A=8Be (1988AJ01)

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⁸Be (1988AJ01)

(See Energy Level Diagrams for ⁸Be)

GENERAL: See also (1984AJ01) and Table 8.4 [Table of Energy Levels] (in PDF or PS) here.

Shell model: (1984PA04, 1984VA06, 1984ZW1A, 1985FI1E, 1987BL18, 1987KI1C, 1988WO04).

Collective, rotational and deformed models: (1984PA04, 1985RO1G).

Cluster and α-particle models: (1981PL1A, 1983CA12, 1983DR09, 1983FU1D, 1983HA41, 1983JA09, 1983SH38, 1984DE24, 1984DU17, 1984LU1A, 1984LU1B, 1985FI1E, 1986GU1F, 1986KR12, 1986SU06, 1988KR01).

Special states: (1981PL1A, 1983AD1B, 1983BI1C, 1983FE07, 1983FI11, 1983HA41, 1984DE24, 1984DU17, 1984LU1A, 1984LU1B, 1984VA06, 1984VAZS, 1984ZW1A, 1985FI1E, 1985GO1A, 1985PO19, 1985PU03, 1985RO1G, 1986AN10, 1987KA18, 1987KI1C, 1987SV1A, 1987WA36, 1988BA75, 1988KR01, 1988KW02, 1988KH03).

Electromagnetic transitions, giant resonances: (1983FI11, 1984VA1B, 1985FI1E, 1985GO1A, 1985GR1A, 1986AN10, 1986QUZZ, 1987KI1C).

Astrophysical questions: (1985BO1E, 1987FU04).

Complex reactions involving ⁸Be: (1982GU21, 1983DEZW, 1983EL1A, 1983SI1A, 1983WA1F, 1983XU1A, 1984AB1C, 1984PA13, 1985BU16, 1985HA1N, 1985KA1E, 1985KA1G, 1985KAZQ, 1985KW03, 1985PO11, 1985PO19, 1985WA22, 1986BA2D, 1986BL12, 1986BR26, 1986GA24, 1986GU1F, 1986IR01, 1986MA1O, 1986PO06, 1986PO12, 1986TA1M, 1987AR19, 1987BL16, 1987CH26, 1987CH33, 1987CH32, 1987DE1O, 1987DU07, 1987GE1B, 1987GL05, 1987HA45, 1987PE1B, 1987PO23, 1987RUZX, 1988AR05, 1988POZZ, 1988RU01, 1988SA09, 1988VA1E).

Reactions involving pions and other mesons: (1981MC09, 1983SP06, 1985BE1C, 1987HU12).

Hypernuclei: (1982KA1D, 1983SH38, 1983SH1E, 1984ZH1B, 1985AH1A, 1985IK1A, 1985MO1F, 1986BA1W, 1986DA1B, 1987BA2K, 1987MI38, 1987PO1H, 1987YA1M, 1988TA29).

Other topics: (1983AD1B, 1983BI1C, 1983FU1D, 1983GR26, 1983MI1E, 1985AN28, 1986BL1D, 1986GL1E, 1986MA1W, 1987AB21, 1987SV1A, 1988AJ1B, 1988BO04, 1988KW02, 1988RU1B, 1988RU1D, 1988WA1E).

Ground-state properties of ⁸Be: (1983ANZQ, 1983DR09, 1984DU17, 1984LU1A, 1984LU1B, 1985AN28, 1985FI1E, 1985GO1A, 1985SH1A, 1987BL18, 1987BO42, 1987KI1C, 1987KO1U, 1987SA15, 1987SV1A, 1988AR05, 1988WO04).

1. ⁸Be → ⁴He⁴He Q_m = 0.09189

Γ_c.m. for ⁸Be_g.s. = 6.8 ± 1.7 eV: see (1974AJ01). See also (1987WE1C, 1988BA86; astrophysics) and (1983DR09; theor.).

2. ⁴He(α, γ)⁸Be Q_m = -0.09189

The yield of Γ₁ has been measured for E_α = 32 to 36 MeV. The yield of Γ₀ for E_α = 33 to 38 MeV is twenty times lower than for Γ₁, consistent with E2 decay. An angular correlation measurement at the resonances corresponding to ⁸Be*(16.6 + 16.9) [2⁺; T = 0 + 1] gives δ = 0.19 ± 0.03, Γ_γ(M1) = 6.4 ± 0.5 eV [weighted mean of the two published measurements listed in (1979AJ01)]. The E_x of ⁸Be*(3.0) is determined in this reaction to be 3.18 ± 0.05 MeV [see also Table 8.4 (in PDF or PS) in (1974AJ01)].

The E2 bremsstrahlung cross section to ⁸Be_g.s. has been calculated as a function of E_x over the 3-MeV state: the total Γ_γ for this transition is 8.3 meV, corresponding to 75 W.u. (1986LA05). A calculation of the Γ_γ from the decay of the 4⁺ 11.4-MeV state to the 2⁺ state yields 0.46 eV (19 W.u.). The maximum cross section for the intrastate γ-ray transition within the 2⁺ resonance is calculated to be ≤ 2.5 nb at E_x ≈ 3.3 MeV (1986LA19). See also (1985BA45; theor.).

3. (a) ⁴He(α, n)⁷Be Q_m = -18.990 E_b = -0.09189
(b) ⁴He(α, p)⁷Li Q_m = -17.3462
(c) ⁴He(α, d)⁶Li Q_m = -22.3716

The cross sections for formation of ⁷Li*(0, 0.48) [E_α = 39 to 49.5 MeV] and ⁷Be*(0, 0.43) [39.4 to 47.4 MeV] both show structures at E_α ≈ 40.0 and ≈ 44.5 MeV: they are due predominantly to the 2⁺ states ⁸Be*(20.1, 22.2): see (1979AJ01). The excitation functions for p₀, p₂, d₀, d₁ for E_α = 54.96 to 55.54 MeV have been measured in order to study the decay of the first T = 2 state in ⁸Be: see Table 8.5 (in PDF or PS) in (1984AJ01). Cross sections for p₀₊₁ are also reported at E_α = 37.5 to 140.0 MeV: see (1979AJ01, 1984AJ01). The cross sections for reaction (c) has been measured at three energies in the range E_α = 46.7 to 49.5 MeV: see (1979AJ01) and below.

The production of ⁶Li, ⁷Li and ⁷Be [and ⁶He] has been studied for E_α = 61.5 to 158.2 MeV by (1982GL01) and at 198.4 MeV by (1985WO11). The production of ⁷Li (via reactions (a) and (b)) and of ⁶Li is discussed. At energies beyond E_α ≈ 250 MeV the α + α reaction does not contribute to the natural abundance of lithium, reinforcing theories which produce ⁶Li in cosmic-ray processes and the "missing" ⁷Li in the Big Bang: thus the universe is open (1985WO11, 1982GL01).

The inclusive cross section for production of ³He has been measured at E_α = 218 MeV (1984AL03). For a fragmentation study at 125 GeV see (1985BE1E). See also (1984AJ01, 1984PA1E, 1984RE14).

