Master defence by Rasmus W. Rasmussen – Niels Bohr Institute - University of Copenhagen

Niels Bohr Institute > Calendar > NBI Calendar 2014 > Master defence by Rasm...

Master defence by Rasmus W. Rasmussen

Determination of the neutrino mixing angle theta_23 octant and differentiation among flavor symmetries

Abstract: This thesis studies the potential/reach for the Proposed IceCube Next Generation Upgrade (PINGU) with respect to the determination of the octant of the atmospheric mixing angle theta_23. In the neutrino sector, this is one of the still unknown parameters which have to be determined by future experiments. Present measurements of theta_23 are not precise enough to establish whether this mixing is maximal or not. If it is non-maximal, there are two solutions to the neutrino oscillation data in that theta_23 can either be below or above 45 degrees, i.e. it lies in the first or second octant.

From Monte Carlo simulations the event rates of neutrinos in PINGU were calculated and a chi square fit was done, assuming the theoretical predicted event rates were fitted in the wrong octant of the atmospheric angle. This provides a way to constrain this mixing parameter. In turn this can potentially differentiate among various flavour symmetries which can underly the neutrino mixing matrix and thereby the oscillation parameters.

By implementing multiple flavour symmetries in the simulations, a comparison of the sensitivities to the various models could be made. This in priciple provides a way to experimentally determine the flavour symmetry for neutrinos.

Date: Wednesday 20 Aug
Time: 13:00
Place: Aud. A