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Sample records for neutrino mass constraint

  1. New constraints on neutrino masses from cosmology

    SciTech Connect

    Melchiorri, A.; Serra, P.; Dodelson, S.; Slosar, A.; /Ljubljana U.

    2006-01-01

    By combining data from cosmic microwave background (CMB) experiments (including the recent WMAP third year results), large scale structure (LSS) and Lyman-{alpha} forest observations, we derive upper limits on the sum of neutrino masses of {summation}m{sub v} < 0.17eV at 95% c.l.. We then constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless + 1 massive neutrino case we bound the mass of the sterile neutrino to m{sub s} < 0.26eV at 95% c.l.. These results exclude at high significance the sterile neutrino hypothesis as an explanation of the LSND anomaly. We then generalize the analysis to account for active neutrino masses which tightens the limit to m{sub s} < 0.23eV and the possibility that the sterile abundance is not thermal. In the latter case, the constraints in the (mass, density) plane are nontrivial. For a mass of > 1eV or < 0.05eV the cosmological energy density in sterile neutrinos is always constrained to be {omega}{sub v} < 0.003 at 95% c.l.. However, for a sterile neutrino mass of {omega}{sub v} 0.25eV, {omega}{sub v} can be as large as 0.01.

  2. Model Independent Constraints of the Averaged Neutrino Masses Revisited

    NASA Astrophysics Data System (ADS)

    Fukuyama, Takeshi; Nishiura, Hiroyuki

    2013-11-01

    Averaged neutrino masses defined by <{m}ν >ab≡ (\\vert∑_ {j = 1}3UajUbjmj) \\vert (a, b = e, μ , τ ) are reanalyzed using up-to-date observed MNS parameters and neutrino masses by the neutrino oscillation experiments together with the cosmological constraint on neutrino masses. The values of ab are model-independently evaluated in terms of effective neutrino mass defined by /line{mν }≡ √ {∑ \\vert Uej\\vert2mj^2} which is observable in the single beta decay. We obtain lower bound for ee in the inverted hierarchy (IH) case, 17 meV ≤ee and one for τμ in the normal hierarchy (NH) case, 5 meV≤τμ. We also obtain that all the averaged masses ab have upper bounds which are at most 80 meV.

  3. Constraints on neutrino masses from future cosmological observations

    SciTech Connect

    Hirano, Koichi

    2014-05-02

    Constraints on neutrino masses are estimated based on future observations of the cosmic microwave background (CMB) including the B-mode polarization produced by CMB lensing using the Planck satellite, and baryon acoustic oscillations distance scale and the galaxy power spectrum from all-sky galaxy redshift survey in the BigBOSS experiment. We estimate the error in the bound on the total neutrino mass to be Δ∑m{sub v} = 0.012 eV with a 68% confidence level. If the fiducial value of the total neutrino mass is ∑m{sub v} = 0.06 eV, this result implies that the neutrino mass hierarchy must be normal.

  4. Observables sensitive to absolute neutrino masses: Constraints and correlations from world neutrino data

    SciTech Connect

    Fogli, G.L.; Lisi, E.; Marrone, A.; Palazzo, A.; Melchiorri, A.; Serra, P.; Silk, J.

    2004-12-01

    In the context of three-flavor neutrino mixing, we present a thorough study of the phenomenological constraints applicable to three observables sensitive to absolute neutrino masses: The effective neutrino mass in Tritium beta-decay (m{sub {beta}}); the effective Majorana neutrino mass in neutrinoless double beta-decay (m{sub {beta}}{sub {beta}}); and the sum of neutrino masses in cosmology ({sigma}). We discuss the correlations among these variables which arise from the combination of all the available neutrino oscillation data, in both normal and inverse neutrino mass hierarchy. We set upper limits on m{sub {beta}} by combining updated results from the Mainz and Troitsk experiments. We also consider the latest results on m{sub {beta}}{sub {beta}} from the Heidelberg-Moscow experiment, both with and without the lower bound claimed by such experiment. We derive upper limits on {sigma} from an updated combination of data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite and the two degrees Fields (2dF) Galaxy Redshifts Survey, with and without Lyman-{alpha} forest data from the Sloan Digital Sky Survey (SDSS), in models with a nonzero running of the spectral index of primordial inflationary perturbations. The results are discussed in terms of two-dimensional projections of the globally allowed region in the (m{sub {beta}},m{sub {beta}}{sub {beta}},{sigma}) parameter space, which neatly show the relative impact of each data set. In particular, the (in)compatibility between {sigma} and m{sub {beta}}{sub {beta}} constraints is highlighted for various combinations of data. We also briefly discuss how future neutrino data (both oscillatory and nonoscillatory) can further probe the currently allowed regions.

  5. Constraints on the relic neutrino abundance and implications for cosmological neutrino mass limits

    SciTech Connect

    Bell, Nicole F.; /Fermilab

    2004-01-01

    The authors examine a mechanism which can lead to flavor transformation of neutrino-antineutrino asymmetries in the early universe, a process which is unavoidable when the neutrino mixing angles are large. This sets the best limit on the lepton number of the universe, and hence on the relic neutrino abundance. They also consider the consequences for the relic neutrino abundance if extra neutrino interactions are allowed, e.g., the coupling of the neutrinos to a light (compared to m{sub {nu}}) boson. For a wide range of couplings not excluded by other considerations, the relic neutrinos would annihilate to bosons at late times, and thus make a negligible contribution to the matter density today. This mechanism evades the neutrino mass limits arising from large scale structure.

  6. Non-linear effects of massive neutrinos and cosmological constraints on their masses

    NASA Astrophysics Data System (ADS)

    Ichiki, Kiyotomo

    Cosmic neutrinos with finite masses constitute some portion of dark matter and have played imporatnt roles in cosmological structure formation. In this poster we first present a constraint on neutrino masses using the weak lensing distortions of distant galaxy images through the suppression effect on clustering strengths of total matter in large-scale structure. We find that, while the WL data alone cannot place a stringent limit on neutrino masses due to parameter degeneracies, the constraint can be significantly improved when combined with other cosmo-logical probes, the cosmic microwave background data (CMB), the distance measurements of type-Ia supernovae (SNe) and baryon acoustic oscillations (BAO). To derive the constraint the effect of non-linear gravitational clustering with massive neutrinos is important. In light of this we present a simple model of spherical collapse of overdensity which consists of cold dark mat-ters, baryons, and massive neutrinos. We then plan to discuss its application for determining neutrino masses from cosmological observations.

  7. Astrophysical constraints on the radiative lifetime of neutrinos with mass between 10 and 100 eV/c-squared

    NASA Technical Reports Server (NTRS)

    Kimble, R.; Bowyer, S.; Jakobsen, P.

    1981-01-01

    Upper limits to astronomical photon backgrounds are used to derive constraints on the radiative lifetime of neutrinos. With the assumption that the radiative decay dominates the decay routes available, comparisons with predicted fluxes exclude radiative lifetimes between 10 to the 13th and 10 to the 22nd-23rd sec for neutrinos which decay to lighter neutrinos and 5-50 eV photons. For a secondary neutrino mass much less than the parent neutrino mass, this photon-energy range corresponds to a parent-neutrino-mass range of 10-100 eV/c-squared.

  8. Constraints on the neutrino mass and mass hierarchy from cosmological observations

    NASA Astrophysics Data System (ADS)

    Huang, Qing-Guo; Wang, Ke; Wang, Sai

    2016-09-01

    Considering the mass splitting between three active neutrinos, we represent the new constraints on the sum of neutrino mass sum m_ν by updating the anisotropic analysis of the Baryon Acoustic Oscillation (BAO) scale in the CMASS and LOWZ galaxy samples from Data Release 12 of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS DR12). Combining the BAO data of 6dFGS, MGS, LOWZ and CMASS with it{Planck} 2015 data of temperature anisotropy and polarizations of the Cosmic Microwave Background (CMB), we find that the 95 % C.L. upper bounds on sum m_ν refer to sum m_{ν,NH}<0.18 eV for the normal hierarchy (NH), sum m_{ν,IH}<0.20 eV for the inverted hierarchy (IH) and sum m_{ν,DH}<0.15 eV for the degenerate hierarchy (DH), respectively, and the normal hierarchy is slightly preferred over the inverted one (Δ χ ^2≡ χ ^2_NH-χ ^2_IH ˜eq -3.4). In addition, the additional relativistic degrees of freedom and massive sterile neutrinos are neither favored at present.

  9. Astrophysical and cosmological constraints to neutrino properties

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Schramm, David N.; Turner, Michael S.

    1989-01-01

    The astrophysical and cosmological constraints on neutrino properties (masses, lifetimes, numbers of flavors, etc.) are reviewed. The freeze out of neutrinos in the early Universe are discussed and then the cosmological limits on masses for stable neutrinos are derived. The freeze out argument coupled with observational limits is then used to constrain decaying neutrinos as well. The limits to neutrino properties which follow from SN1987A are then reviewed. The constraint from the big bang nucleosynthesis on the number of neutrino flavors is also considered. Astrophysical constraints on neutrino-mixing as well as future observations of relevance to neutrino physics are briefly discussed.

  10. Neutrino mass

    SciTech Connect

    Bowles, T.J.

    1994-04-01

    The existence of a finite neutrino mass would have important consequences in particle physics, astrophysics, and cosmology. Experimental sensitivities have continued to be pushed down without any confirmed evidence for a finite neutrino mass. Yet there are several observations of discrepancies between theoretical predictions and observations which might be possible indications of a finite neutrino mass. Thus, extensive theoretical and experimental work is underway to resolve these issues.

  11. Cosmological axion and neutrino mass constraints from Planck 2015 temperature and polarization data

    NASA Astrophysics Data System (ADS)

    Di Valentino, Eleonora; Giusarma, Elena; Lattanzi, Massimiliano; Mena, Olga; Melchiorri, Alessandro; Silk, Joseph

    2016-01-01

    Axions currently provide the most compelling solution to the strong CP problem. These particles may be copiously produced in the early universe, including via thermal processes. Therefore, relic axions constitute a hot dark matter component and their masses are strongly degenerate with those of the three active neutrinos, as they leave identical signatures in the different cosmological observables. In addition, thermal axions, while still relativistic states, also contribute to the relativistic degrees of freedom, parameterized via Neff. We present the cosmological bounds on the relic axion and neutrino masses, exploiting the full Planck mission data, which include polarization measurements. In the mixed hot dark matter scenario explored here, we find the tightest and more robust constraint to date on the sum of the three active neutrino masses, ∑mν < 0.136 eV at 95% CL, as it is obtained in the very well-known linear perturbation regime. The Planck Sunyaev-Zeldovich cluster number count data further tightens this bound, providing a 95% CL upper limit of ∑mν < 0.126 eV in this very same mixed hot dark matter model, a value which is very close to the expectations in the inverted hierarchical neutrino mass scenario. Using this same combination of data sets we find the most stringent bound to date on the thermal axion mass, ma < 0.529 eV at 95% CL.

  12. Forecasts on neutrino mass constraints from the redshift-space two-point correlation function

    NASA Astrophysics Data System (ADS)

    Petracca, F.; Marulli, F.; Moscardini, L.; Cimatti, A.; Carbone, C.; Angulo, R. E.

    2016-11-01

    We provide constraints on the accuracy with which the neutrino mass fraction, fν, can be estimated when exploiting measurements of redshift-space distortions, describing in particular how the error on neutrino mass depends on three fundamental parameters of a characteristic galaxy redshift survey: density, halo bias and volume. In doing this, we make use of a series of dark matter halo catalogues extracted from the BASICC simulation. The mock data are analysed via a Markov Chain Monte Carlo likelihood analysis. We find a fitting function that well describes the dependence of the error on bias, density and volume, showing a decrease in the error as the bias and volume increase, and a decrease with density down to an almost constant value for high-density values. This fitting formula allows us to produce forecasts on the precision achievable with future surveys on measurements of the neutrino mass fraction. For example, a Euclid-like spectroscopic survey should be able to measure the neutrino mass fraction with an accuracy of δfν ≈ 3.1 × 10-3 (which is equivalent to δ∑mν ≈ 0.039eV), using redshift-space clustering once all the other cosmological parameters are kept fixed to the ΛCDM case.

  13. Forecasts on neutrino mass constraints from the redshift-space two-point correlation function

    NASA Astrophysics Data System (ADS)

    Petracca, F.; Marulli, F.; Moscardini, L.; Cimatti, A.; Carbone, C.; Angulo, R. E.

    2016-08-01

    We provide constraints on the accuracy with which the neutrino mass fraction, fν, can be estimated when exploiting measurements of redshift-space distortions, describing in particular how the error on neutrino mass depends on three fundamental parameters of a characteristic galaxy redshift survey: density, halo bias and volume. In doing this, we make use of a series of dark matter halo catalogues extracted from the BASICC simulation. The mock data are analysed via a Markov Chain Monte Carlo likelihood analysis. We find a fitting function that well describes the dependence of the error on bias, density and volume, showing a decrease in the error as the bias and volume increase, and a decrease with density down to an almost constant value for high density values. This fitting formula allows us to produce forecasts on the precision achievable with future surveys on measurements of the neutrino mass fraction. For example, a Euclid-like spectroscopic survey should be able to measure the neutrino mass fraction with an accuracy of δfν ≈ 3.1 × 10-3 (which is equivalent to δ∑mν ≈ 0.039eV), using redshift-space clustering once all the other cosmological parameters are kept fixed to the ΛCDM case.

  14. Updating neutrino magnetic moment constraints

    NASA Astrophysics Data System (ADS)

    Cañas, B. C.; Miranda, O. G.; Parada, A.; Tórtola, M.; Valle, J. W. F.

    2016-02-01

    In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs), discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1 ×10-11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1 | ≤ 5.6 ×10-11μB, |Λ2 | ≤ 4.0 ×10-11μB, and |Λ3 | ≤ 3.1 ×10-11μB (90% C.L.), irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.

  15. Combined limit on the neutrino mass from neutrinoless double-β decay and constraints on sterile Majorana neutrinos

    NASA Astrophysics Data System (ADS)

    Guzowski, Pawel; Barnes, Luke; Evans, Justin; Karagiorgi, Georgia; McCabe, Nathan; Söldner-Rembold, Stefan

    2015-07-01

    We present a framework to combine data from the latest neutrinoless double-β decay experiments for multiple isotopes and derive a limit on the effective neutrino mass mβ β using the experimental energy distributions. The combined limits on mβ β range between 130 and 310 meV, where the spread is due to different model calculations of nuclear matrix elements. The statistical consistency (p values) between this result and the signal observation claimed by the Heidelberg-Moscow experiment is derived. The limits on mβ β are also evaluated in a (3 +1 ) sterile neutrino model, assuming all neutrinos are Majorana particles.

  16. WMAPping out neutrino masses

    SciTech Connect

    Pierce, Aaron; Murayama, Hitoshi

    2003-10-28

    Recent data from the Wilkinson Microwave Anisotropy Probe (WMAP) place important bounds on the neutrino sector. The precise determination of the baryon number in the universe puts a strong constraint on the number of relativistic species during Big-Bang Nucleosynthesis. WMAP data, when combined with the 2dF Galaxy Redshift Survey (2dFGRS), also directly constrain the absolute mass scale of neutrinos. These results impinge upon a neutrino oscillation interpretation of the result from the Liquid Scintillator Neutrino Detector (LSND).We also note that the Heidelberg-Moscow evidence for neutrinoless double beta decay is only consistent with the WMAP+2dFGRS data for the largest values of the nuclear matrix element.

  17. Constraints on neutrino masses from the study of the nearby large-scale structure and galaxy cluster counts

    NASA Astrophysics Data System (ADS)

    Böhringer, Hans; Chon, Gayoung

    2016-07-01

    The high precision measurements of the cosmic microwave background by the Planck survey yielded tight constraints on cosmological parameters and the statistics of the density fluctuations at the time of recombination. This provides the means for a critical study of structure formation in the Universe by comparing the microwave background results with present epoch measurements of the cosmic large-scale structure. It can reveal subtle effects such as how different forms of Dark Matter may modify structure growth. Currently most interesting is the damping effect of structure growth by massive neutrinos. Different observations of low redshift matter density fluctuations provided evidence for a signature of massive neutrinos. Here we discuss the study of the cosmic large-scale structure with a complete sample of nearby, X-ray luminous clusters from our REFLEX cluster survey. From the observed X-ray luminosity function and its reproduction for different cosmological models, we obtain tight constraints on the cosmological parameters describing the matter density, Ωm, and the density fluctuation amplitude, σ8. A comparison of these constraints with the Planck results shows a discrepancy in the framework of a pure ΛCDM model, but the results can be reconciled, if we allow for a neutrino mass in the range of 0.17 eV to 0.7 eV. Also some others, but not all of the observations of the nearby large-scale structure provide evidence or trends for signatures of massive neutrinos. With further improvement in the systematics and future survey projects, these indications will develop into a definitive measurement of neutrino masses.

  18. Constraints on neutrino masses from the study of the nearby large-scale structure and galaxy cluster counts

    NASA Astrophysics Data System (ADS)

    Böhringer, Hans; Chon, Gayoung

    2016-07-01

    The high precision measurements of the cosmic microwave background by the Planck survey yielded tight constraints on cosmological parameters and the statistics of the density fluctuations at the time of recombination. This provides the means for a critical study of structure formation in the Universe by comparing the microwave background results with present epoch measurements of the cosmic large-scale structure. It can reveal subtle effects such as how different forms of Dark Matter may modify structure growth. Currently most interesting is the damping effect of structure growth by massive neutrinos. Different observations of low redshift matter density fluctuations provided evidence for a signature of massive neutrinos. Here we discuss the study of the cosmic large-scale structure with a complete sample of nearby, X-ray luminous clusters from our REFLEX cluster survey. From the observed X-ray luminosity function and its reproduction for different cosmological models, we obtain tight constraints on the cosmological parameters describing the matter density, Ωm, and the density fluctuation amplitude, σ8. A comparison of these constraints with the Planck results shows a discrepancy in the framework of a pure ΛCDM model, but the results can be reconciled, if we allow for a neutrino mass in the range of 0.17 eV to 0.7 eV. Also some others, but not all of the observations of the nearby large-scale structure provide evidence or trends for signatures of massive neutrinos. With further improvement in the systematics and future survey projects, these indications will develop into a definitive measurement of neutrino masses.

  19. Constraints from primordial nucleosynthesis on the mass of the tau neutrino

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Turner, Michael S.; Chakravorty, A.; Schramm, David N.

    1991-01-01

    It is shown that primordial nucleosynthesis excludes a tau-neutrino mass from 0.3 to 25 MeV (Dirac) and 0.5 to 25 MeV (Majorana) provided that its lifetime is not less than about 1 sec, and from 0.3 to 30 MeV (Dirac) and 0.5 to 32 MeV (Majorana) for a lifetime of not less than about 1000 sec. A modest improvement in the laboratory mass limit - from 35 to 25 MeV - would imply that the tau-neutrino mass must be less than 0.5 MeV (provided the lifetime is not less than about 1 sec).

  20. Constraints on texture zero and cofactor zero models for neutrino mass

    SciTech Connect

    Whisnant, K.; Liao, Jiajun; Marfatia, D.

    2014-06-24

    Imposing a texture or cofactor zero on the neutrino mass matrix reduces the number of independent parameters from nine to seven. Since five parameters have been measured, only two independent parameters would remain in such models. We find the allowed regions for single texture zero and single cofactor zero models. We also find strong similarities between single texture zero models with one mass hierarchy and single cofactor zero models with the opposite mass hierarchy. We show that this correspondence can be generalized to texture-zero and cofactor-zero models with the same homogeneous costraints on the elements and cofactors.

  1. Constraints on texture zero and cofactor zero models for neutrino mass

    NASA Astrophysics Data System (ADS)

    Whisnant, K.; Liao, Jiajun; Marfatia, D.

    2014-06-01

    Imposing a texture or cofactor zero on the neutrino mass matrix reduces the number of independent parameters from nine to seven. Since five parameters have been measured, only two independent parameters would remain in such models. We find the allowed regions for single texture zero and single cofactor zero models. We also find strong similarities between single texture zero models with one mass hierarchy and single cofactor zero models with the opposite mass hierarchy. We show that this correspondence can be generalized to texture-zero and cofactor-zero models with the same homogeneous costraints on the elements and cofactors.

  2. Review of direct neutrino mass experiments

    SciTech Connect

    Dragoun, O.

    2015-10-28

    Advantages and drawbacks of the kinematic methods of the neutrino mass determination are discussed. The meaning of the effective neutrino mass, resulting from measurements of the endpoint region of β-spectra is clarified. Current experimental constraints on the mass of active as well as sterile neutrinos are presented. Several new experiments are briefly outlined.

  3. Revised WMAP constraints on neutrino masses and other extensions of the minimal {lambda}CDM model

    SciTech Connect

    Kristiansen, Jostein R.; Elgaroey, Oystein; Eriksen, Hans Kristian

    2006-12-15

    Recently, two issues concerning the three-year Wilkinson Microwave Anisotropy Probe (WMAP) likelihood code were pointed out. On large angular scales (l(less-or-similar sign)30), a suboptimal likelihood approximation resulted in a small power excess. On small angular scales (l(greater-or-similar sign)300), over-subtraction of unresolved point sources produced a small power deficit. For a minimal six-parameter cosmological model, these two effects conspired to decrease the value of n{sub s} by {approx}0.7{sigma}. In this paper, we study the change in preferred parameter ranges for extended cosmological models, including running of n{sub s}, massive neutrinos, curvature, and the equation of state for dark energy. We also include large-scale structure and supernova data in our analysis. We find that the parameter ranges for {alpha}{sub s}, {omega}{sub k} and w are not much altered by the modified analysis. For massive neutrinos the upper limit on the sum of the neutrino masses decreases from M{sub {nu}}<1.90 eV to M{sub {nu}}<1.57 eV when using the modified WMAP code and WMAP data only. We also find that the shift of n{sub s} to higher values is quite robust to these extensions of the minimal cosmological model.

  4. Constraints on neutrinos and axions from cosmology

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1981-01-01

    A review is made of the astrophysical arguments with regard to neutrino properties. It is shown that the best fit to the present baryon density and He-4 abundance is obtained with three neutrino species. It is also shown that astrophysical constraints on neutrino and axion lifetime-mass combinations rule out weakly interacting particles with lifetimes between 1/1000 to 10 to the 23rd sec for M up to 10 MeV. There is an allowed astrophysical window for neutrinos with M up to 10 MeV and tau less than 1000 sec. The possible role of massive neutrinos in the dark mass of galaxies is discussed. It is shown that the baryon density in the universe is comparable to the density obtained from the dynamics of binary galaxies. Therefore, massive neutrinos are only required if the cosmological mass density is greater than that implied by binaries and small groups of galaxies. The only objects which might imply such high densities are large clusters. For neutrinos to cluster with these large clusters requires a neutrino mass of at least 3 eV.

  5. Constraints on Neutrino Masses from the Lensing Dispersion of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Hada, Ryuichiro; Futamase, Toshifumi

    2016-09-01

    We investigate how accurately the total mass of neutrinos is constrained from the magnitude dispersion of SNe Ia due to the effects of gravitational lensing. For this purpose, we use the propagation equation of light bundles in a realistic inhomogeneous universe and propose a sample selection for supernovae to avoid difficulties associated with small-scale effects such as strong lensing or shear effects. With a fitting formula for the nonlinear matter power spectrum taking account of the effects of massive neutrinos, we find that in our model it is possible to obtain the upper limit {{Σ }}{m}ν ≃ 1.0[{{eV}}] for future optical imaging surveys with the Wide-Field InfraRed Survey Telescope and Large Synoptic Survey Telescope. Furthermore, we discuss how far we need to observe SNe Ia and to what extent we have to reduce the magnitude error except for lensing in order to realize the current tightest limit {{Σ }}{m}ν \\lt 0.2[{{eV}}].

  6. Neutrino masses, neutrino oscillations, and cosmological implications

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1982-01-01

    Theoretical concepts and motivations for considering neutrinos having finite masses are discussed and the experimental situation on searches for neutrino masses and oscillations is summarized. The solar neutrino problem, reactor, deep mine and accelerator data, tri decay experiments and double beta-decay data are considered and cosmological implications and astrophysical data relating to neutrino masses are reviewed. The neutrino oscillation solution to the solar neutrino problem, the missing mass problem in galaxy halos and galaxy cluster galaxy formation and clustering, and radiative neutrino decay and the cosmic ultraviolet background radiation are examined.

  7. Neutrino mass without cosmic variance

    NASA Astrophysics Data System (ADS)

    LoVerde, Marilena

    2016-05-01

    Measuring the absolute scale of the neutrino masses is one of the most exciting opportunities available with near-term cosmological data sets. Two quantities that are sensitive to neutrino mass, scale-dependent halo bias b (k ) and the linear growth parameter f (k ) inferred from redshift-space distortions, can be measured without cosmic variance. Unlike the amplitude of the matter power spectrum, which always has a finite error, the error on b (k ) and f (k ) continues to decrease as the number density of tracers increases. This paper presents forecasts for statistics of galaxy and lensing fields that are sensitive to neutrino mass via b (k ) and f (k ). The constraints on neutrino mass from the auto- and cross-power spectra of spectroscopic and photometric galaxy samples are weakened by scale-dependent bias unless a very high density of tracers is available. In the high-density limit, using multiple tracers allows cosmic variance to be beaten, and the forecasted errors on neutrino mass shrink dramatically. In practice, beating the cosmic-variance errors on neutrino mass with b (k ) will be a challenge, but this signal is nevertheless a new probe of neutrino effects on structure formation that is interesting in its own right.

  8. Neutrino mass constraint from the Sloan Digital Sky Survey power spectrum of luminous red galaxies and perturbation theory

    NASA Astrophysics Data System (ADS)

    Saito, Shun; Takada, Masahiro; Taruya, Atsushi

    2011-02-01

    We compare the model power spectrum, computed based on perturbation theory, with the power spectrum of luminous red galaxies (LRG) measured from the Sloan Digital Sky Survey Data Release 7 catalog, assuming a flat, cold dark matter-dominated cosmology. The model includes the effects of massive neutrinos, nonlinear matter clustering and nonlinear, scale-dependent galaxy bias in a self-consistent manner. We first test the accuracy of the perturbation theory model by comparing the model predictions with the halo power spectrum in real- and redshift-space, measured from 70 simulation realizations for a cold dark matter model without massive neutrinos. We show that the perturbation theory model with bias parameters being properly adjusted can fairly well reproduce the simulation results. As a result, the best-fit parameters obtained from the hypothetical parameter fitting recover, within statistical uncertainties, the input cosmological parameters in simulations, including an upper bound on neutrino mass, if the power spectrum information up to k≃0.15hMpc-1 is used. However, for the redshift-space power spectrum, the best-fit cosmological parameters show a sizable bias from the input values if using the information up to k≃0.2hMpc-1, probably due to nonlinear redshift distortion effect. Given these tests, we decided, as a conservative choice, to use the LRG power spectrum up to k=0.1hMpc-1 in order to minimize possible unknown nonlinearity effects. In combination with the recent results from Wilkinson Microwave Background Anisotropy Probe (WMAP), we derive a robust upper bound on the sum of neutrino masses, given as ∑mν≤0.81eV (95% C.L.), marginalized over other parameters including nonlinear bias parameters and dark energy equation of state parameter. The upper bound is only slightly improved to ∑mν≤0.80eV if including the LRG spectrum up to k=0.2hMpc-1, due to severe parameter degeneracies, although the constraint may be biased as discussed above. The

  9. Mass determination of neutrinos

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1988-01-01

    A time-energy correlation method has been developed to determine the signature of a nonzero neutrino mass in a small sample of neutrinos detected from a distant source. The method is applied to the Kamiokande II (Hirata et al., 1987) and IMB (Bionta et al., 1987) observations of neutrino bursts from SN 1987A. Using the Kamiokande II data, the neutrino rest mass is estimated at 2.8 + 2.0, - 1.4 eV and the initial neutrino pulse is found to be less than 0.3 sec full width, followed by an emission tail lasting at least 10 sec.

  10. Constraints on neutrino oscillations using 1258 days of Super-Kamiokande solar neutrino data.

    PubMed

    Fukuda, S; Fukuda, Y; Ishitsuka, M; Itow, Y; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Okada, A; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Toshito, T; Totsuka, Y; Yamada, S; Desai, S; Earl, M; Kearns, E; Messier, M D; Scholberg, K; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Kropp, W R; Mine, S; Liu, D W; Price, L R; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Hayato, Y; Ishii, T; Kobayashi, T; Nakamura, K; Obayashi, Y; Oyama, Y; Sakai, A; Sakuda, M; Kohama, M; Suzuki, A T; Inagaki, T; Nakaya, T; Nishikawa, K; Haines, T J; Blaufuss, E; Dazeley, S; Lee, K B; Svoboda, R; Goodman, J A; Guillian, G; Sullivan, G W; Turcan, D; Habig, A; Hill, J; Jung, C K; Martens, K; Malek, M; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Mitsuda, C; Miyano, K; Saji, C; Shibata, T; Kajiyama, Y; Nagashima, Y; Nitta, K; Takita, M; Yoshida, M; Kim, H I; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Etoh, M; Gando, Y; Hasegawa, T; Inoue, K; Ishihara, K; Maruyama, T; Shirai, J; Suzuki, A; Koshiba, M; Hatakeyama, Y; Ichikawa, Y; Koike, M; Nishijima, K; Fujiyasu, H; Ishino, H; Morii, M; Watanabe, Y; Golebiewska, U; Kielczewska, D; Boyd, S C; Stachyra, A L; Wilkes, R J; Young, K K

    2001-06-18

    We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande. The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way. Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found.

  11. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  12. Planck 2015 constraints on neutrino physics

    NASA Astrophysics Data System (ADS)

    Lattanzi, Massimiliano

    2016-05-01

    Anisotropies of the cosmic microwave background radiation represent a powerful probe of neutrino physics, complementary to laboratory experiments. Here I review constraints on neutrino properties from the recent 2015 data from the Planck satellite.

  13. Global constraints on heavy neutrino mixing

    NASA Astrophysics Data System (ADS)

    Fernandez-Martinez, Enrique; Hernandez-Garcia, Josu; Lopez-Pavon, Jacobo

    2016-08-01

    We derive general constraints on the mixing of heavy Seesaw neutrinos with the SM fields from a global fit to present flavour and electroweak precision data. We explore and compare both a completely general scenario, where the heavy neutrinos are integrated out without any further assumption, and the more constrained case were only 3 additional heavy states are considered. The latter assumption implies non-trivial correlations in order to reproduce the correct neutrino masses and mixings as observed by oscillation data and thus some qualitative differences can be found with the more general scenario. The relevant processes analyzed in the global fit include searches for Lepton Flavour Violating (LFV) decays, probes of the universality of weak interactions, CKM unitarity bounds and electroweak precision data. In particular, a comparative and detailed study of the present and future sensitivity of the different LFV experiments is performed. We find a mild 1-2σ preference for non-zero heavy neutrino mixing of order 0.03-0.04 in the electron and tau sectors. At the 2σ level we derive bounds on all mixings ranging from 0.1 to 0.01 with the notable exception of the e - μ sector with a more stringent bound of 0.005 from the μ → eγ process.

  14. Determining the neutrino mass hierarchy with cosmology

    SciTech Connect

    De Bernardis, Francesco; Kitching, Thomas D.; Heavens, Alan; Melchiorri, Alessandro

    2009-12-15

    The combination of current large-scale structure and cosmic microwave background anisotropies data can place strong constraints on the sum of the neutrino masses. Here we show that future cosmic shear experiments, in combination with cosmic microwave background constraints, can provide the statistical accuracy required to answer questions about differences in the mass of individual neutrino species. Allowing for the possibility that masses are nondegenerate we combine Fisher matrix forecasts for a weak lensing survey like Euclid with those for the forthcoming Planck experiment. Under the assumption that neutrino mass splitting is described by a normal hierarchy we find that the combination Planck and Euclid will possibly reach enough sensitivity to put a constraint on the mass of a single species. Using a Bayesian evidence calculation we find that such future experiments could provide strong evidence for either a normal or an inverted neutrino hierarchy. Finally we show that if a particular neutrino hierarchy is assumed then this could bias cosmological parameter constraints, for example, the dark energy equation of state parameter, by > or approx. 1{sigma}, and the sum of masses by 2.3{sigma}. We finally discuss the impact of uncertainties on the theoretical modeling of nonlinearities. The results presented in this analysis are obtained under an approximation to the nonlinear power spectrum. This significant source of uncertainty needs to be addressed in future work.

  15. ν generation: Present and future constraints on neutrino masses from global analysis of cosmology and laboratory experiments

    NASA Astrophysics Data System (ADS)

    Gerbino, Martina; Lattanzi, Massimiliano; Melchiorri, Alessandro

    2016-02-01

    We perform a joint analysis of current data from cosmology and laboratory experiments to constrain the neutrino mass parameters in the framework of Bayesian statistics, also accounting for uncertainties in nuclear modeling, relevant for neutrinoless double β decay (0 ν 2 β ) searches. We find that a combination of current oscillation, cosmological, and 0 ν 2 β data constrains mβ β<0.045 eV (0.014 eV mass of 0.1 eV, and assuming a factor-of-two uncertainty in the modeling of the relevant nuclear matrix elements, it will be possible to measure the total mass itself, the effective Majorana mass and the effective electron mass with an accuracy (at 95% C.L.) of 0.05, 0.015, 0.02 eV, respectively, as well as to be sensitive to one of the Majorana phases. This assumes that neutrinos are Majorana particles and that the mass mechanism gives the dominant contribution to 0 ν 2 β decay. We argue that more precise nuclear modeling will be crucial to improve these sensitivities.

  16. Neutrino mass in GUT constrained supersymmetry with R-parity violation in light of neutrino oscillations

    SciTech Connect

    Gozdz, Marek; Kaminski, Wieslaw A.; Simkovic, Fedor

    2004-11-01

    The neutrino masses are generated in grand unified theory (GUT) constrained supersymmetric model with R-parity violation. The neutrinos acquire masses via tree-level neutrino-neutralino mixing as well as via one-loop radiative corrections. The theoretical mass matrix is compared with the phenomenological one, which is reconstructed by using neutrino oscillation and neutrinoless double beta decay data. This procedure allows to obtain significantly stronger constraints on R-parity breaking parameters than those existing in the literature. The implication of normal and inverted neutrino mass hierarchy on the sneutrino expectation values, lepton-Higgs bilinear and trilinear R-parity breaking couplings is also discussed.

  17. Neutrino Masses and Flavor Mixing

    NASA Astrophysics Data System (ADS)

    Xing, Zhi-zhong

    2010-06-01

    I give a theoretical overview of some basic properties of massive neutrinos in these lectures. Particular attention is paid to the origin of neutrino masses, the pattern of lepton flavor mixing, the feature of leptonic CP violation and the electromagnetic properties of massive neutrinos. I highlight the TeV seesaw mechanisms as a possible bridge between neutrino physics and collider physics in the era characterized by the Large Hadron Collider.

  18. Observables sensitive to absolute neutrino masses. II

    SciTech Connect

    Fogli, G. L.; Marrone, A.; Rotunno, A. M.; Lisi, E.; Melchiorri, A.; Palazzo, A.; Silk, J.; Slosar, A.

    2008-08-01

    In this followup to Phys. Rev. D 75, 053001 (2007) , we report updated constraints on neutrino mass-mixing parameters, in light of recent neutrino oscillation data (KamLAND, SNO, and MINOS) and cosmological observations (WMAP 5-year and other data). We discuss their interplay with the final 0{nu}2{beta} decay results in {sup 76}Ge claimed by part of the Heidelberg-Moscow Collaboration, using recent evaluations of the corresponding nuclear matrix elements, and their uncertainties. We also comment on the 0{nu}2{beta} limits in {sup 130}Te recently set by Cuoricino and on prospective limits or signals from the Karlsruhe tritium neutrino experiment.

  19. Neutrino Oscillations with Nil Mass

    NASA Astrophysics Data System (ADS)

    Floyd, Edward R.

    2016-09-01

    An alternative neutrino oscillation process is presented as a counterexample for which the neutrino may have nil mass consistent with the standard model. The process is developed in a quantum trajectories representation of quantum mechanics, which has a Hamilton-Jacobi foundation. This process has no need for mass differences between mass eigenstates. Flavor oscillations and ν ,bar{ν } oscillations are examined.

  20. Pair Production Constraints on Superluminal Neutrinos Revisited

    SciTech Connect

    Brodsky, Stanley J.; Gardner, Susan; /Kentucky U.

    2012-02-16

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

  1. Neutrino Masses and Flavor Oscillations

    NASA Astrophysics Data System (ADS)

    Wang, Yifang; Xing, Zhi-Zhong

    2016-10-01

    This essay is intended to provide a brief description of the peculiar properties of neutrinos within and beyond the standard theory of weak interactions. The focus is on the flavor oscillations of massive neutrinos, from which one has achieved some striking knowledge about their mass spectrum and flavor mixing pattern. The experimental prospects towards probing the absolute neutrino mass scale, possible Majorana nature and CP-violating effects, will also be addressed.

  2. Constraints to the decays of Dirac neutrinos from SN 1987A

    NASA Technical Reports Server (NTRS)

    Dodelson, Scott; Frieman, Joshua A.; Turner, Michael S.

    1992-01-01

    The decay mode of a keV-mass Dirac neutrino is addressed with reference to the nineteen neutrino events associated with SN 1987A that were detected by the Kamiokande II and Irvine-Brookhaven-Michigan detectors. A complementary constraint is presented which is based upon a distinctive signal associated with the decay of wrong-helicity neutrinos that was not seen: high-energy (50 MeV and higher) neutrino events. The absence of such events excludes the decay of wrong-helicity neutrinos into proper-helicity neutrinos for a Dirac neutrino of mass between 1 and 300 keV. The constraint also rules out models of the 17-keV neutrino.

  3. Substructure lensing in galaxy clusters as a constraint on low-mass sterile neutrinos in tensor-vector-scalar theory: The straight arc of Abell 2390

    SciTech Connect

    Feix, Martin; Zhao Hongsheng; Fedeli, Cosimo; Hoekstra, Henk

    2010-12-15

    Certain covariant theories of the modified Newtonian dynamics paradigm seem to require an additional hot dark matter (HDM) component--in the form of either heavy ordinary neutrinos or more recently light sterile neutrinos (SNs) with a mass around 11 eV--to be relieved of problems ranging from cosmological scales down to intermediate ones relevant for galaxy clusters. Here we suggest using gravitational lensing by galaxy clusters to test such a marriage of neutrino HDM and modified gravity, adopting the framework of tensor-vector-scalar theory (TeVeS). Unlike conventional cold dark matter (CDM), such HDM is subject to strong phase-space constraints, which allows one to check cluster lens models inferred within the modified framework for consistency. Since the considered HDM particles cannot collapse into arbitrarily dense clumps and only form structures well above the galactic scale, systems which indicate the need for dark substructure are of particular interest. As a first example, we study the cluster lens Abell 2390 and its impressive straight arc with the help of numerical simulations. Based on our results, we outline a general and systematic approach to model cluster lenses in TeVeS which significantly reduces the calculation complexity. We further consider a simple bimodal lens configuration, capable of producing the straight arc, to demonstrate our approach. We find that such a model is marginally consistent with the hypothesis of 11 eV SNs. Future work including more detailed and realistic lens models may further constrain the necessary SN distribution and help to conclusively assess this point. Cluster lenses could therefore provide an interesting discriminator between CDM and such modified gravity scenarios supplemented by SNs or other choices of HDM.

  4. Experimental constraints on the neutrino oscillations and a simple model of three-flavor mixing

    SciTech Connect

    Raczka, P.A.; Szymacha, A. ); Tatur, S. )

    1994-02-01

    A simple model of neutrino mixing is considered which contains only one right-handed neutrino field coupled, via the mass term, to the three usual left-handed fields. This is the simplest model that allows for three-flavor neutrino oscillations. The existing experimental limits on the neutrino oscillations are used to obtain constraints on the two free-mixing parameters of the model. A specific sum rule relating the oscillation probabilities of different flavors is derived.

  5. Neutrino mass models and CP violation

    SciTech Connect

    Joshipura, Anjan S.

    2011-10-06

    Theoretical ideas on the origin of (a) neutrino masses (b) neutrino mass hierarchies and (c) leptonic mixing angles are reviewed. Topics discussed include (1) symmetries of neutrino mass matrix and their origin (2) ways to understand the observed patterns of leptonic mixing angles and (3)unified description of neutrino masses and mixing angles in grand unified theories.

  6. Cosmological neutrino mass detection: The Best probe of neutrino lifetime

    SciTech Connect

    Serpico, Pasquale D.; /Fermilab

    2007-01-01

    Future cosmological data may be sensitive to the effects of a finite sum of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a cosmological detection of neutrino mass at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on neutrino secret interactions with (quasi-)massless particles as in majoron models. On the other hand, neutrino decay may provide a way-out to explain a discrepancy {approx}< 0.1 eV between cosmic neutrino bounds and Lab data.

  7. Cosmological constraints on neutrinos with Planck data

    SciTech Connect

    Spinelli, M.

    2015-07-15

    Neutrinos take part in the dance of the evolving Universe influencing its history from leptogenesis, to Big Bang nucleosynthesis, until late time structure formation. This makes cosmology, and in particular one of its primary observables the Cosmic Microwave Background (CMB), an unusual but valuable tool for testing Neutrino Physics. The best measurement to date of full-sky CMB anisotropies comes from the Planck satellite launched in 2009 by the European Space Agency (ESA) and successful follower of COBE and WMAP. Testing Planck data against precise theoretical predictions allow us to shed light on various interesting open questions such as the value of the absolute scale of neutrino masses or their energy density. We revise here the results concerning neutrinos obtained by the Planck Collaboration in the 2013 data release.

  8. Cosmological constraints on neutrinos with Planck data

    NASA Astrophysics Data System (ADS)

    Spinelli, M.

    2015-07-01

    Neutrinos take part in the dance of the evolving Universe influencing its history from leptogenesis, to Big Bang nucleosynthesis, until late time structure formation. This makes cosmology, and in particular one of its primary observables the Cosmic Microwave Background (CMB), an unusual but valuable tool for testing Neutrino Physics. The best measurement to date of full-sky CMB anisotropies comes from the Planck satellite launched in 2009 by the European Space Agency (ESA) and successful follower of COBE and WMAP. Testing Planck data against precise theoretical predictions allow us to shed light on various interesting open questions such as the value of the absolute scale of neutrino masses or their energy density. We revise here the results concerning neutrinos obtained by the Planck Collaboration in the 2013 data release.

  9. Constraint on neutrino decay with medium-baseline reactor neutrino oscillation experiments

    NASA Astrophysics Data System (ADS)

    Abrahão, Thamys; Minakata, Hisakazu; Nunokawa, Hiroshi; Quiroga, Alexander A.

    2015-11-01

    The experimental bound on lifetime of ν 3, the neutrino mass eigenstate with the smallest ν e component, is much weaker than those of ν 1 and ν 2 by many orders of magnitude to which the astrophysical constraints apply. We argue that the future reactor neutrino oscillation experiments with medium-baseline (˜50 km), such as JUNO or RENO-50, has the best chance of placing the most stringent constraint on ν3 lifetime among all neutrino experiments which utilize the artificial source neutrinos. Assuming decay into invisible states, we show by a detailed χ 2 analysis that the ν 3 lifetime divided by its mass, τ 3 /m 3, can be constrained to be τ 3 /m 3 > 7 .5 (5 .5) × 10-11 s/eV at 95% (99%) C.L. by 100 kt·years exposure by JUNO. It may be further improved to the level comparable to the atmospheric neutrino bound by its longer run. We also discuss to what extent ν 3 decay affects mass-ordering determination and precision measurements of the mixing parameters.

  10. What masses do the neutrinos have? Mixing

    SciTech Connect

    Efrosinin, V. P.

    2010-06-15

    Possible mechanisms for the production of low-mass neutrinos and sterile neutrinos are considered. The quark mixing angles are calculated under the assumption that the traces of left-right symmetry are stable with respect to the masses of constituent quarks. Order-of-magnitude estimates of the neutrino masses are obtained with the aid of experimental data on neutrino oscillations.

  11. Atomic ionization by sterile-to-active neutrino conversion and constraints on dark matter sterile neutrinos with germanium detectors

    NASA Astrophysics Data System (ADS)

    Chen, Jiunn-Wei; Chi, Hsin-Chang; Lin, Shin-Ted; Liu, C.-P.; Singh, Lakhwinder; Wong, Henry T.; Wu, Chih-Liang; Wu, Chih-Pan

    2016-05-01

    The transition magnetic moment of a sterile neutrino can give rise to its conversion to an active neutrino through radiative decay or nonstandard interaction (NSI) with matter. For sterile neutrinos of keV-mass as dark matter candidates, their decay signals are actively searched for in cosmic x-ray spectra. In this work, we consider the NSI that leads to atomic ionization, which can be detected by direct dark matter experiments. It is found that this inelastic scattering process for a nonrelativistic sterile neutrino has a pronounced enhancement in the differential cross section at energy transfer about half of its mass, manifesting experimentally as peaks in the measurable energy spectra. The enhancement effects gradually smear out as the sterile neutrino becomes relativistic. Using data taken with low-threshold low-background germanium detectors, constraints on sterile neutrino mass and its transition magnetic moment are derived and compared with those from astrophysical observations.

  12. Small neutrino masses from gravitational θ -term

    NASA Astrophysics Data System (ADS)

    Dvali, Gia; Funcke, Lena

    2016-06-01

    We present how a neutrino condensate and small neutrino masses emerge from a topological formulation of gravitational anomaly. We first recapitulate how a gravitational θ -term leads to the emergence of a new bound neutrino state analogous to the η' meson of QCD. Then we show the consequent formation of a neutrino vacuum condensate, which effectively generates small neutrino masses. Afterwards we outline numerous phenomenological consequences of our neutrino mass generation model. The cosmological neutrino mass bound vanishes since we predict the neutrinos to be massless until the phase transition in the late Universe, T ˜meV . Coherent radiation of new light particles in the neutrino sector can be detected in prospective precision experiments. Deviations from an equal flavor rate due to enhanced neutrino decays in extraterrestrial neutrino fluxes can be observed in future IceCube data. These neutrino decays may also necessitate modified analyses of the original neutrino spectra of the supernova SN 1987A. The current cosmological neutrino background only consists of the lightest neutrinos, which, due to enhanced neutrino-neutrino interactions, either bind up, form a superfluid, or completely annihilate into massless bosons. Strongly coupled relic neutrinos could provide a contribution to cold dark matter in the late Universe, together with the new proposed particles and topological defects, which may have formed during neutrino condensation. These enhanced interactions could also be a source of relic neutrino clustering in our Galaxy, which possibly makes the overdense cosmic neutrino background detectable in the KATRIN experiment. The neutrino condensate provides a mass for the hypothetical B -L gauge boson, leading to a gravity-competing force detectable in short-distance measurements. Prospective measurements of the polarization intensities of gravitational waves can falsify our neutrino mass generation model.

  13. Koide's Mass Formula for Neutrinos

    NASA Astrophysics Data System (ADS)

    Brannen, Carl

    2006-05-01

    We derive Koide's mass formula as an eigenvector equation. We show that to within current experimental error, the square roots of the masses of the charged leptons follow the simple equation (m^-n)^0.5 = μ1(1 + √2(δ1+ 2nπ/3)) where δ1 is the interesting number .22222204717(48) and μ1 is a constant. Next we generalize the Koide formula to the neutrinos by assuming that the square root of the mass of the smallest neutrino must be taken to be negative. Then masses of the simple form (m^0n)^0.5 = μ0(1 + √2(δ1+ π/12 + 2nπ/3)) where 3;μ0= 3^12 ;μ1, satisfy recent neutrino oscillation measurements close to the centers of the error bars. Finally, we discuss the preon model for the fermions that led to the above discovery.

  14. Constraints on secret neutrino interactions after Planck

    NASA Astrophysics Data System (ADS)

    Forastieri, Francesco; Lattanzi, Massimiliano; Natoli, Paolo

    2015-07-01

    Neutrino interactions beyond the standard model of particle physics may affect the cosmological evolution and can be constrained through observations. We consider the possibility that neutrinos possess secret scalar or pseudoscalar interactions mediated by the Nambu-Goldstone boson of a still unknown spontaneously broken global U(1) symmetry, as in, e.g., Majoron models. In such scenarios, neutrinos still decouple at Tsimeq 1 MeV, but become tightly coupled again (``recouple'') at later stages of the cosmological evolution. We use available observations of the cosmic microwave background (CMB) anisotropies, including Planck 2013 and the joint BICEP2/Planck 2015 data, to derive constraints on the quantity γνν4, parameterizing the neutrino collision rate due to scalar or pseudoscalar interactions. We consider both a minimal extension of the standard ΛCDM model, and more complicated scenarios with extra relativistic degrees of freedom or non-vanishing tensor amplitude. For a wide range of dataset and model combinations, we find a typical constraint γνν4 lesssim 0.9× 10-27 (95% C.L.), implying an upper limit on the redshift zνrec of neutrino recoupling 0lesssim 850, leaving open the possibility that the latter occured well before hydrogen recombination. In the framework of Majoron models, the upper limit on γνν roughly translates on a constraint g lesssim 8.2× 10-7 on the Majoron-neutrino coupling constant g. In general, the data show a weak (~ 1σ) but intriguing preference for non-zero values of γνν4, with best fits in the range γνν4 = (0.15-0.35)× 10-27, depending on the particular dataset. This is more evident when either high-resolution CMB observations from the ACT and SPT experiments are included, or the possibility of non-vanishing tensor modes is considered. In particular, for the minimal model ΛCDM+γνν and including the Planck 2013, ACT and SPT data, we report γνν4=(0.44+0.17-0.36)×10-27 (0300 lesssim zνrec lesssim 550) at 68

  15. Probing Late Neutrino Mass Properties With SupernovaNeutrinos

    SciTech Connect

    Baker, Joseph; Goldberg, Haim; Perez, Gilad; Sarcevic, Ina

    2007-08-08

    Models of late-time neutrino mass generation contain new interactions of the cosmic background neutrinos with supernova relic neutrinos (SRNs). Exchange of an on-shell light scalar may lead to significant modification of the differential SRN flux observed at earth. We consider an Abelian U(1) model for generating neutrino masses at low scales, and show that there are cases for which the changes induced in the flux allow one to distinguish the Majorana or Dirac nature of neutrinos, as well as the type of neutrino mass hierarchy (normal or inverted or quasi-degenerate). In some region of parameter space the determination of the absolute values of the neutrino masses is also conceivable. Measurements of the presence of these effects may be possible at the next-generation water Cerenkov detectors enriched with Gadolinium, or a 100 kton liquid argon detector.

  16. Upper bound on neutrino mass based on T2K neutrino timing measurements

    NASA Astrophysics Data System (ADS)

    Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bartet-Friburg, P.; Bass, M.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berger, B. E.; Berkman, S.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Escudero, L.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haegel, L.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, R. A.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; King, S.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Koga, T.; Kolaceke, A.; Konaka, A.; Kopylov, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Lopez, J. P.; Ludovici, L.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Riccio, C.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaker, F.; Shaw, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Tanaka, M. M.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Wakamatsu, K.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoo, J.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

    2016-01-01

    The Tokai to Kamioka (T2K) long-baseline neutrino experiment consists of a muon neutrino beam, produced at the J-PARC accelerator, a near detector complex and a large 295-km-distant far detector. The present work utilizes the T2K event timing measurements at the near and far detectors to study neutrino time of flight as a function of derived neutrino energy. Under the assumption of a relativistic relation between energy and time of flight, constraints on the neutrino rest mass can be derived. The sub-GeV neutrino beam in conjunction with timing precision of order tens of ns provide sensitivity to neutrino mass in the few MeV /c2 range. We study the distribution of relative arrival times of muon and electron neutrino candidate events at the T2K far detector as a function of neutrino energy. The 90% C.L. upper limit on the mixture of neutrino mass eigenstates represented in the data sample is found to be mν2<5.6 MeV2/c4 .

  17. Constraints and tests of the OPERA superluminal neutrinos.

    PubMed

    Bi, Xiao-Jun; Yin, Peng-Fei; Yu, Zhao-Huan; Yuan, Qiang

    2011-12-01

    The superluminal neutrinos detected by OPERA indicate Lorentz invariance violation (LIV) of the neutrino sector at the order of 10(-5). We study the implications of the result in this work. We find that such a large LIV implied by OPERA data will make the neutrino production process π → μ + ν(μ) kinematically forbidden for a neutrino energy greater than about 5 GeV. The OPERA detection of neutrinos at 40 GeV can constrain the LIV parameter to be smaller than 3×10(-7). Furthermore, the neutrino decay in the LIV framework will modify the neutrino spectrum greatly. The atmospheric neutrino spectrum measured by the IceCube Collaboration can constrain the LIV parameter to the level of 10(-12). The future detection of astrophysical neutrinos of galactic sources is expected to be able to give an even stronger constraint on the LIV parameter of neutrinos.

  18. Model of neutrino effective masses

    SciTech Connect

    Dinh Nguyen Dinh; Nguyen Thi Hong Van; Nguyen Anh Ky; Phi Quang Van

    2006-10-01

    It is shown that an effective (nonrenormalizable) coupling of lepton multiplets to scalar triplets in the 331 model with sterile/exotic neutrinos, can be a good way for generating neutrino masses of different types. The method is simple and avoids radiative/loop calculations which, sometimes, are long and complicated. Basing on some astrophysical arguments it is also stated that the scale of SU(3){sub L} symmetry breaking is at TeV scale, in agreement with earlier investigations. Or equivalently, starting from this symmetry breaking scale we could have sterile/exotic neutrinos with mass of a few keV's which could be used to explain several astrophysical and cosmological puzzles, such as the dark matter, the fast motion of the observed pulsars, the re-ionization of the Universe, etc.

  19. Supernova constraints on neutrino oscillation and EoS for proto-neutron star

    SciTech Connect

    Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Shibagaki, S.; Mathews, G. J.; Nakamura, K.; Suzuki, T.

    2014-05-02

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We here discuss how to determine the neutrino temperatures and propose a method to determine still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. Combining the recent experimental constraints on θ{sub 13} with isotopic ratios of the light elements discovered in presolar grains from the Murchison meteorite, we show that our method suggests at a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  20. Texture and cofactor zeros of the neutrino mass matrix

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun; Marfatia, D.; Whisnant, K.

    2014-09-01

    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.

  1. Neutrino Mass and Flavour Models

    SciTech Connect

    King, Stephen F.

    2010-02-10

    We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and unification, and show how such models can also solve the SUSY flavour and CP problems. We also discuss the theoretical implications of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

  2. Planck-scale physics and neutrino masses

    NASA Astrophysics Data System (ADS)

    Akhmedov, Evgenii Kh.; Berezhiani, Zurab G.; Senjanovic, Goran

    1992-11-01

    We discuss gravitationally induced masses and mass splittings of Majorana, Zeldovich-Konopinski-Mahmoud, and Dirac neutrinos. Among other implications, these effects can provide a solution of the solar neutrino puzzle. In particular, we show how this may work in the 17 keV neutrino picture.

  3. Predictive models of radiative neutrino masses

    NASA Astrophysics Data System (ADS)

    Julio, J.

    2016-06-01

    We discuss two models of radiative neutrino mass generation. The first model features one-loop Zee model with Z4 symmetry. The second model is the two-loop neutrino mass model with singly- and doubly-charged scalars. These two models fit neutrino oscillation data well and predict some interesting rates for lepton flavor violation processes.

  4. Solar mass-varying neutrino oscillations.

    PubMed

    Barger, V; Huber, Patrick; Marfatia, Danny

    2005-11-18

    We propose that the solar neutrino deficit may be due to oscillations of mass-varying neutrinos (MaVaNs). This scenario elucidates solar neutrino data beautifully while remaining comfortably compatible with atmospheric neutrino and K2K data and with reactor antineutrino data at short and long baselines (from CHOOZ and KamLAND). We find that the survival probability of solar MaVaNs is independent of how the suppression of neutrino mass caused by the acceleron-matter couplings varies with density. Measurements of MeV and lower energy solar neutrinos will provide a rigorous test of the idea.

  5. Can we measure the neutrino mass hierarchy in the sky?

    SciTech Connect

    Jimenez, Raul; Verde, Licia; Kitching, Thomas; Peña-Garay, Carlos E-mail: tdk@roe.ac.uk E-mail: liciaverde@icc.ub.edu

    2010-05-01

    Cosmological probes are steadily reducing the total neutrino mass window, resulting in constraints on the neutrino-mass degeneracy as the most significant outcome. In this work we explore the discovery potential of cosmological probes to constrain the neutrino hierarchy, and point out some subtleties that could yield spurious claims of detection. This has an important implication for next generation of double beta decay experiments, that will be able to achieve a positive signal in the case of degenerate or inverted hierarchy of Majorana neutrinos. We find that cosmological experiments that nearly cover the whole sky could in principle distinguish the neutrino hierarchy by yielding 'substantial' evidence for one scenario over the another, via precise measurements of the shape of the matter power spectrum from large scale structure and weak gravitational lensing.

  6. Limits on the neutrino mass from cosmology

    SciTech Connect

    Melchiorri, Alessandro; De Bernardis, Francesco; Menegoni, Eloisa

    2010-07-12

    We use measurements of luminosity-dependent galaxy bias at several different redshifts, SDSS at z = 0.05, DEEP2 at z = 1 and LBGs at z = 3.8, combined with WMAP five-year cosmic microwave background anisotropy data and SDSS Red Luminous Galaxy survey three-dimensional clustering power spectrum to put constraints on cosmological parameters. Fitting this combined dataset, we show that the luminosity-dependent bias data that probe the relation between halo bias and halo mass and its redshift evolution are very sensitive to sum of the neutrino masses: in particular we obtain the upper limit of {Sigma}m{sub {nu}<}0.28 eV at the 95% confidence level for a {Lambda}CDM+m{sub {nu}}model, with a {sigma}8 equal to {sigma}8 = 0.759{+-}0.025 (1{sigma}). When we allow the dark energy equation of state parameter w to vary we find w -1.30{+-}0.19 for a general wCDM+m{sub {nu}}model with the 95% confidence level upper limit on the neutrino masses at {Sigma}m{sub {nu}<}0.59 eV. The constraint on the dark energy equation of state further improves to w = -1.125{+-}0.092 when using also ACBAR and supernovae Union data, in addition to above, with a prior on the Hubble constant from the Hubble Space Telescope. Finally, we have investigated the ability of future cosmic shear measurements, like those achievable with the proposed Euclid mission, to constrain differences in the mass of individual neutrino species.

