Precise Neutron Lifetime Measurement Using Pulsed Neutron Beams at J-PARC

Understand

A neutron decays into a proton, an electron, and an anti-neutrino through the beta-decay process.

• The decay lifetime ($\sim$880 s) is an important parameter in the weak interaction.
• For example, the neutron lifetime is a parameter used to determine the |$V_{\rm ud}$| parameter of the CKM quark mixing matrix.
• The lifetime is also one of the input parameters for the Big Bang Nucleosynthesis, which predicts light element synthesis in the early universe.