Is dark matter a thermal-relic weakly interacting massive particle? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Is dark matter a thermal-relic weakly interacting massive particle?
Plain
A popular idea is that dark matter is a heavy particle that was in equilibrium with ordinary matter in the hot early universe and froze out at the right abundance. Underground detectors look for it hitting atomic nuclei.
Precise · changed · core
Revision 1: Does a particle of mass $1\,\mathrm{GeV}\text{ to }100\,\mathrm{TeV}$, produced by thermal freeze-out with annihilation cross section $\langle \sigma v\rangle \sim 3e-26\,\mathrm{cm}^{3}/\mathrm{s}$, make up $\Omega_c$? Answer yes (a detection of nuclear recoils, annihilation products or collider production consistent with the thermal cross section) or no for named benchmarks: exclusion of Higgs-portal and Z-portal thermal relics by direct detection, and of the pure wino ($\sim 2.9\,\mathrm{TeV}$) and pure Higgsino ($\sim 1.1\,\mathrm{TeV}$) thermal relics by gamma-ray line and continuum searches from the Galactic Center. Thermal relics with loop-suppressed nuclear couplings (pure Higgsino, $\sigma_{\mathrm{SI}} \sim 1e-49\text{ to }1e-48\,\mathrm{cm}^{2}$) lie at or below the xenon neutrino background floor, so direct detection alone cannot close the question.
Revision 2: Does a particle of mass $1\,\mathrm{GeV}\text{ to }100\,\mathrm{TeV}$, produced by thermal freeze-out with annihilation cross section $\langle \sigma v\rangle \sim 3 \times 10^{-26}\,\mathrm{cm}^{3}/\mathrm{s}$, make up $\Omega_c$? Answer yes (a detection of nuclear recoils, annihilation products or collider production consistent with the thermal cross section) or no for named benchmarks: exclusion of Higgs-portal and Z-portal thermal relics by direct detection, and of the pure wino ($\sim 2.9\,\mathrm{TeV}$) and pure Higgsino ($\sim 1.1\,\mathrm{TeV}$) thermal relics by gamma-ray line and continuum searches from the Galactic Center. Thermal relics with loop-suppressed nuclear couplings (pure Higgsino, $\sigma_{\mathrm{SI}} \sim 10^{-49}\text{ to }10^{-48}\,\mathrm{cm}^{2}$) lie at or below the xenon neutrino background floor, so direct detection alone cannot close the question.
Settled by
Liquid-xenon or argon detectors reaching the neutrino background floor over $10\,\mathrm{GeV}$ to $10\,\mathrm{TeV}$, combined with gamma-ray line and continuum searches sensitive to wino and Higgsino annihilation at the thermal cross section.
Kind
well-posed
Answer type
yes-no
References
(empty)
Literature status
open
Status note · changed
Revision 1: LZ (2025, 4.2 tonne-years) found no excess and excluded spin-independent WIMP-nucleon cross sections above $2.2e-48\,\mathrm{cm}^{2}$ at 40 GeV (90 percent confidence).
Revision 2: LZ (2025, 4.2 tonne-years) found no excess and excluded spin-independent WIMP-nucleon cross sections above $2.2 \times 10^{-48}\,\mathrm{cm}^{2}$ at 40 GeV (90 percent confidence).
Posed since
1977

Decisions