Revision 1

Superseded · first revision · record

Title: Can recoil direction separate dark matter from solar neutrinos?
Plain: Solar neutrinos push nuclei away from the Sun, while dark matter pushes them along Earth's path through the galaxy. A detector that measures recoil directions could tell them apart, if it can track recoils only a few keV in energy.
Precise: In the neutrino fog, defined by O'Hare as the region where the discovery-limit index $n = -(d \ln \sigma / d \ln \mathrm{exposure})^{-1}$ exceeds 2, sensitivity grows slower than $1/\sqrt{\mathrm{exposure}}$. The question is the angular resolution, head-tail recognition efficiency and threshold (e.g., in a He:SF6 or CF4 gas time projection chamber) needed to restore n near 1 at WIMP masses 5-10 GeV and cross sections about one order of magnitude below the 8B fog boundary for the chosen target, and the exposure this requires.
Settled by: Demonstrated head-tail sensitivity and angular resolution for few-keV nuclear recoils in a prototype, combined with a sensitivity calculation using the measured performance.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)