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arXiv · 1712.05761

New experimental limits on neutron - mirror neutron oscillations in the presence of mirror magnetic field

Z. Berezhiani·R. Biondi·P. Geltenbort·I. A. Krasnoshchekova·V. E. Varlamov·A. V. Vassiljev·O. M. Zherebtsov
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Abstract

Present probes do not exclude that the neutron ($n$) oscillation into mirror neutron ($n'$), a sterile state exactly degenerate in mass with the neutron, can be a very fast process, in fact faster than the neutron decay itself. This process is sensitive to the magnetic field. Namely, if the mirror magnetic field $\vec{B}'$ exists at the Earth, $n-n'$ oscillation probability can be suppressed or resonantly amplified by the applied magnetic field $\vec{B}$, depending on its strength and on the angle $β$ between $\vec{B}$ and $\vec{B}'$. We present the results of ultra-cold neutron storage measurements aiming to check the anomalies observed in previous experiments which could be a signal for $n-n'$ oscillation in the presence of mirror magnetic field $B'\sim 0.1$~G. Analyzing the experimental data on neutron loses, we obtain a new lower limit on $n-n'$ oscillation time $τ_{nn'} > 17$ s (95 % C.L.) for any $B'$ between 0.08 and 0.17 G, and $τ_{nn'}/\sqrt{\cosβ} > 27 $s (95 % C.L.) for any $B'$ in the interval ($0.06\div0.25$) G.

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Z. Berezhiani, R. Biondi, P. Geltenbort, I. A. Krasnoshchekova, V. E. Varlamov, A. V. Vassiljev, O. M. Zherebtsov. 2017-12-15. New experimental limits on neutron - mirror neutron oscillations in the presence of mirror magnetic field. https://doi.org/10.1140/epjc%2Fs10052-018-6189-y

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