
^{16}O (1993TI07)(See Energy Level Diagrams for ^{16}O)
GENERAL: See 2 [Electromagnetic Transitions in A = 1617] (in PDF or PS), 16.12 [General Table] (in PDF or PS), 16.13 [Table of Energy Levels] (in PDF or PS) and 16.14 [Radiative decays in
Abundance = (99.762 ± 0.015)% (1984DE53) g = 0.556 ± 0.004 (1984AS03)
Total reaction cross sections and characteristic γray cross sections for ^{9}Be + ^{9}Be were measured for E_{c.m.} = 1.4  3.4 MeV (1988LA25). Gamma rays were observed from levels at 6.13 (3^{}), 6.917 (2^{+}), and 7.1117 (1^{}) MeV populated by the ^{9}Be(^{9}Be, 2n)^{16}O reaction. Cross sections calculated with optical models agreed with elastic scattering data, but the total reaction cross section was underpredicted by a factor of 2 to 3.
Energy spectra of the ^{16}O nuclei were measured (1986BE35) for incident ^{11}B energies of 88 MeV to obtain information on the ^{4}He system.
This reaction was studied by (1988BEYJ).
At E(^{6}Li) = 4.9 MeV, the cross sections for reactions (b) to (f) leading to lowlying states in the residual nuclei are proportional to 2J_{f} + 1: this is interpreted as indicating that the reactions proceed via a statistical compound nucleus mechanism. For highly excited states, the cross section is higher than would be predicted by a 2J_{f} + 1 dependence: see (1982AJ01, 1986AJ04).
States of ^{16}O observed at E(^{10}B) = 20 MeV are displayed in 16.10 (in PDF or PS) of (1977AJ02). At the higher excitation energies, states are reported at E_{x} = 17.200 ± 0.020, 17.825 ± 0.025, 18.531 ± 0.025, 18.69 ± 0.03, 18.90 ± 0.035, 19.55 ± 0.035, 19.91 ± 0.02, 20.538 ± 0.015, 21.175 ± 0.015, 21.84 ± 0.025, 22.65 ± 0.03 and 23.51 ± 0.03 MeV. The reaction excites known T = 0 states: σ_{t} follows 2J_{f} + 1 for 11 of 12 groups leading to states of known J. The angular distributions show little structure: see (1977AJ02).
Cross section measurements at E_{c.m.} = 1.46  6.10 MeV were reported in (1990DA03).
The yield of capture γrays has been studied for E_{α} up to 42 MeV [see 16.11 (in PDF or PS) in (1977AJ02) and (1982AJ01)]. See also (1986AJ04). Observed resonances are displayed in 16.15 (in PDF or PS) here. This reaction plays an important role in astrophysical processes. The cross sections at astrophysical energies have been obtained by fitting measured cross sections and extrapolating them to low energies utilizing standard Rmatrix, Hybrid Rmatrix and Kmatrix procedures. A list of recent values of the E2 and E1 astrophysical factors for E_{0} = 300 keV obtained from fits to the data is given in 16.16 (in PDF or PS). The influence of vacuum polarization effects on subbarrier fusion is evaluated in (1988AS03), and the relevance of Coulomb dissociation of ^{16}O into ^{12}C + α is studied in (1986BA50, 1989BA64, 1992SH11). Calculations to test the sensitivity of stellar nucleosynthesis to the level in ^{12}C at 7.74 MeV are described in (1989LI29). For other astrophysical studies see (1982AJ01, 1986AJ04) and (1985TA1A, 1986FI15, 1986MA1E, 1986WO1A, 1987AR1C, 1987BO1B, 1987DE32, 1987RO25, 1988CA26, 1988PA1H, 1988TRZZ, 1990BL1K, 1990BR1Q, 1990JI02). At higher energies the E2 cross section shows resonances at E_{x} = 13.2, 15.9, 16.5, 18.3, 20.0, and 26.5 MeV [see 16.16 (in PDF or PS)]. Some E2 strength is also observed for E_{x} = 14 to 15.5 and 20.5 to 23 MeV. In the range E_{α} = 7 to 27.5 MeV the T = 0 E2 strength is ≈ 17% of the sumrule value. It appears from this and other experiments that the E2 centroid is at E_{x} ≈ 15 MeV, with a 15 MeV spread. Structures are observed in the yield of γrays from the decay to ^{16}O*(14.8 ± 0.1) for E_{x} = 34  39 MeV. It is suggested that these correspond to a giant quadrupole excitation with J^{π} = 8^{+} built on the 6^{+}_{1} state at E_{x} = 14.815 MeV: see (1982AJ01, 1986AJ04).
For reaction (a) cross section measurements from threshold to E_{α} = 24.7 MeV [see (1986AJ04)], and at E_{α} = 10.5 to 20 MeV (see 16.16 (in PDF or PS) here). For excitation functions from E_{α} = 21.8 to 27.2 MeV, see (1986AJ04). Thicktarget neutron yields have been measured for E_{α} = 1.0 to 9.8 MeV (1989HE04) and for 4  7 MeV (1982WE16). For reaction (b) cross section measurements from threshold to 33 MeV, see (1986AJ04). The excitation curve for p_{3} (to ^{15}N*(6.32), measured for E_{α} = 24 to 33 MeV, shows a large peak at E_{x} ≈ 29 MeV, Γ ≈ 4 MeV. It is suggested that it is related to the GQR in ^{16}O: see (1982AJ01). For reaction (c) deuteron spectra have been measured for E_{α} = 200, 400, 600, 800 MeV/nucleon (1991MO1B). For the observed resonances see 16.16 (in PDF or PS) here.
The yield of αparticles leading to ^{12}C*(0, 4.4, 7.7) and 4.4, 12.7 and 15.1 MeV γrays has been studied at many energies in the range E_{α} = 2.5 to 42 MeV [see (1986AJ04)], and at E_{α} = 0.4  1.8 MeV (1990TO09). Observed resonances are displayed in 16.15 (in PDF or PS). Attempts have been made to observe narrow states near ^{16}O*(8.87, 9.85). No evidence has been found for a narrow (100 eV) 0^{+} state in the vicinity of the 2^{} state at 8.87 MeV [see (1982AJ01)] nor for a 3^{} state near the 2^{+} state at 9.84 MeV (1986AJ04). For total cross section measurements see (1986AJ04) and for E_{α} = 100 MeV (1986DU15). For integral cross sections for inelastic scattering at 50.5 MeV, see (1987BU27). For elastic scattering differential cross sections at E_{α} = 96.6 MeV see (1990KO2C), at 90 MeV (1990GL02), at 90 and 98 MeV (1991GO25). For diffraction scattering at momentum 17.9 GeV/c, see (1991AB1F). For inelastic scattering and polarization of ^{12}C (9.64 MeV, 3^{}) see (1989KO55, 1991KO40), who report that the reaction at E_{α} = 27.2 MeV proceeds mostly via an 8^{+} state in the compound system. For pion production at momenta 4.5 GeV/c per nucleon see (1990AB1D), at 4.2 GeV/c per nucleon (1987AG1A), at energies of 3.6 GeV per nucleon (1987AN20), and at 200 to 800 MeV per nucleon (1987LH01), at E_{α} = 0.8, 1.6 GeV (1991LE06). Differential cross sections at E_{α} = 1  6.6 MeV measured to obtain information on ^{12}C(α, γ) stellar reaction rates are reported by (1987PL03). Calculations of total cross sections for E_{α} = 96.6  172.5 MeV are presented in (1989KU30) and distributions of αparticle strengths in (1988LE05). Energy dependence at high energies (≈ 1 GeV/nucleon) is studied in (1988MO18). The iterativeperturbative method for Smatrix to potential inversion was applied to α + ^{12}C phase shifts at E_{lab} = 1.0  6.6 MeV in (1990CO29). See also (1991LI25). Nucleusnucleus scattering and interaction radii were studied in (1986SA30). Coreplus alpha particle states in ^{16}O populated in α + ^{12}C scattering are studied in terms of vibron models in (1988CS01). See also (1991AB10, 1991DE15, 1991ES1B, 1991RU1B, 1992SA26). The effects of electron screening on low energy fusion reactions of astrophysical interest are explored in (1987AS05, 1990TO09). The nature of the α + ^{12}C potential at low energy is explored in (1990AL05). For other theoretical work see (1986MI24, 1986SU06, 1987BA83, 1989BA92, 1990DA1Q).
The yield of ^{8}Be from reaction (a) shows a number of resonances: see 16.16 (in PDF or PS). There is no evidence below E_{x} ≈ 24 MeV for J^{π} = 8^{+} states although the existence of such states below this energy cannot be ruled out since it is possible that the L of the entrance channel inhibits the formation of such states. Above 26 MeV L = 8 becomes dominant: see (1982AJ01, 1986AJ04). See also the angular distribution measurements of (1991GL03) at E_{α} = 90 MeV. For differential cross sections for reaction (b) at E_{α} = 27.2 MeV see (1987KO1E). See also (1977AJ02).
This reaction has been studied at many energies: see (1977AJ02) and 16.17 (in PDF or PS) here. At higher energies the spectra are dominated by states with J ≥ 4 and natural parity (1986AJ04). A kinematic coincidence technique was applied in (1986CA19) to study the unresolved doublet at E_{x} = 11.09 MeV enabling clear observation of the γdecaying 3^{+} member at 11.080 MeV although it contributes only ≈ 15% of the singles yield of the doublet which is dominated by the 4^{+} member at 11.096 MeV. Angular correlation measurements (1980CU08) suggested that the 11.096 4^{+} state is populated via a twostep process, and this interpretation was confirmed in calculations by (1988SE07). See also (1986AJ04). An interference effect was observed in the angular correlation function for the 7^{} level at E_{x} = 20.9 MeV in measurements by (1987AR28). See also (1986AR1A, 1987BE1C, 1987GO1C, 1988ARZU). Inclusive deuteron spectra from the breakup of ^{6}Li ions at 156 MeV are described in (1989JE07). See also (1986AJ04). A numerical method for evaluation of (^{6}Li, d) stripping into the 5^{} (15.6 MeV) and 6^{+} (16.3 MeV) states is presented in (1989SE06). See also (1991SE12). An extensive discussion of alpha clustering in nuclei is presented in (1990HO1Q). Cluster stripping and heavygroup substitution in the reaction is discussed in (1988BE49), and the effect of including Coulomb forces in the Faddeev formalism is studied in (1988OS05).
This reaction has been studied extensively: see (1977AJ02, 1982AJ01) and 16.17 (in PDF or PS) here. Measurements of αt angular correlations for the process ^{12}C(^{7}Li, t)^{16}O(α)^{12}C are reported in (1988AR22) for the 7^{} (20.9 MeV), 6^{+} (16.3 MeV), and 5^{} (14.6 MeV) levels in ^{16}O. Analyses of the (^{7}Li, t) reaction for cluster states in ^{16}O are reported in (1986CO15, 1988BE49). See also (1987BE1C, 1988BE1D, 1988BEYB, 1989AL1D, 1990HO1Q) and the sections on ^{19}F in (1983AJ01, 1987AJ02).
Angular distributions at E(^{10}B) = 18 and 45 MeV have been studied involving ^{16}O*(0, 6.1, 7.1, 8.9, 9.9, 10.4). At E(^{10}B) = 68 MeV angular distributions to ^{16}O*(0, 6.1, 6.9, 10.4, 11.1, 14.7, 16.2, 20.9) are forward peaked and fairly structureless. ^{16}O*(0, 6.9, 11.1) are weakly excited: see (1982AJ01, 1986AJ04, 1990HO1Q).
