By using a fresh analysis of SN1987A data it is shown that mass of the electron neutrino is zero. The masses of other neutrino flavors are found to be non-zero. The neutrino astrophysics has been the subject of great interest for the last many decades. Since it was postulated in 1930, the properties of neutrino and in particular the question of its mass have gained much attention on both theore...

If future neutrino oscillation experiments show that the neutrino mass spectrum is with normal ordering, m1 < m2 < m3, and the searches for neutrinoless double beta ((ββ)0ν -) decay with sensitivity to values of the effective Majorana mass || ∼> 10 −2 eV give negative results, the next frontier in the quest for (ββ)0ν -decay will correspond to || ∼ 10−3 eV. Assuming that massive neutrinos...

Recent evidence for neutrino oscillations has revolutionized the study of neutrino masses and mixing. This report gives an overview of what we are learning from the neutrino oscillation experiments, the prospects for the near term, and the bright future of neutrino mass studies. Tree-level mass generation occurs through the Higgs mechanism. The Dirac mass m D arises in a lepton conserving (∆L =...

We have discussed predictions of |Ue3| and JCP in the framework of the neutrino mass matrix with two zeros. The lower bound of |Ue3| is 0.05, which depends on tan θ12 and tan θ23. We have investigated the stability of these predictions taking account of small corrections to zeros, which may come from radiative corrections or off-diagonal elements of the charged lepton mass matrix. The lower bou...

We have discussed predictions of Ue3 and JCP in the framework of the neutrino mass matrix with two zeros. The lower bound of Ue3 is 0.05, which depends on tan θ12 and tan θ23. We have investigated the stability of these predictions taking account of small corrections to zeros, which may come from radiative corrections or off-diagonal elements of the charged lepton mass matrix. We have found tha...

Degenerate neutrino masses are excluded by experiment. The experimentally measured mass squared differences together with the yet undetermined absolute neutrino mass scale allow for a quasi-degenerate mass spectrum. For the lightest neutrino mass larger than roughly 0.1eV, we analyze the influence of threshold corrections at the electroweak scale. We show that typical one-loop corrections can g...

A formal proof is given that in a seesaw type neutrino mass matrix with only two neutrino mass scales (m D ≪ m R) and the maximal rank of m R(D) we can not get a fourth light sterile neutrino.

We analyze the impact of a measurement, or of an improved bound, on θ13 for the determination of the effective neutrino mass in neutrino-less double beta decay and cosmology. In particular, we discuss how an improved limit on (or a specific value of) θ13 can influence the determination of the neutrino mass spectrum via neutrinoless double beta decay. We also discuss the interplay with improved ...

Recent theoretical developments have shown that extra spacetime dimensions can lower the fundamental GUT, Planck, and string scales. However, recent evidence for neutrino oscillations suggests the existence of light nonzero neutrino masses, which in turn suggests the need for a heavy mass scale via the seesaw mechanism. In this short note, we make two observations. First, we show that a higher-...