Improved Upper Limit to the Electric Dipole Moment of the Neutron

A neutron-beam magnetic-resonance experiment has been used to measure the electric dipole moment ${\mu }_e$ of the neutron. Although the results for ${\mu }_e$ differ from zero by 1.4 times the statistical error, the measurement is best interpreted as setting an upper limit on ${\mu }_e$ of $\left|\frac{{\mu }_e}{e}\right|<\mathrm{}5\mathrm{}\times {10}^{-23\mathrm{}}$ cm, where $e$ is the charge on the proton.