Exotic decay channels are not the cause of the neutron lifetime anomaly

Understand

Since long neutron lifetimes measured with a beam of cold neutrons are significantly different from lifetimes measured with ultracold neutrons bottled in a trap.

• It is often speculated that this "neutron anomaly" is due to an exotic dark neutron decay channel of unknown origin.
• We show that this explanation of the neutron anomaly can be excluded with a high level of confidence when use is made of new data on neutron decay parameters.
• Furthermore, data from neutron decay now compare well with Ft data derived from nuclear \b{eta} decays.