  7. Renormalization of a two-loop neutrino mass model

    SciTech Connect

    Babu, K. S.; Julio, J.

    2014-01-01

    We analyze the renormalization group structure of a radiative neutrino mass model consisting of a singly charged and a doubly charged scalar fields. Small Majorana neutrino masses are generated by the exchange of these scalars via two-loop diagrams. We derive boundedness conditions for the Higgs potential and show how they can be satisfied to energies up to the Planck scale. Combining boundedness and perturbativity constraints with neutrino oscillation phenomenology, new limits on the masses and couplings of the charged scalars are derived. These in turn lead to lower limits on the branching ratios for certain lepton flavor violating (LFV) processes such as μ→eγ, μ→3e and μ – e conversion in nuclei. Improved LFV measurements could test the model, especially in the case of inverted neutrino mass hierarchy where these are more prominent.

  8. Renormalization of a two-loop neutrino mass model

    NASA Astrophysics Data System (ADS)

    Babu, K. S.; Julio, J.

    2014-06-01

    We analyze the renormalization group structure of a radiative neutrino mass model consisting of a singly charged and a doubly charged scalar fields. Small Majorana neutrino masses are generated by the exchange of these scalars via two-loop diagrams. We derive boundedness conditions for the Higgs potential and show how they can be satisfied to energies up to the Planck scale. Combining boundedness and perturbativity constraints with neutrino oscillation phenomenology, new limits on the masses and couplings of the charged scalars are derived. These in turn lead to lower limits on the branching ratios for certain lepton flavor violating (LFV) processes such as μ→eγ, μ→3e and μ - e conversion in nuclei. Improved LFV measurements could test the model, especially in the case of inverted neutrino mass hierarchy where these are more prominent.

  9. Neutrino constraints from future nearly all-sky spectroscopic galaxy surveys

    SciTech Connect

    Carbone, Carmelita; Cimatti, Andrea; Verde, Licia; Wang, Yun E-mail: liciaverde@icc.ub.edu E-mail: a.cimatti@unibo.it

    2011-03-01

    We examine whether future, nearly all-sky galaxy redshift surveys, in combination with CMB priors, will be able to detect the signature of the cosmic neutrino background and determine the absolute neutrino mass scale. We also consider what constraints can be imposed on the effective number of neutrino species. In particular we consider two spectroscopic strategies in the near-IR, the so-called ''slitless'' and ''multi-slit'' approaches, whose examples are given by future space-based galaxy surveys, as EUCLID for the slitless case, or SPACE, JEDI, and possibly WFIRST in the future, for the multi-slit case. We find that, in combination with Planck, these galaxy probes will be able to detect at better than 3-sigma level and measure the mass of cosmic neutrinos: a) in a cosmology-independent way, if the sum of neutrino masses is above 0.1 eV; b) assuming spatial flatness and that dark energy is a cosmological constant, otherwise. We find that the sensitivity of such surveys is well suited to span the entire range of neutrino masses allowed by neutrino oscillation experiments, and to yield a clear detection of non-zero neutrino mass. The detection of the cosmic relic neutrino background with cosmological experiments will be a spectacular confirmation of our model for the early Universe and a window into one of the oldest relic components of our Universe.

  10. Neutrino mass measurement from correlation dipoles

    NASA Astrophysics Data System (ADS)

    Chen, Xuelei

    2015-08-01

    The large scale structure measurement can be used as a precision probe for neutrinos. It is well known that the power spectrum is suppressed at relatively small scales by the free-streaming of neutrinos, and this is used to measure the neutrino mass. However, this method is prone to scale-dependent galaxy bias, which can lead to significant system error in the measurement. We proposed a new method to measure the neutrino mass which is free of this problem. Due to their smaller masses, the neutrinos can develop large relative velocities with respect to the dark matter, the neutrino distribution can then affect the structure formation process. Although the effect is very small, it may generate significant dipole in the galaxy cross-correlation function or the galaxy lensing. The neutrino mass may by determined by such observations. We present the feasibility for such measurement.

  11. Neutrino oscillations and the seesaw origin of neutrino mass

    NASA Astrophysics Data System (ADS)

    Miranda, O. G.; Valle, J. W. F.

    2016-07-01

    The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.

  12. Neutrino Masses from a Pseudo-Dirac Bino.

    PubMed

    Coloma, Pilar; Ipek, Seyda

    2016-09-01

    We show that, in U(1)_{R}-symmetric supersymmetric models, the bino and its Dirac partner (the singlino) can play the role of right-handed neutrinos and generate the neutrino masses and mixing, without the need for traditional bilinear or trilinear R-parity violating operators. The two particles form a pseudo-Dirac pair, the "biνo." An inverse seesaw texture is generated for the neutrino-biνo sector, and the lightest neutrino is predicted to be massless. Unlike in most models with heavy right-handed neutrinos, the biνo can be sizably produced at the LHC through its interactions with colored particles, while respecting low energy constraints from neutrinoless double-beta decay and charged lepton flavor violation. PMID:27661681

  13. Effective Theories of Neutrino Masses

    NASA Astrophysics Data System (ADS)

    Gavela, M. B.

    2013-02-01

    The importance of improving the bounds on those effective non-standard neutrino interactions (NSI) which are a signal of all fermionic-mediated Seesaws is stressed: they are revealed as non-unitarity of the leptonic mixing matrix, and at experimental reach for seesaw scales ⩽ O(TeV). Some recent activity in the literature on other - theoretically not well motivated - ill-constrained NSI are also summarized. Furthermore, the status of the simplest Seesaw scenario with only two heavy neutrinos is reviewed. This model happens to be a explicit realization of the effective Minimal Flavour Violation approach. We derive the scalar potential for the fields whose background values are the Yukawa couplings of that model, and explore its minima. The Majorana character plays a distinctive role: the minimum of the potential allows for large mixing angles - in contrast to the simplest quark case - and predicts a maximal Majorana phase. This points in turn to a strong correlation between neutrino mass hierarchy and mixing pattern.

  14. Probing the Absolute Mass Scale of Neutrinos

    SciTech Connect

    Prof. Joseph A. Formaggio

    2011-10-12

    The experimental efforts of the Neutrino Physics Group at MIT center primarily around the exploration of neutrino mass and its significance within the context of nuclear physics, particle physics, and cosmology. The group has played a prominent role in the Sudbury Neutrino Observatory, a neutrino experiment dedicated to measure neutrino oscillations from 8B neutrinos created in the sun. The group is now focusing its efforts in the measurement of the neutrino mass directly via the use of tritium beta decay. The MIT group has primary responsibilities in the Karlsruhe Tritium Neutrino mass experiment, expected to begin data taking by 2013. Specifically, the MIT group is responsible for the design and development of the global Monte Carlo framework to be used by the KATRIN collaboration, as well as responsibilities directly associated with the construction of the focal plane detector. In addition, the MIT group is sponsoring a new research endeavor for neutrino mass measurements, known as Project 8, to push beyond the limitations of current neutrino mass experiments.

  15. Neutrino mass and dark energy from weak lensing.

    PubMed

    Abazajian, Kevork N; Dodelson, Scott

    2003-07-25

    Weak gravitational lensing of background galaxies by intervening matter directly probes the mass distribution in the Universe. This distribution is sensitive to both the dark energy and neutrino mass. We examine the potential of lensing experiments to measure features of both simultaneously. Focusing on the radial information contained in a future deep 4000 deg(2) survey, we find that the expected (1-sigma) error on a neutrino mass is 0.1 eV, if the dark-energy parameters are allowed to vary. The constraints on dark-energy parameters are similarly restrictive, with errors on w of 0.09. PMID:12906650

  16. Model for neutrino masses and dark matter

    NASA Astrophysics Data System (ADS)

    Krauss, Lawrence M.; Nasri, Salah; Trodden, Mark

    2003-04-01

    We propose a model for neutrino masses that simultaneously results in a new dark matter candidate, the right-handed neutrino. We derive the dark matter abundance in this model, show how the hierarchy of neutrino masses is obtained, and verify that the model is compatible with existing experimental results. The toy model provides a potentially economical method of unifying two seemingly separate puzzles in contemporary particle physics and cosmology.

  17. Radiative neutrino mass, dark matter, and leptogenesis

    SciTech Connect

    Gu Peihong; Sarkar, Utpal

    2008-05-15

    We propose an extension of the standard model, in which neutrinos are Dirac particles and their tiny masses originate from a one-loop radiative diagram. The new fields required by the neutrino mass generation also accommodate the explanation for the matter-antimatter asymmetry and dark matter in the Universe.

  18. Models for neutrino mass with discrete symmetries

    NASA Astrophysics Data System (ADS)

    Morisi, S.

    2011-08-01

    Discrete non-abelian flavor symmetries give in a natural way tri-bimaximal (TBM) mixing as showed in a prototype model. However neutrino mass matrix pattern may be very different from the tri-bimaximal one if small deviations of TBM will be observed. We give the result of a model independent analysis for TBM neutrino mass pattern.

  19. Dual models of the neutrino mass spectrum

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun; Marfatia, D.; Whisnant, K.

    2014-01-01

    We show that any model with a homogeneous relationship among elements of the neutrino mass matrix with one mass hierarchy yields predictions for the oscillation parameters and Majorana phases similar to those given by a model with the same homogeneous relationship among cofactors of the neutrino mass matrix with the opposite mass hierarchy, except when the lightest mass is of order 20 meV or less.

  20. PINGU sensitivity to neutrino mass hierarchy

    SciTech Connect

    Groß, Andreas; Collaboration: IceCube-PINGU Collaboration

    2014-11-18

    Determination of the neutrino mass hierarchy (NMH) is among the most fundamental questions in particle physics. Recent measurements of 1) a large mixing angle between the first and the third neutrino mass eigenstates and 2) the first observation of atmospheric neutrino oscillations at tens of GeV with neutrino telescopes, open the intriguing new possibility to exploit matter effects in neutrino oscillation to determine the neutrino mass hierarchy. A further extension of IceCube/DeepCore called PINGU (Precision IceCube Next Generation Upgrade) has been recently envisioned with the ultimate goal to measure neutrino mass hierarchy. PINGU would consist of additional IceCube-like strings of detectors deployed in the deepest and cleanest ice in the center of IceCube. More densely deployed instrumentation would provide a threshold substantially below 10 GeV and enhance the sensitivity to the mass hierarchy signal in atmospheric neutrinos. Here we discuss an estimate of the PINGU sensitivity to the mass hierarchy determined using an approximation with an Asimov dataset and an oscillation parameter fit.

  1. Constraining bilinear R-parity violation from neutrino masses

    SciTech Connect

    Gozdz, Marek; Kaminski, Wieslaw A.

    2008-10-01

    We confront the R-parity violating minimal supersymmetric standard model with the neutrino oscillation data. Investigating the 1-loop particle-sparticle diagrams with additional bilinear insertions on the external neutrino lines we construct the relevant contributions to the neutrino mass matrix. A comparison of the so-obtained matrices with the experimental ones assuming normal or inverted hierarchy and taking into account possible CP-violating phases allows to set constraints on the values of the bilinear coupling constants. A similar calculation is presented with the input from the Heidelberg-Moscow neutrinoless double beta decay experiment. We base our analysis on the renormalization group evolution of the minimal supersymmetric standard model parameters which are unified at the grand unified theory scale. Using the obtained bounds we calculate the contributions to the Majorana neutrino transition magnetic moments.

  2. Zeros in the magic neutrino mass matrix

    NASA Astrophysics Data System (ADS)

    Gautam, Radha Raman; Kumar, Sanjeev

    2016-08-01

    We study the phenomenological implications of the presence of two zeros in a magic neutrino mass matrix. We find that only two such patterns of the neutrino mass matrix are experimentally acceptable. We express all the neutrino observables as functions of one unknown phase ϕ and two known parameters Δ m122, r =Δ m122/Δ m232. In particular, we find sin2θ13=(2 /3 )r /(1 +r ). We also present a mass model for the allowed textures based upon the group A4 using the type I +II seesaw mechanism.

  3. Predictive model of radiative neutrino masses

    NASA Astrophysics Data System (ADS)

    Babu, K. S.; Julio, J.

    2014-03-01

    We present a simple and predictive model of radiative neutrino masses. It is a special case of the Zee model which introduces two Higgs doublets and a charged singlet. We impose a family-dependent Z4 symmetry acting on the leptons, which reduces the number of parameters describing neutrino oscillations to four. A variety of predictions follow: the hierarchy of neutrino masses must be inverted; the lightest neutrino mass is extremely small and calculable; one of the neutrino mixing angles is determined in terms of the other two; the phase parameters take CP-conserving values with δCP=π; and the effective mass in neutrinoless double beta decay lies in a narrow range, mββ=(17.6-18.5) meV. The ratio of vacuum expectation values of the two Higgs doublets, tanβ, is determined to be either 1.9 or 0.19 from neutrino oscillation data. Flavor-conserving and flavor-changing couplings of the Higgs doublets are also determined from neutrino data. The nonstandard neutral Higgs bosons, if they are moderately heavy, would decay dominantly into μ and τ with prescribed branching ratios. Observable rates for the decays μ →eγ and τ→3μ are predicted if these scalars have masses in the range of 150-500 GeV.

  4. Neutrino masses from neutral top partners

    NASA Astrophysics Data System (ADS)

    Batell, Brian; McCullough, Matthew

    2015-10-01

    We present theories of "natural neutrinos" in which neutral fermionic top partner fields are simultaneously the right-handed neutrinos (RHN), linking seemingly disparate aspects of the Standard Model structure: (a) The RHN top partners are responsible for the observed small neutrino masses, (b) they help ameliorate the tuning in the weak scale and address the little hierarchy problem, and (c) the factor of 3 arising from Nc in the top-loop Higgs mass corrections is countered by a factor of 3 from the number of vectorlike generations of RHN. The RHN top partners may arise in pseudo-Nambu-Goldstone-Boson Higgs models such as the twin Higgs, as well as more general composite, little, and orbifold Higgs scenarios, and three simple example models are presented. This framework firmly predicts a TeV-scale seesaw, as the RHN masses are bounded to be below the TeV scale by naturalness. The generation of light neutrino masses relies on a collective breaking of the lepton number, allowing for comparatively large neutrino Yukawa couplings and a rich associated phenomenology. The structure of the neutrino mass mechanism realizes in certain limits the inverse or linear classes of seesaw. Natural neutrino models are testable at a variety of current and future experiments, particularly in tests of lepton universality, searches for lepton flavor violation, and precision electroweak and Higgs coupling measurements possible at high energy e+e- and hadron colliders.

  5. Flavour dependent gauged radiative neutrino mass model

    NASA Astrophysics Data System (ADS)

    Baek, Seungwon; Okada, Hiroshi; Yagyu, Kei

    2015-04-01

    We propose a one-loop induced radiative neutrino mass model with anomaly free flavour dependent gauge symmetry: μ minus τ symmetry U(1) μ- τ . A neutrino mass matrix satisfying current experimental data can be obtained by introducing a weak isospin singlet scalar boson that breaks U(1) μ- τ symmetry, an inert doublet scalar field, and three right-handed neutrinos in addition to the fields in the standard model. We find that a characteristic structure appears in the neutrino mass matrix: two-zero texture form which predicts three non-zero neutrino masses and three non-zero CP-phases from five well measured experimental inputs of two squared mass differences and three mixing angles. Furthermore, it is clarified that only the inverted mass hierarchy is allowed in our model. In a favored parameter set from the neutrino sector, the discrepancy in the muon anomalous magnetic moment between the experimental data and the the standard model prediction can be explained by the additional neutral gauge boson loop contribution with mass of order 100 MeV and new gauge coupling of order 10-3.

  6. Late Time Neutrino Masses, the LSND Experiment and the Cosmic Microwave Background

    SciTech Connect

    Chacko, Z.; Hall, Lawrence J.; Oliver, Steven J.; Perelstein, Maxim

    2004-05-07

    Models with low-scale breaking of global symmetries in the neutrino sector provide an alternative to the seesaw mechanism for understanding why neutrinos are light. Such models can easily incorporate light sterile neutrinos required by the LSND experiment. Furthermore, the constraints on the sterile neutrino properties from nucleosynthesis and large scale structure can be removed due to the non-conventional cosmological evolution of neutrino masses and densities. We present explicit, fully realistic supersymmetric models, and discuss the characteristic signatures predicted in the angular distributions of the cosmic microwave background.

  7. Constraints on Non-flat Cosmologies with Massive Neutrinos after Planck 2015

    NASA Astrophysics Data System (ADS)

    Chen, Yun; Ratra, Bharat; Biesiada, Marek; Li, Song; Zhu, Zong-Hong

    2016-10-01

    We investigate two dark energy cosmological models (i.e., the ΛCDM and ϕCDM models) with massive neutrinos assuming two different neutrino mass hierarchies in both the spatially flat and non-flat scenarios, where in the ϕCDM model the scalar field possesses an inverse power-law potential, V(ϕ) ∝ ϕ -α (α > 0). Cosmic microwave background data from Planck 2015, baryon acoustic oscillation data from 6dFGS, SDSS-MGS, BOSS-LOWZ and BOSS CMASS-DR11, the joint light-curve analysis compilation of SNe Ia apparent magnitude observations, and the Hubble Space Telescope H 0 prior, are jointly employed to constrain the model parameters. We first determine constraints assuming three species of degenerate massive neutrinos. In the spatially flat (non-flat) ΛCDM model, the sum of neutrino masses is bounded as Σm ν < 0.165(0.299) eV at 95% confidence level (CL). Correspondingly, in the flat (non-flat) ϕCDM model, we find Σm ν < 0.164(0.301) eV at 95% CL. The inclusion of spatial curvature as a free parameter results in a significant broadening of confidence regions for Σm ν and other parameters. In the scenario where the total neutrino mass is dominated by the heaviest neutrino mass eigenstate, we obtain similar conclusions to those obtained in the degenerate neutrino mass scenario. In addition, the results show that the bounds on Σm ν based on two different neutrino mass hierarchies have insignificant differences in the spatially flat case for both the ΛCDM and ϕCDM models; however, the corresponding differences are larger in the non-flat case.

  8. New development in radiative neutrino mass generation

    NASA Astrophysics Data System (ADS)

    Julio

    2014-10-01

    We present a simple and predictive model of radiative neutrino masses. It is a special case of the Zee model with a family-dependent Z4 symmetry acting on the leptons. A variety of predictions follow: The hierarchy of neutrino masses must be inverted; the lightest neutrino mass is extremely small and calculable; one of the neutrino mixing angles is determined in terms of the other two; the phase parameters take CP-conserving values with δCP = π and the effective mass in neutrinoless double beta decay lies in a narrow range, mββ =(17.6-18.5) meV. The ratio of vacuum expectation values of the two Higgs doublets, tan β, is determined to be either 1.9 or 0.19 from neutrino oscillation data. Flavor-conserving and flavor-changing couplings of the Higgs doublets are also determined from neutrino data. The non-standard neutral Higgs bosons, if they are moderately heavy, decay significantly into μ and τ with prescribed branching ratios. Observable rates for the decays μ → eγ and τ → 3μ are predicted if these scalars have masses in the range of 150-500 GeV.

  9. Hierarchical majorana neutrinos from democratic mass matrices

    NASA Astrophysics Data System (ADS)

    Yang, Masaki J. S.

    2016-09-01

    In this paper, we obtain the light neutrino masses and mixings consistent with the experiments, in the democratic texture approach. The essential ansatz is that νRi are assumed to transform as "right-handed fields" 2R +1R under the S3L ×S3R symmetry. The symmetry breaking terms are assumed to be diagonal and hierarchical. This setup only allows the normal hierarchy of the neutrino mass, and excludes both of inverted hierarchical and degenerated neutrinos. Although the neutrino sector has nine free parameters, several predictions are obtained at the leading order. When we neglect the smallest parameters ζν and ζR, all components of the mixing matrix UPMNS are expressed by the masses of light neutrinos and charged leptons. From the consistency between predicted and observed UPMNS, we obtain the lightest neutrino masses m1 = (1.1 → 1.4) meV, and the effective mass for the double beta decay ≃ 4.5 meV.

  10. Neutrino masses and ordering via multimessenger astronomy

    NASA Astrophysics Data System (ADS)

    Langæble, Kasper; Meroni, Aurora; Sannino, Francesco

    2016-09-01

    We define the theoretical framework and deduce the conditions under which multimessenger astronomy can provide useful information about neutrino masses and their ordering. The framework uses time differences between the arrival of neutrinos and the other light messenger, i.e. the graviton, emitted in astrophysical catastrophes. We also provide a preliminary feasibility study elucidating the experimental reach and challenges for planned neutrino detectors such as Hyper-Kamiokande as well as future several-megaton detectors. This study shows that future experiments can be useful in independently testing the cosmological bounds on absolute neutrino masses. Concretely, the success of such measurements depends crucially on the available rate of astrophysical events and further requires development of high resolution timing besides the need for megaton-size detectors.

  11. Measurement of neutrino masses from relative velocities.

    PubMed

    Zhu, Hong-Ming; Pen, Ue-Li; Chen, Xuelei; Inman, Derek; Yu, Yu

    2014-09-26

    We present a new technique to measure neutrino masses using their flow field relative to dark matter. Present day streaming motions of neutrinos relative to dark matter and baryons are several hundred km/s, comparable with their thermal velocity dispersion. This results in a unique dipole anisotropic distortion of the matter-neutrino cross power spectrum, which is observable through the dipole distortion in the cross correlation of different galaxy populations. Such a dipole vanishes if not for this relative velocity and so it is a clean signature for neutrino mass. We estimate the size of this effect and find that current and future galaxy surveys may be sensitive to these signature distortions. PMID:25302878

  12. Neutrino constraints: what large-scale structure and CMB data are telling us?

    NASA Astrophysics Data System (ADS)

    Costanzi, Matteo; Sartoris, Barbara; Viel, Matteo; Borgani, Stefano

    2014-10-01

    We discuss the reliability of neutrino mass constraints, either active or sterile, from the combination of different low redshift Universe probes with measurements of CMB anisotropies. In our analyses we consider WMAP 9-year or Planck Cosmic Microwave Background (CMB) data in combination with Baryonic Acoustic Oscillations (BAO) measurements from BOSS DR11, galaxy shear measurements from CFHTLenS, SDSS Ly α forest constraints and galaxy cluster mass function from Chandra observations. At odds with recent similar studies, to avoid model dependence of the constraints we perform a full likelihood analysis for all the datasets employed. As for the cluster data analysis we rely on to the most recent calibration of massive neutrino effects in the halo mass function and we explore the impact of the uncertainty in the mass bias and re-calibration of the halo mass function due to baryonic feedback processes on cosmological parameters. We find that none of the low redshift probes alone provide evidence for massive neutrino in combination with CMB measurements, while a larger than 2σ detection of non zero neutrino mass, either active or sterile, is achieved combining cluster or shear data with CMB and BAO measurements. Yet, the significance of the detection exceeds 3σ if we combine all four datasets. For a three active neutrino scenario, from the joint analysis of CMB, BAO, shear and cluster data including the uncertainty in the mass bias we obtain ∑ mν =0.29+0.18-0.21 eV and ∑ mν =0.22+0.17-0.18 eV 95%CL) using WMAP9 or Planck as CMB dataset, respectively. The preference for massive neutrino is even larger in the sterile neutrino scenario, for which we get mseff=0.44+0.28-0.26 eV and Δ Neff=0.78+0.60-0.59 95%CL) from the joint analysis of Planck, BAO, shear and cluster datasets. For this data combination the vanilla ΛCDM model is rejected at more than 3σ and a sterile neutrino mass as motivated by accelerator anomaly is within the 2σ errors. Conversely, the Ly

  13. Neutrino constraints: what large-scale structure and CMB data are telling us?

    SciTech Connect

    Costanzi, Matteo; Sartoris, Barbara; Borgani, Stefano; Viel, Matteo E-mail: sartoris@oats.inaf.it E-mail: borgani@oats.inaf.it

    2014-10-01

    We discuss the reliability of neutrino mass constraints, either active or sterile, from the combination of different low redshift Universe probes with measurements of CMB anisotropies. In our analyses we consider WMAP 9-year or Planck Cosmic Microwave Background (CMB) data in combination with Baryonic Acoustic Oscillations (BAO) measurements from BOSS DR11, galaxy shear measurements from CFHTLenS, SDSS Ly α forest constraints and galaxy cluster mass function from Chandra observations. At odds with recent similar studies, to avoid model dependence of the constraints we perform a full likelihood analysis for all the datasets employed. As for the cluster data analysis we rely on to the most recent calibration of massive neutrino effects in the halo mass function and we explore the impact of the uncertainty in the mass bias and re-calibration of the halo mass function due to baryonic feedback processes on cosmological parameters. We find that none of the low redshift probes alone provide evidence for massive neutrino in combination with CMB measurements, while a larger than 2σ detection of non zero neutrino mass, either active or sterile, is achieved combining cluster or shear data with CMB and BAO measurements. Yet, the significance of the detection exceeds 3σ if we combine all four datasets. For a three active neutrino scenario, from the joint analysis of CMB, BAO, shear and cluster data including the uncertainty in the mass bias we obtain ∑ m{sub ν} =0.29{sup +0.18}{sub -0.21} eV and ∑ m{sub ν} =0.22{sup +0.17}{sub -0.18} eV 95%CL) using WMAP9 or Planck as CMB dataset, respectively. The preference for massive neutrino is even larger in the sterile neutrino scenario, for which we get m{sub s}{sup eff}=0.44{sup +0.28}{sub -0.26} eV and Δ N{sub eff}=0.78{sup +0.60}{sub -0.59} 95%CL) from the joint analysis of Planck, BAO, shear and cluster datasets. For this data combination the vanilla ΛCDM model is rejected at more than 3σ and a sterile neutrino mass

  14. Phenomenological relations for neutrino masses and mixing parameters

    SciTech Connect

    Khruschov, V. V.

    2013-11-15

    Phenomenological relations for masses, angles, and CP phases in the neutrino mixing matrix are proposed with allowance for available experimental data. For the case of CP violation in the lepton sector, an analysis of the possible structure of the neutrino mass matrix and a calculation of the neutrino mass features and the Dirac CP phase for the bimodal-neutrino model are performed. The values obtained in this way can be used to interpret and predict the results of various neutrino experiments.

  15. Zero minors of the neutrino mass matrix

    SciTech Connect

    Lashin, E. I.; Chamoun, N.

    2008-10-01

    We examine the possibility that a certain class of neutrino mass matrices, namely, those with two independent vanishing minors in the flavor basis, regardless of being invertible or not, is sufficient to describe current data. We compute generic formulas for the ratios of the neutrino masses and for the Majorana phases. We find that seven textures with two vanishing minors can accommodate the experimental data. We present an estimate of the mass matrix for these patterns. All of the possible textures can be dynamically generated through the seesaw mechanism augmented with a discrete Abelian symmetry.

  16. Evidence for neutrino mass: A decade of discovery

    SciTech Connect

    Heeger, Karsten M.

    2004-12-08

    Neutrino mass and mixing are amongst the major discoveries of recent years. From the observation of flavor change in solar and atmospheric neutrino experiments to the measurements of neutrino mixing with terrestrial neutrinos, recent experiments have provided consistent and compelling evidence for the mixing of massive neutrinos. The discoveries at Super-Kamiokande, SNO, and KamLAND have solved the long-standing solar neutrino problem and demand that we make the first significant revision of the Standard Model in decades. Searches for neutrinoless double-beta decay probe the particle nature of neutrinos and continue to place limits on the effective mass of the neutrino. Possible signs of neutrinoless double-beta decay will stimulate neutrino mass searches in the next decade and beyond. I review the recent discoveries in neutrino physics and the current evidence for massive neutrinos.

  17. Small Neutrino Masses from Supersymmetry Breaking

    SciTech Connect

    Arkani-Hamed, Nima; Hall, Lawrence; Murayama, Hitoshi; Smith, David; Weiner, Neal

    2000-06-27

    An alternative to the conventional see-saw mechanism is proposed to explain the origin of small neutrino masses in supersymmetric theories. The masses and couplings of the right-handed neutrino field are suppressed by supersymmetry breaking, in a way similar to the suppression of the Higgs doublet mass, $\\mu$. New mechanisms for light Majorana, Dirac and sterile neutrinos arise, depending on the degree of suppression. Superpartner phenomenology is greatly altered by the presence of weak scale right-handed sneutrinos, which may have a coupling to a Higgs boson and a left-handed sneutrino. The sneutrino spectrum and couplings are quite unlike the conventional case - the lightest sneutrino can be the dark matter and predictions are given for event rates at upcoming halo dark matter direct detection experiments. Higgs decays and search strategies are changed. Copious Higgs production at hadron colliders can result from cascade decays of squarks and gluinos.

  18. Small neutrino masses and gauge coupling unification

    NASA Astrophysics Data System (ADS)

    Boucenna, Sofiane M.; Fonseca, Renato M.; González-Canales, Félix; Valle, José W. F.

    2015-02-01

    The physics responsible for gauge coupling unification may also induce small neutrino masses. We propose a novel gauge-mediated radiative seesaw mechanism for calculable neutrino masses. These arise from quantum corrections mediated by new S U (3 )C⊗S U (3 )L⊗U (1 )X (3-3-1) gauge bosons and the physics driving gauge coupling unification. Gauge couplings unify for a 3-3-1 scale in the TeV range, making the model directly testable at the LHC.

  19. Neutrinoless double beta decay and neutrino masses

    SciTech Connect

    Duerr, Michael

    2012-07-27

    Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.

  20. Supernova heavy element nucleosynthesis: Can it tell us about neutrino masses?

    SciTech Connect

    Fuller, George M.

    1997-05-20

    Here we describe a new probe of neutrino properties based on heavy element nucleosynthesis. This technique is in many ways akin to the familiar light element Primordial Nucleosynthesis probe of conditions in the early universe. Our new probe is based on the fact that neutrino masses and vacuum mixings can engender matter-enhanced neutrino flavor transformation in the post core bounce supernova environment. Transformations of the type {nu}{sub {mu}}{sub (r)}<-->{nu}{sub e} in this site will have significant effects on the synthesis of the rapid neutron capture (r-Process) elements and the light p-nuclei. We suggest that an understanding of the origin of these nuclides, combined with the measured abundances of these species, may provide a ''Rosetta Stone'' for neutrino properties. Heavy element nucleosynthesis abundance considerations give either constraints/evidence for neutrino masses and flavor mixings, or strong constraints on the site of origin of r-Process nucleosynthesis. The putative limits on neutrino characteristics are complimentary to those derived from laboratory neutrino oscillation studies and solar and atmospheric neutrino experiments. Preliminary studies show that the existence of r-Process nuclei in the abundances observed in the Galaxy cannot be understood unless neutrinos have small masses (possibly in the cosmologically significant range)

  1. Neutrino mass as the probe of intermediate mass scales

    SciTech Connect

    Senjanovic, G.

    1980-01-01

    A discussion of the calculability of neutrino mass is presented. The possibility of neutrinos being either Dirac or Majorana particles is analyzed in detail. Arguments are offered in favor of the Majorana case: the smallness of neutrino mass is linked to the maximality of parity violation in weak interactions. It is shown how the measured value of neutrino mass would probe the existence of an intermediate mass scale, presumably in the TeV region, at which parity is supposed to become a good symmetry. Experimental consequences of the proposed scheme are discussed, in particular the neutrino-less double ..beta.. decay, where observation would provide a crucial test of the model, and rare muon decays such as ..mu.. ..-->.. e..gamma.. and ..mu.. ..-->.. ee anti e. Finally, the embedding of this model in an O(10) grand unified theory is analyzed, with the emphasis on the implications for intermediate mass scales that it offers. It is concluded that the proposed scheme provides a distinct and testable alternative for understanding the smallness of neutrino mass. 4 figures.

  2. Cosmological constraints on neutrino plus axion hot dark matter: update after WMAP-5

    SciTech Connect

    Hannestad, S; Mirizzi, A; Raffelt, G G; Wong, Y Y Y E-mail: amirizzi@mppmu.mpg.de E-mail: ywong@mppmu.mpg.de

    2008-04-15

    We update our previous constraints on two-component hot dark matter (axions and neutrinos), including the recent WMAP five-year data release. Marginalizing over {Sigma}m{sub {nu}} provides m{sub a}<1.02 eV (95% C.L.) for the axion mass. In the absence of axions we find {Sigma}m{sub {nu}}<0.63 eV (95% C.L.)

  3. Strong thermal leptogenesis and the absolute neutrino mass scale

    SciTech Connect

    Bari, Pasquale Di; King, Sophie E.; Fiorentin, Michele Re E-mail: sk1806@soton.ac.uk

    2014-03-01

    We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m{sub 1}∼>10 meV for normal ordering (NO) and m{sub 1}∼>3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |Ω{sub ij}{sup 2}|∼<2. We show analytically why lower values of m{sub 1} require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m{sub 1}. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m{sub 1}. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.

  4. Higgs Boson Mass, Neutrino Oscillations and Inflation

    SciTech Connect

    Shafi, Qaisar

    2008-11-23

    Finding the Standard Model scalar (Higgs) boson is arguably the single most important mission of the LHC. I review predictions for the Higgs boson mass based on stability and perturbativity arguments, taking into account neutrino oscillations. Primordial inflation based on the Coleman-Weinberg potential is briefly discussed.

  5. Neutrino masses, Majorons, and muon decay

    SciTech Connect

    Santamaria, A.; Bernabeu, J.; Pich, A.

    1987-09-01

    The contributions to the parameters xi, delta, rho, and eta in muon decay coming from double Majoron emission, Majorana neutrino masses, and effects of charged scalars are evaluated in the scalar-triplet model. The relevance of these effects for planned experiments is discussed.

  6. Unique forbidden beta decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-28

    The measurement of the electron energy spectrum in single β decays close to the endpoint provides a direct determination of the neutrino masses. The most sensitive experiments use β decays with low Q value, e.g. KATRIN (tritium) and MARE (rhenium). We present the theoretical spectral shape of electrons emitted in the first, second, and fourth unique forbidden β decays. Our findings show that the Kurie functions for these unique forbidden β transitions are linear in the limit of massless neutrinos like the Kurie function of the allowed β decay of tritium.

  7. 11B and constraints on neutrino oscillations and spectra from neutrino nucleosynthesis.

    PubMed

    Austin, Sam M; Heger, Alexander; Tur, Clarisse

    2011-04-15

    We study the sensitivity to variations in the triple-alpha and 12C(α,γ)16O reaction rates, of the yield of the neutrino-process isotopes 7Li, 11B, 19F, 138La, and 180Ta in core-collapse supernovae. Compared to solar abundances, less than 15% of 7Li, about 25%-80% of 19F, and about half of 138La is produced in these stars. Over a range of ±2σ for each helium-burning rate, 11B is overproduced and the yield varies by an amount larger than the variation caused by the effects of neutrino oscillations. The total 11B yield, however, may eventually provide constraints on supernova neutrino spectra. PMID:21568548

  8. 11B and constraints on neutrino oscillations and spectra from neutrino nucleosynthesis.

    PubMed

    Austin, Sam M; Heger, Alexander; Tur, Clarisse

    2011-04-15

    We study the sensitivity to variations in the triple-alpha and 12C(α,γ)16O reaction rates, of the yield of the neutrino-process isotopes 7Li, 11B, 19F, 138La, and 180Ta in core-collapse supernovae. Compared to solar abundances, less than 15% of 7Li, about 25%-80% of 19F, and about half of 138La is produced in these stars. Over a range of ±2σ for each helium-burning rate, 11B is overproduced and the yield varies by an amount larger than the variation caused by the effects of neutrino oscillations. The total 11B yield, however, may eventually provide constraints on supernova neutrino spectra.

  9. Constraints on neutrino-nucleon interactions at energies of 1 EeV with the IceCube Neutrino Observatory

    SciTech Connect

    Yoshida, Shigeru

    2010-11-15

    A search for extremely high energy cosmic neutrinos has been carried out with the IceCube Neutrino Observatory. The main signals in the search are neutrino-induced energetic charged leptons and their rate depends on the neutrino-nucleon cross section. The upper limit on the neutrino flux has implications for possible new physics beyond the standard model such as the extra space-time dimension scenarios which lead to a cross section much higher than the standard particle physics prediction. In this study we constrain the neutrino-nucleon cross section at energies beyond 10{sup 9} GeV with the IceCube observation. The constraints are obtained as a function of the extraterrestrial neutrino flux in the relevant energy range, which accounts for the astrophysical uncertainty of neutrino production models.

  10. Relating neutrino masses to dilepton modes of doubly charged scalars

    SciTech Connect

    Chen, Chian-Shu; Geng, C. Q.

    2010-11-15

    We study a model with Majorana neutrino masses generated through doubly charged scalars at two-loop level. We give explicit relationships between the neutrino masses and the same sign dilepton decays of the doubly charged scalars. In particular, we demonstrate that in the tribimaximal limit of the neutrino mixings, the absolute neutrino masses and Majorana phases can be extracted through the measurements of the dilepton modes at colliders.

  11. QLC relation and neutrino mass hierarchy

    SciTech Connect

    Ferrandis, Javier; Pakvasa, Sandip

    2005-01-27

    Latest measurements have revealed that the deviation from a maximal solar mixing angle is approximately the Cabibbo angle, i.e., QLC relation. We argue that it is not plausible that this deviation from maximality, be it a coincidence or not, comes from the charged lepton mixing. Consequently we have calculated the required corrections to the exactly bimaximal neutrino mass matrix ansatz necessary to account for the solar mass difference and the solar mixing angle. We point out that the relative size of these two corrections depends strongly on the hierarchy case under consideration. We find that the inverted hierarchy case with opposite CP parities, which is known to guarantee the RGE stability of the solar mixing angle, offers the most plausible scenario for a high energy origin of a QLC-corrected bimaximal neutrino mass matrix. This possibility may allow us to explain the QLC relation in connection with the origin of the charged fermion mass matrices.

  12. Right-handed neutrinos at CERN LHC and the mechanism of neutrino mass generation

    SciTech Connect

    Kersten, Joern; Smirnov, Alexei Yu.

    2007-10-01

    We consider the possibility to detect right-handed neutrinos, which are mostly singlets of the standard model gauge group, at future accelerators. Substantial mixing of these neutrinos with the active neutrinos requires a cancellation of different contributions to the light neutrino mass matrix at the level of 10{sup -8}. We discuss possible symmetries behind this cancellation and argue that for three right-handed neutrinos they always lead to conservation of total lepton number. Light neutrino masses can be generated by small perturbations violating these symmetries. In the most general case, LHC physics and the mechanism of neutrino mass generation are essentially decoupled; with additional assumptions, correlations can appear between collider observables and features of the neutrino mass matrix.

  13. Neutrino Mass Bounds from 0{nu}{beta}{beta} Decays and Large Scale Structures

    SciTech Connect

    Keum, Y.-Y.; Ichiki, K.; Kajino, T.

    2008-05-21

    We investigate the way how the total mass sum of neutrinos can be constrained from the neutrinoless double beta decay and cosmological probes with cosmic microwave background (WMAP 3-year results), large scale structures including 2dFGRS and SDSS data sets. First we discuss, in brief, on the current status of neutrino mass bounds from neutrino beta decays and cosmic constrain within the flat {lambda}CMD model. In addition, we explore the interacting neutrino dark-energy model, where the evolution of neutrino masses is determined by quintessence scalar filed, which is responsable for cosmic acceleration today. Assuming the flatness of the universe, the constraint we can derive from the current observation is {sigma}m{sub {nu}}<0.87 eV at the 95% confidence level, which is consistent with {sigma}m{sub {nu}}<0.68 eV in the flat {lambda}CDM model.

  14. Neutrino mass and mixing in the seesaw playground

    NASA Astrophysics Data System (ADS)

    King, Stephen F.

    2016-07-01

    We discuss neutrino mass and mixing in the framework of the classic seesaw mechanism, involving right-handed neutrinos with large Majorana masses, which provides an appealing way to understand the smallness of neutrino masses. However, with many input parameters, the seesaw mechanism is in general not predictive. We focus on natural implementations of the seesaw mechanism, in which large cancellations do not occur, where one of the right-handed neutrinos is dominantly responsible for the atmospheric neutrino mass, while a second right-handed neutrino accounts for the solar neutrino mass, leading to an effective two right-handed neutrino model. We discuss recent attempts to predict lepton mixing and CP violation within such natural frameworks, focusing on the Littlest Seesaw and its distinctive predictions.

  15. Measuring the neutrino mass from future wide galaxy cluster catalogues

    SciTech Connect

    Carbone, Carmelita; Moscardini, Lauro; Cimatti, Andrea; Fedeli, Cosimo E-mail: cosimo.fedeli@astro.ufl.edu E-mail: a.cimatti@unibo.it

    2012-03-01

    We present forecast errors on a wide range of cosmological parameters obtained from a photometric cluster catalogue of a future wide-field Euclid-like survey. We focus in particular on the total neutrino mass as constrained by a combination of the galaxy cluster number counts and correlation function. For the latter we consider only the shape information and the Baryon Acoustic Oscillations (BAO), while marginalising over the spectral amplitude and the redshift space distortions. In addition to the cosmological parameters of the standard ΛCDM+ν model we also consider a non-vanishing curvature, and two parameters describing a redshift evolution for the dark energy equation of state. For completeness, we also marginalise over a set of ''nuisance'' parameters, representing the uncertainties on the cluster mass determination. We find that combining cluster counts with power spectrum information greatly improves the constraining power of each probe taken individually, with errors on cosmological parameters being reduced by up to an order of magnitude. In particular, the best improvements are for the parameters defining the dynamical evolution of dark energy, where cluster counts break degeneracies. Moreover, the resulting error on neutrino mass is at the level of σ(M{sub ν}) ∼ 0.9 eV, comparable with that derived from present Lyα forest measurements and Cosmic Microwave background (CMB) data in the framework of a non-flat Universe. Further adopting Planck priors and reducing the number of free parameters to a ΛCDM+ν cosmology allows to place constraints on the total neutrino mass of σ(M{sub ν}) ∼ 0.08 eV, close to the lower bound enforced by neutrino oscillation experiments. Finally, in the optimistic case where uncertainties in the calibration of the mass-observable relation were so small to be neglected, the combination of Planck priors with cluster counts and power spectrum would constrain the total neutrino mass down to σ(M{sub ν}) ∼ 0.034 eV, i

  16. Generalized mass ordering degeneracy in neutrino oscillation experiments

    NASA Astrophysics Data System (ADS)

    Coloma, Pilar; Schwetz, Thomas

    2016-09-01

    We consider the impact of neutral-current (NC) nonstandard neutrino interactions (NSI) on the determination of the neutrino mass ordering. We show that in the presence of NSI there is an exact degeneracy which makes it impossible to determine the neutrino mass ordering and the octant of the solar mixing angle θ12 at oscillation experiments. The degeneracy holds at the probability level and for arbitrary matter density profiles, and hence solar, atmospheric, reactor, and accelerator neutrino experiments are affected simultaneously. The degeneracy requires order-1 corrections from NSI to the NC electron neutrino-quark interaction and can be tested in electron neutrino NC scattering experiments.

  17. The simplest models of radiative neutrino mass

    NASA Astrophysics Data System (ADS)

    Law, Sandy S. C.; McDonald, Kristian L.

    2014-04-01

    The complexity of radiative neutrino-mass models can be judged by: (i) whether they require the imposition of ad hoc symmetries, (ii) the number of new multiplets they introduce and (iii) the number of arbitrary parameters that appear. Considering models that do not employ new symmetries, the simplest models have two new multiplets and a minimal number of new parameters. With this in mind, we search for the simplest models of radiative neutrino mass. We are led to two models, containing a real scalar triplet and a charged scalar doublet (respectively), in addition to the charged singlet scalar considered by Zee [h+ (1, 1, 2)]. These models are essentially simplified versions of the Zee model and appear to be the simplest models of radiative neutrino mass. However, despite successfully generating nonzero masses, present-day data is sufficient to rule these simple models out. The Zee and Zee-Babu models therefore remain as the simplest viable models. Moving beyond the minimal cases, we find a new model of two-loop masses that employs the charged doublet Φ (1, 2, 3) and the doubly-charged scalar k++ (1, 1, 4). This is the sole remaining model that employs only three new noncolored multiplets.

  18. Updated constraints on non-standard neutrino interactions from Planck

    SciTech Connect

    Archidiacono, Maria; Hannestad, Steen E-mail: sth@phys.au.dk

    2014-07-01

    We provide updated bounds on non-standard neutrino interactions based on data from the Planck satellite as well as auxiliary cosmological measurements. Two types of models are studied - A Fermi-like 4-point interaction and an interaction mediated by a light pseudoscalar - and we show that these two models are representative of models in which neutrinos either decouple or recouple in the early Universe. Current cosmological data constrain the effective 4-point coupling to be G{sub X} ≤ (0.06 GeV){sup -2}, corresponding to G{sub X} ≤ 2.5 × 10{sup 7} G{sub F}. For non-standard pseudoscalar interactions we set a limit on the diagonal elements of the dimensionless coupling matrix, g{sub ij}, of g{sub ii} ≤ 1.2 × 10{sup -7}. For the off-diagonal elements which induce neutrino decay the bound is significantly stronger, corresponding to g{sub ij} ≤ 2.3 × 10{sup -11}(m/0.05 eV){sup -2}, or a lifetime constraint of τ ≥ 1.2 × 10{sup 9} s (m/0.05 eV){sup 3} . This is currently the strongest known bound on this particular type of neutrino decay. We finally note that extremely strong neutrino self-interactions which completely suppress anisotropic stress over all of cosmic history are very highly disfavored by current data Δ χ{sup 2} ∼ 10{sup 4})

  19. Neutrino mass, mixing and discrete symmetries

    NASA Astrophysics Data System (ADS)

    Smirnov, Alexei Y.

    2013-07-01

    Status of the discrete symmetry approach to explanation of the lepton masses and mixing is summarized in view of recent experimental results, in particular, establishing relatively large 1-3 mixing. The lepton mixing can originate from breaking of discrete flavor symmetry Gf to different residual symmetries Gl and Gv in the charged lepton and neutrino sectors. In this framework the symmetry group condition has been derived which allows to get relations between the lepton mixing elements immediately without explicit model building. The condition has been applied to different residual neutrino symmetries Gv. For generic (mass independent) Gv = Z2 the condition leads to two relations between the mixing parameters and fixes one column of the mixing matrix. In the case of Gv = Z2 × Z2 the condition fixes the mixing matrix completely. The non-generic (mass spectrum dependent) Gv lead to relations which include mixing angles, neutrino masses and Majorana phases. The symmetries Gl, Gv, Gf are identified which lead to the experimentally observed values of the mixing angles and allow to predict the CP phase.

  20. Reactor mixing angle from hybrid neutrino masses

    NASA Astrophysics Data System (ADS)

    Sierra, D. Aristizabal; de Medeiros Varzielas, I.

    2014-07-01

    In terms of its eigenvector decomposition, the neutrino mass matrix (in the basis where the charged lepton mass matrix is diagonal) can be understood as originating from a tribimaximal dominant structure with small deviations, as demanded by data. If neutrino masses originate from at least two different mechanisms, referred to as "hybrid neutrino masses", the experimentally observed structure naturally emerges provided one mechanism accounts for the dominant tribimaximal structure while the other is responsible for the deviations. We demonstrate the feasibility of this picture in a fairly model-independent way by using lepton-number-violating effective operators, whose structure we assume becomes dictated by an underlying A 4 flavor symmetry. We show that if a second mechanism is at work, the requirement of generating a reactor angle within its experimental range always fixes the solar and atmospheric angles in agreement with data, in contrast to the case where the deviations are induced by next-to-leading order effective operators. We prove this idea is viable by constructing an A 4-based ultraviolet completion, where the dominant tribimaximal structure arises from the type-I seesaw while the subleading contribution is determined by either type-II or type-III seesaw driven by a non-trivial A 4 singlet (minimal hybrid model). After finding general criteria, we identify all the N symmetries capable of producing such A 4-based minimal hybrid models.

  1. Supersymmetry and the calculation of neutrino masses

    NASA Astrophysics Data System (ADS)

    Aulakh, C. S.; Mohapatra, R. N.

    1983-01-01

    We point out that in a recently proposed supersymmetric extension of the standard SU(2)L X U(1) model where global lepton number symmetry is spontaneously broken, the neutrino masses are computable as a higher order effect and are small, without the need for an accompanying heavy (or superheavy) right-handed neutral lepton. The neutrino masses in this picture are inversely proportional to the scale of supersymmetry breaking and are expected to be in the range of 10-7-10-5 eV for reasonable choice of parameters. Work supported in part by National Science Foundation Grant No. PHY-78-24888 and CUNY-PSC-BHE Faculty Research Award.

  2. Neutrino mass hierarchy and stepwise spectral swapping of supernova neutrino flavors.

    PubMed

    Duan, Huaiyu; Fuller, George M; Carlson, J; Qian, Yong-Zhong

    2007-12-14

    We examine a phenomenon recently predicted by numerical simulations of supernova neutrino flavor evolution: the swapping of supernova nu(e) and nu(mu,tau) energy spectra below (above) energy E(C) for the normal (inverted) neutrino mass hierarchy. We present the results of large-scale numerical calculations which show that in the normal neutrino mass hierarchy case, E(C) decreases as the assumed effective 2x2 vacuum nu(e)<==>nu(mu,tau) mixing angle (approximately theta13) is decreased. In contrast, these calculations indicate that E(C) is essentially independent of the vacuum mixing angle in the inverted neutrino mass hierarchy case. With a good neutrino signal from a future galactic supernova, the above results could be used to determine the neutrino mass hierarchy even if theta13 is too small to be measured by terrestrial neutrino oscillation experiments.

  3. Neutrino mass matrices with one texture zero and a vanishing neutrino mass

    NASA Astrophysics Data System (ADS)

    Gautam, Radha Raman; Singh, Madan; Gupta, Manmohan

    2015-07-01

    Assuming the Majorana nature of neutrinos, we investigate the singular one texture zero neutrino mass matrices in the flavor basis. We find that for the normal mass ordering with m1=0 , all six one texture zero classes are now ruled out at 3 σ confidence level, whereas for inverted mass ordering with m3=0 only four classes out of the six total can accommodate the latest neutrino oscillation data at 3 σ confidence level. Moreover, only two classes can accommodate the present data at 1 σ confidence level. We examine the phenomenological implications of the allowed classes for the effective Majorana mass and Dirac and Majorana C P -violating phases. Working within the framework of the type-I seesaw mechanism, we present simple discrete Abelian symmetry models leading to all the phenomenologically allowed classes.

  4. Measuring neutrino masses with weak lensing

    SciTech Connect

    Wong, Yvonne Y. Y.

    2006-11-17

    Weak gravitational lensing of distant galaxies by large scale structure (LSS) provides an unbiased way to map the matter distribution in the low redshift universe. This technique, based on the measurement of small distortions in the images of the source galaxies induced by the intervening LSS, is expected to become a key cosmological probe in the future. We discuss how future lensing surveys can probe the sum of the neutrino masses at the 0 05 eV level.

  5. Evidence for a tau-neutrino mass

    SciTech Connect

    Samuel, M.A.; Mendel, R.R.

    1988-03-01

    In a recent experiment, the measured lifetime of the tau lepton indicates that the e - ..mu.. universality may not hold in the case of the third-generation leptons. It is shown here that the universality of weak interactions can be restored if the tau-neutrino has a non-zero mass. This results is m/sub v/tau/sub / = (160 +- 70) MeV.

  6. Neutrino mass matrices with two vanishing cofactors and Fritzsch texture for charged lepton mass matrix

    NASA Astrophysics Data System (ADS)

    Wang, Weijian; Guo, Shu-Yuan; Wang, Zhi-Gang

    2016-04-01

    In this paper, we study the cofactor 2 zero neutrino mass matrices with the Fritzsch-type structure in charged lepton mass matrix (CLMM). In the numerical analysis, we perform a scan over the parameter space of all the 15 possible patterns to get a large sample of viable scattering points. Among the 15 possible patterns, three of them can accommodate the latest lepton mixing and neutrino mass data. We compare the predictions of the allowed patterns with their counterparts with diagonal CLMM. In this case, the severe cosmology bound on the neutrino mass set a strong constraint on the parameter space, rendering two patterns only marginally allowed. The Fritzsch-type CLMM will have impact on the viable parameter space and give rise to different phenomenological predictions. Each allowed pattern predicts the strong correlations between physical variables, which is essential for model selection and can be probed in future experiments. It is found that under the no-diagonal CLMM, the cofactor zeros structure in neutrino mass matrix is unstable as the running of renormalization group (RG) from seesaw scale to the electroweak scale. A way out of the problem is to propose the flavor symmetry under the models with a TeV seesaw scale. The inverse seesaw model and a loop-induced model are given as two examples.

  7. Observables sensitive to absolute neutrino masses: A reappraisal after WMAP 3-year and first MINOS results

    SciTech Connect

    Fogli, G. L.; Lisi, E.; Marrone, A.; Melchiorri, A.; Serra, P.; Palazzo, A.; Silk, J.; Slosar, A.

    2007-03-01

    In the light of recent neutrino oscillation and nonoscillation data, we revisit the phenomenological constraints applicable to three observables sensitive to absolute neutrino masses: The effective neutrino mass in single beta decay (m{sub {beta}}); the effective Majorana neutrino mass in neutrinoless double beta decay (m{sub {beta}}{sub {beta}}); and the sum of neutrino masses in cosmology ({sigma}). In particular, we include the constraints coming from the first Main Injector Neutrino Oscillation Search (MINOS) data and from the Wilkinson Microwave Anisotropy Probe (WMAP) three-year (3y) data, as well as other relevant cosmological data and priors. We find that the largest neutrino squared mass difference is determined with a 15% accuracy (at 2{sigma}) after adding MINOS to world data. We also find upper bounds on the sum of neutrino masses {sigma} ranging from {approx}2 eV (WMAP-3y data only) to {approx}0.2 eV (all cosmological data) at 2{sigma}, in agreement with previous studies. In addition, we discuss the connection of such bounds with those placed on the matter power spectrum normalization parameter {sigma}{sub 8}. We show how the partial degeneracy between {sigma} and {sigma}{sub 8} in WMAP-3y data is broken by adding further cosmological data, and how the overall preference of such data for relatively high values of {sigma}{sub 8} pushes the upper bound of {sigma} in the sub-eV range. Finally, for various combination of data sets, we revisit the (in)compatibility between current {sigma} and m{sub {beta}}{sub {beta}} constraints (and claims), and derive quantitative predictions for future single and double beta decay experiments.

  8. Cosmology of mass-varying neutrinos driven by quintessence: Theory and observations

    SciTech Connect

    Brookfield, A.W.; Bruck, C. van de; Mota, D.F.; Tocchini-Valentini, D.

    2006-04-15

    The effects of mass-varying neutrinos on cosmic microwave background (CMB) anisotropies and large scale structures (LSS) are studied. In these models, dark energy and neutrinos are coupled such that the neutrino masses are functions of the scalar field playing the role of dark energy. We begin by describing the cosmological background evolution of such a system. It is pointed out that, similar to models with a dark matter/dark energy interaction, the apparent equation of state measured with SNIa can be smaller than -1. We then discuss the effect of mass-varying neutrinos on the CMB anisotropies and the matter power spectrum. A suppression of power in the CMB power spectrum at large angular scales is usually observed. We give an explanation for this behavior and discuss different couplings and quintessence potentials to show the generality of the results obtained. We perform a likelihood analysis using wide-ranging SNIa, CMB, and LSS observations to assess whether such theories are viable. Treating the neutrino mass as a free parameter we find that the constraints on the coupling are weak, since CMB and LSS surveys give only upper bounds on the neutrino mass. However, fixing a priori the neutrino masses, we find that there is some evidence that the existence of such a coupling is actually preferred by current cosmological data over the standard {lambda}CDM cosmology.

  9. Status of the neutrino mass experiment KATRIN

    SciTech Connect

    Bornschein, L.; Bornschein, B.; Sturm, M.; Roellig, M.; Priester, F.

    2015-03-15

    The most sensitive way to determine the neutrino mass scale without further assumptions is to measure the shape of a tritium beta spectrum near its kinematic end-point. Tritium is the nucleus of choice because of its low endpoint energy, superallowed decay and simple atomic structure. Within an international collaboration the Karlsruhe Tritium Neutrino experiment (KATRIN) is currently being built up at KIT. KATRIN will allow a model-independent measurement of the neutrino mass scale with an expected sensitivity of 0.2 eV/c{sup 2} (90% CL). KATRIN will use a source of ultrapure molecular tritium. This contribution presents the status of the KATRIN experiment, thereby focusing on its Calibration and Monitoring System (CMS), which is the last component being subject to research/development. After a brief overview of the KATRIN experiment in Section II the CMS is introduced in Section III. In Section IV the Beta Induced X-Ray Spectroscopy (BIXS) as method of choice to monitor the tritium activity of the KATRIN source is described and first results are presented.

  10. Implications of results of neutrino mass experiments

    SciTech Connect

    McKellar, B.H.; Garbutt, M.

    2000-10-01

    The long standing negative (mass){sup 2} anomaly encountered in attempts to measure the mass of the electron neutrino may be an indication of physics beyond the standard model. It is demonstrated that an additional charged current interaction which is not of V--A form, and which is at least an order of magnitude weaker than the standard model charged current interaction, will produce a spectrum, which, if fitted by the standard model, may give a negative value for m{sub {nu}}{sup 2}. A possible physical explanation of the time dependent effects seen by the Troitsk experiment is also provided.

  11. The one loop corrections to the neutrino masses in BLMSSM

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Min; Feng, Tai-Fu; Dong, Xing-Xing; Zhang, Hai-Bin; Ning, Guo-Zhu; Guo, Tao

    2016-09-01

    The neutrino masses and mixings are studied in the model which is the supersymmetric extension of the standard model with local gauged baryon and lepton numbers (BLMSSM). At tree level the neutrinos can obtain tiny masses through the See-Saw mechanism in the BLMSSM. The one-loop corrections to the neutrino masses and mixings are important, and they are studied in this work with the mass insertion approximation. We study the numerical results and discuss the allowed parameter space of BLMSSM. It can contribute to study the neutrino masses and to explore the new physics beyond the standard model (SM).

