11Li

β--Decay Evaluated Data



Measurements
1969KL08: 11Li; measured T1/2.
1974RO31: 11Li; measured Eγ, Iγ, T1/2, delayed neutrons, βγ-coin, Eβ.
1975TH08: 11Li; measured neutron binding energy, delayed neutron branching ratio, T1/2; deduced log ft.
1979ANZZ: 11Li; 11Li deduced evidence for β-delayed 2n emission.
1979AZ03: 11Li; measured β-delayed En, nn-coin. 11Be levels deduced 1n, 2n decay probabilities.
1979DEYX, 1980DE39, 1980DEZF: 11Li; measured Eγ, Iγ, Iβ, β-delayed En, In; deduced log ft, total β-delayed neutron emission probability.
1980AZ01: 11Li; measured β-delayed, one-, two-, three-neutron emission intensity In, relative two-, three-neutron branching ratios.
1981BJ01: 11Li; measured βn-coin; 11Li measured T1/2, βγ-coin; deduced log ft, β-delayed neutron emission probability.
1981JOZV: 11Li(β-n); compiled, reviewed β-delayed multineutron emission probabilities.
1981LA11: 11Li; measured β-delayed Eα, βα-coin. 11Li; measured β-delayed E(6He), β(6He)-coin; deduced log ft. 11Li deduced three neutron emission probability, β-delayed I(n). 11Be levels deduced anti-analog character.
1984LA27: 11Li(β-); measured β-delayed charged particle spectra; deduced branching ratios for β-delayed triton emission and other channels. 11Be deduced levels, decay branches.
1984LAZS: 11Li(β-); measured β-delayed n-, t-emission.
1986CU01, 1986HAYX, 1993SHZW: 11Li; measured β-decay T1/2.
1987AR22, 1987ARZN: 11Li(β-); measured β-asymmetry, NMR, hfs. 11Li deduced level J, μ.
1991BO31, 1995BOZT: 11Li; measured continuum particle spectra following β-decay; deduced log ft, Gamow-Teller transition strength, level width, di-neutron, neutron halo roles.
1992LI24: 11Li(β-); measured β NMR asymmetry; deduced quadrupole moment ratio.
1993NE08: 11Li(β-); measured β-NMR asymmetry; deduced 11Li quadrupole moments.
1994AR19: 11Li(β-); measured β-NMR, polarized source; deduced quadrupole moment ratio.
1994JO04: 11Li(β-); compiled, reviewed β-decay data; deduced halo role.
1996MU19: 11Li(β-); measured β-delayed deuteron-, triton-total energy spectra, β-delayed charged particles count rate vs elapsed time; deduced β-delayed deuteron emission associated branching ratio lower limit.
1997AO01, 1997AO04: 11Li(β-); measured beta-delayed neutron-, γ-spectra, γγγ-coin; deduced log ft, halo neutron related features. 11Be deduced levels. Tof.
1997BO01: 11Li(β-); measured βγ-coin, Eγ, Iγ. 11Be levels deduced branching ratio. 11Li deduced ground state s-wave component.
1997BO03: 11Li(β-); measured β-delayed d, t, 4,6He, 9,10Be spectra. 11Be level deduced Gamow-Teller strength, branching ratios.
1997MO35: 11Li(β-n); measured β-delayed En, In, Eγ, Iγ, T1/2. 11Be deduced levels, branching ratios, Gamow-Teller strength distributions, 11Li neutron halo dependence.
1997MU06: 11Li(β-); analyzed β-delayed deuteron, triton spectra, α-, 6He-, 9,10Be-spectra. 11Be deduced possible level, Γ, Gamow-Teller strength.
1997RI04: 11Li(β-); compiled, reviewed β-delayed deuteron, triton spectra, particle correlation; deduced halo orbital structure role.
1997SO34: 11Li(β-n); measured decay products, En, In; deduced neutron emission probabilities.
1997YOZW: 11Li(β-n); measured Eβ, E(n), Eγ, βnγ-coin; deduced log ft. 11Be deduced levels, J, π:, delayed neutron branchings.
2004FY01: 11Li(β-), (β-n); measured β-delayed Eγ, Iγ, βγ-coin, DSA; deduced neutron spectrum. 10,11Be deduced excited states T1/2.
2004HI12: 11Li(β-), (β-n); measured β-delayed En, Eγ, βγ-, nβ-coin following decay of spin-polarized source; deduced log ft. 11Be deduced levels, J, π, neutron spectroscopic factors. 10Be deduced levels, transition intensities.
2004HI24: 11Li(β-), (β-n); measured β-delayed Eγ, En, asymmetry following decay of spin-polarized source. 10,11Be deduced levels, J, π.
2004SA46: 11Li(β-), (β-n); measured Eγ, Iγ, β-delayed neutron spectra. 10,11Be deduced levels, J, π, halo features.
2005HI03: 11Li(β-), (β-n); measured β-delayed Eγ, En, asymmetry following decay of spin-polarized source. 10,11Be deduced levels, J, π, S-factors.
2007RAZS: 11Li(β-); measured β-delayed deuteron, triton, charged particle total energy spectra.
2008MA34: 11Li(β-); measured β-delayed charged-particle spectra. 11Be deduced subsequent break-up decay channels.
2008MAZY: 11Li(β-); measured β-delayed Eα, Iα, αα-coin. 11Be; deduced levels, partial decay branches.
2008RA23: 11Li(β-); measured β-delayed deuteron spectrum. Deduced transition probability.
2009BAZT: 11Li(β-); measured Eβ, Iβ, Eγ, Iγ, β-γ-coin.; deduced J, π, transition strengths.
2009MA31: 11Li(β-); Measured Eβ, Iβ, Eα, Iα, (charged-particle)(charged-particle)-coin in a kinematically complete experiment; deduced B(GT). 11Be; deduced level energy, J, π using Monte Carlo.
2009MA54: 11Li(β-), (β-n); Measured Eγ, Iγ, γγ-, βγ-coin, half-lives by line-shape method using 8π array. 11Be; deduced levels, J, π, branching ratios, B(E1), delayed neutron emission probabilities.
2011RA16: 11Li(β-); measured decay products; deduced neutron halo.
Measured half-life for 11Li(β-)11Be

