Searching for Ultralight Dark Matter with M{ö}ssbauer Resonance

TL;DR

The paper addresses the question of whether ultralight scalar dark matter can be probed through time-dependent shifts in nuclear energy levels detectable by Mossbauer spectroscopy. It develops a stationary Mossbauer scheme using ultra-sharp transitions in isotopes such as $^{109}\mathrm{Ag}$, $^{45}\mathrm{Sc}$, and $^{67}\mathrm{Zn}$ to transduce DM-induced energy shifts into a measurable vertical displacement of the Mossbauer resonance, $\Delta Z_0$, via gravitational and spectroscopic effects. By modeling the DM field as $\phi(t)=\frac{\sqrt{2\rho_{\rm DM}}}{m_\phi}\cos(\omega_\phi t)$ and deriving the resulting shifts from photon, quark, and gluon couplings, the authors project sensitivities to the inverse couplings $f_\gamma^{-1}$, $f_g^{-1}$, and $y_d$ across a DM mass range $m_\phi \sim 10^{-15}$–$10^{-8}$ eV, finding that $^{109}\mathrm{Ag}$ can reach $f_\gamma^{-1} \sim 10^{-18}$ GeV$^{-1}$, $f_g^{-1} \sim 10^{-21}$ GeV$^{-1}$, and $y_d \sim 10^{-22}$ GeV$^{-1}$. The results indicate that Mossbauer techniques can be competitive with or surpass several existing bounds in parts of the parameter space, especially with longer baselines and next-generation X-ray sources. Overall, the work demonstrates a viable, tabletop approach to probing ultralight DM interactions with Standard Model particles and outlines paths for significant experimental enhancements.

Abstract

We investigate the feasibility of probing the interaction between ultralight scalar dark matter and atomic nuclei using a stationary Mossbauer spectroscopy scheme. The exceptional energy resolution of the Mossbauer resonance enables testing nuclear energy shifts arising from the local dark matter field. In principle, a stationary measurement allows faster data acquisition and becomes advantageous at higher dark matter masses in the range 10^{-15} - 10^{-8} eV. We present the projected sensitivity to the dark matter parameter space for three candidate Mossbauer isotopes, Ag-109, Sc-45, and Zn-67. Among them, Ag-109 provides the highest sensitivity, followed by Zn-67. For Ag-109, the scalar dark matter photon coupling f_gamma^{-1} can be constrained down to the level of 10^{-18} GeV^{-1}}, exceeding the sensitivity of several existing experiments. The scalar dark matter gluon coupling f_g^{-1} can be probed down to 10^{-21} GeV^{-1}, while the scalar dark matter quark coupling y_d can reach approximately 10^{-22} GeV^{-1}. These results demonstrate that Mossbauer based techniques offer a promising and competitive approach for probing ultralight dark matter interactions with Standard Model particles.

Figures (4)

• Figure 1: Illustration for a vertical shift in resonance location.
• Figure 2: For the $^{109}\text{Ag}$ nucleus: Simulated peak position accuracy $\Delta Z_{0}$ obtained from a single pseudo-experiment measuring the position of the absorption Lorentzian peak, assuming an experimental linewidth of $20~\mathrm{\mu m}$, z-axis bin width of $10~\mathrm{\mu m}$, 500 arriving photons per bin, recoil-free fraction $f_S$ =0.5, and absorption fraction $\epsilon$=0.8.
• Figure 3: Projected sensitivity to the scalar DM–photon coupling $f_{\gamma}^{-1}$ versus the dark matter mass $m_{\phi}$. Time exposure assumes one dark matter coherent time, $t_c=10^6\cdot 2\pi m_\phi^{-1}$. Red, black, and blue dashed lines denote results for $^{109}\text{Ag}$, $^{45}\text{Sc}$ and $^{67}\text{Zn}$, respectively. while the black dot-dashed line corresponds to $^{45}\text{Sc(SR)}$ with synchrotron radiation. Existing constraints from GEO 600 Vermeulen:2021epa, DD Aharony:2019iad, DAMNED Savalle:2020vgz, Holometer Aiello:2021wlp, as well as equivalence-principle tests by MICROSCOPE Touboul:2017grnBerge:2017ovy and Eöt-Wash Smith:1999crSchlamminger:2007ht, are shown for comparison. For $^{109}\text{Ag}$, $^{45}\text{Sc}$, and $^{67}\text{Zn}$ using traditional radioactive sources, the source activity is fixed at $0.1~\mathrm{Ci}$. For $^{45}\text{Sc}$ with synchrotron radiation (SR), a spectral photon flux of $1\times10^{12}\,\mathrm{ph\,s^{-1}\,meV^{-1}}$ is assumed. The baseline distance is $1~\mathrm{m}$ for $^{109}\text{Ag}$ and $^{45}\text{Sc}$, and $50~\mathrm{m}$ for $^{67}\text{Zn}$.
• Figure 4: Projected sensitivity to the scalar DM-gluon coupling $f_{g}^{-1}$ (a) and the scalar DM-quarks coupling $y_{d}$ (b), versus the dark matter mass $m_{\phi}$. Red, black, and blue dashed lines denote results for $^{109}\text{Ag}$, $^{45}\text{Sc}$ and $^{67}\text{Zn}$, respectively. while the black dot-dashed line corresponds to $^{45}\text{Sc}$ with synchrotron radiation. Existing constraints from equivalence-principle tests by MICROSCOPE Touboul:2017grnBerge:2017ovy and Eöt-Wash Smith:1999crSchlamminger:2007ht are shown for comparison.