# Solar neutrino flux measurements by the Soviet-American gallium experiment (SAGE) for half the 22-year solar cycle

**ABSTRACT** We present measurements of the solar neutrino capture rate on metallic gallium in the Soviet-American gallium experiment (SAGE)

over a period of slightly more than half the 22-year solar cycle. A combined analysis of 92 runs over the twelve-year period

from January 1990 until December 2001 yields a capture rate of 70.8

−5.2

+5.3

(stat)

−3.2

+3.7

(sys) SNU for solar neutrinos with energies above 0.233 MeV. This value is slightly more than half the rate predicted by

the standard solar model, 130 SNU. We present the results of new runs since April 1998 and analyze all runs combined by years,

months, and bimonthly periods beginning in 1990. A simple analysis of the SAGE results together with the results of other

solar neutrino experiments gives an estimate of (4.6±1.2)× 1010 neutrinos cm−2 s−1 for the flux of the electron pp neutrinos that reach the Earth without changing their flavor. The flux of the pp neutrinos produced in thermonuclear reactions in the Sun is estimated to be (7.6 ± 2.0) × 1010 neutrinos cm−2 s−1, in agreement with the value of (5.95±0.06)×1010 neutrinos cm−2 s−1 predicted by the standard solar model.

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**ABSTRACT:**We present an analysis of normal and inverted hierarchical neutrino mass models within the framework of tri-bimaximal mixing. Considering the neutrinos to be quasidegenerate (QDN), we study two different neutrino mass models with mass eigenvalues (m1,-m2,m3) and (m1,m2,m3) for both normal hierarchical and inverted hierarchical cases. Parameterizing the neutrino mass matrix using best-fit oscillation and cosmology data for a QDN scenario, we find the right-handed Majorana mass matrix using the type I seesaw formula for two types of Dirac neutrino mass matrices: charged lepton type and up quark type. Incorporating the presence of the type II seesaw term which arises naturally in generic left-right symmetric models along with the type I term, we compare the predictions for neutrino mass parameters with the experimental values. Within such a framework and incorporating both oscillation as well as cosmology data, we show that a QDN scenario of neutrino masses can still survive in nature with some minor exceptions. A viable extension of the standard model with an Abelian-gauged flavor symmetry is briefly discussed which can give rise to the desired structure of the Dirac and Majorana mass matrices.Physical Review D 11/2012; 86(9-Phys. Rev. D 86, 095006):095006. DOI:10.1103/PhysRevD.86.095006 · 4.86 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**In the flavor basis there are seven cases of two vanishing minors in the neutrino mass matrix which can accommodate the present neutrino oscillation data including the recent T2K data. It is found that two of these cases, namely $B_5$ and $B_6$ predict near maximal atmospheric neutrino mixing in the limit of large effective neutrino mass. This feature remains irrespective of the values of solar and reactor mixing angles. A non-zero reactor mixing angle is naturally accommodated in these textures.Physics Letters B 11/2011; 706(2-3). DOI:10.1016/j.physletb.2011.11.005 · 6.02 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**We review the status of three-neutrino mixing and the results of global analyses of short-baseline neutrino oscillation data in 3 + 1, 3 + 2 and 3 + 1 + 1 neutrino mixing schemes.Physics of Particles and Nuclei 03/2015; 46(2):123-130. DOI:10.1134/S1063779615020069 · 0.74 Impact Factor