Recommended value (August, 2015): 8.74 ± 0.15 ms
Summary Table of Uncertainty Analysis:     Table 11Li preview (PDF)  
Measured values: 8.99 ± 0.10 ms (1997MO35)
8.0 ± 1.0 ms (1997SO34) (Excluded: insufficient experimental details)
8.2 ± 0.2 ms (1996MU19)
8.4 ± 0.2 ms (1995RE1M: see also 8.4 ± 0.2 ms in the unpublished private
communications of (2008REZZ)/(1995REZZ).)
7.7 ± 0.6 ms (1986CU01)
8.83 ± 0.12 ms (1981BJ01)
8.5 ± 0.2 ms (1974RO31)
8.8 ± 1.4 ms (1974RO31)
9.0 ± 0.8 ms (1974RO31)
8.5 ± 1 ms    (1969KL08)
Other Reviews: 8.58 ± 0.32 ms (2015BI05)


Previous Measurements

 

Eγ a (keV) Ei → Ef a T1/2 (fs) I (%)
(2004HI12) a (2004HI12) (2004FY01) b (1997MO35) (1997BO01) c (1981BJ01) (1980DE39)
  219.2 ± 0.5     6180.3 ± 0.5 → 5961.1 ± 0.5   0.67 ± 0.03 0.46 ± 0.09 0.31 ± 0.05    0.78 ± 0.06 0.55 ± 0.10 0.5   0.95 ± 0.35
  320.0 ± 0.5 11Be*(0.320 → 0)               7.69 ± 0.40 7.7 ± 0.8 6.3 ± 0.6    7.8 ± 0.8 6.3 ± 0.6 7.6 ± 0.8 9.2 ± 0.7 5.2 ± 1.4
2590.3 ± 0.5 5958.4 ± 0.5 → 3368.0      e, f 0.23 ± 0.10 9.3 ± 1.4 7.6 ± 0.3    6 ± 1 8.0 ± 1.2 8.5   3.5 ± 1.0
2592.7 ± 0.5 5961.1 ± 0.5 → 3368.0      e, f 8.75 ± 0.20 0.08+3-5 0.8 ± 0.1             
2811.8 ± 0.5 6180.3 ± 0.5 → 3368.0      e, f 1.03 ± 0.03 1.2 ± 0.2 1.07 ± 0.20    2.8 ± 0.3 0.8 ± 0.2 1.0   1.6 ± 0.7
2896.0 ± 0.5 6264.5 ± 0.5 g → 3368.0         85+27-17 e, f 1.05 ± 0.53 2.2 ± 0.4 1.47 ± 0.25 d          
3367.1 ± 0.5 3368.0 → 0        33 a 37.0 ± 5.5   33 a 33 ± 3   29 ± 3   33.3   35 ± 3   21 ± 6  
5956.5 ± 1.0 5958.4 → 0        0.96 ± 0.3   0.36 ± 0.20 3.0 ± 0.7             
5959.2 ± 1.0 5961.1 ± 0.5 → 0                 0.43 ± 0.10 0.38 ± 0.09            
a) (2004SA46). Intensity normalized here to give I(3368) = 33%.
b) Assuming I(3368) = 33% from (1997MO35, 1997AO01)
c) (1997AO01, 1997AO04)
d) (1980DE39).
e) (2004SA46) deduced T1/2 = 85 ± 6 (stat.) ± 10 (sys.) fs, 870 ± 70 ± 160 fs, less than a few hundred fs, and 60.0 ± 1.6 ± 6.0 fs for 10Be*(6.264, 6.180, 5.961, 5.958), respectively.
f) (2004FY01) deduced T1/2 = 230 ± 60 fs, 1.10 ± 0.25 ps, 330 ± 130 fs, and > 50 fs for 10Be*(6.264, 6.180, 5.961, 5.958), respectively.
g) (2004FY01) measured Ei = 6264.5 ± 2.0.

