Magnetic anomaly in UCN trapping: signal for neutron oscillations to parallel world?

Abstract

Present experiments do not exclude that the neutron n oscillates, with an appreciable probability, into its invisible degenerate twin from a parallel world, the so-called mirror neutron n . These oscillations were searched experimentally by monitoring the neutron losses in ultra-cold neutron traps, where they can be revealed by the magnetic field dependence of n-n transition probability. In this work we reanalyze the experimental data acquired by the group of A.P. Serebrov at Institute Laue-Langevin, and find a dependence at more than 5σ away from the null hypothesis. This anomaly can be interpreted as oscillation of neutrons to mirror neutrons with a timescale of few seconds, in the presence of a mirror magnetic field order 0.1 G at the Earth. This result, if confirmed by future experiments, will have deepest consequences for fundamental particle physics, astrophysics and cosmology.

Neutron–antineutron oscillation and baryonic majoron: low scale spontaneous baryon violation

“…Existing experimental limits on the n-n transition [32][33][34][35][36] allow the neutron-mirror neutron oscillation time to be less than the neutron lifetime, with interesting implications for astrophysics and particle phenomenology [5,[37][38][39][40][41][42][43]. Let us discuss the physics of the baryo-majoron, β, Goldstone boson related to the spontaneous breaking of global U (1) B symmetry.…”

Gauged $$B-L$$ B - L number and neutron–antineutron oscillation: long-range forces mediated by baryophotons

“…for M D ∼ 100 TeV the n-n mixing mass can be as large as ε nñ ∼ 10 −17 eV, corresponding to an n-ñ oscillation time τ nñ = ε −1 nñ of the order of 100 s. As a matter of fact, n-ñ mixing can indeed be much larger than n-ñ. Existing experimental limits [47][48][49][50][51][52] allow the nn oscillation time to be less than the neutron lifetime, with interesting implications for astrophysics and particle phenomenology [4,44,[53][54][55][56].…”

A quest for new physics inside the neutron

“…Here comes the hypothesis [9] that inside a trap neutrons may undergo oscillations into mirror neutrons which freely leave the trap. More than that, neutron-mirror-neutron oscillation frequency is sensitive to the direction of a hypothetical mirror magnetic field.…”

“…Pomeranchuk in 1966. Necessary to note, however, that for the proposal [9] to work the oscillation time τ nn ′ has to be as small as a few seconds. Present experimental lower limit on τ nn ′ is τ nn ′ > 414s [10].…”