4. ⁴He(α, α)⁴He E_b = -0.09189

The α-α scattering reveals the ground state as a resonance with Q₀ = 92.12 ± 0.05 keV, Γ_c.m. = 6.8 ± 1.7 eV [τ = (0.97 ± 0.24) × 10^-16 sec]. For E_α = 30 to 70 MeV the l = 0 phase shift shows resonant behavior at E_α = 40.7 MeV, corresponding to a 0⁺ state at E_x = 20.2 MeV, Γ < 1 MeV, Γ_α/Γ < 0.5. No evidence for other 0⁺ states is seen above E_α = 43 MeV.

The d-wave phase shift becomes appreciable for E_α > 2.5 MeV and passes through resonance at E_α = 6 MeV (E_x = 3.18 MeV, Γ = 1.5 MeV, J^π = 2⁺): see Table 8.4 (in PDF or PS) in (1974AJ01). Five 2⁺ levels are observed from l = 2 phase shifts measured from E_α = 30 to 70 MeV: ⁸Be*(16.6, 16.9) with Γ_α = Γ [see Table 8.5 (in PDF or PS)], and states with E_x = 20.1, 22.2 and 25.2 MeV. The latter has a small Γ_α. The l = 2 α-α phase shifts have been analyzed by (1986WA01) up to E_α = 34 MeV: intruder states below E_x = 26 MeV need not be introduced.

The l = 4 phase shift rises from E_α ≈ 11 MeV and indicates a broad 4⁺ level at E_x = 11.5 ± 0.3 MeV [Γ = 4.0 ± 0.4 MeV]. A rapid rise of δ₄ at E_α = 40 MeV corresponds to a 4⁺ state at 19.9 MeV with Γ_α/Γ ≈ 0.96; Γ < 1 MeV and therefore Γ_α < 1 MeV, which is < 5% of the Wigner limit. A broad 4⁺ state is also observed near E_α = 51.3 MeV (E_x = 25.5 MeV).

Over the range E_α = 30 to 70 MeV a gradual increase in δ₆ is observed. Some indications of a 6⁺ state at E_x ≈ 28 MeV and of an 8⁺ state at ≈ 57 MeV have been reported; Γ_c.m. ≈ 20 and ≈ 73 MeV, respectively. A resonance is not observed at the first T = 2 state, ⁸Be*(27.49). See (1979AJ01) for references.

The elastic scattering has also been studied at E_α = 56.3 to 95.5 MeV (1987NE1C; prelim.), 158.2 MeV, 650 and 850 MeV and at 4.32 and 5.07 GeV/c [see (1979AJ01, 1984AJ01)] as well as at 198.4 MeV (1985WO11). For α-α correlations involving ⁸Be*(0, 3.0) see (1987CH33, 1987PO03). See also (1985KR21, 1986FO04, 1986GOZY, 1986UC1A, 1987FO08) and the "General" section here. For inclusive cross sections see (1984AJ01) and (1984AL03; 218 MeV).

For studies at very high energies see reaction 3 and (1982AB1B, 1984SA39, 1984TA1D, 1984TA1G, 1985AB1A, 1985AK1A, 1985CA1C, 1986BE2N, 1986BE1S, 1986BE1T, 1986TA1N, 1986TA1P, 1987BA13). See also (1986CH1M), (1982NA1B, 1983FA1A, 1984FA1B, 1984FR1C, 1985CA41, 1985FA1A, 1985FR1E, 1985WI1B, 1986AN1F, 1986CH1J, 1986ST1D, 1987HE1B, 1987OT1D ), (1985NO1B, 1986LA16, 1987FU04, 1987MU1B; astrophysics) and (1982WE15, 1983AL1C, 1983BU15, 1983FI11, 1983GO25, 1983KO41, 1983MA73, 1983OK06, 1983PR09, 1983SA16, 1984DE24, 1984FI11, 1984FI13, 1984FR10, 1984HE1D, 1984KR10, 1984LI28, 1984MA16, 1984MA1H, 1984MA68, 1984NA11, 1984OK03, 1984TA1E, 1984VAZS, 1984ZA1B, 1985BA45, 1985FI1E, 1985FR1F, 1985HO1B, 1985KI11, 1985PR1A, 1985PR1B, 1985SP05, 1985TH08, 1985YA05, 1985YI1B, 1985YI1C, 1986CR1B, 1986FR12, 1986HO33, 1986LA12, 1986MA03, 1986OC1A, 1986SA30, 1986SU06, 1986WI04, 1986YU1A, 1987BA35, 1987FR1D, 1987KA1W, 1987KR03, 1987OC1B, 1987PR01, 1987SA37, 1987SH1M, 1987WA07, 1988BA75, 1988KR01, 1988MO05; theor.).

5. ⁶Li(d, γ)⁸Be Q_m = 22.2798

The yield of γ-rays to ⁸Be*(17.64) [1⁺; T = 1] has been measured for E_d = 6.85 to 7.10 MeV. A resonance is observed at E_d = 6965 keV [E_x = 27495.8 ± 2.4 keV, Γ_c.m. = 5.5 ± 2.0 keV]; Γ_γ = 23 ± 4 eV [1.14 ± 0.20 W.u.] for this M1 transition from the first 0⁺; T = 2 state in ⁸Be, in good agreement with the intermediate coupling model: see Table 8.5 (in PDF or PS) in (1984AJ01). See also (1979AJ01).

6. ⁶Li(d, n)⁷Be Q_m = 3.381 E_b = 22.2798

Yield curves and cross sections have been measured for E_d = 48 keV to 17 MeV: see (1979AJ01, 1984AJ01). See also (1983SZZY). Polarization measurements are reported at E_d = 0.27 to 3.7 MeV. Comparisons of the populations of ⁷Be*(0, 0.43) and of ⁷Li*(0, 0.48) have been made at many energies, to E_d = 7.2 MeV. The n/p ratios are closely equal for analog states, as expected for charge symmetry: see (1979AJ01). However, the n₁ p₁ yield ratio decreases from 1.05 at E_d = 160 keV to 0.94 at 60 keV: it is suggested that this is due to polarization of the deuteron (1985CE12). See also ⁷Be, (1985WA1C) and (1984KU15; theor.).

7. ⁶Li(d, p)⁷Li Q_m = 5.0255 E_b = 22.2798

Excitation functions have been measured for E_d = 30 keV to 5.4 MeV: see (1979AJ01, 1984AJ01). The thick target yield of 0.48-MeV γ-rays is reported from ≈ 50 to ≈ 170 keV (1985CE12). See also (1983SZZY). An anomaly is observed in the p₁/p₀ intensity ratio at E_d = 6.945 MeV, corresponding to the first 0⁺; T = 2 state, Γ = 10 ± 3 keV, Γ_p₀ ≪ Γ_p₁, Γ_p₀ < Γ_d. Polarization measurements have been reported at E_d = 0.6 to 10.9 MeV: see (1979AJ01). See also ⁷Li and (1984KU15; theor.).

