1. Funded by: NSF-Exp. Timothy C. Steimle Hailing Wang & Anh Le Dept. Chem. & BioChem., Arizona State University, Tempe, AZ,USA The A 2  -X 2  + Band System of SrF Revisited The 64 th International Symposium on Molecular Spectroscopy, June 2009

2. Motivation Proposal 1 : Use 87 SrF to measure the P-odd nuclear spin- dependent parity non-conservation (NSD-PNC) effect resulting from the interaction of the anapole moment of 87 Sr nucleus with the unpaired electron of the X 2  + state. 1.D. DeMille, S.B. Cahn, D. Murphree, D. A. Rahmlow and M.G. Kozlov, Phys. Rev. Lett, 100, 023008, (2008). NSD-PNC Mixing A 2  -X 2  + Band System LIF Detection X2+X2+

3. Background Numerous Optical and Microwaves studies of 88 SrF by Törring, Childs, Ernst, Steimle, Bernath and others. % abundanceNucl. Spin I Mag. Mom (nucl. Magneton) Quad.mom (Barns) 86 Sr9.860 87 Sr7.009/2-1.0930.335 88 Sr82.780 19 F1001/2+2.628 X 2  + 87 SrF: Studied by rf-optical pump/probe double resonance (Azuma, Childs, Goodman & Steimle JCP 93 5533 (1990) A 2  87 SrF: No previous spectroscopic characterization.

4. Fine and hyperfine structure in (v=0)X 2  + 87 SrF -from Azuma et al results G(=I+S) 5 4 Case b  S Limit Case b  J Limit J=N+1/2 J=N-1/2 Previously recorded mag. Dipole spi- rot. transitions (Azuma et al, JCP) Levels of interest in parity Non-conservation experiments Spin-rotation splitting Can the Azuma et al parameters model the low-N levels of interest? Rotational quantum number N Energy-BJ(J+1) cm -1 X2+X2+

5. Well collimated molecular beam Rot.Temp.<10 K Single freq. tunable laser radiation PMT Gated photon counter Experimental set up for LIF studies Metal target Pulse valve skimmer Ablation laser Reagent & Carrier Sr

6. Q 1 (0) X 2  + 87 SrF Energy (cm -1 ) 0.00 0.10 N G F 0 5 4.5 0 5 5.5 0 4 4.5 0 4 3.5 A 2   87 SrF 0.00 J F 1 F 1/2 4,5 4.5,5.5 Energy (cm -1 )-15076 R 2 +Q 21 (1) Energy (cm -1 )-15357 X 2  + 87 SrF Energy (cm -1 ) 0..46 0.56 N G F 1 5 3.5-6.5 A 2   87 SrF 1 4 2.5-2.5 0.80 J F 1 F 3/2 3-6 2.5-6.5 Energy levels associated with sample spectra

7. Are New Measurements/Analyses for 87 SrF Required? Observed 87 SrF 87 SrF-Predicted X 2  Azuma et.al A 2  Isotopic scaling hyf=0 88 SrF 88 SrF-Predicted 88 SrF 87 SrF(G=4) 87 SrF(G=5) Laser Wavenumber LIF Signal 15076.0 15076.1 Q 1 (0) Large difference

8. Are New Measurements/Analyses for 87 SrF Required? (cont.) Laser Wavenumber LIF Signal Observed 88 SrF 88 SrF-Predicted 87 SrF hyf=0 87 SrF-Predicted X 2  Azuma et.al A 2  Isotopic scaling hyf=0 R 2 +Q 21 (1) 87 SrF (G=5) 87 SrF (G=4) 86 SrF 88 SrF Small difference

9. General conclusions from “Combination/Difference” a) The previously determined hyperfine parameters for the X 2  + state are applicable. b) The fine structure parameters for both the X 2  + and A 2  states need to  slightly altered from those given by isotopic relationships. c) The hyperfine structure, particularly for the A 2    spin component has to be optimized. Need to fit the optical spectra!

10. Field-free Hamiltonian: X 2  + :20×20 mat.rep.,Hund’s case (a) BN 2 -DN 4 +γN·S+b F (F)I·S+c(F)×(I z S z -1/3I·S) A 2  1/2 :40×40 mat.rep.,Hund’s case (a) T 0,0 +AL z S z +1/2A D [N 2 L z S z +L z S z N 2 ]+BN 2 -DN 4 + ½(p+2q)(e -2i  J + S + +e -2i  J - S - )+aI z L z +b F I·S+c(L z S z - ½I·S)+½d(e -2i  I + S + +e -2i  I - S - ) Analysis State Par Fitted value & error X 2  + (v=0)B 0.2505(2) A 2  (v=0)A 281.459(2) B 0.2535(2) p+2q-0.1336(5) d-0.0017(7) T 00 15216.595(1) optimized

11. Are New Measurements/Analyses for 87 SrF Required? Observed 88 SrF 88 SrF-Predicted 88 SrF 87 SrF(G=4) 87 SrF(G=5) Laser Wavenumber LIF Signal 15076.0 15076.1 Q 1 (0) 87 SrF 87 SrF-Predicted X 2  Azuma et.al A 2  Fitted Par. hyf  0 Small difference

12. Summary We have analyzed the low-J branch features of the (0,0)A 2  -X 2  + band of 87 SrF. We performed a combined fit of the (1,0) and (0,0) low-J branch features of the (0,0)A 2  -X 2  + band and microwave spectra of 88 SrF. (not presented here) We are in the process of modeling the optical Zeeman spectra. (not discussed here)

13. Thank You !

14. Are New Measurements/Analyses for 87 SrF Required? Q 1 (4.5) +R 12 (3.5) Laser Wavenumber LIF Signal Observed 88 SrF 88 SrF-Predicted 87 SrF 87 SrF-Predicted X 2  Azuma et.al A 2  Isotopic scaling 86 SrF 88 SrF 87 SrF (G=4) 87 SrF (G=5)

15. 87 SrF hyf=0 Observed Laser Wavenumber LIF Signal 15075.7415075.68 15075.62 P 1 +Q 12 (1) 88 SrF 87 SrF hyf=0

16. Are New Measurements/Analyses for 87 SrF Required? 87 SrF hyf=0 88 SrF Observed 87 SrF hyf=0 Q 1 (4.5) +R 12 (3.5) Laser Wavenumber LIF Signal