Angular distributions have been reported at E(^{12}C) to 63 MeV [see (1977AJ02)] and at 4.9 to 10.5 MeV, and 11.2 to 12.6 MeV [see (1986AJ04)]. Angular correlations at E(^{12}C) = 78 MeV confirm J^{π} = 4^{+}, 5^{}, 6^{+} and 7^{} for ^{16}O*(10.36, 14.59, 16.3, 20.9). Γ_{γ0}/Γ = 0.90 ± 0.10, 0.75 ± 0.15 and 0.90 ± 0.10, respectively, for the first three of these states. In addition a state is reported at E_{x} = 22.5 ± 0.5 MeV which may be the 8^{+} member of the K^{π} = 0^{+}, 4p4h rotational band (1979SA29). For further work at E(^{12}C) = 90, 110 and 140 MeV see (1986SH10). At E(^{12}C) = 120 MeV α_{0} decays of ^{16}O*(16.3, 20.9) [J^{π} = 6^{+}, 7^{}] and α_{1} decays of ^{16}O*(19.1, 22.1, 23.5) are observed as is a broad structure in both channels corresponding to ^{16}O*(30.0) with J^{π} = 9^{} + 8^{+}. A gross structure ^{12}C  ^{12}C resonance at E_{c.m.} = 25 MeV in the reaction leading to the ^{16}O 11.09 MeV 4^{+} state is reported in (1987RA22). For other work on alpha cluster resonances see (1986ALZN, 1986RAZI, 1987RA02, 1990HO1Q). Measurements of differential cross sections at subbarrier energies 2.43 ≤ E_{c.m.} ≤ 5.24 MeV are reported in (1989CU03) and a statistical model calculation is discussed in (1990KH05). See also (1991CE09). For the decay of ^{20}Ne states see (1983AJ01, 1986AJ04, 1987AJ02), and for excitation functions see (1986AJ04).
Angular distributions are reported at E(^{14}N) = 53 MeV involving ^{16}O*(0, 6.05, 6.13, 6.92) and various states of ^{10}B, and at 78.8 MeV involving ^{16}O_{g.s.}: see (1982AJ01). Angular distributions have been measured for the g.s. in reaction (b) for E(^{17}O) = 40 to 70 MeV (1986AJ04). See also (1986AR04, 1989WUZZ, 1990HO1Q), the twocenter shell model basis calculations of (1991TH04) and the review of LandauZener effect investigations in (1990TH1D).
Angular distributions have been measured to E(^{20}Ne) = 147 MeV: see (1977AJ02). For yield measurements see (1986AJ04). Studies of projectilebreakup and transfer reemission in the ^{12}C + ^{20}Ne system at an incident ^{20}Ne energy of 157 MeV are described in (1987SI06). See also (1990HO1Q).
The yield of capture γrays (reaction (a)) has been studied for E(^{3}He) up to 16 MeV [see (1977AJ02)], as have angular distributions. Observed resonances are displayed in 16.18 (in PDF or PS). It is suggested that the structures at E_{x} ≈ 26  29 MeV are related to the giant resonances built on the first few excited states of ^{16}O (1979VE02). See also (1986AJ04). The excitation functions (reaction (b)) up to E(^{3}He) = 11 MeV are marked at low energies by complex structures and possibly by two resonances at E(^{3}He) = 1.55 and 2.0 MeV: see 16.18 (in PDF or PS). See also (1977AJ02) for polarization measurements. Excitation functions (reaction (c)) for E(^{3}He) = 3.6 to 6.6 MeV have been measured for p_{0}, p_{1+2}, p_{3}: a resonance is reported at E(^{3}He) = 4.6 MeV. A resonance at 6 MeV has also been observed: see 16.18 (in PDF or PS). A comparison of polarization measured in this reaction and of analyzing powers measured in ^{15}N(p, ^{3}He) has been made [see (1986AJ04)]. Analyzing powers have been measured at E(^{3}He) = 33 MeV for the elastic scattering (reaction (d)) and the deuteron groups to ^{14}N*(0, 2.31, 3.95, 9.51) (1986DR03). Yields of α_{0}, α_{1}, α_{2}, and γrays from the decay of ^{12}C*(12.71, 15.11) (reaction (f)) have been studied up to E(^{3}He) = 12 MeV. Observed resonances are displayed in 16.18 (in PDF or PS). Those seen in the yield of γ_{15.1} are assumed to correspond to ^{16}O states which have primarily a T = 1 character. Analyzing power measurements are reported at E(^{3}He) = 33 MeV to ^{12}C*(4.4). Excitation functions for α_{0} and α_{1} are also reported for E(^{3}He) = 16 to 23 MeV (1986AJ04). DWBA analyses for data at E(^{3}He) = 50, 60 MeV are described in (1990ADZU). See also (1986ZE1B). The excitation function for ^{8}Be_{g.s.} (reaction (g)) has been studied for E(^{3}He) = 2 to 6 MeV. It shows a strong resonance at E(^{3}He) = 5.6 MeV corresponding to a state in ^{16}O at E_{x} = 27.3 MeV. J^{π} appears to be 2^{+} from angular distribution measurements. A search for anomalous deuterons at 10.8 GeV has been reported (1986AJ04).
Angular distributions for the n_{0} group have been measured for E_{α} = 12.8 to 22.5 MeV: see (1971AJ02). Polarization measurements for n_{0} at θ = 0  70° at E_{α} = 2.406 and 3.308 MeV are reported in (1990WE10). The energy of the γray from the decay of ^{16}O*(6.13) is 6129.266 ± 0.054 keV (1986AJ04) [based on the ^{198}Au standard E_{γ} = 411804.4 ± 1.1eV]. See also (1982AJ01). Analytical expressions for reaction rates for ^{13}C(α, n)^{16}O and other astrophysically important lowmass reactions are given in (1988CA26). See also the related work of (1986SM1A, 1987HA1E, 1989KA24, 1990HO1I).
See 16.19 (in PDF or PS). See also (1982AJ01) and ^{19}F in (1983AJ01).
See (1986AJ04).
At E(^{13}C) = 105 MeV, ^{16}O*(6.05, 6.13, 10.35, 16.3, 20.7) are strongly populated: see (1977AJ02, 1982AJ01, 1986AJ04). Excitation functions (E_{c.m.} = 13.4  16.8 MeV) and angular distributions (E_{c.m.} = 13.4, 16.38 MeV) have been measured (1988JA1B).
See (1982AJ01).
At E(^{3}He) = 11 to 16 MeV, neutron groups are observed to T = 2 states at E_{x} = 22.717 ± 0.008 and 24.522 ± 0.011 MeV (Γ < 30 keV and < 50 keV, respectively). These two states are presumably the first two T = 2 states in ^{16}O, the analog states to ^{16}C*(0, 1.75). J^{π} for ^{16}O*(24.52) is found to be 2^{+} from angular distribution measurements (1970AD01). At E(^{3}He) = 25.4 MeV forward angle differential cross sections have been determined to the 0^{+} states of ^{16}O*(0, 6.05, 12.05) (1986AJ04).
The γ_{0} yield has been studied for E_{d} = 0.5 to 5.5 MeV. Observed resonances are displayed in 16.20 (in PDF or PS). Radiative capture in the region of the GDR [E_{d} = 1.5 to 4.8 MeV] has been measured with polarized deuterons. See (1986AJ04).
For E_{d} = 0.66 to 5.62 MeV, there is a great deal of resonance structure in the excitation curves with the anomalies appearing at different energies at different angles: the more prominent structures in the yield curves are displayed in 16.20 (in PDF or PS). For polarization measurements see (1977AJ02) and (1981LI23) in ^{15}O (1986AJ01).
The yield of various proton groups for E_{d} < 5.0 MeV shows some fluctuations and two resonances: see 16.20 (in PDF or PS) and (1982AJ01). For polarization measurements see (1982AJ01, 1986AJ04). Analyzing power measurements at E_{d} = 70 MeV are reported in (1986MO27).
The yield of elastically scattered deuterons has been studied for E_{d} = 0.65 to 5.5 MeV and for 14.0 to 15.5 MeV: see (1971AJ02, 1977AJ02). There is indication of broad structure at E_{d} = 5.9 MeV and of sharp structure at E_{d} = 7.7 MeV in the total cross section of the d_{1} group to the T = 1 (isospinforbidden), J^{π} = 0^{+} state at E_{d} = 2.31 MeV in ^{14}N. The yield of deuterons (d_{2}) to ^{14}N*(3.95) [J^{π} = 1^{+}, T = 0] shows gross structures at E_{d} = 7.4 and 10.2 MeV (1970DU04): see 16.20 (in PDF or PS). The yield of d_{1} has also been studied for E_{d} = 10.0 to 17.9 MeV: see (1982AJ01). For polarization measurements see (1982AJ01, 1986AJ04).
See (1982AJ01).
There is a great deal of structure in the yields of various αparticle groups for E_{d} = 0.5 to 12 MeV. Broad oscillations (Γ ≈ 0.5 MeV) are reported in the α_{0} and α_{1} yields for E_{d} = 2.0 to 5.0 MeV. In addition, ^{16}O*(23.54) is reflected in the α_{3} yield (see 16.20 (in PDF or PS)). The yield of 15.11 MeV γrays, [from the decay of ^{12}C*(15.11), J^{π} = 1^{+}, T = 1] which is isospinforbidden, has been studied for E_{d} = 2.8 to 12 MeV. Pronounced resonances are observed at E_{d} = 4.2, 4.58 and 5.95 MeV and broader peaks occur at E_{d} = 7.1 and, possibly, at 8.5 MeV: see (1982AJ01). For polarization measurements see (1982AJ01, 1986AJ04).
Observed proton groups are displayed in 16.21 (in PDF or PS). Angular distributions have been measured at E(^{3}He) = 2.5 to 24.7 MeV: see (1982AJ01). Branching ratios and τ_{m} measurements are shown in 16.13 (in PDF or PS) and 16.14 (in PDF or PS).
Angular distributions to states of ^{16}O have been reported at many energies to E_{α} = 48 MeV: see (1971AJ02, 1977AJ02). Among the states which have been reported [see 16.7 (in PDF or PS) in (1977AJ02)] are ^{16}O*(11.094 ± 3, 13.98 ± 50, 14.32 ± 20, 14.400 ± 3, 14.815 ± 2, 15.17 ± 50, 15.44 ± 50, 15.78 ± 50, 16.214 ± 15, 17.18 ± 50) [MeV ± keV]: the results are consistent with J^{π} = 5^{+}, 6^{+}, 4^{+} for ^{16}O*(14.40, 14.82, 16.29) [2p2h] and with 6^{+} for ^{16}O*(16.30) [4p4h]. [See refs. in (1977AJ02).] Work reported in (1979CL10) and reviewed in (1982AJ01) determined Γ_{c.m.} = 34 ± 12, 27 ± 5 and 70 ± 8 keV, respectively for ^{16}O*(14.31 ± 10, 14.40 ± 10, 14.81).
See (1977AJ02).
For reactions (a) and (c) see (1982AJ01). For reactions (b), (c), and (d) see (1986AJ04).
The yield of γrays has been measured for E_{p} = 0.15 to 27.4 MeV [see (1986AJ04)] and for E_{p} = 6.25  13.75 MeV (1988WI16), 20  100 MeV (1988HA04), 20  90 MeV (1989KA02), and 10  17 MeV (1987BA71): observed resonances are displayed in 16.22 (in PDF or PS). The γ_{0} cross section shows a great deal of structure up to E_{p} = 17 MeV. Above that energy the γ_{0} yield decreases monotonically. Besides the GDR which peaks at ^{16}O*(22.15) there is evidence for the emergence of a giant structure (E2) with E_{x} = 24  29 MeV in the γ_{1} + 2 + 3 + 4 yield (1978OC01). Measurements for (p, γ_{0}) cross sections and analyzing powers for E_{p} = 6.25  13.75 MeV indicated a clear enhancement of the E2 cross section above E_{x} = 22 MeV. Differential cross sections for γ_{0} and several other (unresolved) γrays at E_{p} ≈ 28 to 48 MeV generally show a broad bump at E_{x} ≈ 34 ± 2 MeV. The angular distributions show a dominant E1 character (1986AJ04). See also (1988HA04, 1988KI1C, 1989BOYV) and the review of (1988HA12). For comparisons with measurements of the inverse reaction see (1991FI08). Measurements of (p, γ_{1}) yields (1987BA71) indicated a pronounced concentration of dipole strength which was interpreted as an E1 giant resonance built on the ^{16}O first excited state. Other measurements of proton capture to excited states for E_{p} = 20  90 MeV are reported in (1989KA02). Cross sections and analyzing powers for capture into the 3^{} state at E_{x} = 6.13 MeV were studied by (1988RA15). Studies of quadrupole and octupole radiation from ^{16}O at E_{x} = 39 MeV determine σ_{E2}/σ_{E1} = 0.124 ± 0.015, and σ_{E3}/σ_{E1} = 0.0051 ± 0.0026 (1989KO29). A study of the M1 decays of ^{16}O*(16.21, 17.14) [both J^{π}; T = 1^{+}; 1] to ^{16}O*(6.05) finds B(M1, 1^{+} → 0^{+}_{2})/B(M1, 1^{+} → 0^{+}_{1}) = 0.48 ± 0.03 and 0.55 ± 0.04, respectively. ^{16}O*(18.03) is a 3^{}; 1 state with a strength Γ_{p}Γ_{γ2}/Γ = 1.96 ± 0.27 eV and ^{16}O*(18.98) is the 4^{}; 1 stretched particlehole state with a strength of (0.85 ± 0.10) eV (1983SN03). See also (1983SN03) for the identification of analog states in ^{16}N and in ^{16}O, and for a discussion of GamowTeller matrix elements in A = 14  18 nuclei. See also the review of (1987BE1G). A study of the strong M2 transitions E_{x} = 12.53 → 0 MeV and E_{x} = 12.97 → 0 MeV is reported in (1986ZI08). For astrophysical considerations see (1986AJ04) and (1985CA41, 1988CA26, 1989BA2P). See also 16.14 (in PDF or PS) here. An application of this reaction for thin film analysis is described in (1992EN02). Calculations of the decay of the GDR and GQR by (1990BU27) have included 1p1h and 2p2h configurations, but the fine structure of the GDR remains unexplained. RPA calculations overestimate p_{0} decay but the use of a nonlocal mean field partially corrects this. The ISGQR is misplaced by RPA calculations, but is lowered by coupling to α  ^{12}C channels. Data from (e, e'α) experiments are needed. RPA spectra have been examined (1988BL10) using a relativistic HartreeFock model for the ground state. HartreeFock based calculations appear to be insensitive to shortrange repulsion. 1^{} and T = 1 strength distributions for ^{16}O have been calculated using Hartree and HartreeFock methods. Shellmodel plus Rmatrix and continuum shellmodel results for 1p shell nuclei have been considered (1987KI1C), but underestimate ground state (γ, N_{0}) decay branches. Ground state shellmodel plus Rmatrix calculations describe the GDR region reasonably well.
