Melissa Diamond, joined by Chris Cappiello, tells us how dark matter interactions with one set of standard model particles might be first constrained via experiments looking for interactions with other particles.

As a first example they explore how loop diagrams that arise when dark matter interacts with quarks (and thus pions, neutrons and protons), necessarily introduce an interaction with electrons too. For light enough dark matter, this would mean that the first direct detection of these dark matter models would come via electron scattering experiments, not nucleon scattering experiments.

At the moment this just adds to constraints in somewhat less-interesting parameter space, but future experiments will push the constraints into well motivated parameter ranges for dark matter production mechanisms.

This loop interaction would also generate a dark matter “millicharge”, which could be combined with astrophysical observations to make even tighter constraints.

Melissa: https://inspirehep.net/authors/1945406
Chris: https://mcdonaldinstitute.ca/chris-cappiello/
Paper: https://arxiv.org/abs/2307.13727