(See Energy Level Diagrams for 16O)
Shell model:(BO69N, FE69C, IK69, WI69G, BO70R, BO70W, DE70S, DO70H, EI70B, EL70E, HA70M, IR70, MA70P, NE70L, RE70J, RU70B, SV70A, ZO70, AG71A, AN71G, AR71O, BA71J, BA71KK, BE71L, BO71I, BR71B, BR71L, GO71M, HE71E, HS71, HU71F, IR71, IR71A, IR71C, IR71D, KH71A, LA71H, LE71O, MA71T, MO71A, RO71B, SU71, VI71B, ZO71, ZO71A, ZO71B, AB72E, BO72M, BR72O, CA72L, EH72, EN72B, FR72H, GE72J, JA72N, JA72S, KA72F, LE72, MC72C, NE72F, NI72E, PA72H, RA72E, RE72A, RO72P, SA72E, SH72F, VA72B, WA72B, WO72, ZA72A, EL73, FE73C, HA73F, IC73, KU73D, LA73S, LO73E, MA73GG, MU73K, RE73G, RO73M, SA73C, SH73F, TR73E, WA73O, YA73, BO74N, DA74J, EL74B, FA74C, KH74A, KU74A, MA74H, NA74D, NE74E, NE74G, SH74L, TA74, WO74C, ZA74F, DI75D, DR75, EN75C, FR75C, GI75E, GR75A, LO75C, MC75I, MI75F, MI75M, MP75, SP75B, VE75B, ZA75, BL76, BO76F, DA76I, SA76H, SC76A, SC76E, ZA76C).
Collective and rotational models:(FE69C, DA70J, FL70A, PA70K, SV70A, AR71O, BO71I, GO71H, IR71D, ON71, OS71C, ZO71A, AB72, BO72M, HO72P, JA72S, LA72I, LE72, ZA72A, CA73C, IC73, KO73E, LA73S, LA73T, RO73M, SH73G, SO73A, YA73, AR74C, MP74, AB75, DR75, LE75D, LE75H, SO75C, BO76S, GO76I).
Cluster and α-particle models:(BA69UU, IK69, TA69G, WI69G, EI70B, KO70O, AB71A, AN71G, FR71B, KH71E, ME71B, NO71, RI71G, AB72, AB72C, AV72B, BA72S, FR72C, GR72O, HO72P, IK72A, LE72, LI72J, NE72B, BE73R, CO73I, CO73J, DE73M, IC73, KU73D, LA73T, YA73, DA74J, DZ74B, GO74I, GO74V, KH74, KH74C, ME74A, SU74A, SU74B, TA74, WA74C, WE74H, BA75H, BU75A, IK75, IN75A, KA75F, KR75A, KU75C, PA75I, TA75B, WA75K, BA76G, GO76B, SA76C, SU76A).
Astrophysical questions:(LE71N, CL72D, KO72J, AR73Q, AU73C, CA73O, CO73EE, CO73FF, GR73O, IB73A, RA73F, SA73F, SM73B, TA73C, TR73I, TR73J, UL73F, WO73E, AR74H, BE74J, PA74F, SC74D, WI74P, AU75D, BA75V, BE75AA, DA75I, EN75B, FA75, IB75A, JA75D, KE75, LA75B, LE75, PE75B, RA75C, RY75, SC75B, SC75H, SC75R, SU75D, TA75I, TR75D, VL75, AU76, DW76, EP76, FI76C, FU76A, GI76C, JA76D, ME76D, OS76, RO76D).
Giant resonance (See also reactions 56 and 57.):(AL70L, KE70D, MA70P, PA70K, DU71F, IR71D, SE71B, GO72A, BA73B, CA73M, DE73M, DE73AA, GE73D, GO73P, HA73BB, KI73M, WA73O, FA74, KR74D, KR74E, KR74H, SH74L, WA74B, WA74F, WO74C, AB75, AU75E, CO75L, DO75H, DU75E, GO75P, GR75A, RA75A, SH75E, VE75B, BE76Q, BR76A, FL76A, FO76D, HO76B, KN76, LI76P, MA76F).
Electromagnetic transitions:(FE69C, DO70H, HA70M, IR71A, IR71D, KH71A, MI71L, RU71E, AB72E, AU72C, BE72U, BE72W, BO72M, EC72A, EN72B, FA72I, LO72H, MI72B, TR72B, YO72C, BE73R, CA73C, EL73, HA73R, HA73BB, HO73O, IA73, JA73M, RE73G, SH73G, SO73A, WE73S, BU74C, FE74A, FI74B, HA74W, KR74E, LA74K, MC74G, AR75L, BE75O, BR75L, BU75A, HO75J, HS75, RA75A, SA75E, VE75B, WE75, ZA75, BL76B, HO76B, KI76, KN76, KR76D, VO76C).
Special levels:(FE69C, WI69G, BO70R, BO70W, DA70J, HA70N, MA70P, NA70F, PA70K, PE70F, RU70B, VA70N, AF71A, AG71A, AR71O, BE71DD, BE71FF, ER71C, GO71M, GR71O, GR71Y, HE71E, HS71, HU71F, IR71A, IR71D, KH71A, KO71B, MC71H, ME71B, OS71C, RO71B, RU71E, SC71C, SE71B, SE71C, SU71, WE71, WE71H, YA71E, AV72B, DO72B, EN72B, FA72I, GR72G, HA72LL, HI72J, JA72N, JA72S, KA72J, LA72I, NI72E, NI72F, PA72H, SU72A, VA72B, BA73LL, DO73N, ER73E, FA73L, FE73C, GA73C, HO73O, IA73, JA73M, KI73M, KN73, KU73C, MA73GG, MU73K, RO73M, SA73C, SH73G, SO73A, YA73, AR74C, DI74G, EL74B, FE74A, GA74J, GO74I, GO74J, GO74V, HA74Q, IT74A, KO74A, KR74H, LO74C, NA74D, NI74, SU74A, VA74H, ZA74F, AR75J, BA75H, BE75O, BO75O, BR75L, BU75A, DI75D, GO75O, HA75BB, HS75, MA75B, MC75I, MC75K, MI75B, MI75M, NA75M, NG75, PE75C, RA75A, SA75J, TA75B, BL76, DA76I, FO76D, JA76B, KI76, LI76P, SA76C, SU76A, WE76K).
Special reactions:(BE70R, AR71, PU72B, KU73D, WI73J, KO74A, WE74H, AL75C, AL75E, AR75C, AR75F, DR75, FA75G, GR75F, KO75J, KU75, KU75G, ME75F, RE75C, RE75E, VO75H, BA76B, EG76, HE76D, HI76C, JA76K, NA76G).
Muon and neutrino capture and reactions:(BU70I, EV70A, KA70K, PR70G, ER71, GR71U, LA71P, MO71O, PA71F, PL71, PL71E, SA71H, BA72AA, BL72, BO72I, DO72C, DO72F, HI72F, LA72C, VO72G, WA72B, WO72B, BA73SS, BE73I, DO73E, DO73H, ER73B, FU73F, JO73K, KA73J, NA73Q, SA73U, WA73L, DU74, EN74A, GO74P, KO74C, VO74F, WA74H, BA75BB, CH75K, DO75F, DO75H, DO75I, FU75D, GE75K, MC75B, PA75A, FO76D, LA76C, SU76).
