An alternative: two-mixing texture for three neutrinos or three-mixing texture for four neutrinos

2000/08/16 by Wojciech Krolikowski
Physics and Astronomy · #hep-ph

paper · pdf

published as Acta Phys.Polon. B32 (2001) 75-84 · 1+8 pages

arxiv created 2000/08/16 · arxiv updated 2009/11/30

Abstract

The alternative formulated in the title has a chance to be settled, when the existence of the LSND effect is experimentally excluded or confirmed. The first option, much discussed in literature, works in the case of three active neutrinos ν_e, ν_μ, ν_τ, when among their massive states ν₁, ν₂, ν₃ there is no direct mixing between ν₁ and ν₃, and the mass hierarchy m²₁ < ∼ m²₂ ≪ m²₃ holds. This option is consistent with the observed deficits of solar ν_e's and atmospheric ν_μ's, if Δm²₂₁ ↔ Δm²_{\rm sol} and Δm²₃₂ ↔ Δm²_{\rm atm}. On the other hand, the second option is an extension of the idea of the former to the case of four neutrinos ν_s, ν_e, ν_μ, ν_τ (including one sterile neutrino ν_s), when among their massive states ν₀, ν₁, ν₂, ν₃ there are no direct mixings between ν₀ and nu₂, ν₀ and ν₃, ν₁ and ν₃, and the mass hierarchy m²₀ < ∼ m²₁ ≪ m²₂ < ∼ m²₃ is now valid. Such an option, belonging to a class of textures widely discussed in literature, may be consistent with the observed deficits of solar ν_e's and atmospheric ν_μ's as well as with the LSND appearance of ν_e's in the beam of accelerator ν_μ's, if now Δm²₁₀ ↔ Δm²_{\rm sol}, Δm²₃₂ ↔ Δm²_{\rm atm} and Δm²₂₁ ↔ Δm²_{\rm LSND}.

Related

• Two-mixing texture for three active neutrinos
• A four-neutrino texture implying bimaximal flavor mixing and reduced LSND effect
• Prediction of LSND effect as a "sterile" perturbation of the bimaximal texture for three active neutrinos
• LSND effect as a Chooz-restricted "sterile" perturbation of three-neutrino texture
• Possible LSND effect as a small perturbation of the bimaximal texture for three active neutrinos