Effects of nonstandard neutrino interactions on MSWLMA solution to the solar neutrino pro.pdfVIP

Effects of non-standard neutrino interactions on MSW-LMA solution to the solar neutrino problem M. M. Guzzo,∗ P. C. de Holanda,† and O. L. G. Peres‡ Instituto de F´ısica Gleb Wataghin - UNICAMP, 13083-970 Campinas SP, Brazil We show that the non-standard neutrino interactions can play a role as sub-leading effect on the solar neutrino oscillations. We observe that very small flavor universality violations of order of 0.1-0.2 G is sufficient to induce two phenomena: suppression of the ν -earth regeneration and F e a shift of the resonance layer in the sun. We obtain these phenomena even in the absence of any flavor changing interactions. We discuss their consequences and confront with a global analysis of solar+KamLAND results. We conclude that a new compatibility region in the ∆m2 × tan2 θ⊙ , which we call very low Large Mixing Angle region is found for ∆m2 ∼ 10−5 eV2 and tan2 θ⊙ = 0.45. 4 PACS numbers: 14.16.Pq, 28.50.Hw 0 0 2 r a I. INTRODUCTION M 9 1 In the last years, the discovery of neutrino oscillation in solar and reactor experiments selected as a more probable 2 explanation to the solar neutrino problem the so called Large Mixing Angle (LMA) MSW solution. The SNO [1, 2] v 4 and the KamLAND [4] experiments confirm and refine the trend of the evidences of neutrino oscillations due the solar 3 1 neutrino observations, as measured by Homestake [5], SAGE [6], GALLEX [7], GNO [8]