Pion capture and reactions:(BA69ZZ, MA69Y, AL70L, BA70CC, CH70V, GO70S, HO70O, HU70J, KE70D, KO70O, WI70J, CA71, CA71I, CH71F, CH71Q, DE71Q, DE71Z, EI71A, FA71E, GU71H, KO71E, KO71J, LI71M, MA71B, MA71R, MA71Y, MO71E, SE71, SR71, BA72UU, BE72F, BI72B, EN72D, FA72G, FL72, HU72, KO72D, KO72K, MA72A, RO72A, SA72A, SE72E, SW72, YO72B, AG73, AL73M, AR73P, BA73Y, BO73II, BR73I, BU73B, CA73M, DO73D, EI73A, GA73A, GE73P, GR73N, KA73F, KO73G, LA73H, LA73I, LE73, LE73H, LE73J, LE73N, MA73J, NY73, PH73A, RE73D, RO73FF, SE73D, SR73A, AM74, BL74B, BO74H, CL74H, HU74E, LA74B, LI74C, LI74L, LU74, LU74D, NE74F, OH74, PH74B, PH74C, PI74A, ST74O, SZ74, TA74A, UL74B, VI74A, VO74F, AR75A, BA75K, BU75I, EN75A, GI75G, HE75B, HU75E, IA75, KA75N, KO75J, KO75K, LI75E, MA75DD, MU75A, NA75A, RA75I, RO75I, TA75E, VE75B, YA75, AL76G, AS76B, BA76O, BO76L, CA76J, CO76H, DO76C, DY76, EN76, GA76G, GU76, JA76A, JO76B, KA76A, KI76E, MA76S, MI76D, MO76D, MO76F, OS76A, TR76D, WA76G).
Other topics:(EL69E, GR69K, AR70J, BA70II, BE70R, BO70W, DR70A, EL70E, GM70A, GU70H, HA70N, KR70K, LO70N, NE70L, PE70F, RE70J, RU70B, TR70E, VA70N, VA70O, ZA70B, ZO70, AF71A, BA71KK, BE71Z, BE71DD, BO71D, BR71L, DA71, DA71C, ER71C, GA71M, GO71M, GR71C, GR71L, GR71O, GR71Y, HE71A, HE71E, IR71, IR71C, IR71D, KA71E, KA71G, KO71B, KO71O, LA71C, LA71H, MA71S, MA71T, MA71AA, MC71H, MU71A, OS71, OS71C, RA71A, RU71E, RY71, SA71I, SC71, SE71C, SR71, VA71C, VI71B, WE71, WE71E, WI71C, WO71B, YA71E, ZO71, ZO71B, AB72C, AB72E, AR72J, AR72N, AU72C, BA72I, BR72O, BR72P, CA72G, CA72L, CU72, DA72I, DO72E, EH72, EL72C, FR72C, FR72H, GR72B, GR72K, GR72R, HA72AA, HA72CC, JA72S, JE72A, KA72F, KR72A, KR72C, LA72I, LA72K, LE72, LE72M, LO72D, MA72P, MC72C, MI72A, MI72F, MU72E, NE72A, NE72F, NI72E, NI72F, PA72M, PL72A, RA72E, RE72A, RO72P, SA72E, SA72I, SH72F, ST72C, ST72F, SU72A, TR72, TR72C, VA72B, WO72, ZH72A, AN73G, AV73B, BA73HH, BA73VV, BE73QQ, BO73H, CI73F, CL73G, DA73D, DI73H, DO73N, EL73, EL73C, ER73A, FA73, FA73C, FA73L, FE73C, FO73I, GA73, GA73C, GO73W, GR73C, GR73I, GR73P, HA73F, HO73H, HO73S, IA73, KI73M, KO73J, KR73F, KU73, KU73C, KU73D, KU73J, LA73Q, LA73T, LO73E, MA73O, MA73Q, MA73FF, MU73H, NE73G, PA73P, PA73U, PE73E, PO73C, RA73H, RE73G, RO73L, RO73DD, SA73C, SA73R, SC73E, SC73O, SC73S, SH73F, SH73G, SI73G, SI73I, SI73O, SP73C, ST73N, TR73E, WA73O, WE73S, ZA73A, AR74C, CO74M, DA74J, DZ74, EL74, EL74B, FA74, FA74C, FE74A, FI74B, FI74D, GA74J, GO74I, GO74J, GR74C, HO74K, MA74H, MA74T, MC74C, ME74A, MI74C, MI74K, MP74, NA74D, NE74E, NE74G, PA74H, RE74, RO74V, SA74A, SE74C, SH74, SH74C, SH74G, TI74B, TR74C, VA74H, WA74C, WE74K, WE74Q, WO74C, YA74B, ZA74A, ZA74C, ZA74F, ZU74, BE75B, BE75O, BE75Z, BO75, CA75B, EN75C, FL75A, FR75C, GI75D, GO75M, HA75CC, HE75E, KH75A, KH75B, KO75C, KR75, KR75E, KU75, LO75A, LO75C, MA75B, MA75U, MC75I, MC75K, MI75A, MI75F, NE75, PA75G, RO75T, SC75K, SH75K, SO75, SO75C, SP75B, WE75, BL76, BO76F, BO76S, BR76A, BR76E, CU76D, DA76C, FA76B, FL76A, GO76C, HO76, KI76, KR76D, MA76B, NA76F, NI76A, OS76D, PA76, PA76G, QU76, SA76D, SC76A, SI76D, VA76B, VA76F, WE76K).
Ground state:(BO69N, BA70II, AF71A, BO71I, DA71C, GR71L, IR71D, LA71H, MO71A, MU71A, NA71B, RU71E, RY71, SC71O, ZO71, AB72C, AB72E, AU72C, BE72U, BR72O, CA72L, CU72, DA72I, EH72, FR72H, GE72J, GR72G, GR72K, GR72O, JA72N, KR72A, KR72C, LE72, NI72E, RO72P, TR72, VA72B, YO72C, AR73R, AV73B, BO73H, CA73C, DA73D, DO73N, ER73A, ER73E, FA73C, FA73H, FO73I, HO73O, HO73AA, KO73J, KU73, LA73Q, LO73E, NE73G, PE73E, RO73DD, SP73C, ST73N, TR73E, VA73G, AD74B, AR74C, BA74T, BE74C, BO74N, CO74M, DA74J, DE74T, EL74, EN74A, FA74C, FI74A, GA74J, HO74L, JA74J, KH74A, MA74H, MA74T, MI74C, MP74, PA74E, PA74H, RE74, RO74V, SH74K, SI74E, SO74C, WA74C, ZA74A, AL75G, BE75B, BE75Q, BU75A, CA75B, FL75A, FR75C, GI75D, HA75CC, KH75B, KU75C, LE75B, MA75J, MA75U, MA75Z, MI75A, MP75, PE75C, RA75J, SA75J, SH75K, SP75B, ZA75, BE76L, CH76F, CU76D, DA76I, FA76B, FL76A, KR76D, NA76F, PA76, PA76G, SA76H, ZA76, ZA76C).
The mass of 16O derived from the work of (SM75B) is 15.994914616 (22) a.m.u. Using the conversion factor 931.5016 (26) MeV/a.m.u., the mass excess of 16O would then be -4737.04 ± 0.02 keV. (WA71M) quotes -4736.68 ± 0.19 keV which we shall continue to assume. See also (SM71).
At E(6Li) = 4.9 MeV, the cross sections for reactions (a) to (e) leading to low-lying states in the residual nuclei are proportional to 2Jf+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 2Jf+1 dependence (MC66A). The yield curves for α0 and α1 (reaction (e)) measured at 0° for E(6Li) = 3.2 to 13.6 MeV show broad structures. At 90°, for E(6Li) = 9.7 to 13.0 MeV no structure is apparent, suggesting that the 0° yield is explainable in terms of Ericson fluctuations (SE67).
States of 16O observed at E(10B) = 20 MeV are displayed in Table 16.10 (in PDF or PS). The reaction excites known T = 0 states: σt follows 2Jf+1 for 11 of 12 groups leading to states of known J. The angular distributions show little structure (AJ76B).
This reaction plays an important role in astrophysical processes. (DY74) has determined σE1 for Eα = 1.88 to 3.92 MeV. From these data S(Eα(lab) = 400 keV) = 0.08+0.05-0.04 MeV · b (KO74) [used a hybrid R-matrix-optical model analysis (α, γ) and (α, α)], 0.08+0.14-0.07 MeV · b (HU76) [used a two channel, two level approximation of a modified K-matrix]. See also (BA71MM, WE74O). (DY74) state that S depends quite strongly on θ2α(6.92)/θ2α(7.12): S may have to be increased to allow for the tail of 16O*(6.92). For astrophysical considerations see (DY74) and (BA71VV, BI71H, AR73O, CL73C, IB73A, BA74AA, FO75B, AU76, SC76O), in addition to the references listed above and in (71AJ02).