Excitation functions and cross sections have been measured for E_{p} = 3.8 to 19.0 MeV: see (1982AJ01). For a listing of observed resonances see 16.23 (in PDF or PS). (1983BY03) have measured the polarization and analyzing power for the n_{0} group for E_{p} = 4.5 to 11.3 MeV and have deduced integrated cross sections. Differential cross sections and analyzing powers at E_{p} = 200 and 494 MeV have been measured (1988CIZZ). See also (1986AJ04). The theoretical work of (1987BE1D) has shown the sensitivity of the (p, n) reaction to spin dynamics and pionic fields for E_{p} = 150  500 MeV and isovector density below 50 MeV. The importance of configuration mixing in GamowTeller quenching is also considered. The authors of (1989RA15) discuss the failure of the DWIA to explain the analyzing power for (p, n) at 500 MeV, focusing on transverse and longitudinal spinflip cross sections and projectile nospinflip cross sections as the sensitive terms primarily responsible for the inadequacies of this method.
Elastic scattering studies have been reported for E_{p} = 0.6 to 15 MeV and angular distributions and excitation functions have been measured for E_{p} = 2.5 to 9.5 MeV for the (p_{1+2}γ) and (p_{3}γ) transitions [see (1986AJ04)]. Measurements of the depolarization parameter K_{y}^{y'} at E_{p} = 65 MeV are reported in (1990NA15). Excitation functions for α_{0} and α_{1} particles [corresponding to ^{12}C*(0, 4.43)] and of 4.43 MeV γrays have been measured for E_{p} = 93 keV to 45 MeV [see (1982AJ01)] and at E_{p} = 77.6 keV to 9.5 MeV (1986AJ04). The yield of 15.1 MeV γrays has been measured for E_{p} = 12.5 to 17.7 MeV (1978OC01). Measurements of the 430 keV resonance in ^{15}N(p, αγ)^{12}C were carried out by (1987OS01, 1987EV01). Observed anomalies and resonances are displayed in 16.22 (in PDF or PS). The resonance at E(^{15}N) = 6.4 MeV observed in the reaction ^{1}H(^{15}N, αγ)^{12}C has been used extensively to determine hydrogen concentration in thin films. See (1987EV01, 1987OS01, 1990FU06, 1990HJ02, 1992FA04). A phase shift analysis of angular distributions of cross section and analyzing power for elastic scattering has yielded information on many ^{16}O states in the range E_{x} = 14.8 to 18.6 MeV. In particular a broad J^{π} = 2^{}, T = 1 state at 17.8 MeV appears to be the analog of the 1p1h (d_{3/2}, p^{}1_{1/2}) ^{16}N state at E_{x} ≈ 5.0 MeV (1986AJ04). The isospin mixing of the 2^{} states ^{16}O*(12.53, 12.97) has been studied by (1983LE25): the chargedependent matrix element responsible for the mixing is deduced to be 181 ± 10 keV. The α_{0} yield and angular distribution study by (1982RE06) leads to a zeroenergy intercept of the astrophysical S(E) factor, S(0) = 65 ± 4 MeV · b. See (1982AJ01, 1986AJ04) for the earlier work. See also (1987RO25), and see the tables of thermonuclear reaction rates in (1985CA41). Among recent theoretical developments related to these reactions, electron screening effects for ^{15}N(p, α)^{12}C at very low energies (< 50 keV) have been evaluated (1987AS05). Expressions for longitudinal and irregular transverse PNC analyzing powers in cases of paritymixed resonances such as ^{15}N(pol. p, p)^{15}N and ^{15}N(pol. p, α)^{12}C are derived in (1989CA1L). Recent theoretical studies of the parity and isospinforbidden αdecay of the 12.97 MeV state to the ^{12}C ground state are reported in (1991DU04, 1991KN03). See also the theoretical study of single particle resonances in (1991TE03). An investigation into the separation of the strength of the giant resonance for underlying levels neglecting statistical assumptions (1986KL06) has shown deviations from statistical behavior at the tops of resonances, leading to missing spectroscopic strength. A calibration method for heavyion accelerators has been described by (1987EV01), who have also determined the energy of the E_{p} = 430 keV resonance in the ^{15}N(p, αγ)^{12}C reaction. Quantum fluctuations are shown to cause structures having collective properties (1986RO26). These new collective states are dissipative. ^{15}N(p, p)^{15}N is considered for 25 < E_{p} < 40 MeV. (1988RO09) consider the transition from resonance to direct reactions as well as the significance of quantum fluctuations.
Observed neutron groups, lvalues and spectroscopic factors are displayed in 16.24 (in PDF or PS). See also (1986AJ04).
The ground state of ^{16}N decays to seven states of ^{16}O: reported branching ratios are listed in 16.25 (in PDF or PS). The ground state transition has the unique firstforbidden shape corresponding to Δ J = 2, fixing J^{π} of ^{16}N as 2^{}: see (1959AJ76). The unique firstforbidden decay rates to the 0^{+} ground state and 6.06MeV level are well reproduced by a largebasis (0 + 2 + 4)ℏω shellmodel calculation (1992WA25). The decays to oddparity states (see 16.25 (in PDF or PS)) are well reproduced by recent calculations of GamowTeller matrix elements (1993CH06). For the βdecay of ^{16}N*(0.12), see reaction 1 in ^{16}N. The βdelayed αdecays of ^{16}O*(8.87, 9.59, 9.84) have been observed: see (1971AJ02). The parityforbidden αdecay from the 2^{} state ^{16}O*(8.87) has been reported: Γ_{α} = (1.03 ± 0.28) × 10^{10} eV [E_{α} = 1282 ± 5 keV]: see (1977AJ02). Transition energies derived from γray measurements are: E_{x} = 6130.40 ± 0.04keV [E_{γ} = 6129.142 ± 0.032 keV (1982SH23)], E_{x} = 6130.379 ± 0.04 [E_{γ} = 6129.119 ± 0.04 keV (1986KE15)] and E_{x} = 7116.85 ± 0.14 keV [E_{γ} = 7115.15 ± 0.14 keV]. See (1977AJ02). See also p.16 in (1982OL01). See (1990JI02) for an Rmatrix analysis for the 9.59MeV level and discussion of its astrophysical significance and see astrophysical related work of (1991BA1K, 1991HU10).
The absorption cross section and the (γ, n) cross section are marked by a number of resonances. On the basis of monoenergetic photon data, excited states of ^{16}O are observed at E_{x} = 17.3 [u], 19.3 [u] and 21.0 MeV [u = unresolved], followed by the giant resonance with its principal structures at 22.1 and 24.1 MeV, and with additional structures at 23 and 25 MeV: see (1986AJ04, 1988DI02). The integrated nuclear absorption cross section for E_{γ} = 10 to 30 MeV is 182 ± 16 MeV · mb (1986AJ04). See also reaction 42. The (γ, n) cross section has been measured for E_{γ} = 17 to 33 MeV: in that energy interval the (γ, 2n) cross section is negligible. The cross section for formation of the GDR at 22.1 MeV is 10.0 ± 0.4mb and the integrated cross section to 30 MeV is 54.8 ± 5 MeV · mb. There is apparently significant single particlehole excitation of ^{16}O near 28 MeV and significant collectivity of the GDR. A sharp rise is observed in the average E_{n} above 26 MeV. The cross section for (γ, n_{0}) decreases monotonically for E_{x} = 25.5 to 43.8 MeV. In the range 30  35 MeV the E2 cross section exhausts about 4% of the isovector E2 EWSR. Over the range 25.5 to 43.8 MeV it exhausts ≈ 68% of the isovector E2 EWSR [see (1986AJ04) and references cited there]. M1, E1, and E2 strengths were studied by recent polarization and cross section measurements for E_{γ} = 17 to 25 MeV (1991FI08). An atlas of photoneutron cross sections obtained with monoenergetic photons is presented in (1988DI02). The absorption cross section has been measured with bremsstrahlung photons of energies from E_{bs} = 10 MeV to above the meson threshold: see (1982AJ01). The (γ, n), (γ, 2n) and (γ, Tn) cross sections have been studied with monoenergetic photons for E_{γ} = 24 to 133 MeV. Above 60 MeV, the main reaction mechanisms appear to be absorption of the photons by a correlated np pair in the nucleus: the integrated cross section from threshold to 140 MeV is 161 ± 16 MeV · mb (1986AJ04). Differential cross sections for (γ, n_{0}) have been measured at E_{γ} = 150, 200, and 250 MeV at θ_{lab} = 49°, 59°, and 88° (1988BE20, 1989BE14). See also ^{15}O in (1991AJ01). For reaction (b) and pion production see (1986AJ04). For reaction (c) measurements have been carried out with bremsstrahlung photons with E_{γ} ≤ 150 MeV (1989VO19), and with tagged photons in the Δ(1232) resonance region (1987KA13). See also (1991VA1F). Measurements of reactions (d) and (e) were made with tagged photons of energies 80  131 MeV (1991MA39). Measurements of the total cross section at E_{γ} = 90  400 MeV are described in (1988AH04). Calculations which indicate that molecular effects are important in screening corrections to the cross section in the Δ resonance region are discussed. The hadron production cross section has been studied over the range 0.25 to 2.7 GeV see (1986AJ04). Sum rules and transition densities for isoscalar dipole resonances are discussed in (1990AM06). For a calculation of monopole giant resonances see (1990AS06). Calculations relating to polarization effects are discussed in (1990BO31, 1990LO20). The contribution of sixquark configurations to the E1 sum rule has been considered (1989AR02), and upper bounds for the production probabilities of 6qclusters have been derived. The continuum selfconsistent RPASK3 theory predicts charge transition densities in ^{16}O for excitation of GDR (1988CA07). Neutron and proton decay is also indicated. See also (1991LI28, 1991LI29). A contiuum shell model description of (γ,n) and (γ,p) data at medium energies is reported in (1990BRZY). Radial dependence of charge densities depends on whether rvalues correspond to the interior of the nucleus or to the surface (1988CA07). In (1985GO1A) (γ, n) and (γ, p) experimental results are compared with those of largebasis shell model calculations. Good results were obtained, but a new source of spreading is warranted. Ratios of (γ, n)to(γ, p) cross sections have been computed using Rmatrix theory including configuration splitting, isospin splitting, and kinematics effects (1986IS09). Computations of the partial photonuclear cross sections have been performed (1987KI1C) using the continuum shell model. GDR and other giant multipole resonances are also considered. The authors of (1988RO1R) use the continuum shell model as a basis for their study of "selforganization". The role of the velocitydependent part of the NN interaction is also examined. A method for solving the RPA equations, and an examination of the longwavelength approximation is discussed in (1988RY03). Levinger's modified quasideuteron model is applied for 7 ≤ A ≤ 238 and E_{γ} = 35  140 MeV (1989TE06). The quantities L = 6.1 ± 2.2 and D = 0.72/A are also deduced. The role of distortion in (γ, np) reactions is explored in (1991BO29).
