(See Energy Level Diagrams for 13C)
Astrophysical questions:(1982BU1A, 1982CA1A, 1982GR1A, 1982WO1A, 1985BR1E, 1985HA1R, 1985HE1F, 1985MI1E, 1985PR1D, 1985RI1B, 1986DO1L, 1986FR1G, 1986GO1Q, 1986LA1C, 1986MA2E, 1986SN1C, 1986SN1D, 1986WI1H, 1987AR1C, 1987AU1A, 1987BE1H, 1987BO1B, 1987BR1P, 1987DO1A, 1987HA1C, 1987HA1U, 1987KR1M, 1987MA1C, 1987MA2G, 1987PI1E, 1987PR1A, 1987SO1F, 1987WA1L, 1987WA1F, 1987ZI1C, 1988AP1A, 1988AR1H, 1988AS1D, 1988CR1A, 1988DE1I, 1988JA1B, 1988JU1C, 1988PI1C, 1988SC1A, 1988TR1H, 1989AB1J, 1989BA2I, 1989BA2K, 1989BO1S, 1989BR1I, 1989BR1M, 1989CH1X, 1989CH1Z, 1989FR1J, 1989GI1E, 1989GU1L, 1989HA1O, 1989HO1F, 1989JI1A, 1989KA1K, 1989LO1C, 1989LO1D, 1989ME1C, 1989NO1A, 1989SM1A, 1989ST1K, 1989WE1G, 1989WH1B, 1989WY1A, 1990CA1O, 1990FU03, 1990HO1I, 1990MO1I, 1990PI1F, 1990TU1A, 1990WE1I).
Applied work:(1986BR1Q, 1986BU1H, 1986DO1M, 1986DR1E, 1986EN1A, 1986FO1D, 1986FR1H, 1986GE1C, 1986HE1F, 1986KI1J, 1986KN1E, 1986KR1F, 1986MA2D, 1986MA2G, 1986NI1C, 1986NO1C, 1986SR1B, 1986ST1K, 1986XU1C, 1987BO1U, 1987DU1A, 1987KI1I, 1987NA1O, 1987ST1C, 1988AR1G, 1988BU1C, 1988DO1D, 1988FA1A, 1988GO1J, 1988MA1A, 1988PU1A, 1988SC1C, 1989CE1D, 1989GR1F, 1989KU1P, 1989MU1A, 1989RA1M, 1990DO1C, 1990FR1F).
Complex reactions involving 13C:(1984BO1H, 1985KI1E, 1985KW03, 1985PO11, 1985PO14, 1985UT01, 1986AV1B, 1986GR1A, 1986HA1B, 1986HO1K, 1986MA19, 1986MA1O, 1986ME06, 1986MO15, 1986PO06, 1986SA30, 1986SO10, 1986UT01, 1986XU02, 1986XU1B, 1987AR19, 1987BA38, 1987BE1I, 1987BU07, 1987GA17, 1987GE1B, 1987LY04, 1987NA01, 1987PE1B, 1987PO23, 1987RI03, 1987SI1C, 1987SN01, 1987ST01, 1987VI02, 1987YA16, 1988BE56, 1988CA06, 1988GA11, 1988HA03, 1988JO1B, 1988KI06, 1988RU01, 1988SA19, 1989AJ1A, 1989BA92, 1989CH1U, 1989GIZV, 1989GRZQ, 1989HO16, 1989KI13, 1989POZT, 1989PR02, 1989SA10, 1989SE03, 1989TE02, 1990CH09).
Pion capture and reactions involving pions and ρ-mesons (See also reactions 27 and 41, and reaction 23 in 13N): (1983MA16, 1984BO1H, 1984CH1K, 1985SA06, 1986BO1N, 1986CE04, 1986DO01, 1986ER1A, 1986KO26, 1986LI1N, 1986LI1P, 1986MI1M, 1986SI07, 1986SI13, 1986SI22, 1986SU18, 1987DU08, 1987GI1C, 1987MI08, 1987PI1B, 1988BU1I, 1988CH24, 1988CH1L, 1988CHZU, 1988GIZU, 1988HA12, 1988KIZW, 1988PE1F, 1988PE1H, 1988PO1H, 1988POZV, 1988US01, 1989CH31, 1989GE10, 1989IT04, 1989JE02, 1989JO07, 1989KI25, 1989MO09, 1989PI11, 1990BE12, 1990CH12, 1990ER03, 1990ER1E, 1990FE01, 1990KO19, 1990TA1K, 1990TI1B).
Kaon capture and reactions:(1984BO1H, 1985GA1C, 1986DO01, 1986FE1A, 1986GA33, 1986MA1C, 1986MA1W, 1987FA1A, 1987PI1B, 1987PO1H, 1988FA1B, 1988PE1F, 1988PE1H, 1988PO1H, 1988ZH1H, 1989CH52, 1989DO1K, 1989PI11, 1990FE01).