  12. Neutrinos

    PubMed Central

    Besson, Dave; Cowen, Doug; Selen, Mats; Wiebusch, Christopher

    1999-01-01

    Neutrinos represent a new “window” to the Universe, spanning a large range of energy. We discuss the science of neutrino astrophysics and focus on two energy regimes. At “lower” energies (≈1 MeV), studies of neutrinos born inside the sun, or produced in interactions of cosmic rays with the atmosphere, have allowed the first incontrovertible evidence that neutrinos have mass. At energies typically one thousand to one million times higher, sources further than the sun (both within the Milky Way and beyond) are expected to produce a flux of particles that can be detected only through neutrinos. PMID:10588680

  13. Bbn Constraints on Neutrino Oscillations Parameters Relaxed or Strengthened

    NASA Astrophysics Data System (ADS)

    Kirilova, Daniela

    Big Bang Nucleosynthesis (BBN) with nonequilibrium νe ↔ νs oscillations, in the more general case of non-zero population of νs before oscillations δNs ≠ 0, is discussed. 4He primordial production Yp(δNs) in the presence of νe ↔ νs oscillations for different initial populations of the sterile neutrino state 0 ≤ δ Ns ≤ 1 and the full range of oscillation parameters is calculated. Non-zero δNs has a two-fold effect on 4He: (i) it enhances the energy density and hence increases the cosmic expansion rate, leading to Yp overproduction, and (ii) it suppresses the kinetic effects of oscillations on BBN, namely, the effects on pre-BBN nucleon kinetics, caused by the νe energy spectrum distortion and the ν e - bar {ν }e asymmetry generation by oscillations, leading to decreased Yp production. Depending on oscillation parameters one or the other effect may dominate, causing, correspondingly, either a relaxation of the cosmological constraints or their strengthening with the increase of δNs. More general BBN constraints on νe ↔ νs oscillation parameters, corresponding to 3% Yp overproduction, for different initial populations of the sterile state are calculated. Previous BBN constraints were derived assuming empty sterile state before oscillations. It is shown that the cosmological constraints strengthen with the increase of δNs value, the change being more considerable for nonresonant oscillations.

  14. Near maximal atmospheric neutrino mixing in neutrino mass models with two texture zeros

    NASA Astrophysics Data System (ADS)

    Dev, S.; Gautam, R. R.; Singh, Lal; Gupta, Manmohan

    2014-07-01

    The implications of a large value of the effective Majorana neutrino mass for a class of two texture zero neutrino mass matrices have been studied in the flavor basis. It is found that these textures predict a near maximal atmospheric neutrino mixing angle in the limit of a large effective Majorana neutrino mass. It is noted that this prediction is independent of the values of solar and reactor neutrino mixing angles. We present the symmetry realization of these textures using the discrete cyclic group Z3. It is found that the texture zeros realized in this work remain stable under renormalization group running of the neutrino mass matrix from the seesaw scale to the electroweak scale, at one-loop level.

  15. New neutrino mass sum rule from the inverse seesaw mechanism

    NASA Astrophysics Data System (ADS)

    Dorame, L.; Morisi, S.; Peinado, E.; Valle, J. W. F.; Rojas, Alma D.

    2012-09-01

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum rules. One of these implies a lower bound on the effective neutrinoless double beta mass parameter, even for normal hierarchy neutrinos. Here we propose a new model based on the S4 flavor symmetry that leads to the new neutrino mass sum rule and discuss how to generate a nonzero value for the reactor angle θ13 indicated by recent experiments, and the resulting correlation with the solar angle θ12.

  16. IceCube constraints on fast-spinning pulsars as high-energy neutrino sources

    NASA Astrophysics Data System (ADS)

    Fang, Ke; Kotera, Kumiko; Murase, Kohta; Olinto, Angela V.

    2016-04-01

    Relativistic winds of fast-spinning pulsars have been proposed as a potential site for cosmic-ray acceleration from very high energies (VHE) to ultrahigh energies (UHE). We re-examine conditions for high-energy neutrino production, considering the interaction of accelerated particles with baryons of the expanding supernova ejecta and the radiation fields in the wind nebula. We make use of the current IceCube sensitivity in diffusive high-energy neutrino background, in order to constrain the parameter space of the most extreme neutron stars as sources of VHE and UHE cosmic rays. We demonstrate that the current non-observation of 1018 eV neutrinos put stringent constraints on the pulsar scenario. For a given model, birthrates, ejecta mass and acceleration efficiency of the magnetar sources can be constrained. When we assume a proton cosmic ray composition and spherical supernovae ejecta, we find that the IceCube limits almost exclude their significant contribution to the observed UHE cosmic-ray flux. Furthermore, we consider scenarios where a fraction of cosmic rays can escape from jet-like structures piercing the ejecta, without significant interactions. Such scenarios would enable the production of UHE cosmic rays and help remove the tension between their EeV neutrino production and the observational data.

  17. Neutrino flavor pendulum in both mass hierarchies

    NASA Astrophysics Data System (ADS)

    Raffelt, Georg; Seixas, David de Sousa

    2013-08-01

    We construct a simple example for self-induced flavor conversion in dense neutrino gases, showing new solutions that violate the symmetries of initial conditions. Our system consists of two opposite momentum modes 1 and 2, each initially occupied with equal densities of νe and ν¯e. Restricting solutions to symmetry under 1↔2 allows for the usual bimodal instability (“flavor pendulum”) in the inverted neutrino mass hierarchy and stability (no self-induced flavor conversion) in the normal hierarchy (NH). Lifting this symmetry restriction allows for a second pendulumlike solution that occurs in NH, where the modes 1 and 2 swing in opposite directions in flavor space. Any small deviation from 1-2 symmetry in the initial condition triggers the new instability in NH. This effect corresponds to the recently identified multi-azimuth angle instability of supernova neutrino fluxes. Both cases show explicitly that solutions of the equations of collective flavor oscillations need not inherit the symmetries of initial conditions, although this has been universally assumed.

  18. Neutrino mass and oscillation in matter and in cosmology

    NASA Astrophysics Data System (ADS)

    Song, Liguo

    2004-11-01

    With improved Z-Burst model for the new cosmology and reasonable distribution of the neutrino cosmic ray sources, the signatures of the Z-Burst absorption dip and the contributing parameters are investigated through numerical calculations. From the results of the numerical calculations, it is learned that the source distribution and the neutrino mass spectrum will be the major contributing parameters for the Z-Burst absorption dip. Also, only Z-Burst absorption dip will not be able to offer enough information for to establish the structure of the neutrino mass spectrum. The heavy neutrino mass of a few 10-1 eV supported by the four- neutrino model and the LSND mass gap is essential for the detection of the Z-Burst absorption dip. The evidence against the (2+2) neutrino model, especially the Sum Rule, is investigated. Through numerical calculations, it is shown that the small mixing angles, especially ɛμμ and ɛμe with the assistance of the MSW matter effect can significantly weaken the Sum Rule. This result casts doubts on the conclusions of the global experiment data fitting, in which two of the small mixing angles ɛμe and ɛ ee are set to zero. With the future extremely high-energy neutrino cosmic ray detectors and the improvement in the neutrino oscillation experiments, the full establishment of the neutrino mass spectrum with the absolute neutrino mass could be achieved in the this decade.

  19. Neutrinos in the early universe

    NASA Astrophysics Data System (ADS)

    Kirilova, D.; Frere, J.-M.

    2012-12-01

    The neutrinos from the Big Bang or the Cosmic Neutrino Background (CNB) carry precious information from the early epoch when our universe was only 1 s old. Although not yet directly detected, CNB may be revealed indirectly through cosmological observations due to neutrino important cosmological influence. We review the cosmological role of neutrinos and the cosmological constraints on neutrino characteristics. Namely, we discuss the impact of neutrinos in the early universe: the cosmic expansion, neutrino decoupling, the role of neutrinos in the primordial production of light elements, leptogenesis, etc. We briefly discuss the role of neutrino at later stages of the universe. Due to the considerable cosmological influence of neutrinos, cosmological bounds on neutrino properties from observational data exist. We review the cosmological constraints on the effective number of neutrino species, neutrino mass and mixing parameters, lepton number of the universe, presence of sterile neutrino, etc.

  20. Neutrino Masses Beyond the Tree Level

    NASA Astrophysics Data System (ADS)

    Aristizabal Sierra, D.

    2012-07-01

    Models for Majorana neutrino masses can be classified according to the level in perturbation theory at which the effective dimension five operator LLHH is realized. The possibilities range from the tree-level up to the three-loop level realizations. We discuss some general aspects of this approach and speculate about a model independent classification of the possible cases. Among all the realizations, those in which the effective operator is induced by radiative corrections open the possibility for lepton number violation near—or at—the electroweak scale. We discuss some phenomenological aspects of two generic realizations: the Babu-Zee model and supersymmetric models with bilinear R-parity violation.

  1. Sterile neutrinos with eV masses in cosmology — How disfavoured exactly?

    SciTech Connect

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.; Wong, Yvonne Y.Y. E-mail: sth@phys.au.dk E-mail: yvonne.wong@physik.rwth-aachen.de

    2011-09-01

    We study cosmological models that contain sterile neutrinos with eV-range masses as suggested by reactor and short-baseline oscillation data. We confront these models with both precision cosmological data (probing the CMB decoupling epoch) and light-element abundances (probing the BBN epoch). In the minimal ΛCDM model, such sterile neutrinos are strongly disfavoured by current data because they contribute too much hot dark matter. However, if the cosmological framework is extended to include also additional relativistic degrees of freedom beyond the three standard neutrinos and the putative sterile neutrinos, then the hot dark matter constraint on the sterile states is considerably relaxed. A further improvement is achieved by allowing a dark energy equation of state parameter w < −1. While BBN strongly disfavours extra radiation beyond the assumed eV-mass sterile neutrino, this constraint can be circumvented by a small ν{sub e} degeneracy. Any model containing eV-mass sterile neutrinos implies also strong modifications of other cosmological parameters. Notably, the inferred cold dark matter density can shift up by 20–75% relative to the standard ΛCDM value.

  2. Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO

    SciTech Connect

    Lu, Jia-Shu; Cao, Jun; Li, Yu-Feng; Zhou, Shun

    2015-05-26

    A high-statistics measurement of the neutrinos from a galactic core-collapse supernova is extremely important for understanding the explosion mechanism, and studying the intrinsic properties of neutrinos themselves. In this paper, we explore the possibility to constrain the absolute scale of neutrino masses m{sub ν} via the detection of galactic supernova neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO) with a 20 kiloton liquid-scintillator detector. In assumption of a nearly-degenerate neutrino mass spectrum and a normal mass ordering, the upper bound on the absolute neutrino mass is found to be m{sub ν}<(0.83±0.24) eV at the 95% confidence level for a typical galactic supernova at a distance of 10 kpc, where the mean value and standard deviation are shown to account for statistical fluctuations. For comparison, we find that the bound in the Super-Kamiokande experiment is m{sub ν}<(0.94±0.28) eV at the same confidence level. However, the upper bound will be relaxed when the model parameters characterizing the time structure of supernova neutrino fluxes are not exactly known, and when the neutrino mass ordering is inverted.

  3. Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO

    SciTech Connect

    Lu, Jia-Shu; Cao, Jun; Li, Yu-Feng; Zhou, Shun E-mail: caoj@ihep.ac.cn E-mail: zhoush@ihep.ac.cn

    2015-05-01

    A high-statistics measurement of the neutrinos from a galactic core-collapse supernova is extremely important for understanding the explosion mechanism, and studying the intrinsic properties of neutrinos themselves. In this paper, we explore the possibility to constrain the absolute scale of neutrino masses m{sub ν} via the detection of galactic supernova neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO) with a 20 kiloton liquid-scintillator detector. In assumption of a nearly-degenerate neutrino mass spectrum and a normal mass ordering, the upper bound on the absolute neutrino mass is found to be m{sub ν} < (0.83 ± 0.24) eV at the 95% confidence level for a typical galactic supernova at a distance of 10 kpc, where the mean value and standard deviation are shown to account for statistical fluctuations. For comparison, we find that the bound in the Super-Kamiokande experiment is m{sub ν} < (0.94 ± 0.28) eV at the same confidence level. However, the upper bound will be relaxed when the model parameters characterizing the time structure of supernova neutrino fluxes are not exactly known, and when the neutrino mass ordering is inverted.

  4. Electroweak absolute, meta-, and thermal stability in neutrino mass models

    NASA Astrophysics Data System (ADS)

    Lindner, Manfred; Patel, Hiren H.; Radovčić, Branimir

    2016-04-01

    We analyze the stability of the electroweak vacuum in neutrino mass models containing right-handed neutrinos or fermionic isotriplets. In addition to considering absolute stability, we place limits on the Yukawa couplings of new fermions based on metastability and thermal stability in the early Universe. Our results reveal that the upper limits on the neutrino Yukawa couplings can change significantly when the top quark mass is allowed to vary within the experimental range of uncertainty in its determination.

  5. DESI and other Dark Energy experiments in the era of neutrino mass measurements

    SciTech Connect

    Font-Ribera, Andreu; McDonald, Patrick; Mostek, Nick; Reid, Beth A.; Seo, Hee-Jong; Slosar, Anže E-mail: PVMcDonald@lbl.gov E-mail: BAReid@lbl.gov E-mail: anze@bnl.gov

    2014-05-01

    We present Fisher matrix projections for future cosmological parameter measurements, including neutrino masses, Dark Energy, curvature, modified gravity, the inflationary perturbation spectrum, non-Gaussianity, and dark radiation. We focus on DESI and generally redshift surveys (BOSS, HETDEX, eBOSS, Euclid, and WFIRST), but also include CMB (Planck) and weak gravitational lensing (DES and LSST) constraints. The goal is to present a consistent set of projections, for concrete experiments, which are otherwise scattered throughout many papers and proposals. We include neutrino mass as a free parameter in most projections, as it will inevitably be relevant — DESI and other experiments can measure the sum of neutrino masses to ∼ 0.02 eV or better, while the minimum possible sum is ∼ 0.06 eV. We note that constraints on Dark Energy are significantly degraded by the presence of neutrino mass uncertainty, especially when using galaxy clustering only as a probe of the BAO distance scale (because this introduces additional uncertainty in the background evolution after the CMB epoch). Using broadband galaxy power becomes relatively more powerful, and bigger gains are achieved by combining lensing survey constraints with redshift survey constraints. We do not try to be especially innovative, e.g., with complex treatments of potential systematic errors — these projections are intended as a straightforward baseline for comparison to more detailed analyses.

  6. Astrophysics and cosmology closing in on neutrino masses

    NASA Technical Reports Server (NTRS)

    Dar, Arnon

    1990-01-01

    Massive neutrinos are expected in most grand unified theories that attempt to unify the strong and electroweak interactions. So far, heroic laboratory experiments have yielded only upper bounds on the masses of the elusive neutrinos. These bounds, however, are not very restrictive and cannot even exclude the possibility that the dark matter in the universe consists of neutrinos. The astrophysical and cosmological bounds on the masses of the muon and tau neutrinos, m(nu sub mu) and m(nu sub tau), which already are much more restrictive than the laboratory bounds, and the laboratory bound on the mass of the electron neutrino, m(nu sub e) can be improved significantly by future astrophysical and cosmological observations that perhaps will pin down the neutrino masses. Indeed, the recent results from the solar neutrino experiments combined with the seesaw mechanism for generating neutrino masses suggest that m(nu sub e) of about 10 to the -8th electron volts, m(nu sub mu) of about 0.001 electron volts, and m(nu sub tau) of about 10 electron volts, which can be tested in the near future by solar neutrino and accelerator experiments.

  7. Prospects for cosmic neutrino detection in tritium experiments in the case of hierarchical neutrino masses

    SciTech Connect

    Blennow, Mattias

    2008-06-01

    We discuss the effects of neutrino mixing and the neutrino mass hierarchy when considering the capture of the cosmic neutrino background (CNB) on radioactive nuclei. The implications of mixing and hierarchy at future generations of tritium decay experiments are considered. We find that the CNB should be detectable at these experiments provided that the resolution for the kinetic energy of the outgoing electron can be pushed to a few 0.01 eV for the scenario with inverted neutrino mass hierarchy, about an order of magnitude better than that of the upcoming KATRIN experiment. Another order of magnitude improvement is needed in the case of normal neutrino mass hierarchy. We also note that mixing effects generally make the prospects for CNB detection worse due to an increased maximum energy of the normal beta decay background.

  8. Flavor structure in D-brane models: Majorana neutrino masses

    NASA Astrophysics Data System (ADS)

    Hamada, Yuta; Kobayashi, Tatsuo; Uemura, Shohei

    2014-05-01

    We study the flavor structure in intersecting D-brane models. We study anomalies of the discrete flavor symmetries. We analyze the Majorana neutrino masses, which can be generated by D-brane instanton effects. It is found that a certain pattern of mass matrix is obtained and the cyclic permutation symmetry remains unbroken. As a result, trimaximal mixing matrix can be realized if Dirac neutrino mass and charged lepton mass matrices are diagonal.

  9. Active and sterile neutrino mass effects on beta decay spectra

    SciTech Connect

    Boillos, Juan Manuel; Moya de Guerra, Elvira

    2013-06-10

    We study the spectra of the emitted charged leptons in charge current weak nuclear processes to analyze the effect of neutrino masses. Standard active neutrinos are studied here, with masses of the order of 1 eV or lower, as well as sterile neutrinos with masses of a few keV. The latter are warm dark matter (WDM) candidates hypothetically produced or captured as small mixtures with the active neutrinos. We compute differential decay or capture rates spectra in weak charged processes of different nuclei ({sup 3}H, {sup 187}Re, {sup 107}Pd, {sup 163}Ho, etc) using different masses of both active and sterile neutrinos and different values of the mixing parameter.

  10. Prospects for Measurement of the Neutrino Mass Hierarchy

    NASA Astrophysics Data System (ADS)

    Patterson, R. B.

    2015-10-01

    The unknown neutrino mass hierarchy—whether the ν3 mass eigenstate is the heaviest or the lightest—represents a major gap in our knowledge of neutrino properties. Determining the hierarchy is a critical step toward further precision measurements in the neutrino sector. The hierarchy is also central to interpreting the next generation of neutrinoless double-β decay results, plays a role in numerous cosmological and astrophysical questions, and serves as a powerful model discriminant for theories of neutrino mass generation and unification. Various current and planned experiments claim sensitivity for establishing the neutrino mass hierarchy. I review the most promising of these here, paying special attention to points of concern and consolidating the projected sensitivities into an outlook for the years ahead.

  11. The extended ROSAT-ESO Flux-Limited X-ray Galaxy Cluster Survey (REFLEX II). VI. Effect of massive neutrinos on the cosmological constraints from clusters

    NASA Astrophysics Data System (ADS)

    Böhringer, Hans; Chon, Gayoung

    2015-02-01

    Clusters of galaxies are important probes for the large-scale structure that allow us to test cosmological models. With the REFLEX II galaxy cluster survey we previously derived tight constraints on the cosmological parameters for the matter density, Ωm, and the amplitude parameter of the matter density fluctuations, σ8. Whereas in these previous studies no effect of massive neutrinos was taken into account, we explore these effects in the present publication. We derive cosmological constraints for the sum of the neutrino masses of the conventional three neutrino families in the range Mν = ∑ imνi = 0 to 0.6 eV. The influence on the constraints of Ωm and σ8 for the expected mass range is weak. Interesting constraints on the neutrino properties can be derived by comparing the cluster data with those from the Planck cosmic microwave background observations. The current tension between the Planck results and clusters can formally be resolved with neutrino masses of about Mν = 0.45(±0.28,1σ) eV. While we caution not to consider this a firm measurement because it might also be the result of unresolved systematics, it is interesting that other measurements of the local large-scale structure fluctuation amplitude, like that of cosmic lensing shear, yield similar results and additionally confirm the effect of massive neutrinos. Among the indicators for massive neutrinos, galaxy clusters and in particular our large and well-controlled cluster survey currently provide the best potential for constraints of the total neutrino mass.

  12. Status and implications of neutrino masses: A brief panorama

    NASA Astrophysics Data System (ADS)

    Valle, José W. F.

    2015-04-01

    With the historic discovery of the Higgs boson our picture of particle physics would have been complete were it not for the neutrino sector and cosmology. I briefly discuss the role of neutrino masses and mixing upon gauge coupling unification, electroweak breaking and the flavor sector. Time is ripe for new discoveries such as leptonic CP violation, charged lepton flavor violation and neutrinoless double beta decay. Neutrinos could also play a role in elucidating the nature of dark matter and cosmic inflation.

  13. Status and Implications of Neutrino Masses: A Brief Panorama

    NASA Astrophysics Data System (ADS)

    Valle, José W. F.

    With the historic discovery of the Higgs boson our picture of particle physics would have been complete were it not for the neutrino sector and cosmology. I briefly discuss the role of neutrino masses and mixing upon gauge coupling unification, electroweak breaking and the flavor sector. Time is ripe for new discoveries such as leptonic CP violation, charged lepton flavor violation and neutrinoless double beta decay. Neutrinos could also play a role in elucidating the nature of dark matter and cosmic inflation.

  14. Neutrino mass and invisible Higgs decays at the LHC

    NASA Astrophysics Data System (ADS)

    Bonilla, Cesar; Romão, Jorge C.; Valle, José W. F.

    2015-06-01

    The discovery of the Higgs boson suggests that neutrinos also get their mass from spontaneous symmetry breaking. In the simplest ungauged lepton-number scheme, the Standard Model Higgs now has two other partners: a massive C P -even scalar, and the massless Nambu-Goldstone boson, called the Majoron. For weak-scale breaking of lepton number the invisible decays of the C P -even Higgs bosons to the Majoron lead to potentially copious sources of events with large missing energy. Using LHC results, we study how the constraints on invisible decays of the Higgs boson restrict the relevant parameters, substantially extending those previously derived from LEP and potentially shedding light on the scale of spontaneous lepton-number violation.

  15. Simple neutrino mass matrix with only two free parameters

    NASA Astrophysics Data System (ADS)

    Nishiura, Hiroyuki; Fukuyama, Takeshi

    2014-09-01

    A simple form of neutrino mass matrix which has only two free parameters is proposed from a phenomenological point of view. Using this mass matrix, we succeed to reproduce all the observed values for the Maki-Nakagawa-Sakata (MNS) lepton mixing angles and the neutrino mass squared difference ratio. Our model also predicts δν = 155° for the Dirac CP violating phase in the lepton sector and the effective neutrino mass = 6.3×10-3eV in the neutrinoless double beta decay.

  16. Statistical Evaluation of Experimental Determinations of Neutrino Mass Hierarchy

    SciTech Connect

    X. Qian, A. Tan, W. Wang, J. J. Ling, R. D. McKeown, C. Zhang

    2012-12-01

    Statistical methods of presenting experimental results in constraining the neutrino mass hierarchy (MH) are discussed. Two problems are considered and are related to each other: how to report the findings for observed experimental data, and how to evaluate the ability of a future experiment to determine the neutrino mass hierarchy, namely, sensitivity of the experiment. For the first problem where experimental data have already been observed, the classical statistical analysis involves constructing confidence intervals for the parameter {Delta}m{sup 2}{sub 32}. These intervals are deduced from the parent distribution of the estimation of {Delta}m{sup 2}{sub 32} based on experimental data. Due to existing experimental constraints on |{Delta}m{sup 2}{sub 32}|, the estimation of {Delta}m{sup 2}{sub 32} is better approximated by a Bernoulli distribution (a Binomial distribution with 1 trial) rather than a Gaussian distribution. Therefore, the Feldman-Cousins approach needs to be used instead of the Gaussian approximation in constructing confidence intervals. Furthermore, as a result of the definition of confidence intervals, even if it is correctly constructed, its confidence level does not directly reflect how much one hypothesis of the MH is supported by the data rather than the other hypothesis. We thus describe a Bayesian approach that quantifies the evidence provided by the observed experimental data through the (posterior) probability that either one hypothesis of MH is true. This Bayesian presentation of observed experimental results is then used to develop several metrics to assess the sensitivity of future experiments. Illustrations are made using a simple example with a confined parameter space, which approximates the MH determination problem with experimental constraints on the |{Delta}m{sup 2}{sub 32}|.

  17. Statistical evaluation of experimental determinations of neutrino mass hierarchy

    NASA Astrophysics Data System (ADS)

    Qian, X.; Tan, A.; Wang, W.; Ling, J. J.; McKeown, R. D.; Zhang, C.

    2012-12-01

    Statistical methods of presenting experimental results in constraining the neutrino mass hierarchy (MH) are discussed. Two problems are considered and are related to each other: how to report the findings for observed experimental data and how to evaluate the ability of a future experiment to determine the neutrino mass hierarchy, namely, the sensitivity of the experiment. For the first problem where experimental data have already been observed, the classical statistical analysis involves constructing confidence intervals for the parameter Δm322. These intervals are deduced from the parent distribution of the estimation of Δm322 based on experimental data. Because of existing experimental constraints on |Δm322|, the estimation of Δm322 is better approximated by a Bernoulli distribution (a binomial distribution with one trial) rather than a Gaussian distribution. Therefore, the Feldman-Cousins approach needs to be used instead of the Gaussian approximation in constructing confidence intervals. Furthermore, as a result of the definition of confidence intervals, even if it is correctly constructed, its confidence level does not directly reflect how much one hypothesis of the MH is supported by the data rather than the other hypothesis. We thus describe a Bayesian approach that quantifies the evidence provided by the observed experimental data through the (posterior) probability that either hypothesis of MH is true. This Bayesian presentation of observed experimental results is then used to develop several metrics to assess the sensitivity of future experiments. Illustrations are made by using a simple example with a confined parameter space, which approximates the MH determination problem with experimental constraints on the |Δm322|.

  18. Neutrino mass limits: Robust information from the power spectrum of galaxy surveys

    NASA Astrophysics Data System (ADS)

    Cuesta, Antonio J.; Niro, Viviana; Verde, Licia

    2016-09-01

    We present cosmological upper limits on the sum of active neutrino masses using large-scale power spectrum data from the WiggleZ Dark Energy Survey and from the Sloan Digital Sky Survey - Data Release 7 (SDSS-DR7) sample of Luminous Red Galaxies (LRG). Combining measurements on the Cosmic Microwave Background temperature and polarisation anisotropies by the Planck satellite together with WiggleZ power spectrum results in a neutrino mass bound of 0.37 eV at 95% C.L., while replacing WiggleZ by the SDSS-DR7 LRG power spectrum, the 95% C.L. bound on the sum of neutrino masses is 0.38 eV. Adding Baryon Acoustic Oscillation (BAO) distance scale measurements, the neutrino mass upper limits greatly improve, since BAO data break degeneracies in parameter space. Within a ΛCDM model, we find an upper limit of 0.13 eV (0.14 eV) at 95% C.L., when using SDSS-DR7 LRG (WiggleZ) together with BAO and Planck. The addition of BAO data makes the neutrino mass upper limit robust, showing only a weak dependence on the power spectrum used. We also quantify the dependence of neutrino mass limit reported here on the CMB lensing information. The tighter upper limit (0.13 eV) obtained with SDSS-DR7 LRG is very close to that recently obtained using Lyman-alpha clustering data, yet uses a completely different probe and redshift range, further supporting the robustness of the constraint. This constraint puts under some pressure the inverted mass hierarchy and favours the normal hierarchy.

  19. Can electron capture tell us the mass of the neutrino?

    NASA Astrophysics Data System (ADS)

    Faessler, Amand; Šimkovic, F.

    2016-04-01

    The neutrino masses are one of the most important open problems in particle physics. Presently major efforts are underway to measure the electron antineutrino-mass by the triton beta decay [1] and the effective Majorana neutrino mass by the double beta decay [2]. The best way to determine the neutrino mass by electron capture was assumed to be in {}163{Ho}. The total decay energy of the excited daughter atom has for all excitations the same upper energy limit of the Q-value minus the mass of the electron neutrino. Recently Robertson [3] claimed, that the excitation of the two-hole states makes the determination of the neutrino mass by this method practically impossible. But Faessler and Simkovic [4] showed, that the influence of the two-hole states is less than 1% near the Q-value, the area relevant for the determination of the neutrino mass. Even weaker are the contributions of the three-hole states [5]. The upper end of the calorimetric deexcitation spectrum of Dy is dominated by the highest energy one-hole resonance. With a Lorentzian profile of this resonance one has to fit after including the experimental sensitivity four parameters: (1) the neutrino mass, (2) the Q-value, (3) the width of the resonance and (4) its strength. This contribution discusses the problems of the determination of the neutrino mass by electron capture in {}163{Ho}. The conclusion of this work is, that the determination of the electron neutrino mass by electron capture in {}163{Ho} is difficult, but (probably) not impossible.

  20. Majorana equations and the rest mass of neutrinos

    SciTech Connect

    von Borzeszkowski, H.; Treder, H.

    1985-02-01

    As is well known, the law of parity conservation does not hold in weak interactions. This type of asymmetry created a number of theoretical problems which were solved, first of all, by a new understanding of the features of neutrinos and their role in weak interactions. These solutions were based, however, essentially on the handedness (chirality) of neutrinos which is closely related to their vanishing rest mass. The thesis of neutrinos with nonvanishing rest mass, newly considered in the literature, therefore requires a rediscussion of the early arguments concerning the relation between the neutrino theory and some weak interaction essentials. When one does this, as in the present paper, it is noted that neutrinos with rest mass lead to some difficulties, in particular to a violation of T invariance.

  1. Probing the origins of neutrino mass with supernova data.

    PubMed

    Davoudiasl, Hooman; Huber, Patrick

    2005-11-01

    We study type II supernova signatures of neutrino mass generation via symmetry breaking at a scale in the range from keV to MeV. The scalar responsible for symmetry breaking is thermalized in the supernova core and restores the symmetry. The neutrinos from scalar decays have about half the average energy of thermal neutrinos. The Bose-Einstein distribution of the scalars can be established with a megaton water Cerenkov detector. The discovery of the bimodal neutrino flux is, however, well within the reach of the Super-Kamiokande detector, without a detailed knowledge of the supernova parameters.

  2. Leptogenesis in a neutrino mass model coupled with inflaton

    NASA Astrophysics Data System (ADS)

    Suematsu, Daijiro

    2016-09-01

    We propose a scenario for the generation of baryon number asymmetry based on the inflaton decay in a radiative neutrino mass model extended with singlet scalars. In this scenario, lepton number asymmetry is produced through the decay of non-thermal right-handed neutrinos caused from the inflaton decay. Since the amount of non-thermal right-handed neutrinos could be much larger than the thermal ones, the scenario could work without any resonance effect for rather low reheating temperature. Sufficient baryon number asymmetry can be generated for much lighter right-handed neutrinos compared with the Davidson-Ibarra bound.

  3. The neutrino mass hierarchy measurement with a neutrino telescope in the Mediterranean Sea: A feasibility study

    SciTech Connect

    Tsirigotis, A. G.; Collaboration: KM3NeT Collaboration

    2014-11-18

    With the measurement of a non zero value of the θ{sub 13} neutrino mixing parameter, interest in neutrinos as source of the baryon asymmetry of the universe has increased. Among the measurements of a rich and varied program in near future neutrino physics is the determination of the mass hierarchy. We present the status of a study of the feasibility of using a densely instrumented undersea neutrino detector to determine the mass hierarchy, utilizing the Mikheyev-Smirnov-Wolfenstein (MSW) effect on atmospheric neutrino oscillations. The detector will use technology developed for KM3NeT. We present the systematic studies of the optimization of a detector in the required 5–10 GeV energy regime. These studies include new tracking and interaction identification algorithms as well as geometrical optimizations of the detector.

  4. Low energy threshold corrections to neutrino masses and mixing angles

    NASA Astrophysics Data System (ADS)

    Chankowski, P. H.; Wąsowicz, P.

    2002-03-01

    We compute the low energy threshold corrections to neutrino masses and mixing in the standard model (SM) and its minimal supersymmetric version, using the effective theory technique. We demonstrate that they stabilize the results for neutrino masses and mixing with respect to the choice of the scale to which the renormalization group (RG) equation is integrated. (This confirms the correctness of the recent re-derivation of the RGE for the SM in hep-ph/0108005.) Since, as is known, those corrections are potentially very important for phenomenology we derive for them the explicit formulae that can be applied to specific models of neutrino masses and mixing.

  5. New constraints on muon-neutrino to electron-neutrino transitions in MINOS

    SciTech Connect

    Adamson, P.; Andreopoulos, C.; Auty, D.J.; Ayres, D.S.; Backhouse, C.; Barr, G.; Bernstein, R.H.; Betancourt, M.; Bhattarai, P.; Bishai, M.; Blake, A.; /Cambridge U. /Fermilab

    2010-06-01

    This letter reports results from a search for {nu}{sub {mu}}{yields}{nu}{sub {mu}} transitions by the MINOS experiment based on a 7 x 1020 protons-on-target exposure. Our observation of 54 candidate e events in the Far Detector with a background of 49.1 {+-} 7.0(stat.) {+-} 2.7(syst.) events predicted by the measurements in the Near Detector requires 2 sin2(2{theta}13) sin2{theta}23 < 0.12 (0.20) at the 90% C.L. for the normal (inverted) mass hierarchy at {delta}CP = 0. The experiment sets the tightest limits to date on the value of {theta}13 for nearly all values of {delta}CP for the normal neutrino mass hierarchy and maximal sin2(2{theta}23).

  6. Dirac neutrino mass from a neutrino dark matter model for the galaxy cluster Abell 1689

    NASA Astrophysics Data System (ADS)

    Nieuwenhuizen, Theodorus Maria

    2016-03-01

    The dark matter in the galaxy cluster Abell 1689 is modelled as an isothermal sphere of neutrinos. New data on the 2d mass density allow an accurate description of its core and halo. The model has no “missing baryon problem” and beyond 2.1 Mpc the baryons have the cosmic mass abundance. Combination of cluster data with the cosmic dark matter fraction - here supposed to stem from the neutrinos - leads to a solution of the dark matter riddle by left and right handed neutrinos with mass (1.861 ± 0.016)h 70 -2eV/c 2. The thus far observed absence of neutrinoless double beta decay points to (quasi-) Dirac neutrinos: uncharged electrons with different flavour and mass eigenbasis, as for quarks. Though the cosmic microwave background spectrum is matched up to some 10% accuracy only, the case is not ruled out because the plasma phase of the early Universe may be turbulent.

  7. Novel Frameworks for Dark Matter and Neutrino Masses

    NASA Astrophysics Data System (ADS)

    Schmidt, Daniel

    2013-12-01

    The established light neutrino masses and the Dark Matter of the Universe both require physics beyond the Standard Model for their theoretical explanation. Models that provide a common framework for these two issues are very attractive. In particular, radiative mechanisms naturally yield light neutrino masses due to loop suppression factors. These corrections can comprise a link to the physics of Dark Matter. In most considerations, the Dark Matter relic density is produced by freeze-out. This thesis contributes to the elds of radiative neutrino masses and frozen-out Dark Matter. In detail, it is shown that in the Ma-model, right-handed neutrino Dark Matter can be directly detected by photon exchange at one-loop level. The Zee{Babu-model is extended such that it enjoys a global symmetry based on baryon and lepton number. This symmetry generates light neutrino masses and a mass for a stable Dark Matter particle by its spontaneous breaking. Moreover, this thesis provides a new production mechanism for keV sterile neutrino Dark Mattetr, which is based on the freeze-in scenario. In particular, keV sterile neutrino Dark Matter produced by the decay of a frozen-in scalar is investigated.

  8. Neutrino masses and mixing in A5 with flavor antisymmetry

    NASA Astrophysics Data System (ADS)

    Joshipura, Anjan S.; Nath, Newton

    2016-08-01

    We discuss the consequences of assuming that the (Majorana) neutrino mass matrix Mν and the charged lepton mass matrix Ml satisfy SνTMνSν=-Mν and Tl†MlMl†Tl=MlMl† with respect to some discrete groups Sν and Tl contained in A5. These assumptions lead to a neutrino mass spectrum with two degenerate and one massless neutrino and also constrain mixing among them. We derive possible mixing patterns following from the choices Sν=Z2 , Z2×Z2 , and Tl=Z2,Z2×Z2,Z3,Z5 as subgroups of A5. One predicts the maximal atmospheric neutrino mixing angle θ23 and μ -τ reflection symmetry in a large number of cases, but it is also possible to obtain nonmaximal values for θ23. Only the third column of the neutrino mixing matrix can be obtained at the leading order due to degeneracy in masses of two of the neutrinos. We take up a specific example within the A5 group and identify Higgs vacuum expectation values which realize the above assumptions. Nonleading terms present in this example are shown to lead to splitting among degenerate pairs and a consistent description of both neutrino masses and mixing angles.

  9. SIMULTANEOUS CONSTRAINTS ON THE NUMBER AND MASS OF RELATIVISTIC SPECIES

    SciTech Connect

    Riemer-Sorensen, Signe; Parkinson, David; Davis, Tamara M.; Blake, Chris

    2013-02-15

    Recent indications from both particle physics and cosmology suggest the possible existence of more than three neutrino species. In cosmological analyses the effects of neutrino mass and number of species can in principle be disentangled for fixed cosmological parameters. However, since we do not have perfect measurements of the standard {Lambda} cold dark matter model parameters, some correlation remains between the neutrino mass and number of species, and both parameters should be included in the analysis. Combining the newest observations of several cosmological probes (cosmic microwave background, large-scale structure, expansion rate), we obtain N {sub eff} = 3.58{sup +0.15} {sub -0.16}(68% CL){sup +0.55} {sub -0.53}(95% CL) and {Sigma}m {sub {nu}} < 0.60 eV(95% CL), which are currently the strongest constraints on N {sub eff} and {Sigma}m {sub {nu}} from an analysis including both parameters. The preference for N {sub eff} >3 is at the 2{sigma} level.

  10. New upper limit on the total neutrino mass from the 2 degree field galaxy redshift survey.

    PubMed

    Elgarøy, Ø; Lahav, O; Percival, W J; Peacock, J A; Madgwick, D S; Bridle, S L; Baugh, C M; Baldry, I K; Bland-Hawthorn, J; Bridges, T; Cannon, R; Cole, S; Colless, M; Collins, C; Couch, W; Dalton, G; De Propris, R; Driver, S P; Efstathiou, G P; Ellis, R S; Frenk, C S; Glazebrook, K; Jackson, C; Lewis, I; Lumsden, S; Maddox, S; Norberg, P; Peterson, B A; Sutherland, W; Taylor, K

    2002-08-01

    We constrain f(nu) identical with Omega(nu)/Omega(m), the fractional contribution of neutrinos to the total mass density in the Universe, by comparing the power spectrum of fluctuations derived from the 2 Degree Field Galaxy Redshift Survey with power spectra for models with four components: baryons, cold dark matter, massive neutrinos, and a cosmological constant. Adding constraints from independent cosmological probes we find f(nu)<0.13 (at 95% confidence) for a prior of 0.1neutrino mass m(nu,tot)<1.8 eV for "concordance" values of Omega(m) and the Hubble constant. PMID:12190573

  11. Neutrino Mass Measurement Using a Directed Mono-Energetic Beam

    NASA Astrophysics Data System (ADS)

    Tsifrinovich, Vladimir; Folan, Lorcan

    2015-04-01

    It was shown that a directed mono-energetic neutrino beam can be generated by electron capture beta-decay in a sample with a strong hyperfine field at the radioactive nuclei. We study the conditions required to measure the neutrino rest mass using the recoil force produced by a directed neutrino beam. We consider the displacement of an atomic force microscope cantilever due to such a recoil force. We find the change in the cantilever displacement associated with the non-zero neutrino mass, as a function of nuclear half-life T1 / 2, cantilever spring constant, and temperature. We consider the opportunity to increase the sensitivity of the neutrino mass measurement using averaging of the measurement signal. We show that the optimal time for the signal accumulation is, approximately, 1.8T1 / 2. We compute the optimal signal-to-noise ratio for 119Sb nuclei decaying to 119Sn with a decrease in the nuclear spin from I = 5/2 to I = 3/2, and T1 / 2 = 38.2 hours. Finally, we present the parameters values required for detection of sub-eV neutrino rest mass, and estimate the angular distribution of neutrino radiation as a function of temperature.

  12. Neutrino masses in lepton number violating mSUGRA

    SciTech Connect

    Kom, Steve C. H.

    2008-11-23

    In SUSY models which violate R-parity, there exist trilinear lepton number violating (LNV) operators which can lead to neutrino masses. If these operators are defined at the unification scale, the renormalization group flow becomes important and generally leads to one neutrino mass much heavier than the others. We study, in a minimal supergravity (mSUGRA) set-up with two trilinear LNV operators and three charged lepton mixing angles, numerically how these parameters may be arranged to be compatible with neutrino oscillation data, and discuss some phenomenological observations.

  13. Neutrino Transport in Black Hole-Neutron Star Binaries: Dynamical Mass Ejection and Neutrino-Driven Wind

    NASA Astrophysics Data System (ADS)

    Kyutoku, K.; Kiuchi, K.; Sekiguchi, Y.; Shibata, M.; Taniguchi, K.

    2016-10-01

    We present our recent results of numerical-relativity simulations of black hole-neutron star binary mergers incorporating approximate neutrino transport. We in particular discuss dynamical mass ejection and neutrino-driven wind.

  14. Neutrino mass matrices with two vanishing elements/cofactors

    NASA Astrophysics Data System (ADS)

    Dev, S.; Singh, Lal; Raj, Desh

    2015-08-01

    We study the phenomenological implications of the recent neutrino data for class B of two texture zeros and two vanishing cofactors for Majorana neutrinos in the flavor basis. We find that the classes () of two texture zeros and the classes () of two vanishing cofactors have similar predictions for neutrino oscillation parameters for the same mass hierarchy. Similar predictions for the classes () of two texture zeros and classes () of two vanishing cofactors are expected. However, a preference for a shift in the quadrant of the Dirac-type CP-violating phase () in contrast to the earlier analysis has been predicted for a relatively large value of the reactor neutrino mixing angle () for class B of two texture zeros and two vanishing cofactors for an inverted mass spectrum. No such shift in the quadrant of has been found for the normal mass spectrum.

  15. Neutrino mass calorimetric searches in the MARE experiment

    NASA Astrophysics Data System (ADS)

    Nucciotti, A.; MARE Collaboration

    2012-08-01

    The international project "Microcalorimeter Arrays for a Rhenium Experiment" (MARE) aims at the direct and calorimetric measurement of the electron neutrino mass with sub-electronvolt sensitivity. Calorimetric neutrino mass experiments measure all the energy released in a beta decay except for the energy carried away by the neutrino, therefore removing the most severe systematic uncertainties which have plagued the traditional and, so far, more sensitive spectrometers. Calorimetric measurements are best realized exploiting the thermal detection technique. This approach uses thermal microcalorimeters whose absorbers contain a low transition energy Q beta decaying isotope. To date the two best options are 187Re and 163Ho. While the first beta decays, the latter decays via electron capture, but both have a Q value around 2.5 keV. The potential of using 187Re for a calorimetric neutrino mass experiment has been already demonstrated. On the contrary, no calorimetric spectrum of 163Ho has been so far measured with the precision required to set a useful limit on the neutrino mass. In this talk we present the status and the perspectives of the MARE project activities for the active isotope selection and the single channel development. We also discuss the neutrino mass statistical sensitivity achievable with both isotopes.

  16. Probing neutrino mass hierarchy by comparing the charged-current and neutral-current interaction rates of supernova neutrinos

    NASA Astrophysics Data System (ADS)

    Lai, Kwang-Chang; Lee, Fei-Fan; Lee, Feng-Shiuh; Lin, Guey-Lin; Liu, Tsung-Che; Yang, Yi

    2016-07-01

    The neutrino mass hierarchy is one of the neutrino fundamental properties yet to be determined. We introduce a method to determine neutrino mass hierarchy by comparing the interaction rate of neutral current (NC) interactions, ν(bar nu) + p → ν(bar nu) + p, and inverse beta decays (IBD), bar nue + p → n + e+, of supernova neutrinos in scintillation detectors. Neutrino flavor conversions inside the supernova are sensitive to neutrino mass hierarchy. Due to Mikheyev-Smirnov-Wolfenstein effects, the full swapping of bar nue flux with the bar nux (x = μ, τ) one occurs in the inverted hierarchy, while such a swapping does not occur in the normal hierarchy. As a result, more high energy IBD events occur in the detector for the inverted hierarchy than the high energy IBD events in the normal hierarchy. By comparing IBD interaction rate with the mass hierarchy independent NC interaction rate, one can determine the neutrino mass hierarchy.

  17. Simple mass matrices of neutrinos and quarks consistent with observed mixings and masses

    NASA Astrophysics Data System (ADS)

    Nishiura, Hiroyuki; Fukuyama, Takeshi

    2016-02-01

    We propose a simple phenomenological model of quarks-leptons mass matrices having fundamentally universal symmetry structure. These mass matrices consist of democratic and semi-democratic mass matrix terms commonly to the neutrino and the quark sectors and have only eight free parameters. We show that this mass matrix model well reproduces all the observed values of the MNS lepton and the CKM quark mixing angles, the neutrino mass squared difference ratio, and quark mass ratios, with an excellent agreement. The model also predicts δCPℓ = - 94 ° for the leptonic CP violating phase and < m > ≃ 0.0073 eV for the effective Majorana neutrino mass.

  18. Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters.

    PubMed

    Ahmad, Q R; Allen, R C; Andersen, T C; Anglin, J D; Barton, J C; Beier, E W; Bercovitch, M; Bigu, J; Biller, S D; Black, R A; Blevis, I; Boardman, R J; Boger, J; Bonvin, E; Boulay, M G; Bowler, M G; Bowles, T J; Brice, S J; Browne, M C; Bullard, T V; Bühler, G; Cameron, J; Chan, Y D; Chen, H H; Chen, M; Chen, X; Cleveland, B T; Clifford, E T H; Cowan, J H M; Cowen, D F; Cox, G A; Dai, X; Dalnoki-Veress, F; Davidson, W F; Doe, P J; Doucas, G; Dragowsky, M R; Duba, C A; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Ferraris, A P; Ford, R J; Formaggio, J A; Fowler, M M; Frame, K; Frank, E D; Frati, W; Gagnon, N; Germani, J V; Gil, S; Graham, K; Grant, D R; Hahn, R L; Hallin, A L; Hallman, E D; Hamer, A S; Hamian, A A; Handler, W B; Haq, R U; Hargrove, C K; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hepburn, J D; Heron, H; Hewett, J; Hime, A; Howe, M; Hykawy, J G; Isaac, M C P; Jagam, P; Jelley, N A; Jillings, C; Jonkmans, G; Kazkaz, K; Keener, P T; Klein, J R; Knox, A B; Komar, R J; Kouzes, R; Kutter, T; Kyba, C C M; Law, J; Lawson, I T; Lay, M; Lee, H W; Lesko, K T; Leslie, J R; Levine, I; Locke, W; Luoma, S; Lyon, J; Majerus, S; Mak, H B; Maneira, J; Manor, J; Marino, A D; McCauley, N; McDonald, A B; McDonald, D S; McFarlane, K; McGregor, G; Meijer Drees, R; Mifflin, C; Miller, G G; Milton, G; Moffat, B A; Moorhead, M; Nally, C W; Neubauer, M S; Newcomer, F M; Ng, H S; Noble, A J; Norman, E B; Novikov, V M; O'Neill, M; Okada, C E; Ollerhead, R W; Omori, M; Orrell, J L; Oser, S M; Poon, A W P; Radcliffe, T J; Roberge, A; Robertson, B C; Robertson, R G H; Rosendahl, S S E; Rowley, J K; Rusu, V L; Saettler, E; Schaffer, K K; Schwendener, M H; Schülke, A; Seifert, H; Shatkay, M; Simpson, J J; Sims, C J; Sinclair, D; Skensved, P; Smith, A R; Smith, M W E; Spreitzer, T; Starinsky, N; Steiger, T D; Stokstad, R G; Stonehill, L C; Storey, R S; Sur, B; Tafirout, R; Tagg, N; Tanner, N W; Taplin, R K; Thorman, M; Thornewell, P M; Trent, P T; Tserkovnyak, Y I; Van Berg, R; Van de Water, R G; Virtue, C J; Waltham, C E; Wang, J-X; Wark, D L; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wittich, P; Wouters, J M; Yeh, M

    2002-07-01

    The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

  19. Neutrino in Cosmology

    NASA Astrophysics Data System (ADS)

    Kirilova, D.

    2010-09-01

    The relic neutrinos from the Big Bang or the Cosmic Neutrino Background (CNB) neutrinos are expected to be the most abundant particles in our universe after the relic photons of the Cosmic Microwave Background (CMB). They carry precious information from the early epoch when our universe was only 1 sec old. Although not yet directly detected, CNB may be revealed indirectly through cosmological observations due to their important cosmological influence. I review the cosmological role of neutrinos and the present cosmological constraints on neutrino characteristics. Namely, I discuss the impact of neutrinos in the cosmic expansion, neutrino decoupling, the role of neutrinos in the primordial production of light elements, their effect on CMB anisotropies, LSS formation, the possible neutrino contribution to the Dark Matter in the universe, leptogenesis, etc. Due to the considerable cosmological influence of neutrinos, cosmological bounds on neutrino properties from observational data exist. I review the cosmological constraints on the neutrino characteristics, such as the effective number of neutrino species, neutrino mass and mixing parameters, lepton number of the universe, gravitational clustering of neutrinos, presence of sterile neutrino, etc.

  20. Neutrino mass hierarchy and three-flavor spectral splits of supernova neutrinos

    SciTech Connect

    Dasgupta, Basudeb; Mirizzi, Alessandro; Tomas, Ricard; Tamborra, Irene

    2010-05-01

    It was recently realized that three-flavor effects could peculiarly modify the development of spectral splits induced by collective oscillations, for supernova neutrinos emitted during the cooling phase of a protoneutron star. We systematically explore this case, explaining how the impact of these three-flavor effects depends on the ordering of the neutrino masses. In inverted mass hierarchy, the solar mass splitting gives rise to instabilities in regions of the (anti)neutrino energy spectra that were otherwise stable under the leading two-flavor evolution governed by the atmospheric mass splitting and by the 1-3 mixing angle. As a consequence, the high-energy spectral splits found in the electron (anti)neutrino spectra disappear, and are transferred to other flavors. Imperfect adiabaticity leads to smearing of spectral swap features. In normal mass hierarchy, the three-flavor and the two-flavor instabilities act in the same region of the neutrino energy spectrum, leading to only minor departures from the two-flavor treatment.

  1. Recent progress of SPAN towards neutrino mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Masuda, T.; Hara, H.; Miyamoto, Y.; Sasao, N.; Tanaka, M.; Uetake, S.; Yoshimi, A.; Yoshimura, K.; Yoshimura, M.

    2016-05-01

    SPAN (Spectroscopy of Atomic Neutrino) project aims to determine the absolute neutrino mass. The process we plan to use is a cooperative de-excitation of atoms in a metastable level emitting a neutrino pair associated with a photon. The photon energy spectrum of this process contains information on the absolute mass of neutrino. Key items of this experiment are a rate amplification using macro-coherence in a target medium in case of plural particles emission and an external triggering of the emission in order to scan the spectrum. We have demonstrated the rate amplification in two-photon emission from para-hydrogen gas which was coherently excited to its first vibrationally excited state. The coherence in the medium was generated by irradiating two driving laser pulses. The emission was stimulated by irradiating a mid-infrared laser pulse. The enhancement factor of more than 1018 with respect to the spontaneous emission was achieved. This paper briefly summarizes the results.

  2. Wave-packet treatment of reactor neutrino oscillation experiments and its implications on determining the neutrino mass hierarchy

    NASA Astrophysics Data System (ADS)

    Chan, Yat-Long; Chu, M.-C.; Tsui, Ka Ming; Wong, Chan Fai; Xu, Jianyi

    2016-06-01

    We derive the neutrino flavor transition probabilities with the neutrino treated as a wave packet. The decoherence and dispersion effects from the wave-packet treatment show up as damping and phase-shifting of the plane-wave neutrino oscillation patterns. If the energy uncertainty in the initial neutrino wave packet is larger than around 0.01 of the neutrino energy, the decoherence and dispersion effects would degrade the sensitivity of reactor neutrino experiments to mass hierarchy measurement to lower than 3 σ confidence level.

  3. Observational constraints on neutron star Masses and Radii

    NASA Astrophysics Data System (ADS)

    Heinke, Craig

    2016-07-01

    There are major uncertainties in the composition and structure of neutron star (NS) interiors, making measurements of the compactness and thermal properties of NSs quite valuable. Dozens of NSs have precisely measured masses (generally through radio timing of pulsars). However, current methods for precise measurement of radius, and thus compactness, generally suffer from conflicting interpretations of observable quantities. I will summarize the questions at issue, and the current state of the data. For instance, for quiescent low-mass X-ray binaries in globular clusters, these include issues of atmospheric composition, distance determination methods, and the possible presence of hot spots on the surface. The thermal properties of NSs, mostly set by neutrino emission from the core, divulge information about the core composition, and its superfluid properties. Young NSs appear to be well-described by "minimal cooling" (see Page's talk), while some old NSs in low-mass X-ray binaries show evidence for strongly enhanced neutrino core cooling. The young NS in Cassiopeia A has been reported to show rapid cooling, that has been interpreted as indicating that the neutrons in the core are transitioning to a superfluid state. The initial cooling measurement was too rapid; it is currently unclear whether the Cas A NS is cooling rapidly or not. I will conclude with some discussion of paths forward toward constraints in these directions, besides the NICER instrument.

  4. A tight SO(10) connection between leptogenesis and neutrino masses

    SciTech Connect

    Frigerio, Michele

    2008-11-23

    We discuss a source of light neutrino masses and leptogenesis in SO(10) unification theories, that was not previously recognized. It is present when the light lepton doublets belong (at least partially) to dimension-10 matter multiplets. At odds with previous leptogenesis scenarios, the CP asymmetry depends only on the low energy flavour parameters of the neutrino sector. We demonstrate that a successful generation of the baryon asymmetry of the Universe is possible.

  5. Neutrino mass and the origin of galactic magnetic fields

    SciTech Connect

    Enqvist, K. ); Semikoz, V. IZMIRAN, Academy of Sciences, Troitsk 142092 ); Shukurov, A. Computing Center, Moscow University, Moscow 119899 ); Sokoloff, D. Isaac Newton Institute, Cambridge University, Cambridge CB3 0EH )

    1993-11-15

    We compare two constraints on the strength of the cosmological primordial magnetic field: the one following from the restrictions on the Dirac neutrino spin flip in the early Universe, and another one based on the galactic dynamo theory for the Milky Way (presuming that the seed magnetic field has a relic origin). Since the magnetic field facilitates transitions between left- and right-handed neutrino states, thereby affecting [sup 4]He production at primordial nucleosynthesis, we can obtain a guaranteed [ital upper] limit on the strength of the relic magnetic field in the protogalaxy, [ital B][sub [ital c

  6. Dark matter, {mu} problem, and neutrino mass with gauged R symmetry

    SciTech Connect

    Choi, Ki-Young; Chun, Eung Jin; Lee, Hyun Min

    2010-11-15

    We show that the {mu} problem and the strong CP problem can be resolved in the context of the gauged U(1){sub R} symmetry, realizing an automatic Peccei-Quinn symmetry. In this scheme, right-handed neutrinos can be introduced to explain small Majorana or Dirac neutrino mass. The U(1){sub R} D-term mediated supersymmetry (SUSY) breaking, called the U(1){sub R} mediation, gives rise to a specific form of the flavor-conserving superpartner masses. For the given solution to the {mu} problem, electroweak symmetry breaking condition requires the superpartners of the standard model at low energy to be much heavier than the gravitino. Thus, the dark matter candidate can be either gravitino or right-handed sneutrino. In the Majorana neutrino case, only gravitino is a natural dark matter candidate. On the other hand, in the Dirac neutrino case, the right-handed sneutrino can be also a dark matter candidate as it gets mass only from SUSY breaking. We discuss the non-thermal production of our dark matter candidates from the late decay of stau and find that the constraints from the big bang nucleosynthesis can be evaded for a TeV-scale stau mass.

  7. New constraints on neutrino physics from BOOMERANG data

    PubMed

    Hannestad

    2000-11-13

    We have performed a likelihood analysis of the recent data on the cosmic microwave background radiation anisotropy from the BOOMERANG experiment. These data place a strong upper bound on the radiation density present at recombination. Expressed in terms of the equivalent number of neutrino species the 2sigma bound is N(nu)neutrinos. The bound also yields a firm upper limit on the lepton asymmetry in the Universe.

  8. Shedding light on neutrino masses with dark forces

    DOE PAGES

    Batell, Brian; Pospelov, Maxim; Shuve, Brian

    2016-08-08

    Heavy right-handed neutrinos, N , provide the simplest explanation for the origin of light neutrino masses and mixings. If MN is at or below the weak scale, direct experimental discovery of these states is possible at accelerator experiments such as the LHC or new dedicated beam dump experiments; in these experiments, N decays after traversing a macroscopic distance from the collision point. The experimental sensitivity to right-handed neutrinos is significantly enhanced if there is a new “dark” gauge force connecting them to the Standard Model (SM), and detection of N can be the primary discovery mode for the new darkmore » force itself. We take the well-motivated example of a B – L gauge symmetry and analyze the sensitivity to displaced decays of N produced via the new gauge interaction in two experiments: the LHC and the proposed SHiP beam dump experiment. In the most favorable case in which the mediator can be produced on-shell and decays to right handed neutrinos (pp → X + VB–L → X + N N ), the sensitivity reach is controlled by the square of the B – L gauge coupling. Here, we demonstrate that these experiments could access neutrino parameters responsible for the observed SM neutrino masses and mixings in the most straightforward implementation of the see-saw mechanism.« less

  9. Shedding light on neutrino masses with dark forces

    NASA Astrophysics Data System (ADS)

    Batell, Brian; Pospelov, Maxim; Shuve, Brian

    2016-08-01

    Heavy right-handed neutrinos, N , provide the simplest explanation for the origin of light neutrino masses and mixings. If M N is at or below the weak scale, direct experimental discovery of these states is possible at accelerator experiments such as the LHC or new dedicated beam dump experiments; in these experiments, N decays after traversing a macroscopic distance from the collision point. The experimental sensitivity to right-handed neutrinos is significantly enhanced if there is a new "dark" gauge force connecting them to the Standard Model (SM), and detection of N can be the primary discovery mode for the new dark force itself. We take the well-motivated example of a B - L gauge symmetry and analyze the sensitivity to displaced decays of N produced via the new gauge interaction in two experiments: the LHC and the proposed SHiP beam dump experiment. In the most favorable case in which the mediator can be produced on-shell and decays to right handed neutrinos ( pp → X + V B- L → X + N N ), the sensitivity reach is controlled by the square of the B - L gauge coupling. We demonstrate that these experiments could access neutrino parameters responsible for the observed SM neutrino masses and mixings in the most straightforward implementation of the see-saw mechanism.

