1KOSSERT 2003 gets $\alpha _{{{\mathit n}}}−\beta _{{{\mathit n}}}$ =($9.8$ $\pm3.6$ ${}^{+2.1}_{-1.1}\pm2.2){\times }10^{-4}~$fm${}^{3}$, and uses $\alpha _{{{\mathit n}}}+\beta _{{{\mathit n}}}$ = ($15.2$ $\pm0.5$) $ \times 10^{-4}~$fm${}^{3}$ from LEVCHUK 2000. Thus the errors on $\alpha _{{{\mathit n}}}$ and $\beta _{{{\mathit n}}}$ are anti-correlated.
2LUNDIN 2003 measures $\alpha _{\mathit N}−\beta _{\mathit N}$ = ($6.4$ $\pm2.4$) $ \times 10^{-4}$ fm${}^{3}$ and uses accurate values for $\alpha _{{{\mathit p}}}$ and $\alpha _{{{\mathit p}}}$ and a precise sum-rule result for $\alpha _{{{\mathit n}}}+\beta _{{{\mathit n}}}$. The second error is a model uncertainty, and errors on $\alpha _{{{\mathit n}}}$ and $\beta _{{{\mathit n}}}$ are anticorrelated.
3KOLB 2000 obtains this value with an upper limit of $7.6 \times 10^{-4}~$fm${}^{3}$ but no lower limit from this experiment alone. Combined with results of ROSE 1990, the 1-$\sigma $ range is ($1.2 - 7.6){\times }10^{-4}~$fm${}^{3}$.
References:
MYERS
2014
PRL 113 262506
Measurement of Compton Scattering from the Deuteron and an Improved Extraction of the Neutron Electromagnetic Polarizabilities
KOSSERT
2003
EPJ A16 259
Quasifree Compton Scattering and the Polarizabilities of the Neutron
Also
PRL 88 162301
Neutron Polarizabilities Investigated by Quasifree Compton Scattering from the Deuteron
LUNDIN
2003
PRL 90 192501
Compton Scattering from the Deuteron and Neutron Polarizabilities
KOLB
2000
PRL 85 1388
Quasifree Compton Scattering from the Deuteron and Nucleon Polarizabilities