  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
non-relativistic 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 GeV/c$^2$ and 24 GeV/c$^2$ are reported for the coupling of
these photon-mediated dark matter-nucleus interactions. The detector was filled
with 52 kg of C$_3$F$_8$ operating at thermodynamic thresholds of 2.45 keV and
3.29 keV, reaching exposures of 1404 kg-day and 1167 kg-day, respectively.

Cosmology and Nongalactic Astrophysics;High Energy Physics - Experiment;High Energy Physics - Phenomenology