Upper limits of the parity forbidden α-decay of 16O*(10.95, 11.08) [Jπ = 0-; T = 0 and 3+; 0, respectively] are < 6 x 10-4 eV and < 5 x 10-4 eV, respectively (BE74E). See also (DA74O) and (GA73H; theor.).
At higher energies the E2 cross section shows resonances at Ex = 13.2, 15.9, 16.5, 18.3, 20.0 and 26.5 MeV [see Table 16.12 (in PDF or PS)]. Some E2 strength is also observed for Ex = 14 to 15.5 and 20.5 to 23 MeV. In the range Eα = 7 to 27.5 MeV the T = 0 E2 strength is ~ 17% of the sum rule. It appears from this and other experiments that the E2 centroid is at Ex ~ 15 MeV, with a 15 MeV spread (SN74). See also (OM69A), (HA73BB, HA73GG), (RA75A; theor.) and (71AJ02) for the earlier work.
Cross section measurements have been made from threshold to Eα = 24.7 MeV: see (71AJ02) and Table 16.11 (in PDF or PS). Observed resonances are displayed in Table 16.12 (in PDF or PS). The resonance in n0 at Eα = 14.6 MeV (16O*(18.1)) does not appear in the p0 yield: a large isospin mixing is suggested for that state (BE71A). An anomaly is observed in the n0 yield corresponding to formation of the first T = 2 state in 16O [16O*(22.7)] (AD73A). See also 15O in (76AJ04).
The yield of protons corresponding to 15N(0) has been studied for Eα = 7.7 to 23 MeV: see Table 16.10 (in PDF or PS) in (71AJ02) and Table 16.11 (in PDF or PS) here. (SP75) have measured the yield of 10.6 MeV γ-rays [from 15N*(10.45 --> 10.80)] at Eα = 22.8 to 27 MeV. Observed resonances are displayed in Table 16.12 (in PDF or PS). An anomaly is observed in the p0 yield corresponding to formation of the T = 2 state 16O*(22.7): see (AD73A) and (WE72D). See also 15N in (76AJ04).
The yield of α-particles corresponding to 12C*(0, 4.4) and of 4.4, 12.7 and 15.1 MeV γ-rays has been studied at many energies in the range 2.5 to 35.5 MeV: see Table 16.11 (in PDF or PS). Observed resonances are displayed in Table 16.12 (in PDF or PS). The parameters of the first T = 2 state of 16O at Ex = 22.7 MeV observed as anomalies in the α0 and α2 yields are displayed in Table 16.12 (in PDF or PS) (NE72D). Astrophsyical considerations are discussed in reaction 5. See also (LE71N, KO74, WE74O, ME75B, ST75H, GL76B, HU76).
For angular correlation measurements see (KE72H, BU72D). For differential cross section measurements at Eα = 58 MeV see (BE74L). For polarization parameters see (BU72D). For τ0 emission at Eα = 710 MeV see (WA76A). For spallation measurements see (FO71G, LE71N, RU72A, GA74H, RA74C, FU75, RA75E).
The yield of 8Be (reaction (a)) shows a number of resonances: see Table 16.12 (in PDF or PS). There is no evidence below Ex ~ 24 MeV for Jπ = 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 (BR76D). See also (SU72A; theor.) and (71AJ02). For reaction (b) see (CO75B). For reaction (c) see (KL70B, RU73B). See also 12C in (75AJ02) and 8Be in (74AJ01).
This reaction has been studied at many energies for E(6Li) < 42 MeV and E(12C) = 18 to 24 MeV: see Table 16.13 (in PDF or PS) in (71AJ02). Angular distributions are also reported at E(6Li) = 32 MeV [(DE74D: to 16O*(10.35, 11.10)), (BA72Q: to 16O*(10.35))], at 32.5 and 35.5 MeV (GO75Y: to 16O*(10.35, 14.6, 16.3, 20.9)) and at 42 MeV (JA76D; to most states with Ex < 16 MeV). At the higher energies the spectra are dominated by states with J >/= 4 (and natural parity). Among these are states with Ex = 10.346 ± 0.006, 16.304 ± 0.020 and 20.88 ± 0.06 MeV [Γcm < 50, 360 ± 40 and 720 ± 100 keV] and Jπ = 4+, (6+), (8+) (BA71K). Angular correlation (d, α0) measurements agree with the 6+ assignment for 16O*(16.3) [Γcm = 370 ± 50 keV] (AR71N, AR72B) but show that 16O*(20.9) [Γcm = 590 ± 100 keV] is a 7- state (AR71N, AR72B, AV75). A state at Ex = 21.8 MeV is reported by (AV75): J = 6. Angular correlations also suggest Jπ = 5- for a state with Ex = 14.6 ± 0.1 MeV, Γcm = 480 ± 100 keV (AR71N, AR75D): the branching ratios for the decay of 16O*(14.6, 16.3, 20.9) to 12Cg.s. is 85 ± 10, 80 ± 10 and 90 ± 10%, respectively (AR71N, AR72B, AR75D).
At E(6Li) = 32 MeV the σ(11.10)/σ(10.35) ~ 0.5 even though the ratio of the reduced widths of these two 4+ states to 12Cg.s. Sα(11.10)/Sα(10.35) < 10-2: a two step process via 12C*(4.4) is suggested (DE74D)†. θ2α for all 16O states with Ex < 10.4 MeV are listed in (LO67). See also (JA76D). Gamma-ray angular distribution measurements have been carried out at E(6Li) = 4.5 to 6.5 MeV (CA72C, ZA72). For angular correlation measurements, see (BA73DD, BA76Z) and 18F in (78AJ03).
† However, compound nuclear effects may account for this ratio (F. Becchetti, private communication).
This reaction has been studied at many energies for E(7Li) < 38 MeV: see Table 16.13 (in PDF or PS) in (71AJ02) and (BA71NN, BA71OO: E(7Li) = 32 MeV) and (CO76C: E(7Li) = 38 MeV). In the latter work the spcetra at forward angles are dominated by members of the 4p-4h Kπ = 0+ band [16O*(6.05, 6.92, 10.35, 16.3): Jπ = 0+, 2+, 4+, 6+] and by those of the Kπ = 0- band [16O*(9.63, 11.60, 14.67, 20.9): Jπ = 1-, 3-, (5-), 7-]. Hauser-Feshbach calculations have been made for many of the 16O states and, in particular, for a state at Ex = 14.363 ± 15 keV which is not resolved at forward angles. The width of this state is < 120 keV and J > 5, π = natural (CO76C; M.E. Cobern, private communication). See also (LA71, CA72B), (BA71RR, GA72P, FO73D, FO73J, OG73, ST74H, GO75Y) and (DO70J, KU72D, IC73, DO74L, PA75I; theor.).
At E(10B) = 18 and 45 MeV angular distributions have been studied involving 16O*(0, 6.1, 7.1, 8.9, 9.9, 10.4): this reaction does not appear to select special states of 16O (HI70B). See (JA70G, YO73D). See also (GA72P) and (KU73D, NE74F; theor.).
Angular distributions have been measured at E(12C) = 42 MeV (AR76: 8Beg.s. + 16O*(0, 6.1, 6.9, 10.4)), 60 --> 63 MeV (MA76C, WE76B, CR73B: 8Beg.s.+16O*(0, 6.1, 6.9, 10.4, 11.1, 14.7, 16.3)), and also for the ground state transitions at E(12C) = 11.6 to 13.4 MeV (CO72K), 18 to 40 MeV (FL76) and 37 MeV (EB75, EB76). Angular correlations at E(12C) = 78 MeV confirm Jπ = 4+, 5-, 6+ and 7- for 16O*(10.35, 14.67, 16.29, 20.88) (SA76F; and P.D. Parker, private communication: 8Be(0°), α0). At the latter energy l = 12 seems dominant: for yield measurements see 24Mg in (EN78). See also (PA72F, WO72A, HO74M, PI75C), (GA72P, FO73D, SC73K, ST74H) and reaction 13 in (71AJ02).
