Majorana neutrino mass matrices with three texture zeros and the sterile neutrino

Abstract

As a consequence of the LSND anomaly and other hints of an eV scale sterile neutrino from particle physics and cosmology, the neutrino sector of the standard model of particle physics has to be extended and the smallest extension is the (3+1) model, i.e., three active neutrinos plus one sterile one. In this work we study the neutrino mass matrix M ν with three texture zeros in the (3+1) model, assuming all the neutrino states are of Majorana type. With the mass hierarchy between the active and sterile neutrinos as well as the smallness of the reactor neutrino mixing and active-sterile mixing, the analytical expressions can be greatly simplified. We systematically examine all the 120 texture zeros, via both analytical and numerical analysis, and find that the 100 textures with zeros in the fourth column and row of M ν can hardly be compatible with experiments; whereas, 19 of the other 20 are feasible. We can foresee that the active neutrino masses are required to be around 0.01 eV and the next generation neutrinoless double beta decay experiments are promising to test these textures. Many other phenomenologically meaningful predictions are also obtained. All the CP conserving (3+1) textures with three zeros are excluded by experiments.

Revisiting Majorana neutrino textures in the light of dark LMA

“…Δm 2 LSND (eV 2 ) 0.7-2.5/0.7-2.5 sin 2 θ 14 0.0098-0.0310/0.0098-0.0310 sin 2 θ 24 0.0059-0.0262/0.0059-0.0262 sin 2 θ 34 0-0.0396/0-0.0396 As shown in several earlier works [51][52][53][54][55][56], such texture zeros can not arise in active-sterile or sterile-sterile sector namely m αs = 0, α = e, μ, τ, s. Therefore, only the active 3 × 3 block of the 4 × 4 mass matrix can have zeros. Even then, there are many possibilities of one-zero, two-zero, three-zero, four-zero and five-zero as discussed in above mentioned works.…”

“…These anomalies received renewed attention recently after the Mini-BooNE collaboration reported their new analysis incorporating twice the size data sample than before [39], confirming the anomaly at 4.8σ significance level which becomes > 6σ effect if combined with LSND. Previous studies on textures of 3 + 1 neutrino scenario have been done in several works [51][52][53][54][55][56][57].…”

Fitting flavour symmetries: the case of two-zero neutrino mass textures

“…4 Generalization to texture zeroes including sterile neutrinos [27][28][29], zeroes of the inverted neutrino mass matrix [30], or other relations among matrix elements [31][32][33][34][35][36] is possible. 5 We use the conventions of [20,21] in which ∆ 31 is replaced by ∆ 32 = m 2 3 − m 2 2 in the IO case.…”

Phenomenological study of neutrino mass, dark matter and baryogenesis within the framework of minimal extended seesaw

“…Recent studies [45,[48][49][50] on this 4 × 4 mass have predicted various number of zeros with better accuracy on different aspects. At present, we proposed to explore the possibility with a maximum of five-zeros in the final mass matrix and study active-sterile mixing phenomenology.…”