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Title: Does crystal-specific NaI(Tl) response hide a DAMA-only signal?
Plain: Sodium iodide crystals turn the energy of a recoiling sodium nucleus into light with an efficiency (the quenching factor) that can differ between crystals. If DAMA's crystals differ from the others, a real signal might show up only in DAMA.
Precise: The sodium recoil quenching factor $Q_{\mathrm{Na}}(E_{R})$ in NaI(Tl) converts nuclear recoil energy to electron-equivalent energy and has been measured between roughly 0.1 and 0.3 for $E_{R} \sim 10-100\, \mathrm{keV}$, with dependence on thallium concentration. The question is the value of $Q_{\mathrm{Na}}(E_{R})$ and of the near-threshold light yield for DAMA's own crystals, and whether any value within that range brings the DAMA modulation into agreement with COSINE-100 and ANAIS-112 when compared at equal nuclear recoil energy rather than equal electron-equivalent energy.
Settled by: A direct neutron-beam quenching-factor measurement on a DAMA-equivalent crystal (same supplier, Tl concentration and growth), followed by a recoil-energy-matched comparison of the three experiments.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: open
Status note: COSINUS (Eur. Phys. J. C 2026, arXiv 2512.05980) measured that lower Tl concentration gives a smaller Na quenching factor, confirming crystal dependence.
Posed since: (empty)