Angular distributions have been measured at E(19F) = 40, 60 and 68.8 MeV involving different states in 15N and 16O*(0, 6.1, 7.0, 10.4) (SC72C). See also (VO70E, PU75A), (GA72P, MO72H, SC73K) and (BO72K; theor.).
At E(20Ne) = 108 and 147 MeV the spectrum involves groups at Ex = 6.1 (u), 7.0 (u), 10.3, 11.1, 14.6 (u) and 16.2 MeV [u = unresolved] (ME74F, PI75C). Angular distributions are reported at E(20Ne) = 78 MeV to Ex = 6.1 (u), 6.9 (u), 8.9 and 10.4 MeV (RO70J). See also 32S in (EN78) and (DO75D). See also (GA72P).
The yield of γ0 has been studied for E(3He) = 3 to 8 MeV (VE72A; abstract) and 3 to 16 MeV (SH74A). In the latter experiments the γ1+2+3+4 yield has also been measured as have many angular distributions: the 90° γ0 yield is characterized by resonances at E(3He) ~ 4 and ~ 6 MeV, the γ1+2+3+4 yield by a single broad structure at ~ 5.5 MeV. The peak cross section for the latter yield is an order of magnitude greater than the cross sections for the peaks observed in the γ0 yield (SH74A). The yield of (γ1 + γ2) [E(3He) = 3.9 to 12 MeV] shows one resonance at E(3He) = 4.5 MeV (CH74C): see Table 16.13 (in PDF or PS) [also measured the (γ3 + γ4) yield in the range 3.9 to 8.7 MeV]. For the earlier work see (PU66). See also (SU73C) and reaction 46.
The excitation functions to E(3He) = 11 MeV [see Table 16.14 (in PDF or PS) of (71AJ02) and (ET72: E(3He) = 4.0 --> 5.8 MeV for n to 15O*(0, 6.18, 7.28, 7.56))] are marked at low energies by complex structures and possibly by two resonances at E(3He) = 1.55 and 2.0 MeV: see Table 16.13 (in PDF or PS). Polarization measurements for the n0 group have been reported at E(3He) = 3.0 to 5.7 MeV [see (71AJ02)] and at E(3He) = 12, 16 and 20 MeV (RH73; abstract). See also 15O in (76AJ04).
The yield curves for p0 and p1+2 for E(3He) = 4.0 to 8.0 MeV show a resonance at 6 MeV (WE68C, WE68I): see Table 16.13 (in PDF or PS). (ST72H) have measured excitation functions for E(3He) = 3.5 to 6 MeV for the p0, p1+2, p3 --> p6 groups: some uncorrelated structures are observed. See also 15N in (76AJ04).
See 14N in (76AJ04).
Yields of α0, α1, α2 and γ-rays from decay of 12C*(12.71, 15.11) have been studied up to E(3He) = 12 MeV: see Table 16.14 (in PDF or PS) in (71AJ02) and (BO71M: E(3He) = 1.2 to 5.4 MeV; α0, α1, α2). Observed resonances are displayed in Table 16.13 (in PDF or PS). Those seen in the yield of γ15.1 are assumed to correspond to 16O states which have primarily a T = 1 character. See (71AJ02) for a summary of the earlier references and 12C in (75AJ02).
The excitation function for 8Beg.s. has been studied for E(3He) = 2 to 6 MeV. It shows a strong resonance at E(3He) = 5.6 MeV corresponding to a state in 16O at Ex = 27.3 MeV. Jπ appears to be 2+ from angular distribution measurements (JA68H).
Angular distributions for the n0 group have been measured for Eα = 12.8 to 22.5 MeV: see (71AJ02). 16O*(6.05) has been observed as a neutron threshold (BO56D). See also 17O, (CL70E, CL73C, TR73J; astrophys. considerations) and (TE71D; theor.).
Angular distributions have been studied at E(6Li) = 20 and 28 MeV to 16O*(0 [at 28 MeV], 6.13, 7.0, 8.87, 9.85, 10.35, 11.09). At these energies the spectra are dominated by the triton groups to 16O*(11.09, 14.30, 14.39, 14.82). At E(6Li) = 25 MeV the excitation of 16O*(14.52, 14.66) is also reported (BA69MM, BA71NN, BA71OO, DE71Y, BA72Q). See also (BA71RR).
At E(12C) = 87 MeV, angular distributions are reported for transitions to 16O*(6.9, 8.9, 10.4, 11.1, 13.5, 14.8, 15.1, 16.1, 16.5) (RO70J). The ground state angular distribution has also been studied at E(13C) = 36 MeV (WE76J).
At E(3He) = 11 to 16 MeV, neutron groups are observed to T = 2 states at Ex = 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 16O, the analog states to 16C*(0, 1.75). Jπ for 16O*(24.52) is found to be 2+ from angular distribution measurements (AD70A). Angular distributions are also reported at E(3He) = 2.1 to 3.4 MeV and at 6 MeV: see (71AJ02). See also (MA74A, CE75B).
See 16C, reaction 4.
The γ0 yield has been studied for Ed = 0.5 to 5.5 MeV (SU66, SU66G) and 2.1 to 2.9 MeV (WE72A). The yield shows a resonance at Ed = 2.40 ± 0.05 MeV, Γcm ~ 0.6 MeV (WE72A, DA74M). The angular distribution of γ0 at resonance is consistent with E1: Jπ = 1-; T = 1: it may be the Gillet 2p-2h quasibound state: see, however, reaction 46. Structures at Ex = 22.2 and 24.5 MeV are also reported (SU66): see Table 16.14 (in PDF or PS). See also (71AJ02), (SU73C) and (JA73C; theor.).
For Ed = 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 Table 16.14 (in PDF or PS) (RE60B, BU65C). Yield measurements are also reported for Ed = 2.9 to 5.0 MeV (RI70: n2, n3, n4, n6, n7). For polarization measurements see Table 16.16 (in PDF or PS) in (71AJ02) and (LI76J: 4.5 to 15 MeV: n1+2), (FO72B: 5.16 MeV; n0, n1+2, n3, n4+5, n6, n7) and (HI71E: 10.0 and 11.8 MeV; n0). See also (WO69H, WA71F, LO74F), (ME70J; theor.) and 15O in (76AJ04).
The yield curves of various proton groups show a great deal of structure: see reaction 30 and Table 16.16 (in PDF or PS) in (71AJ02) for a summary of the earlier work. Resonant structure reported by (GO62L, NE72D) is displayed in Table 16.14 (in PDF or PS). For polarization measurements see Table 16.16 (in PDF or PS) in (71AJ02), (PA76F; 11.8 MeV, p0) and (EG71; 13.8 MeV; p0). See also (DA74E), (LO74F), (KO72L; theor.) and 15N in (76AJ04).
The yield of elastically scattered deuterons has been studied for Ed = 0.65 to 5.5 MeV [see Table 16.16 (in PDF or PS) in (71AJ02)] and for 14.0 to 15.52 MeV (BU74). (FL67B) report a number of resonances in the d0 yield corresponding to states in 16O with 22.6 < / = Ex < / = 25.2 MeV. There is indication of broad structure at Ed = 5.9 MeV and of sharp structure at Ed = 7.7 MeV in the total cross section of the d1 group to the T = 1 (isospin-forbidden), Jπ = 0+ state at Ex = 2.31 MeV in 14N. The yield of deuterons (d2) to 14N*(3.95) [Jπ = 1+; T = 0] shows gross structures at Ed = 7.4 and 10.2 MeV (DU70): see Table 16.14 (in PDF or PS). Polarization measurements involving the elastic group are reported at Ed = 11.6 MeV (BR73H) and 15 MeV (DA73L, BU74). See also 14N in (76AJ04) and (ME70J, FA74; theor.).
