RA07 Current Status of the University of Oklahoma e-EDM Search. John Moore-Furneaux*, Neil Shafer-Ray Columbus OH, 6/23/2011 *J.E. Furneaux

Recent combination of Microwave Spectra (Hannover) and Optical Spectra (Oklahoma) has allowed us to characterize the ground state of PbF. INTRODUCTION Molecular Spectroscopy and the e-EDM More Details: Theory: RA05 Experiment: RA06, RA08, RA09, FD01

INTRODUCTION Take a closer look at the ground states of 208 Pb 19 F

J=1/2,  +, F=1 J=1/2,  +, F=0 M = -1 M = 0 M= 1 M=0 INTRODUCTION A MAGNETIC FIELD LIFTS ALL DEGENERACIES

J=1/2,  +, F=1 J=1/2,  +, F=0 M=0 INTRODUCTION M=1, M = -1 IN AN APPLIED ELECTRIC FIELD, 1 DEGENERACY REMAINS.

To search for an e-EDM we will look for  U =U +M –U -M in a strong E field. Time reversal (or CP) Symmetry leads to a ±M degeneracy of any system that is not broken by an electric field along the quantization axis. The existence of an electron electric dipole moment would break this symmetry. INTRODUCTION

Super Sym. Std. Mod. (Hoogeveen 1990) (Arnowitt 2001) INTRODUCTION Since its proposal in 1950 by Purcell and Ramsey**, many have hunted for the e-EDM with the most recent limit of e-cm reported this year by the Hinds* group at Imperial College found by probing the YbF molecule. *Nature 473, 493–496, 2011.**Phys. Rev. 78, 807, 1950.

This Talk 1)The PbF molecule vs other systems. 2)Outline of our measurement strategy. 3)pc-REMPI spectroscopy of the X 1  A transition 4)Demonstration of laser frequency and polarization control needed for a ~ e-cm measurement. 5)The dream: A beam line measurement of the e-EDM.

+ Hudson, PRL , 2002 *Meyer, Bohn, PRA 78, R 2008 **DeMille, PRA , 2000 ***Prepint, Learnhardt, 2010 # internal field (GV/cm) g-factor magnitude g Radiative lifetime (ms) approximate polarization field (kV/cm) molecule 207 e * * * * * * * * * * g g g-2 g g ** ? 1.0* 100.* *** ~0.0001* Comparison of PbF to other e-EDM sensitive molecules WC -60 # g-2 - ~0.001 # PbF is about a factor of 3 times less sensitive than HgF or ThO and 2 less than WC. PbF is a “g-2” e-EDM system. “g-2” implies g factor of ~0.04 “g” implies g factor of ~1 The ground-state of PbF is sensitive to an e-EDM 207 PbF can be polarized by a field as small as 0.2 kV/cm, e PbF requires ~5kV/cm

R(Bohr) energy (eV ) D 2  1/2 PbF + + e X 2  1/2 A 2  1/2 X state A-state (lifetime ~4usec) A NEW TYPE OF REMPI developed for the PbF e-EDM effort. Measurement Strategy D-state (lifetime ~150 ps) pc-REMPI Sivakumar et al, Mol Phys, 108, (972) Nm,76 MHz 6ps 800 mW 436 nm CW 10MHz

mass (u) photoelectron - photoion delay (ns) frequency offset (GHz) Ground hyperfine states resolved! Measurement Strategy

Frequency (GHz) Signal (counts) Entire e-EDM measurement occurs while our CW excitation laser is locked to the Q fe (1/2) F=1  F=0 transition at nm or nm.

Measurement Strategy Salient Features: 1)No atomic Reference needed (We can lock anywhere!) 2)Inexpensive (No Frequency Comb Needed) 3)Reference and diode laser continuously locked (Very tight lock)

Saturated absorption spectroscopy of Te 2 about 1GHz from the bandhead of the X 1  A transition of PbF Frequency range: 674,611, MHz N 2 pressure range: 1140 – 1240 torr Time period: 48 hours. Stability: ~2MHz / 48hours

PBS EOAM /4 Laser PbF PbF+ e-e-  if /2 EiEi EfEf EAEA EBEB ECEC EDED E 0 2 t(ms) volts A B C D E Incoherent superposition of M=1 and M=-1 states

PBS EOAM /4 Laser PbF PbF+ e-e- Incoherent superposition of M=1 and M=-1 states  if /2 EiEi EfEf EAEA EBEB ECEC EDED E 0 2 t(ms) volts A B C D E PBS voltage to frequency converter pulse generator e-e- PbF+ faux e-EDM photodetector  faux data collection electronics A B C D E synchronization time(2 ms) e - - PbF + correlation time(ns) synchronization time(2ms) counts faux e-EDM labview signal

Total of 200 reversals in 4 hrs

Status of the OU e-EDM experiment (1)We have demonstrated complete hyperfine state resolution with an ultrasensitive continuous resonance enhanced multi-photon ionization scheme. (2)We have created rotating linear light with sufficient phase and frequency stability to measure an e-EDM at the < e cm level. (3)We have tested our data collection system by creating a faux e-EDM signal.

Coherence time (  sec) /17/057/2/0611/14/073/28/098/10/10 ? ? 10, ,0000 GUIDED e-EDM EXPERIMENT

The Proposed PbF Beam Line Experiment ~10 m FEATURES: 50 ms coherence time, 100kHz data collection rate. At e cm, the (PbF) phase rotation is 3 mrad.

Graduate Students StudentWhere They Are Now Sivakumar Poopalasingam, 2009Post Doc, Delaware State C.P. McRaven, 2010Post Doc, Brookhaven National Laboratory Milinda Rupasinghe (2011)Graduate Student Tao YangGraduate Student James CokerGraduate Student Haoquan Fan Jeffery Gillean Graduate Student Undergraduate

Senior Collaborators Senior PIWhere They Are Greg HallBrookhaven National Laboratory Trevor SearsBrookhaven National Laboratory, Stony Brook John FurneauxOU Jens-Uwe GrabowGottfried-Wilhelm-Leibniz-Universität, Hannover Richard MawhorterPomona College Neil Shafer-RayOU

Funding Agencies DOEDOE-FG02-07ER46361 NSFNSF-PHY , University of OklahomaBoard of Regents Exploration Grant

polarization laser probe laser E volts volts CURVE THE PLATES! Potential Minimum in U = U STARK + mg guides the beam. After ~2 meters, the PbF beam stops diverging! A GUIDED e-EDM EXPERIMENT

The Proposed PbF Beam Line Experiment ~1 km FEATURES: 5 s coherence time, 100kHz data collection rate. At e cm, the (PbF) phase rotation is 300 mrad.

PbF + e-e- MCP multichannel scalar 476.nm 76 MHz 6ps 800 mW 436 nm cw 10MHz Measurement Strategy

Expected Spectra of the Q[1/2] Transition in an E Field (95% Uniformity)