJ01). |
| d) B(GT) includes the factor (gA/gB)2. The empirical quenching found by (1993CH06) gives (gA/gB)2eff = 1.14 and permits a comparison with p-shell calculations. |
| e) Pn = (50 ± 4)% (1981BJ01); Pn = (49.5 ± 5)% (1981LA11). |
| f) Obtained using Pn = (50.8 ± 0.9)%, which is the average of (50.0 ± 1.8)%(1991RE02)and (51.0 ± 1.0)% (1992TE03). |
| g) See also (1973RO2F). |
| h) (1990NY01). |
| i) 2.78 ± 0.12 MeV, Γc.m. = 1.10 ± 0.12 MeV; θ2p = 0.48 ± 0.06 (1970CH07). |
| j) For decay to an unbound level B(GT) is not well defined. (1990NY01) deduce B(GT) taking into account the variation of the statistical factor over the width of the final states and the considerable error in this procedure is reflected in the errors tabulated. |
| k) (1981LA11) suggest (1/2-) on the basis of the branching ratios. |
| l) From (1990NY01). |
| m) A 7/2- level is known at this energy. A strong β transition implies Jπ = 1/2-, 3/2-, or 5/2-, with 5/2- unlikely on theoretical grounds given that the 11.8 MeV state has been assigned 5/2-. |
| n) (1981LA11) suggest (3/2-) on the basis of the branching ratios. |
| o) (1981LA11) suggest that the very low log ft value implies that 9Be*(11.28) is the anti-analog of 9Li(0). |
| p) (2003PR11) find that the decay mainly populates the 11.8 MeV state, determine a spin of 5/2-, and extract a B(GT) value of 8.5 ± 1.5. |
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Last modified: 28 June 2021