학술논문
Statistical sensitivity of the nEDM apparatus at PSI to neutron mirror-neutron oscillations
Document Type
Working Paper
Author
Abel, C.; Ayres, N.; Bison, G.; Bodek, K.; Bondar, V.; Chiu, P. -J.; Daum, M.; Emmenegger, S.; Flaux, P.; Ferraris-Bouchez, L.; Griffth, W. C.; Hild, N.; Kirch, K.; 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.; Ries, D.; Roccia, S.; Rozpedzik, D.; Schmidt-Wellenburg, P.; Schnabel, A.; Severijns, N.; Thorne, J.; Virot, R.; Zejma, J.; Zsigmond, G.
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Subject
Language
Abstract
The neutron and its hypothetical mirror counterpart, a sterile state degenerate in mass, could spontaneously mix in a process much faster than the neutron $\beta$-decay. Two groups have performed a series of experiments in search of neutron - mirror-neutron ($n-n'$) oscillations. They reported no evidence, thereby setting stringent limits on the oscillation time $\tau_{nn'}$. Later, these data sets have been further analyzed by Berezhiani et al.(2009-2017), and signals, compatible with $n-n'$ oscillations in the presence of mirror magnetic fields, have been reported. The Neutron Electric Dipole Moment Collaboration based at the Paul Scherrer Institute performed a new series of experiments to further test these signals. In this paper, we describe and motivate our choice of run configurations with an optimal filling time of $29~$s, storage times of $180~$s and $380~$s, and applied magnetic fields of $10~\mu$T and $20~\mu$T. The choice of these run configurations ensures a reliable overlap in settings with the previous efforts and also improves the sensitivity to test the signals. We also elaborate on the technique of normalizing the neutron counts, making such a counting experiment at the ultra-cold neutron source at the Paul Scherrer Institute possible. Furthermore, the magnetic field characterization to meet the requirements of this $n-n'$ oscillation search is demonstrated. Finally, we show that this effort has a statistical sensitivity comparable to the current leading constraints for $n-n'$ oscillations.
Comment: Proceedings of International Workshop on Particle Physics at Neutron Sources, PPNS-2018; May 24-26, 2018, LPSC, Grenoble, France; Abs. ID: 28 and 60. 10 Pages, 9 Figures
Comment: Proceedings of International Workshop on Particle Physics at Neutron Sources, PPNS-2018; May 24-26, 2018, LPSC, Grenoble, France; Abs. ID: 28 and 60. 10 Pages, 9 Figures