There is a great deal of structure in the yields of various α-particle groups for Ed = 0.5 to 12 MeV: see Table 16.16 (in PDF or PS) in (71AJ02) for the earlier work. The more prominent structures are shown in Table 16.14 (in PDF or PS) (IS61D, IS62, LA67J, NE72D). The yield of 15.11 MeV γ-rays [from the decay of 12C*(15.11), Jπ = 1+; T = 1] which is isospin-forbidden has been studied for Ed = 2.8 to 12 MeV. Pronounced resonances are observed at Ed = 4.2, 4.58 and 5.95 MeV and broader peaks occur at Ed = 7.1 and, possibly, at 8.5 MeV (see Table 16.14 (in PDF or PS)). Above Ed = 9.5 MeV, the yield curve is quite featureless (BR65F). See also 12C in (75AJ02). Polarization measurements have been carried out at Ed = 15 MeV (LU76; α0, α1, (α2)).
Observed proton groups are displayed in Table 16.16 (in PDF or PS) (BR64F). Angular distributions have been measured at E(3He) = 2.5 to 18 MeV: see (71AJ02), (BI72: E(3He) = 7.96 --> 18.0 MeV), (GU76J: E(3He) = 9 MeV) and (WE71Q: 18 MeV). Analysis by DWBA is satisfactory for 16O*(6.13, 7.12, 8.87, 10.95). 16O*(6.05, 6.92, 10.35) are very weakly populated in accord with their presumed 4p-4h character. It is suggested that the 2p-2h strength lies mainly above Ex = 14 MeV (WE71Q). Branching ratios (shown in Table 16.15 (in PDF or PS)) and pγ correlation measurements lead to Jπ = 2-, 0- and 3+ for 16O*(8.87, 10.95, 11.08) (BR59, KU59); τm are shown in Table 16.21 (in PDF or PS).
At E(3He) = 8 MeV a study of the protons in coincidence with 4.4 MeV γ-rays (reaction (b)) indicates that the reaction proceeds via 16O*(12.51, 13.97, 14.39, 14.92, 15.82, 16.23, 17.16, 17.82, 18.04) [± 40 keV] (HO69H). See also (ME70O, OT75), (BR72R) and (AL72E; theor.). For the decay of T = 3/2 states of 17F, see reaction 9 in 17F and (AD73B).
Deuteron angular distributions to states of 16O have been reported at many energies up to Eα = 48 MeV: see (71AJ02) for the earlier references and (TU75: Eα = 21 MeV) and (LO72B: Eα = 29.98 MeV; see Table 16.17 (in PDF or PS)). The results of (LO72B) are consistent with Jπ = 5+, 6+ and 4+ for 16O*(14.40, 14.82, 16.29) [2p-2h] and with 6+ for 16O*(16.30) [4p-4h].
An experiment to test time-reversal invariance by the principle of detailed balance in this reaction and in 16O(d, α)14N leads to an upper limit of 0.2% for the time-reversal non-invarinat part of the reaction amplitudes (TH71F).
The two-stage reaction (reaction (b)) at Eα = 22.9 MeV appears to proceed via 16O states at Ex = 9.85 ± 0.07, 10.37 ± 0.07 and 11.14 ± 0.07 MeV (BA69N). See also (BA71NN, BA71RR, OG73, LE76G) and (BU71K, TE71D; theor.).
The yield of ground state radiation (γ0) has been measured for Ep = 0.15 to 27.4 MeV: see Table 16.18 (in PDF or PS) for a listing of the measurements and Table 16.19 (in PDF or PS) for a display of the parameters of the obeserved resonances.
Below Ep = 0.4 MeV capture to the ground state is dominant: S(0) = 64 ± 6 keV · b, a value which makes the oxygen side cycle in CNO burning more important than previously thought. Study of the direct radiative capture process leads to a single particle spectriscopic factor C2S = 1.8 ± 0.4 for 16Og.s. (RO74S). The cross section shows a great deal of structure up to Ep = 17 MeV. Above that energy the γ0 yield decreases monotonically to 27.4 MeV. In the same energy region the γ-yield to 16O states at 6 - 7 MeV and ~ 12.9 MeV is large and it also decreases with increasing energy (OC73; prelim. results.).
Measurements with polarized protons have been made over the giant dipole resonance at Ex = 22.2 MeV (HA72EE) and over a broad E2 giant resonance at Ex ~ 24 MeV (HA74A). See also (BU76F). The giant M2 resonance is probably centered at Ex = 20.4 MeV (CH74C).
See also (CA72I, JA73A), (HA72OO, GL73, GL73A, HA73W, HA73BB, SU73C, HA74N, HA74W, CA75, GL76C), (BA72RR, BA73B, GO73P, HO73S, DA74M, MA75, RA75, RA75A, SN75, SN75A, LO76, MA76R; theor.) and (BA71VV, CL73C, TR73; astrophys. considerations).
Elastic scattering studies are reported for Ep = 0.6 to 11.7 MeV: see Table 16.20 (in PDF or PS) in (71AJ02) and Table 16.18 (in PDF or PS) here. Observed anomalies are displayed in Table 16.19 (in PDF or PS) (DR71B). Inelastic scattering has been studied for Ep = 8.5 to 11.6 MeV: the p1 yield is dominated by a structure at Ep = 10.6 MeV, Γcm ~ 650 keV (DR71B). A study of the elastic yield and the polarization (Ep = 8.4 to 10.5 MeV) shows that a narrow s-wave resonance does not exist at the deuteron threshold (Ex = 20.74 MeV) (FI75A). See also (HO73S; theor.).
The absolute total cross section has been measured with excellent resolution and statistics for Ep = 3.8 to 12 MeV by (BA68QQ): observed resonances are displayed in Table 16.20 (in PDF or PS) (BA68QQ) also discusses in detail the relationship of his results and the data reported in other experiments, including a comparison with analog states in 16N [see Fig. 5]. Excitation functions have also been reported from threshold to 13.6 MeV: see Table 16.20 (in PDF or PS) in (71AJ02). Polarization measurements for n0 have been carried out at Ep = 7.9 to 12.3 MeV (WA65A) and at 10.3 and 11.3 MeV (BY76, BY76A). See also (LO74F) and (DU72A, BA73B, HO73S, VO73I, HO74R, MA74E, RO75U, AR76B; theor.).
The yields of the first three triton and 3He groups have been measured for Ep = 24.0 to 43.5 MeV (PI74B, MI75). Polarized protons with Ep = 43.8 MeV have been used to study the transitions to 13C*(0, 3.68, 7.55, 15.11) and 13N*(0, 3.51, 7.38, 15.07) (MA74C). See also (HA70D, HA72HH).
Excitation functions for α0 and α1 particles [corresponding to 12C*(0, 4.43)] and of 4.43 MeV γ-rays have been measured for Ep = 0.093 to 45 MeV: see Table 16.20 (in PDF or PS) in (71AJ02) and Table 16.18 (in PDF or PS) here. Observed resonances are shown in Table 16.19 (in PDF or PS). Angular correlation measurements lead to Jπ = 2-, 1-, 3- and 1+ for 16O*(12.97, 13.09, 13.26, 13.66) (CL69B). For Ep > 3.5 MeV there is continuing structure in the yield curves which is interpreted in terms of fluctuations: see (71AJ02). For polarization measurements see (PE76A, PE76F: 0.34 to 1.21 MeV).
A study of α1γ for Ep = 0.15 to 2.50 MeV leads to S(0) ~ 0.1 keV · b and shows that this reaction makes a negligible contribution to hydrogen burning at stellar energies compared to the (p, γ0) and (p, α0) processes (RO74S). See also (JA73A), (CL74, LA75E, LA76A; applications), (BA71VV; astrophys. considerations) and (MA72J, GA76B; theor.).
Observed neutron groups are displayed in Table 16.22 (in PDF or PS). Angular distributions have been reported for Ed to 6 MeV: see (71AJ02) and (MU71B, FO72E: Ed = 4.83 and 5.84 MeV) and (BA73O: Ed = 5.0, 5.5 and 6.0 MeV): l-values and spectroscopic factors are also shown in Table 16.22 (in PDF or PS).
