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

I. Altarev , G. Ban (1) , G. Bison , K. Bodek , M. Daum , M. Fertl , P. Fierlinger , B. Franke , E. Gutsmiedl , W. Heil , R. Henneck , M. Horras , N. Khomutov , K. Kirch , S. Kistryn , A. Kraft , A. Knecht , P. Knowles , A. Kozela , T. Lauer , B. Lauss , T. Lefort (1) , Y. Lemière (1) , A. Mtchedlishvili , O. Naviliat-Cuncic (1) , A. Pazgalev , G. Petzoldt , F. M. Piegsa , E. Pierre (1) , G. Pignol , G. Quéméner (1) , M. Rebetez , D. Rebreyend (2) , S. Roccia , P. Schmidt-Wellenburg , N. Severijns , Yu. Sobolev , A. Weis , J. Zejma , J. Zenner , G. Zsigmond

1 LPCC - Laboratoire de physique corpusculaire de Caen
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie

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 using 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 weak magnetic field using the Ramsey resonance technique. An non-zero cosmic axial field, violating rotational symmetry, would induce a daily variation of the precession frequency. Our null result constitutes one of the most stringent tests of Lorentz invariance to date.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique Nucléaire Expérimentale [nucl-ex]; Physique Atomique [physics.atom-ph]

I. Altarev, G. Ban, G. Bison, K. Bodek, M. Daum, et al.. Testing isotropy of the universe using the Ramsey resonance technique on ultracold neutron spins. 8th international workshop on Polarised Neutrons in Condensed Matter Investigations (PNCMI 2010), Jul 2010, Delft, Netherlands. pp.2365-2369, ⟨10.1016/j.physb.2010.09.044⟩. ⟨in2p3-00523395⟩