23 questions · 9 almanac · 0 findings

Neutrino Physics

Detection, oscillation, and properties of neutrinos.

Almanac Ghost Particle Caught Near a Reactor
  • What discrepancy in beta decay led Wolfgang Pauli to propose the neutrino in 1930?
  • Why did Pauli himself doubt the neutrino could ever be detected?
  • How did Reines and Cowan's liquid-scintillator detector confirm antineutrinos near the Savannah River reactor in 1956?
  • What made the double flash of gamma rays the signature that proved a neutrino collision had occurred?
Almanac The Neutrinos Arrived Three Hours Early
  • Why did neutrino detectors in Japan and Ohio register a burst of particles three hours before the supernova's light arrived?
  • How did the neutrino burst confirm decades of theoretical predictions about core-collapse supernovae?
Almanac Matter Comes in Two Flavours, Not One
  • How did Lederman, Schwartz, and Steinberger manage to create a directed beam out of particles that barely interact with anything?
  • What did the Brookhaven experiment reveal about the muon neutrino versus the electron neutrino?
Almanac A Particle Caught Changing Its Identity Underground
  • What assumption about neutrino mass did the Standard Model make before 1998, and why?
  • How is the Super-Kamiokande detector built, and why is it buried a kilometre underground?
  • What did it mean for atmospheric muon-neutrinos to 'oscillate' into tau-neutrinos as they passed through the Earth?
  • Why does a particle's ability to oscillate between identities require it to have mass?
Almanac A Thirty-Year Deficit Finally Explained
  • Why did Raymond Davis Jr.'s solar neutrino experiment consistently detect only a third of the predicted count?
  • What did Masatoshi Koshiba's detection of neutrinos from a 1987 supernova prove for the first time?
  • Why did neutrino mass contradict the Standard Model's original predictions?
Almanac A Loose Cable, Not a Broken Universe
  • What did the OPERA experiment initially claim about neutrinos traveling from CERN to Gran Sasso?
  • What two equipment errors were eventually found to explain the anomalous timing?
  • Why would faster-than-light neutrinos have threatened special relativity if the result had held up?
Almanac Trillions of Liars Pass Through You Nightly
  • Why can a particle only oscillate between flavours if it has mass?
  • How did detectors buried underground manage to catch neutrinos changing flavour?
  • What does a nonzero neutrino mass imply for physics beyond the Standard Model?