  10. Renormalization of the neutrino mass matrix

    NASA Astrophysics Data System (ADS)

    Chiu, S. H.; Kuo, T. K.

    2016-09-01

    In terms of a rephasing invariant parametrization, the set of renormalization group equations (RGE) for Dirac neutrino parameters can be cast in a compact and simple form. These equations exhibit manifest symmetry under flavor permutations. We obtain both exact and approximate RGE invariants, in addition to some approximate solutions and examples of numerical solutions.

  11. Relic Neutrino Absorption Spectroscopy

    SciTech Connect

    Eberle, b

    2004-01-28

    Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmological parameters determining the expansion rate of the universe, and by the large redshift history of the cosmic neutrino sources. We investigate the possibility of determining the existence of the cosmic neutrino background within the next decade from a measurement of these absorption dips in the neutrino flux. As a by-product, we study the prospects to infer the absolute neutrino mass scale. We find that, with the presently planned neutrino detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant energy regime above 10{sup 21} eV, relic neutrino absorption spectroscopy becomes a realistic possibility. It requires, however, the existence of extremely powerful neutrino sources, which should be opaque to nucleons and high-energy photons to evade present constraints. Furthermore, the neutrino mass spectrum must be quasi-degenerate to optimize the dip, which implies m{sub {nu}} 0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.

  12. Predictive model for radiatively induced neutrino masses and mixings with dark matter.

    PubMed

    Gustafsson, Michael; No, Jose M; Rivera, Maximiliano A

    2013-05-24

    A minimal extension of the standard model to naturally generate small neutrino masses and provide a dark matter candidate is proposed. The dark matter particle is part of a new scalar doublet field that plays a crucial role in radiatively generating neutrino masses. The symmetry that stabilizes the dark matter also suppresses neutrino masses to appear first at three-loop level. Without the need of right-handed neutrinos or other very heavy new fields, this offers an attractive explanation of the hierarchy between the electroweak and neutrino mass scales. The model has distinct verifiable predictions for the neutrino masses, flavor mixing angles, colliders, and dark matter signals. PMID:23745861

  13. Predictive model for radiatively induced neutrino masses and mixings with dark matter.

    PubMed

    Gustafsson, Michael; No, Jose M; Rivera, Maximiliano A

    2013-05-24

    A minimal extension of the standard model to naturally generate small neutrino masses and provide a dark matter candidate is proposed. The dark matter particle is part of a new scalar doublet field that plays a crucial role in radiatively generating neutrino masses. The symmetry that stabilizes the dark matter also suppresses neutrino masses to appear first at three-loop level. Without the need of right-handed neutrinos or other very heavy new fields, this offers an attractive explanation of the hierarchy between the electroweak and neutrino mass scales. The model has distinct verifiable predictions for the neutrino masses, flavor mixing angles, colliders, and dark matter signals.

  14. Lepton mass and mixing in a neutrino mass model based on S4 flavor symmetry

    NASA Astrophysics Data System (ADS)

    Vien, V. V.

    2016-03-01

    We study a neutrino mass model based on S4 flavor symmetry which accommodates lepton mass, mixing with nonzero θ13 and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic neutrino mass and mixing pattern at the tree-level with renormalizable interactions. Indeed, the neutrinos get small masses from one SU(2)L doublet and two SU(2)L singlets in which one being in 2̲ and the two others in 3̲ under S4 with both the breakings S4 → S3 and S4 → Z3 are taken place in charged lepton sector and S4 →𝒦 in neutrino sector. The model also gives a remarkable prediction of Dirac CP violation δCP = π 2 or -π 2 in both the normal and inverted spectrum which is still missing in the neutrino mixing matrix. The relation between lepton mixing angles is also represented.

  15. Updated constraints on the light-neutrino exchange mechanisms of the 0νββ-decay

    NASA Astrophysics Data System (ADS)

    Štefánik, Dušan; Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-01

    The neutrinoless double-beta (0νββ) decay associated with light neutrino exchange mechanisms, which are due to both left-handed V-A and right-handed V+A leptonic and hadronic currents, is discussed by using the recent progress achieved by the GERDA, EXO and KamlandZen experiments. The upper limits for effective neutrino mass mββ and the parameters <λ> and <η> characterizing the right handed current mechanisms are deduced from the data on the 0νββ-decay of 76Ge and 136Xe using nuclear matrix elements calculated within the nuclear shell model and quasiparticle random phase approximation and phase-space factors calculated with exact Dirac wave functions with finite nuclear size and electron screening. The careful analysis of upper constraints on effective lepton number violating parameters assumes a competition of the above mechanisms and arbitrary values of involved CP violating phases.

  16. Consistency of WIMP Dark Matter as radiative neutrino mass messenger

    NASA Astrophysics Data System (ADS)

    Merle, Alexander; Platscher, Moritz; Rojas, Nicolás; Valle, José W. F.; Vicente, Avelino

    2016-07-01

    The scotogenic scenario provides an attractive approach to both Dark Matter and neutrino mass generation, in which the same symmetry that stabilises Dark Matter also ensures the radiative seesaw origin of neutrino mass. However the simplest scenario may suffer from inconsistencies arising from the spontaneous breaking of the underlying ℤ 2 symmetry. Here we show that the singlet-triplet extension of the simplest model naturally avoids this problem due to the presence of scalar triplets neutral under the ℤ 2 which affect the evolution of the couplings in the scalar sector. The scenario offers good prospects for direct WIMP Dark Matter detection through the nuclear recoil method.

  17. New Stringy Instanton Effects And Neutrino Majorana Masses

    SciTech Connect

    Cvetic, M.; Richter, R.; Weigand, T.

    2007-10-03

    D-brane instantons can generate open string couplings in the superpotential which violate global abelian symmetries and are therefore perturbatively forbidden. After discussing the main ingredients, focussing for concretenes on Type IIA orientifold compactifications, we exemplify the computation of instanton-induced Majorana mass terms for right-handed neutrinos in a local SU(5) GUT-like model. In particular, we show that the instanton allows for naturally engineering the intermediate scale of the Majorana masses, thereby realizing the seesaw mechanism for neutrinos.

  18. On Morphing Neutrinos and Why They Must Have Mass

    NASA Astrophysics Data System (ADS)

    Hecht, Eugene

    2003-03-01

    This paper explores the recently confirmed hypothesis that neutrinos have mass and that they spontaneously transform from one type to another. That immensely important discovery culminates 40 years of experimental research. After briefly discussing that work, we'll study the quantum mechanical explanation of these phenomena elaborating the concepts of particle mixing, and the oscillation of flavor types. These rather esoteric ideas lead to the prediction that morphing neutrinos must have mass, but there's a much more elegant relativistic argument that brings us to this same conclusion.

  19. Probing the neutrino mass through the cross correlation between the Rees-Sciama effect and weak lensing

    NASA Astrophysics Data System (ADS)

    Xu, Lixin

    2016-08-01

    Cosmology plays a fundamental role to determine the neutrino mass, therefore also to determine its mass hierarchy, since the massive neutrino contributes to the total matter density in the Universe at the background and perturbation levels, once it becomes non-relativistic. After the non-relativistic transition the fluctuations are smashed out at the scales k gg kfs. Therefore, the missing fluctuation in the total matter is imprinted on the large scale structure, say the suppression of the matter power spectrum ΔP/P ≈ -8fν at the scales k gg kfs. In this paper, instead of considering the linear perturbation theory, which is well understood in the presence of neutrino, we propose to use the cross correlation between the Rees-Sciama effect and weak lensing to probe the neutrino mass. At the small scales, the density contrast grows faster than the background scale factor δ ~ a, that makes a sign flipping on Φ' propto Script Hδ d ln (δ/a)/d ln a, which happens only in the non-linear regime. We show that the flipping scale in the cross power spectrum between the Rees-Sciama effect and weak lensing depends on the neutrino mass by assuming the shallow and deep weak lensing surveys. Our analysis shows that the Deep survey has larger signal-to-noise ratio S/N ~ 160. Finally, we use the Fisher information matrix to forecast constraint on the neutrino mass.

  20. Probing the neutrino mass through the cross correlation between the Rees-Sciama effect and weak lensing

    NASA Astrophysics Data System (ADS)

    Xu, Lixin

    2016-08-01

    Cosmology plays a fundamental role to determine the neutrino mass, therefore also to determine its mass hierarchy, since the massive neutrino contributes to the total matter density in the Universe at the background and perturbation levels, once it becomes non-relativistic. After the non-relativistic transition the fluctuations are smashed out at the scales k gg kfs. Therefore, the missing fluctuation in the total matter is imprinted on the large scale structure, say the suppression of the matter power spectrum ΔP/P ≈ ‑8fν at the scales k gg kfs. In this paper, instead of considering the linear perturbation theory, which is well understood in the presence of neutrino, we propose to use the cross correlation between the Rees-Sciama effect and weak lensing to probe the neutrino mass. At the small scales, the density contrast grows faster than the background scale factor δ ~ a, that makes a sign flipping on Φ' propto Script Hδ d ln (δ/a)/d ln a, which happens only in the non-linear regime. We show that the flipping scale in the cross power spectrum between the Rees-Sciama effect and weak lensing depends on the neutrino mass by assuming the shallow and deep weak lensing surveys. Our analysis shows that the Deep survey has larger signal-to-noise ratio S/N ~ 160. Finally, we use the Fisher information matrix to forecast constraint on the neutrino mass.

  1. Determining neutrino mass hierarchy from electron disappearance at a low energy neutrino factory

    NASA Astrophysics Data System (ADS)

    Dutta, Rupak; Sinha, Nita; Raut, Sushant K.

    2014-04-01

    Recent measurements of large θ13 by the reactor experiments have opened up the possibility of determining the neutrino mass hierarchy, i.e., the sign of the mass squared splitting Δm312, the CP-violating phase δCP, and the octant of θ23. In light of this result, we study the performance of a low energy neutrino factory (LENF) for determination of the mass hierarchy. In particular, we explore the potential of the νe and ν¯e disappearance channels at LENF to determine the neutrino mass hierarchy, that is free from the uncertainties arising from the unknown δCP phase and the θ23 octant. We find that using these electron neutrino (antineutrino) disappearance channels with a standard LENF, it is possible to exclude the wrong hierarchy at 5σ with only 2 years of running, with a muon beam energy above ˜3.5(5.0-10.0) GeV and baseline longer than ˜1400(1900-2400) km for an optimistic (conservative) systematic error of 2% (5%).

  2. Neutrino masses and lepton flavor violation in the 3-3-1 model with right-handed neutrinos

    SciTech Connect

    Dong, P. V.; Long, H. N.

    2008-03-01

    We show that, in the 3-3-1 model with right-handed neutrinos, small neutrino masses and large lepton flavor violating processes such as {mu}{yields}3e and {mu}{yields}e{gamma} can be obtained by just introducing an additional Higgs sextet. In the limit of vanishing of the Yukawa interaction among Higgs and lepton triplets (h{sup {nu}}=0), the decay {mu}{yields}3e strongly depends on the neutrino-mass patterns, but the {mu}{yields}e{gamma} almost does not. The neutrino masses are not constrained by such processes in the cases of h{sup {nu}}{ne}0.

  3. Reconstructing SUSY and R-Neutrino Masses in SO(10)

    SciTech Connect

    Deppisch, F.; Freitas, A.; Porod, W.; Zerwas, P. M.

    2008-11-23

    We report on the extrapolation of scalar mass parameters in the lepton sector to reconstruct SO(10) scenarios close to the unification scale. The method is demonstrated for an example in which SO(10) is broken directly to the Standard Model, based on the expected precision from coherent LHC and ILC collider analyses. In addition to the fundamental scalar mass parameters at the unification scale, the mass of the heaviest right-handed neutrino can be estimated in the seesaw scenario.

  4. Measuring neutrino masses with a future galaxy survey

    SciTech Connect

    Hamann, Jan; Hannestad, Steen; Wong, Yvonne Y.Y. E-mail: sth@phys.au.dk

    2012-11-01

    We perform a detailed forecast on how well a EUCLID-like photometric galaxy and cosmic shear survey will be able to constrain the absolute neutrino mass scale. Adopting conservative assumptions about the survey specifications and assuming complete ignorance of the galaxy bias, we estimate that the minimum mass sum of Σm{sub ν} ≅ 0.06 eV in the normal hierarchy can be detected at 1.5σ to 2.5σ significance, depending on the model complexity, using a combination of galaxy and cosmic shear power spectrum measurements in conjunction with CMB temperature and polarisation observations from PLANCK. With better knowledge of the galaxy bias, the significance of the detection could potentially reach 5.4σ. Interestingly, neither PLANCK+shear nor PLANCK+galaxy alone can achieve this level of sensitivity; it is the combined effect of galaxy and cosmic shear power spectrum measurements that breaks the persistent degeneracies between the neutrino mass, the physical matter density, and the Hubble parameter. Notwithstanding this remarkable sensitivity to Σm{sub ν}, EUCLID-like shear and galaxy data will not be sensitive to the exact mass spectrum of the neutrino sector; no significant bias ( < 1σ) in the parameter estimation is induced by fitting inaccurate models of the neutrino mass splittings to the mock data, nor does the goodness-of-fit of these models suffer any significant degradation relative to the true one (Δχ{sub eff}{sup 2} < 1)

  5. PQ-symmetry for a small Dirac neutrino mass, dark radiation and cosmic neutrinos

    SciTech Connect

    Park, Wan-Il

    2014-06-01

    We propose a supersymmetric scenario in which the small Yukawa couplings for the Dirac neutrino mass term are generated by the spontaneous-breaking of Pecci-Quinn symmetry. In this scenario, a right amount of dark matter relic density can be obtained by either right-handed sneutrino or axino LSP, and a sizable amount of axion dark radiation can be obtained. Interestingly, the decay of right-handed sneutrino NLSP to axino LSP is delayed to around the present epoch, and can leave an observable cosmological background of neutrinos at the energy scale of O(10−100) GeV.

  6. Dark Matter and neutrino masses from global U(1) B - L symmetry breaking

    NASA Astrophysics Data System (ADS)

    Lindner, Manfred; Schmidt, Daniel; Schwetz, Thomas

    2011-11-01

    We present a scenario where neutrino masses and Dark Matter are related due to a global U(1) B - L symmetry. Specifically we consider neutrino mass generation via the Zee-Babu two-loop mechanism, augmented by a scalar singlet whose VEV breaks the global U(1) B - L symmetry. In order to obtain a Dark Matter candidate we introduce two Standard Model singlet fermions. They form a Dirac particle and are stable because of a remnant Z2 symmetry. Hence, in this model the stability of Dark Matter follows from the global U(1) B - L symmetry. We discuss the Dark Matter phenomenology of the model, and compare it to similar models based on gauged U(1) B - L. We argue that in contrast to the gauged versions, the model based on the global symmetry does not suffer from severe constraints from Z‧ searches.

  7. Improved statistical determination of absolute neutrino masses via radiative emission of neutrino pairs from atoms

    NASA Astrophysics Data System (ADS)

    Zhang, Jue; Zhou, Shun

    2016-06-01

    The atomic transition from an excited state |e ⟩ to the ground state |g ⟩ by emitting a neutrino pair and a photon, i.e., |e ⟩→|g ⟩+|γ ⟩+|νi⟩+|ν¯j⟩ with i , j =1 , 2, 3, has been proposed by Yoshimura and his collaborators as an alternative way to determine the absolute scale m0 of neutrino masses. More recently, a statistical analysis of the fine structure of the photon spectrum from this atomic process has been performed [N. Song et al. Phys. Rev. D 93, 013020 (2016)] to quantitatively examine the experimental requirements for a realistic determination of absolute neutrino masses. In this paper, we show how to improve the statistical analysis and demonstrate that the previously required detection time can be reduced by one order of magnitude for the case of a 3 σ determination of m0˜0.01 eV with an accuracy better than 10%. Such an improvement is very encouraging for further investigations on measuring absolute neutrino masses through atomic processes.

  8. NEW NEUTRINO MASS BOUNDS FROM SDSS-III DATA RELEASE 8 PHOTOMETRIC LUMINOUS GALAXIES

    SciTech Connect

    De Putter, Roland; Mena, Olga; Giusarma, Elena; Ho, Shirley; Seo, Hee-Jong; White, Martin; Ross, Nicholas P.; Cuesta, Antonio; Ross, Ashley J.; Percival, Will J.; Bizyaev, Dmitry; Brewington, Howard; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Shelden, Alaina; Simmons, Audrey; Kirkby, David; Schneider, Donald P.; and others

    2012-12-10

    We present neutrino mass bounds using 900,000 luminous galaxies with photometric redshifts measured from Sloan Digital Sky Survey III Data Release 8. The galaxies have photometric redshifts between z = 0.45 and z = 0.65 and cover 10,000 deg{sup 2}, thus probing a volume of 3 h {sup -3} Gpc{sup 3} and enabling tight constraints to be derived on the amount of dark matter in the form of massive neutrinos. A new bound on the sum of neutrino masses {Sigma}m{sub {nu}} < 0.27 eV, at the 95% confidence level (CL), is obtained after combining our sample of galaxies, which we call ''CMASS'', with Wilkinson Microwave Anisotropy Probe (WMAP) seven-year cosmic microwave background data and the most recent measurement of the Hubble parameter from the Hubble Space Telescope (HST). This constraint is obtained with a conservative multipole range of 30 < l < 200 in order to minimize nonlinearities, and a free bias parameter in each of the four redshift bins. We study the impact of assuming this linear galaxy bias model using mock catalogs and find that this model causes a small ({approx}1{sigma}-1.5{sigma}) bias in {Omega}{sub DM} h {sup 2}. For this reason, we also quote neutrino bounds based on a conservative galaxy bias model containing additional, shot-noise-like free parameters. In this conservative case, the bounds are significantly weakened, e.g., {Sigma}m{sub {nu}} < 0.38 eV (95% CL) for WMAP+HST+CMASS (l{sub max} = 200). We also study the dependence of the neutrino bound on the multipole range (l{sub max} = 150 versus l{sub max} = 200) and on which combination of data sets is included as a prior. The addition of supernova and/or baryon acoustic oscillation data does not significantly improve the neutrino mass bound once the HST prior is included. A companion paper describes the construction of the angular power spectra in detail and derives constraints on a general cosmological model, including the dark energy equation of state w and the spatial curvature {Omega}{sub K

  9. Distinguishing neutrino mass hierarchies using dark matter annihilation signals at IceCube

    SciTech Connect

    Allahverdi, Rouzbeh; Dutta, Bhaskar; Ghosh, Dilip Kumar; Knockel, Bradley; Saha, Ipsita

    2015-12-01

    We explore the possibility of distinguishing neutrino mass hierarchies through the neutrino signal from dark matter annihilation at neutrino telescopes. We consider a simple extension of the standard model where the neutrino masses and mixing angles are obtained via the type-II seesaw mechanism as an explicit example. We show that future extensions of IceCube neutrino telescope may detect the neutrino signal from DM annihilation at the Galactic Center and inside the Sun, and differentiate between the normal and inverted mass hierarchies, in this model.

  10. Neutrino mixing and mass hierarchy in Gaussian landscapes

    SciTech Connect

    Hall, Lawrence J.; Salem, Michael P.; Watari, Taizan

    2009-01-15

    The flavor structure of the standard model may arise from random selection on a landscape. In a class of simple models, called ''Gaussian landscapes,'' Yukawa couplings derive from overlap integrals of Gaussian zero-mode wave functions on an extra-dimensional space. Statistics of vacua are generated by scanning the peak positions of these wave functions, giving probability distributions for all flavor observables. Gaussian landscapes can account for all of the major features of flavor, including both the small electroweak mixing in the quark sector and the large mixing observed in the lepton sector. We find that large lepton mixing stems directly from lepton doublets having broad wave functions on the internal manifold. Assuming the seesaw mechanism, we find the mass hierarchy among neutrinos is sensitive to the number of right-handed neutrinos and can provide a good fit to neutrino oscillation measurements.

  11. Models of neutrino mass, mixing and CP violation

    NASA Astrophysics Data System (ADS)

    King, Stephen F.

    2015-12-01

    In this topical review we argue that neutrino mass and mixing data motivates extending the Standard Model (SM) to include a non-Abelian discrete flavour symmetry in order to accurately predict the large leptonic mixing angles and {C}{P} violation. We begin with an overview of the SM puzzles, followed by a description of some classic lepton mixing patterns. Lepton mixing may be regarded as a deviation from tri-bimaximal mixing, with charged lepton corrections leading to solar mixing sum rules, or tri-maximal lepton mixing leading to atmospheric mixing rules. We survey neutrino mass models, using a roadmap based on the open questions in neutrino physics. We then focus on the seesaw mechanism with right-handed neutrinos, where sequential dominance (SD) can account for large lepton mixing angles and {C}{P} violation, with precise predictions emerging from constrained SD (CSD). We define the flavour problem and discuss progress towards a theory of favour using GUTs and discrete family symmetry. We classify models as direct, semidirect or indirect, according to the relation between the Klein symmetry of the mass matrices and the discrete family symmetry, in all cases focussing on spontaneous {C}{P} violation. Finally we give two examples of realistic and highly predictive indirect models with CSD, namely an A to Z of flavour with Pati-Salam and a fairly complete A 4 × SU(5) SUSY GUT of flavour, where both models have interesting implications for leptogenesis.

  12. Forbidden unique beta-decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2013-12-30

    The measurement of the electron spectrum in beta-decays provides a robust direct determination of the values of neutrino masses. The planned rhenium beta-decay experiment, called the “Microcalorimeter Arrays for a Rhenium Experiment” (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which is expected to collect data in a near future. In this contribution we discuss the spectrum of emitted electrons close to the end point in the case of the first unique forbidden beta-decay of {sup 79}Se, {sup 107}Pd and {sup 187}Re. It is found that the p{sub 3/2}-wave emission dominates over the s{sub 1/2}-wave. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed beta-decay of {sup 3}H.

  13. One vanishing minor in the neutrino mass matrix

    SciTech Connect

    Lashin, E. I.; Chamoun, N.

    2009-11-01

    We study a specific texture of the neutrino mass matrix, namely the models with one 2x2 subdeterminant equal to zero. We carry out a complete phenomenological analysis with all possible relevant correlations. Every pattern of the six possible ones is found able to accommodate the experimental data, with three cases allowing also for noninvertible mass matrices. We present symmetry realizations for all the models.

  14. Neutrino-Antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis

    NASA Astrophysics Data System (ADS)

    Fujikawa, Kazuo; Tureanu, Anca

    By adding a neutrino mass term to the Standard Model, which is Lorentz and SU(2) × U(1) invariant but nonlocal to evade CPT theorem, it is shown that nonlocality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at ˜ 10-20 eV, well below the experimental bound < 10-2 eV. The induced CPT violation in the K-meson in the Standard Model is expected to be even smaller and well below the experimental bound |m_{K} - m_{bar{K}}| < 0.44 × 10^{-18} GeV.

  15. Neutrino-antineutrino mass splitting in the Standard Model: Neutrino oscillation and baryogenesis

    NASA Astrophysics Data System (ADS)

    Fujikawa, Kazuo; Tureanu, Anca

    2015-07-01

    By adding a neutrino mass term to the Standard Model, which is Lorentz and SU(2) × U(1) invariant but nonlocal to evade CPT theorem, it is shown that nonlocality within a distance scale of the Planck length, that may not be fatal to unitarity in generic effective theory, can generate the neutrino-antineutrino mass splitting of the order of observed neutrino mass differences, which is tested in oscillation experiments, and non-negligible baryon asymmetry depending on the estimate of sphaleron dynamics. The one-loop order induced electron-positron mass splitting in the Standard Model is shown to be finite and estimated at ˜ 10-20 eV, well below the experimental bound < 10-2 eV. The induced CPT violation in the K-meson in the Standard Model is expected to be even smaller and well below the experimental bound |mK - mK¯| < 0.44 × 10-18GeV.

  16. Textures with two traceless submatrices of the neutrino mass matrix

    SciTech Connect

    Alhendi, H. A.; Mudlej, A. A.; Lashin, E. I.

    2008-01-01

    We propose a new texture for the light neutrino mass matrix. The proposal is based upon imposing a zero-trace condition on the two-by-two submatrices of the complex symmetric Majorana mass matrix in the flavor basis where the charged lepton mass matrix is diagonal. Restricting the mass matrix to have two traceless submatrices may be found sufficient to describe the current data. Eight out of 15 independent possible cases are found to be compatible with current data. Numerical and some approximate analytical results are presented.

  17. Ultra-low Q values for neutrino mass measurements

    SciTech Connect

    Kopp, Joachim; Merle, Alexander; /Heidelberg, Max Planck Inst.

    2009-11-01

    We investigate weak nuclear decays with extremely small kinetic energy release (Q value) and thus extremely good sensitivity to the absolute neutrino mass scale. In particular, we consider decays into excited daughter states, and we show that partial ionization of the parent atom can help to tune Q values to << 1 keV. We discuss several candidate isotopes undergoing {beta}{sup {+-}}, bound state {beta}, or electron capture decay, and come to the conclusion that a neutrino mass measurement using low-Q decays might only be feasible if no ionization is required, and if future improvements in isotope production technology, nuclear mass spectroscopy, and atomic structure calculations are possible. Experiments using ions, however, are extremely challenging due to the large number of ions that must be stored. New precision data on nuclear excitation levels could help to identify further isotopes with low-Q decay modes and possibly less challenging requirements.

  18. Neutrino mass, dark energy, and the linear growth factor

    NASA Astrophysics Data System (ADS)

    Kiakotou, Angeliki; Elgarøy, Øystein; Lahav, Ofer

    2008-03-01

    We study the degeneracies between neutrino mass and dark energy as they manifest themselves in cosmological observations. In contradiction to a popular formula in the literature, the suppression of the matter power spectrum caused by massive neutrinos is not just a function of the ratio of neutrino to total mass densities fν=Ων/Ωm, but also each of the densities independently. We also present a fitting formula for the logarithmic growth factor of perturbations in a flat universe, f(z,k;fν,w,ΩDE)≈[1-A(k)ΩDEfν+B(k)fν2-C(k)fν3]Ωmα(z), where α depends on the dark energy equation of state parameter w. We then discuss cosmological probes where the f factor directly appears: peculiar velocities, redshift distortion, and the integrated Sachs-Wolfe effect. We also modify the approximation of Eisenstein and Hu [Astrophys. J.ASJOAB0004-637X 511, 5 (1999)10.1086/306640] for the power spectrum of fluctuations in the presence of massive neutrinos and provide a revised code [http://www.star.ucl.ac.uk/~lahav/nu_matter_power.f].

  19. Effect of neutrino rest mass on ionization equilibrium freeze-out

    NASA Astrophysics Data System (ADS)

    Grohs, E.; Fuller, G. M.; Kishimoto, C. T.; Paris, M. W.

    2015-12-01

    We show how small neutrino rest masses can increase the expansion rate near the photon decoupling epoch in the early Universe, causing an earlier, higher temperature freeze-out for ionization equilibrium compared to the massless neutrino case. This yields a larger free-electron fraction, thereby affecting the photon diffusion length differently than the sound horizon at photon decoupling. This neutrino-mass and recombination effect depends strongly on the neutrino rest masses. Though below current sensitivity, this effect could be probed by next-generation cosmic microwave background experiments, giving another observational handle on neutrino rest mass.

  20. Effect of neutrino rest mass on ionization equilibrium freeze-out

    SciTech Connect

    Grohs, Evan Bradley; Fuller, George M.; Kishimoto, Chad T.; Paris, Mark W.

    2015-12-23

    We show how small neutrino rest masses can increase the expansion rate near the photon decoupling epoch in the early Universe, causing an earlier, higher temperature freeze-out for ionization equilibrium compared to the massless neutrino case. This yields a larger free-electron fraction, thereby affecting the photon diffusion length differently than the sound horizon at photon decoupling. This neutrino-mass and recombination effect depends strongly on the neutrino rest masses. Ultimately, though below current sensitivity, this effect could be probed by next-generation cosmic microwave background experiments, giving another observational handle on neutrino rest mass.

  1. Sterile neutrinos in the early universe

    SciTech Connect

    Malaney, R.A. ); Fuller, G.M. . Dept. of Physics)

    1990-11-14

    We discuss the role played by right-handed sterile neutrinos in the early universe. We show how well known {sup 4}He constraint on the number of relativistic degrees of freedom at early times limits the equilibration of the right handed neutrino sea with the background plasma. We discuss how this allows interesting constraints to be placed on neutrino properties. In particular, a new limit on the Dirac mass of the neutrino is presented. 12 refs.

  2. Born-Infeld condensate as a possible origin of neutrino masses and dark energy

    NASA Astrophysics Data System (ADS)

    Addazi, Andrea; Capozziello, Salvatore; Odintsov, Sergei

    2016-09-01

    We discuss the possibility that a Born-Infeld condensate coupled to neutrinos can generate both neutrino masses and an effective cosmological constant. In particular, an effective field theory is provided capable of dynamically realizing the neutrino superfluid phase firstly suggested by Ginzburg and Zharkov. In such a case, neutrinos acquire a mass gap inside the Born-Infeld ether forming a long-range Cooper pair. Phenomenological implications of the approach are also discussed.

  3. Constraints on decaying neutrinos from the far-ultraviolet extragalactic background light

    NASA Technical Reports Server (NTRS)

    Overduin, J. M.; Wesson, P. S.; Bowyer, S.

    1993-01-01

    We consider light neutrinos as dark matter candidates, concentrating on those proposed by Sciama, with rest energies near 30 eV and decay lifetimes of (2 +/- 1) x 10 exp 23 s. Using equations developed by Wesson et al. (1987) for the visible extragalactic background light, and assuming that the neutrinos are clustered in galactic halos similar to that around our own Galaxy, we show that their decay would be capable of significant contributions to the far-ultraviolet background. Observations in this region by Martin and Bowyer (1989) limit the possible mass of the neutrino halos to 2 x 10 exp 11 M(solar), which is less than the required galactic 'missing mass'. In order to form galactic halos of mass 5 x 10 exp 11 M(solar), such neutrinos would have to decay with lifetimes of at least 3 x 10 exp 23 s to be consistent with the observations. Sciama's proposal remains marginally viable, but more observational data will test it and similar neutrino models critically.

  4. Neutrino masses in the SU(4)L ⊗ U(1)X electroweak extension of the Standard Model

    NASA Astrophysics Data System (ADS)

    Palacio, Guillermo

    2016-09-01

    We study the neutrino mass generation in the SU(4)L ⊗ U(1)X electroweak extension of the Standard Model by considering nonrenormalizable dimension 5 effective operators. It is shown that there exist two topologies for the realizations of such an operator at the tree-level and for one of the three-family models the neutrino phenomenology is explored after extending its particle content with an SU(4)L fermion singlet and a scalar decuplet. Constraints in the available parameters space of the model are partially discussed.

  5. Determining neutrino mass hierarchy by precision measurements in electron and muon neutrino disappearance experiments

    SciTech Connect

    Minakata, H.; Nunokawa, H.; Parke, S.J.; Zukanovich Funchal, R.; /Sao Paulo U.

    2006-07-01

    Recently a new method for determining the neutrino mass hierarchy by comparing the effective values of the atmospheric {Delta}m{sup 2} measured in the electron neutrino disappearance channel, {Delta}m{sup 2}(ee), with the one measured in the muon neutrino disappearance channel, {Delta}m{sup 2}({mu}{mu}), was proposed. If {Delta}m{sup 2}(ee) is larger (smaller) than {Delta}m{sup 2} ({mu}{mu}) the hierarchy is of the normal (inverted) type. We re-examine this proposition in the light of two very high precision measurements: {Delta}m{sup 2}({mu}{mu}) that may be accomplished by the phase II of the Tokai-to-Kamioka (T2K) experiment, for example, and {Delta}m{sup 2}(ee) that can be envisaged using the novel Moessbauer enhanced resonant {bar {nu}}{sub e} absorption technique. Under optimistic assumptions for the systematic uncertainties of both measurements, we estimate the parameter region of ({theta}{sub 13}, {delta}) in which the mass hierarchy can be determined. If {theta}{sub 13} is relatively large, sin{sup 2} 2{theta}{sub 13} {approx}> 0.05, and both of {Delta}m{sup 2}(ee) and {Delta}m{sup 2}({mu}{mu}) can be measured with the precision of {approx} 0.5 % it is possible to determine the neutrino mass hierarchy at > 95% CL for 0.3{pi} {approx}< {delta} {approx}< 1.7 {pi} for the current best fit values of all the other oscillation parameters.

  6. Evaluation of the Majorana phases of a general Majorana neutrino mass matrix: Testability of hierarchical flavour models

    NASA Astrophysics Data System (ADS)

    Samanta, Rome; Chakraborty, Mainak; Ghosal, Ambar

    2016-03-01

    We evaluate the Majorana phases for a general 3 × 3 complex symmetric neutrino mass matrix on the basis of Mohapatra-Rodejohann's phase convention using the three rephasing invariant quantities I12, I13 and I23 proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses (Σimi) and the neutrinoless double beta decay (ββ0ν) parameter |m11 |. This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted hierarchy section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub cases following the normal hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.

  7. Measuring Neutrino Mass with Radioactive Ions in a Storage Ring

    SciTech Connect

    Lindroos, Mats; McElrath, Bob; Orme, Christopher; Schwetz, Thomas

    2010-03-30

    A method to measure the neutrino mass kinematically using beams of ions which undergo beta decay is proposed. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. By counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for m{sub n}u<0.2 eV, it is necessary to control the ion momentum with a precision better than deltap/p<10{sup -5}, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least O(10{sup 18}) decays.

  8. Radiative neutrino mass generation from WIMP dark matter

    NASA Astrophysics Data System (ADS)

    Lineros, Roberto A.

    2016-05-01

    The minimal seesaw extension of the Standard Model requires two electroweak singlet fermions in order to accommodate the neutrino oscillation parameters at tree level. Here we consider a next to minimal extension where light neutrino masses are generated radiatively by two electroweak fermions: one singlet and one triplet under SU(2). These should be odd under a parity symmetry and their mixing gives rise to a stable weakly interactive massive particle dark matter candidate. For mass in the GeV-TeV range, it reproduces the correct relic density, and provides an observable signal in nuclear recoil direct detection experiments. The fermion triplet component of the dark matter has gauge interactions, making it also detectable at present and near future collider experiments.

  9. Measuring neutrino mass with radioactive ions in a storage ring

    NASA Astrophysics Data System (ADS)

    Lindroos, Mats; McElrath, Bob; Orme, Christopher; Schwetz, Thomas

    2009-12-01

    We propose a method to measure the neutrino mass kinematically using beams of ions which undergo beta decay. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. Then, by counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for m ν <0.2 eV, it is necessary to control the ion momentum with a precision better than δ p/ p<10-5, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least mathcal{O}(10^{18}) decays.

  10. Measuring neutrino mass with radioactive ions in a storage ring

    NASA Astrophysics Data System (ADS)

    Lindroos, Mats; McElrath, Bob; Orme, Christopher; Schwetz, Thomas

    2010-01-01

    We propose a method to measure the neutrino mass kinematically using beams of ions which undergo beta decay. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. Then, by counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for mν < 0.2 eV, it is necessary to control the ion momentum with a precision better than δp/p < 10-5, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least Script O(1018) decays.

  11. Measuring Neutrino Mass with Radioactive Ions in a Storage Ring

    NASA Astrophysics Data System (ADS)

    Lindroos, Mats; McElrath, Bob; Orme, Christopher; Schwetz, Thomas

    2010-03-01

    A method to measure the neutrino mass kinematically using beams of ions which undergo beta decay is proposed. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. By counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for mν<0.2 eV, it is necessary to control the ion momentum with a precision better than δp/p<10-5, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least O(1018) decays.

  12. Cosmology with massive neutrinos III: the halo mass function and an application to galaxy clusters

    SciTech Connect

    Costanzi, Matteo; Borgani, Stefano; Villaescusa-Navarro, Francisco; Viel, Matteo; Xia, Jun-Qing; Castorina, Emanuele; Sefusatti, Emiliano E-mail: villaescusa@oats.inaf.it E-mail: xiajq@ihep.ac.cn E-mail: castori@sissa.it

    2013-12-01

    We use a suite of N-body simulations that incorporate massive neutrinos as an extra-set of particles to investigate their effect on the halo mass function. We show that for cosmologies with massive neutrinos the mass function of dark matter haloes selected using the spherical overdensity (SO) criterion is well reproduced by the fitting formula of Tinker et al. (2008) once the cold dark matter power spectrum is considered instead of the total matter power, as it is usually done. The differences between the two implementations, i.e. using P{sub cdm}(k) instead of P{sub m}(k), are more pronounced for large values of the neutrino masses and in the high end of the halo mass function: in particular, the number of massive haloes is higher when P{sub cdm}(k) is considered rather than P{sub m}(k). As a quantitative application of our findings we consider a Planck-like SZ-clusters survey and show that the differences in predicted number counts can be as large as 30% for ∑m{sub ν} = 0.4 eV. Finally, we use the Planck-SZ clusters sample, with an approximate likelihood calculation, to derive Planck-like constraints on cosmological parameters. We find that, in a massive neutrino cosmology, our correction to the halo mass function produces a shift in the σ{sub 8}(Ω{sub m}/0.27){sup γ} relation which can be quantified as Δγ ∼ 0.05 and Δγ ∼ 0.14 assuming one (N{sub ν} = 1) or three (N{sub ν} = 3) degenerate massive neutrino, respectively. The shift results in a lower mean value of σ{sub 8} with Δσ{sub 8} = 0.01 for N{sub ν} = 1 and Δσ{sub 8} = 0.02 for N{sub ν} = 3, respectively. Such difference, in a cosmology with massive neutrinos, would increase the tension between cluster abundance and Planck CMB measurements.

  13. How can we test the neutrino mass seesaw mechanism experimentally?

    PubMed

    Buckley, Matthew R; Murayama, Hitoshi

    2006-12-01

    The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve data from the CERN Large Hadron Collider, International Linear Collider, cosmology, underground, and low-energy flavor experiments to establish the case. PMID:17280194

  14. How can we test the neutrino mass seesaw mechanism experimentally?

    PubMed

    Buckley, Matthew R; Murayama, Hitoshi

    2006-12-01

    The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve data from the CERN Large Hadron Collider, International Linear Collider, cosmology, underground, and low-energy flavor experiments to establish the case.

  15. Peccei-Quinn symmetry, dark matter, and neutrino mass

    SciTech Connect

    Ma, Ernest

    2014-06-24

    It is pointed out that a residual Z{sub 2} symmetry of the usual anomalous Peccei-Quinn U(1){sub PQ} symmetry (which solves the strong CP problem) may be used for an absolutely stable heavy dark-matter particle in addition to the long-lived axion. The same Z{sub 2} symmetry may also be used to generate radiative neutrino mass.

  16. Sneutrino-antisneutrino mixing and neutrino mass in anomaly-mediated supersymmetry breaking scenario.

    PubMed

    Choi, Kiwoon; Hwang, Kyuwan; Song, Wan Young

    2002-04-01

    In supersymmetric models with nonzero Majorana neutrino mass, the sneutrino and antisneutrino mix, which may lead to same-sign dilepton signals in future collider experiments. We point out that the anomaly-mediated supersymmetry breaking scenario has a good potential to provide an observable rate of such signals for the neutrino masses suggested by the atmospheric and solar neutrino oscillations. It is noted also that the sneutrino-antisneutrino mixing can provide much stronger information on some combinations of the neutrino masses and mixing angles than the neutrino experiments.

  17. Examining the geometrical model with inverted mass hierarchy for neutrinos

    SciTech Connect

    Honda, Mizue; Tanimoto, Morimitsu

    2007-05-01

    The comprehensive analyses are presented in the model with the inverted mass hierarchy for neutrinos, which follows from a geometrical structure of a (1+5) dimensional space-time where two extra dimensions are compactified on the T{sup 2}/Z{sub 3} orbifold. The model gives two large lepton flavor mixings due to the S{sub 3} structure in the (1+5) dimensional space-time. It also predicts the lightest neutrino mass as m{sub 3}=(1-50)x10{sup -5} eV and the effective neutrino mass responsible for neutrinoless double beta decays as {sub ee}{approx_equal}50 meV. The low energy CP violation, J{sub CP} could be 0.02. On the other hand, the observed baryon asymmetry in the present universe is produced by the nonthermal leptogenesis, which works even at the reheating temperature T{sub R}=10{sup 4}-10{sup 6} GeV. The correlation between the baryon asymmetry and the low energy CP violation is examined in this model.

  18. Neutrino seesaw mechanism with texture zeros

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun; Marfatia, D.; Whisnant, K.

    2015-11-01

    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.

  19. NEUTRINO CONSTRAINTS TO THE DIFFUSE GAMMA-RAY EMISSION FROM ACCRETION SHOCKS

    SciTech Connect

    Dobardžić, A.; Prodanović, T. E-mail: prodanvc@df.uns.ac.rs

    2015-06-20

    Accretion of gas during the large-scale structure formation has been thought to give rise to shocks that can accelerate cosmic rays. This process then results in an isotropic extragalactic gamma-ray emission contributing to the extragalactic gamma-ray background (EGRB) observed by Fermi-LAT. Unfortunately, this emission has been difficult to constrain and thus presents an uncertain foreground to any attempts to extract a potential dark matter signal. Recently, IceCube has detected high-energy isotropic neutrino flux that could be of an extragalactic origin. In general, neutrinos can be linked to gamma rays since cosmic-ray interactions produce neutral and charged pions where neutral pions decay into gamma rays, while charged pions decay to give neutrinos. By assuming that isotropic high-energy IceCube neutrinos are entirely produced by cosmic rays accelerated in accretion shocks during the process of structure formation, we obtain the strongest constraint to the gamma-ray emission from large-scale structure formation (strong) shocks and find that they can make at best ∼20% of the EGRB, corresponding to neutrino flux with spectral index α{sub ν} = 2, or ∼10% for spectral index α{sub ν} = 2.46. Since typical objects where cosmic rays are accelerated in accretion shocks are galaxy clusters, observed high-energy neutrino fluxes can then be used to determine the gamma-ray emission of a dominant cluster type and constrain acceleration efficiency, and thus probe the process of large-scale structure formation.

  20. Constraint on the magnetic dipole moment of neutrinos by the tip-RGB luminosity in ω-Centauri

    NASA Astrophysics Data System (ADS)

    Arceo-Díaz, S.; Schröder, K.-P.; Zuber, K.; Jack, D.

    2015-10-01

    In this work, we use models constructed with the Eggleton code for stellar evolution, along with the photometric data of the super-rich globular cluster ω-Centauri (Sollima et al., 2004), to put a constraint on the magnetic dipole moment of neutrinos. We begin with a review of the idea proposed by Raffelt and Dearborn (1988), in which, as a consequence of a non-zero magnetic dipole moment, the tip-RGB luminosity of low mass stars gets increased over its standard value. First, we measure the dependence of the He-core mass and bolometric luminosity, at the tip-RGB, on the existing fits to characterize plasmon decay into neutrinos, namely those from Itoh et al. (1992), Haft et al. (1994), and the more recent results from Kantor and Gushakov (2007). Then, stating our definition of the tip-RGB, we revise multiple theoretical aspects: the consequences of non-standard neutrino emission on the internal structure of stellar models, its impact on the calibration of the Reimers mass-loss rate and later evolutionary phases and the influence of initial Helium abundance, metallicity, convection theory and opacities. Finally, we consider the specific case of ω-Cen. Using our tip-RGB models, and the bolometric correction obtained by the PHOENIX code for stellar atmospheres, to estimate the luminosity for canonical and non-standard evolution, also measuring the impact of the reported chemical spread in ω-Cen on our results. We find that the upper limit μν ≤ 2.2 ×10-12μB is already well constrained by observations. This result compares with the one obtained by Viaux et al. (2013), μν ≤ 2.6 ×10-12μB , from photometric study of the globular cluster M5.

  1. Geologic constraints on Rhea's bombardment mass

    NASA Astrophysics Data System (ADS)

    Leight, Clarissa; Rivera-Valentin, Edgard G.

    2016-10-01

    The mid-sized moons (MSMs) of Saturn display a peculiar set of properties that indicate the system may have been altered early in its history. The MSMs have a large spread in silicate content and diverse inferred thermal and physical histories that, unlike the Galilean satellites, do not demonstrate a trend with semi-major axis or size, which would indicate orbital evolution was a significant driver of their thermal histories. Rather, these features may indicate a significant role for impact-induced thermal and physical evolution. Geophysical properties along with measured crater counts can be used to constrain the bombardment history of the MSMs. Here we apply a fully three-dimensional Monte Carlo cratering model along with Rhea's measured cratering to provide constraints on the cumulative bombardment mass (Mb) experienced by the moon. The classic Nice model estimates Rhea's cumulative bombardment mass (MNice) to be 8.4x10^19 kg; our preliminary results suggest Rhea experienced a bombardment of 0.05 MNice < Mb < 0.06 MNice. Results agree well with similar constraints from Iapetus and provide further support to the Nice II model, which suggests a reduced bombardment for the outer solar system due to the planetesimals having higher kinetic energies. The inferred Mb and typical impact characteristics suggests Rhea may avoid runaway differentiation.

  2. Majorana neutrino masses and the neutrinoless double-beta decay

    SciTech Connect

    Faessler, A.

    2006-12-15

    Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in {sup 76}Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters.

  3. Measurement of the Top Quark Mass in Dilepton Final States with the Neutrino Weighting Method

    SciTech Connect

    Ilchenko, Yuriy

    2012-12-15

    The top quark is the heaviest fundamental particle observed to date. The mass of the top quark is a free parameter in the Standard Model (SM). A precise measurement of its mass is particularly important as it sets an indirect constraint on the mass of the Higgs boson. It is also a useful constraint on contributions from physics beyond the SM and may play a fundamental role in the electroweak symmetry breaking mechanism. I present a measurement of the top quark mass in the dilepton channel using the Neutrino Weighting Method. The data sample corresponds to an integrated luminosity of 4.3 fb-1 of p$\\bar{p}$ collisions at Tevatron with √s = 1.96 TeV, collected with the DØ detector. Kinematically under-constrained dilepton events are analyzed by integrating over neutrino rapidity. Weight distributions of t$\\bar{t}$ signal and background are produced as a function of the top quark mass for different top quark mass hypotheses. The measurement is performed by constructing templates from the moments of the weight distributions and input top quark mass, followed by a subsequent likelihood t to data. The dominant systematic uncertainties from jet energy calibration is reduced by using a correction from `+jets channel. To replicate the quark avor dependence of the jet response in data, jets in the simulated events are additionally corrected. The result is combined with our preceding measurement on 1 fb-1 and yields mt = 174.0± 2.4 (stat.) ±1.4 (syst.) GeV.

  4. Hybrid textures of the right-handed Majorana neutrino mass matrix

    NASA Astrophysics Data System (ADS)

    Dev, S.; Gautam, Radha Raman; Singh, Lal

    2013-08-01

    We perform a systematic study of neutrino mass matrices having a vanishing cofactor and an equality between two cofactors of the mass matrix. Such texture structures of the effective neutrino mass matrix arise from the type-I seesaw mechanism when the Dirac neutrino mass matrix is diagonal with two equal elements and the right-handed Majorana neutrino mass matrix has hybrid textures with one equality of matrix elements and one zero matrix element. For three right-handed neutrinos there are sixty possible hybrid textures out of which only six are excluded by the present experimental data. We show that such textures can be derived using discrete symmetries. The predictions of experimentally allowed textures are examined for unknown parameters such as the effective Majorana mass of the electron neutrino and the Dirac-type CP-violating phase.

  5. Connecting Dirac and Majorana neutrino mass matrices in the minimal left-right symmetric model.

    PubMed

    Nemevšek, Miha; Senjanović, Goran; Tello, Vladimir

    2013-04-12

    Probing the origin of neutrino mass by disentangling the seesaw mechanism is one of the central issues of particle physics. We address it in the minimal left-right symmetric model and show how the knowledge of light and heavy neutrino masses and mixings suffices to determine their Dirac Yukawa couplings. This in turn allows one to make predictions for a number of high and low energy phenomena, such as decays of heavy neutrinos, neutrinoless double beta decay, electric dipole moments of charged leptons, and neutrino transition moments. We also discuss a way of reconstructing the neutrino Dirac Yukawa couplings at colliders such as the LHC.

  6. Neutrino masses, leptogenesis, and dark matter in a hybrid seesaw model

    SciTech Connect

    Gu Peihong; Hirsch, M.; Valle, J. W. F.

    2009-02-01

    We suggest a hybrid seesaw model where relatively light right-handed neutrinos give no contribution to neutrino mass matrix due to a special symmetry. This allows their Yukawa couplings to the standard model particles to be relatively strong, so that the standard model Higgs boson can decay dominantly to a left- and a right-handed neutrino, leaving another stable right-handed neutrino as cold dark matter. In our model neutrino masses arise via the type-II seesaw mechanism, the Higgs triplet scalars being also responsible for the generation of the matter-antimatter asymmetry via the leptogenesis mechanism.

  7. A Type 2 supernovae constraint on neutrino(sub e) - neutrino(sub s) mixing

    NASA Technical Reports Server (NTRS)

    Shi, X.; Sigl, G.

    1993-01-01

    The role of a resonant nu(e) - nu(s) oscillation is discussed in the event of a supernova explosion. It is concluded that a significant nu(e) - nu(s) mixing may hinder the ability of the supernova to explode. It may also cool the proto-neutron star too quickly with respect to the observed cooling time of several seconds. The constraints on the nu(e) - nu(s) mixing parameters based on the above arguments are calculated.

  8. Form invariance and symmetry in the neutrino mass matrix

    SciTech Connect

    Lashin, E. I.; Nasri, S.; Malkawi, E.; Chamoun, N.

    2011-01-01

    We present the general form of the unitary matrices keeping invariant the Majorana neutrino mass matrix of specific texture suitable for explaining oscillation data. In the case of the tri-bimaximal pattern with two degenerate masses, we give a specific realization of the underlying U(1) symmetry which can be uplifted to a symmetry in a complete theory including charged leptons. For this, we present a model with three light SM-like Higgs doublets and one heavy Higgs triplet and find that one can accommodate the hierarchy of the charged-lepton masses. The lepton mass spectrum can also be achieved in another model extending the SM with three SM-singlet scalars transforming nontrivially under the flavor symmetry. We discuss how such a model has room for generating enough baryon asymmetry through leptogenesis in the framework of type-I and -II seesaw mechanisms.

  9. Neutrino Experiments

    SciTech Connect

    McKeown, R. D.

    2010-08-04

    Recent studies of neutrino oscillations have established the existence of finite neutrino masses and mixing between generations of neutrinos. The combined results from studies of atmospheric neutrinos, solar neutrinos, reactor antineutrinos and neutrinos produced at accelerators paint an intriguing picture that clearly requires modification of the standard model of particle physics. These results also provide clear motivation for future neutrino oscillation experiments as well as searches for direct neutrino mass and nuclear double-beta decay. I will discuss the program of new neutrino oscillation experiments aimed at completing our knowledge of the neutrino mixing matrix.

  10. a Cylindrical Mirror Analyser for Neutrino Mass Measurement.

    NASA Astrophysics Data System (ADS)

    Williams, Simon Shaughan

    Available from UMI in association with The British Library. Requires signed TDF. The design of an electrostatic Cylindrical Mirror Analyser (CMA) for neutrino mass measurement is given. The resolution is 15 eV FWHM, being achieved with second order focusing and tight collimation. The field-matching grids are unique, being sets of accurately positioned vertical wires producing negligible resolution effects. Luminosity is maximised with an extended source and by utilisation of the full 2pi of the CMA. Background is minimised as the deflecting voltage is half the analysing energy so that field--emission can be discriminated against. Cosmic -ray secondaries are largely removed by high resolution silicon surface barrier detectors. The construction of the CMA to an accuracy of ~10 eV in base resolution, and of the magnetic shielding and vacuum systems is outlined. The power supplies and monitoring systems, signal processing electronics and data acquisition software are also described. Ytterbium conversion electron measurements confirm the calculated CMA optical resolution function to better than 10% in half-width. These measurements demonstrate that the CMA calibration and dispersion are at their theoretical values and also identify a small mis-alignment in the CMA, consistent with construction accuracy. Correcting fields are subsequently designed. The end-point spectrum of tritium is measured using a Langmuir-Blodgett mono-layer source, yielding a neutrino mass limit of <64 eV (90% CL), including total resolution systematic error and being limited principally by statistical errors. Tritium measurements also verify the luminosity of the CMA as ~ 9 times 10^ {-4} cm^2 and demonstrate the extremely low background of 2 times 10^{-3} s^{-1} . Monte-Carlo simulations indicate that with this optical resolution, knowledge of molecular final states and energy loss, a lower limit of 10 eV (95% CL) should be measured for a neutrino mass of 30 eV with a suitable source. For a zero

  11. Very Low Energy Supernovae From Neutrino Mass Loss

    NASA Astrophysics Data System (ADS)

    Lovegrove, Elizabeth; Woosley, S. E.

    2013-01-01

    The continuing difficulty of achieving a reliable core-collapse supernova in simulation has led many to speculate about what transients might be visible if a core-collapse supernova fails. If some percentage of such supernovae fail, there may be many more types of transients occurring than are currently being detected and catalogued as supernovae. Even if the original outgoing shock in a collapsing presupernova star fails, one must still consider the hydrodynamic response of the star to the abrupt loss of a small amount of mass via neutrinos as the core forms a protoneutron star. Following a suggestion by Nadezhin (1980), we use the Kepler and CASTRO codes to model the hydrodynamical responses of typical supernova progenitor stars to the loss of approximately 0.2 - 0.5 solar masses of gravitational mass from their centers. In a red supergiant star, a very weak supernova with total kinetic energy ~1047 ergs results. The binding energy of the hydrogen envelope before the explosion is of the same order and, depending upon assumptions regarding the neutrino loss rates, most of it is ejected. Ejection speeds are ~50 km/s and luminosities ~1039 ergs/s are maintained for about a year. A significant part of the energy comes from the recombination of hydrogen. The color of the explosion is extremely red and the events bear some similarity to the detected transients catalogued as "luminous red novae."

  12. Constraints on nucleon decay via invisible modes from the Sudbury Neutrino Observatory.

    PubMed

    Ahmed, S N; Anthony, A E; Beier, E W; Bellerive, A; Biller, S D; Boger, J; Boulay, M G; Bowler, M G; Bowles, T J; Brice, S J; Bullard, T V; Chan, Y D; Chen, M; Chen, X; Cleveland, B T; Cox, G A; Dai, X; Dalnoki-Veress, F; Doe, P J; Dosanjh, R S; Doucas, G; Dragowsky, M R; Duba, C A; Duncan, F A; Dunford, M; Dunmore, J A; Earle, E D; Elliott, S R; Evans, H C; Ewan, G T; Farine, J; Fergani, H; Fleurot, F; Formaggio, J A; Fowler, M M; Frame, K; Frati, W; Fulsom, B G; Gagnon, N; Graham, K; Grant, D R; Hahn, R L; Hall, J C; Hallin, A L; Hallman, E D; Hamer, A S; Handler, W B; Hargrove, C K; Harvey, P J; Hazama, R; Heeger, K M; Heintzelman, W J; Heise, J; Helmer, R L; Hemingway, R J; Hime, A; Howe, M A; Jagam, P; Jelley, N A; Klein, J R; Kos, M S; Krumins, A V; Kutter, T; Kyba, C C M; Labranche, H; Lange, R; Law, J; Lawson, I T; Lesko, K T; Leslie, J R; Levine, I; Luoma, S; MacLellan, R; Majerus, S; Mak, H B; Maneira, J; Marino, A D; McCauley, N; McDonald, A B; McGee, S; McGregor, G; Mifflin, C; Miknaitis, K K S; Miller, G G; Moffat, B A; Nally, C W; Neubauer, M S; Nickel, B G; Noble, A J; Norman, E B; Oblath, N S; Okada, C E; Ollerhead, R W; Orrell, J L; Oser, S M; Ouellet, C; Peeters, S J M; Poon, A W P; Robertson, B C; Robertson, R G H; Rollin, E; Rosendahl, S S E; Rusu, V L; Schwendener, M H; Simard, O; Simpson, J J; Sims, C J; Sinclair, D; Skensved, P; Smith, M W E; Starinsky, N; Stokstad, R G; Stonehill, L C; Tafirout, R; Takeuchi, Y; Tesić, G; Thomson, M; Thorman, M; Van Berg, R; Van de Water, R G; Virtue, C J; Wall, B L; Waller, D; Waltham, C E; Tseung, H Wan Chan; Wark, D L; West, N; Wilhelmy, J B; Wilkerson, J F; Wilson, J R; Wittich, P; Wouters, J M; Yeh, M; Zuber, K

    2004-03-12

    Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to "invisible" modes, such as n-->3nu. The analysis was based on a search for gamma rays from the deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from 16O. A limit of tau(inv)>2 x 10(29) yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.

  13. Updated constraints on the light-neutrino exchange mechanisms of the 0νββ-decay

    SciTech Connect

    Štefánik, Dušan; Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-28

    The neutrinoless double-beta (0νββ) decay associated with light neutrino exchange mechanisms, which are due to both left-handed V-A and right-handed V+A leptonic and hadronic currents, is discussed by using the recent progress achieved by the GERDA, EXO and KamlandZen experiments. The upper limits for effective neutrino mass m{sub ββ} and the parameters 〈λ〉 and 〈η〉 characterizing the right handed current mechanisms are deduced from the data on the 0νββ-decay of {sup 76}Ge and {sup 136}Xe using nuclear matrix elements calculated within the nuclear shell model and quasiparticle random phase approximation and phase-space factors calculated with exact Dirac wave functions with finite nuclear size and electron screening. The careful analysis of upper constraints on effective lepton number violating parameters assumes a competition of the above mechanisms and arbitrary values of involved CP violating phases.

