WG1 Determination of Neutrino Mass Hierarchy with T2K and NOvA

Not scheduled

Speaker

Mr Suprabh Prakash (Indian Institute of Technology Bombay)

Description

We consider the ability of T2K and NOvA experiments to determine the neutrino mass hierarchy in light of the recent T2K results. Given the relatively high lower limit sin**2(2*theta13) > 0.03 set by T2K, it is worth exploring this problem. The numu ---> nue oscillation probability depends on the three (until now) unknown parameters theta13, deltaCP and neutrino mass hierarchy. Now that we have a lower limit on theta13, it is possible to determine the mass hierarchy if we have some knowledge regarding deltaCP. We first consider the ability of T2K to determine deltaCP. We simulate T2K data for 3 years of neutrino running plus 4 years of anti-neutrino running. Using this data, we compute the 90% C.L. allowed regions of deltaCP. We find that, for deltaCP true values in the range pi/4 < deltaCP < 3*pi/4, the T2K allowed range is 0 < deltaCP < pi. Similarly for deltaCP true values in the range 5*pi/4 < deltaCP < 7*pi/4, the T2K allowed range is pi < deltaCP < 2*pi. Next we simulate the data for NOvA for 3 years of neutrino running plus 3 years of anti-neutrino running and compute the ability of NOvA to determine the mass hierarchy. We restrict range of true values of deltaCP to be either pi/4 < deltaCP < 3*pi/4 or 5*pi/4 < deltaCP < 7*pi/4. That is we confine our attention to those values of deltaCP, which T2K can determine at 90% C.L. We find that, for these ranges, NOvA can determine the neutrino mass hierarchy at 90% C.L. for sin**2(2*theta13) > 0.08. Thus we conclude that, for half the range of deltaCP, NOvA can determine the mass hierarchy at 90% C.L., if sin**2(2*theta13) > 0.08.

Primary author

Mr Suprabh Prakash (Indian Institute of Technology Bombay)

Co-authors

Dr S. UMA SANKAR (Indian Institute of Technology Bombay) Mr Sushant RAUT (Indian Institute of Technology Bombay)

Presentation Materials