Bulletin of the American Physical Society
54th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 68, Number 7
Monday–Friday, June 5–9, 2023; Spokane, Washington
Session K05: Fundamental Symmetries with Atoms and Molecules |
Hide Abstracts |
Chair: Michael Tarbutt, Imperial College London Room: 205 |
Wednesday, June 7, 2023 10:30AM - 10:42AM |
K05.00001: A New Bound on the Electron's Electric Dipole Moment Trevor Wright, Luke A Caldwell, Tanya Roussy, Kia Boon Ng, Sun Yool Park, Noah Schlossberger, Anzhou Wang, Eric A Cornell, Jun Ye The Standard Model cannot explain the predominance of matter over anti-matter in our universe. This asymmetry indicates the existence of new CP-violating interactions, which would induce an electric dipole moment of the electron (eEDM). I will present the most precise measurment of the eEDM to date using electrons confined inside hafnium flouride ions (HfF+). We trap HfF+ in corotating electric and magnetic fields, and measure the eEDM signal by preforming Ramsey spectroscopy with coherence times up to 3 seconds. Our result is consistent with zero and improves on the previous best upper limit by a factor of ∼ 2.4. |
Wednesday, June 7, 2023 10:42AM - 10:54AM |
K05.00002: in situ magnetometry and active field cancellation for the ACME electron EDM search Xing Wu, Peiran Hu, Zhen Han, Daniel G Ang, Takahiko Masuda, Cole Meisenhelder, Siyuan Liu, Ayami Hiramoto, Maya Watts, Collin Diver, Noboru Sasao, Satoshi Uetake, Koji Yoshimura, Gerald Gabrielse, John M Doyle, David P DeMille Precision spectroscopy measurements are often affected by uncompensated changes in the magnetic fields. This can generally lead to systematic effects that are difficult to correct. In the search for electron and neutron electric dipole moments (EDM), co-magnetometry has been effective in monitoring and cancelling residual magnetic fields. The ACME electron EDM search, using a cold ThO molecular beam, aims to achieve over one order of magnitude improvement from our previous best limit [Nature, 562, 355 (2018)], |de|<1.1x10-29 e·cm. Known systematic effects associated with magnetic field and its gradients are predicted to be under control once their values reach below 10uG and 1uG/cm. Here, we demonstrate in situ magnetometry with the ThO beam in the ACME experimental configuration. While the H 3Δ1 state of ThO is used for EDM measurement, the magnetically sensitive Q 3Δ2 state of the molecule [NJP 22, 023013 (2020)] is now used to probe residual B-fields at the ~200nG absolute accuracy level and <1 cm spatial resolution, over a 20 cm long prototype region. External compensation coils are applied in a feedback loop to cancel the residual field and gradients to below 1uG and 200nG/cm. This is sufficient to suppress systematic errors related to stray magnetic field and gradients in the upcoming ACME III EDM search. |
Wednesday, June 7, 2023 10:54AM - 11:06AM |
K05.00003: Progress toward the measurement of CP violating electromagnetic moments in YbOH Yuiki Takahashi, Chandler Conn, Arian Jadbabaie, Ashay N Patel, Phelan Yu, Yi Zeng, Chi Zhang, Timothy C Steimle, Nicholas R Hutzler Precision measurements of molecules with heavy elements have established themselves as an effective tool in the search for physics beyond the Standard Model, thanks to their high sensitivity to charge parity (CP) violating electromagnetic moments. The polyatomic molecule YbOH presents a favorable opportunity for exploring such physics in both the leptonic and hadronic sectors, through the measurement of the electron's electric dipole moment (eEDM) in the 174YbOH isotopologue and the nuclear magnetic quadrupole moment (nMQM) in the 173YbOH isotopologue. The presence of a localized electron around the Yb nucleus facilitates photon cycling, and its mechanical bending mode generates parity doublets in the electronic ground state, allowing for full polarization and robust systematic error rejection. We provide an update on recent theoretical and experimental efforts aimed at achieving these goals, including the high-resolution spectroscopy of states pertinent to CP-violation searches, investigation of novel state preparation schemes, observation of coherent state preparation and readout, and progress toward measurement of the nMQM. |