  14. Determining neutrino mass hierarchy by precise measurements of two delta m**2 in electron-neutrino and muon-neutrino disappearance experiments

    SciTech Connect

    Minakata, H.; Nunokawa, H.; Parke, Stephen J.; Zukanovich Funchal, R.; /Sao Paulo U.

    2006-09-01

    In this talk, the authors discuss the possibility of determining the neutrino mass hierarchy by comparing the two effective atmospheric neutrino mass squared differences measured, respectively, in electron, and in muon neutrino disappearance oscillation experiments. if the former, is larger (smaller) than the latter, the mass hierarchy is of normal (inverted) type. They consider two very high precision (a few per mil) measurements of such mass squared differences by the phase II of the T2K (Tokai-to-Kamioka) experiment and by the novel Moessbauer enhanced resonant {bar {nu}}{sub e} absorption technique. Under optimistic assumptions for the systematic errors of both measurements, they determine the region of sensitivities where the mass hierarchy can be distinguished. Due to the tight space limitation, they present only the general idea and show a few most important plots.

  15. Probing models of Dirac neutrino masses via the flavor structure of the mass matrix

    NASA Astrophysics Data System (ADS)

    Kanemura, Shinya; Sakurai, Kodai; Sugiyama, Hiroaki

    2016-07-01

    We classify models of the Dirac neutrino mass by concentrating on flavor structures of the mass matrix. The advantage of our classification is that we do not need to specify detail of models except for Yukawa interactions because flavor structures can be given only by products of Yukawa matrices. All possible Yukawa interactions between leptons (including the right-handed neutrino) are taken into account by introducing appropriate scalar fields. We also take into account the case of Yukawa interactions of leptons with the dark matter candidate. Then, we see that flavor structures can be classified into seven groups. The result is useful for the efficient test of models of the neutrino mass. One of seven groups can be tested by measuring the absolute neutrino mass. Other two can be tested by probing the violation of the lepton universality in ℓ →ℓ‧ ν ν ‾. In order to test the other four groups, we can rely on searches for new scalar particles at collider experiments.

  16. New experimental approaches to search for neutrino mass

    SciTech Connect

    Gironi, L.

    2013-12-30

    In order to obtain high sensitivity in the study of the neutrino mass it is necessary to design experiments able to optimize all the sensitivity parameters. One of the most promising techniques to achieve this goal is the bolometric technique because of its intrinsic characteristics: high detection efficiency, excellent energy resolution, low intrinsic background and the possibility to study many different compounds. The bolometric technique has already obtained excellent results on the neutrino mass study with Cuoricino. The Cuoricino experiment has also shown that surface contaminations of materials facing the detectors would be the limiting factor for the sensitivity of next generation experiments with bolometers. Mainly for this reason scintillating bolometers have been developed allowing a very efficient discrimination of alpha particles thanks to their double readout. Tests performed on these crystals showed moreover the possibility to discriminate the interacting particles through a pulse shape analysis. This feature is very promising because it allows to reach the same results on the background reduction obtained with the hybrid detectors but without complicating the experimental assembly.

  17. Probing the neutrino mass hierarchy with cosmic microwave background weak lensing

    NASA Astrophysics Data System (ADS)

    Hall, Alex C.; Challinor, Anthony

    2012-09-01

    We forecast constraints on cosmological parameters with primary cosmic microwave background (CMB) anisotropy information and weak lensing reconstruction with a future post-Planck CMB experiment, the Cosmic Origins Explorer (COrE), using oscillation data on the neutrino mass splittings as prior information. Our Markov chain Monte Carlo (MCMC) simulations in flat models with a non-evolving equation of state of dark energy w give typical 68 per cent upper bounds on the total neutrino mass of 0.136 and 0.098 eV for the inverted and normal hierarchies, respectively, assuming the total summed mass is close to the minimum allowed by the oscillation data for the respective hierarchies (0.10 and 0.06 eV). Including geometric information from future baryon acoustic oscillation measurements with the complete Baryon Oscillation Spectroscopic Survey, Type Ia supernovae distance moduli from Wide-Field Infrared Survey Telescope (WFIRST) and a realistic prior on the Hubble constant, these upper limits shrink to 0.118 and 0.080 eV for the inverted and normal hierarchies, respectively. Addition of these distance priors also yields per cent-level constraints on w. We find tension between our MCMC results and the results of a Fisher matrix analysis, most likely due to a strong geometric degeneracy between the total neutrino mass, the Hubble constant and w in the unlensed CMB power spectra. If the minimal-mass, normal hierarchy were realized in nature, the inverted hierarchy should be disfavoured by the full data combination at typically greater than the 2σ level. For the minimal-mass inverted hierarchy, we compute the Bayes factor between the two hierarchies for various combinations of our forecast data sets, and find that the future cosmological probes considered here should be able to provide 'strong' evidence (odds ratio 12:1) for the inverted hierarchy. Finally, we consider potential biases of the other cosmological parameters from assuming the wrong hierarchy and find that all

  18. Neutrinos and dark energy after Planck and BICEP2: data consistency tests and cosmological parameter constraints

    SciTech Connect

    Zhang, Jing-Fei; Geng, Jia-Jia; Zhang, Xin E-mail: gengjiajia163@163.com

    2014-10-01

    The detection of the B-mode polarization of the cosmic microwave background (CMB) by the BICEP2 experiment implies that the tensor-to-scalar ratio r should be involved in the base standard cosmology. In this paper, we extend the ΛCDM r+neutrino/dark radiation models by replacing the cosmological constant with the dynamical dark energy with constant w. Four neutrino plus dark energy models are considered, i.e., the wCDM r ∑ m{sub ν}, wCDM r N{sub eff}, wCDM r ∑ m{sub ν} N{sub eff}, and wCDM r N{sub eff} m{sub ν,sterile}{sup eff} models. The current observational data considered in this paper include the Planck temperature data, the WMAP 9-year polarization data, the baryon acoustic oscillation data, the Hubble constant direct measurement data, the Planck Sunyaev-Zeldovich cluster counts data, the Planck CMB lensing data, the cosmic shear data, and the BICEP2 polarization data. We test the data consistency in the four cosmological models, and then combine the consistent data sets to perform joint constraints on the models. We focus on the constraints on the parameters w, ∑ m{sub ν}, N{sub eff}, and m{sub ν,sterile}{sup eff}.

  19. Baryon Triality And Neutrino Masses From An Anomalous FlavorU(1)

    SciTech Connect

    Dreiner, Herbi K.; Luhn, Christoph; Murayama, Hitoshi; Thormeier,Marc

    2007-08-15

    We construct a concise U(1){sub X} Froggatt-Nielsen model in which baryon triality, a discrete gauge Z{sub 3}-symmetry, arises from U(1){sub X} breaking. The proton is thus stable, however, R-parity is violated. With the proper choice of U(1){sub X} charges we can obtain neutrino masses and mixings consistent with an explanation of the atmospheric and solar neutrino anomalies in terms of neutrino oscillations, with no right-handed neutrinos required. The only mass scale apart from M{sub grav} is m{sub soft}.

  20. Neutrino masses and leptogenesis in type I and type II seesaw models

    NASA Astrophysics Data System (ADS)

    Borah, Debasish; Das, Mrinal Kumar

    2014-07-01

    The baryon to photon ratio in the present Universe is very accurately measured to be (6.065±0.090)×10-10. We study the possible origin of this baryon asymmetry in the neutrino sector through the generic mechanism of baryogenesis through leptogenesis. We consider both the type I and type II seesaw origin of neutrino masses within the framework of left-right symmetric models (LRSM). Using the latest best-fit global neutrino oscillation data of mass squared differences, mixing angles and Dirac CP phase, we compute the predictions for baryon to photon ratio keeping the Majorana CP phases as free parameters for two different choices of lightest neutrino mass eigenvalue for both normal and inverted hierarchical patterns of neutrino masses. We do our calculation with and without lepton flavor effects being taken into account. We choose different diagonal Dirac neutrino mass matrix for different flavor effects in such a way that the lightest right-handed neutrino mass is in the appropriate range. We also study the predictions for baryon asymmetry when the neutrino masses arise from a combination of both type I and type II seesaw (with dominating type I term) and discriminate between several combinations of Dirac and Majorana CP phases by demanding successful predictions for baryon asymmetry.

  1. Neutrino Physics

    NASA Astrophysics Data System (ADS)

    Bergström, L.; Hulth, P. O.; Botner, O.; Carlson, P.; Ohlsson, T.

    2006-03-01

    J. N. Bahcall (1934-2005) -- Preface -- List of participants -- Committees -- Nobel symposium on neutrino physics - program -- The history of neutrino oscillations / S. M. Bilenky -- Super-Kamiokande results on neutrino oscillations / Y. Suzuki -- Sudbury neutrino observatory results / A. B. McDonald -- Results from KamLAND reactor neutrino detection / A. Suzuki -- New opportunities for surprise / J. Conrad -- Solar models and solar neutrinos / J. N. Bahcall -- Atmospheric neutrino fluxes / T. K. Gaisser -- The MSW effect and matter effects in neutrino oscillations / A. Yu. Smirnov -- Three-flavour effects and CP- and T-violation in neutrino oscillations / E. Kh. Akhmedov -- Global analysis of neutrino data / M. C. Gonzalez-Garcia -- Future precision neutrino oscillation experiments and theoretical implications / M. Lindner -- Experimental prospects of neutrinoless double beta decay / E. Fiorini -- Theoretical prospects of neutrinoless double beta decay / S. T. Petcov -- Supernova neutrino oscillations / G. G. Raffelt -- High-energy neutrino astronomy / F. Halzen -- Neutrino astrophysics in the cold: Amanda, Baikal and IceCube / C. Spiering -- Status of radio and acoustic detection of ultra-high energy cosmic neutrinos and a proposal on reporting results / D. Saltzberg -- Detection of neutrino-induced air showers / A. A. Watson -- Prospect for relic neutrino searches / G. B. Gelmini -- Leptogenesis in the early universe / T. Yanagida -- Neutrinos and big bang nucleosynthesis / G. Steigman -- Extra galactic sources of high energy neutrinos / E. Waxman -- Cosmological neutrino bounds for non-cosmologists / M. Tegmark -- Neutrino intrinsic properties: the neutrino-antineutrino relation / B. Kayser -- NuTeV and neutrino properties / M. H. Shaevitz -- Absolute masses of neutrinos - experimental results and future possibilities / C. Weinheimer -- Flavor theories and neutrino masses / P. Ramond -- Neutrino mass models and leptogenesis / S. F. King -- Neutrino mass and

  2. Dark matter and neutrino masses from a scale-invariant multi-Higgs portal

    NASA Astrophysics Data System (ADS)

    Karam, Alexandros; Tamvakis, Kyriakos

    2015-10-01

    We consider a classically scale invariant version of the Standard Model, extended by an extra dark S U (2 )X gauge group. Apart from the dark gauge bosons and a dark scalar doublet which is coupled to the Standard Model Higgs through a portal coupling, we incorporate right-handed neutrinos and an additional real singlet scalar field. After symmetry breaking à la Coleman-Weinberg, we examine the multi-Higgs sector and impose theoretical and experimental constraints. In addition, by computing the dark matter relic abundance and the spin-independent scattering cross section off a nucleon we determine the viable dark matter mass range in accordance with present limits. The model can be tested in the near future by collider experiments and direct detection searches such as XENON 1T.

  3. Leptogenesis, radiative neutrino masses and inert Higgs triplet dark matter

    NASA Astrophysics Data System (ADS)

    Lu, Wen-Bin; Gu, Pei-Hong

    2016-05-01

    We extend the standard model by three types of inert fields including Majorana fermion singlets/triplets, real Higgs singlets/triplets and leptonic Higgs doublets. In the presence of a softly broken lepton number and an exactly conserved Z2 discrete symmetry, these inert fields together can mediate a one-loop diagram for a Majorana neutrino mass generation. The heavier inert fields can decay to realize a successful leptogenesis while the lightest inert field can provide a stable dark matter candidate. As an example, we demonstrate the leptogenesis by the inert Higgs doublet decays. We also perform a systematic study on the inert Higgs triplet dark matter scenario where the interference between the gauge and Higgs portal interactions can significantly affect the dark matter properties.

  4. Measurable neutrino mass scale in A{sub 4}xSU(5)

    SciTech Connect

    Antusch, S.; Spinrath, M.; King, Stephen F.

    2011-01-01

    We propose a supersymmetric A{sub 4}xSU(5) model of quasidegenerate neutrinos which predicts the effective neutrino mass m{sub ee} relevant for neutrinoless double beta decay to be proportional to the neutrino mass scale, thereby allowing its determination approximately independently of unknown Majorana phases. Such a natural quasidegeneracy is achieved by using A{sub 4} family symmetry (as an example of a non-Abelian family symmetry with real triplet representations) to enforce a contribution to the neutrino mass matrix proportional to the identity. Tribimaximal neutrino mixing as well as quark CP violation with {alpha}{approx_equal}90 deg. d a leptonic CP phase {delta}{sub MNS{approx_equal}}90 deg. arise from the breaking of the A{sub 4} family symmetry by the vacuum expectation values of four 'flavon' fields pointing in specific postulated directions in flavor space.

  5. Dark matter and strong electroweak phase transition in a radiative neutrino mass model

    SciTech Connect

    Ahriche, Amine; Nasri, Salah E-mail: snasri@uaeu.ac.ae

    2013-07-01

    We consider an extension of the standard model (SM) with charged singlet scalars and right handed (RH) neutrinos all at the electroweak scale. In this model, the neutrino masses are generated at three loops, which provide an explanation for their smallness, and the lightest RH neutrino, N{sub 1}, is a dark matter candidate. We find that for three generations of RH neutrinos, the model can be consistent with the neutrino oscillation data, lepton flavor violating processes, N{sub 1} can have a relic density in agreement with the recent Planck data, and the electroweak phase transition can be strongly first order. We also show that the charged scalars may enhance the branching ratio h→γγ, where as h→γZ get can get few percent suppression. We also discuss the phenomenological implications of the RH neutrinos at the collider.

  6. Cosmic Neutrinos

    SciTech Connect

    Quigg, Chris; /Fermilab /CERN

    2008-02-01

    I recall the place of neutrinos in the electroweak theory and summarize what we know about neutrino mass and flavor change. I next review the essential characteristics expected for relic neutrinos and survey what we can say about the neutrino contribution to the dark matter of the Universe. Then I discuss the standard-model interactions of ultrahigh-energy neutrinos, paying attention to the consequences of neutrino oscillations, and illustrate a few topics of interest to neutrino observatories. I conclude with short comments on the remote possibility of detecting relic neutrinos through annihilations of ultrahigh-energy neutrinos at the Z resonance.

  7. Diffuse supernova neutrinos: oscillation effects, stellar cooling and progenitor mass dependence

    SciTech Connect

    Lunardini, Cecilia; Tamborra, Irene E-mail: tamborra@mpp.mpg.de

    2012-07-01

    We estimate the diffuse supernova neutrino background (DSNB) using the recent progenitor-dependent, long-term supernova simulations from the Basel group and including neutrino oscillations at several post-bounce times. Assuming multi-angle matter suppression of collective effects during the accretion phase, we find that oscillation effects are dominated by the matter-driven MSW resonances, while neutrino-neutrino collective effects contribute at the 5–10% level. The impact of the neutrino mass hierarchy, of the time-dependent neutrino spectra and of the diverse progenitor star population is 10% or less, small compared to the uncertainty of at least 25% of the normalization of the supernova rate. Therefore, assuming that the sign of the neutrino mass hierarchy will be determined within the next decade, the future detection of the DSNB will deliver approximate information on the MSW-oscillated neutrino spectra. With a reliable model for neutrino emission, its detection will be a powerful instrument to provide complementary information on the star formation rate and for learning about stellar physics.

  8. Neutrino mass matrices with two equalities between the elements or cofactors

    NASA Astrophysics Data System (ADS)

    Dev, S.; Gautam, Radha Raman; Singh, Lal

    2013-04-01

    We study the implications of the existence of two equalities between the elements or cofactors of the neutrino mass matrix. There are 65 structures of this type for each case. Phenomenological implications for unknown parameters like the effective Majorana mass of the electron neutrino and CP-violating phases are examined for the viable cases. To illustrate how such forms of the neutrino mass matrices may be realized, we also present a simple A4 model for one of the classes in each case.

  9. Unified description of fermion masses with quasi-degenerate neutrinos in SO(10)

    SciTech Connect

    Joshipura, Anjan S.; Patel, Ketan M.

    2011-10-06

    Obtaining a unified description of the quasi-degenerate neutrino mass spectrum together with the hierarchical charged fermions is a challenging task. In this talk, we discuss two distinct possible scenarios leading to such spectra in the supersymmetric SO(10) grand unified framework. Consistency of both scenarios is demonstrated through detailed fits to fermion masses and mixing angles, all of which can be explained with reasonable accuracy in a model with the most general Yukawa sector of SO(10). The origin of large neutrino mixing angles is linked to neutrino mass degeneracy in both the scenarios.

  10. Neutrino mass matrices with M{sub ee}=0

    SciTech Connect

    BenTov, Yoni; Zee, A.

    2011-10-01

    Motivated by the possibility that the amplitude for neutrinoless double beta decay may be much smaller than the planned sensitivity of future experiments, we study Ansaetze for the neutrino mass matrix with M{sub ee}=0. For the case in which CP is conserved, we consider two classes of real-valued mass matrices: ''Class I'' defined by |M{sub e{mu}|}=|M{sub e{tau}|}, and ''Class II'' defined by |M{sub {mu}{mu}|}=|M{sub {tau}{tau}|}. The important phenomenological distinction between the two is that Class I permits only small values of V{sub e3} up to {approx}0.03, while Class II admits large values of V{sub e3} up to its empirical upper limit of 0.22. Then we introduce CP-violating complex phases into the mass matrix. We show that it is possible to have tribimaximal mixing with M{sub ee}=0 and |M{sub {mu}{tau}|}=|M{sub {mu}{mu}|}=|M{sub {tau}{tau}|} if the Majorana phase angles are {+-}{pi}/4. Alternatively, for smaller values of |M{sub {mu}{tau}|}=|M{sub {mu}{mu}|}=|M{sub {tau}{tau}|} it is possible to obtain |V{sub e3}|{approx}0.2 and generate relatively large CP-violating amplitudes. To eliminate phase redundancy, we emphasize rephasing any mass matrix with M{sub ee}=0 into a standard form with two complex phases. The discussion alternates between analytical and numerical but remains purely phenomenological, without any attempt to derive mass matrices from a fundamental theory.

  11. Seesaw scale discrete dark matter and two-zero texture Majorana neutrino mass matrices

    NASA Astrophysics Data System (ADS)

    Lamprea, J. M.; Peinado, E.

    2016-09-01

    In this paper we present a scenario where the stability of dark matter and the phenomenology of neutrinos are related by the spontaneous breaking of a non-Abelian flavor symmetry (A4). In this scenario the breaking is done at the seesaw scale, in such a way that what remains of the flavor symmetry is a Z2 symmetry, which stabilizes the dark matter. We have proposed two models based on this idea, for which we have calculated their neutrino mass matrices achieving two-zero texture in both cases. Accordingly, we have updated this two-zero texture phenomenology finding an interesting correlation between the reactor mixing angle and the sum of the light neutrino masses. We also have a correlation between the lightest neutrino mass and the neutrinoless double beta decay effective mass, obtaining a lower bound for the effective mass within the region of the nearly future experimental sensitivities.

  12. Neutrino mass hierarchy and electron neutrino oscillation parameters with one hundred thousand reactor events

    NASA Astrophysics Data System (ADS)

    Capozzi, F.; Lisi, E.; Marrone, A.

    2014-01-01

    Proposed medium-baseline reactor neutrino experiments offer unprecedented opportunities to probe, at the same time, the mass-mixing parameters which govern νe oscillations both at long wavelength (δm2 and θ12) and at short wavelength (Δm2 and θ13), as well as their tiny interference effects related to the mass hierarchy (i.e., the relative sign of Δm2 and δm2). In order to take full advantage of these opportunities, precision calculations and refined statistical analyses of event spectra are required. In such a context, we revisit several input ingredients, including nucleon recoil in inverse beta decay and its impact on energy reconstruction and resolution, hierarchy and matter effects in the oscillation probability, spread of reactor distances, irreducible backgrounds from geoneutrinos and from far reactors, and degeneracies between energy scale and spectrum shape uncertainties. We also introduce a continuous parameter α, which interpolates smoothly between normal hierarchy (α =+1) and inverted hierarchy (α =-1). The determination of the hierarchy is then transformed from a test of hypothesis to a parameter estimation, with a sensitivity given by the distance of the true case (either α=+1 or α =-1) from the "undecidable" case (α=0). Numerical experiments are performed for the specific setup envisaged for the JUNO project, assuming a realistic sample of O(105) reactor events. We find a typical sensitivity of ˜2σ to the hierarchy in JUNO, which, however, can be challenged by energy scale and spectrum shape systematics, whose possible conspiracy effects are investigated. The prospective accuracy reachable for the other mass-mixing parameters is also discussed.

  13. Leptonic unitarity triangles and effective mass triangles of the Majorana neutrinos

    NASA Astrophysics Data System (ADS)

    Xing, Zhi-zhong; Zhu, Jing-yu

    2016-07-01

    Given the best-fit results of six neutrino oscillation parameters, we plot the Dirac and Majorana unitarity triangles (UTs) of the 3 × 3 lepton flavor mixing matrix to show their real shapes in the complex plane. The connections of the three Majorana UTs with neutrino-antineutrino oscillations and neutrino decays are explored, and the possibilities of right or isosceles UTs are discussed. In the neutrino mass limit of m1 → 0 or m3 → 0, which is definitely allowed by current data, we show how the six triangles formed by the effective Majorana neutrino masses αβ (for α , β = e , μ , τ) and their corresponding component vectors look like in the complex plane. The relations of such triangles to the Majorana phases and to the lepton-number-violating decays H++ →α+β+ in the type-II seesaw mechanism are also illustrated.

  14. NOvA and T2K: The Race for the neutrino mass hierarchy

    SciTech Connect

    Mena, Olga; Nunokawa, Hiroshi; Parke, Stephen J.; /Fermilab

    2006-09-01

    The determination of the ordering of the neutrino masses (the hierarchy) is probably a crucial prerequisite to understand the origin of lepton masses and mixings and to establish their relationship to the analogous properties in the quark sector. Here, we follow an alternative strategy to the usual neutrino-antineutrino comparison in long baseline neutrino oscillation experiments: we exploit the combination of the neutrino-only data from the NOvA and the T2K experiments by performing these two off-axis experiments at different distances but at the same /L, where is the mean neutrino energy and L is the baseline. This would require a minor adjustment to the proposed off-axis angle for one or both of the proposed experiments.

  15. Impact of eV-mass sterile neutrinos on neutrino-driven supernova outflows

    SciTech Connect

    Tamborra, Irene; Raffelt, Georg G.; Hüdepohl, Lorenz; Janka, Hans-Thomas E-mail: raffelt@mpp.mpg.de E-mail: thj@mpa-garching.mpg.de

    2012-01-01

    Motivated by recent hints for sterile neutrinos from the reactor anomaly, we study active-sterile conversions in a three-flavor scenario (2 active + 1 sterile families) for three different representative times during the neutrino-cooling evolution of the proto-neutron star born in an electron-capture supernova. In our ''early model'' (0.5 s post bounce), the ν{sub e}-ν{sub s} MSW effect driven by Δm{sup 2} = 2.35eV{sup 2} is dominated by ordinary matter and leads to a complete ν{sub e}-ν{sub s} swap with little or no trace of collective flavor oscillations. In our ''intermediate'' (2.9 s p.b.) and ''late models'' (6.5 s p.b.), neutrinos themselves significantly modify the ν{sub e}-ν{sub s} matter effect, and, in particular in the late model, νν refraction strongly reduces the matter effect, largely suppressing the overall ν{sub e}-ν{sub s} MSW conversion. This phenomenon has not been reported in previous studies of active-sterile supernova neutrino oscillations. We always include the feedback effect on the electron fraction Y{sub e} due to neutrino oscillations. In all examples, Y{sub e} is reduced and therefore the presence of sterile neutrinos can affect the conditions for heavy-element formation in the supernova ejecta, even if probably not enabling the r-process in the investigated outflows of an electron-capture supernova. The impact of neutrino-neutrino refraction is strong but complicated, leaving open the possibility that with a more complete treatment, or for other supernova models, active-sterile neutrino oscillations could generate conditions suitable for the r-process.

  16. Neutrino masses and mixings: Status of known and unknown 3ν parameters

    NASA Astrophysics Data System (ADS)

    Capozzi, F.; Lisi, E.; Marrone, A.; Montanino, D.; Palazzo, A.

    2016-07-01

    Within the standard 3ν mass-mixing framework, we present an up-to-date global analysis of neutrino oscillation data (as of January 2016), including the latest available results from experiments with atmospheric neutrinos (Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K ν ‾ and NO νAν runs in both appearance and disappearance modes), and at short-baseline reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis of older KamLAND data in the light of the "bump" feature recently observed in reactor spectra. We discuss improved constraints on the five known oscillation parameters (δm2, | Δm2 |, sin2 ⁡θ12, sin2 ⁡θ13, sin2 ⁡θ23), and the status of the three remaining unknown parameters: the mass hierarchy [sign (± Δm2)], the θ23 octant [sign (sin2 ⁡θ23 - 1 / 2)], and the possible CP-violating phase δ. With respect to previous global fits, we find that the reanalysis of KamLAND data induces a slight decrease of both δm2 and sin2 ⁡θ12, while the latest accelerator and atmospheric data induce a slight increase of | Δm2 |. Concerning the unknown parameters, we confirm the previous intriguing preference for negative values of sin ⁡ δ (with best-fit values around sin ⁡ δ ≃ - 0.9), but we find no statistically significant indication about the θ23 octant or the mass hierarchy (normal or inverted). Assuming an alternative (so-called LEM) analysis of NO νA data, some δ ranges can be excluded at > 3 σ, and the normal mass hierarchy appears to be slightly favored at ∼ 90% C.L. We also describe in detail the covariances of selected pairs of oscillation parameters. Finally, we briefly discuss the implications of the above results on the three non-oscillation observables sensitive to the (unknown) absolute ν mass scale: the sum of ν masses Σ (in cosmology), the effective νe mass mβ (in beta decay), and the effective Majorana mass mββ (in neutrinoless double beta decay).

  17. Leptoquark patterns unifying neutrino masses, flavor anomalies, and the diphoton excess

    NASA Astrophysics Data System (ADS)

    Deppisch, F. F.; Kulkarni, S.; Päs, H.; Schumacher, E.

    2016-07-01

    Vector leptoquarks provide an elegant solution to a series of anomalies and at the same time generate naturally light neutrino masses through their mixing with the standard model Higgs boson. We present a simple Froggatt-Nielsen model to accommodate the B physics anomalies RK and RD , neutrino masses, and the 750 GeV diphoton excess in one cohesive framework adding only two vector leptoquarks and two singlet scalar fields to the standard model field content.

  18. Direct x-ray constraints on sterile neutrino warm dark matter

    SciTech Connect

    Watson, Casey R.; Yueksel, Hasan; Beacom, John F.; Walker, Terry P.

    2006-08-01

    Warm dark matter might more easily account for small scale clustering measurements than the heavier particles typically invoked in {lambda} cold dark matter ({lambda}CDM) cosmologies. In this paper, we consider a {lambda}WDM cosmology in which sterile neutrinos {nu}{sub s}, with a mass m{sub s} of roughly 1-100 keV, are the dark matter. We use the diffuse x-ray spectrum (total minus resolved point source emission) of the Andromeda galaxy to constrain the rate of sterile neutrino radiative decay: {nu}{sub s}{yields}{nu}{sub e,{mu}}{sub ,{tau}}+{gamma}. Our findings demand that m{sub s}<3.5 keV (95% C.L.) which is a significant improvement over the previous (95% C.L.) limits inferred from the x-ray emission of nearby clusters, m{sub s}<8.2 keV (Virgo A) and m{sub s}<6.3 keV (Virgo A+Coma)

  19. Measurement of the Neutrino Mass Splitting and Flavor Mixing by MINOS

    SciTech Connect

    Adamson, P.

    2011-05-01

    Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of 7.25 x 10$^{20}$ protons on target. A fit to neutrino oscillations yields values of |Δm$^{2}$| = (2.32$^{+0.12}_{-0.08}$) x 10$^{-3}$ eV$^{2}$ for the atmospheric mass splitting and sin $^{2}$(2θ) > 0.90 (90% C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively.

  20. Measurement of the neutrino mass splitting and flavor mixing by MINOS.

    PubMed

    Adamson, P; Andreopoulos, C; Armstrong, R; Auty, D J; Ayres, D S; Backhouse, C; Barr, G; Bishai, M; Blake, A; Bock, G J; Boehnlein, D J; Bogert, D; Cavanaugh, S; Cherdack, D; Childress, S; Choudhary, B C; Coelho, J A B; Coleman, S J; Corwin, L; Cronin-Hennessy, D; Danko, I Z; de Jong, J K; Devenish, N E; Diwan, M V; Dorman, M; Escobar, C O; Evans, J J; Falk, E; Feldman, G J; Frohne, M V; Gallagher, H R; Gomes, R A; Goodman, M C; Gouffon, P; Graf, N; Gran, R; Grant, N; Grzelak, K; Habig, A; Harris, D; Hartnell, J; Hatcher, R; Himmel, A; Holin, A; Huang, X; Hylen, J; Ilic, J; Irwin, G M; Isvan, Z; Jaffe, D E; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Koizumi, G; Kopp, S; Kordosky, M; Kreymer, A; Lang, K; Lefeuvre, G; Ling, J; Litchfield, P J; Litchfield, R P; Loiacono, L; Lucas, P; Mann, W A; Marshak, M L; Mayer, N; McGowan, A M; Mehdiyev, R; Meier, J R; Messier, M D; Michael, D G; Miller, W H; Mishra, S R; Mitchell, J; Moore, C D; Morfín, J; Mualem, L; Mufson, S; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nowak, J A; Oliver, W P; Orchanian, M; Ospanov, R; Paley, J; Patterson, R B; Pawloski, G; Pearce, G F; Petyt, D A; Phan-Budd, S; Plunkett, R K; Qiu, X; Ratchford, J; Raufer, T M; Rebel, B; Rodrigues, P A; Rosenfeld, C; Rubin, H A; Sanchez, M C; Schneps, J; Schreiner, P; Shanahan, P; Smith, C; Sousa, A; Stamoulis, P; Strait, M; Tagg, N; Talaga, R L; Thomas, J; Thomson, M A; Tinti, G; Toner, R; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Weber, A; Webb, R C; White, C; Whitehead, L; Wojcicki, S G; Yang, T; Zwaska, R

    2011-05-01

    Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of 7.25×10(20) protons on target. A fit to neutrino oscillations yields values of |Δm(2)|=(2.32(-0.08)(+0.12))×10(-3) eV(2) for the atmospheric mass splitting and sin(2)(2θ)>0.90 (90% C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively.

  1. Cosmology based on f(R) gravity admits 1 eV sterile neutrinos.

    PubMed

    Motohashi, Hayato; Starobinsky, Alexei A; Yokoyama, Jun'ichi

    2013-03-22

    It is shown that the tension between recent neutrino oscillation experiments, favoring sterile neutrinos with masses of the order of 1 eV, and cosmological data which impose stringent constraints on neutrino masses from the free streaming suppression of density fluctuations, can be resolved in models of the present accelerated expansion of the Universe based on f(R) gravity.

  2. Low mass binary neutron star mergers : gravitational waves and neutrino emission

    NASA Astrophysics Data System (ADS)

    Foucart, Francois; SXS Collaboration Collaboration

    2016-03-01

    We present numerical simulations of low mass binary neutron star mergers (1 . 2M⊙ - 1 . 2M⊙) with the SpEC code for a set of three nuclear-theory based, finite temperature equations of state. The merger remnant is a massive neutron star which is either permanently stable or long-lived. We focus on the post-merger gravitational wave signal, and on neutrino-matter interactions in the merger remnant. We show that the frequency peaks of the post-merger gravitational wave signal are in good agreement with predictions obtained from simulations using a simpler treatment of gravity. We then estimate the neutrino emission of the remnant using a neutrino leakage scheme and, in one case, compare these results with a gray two-moment neutrino transport scheme. We confirm the complex geometry of the neutrino emission, also observed in previous simulations with neutrino leakage, and show explicitly the presence of important differences in the neutrino luminosity, disk composition, and outflow properties between the neutrino leakage and transport schemes. We discuss the impact of our results on our ability to measure the neutron star equation of state, and on the post-merger electromagnetic signal and r-process nucleosynthesis in neutron star mergers. Einstein Fellow.

  3. Neutrinos

    NASA Astrophysics Data System (ADS)

    Winter, K.; Murdin, P.

    2000-11-01

    Neutrinos are electrically neutral ELEMENTARY PARTICLES which experience only the weak nuclear force and gravity. Their existence was introduced as a hypothesis by Wolfgang Pauli in 1930 to explain the apparent violation of energy conservation in radioactive beta decay. Chadwick had discovered in 1914 that the energy spectrum of electrons emitted in beta decay was not monoenergetic but continuous...

  4. Flavor dependence of CP asymmetries and thermal leptogenesis with strong right-handed neutrino mass hierarchy

    SciTech Connect

    Vives, O.

    2006-04-01

    We prove that taking correctly into account the lepton flavour dependence of the CP asymmetries and washout processes, it is possible to obtain successful thermal leptogenesis from the decays of the second right-handed neutrino. The asymmetries in the muon and tau-flavour channels are then not erased by the inverse decays of the lightest right-handed neutrino N{sub 1}. In this way, we reopen the possibility of ''thermal leptogenesis'' in models with a strong hierarchy in the right-handed Majorana masses that is typically the case in models with up-quark neutrino-Yukawa unification.

  5. Neutrino Oscillations With Two Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Kisslinger, Leonard S.

    2016-10-01

    This work estimates the probability of μ to e neutrino oscillation with two sterile neutrinos using a 5×5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4×4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.

  6. Neutrino Oscillations With Two Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Kisslinger, Leonard S.

    2016-06-01

    This work estimates the probability of μ to e neutrino oscillation with two sterile neutrinos using a 5×5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4×4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.

  7. Correlation mass method for analysis of neutrinos from supernova 1987A

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee; Chan, Kwing L.; Kondo, Yoji

    1988-01-01

    Application of a time-energy correlation method to the Kamiokande II (KII) observations of neutrinos apparently emitted from supernova 1987A has yielded a neutrino rest mass of 3.6 eV. A Monte Carlo analysis shows a reconfirming probabilty distribution for the neutrino rest mass peaked at 2.8, and dropping to 50 percent of the peak at 1.4 and 4.8 eV. Although the KII data indicate a very short time scale of emission, over an extended period on the order of 10 sec, both data from the Irvine-Michigan-Brookhaven experiment and the KII data show a tendency for the more energetic neutrinos to be emitted earlier at the source, suggesting the possibility of cooling.

  8. Cosmology Favoring Extra Radiation and Sub-eV Mass Sterile Neutrinos as an Option

    SciTech Connect

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.; Tamborra, Irene; Wong, Yvonne Y. Y.

    2010-10-29

    Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{sub s} and effective number N{sub s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{sub s} is in the sub-eV range.

  9. Cosmology favoring extra radiation and sub-eV mass sterile neutrinos as an option.

    PubMed

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G; Tamborra, Irene; Wong, Yvonne Y Y

    2010-10-29

    Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{s} and effective number N{s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{s} is in the sub-eV range.

  10. Cosmology favoring extra radiation and sub-eV mass sterile neutrinos as an option.

    PubMed

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G; Tamborra, Irene; Wong, Yvonne Y Y

    2010-10-29

    Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{s} and effective number N{s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{s} is in the sub-eV range. PMID:21231094

  11. EFFECTS OF THE NEUTRINO MASS SPLITTING ON THE NONLINEAR MATTER POWER SPECTRUM

    SciTech Connect

    Wagner, Christian; Verde, Licia; Jimenez, Raul

    2012-06-20

    We have performed cosmological N-body simulations which include the effect of the masses of the individual neutrino species. The simulations were aimed at studying the effect of different neutrino hierarchies on the matter power spectrum. Compared to the linear theory predictions, we find that nonlinearities enhance the effect of hierarchy on the matter power spectrum at mildly nonlinear scales. The maximum difference between the different hierarchies is about 0.5% for a sum of neutrino masses of 0.1 eV. Albeit this is a small effect, it is potentially measurable from upcoming surveys. In combination with neutrinoless double-{beta} decay experiments, this opens up the possibility of using the sky to determine if neutrinos are Majorana or Dirac fermions.

  12. Nonstandard interactions and resolving the ordering of neutrino masses at DUNE and other long baseline experiments

    NASA Astrophysics Data System (ADS)

    Masud, Mehedi; Mehta, Poonam

    2016-09-01

    In the era of precision neutrino physics, we study the influence of nonstandard interactions (NSI) of matter on the question of neutrino mass ordering and its resolution. At long-baseline experiments, since matter effects play a crucial role in addressing this very important question, it is timely to investigate how subleading effects due to NSI may affect and drastically alter inferences pertaining to this question. We demonstrate that the sensitivity to mass ordering gets significantly impacted due to NSI effects for various long-baseline experiments, including the upcoming long-baseline experiment Deep Underground Neutrino Experiment (DUNE). Finally, we draw a comparison between DUNE and the sensitivities offered by two of the current neutrino beam experiments, NOvA and T2K.

  13. Absolute mass of neutrinos and the first unique forbidden {beta} decay of {sup 187}Re

    SciTech Connect

    Dvornicky, Rastislav; Simkovic, Fedor; Muto, Kazuo; Faessler, Amand

    2011-04-15

    The planned rhenium {beta}-decay experiment, called the ''Microcalorimeter Arrays for a Rhenium Experiment'' (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which will take commissioning data in 2011 and will proceed for 5 years. We present the energy distribution of emitted electrons for the first unique forbidden {beta} decay of {sup 187}Re. It is found that the p-wave emission of electron dominates over the s wave. By assuming mixing of three neutrinos, the Kurie function for the rhenium {beta} decay is derived. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed {beta} decay of {sup 3}H.

  14. Grand unification and low scale implications: D₂ parity for unification and neutrino masses

    SciTech Connect

    Tavartkiladze, Zurab

    2014-01-01

    The Grand Unified SU(5)-SU(5)´ model, augmented with D₂ Parity, is considered. The latter play crucial role for phenomenology. The model has several novel properties and gives interesting phenomenological implications. The charged leptons together with right handed (or sterile) neutrinos emerge es composite states. Within considered scenario, we study the charged fermion and neutrino mass generation. Moreover, we show that the model gives successful gauge coupling unification.

  15. Neutrinos Masses in a Multi-Higgs Model with A4 symmetry

    NASA Astrophysics Data System (ADS)

    Machado, A. C. B.; Montero, J. C.; Pleitez, V.

    2012-08-01

    Presently it is well known that neutrino oscillation data are well described by massive neutrinos and their mixing. This suggests changes in the standard model (SM) and makes the flavor physics even more interesting. Recently, it has been proposed a multi-Higgs extension of the SM with Abelian and non-Abelian discrete symmetries which seeks to explain the origin of the masses and mixing matrices in all charge sectors.

  16. Upper bound of 0.28 eV on neutrino masses from the largest photometric redshift survey.

    PubMed

    Thomas, Shaun A; Abdalla, Filipe B; Lahav, Ofer

    2010-07-16

    We present a new limit of ∑m(v) ≤ 0.28 (95% CL) on the sum of the neutrino masses assuming a flat ΛCDM cosmology. This relaxes slightly to ∑m(ν) ≤ 0.34 and ∑m(v) ≤ 0.47 when quasinonlinear scales are removed and w≠ -1, respectively. These are derived from a new photometric catalogue of over 700,000 luminous red galaxies (MegaZ DR7) with a volume of 3.3  (Gpc h(-1))(3) and redshift range 0.45 < z < 0.65. The data are combined with WMAP 5-year CMB, baryon acoustic oscillations, supernovae, and a Hubble Space Telescope prior on h. When combined with WMAP these data are as constraining as adding all supernovae and baryon oscillation data available. The upper limit is one of the tightest constraints on the neutrino from cosmology or particle physics. Further, if these bounds hold, they all predict that current-to-next generation neutrino experiments, such as KATRIN, are unlikely to obtain a detection.

  17. Upper bound of 0.28 eV on neutrino masses from the largest photometric redshift survey.

    PubMed

    Thomas, Shaun A; Abdalla, Filipe B; Lahav, Ofer

    2010-07-16

    We present a new limit of ∑m(v) ≤ 0.28 (95% CL) on the sum of the neutrino masses assuming a flat ΛCDM cosmology. This relaxes slightly to ∑m(ν) ≤ 0.34 and ∑m(v) ≤ 0.47 when quasinonlinear scales are removed and w≠ -1, respectively. These are derived from a new photometric catalogue of over 700,000 luminous red galaxies (MegaZ DR7) with a volume of 3.3  (Gpc h(-1))(3) and redshift range 0.45 < z < 0.65. The data are combined with WMAP 5-year CMB, baryon acoustic oscillations, supernovae, and a Hubble Space Telescope prior on h. When combined with WMAP these data are as constraining as adding all supernovae and baryon oscillation data available. The upper limit is one of the tightest constraints on the neutrino from cosmology or particle physics. Further, if these bounds hold, they all predict that current-to-next generation neutrino experiments, such as KATRIN, are unlikely to obtain a detection. PMID:20867754

  18. Constraints on Cosmic Neutrino Fluxes from the Antarctic Impulsive Transient Antenna Experiment

    SciTech Connect

    Barwick, S.W.; Goldstein, D.; Nam, J.; Silvestri, A.; Wu, F.; Beatty, J.J.; Nichol, R.; Palladino, K.; Besson, D.Z.; Binns, W.R.; Dowkontt, P.F.; Israel, M.H.; Cai, B.; DuVernois, M.A.; Clem, J.M.; Evenson, P.A.; Seckel, D.; Connolly, A.; Saltzberg, D.; Cowen, D.F.

    2006-05-05

    We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004. We search for impulsive events that could be associated with ultrahigh energy neutrino interactions in the ice and derive limits that constrain several models for ultrahigh energy neutrino fluxes and rule out the long-standing Z-burst model.

  19. A model-independent investigation on quasi-degenerate neutrino mass models and their significance

    NASA Astrophysics Data System (ADS)

    Roy, Subhankar; Singh, N. Nimai

    2013-12-01

    The prediction of possible hierarchy of neutrino masses mostly depends on the model chosen. Dissociating the μ-τ interchange symmetry from discrete flavor symmetry based models, makes the neutrino mass matrix less predictive and motivates one to seek the answer from different phenomenological frameworks. This insists on proper parametrization of the neutrino mass matrices concerning individual hierarchies. In this work, an attempt has been made to study the six different cases of quasi-degenerate (QDN) neutrino models with mass matrices, mLLν parametrized with two free parameters (α,η), standard Wolfenstein parameter (λ) and input mass scale, m0˜0.08 eV. We start with a μ-τ symmetric neutrino mass matrix followed by a correction from charged lepton sector. The parametrization emphasizes on the existence of four independent texture zero building blocks common to all the QDN models under μ-τ symmetric framework and is found to be invariant under any choice of solar angle. In our parametrization, solar angle is controlled from neutrino sector whereas the charged lepton sector drives the reactor and atmospheric mixing angles. The individual models are tested in the framework of oscillation experiments, cosmological observation and future experiments involving β-decay and 0νββ experiments, and any reason to discard the QDN mass models with relatively lower mass is unfounded. Although the QDNH-Type IA model shows strong preference for sin2θ12=0.32, yet this is not sufficient to rule out the other models. The present work leaves a scope to extend the search of most favorable QDN mass model from observed baryon asymmetry of the Universe.

  20. One diagonal texture or cofactor zero of the neutrino mass matrix

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun; Marfatia, D.; Whisnant, K.

    2013-08-01

    In view of the recent measurement of nonzero θ13, we carry out a systematic study of a simple class of neutrino models that has one diagonal texture or cofactor zero in the mass matrix. There are seven free parameters in the model, and five of them are already measured by neutrino oscillation experiments; some cases for the normal or inverted hierarchy are excluded, and for the rest we obtain the preferred values for the lightest neutrino mass and Dirac CP phase. We find that there are strong similarities between one diagonal texture zero models with one mass hierarchy and one diagonal cofactor zero models with the opposite mass hierarchy. We also make predictions for neutrinoless double beta decay for these models. For the one cofactor zero models, we present a simple realization based on a new U(1) gauge symmetry.

  1. Atmospheric neutrinos and discovery of neutrino oscillations.

    PubMed

    Kajita, Takaaki

    2010-01-01

    Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations.

  2. Atmospheric neutrinos and discovery of neutrino oscillations

    PubMed Central

    Kajita, Takaaki

    2010-01-01

    Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations. PMID:20431258

  3. Neutrino physics

    SciTech Connect

    Harris, Deborah A.; /Fermilab

    2008-09-01

    The field of neutrino physics has expanded greatly in recent years with the discovery that neutrinos change flavor and therefore have mass. Although there are many neutrino physics results since the last DIS workshop, these proceedings concentrate on recent neutrino physics results that either add to or depend on the understanding of Deep Inelastic Scattering. They also describe the short and longer term future of neutrino DIS experiments.

  4. Constraints on the dark matter particle mass from the number of Milky Way satellites

    SciTech Connect

    Polisensky, Emil; Ricotti, Massimo

    2011-02-15

    We have conducted N-body simulations of the growth of Milky Way-sized halos in cold and warm dark matter cosmologies. The number of dark matter satellites in our simulated Milky Ways decreases with decreasing mass of the dark matter particle. Assuming that the number of dark matter satellites exceeds or equals the number of observed satellites of the Milky Way, we derive lower limits on the dark matter particle mass. We find with 95% confidence m{sub s}>13.3 keV for a sterile neutrino produced by the Dodelson and Widrow mechanism, m{sub s}>8.9 keV for the Shi and Fuller mechanism, m{sub s}>3.0 keV for the Higgs decay mechanism, and m{sub WDM}>2.3 keV for a thermal dark matter particle. The recent discovery of many new dark matter dominated satellites of the Milky Way in the Sloan Digital Sky Survey allows us to set lower limits comparable to constraints from the complementary methods of Lyman-{alpha} forest modeling and x-ray observations of the unresolved cosmic x-ray background and of dark matter halos from dwarf galaxy to cluster scales. Future surveys like LSST, DES, PanSTARRS, and SkyMapper have the potential to discover many more satellites and further improve constraints on the dark matter particle mass.

  5. Neutrino mass and mixing in the 3-3-1 model with neutral leptons based on D4 flavor symmetry

    NASA Astrophysics Data System (ADS)

    Vien, V. V.

    2014-07-01

    We propose a new D4 flavor model based on SU(3)C⊗SU(3)L ⊗U(1)X gauge symmetry responsible for fermion masses and mixings in which all fermion fields act only as singlets under D4 which differs from our previous work. The neutrinos get small masses from two SU(3)L anti-sextets and one SU(3)L triplet which are all in singlets under D4. If a SU(3)L Higgs triplet, lying in {1}''' under D4, is considered as a perturbation the corresponding neutrino mass mixing matrix gets the most general form. In this case, the model can fit the most recent data on neutrino masses and mixing with nonzero θ13. Our results show that the neutrino masses are naturally small. The sum of three light neutrino masses and the effective mass governing neutrinoless double beta decay are obtained that are consistent with the recent data.

  6. Constraints on the neutrino emission from the Galactic Ridge with the ANTARES telescope

    NASA Astrophysics Data System (ADS)

    Adrián-Martínez, S.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Păvălaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D. F. E.; Sánchez-Losa, A.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.

    2016-09-01

    A highly significant excess of high-energy astrophysical neutrinos has been reported by the IceCube Collaboration. Some features of the energy and declination distributions of IceCube events hint at a North/South asymmetry of the neutrino flux. This could be due to the presence of the bulk of our Galaxy in the Southern hemisphere. The ANTARES neutrino telescope, located in the Mediterranean Sea, has been taking data since 2007. It offers the best sensitivity to muon neutrinos produced by galactic cosmic ray interactions in this region of the sky. In this letter a search for an extended neutrino flux from the Galactic Ridge region is presented. Different models of neutrino production by cosmic ray propagation are tested. No excess of events is observed and upper limits for different neutrino flux spectral indices Γ are set. For Γ = 2.4 the 90% confidence level flux upper limit at 100 TeV for one neutrino flavour corresponds to Φ01 f (100 TeV) = 2.0 ṡ10-17 GeV-1cm-2s-1sr-1. Under this assumption, at most two events of the IceCube cosmic candidates can originate from the Galactic Ridge. A simple power-law extrapolation of the Fermi-LAT flux to account for IceCube High Energy Starting Events is excluded at 90% confidence level.

  7. Phase space and quark mass effects in neutrino emissions in a color superconductor

    NASA Astrophysics Data System (ADS)

    Wang, Qun; Wang, Zhi-Gang; Wu, Jian

    2006-07-01

    We study the phase space for neutrino emissions with massive quarks in direct Urca processes in normal and color-superconducting quark matter. We derive in QCD and the Nambu-Jona-Lasinio model the Fermi momentum reduction resulting from Fermi liquid properties which opens up the phase space for neutrino emissions. The relation between the Fermi momentum and chemical potential is found to be pF≈μ(1-κ) with κ depending on coupling constants. We find in the weak coupling regime that κ is a monotonically increasing function of the chemical potential. This implies quenched phase space for neutrino emissions at low baryon densities. We calculate neutrino emissivities with massive quarks in a spin-one color superconductor. The quark mass corrections are found to be of the same order as the contributions in the massless case, which will bring sizable effects on the cooling behavior of compact stars.

  8. Triviality and vacuum stability bounds in the three-loop neutrino mass model

    SciTech Connect

    Aoki, Mayumi; Kanemura, Shinya; Yagyu, Kei

    2011-04-01

    We study theoretical constraints on the parameter space under the conditions from vacuum stability and triviality in the three-loop radiative seesaw model with TeV-scale right-handed neutrinos which are odd under the Z{sub 2} parity. In this model, some of the neutrino Yukawa coupling constants can be of the order of 1. The requirement of a strongly first order phase transition for successful electroweak baryogenesis also prefers order-one coupling constants in the scalar sector. Hence, it is important to clarify whether this model satisfies those theoretical conditions up to a given cutoff scale. It is found that the model can be consistent up to the scale above 10 TeV in the parameter region where the neutrino data, the lepton-flavor violation data, the thermal relic abundance of dark matter as well as the requirement from the strongly first order phase transition are satisfied.

  9. A combined limit on the neutrino mass from neutrinoless double-beta decay searches in multiple isotopes

    NASA Astrophysics Data System (ADS)

    Guzowski, P.

    2016-05-01

    We set a combined limit on the effective Majorana neutrino mass mββ from experimental searches for neutrinoless double-beta decay of multiple isotopes. The limits on mββ range between 130-310 meV, depending on the choice of nuclear matrix element calculation. The limits on mββ can also be translated into a limit on the neutrino mass and mixing parameters of a fourth sterile neutrino.

  10. Beta Decay in the Field of an Electromagnetic Wave and Experiments on Measuring the Neutrino Mass

    SciTech Connect

    Dorofeev, O.F.; Lobanov, A.E.

    2005-06-01

    Investigations of the effect of an electromagnetic wave field on the beta-decay process are used to analyze the tritium-decay experimental data on the neutrino mass. It is shown that the electromagnetic wave can distort the beta spectrum, shifting the end point to the higher energy region. This phenomenon is purely classical and it is associated with the electron acceleration in the radiation field. Since strong magnetic fields exist in setups for precise measurement of the neutrino mass, the indicated field can appear owing to the synchrotron radiation mechanism. The phenomenon under consideration can explain the experimentally observed anomalies in the spectrum of the decay electrons; in particular, the effect of the 'negative square of the neutrino mass'.

  11. Three-loop neutrino mass model with doubly charged particles from isodoublets

    NASA Astrophysics Data System (ADS)

    Okada, Hiroshi; Yagyu, Kei

    2016-01-01

    We propose a new type of a three-loop induced neutrino mass model with dark matter candidates which are required for the neutrino mass generation. The smallness of neutrino masses can be naturally explained without introducing super heavy particles, namely, much heavier than a TeV scale and quite small couplings as compared to the gauge couplings. We find that as a bonus, the anomaly of the muon anomalous magnetic moment can simultaneously be explained by loop effects of new particles. In our model, there are doubly charged scalar bosons and leptons from isospin doublet fields which give characteristic collider signatures. In particular, the doubly charged scalar bosons can decay into the same-sign dilepton with its chirality of both right-handed or left- and right-handed. This can be a smoking gun signature to identify our model and be useful to distinguish other models with doubly charged scalar bosons at collider experiments.

  12. Confronting electron and neutrino-nucleus interactions: Can the axial mass anomaly be resolved?

    NASA Astrophysics Data System (ADS)

    Benhar, Omar

    2014-04-01

    Comparison between electron- and neutrino-nucleus scattering data suggests that the so-called axial mass anomaly — i.e., the large disagreement between the value of the nucleon axial mass extracted from the analysis of neutrino interactions with carbon and oxygen and that obtained from deuteron data — is a manifestation of the difficulties in the interpretation of the flux averaged neutrino cross-sections. In this short review, I discuss the role of reaction mechanisms leading to the excitation of two particle-two hole final states of the target nucleus, which are believed to be responsible for the observed excess of quasielastic events, and argue that taking into account their effect may help to reconcile the sizeably different values of the axial mass reported by the MiniBooNe and NOMAD Collaborations.

  13. Systematic U(1 ) B - L extensions of loop-induced neutrino mass models with dark matter

    NASA Astrophysics Data System (ADS)

    Ho, Shu-Yu; Toma, Takashi; Tsumura, Koji

    2016-08-01

    We study the gauged U(1 ) B - L extensions of the models for neutrino masses and dark matter. In this class of models, tiny neutrino masses are radiatively induced through the loop diagrams, while the origin of the dark matter stability is guaranteed by the remnant of the gauge symmetry. Depending on how the lepton number conservation is violated, these models are systematically classified. We present complete lists for the one-loop Z2 and the two-loop Z3 radiative seesaw models as examples of the classification. The anomaly cancellation conditions in these models are also discussed.

  14. Proton hexality from an anomalous flavor U(1) and neutrino masses: Linking to the string scale

    NASA Astrophysics Data System (ADS)

    Dreiner, Herbi K.; Luhn, Christoph; Murayama, Hitoshi; Thormeier, Marc

    2008-05-01

    We devise minimalistic gauged U(1 Froggatt-Nielsen models which at low-energy give rise to the recently suggested discrete gauge Z-symmetry, proton hexality, thus stabilizing the proton. Assuming three generations of right-handed neutrinos, with the proper choice of X-charges, we obtain viable neutrino masses. Furthermore, we find scenarios such that no X-charged hidden sector superfields are needed, which from a bottom-up perspective allows the calculation of g, g and G's Kač-Moody levels. The only mass scale apart from M is m.

  15. Solar neutrino limit on axions and keV-mass bosons

    SciTech Connect

    Gondolo, Paolo; Raffelt, Georg G.

    2009-05-15

    The all-flavor solar neutrino flux measured by the Sudbury Neutrino Observatory constrains nonstandard energy losses to less than about 10% of the Sun's photon luminosity, superseding a helioseismological argument and providing new limits on the interaction strength of low-mass particles. For the axion-photon coupling strength we find g{sub a{gamma}}<7x10{sup -10} GeV{sup -1}. We also derive explicit limits on the Yukawa coupling to electrons of pseudoscalar, scalar, and vector bosons with keV-scale masses.

  16. A new radiative neutrino mass generation mechanism with higher dimensional scalar representations and custodial symmetry

    NASA Astrophysics Data System (ADS)

    Aranda, Alfredo; Peinado, Eduardo

    2016-03-01

    A new realization for radiative neutrino mass generation is presented. Based on the requirement of tree-level custodial symmetry and the introduction of higher (greater than two) dimensional representations for scalar fields, a specific scenario with a scalar septet is presented that generates neutrino Majorana masses radiatively. This is accomplished through an eleven dimensional operator that requires the addition of several scalar fields and a SU(2) 5-plet of new fermions, together with a Z2 that guarantees the preservation of custodial symmetry. The phenomenology of the setup is rather rich and includes a dark matter candidate.

  17. Galaxy clustering, CMB and supernova data constraints on ϕCDM model with massive neutrinos

    NASA Astrophysics Data System (ADS)

    Chen, Yun; Xu, Lixin

    2016-01-01

    We investigate a scalar field dark energy model (i.e., ϕCDM model) with massive neutrinos, where the scalar field possesses an inverse power-law potential, i.e., V (ϕ) ∝ϕ-α (α > 0). We find that the sum of neutrino masses Σmν has significant impacts on the CMB temperature power spectrum and on the matter power spectrum. In addition, the parameter α also has slight impacts on the spectra. A joint sample, including CMB data from Planck 2013 and WMAP9, galaxy clustering data from WiggleZ and BOSS DR11, and JLA compilation of Type Ia supernova observations, is adopted to confine the parameters. Within the context of the ϕCDM model under consideration, the joint sample determines the cosmological parameters to high precision: the angular size of the sound horizon at recombination, the Thomson scattering optical depth due to reionization, the physical densities of baryons and cold dark matter, and the scalar spectral index are estimated to be θ* = (1.0415-0.0011+0.0012) ×10-2, τ =0.0914-0.0242+0.0266, Ωbh2 = 0.0222 ± 0.0005, Ωch2 = 0.1177 ± 0.0036, and ns =0.9644-0.0119+0.0118, respectively, at 95% confidence level (CL). It turns out that α < 4.995 at 95% CL for the ϕCDM model. And yet, the ΛCDM scenario corresponding to α = 0 is not ruled out at 95% CL. Moreover, we get Σmν < 0.262 eV at 95% CL for the ϕCDM model, while the corresponding one for the ΛCDM model is Σmν < 0.293 eV. The allowed scale of Σmν in the ϕCDM model is a bit smaller than that in the ΛCDM model. It is consistent with the qualitative analysis, which reveals that the increases of α and Σmν both can result in the suppression of the matter power spectrum. As a consequence, when α is larger, in order to avoid suppressing the matter power spectrum too much, the value of Σmν should be smaller.

  18. Quantum-gravity decoherence effects in neutrino oscillations: Expected constraints from CNGS and J-PARC

    SciTech Connect

    Mavromatos, Nick E.; Sarkar, Sarben; Meregaglia, Anselmo; Sakharov, Alexander S.

