Many compelling models predict dark matter coupling to the electromagnetic current through higher multipole interactions, while remaining electrically neutral. Different multipole couplings have been studied, among them anapole moment, electric and magnetic dipole moments, and millicharge. This study sets limits on the couplings for these photon-mediated interactions using nonrelativistic contact operators in an effective field theory framework. Using data from the PICO-60 bubble chamber leading limits for dark matter masses between 2.7 and $24\mathrm{GeV}/{\mathrm{c}}^2$ and above $265\mathrm{GeV}/{\mathrm{c}}^2$ (anapole moment), 2.7 and $11.7\mathrm{GeV}/{\mathrm{c}}^2$ (electric moment), 3 and $9.5\mathrm{GeV}/{\mathrm{c}}^2$ (magnetic moment), and 2.7 and $12\mathrm{GeV}/{\mathrm{c}}^2$ (millicharged) are reported for the coupling of these photon-mediated dark matter-nucleus interactions. The detector was filled with 52 kg of ${\mathrm{C}}_3{\mathrm{F}}_8$ operating at thermodynamic thresholds of 2.45 keV and 3.29 keV, reaching exposures of $1404\mathrm{kg}\text{−}\mathrm{day}$ and $1167\mathrm{kg}\text{−}\mathrm{day}$, respectively.

• Received 26 April 2022
• Accepted 28 July 2022

DOI:https://doi.org/10.1103/PhysRevD.106.042004