Slow neutron thresholds have been observed to 16O*(10.954 ± 0.010, 11.080 ± 0.015) (WE57B). 16O*(10.95) γ-decays only to 16O*(7.12), Jπ = 1-. This suggests Jπ = 0- for 16O*(10.95), an assignment also strongly favored by the γ-γ correlation (BE57F). See also 17O.
Angular distributions have been measured at E(3He) = 11 MeV (BO69C, BO71B) and at E(3He) = 16.0 and 24.9 MeV (FU69): l- and S-values are shown in Table 16.22 (in PDF or PS). See also (FR73), (OG73), (CO70Q, EN72B, HS75; theor.).
The ground state of 16N decays to seven states of 16O: reported branching ratios are listed in Table 16.23 (in PDF or PS). The ground state transition has the unique first-forbidden shape corresponding to ΔJ = 2, yes, fixing Jπ of 16N as 2-: see (59AJ76). For the β-decay of 16N*(0.12) see reaction 1 in 16N (PA75A).
The α-decay of 16O*(8.87, 9.63, 9.85) has been observed: see (71AJ02). The parity-forbidden α-decay from the 2- state 16O*(8.87) has been reported: Γα = (1.03 ± 0.28) x 10-10 eV [Eα = 1282 ± 5 keV] (HA70I, NE74D). (WE71P) suggests that the α-width of 16O*(7.12) is an order of magnitude smaller than that for 16O*(9.58). See also (SP70D).
Recently reported transition energies derived from γ-ray measurements are: Ex = 6130.43 ± 0.05 keV [Eγ = 6129.170 ± 0.043 keV (SH75H)] and 7116.85 ± 0.14 keV [Eγ = 7115.15 ± 0.14 keV (AL76D)]. See also (CH67I, AL74) and (DO73H, WI74B, BO75G, DO75H, LO76; theor.).
The absorption cross section and the (γ, n) cross section are marked by a number of resonances. Some of the reported structure is displayed in Table 16.25 (in PDF or PS) of (71AJ02). In view of the availability of experiments using monoenergetic photons and good resolution and statistics we suggest, on the basis of the work of (VE74D, BE75P, BE75T, CA65B) that excited states of 16O are observed at Ex = 17.3 [u], 19.3 [u] and 21.0 MeV [u = unresolved], followed by the giant resonance whose principal structures are at ~ 22.2 and 24.1 MeV, with additional structures at 23 and 25 MeV. See also (WA72C; theor.). The best resolution achieved so far appears to be that of (VE74D) who measured the (γ, n+γ, pn), (γ, pn) and (γ, 2n) cross sections separately to Eγ = 37 MeV. Besides the monoenergetic photon work, there are still a number of reports of bremsstrahlung studies: the most convincing of these is by (JO75A) and (JU70B). These time-of-flight data confirm the structure indicated above. See also (BA71SS, IS71, TH72I, SY73). The yield of reaction (a) has been measured for Ebs = 100 to 800 MeV (AD71, FR71F; also 6.18 γ). The absorption cross section has been measured from Ebs = 10 MeV to above the meson threshold (AH75B). The cross section for reaction (b) has been measured between threshold and Eγ = 120 MeV: it is usually small compared to the (γ, n) cross section at corresponding energies (FI70E). Polarization measurements for the n0 group have been carried out at Ebs = 20 to 30 MeV and at 64 MeV (CO70S, CO71F, NA73B).
Branching ratios for the decay of 16O in the giant resonance region to various excited states in 15O are discussed in 15O (76AJ04).
See also (KA71A, SC75E), (FI70C, HA70T, BU72G, GL73, GL73A, HA73BB, BU74I, BR75H), (AL76G; applied work) and (HU70J, MU70E, VA70N, AN71D, PE71A, SH71B, WE71A, AG72, DU72A, FI72A, BA73B, BA73YY, CI73F, DE73M, GO73R, HO73S, IS73B, MA73T, RO73W, SR73, WA73C, DO74H, FA74C, FI74B, KR74D, MU74C, WA74B, DU75E, MA75, RO75U, HE76H, KA76H, KA76I, NI76; theor.).
The (γ, p0) cross section derived from the inverse capture reaction (reaction 46) confirms the giant resonance structure indicated above as do also the direct (γ, p0) measurements. The total (γ, p) cross section is given by (DE68G). For yields at higher energies see (MA73V: Ebs = 50 --> 80 MeV) and (AD71: 100 --> 800 MeV; 6.32 γ-ray). Branching ratios for the decays of 16O states in the giant resonance region to various excited states in 15N are discussed in 15N in (76AJ04) and in (DI73F, BE75T). For a comparison with results from the 15N(p, γ)16O reaction see (HA74A).
See also (DO73K, MA76), (FI70C, HA70T, BU72G, CO73T, HA73BB, HA74W) and (GR69K, HU70J, MU70E, WE70K, DE71E, WE71A, FI72A, WA72C, BA73B, BL73B, CI73F, DE73M, HO73S, MA73T, FA74C, KR74D, RA75A, FI76E, HE76H, KA76I, NI76; theor.).
For reactions (a) and (c) see (71AJ02). A study of the 16O(γ, α0) reaction at θ = 45° and 90° shows a 2+ resonance at Ex = 18.2 MeV with an E2 strength which is spread out over a wide energy interval. A strong resonance corresponding to an isospin forbidden 1- state at Ex ~ 21.1 is also observed (SK75A). See also (HA73BB, MA76K, MA76N) and (71AJ02).
The differential scattering cross section has been measured for Eγ = 18.5 to 33 MeV: the main giant resonance peaks are located at ~ 22 and ~ 25 MeV (LL67C). (AH70A) report resonances at Eγ = 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 60 NZ/A MeV · mb by a factor 1.4. For lifetime measurements of 16O*(6.9, 7.1), see Table 16.19 (in PDF or PS) in (71AJ02); for widths, see Table 16.12 (in PDF or PS) in (71AJ02). The separation between the (7.12) and (6.92) γ-lines is 199.8 ± 0.5 keV (SW70). Based on 7116.85 ± 0.14 keV (Table 16.9 (in PDF or PS)), Ex for the lower state is 6917.1 ± 0.6 keV.
The 16O charge radius = 2.718 ± 0.021 fm (SC75L, FE73F). See also (BE71P) and (71AJ02). Form factors for transitions to the ground and to excited states of 16O have been reported in many studies: see (71AJ02) and (SI70L, BE73FF, BE73GG). Table 16.24 (in PDF or PS) lists the excited states observed from spectra of inelastically scattered electrons. The isospin-forbidden (E1) excitation of 16O*(7.12) has been reported by (MI75I, MI75L): the isovector contribution interferes destructively with the isoscalar part and has strength ~ 1% of the T = 0 amplitude (MI75I; and H.H. Miska, private communication).
The 0+ states 16O*(6.05, 12.05, 14.00) saturate ~ 19% of an isoscalar monopole sum rule (BE73GG). As for the E2 strength it is distributed over a wide energy region: see Table 16.24 (in PDF or PS) and (HO74J).
See also (SI70K, BI71H, HI75B), (BR70R, TH72D, TH73F, DE74T, BE75C, BE75W, SI75D) and (DO70H, FU70A, BO71A, BR71P, DU71C, EI71A, ER71C, FR71H, KH71B, LE71Q, MA71M, CA72L, DO72B, DO72F, FI72B, FR72D, GA72O, GU72B, WE72J, BL73A, BO73R, DO73H, EL73A, ER73E, FA73H, GA73K, GO73F, HO73L, HO73O, MA73P, SP73C, WA73L, BA74T, BO74H, CI74, DZ74A, DZ74B, FA74C, FR74D, SO74D, TR74C, AB75, AR75L, DE75F, DO75H, DO75I, DZ75, IN75A, LA75A, LE75H, RA75A, RO75P, WA75K, BU76A, CU76D, FA76B, RA76E; theor.).