    2008-03-01

    Quantum decoherence, the evolution of pure states into mixed states, may be a feature of quantum-gravity models. In most cases, such models lead to fewer neutrinos of all active flavors being detected in a long-baseline experiment as compared to three-flavor standard neutrino oscillations. We discuss the potential of the CNGS and J-PARC beams in constraining models of quantum-gravity induced decoherence using neutrino oscillations as a probe. We use as much as possible model-independent parametrizations, even though they are motivated by specific microscopic models, for fits to the expected experimental data which yield bounds on quantum-gravity decoherence parameters.

  19. Neutrino physics

    SciTech Connect

    Kayser, Boris; /Fermilab

    2005-06-01

    Thanks to compelling evidence that neutrinos can change flavor, we now know that they have nonzero masses, and that leptons mix. In these lectures, we explain the physics of neutrino flavor change, both in vacuum and in matter. Then, we describe what the flavor-change data have taught us about neutrinos. Finally, we consider some of the questions raised by the discovery of neutrino mass, explaining why these questions are so interesting, and how they might be answered experimentally.

  20. Computation of neutrino masses in R-parity violating supersymmetry: SOFTSUSY3.2

    NASA Astrophysics Data System (ADS)

    Allanach, B. C.; Kom, C. H.; Hanussek, M.

    2012-03-01

    The program SOFTSUSY can calculate tree-level neutrino masses in the R-parity violating minimal supersymmetric standard model (MSSM) with real couplings. At tree-level, only one neutrino acquires a mass, in contradiction with neutrino oscillation data. Here, we describe an extension to the SOFTSUSY program which includes one-loop R-parity violating effects' contributions to neutrino masses and mixing. Including the one-loop effects refines the radiative electroweak symmetry breaking calculation, and may result in up to three massive, mixed neutrinos. This paper serves as a manual to the neutrino mass prediction mode of the program, detailing the approximations and conventions used. Program summaryProgram title: SOFTSUSY Catalogue identifier: ADPM_v3_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADPM_v3_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 93 291 No. of bytes in distributed program, including test data, etc.: 1 288 618 Distribution format: tar.gz Programming language: C++, Fortran Computer: Personal computer Operating system: Tested on Linux 4.x Word size: 32 bits Classification: 11.1, 11.6 Catalogue identifier of previous version: ADPM_v2_0 Journal reference of previous version: Comput. Phys. Comm. 181 (2010) 232 Does the new version supersede the previous version?: Yes Nature of problem: Calculation of neutrino masses and the neutrino mixing matrix at one-loop level in the R-parity violating minimal supersymmetric standard model. The solution to the renormalisation group equations must be consistent with a high or weak-scale boundary condition on supersymmetry breaking parameters and R-parity violating parameters, as well as a weak-scale boundary condition on gauge couplings, Yukawa couplings and the Higgs potential parameters. Solution method: Nested iterative algorithm

  1. S3 × Bbb Z2 model for neutrino mass matrices

    NASA Astrophysics Data System (ADS)

    Grimus, Walter; Lavoura, Luís

    2005-08-01

    We propose a model for lepton mass matrices based on the seesaw mechanism, a complex scalar gauge singlet and a horizontal symmetry S3 × Bbb Z2. In a suitable weak basis, the charged-lepton mass matrix and the neutrino Dirac mass matrix are diagonal, but the vacuum expectation value of the scalar gauge singlet renders the Majorana mass matrix of the right-handed neutrinos non-diagonal, thereby generating lepton mixing. When the symmetry S3 is not broken in the scalar potential, the effective light-neutrino Majorana mass matrix enjoys μ-τ interchange symmetry, thus predicting maximal atmospheric neutrino mixing together with Ue3 = 0. A partial and less predictive form of μ-τ interchange symmetry is obtained when the symmetry S3 is softly broken in the scalar potential. Enlarging the symmetry group S3 × Bbb Z2 by an additional discrete electron-number symmetry Bbb Z2(e), a more predicitive model is obtained, which is in practice indistinguishable from a previous one based on the group D4.

  2. Supernova neutrinos and explosive nucleosynthesis

    SciTech Connect

    Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Shibagaki, S.; Mathews, G. J.; Nakamura, K.; Suzuki, T.

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  3. rho. parameter constraints on fourth generation quark masses

    SciTech Connect

    Barger, V.; Hewett, J.L. . Dept. of Physics); Risso, T.G. . Dept. of Physics)

    1990-04-20

    Constraints on the masses of possible fourth generation quarks (a,{upsilon}) are obtained from measurements of the {rho} parameter and the elements of the quark mixing matrix. Stringent mass limits are found when the off-diagonal elements V{sub t{upsilon}} and V{sub ab} are large. For example, with m{sub t} = 90 GeV and {vert bar}V{sub t{upsilon}}{vert bar} {approx equal} 0.5 the authors find m{sub a,{upsilon}} {le} 300 GeV. Stronger constraints are obtained as m{sub 1}or {vert bar}V{sub t{upsilon}}{vert bar} increase.

  4. Origin of howardites, diogenites and eucrites - A mass balance constraint

    NASA Technical Reports Server (NTRS)

    Warren, P. H.

    1985-01-01

    Two petrogenetic models for the noncumulate-basaltic parts of howardite meteorites are discussed. A mass balance constraint is developed which indicates that more than half of the basaltic components in howardites formed as residual liquids from fractional crystallization of melts that had earlier produced diogentelike pyroxene cumulate components. Other model constriants involving scandium trends, clustering near olivine-pyroxene-plagioclase peritectic, and MgO/(MgO + FeO) ratios are discussed.

  5. Measuring the mass of a sterile neutrino with a very short baseline reactor experiment

    SciTech Connect

    Latimer, D. C.; Escamilla, J.; Ernst, D. J.

    2007-04-15

    An analysis of the world's neutrino oscillation data, including sterile neutrinos, [M. Sorel, C. M. Conrad, and M. H. Shaevitz, Phys. Rev. D 70, 073004 (2004)] found a peak in the allowed region at a mass-squared difference {delta}m{sup 2} congruent with 0.9 eV{sup 2}. We trace its origin to harmonic oscillations in the electron survival probability P{sub ee} as a function of L/E, the ratio of baseline to neutrino energy, as measured in the near detector of the Bugey experiment. We find a second occurrence for {delta}m{sup 2} congruent with 1.9 eV{sup 2}. We point out that the phenomenon of harmonic oscillations of P{sub ee} as a function of L/E, as seen in the Bugey experiment, can be used to measure the mass-squared difference associated with a sterile neutrino in the range from a fraction of an eV{sup 2} to several eV{sup 2} (compatible with that indicated by the LSND experiment), as well as measure the amount of electron-sterile neutrino mixing. We observe that the experiment is independent, to lowest order, of the size of the reactor and suggest the possibility of a small reactor with a detector sitting at a very short baseline.

  6. 7.1 keV sterile neutrino constraints from X-ray observations of 33 clusters of galaxies with Chandra ACIS

    NASA Astrophysics Data System (ADS)

    Hofmann, F.; Sanders, J. S.; Nandra, K.; Clerc, N.; Gaspari, M.

    2016-08-01

    Context. Recently an unidentified emission line at 3.55 keV has been detected in X-ray spectra of clusters of galaxies. The line has been discussed as a possible decay signature of 7.1 keV sterile neutrinos, which have been proposed as a dark matter (DM) candidate. Aims: We aim to put constraints on the proposed line emission in a large sample of Chandra-observed clusters and obtain limits on the mixing angle in a 7.1 keV sterile neutrino DM scenario. Methods: For a sample of 33 high-mass clusters of galaxies, we merge all observations from the Chandra data archive. Each cluster has more than 100 ks of combined exposure. The resulting high signal-to-noise spectra are used to constrain the flux of an unidentified line emission at 3.55 keV in the individual spectra and a merged spectrum of all clusters. Results: We obtained very detailed spectra around the 3.55 keV range and limits on an unidentified emission line. Assuming all DM were made of 7.1 keV sterile neutrinos, the upper limits on the mixing angle are sin2(2Θ) < 10.1×10-11 from ACIS-I and < 40.3×10-11 from ACIS-S data at 99.7 per cent confidence level. Conclusions: We do not find evidence for an unidentified emission line at 3.55 keV. The sample extends the list of objects searched for an emission line at 3.55 keV and will help to identify the best targets for future studies of the potential DM decay line with upcoming X-ray observatories like Hitomi (Astro-H), eROSITA, and Athena.

  7. Can sterile neutrinos be the dark matter?

    PubMed

    Seljak, Uros; Makarov, Alexey; McDonald, Patrick; Trac, Hy

    2006-11-10

    We use the Ly-alpha forest power spectrum measured by the Sloan Digital Sky Survey and high-resolution spectroscopy observations in combination with cosmic microwave background and galaxy clustering constraints to place limits on a sterile neutrino as a dark matter candidate in the warm dark matter scenario. Such a neutrino would be created in the early Universe through mixing with an active neutrino and would suppress structure on scales smaller than its free-streaming scale. We ran a series of high-resolution hydrodynamic simulations with varying neutrino masses to describe the effect of a sterile neutrino on the Ly-alpha forest power spectrum. We find that the mass limit is m(s) >13 keV at 95% C.L. (9 keV at 99.9%), which is above the upper limit allowed by x-ray constraints, excluding this candidate from being all of the dark matter in this model. PMID:17155611

  8. Project 8: Determining neutrino mass from tritium beta decay using a frequency-based method

    SciTech Connect

    Doe, Peter J.; Kofron, Jared N.; MCBride, Lisa; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Doelman, S.; Rogers, Alan E.; Formaggio, Joseph; Furse, Daniel; Oblath, Noah S.; LaRoque, Benjamin; Leber, Michelle; Monreal, Ben; Bahr, Matthew; Asner, David M.; Jones, Anthony M.; Fernandes, Justin L.; VanDevender, Brent A.; Patterson, Ryan B.; Bradley, Rich; Thummler, Thomas

    2013-10-04

    A general description is given of Project 8, a new approach to measuring the neutrino mass scale via the beta decay of tritium. In Project 8, the energy of electrons emitted in beta decay is determined from the frequency of cyclotron radiation emitted as the electrons spiral in a uniform magnetic field

  9. Majorana neutrino masses from neutrinoless double-beta decays and lepton-number-violating meson decays

    NASA Astrophysics Data System (ADS)

    Liu, Jun-Hao; Zhang, Jue; Zhou, Shun

    2016-09-01

    The Schechter-Valle theorem states that a positive observation of neutrinoless double-beta (0 νββ) decays implies a finite Majorana mass term for neutrinos when any unlikely fine-tuning or cancellation is absent. In this note, we reexamine the quantitative impact of the Schechter-Valle theorem, and find that current experimental lower limits on the half-lives of 0 νββ-decaying nuclei have placed a restrictive upper bound on the Majorana neutrino mass | δ mνee | < 7.43 ×10-29 eV radiatively generated at the four-loop level. Furthermore, we generalize this quantitative analysis of 0 νββ decays to that of the lepton-number-violating (LNV) meson decays M- →M‧+ + ℓα- + ℓβ- (for α , β = e or μ). Given the present upper limits on these rare LNV decays, we have derived the loop-induced Majorana neutrino masses | δ mνee | < 9.7 ×10-18 eV, | δ mνeμ | < 1.6 ×10-15 eV and | δ mνμμ | < 1.0 ×10-12 eV from K- →π+ +e- +e-, K- →π+ +e- +μ- and K- →π+ +μ- +μ-, respectively. A partial list of radiative neutrino masses from the LNV decays of D, Ds and B mesons is also given.

  10. Constraints on the neutrino magnetic dipole moment: The tip-RGB luminosity of globular clusters

    NASA Astrophysics Data System (ADS)

    Arceo-Díaz, S.; Schröder, K.-P.; Zuber, K.; Jack, D.

    2015-10-01

    In this work we compared the predictions about the tip-RGB bolometric luminosity of low-mass stars in stellar models built with the Cambridge-STARS code for stellar evolution, with the evidence provided by the observational data of 25 globular clusters from the largest homogeneous database in the NIR. We found that 12 well populated globular clusters (headed up by omega Centauri, the largest globular cluster in the galaxy) suggest mu_{nu}≤ 2.2× 10(-12}mu_{B) , while the uncertainties of both the stellar models and the observations require the more robust constraint mu_{nu}≤ 2.6× 10(-12}mu_{B) . Finally, using synthetic spectra constructed with the PHOENIX code for stellar atmospheres, we qualitatively estimated the effect on the brightness of specific NIR-bands.

  11. Neutrino mass textures with one vanishing minor and two equal cofactors

    NASA Astrophysics Data System (ADS)

    Wang, Weijian

    2013-09-01

    In this paper, we carry out a numerical and systematic analysis of the neutrino mass textures, which contain one vanishing minor and equality between two cofactors. Among 60 logically possible textures, only eight of them are excluded for both the normal and inverted hierarchy by the current experimental data at 3 σ level. We also demonstrate that the future long-baseline neutrino oscillation experiments, especially for the measurement of the θ 23 mixing angle, will play an important role in the model selection. The phenomenological implications from neutrinoless double-beta decay and the cosmology observation are also examined. A discussion of the flavor symmetry realization of the textures is also given.

  12. MASS CONSTRAINTS FROM ECLIPSE TIMING IN DOUBLE WHITE DWARF BINARIES

    SciTech Connect

    Kaplan, David L.

    2010-07-10

    I demonstrate that an effect similar to the Roemer delay, familiar from timing radio pulsars, should be detectable in the first eclipsing double white dwarf (WD) binary, NLTT 11748. By measuring the difference of the time between the secondary and primary eclipses from one-half period (4.6 s), one can determine the physical size of the orbit and hence constrain the masses of the individual WDs. A measurement with uncertainty <0.1 s-possible with modern large telescopes-will determine the individual masses to {+-}0.02 M{sub sun} when combined with good-quality (<1 km s{sup -1}) radial velocity data, although the eccentricity must also be known to high accuracy ({+-}10{sup -3}). Mass constraints improve as P {sup -1/2} (where P is the orbital period), so this works best in wide binaries and should be detectable even for non-degenerate stars, but such constraints require the mass ratio to differ from 1, as well as undistorted orbits.

  13. Do WMAP data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?

    SciTech Connect

    Bonometto, S. A.; La Vacca, G.; Kristiansen, J. R.; Mainini, R.; Colombo, L. P. L.

    2010-06-23

    We fit WMAP5 and related data by allowing for a CDM-DE coupling and non-zero neutrino masses, simultaneously. We find a significant correlation between these parameters, so that simultaneous higher coupling and {nu}-masses are allowed. Furthermore, models with a significant coupling and {nu}-mass are statistically favoured in respect to a cosmology with no coupling and negligible neutrino mass (our best fits are: C{approx}1/2 m{sub p}, m{sub {nu}{approx}0}.12 eV per flavor). We use a standard Monte Carlo Markov Chain approach, by assuming DE to be a scalar field self-interacting through Ratra-Peebles or SUGRA potentials.

  14. Addendum to "Updating neutrino magnetic moment constraints" [Phys. Lett. B 753 (2016) 191-198

    NASA Astrophysics Data System (ADS)

    Cañas, B. C.; Miranda, O. G.; Parada, A.; Tórtola, M.; Valle, J. W. F.

    2016-06-01

    After the publication of this work we noticed that the uncertainties in the considered backgrounds in Borexino may affect our reported limit on the neutrino magnetic moment from Borexino data. Indeed, we have found that a more precise treatment of the uncertainties in the total normalization of these backgrounds results in a weaker sensitivity on the neutrino magnetic moment. This point will be hopefully improved in the near future thanks to the purification processes carried out in the second phase of the Borexino experiment. Meanwhile, however, we think it would be more reliable to adopt the bound on the neutrino magnetic moment reported by Borexino: μν < 5.4 ×10-11μB[1].

  15. Neutrino masses via the Zee mechanism in the 5D split fermion model

    SciTech Connect

    Chang, We-Fu; Chen, I-Ting; Liou, Siao-Cing

    2011-01-15

    We study the original version of the Zee model, where both of the SU(2){sub L} Higgs doublets are allowed to couple to the leptons, in the framework of the split fermion model in M{sub 4}xS{sub 1}/Z{sub 2} space-time. The neutrino masses are generated through 1-loop diagrams without introducing the right-handed neutrinos. By assuming an order one anarchical complex 5D Yukawa couplings, all the effective 4D Yukawa couplings are determined by the wave function overlap between the split fermions and the bulk scalars in the fifth dimension. The predictability of the Yukawa couplings is in sharp contrast to the original Zee model in 4D where the Yukawa couplings are unknown free parameters. This setup exhibits a geometrical alternative to the lepton flavor symmetry. By giving four explicit sets of the split fermion locations, we demonstrate that it is possible to simultaneously fit the lepton masses and neutrino oscillation data by just a handful free parameters without much fine tuning. Moreover, we are able to make definite predictions for the mixing angle {theta}{sub 13}, the absolute neutrino masses, and the lepton flavor violation processes for each configuration.

  16. ANTARES constraints on a Galactic component of the IceCube cosmic neutrino flux

    NASA Astrophysics Data System (ADS)

    Spurio, Maurizio

    2016-07-01

    The IceCube evidence for cosmic neutrinos has inspired a large number of hypothesis on their origin, mainly due to the poor precision on the measurement of the direction of showering events. A North/South asymmetry in the present data set suggests the presence of a possible Galactic component. This could be originated either by single point-like sources or from an extended Galactic region. Expected fluxes derived from these hypotheses are presented. Some values have been constrained from the present available upper limits from the ANTARES neutrino telescope.

  17. Neutrino masses and deviation from tribimaximal mixing in Δ (27 ) model with inverse seesaw mechanism

    NASA Astrophysics Data System (ADS)

    Abbas, Mohammed; Khalil, Shaaban; Rashed, Ahmed; Sil, Arunansu

    2016-01-01

    We propose a scheme, based on Δ (27 ) flavor symmetry and supplemented by other discrete symmetries and the inverse seesaw mechanism, where both the light neutrino masses and the deviation from tribimaximal mixing matrix can be linked to the source of lepton number violation. The hierarchies of the charged leptons are explained. We find that the quark masses including their hierarchies and the mixing can also be constructed in a similar way.

  18. Stellar masses and radii as constraints on stellar models

    NASA Astrophysics Data System (ADS)

    Andersen, Johannes

    1993-01-01

    The current status of empirical data on stellar masses and radii of sufficient accuracy to give constraints on stellar models is reviewed. Results from the best-studied eclipsing binaries can already trace the main-sequence evolution of 1-10-solar-mass stars in considerable detail and will be even more useful when supplemented by chemical abundance data. Taking the deceptively simple question of the observed width of the main sequence as an example, it is shown how careful attention to the details of the data is required to reach robust conclusions about such features of modern stellar evolution models as opacity tables or convective overshooting. Only detailed modeling of specific systems with known masses, radii, and metal abundance constrain the theory strongly enough that a truly critical test is achieved. The same is true when using tidal interactions in binaries (apsidal motion, rotational synchronization, and orbital circularization) as another probe into stellar interiors.

  19. Supernova bound on keV-mass sterile neutrinos reexamined

    SciTech Connect

    Raffelt, Georg G.; Zhou Shun

    2011-05-01

    Active-sterile neutrino mixing is strongly constrained for m{sub s} < or approx. 100 keV to avoid excessive energy losses from supernova cores. For smaller m{sub s}, matter effects suppress the effective mixing angle except for a resonant range of energies where it is enhanced. We study the case of {nu}{sub {tau}-{nu}s} mixing where a {nu}{sub {tau}-{nu}{tau}} asymmetry builds up due to the strong excess of {nu}{sub s} over {nu}{sub s} emission or vice versa, reducing the overall emission rate. In the warm dark matter range m{sub s} < or approx. 10 keV the mixing angle is essentially unconstrained.

  20. Neutrino mixing and masses in SO(10) GUTs with hidden sector and flavor symmetries

    NASA Astrophysics Data System (ADS)

    Chu, Xiaoyong; Smirnov, Alexei Yu.

    2016-05-01

    We consider the neutrino masses and mixing in the framework of SO(10) GUTs with hidden sector consisting of fermionic and bosonic SO(10) singlets and flavor symmetries. The framework allows to disentangle the CKM physics responsible for the CKM mixing and different mass hierarchies of quarks and leptons and the neutrino new physics which produces smallness of neutrino masses and large lepton mixing. The framework leads naturally to the relation U PMNS ˜ V CKM † U 0, where structure of U 0 is determined by the flavor symmetry. The key feature of the framework is that apart from the Dirac mass matrices m D , the portal mass matrix M D and the mass matrix of singlets M S are also involved in generation of the lepton mixing. This opens up new possibilities to realize the flavor symmetries and explain the data. Using A 4 × Z 4 as the flavor group, we systematically explore the flavor structures which can be obtained in this framework depending on field content and symmetry assignments. We formulate additional conditions which lead to U 0 ˜ U TBM or U BM. They include (i) equality (in general, proportionality) of the singlet flavons couplings, (ii) equality of their VEVs; (iii) correlation between VEVs of singlets and triplet, (iv) certain VEV alignment of flavon triplet(s). These features can follow from additional symmetries or be remnants of further unification. Phenomenologically viable schemes with minimal flavon content and minimal number of couplings are constructed.

  1. OBSERVATIONAL CONSTRAINTS ON THE DEGENERATE MASS-RADIUS RELATION

    SciTech Connect

    Holberg, J. B.; Oswalt, T. D.; Barstow, M. A. E-mail: toswalt@fit.edu

    2012-03-15

    The white dwarf mass-radius relationship is fundamental to modern astrophysics. It is central to routine estimation of DA white dwarf masses derived from spectroscopic temperatures and gravities. It is also the basis for observational determinations of the white dwarf initial-final-mass relation. Nevertheless, definitive and detailed observational confirmations of the mass-radius relation (MRR) remain elusive owing to a lack of sufficiently accurate white dwarf masses and radii. Current best estimates of masses and radii allow only broad conclusions about the expected inverse relation between masses and radii in degenerate stars. In this paper, we examine a restricted set of 12 DA white dwarf binary systems for which accurate (1) trigonometric parallaxes, (2) spectroscopic effective temperatures and gravities, and (3) gravitational redshifts are available. We consider these three independent constraints on mass and radius in comparison with an appropriate evolved MRR for each star. For the best-determined systems it is found that the DA white dwarfs conform to evolve theoretical MRRs at the 1{sigma} to 2{sigma} level. For the white dwarf 40 Eri B (WD 0413-077) we find strong evidence for the existence of a 'thin' hydrogen envelope. For other stars improved parallaxes will be necessary before meaningful comparisons are possible. For several systems current parallaxes approach the precision required for the state-of-the-art mass and radius determinations that will be obtained routinely from the Gaia mission. It is demonstrated here how these anticipated results can be used to firmly constrain details of theoretical mass-radius determinations.

  2. Neutrinos and the age of the universe

    NASA Technical Reports Server (NTRS)

    Symbalisty, E. M. D.; Yang, J.; Schramm, D. N.

    1980-01-01

    The age of the universe should be calculable by independent methods with similar results. Previous calculations using nucleochronometers, globular clusters and dynamical measurements coupled with Friedmann models and nucleosynthesis constraints have given different values of the age. A consistent age is reported, whose implications for the constituent mass density are very interesting and are affected by the existence of a third neutrino flavor, and by allowing the possibility that neutrinos may have a non-zero rest mass.

  3. Neutrino mass, dark matter, and Baryon asymmetry via TeV-scale physics without fine-tuning.

    PubMed

    Aoki, Mayumi; Kanemura, Shinya; Seto, Osamu

    2009-02-01

    We propose an extended version of the standard model, in which neutrino oscillation, dark matter, and the baryon asymmetry of the Universe can be simultaneously explained by the TeV-scale physics without assuming a large hierarchy among the mass scales. Tiny neutrino masses are generated at the three-loop level due to the exact Z2 symmetry, by which the stability of the dark matter candidate is guaranteed. The extra Higgs doublet is required not only for the tiny neutrino masses but also for successful electroweak baryogenesis. The model provides discriminative predictions especially in Higgs phenomenology, so that it is testable at current and future collider experiments.

  4. Cosmological and supernova neutrinos

    NASA Astrophysics Data System (ADS)

    Kajino, T.; Aoki, W.; Balantekin, A. B.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Kusakabe, M.; Mathews, G. J.; Nakamura, K.; Pehlivan, Y.; Shibagaki, S.; Suzuki, T.

    2014-06-01

    The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial 7Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and 7Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like 7Li, 11B, 92Nb, 138La and 180Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ13 with predicted and observed supernova-produced abundance ratio 11B/7Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

  5. Cosmological and supernova neutrinos

    SciTech Connect

    Kajino, T.; Aoki, W.; Balantekin, A. B.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Shibagaki, S.; Kusakabe, M.; Mathews, G. J.; Nakamura, K.; Pehlivan, Y.; Suzuki, T.

    2014-06-24

    The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

  6. Low mass binary neutron star mergers: Gravitational waves and neutrino emission

    NASA Astrophysics Data System (ADS)

    Foucart, Francois; Haas, Roland; Duez, Matthew D.; O'Connor, Evan; Ott, Christian D.; Roberts, Luke; Kidder, Lawrence E.; Lippuner, Jonas; Pfeiffer, Harald P.; Scheel, Mark A.

    2016-02-01

    Neutron star mergers are among the most promising sources of gravitational waves for advanced ground-based detectors. These mergers are also expected to power bright electromagnetic signals, in the form of short gamma-ray bursts, infrared/optical transients powered by r-process nucleosynthesis in neutron-rich material ejected by the merger, and radio emission from the interaction of that ejecta with the interstellar medium. Simulations of these mergers with fully general relativistic codes are critical to understand the merger and postmerger gravitational wave signals and their neutrinos and electromagnetic counterparts. In this paper, we employ the Spectral Einstein Code to simulate the merger of low mass neutron star binaries (two 1.2 M⊙ neutron stars) for a set of three nuclear-theory-based, finite temperature equations of state. We show that the frequency peaks of the postmerger gravitational wave signal are in good agreement with predictions obtained from recent simulations using a simpler treatment of gravity. We find, however, that only the fundamental mode of the remnant is excited for long periods of time: emission at the secondary peaks is damped on a millisecond time scale in the simulated binaries. For such low mass systems, the remnant is a massive neutron star which, depending on the equation of state, is either permanently stable or long lived (i.e. rapid uniform rotation is sufficient to prevent its collapse). We observe strong excitations of l =2 , m =2 modes, both in the massive neutron star and in the form of hot, shocked tidal arms in the surrounding accretion torus. We estimate the neutrino emission of the remnant using a neutrino leakage scheme and, in one case, compare these results with a gray two-moment neutrino transport scheme. We confirm the complex geometry of the neutrino emission, also observed in previous simulations with neutrino leakage, and show explicitly the presence of important differences in the neutrino luminosity, disk

  7. Constraints on the flux of ultra-high energy neutrinos from Westerbork Synthesis Radio Telescope observations

    NASA Astrophysics Data System (ADS)

    Buitink, S.; Scholten, O.; Bacelar, J.; Braun, R.; de Bruyn, A. G.; Falcke, H.; Singh, K.; Stappers, B.; Strom, R. G.; Yahyaoui, R. Al

    2010-10-01

    Context. Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath the Moon's surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observation of these pulses with radio telescopes on the Earth is around 150 MHz. Aims: By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHE neutrino flux. Methods: The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a sampling frequency of 40 MHz. The narrowband radio interference is digitally filtered out and the dispersive effect of the Earth's ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, the detection efficiency for pulses of various strength is calculated. Results: With 47.6 hours of observation time, we are able to set a limit on the UHE neutrino flux. This new limit is an order of magnitude lower than existing limits. In the near future, the digital radio array LOFAR will be used to achieve an even lower limit.

  8. Gamma-ray constraints on maximum cosmogenic neutrino fluxes and UHECR source evolution models

    SciTech Connect

    Gelmini, Graciela B.; Kalashev, Oleg; Semikoz, Dmitri V. E-mail: kalashev@ms2.inr.ac.ru

    2012-01-01

    The dip model assumes that the ultra-high energy cosmic rays (UHECRs) above 10{sup 18} eV consist exclusively of protons and is consistent with the spectrum and composition measure by HiRes. Here we present the range of cosmogenic neutrino fluxes in the dip-model which are compatible with a recent determination of the extragalactic very high energy (VHE) gamma-ray diffuse background derived from 2.5 years of Fermi/LAT data. We show that the largest fluxes predicted in the dip model would be detectable by IceCube in about 10 years of observation and are within the reach of a few years of observation with the ARA project. In the incomplete UHECR model in which protons are assumed to dominate only above 10{sup 19} eV, the cosmogenic neutrino fluxes could be a factor of 2 or 3 larger. Any fraction of heavier nuclei in the UHECR at these energies would reduce the maximum cosmogenic neutrino fluxes. We also consider here special evolution models in which the UHECR sources are assumed to have the same evolution of either the star formation rate (SFR), or the gamma-ray burst (GRB) rate, or the active galactic nuclei (AGN) rate in the Universe and found that the last two are disfavored (and in the dip model rejected) by the new VHE gamma-ray background.

  9. Neutrino mass from the beta spectrum in the decay of tritium

    SciTech Connect

    Boris, S.; Golutvin, A.; Laptin, L.; Lubimov, V.; Nagovizin, V.; Nozik, V.; Novikov, E.; Soloshenko, V.; Tihomirov, I.; Tretjakov, E.; and others

    1987-05-18

    The data from the spectrum measurement of the tritium decay in a valine molecule carried out in a wide energy range (3.4 KeV) with the ITEP spectrometer are analyzed. The combined analysis of both these data and the data of the previous cycle gives the neutrino mass 30.3/sub -8//sup +2/ eV. The model-independent mass interval 17mass difference of the doublet /sup 3/H-/sup 3/He.

  10. Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen.

    PubMed

    Gando, A; Gando, Y; Hachiya, T; Hayashi, A; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Karino, Y; Koga, M; Matsuda, S; Mitsui, T; Nakamura, K; Obara, S; Oura, T; Ozaki, H; Shimizu, I; Shirahata, Y; Shirai, J; Suzuki, A; Takai, T; Tamae, K; Teraoka, Y; Ueshima, K; Watanabe, H; Kozlov, A; Takemoto, Y; Yoshida, S; Fushimi, K; Banks, T I; Berger, B E; Fujikawa, B K; O'Donnell, T; Winslow, L A; Efremenko, Y; Karwowski, H J; Markoff, D M; Tornow, W; Detwiler, J A; Enomoto, S; Decowski, M P

    2016-08-19

    We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26}  yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region. PMID:27588852

  11. Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen.

    PubMed

    Gando, A; Gando, Y; Hachiya, T; Hayashi, A; Hayashida, S; Ikeda, H; Inoue, K; Ishidoshiro, K; Karino, Y; Koga, M; Matsuda, S; Mitsui, T; Nakamura, K; Obara, S; Oura, T; Ozaki, H; Shimizu, I; Shirahata, Y; Shirai, J; Suzuki, A; Takai, T; Tamae, K; Teraoka, Y; Ueshima, K; Watanabe, H; Kozlov, A; Takemoto, Y; Yoshida, S; Fushimi, K; Banks, T I; Berger, B E; Fujikawa, B K; O'Donnell, T; Winslow, L A; Efremenko, Y; Karwowski, H J; Markoff, D M; Tornow, W; Detwiler, J A; Enomoto, S; Decowski, M P

    2016-08-19

    We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26}  yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

  12. Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen

    NASA Astrophysics Data System (ADS)

    Gando, A.; Gando, Y.; Hachiya, T.; Hayashi, A.; Hayashida, S.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Karino, Y.; Koga, M.; Matsuda, S.; Mitsui, T.; Nakamura, K.; Obara, S.; Oura, T.; Ozaki, H.; Shimizu, I.; Shirahata, Y.; Shirai, J.; Suzuki, A.; Takai, T.; Tamae, K.; Teraoka, Y.; Ueshima, K.; Watanabe, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Fushimi, K.; Banks, T. I.; Berger, B. E.; Fujikawa, B. K.; O'Donnell, T.; Winslow, L. A.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Decowski, M. P.; KamLAND-Zen Collaboration

    2016-08-01

    We present an improved search for neutrinoless double-beta (0 ν β β ) decay of 136Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the Agm110 contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0 ν β β decay half-life of T1/2 0 ν>1.07 ×1 026 yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

  13. Scales of mass generation for quarks, leptons, and majorana neutrinos.

    PubMed

    Dicus, Duane A; He, Hong-Jian

    2005-06-10

    We study 2-->n inelastic fermion-(anti)fermion scattering into multiple longitudinal weak gauge bosons and derive universal upper bounds on the scales of fermion mass generation by imposing unitarity of the S matrix. We place new upper limits on the scales of fermion mass generation, independent of the electroweak symmetry breaking scale. Strikingly, we find that the strongest 2-->n limits fall in a narrow range, 3-170 TeV (with n=2-24), depending on the observed fermion masses.

  14. The MARE project: a new 187Re neutrino mass experiment with sub eV sensitivity

    NASA Astrophysics Data System (ADS)

    Schaeffer, D.; Gatti, F.; Gallinaro, G.; Pergolesi, D.; Repetto, P.; Ribeiro-Gomes, M.; Kelley, R.; Kilbourne, C. A.; Porter, F. S.; Enss, C.; Fleischmann, A.; Gastaldo, L.; Andreotti, E.; Foggetta, L.; Giuliani, A.; Pedretti, M.; Prest, M.; Rusconi, C.; Sangiorgio, S.; Arnaboldi, C.; Brofferio, C.; Capelli, S.; Cremonesi, O.; Fiorini, E.; Gorla, P.; Kraft, S.; Nucciotti, A.; Pavan, M.; Pessina, G.; Previtali, E.; Sisti, M.; Irwin, K. D.; Margesin, B.; Monfardini, A.; Beyer, J.; Galeazzi, M.; de Bernardis, P.; Calvo, M.; Masi, S.; Petcov, S.; Heeger, K.; Maruyama, R.; McCammon, D.

    2011-12-01

    A large worldwide collaboration is growing around the project of Micro-calorimeter Arrays for a Rhenium Experiment (MARE) for a direct calorimetric measurement of the neutrino mass with a sensitivity of about 0.2 eV/c2. Many groups are joining their experience and technical expertise in a common effort towards this challenging experiment which will use the most recent and advanced developments of the thermal detection technique.

  15. A critical analysis of one-loop neutrino mass models with minimal dark matter

    NASA Astrophysics Data System (ADS)

    Ahriche, Amine; McDonald, Kristian L.; Nasri, Salah; Picek, Ivica

    2016-06-01

    A recent paper investigated minimal RνMDM models with the type T1-iii and T3 one-loop topologies. However, the candidate most-minimal model does not possess an accidental symmetry - the scalar potential contains an explicit symmetry breaking term, rendering the dark matter unstable. We present two models that cure this problem. However, we further show that all of the proposed minimal one-loop RνMDM models suffer from a second problem - an additional source of explicit Z2 symmetry breaking in the Yukawa sector. We perform a more-general analysis to show that neutrino mass models using either the type T3 or type T1-iii one-loop topologies do not give viable minimal dark matter candidates. Consequently, one-loop models of neutrino mass with minimal dark matter do not appear possible. Thus, presently there remains a single known (three-loop) model of neutrino mass that gives stable dark matter without invoking any new symmetries.

  16. Calcium isotope constraints on the end-Permian mass extinction

    PubMed Central

    Payne, Jonathan L.; Turchyn, Alexandra V.; Paytan, Adina; DePaolo, Donald J.; Lehrmann, Daniel J.; Yu, Meiyi; Wei, Jiayong

    2010-01-01

    The end-Permian mass extinction horizon is marked by an abrupt shift in style of carbonate sedimentation and a negative excursion in the carbon isotope (δ13C) composition of carbonate minerals. Several extinction scenarios consistent with these observations have been put forward. Secular variation in the calcium isotope (δ44/40Ca) composition of marine sediments provides a tool for distinguishing among these possibilities and thereby constraining the causes of mass extinction. Here we report δ44/40Ca across the Permian-Triassic boundary from marine limestone in south China. The δ44/40Ca exhibits a transient negative excursion of ∼0.3‰ over a few hundred thousand years or less, which we interpret to reflect a change in the global δ44/40Ca composition of seawater. CO2-driven ocean acidification best explains the coincidence of the δ44/40Ca excursion with negative excursions in the δ13C of carbonates and organic matter and the preferential extinction of heavily calcified marine animals. Calcium isotope constraints on carbon cycle calculations suggest that the average δ13C of CO2 released was heavier than -28‰ and more likely near -15‰; these values indicate a source containing substantial amounts of mantle- or carbonate-derived carbon. Collectively, the results point toward Siberian Trap volcanism as the trigger of mass extinction. PMID:20421502

  17. Calcium isotope constraints on the end-Permian mass extinction.

    PubMed

    Payne, Jonathan L; Turchyn, Alexandra V; Paytan, Adina; Depaolo, Donald J; Lehrmann, Daniel J; Yu, Meiyi; Wei, Jiayong

    2010-05-11

    The end-Permian mass extinction horizon is marked by an abrupt shift in style of carbonate sedimentation and a negative excursion in the carbon isotope (delta(13)C) composition of carbonate minerals. Several extinction scenarios consistent with these observations have been put forward. Secular variation in the calcium isotope (delta(44/40)Ca) composition of marine sediments provides a tool for distinguishing among these possibilities and thereby constraining the causes of mass extinction. Here we report delta(44/40)Ca across the Permian-Triassic boundary from marine limestone in south China. The delta(44/40)Ca exhibits a transient negative excursion of approximately 0.3 per thousand over a few hundred thousand years or less, which we interpret to reflect a change in the global delta(44/40)Ca composition of seawater. CO(2)-driven ocean acidification best explains the coincidence of the delta(44/40)Ca excursion with negative excursions in the delta(13)C of carbonates and organic matter and the preferential extinction of heavily calcified marine animals. Calcium isotope constraints on carbon cycle calculations suggest that the average delta(13)C of CO(2) released was heavier than -28 per thousand and more likely near -15 per thousand; these values indicate a source containing substantial amounts of mantle- or carbonate-derived carbon. Collectively, the results point toward Siberian Trap volcanism as the trigger of mass extinction. PMID:20421502

  18. Neutrinos from SN 1987A - Implications for cooling of the nascent neutron star and the mass of the electron antineutrino

    NASA Technical Reports Server (NTRS)

    Loredo, Thomas J.; Lamb, Don Q.

    1989-01-01

    Data on neutrinos from SN 1987A are compared here with parameterized models of the neutrino emission using a consistent and straightforward statistical methodology. The empirically measured detector background spectra are included in the analysis, and the data are compared with a much wider variety of neutrino emission models than was explored previously. It is shown that the inferred neutrino emission model parameters are strongly correlated. The analysis confirms that simple models of the neutrino cooling of the nascent neutron star formed by the SN adequately explain the data. The inferred radius and binding energy of the neutron star are in excellent agreement with model calculations based on a wide range of equations of state. The results also raise the upper limit of the electron antineutrino rest mass to roughly 25 eV at the 95 percent confidence level, roughly 1.5-5 times higher than found previously.

  19. Probing neutrinos from Planck and forthcoming galaxy redshift surveys

    SciTech Connect

    Takeuchi, Yoshitaka; Kadota, Kenji E-mail: kadota.kenji@f.nagoya-u.jp

    2014-01-01

    We investigate how much the constraints on the neutrino properties can be improved by combining the CMB, the photometric and spectroscopic galaxy redshift surveys which include the CMB lensing, galaxy lensing tomography, galaxy clustering and redshift space distortion observables. We pay a particular attention to the constraint on the neutrino mass in view of the forthcoming redshift surveys such as the Euclid satellite and the LSST survey along with the Planck CMB lensing measurements. Combining the transverse mode information from the angular power spectrum and the longitudinal mode information from the spectroscopic survey with the redshift space distortion measurements can determine the total neutrino mass with the projected error of O(0.02) eV. Our analysis fixes the mass splittings among the neutrino species to be consistent with the neutrino oscillation data, and we accordingly study the sensitivity of our parameter estimations on the minimal neutrino mass. The cosmological measurement of the total neutrino mass can distinguish between the normal and inverted mass hierarchy scenarios if the minimal neutrino mass ∼<0.005 eV with the predicted 1–σ uncertainties taken into account.

  20. Neutrino mixing and oscillation in a grand unified field theory SO(10)

    SciTech Connect

    Tanaka, K.

    1980-01-01

    The investigation shows that it is very difficult to achieve neutrino mixing of other than the V/sub ..mu../-..nu../sub tau/ type in any minimal SO(10) model in which neutrino masses are generated by the Gell-Mann-Ramond-Slansky mechanism, because of the severe constraints placed on the mass matrix by quark phenomenology.

  1. Constraints on the flux of Ultra-High Energy neutrinos from WSRT observations

    SciTech Connect

    Scholten, O; Bacelar, J; Braun, R; de Bruyn, A G; Falcke, H; Singh, K; Stappers, B; Strom, R G; al Yahyaoui, R

    2010-04-02

    Context. Ultra-high energy (UHE) neutrinos and cosmic rays initiate particle cascades underneath the Moon's surface. These cascades have a negative charge excess and radiate Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observation of these pulses with radio telescopes on the Earth is around 150 MHz. Aims. By observing the Moon with the Westerbork Synthesis Radio Telescope array we are able to set a new limit on the UHEneutrino flux. Methods. The PuMa II backend is used to monitor the Moon in 4 frequency bands between 113 and 175 MHz with a sampling frequency of 40 MHz. The narrow band radio interference is digitally filtered out and the dispersive effect of the Earth?s ionosphere is compensated for. A trigger system is implemented to search for short pulses. By inserting simulated pulses in the raw data, the detection efficiency for pulses of various strength is calculated. Results. With 47.6 hours of observation time, we are able to set a limit on the UHE neutrino flux. This new limit is an order of magnitude lower than existing limits. In the near future, the digital radio array LOFAR will be used to achieve an even lower limit.

  2. Experimental Neutrino Physics: Final Report

    SciTech Connect

    Lane, Charles E.; Maricic, Jelena

    2012-09-05

    Experimental studies of neutrino properties, with particular emphasis on neutrino oscillation, mass and mixing parameters. This research was pursued by means of underground detectors for reactor anti-neutrinos, measuring the flux and energy spectra of the neutrinos. More recent investigations have been aimed and developing detector technologies for a long-baseline neutrino experiment (LBNE) using a neutrino beam from Fermilab.

  3. Neutrinos: Theory and Phenomenology

    SciTech Connect

    Parke, Stephen

    2013-10-22

    The theory and phenomenology of neutrinos will be addressed, especially that relating to the observation of neutrino flavor transformations. The current status and implications for future experiments will be discussed with special emphasis on the experiments that will determine the neutrino mass ordering, the dominant flavor content of the neutrino mass eigenstate with the smallest electron neutrino content and the size of CP violation in the neutrino sector. Beyond the neutrino Standard Model, the evidence for and a possible definitive experiment to confirm or refute the existence of light sterile neutrinos will be briefly discussed.

  4. Ground state mass of 81Kr and the solar neutrino problem

    NASA Astrophysics Data System (ADS)

    Kouzes, R. T.; Lowry, M. M.; Bennett, C. L.

    1982-02-01

    The 81Br(3He,t)81Kr, reaction has been used to determine an improved value for the ground state mass of 81Kr. A comparison is made with 51V(3He,t)51Cr and the implications for calibration of the proposed bromine solar neutrino detector are presented. NUCLEAR REACTIONS 81Br(3He,t)81Kr, 51V(3He,t)51Cr, 87Rb(3He,t)87Sr, 85Rb(3He,t)85Sr, E(3He)=24.7 MeV; Q values measured, ground state 81Kr mass inferred.

  5. An upper limit on the neutrino rest mass.

    NASA Technical Reports Server (NTRS)

    Cowsik, R.; Mcclelland, J.

    1972-01-01

    It is pointed out that the measurement of the deceleration parameter by Sandage (1972) implies an upper limit of a few tens of electron volts on the sum of the masses of all the possible light, stable particles that interact only weakly. In the discussion of the problem, it is assumed that the universe is expanding from an initially hot and condensed state as envisaged in the 'big-bang' theories.

  6. Neutrino Analysis of the September 2010 Crab Nebula Flare and Time-integrated Constraints on Neutrino Emission From the Crab Using IceCube

    NASA Technical Reports Server (NTRS)

    Stamatikos, M.; Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguliar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Alba, J. L. Bazo; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K. -H.; Benabderrahmane, M. L.; BenZvi, SW.; Berdermann, J.; Berghaus, P.; Berley, D.

    2012-01-01

    We present the results for a search of high-energy muon neutrinos with the IceCube detector in coincidence with the Crab nebula flare reported on September 2010 by various experiments. Due to the unusual flaring state of the otherwise steady source we performed a prompt analysis of the 79-string configuration data to search for neutrinos that might be emitted along with the observed gamma-rays. We performed two different and complementary data selections of neutrino events in the time window of 10 days around the flare. One event selection is optimized for discovery of E(sub nu)(sup -2) neutrino spectrum typical of 1st order Fermi acceleration. A similar event selection has also been applied to the 40-string data to derive the time-integrated limits to the neutrino emission from the Crab [35]. The other event selection was optimized for discovery of neutrino spectra with softer spectral index and TeV energy cut-offs as observed for various galactic sources in gamma-rays. The 90% CL best upper limits on the Crab flux during the 10 day flare are 4.73 x 10(exp -11) per square centimeter per second TeV (sup -1) for an E(sub nu) (sup -2) neutrino spectrum and 2.50 x 10(exp -10) per square centimeter per second TeV(sup -1) for a softer neutrino spectra of E(sub nu)(sup -2.7), as indicated by Fermi measurements during the flare. IceCube has also set a time-integrated limit on the neutrino emission of the Crab using 375.5 days of livetime of the 40-string configuration data. This limit is compared to existing models of neutrino production from the Crab and its impact on astrophysical parameters is discussed. The most optimistic predictions of some models are already rejected by the IceCube neutrino telescope with more than 90% CL.

  7. Model independent extraction of the axial mass parameter in CCQE anti neutrino-nucleon scattering

    NASA Astrophysics Data System (ADS)

    Grebe, Heather

    2013-10-01

    Neutrino oscillation studies depend on a consistent value for the axial mass. For this reason, a model-independent extraction of this parameter from quasielastic (anti)neutrino-nucleon scattering data is vital. While most studies employ a model-dependent extraction using the dipole model of the axial form factor, we present a model-independent description using the z expansion of the axial form factor. Quasielastic antineutrino scattering data on C-12 from the MiniBooNE experiment are analyzed using this model-independent description. The value found, mA = 0 .85-0 . 06 + 0 . 13 +/- 0 . 13 GeV, differs significantly from the value utilized by the MiniBooNE Collaboration, mA = 1 . 35 GeV. Advisor: Dr. Gil Paz Wayne State Univerity.

  8. How the inverse seesaw mechanism can reveal itself natural, canonical, and independent of the right-handed neutrino mass

    NASA Astrophysics Data System (ADS)

    Dias, A. G.; de S. Pires, C. A.; Rodrigues da Silva, P. S.

    2011-09-01

    The common lore in the literature of neutrino mass generation is that the canonical seesaw mechanism beautifully offers an explanation for the tiny neutrino mass but at the cost of introducing right-handed neutrinos at a scale that is out of range for the current experiments. The inverse seesaw mechanism is an interesting alternative to the canonical one once it leads to tiny neutrino masses with the advantage of being testable at the TeV scale. However, this last mechanism suffers from an issue of naturalness concerning the scale responsible for such small masses, namely, the parameter μ that is related to lepton number violation and is supposed to be at the keV scale, much lower than the electroweak one. However, no theoretical framework was built that offers an explanation for obtaining this specific scale. In this work, we propose a variation of the inverse seesaw mechanism by assuming a minimal scalar and fermionic set of singlet fields, along with a Z5⊗Z2 symmetry, that allows a dynamical explanation for the smallness of μ, recovering the neat canonical seesaw formula and with right-handed (RH) neutrinos free to be at the electroweak scale, thus testable at LHC and current neutrino experiments.

  9. Explaining the CMS excesses, baryogenesis, and neutrino masses in a E6 motivated U (1 )N model

    NASA Astrophysics Data System (ADS)

    Dhuria, Mansi; Hati, Chandan; Sarkar, Utpal

    2016-01-01

    We study the superstring inspired E6 model motivated U (1 )N extension of the supersymmetric standard model to explore the possibility of explaining the recent excess CMS events and the baryon asymmetry of the Universe in eight possible variants of the model. In light of the hints from short-baseline neutrino experiments at the existence of one or more light sterile neutrinos, we also study the neutrino mass matrices dictated by the field assignments and the discrete symmetries in these variants. We find that all the variants can explain the excess CMS events via the exotic slepton decay, while for a standard choice of the discrete symmetry four of the variants have the feature of allowing high scale baryogenesis (leptogenesis). For one other variant three body decay induced soft baryogenesis mechanism is possible which can induce baryon number violating neutron-antineutron oscillation. We also point out a new discrete symmetry which has the feature of ensuring proton stability and forbidding tree level flavor changing neutral current processes while allowing for the possibility of high scale leptogenesis for two of the variants. On the other hand, neutrino mass matrix of the U (1 )N model variants naturally accommodates three active and two sterile neutrinos which acquire masses through their mixing with extra neutral fermions giving rise to interesting textures for neutrino masses.

  10. Identifying Neutrino Mass Hierarchy at Extremely Small {theta}{sub 13} through Earth Matter Effects in a Supernova Signal

    SciTech Connect

    Dasgupta, Basudeb; Dighe, Amol; Mirizzi, Alessandro

    2008-10-24

    Collective neutrino flavor transformations deep inside a supernova are sensitive to the neutrino mass hierarchy even at extremely small values of {theta}{sub 13}. Exploiting this effect, we show that comparison of the antineutrino signals from a galactic supernova in two megaton class water Cherenkov detectors, one of which is shadowed by Earth, will enable us to distinguish between the hierarchies if sin{sup 2}{theta}{sub 13} < or approx. 10{sup -5}, where long baseline neutrino experiments would be ineffectual.

  11. Weighing Neutrinos with Cosmic Neutral Hydrogen

    NASA Astrophysics Data System (ADS)

    Villaescusa-Navarro, Francisco; Bull, Philip; Viel, Matteo

    2015-12-01

    We investigate the signatures left by massive neutrinos on the spatial distribution of neutral hydrogen (H i) in the post-reionization era by running hydrodynamic simulations that include massive neutrinos as additional collisionless particles. We find that halos in massive/massless neutrino cosmologies host a similar amount of neutral hydrogen, although for a fixed halo mass, on average, the H i mass increases with the sum of the neutrino masses. Our results show that H i is more strongly clustered in cosmologies with massive neutrinos, while its abundance, ΩH i(z), is lower. These effects arise mainly from the impact of massive neutrinos on cosmology: they suppress both the amplitude of the matter power spectrum on small scales and the abundance of dark matter halos. Modeling the H i distribution with hydrodynamic simulations at z > 3 and a simple analytic model at z < 3, we use the Fisher matrix formalism to conservatively forecast the constraints that Phase 1 of the Square Kilometre Array will place on the sum of neutrino masses, Mν ≡ Σ mν. We find that with 10,000 hr of interferometric observations at 3 ≲ z ≲ 6 from a deep and narrow survey with SKA1-LOW, the sum of the neutrino masses can be measured with an error σ(Mν) ≲ 0.3 eV (95% CL). Similar constraints can be obtained with a wide and deep SKA1-MID survey at z ≲ 3, using the single-dish mode. By combining data from MID, LOW, and Planck, plus priors on cosmological parameters from a Stage IV spectroscopic galaxy survey, the sum of the neutrino masses can be determined with an error σ(Mν) ≃ 0.06 eV (95% CL).

  12. WEIGHING NEUTRINOS WITH COSMIC NEUTRAL HYDROGEN

    SciTech Connect

    Villaescusa-Navarro, Francisco; Viel, Matteo; Bull, Philip E-mail: viel@oats.inaf.it

    2015-12-01

    We investigate the signatures left by massive neutrinos on the spatial distribution of neutral hydrogen (H i) in the post-reionization era by running hydrodynamic simulations that include massive neutrinos as additional collisionless particles. We find that halos in massive/massless neutrino cosmologies host a similar amount of neutral hydrogen, although for a fixed halo mass, on average, the H i mass increases with the sum of the neutrino masses. Our results show that H i is more strongly clustered in cosmologies with massive neutrinos, while its abundance, Ω{sub H} {sub i}(z), is lower. These effects arise mainly from the impact of massive neutrinos on cosmology: they suppress both the amplitude of the matter power spectrum on small scales and the abundance of dark matter halos. Modeling the H i distribution with hydrodynamic simulations at z > 3 and a simple analytic model at z < 3, we use the Fisher matrix formalism to conservatively forecast the constraints that Phase 1 of the Square Kilometre Array will place on the sum of neutrino masses, M{sub ν} ≡ Σ m{sub ν}. We find that with 10,000 hr of interferometric observations at 3 ≲ z ≲ 6 from a deep and narrow survey with SKA1-LOW, the sum of the neutrino masses can be measured with an error σ(M{sub ν}) ≲ 0.3 eV (95% CL). Similar constraints can be obtained with a wide and deep SKA1-MID survey at z ≲ 3, using the single-dish mode. By combining data from MID, LOW, and Planck, plus priors on cosmological parameters from a Stage IV spectroscopic galaxy survey, the sum of the neutrino masses can be determined with an error σ(M{sub ν}) ≃ 0.06 eV (95% CL)

  13. Very low-energy neutrino interactions

    NASA Astrophysics Data System (ADS)

    Suzuki, Toshio

    2015-05-01

    Neutrino-nucleus reaction cross sections are now evaluated rather accurately by shell-model (SM) or SM+RPA calculations based on recent advances in nuclear structure studies. Due to these achievements, reliable constraints on super-nova neutrino temperatures as well as neutrino oscillation parameters become possible. Supernova neutrino tempeatures are constrained from abundances of elements obtained by using new ν-nucleus reaction cross sections. A possibility of constructing supernova neutrino spectrum from beta-beam measurements is pointed out. Neutrino mass hierarchy and mixing angle θ13 can be determined from abundance ratio of 7Li/11B, which is sensitive to the MSW matter oscillation effects in supernova explosions. Inverted mass hierarchy is shown to be statistically more favored based on a recent analysis of presolar grains. Effects of neutrino-neutrino interactions are also shown to play important roles in r-process nucleosynthesis. Importance and possibilities of direct measurements of ν-induced cross sections on 40Ar and 208Pb are discussed for future supernova neutrino detections. Recent calculations of the cross sections for ν-40Ar are presented. The need for new theoretical evaluations of the cross sections for ν-208Pb is pointed out. Challenges to experiments on coherent elastic scattering are presented.

  14. Very low-energy neutrino interactions

    SciTech Connect

    Suzuki, Toshio

    2015-05-15

    Neutrino-nucleus reaction cross sections are now evaluated rather accurately by shell-model (SM) or SM+RPA calculations based on recent advances in nuclear structure studies. Due to these achievements, reliable constraints on super-nova neutrino temperatures as well as neutrino oscillation parameters become possible. Supernova neutrino tempeatures are constrained from abundances of elements obtained by using new ν-nucleus reaction cross sections. A possibility of constructing supernova neutrino spectrum from beta-beam measurements is pointed out. Neutrino mass hierarchy and mixing angle θ{sub 13} can be determined from abundance ratio of {sup 7}Li/{sup 11}B, which is sensitive to the MSW matter oscillation effects in supernova explosions. Inverted mass hierarchy is shown to be statistically more favored based on a recent analysis of presolar grains. Effects of neutrino-neutrino interactions are also shown to play important roles in r-process nucleosynthesis. Importance and possibilities of direct measurements of ν-induced cross sections on {sup 40}Ar and {sup 208}Pb are discussed for future supernova neutrino detections. Recent calculations of the cross sections for ν-{sup 40}Ar are presented. The need for new theoretical evaluations of the cross sections for ν-{sup 208}Pb is pointed out. Challenges to experiments on coherent elastic scattering are presented.

  15. Phenomenological studies of neutrino physics

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun

    In this thesis, we studied the phenomenological results of several classes of neutrino models. We begin with an investigation of the effect of small perturbations on the mu-tau symmetrical models. We found that since m 1 and m2 are nearly degenerate, mu-tau symmetry mixing scenarios are able to explain the experimental data with about the same size perturbation for most values of &theta12. This suggests that the underlying unperturbed mixing need not have &theta12 close to the experimentally preferred value. Then we studied a simple case of type I seesaw model that have four texture zeros in the Yukawa couplings matrix, which is equivalent to a single texture or cofactor zero for an off-diagonal element of the light neutrino mass matrix M in the context of low energy phenomenology. Furthermore we studied a variety of neutrino models that have one or two texture and/or cofactor zeros. We determined the constraints in the space of the CP phase and lightest neutrino mass using a global fit to neutrino parameters, including recent data on &theta 13. We used leptogenesis to further constrain the parameter space for the seesaw models with four zeros in the Yukawa matrix, and made predictions on neutrinoless double beta decay for these models. Finally we showed that any neutrino model with a homogeneous relationship among elements of the light neutrino mass matrix with one mass hierarchy predicts oscillation parameters and Majorana phases similar to those of models with the same homogeneous relationship among cofactors of the mass matrix with the opposite mass hierarchy if the lightest mass is not too small, e.g., less than about 20 meV. This general result applies to texture and/or cofactor zero models, scaling models, and models that have two equal mass matrix elements or cofactors, e.g. mu-tau symmetric models.

  16. Neutrino fluxes from nonuniversal Higgs mass LSP annihilations in the Sun

    SciTech Connect

    Ellis, John; Olive, Keith A.; Savage, Christopher; Spanos, Vassilis C.

