A dual-isotope rubidium comagnetometer to search for anomalous long-range spin-mass (spin-gravity) couplings of the proton

TL;DR

This paper proposes a dual-isotope rubidium comagnetometer to detect potential long-range spin-mass couplings of the proton, aiming to explore new physics beyond the Standard Model.

Contribution

It introduces a novel experimental setup using overlapping Rb-85 and Rb-87 ensembles to suppress magnetic noise and enhance sensitivity to spin-dependent interactions.

Findings

Initial data demonstrate the system's stability and sensitivity.

Systematic effects are analyzed to optimize detection capabilities.

The method shows promise for probing anomalous spin-mass couplings.

Abstract

The experimental concept of a search for a long-range coupling between rubidium (Rb) nuclear spins and the mass of the Earth is described. The experiment is based on simultaneous measurement of the spin precession frequencies for overlapping ensembles of Rb-85 and Rb-87 atoms contained within an evacuated, antirelaxation-coated vapor cell. Rubidium atoms are spin-polarized in the presence of an applied magnetic field by synchronous optical pumping with circularly polarized laser light. Spin precession is probed by measuring optical rotation of far-off-resonant, linearly polarized laser light. Simultaneous measurement of Rb-85 and Rb-87 spin precession frequencies enables suppression of magnetic-field-related systematic effects. The nuclear structure of the Rb isotopes makes the experiment particularly sensitive to anomalous spin-dependent interactions of the proton. Experimental sensitivity and a variety of systematic effects are discussed, and initial data are presented.