text: This scientist names a hypothetical dark matter candidate which is the Goldstone boson for the spontaneous breaking of ungauged lepton number symmetry.
full_question: This scientist names a hypothetical dark matter candidate which is the Goldstone boson for the spontaneous breaking of ungauged lepton number symmetry. The search for another hypothetical particle named for this scientist is being performed in experiments utilizing liquid xenon in a time projection chamber and cadmium zinc telluride crystalsthose are the EXO and COBRA experiments. This scientist names a representation in which the gamma matrices are all either purely real or purely imaginary, causing the spinors to be purely real. A right-handed spinor is multiplied by its charge conjugate in a mass term named for this scientist appearing in the Lagrangian which explains the seesaw mechanism. The existence of a type of particle named for this scientist would be confirmed by observing neutrinoless double beta decay. Dirac fermions are contrasted with, for 10 points, what scientist's namesake type of fermion, which is its own antiparticle?
first_sentence: This scientist names a hypothetical dark matter candidate which is the Goldstone boson for the spontaneous breaking of ungauged lepton number symmetry.
raw_answer: Ettore Majorana [or Majorana fermions; or Majorana spinors]