8. (a) ⁶Li(d, d)⁶Li E_b = 22.2798
(b) ⁶Li(d, t)⁵Li Q_m = 0.59

The yield of elastically scattered deuterons has been measured for E_d = 2 to 7.14 MeV. No resonances are observed: see (1974AJ01). See also (1983HA1D, 1985LI1C; theor.). The cross section for tritium production rises rapidly to 190 mb at 1 MeV, then more slowly to 290 mb near 4 MeV: see (1974AJ01). For VAP and TAP measurements at E_{pol. d} = 191 and 395 MeV see (1986GA18).

9. (a) ⁶Li(d, α)⁴He Q_m = 22.3716 E_b = 22.2798
(b) ⁶Li(d, αp)³H Q_m = 2.5576

Cross sections and angular distributions (reaction (a)) have been measured at E_d = 30 keV to 31 MeV: see (1979AJ01, 1984AJ01). See also (1983SZZY). A critical analysis of the low-energy data has led to a calculation of the reaction rate parameters for thermonuclear reactions for plasma temperatures of 2 keV to 1 MeV: see (1984AJ01). Polarization measurements are reported in the range 0.4 to 11 MeV: see (1979AJ01, 1984AJ01) and see below.

Pronounced variations are observed in the cross sections and in the analyzing powers. Maxima are seen at E_d = 0.8 MeV, Γ_lab ≈ 0.8 MeV and E_d = 3.75 MeV, Γ_lab ≈ 1.4 MeV. The 4 MeV peak is also observed in the tensor component coefficients with L = 0, 4 and 8 and in the vector component coefficients: two overlapping resonances are suggested. At higher energies all coefficients show a fairly smooth behavior which suggests that only broad resonances can exist. The results are in agreement with those from reaction 4, that is with two 2⁺ states at E_x = 22.2 and 25.2 MeV and a 4⁺ state at 25.5 MeV. A strong resonance is seen in the α* channel [to ⁴He(20.1), J^π = 0⁺] presumably due to ⁸Be*(25.2, 25.5). In addition the ratio of the α*/α differential cross sections at 30° shows a broad peak centered at E_x ≈ 26.5 MeV (which may be due to interference effects) and suggests a resonance-like anomaly at E_x ≈ 28 MeV. A_yy = 1 points are reported at E_d = 5.55 ± 0.12 (θ_c.m. = 29.7 ± 1.0°) and 8.80 ± 0.25 MeV (θ_c.m. = 90.0 ± 1.0°) [corresponds to E_x = 26.44 and 28.87 MeV]. For references see (1974AJ01, 1979AJ01).

At E_d = 6.945 MeV, the α₀ yield shows an anomaly corresponding to ⁸Be*(27.49), the 0⁺; T = 2 analog of ⁸He_g.s.. This T = 2 state has recently been studied using both polarized deuterons and ⁶Li ions. The ratio of the partial widths for decay into ⁶Li + d states with channel spin 2 and 0, Γ₂/Γ₁ = 0.322 ± 0.091 (1986SO07).

A kinematically complete study of reaction (b) has been reported at E_d = 1.2 to 8.0 MeV: the transition matrix element squared plotted as a function of E_αα* (the relative energy in the channel ⁴He_g.s. + ⁴He*(20.1) [0⁺]) shows a broad maximum at E_x ≈ 25 MeV. Analysis of these results, and of a study of ⁷Li(p, α)α* [see reaction 18] which shows a peak of different shape at E_x ≈ 24 MeV, indicate the formation and decay of overlapping states of high spatial symmetry, if the observed structures are interpreted in terms of ⁸Be resonances: see (1984AJ01). For other work see (1984AJ01). See also ⁶Li, (1986ST1E), (1984VO1A, 1988KU1E; applications) and (1983HA1D, 1984KR1B, 1984KU15; theor.).

10. ⁶Li(t, n)⁸Be Q_m = 16.0225

At E_t = 2 to 4.5 MeV ⁸Be*(0, 3.0, 16.6, 16.9) are populated (1984LIZY; prelim.). See also (1966LA04, 1974AJ01).

11. (a) ⁶Li(³He, p)⁸Be Q_m = 16.7863
(b) ⁶Li(³He, p)⁴He⁴He Q_m = 16.8782

Angular distributions have been studied in the range E(³He) = 0.46 to 17 MeV and at E(pol. ⁶Li) = 21 MeV. ⁸Be*(0, 3.0, 16.63, 16.92, 17.64, 18.15, 19.0, 19.4, 19.9) are populated in this reaction: see (1974AJ01, 1979AJ01, 1984AJ01). For reaction (b) see (1974AJ01) and (1987ZA07). See also ⁹B.

12. (a) ⁶Li(α, d)⁸Be Q_m = -1.5669
(b) ⁶Li(α, 2α)²H Q_m = -1.4750

Deuteron groups have been observed to ⁸Be*(0, 3.0, 11.3 ± 0.4). Angular distributions have been measured at E_α = 15.8 to 48 MeV: see (1974AJ01, 1979AJ01). A study of reaction (b) shows that the peak due to ⁸Be*(3.0) is best fitted by using Γ = 1.2 ± 0.3 MeV. At E_α = 42 MeV the α-α FSI is dominated by ⁸Be*(0, 3.0). See also Table 8.4 (in PDF or PS) in (1974AJ01) and (1983BE51; theor.).

13. (a) ⁶Li(⁶Li, α)⁸Be Q_m = 20.805
(b) ⁶Li(⁶Li, α)⁴He⁴He Q_m = 20.897
(c) ⁶Li(⁶Li, 2d)⁴He⁴He Q_m = -2.950

At E_max(⁶Li) = 13 MeV reaction (a) proceeds via ⁸Be*(0, 3.0, 16.6, 16.9, 22.5). The involvement of a state at E_x = 19.9 MeV (Γ = 1.3 MeV) is suggested. Good agreement with the shapes of the peaks corresponding to ⁸Be*(16.6, 16.9) is obtained by using a simple two-level formula with interference, corrected for the effect of final-state Coulomb interaction, assuming Γ(16.6) = 90 keV and Γ(16.9) = 70 keV: see also Table 8.5 (in PDF or PS). The ratio of the intensities of the groups corresponding to ⁸Be*(16.6, 16.9) remains constant for E(⁶Li) = 4.3 to 5.5 MeV: I(16.6)/I(16.9) = 1.22 ± 0.08. Partial angular distributions for the α₀ group have been measured at fourteen energies for E(⁶Li) = 4 to 24 MeV. See (1979AJ01) for the references.

At E(⁶Li) = 36 to 46 MeV sequential decay (reaction (b)) via ⁸Be states at E_x = 3.0, 11.4, 16.9 and 19.65 MeV is reported: see (1984AJ01). (1987LA25) report the possible involvement of the 2⁺ state ⁸Be*(22.2).

For reaction (c) see (1983WA09) and ¹²C in (1985AJ01). See also (1983MI10) and (1982LA19, 1985NO1A; theor.).