Hypernuclei:(1984BO1H, 1984ZH1B, 1985BA1F, 1985BA2D, 1985GA1C, 1985KO1W, 1985KO2B, 1985YA1C, 1986AN1R, 1986BA1H, 1986DA1G, 1986DA1B, 1986DO01, 1986ER1A, 1986FE1A, 1986GA33, 1986KO1A, 1986LA1R, 1986MA1C, 1986MA1W, 1986ME1F, 1986WU1C, 1986WU1D, 1986YA1F, 1987CO1E, 1987FA1A, 1987MA08, 1987MI38, 1987PI1C, 1987PO1H, 1988CH48, 1988FA1B, 1988GA1A, 1988GA1I, 1988IT02, 1988MA1G, 1988MA58, 1988MO1L, 1988PE1H, 1988PO1H, 1988TA29, 1988WA1B, 1988ZH1H, 1989BA92, 1989BA93, 1989CH52, 1989DO1K, 1989DO1N, 1989FE07, 1989IT04, 1989KI25, 1989KO1H, 1989KO37, 1989KO48, 1989LA1H, 1989LA1I, 1989MA30, 1989MI30, 1989PI11, 1990FE01, 1990IT1A, 1990OS1A).
Ground state of 13C:(1985AN28, 1985GO1A, 1986GL1A, 1986SI22, 1987AB03, 1987FU06, 1987GI1C, 1987KI1C, 1987SA15, 1988AR1I, 1988KE1B, 1988VA03, 1988WA08, 1988WO04, 1989AM02, 1989AN12, 1989FU05, 1989GOZQ, 1989WO1E, 1990VA01).
< r2 > 1/2 = 2.4628(39) fm (1985DE42) [charge radius, from muonic 13C]
[The neutron r.m.s. radius is 2.35 (3) fm (1979JO08).]
Natural abundance:(1.10 ± 0.03)% (1984DE53)
The yield curves for d0 (E(6Li) = 4 to 14 MeV), T0 (E(7Li) = 5 to 14 MeV) and α0 (E(6Li) = 4 to 14 MeV) show broad, uncorrelated structures. Energy-averaged differential cross sections are also reported for a number of 12B, 11B and 10B states. Total cross sections have been measured for E(7Li) = 3.8 to 6.0 MeV for p0 → p2, p3+4, p5; d0 → d3, d4+5, d6; t0 → t2; and α0: the total cross sections generally increase smoothly with energy without showing any structure: see (1981AJ01). For reaction (b) see (1987SC11).
Resonances for n0 and n1, for γ-rays from 12C*(4.4, 12.7, 15.1) and resonances in the total neutron cross section are given in Table 13.7 (in PDF or PS). In addition the yield of neutrons to 12C*(7.65, 9.64) has been measured in the range Eα = 2.9 - 6.4 MeV. The n0 and n1 excitation functions exhibit weak resonance anomalies at Eα = 6.44 MeV corresponding to the Jπ = 3/2-, T = 3/2 state at Ex = 15.11 MeV: see Tables 13.6 (in PDF or PS) and 13.7 (in PDF or PS) (1978HI06). For thick target yields see (1982WE16). See also (1989HE04). For polarization measurements (Eα to 100 MeV) see (1981AJ01). Reaction (b) has been studied at a number of energies for Eα = 17 to 44 MeV: see (1981AJ01, 1986AJ01). See also 12C in (1990AJ01), (1987EL1B, 1989CR07; applied) and (1985CA41; astrophysics).
Excitation curves have been measured for Eα = 15 to 27.5 MeV for reaction (a) [involving d0, d1 and at the higher energies d2, d3, d4+5, d6] and at 26.0 to 27.5 MeV for reaction (b) [t0, t1, t3]: no structures are observed: see (1981AJ01). See also 11B in (1990AJ01) and (10B in 1988AJ01).
A number of excitation functions have been measured for elastically scattered α-particles for Eα = 1.4 to 20 MeV: these show considerable resonance structure with the variations being most prominent below 10 MeV but persisting up to 20 MeV. The parameters resulting from a best-fit of the excitation functions are displayed in Table 13.8 (in PDF or PS): see the footnotes to that table for a summary of the most important caveats. A weak resonance is observed in the α0 yield at Eα = 6.44 MeV corresponding to the excitation of the first T = 3/2 state at Ex = 15.11 MeV: see Table 13.6 (in PDF or PS) for the parameters of that state. For a measurement of the total reaction cross section at Eα = 100 MeV see (1986DU15). See also (1987BU27) and (1986SA30; theor.).
