Quantum dynamics in atomic-fountain experiments for measuring the electric dipole moment of the electron with improved sensitivity

TL;DR

This paper proposes an advanced atomic fountain experiment with enhanced sensitivity for measuring the electron's electric dipole moment, utilizing a strong perpendicular electric field and systematic error suppression techniques.

Contribution

It introduces a novel theoretical framework for analyzing atomic fountain experiments and proposes a double-differential setup to significantly improve EDM measurement sensitivity.

Findings

Complete time evolution operator expansion for F=3,4,5 atoms.

Systematic errors suppressed as even powers of 1/mu in entangled hyperfine states.

Potential to drastically improve EDM limits and constrain SUSY models.

Abstract

An improved measurement of the electron electric dipole moment (EDM) appears feasible using ground-state alkali atoms in an atomic fountain in which a strong electric field, which couples to a conceivable electron dipole moment (EDM), is applied perpendicular to the fountain axis. In a practical fountain, the ratio of the atomic tensor Stark shift to the Zeeman shift is a facto mu~100. We expand the complete time evolution operator in inverse powers of this ratio; complete results are presented for atoms of total spin F=3, 4, and 5. For a specific set of entangled hyperfine sublevels (coherent states), potential systematic errors enter only as even powers of 1/mu, making the expansion rapidly convergent. The remaining EDM mimicking effects are further suppressed in a proposed double-differential setup, where the final state is interrogated in a differential laser configuration, and the direction of the strong electric field also is inverted. Estimates of the signal available at existing accelerator facilities indicate that the proposed apparatus offers the potential for a drastic improvement in EDM limits over existing measurements, and for constraining the parameter space of supersymmetric (SUSY) extensions of the Standard Model.