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

Abstract

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, ImE pv 1 = (−808 ± 21) × 10 −14 ea0, 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.

Spin Dependent Selection Rules for Photonic Transitions in Hydrogen-Like Atoms

“…According to the conventional selection rules ( 1 l    and 0 s   ) which are derived from the Schrödinger equation in the same way as in Section 3, a transition such as 6s 7s  is not allowed ( because this is a transition ( 0 l   0 l  ) in which 0 l   , so it does not meet the condition 1 l    ). But 6s 7s  transition in Cs atom has been already observed [7][8][9]. However, the present spin dependent selection rules allow the transition: 6s   7s  in Cs atom.…”

“…By applying the present spin dependent selection rules we can explain the observed (6 s  7 s) transition in Cesium (Cs) atom [7,8]. Because in the (6s  7s) transition in Cesium (Cs) atom we have [ 0 j   while 0 j m   ] which is an allowed transition according to the present selection rules given in Equation (28).…”

Polarization rotation of slow light with orbital angular momentum in ultracold atomic gases

“…Thus the difference in the angle of the polarisation plane rotation is ∆α ℓ ≈ 4πℓ × 10 −5 . This is a small angle, yet by no means beyond current experimental expertise [31]. For fast light the corresponding angle ∆α ℓ should be far too small to be observed.…”

Parity and Time-Reversal Violation in Atomic Systems

“…The precision of the Boulder measurement for the first (and so-far only) time also allowed for the detection of NSD-PNC effects, which led to a determination of the 133 Cs nuclear AM [3,45]. The more recent measurements of the Paris group [34,35] (see also [46]) used a different method-chiral optical gain-to detect the PNC signal. The results using this method are not at the same level of accuracy as the Boulder measurements [3], however, promising progress has been made.…”