1205.5223 (Yoshihiko Oyama et al.)

Determination of neutrino mass hierarchy by 21 cm line and CMB B-mode polarization observations    [PDF]

Yoshihiko Oyama, Akie Shimizu, Kazunori Kohri

We focus on the ongoing and future observations for both the 21 cm line and the CMB B-mode polarization produced by a CMB lensing, and study their sensitivities to the effective number of neutrino species, the total neutrino mass, and the neutrino mass hierarchy. We find that combining the CMB observations with future square kilometer arrays optimized for 21 cm line such as Omniscope can determine the neutrino mass hierarchy at a 95% C.L. We also show that the combination of Planck+ \textsc{Polarbear} and SKA can strongly improves the bounds of the total neutrino mass and the effective number of neutrino species to be $\Delta\Sigma m_{\nu} \sim 0.15$ eV and $\Delta N_{\nu}\sim 0.35$ at 95% C.L, respectively.

View original: http://arxiv.org/abs/1205.5223