Searching for Ultralight Dark Matter with M{\"o}ssbauer Resonance
We investigate the feasibility of probing the interactions between ultralight scalar dark matter and atomic nuclei using a stationary M\"ossbauer spectroscopy scheme. The exceptional energy resolution of the M\"ossbauer resonance enables searches for tiny nuclear energy shifts induced by the local dark matter field. The dark matter mass range considered in this work is $10^{-18}$--$10^{-8}~\mathrm{eV}$. We present projected constraints for two candidate M\"ossbauer isotopes, $^{109}\mathrm{Ag}$ and $^{45}\mathrm{Sc}$, with $^{109}\mathrm{Ag}$ providing the strongest sensitivity. For $^{109}\mathrm{Ag}$, projected sensitivities as low as approximately $10^{-19}$, $10^{-22}$, and $10^{-21}~\mathrm{GeV^{-1}}$ can be achieved for the scalar DM--photon, DM--gluon, and DM--quark couplings $f_{\gamma}^{-1}$, $f_{g}^{-1}$, and $f_{\hat{m}}^{-1}$, respectively. In the low-mass region, the projected sensitivity to the scalar DM--photon coupling approaches the current constraints from equivalence-principle (EP) tests. These results demonstrate that M\"ossbauer-based techniques provide a promising and competitive approach for probing ultralight dark matter interactions with Standard Model particles.