Neutron lifetime puzzle and neutron -- mirror neutron oscillation

Abstract

The discrepancy between the neutron lifetimes measured in the beam and trap experiments can be explained via the neutron $n$ conversion into mirror neutron $n^{\prime }$, its dark partner from parallel mirror sector, provided that $n$ and $n^{\prime }$ have a tiny mass splitting order $10^{-7}$ eV. In large magnetic fields used in beam experiments $n-n^{\prime }$ transition is resonantly enhanced and can transform of about a per cent fraction of neutrons into mirror neutrons which decay in invisible mode. Thus less protons will be produced and the measured value ${\tau }_{\mathrm{beam}}$ appears larger than $\beta$-decay time ${\tau }_{\beta }={\tau }_{\mathrm{trap}}$. Some phenomenological and astrophysical consequences of this scenario are also briefly discussed.

Comments: 6 pages, 2 figures