
^{7}Li (1974AJ01)(See Energy Level Diagrams for ^{7}Li) GENERAL: See also (1966LA04) and Table 7.1 [Table of Energy Levels] (in PDF or PS). Shell model: (1961KO1A, 1965CO25, 1965KU09, 1965VO1A, 1966BA26, 1966HA18, 1966WI1E, 1967BO1C, 1967BO22, 1967CO32, 1967FA1A, 1969GU03, 1969TA1H, 1969VA1C, 1970ZO1A, 1971CO28, 1972LE1L, 1973HA49, 1973KU03). Cluster model: (1965NE1B, 1968HA1G, 1968KU1B, 1969ME1C, 1969SM1A, 1969VE1B, 1969WI21, 1970BA1Q, 1972HA06, 1972HI16, 1972JA23, 1972KU12, 1972LE1L, 1973KU03, 1973KU12). Rotational and deformed models: (1965VO1A, 1966EL08). Special levels: (1966BA26, 1966EL08, 1967BO22, 1967CO32, 1967FA1A, 1969GU03, 1969HA1G, 1969HA1F, 1970FR1C, 1971CO28, 1972BB26, 1973AS02, 1973FE1J, 1973MA1K). Electromagnetic transitions: (1965CO25, 1965KU09, 1966BA26, 1966EL08, 1967BO22, 1968EL06, 1968KU1D, 1969HA1G, 1969HA1F, 1969VA1C, 1973AS02, 1973HA49, 1973HA1V, 1973SU1C). Astrophysical questions: (1967DA1C, 1967MI1A, 1968HA1C, 1969BA2A, 1970BA1M, 1972CL1A, 1972KO1E, 1972RA30, 1973AU1H, 1973LA19, 1973RE1G, 1973SA1J, 1973SC1T, 1974AU1A). Special reactions: (1965GR1C, 1965ZH1A, 1967AU1B, 1968YI01, 1969GA18, 1969YI1A, 1972HA06, 1972RA30, 1972VO06, 1973KO1D, 1973KU03, 1973LA19, 1973OS1C, 1973PF02). Muon capture: (1965LO1B, 1969WU1A, 1970FA15, 1971DE2D, 1973MU11). Pion capture and reactions: (1966DA1A, 1966DE1G, 1968BO32, 1968BO1T, 1968KU1B, 1968LO1A, 1968NO1A, 1968PE1B, 1968WI1B, 1969BU1C, 1969KO30, 1969MI10, 1969MI1G, 1969MO1E, 1970BA1E, 1970BO1V, 1970JA23, 1971CA01, 1971CA1J, 1971FA09, 1971GO22, 1971KO02, 1972HU1A, 1972SW1A, 1973BA2R, 1973BA2V, 1973BA2G, 1973DO1F, 1973NY04, 1973PE1E, 1973SQ01). Kaon reactions: (1973BA1Y). Other topics: (1965CO25, 1965VO1A, 1966DE1E, 1966HA18, 1966WI1E, 1966YO1B, 1967BO1C, 1967CA17, 1967FA1A, 1968EL06, 1969GU03, 1969HE1N, 1969HO1M, 1970HO1J, 1970ZO1A, 1971BA2Y, 1971CH1H, 1971GR16, 1971ZA1D, 1972AB14, 1972AN05, 1972BB26, 1972CA37, 1972DA21, 1972FR09, 1972GA1L, 1972LE1L, 1972PN1A, 1973BA1Y, 1973CL09, 1973JU2A, 1973KU03, 1973MA48, 1973RO1R). Ground state properties: (1965CO25, 1965HU13, 1965KU09, 1965MO17, 1965PR04, 1965VO1A, 1966BA26, 1966CA1F, 1966EL08, 1966WI1E, 1967BO22, 1967PA1G, 1967SH05, 1967SH14, 1968PE16, 1968PE1B, 1969GU03, 1969VA1C, 1972FR09, 1972LE1L, 1973DO1F, 1973MA1K).
μ = 3.255985 (2) nm [quoted in (1973CO1P)]; Q = 0.058 ± 0.010 b (1966IS01); Q = 0.04 b (1969FU11); see also (1971SH26, 1972BA77). B(E2: 3/2^{} → 1/2^{}) = 8.3 ± 0.6 e^{2} · fm^{4} (1972HA06, 1973HA47); = 7.4 ± 0.1 e^{2} · fm^{4} (1972BA77) [see also (1973HA47)].
