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TitleEnergy Levels of Light Nuclei A = 14
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14Revised Manuscript 06 November 2000

Energy Levels of Light Nuclei
A = 14

F. Ajzenberg-Selove

University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396

Abstract: An evaluation of A = 13–15 was published in Nuclear Physics A523 (1991),
p. 1. This version of A = 14 differs from the published version in that we have corrected
some errors discovered after the article went to press. Introductory tables have
been omitted from this manuscript. Also, reference key numbers have been changed to the
NNDC/TUNL format.

(References closed July 1, 1990)

The original work of Fay Ajzenberg-Selove was supported by the US Department of Energy [DE-FG02-
86ER40279]. Later modification by the TUNL Data Evaluation group was supported by the US Department
of Energy, Office of High Energy and Nuclear Physics, under: Contract No. DEFG05-88-ER40441 (North
Carolina State University); Contract No. DEFG05-91-ER40619 (Duke University).

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Nucl. Phys. A523 (1991) 1 A = 14

Table of Contents for A = 14

Below is a list of links for items found within the PDF document. Links for the Update Lists
provide brief descriptions on important research bearing on level information published since the
last full evaluation.

A. Nuclides: 14He, 14Li, 14Be, 14B, 14C, 14N, 14O, 14F, 14Ne, 14Na, 14Mg

B. Master Tables:

Table 14.1: Energy levels of 14B

Table 14.3: Energy levels of 14C

Table 14.10: Energy levels of 14N

Table 14.22: Energy levels of 14O

C. References

D. Figures: 14B, 14C, 14N, 14O, Isobar diagram

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Angular distributions have been studied at E(6Li) = 34 and 62 MeV [see (86AJ01)], at 93 MeV
(86BR33, 87DE1G, 88DE1G, 89DE34; to 14N*(0, 3.95)) and at 84, 150 and 210 MeV (87WI09,
86AN29, 88AN06; to 14N*(0, 2.31, 3.95)). 14N*(3.95) dominates the spectra: see e.g. (87WI09).
14N*(5.11, 5.83, 6.20, 7.03, 8.49) are also populated (80WH03, 87WI09). For studies of the GT
strength see (80WH03, 87WI09). See also (87AU04, 88AU1E, 88GA1N, 89AU1B) and (86AJ01).

40. (a) 14N(γ, n)13N Qm = −10.5535
(b) 14N(γ, p)13C Qm = −7.55063
(c) 14N(γ, d)12C Qm = −10.27239
(d) 14N(γ, π+)14C Qm = −139.725

The total absorption over the range Eγ = 9 to 31 MeV is dominated by a single peak at 22.5
MeV [estimated σ ≈ 29 mb, Γ ≈ 2− 3 MeV] and appreciable strength extending beyond 30 MeV.
The cross section cannot be accounted for solely by the (γ, n) and (γ, p0) processes: particle-
unstable excited states of 13C, 13N are involved. The combined (γ, n) and (γ, pn) cross section
begins to rise rapidly above 18 MeV, reaches its maximum value of 15 mb at 23.3 MeV and exhibits
structure at about 19, 20.5 and 26 MeV. The main peak (Γ ≈ 3.5 MeV: see (70AJ04)) at 23.3 MeV
appears to be split into two absorption levels: see (81AJ01). Maxima reported in other experiments
and “breaks” in the (γ, n) activation curve are listed in (70AJ04). Most of the photon absorption
in the giant resonance region forms Jπ = 2− states in 14N which decay by d-wave neutron emission
to 13Ng.s.. Some evidence is found for the existence of Jπ = 0− strength at the peak of the giant
resonance and for a small amount of isospin T = 0 mixing near 22.5 MeV: see (81AJ01). The cross
section for the (γ, n) reaction has recently been measured from threshold to 15.5 MeV (87FA14).
See also (88DI02).

The (γ, p0) and (γ, p2) cross sections and angular distributions have been measured in the
giant resonance region. The giant dipole states [(p3/2)

−1 (2s1d)] which decay by p0 emission to
13C*(3.68) appear to carry ≈ 90% of the E1 strength and do not contibute substantially to the (γ,
p0) process which is populated by (p1/2)

−1 (2s1d) giant dipole states. Above Eγ = 22 MeV d-wave
emission from 2− states appears to dominate the (γ, p0) cross section: see (76AJ04). For reaction
(c) see (87IM02). For rection (d) see 14C. See also (85FU1C) and (85GO1A, 86WI10, 87HU01,
87KI1C, 87LU1B, 88DU04; theor.).

41. 14N(γ, γ)14N

A measurement of the protons from the 14N(γ, p)13C reaction and a resonant absorption mea-
surement lead to Γγ0/Γ = 0.052 ± 0.004 for 14N*(9.17) and to Γ = 122± 8 eV (89VA21). See also
(86AJ01), Table 14.19, (85BE2F, 87BE1K) and (86DU1F; theor.).

42. (a) 14N(e, e)14N

(b) 14N(e, ep)13C Qm = −7.55063

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Table 14.19: 14N states from 14N(γ, γ′) and 14N(e, e′) a

Ex (MeV± keV) Mult. Jπ; T Γγ0 (eV) Γ (keV)
8.06 E1 1−; 1 10.5± 6
8.91 M2 3−; 1 (6.6± 2.2)× 10−3

9.17 M1 2+; 1 7.2± 0.4 b

6.3± 0.3 c

10.43 d M1 2+; 1 9.6± 1.9 e

11.24 f C3 (3−)

12.54± 100 e (M1, C2) J = 0, 1, 2, 3 14.7± 3.2
2J + 1

12.81 f C3 4−

13.27± 100 e (M1, M2, C2) J = 0, 1, 2, 3
13.76± 100 e (M1, C1) J = 0, 1, 2 (4± 1)× 10−3 g

14.72± 30 f M2 (2−; 1) ≈ 100
15.01± 30 f M4 3−, 4−; ≈ 1 ≈ 100
16.11± 100 e (M2) J = 0, 1, 2, 3
16.91± 20 f M4 5−; ≈ 1 170± 20
18.48± 40 f M4 5−; ≈ 1
20.11± 20 f M4 3−, 4−; ≈ 1 120± 20

a See Table 14.19 in (81AJ01) for references and additional information. See also Table 14.11
here.

b (81BI17)
c A. Richter and G. Kuehner, private communication; adopted.
d Γ = 44 keV, Γ
0 = 8.8 eV (A. Richter and G. Kuehner, private communication).
e (79EN01).
f (84BE13).
g And Γ = 105± 20 keV (A. Richter and G. Kuehner, private communication).

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