Energy Levels of Light Nuclei A = 14 - Triangle Universities Nuclear ...

14 O
(Figs. 4 and 5)
GENERAL (See also (86AJ01)).
Nuclear models: (85BA75, 87BL15).
Electromagnetic transitions: (89RA16, 89SP01).
Astrophysical questions: (85TA1A, 87RA1D).
Applied work: (89AR1J).
Complex reactions involving 14 O: (87PE1C, 88ST1D, 89BA92, 89DR03, 89KI13).
Reactions involving pions (See also reactions 5 and 7.): (86BA1C, 86BO1N, 86FO06, 86GE06,
86SI11, 87BL15, 87KA39, 87KO1O, 87KO1Q, 87MI02, 87PA1H, 88AU1D, 88HA37, 88YU04,
90HAZV).
Hypernuclei: (89BA93).
Other topics: (85AN28, 86AN07).
Ground state of 14 O: (85AN28, 86HE26, 87SA15, 88WRZZ).
For searches for 4 nand 4 H involving the production of 14 Osee(86BE35, 86BE54, 88BE02).
1. 14 O(β + ) 14 N Q m =5.1431
The best value of τ 1/2 =70.606 ± 0.018 s: see (78WI04). See also (76AJ04). 14 O decays
predominantly to its analog state 14 N*(2.31) [J π ; T =0 + ; 1; E x = 2312.798 (11) keV, E γ =
2312.593 (11) keV (82WA1D)]. The branching ratio to the state is (99.336 ± 0.010)%. This value is
obtained by adopting (0.61 ± 0.01)% and (0.054 ± 0.002)% for the branching ratios to 14 N*(0, 3.95)
[both 1 + ; 0 states]. Log f R t =3.4892 (2) for the 0 + → 0 + transition (81WH03), using the Wapstra
masses for the atomic mass excess of 14 N, 1 H and n; E thresh· for the 14 N (p, n) threshold (81WH03)
and E x shown above for 14 N*(2.31) (82WA1D). See (89OR01, 89OR09) for other calculations of
log ft [3.4884 (5)] and comments. Critical surveys of superallowed Fermi transitions lead to values
for the first row of the Kobayashi-Maskawa matrix= 0.9970 ± 0.0021 (90HA13), 0.9989 ± 0.0012
(90WI1J, 90WI10, 90WI05) [and D.H. Wilkinson, private communication].
For the transitions to 14 N*(0, 3.95) log ft =7.266±0.009 (80WI13)and3.15±0.02, respectively.
The Q-value difference between the 0 + −0 + transition in this decay and in the 26m Al decay has been
measured by (87KO34). For a study of the longitudinal polarization of the positrons see (88GI02,
89CA1J, 90CA1U). See also (89HA1X, 90HA1Q) and(86IS07, 86JA07, 86SI1H, 87JA07, 88LO01,
89SA1P, 89WO1E; theor.).
2. (a) 9 Be( 13 C, 8 He) 14 O Q m = −25.13
(b) 9 Be( 14 C, 9 He) 14 O Q m = −34.44
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