The neutrino was first experimentally detected in 1956.
Notes on verification
Well-documented by Nobel Prize committee, APS history archive, and standard physics references; multiple independent sources converge on the 1956 Cowan-Reines experiment. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=1.0 clusters=2 claim_tier=notable | kind=empirical eligibility=high]
Sources
- Un neutrino éblouit l’astrophysique | CNRS Le journal (seed:science_and_space)
- https://www.nobelprize.org/prizes/physics/1995/reines/facts/ (corroboration)
- https://www.aps.org/apsnews/2007/12/1956-first-experimental-detection-neutrino (corroboration)