11Li Decay Scheme

 

β-decay to 11Be*
(MeV)
Branching ratio to
10Be excited states (%)
11Be n-decay to 10Be*
(MeV)
Branching ratio
(%)
A B A B A B A B
  0.320 0.320 6.3 ± 0.6 7.69 ± 0.40    
  3.41+   20.92 ± 0.69     3.368   20.92 ± 0.69  
3.96(+3.86)   7.5 ± 1.1   3.368   7.5 ± 1.1  
5.85   6.6 ± 1.3   3.368   6.6 ± 1.3  
  8.03 ± 0.07   8.35 ± 0.20   6.180   1.71 ± 0.05
  5.958   6.63 ± 0.20
8.82 8.81 ± 0.04 8.0 ±       5.12 ± 0.20 6.265 6.264 1.47 ± 0.25 2.05 ± 0.05
5.958 5.958 6.45 ± 0.30 3.07 ± 0.20
  9.6-10.0   8.0 ± 1.5   3.368   8.0 ± 1.5  
11-16   3.5 ± 0.8   5.960   3.5 ± 0.8  
13.5-16      1.15 ± 0.1     5.958   1.15 ± 0.1    
13.5-20      1.38 ± 0.25   6.179   1.38 ± 0.25  
A: (2004FY01). Normalized to give I (10Be*(3.368 → 0)) = 33%.
B: (2004SA46). Normalized to give I (10Be*(3.368 → 0)) = 33%.

γ-Rays Observed in 11Li Decay (2005HI03)

 

β-decay to 11Be*
(MeV)
Jπ Branching ratio
(%)
log ft 11Be n-decay to 10Be*
(MeV)
Branching ratio
(%)
0.32    1/2- a 7.7 ± 0.8 5.67 ± 0.04    
2.69 3/2- 17 ± 4   5.06 ± 0.10 0 17 ± 4  
3.41 3/2- 0.9 ± 0.4 6.25 ± 0.10 (0) (0.9 ± 0.4)
3.89 5/2- 22.7 ± 4.5   4.78+0.07-0.10 0 8.7 ± 2.0
3.368 14+3.2-4.7
3.96 3/2- 6.8 ± 2.4 5.30+0.28-0.13 0 1.5 ± 0.3
3.368 5.3+4.4-2.1
5.24 5/2- 2.4 ± 0.5 5.55 ± 0.08 3.368 2.4 ± 0.5
7.03 (5/2-) 0.86 ± 0.17 5.77 ± 0.09 (3.368) (0.86 ± 0.17)
8.02 3/2- 15.5 ± 3.1   4.30 ± 0.08 0 0.8 ± 0.1
3.368 3.5 ± 0.7
5.958 9.7 ± 1.4
6.179 1.7 ± 0.3
8.82 3/2- 8.9 ± 1.4    4.46 ± 0.07 b 6.263 2.2 ± 0.4
(7.371) (6.7 ± 1.3)
10.6     5/2- 7.8 ± 1.8    4.18 ± 0.12 b 0 0.20 ± 0.05
(3.368) (0.41 ± 0.08)
(9.27+9.4) c (7.2 ± 1.7)
a) From Adopted Levels.
b) Decay path assumed to account for neutron energy spectrum.
c) Decays to 9Be + n with intensity 3.4 ± 0.7 per 100 11Li decay.

11Be(β-)11B Evaluated Data

11C(β+)11B Evaluated Data

A = 11 Beta-Decays Diagram

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Last modified: 21 May 2018