
^{8}B (1988AJ01)(See Energy Level Diagrams for ^{8}B) GENERAL: See also (1984AJ01) and Table 8.9 [Table of Energy Levels] (in PDF or PS) here. Model calculations: (1983SH38). Special states: (1982PO12, 1988KH03). Complex reactions involving ^{8}B: (1982AL08, 1983OL1A, 1984GR08, 1986HA1B, 1987TAZU, 1988AR05, 1988KI05). Astrophysical questions: (1984HA1B, 1985BO1E, 1985GI1C, 1985KL1A, 1985LA1C, 1988BA86). Reactions involving pions: (1983SP06). Hypernuclei: (1983SH38). Other topics: (1985AN28). Ground state of ^{8}B: (1983ANZQ, 1985AN28, 1986GL1A, 1987VA26, 1988AR05, 1988VA03)
The β^{+} decay leads mainly to ^{8}Be*(3.0). The mean of halflives listed in (1974AJ01) is 770 ± 3 msec; log ft= 5.6. There is also a branch to ^{8}Be*(16.63): see (1986WA01) and reactions 24 and 25 in ^{8}Be. Log ft= 3.3. See also (1985GR1A) and (1986QUZZ; theor.).
At E_{d} = 300 and 600 MeV ^{8}B*(0, 0.77, 2.32) are populated: see (1984AJ01).
Angular distributions for the n_{0} group have been reported at E(^{3}He) = 4.8 to 5.7 MeV: L= 0. Two measurements for the E_{x} of ^{8}B*(0.77) are 767 ± 12 and 783 ± 10 keV [Γ = 40 ± 10 keV]: see (1974AJ01) and ^{9}B.
Angular distributions and analyzing powers have been measured for the transitions to ^{8}B*(0, 0.77, 2.32) at E_{pol. p} = 199.2 MeV: the A_{y} to ^{8}B*(2.32) is characteristic of that to a stretched highspin, twoparticle onehole final state [J^{π} of ^{8}B*(2.32) is 3^{+}] (1987CA06). See also (1987CA05).
See ^{6}H.
Absolute cross sections have been measured for E_{p} = 134 keV to 10.0 MeV. A resonance is observed at E_{p} = 723 keV [E_{R}(c.m.) = 632 ± 10 keV; E_{x} = 770 ± 10 keV], Γ_{c.m.} = 37 ± 5 keV [assuming Γ_{p} ≫ Γ_{γ}] and σ_{peak} = 1.18 ± 0.12 μb. Γ_{γ} is then 25 ± 4 meV. The zeroenergy crosssection factor S_{17}(0) = 0.0238 ± 0.0023 keV · b (1983FI13). See (1979AJ01) for the earlier work, and the discussion in (1986BA38). See also (1984AJ01), (1984HA1F, 1987SA1L) and (1982BA1J, 1982KA1E, 1983BA45, 1983FO1A, 1983HA1B, 1984DA1H, 1984HA1M, 1984YA1A, 1985BA1Q, 1985CA41, 1985FI1D, 1986FI15, 1987KI01, 1987RO25, 1988BA86, 1988BA29, 1988FO1A; astrophysics).
At E_{p} = 49.5 MeV [see (1974AJ01)] and 51.9 MeV (1983YA05) angular distributions have been measured for the tritons to ^{8}B*(0, 2.32): L = 2 and L = 0 + 2 leading to J^{π} = 2^{+} and 3^{+}, respectively. Measurements of E_{x} for ^{8}B*(2.32) yield 2.29 ± 0.05 MeV, 2.34 ± 0.04 MeV [Γ_{lab} = 0.39 ± 0.04 MeV]. ^{8}B*(0.77) is also observed: see (1974AJ01).
At E(^{3}He) = 72 MeV the first T= 2 state is observed at E_{x} = 10.619 ± 0.009 MeV, Γ < 60 keV: dσ/ dΩ (lab) = 190 nb/sr at θ_{lab} = 9°. No other states are observed within 2.4 MeV of this state. ^{8}B*(0, 0.77, 2.32) have also been populated: see (1979AJ01).