The (γ, p_{0}) cross section derived from the inverse capture reaction (reaction 34) confirms the giant resonance structure indicated above in reaction 40, as do the direct (γ, p_{0}) measurements. For the earlier work see (1982AJ01). For results of measurements with linear polarized photons at E_{bs} = 22 and 30 MeV and for differential cross sections at E_{γ} = 101.5  382 MeV and proton spectra at E_{γ} ≈ 360 MeV, see (1986AJ04). See also the reviews (1987BE1G, 1988KO1S), and see (1987MA1K). Angular distributions for (γ, p) reactions populating lowlying states of ^{15}N were measured (1988AD07) with bremsstrahlung photons with E_{γ} = 196  361 MeV. Differential cross sections measurements with E_{γ} ≈ 300 MeV tagged photons (1990VA07) were used to study the interaction mechanism. Proton spectra measured at 90° (1990VA07) showed evidence for an absorption process in which the photon interacts with a T = 1 np pair. See also the comment (1992SI01) and reply on the interpretation of these data. A related calculation concerning quasideuteron behavior of np pairs is described in (1992RY02). See also (1987OL1A). For reaction (b) see (1982AJ01). A study of the ^{16}O(γ, α_{0}) reaction (c) at θ = 45° and 90° shows a 2^{+} resonance at E_{x} = 18.2 MeV with an E2 strength which is spread out over a wide energy interval. A strong resonance corresponding to an isospinforbidden 1^{} state at E_{x} ≈ 21.1 MeV is also observed (1986AJ04). The systematics of cross sections for reaction (d) are discussed in (1991BO26). For pion production reaction (e), pion angular distributions were measured for a mixed flux of real and virtual photons at E_{γ} = 320 MeV (1987YA02). Double differential cross sections with tagged photons with E_{γ} = 220  450 MeV are reported in (1991AR06). See also ^{16}N and (1986AJ04). Exclusive cross sections for reaction (g) in the Δ resonance region are reported by (1992PH01). Recent theoretical work includes calculations of sum rules and transition densities (1990AM06), monopole giant resonances (1990AS06), and polarization effects (1990BO31, 1990LO20). A scheme using fractionalparentage coefficients to separate the wavefunction into three fragments in arbitrary internal states has been proposed, and examples include ^{7}Li(γ, t)^{4}He, ^{16}O(γ, dd)^{12}C and ^{12}C(γ, pd)^{9}Be (1988BU06). A formula for cross sections for A(γ, dγ')A  2 reactions with E_{γ} = 2.23 MeV has been derived (1988DU04). In a study of Dirac negative energy bound states, a relativistic shell model predicts γ + ^{16}O → ^{15}_{pbar} N + p has a threshold at 1.2 GeV and rises to about 5 μb by 1.6 GeV (1988YA08). (1988LO07) calculate ^{16}O(γ, p)^{15}N using Dirac phenomenology. Dirac spinors are used to describe the proton dynamics in a DWBA calculation, and results are compared to data. ^{16}O(γ, p)^{15}N for E_{γ} = 50  400 MeV has been calculated (1986LU1A) using a coupledchannels continuum shellmodel technique. A single particle direct knockout model is used by (1987RY03) to calculate (γ, π) cross sections for E_{γ} = 40  400 MeV. See also (1990BRZY, 1991IS1D). ^{16}O(γ, p) at intermediate energies has been calculated using both a single particle and a pionexchangecurrent mechanism in a relativistic form of the nucleon current operator and fourcomponent nucleon wave functions (1988MC03). See also the study of the effects of current conservation in these reactions (1991MA39) and of scaling (1991OW01). An expression for the (γ, N) cross section with incident circularly polarized photons and outgoing nucleon polarization being detected is given in (1986PO14). A directsemidirect model calculation for ^{16}O(γ, N_{0}) at 60 MeV is given as an example. A model, based on basic interactions between photons, pions, nucleons and isobars, providing an adequate description of the γN → πN reaction is described in (1992CA04).
Resonances have been reported (1970AH02) at E_{γ} = 22.5 ± 0.3, 25.2 ± 0.3, 31.8 ± 0.6 and 50 ± 3 MeV: the dipole sum up to 80 MeV exceeds the classical value by a factor 1.4. Elastic photon scattering cross sections for E_{γ} = 25 to 39 MeV have been measured. The E2 strength is 1.25^{+1.3}_{0.9} times the total EWSR strength over that interval. The widths of ^{16}O*(6.92, 7.12) are, respectively, 94 ± 4 and 54 ± 4 MeV (1985MO10, 1986AJ04). Differential cross sections at angles of 135° and 45° for elastic scattering of tagged photons between 21.7 and 27.5 MeV in the giant dipole resonance region have been measured by (1987LE12). Differential cross sections for tagged photons with E_{γ} = 27  68 MeV have been reported by (1990MEZV). Polarizabilities of nucleons imbedded in ^{16}O were measured via Compton scattering of 61 and 77 MeV photons by (1992LU01). See also 16.14 (in PDF or PS). A nonperturbative study of damping of dipole and quadrupole motion in ^{16}O is discussed in (1992DE06). (1987VE03) have used an extended isobar doorway model including openshell configurations in both ground and excited states to calculate elastic and inelastic photon scattering in the Δregion, and for linearly polarized photons.
The ^{16}O charge radius = 2.710 ± 0.015 fm (1978KI01). Form factors for transitions to the ground and to excited states of ^{16}O have been reported in many earlier studies [see (1982AJ01, 1986AJ04)], and by (1987HY01); see 16.26 (in PDF or PS). 16.26 (in PDF or PS) lists the excited states observed from (e, e'). The form factor for ^{16}O*(9.84) indicates a transition density peaked in the interior (1986BU02). The energyweighted M2 strength is nearly exhausted by the M2 states which have been observed. The isospinforbidden (E1) excitation of ^{16}O*(7.12) is reported: the isovector contribution interferes destructively with the isoscalar part and has a strength ≈ 1% of the T = 0 amplitude. The 0^{+} states of ^{16}O*(6.05, 12.05, 14.00) saturate ≈ 19% of an isoscalar monopole sum rule. In a recent measurement, the magnetic monopole 0^{+} → 0^{} transition to ^{16}O*(10.957) was observed (1991VO02). The E2 strength is distributed over a wide energy region: see 16.26 (in PDF or PS), and (1982AJ01, 1986AJ04) for references. See also the compilation of nuclear charge density distribution parameters (1987DEZV), and the reviews of (1989DR1C, 1987HO1F). A study of reaction (b) at 500 MeV shows separation energies of 12.2 and 18.5 MeV, corresponding to ^{15}N*(0, 6.32). The momentum distribution of the recoiling nucleus has been measured. High precision data with ≈ 100 keV resolution in the missing mass are reviewed in (1990DE16). The excitation of ^{16}O*(11.52, 12.05, 22.3) and some other states is reported at E_{e} = 112  130 MeV in (e, e'). The (e, e'p) and (e, eα) processes lead to the excitation of ^{15}N*(0, 6.32) and of ^{12}C*(0, 4.44). (See (1982AJ01, 1986AJ04) for the references). In a recent measurement the nuclear response function R_{LT} for ^{15}N*(0, 6.32) was determined in (e, e'p) by (1991CH39). See also (1990MO1K). Coincidence experiments at E_{e} = 130 MeV are reported by (1987DM01). See also (1987RI1A). Nonspherical components in the ^{16}O ground state are indicated by the (e, e'p) data of (1988LEZW). The inelastic cross section for 537 and 730 MeV electrons has been measured by (1987OC01), and the electromagnetic excitation of the Δ resonance was studied. Angular correlation measurements for reaction (c) to determine isoscalar E2 strengths in ^{16}O are reported in (1992FR05). Inelastic electronnucleus interactions for ^{16}O at 5 GeV are reported in (1990DE1M). In theoretical work on reactions (a) and (b), models for relativistic Coulomb sum rules are developed in (1989DO05). See also (1991LE14). A shellmodel study of giant resonances and spectroscopic factors in ^{16}O is described in (1988HO10). See also (1990BO31). (1988AM03) studied an isoscalar dipole excitation in ^{16}O (7.12 MeV state). Core polarization was used in their limited shell model treatment. Exchange amplitudes proved crucial in fitting (p, p') data. A relativistic DiracHartreeFock approach is shown to give a reasonably good account of binding energies, singleparticle energies and charge, as well as proton and neutron densities of ^{16}O and other closed shell nuclei (1988BL1I). The application of Monte Carlo methods in light nuclei including ^{16}O is reviewed in (1991CA35). Nonlocality of the nucleonnucleus optical potential has been used (1987BO54) to evaluate the missing single particle strength observed in (e, e'p) data. (1988BO40) have studied the charge form factor by taking the one and twobody isoscalar charge operands into account in the topological soliton model. Nuclear responses were calculated (1987CA16) using selfconsistent HF and RPA theory with a SK3 interaction. Decay properties in (e, e'p) and (e, e'n) for semidirect and knockout processes are also discussed. A selfconsistent RPA with the SK3 interaction has been used by (1988CA10) to calculate (pol. e, e'x) reactions. Polarization structure functions are also discussed. (1989CA13) use selfconsistent RPA with SK3 interactions to calculate monopole excitations in (e, e') and (pol. e, e'x) reactions. Evidence has been presented by (1989FR02) for a violation of Siegert's theorem, based on cross section measurements of the electroexcitation of the first 1^{} level in ^{16}O. Previous HartreeFock calculations were used by (1990CA34) to study Siegert's Theorem in E1 decay in ^{16}O. Their results show that the previously claimed violation cannot be definitely asserted. A pole graph method is used by (1987CH10) to calculate production of hypernuclei in the continuum. Radial wave functions obtained from realistic nuclear potentials have been used to calculate electron scattering form factors for stretched configurations, which are compared to data (1988CL03). (1987CO24) exhibit and discuss DWBA structure functions for (pol. e, e'x) cross sections. A numerical study of the decay of giant resonances of ^{16}O was also conducted. The ratio of transversetolongitudinal electromagnetic response in (e, e'p) reactions has been examined in terms of relativistic dynamics and medium modifications (1987CO26). Electron scattering form factors have been calculated (1990DA14) using relativistic selfconsistent RPA descriptions of discrete excitations. (1986GU05) derived an expression for the transition charge density in the Helm model, and (1988GU03) calculated charge density distributions using harmonic oscillator wave functions. Experimental values have been compared with calculated transition charge densities from various models in (1988GU14). (1988KU18) calculated binding energy, excitation spectra to ≈ 12 MeV, and escattering form factors using the meanfield approximation and the BZM boson image of the shell model Hamiltonian. Results appear superior to the standard shell model. The twobody pion exchange current contributions to the form factor of inelastic electron scattering has been calculated by (1986LA15) using the effective pion propagator approximation. Effects due to meson exchange currents and unbound wavefunctions for the valence nucleon were included in calculations of electron scattering form factors (1987LI30). Special attention was paid to 1ℏω stretched states. A Sum Rule formalism was used by (1989LI1G) to investigate giant resonances. Surface effects, nonHermitian operators, and magnetic excitations were considered. Normalized correlated wavefunctions were used by (1988MA29) to simplify a previously derived expression for the charge form factor in the nonunitary model operator approach, and compared to data. (1989MA06, 1990MA63) derived an approximate formula for the twobody term in the cluster expansion of the charge form factor, and discussed the correlation parameter. (1989MC05) used the Gelerkin approach to calculate a finite nucleus Dirac mean field spectrum, and then applied it to Dirac RPA response and the present results for 1^{} and 3^{} longitudinal form factors. A comprehensive study of a full set of 18 response functions relevant to the (pol. e, e'p) reaction is presented by (1989PI07). (1988PR05) have studied the linear response of ^{16}O to external electroweak current in a relativistic model. HartreeFockRPA quasielastic cross sections for ^{16}O(e, e'p) are calculated by (1989RY01), who also discuss final state interactions. Electromagnetic quasifree proton knockout in a onephoton exchange approximation is studied in (1991BO10, 1991PA06). (1989RY06) performed selfconsistent HFRPA model calculations for (e, e'p) and (e, e'n) using Skyrme interactions in parallel and perpendicular kinematics. A consistent extension of the QHD1 meanfield RPA theory including correlations induced by isoscalar σ and ω mesons of QHD1 is used by (1989SH27) to calculate (e, τ') form factors and transition charge and current densities. See also (1991ZH17). (1986TK01) calculated M1 resonances taking 1p1h × phonon excitations into account. Comparisons were made with data. (1987YO04) studied 1ℏω stretched excitations in configuration mixing calculations based on firstorder perturbation theory.
