Pump-probe measurement of atomic parity violation in caesium with a precision of 2.6%

Michel Lintz (1) , Jocelyne Guéna (1) , Marie-Anne Bouchiat (1)

1 LKB (Lhomond) - Laboratoire Kastler Brossel

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 20 ns. 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, ImE1^{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.

Mots clés: weak interaction in atoms; weak charge; Atomic Parity Violation; Asymmetry Amplification by stimulated emission; Polarization-tilt magnifier; Highly forbidden transition; Stark effect

Domaines: Physique Atomique [physics.atom-ph]; Physique Générale [physics.gen-ph]

Michel Lintz, Jocelyne Guéna, Marie-Anne Bouchiat. Pump-probe measurement of atomic parity violation in caesium with a precision of 2.6%. European Physical Journal A, 2007, 32 (4), pp.525-529. ⟨10.1140/epja/i2006-10433-9⟩. ⟨hal-00104245v2⟩