(See Energy Level Diagrams for 8Li)
Electromagnetic transitions: (1983KU17).
Complex reactions involving 8Li: (1983FR1A, 1983GU1A, 1983OL1A, 1983WI1A, 1984GR08, 1984HI1A, 1984LA27, 1985JA18, 1985MA02, 1985MA13, 1985MO17, 1985MO24, 1986AV1B, 1986CS1A, 1986GO1G, 1986HA1B, 1986MA19, 1986NAZV, 1986SA30, 1986SIZS, 1986WE1C, 1986XU02, 1987BA38, 1987BE58, 1987BL13, 1987CH26, 1987DE37, 1987GR11, 1987JA06, 1987LY04, 1987TAZU, 1987WA09, 1988AU1A, 1988BL09, 1988CA06, 1988KI05, 1988LI1A, 1988RU01, 1988ST06, 1988TA1A).
Other topics: (1985AN28).
μ = +1.65335 ± 0.00035 nm: see (1978LEZA)
Q = 24 ± 2 mb: see (1979AJ01).
The interaction nuclear radius of 8Li is 2.36 ± 0.02 fm (1985TA18) [see also for derived nuclear matter, charge and neutron matter r.m.s. radii].
Angular distributions have been obtained at Et = 23 MeV for the proton groups to 8Li*(0, 0.98, 2.26, 6.54 ± 0.03); Γc.m. for 8Li*(2.26, 6.54) are 35 ± 10 and 35 ± 15 keV, respectively. J for the latter is ≥ 4: see (1979AJ01).
The cross section for capture radiation has been measured for En = 40 to 1000 keV; it decreases from 50 μb to 5 μb over that interval. The cross section shows the resonance corresponding to 8Li*(2.26): Eres = 254 ± 3 keV, Γn = 31 ± 7 keV, Γγ = 0.07 ± 0.03 eV: see Table 8.3 (in PDF or PS) and (1974AJ01). See also (1985SM1B), (1981MUZQ, 1984SH1N, 1986AB1E). The decay of 8Li*(2.26) → 7Lig.s. + n in the interaction of 35 MeV/A 14N ions on Ag is reported by (1987BL13).
The thermal cross section is 0.97 ± 0.04 b [see (1981MUZQ)], σfree = 1.07 ± 0.03 b (1983KO17). The real coherent scattering length is - 2.22 ± 0.01 fm. The complex scattering lengths are b+ = - 4.15 ± 0.06 fm and b- = 1.00 ± 0.08 fm (1983KO17); see also (1979GL12). See (1984AJ01) for earlier references.
Total and elastic cross sections have been reported for En = 5 eV to 49.6 MeV: see (1974AJ01, 1979AJ01, 1984AJ01). Cross sections have also been reported for n0, n0 + 1 and n2 at En = 6.82, 8.90 and 9.80 MeV. (1987SC08; n2 at the two higher energies).
A pronounced resonance is observed at En = 254 keV with Jπ = 3+, formed by p-waves: see Table 8.3 (in PDF or PS). A good account of the polarization is given by the assumption of levels at En = 0.25 and 3.4 MeV, with Jπ = 3+ and 2-, together with a broad Jπ = 3- level at higher energy. Broad peaks are reported at En = 4.6 and 5.8 MeV (± 0.1 MeV) [8Li*(6.1, 7.1)] with Γ ≈ 1.0 and 0.4 MeV, respectively, and there is indication of a narrow peak at En = 5.1 MeV [8Li*(6.5)] with Γ ≪ 80 keV and of a weak, broad peak at En = 3.7 MeV: see (1974AJ01, 1984AJ01). A multi-level, multi-channel R-matrix calculation is reported by (1987KN04). This analysis leads to predictions for the cross section for elastic scattering, for (n, n') to 7Li*(0.48, 4.68, 6.68) and for triton production. A number of additional (broad) states of 8Li, unobserved directly in this and in other reactions, derive from this analysis (1987KN04). See also (1984FE1A, 1984MO1J), (1983DA22, 1983GO1H, 1984SH1N, 1984SH1B, 1986BOZG, 1987LE33, 1988MA1H) and (1983FA17, 1986BA09, 1986FIZX, 1987VE02; theor.).
The excitation function for 0.48 MeV γ-rays shows an abrupt rise from threshold (indicating s-wave formation and emission) and a broad maximum (Γ ≈ 1 MeV) at En = 1.35 MeV. A good fit is obtained with either Jπ = 1- or 1+ (2+ not excluded), Γlab = 1.14 MeV. A prominent peak is observed at En = 3.8 MeV (Γlab = 0.75 MeV) and there is some indication of a broad resonance (Γlab = 1.30 MeV) at En = 5.0 MeV. At higher energies there is some evidence for structuree at En = 6.8 and 8 MeV followed by a decrease in the cross section to 20 MeV: see (1979AJ01, 1984AJ01). The total cross section for n0 + n1) and n2 have been reported at En = 8.9 MeV (1984FE1A; prelim.). For R-matrix analyses see (1987KN04) in reaction 4 and (1984AJ01).