Angular distributions have been studied at E(6Li) = 32 MeV to 13C*(0, 3.09, 3.68 + 3.85, 6.86, 7.5, 9.5, 9.9, 10.75, 13.42). The spectra are dominated by the deuteron group to a state (or states) at Ex = 10.75 ± 0.018 MeV, with Γ = 130 keV [suggesting that both 13C*(10.75, 10.82) are populated]. Two states, consistent with 13C*(11.35, 12.13) are also populated, as is a broad group at 14.13 MeV (1989AS01; see for spectroscopic factors).
Angular distributions for t0, t1, t2+3, T4 are reported at E(7Li) = 5.6 to 6.2 MeV: see (1976AJ04).
Cross sections for gamma rays from the decay of 13C*(3.09, 3.68, 3.84) are reported by (1988LA25) for E(9Be) = 2.8 to 6 MeV.
Yields have been measured for Et = 0.5 to 2.0 MeV. There is no evidence of resonance behavior: see (1981AJ01). In the range Et = 3.0 to 7.3 MeV a broad structure is reported in the activation cross section (reaction (a)) at Et ~ 5.5 MeV, Γ ~ 2.7 MeV (1985AB10). See also 9Be in (1988AJ01).
At E(3He) = 260 and 280 MeV, 13Cg.s. and an unresolved group at Ex ~ 3.6 MeV are observed: see (1986AJ01).
Angular distributions have been measured at many energies up to Eα = 31.2 MeV: see (1970AJ04, 1986AJ01). For γ-decay measurements see Table 13.6 (in PDF or PS). At Eα = 218 MeV, 13C*(0, 3.09, 3.7, 6.9, 7.6, 9.9) are populated (1987BI1C; prelim.). For a study of high Ex states see (1987BRZV, 1987MIZY, 1988BRZY; prelim.). See also 14N, (1989BR1J) and (1986BA58; axion search).
Comparisons of the relative intensities of the 3He groups in this reaction and of the triton groups in the mirror reaction (see reaction 6 in 13N) at E(6Li) = 18 MeV suggest that the following states are analogs: 6.86 - 6.36, 7.49 - 7.16, 9.50 - 9.00, 9.90 - 9.48, (10.82 + 10.75) - (10.36 + 10.36) [the first (set of) Ex is in 13C, the second in 13N]: see (1981AJ01).
Angular distributions have been measured at E(7Li) = 5.20 MeV for the α0, α1, α2+3 and α4 groups: see (1981AJ01).
At E(10B) = 100 MeV angular distributions are reported for the transitions to 13C*(0, 3.7, 7.5, 11.8): see (1981AJ01).
The 90° γ0 excitation curve measured for Ed = 1.0 to 12.0 MeV shows resonant structure at Ed = 2.0 ± 0.1 and 4.0 ± 0.1 MeV, Γ ~ 0.6 and ~ 1 MeV, corresponding to states at Ex = 20.4 and 22.1 MeV: see Table 13.9 (in PDF or PS) and (1986AJ01). More recently (1985AU10) have studied the 90° γ0 differential cross sections at Epol. d = 1.65 to 3.5 MeV, angular distributions at 1.6, 1.8, 2.0 and 4.0 MeV, and analyzing powers at Epol. d = 2.0 and 4.0 MeV (90°) and 1.6 and 1.8 MeV (125°). The data are interpreted in terms of two doorway states at Ex = 20.57 ± 0.84 and 20.20 ± 0.07 MeV with Γc.m. = 5.64 ± 0.43 and 0.56 ± 0.09 MeV, respectively (1985AU10). See also reaction 22 and (1990HO06).
The yields of neutron and 15.1 MeV γ-rays have been measured in the range Ed = 0.2 to 11 MeV: see Table 13.9 (in PDF or PS). At Epol. d = 79 MeV, VAP measurements are reported for 12C*(0, 4.4, 9.6, 12.7, 15.1) (1987FO22, 1986FO08). See also (1981AJ01). The thick-target yield in reaction (b) has been measured for Ed = 7.00 to 16.01 MeV: see (1986AJ01). See also 12C in (1990AJ01).
For reaction (a) see also (1981AJ01, 1986AJ01). For Ed = 2.99 to 6.99 MeV the activation cross section does not show any evidence of structure (1985AB10). For reaction (b) see (1981AJ01). See also 12B in (1990AJ01).
At low energies the excitation functions for α0 and α1 increase monotonically: see (1970AJ04). Then at Ed = 1.85 MeV a pronounced resonance is observed in the α0, α1, α2 and α3 yields: see Table 13.9 (in PDF or PS). Some gross structure is also observed in these yields for Ed = 1.0 to 3.2 MeV: see (1981AJ01). See also 9Be in (1988AJ01).
