An Improved Search for the Neutron Electric Dipole Moment

M. Burghoff; A. Schnabel; G. Ban; T. Lefort; Y. Lemiere; O. Naviliat-Cuncic; E. Pierre; G. Quemener; J. Zejma; M. Kasprzak; P. Knowles; A. Weis; G. Pignol; D. Rebreyend; S. Afach; G. Bison; J. Becker; N. Severijns; S. Roccia; C. Plonka-Spehr; J. Zennerz; W. Heil; H. C. Koch; A. Kraft; T. Lauer; Yu. Sobolev; Z. Chowdhuri; J. Krempel; B. Lauss; A. Mtchedlishvili; P. Schmidt-Wellenburg; G. Zsigmond; M. Fertl; B. Franke; M. Horras; K. Kirch; F. Piegsa

arXiv · 1110.1505

An Improved Search for the Neutron Electric Dipole Moment

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Abstract

A permanent electric dipole moment of fundamental spin-1/2 particles violates both parity (P) and time re- versal (T) symmetry, and hence, also charge-parity (CP) symmetry since there is no sign of CPT-violation. The search for a neutron electric dipole moment (nEDM) probes CP violation within and beyond the Stan- dard Model. The experiment, set up at the Paul Scherrer Institute (PSI), an improved, upgraded version of the apparatus which provided the current best experimental limit, dn < 2.9E-26 ecm (90% C.L.), by the RAL/Sussex/ILL collaboration: Baker et al., Phys. Rev. Lett. 97, 131801 (2006). In the next two years we aim to improve the sensitivity of the apparatus to sigma(dn) = 2.6E-27 ecm corresponding to an upper limit of dn < 5E-27 ecm (95% C.L.), in case for a null result. In parallel the collaboration works on the design of a new apparatus to further increase the sensitivity to sigma(dn) = 2.6E-28 ecm.

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M. Burghoff, A. Schnabel, G. Ban, T. Lefort, Y. Lemiere, O. Naviliat-Cuncic, E. Pierre, G. Quemener, J. Zejma, M. Kasprzak, P. Knowles, A. Weis, G. Pignol, D. Rebreyend, S. Afach, G. Bison, J. Becker, N. Severijns, S. Roccia, C. Plonka-Spehr, J. Zennerz, W. Heil, H. C. Koch, A. Kraft, T. Lauer, Yu. Sobolev, Z. Chowdhuri, J. Krempel, B. Lauss, A. Mtchedlishvili, P. Schmidt-Wellenburg, G. Zsigmond, M. Fertl, B. Franke, M. Horras, K. Kirch, F. Piegsa. 2011-10-07. An Improved Search for the Neutron Electric Dipole Moment. https://arxiv.org/abs/1110.1505

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