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Annual modulations from secular variations: relaxing DAMA?

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The DAMA collaboration reported an annually modulated rate with a phase compatible with a Dark Matter induced signal. We point out that a slowly varying rate can bias or even simulate an annual modulation if data are analyzed in terms of residuals computed by subtracting approximately yearly averages starting from a fixed date, rather than a background continuous in time. In the most extreme case, the amplitude and phase of the annual modulation reported by DAMA could be alternatively interpreted as a decennial growth of the rate. This possibility appears mildly disfavoured by a detailed study of the available data, but cannot be safely excluded. In general, a decreasing or increasing rate could partially reduce or enhance a true annual modulation, respectively. The issue could be clarified by looking at the full time-dependence of the DAMA total rate, not explicitly published so far.


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Correspondence to Paolo Panci.

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ArXiv ePrint: 2002.00459

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Buttazzo, D., Panci, P., Rossi, N. et al. Annual modulations from secular variations: relaxing DAMA?. J. High Energ. Phys. 2020, 137 (2020).

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  • Dark Matter and Double Beta Decay (experiments)
  • Dark matter