Determination of Mass hierarchy and Leptonic CP violation with upgraded NOvA and T2K in light of large theta13
Starts 25 Sep 2012 17:30
Ends 25 Sep 2012 20:00
Central European Time
ICTP
Leonardo da Vinci Building Luigi Stasi Seminar Room
Strada Costiera, 11
I - 34151 Trieste (Italy)
We explore the combined physics potential of T2K and NOvA in light of the moderately large measured value of $\theta_{13}$. For $\sin^2 2 \theta_{13} = 0.1$, which is close to the best fit value, a 90\% C.L. evidence for the hierarchy can be obtained only for the combinations (NH, $-170^\circ \leq \dcp \leq 0$) and (IH, $0^\circ \leq \dcp \leq 170^\circ$), with the currently planned runs of NOvA and T2K. However, the hierarchy can essentially be determined for any value of $\delta_{CP}$, if the statistics of NOvA are increased by $50\%$ and those of T2K are doubled. Such an increase will also give an allowed region of $\delta_{CP}$ around the its true value, except for the CP conserving cases $\delta_{CP} = 0 \ {\rm or} \pm 180^\circ$.
NOvA experiment has reoptimized its event selection criteria after recent measurements of $\theta_{13}$ by the reactor neutrinos. We study the improvement in the sensitivity to the neutrino mass hierarchy and to leptonic CP violation due to these new features. For favourable values of $\delta_{CP}$, NOvA sensitivity to mass hierarchy and leptonic CP violation is increased by 20\%. Addition of 5 years of neutrino data from T2K to NOvA more than doubles the range of $\delta_{CP}$ for which the leptonic CP violation can be discovered, compared to stand alone NOvA. But for unfavourable values of $\delta_{CP}$, the combination of NOvA and T2K are not enough to provide even a 90\% C.L.
hint of hierarchy discovery. Therefore, we further explore the improvement in the hierarchy and CP violation sensitivities due to the addition of a 10 kt liquid argon detector placed close to NOvA site.