Speaker
Description
Effective field theory (EFT) provides a model-independent framework for interpreting the results of dark matter (DM) direct detection experiments. In this study, we demonstrate that two fermionic DM-quark tensor operators ($(\bar{\chi} i\sigma^{\mu\nu} \gamma^5 \chi) (\bar{q} \sigma_{\mu\nu}q)$ and $(\bar{\chi} \sigma^{\mu\nu} \chi) (\bar{q} \sigma_{\mu\nu} q)$) can contribute to the DM electric and magnetic dipole moments via non-perturbative QCD effect, in addition to the well-studied contact DM-nucleon operators. We then investigate the constraints on these two operators by translating the existing bounds on DM dipole operators from various direct detection experiments. For $m_\chi < 1 ~\rm GeV$, our results significantly extend the reach of constraints on DM-quark tensor operators to masses as low as $3 ~\rm MeV$, with the bound exceeding that of obtained by the Migdal effect by an order of magnitude or so.In particular, for the operator $(\bar{\chi} \sigma^{\mu\nu}i\gamma_5 \chi) (\bar{q} \sigma_{\mu\nu}q)$ with DM mass $m_\chi > 10 ~\rm GeV$, the latest PandaX constraint on the DM electric dipole moment puts more stringent bounds as compared to the previous direct detection limit.