Levels derived from proton groups are displayed in Table 13.11 (in PDF or PS) of (1981AJ01). [The only level parameters included in the values of Table 13.4 (in PDF or PS) are Ex = 7500 ± 12 keV and Γc.m. < 5, 70 ± 10 and 150 ± 30 keV for 13C*(7.49, 7.69, 8.86).] The neutron decays of 13C*(6.86, 9.90, 11.75) are to 12Cg.s. (99 ± 9)% and (100 ± 20)% for the first two states, and to 12C*(0, 4.4) (67 ± 16)% and (33 ± 8)% for the third (1973AD02). The decay parameters for the first T = 3/2 state, 13C*(15.11), are shown in Table 13.6 (in PDF or PS). See also (1986AJ01).
The thermal capture cross section is 3.53 ± 0.07 mb. The capture is (67.47 ± 0.92)%, (0.16 ± 0.01)% and (32.36 ± 0.44)% via 13C*(0, 3.09, 3.68): see (1986AJ01) for references and additional information. Based on unpublished measurements quoted in (1986AJ01), the energies of the γ-rays involved in C → 0, C → 3.68 and 3.68 → 0 are 4946.362 ± 0.021, 1261.855 ± 0.006 and 3684.507 ± 0.019 keV. The branching ratios for the decay of 13C*(3.68) to 13C*(0, 3.09) are (99.3 ± 2.0)% and (0.74 ± 0.05)%, respectively: see (1986AJ01). (1990WA22) proposes 3683.915 ± 0.015 keV for Eγ[3.68 → 0].
Differential cross sections for γ0 (90°) have been studied for En = 6.5 to 18.5 MeV (1987AU02), 7.0 to 19.5 MeV (1986BE17) and at 7.8, 9.3 and 10.8 MeV (1990HA19). Broad structures are seen at ~ 9 and 17.2 MeV (13C*(13.2, 20.8)) [the latter has Γ ~ 2.5 MeV]. It should be noted that the cross sections reported by (1987AU02) are substantially higher than those reported in the other two references. The variation of the cross section with energy is similar to that from the 13C(γ, n0) reaction but the magnitudes of the cross section are smaller: see, for instance, (1990HA19). Angular distributions and analyzing powers of γ0 for En = 12.0 to 18.8 MeV suggest two doorway states at Ex = 21.1 ± 0.6 and 20.52 ± 0.07 MeV with Γ = 4.2 ± 0.4 and 0.51 ± 0.07 MeV, respectively (1984WO05). See also (1989HU15). For work to 50 MeV see (in 1988DO1E; prelim.). See also (1986MU1B, 1986RA1B, 1986WE1D, 1988MCZT), (1988MA1U, 1989GU1J; astrophysics) and (1987HO23, 1987LY01: theor.).
The coherent scattering length (thermal, bound) acoh = 6.6535 ± 0.0014 fm; σscatt = 4.7456 ± 0.0020 (1979KO26).
Total cross sections have been measured in the range En = 1 keV to 273 GeV/c [see (1981AJ01, 1986AJ01)] and at 0.14, 1.3 and 2.1 MeV (1988KO18) and 160 to 575 MeV (1988FR23): see the compilation of (1988MCZT). See also (1986BA40). Various elastic, inelastic and non-elastic cross sections have been reported over a wide range of energies: [see (1986AJ01, 1988MCZT)], most recently at 6.23 to 13.75 MeV (1986BO1M; prelim.; elastic and inelastic scattering cross sections), from 16.5 to 22.0 MeV (1989OL02, 1989OL1C; σt, σel and σ to 12C*(4.4, 7.7, 9.6)) and from threshold to 25 MeV (1988WE06; prelim.; cross section for scattering to 12C*(4.4)). Polarization measurements have been reported for En = 1.5 to 16.3 MeV [see (1976AJ04, 1981AJ01, 1986AJ01)] and at En = 15.55 to 17.35 MeV (1987TO03, 1987TO07) and 18.2 MeV (1988TO01). See also (1986BE2D, 1987BEYP).
Observed resonances are displayed in Table 13.10 (in PDF or PS) here, and in Table 13.13 (in PDF or PS) in (1981AJ01) [the latter for (n, n'γ4.4)]. In Table 13.10 (in PDF or PS) the assignment of the broad states above Ex = 11.7 MeV are from phase-shift analyses (σ(θ) and Ay) referred to here and in (1986AJ01). Five weak anomalies in the total cross section are thought to be due to T = 3/2 states (1987HI03).
For reactions (c) and (d) see reactions 23 and 24 in (1986AJ01) and (1988MCZT). For pion production see (1988BU16). See also 12C in (1990AJ01) and (1984BE1L, 1985FI09, 1985KU1F, 1985ME16, 1985RA1E, 1986BAYL, 1986DR10, 1986ROZW, 1987NEZY, 1988AN1F, 1989SA1J), (1986AL1N, 1986WE1B, 1986WI1B, 1989OL1C; applied), (1988FR1M; astrophys.), (1987BR06, 1988MA1H) and (1985KO1U, 1985TI07, 1986BE2F, 1986LI16, 1988BA1P, 1988RU1C, 1989MI20, 1990LE1Q; theor.).