Excitation functions and angular distributions have been studied for E_{α} = 0.5 to 1.9 MeV (1959HO03, 1961GR27). The cross section rises smoothly as expected for a direct capture process: at E_{α} = 1.32 MeV, σ = 3.58 ± 0.06 μb and the corresponding reduced cross section factor S = 0.064 ± 0.016 keV · b (1961GR27). Cross sections of (1961GR27) are 2 to 2.5 times higher than those of (1959HO03). See (1966LA04) for further comments and (1972BA77, 1972HA06, 1972SM0 2).
The cross section for this reaction has been measured for E_{α} = 11 to 18 MeV: the data show the effect of ^{7}Li*(7.47) and indicate a broad resonance near E_{α} = 16.8 MeV [^{7}Li*(9.6)]. The level parameters derived from this reaction and from reaction 3 (1967SP10) are displayed in Table 7.2 (in PDF or PS). See also (1972BA26; theor.).
The elastic scattering has been studied for E_{α} = 3.6 to 18.2 MeV. The excitation curves show the effects of ^{7}Li*(4.63, 6.68, 7.47, 9.61). The derived level parameters are displayed in Table 7.2 (in PDF or PS). Polarization parameters are calculated (1967SP10, 1968IV01). Polarization measurements are reported for E_{t} = 6.0 to 12.3 MeV (1968KE03, 1971AR1K) and angular distributions have also been measured for E_{α} = 2.13 to 2.98 MeV (1971CH42). See also (1970LI06) and (1968BR1H, 1971KU22, 1972BB26, 1972CL1C, 1972NE17, 1973KO1Q; theor).
See (1958BU38).
See (1971PO1A).
The total radiative capture cross section for thermal neutrons is 38.5 ± 3.0 mb (E.T. Jurney, private communication). Two γrays with E_{γ} = 7247 ± 2 and 6769 ± 2 keV are observed corresponding to transitions to ^{7}Li*(0, 0.48) with branching ratios of 61 ± 3 and 39 ± 2%, respectively^{†}. Gamma rays with E_{γ} = 4.63, 4.15 and 2.62 MeV corresponding to the decays of, and the transition to, ^{7}Li*(4.63) are not observed: upper limits ar 2, 2 and 6%, respectively (1967TH05), 1% (E.T. Jurney, private communication). See also (1968SP01). For astrophysical implications of this reaction see (1968FOZY).
^{†} E_{γ} = 477.6 ± 0.5, 6770.4 ± 1.5 and 7246.6 ± 1.5 keV, and the branching ratios are 61 ± 1 and 39 ± 1% to the ground state and to E_{x} = 477.6 ± 0.5 keV (E.T. Jurney, private communication).
The total cross section has been measured for E_{n} = 4 eV to 29 MeV: see (1960HU08, 1964ST25, 1966LA04). Recent measurements have been carried out at E_{n} = 10 to 1236 keV (1968HI1E), 50 to 650 keV (1968FA1D), 100 to 1500 keV (1972ME17), 0.7 to 30 MeV (1973GO2B, and C.A. Goulding, private communication) and 2.5 to 15 MeV (1971FO1P, 1971FO24). A pronounced resonance occurs at E_{n} = 255 keV with a peak cross section of about 11.0 b (1960HU08, 1968HI1E, 1972ME17). See also (1968FA1D). The elastic contribution is 7.2 b (1961LA1A). No other clearly defined resonance is observed although the total cross section exhibits its a broad maximum at E_{n} ≈ 5 MeV (1954JO17, 1960HU08). The coherent scattering length (thermal, bound) is 1.8 + 0.25i fm (1969BA1P, 1973MU14). Angular distributions are tabulated by (1970GA1A) and in reaction 11 of ^{6}Li. All observations near the 255 keV resonance are consistent with pwave formation of a J^{π} = 5/2^{} level [^{7}Li*(7.47)]. Table 7.3 (in PDF or PS) gives the resonance parameters compared with those for ^{7}Be*(7.18). These states are believed to have a ^{4}P_{5/2} character, in agreement with their large θ^{2}_{n} and θ^{2}_{p} (1959GA08, 1963MC09). The excitation function for 3.56 MeV γrays exhibits an anomaly, also seen in the (n, p) reaction [reaction 6]. The data are well fitted assuming E_{res} = 3.50 and 4.60 MeV [E_{x} = 10.25 ± 0.10 and 11.19 ± 0.05 MeV]. T = 1/2 and 3/2, Γ_{cm} = 1.40 ± 0.10 and 0.27 ± 0.05 MeV, respectively. Both states have J^{π} = 3/2^{}. The reduced widths for the T = 3/2 state [^{7}Li*(11.19)] are θ^{2}_{n} = 2 × 10^{4}, θ^{2}_{n}'' = 0.16 [to ^{6}Li*(3.56)] and θ^{2}_{p} = 0.09 (1969PR04). Crosssection measurements are also reported at E_{n} = 1 to 100 keV (1970AS1E), 4.8, 5.7 and 7.5 MeV (1968HO03), 10 MeV (1967CO01) and 14 MeV (1966ME1C). See also (1966AG1A, 1971RE07, 1973LA26; theor.). Polarization measurements are reported at E_{n} = 3.4 MeV (1968WO1F) and at 4.4 MeV (1966ST09). See also (1967BE1F; theor.) and (1966LA04) for earlier measurements.
The excitation function, measured from threshold to E_{n} = 8.9 MeV, exhibits an anomaly at E_{n} = 4.6 MeV: see reaction 6 (1969PR04). See also (1966JE1B, 1971CU1B, 1971PR09, 1972ED01, 1973BO1Y).
See (1969LI1F, 1973BO1Y) and (1966LA04).
See (1963AS01).
Excitation functions and angular distributions are summarized in (1960HU08, 1964ST25, 1966LA04, 1970GA1A). More recent crosssection measurements are reported by (1967CO1N: E_{n} = 10.7 to 102 keV), (1966BA1V: 25, 67 and 100 keV), (1970FO1E: 81.8 to 517 keV) [see below for thermal measurements]. Recent angular distributions are given in (1971OV1A: 0.10 to 1.80 MeV) and in (1966RO1L: 0.25, 0.39 and 0.60 MeV). The isotropic thermal cross section is 938 ± 6 b (1970ME1F), 940 ± 4 b (1970SO1A) [the value listed in (1966LA04) is in error: it should have been 945 b]. Below 5 keV, the total cross section is given by σ = (149.5/√E (square root of E)(eV))+0.696 b (1970SO1A). (1970SO1A) have also measured the ratio of (n, α) cross sections for ^{6}Li and ^{10}B in the range E_{n} = 10 eV to 80 keV. A resonance occurs at E_{n} = 258 keV, with σ_{max} = 2.75 b (1959BA46), 2.80 ± 0.22 b (1959GA08). The resonance is formed by pwaves, J^{π} = 5/2^{}, and has a large neutron width and a small αwidth: see Table 7.3 (in PDF or PS) (1959GA08). Above the resonance the cross section decreases monotonically to E_{n} = 18 MeV, except for a slight bump near E_{n} = 1.6 to 2.1 MeV (1959GA08, 1959MU25). See also (1970MC1A, 1971MA1Y, 1972ZV1A, 1973BO1Y, 1974BA1K), (1966JE1B, 1968GI1D, 1970DE1H) and (1966BL1C, 1966MA1L, 1968FA1D, 1968SE1A, 1972LA1F). For astrophysical implications, see (1964FO1A, 1965BU1C).