Angular distributions of elastically scattered pions have been studied at E_{π} = 20 to 240 MeV and at 1 GeV/c as well as at E_{π±} = 20 to 315 MeV [see (1982AJ01, 1986AJ04)] and recently at E_{π±} = 100  250 MeV at 175° (lab) (1987DH01), and at E_{π} = 30, 50 MeV (1990SE04). At E_{π±} = 164 MeV, ^{16}O*(0, 6.1, 6.9, 7.1, 11.5, 17.8, 19.0, 19.8) are relatively strongly populated. The π^{+} and π^{} cross sections to ^{16}O*(17.8, 19.8) [J^{π} = 4^{}; T = 0] are substantially different while those to ^{16}O*(19.0)[4^{}; 1] are equal. Isospin mixing is suggested with offdiagonal chargedependent mixing matrix elements of 147 ± 25 and 99 ± 17 keV (1980HO13). [See also reaction 67, ^{17}O(d, t)]. The inelastic pion scattering is dominated by a single quasifree pionnucleon interaction mechanism at E_{π+} = 240 MeV (1983IN02): this is not the case at energies below the Δresonance (114 and 163 MeV). For recent inelastic measurements see (1987BLZZ). For a study of (π^{+}, 2p) and (π^{±}, pn) at T_{π+} = 165 MeV see (1986AL22), at T_{π+} = 115 MeV see (1992MA09). See also (1986KY1A, 1986KY1B). Pion absorption at T_{π+} = 65 MeV followed by multinucleon emission is reported by (1992BA31). For (π^{+}, π^{0}p) at T_{π+} = 165 and 245 MeV see (1986GI15, 1988HO1L, 1991HO03). For (π^{+}, π^{}) and (π^{}, π^{+}) at T_{π+} = 180, 240 MeV see (1989GR06). For (π^{+}, π^{+}π^{}) at T_{π+} = 280 MeV see (1989GR05). See also (1987ME12, 1989ME10, 1990KO36). A calculation of differential elastic cross sections in a local approximation to the deltahole model is described in (1991GA07). Opticalmodel calculations for pion scattering on ^{16}O are discussed in (1990CA09, 1990LI10).
Angular distributions have been measured at E_{n} to 24 MeV [see (1982AJ01, 1986AJ04)] and recently at E_{n} = 18 to 26 MeV (1987IS04, 1988MEZX); n's were observed leading to ^{16}O*(6.05, 6.13, 6.92, 7.12, 9.85, 10.35, 11.0, 11.52). For smallangle measurements at E_{n} = 14.8 MeV, see (1992QI02). Differential cross sections for (n, n) and (n, n') at E_{n} = 21.6 MeV are reported by (1990OL01). Polarization of gamma rays from (n, n') with polarized neutrons to ^{16}O*(6.05, 6.13) was studied by (1988LI34) [see also (1987PO11)]. See also the evaluation of E_{n} = 10^{5} eV  20 MeV neutron data for ^{16}O in (1990SH1D). The folding model has been used to calculate the nucleon  ^{16}O interaction potential, and the effect of different nucleonnucleon forces has been discussed (1989HA24). See also the analysis with nonlocal potentials based on RGM formulations by (1992KA21) and the optical model study of (1992BO04). See also (1991KA19, 1991KA22, 1991SH08).
Angular distributions of elastically and inelastically scattered protons have been measured at many energies up to E_{p} = 1000 MeV [see (1982AJ01, 1986AJ04)] and recently at E_{p} = 7.58 MeV (1987KR19; p to ^{16}O*(6.05)), 8.9  50 MeV, (1988LE08; p to ^{16}O*(6.129)), 35 MeV, (1990OH04); p to ^{16}O*(E_{x} ≤ 12.97)), 40  85 MeV, (1987LA11; p to ^{16}O*(6.1299, 8.8719)), 22, 35, 42 MeV, (1988SA1B; p to ^{16}O*(6.129)), 135 MeV, (1986GA31; p to ^{16}O*(6.044, 7.117, 12.043)), (1989KE03; p to ^{16}O*(6.049, 6.130, 6.917, 7.117, 9.847, 10.353, 11.09)), 180 MeV, (1990KE03; p to ^{16}O*(E_{x} ≤ 12.1)), 200 MeV, (1986KIZW; p to ^{16}O*(10.957)), (1989SAZZ; p to ^{16}O*(10.957, 12.797)), 201 MeV. (1987DJ01; p to many states [see 16.27 (in PDF or PS)]), 320  800 MeV (1988BL07), 318 and 500 MeV, (1988FEZX, 1989FEZV, 1991FL01, 1991KE02), 100 and 200 MeV (1988SEZU, 1990GL09), 200, 318 MeV, (1990FEZY), 400 MeV (1991KI08), and 1000 MeV (1988BE2B). Parameters of the observed groups are displayed in 16.27 (in PDF or PS). See also (1990OP01) and the analysis of (1990ER09). For reaction (b) see (1991CO13; 151 MeV), (1986MC10; 505 MeV) and the review of (1987VD1A). For reaction (c) see (1986BO1A; 50 MeV), (1986SA24; 76.1, 101.3 MeV). For reaction (p, pα) see (1986VD04; 50 MeV). See also the study with antiproton beams of (1986KO22). (1987CO25) have performed calculations using the Dirac equation for p and n distortions for the ^{16}O(pol. p, nπ^{+})^{16}O reaction. A coupledchannels calculation using Dirac phenomenology for inelastic scattering of 800 MeV protons from ^{16}O is presented in (1988DE35). (1988DE31) have studied the importance of a deformed spinorbit potential in the calculations of (1988DE35). Approximate treatment of the nucleonnucleus interaction in the resonating group method is discussed in (1991KA19). First order KermanMcManusThaler optical potentials have been constructed from realistic mesonexchange models of NN interaction including offshell effects, and are found to be important for spin observables at 200  500 MeV (1989EL02). Optical phase shifts have been calculated to fifth order by (1988FR06), taking into account cm correlations. The significance of higherorder corrections is assessed. (1989GU06) consider breakup reactions in high temperature plasmas, including production of 6.129 MeV γ's from ^{16}O: mainly from p + ^{16}O → p' + ^{16}O*, γ + ^{16}O → γ' + ^{16}O*, and p + ^{20}Ne → X + ^{16}O*. (1988HA08) found Dirac optical potentials constrained by relativistic Hartree theory to give good agreement with elastic scattering data. See also (1990TJ01, 1991SH08). Spin observables have been calculated by (1988HO1K) for proton quasielastic scattering in the relativistic plane waveimpulse approximation, and compared to (p, p') data at 490 MeV. Isoscalar spin response functions are studied in (1990SH10). (1987KE1A) constructed a parametrization of medium modifications of the 2N effective interaction to reproduce nuclear matter theory, and adjusted it to reproduce proton inelastic scattering data. They obtained good fits to cross section and analyzing power for nine states simultaneously. (1989KE05) performed similar calculations, and fitted 135 MeV proton cross section and analyzing power data with the effective interactions. (1986KU15) performed a DWIA calculation of σ(θ) and A_{y}(θ) for ^{16}O(pol. p, 2p) at 200 MeV including spinorbit and offshell effects. (1987LU02) performed a semirelativistic multiple scattering model calculation of intermediate energy proton elastic scattering, and investigated target nucleon correletion contributions. Multiple diffraction scattering theory was used to calculate cross sections and polarization observables in (1988BE57, 1991BE1E, 1991BE45, 1992BE03). See also (1991CH28, 1991CR04 1992CR05). A Skyrme force approach was explored in (1988CH08). A scalarvector form of a secondorder relativistic impulse approximation optical model including dispersion effects was used by (1988LU03) to calculate elastic proton scattering at 500 and 800 MeV. Evidence for a small imaginary potential or actual flux emission was presented (1988MA05) for nucleon scattering from ^{16}O at 30 MeV. As an alternate explanation of the (1988MA05) findings, (1988MA31) discuss the "ψpotential", related to projectile current. (1988MA1X) contains a review of relativistic theory of nuclear matter and finite nuclei. A relativistic microscopic optical potential derived from the relativistic BruecknerBetheGoldstone equation is discussed in (1992CH1E). Polarization transfer measurements in (p, p') reactions have been examined by (1986OR03) with regard to correlations of tensor character. (1986OS08) used the Tmatrix approximation with distorted waves to analyze knockoff nucleon (p, pN) and cluster (p, pX) proton induced reactions from 30 to 100 MeV. The scattering of 500 MeV protons has been calculated by (1987OT02) using the Dirac equation with and without recoil corrections. Both cross section and spin observables are examined and compared to data. See also (1991KA22). (1988OT04) present systematics of Dirac impulse approximation for cross sections and spin observables in elastic p scattering at 200, 500, and 800 MeV. Results are compared to data. A mixeddensity expansion of the offdiagonal density matrix is used by (1988PE09) to study the nonlocal knockout exchange amplitude for nucleonnucleus scattering. (1987PI02) studied 0^{+} → 0^{} transitions by medium energy protons using the relativistic impulse approximation. (1989PI01) considered corrections arising from the energy dependence of the NN interaction, especially for 0^{+} (pol. p, pol. p')0^{} reactions. Relativistic and nonrelativistic dynamical scattering models have been used by (1988RA02) to predict elastic scattering observables in the forward angle for p + ^{16}O at 500 and 800 MeV. See also (1990CO19, 1990RA12). (1989RA02) have obtained the leading threebody antisymmetrization correction to nucleonnucleus elastic scattering calculations using multiple scattering theory. Small effects are found at intermediate energies. Folding model potentials are used by (1986YA16) to perform a systematic analysis of proton elastic scattering from 65  200 MeV. See also (1990AR11, 1990CR02, 1990EL01, 1991AR11, 1991AR1K). Effects of shortrange correlations on the self energy in the optical model of ^{16}O are studied in (1992BO04). See also (1992LI1D).
Angular distribution studies have been carried out for E_{d} up to 700 MeV [see (1986AJ04)] and recently angular distributions and analyzing powers with polarized deuterons were measured at 19  24 MeV (1991ER03) and at 200, 400, 700 MeV (1987NG01). Observed deuteron groups are displayed in 16.27 (in PDF or PS). See also ^{18}F in (1987AJ02), and see the analysis of (1990ER09). Reaction (b) has been used for analysis of oxygen in Fluoride glasses (1990BA1M). Coupledchannels variational formalism is discussed and applied to ^{16}O(d, d)^{16}O (1986KA1A). Coupling to the proton channel is significant at 11 MeV, but can be ignored at ≥ 40 MeV. Coupling to dbreakup channels decreases as E increases, but is still significant at 60 MeV. (1988IS02) use folding interactions to investigate polarized dscattering at E_{d} = 56 MeV. Breakup channels are important, as is the Dstate admixture in the deuteron ground state  especially for tensor analyzing powers. (1988IS02) employed the continuumdiscretized coupledchannels (CDCC) method, and obtained good agreement with data. (1987GR16) studied dscattering at 400 MeV using the folding model, but failed to describe A_{yy} at relatively low momentum transfers. They attribute this failure to inadequacies in offshell properties of NN potentials. (1986MA32) analyzed elastic data at 56 MeV using an optical model potential containing a complex tensor term. The OM potential was compared with foldingmodel results. (1987MA09) evaluate the Pauliblocking correction of the threebody Schrödinger equation for dnucleus reactions.
Angular distributions are reported for E_{t} to 20.01 MeV: see (1977AJ02) and recently at 36 MeV (1986PE13, 1987EN06). See also ^{19}F in (1987AJ02), and see the analysis of (1990ER09). (1989WA26) studied the spinorbit potential for triton scattering to explain previous discrepancies with folding model predictions.
