Seminar

Title: New Aspects of Neutrino Oscillation

Speaker: Prof. Shao-Feng Ge (葛韶锋) (Tsung-Dao Lee Institute, SJTU)

Time: 3:00PM (Beijing Time), Monday, 2020-12-28

Place: R319, TPD, IHEP；Zoom: 2151583083 (Code: 12345)   

Zoom ID:2151583083

Abstract: The current explanation of neutrino oscillation is based on the transition among different flavors with a non-diagonal neutrino mass matrix. In this talk I will introduce some new thoughts about the underlying physics behind neutrino oscillation. First, the neutrino mass that derives neutrino oscillation needs not to be a genuine mass term but an effective environmental effect. With scalar interaction, the forward scattering with the (dark) matter medium can introduce a matter effect that can mimic the neutrino mass term. Neutrino oscillation does indicate there is something beyond the Standard Model, but it needs not to be a genuine neutrino mass. In addition, the current formalism of neutrino oscillation only considers the oscillation among different flavors with an overall evolution phase for each mass eigenstate. This effectively treats neutrino mass eigenstate as a scalar rather than a fermion. When parity violation taken into account, the chiral nature of neutrino would introduce chiral oscillation between the left- and right-handed components in addition to the usual flavor oscillation. The chiral oscillation can already happen with only one flavor or mass eigenstate. I will introduce a novel way of testing chiral oscillation with cosmological relic neutrinos.