Analysis of atmospheric neutrino oscillations in three-flavor neutrinos

Abstract

We analyze the atmospheric neutrino experiments of Super-Kamiokande (830-920 live days) using the three-flavor neutrino framework with the mass hierarchy m_1 nearly equal m_2 << m_3. We study the sub-GeV, multi- GeV neutrinos and upward through-going and stopping muons zenith angle distributions taking account of the Earth matter effects thoroughly. We obtain the allowed regions of mass and mixing parameters Delm^2_{23}, theta_{13} and theta_{23}. Delm^2_{23} is restricted to 0.002-0.01eV^2 and theta_{13}<13degrees, 35degrees<theta_{23}<55degrees in 90% C.L. For theta_{12}, there is no difference between the large angle solar neutrino solution and small one. From chi^2 fit, the minimum chi^2=55(54DOF) is obtained at Delm^2_{23}=4x10^(-3)eV^2, theta_{13}=10degrees and theta_{23} =45degrees.Comment: 16 pages, 3 figures, LaTe

Three-flavor solar neutrino oscillations with terrestrial neutrino constraints

“…Concerning atmospheric neutrinos, it has been shown in several analyses that the usual bounds on the dominant ν µ → ν τ oscillation parameters (∆m 2 , θ 23 ) are rather robust under perturbations beyond the one-mass-scale dominance, induced by either θ 13 > 0 [9,20,21,22] or by δm 2 > 0 or both [19,23,24,25,26] (within reactor bounds). 3 Moreover, since the θ 23 value is irrelevant for the analysis of both solar and reactor neutrino data, we only need to know the atmospheric ∆m 2 scale in our analysis, as derived by a combination of the (preliminary) SK and K2K bounds [9,10] for unconstrained θ 23 (see the next section).…”

“…Concerning atmospheric neutrinos, it has been shown in several analyses that the usual bounds on the dominant ν µ → ν τ oscillation parameters (∆m 2 , θ 23 ) are rather robust under perturbations beyond the one-mass-scale dominance, induced by either θ 13 > 0 [9,20,21,22] or by δm 2 > 0 or both [19,23,24,25,26] (within reactor bounds).…”

Nonstandard interactions of tau neutrino via charged Higgs andW′contributions

“…The process ν τ + n → τ − + p will impact the measurement of the oscillation probability for ν µ → ν τ transition and hence the extraction of the mixing angle θ 23 . The measurement of the atmospheric mixing angle θ 23 relies on the following relationship [52] N(ν…”

Tau-neutrino as a probe of nonstandard interactions via charged Higgs and W′ contribution

“…The process ν τ + N → τ − + X will impact the measurement of the oscillation probability for the ν µ → ν τ transition and hence the extraction of the mixing angle θ 23 . The measurement of the atmospheric mixing angle θ 23 relies on the following relationship [11]:…”