14. ⁷Li(p, γ)⁸Be Q_m = 17.2543

Cross sections and angular distributions have been reported from E_p = 30 keV to 18 MeV. Gamma rays are observed to the ground (Γ₀) and to the broad, 2⁺, excited state at 3.0 MeV (Γ₁) and to ⁸Be*(16.6, 16.9) (Γ₃, Γ₄). Resonances for both Γ₀ and Γ₁ occur at E_p = 0.44 and 1.03 MeV, and for Γ₁ alone at 2, 4.9, 6.0, 7.3, and possibly at 3.1 and 11.1 MeV. In addition broad resonances are reported at E_p ≈ 5 MeV (Γ₀), Γ ≈ 4-5 MeV, and at E_p ≈ 7.3 MeV (Γ₁), Γ ≈ 8 MeV: see Table 8.6 (in PDF or PS). The E_p ≈ 5 MeV resonance (E_x ≈ 22 MeV) represents the giant dipole resonance based on ⁸Be(0) while the Γ₁ resonance, ≈ 2.2 MeV higher, is based on ⁸Be*(3.0). The Γ₀ and Γ₁ giant resonance peaks each contain about 10% of the dipole sum strength. The main trend between E_p = 8 and 17.5 MeV is a decreasing cross section.

At the E_p = 0.44 MeV resonance (E_x = 17.64 MeV) the radiation is nearly isotropic consistent with p-wave formation, J^π = 1⁺, with channel spin ratio σ(J_c = 2)/σ(J_c = 1) = 3.2 ± 0.5. Radiative widths for the Γ₀ and Γ₁ decay are displayed in Table 8.7 (in PDF or PS). A careful study of the α-breakup of ⁸Be*(16.63, 16.92) [both J^π = 2⁺] for E_p = 0.44 to 2.45 MeV shows that the non-resonant part of the cross section for production of ⁸Be*(16.63) is accounted for by an extranuclear direct-capture process. Resonances for production of ⁸Be*(16.63, 16.92) are observed at E_p = 0.44, 1.03 and 1.89 MeV [⁸Be*(17.64, 18.15, 18.9)]. The results are consistent with the hypothesis of nearly maximal isospin mixing for ⁸Be*(16.63, 16.92): decay to these states is not observed from the 3⁺ states at E_x = 19 MeV, but rather from the 2^- state at E_x = 18.9 MeV. Squared T = 1 components calculated for ⁸Be*(16.6, 16.9) are 40 and 60%, and 95 and 5% for ⁸Be*(17.6, 18.2). The cross section for (γ₃ + γ₄) has also been measured for E_p =11.5 to 30 MeV (θ = 90°) by detecting the γ-rays and for E_p = 4 to 13 MeV (at five energies) by detecting the two α-particles from the decay of ⁸Be*(16.6, 16.9): a broad bump is observed at E_p = 8 ± 2 MeV (1981MA33). The angle and energy integrated yield only exhausts 8.6% of the classical dipole sum for E_p = 4 to 30 MeV, suggesting that this structure does not represent the GDR built on ⁸Be*(16.6, 16.9). A weak, very broad [Γ ≥ 20 MeV] peak may also be present at E_x = 20 - 30 MeV. A direct capture calculation adequately describes the observed cross section (1981MA33). A study of the γ-decay of ⁸Be*(17.64, 18.15) shows no evidence for a pseudoscalar particle postulated to account for narrow peaks in e⁺ spectra in heavy-ion reactions (1988SA2A). For the earlier references see (1979AJ01). See also (1983CH1C), (1986WE1D), (1984DA1H; astrophysics), (1988KI1C; applied) and (1983GO1B, 1984SE16, 1985GO1B, 1987KI1C; theor.).

15. ⁷Li(p, n)⁷Be Q_m = -1.644 E_b = 17.2543

Measurements of cross sections have been reported for E_p = 1.9 to 199.1 MeV [see (1974AJ01, 1979AJ01, 1984AJ01)] and in the range 60.1 to 480.0 MeV (1984DA22; activation σ). Polarization measurements have been reported at E_p = 2.05 to 5.5 MeV, 30 and 50 MeV [see (1974AJ01)] and at E_{pol. p} = 52.8 MeV (1988HE08) [K_z^z' = 0.07 ± 0.02]. See also below.

The yield of ground state neutrons (n₀) rises steeply from threshold and shows pronounced resonances at E_p = 2.25 and 4.9 MeV. The yield of n₁ also rises steeply from threshold and exhibits a broad maximum near E_p = 3.2 MeV and a broad dip at E_p ≈ 5.5 MeV, also observed in the p₁ yield. Multi-channel scattering length approximation analysis of the 2^- partial wave near the n₀ threshold indicates that the 2^- state at E_x = 18.9 MeV is virtual relative to the threshold and that its width Γ = 50 ± 20 keV. The ratio of the cross section for ⁷Li(p, γ)⁸Be*(18.9) → ⁸Be*(16.6 + 16.9) + Γ to the thermal neutron capture cross section ⁷Be(n, γ)⁸Be*(18.9) → ⁸Be*(16.6 + 16.9) + Γ, provides a rough estimate of the isospin impurity of ⁸Be*(18.9): σ_p, Γ/σ_n, Γ ≈ 1.5 × 10^-5. The T = 1 isospin impurity is ≤ 10% in intensity. See also reaction 23. See (1979AJ01, 1984AJ01).

The structure at E_p = 2.25 MeV is ascribed to a 3⁺, T = (1), l = 1 resonance with Γ_n ≈ Γ_p and Γ²_n/Γ²_p = 3 to 10: see (1966LA04). At higher energies the broad peak in the n₀ yield at E_p =4.9 MeV can be fitted by J^π = 3⁽⁺⁾ with Γ = 1.1 MeV, Γ²_n ≈ Γ²_p. The behavior of the n₁ cross section can be fitted by assuming a 1^- state at E_x = 19.5 MeV and a J = 0, 1, 2, positive-parity state at 19.9 MeV [presumably the 20.1 - 20.2 MeV states reported in reaction 4]. In addition the broad dip at E_p ≈ 5.5 MeV may be accounted for by the interference of two 2⁺ states. See Table 8.8 (in PDF or PS) in (1979AJ01). The 0° differential cross section increases rapidly to ≈ 35 mb/sr at 30 MeV and then remains constant to 100 MeV: see (1985BO1C). The total reaction cross section [⁷Be*(0, 0.43)] decreases inversely with E_p in the range 60.1 to 480.0 MeV (1984DA22) [note: the values of σ_t supersede those reported earlier]. The transverse polarization transfer, D_NN (0°), for the g.s. transition has been measured at E_{pol. p} = 160 MeV (1984TA07). See also (1986MC09; E_{pol. p} = 800 MeV), (1987WAZT), 1984BA1U), (1985CA41; astrophysics), (1983LO12; applications), (1986RA21, 1987TA22) and (1988GU1F; theor.).

16. (a) ⁷Li(p, p)⁷Li E_b = 17.2543
(b) ⁷Li(p, p')⁷Li

Absolute differential cross sections for elastic scattering have been reported for E_p = 0.4 to 12 MeV and at 14.5, 20.0 and 31.5 MeV. The yields of inelastically scattered protons (to ⁷Li*(0.48)) and of 0.48 MeV γ-rays have been measured for E_p = 0.8 to 12 MeV: see (1974AJ01). Polarization measurements have been reported at a number of energies in the range E_p = 0.67 MeV to 2.1 GeV/c [see (1974AJ01, 1979AJ01, 1984AJ01)], at E_{pol. p} = 1.89 to 2.59 MeV (1986SA1P; p₀; prelim.) and at 65 MeV (1987TO06; continuum; prelim.). See also (1983GLZZ).