Angular distributions have been measured to E(^{3}He) = 132 MeV [see (1982AJ01, 1986AJ04)] and at E(^{3}He) = 60 MeV (1990ADZU). The matter radius < r^{2} > ^{1/2} = 2.46 ± 0.12 fm (1982VE13). Inelastic groups are shown in 16.27 (in PDF or PS). See also the analysis of (1990ER09). Differential cross sections for reaction (b) have been measured at E(^{3}He) = 60 MeV (1990ADZT). The reaction has also been used in thin film analysis (1990AB1G). (1986WA1U) studied the spinorbit potential for ^{3}He scattering to explain previous discrepancies with folding model predictions. The M3Y double folding model is used (1987CO07) to fit data at 33 MeV. No change in the spinorbit strength is necessary. The threeparameter strong absorption model of Trahn and Venter is applied to data at 25 and 41 MeV. (1987RA36) obtain radii, diffusivities and quadrupole deformation parameters. (1987TR01) perform a simple optical model analysis of elastic ^{3}He scattering from 10 to 220 MeV.
Angular distributions and/or differential cross sections of αparticles have been measured up to E_{α} = 146 MeV [see (1982AJ01, 1986AJ04)] and recently at E_{α} = 48.7, 54.1 MeV (1987AB03; α_{0}): see ^{20}Ne in (1983AJ01, 1987AJ02). See also the work on (α, α_{0}) resonances at E_{α} = 2.0  3.6 MeV (1985JA17, 1988BL1H). A search at E_{α} = 10.2  18 MeV for continuum levels in ^{20}Ne with a large [^{16}O*(0^{+}_{2}) + α] parentage is described in (1992LA01). Reaction (a) has also been observed in astrophysical measurements (1989LA1G). Observed excited states are displayed in 16.27 (in PDF or PS). See also the analysis of (1990ER09), and see (1990DA1Q, 1990IR01). Reaction (b) has been studied at E_{α} = 13.92 MeV in a quasifree geometry (1987SA01). Angular correlations (reaction (c)) have been studied to ^{12}C_{g.s.} at E_{α} = 23.0 to 27.5 MeV to try to determine if a 3^{} state exists near the 2^{+} state ^{16}O*(9.84): the evidence is strong that this is not the case (1986AJ04). The isoscalar (E2, T = 0) giant resonance decays predominantly via the α_{1} channel which contains ≈ 40% of the E2 EWSR, rather than via the α_{0} and p_{0} channels. For the (α, αd), (α, αt) and (α, α^{3}He) reactions see references in (1986AJ04). In a theoretical study of nucleusnucleus potentials, (1987BA35) determine shallow potentials that are phase equivalent to deep ones. This method eliminates nonphysical bound states encountered in some microscopically founded potentials. (1987BU06) calculate the probability of direct alphadecay of the giant quadrupole resonance in ^{16}O. They find direct and statistical mechanisms to be commensurate, and obtain good agreement with the data. The construction of a cranked cluster wave function for molecularlike states is discussed by (1986HO33). (1986MA35) study the radial shape and the energy dependence of the dispersive contribution to the real potential and apply it to alphaparticle scattering from ^{16}O. (1989MI06) show that alphaparticle scattering from ^{16}O near the Coulomb barrier can be described if the interaction is angular momentum dependent and has a less diffuse surface than that used to describe scattering at higher energies. The potential separable expansion method based on CoulombSturmian functions is presented (1988PA21) and the l = 3 phase shift is calculated for α + ^{16}O at E = 12 MeV. (1987SA55) show the onechannel orthogonality condition model provides results which agree with experiment for E_{α} ≤ 7.5 MeV. (1987WA1B) compare a microscopic potential obtained from RGM calculations with the optical model potential. They conclude that internucleus antisymmetrization is responsible for a large part of the energy dependence of the real part of OM potential. (1989YA15, 1991YA08) use the many body theory which takes the Pauli principle into account to calculate the α  ^{16}O complex potential from a realistic effective twonucleon interaction. The role of the Pauli principle is also examined in (1991OM03). Internucleus potentials in α + ^{16}O systems are calculated with Skyrmetype forces in (1990WA01). Nuclear molecular resonances are discussed in the analyses of (1990AB10, 1992SA26). See also (1990KR16). A peripheral 3body coupling model is applied to reaction (c) in (1992JA04).
Elastic angular distributions for reaction (a) have been measured at E(^{6}Li) = 4.5 to 75.4 MeV and E(^{16}O) = 36 to 94.2 MeV [see (1986AJ04) and 16.25 (in PDF or PS) in (1977AJ02) and 16.23 (in PDF or PS) in (1982AJ01)] and recently at E(^{6}Li) = 50 MeV (1988TRZY). See also (1987GO1C). Vector analyzing power has been measured with polarized ^{6}Li beams at E(^{6}Li) = 25.7 MeV (1987VAZY, 1989VA04). See also ^{6}Li in (1988AJ01). For studies of d  α angular correlations see ^{20}Ne in (1983AJ01, 1987AJ02). For a fusion cross section study see (1986MA19). Inelastic scattering to states in ^{16}O are reported at E(^{6}Li) = 50 MeV by (1990TR02). Elastic distributions for reaction (b) have been studied at E(^{7}Li) = 9.0 to 68 MeV [see (1986AJ04) and 16.25 (in PDF or PS) in (1977AJ02) and 16.23 (in PDF or PS) in (1982AJ01)] as well as at E(^{7}Li) = 10.3  22.40 MeV (1988MA07). For fusion cross section studies see (1988SC14) and references in (1986AJ04). See also (1988KE07). A generalized optical model within the method of orthogonal conditions (MOC) has been formulated by (1988GR32). Taking account of antisymmetrization improves the description of angular distribution data. See also (1990SA1O).
Elastic angular distributions have been reported at E(^{9}Be) = 20 to 43 MeV and E(^{16}O) = 15 to 29.5 MeV [see (1986AJ04) and 16.23 (in PDF or PS) in (1982AJ01)] and recently at E_{c.m.} = 7.2, 8.4, 9.0, 9.6, 10.2 MeV (1989WE1I). Projectile decomposition measurements were reported at E(^{16}O) = 32 MeV/nucleon. For fusion cross sections see (1982AJ01, 1986AJ04, 1988HAZS). See also (1985BE1A).
Angular distributions have been reported at E(^{10}B) = 33.7 to 100 MeV and at E(^{11}B) = 41.6, 49.5 and 115 MeV [see (1986AJ04) and 16.23 (in PDF or PS) in (1982AJ01)] and recently at E_{c.m.} = 14.17, 16.15, and 18.65 MeV (1989KO10). See also (1989KO2A). For fusion cross section measurements (reaction (a)) see (1982AJ01, 1986AJ04).
Angular distributions have been reported at many energies to E(^{16}O) = 1503 MeV [see (1982AJ01, 1986AJ04)] and recently at E(^{16}O) = 49.14, 48.14, 48.06 MeV (1986BA80). A peak in the excitation function at E_{c.m.} = 33.5 MeV was observed by (1990KO1X). See also the review of (1986BA1D) and analyses of (1988BR04, 1988RO01, 1989VI09). Many of the studies of this reaction have involved yield and cross section measurements, as they apply to compound structures in ^{28}Si, fusion cross sections and evaporation residues. See (1990SN1A). Some involve multinucleon transfer. Others involve fragmentation of the incident particle. See (1982AJ01, 1986AJ04) and (1986GA13, 1986IK03, 1986SU1G, 1987SU03, 1988KO17, 1988SZ02, 1990BO1X). See also (1986CH41, 1986DE40, 1986SN1B, 1986WU03, 1987HO1C, 1987NA1C, 1987YO1A, 1988BR1N, 1988CAZV, 1988KR11, 1988ME1H, 1989BEZC, 1989KRZX, 1989SU1I, 1989WE1E, 1990BA1Z). At E(^{16}O) = 100 MeV members of the K^{π} = 0^{+} [^{16}O*(6.05, 6.92, 10.35, 16.3)] and K^{π} = 0^{} bands [^{16}O*(9.63, 11.60, 14.67)] are reported to be preferentially populated. In reaction (b), as well as in the scattering of 140 MeV ^{16}O on ^{13}C and ^{28}Si, ^{16}O* states (9.83, 10.33, 11.04, 11.47, 11.98, 12.38, 13.81, 14.75, 15.33, 17.76), with J^{π} = 2^{+}, 4^{+}, 4^{+}, 2^{+}, 0^{+}, 1^{}, 2^{+}, 4^{+}, 6^{+}, 3^{}, respectively, for the first ten states, are populated: the state at 11.5 MeV is preferentially populated [see references in (1982AJ01, 1986AJ04)]. For pion emission see (1986AJ04, 1988SA31, 1989LE12). (1987BA50) have investigated the twoproton correlation function using the BUU (semiclassical transport equations) model with conserved total momentum. Experimental features of the correlation function are reproduced. (1988BA43) study the energy dependence of the real part of the nucleusnucleus potential using a modified SeylerBlanchard twobody effective interaction containing density and momentum dependence. (1987BRZW) perform an optical model analysis of ^{12}C  ^{12}C and ^{16}O  ^{12}C elastic scattering from 10  94 MeV; real part: double folding of a density dependent M3Y interaction  imaginary part: phenomenological. (1988BR20) examine dips in the farside cross sections which reduce or eliminate potential ambiguities from analyses as in (1987BRZW). (1988BR29) analyzed elastic data at 9 to 120 MeV per nucleon using a folded potential based on the density and energydependent DDM3Y interaction. (1987DA02) present a solution to the inversion problem (i.e., obtaining potentials from data) and apply it to ^{16}O + ^{12}C at 1503 MeV with good results. A microscopic calculation of pionproduction in heavyion collisions is applied (1986DE15) to coherent pionproduction in ^{16}O + ^{12}C collisions. Effects of Pauli blocking and a surface contribution to the optical potential are investigated by (1989EL01). Data require that a collective surface contribution be added to the volume part. (1988FR14) resolve optical potential model ambiguities by using dips in far side cross section data along with other special features of the angular distributions of elastic scattering data. (1986HA13) performed a barrier penetration calculation of heavyion fusion cross sections, valid both above and below the Coulomb barrier. (1986KA1B) survey projectile breakup processes using the method of coupled discretized continuum channels. An optical model potential containing a parity dependence which accounts for elastic αparticle transfer can explain the oscillations seen in the total fusion excitation function of ^{16}O on ^{12}C (1988KA13). (1988KO27) perform an optical model analysis of ^{16}O scattering data at E/A = 94 MeV. They explored potential shapes more general than folded or WoodsSaxon; no improvement in agreement with data. (1989LE23) analyzed reaction data using an eikonal approach. They input only the densities and transition densities of the nuclei and elementary nucleonnucleon scattering amplitudes. Good agreement with data was obtained. The ^{12}C + ^{16}O internucleus potential is calculated with the use of Skyrme type forces by (1990WA01). (1989MI1K) calculate zerodegree and transverse energy for relativistic collisions. Results fit data very well. Low energy optical potentials are derived (1987PA24) from effective interactions using doublefolding. Only the effective interaction of Satchler and Love give good results over a wide energy range. (1988RA1G) explores the relationship between clustering and shell effects, and find that this relationship is a close one. (1986SA1D) perform a microscopic coupledchannels calculation. Breakup and virtual breakup effects are found to be important. (1987SC34) present an expression for the real part of the nucleusnucleus potential (energy dependent) which arises in the framework of the elastic model for heavyion fusion. This model is applied to subbarrier fusion. (1988WU1A) propose a noncompact group model to describe quasimolecular nuclei.
For elastic scattering studies see 16.23 (in PDF or PS) in (1982AJ01), and see the more recent work at E_{c.m.} = 48.06, 48.48, 49.14 MeV (1986BA80), and E_{c.m.} = 19  30 MeV (1989FR04). For fusion cross sections see (1986AJ04) and recent work at E_{c.m.} = 7.8  14.6 MeV (1986PA10). See also the review of (1986ST1A). For the excitation of a number of states in ^{16}O in reaction (a) see (1986AJ04). Cross sections for different exit channels of ^{16}O + ^{13}C at E_{c.m.} = 4.8  9.8 MeV were measured by (1991DA05). Emission ratios for pn to d and αpn to αd were studied in (1986GA13). Competition between p2n, dn, and t emission was studied at E_{c.m.} = 10  16 MeV (1990XE01). For reaction (b) a search for resonances in elastic scattering at E_{lab} = 38  54 MeV is reported in (1990AB07). (1987DA34) performed a sixparameter optical model analysis of ^{13}C(^{16}O, ^{16}O)^{13}C. A twocenter shell model is applied (1987NU02) to the ^{13}C + ^{16}O system. Parity dependence of collisions between p and sdshell nuclei is studied (1986BA69) microscopically in the twocenter harmonic oscillator model.
