Université de Fribourg

A measurement of the neutron to 199Hg magnetic moment ratio

Afach, S. ; Baker, C. A. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Burghoff, M. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Grujic, Zoran ; Harris, P. G. ; Heil, W. ; Hélaine, V. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. N. ; Kasprzak, Malgorzata ; Kermaïdic, Y. ; Kirch, K. ; Knecht, A. ; Koch, Hans-Christian ; Krempel, J. ; Kuźniak, M. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pendlebury, J. M. ; Perkowski, M. ; Pierre, E. ; Piegsa, F. M. ; Pignol, G. ; Prashanth, P. N. ; Quéméner, G. ; Rebreyend, D. ; Ries, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Schnabel, A. ; Severijns, N. ; Shiers, D. ; Smith, K.F. ; Voigt, J. ; Weis, Antoine

In: Physics Letters B, 2014, vol. 739, p. 128–132

The neutron gyromagnetic ratio has been measured relative to that of the 199Hg atom with an uncertainty of 0.8 ppm. We employed an apparatus where ultracold neutrons and mercury atoms are stored in the same volume and report the result γn/γHg=3.8424574(30)γn/γHg=3.8424574(30).

Université de Fribourg

Testing isotropy of the universe using the Ramsey resonance technique on ultracold neutron spins

Altarev, I. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Daum, M. ; Fertl, M. ; Fierlinger, P. ; Franke, B. ; Gutsmiedl, E. ; Heil, W. ; Henneck, R. ; Horras, M. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Kraft, A. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pazgalev, Anatoly S. ; Petzoldt, G. ; Piegsa, F.M. ; Pierre, E. ; Pignol, G. ; Quéméner, G. ; Rebetez, M. ; Rebreyend, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Severijns, N. ; Sobolev, Yu. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

In: Physica B: Condensed Matter, 2011, vol. 406, no. 12, p. 2365-2369

Physics at the Planck scale could be revealed by looking for tiny violations of fundamental symmetries in low energy experiments. In 2008, a sensitive test of the isotropy of the universe has been performed with stored ultracold neutrons (UCN), this is the first clock-comparison experiment performed with free neutrons. During several days we monitored the Larmor frequency of neutron spins in a...

Université de Fribourg

The search for the neutron electric dipole moment at the Paul Scherrer Institute

Baker, C.A. ; Ban, G. ; Bodek, K. ; Burghoff, M. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Geltenbort, P. ; Green, K. ; Grinten, M.G.D. van der ; Gutsmiedl, E. ; Harris, P.G. ; Henneck, R. ; Iaydjiev, P. ; Ivanov, S.N. ; Khomutov, N. ; Kasprzak, Malgorzata ; Kirch, K. ; Kistryn, S. ; Knappe-Gr̈uneberg, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Naviliat-Cuncic, O. ; Pendlebury, J.M. ; Pierre, E. ; Piegsa, F.M. ; Pignol, G. ; Quéméner, G. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Shiers, D. ; Smith, K.F. ; Schnabel, A. ; Trahms, L. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

In: Physics Procedia, 2011, vol. 17, p. 159-167

The measurement of the neutron electric dipole moment (nEDM) constrains the contribution of CP-violating terms within both the Standard Model and its extensions. The experiment uses ultracold neutrons (UCN) stored in vacuum at room temperature. This technique provided the last (and best) limit by the RAL/Sussex/ILL collaboration in 2006: dn < 2:9 × 10⁻²⁶ e cm (90% C.L.). We aim to improve...

Université de Fribourg

Production of ultracold neutrons from cryogenic ²H₂, O₂, and C²H₄ converters

Atchison, F. ; Blau, B. ; Bodek, K. ; Brandt, B. van den ; Bryś, T. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Hautle, P. ; Henneck, R. ; Heule, S. ; Holley, A. ; Kasprzak, Malgorzata ; Kirch, K. ; Knecht, A. ; Konter, J. A. ; Kuźniak, M. ; Liu, C.-Y. ; Pichlmaier, A. ; Plonka, C. ; Pokotilovski, Y. ; Saunders, A. ; Tortorella, D. ; Wohlmuther, M. ; Young, A. R. ; Zejma, J. ; Zsigmond, G.

In: EPL - Europhysics Letters, 2011, vol. 95, no. 1, p. 12001

Ultracold neutrons (UCN) have been produced using the cold neutron (CN) beam FUNSPIN at SINQ on cryogenic oxygen (O₂), tetradeuteromethane (C²H₄), and deuterium (²H₂) targets. The target cell (40 mm long, fiducial volume about 45 cm³) was operated between room temperature and 8 K and UCN were produced from gaseous, liquid and solid targets. UCN rates have been measured as a convolution...

Université de Fribourg

Test of Lorentz invariance with spin precession of ultracold neutrons

Altarev, I. ; Baker, C. A. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Gutsmiedl, E. ; Harris, P. G. ; Heil, W. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. N. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Kuchler, F. ; Kuźniak, M. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pazgalev, Anatoly ; Pendlebury, J. M. ; Petzoldt, G. ; Pierre, E. ; Pignol, G. ; Quéméner, G. ; Rebetez, Martin ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Severijns, N. ; Shiers, D. ; Sobolev, Yu. ; Weis, Antoine ; Zejma, J. ; Zsigmond, G.

In: Physical Review Letters, 2009, vol. 103, no. 8, p. 081602

A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and ¹⁹⁹Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b⊥<2×10⁻²⁰ eV (95% C.L.). This is the first limit for the free neutron. This result...

