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GENERAL: See also (1985AJ01) and 12.22 [Table of Energy Levels] (in PDF or PS) here.

Model calculations:(1984KA1H, 1984SA19).

Astrophysical questions:(1985CA41, 1987RA1D, 1988CA26, 1988LE08, 1989KR1C).

Applied work:(1987KU17, 1987MI24).

Complex reactions involving ¹²N:(1985NO1E, 1986GA1P, 1987BA1T, 1987RI03, 1988BE02, 1988LE08).

Muon and neutrino capture and reactions:(1986DA1J, 1987KR1L, 1988AL1O, 1988BO1X, 1988FU08, 1988MI1H, 1988MI20, 1989DR1A, 1989KR1C, 1989MI1I).

Pion capture and reactions:(1983AS01, 1984AS05, 1988HA12, 1988KIZW).

Other topics:(1984KA1H, 1984SA19, 1985AN28, 1986YA1F).

Ground-state properties of ¹²N:(1985AN28, 1985NA1A, 1986GL1A, 1986HA1P, 1987VA26, 1988VA03).

1. 12N(β+)12C

Qm = 17.338

The half-life of ¹²N is 11.000 ± 0.016 ms: ¹²N decays to ¹²C*(0, 4.44, 7.65, 10.3, 12.71, 15.11): see 12.21 (in PDF or PS). Since the transitions to ¹²C*(0, 4.4) are allowed the J^π of ¹²N_g.s. is 1⁺. For measurements of the angular distribution functions from aligned ¹²N nuclei see (1986MI1P, 1986MI1T, 1987MI1P). See also (1985AJ01), (1986CA1P, 1986MI1Q, 1986MI1R, 1987MI20, 1987VA1P), (1985BA2L; applied), (1985GR1A, 1985MI1A) and (1984DU1E, 1985MO13, 1986KE1A, 1986KO2C, 1986TO1A, 1987DR1A, 1987SA1N, 1988AL1E, 1988SA12, 1989SA1H; theor.).

2. 10B(3He, n) 12N

Qm = 1.573

Observed neutron groups are displayed in Table 12.23 (in PDF or PS).

3. 12C(γ, π-)12N

Qm = -156.907

The total cross section has been measured from threshold to E_e = 360 MeV: see (1985AJ01).

4. 12C(p, n)12N

Qm = -18.120

Angular distributions have been studied at E_p = 30.5 to 200 MeV [see (1980AJ01, 1985AJ01)] and at 35 and 40 MeV (1987OH04; n₀, n₁, n₂; DWBA), at 160 MeV (1984GA11; n₀; also A_y; comparison with (p, p') to ¹²C*(15.1)). The angular distribution to ¹²N(4.2) [u?] is consistent with J^π = 2^- predicted by theory. A structure at E_x ≈ 7.2 MeV is also observed. Unresolved angular distributions over the range E_x = 2 - 17 MeV (and θ = 5° - 13°) are dominated by l = 1 transitions (1984GA11) [as would be expected at those angles]. (1987TA13, 1989RA09) discuss the relationships between the GT strength and the 0° differential cross section in this and other (p, n) reactions. At E _{pol. p} = 65 MeV the spin transfer coefficient K^y'_y (0°) for pol. n₀ + pol. n₁ has been measured by (1984SA12). See also (1985AJ01), ¹³N in (1991AJ01), (1984BA1R, 1988HIZX, 1988NI1C, 1988TAZY, 1989PRZZ), (1988LE08; astrophysics), (1985BA2L), (1984GA36, 1984TAZS, 1985SH1C, 1986GA1P, 1986LI1T, 1987EL08, 1987EL14, 1987LI29, 1987RA32) and (1984SA19, 1987BE1D, 1988HO09, 1988PI08, 1988UD03; theor.).

5. 12C(3He, t)12N

Qm = -17.357

Observed triton groups are displayed in 12.23 (in PDF or PS). Angular distributions of inelastically scattered ³He to ¹²C*(15.11, 16.11, 16.58, 17.77, 19.57) have been compared with those of tritons to ¹²N*(0, 0.96, 1.19, 2.42, 4.25). When the ³He cross sections are corrected for phase-space and isospin factors the angular distributions are closely similar to those for the triton groups, strongly suggesting isobaric analogs: see (1980AJ01) for references. [If ¹²C*(17.77) and ¹²N*(2.42) are analogs, then the latter is a 0⁺ state.] Angular distributions have been reported at 81 MeV (1983ST10) [to many of the states shown in 12.23 (in PDF or PS)]. [Compare the ¹²B and the ¹²N level structure: it is clear that not all the analog states have been observed in ¹²N.] Angular distributions have also been studied at E(³He) = 0.6 to 2 GeV (1987BE25; to ¹²N*(0 + 0.96, 4., 7.). ¹²N*(4.) is assumed to be a 2^- state while ¹²N*(7.) corresponds to a group of 1^- states. The reaction appears to be single-step direct and is well described by DWIA (1987BE25). At E(³He) = 197 MeV (θ = 0°) the spectrum shows ¹²N*(0, 0.96), an ≈ 1 MeV wide state at 4.3 MeV (possibly 2^-, 4^-) and the GDR at ≈ 10 MeV (≈ 84% of the strength is 1^-). No structure is observed between E_x = 15 and 70 MeV (1984TA11). The spectra of inelastically scattered ³He ions (see ¹²C) and of tritons have been studied at E(³He) = 170 MeV. The triton spectrum has been compared with photoabsorption results. (1982TA05) conclude that the isovector GDR is preferentially excited in the (³He, t) process while the (³He, ³He) process preferentially excites the isoscalar giant multipole resonances. Delta isobar excitation has been studied at 1.5, 2.0 and 2.3 GeV (1986CO03). See also (1988AB08), (1984AB06, 1988JA1F, 1989JAZY), (1984GA36, 1984GE1A, 1985RO1N, 1986EL1C, 1986GA1P, 1987EL08, 1987EL14, 1988RO17) and (1984CH1N, 1985JA13, 1987DM02, 1987GU07, 1988ES1A, 1988UD03; theor.).

6. 12C(6Li, 6He)12N

At E(⁶Li) = 25 and 35 MeV/A angular distributions have been studied to ¹²N_g.s. (1987WI09). At the higher energy ¹²N*(1.0) is also populated as is a broad structure near 4.25 MeV. At forward angles the cross section for the GT transition in this and in other (⁶Li, ⁶He) reactions is found to be proportional to the β-decay strength (1986AN29). See also (1984GL06) and (1987AU04, 1988AN06, 1988AU1E, 1989AU1B).

7. 12C(12C, 12B)12N

Qm = -30.708

See ¹²B.

8. 12C(13C, 13B)12N

Qm = -30.776

At E(¹³C) = 30 MeV/A ¹²N*(0, 1.0) are populated but the dominant groups in the forward direction are broad structures at E_x = 4.2 and 7.5 MeV attributed to 2^- and 1^- states (1986VO02, 1988VO06).

9. 12C(14N, 14C)12N

Qm = -17.495

See (1986BA16, 1986EL1C, 1986RO1Q).

10. 14N(p, t)12N

Qm = -22.136

At E_p = 51.9 MeV angular distributions of the tritons to ¹²N*(0, 0.96) and of the ³He ions to the analog T = 1 states [¹²C*(15.11, 16.11)] have been measured. At E_p = 52.5 MeV the angular distribution to ¹²N*(2.44) has been studied. See (1980AJ01) for references.