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Synopsis

The neutron is one of the most fundamental particles in the universe. A part of almost every atom, we know that the neutron is crucial for the stability of many atomic nuclei. Understanding the lifetime and decay of the free neutron is important for particle physics and for cosmology. There are two types of experiments for determining free neutron lifetime: the bottle experiment and the beam experiment, that yield different values for the lifetime of the free neutron. These two styles of experiments will be described in the talk. Assuming a good understanding of the neutron’s decay channels, these two experiments should yield the same results for the free neutron’s lifetime. The precise lifetime of the free neutron has puzzled physicists since the early 1990s, when the differences in the two styles of experiments changed from statistical fluctuation to a real 4σ phenomenon that demanded an explanation with τbottle ≈ 877.75s and τbeam ≈ 887.7s.