  We report the best limit on coherent elastic scattering of electron
antineutrinos emitted from a nuclear reactor off germanium nuclei. The
measurement was performed with the CONUS detectors positioned at 17.1m from the
3.9GWth reactor core of the nuclear power plant in Brokdorf, Germany. The
antineutrino energies of less than 10 MeV assure interactions in the fully
coherent regime. The analyzed dataset includes 248.7 kgd with the reactor
turned on and background data of 58.8 kgd with the reactor off. With a
quenching parameter of k = 0.18 for germanium, we determined an upper limit on
the number of neutrino events of 85 in the region of interest at 90% confidence
level. This new CONUS dataset disfavors quenching parameters above k = 0.27,
under the assumption of standard-model-like coherent scattering of the reactor
antineutrinos.
