Exploring Direct Detection of Massive Particles Using Wave Propagation from Gravitational Coupling with a Wire Under Tension

Abstract

We investigate the feasibility of detecting galactic orbit dark matter passing through Earth by measuring its gravitational coupling with a wire under tension. We do so by exploring the transverse and longitudinal waves induced on the wire to detect a massive particle passing within $\sim 1$ m of the wire. The particle's $r^{-2}$ interaction with the wire provides an initial momentum which develops into a propagating wave carrying a distinctive time dependent displacement. Most interestingly, we find that both transverse and longitudinal waves develop with unique profiles, allowing for a full, three dimensional reconstruction of the particle's trajectory and its mass over velocity ratio. We find that, at interaction distances of 0.1 to 100 mm with a 90 micron diameter copper beryllium wire, Planck scale dark matter with mass $\sim 10^{19}$ GeV/$c^2$ would create immeasurable displacements on the scale of $10^{-24}$ to $10^{-26}$ m. In order to create displacements detectable by modern, commercially available, displacement sensors on the nanometer scale we require dark matter with a particle mass greater than $4 \times 10^7$ kg ($\sim 2 \times 10^{32}$ GeV/$c^2$). This is outside the upper limit of the Planck scale by 13 orders of magnitude and would also have such a low particle flux that a detection event would be implausible. Finally, we perform a similar analysis for a charged wire and an elementary charged particle with their electrostatic interaction, finding that a sufficiently slow charged particle would produce a transverse displacement comparable to the sensitivity of currently available sensors.