229 research outputs found
Robust Cosmological Bounds on Neutrinos and their Combination with Oscillation Results
We perform a global analysis of cosmological observables in generalized
cosmologies which depart from CDM models by allowing non-vanishing
curvature , dark energy with equation of state with , the presence of additional relativistic degrees of freedom , and neutrino masses . By combining the data from
cosmic microwave background (CMB) experiments (in particular the latest results
from WMAP-7), the present day Hubble constant (H0) measurement, the
high-redshift Type-I supernovae (SN) results and the information from large
scale structure (LSS) surveys, we determine the parameters in the
10-dimensional parameter space for such models. We present the results from the
analysis when the full shape information from the LSS matter power spectrum
(LSSPS) is included versus when only the corresponding distance measurement
from the baryon acoustic oscillations (BAO) is accounted for. We compare the
bounds on the neutrino mass scale in these generalized scenarios with those
obtained for the 6+1 parameter analysis in models and
we also study the dependence of those on the set of observables included in the
analysis. Finally we combine these results with the information on neutrino
mass differences and mixing from the global analysis of neutrino oscillation
experiments and derive the presently allowed ranges for the two laboratory
probes of the absolute scale of neutrino mass: the effective electron neutrino
mass in single beta decay and the effective Majorana neutrino mass in
neutrinoless decay.Comment: 19 pages, 4 figures. Acknowledgments correcte
Updated global fit to three neutrino mixing: status of the hints of theta13 > 0
We present an up-to-date global analysis of solar, atmospheric, reactor and
accelerator neutrino data in the framework of three-neutrino oscillations. We
discuss in detail the statistical significance of the observed "hint" of
non-zero theta13 in the solar sector at the light of the latest experimental
advances, such as the Borexino spectral data, the lower value of Gallium rate
recently measured in SAGE, and the low energy threshold analysis of the
combined SNO phase I and phase II. We also study the robustness of the results
under changes of the inputs such as the choice of solar model fluxes and a
possible modification of the Gallium capture cross-section as proposed by SAGE.
In the atmospheric sector we focus on the latest results for nu_e appearance
from MINOS and on the recent Super-Kamiokande results from the combined phases
I, II and III, and we discuss their impact on the determination of theta13.
Finally, we combine all the data into a global analysis and determine the
presently allowed ranges of masses and mixing.Comment: 20 pages, 9 figures. Acknowledgments correcte
Global fit to three neutrino mixing: critical look at present precision
We present an up-to-date global analysis of solar, atmospheric, reactor, and
accelerator neutrino data in the framework of three-neutrino oscillations. We
provide results on the determination of theta_13 from global data and discuss
the dependence on the choice of reactor fluxes. We study in detail the
statistical significance of a possible deviation of theta_23 from maximal
mixing, the determination of its octant, the ordering of the mass states, and
the sensitivity to the CP violating phase, and discuss the role of various
complementary data sets in those respects.Comment: 23 pages, 7 figures. v3: final version to appear in JHEP. Updated
results will be provided at http://www.nu-fit.or
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