Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,
Tel (Office): (865) 574-6124 (FAX): (865) 574-1268
The only experimentally observed phenomenon that lies outside the standard model is neutrino oscillations: the coherent mixing of propagating neutrino mass eigenstates that leads to neutrino flavor conversion in the lab. A current goal in the field is to determine the values of the mixing angles and mass splittings that characterize this mixing. However, a related open question is the hierarchy question, which mass state is lightest and which heaviest? We point out a broken symmetry in the oscillation probability relevant to this question. For the recently measured, surprisingly large, value of the mixing angle theta-13, we find that this broken symmetry lifts a four-fold degeneracy. This symmetry breaking effect proves very meaningful for the hierarchy question: in the global data, it leads to a preference for the inverse hierarchy at the 97.2% level.
Contact: Alfredo Galindo-Uribarri, 574-6124