Angular distribution measurements have been recently carried out at E_{d} = 1 to 2 MeV (1966BR25; p_{0}, p_{1}), 1.48 to 2.94 MeV (1968TU1A; p_{0}, p_{1}), 1.5 MeV (1965RI09; p_{0}, p_{1}, p_{2}), 2.9 MeV (1966RO1J; p_{0}, p_{1}), 4.5 to 5.5 MeV (1970PO03; p_{0}, p_{1}) and 12 MeV (1967SC29; p_{0}, p_{1}). See also (1969HO39, 1969VI06) and (1966LA04) for earlier references. The p_{0} and the p_{1} [E_{x} = 477 ± 2 keV (1959AJ76)] groups show stripping patterns with l_{n} = 1. The p_{2} [E_{x} = 4.630 ± 0.009 MeV, Γ_{cm} = 93 ± 8 keV (1966LA04)] angular distribution is isotropic (1960HA14). In addition the excitation of ^{7}Li*(7.47) with E_{x} = 7.464 ± 0.010 MeV, Γ_{cm} = 91 ± 8 keV, is also reported (1957BR97). See also (1966LA04). Ratios of observed θ^{2}_{n} [see Table 7.3 (in PDF or PS) in (1966LA04)] are consistent with assignments ^{22}P to ^{7}Li*(0, 0.48) and ^{24}P to ^{7}Li*(7.47) (1960HA14, 1960MA32). At E_{d} = 12 MeV spectroscopic factors for ^{7}Li*(0, 0.48) [S = 0.90, 1.15] derived by DWBA are in good accord with the shell model calculations of (1967CO32, 1967SC29). The angular correlation between p_{1} and the 0.48 MeV γrays is isotropic (1959AJ76): ^{7}Li*(0.48) has J^{π} = 1/2. Using vector polarized deuterons with E_{d} = 10 MeV, (1970FI07) determined the probabilities p_{j} for transfer of a neutron with total angular momentum j. The results are in quite good agreement with the shellmodel calculations of (1965CO25, 1967CO32). The circular polarization of the 0.48 MeV γrays has been determined by (1966SC1E). See also ^{8}Be (1966AU1A, 1966BE1E, 1968BE1P, 1969LE22) and (1967OG1A). A kinematically complete study of reaction (b) at E_{d} = 10 MeV shows pronounced final state interactions vua ^{7}Li*(7.47) and possibly ^{7}Li*(9.6) [Γ = 0.5 ± 0.1 MeV] (1971VO07). See also ^{8}Be.
See (1954AL35, 1961HO21, 1967BI1E).
Not reported.
See (1966LA04), ^{12}C in (1968AJ02) and ^{15}N in (1970AJ04).
For a listing of lifetime measurements of ^{7}Li*(0.48), see Table 7.4 (in PDF or PS) in (1966LA04): τ_{m} = 0.107 ± 0.005 psec.
Reports on the structure of the (γ, n) cross section [reaction (a)] differ widely. The total photoneutron cross section rises sharply from 10 MeV to reach a broad plateau of about 1.5 mb from 14 to 20 MeV, decreases more slowly to about 0.5 mb at 25 MeV and then remains approximately constant to 30 MeV. There are indications of weak structure through the entire region particularly at E_{γ} = 7.5 and 10.5 MeV (1973BR1M; monoenergetic photons). See also (1954GO1A, 1958RY77, 1966BR1M). There are many reports of fine structure [see Table 7.5 (in PDF or PS) in (1966LA04) and (1965HA19, 1965WA19, 1966BA1W)]. See also (1970HA1F) and (1968KA38, 1968RA1E, 1969MU1C). The integrated cross sections from threshold to 32 MeV are 20 MeV · mb and 10 MeV · mb for the total neutron yield and for reaction (b), respectively (1966BR1M). See also (1971KA70, 1973AH1A). The cross section for the (γ, p) reaction (reaction (c)) shows a maximum at ≈ 15.6 MeV with a width of ≈ 4 MeV (1954TI16, 1962GR08) [however a number of authors claim the existence of many additional peaks: see (1966LA04)]. The energy distribution of the photoprotons has been measured with bremsstrahlung radiation E_{bs} = 50 to 34 MeV (1970SA14) and 100 MeV (1968MA19) and at E_{γ} = 60 MeV (1973GA16). The polarization of the protons produced in the interaction between highenergy γrays and ^{7}Li has been studied by (1969AN20, 1970TO09). See also ^{6}He and (1966MA17, 1967DE11, 1969AN1H, 1969MU1C, 1970AN05, 1970WO10, 1971AN04, 1973DO13) and (1970HA1F). For reaction (d) see (1967SM1A). For reaction (e) see (1967DE11, 1969AN1H, 1971AN04, 1971AN15). A number of peaks have been reported in the (γ, t) cross section: see Table 7.5 (in PDF or PS) in (1966LA04) and (1970SE1D). See also (1965DA06, 1966DZ07, 1966MA17, 1967DE11, 1969DE28, 1969HU1E, 1970SE1A). See also (1967SH1E, 1973AR1L, 1973CO1N) and (1968EL06, 1970RA1H, 1973AS02; theor.).
