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13B (86AJ01)(See Energy Level Diagrams for 13B) (Reactions on which no new work is reported are not always discussed.) GENERAL: See also (81AJ01) and Table 13.1 [Table of Energy Levels] (in PDF or PS). Model calculations: (SE81C, VA84). Complex reactions involving 13B: (EN83A, MA83, OL83, WI83H, HI84). Muon and neutrino capture and reactions: (KO84K). Pion capture and reactions (See also reactions 4 and 5.): (OS81A, CH82F, LI83T). Hypernuclei: (FE83A). Other topics: (SE81C, WA81D, NG82, PO84E). Ground-state properties of 13B: (FU80H, NG82, AN83D, KU84B). Mass of 13B: From the Q0 of the 11B(t, p)13B reaction [-233.4 ± 1.0 keV], the atomic mass excess of 13B is 16561.3 ± 1.4 keV.
μ = +3.17778 (51) nm (LE78N).
The half-life of 13B is 17.36 ± 0.16 msec: see (81AJ01). The branching ratios to various 13C states are shown in Table 13.2 (in PDF or PS): they indicate Jπ = 1/2- or 3/2- for 13Bg.s.. See also (KO81K; theor.).
Observed proton and γ-ray groups are shown in Table 13.3 (in PDF or PS). See also 14C.
Q0 = -233.36 ± 1.00 keV (AN83M). Observed proton groups are displayed in Table 13.3 (in PDF or PS).
Differential cross sections have been measured to 13Bg.s. (Eπ+ = 18, 29, 42 MeV) and the unresolved structure at Ex ~ 3.5 - 3.7 MeV (Eπ+ = 42 MeV) (LE82O) and to 13Bg.s. (SH83; Eγ = 194 MeV, Eπ+ ~ 40 MeV) [see the latter for a discussion of the comparison of the results with DWIA]. At Ee = 195 MeV the 13B Ex region to 12 MeV has been studied by (MI83D): they find that the photopion reaction predominantly excites M2 states at low q and M4 states at high q. Fits to the data are obtained by assuming the excitation of 13Bg.s. and 13B*(3.5, 6.4, 9.0) [the latter are clearly due to unresolved groupings of levels]. Comparisons are made with the 13C(e, e') work in the analog region in 13C (MI83D). [For T = 3/2 states see Table 13.6 (in PDF or PS).] See also reaction 43 in 13C and the "General" section here.
Gamma rays have been observed which are associated with the 13B ground state; an unresolved doublet at Ex ~ 3.5 - 3.7 MeV; sharp states at Ex ~ 6.5 and 7.6 MeV; a broad level (or unresolved levels) at ~ 10.2 MeV (MA83E; see for radiative capture branching ratios). The analogs of the peaks at Ex = 6.5, 7.6 and 10.2 MeV, calculated to be at 13C*(21.6, 22.7, 25.3), are attributed to a Δ L = 1, Δ S = 1, Δ T = 1 spin-isospin giant dipole resonance of 13C (MA83E). See also the "General" section here.
See (AL82B, GL84; E(7Li) = 78 MeV).
See (81AJ01).
At Et = 23 MeV the angular distribution for α 0 has been analyzed by (SE79C): the DWBA fit is poor. The extracted S(3/2) = 5.7, near that predicted for a filled p3/2 shell.
See (NE84A).
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