    2011-04-15

    We extend our previous studies of the neutrino fluxes expected from neutralino LSP annihilations inside the Sun to include variants of the minimal supersymmetric extension of the Standard Model (MSSM) with squark, slepton and gaugino masses constrained to be universal at the GUT scale, but allowing one or two nonuniversal supersymmetry breaking parameters contributing to the Higgs masses (NUHM1,2). As in the constrained MSSM (CMSSM) with universal Higgs masses, there are large regions of the NUHM parameter space where the LSP density inside the Sun is not in equilibrium, so that the annihilation rate may be far below the capture rate, and there are also large regions where the capture rate is not dominated by spin-dependent LSP-proton scattering. The spectra possible in the NUHM are qualitatively similar to those in the CMSSM. We calculate neutrino-induced muon fluxes above a threshold energy of 10 GeV, appropriate for the IceCube/DeepCore detector, for points where the NUHM yields the correct cosmological relic density for representative choices of the NUHM parameters. We find that the IceCube/DeepCore detector can probe regions of the NUHM parameter space in addition to analogues of the focus point strip and the tip of the coannihilation strip familiar from the CMSSM. These include regions with enhanced Higgsino-gaugino mixing in the LSP composition, that occurs where neutralino mass eigenstates cross over. On the other hand, rapid-annihilation funnel regions in general yield neutrino fluxes that are unobservably small.

  17. Dark matter, baryogenesis and neutrino oscillations from right-handed neutrinos

    NASA Astrophysics Data System (ADS)

    Canetti, Laurent; Drewes, Marco; Frossard, Tibor; Shaposhnikov, Mikhail

    2013-05-01

    We show that, leaving aside accelerated cosmic expansion, all experimental data in high energy physics that are commonly agreed to require physics beyond the Standard Model can be explained when completing the model by three right-handed neutrinos that can be searched for using present-day experimental techniques. The model that realizes this scenario is known as the Neutrino Minimal Standard Model (νMSM). In this article we give a comprehensive summary of all known constraints in the νMSM, along with a pedagogical introduction to the model. We present the first complete quantitative study of the parameter space of the model where no physics beyond the νMSM is needed to simultaneously explain neutrino oscillations, dark matter, and the baryon asymmetry of the Universe. The key new point of our analysis is leptogenesis after sphaleron freeze-out, which leads to resonant dark matter production, thus evading the constraints on sterile neutrino dark matter from structure formation and x-ray searches. This requires one to track the time evolution of left- and right-handed neutrino abundances from hot big bang initial conditions down to temperatures below the QCD scale. We find that the interplay of resonant amplifications, CP-violating flavor oscillations, scatterings, and decays leads to a number of previously unknown constraints on the sterile neutrino properties. We furthermore reanalyze bounds from past collider experiments and big bang nucleosynthesis in the face of recent evidence for a nonzero neutrino mixing angle θ13. We combine all our results with existing constraints on dark matter properties from astrophysics and cosmology. Our results provide a guideline for future experimental searches for sterile neutrinos. A summary of the constraints on sterile neutrino masses and mixings has appeared in Canetti et al. [Phys. Rev. Lett. 110, 061801 (2013)PRLTAO0031-9007]. In this article we provide all details of our calculations and give constraints on other model

  18. Neutrinos in Nuclear Physics

    SciTech Connect

    McKeown, Bob

    2015-06-01

    Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.

  19. Neutrino masses in supersymmetric SU(3){sub c} x SU(3){sub L} x U(1){sub X} models

    SciTech Connect

    Rodriguez, J-Alexis; Duarte, J.

    2008-11-23

    The mass spectra and the superpotential of two different supersymetric models based on the gauge symmetry SU(3){sub C} x SU(3){sub L} x U(1){sub X}(331) without any exotic charges assigned to the fermionic spectra are studied. These two models have three families in different representations of the gauge group. In these kind of models, the diagonalization of the neutralino mass matrix allows that three light neutrinos get different mass values. Possible values for the neutrino masses are calculated covering the parameter space of the models. These values have to agree with the available data coming from the neutrino oscillations experiments. Therefore, a reduced space of parameters for the superpotential and the vacuum expectation values allowed in the framework of the 331 supersymetric models can be obtained.

  20. Computation with Inverse States in a Finite Field FP: The Muon Neutrino Mass, the Unified Strong-Electroweak Coupling Constant, and the Higgs Mass

    SciTech Connect

    DAI,YANG; BORISOV,ALEXEY B.; BOYER,KEITH; RHODES,CHARLES K.

    2000-08-11

    The construction of inverse states in a finite field F{sub P{sub {alpha}}} enables the organization of the mass scale with fundamental octets in an eight-dimensional index space that identifies particle states with residue class designations. Conformance with both CPT invariance and the concept of supersymmetry follows as a direct consequence of this formulation. Based on two parameters (P{sub {alpha}} and g{sub {alpha}}) that are anchored on a concordance of physical data, this treatment leads to (1) a prospective mass for the muon neutrino of {approximately}27.68 meV, (2) a value of the unified strong-electroweak coupling constant {alpha}* = (34.26){sup {minus}1} that is physically defined by the ratio of the electron neutrino and muon neutrino masses, and (3) a see-saw congruence connecting the Higgs, the electron neutrino, and the muon neutrino masses. Specific evaluation of the masses of the corresponding supersymmetric Higgs pair reveals that both particles are superheavy (> 10{sup 18}GeV). No renormalization of the Higgs masses is introduced, since the calculational procedure yielding their magnitudes is intrinsically divergence-free. Further, the Higgs fulfills its conjectured role through the see-saw relation as the particle defining the origin of all particle masses, since the electron and muon neutrino systems, together with their supersymmetric partners, are the generators of the mass scale and establish the corresponding index space. Finally, since the computation of the Higgs masses is entirely determined by the modulus of the field P{sub {alpha}}, which is fully defined by the large-scale parameters of the universe through the value of the universal gravitational constant G and the requirement for perfect flatness ({Omega} = 1.0), the see-saw congruence fuses the concepts of mass and space and creates a new unified archetype.

  1. Gauge B-L model of radiative neutrino mass with multipartite dark matter

    NASA Astrophysics Data System (ADS)

    Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

    2016-08-01

    We propose an extension of the Standard Model of quarks and leptons to include gauge B-L symmetry with an exotic array of neutral fermion singlets for anomaly cancellation. With the addition of suitable scalars also transforming under U(1)B-L, this becomes a model of radiative seesaw neutrino mass with possible multipartite dark matter. If leptoquark fermions are added, necessarily also transforming under U(1)B-L, the diphoton excess at 750 GeV, recently observed at the Large Hadron Collider, may also be explained.

  2. Impact of semi-annihilation of Bbb Z3 symmetric dark matter with radiative neutrino masses

    NASA Astrophysics Data System (ADS)

    Aoki, Mayumi; Toma, Takashi

    2014-09-01

    We investigate a Bbb Z3 symmetric model with two-loop radiative neutrino masses. Dark matter in the model is either a Dirac fermion or a complex scalar as a result of an unbroken Bbb Z3 symmetry. In addition to standard annihilation processes, semi-annihilation of the dark matter contributes to the relic density. We study the effect of the semi-annihilation in the model and find that those contributions are important to obtain the observed relic density. The experimental signatures in dark matter searches are also discussed, where some of them are expected to be different from the signatures of dark matter in Bbb Z2 symmetric models.

  3. Radiative decay of keV-mass sterile neutrinos in a strongly magnetized plasma

    NASA Astrophysics Data System (ADS)

    Dobrynina, Alexandra A.; Mikheev, Nicolay V.; Raffelt, Georg G.

    2014-12-01

    The radiative decay of sterile neutrinos with typical masses of 10 keV is investigated in the presence of a strong magnetic field and degenerate plasma. A full account is taken of the strongly modified photon dispersion relation relative to vacuum. The limiting cases of relativistic and nonrelativistic plasma are analyzed. The decay rate in a strongly magnetized plasma as a function of the electron number density is compared with the unmagnetized case. We find that a strong magnetic field suppresses the catalyzing influence of the plasma on the decay rate.

  4. Lensing convergence and the neutrino mass scale in galaxy redshift surveys

    NASA Astrophysics Data System (ADS)

    Cardona, Wilmar; Durrer, Ruth; Kunz, Martin; Montanari, Francesco

    2016-08-01

    We demonstrate the importance of including the lensing contribution in galaxy clustering analyses with large galaxy redshift surveys. It is well known that radial cross-correlations between different redshift bins of galaxy surveys are dominated by lensing. But we show here that also neglecting lensing in the autocorrelations within one bin severely biases cosmological parameter estimation with redshift surveys. It leads to significant shifts for several cosmological parameters, most notably the scalar spectral index and the neutrino mass scale. Especially the latter parameter is one of the main targets of future galaxy surveys.

  5. Neutrino mass, proton decay, and neutron oscillations as crucial tests of unification models (A Review)

    PubMed Central

    Marshak, R. E.

    1982-01-01

    Several crucial tests of three popular unification models (of strong, electromagnetic, and weak interactions) are described. The models are SU(5) and SO(10) at the grand unification theory (GUT) level and SU(4)C × SU(2)L × SU(2)R at the partial unification theory (PUT) level. The tests selected for discussion are the finiteness of the neutrino mass in the electron volt region, the decay of protons into antileptons in the range of 1031± yr, and the detectability of neutron oscillations at all. The PUT group can also be tested by establishing the existence of four generations of quarks and leptons.

  6. Mass production test of Hamamatsu MPPC for T2K neutrino oscillation experiment

    NASA Astrophysics Data System (ADS)

    Yokoyama, M.; Nakaya, T.; Gomi, S.; Minamino, A.; Nagai, N.; Nitta, K.; Orme, D.; Otani, M.; Murakami, T.; Nakadaira, T.; Tanaka, M.

    2009-10-01

    In the T2K near neutrino detectors, about 60 000 Hamamatsu Multi-Pixel Photon Counters (MPPCs) will be used. The mass production of MPPC has started in February 2008. In order to perform quality assurance and to characterize each device, we have developed an MPPC test system. For each MPPC, gain, breakdown voltage, noise rate, photo detection efficiency, and cross-talk and after-pulse rate are measured as functions of the bias voltage and temperature. The design of the test system and the measurement procedure are described.

  7. Is cosmology compatible with sterile neutrinos?

    SciTech Connect

    Dodelson, Scott; Melchiorri, Alessandro; Slosar, Anze; /Ljubljana U.

    2005-11-01

    By combining data from cosmic microwave background (CMB) experiments (including the recent BOOMERANG-2K2 results), large scale structure (LSS) and Lyman-{alpha} forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless + 1 massive neutrino case we bound the mass of the sterile neutrino to m{sub s} < 0.55eV at 95% c.l.. These results exclude at high significance the sterile neutrino hypothesis as an explanation of the LSND anomaly. We then generalize the analysis to account for active neutrino masses (which tightens the limit to m{sub s} < 0.51eV) and the possibility that the sterile abundance is not thermal. In the latter case, the constraints in the (mass, density) plane are non-trivial. For a mass of > 1eV or < 0.05eV the cosmological energy density in sterile neutrinos is always constrained to be {omega}{sub {nu}} < 0.005 at 95% c.l.. However, for a sterile neutrino mass of {approx} 0.25 eV, {omega}{sub {nu}} can be as large as 0.015.

  8. NEUTRINO ANALYSIS OF THE 2010 SEPTEMBER CRAB NEBULA FLARE AND TIME-INTEGRATED CONSTRAINTS ON NEUTRINO EMISSION FROM THE CRAB USING ICECUBE

    SciTech Connect

    Abbasi, R.; Aguilar, J. A.; Andeen, K.; Baker, M.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Ahlers, M.; Altmann, D.; Auffenberg, J.; Becker, K.-H.; Bai, X.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Benabderrahmane, M. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; and others

    2012-01-20

    We present the results of a search for high-energy muon neutrinos with the IceCube detector in coincidence with the Crab Nebula flare reported on 2010 September by various experiments. Due to the unusual flaring state of the otherwise steady source we performed a prompt analysis of the 79-string configuration data to search for neutrinos that might be emitted along with the observed {gamma}-rays. We performed two different and complementary data selections of neutrino events in the time window of 10 days around the flare. One event selection is optimized for discovery of E{sup -2}{sub {nu}} neutrino spectrum typical of first-order Fermi acceleration. A similar event selection has also been applied to the 40-string data to derive the time-integrated limits to the neutrino emission from the Crab. The other event selection was optimized for discovery of neutrino spectra with softer spectral index and TeV energy cutoffs as observed for various Galactic sources in {gamma}-rays. The 90% confidence level (CL) best upper limits on the Crab flux during the 10 day flare are 4.73 Multiplication-Sign 10{sup -11} cm{sup -2} s{sup -1} TeV{sup -1} for an E{sup -2}{sub {nu}} neutrino spectrum and 2.50 Multiplication-Sign 10{sup -10} cm{sup -2} s{sup -1} TeV{sup -1} for a softer neutrino spectra of E{sup -2.7}{sub {nu}}, as indicated by Fermi measurements during the flare. In this paper, we also illustrate the impact of the time-integrated limit on the Crab neutrino steady emission. The limit obtained using 375.5 days of the 40-string configuration is compared to existing models of neutrino production from the Crab and its impact on astrophysical parameters is discussed. The most optimistic predictions of some models are already rejected by the IceCube neutrino telescope with more than 90% CL.

  9. Tom Bonner Prize Lecture: The Beta Spectrum of Tritium and the Problem of Neutrino Mass

    NASA Astrophysics Data System (ADS)

    Robertson, R. G. Hamish

    1997-04-01

    Enrico Fermi showed more than 60 years ago that the shape of beta spectra was sensitive to the mass of the unobserved particle, the neutrino, proposed by Wolfgang Pauli. With the discovery of tritium and its small decay energy, increasingly stringent limits were placed on the electron antineutrino mass. A roadblock at about 50 eV, namely the atomic and molecular structure of tritium-containing substances, was surmounted in the 1980s with the development at Los Alamos of methods for high-resolution beta spectroscopy with gases, together with worldwide theoretical work on the structure of diatomic T2 and T^3He^+. It was then possible to reach the very interesting region of cosmological relevance below 20 eV. An unexpected and strange new roadblock has now been encountered in all experiments on T_2. The spectrum near the endpoint is not consistent with theory either with or without neutrino mass. The questions now are, do the experiments all report the same phenomenon, and (if so) is it atomic theory, particle theory, or perhaps cosmology that needs repair?

  10. Seesaw majoron model of neutrino mass and novel signals in Higgs boson production at LEP

    NASA Astrophysics Data System (ADS)

    Díaz, Marco A.; García-Jareño, M. A.; Restrepo, Diego A.; Valle, José W. F.

    1998-08-01

    We perform a careful study of the neutral scalar sector of a model which includes a singlet, a doublet, and a triplet scalar field under SU(2). This model is motivated by neutrino physics, since it is simply the most general version of the seesaw model of neutrino mass generation through spontaneous violation of lepton number. The neutral Higgs sector contains three CP-even and one massive CP-odd Higgs boson A, in addition to the massless CP-odd mojoron J. The weakly interacting majoron remains massless if the breaking of lepton number symmetry is purely spontaneous. We show that the massive CP-odd Higgs boson may invisibly decay to three majorons, as well as to a CP-even Higgs H boson plus a majoron. We consider the associated Higgs production e+e- → Z → HA followed by invisible decays A → JJJ and H → JJ and derive the corresponding limits on masses and coupling that follow from LEP I precision measurements of the invisible Z width. We also study a novel b overlinebb overlinebp T signal predicted by the model, analyze the background and perform a Monte Carlo simulation of the signal in order to illustrate the limits on Higgs boson mass, couplings and branching ratios that follow from that.

  11. Gauge-Higgs unification, neutrino masses, and dark matter in warped extra dimensions

    SciTech Connect

    Carena, Marcela; Medina, Anibal D.; Shah, Nausheen R.; Wagner, Carlos E. M.

    2009-05-01

    Gauge-Higgs unification in warped extra dimensions provides an attractive solution to the hierarchy problem. The extension of the standard model gauge symmetry to SO(5)xU(1){sub X} allows the incorporation of the custodial symmetry SU(2){sub R} plus a Higgs boson doublet with the right quantum numbers under the gauge group. In the minimal model, the Higgs mass is in the range 110-150 GeV, while a light Kaluza-Klein excitation of the top quark appears in the spectrum, providing agreement with precision electroweak measurements and a possible test of the model at a high luminosity LHC. The extension of the model to the lepton sector has several interesting features. We discuss the conditions necessary to obtain realistic charged lepton and neutrino masses. After the addition of an exchange symmetry in the bulk, we show that the odd neutrino Kaluza-Klein modes provide a realistic dark-matter candidate, with a mass of the order of 1 TeV, which will be probed by direct dark-matter detection experiments in the near future.

  12. Neutrino Oscillations and the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Wark, David

    2001-04-01

    When the existence of the neutrino was almost apologetically first proposed by Wolfgang Pauli it was intended to explain the mysterious apparent absence of energy and momentum in beta decay. 70 years later the neutrino has indeed solved that mystery, but it has generated still more of its own. Are neutrinos massive? Is it possible to create a neutrino with its spin in the same direction as its momentum? What fraction of the mass of the Universe is made up of neutrinos? Are the flavour labels which we put on neutrinos, like electron and muon, really fixed or can they change? Why does no experiment see the predicted flux of neutrinos from the Sun? Why do there appear to be roughly equal numbers of muon and electron neutrinos created in our atmosphere, rather than the 2:1 ratio we would expect? Many of these questions were coupled when Bruno Pontecorvo first suggested that the shortfall in solar neutrino measurements were caused by neutrino oscillations - neutrinos spontaneously changing flavour as they travel from the Sun. 30 years later we still await definitive proof of that conjecture, and providing that proof is the reason for the Sudbury Neutrino Observatory. The talk will discuss the current state of neutrino oscillations studies, and show how the unique capabilities of the Sudbury Neutrino Observatory can provide definitive proof of whether neutrino oscillations are the long-sought answer to the solar neutrino problem.

  13. Lepton flavor violating decay of SM-like Higgs boson in a radiative neutrino mass model

    NASA Astrophysics Data System (ADS)

    Thuc, T. T.; Hue, L. T.; Long, H. N.; Nguyen, T. Phong

    2016-06-01

    The lepton flavor violating decay of the Standard Model-like Higgs boson (LFVHD) is discussed in the framework of the radiative neutrino mass model built in [K. Nishiwaki, H. Okada, and Y. Orikasa, Phys. Rev. D 92, 093013 (2015)]. The branching ratio (BR) of the LFVHD is shown to reach 10-5 in the most interesting region of the parameter space shown in [K. Nishiwaki, H. Okada, and Y. Orikasa, Phys. Rev. D 92, 093013 (2015)]. The dominant contributions come from the singly charged Higgs mediations, namely, the coupling of h2± with exotic neutrinos. Furthermore, if the doubly charged Higgs boson is heavy enough to allow the mass of h2± around 1 TeV, the mentioned BR can reach 10-4 . In addition, we obtain that the large values of Br (h →μ τ ) lead to very small ones of Br (h →e τ ) , much smaller than the various sensitivities of current experiments.

  14. Neutrino catalyzed diphoton excess

    NASA Astrophysics Data System (ADS)

    Chao, Wei

    2016-10-01

    In this paper we explain the 750 GeV diphoton resonance observed at the run-2 LHC as a scalar singlet S, that plays a key role in generating tiny but nonzero Majorana neutrino masses. The model contains four electroweak singlets: two leptoquarks, a singly charged scalar and a neutral scalar S. Majorana neutrino masses might be generated at the two-loop level as S gets nonzero vacuum expectation value. S can be produced at the LHC through the gluon fusion and decays into diphoton with charged scalars running in the loop. The model fits perfectly with a narrow width of the resonance. Constraints on the model are investigated, which shows a negligible mixing between the resonance and the standard model Higgs boson.

  15. Testing for new physics: neutrinos and the primordial power spectrum

    NASA Astrophysics Data System (ADS)

    Canac, Nicolas; Aslanyan, Grigor; Abazajian, Kevork N.; Easther, Richard; Price, Layne C.

    2016-09-01

    We test the sensitivity of neutrino parameter constraints from combinations of CMB and LSS data sets to the assumed form of the primordial power spectrum (PPS) using Bayesian model selection. Significantly, none of the tested combinations, including recent high-precision local measurements of H0 and cluster abundances, indicate a signal for massive neutrinos or extra relativistic degrees of freedom. For PPS models with a large, but fixed number of degrees of freedom, neutrino parameter constraints do not change significantly if the location of any features in the PPS are allowed to vary, although neutrino constraints are more sensitive to PPS features if they are known a priori to exist at fixed intervals in log k. Although there is no support for a non-standard neutrino sector from constraints on both neutrino mass and relativistic energy density, we see surprisingly strong evidence for features in the PPS when it is constrained with data from Planck 2015, SZ cluster counts, and recent high-precision local measurements of H0. Conversely combining Planck with matter power spectrum and BAO measurements yields a much weaker constraint. Given that this result is sensitive to the choice of data this tension between SZ cluster counts, Planck and H0 measurements is likely an indication of unmodeled systematic bias that mimics PPS features, rather than new physics in the PPS or neutrino sector.

  16. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2015-11-11

    We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at √s= 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. Furthermore, we improve the calibration of jet energies using the calibration determined in tt¯ → lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. As a result, the measured top quark mass is mt = 173.32±1.36(stat)±0.85(syst) GeV.

  17. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cuth, J.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schott, M.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.; Yu, J. M.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.

    2016-01-01

    We measure the top quark mass in dilepton final states of t t bar events in p p bar collisions at √{ s} = 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. We also improve the calibration of jet energies using the calibration determined in t t bar →lepton +jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured top quark mass is mt = 173.32 ± 1.36 (stat) ± 0.85 (syst) GeV.

  18. Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass

    SciTech Connect

    Vergados, J. D.

    2011-12-16

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0{nu}{beta}{beta}-decay in three different nuclei, e.g. {sup 76}Ge, {sup 100}Mo and {sup 130}Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.

  19. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    DOE PAGES

    Abazov, Victor Mukhamedovich

    2015-11-11

    We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at √s= 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. Furthermore, we improve the calibration of jet energies using the calibration determined in tt¯ → lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. As a result, the measured top quark mass is mt = 173.32±1.36(stat)±0.85(syst) GeV.

  20. Update on two-zero textures of the Majorana neutrino mass matrix in light of recent T2K, Super-Kamiokande and NOνA results

    NASA Astrophysics Data System (ADS)

    Zhou, Shun

    2016-03-01

    The latest results from atmospheric and accelerator neutrino experiments indicate that the normal neutrino mass ordering m 1 < m 2 < m 3, a maximal leptonic CP-violating phase δ = 270° and the second octant of neutrino mixing angle θ 23 > 45° are favored. In light of new experimental results, we update previous phenomenological studies on two-zero textures of the Majorana neutrino mass matrix M ν, in the flavor basis where the charged-lepton mass matrix M l is diagonal. When the 1σ ranges of neutrino mixing parameters are taken into account, only four (i.e., A 1, 2 and B 2,4) among seven two-zero patterns of M ν show the aforementioned features of neutrino mass spectrum, mixing angle θ 23 and CP-violating phase δ, and thus are compatible with the latest neutrino oscillation data. The correlative relations among neutrino masses and mixing parameters have been derived analytically for these four patterns, and the allowed regions of neutrino mixing angles and the CP-violating phase are also given. Possible realizations of four viable two-zero textures via non-Abelian discrete flavor symmetries are discussed. Supported in part by the Innovation Program of the Institute of High Energy Physics (Y4515570UI), National Youth Thousand Talents Program, and the CAS Center for Excellence in Particle Physics (CCEPP)

  1. Determining the neutrino mass hierarchy and CP violation in NoVA with a second off-axis detector

    SciTech Connect

    Mena, Olga; Palomares-Ruiz, Sergio; Pascoli, Silvia; /CERN /Durham U., IPPP

    2005-10-01

    We consider a Super-NOVA-like experimental configuration based on the use of two detectors in a long-baseline experiment as NOVA. We take the far detector as in the present NOVA proposal and add a second detector at a shorter baseline. The location of the second off-axis detector is chosen such that the ratio L/E is the same for both detectors, being L the baseline and E the neutrino energy. We consider liquid argon and water- Cerenkov techniques for the second off-axis detector and study, for different experimental setups, the detector mass required for the determination of the neutrino mass hierarchy, for different values of {theta}{sub 13}. We also study the capabilities of such an experimental setup for determining CP-violation in the neutrino sector. Our results show that by adding a second off-axis detector a remarkable enhancement on the capabilities of the current NOVA experiment could be achieved.

  2. Neutrino refraction by the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Díaz, J. S.; Klinkhamer, F. R.

    2016-03-01

    We have determined the dispersion relation of a neutrino test particle propagating in the cosmic neutrino background. Describing the relic neutrinos and antineutrinos from the hot big bang as a dense medium, a matter potential or refractive index is obtained. The vacuum neutrino mixing angles are unchanged, but the energy of each mass state is modified. Using a matrix in the space of neutrino species, the induced potential is decomposed into a part which produces signatures in beta-decay experiments and another part which modifies neutrino oscillations. The low temperature of the relic neutrinos makes a direct detection extremely challenging. From a different point of view, the identified refractive effects of the cosmic neutrino background constitute an ultralow background for future experimental studies of nonvanishing Lorentz violation in the neutrino sector.

  3. The case for mixed dark matter from sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Lello, Louis; Boyanovsky, Daniel

    2016-06-01

    Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via standard model charged and neutral current vertices under a minimal set of assumptions: i) the mass basis contains a hierarchy of heavy neutrinos, ii) these have very small mixing angles with the active (flavor) neutrinos, iii) standard model particles, including light (active-like) neutrinos are in thermal equilibrium. If kinematically allowed, the same weak interaction processes that produce active-like neutrinos also produce the heavier species. We introduce the quantum kinetic equations that describe their production, freeze out and decay and discuss the various processes that lead to their production in a wide range of temperatures assessing their feasibility as dark matter candidates. The final distribution function at freeze-out is a mixture of the result of the various production processes. We identify processes in which finite temperature collective excitations may lead to the production of the heavy species. As a specific example, we consider the production of heavy neutrinos in the mass range Mh lesssim 140 MeV from pion decay shortly after the QCD crossover including finite temperature corrections to the pion form factors and mass. We consider the different decay channels that allow for the production of heavy neutrinos showing that their frozen distribution functions exhibit effects from ``kinematic entanglement'' and argue for their viability as mixed dark matter candidates. We discuss abundance, phase space density and stability constraints and argue that heavy neutrinos with lifetime τ> 1/H0 freeze out of local thermal equilibrium, and conjecture that those with lifetimes τ ll 1/H0 may undergo cascade decay into lighter DM candidates and/or inject non-LTE neutrinos into the cosmic neutrino background. We provide a

  4. Implications of a class of neutrino mass matrices with texture zeros for nonzero {theta}{sub 13}

    SciTech Connect

    Kumar, Sanjeev

    2011-10-01

    A class of neutrino mass matrices with texture zeros realizable using the group Z{sub 3} within the framework of type (I+II) seesaw mechanism naturally admits a nonzero {theta}{sub 13}, and allows for deviations from maximal mixing. The phenomenology of this model is reexamined in the light of recent hints for nonzero {theta}{sub 13}.

  5. Neutrino telescopes

    SciTech Connect

    Costantini, H.

    2012-09-15

    Neutrino astrophysics offers a new possibility to observe our Universe: high-energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos: this young discipline extends in fact the conventional astronomy beyond the usual electromagnetic probe. The weak interaction of neutrinos with matter allows them to escape from the core of astrophysical objects and in this sense they represent a complementary messenger with respect to photons. However, their detection on Earth due to the small interaction cross section requires a large target mass. The aim of this article is to review the scientific motivations of the high-energy neutrino astrophysics, the detection principles together with the description of a running apparatus, the experiment ANTARES, the performance of this detector with some results, and the presentation of other neutrino telescope projects.

  6. Electroweak breaking and neutrino mass: ‘invisible’ Higgs decays at the LHC (type II seesaw)

    NASA Astrophysics Data System (ADS)

    Bonilla, Cesar; Romão, Jorge C.; Valle, José W. F.

    2016-03-01

    Neutrino mass generation through the Higgs mechanism not only suggests the need to reconsider the physics of electroweak symmetry breaking from a new perspective, but also provides a new theoretically consistent and experimentally viable paradigm. We illustrate this by describing the main features of the electroweak symmetry breaking sector of the simplest type-II seesaw model with spontaneous breaking of lepton number. After reviewing the relevant ‘theoretical’ and astrophysical restrictions on the Higgs sector, we perform an analysis of the sensitivities of Higgs Boson searches at the ongoing ATLAS and CMS experiments at the LHC, including not only the new contributions to the decay channels present in the standard model (SM) but also genuinely non-SM Higgs Boson decays, such as ‘invisible’ Higgs Boson decays to majorons. We find sensitivities that are likely to be reached at the upcoming run of the experiments.

  7. Gravitino Dark Matter, Neutrino Masses and Lepton Flavor Violation from broken R-parity

    SciTech Connect

    Lola, S.

    2009-04-17

    We study gravitino dark matter and slow gravitino decays in supersymmetric theories with broken R-parity. It turns out that for the model parameters that may give rise to viable radiative neutrino masses, and visible R-violating signatures in colliders, gravitinos are cosmologically stable and can be good dark matter candidates. On the contrary, the decays of the Next-to-Lightest Supersymmetric Particle are fast, and can be easily reconciled with Big Bang Nucleosynthesis. For the interesting range of parameters, observable lepton flavour violation is also to be expected, with rates that are strongly dependent from the flavour structure of the R-violating operators, and with distinct correlations that should be distinguishable in the coming generation of experiments.

  8. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters

    SciTech Connect

    Prasai, K.; Yanardag, S. Basak; Galeazzi, M.; Uprety, Y.; Alves, E.; Rocha, J.; Bagliani, D.; Biasotti, M.; Gatti, F.; Gomes, M. Ribeiro

    2013-08-15

    In a microcalorimetric neutrino mass experiment using the radioactive decay of {sup 163}Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the {sup 163}Ho fabrication), in the temperature range 70 mK–300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

  9. Constraints on Thermal X-Ray Radiation from SAX J1808.4-3658 and Implications for Neutron Star Neutrino Emission

    NASA Astrophysics Data System (ADS)

    Heinke, C. O.; Jonker, P. G.; Wijnands, R.; Taam, R. E.

    2007-05-01

    Thermal X-ray radiation from neutron star soft X-ray transients in quiescence provides the strongest constraints on the cooling rates of neutron stars and thus on the interior composition and properties of matter in the cores of neutron stars. We analyze new (2006) and archival (2001) XMM-Newton observations of the accreting millisecond pulsar SAX J1808.4-3658 in quiescence, which provide the most stringent constraints to date. The X-ray spectrum of SAX J1808.4-3658 in the 2006 observation is consistent with a power law of photon index 1.83+/-0.17, without requiring the presence of a blackbody-like component from a neutron star atmosphere. Our 2006 observation shows a slightly lower 0.5-10 keV X-ray luminosity, at a level of 68+15-13% of that inferred from the 2001 observation. Simultaneous fitting of all available XMM-Newton data allows a constraint on the quiescent neutron star (0.01-10 keV) luminosity of LNS<1.1×1031 ergs s-1. This limit excludes some current models of neutrino emission mediated by pion condensates and provides further evidence of additional cooling processes, such as neutrino emission via direct Urca processes involving nucleons and/or hyperons, in the cores of massive neutron stars. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

  10. Cosmology with massive neutrinos II: on the universality of the halo mass function and bias

    SciTech Connect

    Castorina, Emanuele; Sefusatti, Emiliano; Sheth, Ravi K.; Villaescusa-Navarro, Francisco; Viel, Matteo E-mail: emiliano.sefusatti@brera.inaf.it E-mail: villaescusa@oats.inaf.it

    2014-02-01

    We use a large suite of N-body simulations to study departures from universality in halo abundances and clustering in cosmologies with non-vanishing neutrino masses. To this end, we study how the halo mass function and halo bias factors depend on the scaling variable σ{sup 2}(M,z), the variance of the initial matter fluctuation field, rather than on halo mass M and redshift z themselves. We show that using the variance of the cold dark matter rather than the total mass field, i.e., σ{sup 2}{sub cdm}(M,z) rather than σ{sup 2}{sub m}(M,z), yields more universal results. Analysis of halo bias yields similar conclusions: when large-scale halo bias is defined with respect to the cold dark matter power spectrum, the result is both more universal, and less scale- or k-dependent. These results are used extensively in Papers I and III of this series.

  11. Frobenius group T13 and the canonical seesaw mechanism applied to neutrino mixing

    NASA Astrophysics Data System (ADS)

    Hartmann, Christine

    2012-01-01

    The compatibility of the Frobenius group T13 with the canonical seesaw mechanism of neutrino mixing is examined. The standard model is extended minimally by introducing a family symmetry and three right-handed neutrinos. To fit experiments and place constraints on the possibilities, tribimaximal mixing is used as a guideline. The application of both a family symmetry group and the canonical seesaw mechanism naturally generates small neutrino masses. The various possibilities from combining these two models are listed. Enough constraints are produced to narrow down the parameters of the neutrino mass matrix to two. This is therefore a predictive model, where the physical neutrino masses and the allowed regions for neutrinoless double beta decay are suggested.

  12. Gamma-ray and neutrino backgrounds as probes of the high-energy universe: hints of cascades, general constraints, and implications for TeV searches

    SciTech Connect

    Murase, Kohta; Beacom, John F.; Takami, Hajime E-mail: beacom.7@osu.edu

    2012-08-01

    Recent observations of isotropic diffuse backgrounds by Fermi and IceCube allow us to get more insight into distant very-high-energy (VHE) and ultra-high-energy (UHE) gamma-ray/neutrino emitters, including cosmic-ray accelerators/sources. First, we investigate the contribution of intergalactic cascades induced by gamma-rays and/or cosmic rays (CRs) to the diffuse gamma-ray background (DGB) in view of the latest Fermi data. We identify a possible 'VHE Excess' from the fact that the Fermi data are well above expectations for an attenuated power law, and show that cascades induced by VHE gamma rays (above ∼ 10 TeV) and/or VHECRs (below ∼ 10{sup 19} eV) may significantly contribute to the DGB above ∼ 100 GeV. The relevance of the cascades is also motivated by the intergalactic cascade interpretations of extreme TeV blazars such as 1ES 0229+200, which suggest very hard intrinsic spectra. This strengthens the importance of future detailed VHE DGB measurements. Then, more conservatively, we derive general constraints on the cosmic energy budget of high-energy gamma rays and neutrinos based on recent Fermi and IceCube observations of extragalactic background radiation. We demonstrate that these multi-messenger constraints are useful and the neutrino limit is very powerful for VHE/UHE hadronic sources. Furthermore, we show the importance of constraints from individual source surveys by future imaging atmospheric Cherenkov telescopes such as Cherenkov Telescope Array, and demonstrate that the cascade hypothesis for the VHE DGB can be tested by searching for distant emitters of cascaded gamma rays.

  13. Muon Neutrino to Electron Neutrino Oscillation in NOnuA

    NASA Astrophysics Data System (ADS)

    Sachdev, Kanika

    NOvA is a long-baseline neutrino oscillation experiment optimized for electron neutrino (nue) appearance in the NuMI beam, a muon neutrino (numu) source at Fermilab. It consists of two functionally identical, nearly fully-active liquid-scintillator tracking calorimeters. The near detector (ND) at Fermilab is used to study the neutrino beam spectrum and composition before oscillation, and measure background rate to the nu e appearance search. The far detector, 810 km away in Northern Minnesota, observes the oscillated beam and is used to extract oscillation parameters from the data. NOnuA's long baseline, combined with the ability of the NuMI beam to operate in the anti-neutrino mode, makes NOnuA sensitive to the last unmeasured parameters in neutrino oscillations- mass hierarchy, CP violation and the octant of mixing angle theta23. This thesis presents the search for nue appearance in the first data collected by the NOnuA detectors from October 2013 till May 2015. Studies of the NuMI neutrino data collected in the NOnuA near detector are also presented, which show large discrepancies between the ND simulation and data. Muon-removed electron (MRE) events, constructed by replacing the muon in numu charged current interactions by a simulated electron, are used to correct the far detector nue appearance prediction for these discrepancies. In the analysis of the first data, a total of 6 nue candidate events are observed in the far detector on a background of 1, a 3.46 sigma excess, which is interpreted as strong evidence for nue appearance. The results are consistent with our expectation, based on constraints from other neutrino oscillation experiments. The result presented here differs from the officially published nu e appearance result from the NOnuA experiment where the systematic error is assumed to cover the MRE correction.

  14. Neutrino oscillation studies with reactors.

    PubMed

    Vogel, P; Wen, L J; Zhang, C

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  15. Neutrino oscillation studies with reactors.

    PubMed

    Vogel, P; Wen, L J; Zhang, C

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  16. Neutrino oscillation studies with reactors

    SciTech Connect

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  17. Neutrino oscillation studies with reactors

    DOE PAGES

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  18. Neutrino oscillation studies with reactors

    PubMed Central

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  19. Neutrino-flavoured sneutrino dark matter

    NASA Astrophysics Data System (ADS)

    March-Russell, John; McCabe, Christopher; McCullough, Matthew

    2010-03-01

    A simple theory of supersymmetric dark matter (DM) naturally linked to neutrino flavour physics is studied. The DM sector comprises a spectrum of mixed lhd-rhd sneutrino states where both the sneutrino flavour structure and mass splittings are determined by the associated neutrino masses and mixings. Prospects for indirect detection from solar capture are good due to a large sneutrino-nucleon cross-section afforded by the inelastic splitting (solar capture limits exclude an explanation of DAMA/LIBRA). We find parameter regions where all heavier states will have decayed, leaving only one flavour mixture of sneutrino as the candidate DM. Such regions have a unique ‘smoking gun’ signature — sneutrino annihilation in the Sun produces a pair of neutrino mass eigenstates free from vacuum oscillations, with the potential for detection at neutrino telescopes through the observation of a hard spectrum of ν μ and ν τ (for a normal neutrino hierarchy). Next generation direct detection experiments can explore much of the parameter space through both elastic and inelastic scattering. We show in detail that the observed neutrino masses and mixings can arise as a consequence of supersymmetry breaking effects in the sneutrino DM sector, consistent with all experimental constraints.

  20. Core-collapse Supernovae from 9 to 120 Solar Masses Based on Neutrino-powered Explosions

    NASA Astrophysics Data System (ADS)

    Sukhbold, Tuguldur; Ertl, T.; Woosley, S. E.; Brown, Justin M.; Janka, H.-T.

    2016-04-01

    Nucleosynthesis, light curves, explosion energies, and remnant masses are calculated for a grid of supernovae (SNe) resulting from massive stars with solar metallicity and masses from 9.0 to 120 {M}⊙ . The full evolution is followed using an adaptive reaction network of up to 2000 nuclei. A novel aspect of the survey is the use of a one-dimensional neutrino transport model for the explosion. This explosion model has been calibrated to give the observed energy for SN 1987A, using five standard progenitors, and for the Crab SN using a 9.6 {M}⊙ progenitor. As a result of using a calibrated central engine, the final kinetic energy of the SN is variable and sensitive to the structure of each pre-SN star. Many progenitors with extended core structures do not explode, but become black holes (BHs), and the masses of exploding stars do not form a simply connected set. The resulting nucleosynthesis agrees reasonably well with the Sun provided that a reasonable contribution from SNe Ia is also allowed, but with a deficiency of light s-process isotopes. The resulting neutron star initial mass function has a mean gravitational mass near 1.4 {M}⊙ . The average BH mass is about 9 {M}⊙ if only the helium core implodes, and 14 {M}⊙ if the entire pre-SN star collapses. Only ˜10% of SNe come from stars over 20 {M}⊙ , and some of these are Type Ib or Ic. Some useful systematics of Type IIp light curves are explored.

  1. Binary Formation Mechanisms: Constraints from the Companion Mass Ratio Distribution

    NASA Astrophysics Data System (ADS)

    Reggiani, Maddalena M.; Meyer, Michael R.

    2011-09-01

    We present a statistical comparison of the mass ratio distribution of companions, as observed in different multiplicity surveys, to the most recent estimate of the single-object mass function. The main goal of our analysis is to test whether or not the observed companion mass ratio distribution (CMRD) as a function of primary star mass and star formation environment is consistent with having been drawn from the field star initial mass function (IMF). We consider samples of companions for M dwarfs, solar-type stars, and intermediate-mass stars, both in the field as well as clusters or associations, and compare them with populations of binaries generated by random pairing from the assumed IMF for a fixed primary mass. With regard to the field we can reject the hypothesis that the CMRD was drawn from the IMF for different primary mass ranges: the observed CMRDs show a larger number of equal-mass systems than predicted by the IMF. This is in agreement with fragmentation theories of binary formation. For the open clusters α Persei and the Pleiades we also reject the IMF random-pairing hypothesis. Concerning young star-forming regions, currently we can rule out a connection between the CMRD and the field IMF in Taurus but not in Chamaeleon I. Larger and different samples are needed to better constrain the result as a function of the environment. We also consider other companion mass functions and we compare them with observations. Moreover the CMRD both in the field and clusters or associations appears to be independent of separation in the range covered by the observations. Combining therefore the CMRDs of M (1-2400 AU) and G (28-1590 AU) primaries in the field and intermediate-mass primary binaries in Sco OB2 (29-1612 AU) for mass ratios, q = M 2/M 1, from 0.2 to 1, we find that the best chi-square fit follows a power law dN/dqvpropq β, with β = -0.50 ± 0.29, consistent with previous results. Finally, we note that the Kolmogorov-Smirnov test gives a ~1% probability

  2. Higgs production from sterile neutrinos at future lepton colliders

    NASA Astrophysics Data System (ADS)

    Antusch, Stefan; Cazzato, Eros; Fischer, Oliver

    2016-04-01

    In scenarios with sterile (right-handed) neutrinos that are subject to an approximate "lepton-number-like" symmetry, the heavy neutrinos (i.e. the mass eigenstates) can have masses around the electroweak scale and couple to the Higgs boson with, in principle, unsuppressed Yukawa couplings while accounting for the smallness of the light neutrinos' masses. In these scenarios, the on-shell production of heavy neutrinos and their subsequent decays into a light neutrino and a Higgs boson constitutes a hitherto unstudied resonant contribution to the Higgs production mechanism. We investigate the relevance of this resonant mono-Higgs production mechanism in leptonic collisions, including thepresent experimental constraints on the neutrino Yukawa couplings, and we determine the sensitivity of future lepton colliders to the heavy neutrinos. With Monte Carlo event sampling and a simulation of the detector response we find that, at future lepton colliders, neutrino Yukawa couplings below the percent level can lead to observable deviations from the SM and, furthermore, the sensitivity improves with higher center-of-mass energies (for identical integrated luminosities).

  3. Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs

    SciTech Connect

    Grohs, E.; Fuller, George M.; Kishimoto, Chad T.; Paris, Mark W.

    2015-05-11

    In this study, we show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and Cosmic Microwave Background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, and scenarios for light and heavy sterile neutrinos.

  4. Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs

    DOE PAGES

    Grohs, E.; Fuller, George M.; Kishimoto, Chad T.; Paris, Mark W.

    2015-05-11

    In this study, we show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and Cosmic Microwave Background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, andmore » scenarios for light and heavy sterile neutrinos.« less

  5. Search for neutrinos from annihilation of captured low-mass dark matter particles in the sun by super-kamiokande.

    PubMed

    Choi, K; Abe, K; Haga, Y; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Tomura, T; Wendell, R A; Irvine, T; Kajita, T; Kametani, I; Kaneyuki, K; Lee, K P; Nishimura, Y; Okumura, K; McLachlan, T; Labarga, L; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Tanaka, H A; Tobayama, S; Goldhaber, M; Carminati, G; Kropp, W R; Mine, S; Renshaw, A; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Bronner, C; Hirota, S; Huang, K; Ieki, K; Ikeda, M; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Itow, Y; Mitsuka, G; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Yanagisawa, C; Ishino, H; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Yano, T; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Martens, K; Marti, Ll; Vagins, M R; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J

    2015-04-10

    Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV/c^{2}-200-GeV/c^{2}) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent WIMP-proton cross section for WIMP masses below 200  GeV/c^{2} (at 10  GeV/c^{2}, 1.49×10^{-39}  cm^{2} for χχ→bb[over ¯] and 1.31×10^{-40}  cm^{2} for χχ→τ^{+}τ^{-} annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent coupling in the few-GeV/c^{2} mass range. PMID:25910107

  6. Search for neutrinos from annihilation of captured low-mass dark matter particles in the sun by super-kamiokande.

    PubMed

    Choi, K; Abe, K; Haga, Y; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Tomura, T; Wendell, R A; Irvine, T; Kajita, T; Kametani, I; Kaneyuki, K; Lee, K P; Nishimura, Y; Okumura, K; McLachlan, T; Labarga, L; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Tanaka, H A; Tobayama, S; Goldhaber, M; Carminati, G; Kropp, W R; Mine, S; Renshaw, A; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Bronner, C; Hirota, S; Huang, K; Ieki, K; Ikeda, M; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Itow, Y; Mitsuka, G; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Yanagisawa, C; Ishino, H; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Yano, T; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Martens, K; Marti, Ll; Vagins, M R; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J

    2015-04-10

    Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV/c^{2}-200-GeV/c^{2}) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent WIMP-proton cross section for WIMP masses below 200  GeV/c^{2} (at 10  GeV/c^{2}, 1.49×10^{-39}  cm^{2} for χχ→bb[over ¯] and 1.31×10^{-40}  cm^{2} for χχ→τ^{+}τ^{-} annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent coupling in the few-GeV/c^{2} mass range.

  7. Neutrino mass, dark matter and anomalous magnetic moment of muon in a U{(1)}_L{{}{_{μ}}}-{{}_L}{_{τ }} model

    NASA Astrophysics Data System (ADS)

    Biswas, Anirban; Choubey, Sandhya; Khan, Sarif

    2016-09-01

    The observation of neutrino masses, mixing and the existence of dark matter are amongst the most important signatures of physics beyond the Standard Model (SM). In this paper, we propose to extend the SM by a local L μ - L τ gauge symmetry, two additional complex scalars and three right-handed neutrinos. The L μ - L τ gauge symmetry is broken spontaneously when one of the scalars acquires a vacuum expectation value. The L μ - L τ gauge symmetry is known to be anomaly free and can explain the beyond SM measurement of the anomalous muon ( g - 2) through additional contribution arising from the extra Z μτ mediated diagram. Small neutrino masses are explained naturally through the Type-I seesaw mechanism, while the mixing angles are predicted to be in their observed ranges due to the broken L μ - L τ symmetry. The second complex scalar is shown to be stable and becomes the dark matter candidate in our model. We show that while the Z μτ portal is ineffective for the parameters needed to explain the anomalous muon ( g - 2) data, the correct dark matter relic abundance can easily be obtained from annihilation through the Higgs portal. Annihilation of the scalar dark matter in our model can also explain the Galactic Centre gamma ray excess observed by Fermi-LAT. We show the predictions of our model for future direct detection experiments and neutrino oscillation experiments.

  8. Pseudoscalar Fields in Torsionful Geometries of the Early Universe, the Baryon Asymmetry and Majorana Neutrino Mass Generation

    NASA Astrophysics Data System (ADS)

    Mavromatos, Nick E.

    2015-11-01

    We discuss here a specific field-theory model, inspired from string theory, in which the generation of a matter-antimatter asymmetry in the Cosmos is due to the propagation of fermions in a non-trivial, spherically asymmetric (and hence Lorentz violating) gravitational background that may characterise the epochs of the early universe. The background induces different dispersion relations, hence populations, between fermions and antifermions, and thus CPT Violation (CPTV) already in thermal equilibrium. Species populations may freeze out leading to leptogenesis and baryogenesis. More specifically, after reviewing some generic models of background-induced CPTV in early epochs of the Universe, we consider a string- inspired scenario, in which the CPTV is associated with a cosmological background with torsion provided by the Kalb-Ramond (KR) antisymemtric tensor field of the string gravitational multiplet. In a four-dimensional space time this field is dual to a pseudoscalar “axion-like” field. The thermalising processes in this model are (right-handed) Majorana neutrino-antineutrino oscillations, which are induced in the presence of the KR axion background. These processes freeze out at a (high) temperature Tc ≫ m, where m is the Majorana neutrino mass, at which the KR background goes to zero or is diminished significantly, through appropriate phase transitions of the (string) universe. An additional, but equally important, role, of the KR field is that its quantum fluctuations and mixing with an ordinary axion, which couples to the Majorana neutrinos via appropriate Yukawa couplings, can also lead to the generation of a Majorana neutrino mass through quantum anomalies. This provides a novel way for generating neutrino masses, independent of the traditional seesaw mechanism.

  9. Report of the Solar and Atmospheric Neutrino Working Group

    SciTech Connect

    Back, H.; Bahcall, J.N.; Bernabeu, J.; Boulay, M.G.; Bowles, T.; Calaprice, F.; Champagne, A.; Freedman, S.; Gai, M.; Galbiati, C.; Gallagher, H.; Gonzalez-Garcia, C.; Hahn, R.L.; Heeger, K.M.; Hime, A.; Jung, C.K.; Klein, J.R.; Koike, M.; Lanou, R.; Learned, J.G.; Lesko, K.T.; Losecco, J.; Maltoni, M.; Mann, A.; McKinsey, D.; Palomares-Ruiz, S.; Pena-Garay, C.; Petcov, S.T.; Piepke, A.; Pitt, M.; Raghavan, R.; Robertson, R.G.H.; Scholberg, K.; Sobel, H.W.; Takeuchi, T.; Vogelaar, R.; Wolfenstein, L.

    2004-10-22

    The highest priority of the Solar and Atmospheric Neutrino Experiment Working Group is the development of a real-time, precision experiment that measures the pp solar neutrino flux. A measurement of the pp solar neutrino flux, in comparison with the existing precision measurements of the high energy {sup 8}B neutrino flux, will demonstrate the transition between vacuum and matter-dominated oscillations, thereby quantitatively testing a fundamental prediction of the standard scenario of neutrino flavor transformation. The initial solar neutrino beam is pure {nu}{sub e}, which also permits sensitive tests for sterile neutrinos. The pp experiment will also permit a significantly improved determination of {theta}{sub 12} and, together with other solar neutrino measurements, either a measurement of {theta}{sub 13} or a constraint a factor of two lower than existing bounds. In combination with the essential pre-requisite experiments that will measure the {sup 7}Be solar neutrino flux with a precision of 5%, a measurement of the pp solar neutrino flux will constitute a sensitive test for non-standard energy generation mechanisms within the Sun. The Standard Solar Model predicts that the pp and {sup 7}Be neutrinos together constitute more than 98% of the solar neutrino flux. The comparison of the solar luminosity measured via neutrinos to that measured via photons will test for any unknown energy generation mechanisms within the nearest star. A precise measurement of the pp neutrino flux (predicted to be 92% of the total flux) will also test stringently the theory of stellar evolution since the Standard Solar Model predicts the pp flux with a theoretical uncertainty of 1%. We also find that an atmospheric neutrino experiment capable of resolving the mass hierarchy is a high priority. Atmospheric neutrino experiments may be the only alternative to very long baseline accelerator experiments as a way of resolving this fundamental question. Such an experiment could be a very

  10. Lepton mixing under the lepton charge nonconservation, neutrino masses and oscillations and the 'forbidden' decay Micro-Sign {sup -} {yields} e{sup -} + {gamma}

    SciTech Connect

    Lyuboshitz, V. L.; Lyuboshitz, V. V.

    2013-08-15

    The lepton-charge (L{sub e}, L{sub {mu}}, L{sub {tau}}) nonconserving interaction leads to the mixing of the electron, muon, and tau neutrinos, which manifests itself in spatial oscillations of a neutrino beam, and also to the mixing of the electron, negative muon, and tau lepton, which, in particular, may be the cause of the 'forbidden' radiative decay of the negative muon into the electron and {gamma} quantum. Under the assumption that the nondiagonal elements of the mass matrices for neutrinos and ordinary leptons, connected with the lepton charge nonconservation, are the same, and by performing the joint analysis of the experimental data on neutrino oscillations and experimental restriction for the probability of the decay Micro-Sign {sup -} {yields} e{sup -} + {gamma} per unit time, the following estimate for the lower bound of neutrino mass has been obtained: m{sup ({nu})} > 1.5 eV/c{sup 2}.

  11. CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy

    SciTech Connect

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Cai, X. Z.; Camacho, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Dafinei, I.; Dally, A.; Datskov, V.; De Biasi, A.; Deninno, M. M.; Di Domizio, S.; di Vacri, M. L.; Ejzak, L.; Fang, D. Q.; Farach, H. A.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Goett, J.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Hennings-Yeomans, R.; Huang, H. Z.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kolomensky, Yu. G.; Li, Y. L.; Ligi, C.; Liu, X.; Ma, Y. G.; Maiano, C.; Maino, M.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Napolitano, T.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; O’Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Wielgus, L.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhu, B. X.; Zucchelli, S.

    2015-03-24

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130Te. With 741 kg of TeO2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6 × 1026 y at 1σ (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with 130Te and possibly other double beta decay candidate nuclei.

  12. CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy

    DOE PAGES

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; et al

    2015-03-24

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130Te. With 741 kg of TeO2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6 × 1026 y at 1σ (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meVmore » (50–130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with 130Te and possibly other double beta decay candidate nuclei.« less

  13. Quark mass variation constraints from Big Bang nucleosynthesis

    SciTech Connect

    Bedaque, P; Luu, T; Platter, L

    2010-12-13

    We study the impact on the primordial abundances of light elements created of a variation of the quark masses at the time of Big Bang nucleosynthesis (BBN). In order to navigate through the particle and nuclear physics required to connect quark masses to binding energies and reaction rates in a model-independent way we use lattice QCD data and an hierarchy of effective field theories. We find that the measured {sup 4}He abundances put a bound of {delta}-1% {approx}< m{sub q}/m{sub 1} {approx}< 0.7%. The effect of quark mass variations on the deuterium abundances can be largely compensated by changes of the baryon-to-photon ratio {eta}. Including the bounds on the variation of {eta} coming from WMAP results and some additional assumptions narrows the range of allowed values of {delta}m{sub q}/m{sub q} somewhat.

  14. NUCLEOSYNTHETIC CONSTRAINTS ON THE MASS OF THE HEAVIEST SUPERNOVAE

    SciTech Connect

    Brown, Justin M.; Woosley, S. E.

    2013-06-01

    We explore the sensitivity of nucleosynthesis in massive stars to the truncation of supernova explosions above a certain mass. It is assumed that stars of all masses contribute to nucleosynthesis by their pre-explosive winds, but above a certain limiting main sequence mass, M{sub BH}, the presupernova star becomes a black hole and ejects nothing more. The solar abundances from oxygen to atomic mass 90 are fit quite well assuming no cutoff at all, i.e., by assuming all stars up to 120 M{sub Sun} make successful supernovae. Little degradation in the fit occurs if M{sub BH} is reduced to 25 M{sub Sun }. If this limit is reduced further however, the nucleosynthesis of the s-process declines precipitously and the production of species made in the winds, e.g., carbon, becomes unacceptably large compared with elements made in the explosion, e.g., silicon and oxygen. By varying uncertain physics, especially the mass loss rate for massive stars and the rate for the {sup 22}Ne({alpha}, n){sup 25}Mg reaction rate, acceptable nucleosynthesis might still be achieved with a cutoff as low as 18 M{sub Sun }. This would require, however, a supernova frequency three times greater than the fiducial value obtained when all stars explode in order to produce the required {sup 16}O. The effects of varying M{sub BH} on the nucleosynthesis of {sup 60}Fe and {sup 26}Al, the production of helium as measured by {Delta}Y/{Delta}Z, and the average masses of compact remnants are also examined.

  15. Revisiting cosmological bounds on sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Vincent, Aaron C.; Fernández Martínez, Enrique; Hernández, Pilar; Mena, Olga; Lattanzi, Massimiliano

    2015-04-01

    We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter RCMB and the sound horizon rs from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin2θ lesssim 0.026 (ms/eV)-2.

  16. Neutrino Physics at Fermilab

    ScienceCinema

    Saoulidou, Niki

    2016-07-12

    Neutrino oscillations provide the first evidence for physics beyond the Standard Model. I will briefly overview the neutrino "hi-story", describing key discoveries over the past decades that shaped our understanding of neutrinos and their behavior. Fermilab was, is and hopefully will be at the forefront of the accelerator neutrino experiments.  NuMI, the most powerful accelerator neutrino beam in the world has ushered us into the era of precise measurements. Its further upgrades may give a chance to tackle the remaining mysteries of the neutrino mass hierarchy and possible CP violation.

  17. Sterile neutrinos with secret interactions—lasting friendship with cosmology

    SciTech Connect

    Chu, Xiaoyong; Dasgupta, Basudeb; Kopp, Joachim E-mail: bdasgupta@theory.tifr.res.in

    2015-10-01

    Sterile neutrinos with mass ≅ 1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these constraints are avoided if sterile neutrinos couple to a new MeV-scale gauge boson A'. However, even this scenario is restricted by structure formation constraints when A'-mediated collisional processes lead to efficient active-to-sterile neutrino conversion after neutrinos have decoupled. In view of this, we reevaluate in this paper the viability of sterile neutrinos with such ''secret'' interactions. We carefully dissect their evolution in the early Universe, including the various production channels and the expected modifications to large scale structure formation. We argue that there are two regions in parameter space—one at very small A' coupling, one at relatively large A' coupling—where all constraints from big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and large scale structure (LSS) data are satisfied. Interestingly, the large A' coupling region is precisely the region that was previously shown to have potentially important consequences for the small scale structure of dark matter halos if the A' boson couples also to the dark matter in the Universe.

  18. Sterile neutrinos with secret interactions — lasting friendship with cosmology

    SciTech Connect

    Chu, Xiaoyong; Dasgupta, Basudeb; Kopp, Joachim

    2015-10-06

    Sterile neutrinos with mass ≃1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these constraints are avoided if sterile neutrinos couple to a new MeV-scale gauge boson A{sup ′}. However, even this scenario is restricted by structure formation constraints when A{sup ′}-mediated collisional processes lead to efficient active-to-sterile neutrino conversion after neutrinos have decoupled. In view of this, we reevaluate in this paper the viability of sterile neutrinos with such “secret” interactions. We carefully dissect their evolution in the early Universe, including the various production channels and the expected modifications to large scale structure formation. We argue that there are two regions in parameter space — one at very small A{sup ′} coupling, one at relatively large A{sup ′} coupling — where all constraints from big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and large scale structure (LSS) data are satisfied. Interestingly, the large A{sup ′} coupling region is precisely the region that was previously shown to have potentially important consequences for the small scale structure of dark matter halos if the A{sup ′} boson couples also to the dark matter in the Universe.

