A search for neutron to mirror-neutron oscillations using the nEDM apparatus at PSI

Abel, C.; Ayres, N.J.; Ban, G.; Bison, G.; Bodek, K.; Bondar, V.; Chanel, E.; Chiu, P.-J.; Crawford, C.; Daum, M.; Dinani, R.T.; Emmenegger, S.; Flaux, P.; Ferraris-Bouchez, L.; Griffith, W.C.; Grujić, Z.D.; Hild, N.; Kirch, K.; Koch, H.-C.; Koss, P.A.; Kozela, A.; Krempel, J.; Lauss, B.; Lefort, T.; Leredde, A.; Mohanmurthy, P.; Naviliat-Cuncic, O.; Pais, D.; Piegsa, F.M.; Pignol, G.; Rawlik, M.; Rebreyend, D.; Rienäcker, I.; Ries, D.; Roccia, S.; Rozpedzik, D.; Schmidt-Wellenburg, P.; Severijns, N.; Thorne, J.; Weis, A.; Wursten, E.; Zejma, J.; Zsigmond, G.

doi:10.1016/j.physletb.2020.135993

A search for neutron to mirror-neutron oscillations using the nEDM apparatus at PSI

Abel C, Ayres NJ, Ban G, Bison G, Bodek K, Bondar V, Chanel E, Chiu P-J, Crawford C, Daum M, Dinani RT, Emmenegger S, Flaux P, Ferraris-Bouchez L, Griffith WC, Grujić ZD, Hild N, Kirch K, Koch H-C, Koss PA, Kozela A, Krempel J, Lauss B, Lefort T, Leredde A, Mohanmurthy P, Naviliat-Cuncic O, Pais D, Piegsa FM, Pignol G, Rawlik M, Rebreyend D, Rienäcker I, Ries D, Roccia S, Rozpedzik D, Schmidt-Wellenburg P, Severijns N, Thorne J, Weis A, Wursten E, Zejma J & Zsigmond G

Citation

Abel, C., Ayres, N. J., Ban, G., Bison, G., Bodek, K., Bondar, V., … Zsigmond, G. (2021). A search for neutron to mirror-neutron oscillations using the nEDM apparatus at PSI. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 812, 135993 (7 pp.). https://doi.org/10.1016/j.physletb.2020.135993

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:35644

It has been proposed that there could be a mirror copy of the standard model particles, restoring the parity symmetry in the weak interaction on the global level. Oscillations between a neutral standard model particle, such as the neutron, and its mirror counterpart could potentially answer various standing issues in physics today. Astrophysical studies and terrestrial experiments led by ultracold neutron storage measurements have investigated neutron to mirror-neutron oscillations and imposed constraints on the theoretical parameters. Recently, further analysis of these ultracold neutron storage experiments has yielded statistically significant anomalous signals that may be interpreted as neutron to mirror-neutron oscillations, assuming nonzero mirror magnetic fields. The neutron electric dipole moment collaboration performed a dedicated search at the Paul Scherrer Institute and found no evidence of neutron to mirror-neutron oscillations. Thereby, the following new lower limits on the oscillation time were obtained: τ_nn’ > 352 s at B’ = 0 (95% C.L.), τ_nn’ > 6 s for 0.4 μT < B’ < 25.7 μT (95% C.L.), and τ_nn’ / √cos β > 9 s for 5.0 μT < B’ < 25.4 μT (95% C.L.), where β is the fixed angle between the applied magnetic field and the local mirror magnetic field, which is assumed to be bound to the Earth. These new constraints are the best measured so far around B’ ∼ 10 μT and B’ ~20 μT.