For elastic scattering studies see (1986AJ04) and 16.23 (in PDF or PS) in (1982AJ01) and (1977AJ02). Recent measurements on reaction (b) at E_{lab} = 30  70 MeV were reported in (1986HA1F). For yield and total fusion crosssection measurements see (1982AJ01, 1986AJ04). See also (1986BA69).
The angular distributions for elastic scattering have been measured with E(^{16}O) up to 140.4 MeV [see (1982AJ01, 1986AJ04)] and recently at E_{c.m.} = 17 MeV (1987TI01), E(^{16}O) = 350 MeV (1989ST08) and E(^{16}O) = 38 MeV/nucleon (1986BR25). Inelastic scattering studies involving ^{16}O*(6.05) [J^{π} = 0^{+}] (1989ZUZZ) are reported at E(^{16}O) = 51.0 to 76.0 MeV, and similar studies involving ^{16}O*(6.13) [J^{π} = 3^{}] (1988PAZZ) are reported at E_{c.m.} = 26.5  43.0 MeV. Coupled channels effects are important at energies a few times the Coulomb barrier (1977AJ02, 1986AJ04). Intermediate and compound structure studies are described in (1986GA10, 1986GA24). For yield and fusion cross sections see (1982AJ01, 1986AJ04) and more recent work (1986IK03, 1986TH1A, 1987GO30, 1987KU02, 1988AU03). At E(^{16}O) = 72 MeV, (1988AU1A) see no evidence for a lowl fusion window. At E(^{16}O) = 70  130 MeV measurements of evaporation residues by (1986IK03) find no evidence for a lowl cutoff. For a study of αtransfer at nearbarrier energies see (1986CA24). Lightparticle emission at E(^{16}O) = 25 MeV/nucleon was studied by (1986CH27). Related work includes an investigation of the role of isospin in the statistical decay of the GDR by (1986HA30) and the review of hot nuclear matter (1989SU1I). See also (1989FE1F, 1989SC1I). (1988AS03) evaluate the influence of the Uehling potential on subbarrier fusion. (1987GO19) report a calculation of the fusion cross section using a classical microscopic equations of motion approach. (1987LO01) study the effect of elastic transfer process on subbarrier fusion reactions between similar nuclei. (1987OH08) show that internal and barrier waves based on a semiclassical picture can account for the oscillations seen in fusion excitation functions. (1987RA28) use statistical theory to study the behavior of high spin states formed in fusion reactions. (1987SP11) calculate the fusion excitation function using the onebody wall friction. (1987TO10) investigate the influence of nucleonnucleon collisions in the low angular momentum limit for fusion predicted by TDHF. A relativistic meanfield model consisting of nucleons coupled to scalar and vector mesons is used to solve the timedependent meanfield equations. A relativistic Vlasov equation derived from mean field theory is applied in (1990JI1C). An extended TDHF theory has been used (1989GO1F) to study mass fluctuations in deepinelastic collisions. Results show differences from conventional TDHF calculations (1987BA10). (1988RE1A) performed TDHF calculations of ^{16}O + ^{16}O using various Skyrme forces. (1986TO14) calculate subthreshold pionproduction using the TDHF formalism, and compare their findings with data. (1986UM02) study fusion of ^{16}O + ^{16}O using TDHF and Skyrme forces. See also the study of (1990SL01). (1986CH44) perform an optical model analysis of elastic scattering data using a calculated real part of the potential. The potentials are constructed in the energy density formalism with nuclear density distributions obtained in the framework of the method of hyperspherical functions. (1989DA1C) develop a simple theory of a heavyion optical model potential. Colliding ions are described as two slabs of nuclear matter, with energy densities from properties of nuclear matter. (1986FA1A) extend and refine the calculation of the real and imaginary parts of the optical model potential in the 20  100 MeV/nucleon range. Techniques for choosing a unique potential are discussed in (1990KO18). See also (1990RE1E). (1988NA10) calculate microscopic nucleusnucleus potentials using the energydensity formalism. See also (1991MA29). (1987PA24) derive real parts of the lowenergy optical potential using the doublefolding model. Pauli exchange effects within this model are studied in (1991KH08). A semiclassical method for calculating elastic scattering cross sections was used in (1991SA20). (1989HU1C) combine the concepts from a partition temperature model and the wounded nucleon model to describe highenergy nucleusnucleus collisions. (1988IT03) have applied coupled equations which treat the relative motion and internal excitation simultaneously to the case of ^{16}O + ^{16}O at intermediate energies. (1987KA04) study subthreshold pion production mechanisms for ^{16}O + ^{16}O at 40 and 80 MeV/nucleon. A quantum transport equation with twobody collisions included via a relaxationtime method is applied to ^{16}O  ^{16}O collisions between 40 and 200 MeV/nucleon (1988KO02). (1988KO09) compare predictions of momentum dependence of nucleusnucleus interactions deduced from various models. (1989KO23) describe resonant phenomena in ^{16}O + ^{16}O in terms of an ionion potential. (1988MA1O) solve the inverse scattering problem for fixed angular momentum using Edependent phases and a PovznerLevian representation of the wave function. Adiabatic bound and Gamow states have been calculated (1986MI22) in a realistic twocenter potential. Specific results for a neutron in a ^{16}O + ^{16}O potential are presented. (1985SH1A) develop a microscopic approach to describe elastic and inelastic cross sections. They employ the quasiparticle phonon model for heavy ions and resolve the "fusionwindowanomaly". The resonating group method is used by (1988WA31) to investigate constituent components of the ^{16}O  ^{16}O exchange potential. A twocenter shell model description is discussed in (1990KH04).
Angular distributions of elastically scattered ions have been studied at E(^{16}O) = 24, 28 and 32 MeV and E(^{17}O) = 53.0 to 66 MeV, E(^{17}O) = 22 MeV (reaction (a)) and at E(^{16}O) = 24 to 54.8 MeV and E(^{18}O) = 35 to 89.3 MeV (reaction (b)) [see (1982AJ01, 1986AJ04)]. Yields and fusion cross sections are reported in (1982AJ01, 1986AJ04). See also the studies on lightparticle emission ratios in these reactions (1986GA13, 1990XE01). (1987IMZZ) have studied the effects of rotational couplings by using the rotating molecular orbitals model. (1987IM1C) develop and use a formalism for dynamical treatment of the molecular orbitals of valence nucleons in nucleusnucleus collisions. (1988IM02) consider the role of rotational coupling interactions in the transition between nucleon molecular orbitals. (1987MA22) use the semiclassical approach including both one and twostep contributions to calculate the twoparticle elastic transfer reaction, while (1988KA39) calculate differential cross sections for transfer of two neutrons taking Coulomb effects into account in a fourbody model. (1986MI22) use a realistic twocenter potential to show that a substantial fraction of the particle emission comes from sequential decay of the excited fragments after separation, and (1986VI08) consider twoparticle exchange reactions using a paritydependent optical potential.
Elastic scattering angular distributions have been studied at E(^{16}O) = 21.4 and 25.8 MeV and at E(^{19}F) = 33 and 36 MeV: see (1977AJ02). Angular distributions in reaction (b) have been measured at E(^{16}O) = 40.7 to 94.8 MeV, 25.6 to 44.5 MeV, 44.1 to 63.9 MeV [see (1986AJ04)], 60  80 MeV (1986FUZV), and at E(^{20}Ne) = 50 MeV (1986AJ04). Recent excitation functions were measured for reaction (b) at E_{c.m.} = 21.5  31.2 MeV (1988HE06). See also (1989SA14). For yield and fusion cross section measurements see (1986AJ04). Projectile breakup studies are reported at 3.6 GeV/nucleon. See also (1987AN1C). Hyperon production is investigated in (1986FUZV, 1988BO46). See also (1986HE1A, 1988BE2A). (1986FU1C) discuss ways of accounting for the phase anomaly between elastic and inelastic scattering of ^{19}F + ^{16}O. (1989GA05) derive a paritydependent potential for ^{16}O + ^{20}Ne.
Elastic angular distributions are reported at E(^{16}O) = 35 to 60.7 MeV (reaction (b)) and 27.4 to 50 MeV (reaction (d)) [see (1982AJ01)] and E(^{16}O) = 150 MeV (1986AJ04; reaction (b); elastic). More recent work on reaction (b) includes elastic scattering excitation function measurements at E_{c.m.} = 31.6  45.2 MeV (1986DR11, 1986DR1B) and inelastic measurements at E_{c.m.} = 33.6  49.2 MeV (1986NU01, 1986NU1A) and at E_{c.m.} = 64  88 MeV (1986PE1G). Orbiting cross sections for reaction (b) are reported in (1989BLZZ). For yield, evaporation residue and fusion measurements, see references in (1982AJ01, 1986AJ04). (1988AL06) show that algebraic scattering theory provides a simple yet detailed description of the complex coupled channels problem (^{16}O + ^{24}Mg). (1989FI03) calculate the effect of the dynamic αtransfer potential on several channels of the ^{24}Mg + ^{16}O systems. (1987NA13) obtain an energy and angular momentumdependent polarization potential from a compound nucleus level density dependent imaginary potential. They find that the elastic and fusion cross sections of ^{16}O + ^{24}Mg are hardly affected by this potential.
An elastic angular distribution has been measured at E(^{16}O) = 46.5 MeV: see (1982AJ01). For yield, fusion and evaporation residue studies see (1982AJ01, 1986AJ04) and (1987IK01, 1988KO01, 1989CA14, 1989DE02, 1990KR1D). See also (1986BR26, 1987DEZV). For fragmentation studies see (1986AJ04) and (1986SH1F, 1987SH1C, 1987SH23, 1988AI1C, 1988BR1N, 1988SH1H, 1989CA14, 1989YI1A, 1990PAZW). For work on deeply inelastic collisions see (1986AJ04) and (1987SH21). For pion production see (1986AJ04) and (1987HU1C, 1988BA21, 1988JU02, 1989FO07). For total reaction cross sections see (1987KO12). Angular correlations have been studied at E(^{16}O) = 65  65.6 MeV (1986AJ04) and at E(^{16}O) = 82.7 MeV (1988SH1H), at 215 MeV (1990KR14), at E_{c.m.} = 80  250 MeV (1988DE1A, 1989DE02), and at E(^{16}O) = 4  5 MeV/nucleon (1987CA1E). The sequential decay of ^{16}O*(10, 11.6, 13.2, 15.2, 16.2, 21) is reported via α_{0} [see (1986AJ04)]. (1987BA01) evaluate the energy dependence of the real part of the nucleusnucleus potential using twobody effective interactions, calculate ^{16}O + ^{27}Al, and compare to data. (1989CA11) introduce "preequilibrium" temperature to describe the thermodynamics of nuclear systems prior to equilibrium. (1988DA11) modify the coalescence model for complexparticle emission by correcting for the Coulomb barrier and the ejectile's binding energy.