The electric form factor measurements for E_{e} = 100 to 600 MeV are well accounted for by a simple harmonic oscillator shell model with a quadrupole contribution described by an undeformed pshell: R_{rms} = 2.39 ± 0.03 fm, Q = 42 ± 2.5 mb (1967SU1A). From results obtained for E_{e} = 24.14 to 97.19 MeV, R_{rms} = 2.35 ± 0.10 fm (model independent), 2.29 ± 0.04 fm (shell model) (1969MO1J, 1972BU01). A study of the ratio of the electric charge scattering from ^{6}Li and from ^{7}Li as a function of (momentum transfer)^{2} yields < r^{2} > ^{1/2}_{6}/ < r^{2} > ^{1/2}_{7} = 1.001 ± 0.008. The r.m.s. radius of the groundstate magnetization density distribution, < r^{2} > ^{1/2}_{M} = 2.98 ± 0.05 fm. From the ratio of the transverse inelastic and elastic cross sections at 180°, B(M1,↑; 0.48) = 2.50 ± 0.12 μ^{2}_{N}. The cross section of the longitudinal excitation of ^{7}Li*(0.48) has been found from the scattering through angles of 90° to 150°, B(C2,↑; 0.48) = 7 ± 4 fm^{4}. The harmonic oscillator length parameter of the 1p shell is found to be a_{1p} = 1.90 ± 0.03 fm (1971VA20). The magnetic form factor has been measured for E_{e} = 70 to 200 MeV. The ratio of the magnetic octupole moment to the dipole moment Ω/μ = 2.30 ± 0.50 fm^{2} (1966RA29). Inelastic scattering studies show peaks corresponding to ^{7}Li*(0 + 0.48, 4.63, 6.68, 7.47, 11.25): see (1967AR1A, 1968HU1C, 1969HU05), (1966LA04) and Table 7.4 (in PDF or PS). See also the review by (1972THZF). For reaction (b) see (1970WO10). See also (1970WA1N), (1966GO1C, 1966GU1C, 1968GO1J) and (1966MU1A, 1967BO22, 1967EL1B, 1967KA1A, 1968BO1R, 1968KU1D, 1968KU1B, 1969HA1N, 1969KR16, 1969KU1C, 1969VI02, 1969WI21, 1971DRZW, 1973HI03; theor.).
Angular distributions have recently been measured at E_{n} = 1.12 to 2.30 MeV (1968KN1B; n_{0}, n_{1}), 3.35 and 4.83 MeV (1968HO03; n_{0}), 5.74 and 7.50 MeV (1968HO03; n_{0} + n_{1}) and 14 MeV (1966RE1B; n_{0} + n_{1}, n_{2}). See (1966LA04) for a listing of earlier references and (1970GA1A). At E_{n} = 14 MeV no states other than ^{7}Li*(0, 0.48, 4.63) are populated (1968HA1J): see, however, (1954AL24, 1966RE1B). See also (1966HU1B, 1967CO01) and (1969WA11; theor.). See also ^{8}Li. For reaction (b) see (1972AN1Q) and ^{5}He.