The cross section for reaction (b) rises from threshold to ≈ 360 mb at En ≈ 6 MeV and then decreases slowly to ≈ 250 mb at En ≈ 16 MeV: see (1985SW01, 1987QA01). Cross sections for tritium production have been reported recently from threshold to En = 16 MeV (1983LI1C; prelim.), 4.57 to 14.1 MeV (1985SW01), 7.9 to 10.5 MeV (1987QA01), 14.74 MeV (1984SMZX; prelim.) and at 14.94 MeV (1985GO18: 302 ± 18 mb). At En = 14.95 MeV the total α production cross section [which includes to (n, 2n d) process] is 336 ± 16 mb (1986KN06). Spectra at 14.6 MeV may indicate the involvement of states of 4H (1986MI11). The half-life of 3H has recently been measured to be 12.38 ± 0.03 mean solar years (1987OL04). See also (1987TI07).
See also (1986DE20, 1986DR10), (1984SH1N, 1985BO1D, 1986BOZG, 1986LI15) and (1986CH1S, 1986FA13, 1986GO1K, 1986IG1A, 1986KO32, 1986MA1R, 1986SE1D, 1986SH1T, 1986SH33, 1986TA1H, 1986VE1A, 1986YA1K, 1986YO1D; applications).
Angular distributions and analyzing powers for the transitions to 8Li*(0, 0.98, 2.26) have been studied at Ep = 200.4 MeV. [The (p, π-) reaction to the analog states in 8B is discussed there.] The (p, π+) cross sections are an order of magnitude greater than the (p, π-) cross sections and show a much stronger angular dependence (1987CA06). Angular distributions and Ay have also been measured at Ep = 250, 354 and 489 MeV to the first three states of 8Li. Those to 8Li*(0, 2.26) have differential cross sections which exhibit a maximum near the invariant mass of the Δ1232 and Ay which are similar to each other and to those of the pol. pp → dπ+ reaction. 8Li*(6.53) is clearly populated (1987HU12).
Angular distributions of the p0 and p1 groups [ln = 1] at Ed = 12 MeV have been analyzed by DWBA: Sexp = 0.87 and 0.48 respectively for 8Li*(0, 0.98). Angular distributions have also been measured at several energies in the range of Ed = 0.49 → 3.44 MeV (p0) and 0.95 to 2.94 MeV (p1). The lifetime of 8Li*(0.98) is 10.1 ± 4.5 fsec: see (1979AJ01). See also (1985FI1D; astrophysics).
For reaction (a) see (1984AJ01) and (1985KI1A). The summed proton spectrum (reaction (b)) at Ep = 156 MeV shows peaks corresponding to 8Li(0) and 8Li*(0.98 + 2.26) [unresolved]. In addition s-states [Jπ = 1-, 2-] are suggested at Ex = 9 and 16 MeV, with Γc.m. ≈ 6 and 8 MeV; the latter may actually be due to continuum protons: see (1974AJ01). At Ep = 1 GeV the separation energy between 5 and 8 MeV broad 1p3/2 and 1s1/2 groups is reported to be 10.7 ± 0.5 MeV (1985BE30, 1985DO16). See also (1987GAZM).
Angular distributions have been reported for the 3He ions to 8Li*(0, 0.98, 2.26, 6.53) at Ed = 28 MeV [C2S(abs.) = 1.63, 0.61, 0.48, 0.092] and 52 MeV. The distributions to 8Li*(6.53)[Γ < 100 keV] are featureless: see (1979AJ01).
At Et = 12.98 MeV, angular distributions of the α-particles to 8Li*(0, 0.98, 2.26, 6.53 ± 0.02 [Γc.m. < 40 keV]) have been measured: see (1974AJ01). At Et = 17 MeV angular distributions to these four states have been analyzed by ZRDWBA and C2S have been derived (1988LI27). At Et = 17 MeV, σ(θ) and Ay measurements, analyzed by CCBA, lead to Jπ = 4+ for 8Li*(6.53): see (1984AJ01). For 8Li*(0.98), τm = 14 ± 5 fsec, Ex = 980.80 ± 0.10 keV: see (1974AJ01).
At Ep = 45 MeV, 3He ions are observed to a state at Ex = 10.8222 ± 0.0055 MeV (Γc.m. < 12 keV): the angular distributions for the transition to this state, and to its analog (8Be*(27.49)), measured in the analog reaction [10Be(p, t)8Be] are very similar. They are both consistent with L = 0 using a DWBA (LZR) analysis: see (1979AJ01).
At E(7Li) = 34 MeV angular distributions have been studied involving 8Li*(0, 0.98) and 10Bg.s. (1987CO16).