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FrPNC @ TRIUMF Atomic Parity Violation in Francium

FrPNC @ TRIUMF Atomic Parity Violation in Francium. Seth Aubin College of William and Mary PANIC 2011 Conference, MIT. FrPNC collaboration. S. Aubin (College of William and Mary) J. A. Behr, K. P. Jackson, M. R. Pearson (TRIUMF) V. V. Flambaum (U. of New South Wales, Australia)

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FrPNC @ TRIUMF Atomic Parity Violation in Francium

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  1. FrPNC @ TRIUMF Atomic Parity Violation in Francium Seth Aubin College of William and Mary PANIC 2011 Conference, MIT

  2. FrPNC collaboration S. Aubin (College of William and Mary) J. A. Behr, K. P. Jackson, M. R. Pearson (TRIUMF) V. V. Flambaum (U. of New South Wales, Australia) E. Gomez (U. Autonoma de San Luis Potosi, Mexico) G. Gwinner, R. Collister (U. of Manitoba) D. Melconian (Texas A&M) L. A. Orozco, J. Zhang (U. of Maryland at College Park) G. D. Sprouse (SUNY Stony Brook) Y. Zhao (Shanxi U., China) Funding

  3. e- e- e- e-  Z0 W,Z0exchange in nucleus N N N N Atomic Parity Violation: Basic Processes e- e-  N N Standard Electromagnetic Interaction (parity conserving) Z0 exchange Electron-Nucleon PNC (nuclear spin-independent) Intra-nuclear PNC Anapole moment (nuclear spin-dependent)

  4. e- e- e- e-  Z0 W,Z0exchange in nucleus N N N N Atomic Parity Violation: Basic Processes e- e- PNC PNC  N N Standard Electromagnetic Interaction (parity conserving) Z0 exchange Electron-Nucleon PNC (nuclear spin-independent) Intra-nuclear PNC Anapole moment (nuclear spin-dependent)

  5. e- e- Z0 G = Fermi constant = 10-5/mp2 Proton: Neutron: N N Z0 exchange Electron-Nucleon PNC (nuclear spin-independent) Motivation 1: Nuclear Spin-Independent PNC Ae The Hamiltonian for this interaction: (infinitely heavy nucleon approximation) VN [Standard Model values for 1, (p,n)]

  6. e- e- Ae Z0 VN nucleons nucleons Motivation 1: Nuclear Spin-Independent PNC For a nucleus with Z protons and N neutrons: Qweak = weak charge of nucleus  -N = 2(1,p Z + 1,n N) Z0 exchange Electron-Nucleons PNC (nuclear spin-independent)

  7. Motivation 1: Testing and Probing the Weak Interaction Parity Violation = Unique Probe of Weak Interaction Atomic PNC (APV) experiments test and constrain the Standard Model

  8. Weak mixing angle Effective e--quark couplings C1u & C1d [figure by G. Gwinner, adapted from Erler et al.Phys. Rev. D72, 073003 (2005)] [figure from Young et al., Phys. Rev. Lett.99, 122003 (2007)] Motivation 1: Testing and Probing the Weak Interaction Parity Violation = Unique Probe of Weak Interaction Atomic PNC (APV) experiments test and constrain the Standard Model

  9. Parity forbidden transitions become possible (slightly) !!!  Francium advantage: 18 relativistic enhancement factor Atomic PNC  Electron wavefunction does not have a definite parity !!!

  10. e- e- e- e-  Z0  W,Z0exchange in nucleus N N N N Intra-nuclear PNC Anapole moment Motivation 2: Nuclear Spin-Dependent PNC e- e- Ae Ve Z0 VN AN N N Z0 exchange Electron-Nucleon PNC (vector) (axial) Hyperfine Interaction + NSI - Z0 exchange (nuclear spin-dependent)

  11. [A. Weis, U. Fribourg (2003)] What’s an Anapole Moment ? Answer: Electromagnetic moment produced by a toroidal current.  Time-reversal conserving.  PNC toroidal current.  Localized moment, contact interaction.

  12. e- e-  W,Z0exchange in nucleus N N Anapole moment Motivation 2: Nuclear Anapole Moment For heavy atoms, the anapole moment term dominates.

  13. e- e-  W,Z0exchange in nucleus N N Anapole moment Motivation 2: Nuclear Anapole Moment For heavy atoms, the anapole moment term dominates.

