Neutron lifetime measurement with pulsed cold neutrons

The neutron lifetime has been measured by comparing the decay rate with the reaction rate of He-3 nuclei of a pulsed neutron beam from the spallation neutron source at the Japan Proton Accelerator Research Complex (J-PARC). The decay rate and the reaction rate were determined by simultaneously detecting electrons from the neutron decay and protons from the He-3(n, p)H-3 reaction using a gas chamber, the working gas of which contains diluted He-3. The measured neutron lifetime was 898 +/- 10(stat) (+15)(-18)(sys) S.

Automated summary

The neutron lifetime was measured by comparing the decay rate with the reaction rate of He-3 nuclei in a pulsed neutron beam from J-PARC, with the measured neutron lifetime being 898 +/- 10(stat) (+15)(-18)(sys) seconds.