Wednesday, June 7, 2023 11:06AM - 11:18AM |
K05.00004: Progress towards a nuclear Schiff moment measurement using 205TlF molecules in CeNTREX Olivier O Grasdijk, David P DeMille, Tanya Zelevinsky, David M Kawall, Steve K Lamoreaux, Oskari Timgren, Jakob Kastelic, Jianhui Li, Tristan Winick, Yuanhang Yang The aim of CeNTREX (Cold molecule Nuclear Time-Reversal Experiment) is to search for the time-reversal and parity-violating Schiff moment of the 205Tl nuclear. The energy shift resulting fomr the 205 Tl Schiff moment is greatly amplified in the polar thallium fluoride (TlF) molecule, relative to the case in atoms. We employ two methods to maximize population in the science state: rotational cooling to pump the lowest rotational states into a single J=0 hyperfine level of the 1Σ+ electric ground state and electrostatic focusing with a quadrupole lens. Rotational cooling pumps into the J=0 state, but the electrostatic lens requires the weak field seeking states in J=2, and the science state is in J=1. This requires multiple state transfer stages, which we perform using adiabatic passage with microwaves. Finally, the Schiff moment measurement requires nulling of the magetic fields in the interaction region to within 10 μG, which is achieved witha combination of passive shielding and shim coils. This talk will discuss progress towards implementing these techniques. |
Wednesday, June 7, 2023 11:18AM - 11:30AM |
K05.00005: Spectroscopic Predictions for Radioactive 205PbF Richard J Mawhorter, Sean Jackson, Martin Blasko, Anastasia Borschevsky, Lukas F Pasteka The 3 spin ½ particles in 207PbF (both nuclei and the unpaired electron) combine to produce the near-degeneracy of two levels of opposite parity, as verified by Fourier transform microwave (FTMW) spectroscopy [1]. The science state is the 2Π1/2 ground state, which is inherently less sensitive to stray magnetic fields, making it an ideal candidate for the study of charge-parity non-conservation effects such as the anapole moment [2] as well as the variation of fundamental constants [3]. Furthermore, both theoretical and experimental work indicate that the finely split 207PbF +/– parity levels grow monotonically closer for higher vibrational states [4]. The current study explores the further impact on the energy levels of the (mildly) radioactive spin 5/2 Pb nucleus in 205PbF, incorporating scaled 207PbF hyperfine constants and the additional nuclear electric quadrupole splitting eQq. New relativistic quantum chemical coupled cluster calculations [5] yield a quite small preliminary eQq value of –6 MHz in contrast with the significantly larger value of about –188 MHz for the 2Π3/2 excited state. This could provide a convenient extra handle for further PbF parity studies, and these implications will also be discussed. |
Wednesday, June 7, 2023 11:30AM - 11:42AM |
K05.00006: Relativistic coupled-cluster calculations of time-reversal symmetry-violating sensitivity parameters as analytic energy derivatives Lan Cheng, Chaoqun Zhang Quantum-mechanical computations for effective electric fields, the time-reversal symmetry-violating sensitivity parameters pertinent to the search for the electron’s electric dipole moment (eEDM), play important roles in the interpretation of experimental measurements and in the selection of candidate molecules. We have developed an analytic-gradient-based method for relativistic exact two-component coupled-cluster calculations of effective electric fields to enhance the efficiency and robustness of the computations. The accuracy of the computed parameters is studied by comparing the results with the four-component calculations and by analyzing the convergence of the results with respect to the level of the treatments for electron-correlation effects. We further report the calculations of effective electric fields for a variety of molecular species and discuss the effects of the electronic-structure properties of these molecules on the computed effective electric fields. |