Angular distributions for reaction (a) have been reported at E(^{16}O) = 29.3 to 215.2 MeV [see (1982AJ01, 1986AJ04)], and recently at E(^{16}O) = 94 MeV/nucleon (1987RO04). Elastic angular distributions for reactions (b) and (c) are reported at E(^{16}O) = 60 MeV (1986AJ04). For yield, fusion cross section and evaporation residue measurements see (1982AJ01, 1986AJ04). See also (1986BL08). For a crystalblocking measurement of time delays in reaction (a) see (1989MA23). For pion production see (1986AJ04). (1988AL08) obtain expressions for the elastic Smatrix which include effects of the coupling to αtransfer channels to all orders. They study ^{16}O + ^{28}Si at 180°. (1988AS03) evaluate the influences of the Uehling potential on subbarrier fusion and obtain noticeable modifications of the barrier penetrability. (1986BR11) study the Edependence of an optical potential which fits all ^{16}O + ^{28}Si elastic data for E = 54.7  215.2 MeV. (1986HO18) employ a fixed energy potential inversion method to generate an optical model potential which fits ^{16}O + ^{28}Si elastic scattering data at 34.8 MeV. (1986BR19) create a deformed optical potential consistent with calculations based on nuclear structure information which fits ^{16}O + ^{28}Si scattering and fusion data. (1986BR23) use an optical model with repulsive core and coupled channels method to describe ^{16}O + ^{28}Si scattering data at large angles for E = 29  35 MeV. (1988CH28) use a Monte Carlo simulation to calculate the nucleon transfer part of the imaginary opticalmodel potential. (1987HU11) find good agreement with back angle elastic data in ^{16}O + ^{28}Si by including a derived αtransfer polarization potential. (1990DE35) employ a multistep αtransfer treatment to study back angle scattering of ^{16}O + ^{28}Si. (1985KH10) use a conventional optical model potential for E_{lab} = 33.16  55 MeV. They parameterize the Smatrix in terms of Regge poles and look at semiclassical features. (1985KR1A) show that existing data do not allow one to draw conclusions about the relevance of Regge poles in ^{16}O + ^{28}Si. (1989MA08) use elastic phase shifts obtained by the algebraic approach to scattering theory in a fixed energy inversion procedure. Results point to an underlying nonlocal interaction. (1987NA13) show that the elastic and fusion cross sections are hardly affected by a strongly attractive realpolarizationpotential. (1987VA03) have applied a fast algorithmbased method for performing unconstrained phaseshift analyses to ^{16}O + ^{28}Si at 21.1 MeV (E_{c.m.}). (1987XI01) formulate a molecular orbit theory for the 3αtransfer process and apply it to ^{16}O + ^{28}Si for E = 18.67  34.80 MeV, and compare it to data.
Elastic angular distributions are reported on ^{40}Ca at E(^{16}O) = 50 to 214.1 MeV [see (1982AJ01, 1986AJ04) and recently at E(^{16}O) = 94 MeV/nucleon (1988RO01). Elastic angular distributions were reported at E(^{16}O) = 60 MeV (^{42,44}Ca; also inelastic distributions) and 150 MeV [see (1986AJ04)]. Similar measurements have been reported for ^{48}Ca at E(^{16}O) = 60 MeV [see (1982AJ01)] and at 56 MeV (1986AJ04; also ^{48}Ca*) and 158.2 MeV (1986AJ04; also ^{48}Ca*). Yield, fusion cross section and evaporation residue measurements are reported in (1982AJ01, 1986AJ04) and by (1986SA25, 1987BEZY, 1987BR20, 1987HI10, 1988KO1U, 1989BE17). See also (1986GU1C). For a measurement of the total nonfusion reaction cross section at E(^{16}O) = 158.2 MeV (reaction (d)) see (1986AJ04). For a study of deep inelastic collisions at 142 MeV (reaction (d)) and for reaction (e) see (1986AJ04). A microscopic study of the ^{16}O + ^{40}Ca potential is discussed in (1986WAZM). (1986AN18) calculate angular distributions for elastic scattering using a simple prescription for the part of the imaginary potential arising from inelastic processes and a folding expression for the real part of the potential, and fit it to the data. (1986CH20) perform a microscopic optical model analysis using folding and realistic NN interactions (direct and exchange terms). They compare their results to data. (1986CH38) calculate the real part of the optical model potential in a folding approximation using the density dependent M3Y interaction in factorized form. They also compare their results to data. (1989DA1C) describe colliding nuclei as two slabs of nuclear matter. Energy density is derived from properties of nuclear matter. (1989ES07) obtain good agreement with elastic and inelastic data using a coupledchannels treatment. (1987GR04) study peripheral reactions. Neutrons and protons behave separately in an effective mean field. They find a transition between incomplete deep inelastic processes and fragmentation reactions near 35 MeV/nucleon. (1986HA13) calculate barrier penetrations with Coulomb included. They obtain good agreement with data in the above and subbarrier fusion regions. (1989HO10) calculated heavyion fusion reactions with a macroscopic model proposed by Bertsch. They give a good account of the fusion cross section up to very high energies. (1987DA23) develop a semimicroscopic model of elastic and inelastic scattering with a full finite range NN interaction. They also study the role of NN exchange correlations. The real and imaginary potentials have been derived (1987VI04) in a model which includes a large set of nonelastic channels. (1988PA20) calculate the particle transfer flux between two scattering nuclei from the timedependent singleparticle wave functions in the field of two moving potential pockets. They deduce the absorptive potentials which compare well with phenomenological ones. (1989SU05) study the excitation of the GDR within the framework of the LandauVlasov equation. They analyze the GDR excited in peripheral ^{16}O + ^{40}Ca reactions at E = 5 MeV/nucleon.
The betadelayed proton emission in the ^{17}Ne decay has been studied by (1988BO39). See 17.16 (in PDF or PS) and 17.27 (in PDF or PS). The half life is measured to be T_{1/2} = 109.3 ± 0.6 ms.
See (1986AJ04, 1989OR07, 1990MC06) and ^{17}O.
Angular distributions for the ground state deuteron group have been studied at E_{p} = 8.62 to 11.44 MeV. At E_{p} = 31 MeV, angular distributions are reported for the deuterons corresponding to ^{16}O*(0, 6.05 + 6.13, 7.12, 8.87, 10.36, 12.97, 13.26). States at E_{x} = 15.22 and 15.42 MeV were also observed. Spectroscopic factors were obtained from a DWBA analysis: see (1977AJ02, 1986AJ04). See also (1989DE1P, 1989OB1B).
Differential cross sections and analyzing powers for the reaction were measured at E_{d} = 89 MeV by (1990SA27) and summarized in 16.28 (in PDF or PS). Earlier information obtained at E_{d} = 52 MeV is displayed in 16.20 (in PDF or PS) of (1986AJ04). As discussed there, comparison of the (d, t) and (d, ^{3}He) reactions leads to assignments of analog states in ^{16}N and in ^{16}O [see 16.10 (in PDF or PS) in (1982AJ01)]. A study of this reaction, the (d, ^{3}He) reaction, and reaction 68 [^{17}O(^{3}He, α)^{16}O] below, suggests that there is more than 17% isospin mixing of the 2^{} states in ^{16}O*(12.97, 12.53): the corresponding mixing matrix element is ≥ 155 ± 30 keV. An isospin mixing matrix element of 110 ± 10 keV for the 4^{} states of ^{16}O*(17.79, 18.98, 19.80) is compatible with the results from this reaction and with pion scattering (1986AJ04). See also reaction 44 [^{16}O(π^{±}, π^{±})^{16}O].
Angular distributions have been reported at E(^{3}He) = 11 MeV [see (1977AJ02)], at E(^{3}He) = 14 MeV (α_{0}) and at E(^{3}He) = 33 MeV (to many states of ^{16}O) [see (1986AJ04)]. 16.28 (in PDF or PS) displays some of the information derived from this reaction. For polarization measurements see (1986AJ04) and ^{20}Ne in (1983AJ01, 1987AJ02). See also (1982AJ01).
See (1986AJ04).
Angular distributions of tritons have been measured for E_{p} = 43.7 MeV [see (1982AJ01)] and at E_{p} = 90 MeV (1986VO10) (to ^{16}O*(6.1, 6.92, 7.12, 9.84, 13.26, 16.35)): see also (1985BLZY). It is noted in (1986VO10) that the 16.35 MeV state may be the (0^{+}, 1^{}, 2^{+}) multiplet at E_{x} = 16.35 and 16.144 MeV (1982AJ01). The population of ^{16}O*(22.7, 24.5) is consistent with L = 0 and 2, respectively, and with assignments of T = 2, J^{π} = 0^{+} and 2^{+}. The decay of ^{16}O*(22.7), J^{π}; T = 0^{+}; 2, is via α_{0}, α_{1} and α_{2} [^{12}C*(0, 4.4, 7.7)] with (1.6 ± 0.7), (1.9 ± 0.7) and (14 ± 2)% branches and Γ_{i}(eV) = 190 ± 100, 230 ± 110 and 1680 ± 550 eV, respectively; via p_{0}, p_{1+2}, p_{3} with (7 ± 2), (11 ± 2) and (5 ± 2)% branches and Γ_{i}(eV) = 840 ± 343, 1320 ± 454 and 600 ± 300 eV; and via n_{1+2} with a (23 ± 15)% branch [Γ_{n}=2760 ± 1970eV] (the n_{0} branch is < 15%) [Γ_{i} are based on a total width of 12 ± 3.5 keV]. See (1986AJ04). See also (1982AJ01) and ^{19}F in (1987AJ02).
Angular distributions have been measured at E_{α} = 58 MeV to ^{16}O*(0, 6.1, 6.92, 7.12). Groups at E_{x} = 10.4, 13.3 ± 0.1 and 16.3 ± 0.1 MeV were also observed: see (1977AJ02, 1986AJ04).
Angular distributions involving ^{16}O_{g.s.} and ^{20}O states are reported at E(^{18}O) = 24 to 36 MeV and at 52 MeV: see (1982AJ01, 1986AJ04).
Angular distributions have been measured at many energies up to E_{p} = 44.5 MeV [see (1982AJ01)] and E_{p} = 1.55 to 2.03 MeV (α_{0}, α_{1}), 1.66 to 1.86 MeV (α_{0}), 10.0 to 11.4 MeV (^{16}O*(0, 6.05, 6.13, 6.92, 7.13, 8.87, 9.84, 10.36, 10.96, 11.08 + 11.10)) [see (1986AJ04)]. See also 16.31 (in PDF or PS) in (1971AJ02). For a DWBA analysis of data for incident energies below the Coulomb barrier see (1991HE16). A recent measurement of the absolute differential cross section at E_{p} = 2  3.4 MeV is reported in (1986OU01). Measurements at E_{p} = 1.55  1.64 MeV by (1990AZZY) were used to study resonances corresponding to states in ^{20}Ne. Absolute yields, angular distributions and resonance widths of the 6.13, 6.92, and 7.12 MeV photons from the 340.5 keV resonance are reported in (1991CR06). See also (1991MC08) for a study of resonanceyield deconvolution techniques. The internal conversion to pair production ratio of the E0 transition ^{16}O*(6.05 → g.s.) [0^{+} → 0^{+}] is (4.00 ± 0.46) × 10^{5}. The ratio of double γemission to pair production Γ_{E1E1}/Γ_{E0}(π) = (2.5 ± 1.1) × 10^{4}. τ_{m} for ^{16}O*(6.05, 6.13) are 96 ± 7 psec and 26.6 ± 0.7 psec, respectively. See (1982AJ01) for references. g for ^{16}O*(6.13) = 0.556 ± 0.004 (1984AS03, 1986AJ04). For γray branching ratios and mixing ratios see 16.14 (in PDF or PS) and (1986AJ04). See also ^{20}Ne in (1983AJ01, 1987AJ02), and see (1986KH1A, 1987KH1A, 1988GN1A, 1988UM1A; applied) and (1988CA26; astrophysics).
Differential cross section measurements at E_{t} = 38 MeV are reported in (1992CL04).
See (1977AJ02).
See (1988SH1E).
See (1982AJ01, 1986AJ04) and ^{20}Ne in (1983AJ01, 1987AJ02). See also (1989TH1C).
See (1988SH05) for a DWBA analysis of differential cross section data at E_{α} = 140 MeV.
Angular distributions have been studied at E_{d} to 80 MeV: see (1982AJ01). At E_{d} = 55 MeV ^{16}O*(0, 6.05, 6.13, 6.92, 9.8, 11.10) are strongly populated (1986AJ04).
The angular distribution to ^{16}O_{g.s.} has been measured at E_{d} = 13.6 MeV (1986AJ04).
Angular distributions have been reported at E_{α} = 22.8 to 25.4 MeV and at 90.3 MeV, the latter to ^{16}O*(0, 6.1, 7.0, 8.8, 9.8, 10.3) [see (1982AJ01)] and at E_{α} = 25.1 to 27.8 MeV (1986AJ04). Excitation functions measured for E_{α} = 26  37 MeV at θ_{lab} = 30°, 40°, 60° have been reported (1986ESZV, 1989ES06). See also (1987SH1B, 1988SH1F).
The ground state angular distribution has been studied at E(^{12}C) = 40 MeV [see (1986AJ04)]. ^{16}O + ^{8}Be breakup of ^{24}Mg following inelastic scattering of ^{24}Mg projectiles on ^{12}C has been reported (1989FU10).
Forwardangle yields of ^{16}O measured at E(^{28}Si) = 100  170 MeV have been reported (1986SH25).
Forwardangle yields of ^{16}O measured at E(^{28}Si) = 100  170 MeV have been reported (1986SH25).
