Theory Deep Dives — Part 2: Dirac vs Majorana fermions
What the difference between Dirac and Majorana mass terms really means — and why neutrinos are the only Standard Model fermions where the distinction has physical consequences.
Tag
Dirac
5 articles tagged with Dirac.
Open Questions — Part 4: Dirac or Majorana? The 0νββ hunt
Is the neutrino its own antiparticle? The answer would reshape the Standard Model. Neutrinoless double beta decay is the only viable experimental test — and the ton-scale generation is being built.
The Higgs and neutrino mass: why the Standard Model still doesn't quite explain it
Every other fermion in the Standard Model gets its mass from coupling to the Higgs field. Neutrinos do too, but at couplings so unnaturally small that nobody quite believes that's the whole story.
What's the difference between a neutrino and an antineutrino?
Neutrinos and antineutrinos have opposite lepton number and opposite helicity. Neutrinos are produced together with positrons in beta-plus decay; antineutrinos with electrons in beta-minus decay. Whether they are actually distinct particles or two faces of the same one is still an open question.
Majorana or Dirac? Why the neutrino's identity is still an open question
Is a neutrino its own antiparticle, or not? The answer would rewrite half a century of particle physics — and explain why we have a universe of matter at all.