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14O (1981AJ01)(See Energy Level Diagrams for 14O) GENERAL: See also (1976AJ04) and Table 14.21 [Table of Energy Levels] (in PDF or PS). Special reactions involving 14O: (1976AB04, 1978AB08). Astrophysical questions: (1977JO1D, 1977SI1D). Applied topics: (1978HI1D). Reactions involving pions: (1976DI10, 1976DI11, 1977HO1B, 1978SH12, 1979LI1H, 1980DE10, 1980SI07). Other topics: (1976IR1B, 1976ST13, 1976VO1C, 1979KA13). Mass of 14O: The recent 14N(p, n)14O threshold measurement by (1977WH01) leads to an atomic mass excess of 8007.1 ± 0.4 keV for 14O. See also (1980BA1M). A preliminary measurement of the 16O(p, t) Q-value (P.A. Barker and J.A. Nolen, private communication) leads to 8008.65 ± 0.51 keV, in excellent agreement with the value adopted by (1977WA08) [8008.3 ± 0.5 keV] which we continue to adopt. See also (1980NO1A).
A recent measurement of the half-life of 14O is 70.613 ± 0.025 sec (1978WI04); [for earlier measurements see (1976AJ04)]. The "best" value of τ1/2 = 70.606 ± 0.018 sec (1978WI04). 14O [Jπ = 0+; T = 1] decays predominantly to the analog state 14N*(2.31): the branching ratio to that state is (99.332 ± 0.011)%. This value is obtained by adopting (0.61 ± 0.01)% (1966SI05) and (0.058 ± 0.004)% (1980WI1H) [Note added in proof: Sum of εK and β-decay in ratio 6/4 (R.W. Kavanagh, private communication).] for the branching ratios to 14N*(0, 3.95) [both 1+; 0 states]. The ft-value for the 0+ → 0+ transition to 14N*(2.31) is 3086.5 ± 2.7 sec (1978WI04): [log ft = 3.4895 ± 0.0004]. For the transition to 14N*(0, 3.95) log ft = 7.266 ± 0.009 (1980WI1H) and 3.112 ± 0.034 (1980WI1H), respectively. See also the discussion in (1976AJ04). See also (1977BA2L, 1977WH01), (1976BE1E, 1978WE1J), (1978DA1H, 1978TA1U; astrophys.) and (1976LO01, 1976WI15, 1977GO13, 1977RI08, 1977RY1B, 1977SZ03, 1977TO11, 1977WI04, 1978SZ03, 1978TO02, 1978VA14, 1978WE1J, 1979DE15, 1979FE02, 1979KI1G, 1979SZ07, 1980LO07; theor.).
Observed neutron groups are displayed in Table 14.22 (in PDF or PS). Angular distributions have been measured at E(3He) = 25.4 MeV [see (1970AJ04, 1976AJ04)] and at 15, 18 and 20 MeV (1978FE03: n0, n1, n2+3+4). See also (1976WA1B) and 15O.
At E(10B) = 100 MeV the angular distributions of the transitions to 14O*(6.27, 9.92) [Jπ = 3-, 4+], the states preferentially excited, have been studied by (1978HA10).
At E(11B) = 114 MeV, 14O*(6.27, 9.9) [Jπ = 3-, 4+] are populated: see (1974AN36).
At E(12C) = 114 MeV, the population of 14O*(0, 6.27, 9.9) is reported: it is suggested that 14O*(9.9) has a (d5/2)24+;1 configuration (1972SC21, 1974AN36). 14Og.s. is weakly populated (1974AN36).
At E(14N) = 118 MeV, the population of 14O*(6.27, 9.9) is reported (1974AN36). At E(14N) = 155 MeV there is some evidence for the excitation of 14O*(5.17, 5.92, 6.27, 8.72, 9.72) (1975NA11). See also (1979NA1G).
See (1979OR01: E(20Ne) = 150 to 294 MeV).
At Ep = 200 MeV the angular distributions of π- and π+ to the ground states of 14O and 14C are very different (1979HO1F). See also (1979JO1C) and (1976NO1D, 1976PO1D; theor.).
Ethresh. = 6353.6 ± 0.4 keV (1977WH01) (See also the "Mass of 14O" section here.); Ethresh. = 6353.99 ± 0.1 keV (1980BA1M; prelim.). Ground state angular distributions have been measured at Ep = 35 MeV (1979TAZW) and 144 MeV ((1980MO10) and to 14O*(7.77)). See also (1976AJ04).
Triton groups have been observed at E(3He) = 44.6 MeV to the first six states shown in Table 14.21 (in PDF or PS) and to levels with Ex = 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 (1967BA13, 1969BA06). See also reaction 50 in 14N. [The states at 6.79 and 8.74 MeV reported in this reaction are relatively weakly excited and are not observed in reaction 2.]
See (1977JO02).
Angular distributions of ground state tritons have been studied to Ep = 54.1 MeV [see (1976AJ04)] and at 28.9, 29.8 and 30.7 MeV (1978GO04). For comparison with the (p, 3He) results see reaction 68 in 14N. Triton groups have also been observed to states with Ex = 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 2], and 9.65 ± 0.06 MeV (1971FL04). Angular distributions have been studied with polarized protons at Ep = 43.8 MeV to 14O*(0, 5.17, 6.27, 6.59, 7.77, 9.72) (1974MA12). See also (1977BA2L, 1979NOZZ), (1976DA1K) and (1978PI1B, 1978PI10; theor.).
See (1975JA10).
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