APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Kazuo Fujikawa (Riken)
Title: Majorana neutrino in seesaw mechanism and Bogoliubov quasiparticle
Date: Wed, Jan 31, 2018, 13:30 - 14:30
Place: Seminar Room A
Abstract: The idea that the Majorana neutrino should be identified as a Bogoliubov quasiparticle is applied to the seesaw mechanism for the three generations of neutrinos in the Standard Model. The Bogoliubov transformation in the present context is a CP preserving canonical transformation but modifies charge conjugation properties in such a way that the C-noninvariant fermion number violating term (condensate) is converted to a Dirac mass term. The puzzling aspects associated with the charge conjugation of chiral Weyl fermions are clarified. A sizable fine tuning in the simple version of seesaw mechanism as perceived by the majority of physicists is illustrated for the three generations of neutrinos; the seesaw mechanism is not natural if the model suffers from the hierarchy problem.