Search for Daily Modulation of MeV Dark Matter Signals with DAMIC-M

Author:

I. Arnquist, N. Avalos, D. Baxter, X. Bertou, N. Castello-Mor, A. E. Chavarria, J. Cuevas-Zepeda, A. Dastgheibi-Fard, C. De Dominicis, O. Deligny, J. Duarte-Campderros, E. Estrada, N. Gadola, R. Gaior, T. Hossbach, L. Iddir, B. J. Kavanagh, B. Kilminster, A. Lantero-Barreda, I. Lawson, S. Lee, A. Letessier-Selvon, P. Loaiza, A. Lopez-Virto, K. J. McGuire, P. Mitra, S. Munagavalasa, D. Norcini, S. Paul, A. Piers, P. Privitera, P. Robmann, S. Scorza, M. Settimo, R. Smida, M. Traina, R. Vilar, G. Warot, R. Yajur, J-P. Zopounidis

Keyword:

High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Cosmology and Nongalactic Astrophysics (astro-ph.CO)

journal:

date:

2023-07-13 16:00:00

Abstract

Dark Matter (DM) particles with sufficiently large cross sections may scatter as they travel through Earth's bulk. The corresponding changes in the DM flux give rise to a characteristic daily modulation signal in detectors sensitive to DM-electron interactions. Here, we report results obtained from the first underground operation of the DAMIC-M prototype detector searching for such a signal from DM with MeV-scale mass. A model-independent analysis finds no modulation in the rate of 1$e^-$ events with periods in the range 1-48 h. We then use these data to place exclusion limits on DM in the mass range [0.53, 2.7] MeV/c$^2$ interacting with electrons via a dark photon mediator. Taking advantage of the time-dependent signal we improve by $\sim$2 orders of magnitude on our previous limit obtained from the total rate of 1$e^-$ events, using the same data set. This daily modulation search represents the current strongest limit on DM-electron scattering via ultralight mediators for DM masses around 1 MeV/c$^2$.

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