Université de Fribourg

Neutron to mirror-neutron oscillations in the presence of mirror magnetic fields

Altarev, I. ; Baker, C. A. ; Ban, G. ; Bodek, K. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Gutsmiedl, E. ; Harris, P. G. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Kuchler, F. ; Kuźniak, M. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Paul, S. ; Pazgalev, Anatoly ; Pendlebury, J. M. ; Petzoldt, G. ; Pierre, E. ; Plonka-Spehr, C. ; Quéméner, G. ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Severijns, N. ; Shiers, D. ; Sobolev, Yu. ; Stoepler, R. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

In: Physical Review D, 2009, vol. 80, no. 3, p. 032003

We performed ultracold neutron storage measurements to search for additional losses due to neutron (n) to mirror-neutron (n') oscillations as a function of an applied magnetic field B. In the presence of a mirror magnetic field B', ultracold neutron losses would be maximal for B~B'. We did not observe any indication for...

Université de Fribourg

Towards a new measurement of the neutron electric dipole moment

Altarev, I. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Burghoff, M. ; Cvijovic, Milan ; Daum, M. ; Fierlinger, P. ; Gutsmiedl, E. ; Hampel, G. ; Heil, W. ; Henneck, R. ; Horras, M. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knappe-Grüneberg, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Kratz, J. V. ; Kuchler, F. ; Kuźniak, M. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Paul, S. ; Pazgalev, Anatoly S. ; Petzoldt, G. ; Pierre, E. ; Plonka-Spehr, C. ; Quéméner, G. ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Sander-Thoemmes, T. ; Schnabel, A. ; Severijns, N. ; Sobolev, Yu. ; Stoepler, R. ; Trahms, L. ; Weis, Antoine ; Wiehl, N. ; Zejma, J. ; Zsigmond, G.

In: Nuclear Instruments and Methods in Physics Research Section A, 2009, p. -

The effort towards a new measurement of the neutron electric dipole moment (nEDM) at the Paul Scherrer Institut's (PSI) new high intensity source of ultracold neutrons (UCN) is described. The experimental technique relies on Ramsey's method of separated oscillatory fields, using UCN in vacuum with the apparatus at ambient temperature. In the first phase, R&D towards the upgrade of the...

Université de Fribourg

Additional results from the first dedicated search for neutron–mirror–neutron oscillations

Bodek, K. ; Kistryn, S. ; Kuźniak, M. ; Zejma, J. ; Burghoff, M. ; Knappe-Grüneberg, S. ; Sander-Thoemmes, T. ; Schnabel, A. ; Trahms, L. ; Ban, G. ; Lefort, T. ; Naviliat-Cuncic, O. ; Khomutov, N. ; Knowles, Paul E. ; Pazgalev, Anatoly S. ; Weis, Antoine ; Rogel, G. ; Quéméner, G. ; Rebreyend, D. ; Roccia, S. ; Bison, Georg ; Severijns, N. ; Eberhardt, K. ; Hampel, G. ; Heil, W. ; Kratz, J.V. ; Lauer, T. ; Plonka-Spehr, C. ; Sobolev, Yu. ; Wiehl, N. ; Altarev, I. ; Fierlinger, P. ; Gutsmiedl, E. ; Paul, S. ; Stoepler, R. ; Daum, M. ; Henneck, R. ; Kirch, K. ; Knecht, A. ; Lauss, B. ; Mtchedlishvili, A. ; Petzoldt, G. ; Zsigmond, G.

In: Nuclear Instruments and Methods in Physics Research Section A, 2009///doi: 10.1016/j.nima.2009.07.047

The existence of a mirror world holding a copy of our ordinary particle spectrum could lead to oscillations between the neutron (n) and its mirror partner (n′). Such oscillations could manifest themselves in storage experiments with ultracold neutrons whose storage lifetime would depend on the applied magnetic field. Here, extended details and measurements from the first dedicated experimental...

Université de Fribourg

Towards a new measurement of the neutron electric dipole moment

Ban, G. ; Bodek, K. ; Daum, M. ; Henneck, R. ; Heule, S. ; Kasprzak, M. ; Khomytov, N. ; Kirch, K. ; Knecht, A. ; Kistryn, S. ; Knowles, Paul E. ; Kuzniak, M. ; Lefort, T. ; Naviliat-Cuncic, O. ; Pichlmaier, A. ; Plonka, C. ; Quéméner, G. ; Rebetez, Martin ; Rebreyend, D. ; Rogel, G. ; Sabirov, B. M. ; Tur, M. ; Weis, Antoine ; Zejma, J.

In: Hyperfine Interactions, 2006, vol. 172, no. 1-3, p. 41-43

Precision measurements of particle electric dipole moments (EDMs) provide extremely sensitive means to search for non-standard mechanisms of T (or CP) violation. For the neutron EDM, the upper limit has been reduced by eight orders of magnitude in 50 years thereby excluding several CP violation scenarios. We report here on a new effort aiming at improving the neutron EDM limit by two orders of...

Université de Fribourg

Direct experimental limit on Neutron–Mirror-Neutron oscillations

Ban, G. ; Bodek, K. ; Daum, M. ; Henneck, R. ; Heule, S. ; Kasprzak, M. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knecht, A. ; Knowles, Paul E. ; Kuźniak, M. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Plonka, C. ; Quéméner, G. ; Rebetez, Martin ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Tur, M. ; Weis, Antoine ; Zejma, J. ; Zsigmond, G.

In: Physical Review Letters, 2007, vol. 99, no. 16, p. 161603

In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron n′, could potentially mix and undergo nn′ oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the...