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GENERAL: See also (1986AJ01) and 14.22 [Table of Energy Levels] (in PDF or PS) here.

Nuclear models: (1985BA75, 1987BL15).

Electromagnetic transitions: (1989RA16, 1989SP01).

Astrophysical questions: (1985TA1A, 1987RA1D).

Applied work: (1989AR1J).

Complex reactions involving ¹⁴O: (1987PE1C, 1988ST1D, 1989BA92, 1989DR03, 1989KI13).

Reactions involving pions (See also reactions 5 and 7.): (1986BA1C, 1986BO1N, 1986FO06, 1986GE06, 1986SI11, 1987BL15, 1987KA39, 1987KO1O, 1987KO1Q, 1987MI02, 1987PA1H, 1988AU1D, 1988HA37, 1988YU04, 1990HAZV).

Hypernuclei: (1989BA93).

Other topics: (1985AN28, 1986AN07).

Ground state of ¹⁴O: (1985AN28, 1986HE26, 1987SA15, 1988WRZZ).
For searches for ⁴n and ⁴H involving the production of ¹⁴O see (1986BE35, 1986BE54, 1988BE02).

1. 14O(β+)14N

Qm = 5.1431

The best value of τ_1/2 = 70.606 ± 0.018 s: see (1978WI04). See also (1976AJ04). ¹⁴O decays predominantly to its analog state ¹⁴N*(2.31) [J^π; T = 0⁺; 1; E_x = 2312.798 (11) keV, E_γ = 2312.593 (11) keV (1982WA16)]. 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 ¹⁴N*(0, 3.95) [both 1⁺; 0 states]. Log f^Rt = 3.4892 (2) for the 0⁺ → 0⁺ transition (1981WH03), using the Wapstra masses for the atomic mass excess of ¹⁴N, ¹H and n; E_thresh · for the ¹⁴N(p, n) threshold (1981WH03) and E_x shown above for ¹⁴N*(2.31) (1982WA16). See (1989OR01, 1989OR09) 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 (1990HA13), 0.9989 ± 0.0012 (1990WI05, 1990WI10, 1990WI1J) [and D.H. Wilkinson, private communication].

For the transitions to ¹⁴N*(0, 3.95) log ft = 7.266 ± 0.009 (1980WI13) and 3.15 ± 0.02, respectively. The Q-value difference between the 0⁺-0⁺ transition in this decay and in the ^26mAl decay has been measured by (1987KO34). For a study of the longitudinal polarization of the positrons see (1988GI02, 1989CA1J, 1990CA1U). See also (1989HA1X, 1990HA1Q) and (1986IS07, 1986JA07, 1986SI1H, 1987JA07, 1988LO01, 1989SA1P, 1989WO1E; theor.).

2. (a) 9Be(13C, 8He)14O	Qm = -25.13
(b) 9Be(14C, 9He)14O	Qm = -34.44

For reaction (a) see (1988BO20). For reaction (b) see (1988BEYJ).

3. 12C(3He, n)14O

Qm = -1.1466

Observed neutron groups are displayed in 14.23 (in PDF or PS). Angular distributions have been measured at E(³He) = 15 to 25.4 MeV [see (1981AJ01)] and at 45.5 MeV (1987AB04; n₀, n₁). For ¹⁴O*(5.17) [J^π = 1^-], Γ_γ/Γ = (7.2 ± 3.5) × 10^-5; using Γ_c.m. from 14.22 (in PDF or PS), Γ_γ = (2.7 ± 1.3) eV (1989FE06). (1989AG1A; prelim.) report Γ_γ = (7.6 ± 3.8) eV.

4. (a) 12C(12C, 10Be)14O	Qm = -20.6136
(b) 12C(14N, 12B)14O	Qm = -18.513

At E(¹²C) = 480 MeV (reaction (a)) forward-angle differential cross sections have been studied for ¹⁴O*(6.27, 9.9, 14.1, 15.7). ¹⁴O*(0, 6.59) are also populated. The forward spectra are dominated by ¹⁴O*(9.9) (1988KR11). For the earlier work on both reactions see (1976AJ04, 1981AJ01). See also (1988ME10).