Anomalies in the elastic scattering appear at E_p = 0.44, 1.03, 1.88, 2.1, 2.5, 4.2 and 5.6 MeV. Resonances at E_p = 1.03, 3 and 5.5 MeV and an anomaly at E_p = 1.88 MeV appear in the inelastic channel. A phase-shift analysis and a review of the cross-section data show that the 0.44 and 1.03 MeV resonances are due to 1⁺ states which are a mixture of ⁵P₁ and ³P₁ with a mixing parameter of +25° ; that the 2^- state at the neutron threshold (E_p = 1.88 MeV) has a width of about 50 keV [see also reaction 14]; and that the E_p = 2.05 MeV resonance corresponds to a 3⁺ state. The anomalous behavior of the ⁵P₃ phase around E_p = 2.2 MeV appears to result from the coupling of the two 3⁺ states [resonances at E_p = 2.05 and 2.25 MeV]. The ³S₁ phase begins to turn positive after 2.2 MeV suggesting a 1^- state at E_p = 2.5 MeV: see Table 8.8 (in PDF or PS). The polarization data show structures at E_p = 1.9 and 2.3 MeV. A phase-shift analysis of the (p, p) data finds no indication of a possible 1^- state with 17.4 < E_x < 18.5 MeV [see, however, reaction 15 in (1979AJ01)].

An attempt has been made to observe the T = 2 state [⁸Be*(27.47)] in the p₀, p₁ and p₂ yields. None of these shows the effect of the T = 2 state. Table 8.5 (in PDF or PS) in (1984AJ01) displays the upper limit for Γ_p₀/Γ.

The proton total reaction has been reported for E_p = 25.1 to 48.1 MeV by (1985CA36). (1987CH33, 1987PO03) have studied p-⁷Li correlations involving ⁸Be*(17.64, 18.15, 18.9 + 19.1 + 19.2). See also ⁷Li, (1984BA1U), (1986BA88), (1986RA1D; applications) and (1986HA1K, 1988GU1F; theor.) and the "General" section here.

17. ⁷Li(p, d)⁶Li Q_m = -5.025 E_b = 17.2543

The excitation function for d₀ measured for E_p = 11.64 to 11.76 MeV does not show any effect from the T = 2 state [⁸Be*(27.47)]: see (1979AJ01). See also (1984BA1T)

18. ⁷Li(p, α)⁴He Q_m = 17.3462 E_b = 17.2543

The cross section increases from (4.3 ± 0.9) × 10^-5 mb at E_p = 28.1 keV to 6.33 mb at 998 keV. Astrophysical S-factors have been calculated over that range: S(0) = 52 ± 8 keV · b (1986RO13). For the earlier work see (1984AJ01).

Excitation functions and angular distributions have been measured at many energies in the range E_p = 23 keV to 62.5 MeV: see (1979AJ01, 1984AJ01). Polarization measurements have been carried out for E_p = 0.8 to 10.6 MeV [see (1974AJ01)]: in the range E_p = 3 to 10 MeV the asymmetry has one broad peak in the angular distribution at all energies except near 5 MeV; the peak value is 0.98 ± 0.04 at 6 MeV and is essentially 1.0 for E_p = 8.5 to 10 MeV.

Broad resonances are reported to occur at E_p = 3.0 MeV [Γ ≈ 1 MeV] and at ≈ 5.7 MeV [Γ ≈ 1 MeV]. Structures are also reported at E_p = 6.8 MeV and at E_p = 9.0 MeV: see (1979AJ01). The 9.0 MeV resonance is also reflected in the behavior of the A₂ coefficient. The experimental data on yields and on polarization appear to require including two 0⁺ states [at E_x ≈ 19.7 and 21.8 MeV] with very small α-particle widths, and four 2⁺ states [at E_x ≈ 15.9, 20.1, 22.2 and 25 MeV]. See, however, reaction 4. A 4⁺ state near 20 MeV was also introduced in the calculation but its contribution was negligible. The observed discrepancies are said to be probably due to the assumption of pure T = 0 for these states. At E_p = 11.64 to 11.76 MeV the excitation function does not show any effect due to the T = 2 state at E_x = 27.47 MeV. See (1979AJ01) for references.

A study of the ⁷Li(p, α)⁴He* reaction to ⁴He*(20.1) [0⁺] at E_p = 4.5 to 12.0 MeV shows a broad maximum at E_x ≈ 24 MeV: see reaction 9 and (1984AJ01). See also (1986ZA09), (1984HA1M, 1984YA1A, 1985BO1K, 1985CA41, 1985DE1K, 1986BO1H, 1987AS05, 1987KA1R, 1987RO25, 1988BA86, 1988FO1A; astrophysics), (1986RA1D, 1986ST1E, 1986TU1B; applications) and (1984BL21, 1984KR1B; theor.).

19. (a) ⁷Li(d, n)⁸Be Q_m = 15.0297
(b) ⁷Li(d, n)⁴He⁴He Q_m = 15.1216

The population of ⁸Be*(0, 3.0, 16.6, 16.9, 17.6, 18.2, 18.9, 19.1, 19.2) has been reported in reaction (a). For the parameters of ⁸Be*(3.0) see Table 8.4 (in PDF or PS) in (1974AJ01). Angular distributions of n₀ and n₁ have been reported at E_d = 0.7 to 3.0 MeV and at E_d = 15.25 MeV [see (1974AJ01, 1979AJ01)] and at 0.19 MeV (1983DA32, 1987DA25) and 0.40 and 0.46 MeV (1984GA07; n₀ only). The angular distributions of the neutrons to ⁸Be*(16.6, 17.6, 18.2) are fit by l_p = 1: see (1974AJ01).

Reaction (b) at E_d = 2.85 to 14.97 MeV proceeds almost entirely through the excitation and sequential decay of ⁸Be*(16.6, 16.9) (1987WA21). ⁸Be*(11.4) may also be involved [E_x = 11.4 ± 0.05 MeV, Γ_c.m. = 2.8 ± 0.2 MeV] as may state(s) at E_x ≈ 20 MeV: see (1979AJ01). See also ⁹Be, (1983BL17, 1986BA40), (1986LE1E; applications) and (1983MU13, 1984BL21; theor.).

20. (a) ⁷Li(³He, d)⁸Be Q_m = 11.7608
(b) ⁷Li(³He, αd)⁴He Q_m = 11.8527

Deuteron groups are observed to ⁸Be*(0, 3.0, 16.6, 16.9, 17.6, 18.2). For the parameters of ⁸Be*(3.0) see Table 8.4 (in PDF or PS) in (1974AJ01). For the J^π = 2⁺ mixed isospin states see Table 8.5 (in PDF or PS). Angular distributions have been measured for E(³He) = 0.9 to 24.3 MeV and at E(pol. ³He) = 33.3 MeV: see (1974AJ01, 1979AJ01, 1984AJ01). Reaction (b) has been studied at E(³He) = 5.0 MeV (1985DA29) and at 9, 11 and 12 MeV (1986ZA09). ⁸Be*(0, 3.0) are reported to be involved (1985DA29). See also ¹⁰B and (1983KU17; theor.).