The cross section exhibits a weak resonance corresponding to Ex ~ 20.5 MeV and a stronger structure at Ex ~ 21.5 MeV: see (1976AJ04). See also the compilation of (1988MCZT). The excitation function for En = 30 to 150 MeV is being studied (1988RAZX; prelim.). For proton production for En = 300 to 580 MeV see (1987FR16). See also 12B in (1990AJ01) and (1985AZ1A, 1986FO1E, 1989BE2P, 1989SOZY), (1986RO1F; applied), (1988FR1M; astrophysics), (1988MA1H) and (1986KO26, 1988PE01; theor.).
Angular distributions have previously been reported for Ep = 147 to 250 MeV: see (1986AJ01). 13C*(0, 3.09, 3.68, 3.85, 6.86, 9.50) have been populated. In the more recent work at Ep = 354 MeV it is found that at 21° the π+ spectrum is dominated by the group to the (2p1h) 9/2+ state at 9.50 MeV. Angular distributions have been measured to 13C*(0, 3.09 + 3.68 + 3.85, 9.50) (1987HU08) [see also for a discussion of the energy dependence of the total cross section, and of the influence of the Δ-resonance]. (1987HO21) report a measurement of ground-state differential cross sections at Ep = 186 MeV.
At Epol. p = 200 MeV angular distributions and Ay measurements have been reported to 13C*(0, 3.09, 3.7[u], 6.86, 7.5[u], 9.5, 21.4) (1989KO21). For the strongly populated group to 13C*(21.4) Ay ~ 0 at all angles. The results are suggestive of those for a 7/2+; T = 3/2 state, but other explanations are also possible (1987KO01, 1989KO21). See also (1990JAZZ). For inclusive differential cross sections and Ay at E pol. p = 400 and 450 MeV see (1986FA03). For other polarization measurements see (1986AJ01). For total cross sections at Ep = 180 and 201 MeV see (1985BI04). See also (1981AJ01), the "General" section, (1987SEZY, 1988SEZT), (1986JA1H) and (1985IQ01, 1986MI09, 1987KU06; theor.).
Measurements of proton groups and γ-rays are summarized in Table 13.11 (in PDF or PS). Angular distributions have been studied at many energies to Ed = 80.2 MeV [see (1981AJ01, 1986AJ01)] as well as at Epol. d = 12 MeV (1988LA03; to 13C*(0, 3.09, 3.68, 3.85, 6.86, 7.50, 7.55, 7.69)) and at Ed = 30 MeV (1986OH01; to all even-parity states below Ex = 10 MeV and to 13C*(0, 3.68, 7.55, 10.75, 11.08)). See also (1989BE2K, 1989IE01, 1989NA1R).
For τm measurements see Table 13.5 (in PDF or PS) and for γ-decay see Table 13.6 (in PDF or PS). For work at very high energies see (1987AZ1C, 1989AV02). See also 14N, (1985LI1H, 1988VI1A, 1989VI1E, 1990CH1J; applied), (1986SI1D; computer program) and (1984BL21, 1986IS1F; theor.).
Angular distributions of the 3He particles to the first three states of 13C have been measured in the range Eα = 56 to 139 MeV. The ground-state distributions in this, and in the mirror reaction 12C(α, t)13N, have also been compared: see (1981AJ01). See also (1989KU1E; Eα = 94 MeV; g.s.; prelim.) and (1989GA1H).
At E(7Li) = 34 MeV angular distributions have been studied to 13C*(0, 3.09, 3.85). The analysis by FRDWBA leads to S = 0.65 ± 0.06, 0.75 ± 0.08 and 0.68 ± 0.10, respectively (1986CO02). See also (1988KE07; theor.). For the earlier work at E(7Li) = 21.1 and E(7Li) = 48 MeV see (1981AJ01, 1986AJ01).
At E(8Li) = 14.3 MeV, an angular distribution is reported involving 13Cg.s. (1989BE28): at θlab = 15°, the differential cross section is ~ 15 mb/sr.
Angular distributions have been reported at E(12C) = 72.5 and 93.8 MeV [see (1981AJ01, 1986AJ01)], at 240 MeV (1985BO39; 13C*(0, 3.85)) and at 300, 420 and 600 MeV (1988WI09, 1989WI07; 13Cg.s.). See also 11C in (1990AJ01) and (1989SA44; theor.).