5. 13C(p, π-)14O

Qm = -137.161

Differential cross sections have been measured at E_p = 250 MeV to ¹⁴O*(0, 5.17, 6.27 + 6.59, 9.92) and at E_p = 354 and 489 MeV to ¹⁴O*(0, 6.27 + 6.59) (1988HU04). At E_p = 489 MeV a broad structure near 23 MeV is also observed (1988HU06) but its origin is unknown (R.D. Bent and G.M. Huber, private communication) [Note: a T = 2 state in ¹⁴O, corresponding to ¹⁴C*(23.2) may be substantially broader and might be more difficult to detect].

At E _{pol. p} = 200 MeV angular distributions and A_y have been measured to ¹⁴O*(0, 5.17, 6.1[u], 6.6[u], 7.8, 9.7 + 9.9, 10.9, (12.0), 14.2, (14.6, 17.4)). It is suggested that ¹⁴O*(14.15) has J^π = 5^-: see ¹³C(p, π⁺)¹⁴C (reaction 15) (1987KO01, 1989KO21). For the earlier work see (1986AJ01). See also the "GENERAL" section here, (1986JA1H, 1987VI13) and (1986KU1J; theor.).

6. 13N(p, γ)14O

Qm = 4.6280

This reaction is important in the hot-CNO cycle if its rate is dominated by l = 0 capture through ¹⁴O*(5.17). Calculations suggest Γ_γ for this state is 1.8 eV (1987FU02), ≥ 4.1 eV (1989DE28). See also (1986AJ01) and references below. For measurements see reactions 3 and 8 and, in particular, (1989FE06) [Γ_γ = 7.6 ± 3.8 eV] for empirical S-factors as f(E). See also (1990SMZZ) and (1982TR1A, 1983HA1B, 1985BA75, 1985CA41, 1986FI15, 1987BU12, 1988CA26, 1988JO1D, 1988RO04, 1988TR1C, 1989AG1A, 1989AR1G, 1989AR1H, 1989BA64).

7. 14C(π+, π-)14O

Qm = -4.9866

Forward-angle cross sections have recently been measured for E_π⁺ = 19 to 79.5 MeV (1989LE11; 0°) and 300 to 500 MeV (1989WI02; 5°). For the earlier work see (1986AJ01). See also (1985AL15, 1986GI06, 1988SE1A, 1989LE1L) and (1987HA29, 1989CH1O, 1989ST1H, 1989YU1A, 1990CH14; theor.).

8. 14N(p, n)14O

Qm = -5.9255

E_thresh. = 6353.04 ± 0.08 keV (1981WH03).

Angular distributions have been measured at E_p = 35.2 and 144 MeV [see (1986AJ01) and (1979MO16)] as well as at 35 MeV (1987OR01; to ¹⁴O*(5.17)). A preliminary value for Γ_γ of ¹⁴O*(5.17) is ≈ 1 eV (1988WAZX) [see also the discussion in (1989FE06)]. See also (1984BA2E, 1990SMZZ) and (1988CA26, 1988LE08; astrophys.).

9. 14N(3He, t)14O

Qm = -5.1617

Triton groups have been observed at E(³He) = 44.6 MeV to the first six states shown in 14.22 (in PDF or PS) and to levels with E_x = 6.79 ± 0.03, 8.74 ± 0.06, 9.74 ± 0.03, 10.89 ± 0.05, 11.24 ± 0.05, 11.97 (unresolved), 12.84 ± 0.05, 13.01 ± 0.05, 14.15 ± 0.04, 14.64 ± 0.06 and 17.40 ± 0.06 MeV: see (1981AJ01). [The states at 6.79 and 8.74 MeV reported in this reaction are relatively weakly excited and are not observed in reaction 3.] Γ_c.m. of ¹⁴O*(5.17) = 38.1 ± 1.8 keV (1985CH06). See also (1987KO34, 1989DE1Q).

10. 16O(p, t)14O

Qm = -20.4045

Angular distributions of ground-state tritons have been studied to E_p = 54.1 MeV: see (1981AJ01). For comparison with the (p, ³He) results see reaction 64 in ¹⁴N.

Triton groups have been observed to states with E_x = 5.21 ± 0.04, 5.92 ± 0.06, 6.28 ± 0.05, 6.59, 7.77, 8.69 ± 0.06 [weak, not observed in reaction 3], and 9.65 ± 0.06 MeV. Angular distributions have been studied with polarized protons at E_p = 43.8 MeV to ¹⁴O*(0, 5.17, 6.27, 6.59, 7.77, 9.72): see (1976AJ04).