Global Network of Optical Magnetometers for Exotic (GNOME): Physics Novel scheme for exotic physics searches

TL;DR

The paper proposes a global network of synchronized optical magnetometers to detect transient exotic spin couplings, enabling the investigation of physics beyond the Standard Model through correlated measurements across distant locations.

Contribution

It introduces a novel scheme for using geographically separated magnetometers to identify transient exotic physics signals, demonstrating initial feasibility with a two-site experiment.

Findings

Successful demonstration of correlated measurements between two magnetometers over 9000 km

Potential to detect transient signals from exotic spin couplings beyond current constraints

Discussion of data analysis methods for transient signal identification

Abstract

A novel experimental scheme enabling investigation of transient exotic spin couplings is discussed. The scheme is based on synchronous measurements of optical-magnetometer signals of several devices operating in magnetically shielded environments in distant locations ($\gtrsim100$ km). Although signatures of such exotic couplings may be present in the signal from a single magnetometer, it would be challenging to distinguish them from noise. By analyzing the correlation between signals from multiple, geographically separated magnetometers, it is not only possible to identify the exotic transient but also to investigate its nature. The ability of the network to probe presently unconstrained physics beyond the Standard Model is examined by considering the spin coupling to stable topological defects (e.g., domain walls) of axion-like fields. In the spirit of this research, a brief ($\sim 2$ hours) demonstration experiment involving two magnetometers located in Krak\'ow and Berkeley ($\sim 9000$ km separation) is presented and discussion of the data-analysis approaches that may allow for the transient signal identification is provided. The prospects of the network are outlined in the last part of the paper.