1. Neon MOT experiment for β-decay studies
Ben Ohayon
Advisor: Prof. Guy Ron
Hebrew University of Jerusalem
EUNPC 2015

2. Intro: The search for new physics
High energy frontier
(soon 13 LHC)
Cosmological frontier (CMB, Dark matter).
Intensity or precision frontier.
Precision: searches for tiny effects in well-controlled environments.

3. What we (think we) know about the Weak interaction:
Interacts with all particles.
Mediated by heavy spin 1 (‘Vector’) Bosons.
Can change Flavor, with respect to CKM matrix.
Violates Parity (maximally), Charge, and Time through Im(CKM).
What are the constraints on non SM scalar interactions?
Is parity symmetry really maximally violated?
Are there any tensor interactions?
Are there any new sources for time reversal violation?
Enrico Fermi 1933

4. Intro: What we (think we) know about Beta-decay:
Review by Baessler et al 2014
GF is obtained with ppm precision from muon lifetime. Beringer J et al Particle data group GF ∝ 𝑣 2 the Higgs’ VEV=246 GeV . Bessler and Pocanic. review on cold neutrons. Neutrons have nuclear spin (and so a magnetic moment - that’s how we trap them), so VUD obtained from superallowed decays (0->0).
CVC confirmed to 10^-4 by superaloowed fermi decays of nuclei. Review by Hardy and Towner 2014.

5. Intro: Fermi and Gamow-Teller transitions
Talk by Latsamy Xayavong Fundamental Symmetries session
Review on superallowed by Hardy & Towner 2014.
Neutron decay is like mirror-decay (where the number of protons of element one=number of neutrons of element two) in which case GT Δ𝐽=0 is NOT allowed.
19Ne->19Fl (10Protons to 10 Neutrons) is a mirror decay!
In Mirror Decays
Talks by Gulfem Dogan (15:00) & Merve Dogan (15:15)
@ Nuclear Structure session

6. Intro: Generalizing the Weak interaction
General weak Hamiltonian:
19 Coupling
Constants
Lee & Young 1956
להתעכב פחות
In the SM:
No T violation:
Parity Violation:
Maximal:
C Conservation:
Experimentally:

7. Different Isotopes – Different parameters
Intro: Implications on Beta-Decay
Jackson, Treiman & Wyld 1957
The Beta Nu correlation coefficient:
Different Isotopes – Different parameters
SM predictions:
Say something about the Sodium
Mirror decay. Cecile Magron Fun’ Sym’

8. 23Ne production WI
• Now replacing NaCl crystals with metallic Na for higher yield.

9. Many Unstable producible isotopes:
Neon scheme & isotopes
Even Ne energy Scheme:
Stable
Isotopes:
Many Unstable producible isotopes:
𝟔𝟒𝟎 𝒏𝒎
Γ~8𝑀𝐻𝑧
Planned at SOREQ
RS notation is: (n2S’+1LJ ) , S’ tot spin of core & valence, L orbital angular momentum of core, J is total angular momentum.
Ground: s2 2s2 2p6
1st Manifold: 1s2 2s2 2p5 3s1
2nd Manifold: 1s2 2s2 2p5 3p1
A(640)=61MHz
A(633)=16MHz
A(651)=30MHz
A(717)=3MHz
𝜏~15 𝑠
𝟕𝟒 𝒏𝒎
Produced at WI
* M. Zinner, P. Spoden, T. Kraemer, G. Birkl, and W. Ertmer (2003)
# Y. Ralchenko, A. E. Kramida, J. Reader, and N. A. S. D. Team, NIST Atomic Spectra Database (2008).

10. Trapping Scheme 19Ne* 2nd MOT Problem: MOT Lifetime 1s, Half-life 20s…
Deceleration Beam
3D Molasses (Damping)
2nd MOT
19Ne*
Better vacuum (longer lifetime)
Less background
Large science chamber (electrodes, detectors)
Magnetic Coils (Spring)
Mention detectors are MCPs
Problem: MOT Lifetime 1s, Half-life 20s…

11. In the lab…
106 Ne Atoms!

12. Recoil TOF detection Shakeoff electrons as trigger for decay event.
Mention detectors are MCPs
When the nucleus changes, the outer shell electrons may find themselves in a state that is not an eigen-state of the atom. If this process also involves the release of electrons from the outer shell, then the process is called shake-off.
Shakeoff electrons as trigger for decay event.

