331 research outputs found

    Meter-baseline tests of sterile neutrinos at Daya Bay

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    We explore the sensitivity of an experiment at the Daya Bay site, with a point radioactive source and a few meter baseline, to neutrino oscillations involving one or more eV mass sterile neutrinos. We find that within a year, the entire 3+2 and 1+3+1 parameter space preferred by global fits can be excluded at the 3\sigma level, and if an oscillation signal is found, the 3+1 and 3+2 scenarios can be distinguished from each other at more than the 3\sigma level provided one of the sterile neutrinos is lighter than 0.5 eV.Comment: 4 pages, 5 figures, 1 table. Version to appear in PL

    Hyperfine splitting in muonic hydrogen constrains new pseudoscalar interactions

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    We constrain the possibility of a new pseudoscalar coupling between the muon and proton using a recent measurement of the 2S hyperfine splitting in muonic hydrogen.Comment: 3 pages, 2 figures. Version to appear in PL

    Neutrino seesaw mechanism with texture zeros

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    In the context of the Type I seesaw mechanism, we carry out a systematic study of the constraints that result from zeros in both the Dirac and right-handed Majorana neutrino mass matrices. We find that most constraints can be expressed in the standard form with one or two element/cofactor zeros alone, while there are 9 classes of nonstandard constraints. We show that all the constraints are stable under one-loop renormalization group running from the lightest right-handed neutrino mass scale to the electroweak scale. We study the predictions of the nonstandard constraints for the lightest neutrino mass, Dirac CP phase and neutrinoless double beta decay.Comment: 43 pages, 9 figures, 3 tables. Version to appear in NP

    Texture and Cofactor Zeros of the Neutrino Mass Matrix

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    We study Majorana neutrino mass matrices that have two texture zeros, or two cofactor zeros, or one texture zero and one cofactor zero. The two texture/cofactor zero conditions give four constraints, which in conjunction with the five measured oscillation parameters completely determine the nine independent real parameters of the neutrino mass matrix. We also study the implications that future measurements of neutrinoless double beta decay and the Dirac CP phase will have on these cases.Comment: 25 pages, 8 tables, 11 figures. Version to appear in JHE

    Partial quark-lepton universality and neutrino CP violation

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    We study a model with partial quark-lepton universality that can naturally arise in grand unified theories. We find that constraints on the model can be reduced to a single condition on the Dirac CP phase Ξ΄\delta in the neutrino sector. Using our current knowledge of the CKM and PMNS mixing matrices, we predict βˆ’32.4∘<Ξ΄<32.0∘-32.4^\circ < \delta < 32.0^\circ at 2Οƒ2\sigma.Comment: 8 pages, 1 figure. Version to appear in the special issue, "Neutrino Masses and Oscillations 2015", of Advances in High Energy Physic
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