P , T -odd effects in YbCu, YbAg, and YbAu

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Condensed Matter Physics

Background:

• Bimetallic molecules like YbCu, YbAg, and YbAu are promising for creating cold molecules via laser-cooled atoms.
• Understanding P,T-odd interactions is key to searching for new physics beyond the Standard Model.

Purpose of the Study:

• To compute molecular enhancement factors for electron electric dipole moment (Wd) and scalar-pseudoscalar nucleon-electron couplings (Ws) in YbCu, YbAg, and YbAu.
• To investigate electronic structure effects influencing these enhancement factors.
• To compare two computational schemes for Wd.

Main Methods:

• Relativistic coupled-cluster approach was employed for high-accuracy electronic structure calculations.
• A comprehensive uncertainty analysis was performed to ensure reliability of the results.
• Two distinct methods for calculating Wd were compared.

Main Results:

• Computed enhancement factors for Wd: (13.32±0.13)×10^24, (12.19±0.12)×10^24, and (2.36±0.48)×10^24 hHzecm for YbCu, YbAg, and YbAu, respectively.
• Computed enhancement factors for Ws: (-48.63 ± 0.53), (-45.68 ± 0.60), and (3.81 ± 2.58) hkHz for YbCu, YbAg, and YbAu, respectively.
• Detailed analysis of electronic structure contributions to the enhancement factors was conducted.

Conclusions:

• The calculated molecular enhancement factors provide crucial data for experiments searching for P,T-odd interactions.
• The study validates the relativistic coupled-cluster approach and offers insights into the electronic structure of these bimetallic systems.
• These results contribute to the development of novel cold molecule techniques for precision measurements.