Search for magnetic monopoles in polar volcanic rocks

TL;DR

This study searched for magnetic monopoles in polar volcanic rocks using a SQUID magnetometer, setting upper limits on monopole density due to no detections, thus constraining their abundance in Earth's mantle.

Contribution

First search for magnetic monopoles in polar volcanic rocks using SQUID magnetometry, providing new upper limits on monopole density in Earth's mantle-derived rocks.

Findings

No monopoles detected in 24.6 kg of rocks.

Set 90% confidence upper limit of 9.8×10^{-5}/gram on monopole density.

Constraints on monopole abundance in Earth's mantle.

Abstract

For a broad range of values of magnetic monopole mass and charge, the abundance of monopoles trapped inside the Earth would be expected to be enhanced in the mantle beneath the geomagnetic poles. A search for magnetic monopoles was conducted using the signature of an induced persistent current following the passage of igneous rock samples through a SQUID-based magnetometer. A total of 24.6 kg of rocks from various selected sites, among which 23.4 kg are mantle-derived rocks from the Arctic and Antarctic areas, was analysed. No monopoles were found and a 90% confidence level upper limit of $9.8\cdot 10^{-5}$/gram is set on the monopole density in the search samples.