Constraining CP Violating Nucleon-Nucleon Long-Range Interactions in Diatomic eEDM Searches

Area of Science:

• Atomic and Molecular Physics
• Particle Physics
• Nuclear Physics

Background:

• Searches for CP violation in molecules (e.g., HfF+, ThO) typically probe the electron's electric dipole moment (eEDM).
• These searches also offer sensitivity to new electron-nucleon and electron-electron interactions.
• The presence of nuclear spin introduces a new CP-violating nucleon-nucleon long-range force that can influence eEDM measurements.

Purpose of the Study:

• To derive a new bound on the hypothetical CP-violating nucleon-nucleon long-range force.
• To provide a new interpretation of experimental results from eEDM searches.
• To motivate independent searches for CP violation in different molecular species.

Main Methods:

• Utilizing data from the HfF+ eEDM search experiment.
• Analyzing the impact of a nonvanishing nuclear spin on CP violation measurements.
• Deriving stringent bounds on hypothetical new physics interactions.

Main Results:

• A new, stringent terrestrial bound has been derived for the CP-violating nucleon-nucleon long-range force.
• This bound is the most stringent to date for interactions in the 1 eV-10 keV mass range.
• The study highlights multiple sources of new physics contributing to CP violation signals.

Conclusions:

• CP violation searches in diatomic molecules are sensitive to both eEDM and nucleon-nucleon forces.
• The HfF+ experiment provides a powerful constraint on hypothetical nucleon-nucleon interactions.
• Independent searches in diverse molecular systems are crucial for obtaining model-independent bounds on new physics.