Angular distributions are reported at E_{p} = 1.0 to 2.0 MeV (1966BA1Q; p_{0}, p_{1}), 24.4 MeV (1967CR1E; p_{0}, p_{1}, p_{2}), 33.6 MeV (1970KU1D; p_{0}), 49.8 MeV (1971MA13, 1971MA44; p_{0}, p_{1}, p_{2}), 100 MeV (1966MA38, 1968LI1C; p_{0} + p_{1}, p_{2}), 144 MeV (1972JA07; p_{0}), 152 MeV (1966RO1C; p_{0}), 155 MeV (1968GE04; p_{0}, p_{1}, p_{2}) and 185 MeV (1967JO1F; p_{1}). (1967CR1E) report that the p_{2} group is strongly excited and that the angular distribution is consistent with the predictions of the collective model for an l = 2 transition. Earlier measurements are reported in (1966LA04). Inelastic proton groups have been observed corresponding to ^{7}Li*(0.48, 4.63, 6.68, 7.47): see (1952AJ38). At E_{p} = 185 MeV proton groups are observed to these states [E_{x} = 4.62 ± 0.04, 6.55 ± 0.20, 7.5 ± 0.2 MeV: (1967JO1F)] as well as to states at E_{x} = 5.5 ± 0.3 MeV (Γ ≈ 0.4 MeV) (1965HA17: not seen by (1967JO1F)) and 9.6 ± 0.2 MeV (1965HA17), 9.4 ± 0.2 MeV (1967JO1F). The width of ^{7}Li*(6.7) is ≈ 1 MeV (1965HA17). At E_{p} = 50 MeV (1968MA02) report ten states of ^{7}Li with E_{x} < 13.6 MeV. τ_{m}(0.48) = 0.106 ± 0.014 psec (1966PA11: Doppler shift measurement), a value consistent with intermediate coupling with LS coupling predominating (a/K < 3.6): see also Table 7.4 (in PDF or PS) in (1966LA04). Analysis of the 155 MeV data yields B(E2↑) = 10.5 ± 2, 28 ± 6 and 4.5 ± 2.3 fm^{4} for ^{7}Li*(0.48, 4.63, 6.68); Γ(E2↓) = 0.43, 0.025 and 0.029 μeV (1965JA1A). A comparison of σ_{t} for ^{7}Li(p, p')^{7}Li*(0.48) and ^{7}Li(p, n)^{7}Be*(0.43) has been carried out for E_{p} = 23 to 52 MeV: the spinflip, isospinflip part of the effective interaction is approximately independent of energy while the pure central part appears to decrease with increasing energy (1967LO07). See also (1966MA1N, 1968GL1A, 1968NE1B, 1969MA1P, 1969NE1A, 1969TI02, 1969WA11, 1970KI1E, 1973KA04; theor.).
For reaction (a) see ^{6}He. See also (1966LA04), (1973CO2B) and (1965BE1E, 1966JA1A, 1967EL1C, 1967JA1E, 1968JA1G, 1969KO1J; theor.). For reaction (b) see (1970TH1F). For reaction (c) see reaction 20 in ^{6}Li and (1973CO2B, 1973KO1M). The momentum distribution of the αparticles in reaction (d) has the shape expected for the knockout of an L = 1 αcluster from ^{7}Li (1970JA17). The reaction proceeds sequentially via ^{7}Li*(4.63) (1967JO1C, 1970JA17) and via ^{7}Li*(6.68) (1970JA17). See also (1969HO1K, 1971GA1J, 1973CO2B), (1972RA1E) and (1972JA23; theor.). For reaction (e) see ^{8}Be. For reaction (f) see (1972FU07, 1973CO2B) and reaction 20 in ^{6}Li.
Angular distributions have been measured at E_{d} = 11.8 MeV (1968LU02; d_{0}, d_{1}), 12 MeV (1971BI11; d_{0}), 14.7 MeV (1969MA13; d_{0}, d_{1}, d_{2}) and 28 MeV (1962SL02; d_{0}, d_{2}). See also (1970EL16; theor.) and (1966LA04).
Angular distributions are reported at E(^{3}He) = 8.7 and 9.7 MeV (1969MA1J; elastic), 11 MeV (1970SC23; elastic), 21, 24 and 27 MeV (1966VA1B, 1967BL1E: to ^{7}Li*(0, 0.48, 4.63)) and 25.2 MeV (1968BR1G: to ^{7}Li*(0, 0.48, 4.63). See also (1967CO1J).
Angular distributions (reaction (a)) are reported at E_{α} = 3.6 MeV (1972BO07; α_{0}, α_{1}), 12.0 to 18.0 MeV (1970BI1B, 1971BI12; α_{0}), 25 MeV (1968DO13; α_{0} + α_{1}, α_{2}) and 29.4 MeV (1968MA25, 1969MA13; α_{0}, α_{1}, α_{2}). See also (1972BE1Z). Reaction (b) has been studied at E_{α} = 23.6 MeV (1968BE1Q), 25 MeV (1968DO13, 1969DO02, 1969DO03), 29.4 MeV (1968MA25), 50 MeV (1970LA14, 1973LA1Q), 55 MeV (1968PI04, 1969PI11, 1970PI1D), 64.3 MeV (1970JA17) and 104 MeV (1969VE1B). ^{7}Li*(4.63) is strongly involved in the sequential decay: see (1968DO13, 1968MA25, 1970JA17, 1970LA14). The population of ^{7}Li*(7.48) is reported by (1970LA14), and (1968MA25) suggests that ^{7}Li*(6.68) is also involved in the sequential decay. At E_{α} = 55 MeV, the effective number of α clusters, N_{eff} = 4^{+4}_{2}% (1969PI11). See also (1969BA2C), (1969HO1K, 1971GA1J) and (1968BA1H, 1972AV04; theor.). See also (1966LA04).