Wednesday, June 7, 2023 11:42AM - 11:54AM |
K05.00007: Atomic cesium embedded in cryogenic argon for electron EDM search daniel comparat, Thomas Battard, Sebastian Lahs, Claudine Crepin EDMs, i.e. electric dipole moments of electrons, neutrons or nuclei are sensitive probes for new physics beyond the Standard Model of particle physics. In the present project, we propose to measure the electron EDM using atoms embedded in a cryogenic solid matrix. Matrices offer unprecedented sample sizes while maintaining characteristics of an atomic physics experiment, such as the possibility of manipulation by lasers. We will present the EDMMA (Towards an Electric Dipole Moment with atoms and molecules in Matrix) project, that is a collaboration between experimental (LAC, ISMO,LPL) and theoretical (CIMAP) groups. We will present our first experimental and theoretical investigation of the spectroscopy of dilute cesium (Cs) atoms in a solid argon (Ar) matrix at cryogenic temperatures. The absorption spectra show evolution of the absorption peaks with temperature. Using the pairwise potentials we perform a trapping site stability and obtained reasonable agreement between observed and simulated absorption line positions and linewidths. We will also discuss recent fluorescence measurments. This should set the ground for further study of systematic effects that can occur for an EDM measurment. |
Wednesday, June 7, 2023 11:54AM - 12:06PM |
K05.00008: An Atomic Source for Short-Lived Radium Isotopes Roy A Ready, Mingyu Fan, Haoran Li, Spencer Kofford, Craig A Holliman, Max Ladabaum, Andrew M Jayich We are developing an effusive oven that produces a thermal beam of short-lived radium isotopes for optical clocks and tests of fundamental symmetries. The oven is loaded with thorium-228 (1.9 year half-life) which decays to radium-224 (3.6 day half-life). Thorium’s vapor pressure is trillions of times lower than radium and therefore remains in the oven when the radium is heated out. Our approach should generate a useful supply of radium atoms over several thorium half-lives, making it suitable for photoionizing and loading the radium into an ion trap. We have produced atomic beams of radium-224 (nuclear spin zero) from an effusive oven and observed the 2S1/2 → 2P1/2 (468 nm) transition with photoionized, trapped radium ions. In a parallel effort we are designing an orthotropic oven which is expected to produce a more collimated beam of radium atoms. We will use the techniques developed with radium-224 to prepare a radium-225 (nuclear spin I=1/2, 15 day half-life) atom source via the nuclear decay of thorium-229 (7900 year half-life). |
Wednesday, June 7, 2023 12:06PM - 12:18PM |
K05.00009: Progress towards atomic parity violation measurements in francium Gerald Gwinner, Timothy B Hucko, Anima Sharma, Seth Aubin, John A Behr, Eduardo Gomez, Alexandre Gorelov, Iris Halilovic, Mukut R Kalita, Jens Lassen, Stephan Malbrunot-Ettenauer, Luis A Orozco, Matthew R Pearson, Andrea Teigelhöfer, Liang Xie Low-energy precision tests of electro-weak physics keep playing an essential role in the search for new physics beyond the Standard Model. Atomic parity violation (APV) experiments measure the strength of highly forbidden atomic transitions induced by the exchange of Z bosons between electrons and quarks in heavy atoms. APV is sensitive to additional interactions such as leptoquarks, and provides complementary sensitivity to parity-violating electron scattering. Our group is working towards a measurement in francium, the heaviest alkali (Z=87), where the APV signal is about 18 times larger than in cesium. Since Fr has no stable isotopes, we have established an online laser trap at the ISAC radioactive beam facility at TRIUMF in Vancouver that can currently confine up to a million cold francium atoms at micro-Kelvin temperatures. I will report on our recent observation of the highly forbidden 7s-8s magnetic dipole transition and on our new highly efficient optical detection scheme which will bring observation of APV in reach. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700