Prsentation PowerPoint

1
THE CESIUM PARITY VIOLATION EXPERIMENT IN
PARIS Determination of E1PV within 2x10-13
eao J. Guéna, M. Lintz and M.-A.
Bouchiat, Département de Physique de l'ENS, 24
rue Lhomond, 75 231 Paris cedex 05, FRANCE
Particle physics... ...without accelerator!
PRINCIPLE OF THE EXPERIMENT
PRESENT RESULTS see Ref.(5)
HOW TO AMPLIFY THE PV EFFECTS?
EXCITATION AND DETECTION
EVOLUTION OF THE RESULTS (7 different cells)
1 point 400 PV data
1 point 200 PV data
2002
August 2004
2002
2004
2003
8 months
7 weeks
- q PVexp (µrad)
?
?
?
E1PV PV E1 6S-7S amplitude interferes
with bEz Stark induced E1 amplitude
Since first 9 result (cell 1, Ref. 1), S/N
improved by 3.5 ? acquisition time for S/N 1
reduced by 12
?
?
Excited vapour gain axes are // (and ?), not to
eexc but to eexc qPV eexcz rotated from
eexc by an angle ? 10-6
rad, odd in Ez ? output probe polarn eprout
eprin k qPVeprinz
atomic factor (Cs density, HFS,..)
cells
Noise reduction
OUR GOAL measurement of E1PV with 1
precision as a cross check of the Boulder 1999
result ? A new independent measur of QW the
weak charge of Cs nucleus as a precise test of
the electroweak theories (Standard Model and
extensions, e.g. extra dimensions, additional
gauge bosons..)
and increased rep. rate 160Hz

• Updated average result qPV 0.950 ? 0.025
  µrad
• together with a 1 accurate Ez field in-situ
  determination from atomic signals
• agrees with ?PV 0.962 ? 0.005 µrad, at 1.62
  kV/cm
• expected from Boulder result for E1PV//b

see Ref.(4)
POLARIMETRIC METHOD OF MEASUREMENT ... and
CALIBRATION
Input probe polarisation parallel to
?ex, rotates during propagation by an angle k
?PV (k atomic factor)
We extract a new determination of E1PV E1PV (-
80.8 ? 2.1) x 10 -13 eao for the 6S ,F3 7S,
F4 hyperfine transition
probe polarimeter
S/N now adequate to reach 1 precision
by lengthening the acquisition time, using last
improved cesium cell (conductive windows, ref.7)
Selection criteria of the PV rotational invariant
0,4s
0,8s
6s
12s
2 mn
4 Polarization configurations 0, 45,
90, 135
1 PV data
cell input
IMPLEMENTATION of the EXPERIMENT
excitation beam
Dichroic mirror
probe beam