The elastic angular distribution has been studied for E(^{7}Li) = 4.0 to 6.5 MeV (1966PI02).
The elastic scattering has been studied at E(^{7}Li) = 20 MeV (1969BE90) [on ^{13}C] and at 34 [^{13}C] and 36 [^{12}C] MeV (1973SC26). See also ^{12}C in (1975AJ02) and ^{13}C in (1976AJ04). The inelastic scattering angular distributions involving ^{7}Li*_{0.48} + ^{12}C_{g.s.} and ^{7}Li*_{0.48} + ^{12}C*_{4.43} have been measured at E(^{7}Li) = 36 MeV (1973SC26).
See (1966LA04).
The decay proceeds to the ground and 0.48 MeV states. The branching ratio to ^{7}Li*(0.48) is 10.32 ± 0.16% (1962TA11), 10.4 ± 0.3% (1972SZ02), 10.42 ± 0.18% (1973PO10). [See also Table 7.8 (in PDF or PS) in (1966LA04)]. The weighted mean value of the halflife is 53.44 ± 0.09 days (1949SE20, 1953KR16, 1956BO36, 1970JO21). Both transitions are superallowed. Log ft = 3.30 and 3.54 for the decays to ^{7}Li*(0, 0.48) respectively^{‡}.
^{‡} G. Fox and B. Zimmerman, private communication. For discussions of astrophysical considerations, see (1969BA1U, 1969FO1D, 1969YI1B, 1971CA1B, 1972BA2M, 1972KO1A, 1973BA2C). See also (1967GE1A, 1969HE1M, 1973HE1M), (1972EM03) and (1965PR04, 1966EL08, 1966BA26, 1968FI02, 1969LE1D, 1969SU15, 1970DA21, 1970FA14, 1970KO41, 1973HA49, 1973MU12, 1973WI11; theor.).
At E_{p} = 43.7 angular distributions have been obtained for the ^{3}He particles corresponding to ^{7}Li*(0, 0.48, 4.63, 7.47). The 7.47 MeV state is strongly excited while the mirror state in ^{7}Be is not appreciably populated in the mirror reaction (see reaction 17 in ^{7}Be). The angular distribution indicates that the transition to ^{7}Li*(7.47) involves both L = 0 and 2, with a somewhat dominant L = 0 character (1966CE05). Reanalysis of the data of (1965DE08) places the J^{π} = 3/2^{}; T = 3/2 level at E_{x} = 11.28 ± 0.04 MeV, Γ = 260 ± 50 keV (1967MC14). See also (1969BA1Z, 1969IN1A).
See (1966LA04).
Angular distributions have been measured recently at E_{d} = 0.3 to 1.0 MeV (1968BE1E; α_{0}, α_{1}), 0.9 to 2.2 MeV (1971SA27; α_{0}, α_{1}), 11.4 and 12.4 MeV (1966DO1A; α_{0}, α_{1}). For older measurements see (1966LA04). A study at E_{d} = 11 MeV finds Γ_{cm} = 93 ± 25 and 80 ± 20 keV, respectively, for ^{7}Li*(4.63, 7.47). No evidence was observed for ^{7}Li*(5.5, 8.6, 9.7, 12.5) or for the T = 3/2 state ^{7}Li*(11.25) (1966HA09). See also (1964MA57, 1966JA05) and (1966ME1E; theor.). In a kinematically complete study of reaction (b) at E_{d} = 26.3 MeV, ^{7}Li*(4.6, 6.5 + 7.5, 9.4) are strongly excited. No sharp αdecaying states of ^{7}Li are observed with 10 < E_{x} < 25 MeV. Parameters for ^{7}Li*(9.6) are E_{x} = 9.36 ± 0.05 MeV, Γ = 0.8 ± 0.2 MeV (1973SO08). See also ^{8}Be.
