Pump-probe measurement of atomic parity violation in cesium with a precision of 2.6%
Département de Physique de l'Ecole Normale Supérieure, Laboratoire Kastler Brossel, 24 Rue Lhomond, 75231, Paris cedex 05, France
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Accepted: 18 March 2007
Published online: 13 July 2007
We present the atomic parity violation measurements made in Cs vapour using a pump-probe scheme. After pulsed excitation of the 6S -7S forbidden transition in the presence of a longitudinal electric field, a laser beam resonant with one of the 7S -6P transitions stimulates the 7S atom emission for a duration of 20ns. The polarisation of the amplified probe beam is analysed. A seven-fold signature allows discrimination of the parity-violating linear dichroism, and real-time calibration by a similar, known, parity-conserving linear dichroism. The zero-field linear dichroism signal due to the magnetic dipole transition moment is observed for the first time, and used for in situ determination of the electric field. The result, ImE 1 pv = (- 808±21)×10-14 ea 0 , is in perfect agreement with the corresponding, more precise measurement obtained by the Boulder group. A transverse field configuration with large probe amplification could bring atomic parity violation measurements to the 0.1% accuracy level.
PACS: 32.80.Ys Weak-interaction effects in atoms – / 11.30.Er Charge conjugation, parity, time reversal, and other discrete symmetries – / 33.55.Be Zeeman and Stark effects – / 42.50.Gy Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption –
© Società Italiana di Fisica and Springer-Verlag, 2007