The main features of the cross sections are a sharp peak corresponding to the T = 3/2 state 13C*(15.11) [Γγ0 = 19.7 ± 2.0 eV], the broad pigmy resonance at Ex = 13 MeV [on which peaks are superimposed at Ex = 11.0, 13.8, 16.5 and 17.8 MeV] and the giant resonance at Ex = 24 MeV (σmax = 9.5 mb) [surrounded by shoulder resonances at Ex = 20.8 and ~ 30 MeV, both of which appear to decay substantially to highly excited states of 12C]. There is also some evidence for a weak resonance at ~ 37 MeV superimposed on the high-energy tail of the GDR. A study of the angular distributions of n0 suggests states at Ex = 7.70 (3/2+), 7.95 (3/2+), 8.95((1/2-)), 10.0 ((3/2-)), 11.0 ((1/2+)) and 12.05 MeV ((3/2+)). See (1981AJ01) for references and for additional information. See also the atlas in (1988DI02), (1985PY01, 1988BE1T, 1988HA12) and (1985GO1A, 1987KI1C; theor.). For comparisons with 12C(n, γ) see reaction 22 and (1985AU10, 1986BE17).
The integrated cross section (reaction (a)) from Eγ = 17.5 (threshold) to 28 MeV is 36 ± 5 MeV · mb. Resonances are observed at Ex = 18.6, (19.7), 20.7, (22), 23.5, 24.5 and (26) MeV. [σmax at Ex ~ 23 MeV is 8 mb]. Below ~ 18 MeV the cross section is dominated by transitions involving T< states. The states at 18.6 and 20.7 MeV have a significant T> component. The two isospin components of the GDR appear to be split by 6.8 MeV (1983ZU02). For the earlier work see (1981AJ01). See also (1988HA12) and (1987KI1C; theor.). For the cross section of reaction (b) from detailed balance calculations from 11B(d, γ) see reaction 15 and (1985AU10).
The elastic scattering has been studied for Ee = 80 to 750 MeV [see (1981AJ01, 1986AJ01)] and (1987HI09, 1989MI01). The form factor for M1 elastic scattering is enhanced above q ~ 2.5 fm-1 (1982HI07, 1987HI09). See also (1987DE43). A number of inelastic groups have been seen: see Tables 13.12 (in PDF or PS) and 13.13 (in PDF or PS) (1970WI04, 1986HI06, 1987HI09, 1989MI01).
A distinct splitting of the giant resonance into two large peaks near Ex = 20.5 and 24.5 MeV, with widths of ~ 3 and ~ 4 MeV, respectively, is observed. It is suggested that these are groupings of narrower peaks. The Ex = 20.5 and 24.5 MeV groups are probably T = 1/2 and T = 3/2, although the 4 MeV splitting is somewhat smaller than expected: see (1981AJ01). See also (1984CH1K, 1988SA06, 1986CH2E, 1986DO11, 1987HO23, 1988MI1J, 1989AM02, 1989WO1E, 1990JE1B; theor.).
Angular distributions have been measured at Eπ = 20 to 180 MeV [see (1981AJ01) and Table 13.13 (in PDF or PS) in (1986AJ01)], at 65 MeV (1988MI02; several states up to Ex = 11.8 MeV) and at Eπ- = 30 and 50 MeV (1990SE04; elastic). Enhanced in π- scattering are 13C*(0, 3.09, 3.85, 9.50, 21.60 ± 0.05), the latter very strongly but with a large uncertainty. Enhanced in π+ scattering are 13C*(3.68, 7.55, 8.86, 11.82, 16.05 ± 0.05, 17.92 ± 0.05, 21.37 ± 0.05). The data for 13C*(9.50, 21.60, 16.05, 21.37) indicate pure neutron particle-hole excitations for the first two states and pure proton excitation for the latter two, however with large uncertainties except for 13C*(9.5). Spin assignments are 9/2+ for 13C*(9.50); 7/2+ or 9/2+ for 13C*(16.05, 17.92, 21.37, 21.60); 5/2+ and/or 7/2+ for 13C(11.82) [unresolved doublet?]. The π-/π+ asymmetry near 21.5 MeV suggests that there is isospin mixing between T = 1/2 and 3/2 states of Jπ = 7/2+ and/or 9/2+ (1982SE04, 1983SE15). Analyzing powers for elastic scattering on pol. 13C have been studied at Eπ± = 100 MeV (1990SM1B) and 114 to 226 MeV (1990YE1C) [both preliminary]. See also the "General" section and (1986AMZX; theor.).
Angular distributions have been measured at En = 4.5 to 17.92 MeV [see (1986AJ01)], at 4.55 to 10.99 MeV (1989RE01, n0 → n3) and at 24 MeV (1985PE10; n0). At En = 8.1 to 11 MeV 13C*(7.55) [Jπ = 5/2-] is involved in the sequential decay to 12Cg.s. (1987RE01). See also 14C, (1988RE09; computer) and (1986AL1L; theor.).