13. Planned experiments in MOT
Metastable lifetime – Fluorescence decay.
Electromagnetically Induced Transparency in
metastable neon.
Compare ionization rates – Ion time of flight in electrical field
Isotope shift – Absorption spectroscopy.
Atomic Physics
Zinner et. al. (2003).
B. Lubotzky, Master's thesis (2013).
Nuclear Physics
Feldker et. al. (2011).
Beta-decay correlation coefficients – Recoil ion TOF spectrum.
Vetter et. al. (2008).
Sensitive to beyond SM physics.
Every isotope provides different information.

14. Thanks for listening!

15. State of the art: Best limits MOT
Constraints on scalar (left) and tensor (right) couplings derived from precision measurements in nuclear beta decay. The regions bounded by the colored lines are allowed. All limits on the graphs are at 90% CL.
a) The data used in the exclusion plots are from the Ft values of superallowed Fermi transitions (gray). The βν angular correlation with 21Na (dark blue) [Vetter: ], 32Ar (red) [1999-foil-32Ar], and 38mK (light blue) [ Kscalarint]; and the relative \lyxmathsym{β}
particle longitudinal polarization, PF/PGT , in pure Fermi and Gamow-Teller transitions (green) [1987-Witchers-PF/PGT, 1991-Carnoy-WeakLimits]. b) The data used in the exclusion plot are from the βν correlation in 6He (green) [Gluck1998]; the \lyxmathsym{β}
asymmetry in 114In (light blue) [WU-typw2] and 60Co (red) [wu-type1]; and the relative \lyxmathsym{β}
particle longitudinal polarization in pure Fermi and Gamow-Teller transitions, PF/PGT (black) [1987-Witchers-PF/PGT, 1991-Carnoy-WeakLimits].
Nathal Severijns and Oscar Naviliat-Cuncic. Symmetry tests in nuclear beta decay. Ann. Rev. Nucl. Part. Sci., 61:23-46, 2011.

16. System Overview Magneto-Optical trap Metastable source & Collimator
Zeeman Slower
Six trapping beams
Water cooled quadrupole coils
Population detection
איזוטופים רדיואקטיביים
Beam slowing to trapping velocity
Modular, flexible design
Individual control – online switching
Beam shaping
Excitation to Metastable state
Beam collimation

17. Metastable source: Design
Neon enters here
Differential pumping
Liquid Nitrogen dewar
RF resonator coil excites Ne
Fast, Metastable Beam going out
80Mhz, Q~150

18. Zeeman-slower: Optimization
Total detuning:
On resonance:
Constant deceleration :
System optimization* :
Optimize velocity\length for a given amount of allowed noise.
Improves capture velocity by ~10%
Easy to take stray fields into account.
* B. Ohayon and G. Ron, Journal of Instrumentation 8, P02016 (2013).

19. MOT: Realization
J. A. Behr and G. Gwinner (2009).

20. Zeeman feedback loop
Mention detectors are MCPs
Paper sent

21. Zeeman-slower: Movement simulation
Dissipative force:
Total detuning:
Iterative simulation:
Monte-Carlo simulation:
Recoil from a single photon:
Scattered photons:
Added velocity:

22. MOT: Principle
H. Metcalf and P. Van Der Straten, Laser Cooling and Trapping, (1999).
J. Tempelaars, Trapping Metastable Neon Atoms (Eindhoven, 2001).

23. Outlook – SM Constraints
The consistent allowed region (1, 2, and 3 SD) The narrow grey band comes from considering Superallowed Beta Decay transitions in many nuclei, and how they show a lack of a Fierz interference term, which would come from a scalar coupling in those decays.
Conclusions:
High statistics measurements of Beta-Decays are a prominent tool for testing the Standard Model and put tight limitations on beyond SM theories.
Trapping Neon isotopes grants us a high statistics measurements and a diversity in parameter space exclusion.
There is much more you can do with trapped Neon…
Scalar or tensor terms could only be as much as 2% of the allowed vector or axial-vector terms.
This means that new Weak bosons must be heavier than about 600 or 700 GeV.