21. (a) ⁷Li(α, t)⁸Be Q_m = -2.5597
(b) ⁷Li(α, αt)⁴He Q_m = -2.4678

Angular distributions have been measured to E_α = 50 MeV: see (1966LA04, 1974AJ01, 1979AJ01). The ground state of ⁸Be decays isotropically in the c.m. system: J^π = 0⁺. Sequential decay (reaction (b)) is reported at E_α = 50 MeV via ⁸Be*(0, 3.0, 11.4, 16.6, 16.9, 19.9): see (1974AJ01). See also (1983BE51, 1985PU03; theor.).

22. ⁷Li(⁷Li, ⁶He)⁸Be Q_m = 7.280

⁸Be*(0, 3.0) have been populated in this reaction (1987BO1M; E(⁷Li) = 22 MeV). See also (1988AL1G).

23. (a) ⁷Be(n, p)⁷Li Q_m = 1.644 E_b = 18.8985
(b) ⁷Be(n, α)⁴He Q_m = 18.9905
(c) ⁷Be(n, γα)⁴He Q_m = 18.9905

The total (n, p) cross section has been measured from 25 × 10^-3 eV to 13.5 keV. For thermal neutrons the cross sections to ⁷Li*(0, 0.48) are 38 400 ± 800 and 420 ± 120 b, respectively. A departure from a 1/v shape in σ_t is observed for E_n > 100 eV. The astrophysical reaction rate is ≈ 1/3 lower than that previously used: this could lead to an increase in the calculated rate of production of ⁷Li in the Big Bang by as much as 20%. A multi-level R-matrix analysis of the data indicates Γ = 122 keV for the 2^- state ⁸Be*(18.9), and a T = 1 impurity of ≈ 24% (1988KO03). At thermal energies the (n, α) cross section is ≤ 0.1 mb and the (n, γα) cross section is 155 mb: see (1974AJ01). See also (1987GLZZ, 1987GL1D), (1979AJ01, 1988BO15) and (1984YA1A, 1985BO1K, 1985DE1K; astrophysics).

24. ⁸Li(β^-)⁸Be Q_m = 16.0039

⁸Li decays to the broad 3.0 MeV, 2⁺ level of ⁸Be, which decays into two α-particles. Both the β-spectrum and the resulting α-spectrum have been extensively studied: see (1955AJ61, 1966LA04). See also ⁸B(β⁺). Studies of the distribution of recoil momenta and neutrino recoil correlations indicate that the decay is overwhelmingly GT, axial vector [see reaction 1 in ⁸Li] and that the ground state of ⁸Li has J^π = 2⁺: see (1980MC07).

(1986WA01) has performed a many-level one-channel approximation R-matrix analysis of the β-delayed α-particle spectra in the decay of both ⁸Li and ⁸B, obtained by (1971WI05) [as well as of the L = 2 α-α phase shifts]. Warburton finds that there is no need to introduce "intruder" states below E_x ≈ 26 MeV [see, e.g., (1974AJ01)]. He extracts the GT matrix elements for the decay to ⁸Be*(3.0) and the doublet near 16 MeV; and he points out the difficulties in extracting meaningful E_x and γ values from the β^± decay for ⁸Be*(3.0), as well as the log ft values for the transitions to that state (1986WA01).

Beta-α angular correlations have been measured for the decays of ⁸Li and ⁸B for the entire final-state distribution: see Table 8.10 (in PDF or PS) in (1979AJ01). (1980MC07) have measured the β-ν-α correlations as a function of E_x in the decay of ⁸Li and ⁸B, detecting both α-particles involved in the ⁸Be decay. They find that the decay is GT for 2 < E_x < 8 MeV. The absence of Fermi decay strength is expected because the isovector contributions from the tails of ⁸Be*(16.6, 16.9) interfere destructively in this energy region: see (1980MC07). The measurement of the β-decay asymmetry as a function of E_β is reported by (1986BI1D, 1985BIZZ; prelim.). (1986NAZZ; prelim.) have measured the β-spectrum and compared it with the spectrum predicted from the α-breakup data. See also (1984KO25, 1985GR1A), (1986HA1P, 1988WA1E), (1986MA1T, 1986NAZZ; astrophysics) and (1983KU17, 1984BA25, 1986QUZZ, 1987LY05, 1988BA75; theor.).

25. ⁸B(β⁺)⁸Be Q_m = 17.979

The decay [see reaction 1 in ⁸B] proceeds mainly to ⁸Be*(3.0) [see Table 8.4 (in PDF or PS) in (1974AJ01) for its parameters]. Detailed study of the high-energy portion of the α-spectrum reveals a maximum near E_α = 8.3 MeV, corresponding to transitions to ⁸Be*(16.63), for which parameters E_x = 16.67 MeV, Γ = 150 to 190 keV or E_x = 16.62 MeV, Γ = 95 keV are derived: see (1974AJ01). Log ft for the transition to ⁸Be*(16.6) is 3.3. An analysis by (1986WA01) of the β⁺ delayed α-spectrum is described in reaction 24. See also (1988WA1E) and (1988BA75; theor.). The β⁺ spectrum has been measured by (1987NA08) for momenta greater than 9 MeV/c. Then using the α spectra from (1986WA01) the ⁸B neutrino spectrum is calculated. The average cross section for the "solar neutrino" ³⁷Cl(ν_e, e^-)³⁷Ar reaction is then (1.07 ± 0.02) × 10^-42 cm² [certain corrections may increase this value by as much as 4%] (1987NA08). See also (1982BA1J, 1983CO1D, 1983FO1A, 1983HA1B, 1983VO1C, 1984DA1H, 1984HA1M, 1985BA1N, 1985BA1M, 1985CH1B, 1986BA21, 1986BE1K, 1986DE1H, 1986GR04, 1986HA1I, 1986MA1T, 1986RO1N, 1986WO1B, 1987BA1X, 1987BA89, 1987CH1G, 1987FR1C, 1987FU1G, 1987KR10, 1987RI1E, 1987WE1C, 1988BA86, 1988EW1A, 1988HA1M; astrophysics).

26. (a) ⁹Be(γ, n)⁸Be Q_m = -1.6654
(b) ⁹Be(n, 2n)⁸Be Q_m = -1.6654
(c) ⁹Be(p, pn)⁸Be Q_m = -1.6654
(d) ⁹Be(t, tn)⁸Be Q_m = -1.6654
(e) ⁹Be(α, αn)⁸Be Q_m = -1.6654

Neutron groups to ⁸Be*(0, 3.0) have been studied for E_γ = 18 to 26 MeV: see (1974AJ01, 1979AJ01) and ⁹Be. Reaction (b) appears to proceed largely via excited states of ⁹Be with subsequent decay mainly to ⁸Be*(3.0): see (1966LA04, 1974AJ01), ⁹Be and ¹⁰Be. Reaction (c) has been studied at E_p = 45 and 47 MeV: the reaction primarily populates ⁸Be*(0, 3.0): see (1979AJ01), ⁹Be and ⁹B. For work at E_p = 1 GeV see (1985BE30, 1985DO16). For reactions (d) and (e) see (1974AJ01) and ⁹Be. For reaction (e) see (1979AJ01).