Angular distributions have been studied at Ep = 1.37 MeV to 1 GeV [see (1981AJ01, 1986AJ01)] and at 30.95 MeV (1988BA30); p0), 35 MeV (1986OH03: p0 → p3), 71.8 MeV (1989VO05, 1990VO02; p0; polarized protons), 135 MeV (1988CO05, to 33 states below Ex = 23 MeV), 500 MeV (1990HO06; p0; polarized protons), 0.8 GeV (1985BL22; p0) and 1 GeV (1985AL16; p0). (1988CO05) assign 7/2+ for 13C*(11.85) [in agreement with the (e, e) work]. (5/2+) for 13C*(11.95, 14.98), ≤ 5/2 for 13C*(12.11, 12.19), (7/2, 9/2)+ for 13C*(14.58, 21.47), (7/2+) for 13C*(16.08), (3/2, 5/2) for 13C*(17.70), (3/2, 5/2)+ for 13C*(18.70), (7/2, 9/2)+ for 13C*(21.47), ≥ 5/2 for 13C*(21.81) and ≤ 5/2 for 13C*(22.2, 23). The widths of 13C*(12.19 ± 0.01, 22.2 ± 0.1) are 110 ± 50 keV and 1100 ± 500 keV, respectively. [The widths for 13C*(11.95, 12.11, 12.19) are appreciably smaller than those reported in Table 13.10. (in PDF or PS)] A state at Ex = 20.93 ± 0.1 MeV with Γ = 240 ± 100 keV is suggested (1988CO05, S. Collins, Ph.D. thesis, and B. Spicer, private communication). See also 14N, (1985PE10) and (1986AMZX, 1986RA05, 1987BE1M, 1987BE1P, 1988GOZH, 1988RA08, 1989AM02, 1989AM05, 1989BEXT, 1989GO14, 1989KU14, 1989KU32, 1989RA1O, 1990DU01; theor.).
Angular distributions (reaction (a)) have been measured at Ed = 0.71 to 56 MeV: see (1981AJ01, 1986AJ01). See also 15N. Angular distributions for the tritons to 13C*(0, 3.09, 3.68, 3.85, 7.55) have been studied at Et = 38 MeV (1988SI08). See also (1981AJ01).
Angular distributions of elastically scattered 3He ions have been studied at E(3He) = 12 to 41 MeV [see (1981AJ01)] and at 39.6 MeV (1987BUZR; prelim.) as well as at E(3He) = 33 MeV (1986DR03). Angular distributions have also been reported at E(3He) = 43.6 MeV for the 3He ions to 13C*(3.09, 3.68, 3.85, 6.86, 7.49 + 7.55, 7.69, 8.86, 9.50, 9.90, 10.75 + 10.82, 11.08, 11.85, 15.11, 16.0) [and these have been compared to the analog states reached in the 13C(3He, t)13N reaction] (1981PE08). See also (1989DE1Q) and (1986ZE04, 1987RA36; theor.).
Angular distributions have been studied at Eα = 15 to 40.5 MeV [see (1981AJ01)], at Eα = 35.5 MeV (1981PE08; to 13C*(3.09, 3.68, 3.85, 6.86, 7.49 + 7.55, 7.69, 8.86, 9.50, 11.08, 11.85)) as well as at Eα = 48.7 and 54.1 MeV (1987AB03; α0). For 13C*(7.69), Ex = 7686 ± 6 keV, Γc.m. = 70 ± 5 keV (1980FU04; also line shapes). An angular correlation study at Eα = 24.35 MeV of the (α, αn) reaction to 12Cg.s. has determined the substate population of 13C*(6.86), Jπ = 5/2+ (1984DE44). Γγ/Γ ≤ 3 × 10-4 for 13C*(6.86). The evidence for states near 7.5 MeV is less clear cut (1985DE11). See also (1987BU27) and (1985SH1D; theor.).
Angular distributions of elastically scattered Li ions have been studied at E(Li) = 4.5 to 40 MeV [see (1981AJ01, 1986AJ01)] as well as at E(7Li) = 34 MeV (1987CO02, 1987CO16). At E(7Li) = 34 MeV angular distributions involving 13C*(3.09, 3.68, 7.55) are also reported (1987CO02). For the (6Li, αd) breakup via states of 17O see (1986AJ01) and (1987CA30, 1989WUZX). For fusion and breakup cross sections see (1986AJ01). See also (1989DE34) and (1988DEZU, 1988DE1F; theor.).
The elastic scattering has been studied at E(13C) = 28.1 and 36.2 MeV [see (1981AJ01)] and at E(9Be) = 50.5 MeV (1990BA16; also to 13C*(3.68, 7.55)). For cross section measurements see (1984DA17, 1986CU02). See also (1986MI24; theor.).
