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The Berkeley Update:Atomic-Physics Tests
of Fundamental SymmetriesParity Violation and Testing Bose Statistics
Dmitry BudkerUniversity of California, Berkeley
Nuclear Science Division, LBNL
http://budker.berkeley.edu/
Cairns
July 25, 2010
Outline
1. Measurement of atomic in Yb
2. Testing for Bose-statistics violation in Ba 2γ transitions
P
Atomic PV (a.k.a. PNC) landmarks• 1959 Ya. B. Zel’dovich:
PNC (Neutr. Current) Opt. Rotation in atoms
• 1974 M.-A. & C. Bouchiat
Z3 enhancement PV observable in heavy atoms
• 1978-9 Novosibirsk, Berkeley
discovery of PV in OR(Bi) and Stark-interf.(Tl)
• …1995 Boulder, Oxford, Seattle, Paris
PV measured to 1-2% in Cs, Tl, Bi, Pb
• 1997 Boulder
0.35% measurement, discovery of anapole moment
• 2009 Berkeley Large APV in Yb (personal landmark)
26 y
ears
What were we doing all this time?• 1983-1988 Bi, diatomic molecules, Sm
(Novosibirsk) with L. M. Barkov and M. Zolotorev
• 1989-1994 Tl(Berkeley) with E. D. Commins, D. DeMille, and M. Zolotorev
• 1989- Dy M. Zolotorev, D. DeMille, E. D. Commins, A.-T.Nguyen,
A. Cingoz, N. Leefer
• 1995-1997 SmS. M. Rochester
• 1995- YbS. J. Freedman, D. DeMille, C. J. Bowers, G. Gwinner, J. E. Stalnaker, D. F. Kimball, V. V. Yashchuk, K. Tsigutkin, A. Family, D. Dounas-Frazer,…
Why did it take so long to detectPNC?
Dr. A.-T. Nguyen says: it was deposited
6
Parity Violation in Yb: motivationAtomic Physics:
Verification of large predicted atomic PV effect (x100 Cs; DeMille, Kozlov et al, Das et
al)
Nuclear Physics:Nuclear spin-dependent PV – anapole moments
(valence neutrons)
Isotopic ratios and neutron distributions (7 stable isotopes; N=8)
Anapole Momentof a current distribution (e.g., a nucleus)
rdrjraRaRA
rdrjrc
mR
RmRA
rdrjcR
RA
rrR
rRRrR
rdrR
rj
cRA
kklkkk
32)2(
33
)1(
3)0(
3
)();(
)(2
1;
0)(1
...1
2
111
||
1
||
)(1
T-conserving; P-violating
Ya. B. Zel’dovich
8
Atomic Yb: energy levels and transitions
PV amplitude: 10-9e·a0
DeMille (1995)
+5d6p
|M1|10-4 μB
J.E. Stalnaker, et al, PRA 66(3), 31403 (2002)
β2·10-8 ea0/(V/cm)C.J. Bowers et al, PRA 59(5), 3513 (1999); J.E. Stalnaker et al, PRA 73,
043416 (2006)
Stark-PV-interference technique (invented by the Bouchiats in 1970s)
10
Electric and magnetic fields define handedness
The Yb PV Experiment
Rotational Invariant: B E B
11
Reversals and pseudo-reversals• E-field reversal (14 ms: 70-Hz modulation)
• Lineshape scan (200 ms/point x 100 pts/lineshape = 40 s)
• B-field reversal (every few minutes)
• Polarization angle (occasionally)
• E-field magnitude
• B-field magnitude
• Angle magnitude
Yb PV Amplitude: Results
Accuracy is affected by HV-amplifier noise, fluctuations of stray fields, and laser drifts → improved for the next phase
/z b=39(4)stat.(5)syst. mV/cm |z|=(8.7±1.4)×10-10 ea0
68% confidence band
0 2 4 6 8 10 12 14 16 18 20-50
0
50
100
150
Mean value
/ (
mV
/cm
)
Run number
Theoretical prediction
Near Future… Verification of expected isotopic dependence PV in odd isotopes: NSD PV, Anapole Moment PV in a string of isotopes; neutron distributions, …
Further Ahead (?) Testing the Standard Model [Brown et al PHYSICAL REVIEW C 79, 035501 (2009)]
Completed Work Lifetime Measurements General Spectroscopy (hyperfine shifts, isotope shifts) dc Stark Shift Measurements Stark-Induced Amplitude (β): 2 independent measurements M1 Measurement (Stark-M1 interference) ac Stark Shift Measurements Verification of APV enhancement
Progress in Yb APV
14
K. Tsigutkin A. Family D. Dounas-Frazer post-doc undergrad grad.student
V. V. Yashchuk S. J. Freedman J. E. Stalnaker
2. The Ba 2γ experiment: violationBES Damon English
The degenerate two-photon transition selection rule
MJ=0MJ=-1 MJ=1
1
1
2
2
Destructive interference of two
quantum paths
S. N. Bose
DeMille 11999
The Berkeley Experiment
Animated version: YouTube: Test of Bose-Einstein statistics for photons
Results
c.l.%90100.4 11
Results
Splitting effect Mixing Effect
Outline1. Measurement of atomic in Yb
2. Testing for Bose-statistics violation in Ba 2γ transitions
P
Yb PNC signature
23
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