2026/05/12 by P. Adhikari, P. -A. Amaudruz, D. J. Auty +113 · 1 voice
#hep-ex
We report experimental evidence for electron neutrino charged-current interactions (neutrino absorption, CC νe) from 8B solar neutrinos on 40Ar using an exposure of (7.29 ± 0.05) tonne⋅years in the DEAP-3600 detector. A region of interest (ROI) of 10.5-13.0 MeV reconstructed energy calibrated on single-peak events, corresponding to incident neutrino energy in 12.0-14.5 MeV, is used for this measurement. We observe 5 single-peak and 1 double-peak neutrino-like events consistent with the 8B solar neutrino energy spectrum in the ROI after correcting for nonlinearities in the detector response at high energies. With an expected background of 0.48~+0.16-0.15 events, the data correspond to a significance of 4.0 σ with respect to the background-only hypothesis. We report an energy-averaged cross section of (4.0~+2.0-1.6~(stat)~+0.8-0.7~(sys))× 10-41 cm2 in the ROI for the CC νe signal, a factor (2.4~+1.3-1.0) higher than predicted by Bhattacharya, Goodman and García (2009).