27. (a) ⁹Be(p, d)⁸Be Q_m = 0.5592
(b) ⁹Be(p, pn)⁸Be Q_m = -1.6654
(c) ⁹Be(p, d)⁴He⁴He Q_m = 0.6511

Angular distributions of deuteron groups have been reported at E_p = 0.11 to 185 MeV [see (1974AJ01, 1979AJ01, 1984AJ01)] and at 18.6 MeV (1986GO23, 1987GO27; d₀ and d₁) and 50 and 72 MeV (1984ZA07; to ⁸Be*(0, 3.0, 16.9, 19.2)). For spectroscopic factors see (1979AJ01, 1984ZA07). The angular distributions to ⁸Be*(0, 3.0, 16.9, 17.6, 18.2, 19.1) are consistent with l_n = 1: see (1974AJ01).

An anomalous group is reported in the deuteron spectra between the d₀ and the d₁ groups. At E_p = 26.2 MeV, its (constant with θ) E_x = 0.6 ± 0.1 MeV. Analyses of the spectral shape and transfer cross sections are consistent with this "ghost" feature being part of the Breit-Wigner tail of the J^π = 0⁺ ⁸Be_g.s.: it contains < 10% of the g.s. transfer strength. An analysis of reported Γ_c.m. for ⁸Be*(3.0) in this reaction shows that there is no E_p dependence. The average Γ_c.m. at E_p = 14.3 and 26.2 MeV is 1.47 ± 0.04 MeV. Γ_c.m. = 5.5 ± 1.3 eV for ⁸Be_g.s. and 5.2 ± 0.1 MeV for ⁸Be*(11.4). Spectroscopic factors for ⁸Be_g.s. (including the "ghost" anomaly) and ⁸Be*(3.0) are 1.23 and 0.22 respectively at E_p = 14.3 MeV, and 1.53 and 1.02 respectively at E_p = 26.2 MeV. The width of ⁸Be*(3.0) is not appreciably (< 10%) reaction dependent but the nearness of the decay threshold indicates that care must be taken in comparing decay widths from reaction and from scattering data: E_R = 3130 ± 25 keV (resonance energy in the α+α c.m. system) [E_x = 3038 ± 25 keV] and Γ_c.m. = 1.50 ± 0.02 MeV for ⁸Be*(3.0): the corresponding observed and formal reaction widths and channel radii are Γ_R² = 580 ± 50 keV, Γ_λ² = 680 ± 100 keV and s = 4.8 fm. See (1979AJ01) for the earlier work. A study of the continuum part of the inclusive deuteron spectra is reported at E_{pol. p} = 60 MeV (1987KA25). For reaction (b) see (1988BO47). For reaction (c) [FSI through ⁸Be*(0, 3.0)] see (1974AJ01, 1984AJ01). See also (1985PU03; theor.) and ¹⁰B.

28. (a) ⁹Be(d, t)⁸Be Q_m = 4.5919
(b) ⁹Be(d, t)⁴He⁴He Q_m = 4.6838

Angular distributions have been measured for E_d = 0.3 to 28 MeV [see (1979AJ01)], at E_d = 18 MeV (1988GO02; t₀, t₁) and at E_{pol. d} = 2.0 to 2.8 MeV (1984AN16; t₀). At E_d = 28 MeV angular distributions of triton groups to ⁸Be*(16.6, 16.9, 17.6, 18.2, 19.1, 19.2, 19.8) have been analyzed using DWUCK: absolute C²S are 0.074, 1.56, 0.22, 0.17, 0.41, 0.48, 0.40 respectively. See also Table 8.5 (in PDF or PS). An isospin amplitude impurity of 0.21 ± 0.03 is found for ⁸Be*(17.6, 18.2): see (1979AJ01).

A kinematically complete study of reaction (b) at E_d = 26.3 MeV indicates the involvement of ⁸Be*(0, 3.0, 11.4, 16.9, 19.9 + 20.1): see (1974AJ01). (1986PAZN; prelim.) report E_x = 3.10 ± 0.15 MeV, Γ ≈ 0.9 - 1.3 MeV. See also (1988NE1A; theor.).

29. (a) ⁹Be(³He, α)⁸Be Q_m = 18.9124
(b) ⁹Be(³He, α)⁴He⁴He Q_m = 19.0043

Angular distributions have been measured in the range E(³He) = 3.0 to 26.7 MeV and at E(pol. ³He) = 33.3 MeV (to ⁸Be*(16.9, 17.6, 19.2)) [S = 1.74, 0.72, 1.17, assuming mixed isospin for ⁸Be*(16.9)]. The possibility of a broad state at E_x ≈ 25 MeV is also suggested: see (1979AJ01). See also (1987VA1I).

Reaction (b) has been studied at E(³He) = 1.0 to 10 MeV [see (1979AJ01, 1984AJ01)], at E(³He) = 3 to 12 MeV (1986LA26) and at 11.9 to 24.0 MeV (1987WA25). The reaction is reported to proceed via ⁸Be*(0, 3.0, 11.4, 16.6, 16.9, 19.9, 22.5): see (1979AJ01) and (1986LA26, 1987WA25). For a discussion of the width of ⁸Be*(11.4) see (1987WA25). See also ⁹Be, and ¹²C in (1980AJ01), (1985MC1C, applications) and (1985PU03; theor.).

30. (a) ⁹Be(⁶Li, ⁷Li)⁸Be Q_m = 5.585
(b) ⁹Be(⁷Li, ⁸Li)⁸Be Q_m = 0.367
(c) ⁹Be(⁹Be, ¹⁰Be)⁸Be Q_m = 5.1466

Angular distributions have been studied at E(⁶Li) = 32 MeV involving ⁸Be*(0, 3.0) and ⁷Li*(0, 0.48) (1985CO09). For reaction (b) see (1984KO25). For reaction (c) see ¹⁰Be (1985JA09). For the earlier work see (1979AJ01).

31. ¹⁰Be(p, t)⁸Be Q_m = 0.0045

Angular distributions for the transition to the first T = 2 state ⁸Be*(27.49), and to ⁸Li*(10.82) reached in the (p, ³He) reaction, are very similar. They are both consistent with L = 0 using a DWBA (LZR) analysis: see (1979AJ01, 1984AJ01) and Table 8.5 (in PDF or PS) in (1984AJ01).

32. ¹⁰Be(π⁺, 2p)⁸Be Q_m = 132.100

See (1988RIZZ; prelim).

33. ¹⁰B(n, t)⁸Be Q_m = 0.2307

The breakup of ¹⁰B by 14.4 MeV neutrons involves, among others, ⁸Be_g.s. (1984TU02). See also (1979AJ01) and ¹¹B in (1990AJ01).

34. ¹⁰B(p, ³He)⁸Be Q_m = -0.5332

Angular distributions of the ³He ions to ⁸Be*(0, 3.0, 16.6, 16.9) have been studied at E_p = 39.4 MeV [see (1974AJ01)] and at E_p = 51.9 MeV (1983YA05; see for a discussion of isospin mixing of the 16.8 MeV states).

