First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector

Dark matter with Planck-scale mass ($\simeq {10}^{19}\mathrm{GeV}/c^2$) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between $8.3\times {10}^6$ and $1.2\times {10}^{19}\mathrm{GeV}/c^2$, and ${}^{40}\mathrm{Ar}$-scattering cross sections between $1.0\times {10}^{-23}$ and $2.4\times {10}^{-18}{\mathrm{cm}}^2$. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

Figure 1

Example simulated PE time distributions for DM with $m_{\chi }={10}^{18}\mathrm{GeV}/c^2$ with low and high ${\sigma }_{T\chi }$.

Figure 2

Simulated $F_{\text{prompt}}$ and $N_{\text{peaks}}$ distributions for DM with $m_{\chi }={10}^{18}\mathrm{GeV}/c^2$ for various ${\sigma }_{T\chi }$.

Figure 3

Probability of DM with $m_{\chi }={10}^{18}\mathrm{GeV}/c^2$ populating each ROI and surviving all cuts at varying ${\sigma }_{T\chi }$.

Figure 4

DM masses $m_{\chi }$ and nucleon scattering cross sections ${\sigma }_{n\chi }$ excluded by DEAP-3600, for Model I (top) and Model II (bottom). Extrapolated regions exclude dark matter above the highest simulated cross sections. Also shown are other constraints using DAMA [26, 51], interstellar gas clouds [52, 53], a recast of CRESST and CDMS-I [28], a detector at the University of Chicago [29], a XENON1T single-scatter analysis [30], and tracks in the Skylab and Ohya plastic etch detectors [51], and in ancient mica [54]. Limits from MAJORANA DEMONSTRATOR [30] are not shown as the corresponding regions are already excluded by DAMA and XENON1T.