Search for a potential Dark Matter daily modulation signal in Sierra Grande, Argentina
The Experiment
The Dark Matter Daily Modulation Experiment (DM2, pronounced DM-square) is a direct dark matter search experiment using the Skipper CCD technology developped by the DAMIC and SENSEI experiments in a site at 40 deg of latitude South in order to exploit the potential daily modulation of Dark Matter induced signals.
The Detector
In DM2 we use the Skipper CCDs developed by DAMIC and SENSEI.
These sensors exhibit world-class low readout noise, down to less than 0.1 electron, allowing individual electron counting, for a potential lower limit on ionization threshold of 1.2 eV.
While they exhibit low dark current, it is still the major limitation at 1 or 2 electron signals and the search for a sideral modulation in these signals is a way to extract a potential signal from background.
The Site
The first operation and calibration is being done in Bariloche, Argentina (41.1 latitude South), at the Bariloche Atomic Center.
The detector will then be moved to the Sierra Grande iron mine (41.6 latitude South) at a reserved site 400 m deep to reduce greatly the cosmic ray background.
At both sites the Dark Matter wind is expected to come from elevations of 0 (ie just at the horizon) to about -80 degrees (mostly from below, crossing the whole Earth).
Operation Schedule
Sep 2019 - Jan 2020
Detector chamber construction
Feb 2020 - Mar 2020
First operation and calibration in Bariloche
Mar 2020 - now
Schedule affected by COVID-19 pandemia
Sep 2020 - now
Surface physics run in Bariloche started
The Collaboration
H. Arnaldi, I. Artola, N. Ávalos, X. Bertou, E. Estrada, M. Gómez Berisso, M.B. Lovino, M. Mantiñan, M. Sofo Haro
Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica (CNEA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCUYO), San Carlos de Bariloche, Argentina.
J. Tiffenberg
Universidad de Buenos Aires, CONICET, Argentina and Fermi National Accelerator Laboratory, IL, USA.
J. Estrada
Fermi National Accelerator Laboratory, IL, USA.
Skipper CCD Image taken in Bariloche (2h30 exposition time)
Results and Publications
Work in ongoing on the first publications for DM2:
Description of the DM2 experiment, setup and operation
First run at the surface in Bariloche, data analysis
Characteristics of the undergound site in Sierra Grande
They will be available on arXiv and sent for peer review in an open access journal when ready.
Outreach and public data
Work is also ongoing on Outreach activities and possibly making part of the data from the first surface run available to the community for analysis and help planning future experiments.