See (1967ST1D).
See (1966SA04, 1968JA08) and ^{11}B in (1975AJ02).
At E_{n} = 14.4 MeV angular distributions have been measured for the n_{0} + n_{1} and for the n_{2} groups (1969AN25). The halflife of ^{7}Li*(0.48) is 92 ± 11 fsec (1967CA02). See also (1966LA04), ^{11}B in (1975AJ02), (1969VA1F, 1970NE03, 1972SE1K) and (1972HA04; theor.). For reaction (b) see (1967VA12).
See reaction 19 in ^{7}Be (1969FO06).
See ^{11}B in (1975AJ02) and (1969MU10).
See (1964BA1C).
For reaction (a) see (1966GE12, 1969FU09). Angular distributions have been measured in reaction (b) at E_{α} = 28.4 and 29.0 MeV for the transitions to ^{8}Be*(0, 2.9) and ^{7}Li*(0, 0.48) (1968KA24). At E_{α} = 65 MeV ^{7}Li*(0, 4.63) are strongly populated and ^{7}Li*(7.47) is weakly excited. The intensity of the group to ^{7}Li*(0.48) is < 15% of the group to ^{7}Li(0) (1973WO06). See also (1966GE12).
At E_{d} = 19.5 MeV, angular distributions have been measured for the transitions to ^{6}Li(0) and ^{7}Li*(0, 0.48) (1971GU07). At E_{d} = 40 MeV the cross section for the transition to ^{6}Li*(3.56) + ^{7}Li(0) is half that for ^{6}He(0) + ^{7}Be(0) [to ± 10%] in agreement with isospin conservation (1972GO1P). See also (1972GA1E).
See (1968OK06).
At E_{d} = 39.8 MeV, angular distributions have been measured for the transitions to ^{7}Li(0) + ^{7}Be(0), ^{7}Li*(0.48) + ^{7}Be(0), ^{7}Li(0) + ^{7}Be*(0.43), and ^{7}Li*(0.48) + ^{7}Be*(0.43). Asymmetries exceeding 20% are observed in the ratio of the cross sections to ^{7}Li(0) and ^{7}Be(0) (1971HO1K, 1971YO06). See also (1971SI28; theor.).
This reaction has been studied at E(^{3}He) = 40.7 MeV (1971DE37).
At E(^{6}Li) = 36 MeV, angular distributions have been obtained for the transitions involving ^{7}Li_{g.s.} + ^{11}C_{g.s.} and ^{7}Li*_{0.48} + ^{11}C_{g.s.} (1973SC26).
At E_{p} = 45.0 MeV angular distribution has been measured for the transition to ^{7}Be(0) + ^{7}Li(0) (1971BR07).
At E_{d} = 14.6 MeV, angular distributions are reported for the transitions to ^{8}Be(0) and ^{7}Li*(0, 0.48) (1967DE03).
At E(^{6}Li) = 34 MeV angular distributions have been measured for the transitions involving ^{7}Li_{g.s.} + ^{12}C_{g.s.}, ^{7}Li*_{0.48} + ^{12}C_{g.s.}, ^{7}Li_{g.s.} + ^{12}C*_{4.4}, and ^{7}Li*_{0.48} + ^{12}C*_{4.4} (1973SC26).
At E_{n} = 14.1 MeV, ^{7}Li*(0, 0.48) are produced with about equal probability (1971SC16).
See (1972RU03).
At E(^{6}Li) = 36 MeV, angular distributions have been determined for the transitions involving ^{7}Li_{g.s.} + ^{15}O_{g.s.} and ^{7}Li*_{0.48} + ^{15}O_{g.s.} (1973SC26).
At E_{d} = 14.6 to 15.0 MeV, angular distributions have been measured for the transitions to ^{12}C(0) + ^{7}Li*(0, 0.48) [reaction (a)], ^{13}C(0) + ^{7}Li*(0, 0.48) [reaction (b)] and ^{14}N(0) + ^{7}Li*(0, 0.48) [reaction (c)] (1967DE03).