Angular distributions for reaction (a) have been reported for E(12C) = 10 to 87 MeV and E(13C) = 12 to 36 MeV [see (1981AJ01, 1986AJ01)], and at E(12C) = 94.5 MeV (and 1986BA80; elastic) and E(13C) = 16.3 to 26.5 MeV (and 1988VO01; 13C*(0, 3.09, 3.85)) and 260 MeV (and 1985BO39; 13Cg.s. + 12C*(0, 4.4)). Elastic distributions for reaction (b) have been studied at E(13C) = 15 to 24 MeV [see (1981AJ01)] and at 14 and 16 MeV and (1988TR01). Angular distributions for reaction (c) have been measured at E(13C) = 15 MeV [see (1981AJ01)] and at 20 to 27.5 MeV (and 1988BI11; 13C(0, 3.09, 3.85)). For excitation functions, fusion and evaporation cross sections see (1986AJ01) and (and 1986HA30, and 1988TR01). For a spin-flip probability study see (1985BY01) and 12C in (1990AJ01).
See also (1982BA1D, 1985BA1T, 1988TR01; astrophysics), (1984FR05, 1985BE1A, 1985CU1A, 1985KO1J, 1986SN1B, 1986ST1A, 1987GR1K, 1987IM1C, 1988BE1W, 1989VO1D, 1990VO1E) and (1985HU04, 1985IM1B, 1985SA1D, 1986BA1D, 1986BA69, 1986EL02, 1986HA13, 1986KA1B, 1986SA1D, 1986VI08, 1987AR1E, 1987BO48, 1987FR06, 1987IM01, 1987MA22, 1987TH04, 1988BR29, 1988JA14, 1988KA27, 1988MI25, 1988PA07, 1989ER1B, 1989FR08, 1989HA19, 1990BA03; theor.).
Elastic angular distributions have been measured for reaction (a) at E(16O) = 10 to 30 MeV and at E(13C) = 36 and 105 MeV [see (1981AJ01)] as well as at E(16O) = 42 to 65 MeV (1989FR04) and at 108.15 MeV (1986BA80). Those for reaction (b) are reported at E(17O) = 29.8, 85.4, 120 and 140 MeV; and those for reaction (c) at E(18O) = 15 to 31 MeV: see (1981AJ01, 1986AJ01). For excitation functions, breakup yields and fusion measurements see (1981AJ01, 1986AJ01) and (1983FR17 [see, however, (1988FR15)], 1985BE40, 1985BE37, 1986GA13, 1986PA10). See also (1985CU1A, 1985HU04, 1985KO1J, 1985RE1C, 1986ST1A, 1989BEZC, 1990SN1A) and (1985MI13, 1986BA69, 1986CI01, 1986MI1A, 1986PA04, 1987AR13, 1987BA01, 1987MO27, 1987DA34, 1987NU02, 1987RE1C, 1989CH2B, 1989TH1A, 1990IM01; theor.).
For reaction (a) see (1988SN1A). The elastic angular distribution for reaction (b) has been studied at E(13C) = 60 MeV (1988YA06). For the earlier work see (1981AJ01, 1986AJ01). See also (1989CH1K; theor.).
At Ep = 35.0 and 40.1 MeV angular distributions (reaction (a)) have been reported [and integrated cross sections and spectroscopic factors have been derived] for the deuterons to the 1/2- states 13C*(0, 8.86, 11.08), the 3/2- states 13C*(3.68, 9.90, 11.75, (13.28), 15.11), the 5/2+ states 13C*(3.85, 6.86), the 1/2+ states 13C*(3.09, 11.0), the 3/2+ states 13C*(7.69, 8.2), 13C*(7.5) [Jπ = 5/2-] and 13C*(9.50) [9/2+] (1990YA01). See also (1981AJ01).
Angular distributions measured in the giant resonance region of 14N are consistent with the proton decay of (p1/2)-1 (2s1d) giant dipole states to 13Cg.s. and of (p3/2)-1 (2s1d) states to 13C*(3.68). The population of 13C*(3.09, 3.85) is also reported. For Eb.s. = 15.5 to 29.5 MeV a large fraction of the neutron yield appears to be associated with sequential decay to 12C via 13C*(7.75, 8.86, 11.80): see (1981AJ01). See also 14N.
At Ed = 52 MeV, angular distributions have been measured for the 3He particles to 13C*(0, 3.09, 3.68, 6.86, 7.5, 8.86, 9.50, 11.9 ± 0.15) and analysed by DWBA: Jπ = 5/2-, 1/2-, 3/2- and 3/2-, respectively, are assigned to 13C*(7.5, 8.86, 9.50, 11.9). [However, 13C*(9.50) is known to have Jπ = 9/2+.] As expected, angular distributions of 3He and of tritons (from 14N(d, t)13N) to analog states are closely the same: this has been shown for the ground-state 3He and triton groups as well as groups to 13C*(8.9 + 9.5) and 13N*(9.2): see (1981AJ01).
See (1987OS1E; theor.).
At Eα = 42 MeV the angular distributions involving 13Cg.s. have been measured: see (1981AJ01).
Angular distributions have been measured in both reactions at Ed = 13.6 MeV involving 13Cg.s.: see (1986AJ01).
At Ed = 13.6 MeV an angular distribution has been reported by (1986GO26).