Angular distributions have been measured at energies to En = 14.1 MeV: see Table 16.27 (in PDF or PS) in (71AJ02) and Table 16.25 (in PDF or PS) here. Gamma rays have been observed corresponding to the ground state decay of 16O states at Ex = 6129.1 ± 1.2 keV [Eγ = 6127.8 ± 1.2 keV] (BE66AA), 6906 ± 15, 7112 ± 10 and 8865 ± 3 keV (NY71). See also (HO74A, PO75G, NO76E) and (JE72A, DA73, SC73D; theor.).
Angular distributions of elastically and inelastically scattered protons have been measured at many energies up to Ep = 1000 MeV: see Table 16.27 (in PDF or PS) in (71AJ02) and Table 16.25 (in PDF or PS) here. Parameters of the observed groups are displayed in Table 16.26 (in PDF or PS). Evidence, based on a study of the angular distribution and polarization involving 16O*(8.87) [Jπ = 2-], has been obtained by (LE76M) for an octupole (E3) giant resonance of predominantly isoscalar nature centered near Ex ~ 35 MeV, Γ ~ 5 MeV.
For reaction (b) see (EI71, HA71FF) and 15N in (76AJ04). For reaction (c) see (71AJ02) and (GO76E). At Ep = 46.8 MeV reaction (d) proceeds predominantly via 16O*(11.0) (EP71B). See also (BO73FF) and (71AJ02), (BU69J, QU70C, BA71G, LO72F, GO73Z, AL74H, HI75, NO76C), (GA71I, PA72P, TH73H, IG75A, KA75G), (BA70HH, CZ70, FE71D, HE71J, RA71K, AU72B, BO72F, BO72N, GE72A, GE72E, JA72B, JO72B, KE72C, LE72M, LE72N, LE72S, PE72C, ST72I, WI72F, BL73D, GE73D, GE73O, GU73H, JA73K, MI73K, RU73A, SC73D, VA73L, BE74U, CI74, GO74U, GU74G, MA74P, PE74, SC74K, SC74N, SI74E, ZE74, AN75P, BA75U, CL75C, DU75B, FR75C, GE75E, MA75T, MA75Z, SC75G, SM75, TH75, DA76F, GO76E, JA76B, YA76A; theor.) and 17F.
Angular distribution studies have been carried out for Ed up to 81.6 MeV: see Table 16.27 (in PDF or PS) in (71AJ02) and Table 16.25 (in PDF or PS) here. Observed deuteron groups are displayed in Table 16.26 (in PDF or PS) (DU74C). For reaction (b) see (NE71D). See also (PA72P), (VE69D, EL70F, OH70C, DO71, SI71G, DM72, GA72I, CH74U, BO75W, CO75I, CO76, LE76C: theor.) and 18F in (78AJ03).
Angular distributions have been measured to E(3He) = 71 MeV: see Table 16.27 (in PDF or PS) in (71AJ02) and Table 16.25 (in PDF or PS) here. Inelastic groups are shown in Table 16.26 (in PDF or PS) (MO74C). See also (KA70I, GO75L), (HA74W) and (CH74U, KU75G, SI75, LE76L; theor.).
Angular distributions of α-particles have been measured up to Eα = 146 MeV: see Table 16.27 (in PDF or PS) in (71AJ02) and Table 16.25 (in PDF or PS) here. The fraction of the isoscalar quadrupole (T = 0, E2) energy weighted sum rule (EWSR) exhausted between Ex = 17 and 25 MeV is 40+20-10% (HA76O). See also (KN75B, MO75, BU76E, YO76C). The forward angular behavior of the giant resonance structure for Ex = 23 - 24 MeV is consistent with l = 0 transfer while l >/= 3 contributions cannot be excluded above Ex = 20 MeV. For low-lying states coupled channel calculations are required to describe the angular distributions to the 2+ and 4+ states at 9.85 and 10.35 MeV while the 1-, T = 0 states require a microscopic wave function analysis (HA76O).
Reaction (b) proceeds via excited states of 16O: see (GU71C, SH75B). (CH76E) find Neff = 0.34+0.09-0.05 at Eα = 850 MeV [square well]. (SH75B) report that the principal parent of 16O in and α-cluster model is 12Cg.s., and not 14C*(4.4).
See also (PI69D, EC73A, LI73K, DO74), (GA71I, HA74W, GR75L, RO75S), (AG70B, BU70J, MI70F, BE71J, LO71I, MC71, MU71H, NO71, TA71E, TE71D, AV72C, BO72H, CA72O, DM72, LO72G, MI72D, SH72C, SU72B, CE73A, CO73J, RU73A, SU73A, BA74K, CA74E, CH74U, FE74, KA74F, MO74G, WA74A, AN75G, FL75, KO75B, KU75G, SI75, SU75B, CO76S, LE76K, PA76D, RE76; theor.) and 20Ne in (78AJ03).
For studies of the elastic scattering see Table 16.25 (in PDF or PS). See also (MI74B), (FO73J, GR75L, FI76B) and (SC70N, WA72G, OH76; theor.). For a study of d-α angular correlations see 20Ne in (78AJ03) and (AR75M). For reaction (c) see (PA74G) and 20Ne in (78AJ03).
The elastic scattering angular distributions have been studied at E(10B) = 100 MeV (NA75J) and, in reaction (b), at E(16O) = 27, 30, 32.5, 35 and 60 MeV (SC72A). At E(16O) = 60 MeV, angular distributions involving states of 11B and 16O*(0, 6.1, 7.0, 10.34) have been measured by (SC72C). See also (DE74E, KO74G; theor.).
The elastic scattering has been studied at E(16O) up to 168 MeV: see reaction 64 in (71AJ02) and Table 16.25 (in PDF or PS) here. The scattering to 16O*(6.05, 6.13, 6.92, 7.12, 8.9, 10.3) has also been studied [see Table 16.25 (in PDF or PS)] (GU73G, SP76) and the populations of 16O*(11.1) (SH75L) and 16O*(15) (GU73G) have been reported. See also (RO70J). Most of the studies of this reaction have involved yield measurements as they apply to compound structures in 28Si: see (EN78) and (MA72H, ST72K, MA73A, MA74, MA75I, SH75L, CH76H, CH76L, EY76, SP76A). For spallation experiments see (WI74D).
See also (MA72Z, HA75T, PI75C), (HE69C, GA72P, BR73N, PA73T, PE73G, ST73H, ST73S, GR75L, VO75D), (AR73O, CL73C, CO74C, CU76; astrophys.), (AN70H, DA71G, BA72BB, CH72J, GO72N, NA72B, RI72, DE73W, FE73I, LO73B, SA73K, GA74I, SA74K, VE74F, WA74A, CH75F, KI75A, PE75, SW75, VE75D, CH76K, YO76A; theor.) and (71AJ02).
The elastic scattering angular distributions have been studied at E(14N) and E(15N) = 25 MeV (BO71U), at E(14N) = 79 MeV (MO76) and at E(14N) = 155 MeV (NA75J). For yield measurements see (ST74D, GO73A, ST76E) and 30P and 31P in (EN78). See also (VO75D) and (KA73L, BA74K, MO75K; theor.).
The angular distributions of elastically scattered 16O ions have been measured with E(16O) up to 140.4 MeV: see reaction 66 in (71AJ02) and Table 16.25 (in PDF or PS) here. See (GO73A) for a general study of the elastic scattering. The angular distributions corresponding to the excitation of the first four excited states of 16O have been studied at E(16O) = 51.5 MeV (RO74B) and at 140.4 MeV (WI62B). The astrophysical import of the cross section for elastic scattering (and of the total reaction cross section) has been studied by (SP74). For other yield measurements see 32S in (EN78) and (HA74U, RO74B, VA74E). See also (RE73A).