35. (a) ¹⁰B(d, α)⁸Be Q_m = 17.8202
(b) ¹⁰B(d, α)⁴He⁴He Q_m = 17.9121

Angular distributions have been reported at E_d = 0.5 to 7.5 MeV: see (1974AJ01, 1979AJ01). At E_d = 7.5 MeV the population of ⁸Be*(16.63, 16.92) is closely the same consistent with their mixed isospin character while ⁸Be*(17.64) is relatively weak consistent with its nearly pure T = 1 character. ⁸Be*(16.63, 16.92, 17.64, 18.15) have been studied for E_d = 4.0 to 12.0 MeV. Interference between the 2⁺ states [⁸Be*(16.63, 16.92)] varies as a function of energy. The cross-section ratios for formation of ⁸Be*(17.64, 18.15) vary in a way consistent with a change in the population of the T = 1 part of the wave function over the energy range: at the higher energies, there is very little isospin violation. At higher E_x only the 3⁺ state at E_x = 19.2 MeV is observed, the neighboring 3⁺ state at E_x = 19.07 MeV is not seen. Γ_16.6 = 90 ± 5 keV, Γ_16.9 = 70 ± 5 keV, ΔQ = 290 ± 7 keV: see Table 8.5 (in PDF or PS) and (1979AJ01).

Reaction (b) [E_d < 5 MeV] takes place mainly by a sequential process involving ⁸Be*(0, 2.9, 11.4, 16.6, 16.9): see (1979AJ01). See also (1983DA11). [The work quoted in (1984AJ01) has not been published.] At E_d = 13.6 MeV in addition to ⁸Be*(16.6, 16.9), states with E_x ≈ 19.9 - 20.2 MeV with Γ ≈ 0.7 - 1.1 MeV are involved (1988KA1K; prelim.). See also (1984SH1D, 1984SHZJ) and (1985PU03, 1988BA75, 1988KA1M; theor.).

36. ¹⁰B(α, ⁶Li)⁸Be Q_m = -4.552

See ⁶Li here and reaction 40 in (1984AJ01). See also (1984SH1D, 1988SH1E).

37. (a) ¹¹B(p, α)⁸Be Q_m = 8.5906
(b) ¹¹B(p, α)⁴He⁴He Q_m = 8.6825

Angular distributions have been measured at E_p = 0.78 to 45 MeV [see (1974AJ01, 1979AJ01, 1984AJ01)], at E = 0.12 to 1.10 MeV (1987BE17; ¹¹B and p; α₀, α₁) and at E_p = 4.5 to 7.5 MeV (1983BO19; α₀). Reaction (b) has been studied for E_p = 0.15 to 20 MeV: see (1974AJ01, 1984AJ01). The reaction proceeds predominantly by sequential two-body decay via ⁸Be*(0, 3.0). See also ¹²C in (1990AJ01) and (1983CO1A, 1985MAZG, 1985PU03; theor.).

38. ¹¹B(³He, ⁶Li)⁸Be Q_m = 4.5721

At E(³He) = 71.8 MeV angular distributions of the ⁶Li ions to ⁸Be*(0, 3.0, 16.6, 16.9, 17.6, 18.2) are reported (1986JA14). For the earlier work at 25.6 MeV see (1979AJ01). See also (1986JA02).

39. ¹¹B(α, ⁷Li)⁸Be Q_m = -8.7556

The work reported in (1984AJ01) has not been published. See also ⁷Li here and (1984SH1D, 1988SH1E).

40. ¹¹B(⁹Be, ¹²B)⁸Be Q_m = 1.705

See (1984DA17) and ¹²B in (1990AJ01).

41. (a) ¹²C(n, nα)⁸Be Q_m = -7.3666
(b) ¹²C(p, pα)⁸Be Q_m = -7.3666
(c) ¹²C(p, d³He)⁸Be Q_m = -25.7198

The first two of these reactions involve ⁸Be*(0, 3.0): see (1974AJ01, 1979AJ01, 1984AJ01), reactions 39 and 42 in ¹²C in (1985AJ01). See also (1986AN22) [reaction (a)] and (1982ZH06, 1985GA1B, 1986VD01; theor.). For reaction (c) see (1983LI18; theor.).

42. (a) ¹²C(d, ⁶Li)⁸Be Q_m = -5.8916
(b) ¹²C(d, dα)⁸Be Q_m = -7.3666

Angular distributions have been studied at E_d = 12.7 to 54.3 MeV [see (1974AJ01, 1979AJ01, 1984AJ01)] and at E_{pol. d} = 18 and 22 MeV (1986YA12; to ⁸Be_g.s.; also VAP, TAP) and 51.7 MeV (1986YA12; to ⁸Be*(0, 3.0, 11.4; also VAP) as well as at E_d = 50 MeV (1987GO1S), 54.2 MeV (1984UM04; FRDWBA) [S_α = 0.48, 0.51 and 0.82 for ⁸Be*(0, 3.0, 11.4)] and 78.0 MeV (1986JA14; to ⁸Be*(0, 3.0, 16.6, 16.9)). See also (1985GO1G; E_d = 50 MeV). For reaction (b) see (1984AJ01). See also (1984NE1A) and (1983GA14, 1983SH39, 1985GA1B, 1987KA1L; theor.).

43. ¹²C(t, ⁷Li)⁸Be Q_m = -4.8988

See ⁷Li.

44. ¹²C(³He, ⁷Be)⁸Be Q_m = -5.7793

Angular distributions have been obtained at E(³He) = 25.5 to 70 MeV [see (1979AJ01, 1984AJ01)] and at E(pol. ³He) = 33.4 MeV (1986CL1B; ⁸Be_g.s.; also A_y; prelim.). ⁸Be*(0, 3.0, 11.4, 16.6, 16.9, 17.6) have been populated. See also (1986RA15; theor.).

45. (a) ¹²C(α, 2α)⁸Be Q_m = -7.3666
(b) ¹²C(α, ⁸Be)⁸Be Q_m = -7.4585

These reactions have been studied at E_α to 104 MeV [see (1979AJ01, 1984AJ01, and ¹²C in (1985AJ01))] and at 31.2 MeV (1986XI1A; reaction (a)): ⁸Be*(0, 3.0, 11.4) are populated. See also (1984ZE1A, 1985GA1B, 1987KO1E; theor.).

46. (a) ¹²C(⁹Be, ¹³C)⁸Be Q_m = 3.2810
(b) ¹²C(¹¹B, ¹⁵N)⁸Be Q_m = 3.6250

Angular distributions involving ⁸Be_g.s. + ¹³C_g.s. (reaction (a)) have been reported at E(⁹Be) = 20 to 22.9 MeV and E(¹²C) = 0.5 to 13.5 MeV: see (1984AJ01). For both eactions see also (1983DEZW).

47. (a) ¹²C(¹²C, ¹⁶O)⁸Be Q_m = -0.2047
(b) ¹²C(¹⁶O, ²⁰Ne)⁸Be Q_m = -2.631
(c) ¹²C(²⁰Ne, α²⁰Ne)⁸Be Q_m = -7.3666