  14. e- e-  W,Z0exchange in nucleus characterize the nucleon-nucleus weak potential. N N Anapole moment Motivation 2: Nuclear Anapole Moment For heavy atoms, the anapole moment term dominates.

  15. Measure anapole in a string of Fr isotopes [Haxton et al., Phys. Rev. C 65, 045502 (2002) and 6Li(n,) from Vesna Phys. Rev. C 77, 035501 (2008)] Motivation 2: Isovector & Isoscalar Nucleon Couplings Cs anapole (Boulder) and low-energy nuclear PNC measurements produce conflicting constraints on weak meson-nucleon couplings. (Desplanques, Donoghue, and Holstein model) Need to understand nuclear structure better.

  16. N=even N=odd [Haxton et al., Phys. Rev. C65, 045502 (2002) and 6Li(n,) from Vesna Phys. Rev. C77, 035501 (2008)] Motivation 2: Isovector & Isoscalar Nucleon Couplings Cs anapole (Boulder) and low-energy nuclear PNC measurements produce conflicting constraints on weak meson-nucleon couplings. (Desplanques, Donoghue, and Holstein model) Francium isotopes provide orthogonal constraints !!! [Behr and Gwinner, J. Phys. G36, 033101 (2009)]

  17. + dipole trap FrPNC program: Atomic PNC Experiments in Francium • Fr is the heaviest of the simple (alkali atoms).  Electronic structure is well understood.  Particle/nuclear physics can be reliably extracted. • Fr has large (relatively) PNC mixing.  PNC ~ 10-10 is still really really small … we’re going to need a lot of Fr. • Fr does not exist sufficiently in nature.

  18. Excitation to continuum (ionization) 506 nm 506 nm 1.3 m 1.7 m Amplification by Stark Interference 718 nm 817 nm Statistical Sensitivity: Atomic PNC in Fr (NSI) EStark k Fr atoms (trapped) BDC M1 is strongly suppressed.

  19. M1 E1PNC Anapole Moment in Fr New Method:Anapole can be measured by driving a parity forbidden E1 transition between two hyperfine states with F=1, mF=1. /2 pulse preparation: the atoms are prepared in a 50/50 superposition of the initial and final states (equivalent to interference amplification) before application of the microwave driving E-field.

  20. M1 E1PNC Anapole Moment in Fr New Method:Anapole can be measured by driving a parity forbidden E1 transition between two hyperfine states with F=1, mF=1. /2 pulse preparation: the atoms are prepared in a 50/50 superposition of the initial and final states (equivalent to interference amplification) before application of the microwave driving E-field.

  21. M1 E1PNC for Emicrowave~0.5 kV/cm and 106 atoms. [E. Gomez et al., Phys. Rev. A75, 033418 (2007)] Anapole Moment in Fr New Method:Anapole can be measured by driving a parity forbidden E1 transition between two hyperfine states with F=1, mF=1. /2 pulse preparation: the atoms are prepared in a 50/50 superposition of the initial and final states (equivalent to interference amplification) before application of the microwave driving E-field.

  22. Simulating the PNC Interference APNC simulated with 10-4 M1 transition Simulating Fr Anapole with Rb 180 ms coherence time in blue-detuned dipole trap (/2 pulse with Rb) [Data by D. Sheng (Orozco Group, U. of Maryland)]

  23. FrPNC: Current Status Present:Construction of an on-line, shielded laser laboratory at TRIUMF with 100 db RF suppression. Fall 2011: (14 shifts in December) Installation of high efficiency MOT (from U. of Maryland). 2012: Physics starts !!! Hyperfine anomaly (Pearson), 7S-8S M1 (Gwinner), Anapole (Orozco), optical PNC (Gwinner), …

  24. FrPNC collaboration S. Aubin (College of William and Mary) J. A. Behr, K. P. Jackson, M. R. Pearson (TRIUMF) V. V. Flambaum (U. of New South Wales, Australia) E. Gomez (U. Autonoma de San Luis Potosi, Mexico) G. Gwinner, R. Collister (U. of Manitoba) D. Melconian (Texas A&M) L. A. Orozco, J. Zhang (U. of Maryland at College Park) G. D. Sprouse (SUNY Stony Brook) Y. Zhao (Shanxi U., China) Funding

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