See also (PU71A), (HE69C, BR73N, PE73G, ST73S, ST74H, VO75D), (WO71G, AR73O, CL73C, AR74H, CO74C, AR76A; astrophys. questions) and (AN70H, MO70H, EC71, FL71B, GR71Z, HE71F, MC71, NE71B, RA71, RA71L, RE71J, TO71A, TO71G, AL72P, AR72D, FL72B, MO72C, PE72E, RE72K, SE72, TA72F, YU72, YU72A, BO73D, FI73F, FU73G, LO73B, PA73R, SC73R, VO73E, FL74B, FR74C, GA74I, GL74, KN74B, KO74F, MO74D, SC74, TA74B, VE74F, WA74A, YA74B, AN75G, BR75E, CU75, DE75, FU75B, KU75I, MA75FF, PH75A, SW75, TO75B, TO75H, BA76A, CH76K, CU76B, FE76, GO76F, JA76C, KO76D, SA76A, SA76G, ZI76; theor.).
Angular distributions of elastically scattered ions have been studied at E(16O) = 24, 28 and 32 MeV (GE73F) and E(17O) = 53.0, 57.1, 61.5 and 66 MeV (KA75J) [reaction (a)] and at E(16O) = 24, 28 and 32 MeV (GE72D), 31.5 and 42.0 MeV (RE75D), 39.9, 44.8, 49.9 and 54.8 MeV (SI72A) and 41.8 and 51.9 MeV (VA74B: also 16O*(6.1)), and at E(18O) = 53.1, 57.4, 61.6, 76.5 and 89.3 MeV (KA75J). See also 17O, and 18O in (78AJ03).
See also (FI73D, GO74T, VO75D) and (BA73W, BA74O, BE74F, BO74E, YU74, IM75A, WO75E; theor.) [reaction (a)] and (FI73D, VO73L, VO75D) and (BO73V, MC73F, GE74B, KU74E, GR75L, GL76E, IM76, OH76; theor.) [reaction (b)].
Angular distributions of elastically scattered ions have been studied at E(16O) = 21.4 and 25.8 MeV (MO75N) and at E(19F) = 33 and 36 MeV (GA73J). See also 19F in (78AJ03), (VO73L, VO75D) and (OH76; theor.).
Elastic scattering angular distributions have been measured at E(16O) = 40.7, 51.1 and 59.4 MeV (ZI75A).
Angular distributions for the ground state deuteron group have been studied at Ep = 8.62, 9.56, 10.5, 11.16 and 11.44 MeV (CR75E). At Ep = 31 MeV, angular distributions are reported for the deuterons corresponding to 16O*(0, 6.05 + 6.13, 7.12, 8.87, 10.35, 12.97, 13.26). States at Ex = 15.22 and 15.42 MeV were also observed. Spectroscopic factors were obtained from a DWBA analysis (ME70).
At Ed = 52 MeV the spectrum at 10° is dominated by 16O*(0, 6.13, 8.87, 12.97, 13.26, 18.97, 19.79). 16O*(18.97, 19.79) are assigned Jπ = (4)-; T = 1 and (4); 0, respectively. Spectroscopic factors are given for various of the 16O states (MA74J). See also reaction 29 in 16N, (WA73N) and (HS75, SC76F; theor.).
Angular distributions to many states of 16O have been observed at E(3He) = 11 MeV: see Table 16.22 (in PDF or PS) for l- and S-values (BO71B). At E(3He) = 36 MeV the widths of 16O*(18.97, 19.79) are < 16 and < 37 keV, respectively (DO74M). See also (WA76C) and (71AJ02).
Angular distributions of tritons (reaction (a)) have been measured for Ep to 43.7 MeV: see (71AJ02) for the earlier work and (FL74D: Ep = 20 MeV; t0 --> t5, t7), (PI74B: Ep = 20.0, 24.4, 29.8, 37.5, 43.6 MeV; t1+2, t3+4, t5, t8), (PI73D: Ep = 24.4 MeV (polarized protons); t0, t1+2, t3 --> t5, t7, t8) and (AD72B: Ep = 41.7 MeV; t0, t1+2 and t to 16O*(11.26, 12.05, 16.33, 22.72)). See also (OL70A). Most of the states are more strongly populated than expected on the basis of simple calculations: it is suggested that complete coupled channels calculations may be necessary [see (FL74D, AD72B)]. The population of 16O*(22.7, 24.5) is consistent with L = 0 and 2, respectively, and with assignments of T = 2, Jπ = 0+ and 2+ (CE64B). A study, at Ep = 43 MeV, of decay of the first T = 2 state at Ex = 22.72 MeV shows that it decays via proton emission [reaction (b)] with branchings of 25 ± 6%, 22 ± 5% and 15 ± 5% to 15N*(0, 5.27 + 5.30, 6.32). The α-decay [reaction (c)] is not observed: the branchings to 12C*(0, 4.4) are 1.1 ± 4.0% and 0.0 ± 3.4%. The remaining decay modes have not been determined (KO73). See also (SO73A, MC74G, CH75L, HO75D, IB75, SE75E; theor.) and 19F in (78AJ03).
Angular distributions have been measured at Eα = 58 MeV to 16O*(0, 6.1, 6.92, 7.12). Groups at Ex = 10.4, 13.3 ± 0.1 and 16.3 ± 0.1 MeV were also observed. The cross sections are about a factor of 20 smaller than in the 18O(p, t) reaction but the angular distributions are consistent with a direct transfer mechanism (VA75E). See also (VA75J).
Angular distributions have been reported at many energies to Ep = 44.5 MeV: see Table 16.30 (in PDF or PS) in (71AJ02) and (BR64Q: Ep = 2.06 to 3.30 MeV; α0) and (BU75B: Ep = 13.5 to 18.0 MeV; α0). Observed states of 16O are displayed in Table 16.31 (in PDF or PS) in (71AJ02).
Very accurate γ-ray measurements are reported by (CH67I) [see reaction 55] and (GA70) [the Eγ of the 8.87 --> 6.13 transition is 2741.5 ± 0.5 keV]. The E0 transition (6.05 --> 0; 0+ --> 0+) has been investigated in some detail: the internal conversion to pair production ratio (4.00 ± 0.46) x 10-5 (LE63B). The ratio of double γ-emission to pair production ΓE1E1/ΓE0(τ) < / = 1.1 x 10-4 (AL64J), (2.5 ± 1.1) x 10-4 (WA75H). The τm for 16O*(6.05) = 96 ± 7 psec (BI73Q). An attempt to observe a scalar boson produced in the decay of 16O*(6.05) was unsuccessful; together with other results it demonstrates that the mass of such a boson cannot be 1.030 < / = m < / = 18.2 MeV (KO74T).
16O*(6.13) has also been studied extensively: |g| = 0.55 ± 0.04, τm = 26.6 ± 0.7 psec (BR73M). A search for double positron-electron pair creation by the 6.13 MeV γ-ray was unsuccessful: the ratio of the cross section for production of such a double pair to the cross section for formation of a single pair is -(2 ± 5) x 10-5 (WI72B). See also (BE71AA, VA72S, KA76D). For γ-ray branching ratios and Γγ for these and other transitions see Table 16.15 (in PDF or PS). See also (71AJ02) and 20Ne in (78AJ03).
Angular distributions have been measured at E(3He) = 22.4, 30 and 40.7 MeV (OH72A; g.s.), 28 MeV (KL70A; g.s. of 16O and various 6Li states) and 40.7 MeV (DE71M; to 16O*(6.13, 6.92, 7.12, 8.87, 11.0, 12.5, 13)). See also (YO72).
The ground state angular distribution has been measured at Eα = 42 MeV (MI68E).
Angular distributions have been studied at Ed = 40 MeV (KI73I, EP74A; to 16O*(0, 8.87)). See also (BE75: quote data at 36 MeV). At Ed = 55 MeV, θ = 16°, the spectrum is dominated by 16O*(0, 6.1, 6.9, 9.85). 16O*(8.87, 10.35) are also observed (MC71C). See also (CO75D).
At Eα = 78.6 MeV the reaction goes predominantly to 16Og.s. with a small yield to 16O*(7.1). Quasifree α-α scattering plays an important role in the reaction (EP74).