  19. Neutrino-driven Supernova of a Low-mass Iron-core Progenitor Boosted by Three-dimensional Turbulent Convection

    NASA Astrophysics Data System (ADS)

    Melson, Tobias; Janka, Hans-Thomas; Marek, Andreas

    2015-03-01

    We present the first successful simulation of a neutrino-driven supernova explosion in three dimensions (3D), using the Prometheus-Vertex code with an axis-free Yin-Yang grid and a sophisticated treatment of three-flavor, energy-dependent neutrino transport. The progenitor is a nonrotating, zero-metallicity 9.6 {{M}⊙ } star with an iron core. While in spherical symmetry outward shock acceleration sets in later than 300 ms after bounce, a successful explosion starts at ˜130 ms postbounce in two dimensions (2D). The 3D model explodes at about the same time but with faster shock expansion than in 2D and a more quickly increasing and roughly 10% higher explosion energy of >1050 erg. The more favorable explosion conditions in 3D are explained by lower temperatures and thus reduced neutrino emission in the cooling layer below the gain radius. This moves the gain radius inward and leads to a bigger mass in the gain layer, whose larger recombination energy boosts the explosion energy in 3D. These differences are caused by less coherent, less massive, and less rapid convective downdrafts associated with postshock convection in 3D. The less violent impact of these accretion downflows in the cooling layer produces less shock heating and therefore diminishes energy losses by neutrino emission. We thus have, for the first time, identified a reduced mass accretion rate, lower infall velocities, and a smaller surface filling factor of convective downdrafts as consequences of 3D postshock turbulence that facilitate neutrino-driven explosions and strengthen them compared to the 2D case.

  20. Mass extinctions and ocean acidification: biological constraints on geological dilemmas

    NASA Astrophysics Data System (ADS)

    Veron, J. E. N.

    2008-09-01

    The five mass extinction events that the earth has so far experienced have impacted coral reefs as much or more than any other major ecosystem. Each has left the Earth without living reefs for at least four million years, intervals so great that they are commonly referred to as ‘reef gaps’ (geological intervals where there are no remnants of what might have been living reefs). The causes attributed to each mass extinction are reviewed and summarised. When these causes and the reef gaps that follow them are examined in the light of the biology of extant corals and their Pleistocene history, most can be discarded. Causes are divided into (1) those which are independent of the carbon cycle: direct physical destruction from bolides, ‘nuclear winters’ induced by dust clouds, sea-level changes, loss of area during sea-level regressions, loss of biodiversity, low and high temperatures, salinity, diseases and toxins and extraterrestrial events and (2) those linked to the carbon cycle: acid rain, hydrogen sulphide, oxygen and anoxia, methane, carbon dioxide, changes in ocean chemistry and pH. By process of elimination, primary causes of mass extinctions are linked in various ways to the carbon cycle in general and ocean chemistry in particular with clear association with atmospheric carbon dioxide levels. The prospect of ocean acidification is potentially the most serious of all predicted outcomes of anthropogenic carbon dioxide increase. This study concludes that acidification has the potential to trigger a sixth mass extinction event and to do so independently of anthropogenic extinctions that are currently taking place.

  1. Mass Distribution in Plumes: constraints from gravity waves

    NASA Astrophysics Data System (ADS)

    Sacks, S. I.; Baines, P. G.

    2012-12-01

    The Soufriere Hills volcano on Montserrat Island in the Caribbean has been active for more than 15 years. A small network, consisting of 4 sites, 5 - 10 km distant from the Soufriere Hills Volcano, was installed early in 2003. Each site has borehole strainmeters as well as micro-barographs and gave clear data from all volcanic events. A number of vulcanian explosions followed the major dome collapse on 13th July, 2003 and have continued until at least January 2008.. The plumes from these fragmentation events gave rise to an ~800 second period atmospheric pressure signal of 20 - 50 pascal amplitude propagating at about 30 m/sec. The onset is rarefaction. The data are consistent with a gravity wave confined to the troposphere. Note that plumes penetrating the stratosphere have a very different air pressure character. Initial modeling indicated that the coda of these waves was sensitive to the mass distribution in the plume. Since only the data beyond about 1000 seconds are found to yield information about mass distribution, we can use a simple impulsive source. The data, and particularly the coda, are best satisfied if most of the effective mass is at mid-plume, with reduced amounts near the surface and high in the troposphere. This suggests that the heavier ash particles fall as the plume rises. Since particle size impacts the event's hazard, this type of observation may have predictive capability.

  2. Neutrino oscillations.

    PubMed

    Thomson, Mark

    2002-05-15

    The wave theory of light, and in particular the principle of interference, was formulated by Thomas Young in 1801. In the 20th century, the principle of interference was extended to the quantum mechanical wave functions describing matter. The phenomenon of quantum mechanical interference of different neutrino states, neutrino oscillations, has provided one of the most exciting developments in high energy particle physics of the last decade. Observations of the flavour oscillations of neutrinos produced by distant sources, such as from the core of the Sun, provide compelling evidence that neutrinos have mass. This article describes the main features and the most significant experimental observations of this unusual application of the principle of interference.

  3. Novel Ideas for Neutrino Beams

    SciTech Connect

    Peach, Ken

    2007-04-23

    Recent developments in neutrino physics, primarily the demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The simplest phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or {pi}, contribute to the otherwise unexplained baryon asymmetry observed in the universe. Exploring the neutrino sector will require very intense beams of neutrinos, and will need novel solutions.

  4. A search for Secluded Dark Matter in the Sun with the ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Adrián-Martínez, S.; Albert, A.; André, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bou-Cabo, M.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Păvălaš, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.

    2016-05-01

    A search for Secluded Dark Matter annihilation in the Sun using 2007-2012 data of the ANTARES neutrino telescope is presented. Three different cases are considered: a) detection of dimuons that result from the decay of the mediator, or neutrino detection from: b) mediator that decays into a dimuon and, in turn, into neutrinos, and c) mediator that decays directly into neutrinos. As no significant excess over background is observed, constraints are derived on the dark matter mass and the lifetime of the mediator.

  5. A search at Super-Kamiokande for low mass dark matter candidates in the T2K neutrino beam

    NASA Astrophysics Data System (ADS)

    Nantais, Corina; T2K Collaboration

    2015-04-01

    The T2K neutrino beam is produced by colliding 30 GeV protons with a graphite target, and some dark sector models predict that a dark matter candidate could be created in the collision. This massive and neutral particle could scatter off a nucleon in Super-Kamiokande, a 50 kilotonne water Cherenkov detector. Similar to the neutral-current quasielastic neutrino-oxygen interaction, the dark matter candidate could interact with the oxygen nucleus, kicking out a nucleon and leaving the nucleus in an excited state. As the nucleus deexcites, 6 MeV gamma-rays are emitted which can be efficiently detected by Super-Kamiokande. The longer time of flight for a dark matter candidate, compared to a neutrino, allows separation between the dark matter induced signal and the neutrino induced background. In the intense global effort to measure dark matter, this complementary search investigates the sub-GeV mass range where other experiments have reduced sensitivity.

  6. Neutrino masses and heavy triplet leptons at the LHC: Testability of the type III seesaw mechanism

    NASA Astrophysics Data System (ADS)

    Li, Tong; He, Xiao-Gang

    2009-11-01

    We study LHC signatures of the type III seesaw mechanism in which SU(2)L triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model particles which depend on how light and heavy leptons mix with each other. We concentrate on the usual solutions with small light and heavy lepton mixing of the order of the square root of the ratio of light and heavy masses, (mν/MνR)1/2. This class of solutions can lead to a visible displaced vertex detectable at the LHC which can be used to distinguish small mixing and large mixing between light and heavy leptons. We show that, in this case, the couplings of light and heavy triplet leptons to gauge and Higgs bosons, which determine the decay widths and branching ratios, can be expressed in terms of light neutrino masses and their mixing. Using these relations, we study heavy triplet lepton decay patterns and production cross section at the LHC. If these heavy triplet leptons are below a TeV or so, they can be easily produced at the LHC due to their gauge interactions from being nontrivial representations of SU(2)L. We consider two ideal production channels, (1) E+E-→ℓ+ℓ+ℓ-ℓ-jj (ℓ=e, μ, τ) and (2) E±N→ℓ±ℓ±jjjj in detail. For case 1, we find that with one or two of the light leptons being τ it can also be effectively studied. With judicious cuts at the LHC, the discovery of the heavy triplet leptons as high as a TeV can be achieved with 100fb-1 integrated luminosity.

  7. Introducing the Hyper Hadrons, Hyper Mesons, Heavy Leptons and Massive Neutrinos of Kazuo Kondo's Mass Quantum Cascade

    NASA Astrophysics Data System (ADS)

    Croll, Grenville J.

    The late Professor Kazuo Kondo (Department of Mathematics, Tokyo University, Japan) l a hitherto unknown a priori particle theory which provides predictions of massive particles which may be detected by the Large Hadron Collider (LHC) and related apparatus. This article briefly introduces Kondo's work and documents the derivation and masses of his expected hyper-mesons, hyper-hadrons, heavy leptons and massive neutrinos. Several particles in these classes may have already been detected.

  8. Revisiting cosmological bounds on radiative neutrino lifetime

    SciTech Connect

    Mirizzi, Alessandro; Montanino, Daniele; Serpico, Pasquale D.

    2007-09-01

    Neutrino oscillation experiments and direct bounds on absolute masses constrain neutrino mass differences to fall into the microwave energy range, for most of the allowed parameter space. As a consequence of these recent phenomenological advances, older constraints on radiative neutrino decays based on diffuse background radiations and assuming strongly hierarchical masses in the eV range are now outdated. We thus derive new bounds on the radiative neutrino lifetime using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board the Cosmic Background Explorer. The lower bound on the lifetime is between a fewx10{sup 19} s and {approx}5x10{sup 20} s, depending on the neutrino mass ordering and on the absolute mass scale. However, due to phase space limitations, the upper bound in terms of the effective magnetic moment mediating the decay is not better than {approx}10{sup -8} Bohr magnetons. We also comment about possible improvements of these limits, by means of recent diffuse infrared photon background data. We compare these bounds with preexisting limits coming from laboratory or astrophysical arguments. We emphasize the complementarity of our results with others available in the literature.

  9. ESTIMATION OF THE NEUTRINO FLUX AND RESULTING CONSTRAINTS ON HADRONIC EMISSION MODELS FOR Cyg X-3 USING AGILE DATA

    SciTech Connect

    Baerwald, P.; Guetta, D.

    2013-08-20

    In this work, we give an estimate of the neutrino flux that can be expected from the microquasar Cyg X-3. We calculate the muon neutrino flux expected here on Earth as well as the corresponding number of neutrino events in the IceCube telescope based on the so-called hypersoft X-ray state of Cyg X-3. If the average emission from Cyg X-3 over a period of 5 yr were as high as during the used X-ray state, a total of 0.8 events should be observed by the full IceCube telescope. We also show that this conclusion holds by a factor of a few when we consider the other measured X-ray states. Using the correlation of AGILE data on the flaring episodes in 2009 June and July to the hypersoft X-ray state, we calculate that the upper limits on the neutrino flux given by IceCube are starting to constrain the hadronic models, which have been introduced to interpret the high-energy emission detected by AGILE.

  10. Determination of neutrino mass ordering in future 76Ge-based neutrinoless double-beta decay experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Jue; Zhou, Shun

    2016-01-01

    Motivated by recent intensive experimental efforts on searching for neutrinoless double-beta decays, we perform a detailed analysis of the physics potential of the experiments based on 76Ge. Assuming no signals, current and future experiments could place a 90% lower limit on the half life T1/2 0 ν≳4 ×1026 yr and T1/2 0 ν≳7 ×1027 yr , respectively. Then, how to report an evidence for neutrinoless double-beta decays is addressed by following the Bayesian statistical approach. For the first time, we present a quantitative description of experimental power to distinguish between normal and inverted neutrino mass orderings. Taking an exposure of 104 kg yr and a background rate of 1 0-4 counts/(keV kg yr ) , we find that a moderate evidence for normal neutrino mass ordering (i.e., with a Bayes factor B given by ln (B )≃2.5 or a probability about 92.3% according to the Jeffreys scale) can be achieved if the true value of effective neutrino mass mβ β turns out to be below 0.01 eV.

  11. Light, rest mass and electric charge quanta all formed by neutrinos?

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    In high energy physics experiments the electric charge and rest mass of particles can commonly transform into the photons, vice versa. Its reason QFT can only give a vague answer: based on the particle creation and annihilation operators. There are not more clear answers or conjecture? At least, light, electric charge and rest mass should have a collective structure component, if not, the transformation is unable understanding. An elementary answer is that neutrino and antineutrino as their collective structure component. In the paper ‘Chen Qiliang & Wang Bin, The formation and characteristics of Chen Shaoguang's formula, China Science &Technology Overview 127101-103 (2011)’, the lowest energy state vertical polarized left spin 1/2 neutrino and right spin 1/2 antineutrino are just the left, right advance unit quanta la _{0}nuυ, ra nuυ _{0} and left, right back unit quanta lb (0) nuυ, rb nuυ (0) , it again compose into spin 1 unit photon la-ra _{0}nuυnuυ _{0} and back-photon lb-rb (0) nuυnuυ (0) , spin 0 unit rest mass ra-rb nuυ _{0}nuυ (0) and anti-mass la-lb _{0}nuυ (0) nuυ, spin 0 unit positive charge la-rb _{0}nuυnuυ (0) and negative charge ra-lb nuυ _{0} (0) nuυ. The physical vacuum is the even collocation of non-combinational nuυ _{0} or _{0}nuυ. It accord to the high energy physics experimental results of the transformation among the photons, masses quanta and charges quanta. In my paper ‘Quanta turn-advance ism, China Science && Technology Overview 131 192-210 (2011)’, QFT four-dimensional uncertainty principle and momentum-energy conservation law had been generalized as a five-dimensional equations: de Broglie wavelength as a position vector \\underline{q}= (i c t, r, s), momentum \\underline{P} = (i E / c, P, U c), \\underline{q} = i h / \\underline{P}, \\underline{q} \\underline{q} = 0, \\underline{P} \\underline{P} = 0, Sigma∑ \\underline{P} = \\underline{P} (0) . The five-dimensional time-space-spin had been quantized as a

  12. Viable chaotic inflation as a source of neutrino masses and leptogenesis

    NASA Astrophysics Data System (ADS)

    Nakayama, Kazunori; Takahashi, Fuminobu; Yanagida, Tsutomu T.

    2016-06-01

    We show that the seesaw mechanism as well as leptogenesis are natural outcomes of a viable chaotic inflation in supergravity. The inflation model contains two superfields, the inflaton and stabilizer fields, which, being singlets under the standard model gauge symmetry, naturally couple to the lepton and Higgs doublets. The inflaton decays into leptons and Higgs fields, and the reheating temperature is predicted to be of O (1013) GeV, for which thermal leptogenesis is possible. On the other hand, gravitinos are copiously produced, and various solutions to the gravitino problem are discussed. We also argue that, if the shift symmetry of the inflaton is explicitly broken down to a discrete one, neutrino Yukawa couplings are periodic in the inflaton field, and masses of leptons and Higgs do not blow up even if the inflaton takes super-Planckian field values. The inflaton potential is given by a sum of sinusoidal functions with different height and periodicity, the so-called multi-natural inflation. We show that the predicted scalar spectral index and tensor-to-scalar ratio lie in the region favored by the Planck data.

  13. Isolation of 163Ho from dysprosium target material by HPLC for neutrino mass measurements

    DOE PAGES

    Mocko, Veronika; Taylor, Wayne  A.; Nortier, Francois M.; Engle, Jonathan  W.; Barnhart, Todd  E.; Nickles, Robert  J.; Pollington, Anthony  D.; Kunde, Gerd  J.; Rabin, Michael  W.; Birnbaum, Eva  R.

    2015-04-29

    The rare earth isotope 163Ho is of interest for neutrino mass measurements. This report describes the isolation of 163Ho from a proton-irradiated dysprosium target and its purification. A Dy metal target was irradiated with 16 MeV protons for 10 h. After target dissolution, 163Ho was separated from the bulk Dy via cation-exchange high performance liquid chromatography using 70 mmol dm–3 α-hydroxyisobutyric acid as the mobile phase. Subsequent purification of the collected Ho fraction was performed to remove the α-hydroxyisobutyrate chelating agent and to concentrate the Ho in a low ionic strength aqueous matrix. The final solution was characterized by MC-ICP-MSmore » to determine the 163Ho/165Ho ratio, 163Ho and the residual Dy content. The HPLC purification process resulted in a decontamination factor 1.4E5 for Dy. As a result, the isolated Ho fraction contained 24.8 ±1.3 ng of 163Ho corresponding to holmium recovery of 72 ± 3%.« less

  14. Development of Microwave Superconducting Microresonators for Neutrino Mass Measurement in the Holmes Framework

    NASA Astrophysics Data System (ADS)

    Giachero, A.; Day, P. K.; Falferi, P.; Faverzani, M.; Ferri, E.; Giordano, C.; Maino, M.; Margesin, B.; Mezzena, R.; Nizzolo, R.; Nucciotti, A.; Puiu, A.; Zanetti, L.

    2016-07-01

    The European Research Council has recently funded HOLMES, a project with the aim of performing a calorimetric measurement of the electron neutrino mass measuring the energy released in the electron capture decay of 163Ho. The baseline for HOLMES are microcalorimeters coupled to transition edge sensors read-out with rf-SQUIDs, for microwave multiplexing purposes. A promising alternative solution is based on superconducting microwave resonators that have undergone rapid development in the last decade. These detectors, called Microwave Kinetic Inductance Detectors (MKIDs), are inherently multiplexed in the frequency domain and suitable for even larger-scale pixel arrays, with theoretical high energy resolution and fast response. The aim of our activity is to develop arrays of microresonator detectors for X-ray spectroscopy and suitable for the calorimetric measurement of the energy spectra of 163Ho. Superconductive multilayer films composed by a sequence of pure Titanium and stoichiometric TiN layers show many ideal properties for MKIDs, such as low loss, large sheet resistance, large kinetic inductance, and tunable critical temperature T_c. We developed Ti/TiN multilayer microresonators with T_c within the range from 70 mK to 4.5 K and with good uniformity. In this contribution, we present the design solutions adopted, the fabrication processes, and the characterization results.

  15. Second unique forbidden {beta} decay of {sup 115}In and neutrino mass

    SciTech Connect

    Dvornicky, R.; Simkovic, F.

    2011-12-16

    The measurement of the electron spectrum in {beta} decays close to the end point provides a robust direct determination of the values of neutrino masses. The most sensitive experiments use tritium and rhenium {beta} decays because these transitions have low Q value. Recent measurement with Penning traps established that the {beta} decay of {sup 115}In(9/2{sup +}) to the first excited state of {sup 115}Sn(3/2{sup +}) is a transition with the smallest Q value among {beta} decays. The decay is associated with a change of spin and parity {Delta}J{sup {pi}} = 3{sup +} ({Delta}L = 2, {Delta}S = 1) of nucleus, i.e., classified as unique second forbidden {beta} decay. Our investigation shows that in this transition electrons are predominantly emitted in d{sub 5/2} partial waves. In addition, it is found that the Kurie function associated with this transition near the end point within a good accuracy reflects a behavior the Kurie function of superallowed {beta} transitions.

  16. Nucleosynthesis and Neutrinos

    SciTech Connect

    Kajino, Toshitaka

    2011-05-06

    Neutrinos play the critical roles in nucleosynthesis of light-to-heavy mass nuclei in core-collapse supernovae. We study the nucleosynthesis induced by neutrino interactions and find suitable average neutrino temperatures in order to explain the observed solar system abundances of several isotopes {sup 7}Li, {sup 11}B, {sup 138}La and {sup 180}Ta. These isotopes are predominantly synthesized by the supernova {nu}-process. We also study the neutrino oscillation effects on their abundances and propose a method to determine the unknown neutrino oscillation parameters, i.e. {theta}{sub 13} and mass hierarchy.

  17. Neutrinoless β β decays to excited 0+ states and the Majorana-neutrino mass

    NASA Astrophysics Data System (ADS)

    Hyvärinen, Juhani; Suhonen, Jouni

    2016-06-01

    The nuclear matrix elements (NMEs) corresponding to the neutrinoless double-β (0 ν β β ) decays to excited 0+ states of major experimental interest are calculated. All these decay transitions are electron emitting (0 ν β-β- decays) and take place in the mass A =76 ,82 ,96 ,100 ,110 ,116 ,124 ,130 ,136 nuclei. This work is an extension of our previous work [Phys. Rev. C 91, 024613 (2015), 10.1103/PhysRevC.91.024613], where 0 ν β β decays to the ground states of the same nuclei were treated. We calculate the NMEs for transitions mediated by both the light (l-NMEs) and the heavy (h-NMEs) Majorana neutrinos. A higher-QRPA (quasiparticle random-phase approximation) framework, the multiple-commutator model, is adopted for the calculations, including a previously omitted contribution to the transitions to two-phonon states. A Bonn G -matrix-based effective nucleon-nucleon interaction is generated by exploiting the recently proposed isoscalar-isovector decomposition of the particle-particle proton-neutron interaction parameter, gpp. All the appropriate short-range correlations, nucleon form factors, and higher-order nucleonic weak currents are included to benchmark our calculations. The relevant nuclear spectroscopy was checked to validate the nuclear models used. The computed l-NMEs and h-NMEs are compared with the available other calculations and the relevance of the new included two-phonon term is discussed. The results are summarized by easy-to-use half-life-Majorana-mass interrelations.

  18. Neutrino mass and proton lifetime in a realistic supersymmetric SO(10) model

    NASA Astrophysics Data System (ADS)

    Severson, Matthew

    This work presents a complete analysis of fermion fitting and proton decay in a supersymmetric SO(10) model previously suggested by Dutta, Mimura, and Mohapatra. A key question in any grand unified theory is whether it satisfies the stringent experimental lower limits on the partial lifetimes of the proton. In more generic models, substantial fine-tuning is required among GUT-scale parameters to satisfy the limits. In the proposed model, the 10, 1¯2¯6¯, and 20 Yukawa couplings contributing to fermion masses have restricted textures intended to give favorable results for proton lifetime, while still giving rise to a realistic fermion sector, without the need for fine-tuning, even for large beta, and for either type-I or type-II dominance in the neutrino mass matrix. In this thesis, I investigate the above hypothesis at a strict numerical level of scrutiny; I obtain a valid fit for the entire fermion sector for both types of seesaw dominance, including theta13 in good agreement with the most recent data. For the case with type-II seesaw, I find that, using the Yukawa couplings fixed by the successful fermion sector fit, proton partial lifetime limits are readily satisfied for all but one of the pertinent decay modes for nearly arbitrary values of the triplet-Higgs mixing parameters, with the K+v¯ mode requiring a minor ∂(10--1) cancellation in order to satisfy its limit. I also find a maximum partial lifetime for that mode of τ( K+v¯) ˜ 1036,years. For the type-I seesaw case, I find that K+ v¯ decay mode is satisfied for any values of the triplet mixing parameters giving no major enhancement, and all other modes are easily satisfied for arbitrary mixing values; I also find a maximum partial lifetime for K+v¯ of nearly 1036years, which is largely sub-dominant to gauge boson decay channels.

  19. Transition-Edge Sensor Arrays of Microcalorimeters with ^{163}Ho for Direct Neutrino Mass Measurements with HOLMES

    NASA Astrophysics Data System (ADS)

    Orlando, A.; Biasotti, M.; Ceriale, V.; De Gerone, M.; Gatti, F.; Hays-Wehle, J.; Pizzigoni, G.; Schmidt, D.; Swetz, D.; Ullom, J.

    2016-08-01

    The HOLMES experiment will provide an important step forward in direct neutrino mass measurements with a calorimetric approach as an alternative to spectrometry. HOLMES will perform a calorimetric measurement of the energy released in the decay of ^{163}Ho and will deploy a large array of transition-edge sensor microcalorimeters with implanted ^{163}Ho nuclei. The resulting mass sensitivity could be as low as 0.4 eV, and it will also establish the potential of this approach to extend the sensitivity down to 0.1 eV and lower.

  20. Neutrino masses and cosmological parameters from a Euclid-like survey: Markov Chain Monte Carlo forecasts including theoretical errors

    SciTech Connect

    Audren, Benjamin; Lesgourgues, Julien; Bird, Simeon; Haehnelt, Martin G.; Viel, Matteo E-mail: julien.lesgourgues@cern.ch E-mail: haehnelt@ast.cam.ac.uk

    2013-01-01

    We present forecasts for the accuracy of determining the parameters of a minimal cosmological model and the total neutrino mass based on combined mock data for a future Euclid-like galaxy survey and Planck. We consider two different galaxy surveys: a spectroscopic redshift survey and a cosmic shear survey. We make use of the Monte Carlo Markov Chains (MCMC) technique and assume two sets of theoretical errors. The first error is meant to account for uncertainties in the modelling of the effect of neutrinos on the non-linear galaxy power spectrum and we assume this error to be fully correlated in Fourier space. The second error is meant to parametrize the overall residual uncertainties in modelling the non-linear galaxy power spectrum at small scales, and is conservatively assumed to be uncorrelated and to increase with the ratio of a given scale to the scale of non-linearity. It hence increases with wavenumber and decreases with redshift. With these two assumptions for the errors and assuming further conservatively that the uncorrelated error rises above 2% at k = 0.4 h/Mpc and z = 0.5, we find that a future Euclid-like cosmic shear/galaxy survey achieves a 1-σ error on M{sub ν} close to 32 meV/25 meV, sufficient for detecting the total neutrino mass with good significance. If the residual uncorrelated errors indeed rises rapidly towards smaller scales in the non-linear regime as we have assumed here then the data on non-linear scales does not increase the sensitivity to the total neutrino mass. Assuming instead a ten times smaller theoretical error with the same scale dependence, the error on the total neutrino mass decreases moderately from σ(M{sub ν}) = 18 meV to 14 meV when mildly non-linear scales with 0.1 h/Mpc < k < 0.6 h/Mpc are included in the analysis of the galaxy survey data.

  1. Direct Measurement of the Mass Difference of (163)Ho and (163)Dy Solves the Q-Value Puzzle for the Neutrino Mass Determination.

    PubMed

    Eliseev, S; Blaum, K; Block, M; Chenmarev, S; Dorrer, H; Düllmann, Ch E; Enss, C; Filianin, P E; Gastaldo, L; Goncharov, M; Köster, U; Lautenschläger, F; Novikov, Yu N; Rischka, A; Schüssler, R X; Schweikhard, L; Türler, A

    2015-08-01

    The atomic mass difference of (163)Ho and (163)Dy has been directly measured with the Penning-trap mass spectrometer SHIPTRAP applying the novel phase-imaging ion-cyclotron-resonance technique. Our measurement has solved the long-standing problem of large discrepancies in the Q value of the electron capture in (163)Ho determined by different techniques. Our measured mass difference shifts the current Q value of 2555(16) eV evaluated in the Atomic Mass Evaluation 2012 [G. Audi et al., Chin. Phys. C 36, 1157 (2012)] by more than 7σ to 2833(30(stat))(15(sys)) eV/c(2). With the new mass difference it will be possible, e.g., to reach in the first phase of the ECHo experiment a statistical sensitivity to the neutrino mass below 10 eV, which will reduce its present upper limit by more than an order of magnitude.

  2. Direct Measurement of the Mass Difference of (163)Ho and (163)Dy Solves the Q-Value Puzzle for the Neutrino Mass Determination.

    PubMed

    Eliseev, S; Blaum, K; Block, M; Chenmarev, S; Dorrer, H; Düllmann, Ch E; Enss, C; Filianin, P E; Gastaldo, L; Goncharov, M; Köster, U; Lautenschläger, F; Novikov, Yu N; Rischka, A; Schüssler, R X; Schweikhard, L; Türler, A

    2015-08-01

    The atomic mass difference of (163)Ho and (163)Dy has been directly measured with the Penning-trap mass spectrometer SHIPTRAP applying the novel phase-imaging ion-cyclotron-resonance technique. Our measurement has solved the long-standing problem of large discrepancies in the Q value of the electron capture in (163)Ho determined by different techniques. Our measured mass difference shifts the current Q value of 2555(16) eV evaluated in the Atomic Mass Evaluation 2012 [G. Audi et al., Chin. Phys. C 36, 1157 (2012)] by more than 7σ to 2833(30(stat))(15(sys)) eV/c(2). With the new mass difference it will be possible, e.g., to reach in the first phase of the ECHo experiment a statistical sensitivity to the neutrino mass below 10 eV, which will reduce its present upper limit by more than an order of magnitude. PMID:26296112

  3. Direct Measurement of the Mass Difference of 163Ho and 163Dy Solves the Q -Value Puzzle for the Neutrino Mass Determination

    NASA Astrophysics Data System (ADS)

    Eliseev, S.; Blaum, K.; Block, M.; Chenmarev, S.; Dorrer, H.; Düllmann, Ch. E.; Enss, C.; Filianin, P. E.; Gastaldo, L.; Goncharov, M.; Köster, U.; Lautenschläger, F.; Novikov, Yu. N.; Rischka, A.; Schüssler, R. X.; Schweikhard, L.; Türler, A.

    2015-08-01

    The atomic mass difference of 163 and 163Dy has been directly measured with the Penning-trap mass spectrometer SHIPTRAP applying the novel phase-imaging ion-cyclotron-resonance technique. Our measurement has solved the long-standing problem of large discrepancies in the Q value of the electron capture in 163Ho determined by different techniques. Our measured mass difference shifts the current Q value of 2555(16) eV evaluated in the Atomic Mass Evaluation 2012 [G. Audi et al., Chin. Phys. C 36, 1157 (2012)] by more than 7 σ to 2833 (30stat)(15sys) eV /c2 . With the new mass difference it will be possible, e.g., to reach in the first phase of the ECHo experiment a statistical sensitivity to the neutrino mass below 10 eV, which will reduce its present upper limit by more than an order of magnitude.

  4. Infrared Constraint on Ultraviolet Theories

    SciTech Connect

    Tsai, Yuhsin

    2012-08-01

    While our current paradigm of particle physics, the Standard Model (SM), has been extremely successful at explaining experiments, it is theoretically incomplete and must be embedded into a larger framework. In this thesis, we review the main motivations for theories beyond the SM (BSM) and the ways such theories can be constrained using low energy physics. The hierarchy problem, neutrino mass and the existence of dark matter (DM) are the main reasons why the SM is incomplete . Two of the most plausible theories that may solve the hierarchy problem are the Randall-Sundrum (RS) models and supersymmetry (SUSY). RS models usually suffer from strong flavor constraints, while SUSY models produce extra degrees of freedom that need to be hidden from current experiments. To show the importance of infrared (IR) physics constraints, we discuss the flavor bounds on the anarchic RS model in both the lepton and quark sectors. For SUSY models, we discuss the difficulties in obtaining a phenomenologically allowed gaugino mass, its relation to R-symmetry breaking, and how to build a model that avoids this problem. For the neutrino mass problem, we discuss the idea of generating small neutrino masses using compositeness. By requiring successful leptogenesis and the existence of warm dark matter (WDM), we can set various constraints on the hidden composite sector. Finally, to give an example of model independent bounds from collider experiments, we show how to constrain the DM–SM particle interactions using collider results with an effective coupling description.

  5. No-neutrino double beta decay: more than one neutrino

    SciTech Connect

    Rosen, S.P.

    1983-01-01

    Interference effects between light and heavy Majorana neutrinos in the amplitude for no-neutrino double beta decay are discussed. The effects include an upper bound on the heavy neutrino mass, and an A dependence for the effective mass extracted from double beta decay. Thus the search for the no-neutrino decay mode should be pursued in several nuclei, and particularly in Ca/sup 48/, where the effective mass may be quite large.

  6. Cosmological bounds on dark-matter-neutrino interactions

    SciTech Connect

    Mangano, Gianpiero; Melchiorri, Alessandro; Serra, Paolo; Cooray, Asantha; Kamionkowski, Marc

    2006-08-15

    We investigate the cosmological effects of a neutrino interaction with cold dark-matter. We postulate a neutrino that interacts with a ''neutrino-interacting dark-matter'' (NIDM) particle with an elastic-scattering cross section that either decreases with temperature as T{sup 2} or remains constant with temperature. The neutrino-dark-matter interaction results in a neutrino-dark-matter fluid with pressure, and this pressure results in diffusion-damped oscillations in the matter power spectrum, analogous to the acoustic oscillations in the baryon-photon fluid. We discuss the bounds from the Sloan Digital Sky Survey on the NIDM opacity (ratio of cross section to NIDM-particle mass) and compare with the constraint from observation of neutrinos from supernova 1987A. If only a fraction of the dark matter interacts with neutrinos, then NIDM oscillations may affect current cosmological constraints from measurements of galaxy clustering. We discuss how detection of NIDM oscillations would suggest a particle-antiparticle asymmetry in the dark-matter sector.

  7. Maximal CP-violation in neutrino mass matrix in light of the latest Daya Bay result on θ13

    NASA Astrophysics Data System (ADS)

    Verma, Surender

    2012-07-01

    The Daya Bay Collaboration (preprint) [1] has recently proclaimed discovery of non-zero reactor angle, θ13, sin2 2θ13=0.092±0.016(stat)±0.005(syst), at 5.2σ which is in conformity with the earlier observations of T2K Collaboration (2011) [2], MINOS Collaboration (2011) [3] and DOUBLE CHOOZ Collaboration (2011) [4] last year. The discovery has immense implication for exploring CP-violation in the leptonic sector. In the present work, we examine CP-violation in Majorana neutrino mass matrix, in the basis where charged lepton mass matrix is diagonal, in which the ratio of elements are equal, also, termed as Strong Scaling Ansatz (SSA). This Ansatz has been known to explain the vanishing of θ13 and predict inverted hierarchy (IH) for the neutrino masses. However, to generate a non-zero value of θ13 consistent with Daya Bay result one has to deviate from SSA. This deviation will have important implications for CP-violation in the leptonic sector and is one of the issues addressed in the present work. CP is maximally violated because, for central value of θ13 obtained from Daya Bay experiment, Dirac-type phase |δ|≈ π/2, 3π/2 which corresponds to |JCP|≈0.03. We have, also, studied imperative implications for Majorana-type phases α, β and effective neutrino mass, Mee. The Majorana-type phases α, β are found to be sharply constrained.

  8. Flavored leptogenesis with quasidegenerate neutrinos in a broken cyclic symmetric model

    NASA Astrophysics Data System (ADS)

    Adhikary, Biswajit; Chakraborty, Mainak; Ghosal, Ambar

    2016-06-01

    Cyclic symmetry in the neutrino sector with the type-I seesaw mechanism in the mass basis of charged leptons and right chiral neutrinos (Ni R, i =e , μ , τ ) generates a twofold degenerate light neutrino and a threefold degenerate heavy neutrino mass spectrum. Consequently, such a scheme produces vanishing one light neutrino mass squared difference and lepton asymmetry. To circumvent such an unphysical outcome, we break cyclic symmetry in the diagonal right chiral neutrino mass term by a small breaking parameter. Nonzero mass squared differences and mixing angles are generated with the help of the small breaking parameter. The smallness of the breaking parameter opens up the possibility of resonant leptogenesis. Assuming complex Yukawa couplings, we derive generalized expressions with flavor-dependent C P asymmetry parameters (ɛiα ) which are valid for the quasidegenerate as well as hierarchical mass spectrum of right-handed neutrinos. Thereafter, we set up the chain of coupled Boltzmann equations (which are flavor dependent too) which have to be solved in order to get the final lepton asymmetries. Depending upon the temperature regime, the C P asymmetries and the Boltzmann equations may also be flavor independent. As our goal is to study the enhancement of C P asymmetry due to the quasidegeneracy of right-handed neutrinos, we select only the lowest allowed (by neutrino oscillation data) value of the breaking parameter (and other corresponding Lagrangian parameters) and estimate the baryon asymmetry parameter YB. The experimental constraint of YB introduces a bound on right-handed neutrino mass which remained unrestricted by neutrino oscillation data.

  9. Physics of neutrino flavor transformation through matter-neutrino resonances

    NASA Astrophysics Data System (ADS)

    Wu, Meng-Ru; Duan, Huaiyu; Qian, Yong-Zhong

    2016-01-01

    In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.

  10. Fermion masses and neutrino mixing in an U(1){sub H} flavor symmetry model with hierarchical radiative generation for light charged fermion masses

    SciTech Connect

    Hernandez-Galeana, Albino

    2007-11-01

    I report the analysis performed on fermion masses and mixing, including neutrino mixing, within the context of a model with hierarchical radiative mass generation mechanism for light charged fermions, mediated by exotic scalar particles at one and two loops, respectively, meanwhile the neutrinos get Majorana mass terms at tree level through the Yukawa couplings with two SU(2){sub L} Higgs triplets. All the resulting mass matrices in the model, for the u, d, and e fermion charged sectors, the neutrinos and the exotic scalar particles, are diagonalized in exact analytical form. Quantitative analysis shows that this model is successful to accommodate the hierarchical spectrum of masses and mixing in the quark sector as well as the charged lepton masses. The lepton mixing matrix, V{sub PMNS}, is written completely in terms of the neutrino masses m{sub 1}, m{sub 2}, and m{sub 3}. Large lepton mixing for {theta}{sub 12} and {theta}{sub 23} is predicted in the range of values 0.7 < or approx. sin{sup 2}2{theta}{sub 12} < or approx. 0.7772 and 0.87 < or approx. sin{sup 2}2{theta}{sub 23} < or approx. 0.9023 by using 0.033 < or approx. s{sub 13}{sup 2} < or approx. 0.04. These values for lepton mixing are consistent with 3{sigma} allowed ranges provided by recent global analysis of neutrino data oscillation. From {delta}m{sub sol}{sup 2} bounds, neutrino masses are predicted in the range of values m{sub 1}{approx_equal}(1.706-2.494)x10{sup -3} eV, m{sub 2}{approx_equal}(6.675-12.56)x10{sup -3} eV, and m{sub 3}{approx_equal}(1.215-2.188)x10{sup -2} eV, respectively. The above allowed lepton mixing leads to the quark-lepton complementary relations {theta}{sub 12}{sup CKM}+{theta}{sub 12}{sup PMNS}{approx_equal}41.543 deg. -44.066 deg. and {theta}{sub 23}{sup CKM}+{theta}{sub 23}{sup PMNS}{approx_equal}36.835 deg. -38.295 deg. The new exotic scalar particles induce flavor changing neutral currents and contribute to lepton flavor violating processes such as E{yields}e{sub 1}e

  11. SOME CONSTRAINTS ON THE LOWER MASS LIMIT FOR DOUBLE-DEGENERATE PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect

    Chen, X.; Han, Z.

    2012-08-10

    Recent theoretical and observational studies both argue that the merging of double carbon-oxygen white dwarfs (WDs) is responsible for at least some Type Ia supernovae (SNe Ia). Previous (standard) studies of the anticipated SN birthrate from this channel have assumed that the merger process is conservative and that the primary criterion for explosion is that the merged mass exceeds the Chandrasekhar mass. Han and Webbink demonstrated that mass transfer and merger in close double WDs will in many cases be non-conservative. Pakmor et al. further suggested that the merger process should be violent in order to initiate an explosion. We have therefore investigated how the SN Ia birthrate from the double-degenerate (DD) channel is affected by these constraints. Using the binary-star population-synthesis method, we have calculated the DD SN Ia birthrate under conservative and non-conservative approximations, and including lower mass and mass-ratio limits indicated by recent smoothed-particle-hydrodynamic calculations. The predicted DD SN Ia rate is significantly reduced by all of these constraints. With dynamical mass loss alone (violent merger) the birthrate is reduced to 56% of the conservative rate. Requiring the mass ratio q > 2/3 further reduces the birthrate to 18% that of the standard assumption. An upper limit of 0.0061 SNuM, or a Galactic rate of 4.6 Multiplication-Sign 10{sup -4} yr{sup -1}, might be realistic.

  12. Neutrino Oscillation Physics

    SciTech Connect

    Kayser, Boris

    2012-06-01

    To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures. Neutrinos and photons are by far the most abundant elementary particles in the universe. Thus, if we would like to comprehend the universe, we must understand the neutrinos. Of course, studying the neutrinos is challenging, since the only known forces through which these electrically-neutral leptons interact are the weak force and gravity. Consequently, interactions of neutrinos in a detector are very rare events, so that very large detectors and intense neutrino sources are needed to make experiments feasible. Nevertheless, we have confirmed that the weak interactions of neutrinos are correctly described by the Standard Model (SM) of elementary particle physics. Moreover, in the last 14 years, we have discovered that neutrinos have nonzero masses, and that leptons mix. These discoveries have been based on the observation that neutrinos can change from one 'flavor' to another - the phenomenon known as neutrino oscillation. We shall explain the physics of neutrino oscillation, deriving the probability of oscillation in a new way. We shall also provide a very brief guide to references that can be used to study some major neutrino-physics topics other than neutrino oscillation.

  13. Physics from solar neutrinos in dark matter direct detection experiments

    NASA Astrophysics Data System (ADS)

    Cerdeño, David G.; Fairbairn, Malcolm; Jubb, Thomas; Machado, Pedro A. N.; Vincent, Aaron C.; Bœhm, Céline

    2016-05-01

    The next generation of dark matter direct detection experiments will be sensitive to both coherent neutrino-nucleus and neutrino-electron scattering. This will enable them to explore aspects of solar physics, perform the lowest energy measurement of the weak angle sin2 θ W to date, and probe contributions from new theories with light mediators. In this article, we compute the projected nuclear and electron recoil rates expected in several dark matter direct detection experiments due to solar neutrinos, and use these estimates to quantify errors on future measurements of the neutrino fluxes, weak mixing angle and solar observables, as well as to constrain new physics in the neutrino sector. Our analysis shows that the combined rates of solar neutrino events in second generation experiments (SuperCDMS and LZ) can yield a measurement of the pp flux to 2.5% accuracy via electron recoil, and slightly improve the 8B flux determination. Assuming a low-mass argon phase, projected tonne-scale experiments like DARWIN can reduce the uncertainty on both the pp and boron-8 neutrino fluxes to below 1%. Finally, we use current results from LUX, SuperCDMS and CDMSlite to set bounds on new interactions between neutrinos and electrons or nuclei, and show that future direct detection experiments can be used to set complementary constraints on the parameter space associated with light mediators.

  14. Seesaw mechanism with four texture zeros in the neutrino Yukawa matrix

    NASA Astrophysics Data System (ADS)

    Liao, Jiajun; Marfatia, D.; Whisnant, K.

    2013-04-01

    With the recent observation of nonzero θ13, five neutrino oscillation parameters are now known. By imposing four zeros in the Yukawa coupling matrix of the type I seesaw model, the number of parameters in the neutrino mass matrix is reduced to seven, and we are able to make predictions for the lightest neutrino mass, Dirac CP phase, and neutrinoless double beta decay. Four texture zeros in the Yukawa coupling matrix is equivalent to either a single texture zero or a single cofactor zero for an off-diagonal element of the light neutrino mass matrix. We find strong similarities between single texture zero models with one mass ordering and single cofactor zero models with the opposite mass ordering. In the context of a specific class of single-flavor leptogenesis models, we find additional constraints on the parameter space.

  15. Cosmological constraint on the light gravitino mass from CMB lensing and cosmic shear

    NASA Astrophysics Data System (ADS)

    Osato, Ken; Sekiguchi, Toyokazu; Shirasaki, Masato; Kamada, Ayuki; Yoshida, Naoki

    2016-06-01

    Light gravitinos of mass lesssim O (10) eV are of particular interest in cosmology, offering various baryogenesis scenarios without suffering from the cosmological gravitino problem. The gravitino may contribute considerably to the total matter content of the Universe and affect structure formation from early to present epochs. After the gravitinos decouple from other particles in the early Universe, they free-stream and consequently suppress density fluctuations of (sub-)galactic length scales. Observations of structure at the relevant length-scales can be used to infer or constrain the mass and the abundance of light gravitinos. We derive constraints on the light gravitino mass using the data of cosmic microwave background (CMB) lensing from Planck and of cosmic shear from the Canada France Hawaii Lensing Survey survey, combined with analyses of the primary CMB anisotropies and the signature of baryon acoustic oscillations in galaxy distributions. The obtained constraint on the gravitino mass is m3/2 < 4.7 eV (95 % C.L.), which is substantially tighter than the previous constraint from clustering analysis of Ly-α forests.

  16. Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

    SciTech Connect

    He, Yudong |

    1995-07-01

    This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled `Neutrino Mass and Oscillation`, `High Energy Neutrino Astrophysics`, `Detection of Dark Matter`, `Search for Strange Quark Matter`, and `Magnetic Monopole Searches`. The report is introduced by a survey of the field and a brief description of each of the author`s papers.

  17. Neutrino experiments: Hierarchy, CP, CPT

    NASA Astrophysics Data System (ADS)

    Gupta, Manmohan; Randhawa, Monika; Singh, Mandip

    2016-07-01

    We present an overview of our recent investigations regarding the prospects of ongoing neutrino experiments as well as future experiments in determining few of the most important unknowns in the field of neutrino physics, specifically the neutrino mass ordering and leptonic CP-violation phase. The effect of matter oscillations on the neutrino oscillation probabilities has been exploited in resolving the degeneracy between the neutrino mass ordering and the CP violation phase in the leptonic sector. Further, we estimate the extent of extrinsic CP and CPT violation in the experiments with superbeams as well as neutrino factories.

  18. Electromagnetic properties of massive neutrinos

    SciTech Connect

    Dobrynina, A. A. Mikheev, N. V.; Narynskaya, E. N.

    2013-10-15

    The vertex function for a virtual massive neutrino is calculated in the limit of soft real photons. A method based on employing the neutrino self-energy operator in a weak external electromagnetic field in the approximation linear in the field is developed in order to render this calculation of the vertex function convenient. It is shown that the electric charge and the electric dipole moment of the real neutrino are zero; only the magnetic moment is nonzero for massive neutrinos. A fourth-generation heavy neutrino of mass not less than half of the Z-boson mass is considered as a massive neutrino.

  19. Dynamical mass and multiplicity constraints on co-orbital bodies around stars

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri; Marsh, Thomas R.; Gänsicke, Boris T.

    2016-09-01

    Objects transiting near or within the disruption radius of both main-sequence (e.g. KOI 1843) and white dwarf (WD 1145+017) stars are now known. Upon fragmentation or disintegration, these planets or asteroids may produce co-orbital configurations of nearly equal mass objects. However, as evidenced by the co-orbital objects detected by transit photometry in the WD 1145+017 system, these bodies are largely unconstrained in size, mass, and total number (multiplicity). Motivated by potential future similar discoveries, we perform N-body simulations to demonstrate if and how debris masses and multiplicity may be bounded due to second-to-minute deviations and the resulting accumulated phase shifts in the osculating orbital period amongst multiple co-orbital equal point masses. We establish robust lower and upper mass bounds as a function of orbital period deviation, but find the constraints on multiplicity to be weak. We also quantify the fuzzy instability boundary, and show that mutual collisions occur in less than 5, 10, and 20 per cent of our simulations for masses of 1021, 1022, and 1023 kg. Our results may provide useful initial rough constraints on other stellar systems with multiple co-orbital bodies.

  20. Are neutrinos their own antiparticles?

    SciTech Connect

    Kayser, Boris; /Fermilab

    2009-03-01

    We explain the relationship between Majorana neutrinos, which are their own antiparticles, and Majorana neutrino masses. We point out that Majorana masses would make the neutrinos very distinctive particles, and explain why many theorists strongly suspect that neutrinos do have Majorana masses. The promising approach to confirming this suspicion is to seek neutrinoless double beta decay. We introduce a toy model that illustrates why this decay requires nonzero neutrino masses, even when there are both right-handed and left-handed weak currents.

  1. Supernova nucleosynthesis and the physics of neutrino oscillation

    SciTech Connect

    Kajino, Toshitaka

    2012-11-20

    We studied the explosive nucleosynthesis in core-collapse supernovae and found that several isotopes of rare elements like {sup 7}Li, {sup 11}B, {sup 138}La, {sup 180}Ta and others are predominantly produced by the neutrino interactions with several abundant nuclei. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here first study how to know the suitable average neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the neutrino oscillation parameters, {theta}{sub 13} and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process {sup 11}B and {sup 7}Li encapsulated in the grains. Combining the recent experimental constraints on {theta}{sub 13}, we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.

  2. Dynamical Constraints on the Core Mass of Hot Jupiter HAT-P-13b

    NASA Astrophysics Data System (ADS)

    Buhler, Peter B.; Knutson, Heather A.; Batygin, Konstantin; Fulton, Benjamin J.; Fortney, Jonathan J.; Burrows, Adam; Wong, Ian

    2016-04-01

    HAT-P-13b is a Jupiter-mass transiting exoplanet that has settled onto a stable, short-period, and mildly eccentric orbit as a consequence of the action of tidal dissipation and perturbations from a second, highly eccentric, outer companion. Owing to the special orbital configuration of the HAT-P-13 system, the magnitude of HAT-P-13b's eccentricity (eb) is in part dictated by its Love number ({k}{2b}), which is in turn a proxy for the degree of central mass concentration in its interior. Thus, the measurement of eb constrains {k}{2b} and allows us to place otherwise elusive constraints on the mass of HAT-P-13b's core (Mcore,b). In this study we derive new constraints on the value of eb by observing two secondary eclipses of HAT-P-13b with the Infrared Array Camera on board the Spitzer Space Telescope. We fit the measured secondary eclipse times simultaneously with radial velocity measurements and find that eb = 0.00700 ± 0.00100. We then use octupole-order secular perturbation theory to find the corresponding {k}{2b}={0.31}-0.05+0.08. Applying structural evolution models, we then find, with 68% confidence, that Mcore,b is less than 25 Earth masses (M⊕). The most likely value is Mcore,b = 11 M⊕, which is similar to the core mass theoretically required for runaway gas accretion. This is the tightest constraint to date on the core mass of a hot Jupiter. Additionally, we find that the measured secondary eclipse depths, which are in the 3.6 and 4.5 μm bands, best match atmospheric model predictions with a dayside temperature inversion and relatively efficient day-night circulation.

  3. Constraints on the Initial-Final Mass Relation from Wide Double White Dwarfs

    NASA Astrophysics Data System (ADS)

    Andrews, Jeff J.; Agüeros, Marcel A.; Gianninas, A.; Kilic, Mukremin; Dhital, Saurav; Anderson, Scott F.

    2015-12-01

    We present observational constraints on the initial-final mass relation (IFMR) using wide double white dwarfs (DWDs). We identify 65 new candidate wide DWDs within the Sloan Digital Sky Survey, bringing the number of candidate wide DWDs to 142. We then engage in a spectroscopic follow-up campaign and collect existing spectra for these objects; using these spectra, we derive masses and cooling ages for 54 hydrogen (DA) WDs in DWDs. We also identify one new DA/DB pair, four candidate DA/DC pairs, four candidate DA/DAH pairs, and one new candidate triple degenerate system. Because wide DWDs are co-eval and evolve independently, the difference in the pre-WD lifetimes should equal the difference in the WD cooling ages. We use this to develop a Bayesian hierarchical framework and construct a likelihood function to determine the probability that any particular IFMR fits a sample of wide DWDs. We then define a parametric model for the IFMR and find the best parameters indicated by our sample of DWDs. We place robust constraints on the IFMR for initial masses of 2-4 {M}⊙ . The WD masses produced by our model for stars within this mass range differ from those predicted by semi-empirical fits to open cluster WDs. Within this mass range, where there are few constraining open cluster WDs and disagreements in the cluster ages, wide DWDs may provide more reliable constraints on the IFMR. Expanding this method to the many wide DWDs expected to be discovered by Gaia may transform our understanding of the IFMR.

  4. Dynamical Constraints on the Core Mass of Hot Jupiter HAT-P-13b

    NASA Astrophysics Data System (ADS)

    Buhler, Peter B.; Knutson, Heather A.; Batygin, Konstantin; Fulton, Benjamin J.; Fortney, Jonathan J.; Burrows, Adam; Wong, Ian

    2016-04-01

    HAT-P-13b is a Jupiter-mass transiting exoplanet that has settled onto a stable, short-period, and mildly eccentric orbit as a consequence of the action of tidal dissipation and perturbations from a second, highly eccentric, outer companion. Owing to the special orbital configuration of the HAT-P-13 system, the magnitude of HAT-P-13b's eccentricity (eb) is in part dictated by its Love number ({k}{2b}), which is in turn a proxy for the degree of central mass concentration in its interior. Thus, the measurement of eb constrains {k}{2b} and allows us to place otherwise elusive constraints on the mass of HAT-P-13b's core (Mcore,b). In this study we derive new constraints on the value of eb by observing two secondary eclipses of HAT-P-13b with the Infrared Array Camera on board the Spitzer Space Telescope. We fit the measured secondary eclipse times simultaneously with radial velocity measurements and find that eb = 0.00700 ± 0.00100. We then use octupole-order secular perturbation theory to find the corresponding {k}{2b}={0.31}-0.05+0.08. Applying structural evolution models, we then find, with 68% confidence, that Mcore,b is less than 25 Earth masses (M⊕). The most likely value is Mcore,b = 11 M⊕, which is similar to the core mass theoretically required for runaway gas accretion. This is the tightest constraint to date on the core mass of a hot Jupiter. Additionally, we find that the measured secondary eclipse depths, which are in the 3.6 and 4.5 μm bands, best match atmospheric model predictions with a dayside temperature inversion and relatively efficient day–night circulation.

  5. Dynamical Constraints on the Core Mass of Hot Jupiter HAT-P-13b

    NASA Astrophysics Data System (ADS)

    Buhler, Peter Benjamin; Knutson, Heather; Batygin, Konstantin; Fulton, Benjamin James; Burrows, Adam Seth; Fortney, Jonathan J.

    2016-01-01

    HAT-P-13b is a Jupiter-mass transiting exoplanet that has settled onto a stable, short-period, and mildly eccentric orbit due to the action of tidal dissipation and perturbations from a second, highly eccentric, outer companion. Due to the special orbital configuration of the HAT-P-13 system, the magnitude of HAT-P-13b's eccentricity is in part dictated by its Love number, i.e. the degree of central mass concentration in its interior. We can therefore directly constrain the fraction of HAT-P-13b's mass contained in its core by measuring its orbital eccentricity. This method offers considerable advantages over the standard approach of inferring core size based on mass and radius measurements alone. In this study we derive new constraints on the value of HAT-P-13b's eccentricity by observing two secondary eclipses of HAT-P-13b with the Infrared Array Camera on board the Spitzer Space Telescope. We fit the measured secondary eclipse times simultaneously with radial velocity measurements and find that the eccentricity of HAT-P-13b is 0.00696 ± 0.00096. We then use octupole-order secular perturbation theory to find that the corresponding Love number is 0.31 (+0.11, -0.05). Applying structural evolution models, we then find, with 68% confidence, that the core mass lies between 0-25 Earth masses, with a most likely value of the core mass of 11 Earth masses. This is the tightest constraint, to date, on the core mass of an exoplanet. We also compare the measured secondary eclipse depths, in the 3.6 and 4.5 micron bands, to the predictions of a suite of atmosphere models and find that the depths are best matched by models with a dayside temperature inversion and relatively efficient day-night circulation.

  6. Accounting for the Unresolved X-ray Background with Sterile Neutrino Dark Matter

    SciTech Connect

    Cumberbatch, D.T.; Silk, Joseph

    2007-11-20

    We consider a scenario where keV sterile neutrinos constitute all of the currently inferred dark matter abundance, whose radiative decays could potentially account for the flux contributions to the X-ray background (XRB) by unresolved sources. Here we apply integrated flux methods to results from the observations of the North/South Chandra deep fields (CDF-N/S) in order to deduce constraints on the sterile neutrino mass-mixing parameters.

  7. Constraining neutrino mass using the large-scale H I distribution in the post-reionization epoch

    NASA Astrophysics Data System (ADS)

    Pal, Ashis Kumar; Guha Sarkar, Tapomoy

    2016-07-01

    The neutral intergalactic medium in the post-reionization epoch allows us to study cosmological structure formation through the observation of the redshifted 21 cm signal and the Lyman α forest. We investigate the possibility of measuring the total neutrino mass through the suppression of power in the matter power spectrum. We investigate the possibility of measuring the neutrino mass through its imprint on the cross-correlation power spectrum of the 21 cm signal and the Lyman α forest. We consider a radio-interferometric measurement of the 21 cm signal with a SKA1-mid-like radio telescope and a BOSS-like Lyman α forest survey. A Fisher matrix analysis shows that at the fiducial redshift z = 2.5, a 10 000 h 21 cm observation distributed equally over 25 radio pointings and a Lyman α forest survey with 30 quasars lines of sights in 1deg2, allows us to measure Ων at a 3.25 per cent level. A total of 25 000 h radio-interferometric observation distributed equally over 25 radio pointings and a Lyman α survey with bar{n} = 60 deg^{-2} will allow Ων to be measured at a 2.26 per cent level. This corresponds to an idealized measurement of ∑mν at the precision of (100 ± 2.26)meV and fν = Ων/Ωm at 2.49 per cent level.

  8. Cryptographic Unification of Mass and Space Links Neutrino Flavor (νe/νμ) Transformations with the Cosmological Constant Λ

    NASA Astrophysics Data System (ADS)

    Dai, Yang; Borisov, Alex B.; Longworth, James W.; Boyer, Keith; Rhodes, Charles K.

    The universe exhibits two striking manifestations, (a) immense complexity and (b) an astonishingly high scale-free precision. Since a cryptographic system based on the modular arithmetic of a finite field can provide a mathematical structure matching these two cardinal characteristics, it is natural to evaluate the theoretical possibilities of a cryptographic analysis of physical phenomena. The organization of the particle mass scale provides a particularly suitable test of this idea, since the cryptographic approach also has the inherent feature that divergences are fully barred, thereby eliminating the need for ad hoc procedures of renormalization. This article (1) shows how such a cryptographic concept can be implemented and (2) demonstrates its surprising ability to synthesize the description of a broad range of phenomena through the development of an interlocking set of quantitative findings. It is found that a cryptographic theoretical framework based solely on two physically anchored parameters, a modulus Pα and a corresponding primitive root gα, can simultaneously achieve six goals. Specifically, it (α) unites the concepts of mass and space, (β) organizes the physical mass scale in a group structure, (γ) produces a quantitative concordance of findings linking the cosmic and micro-scales that includes values for the fine structure constant α and the unified strong-electroweak coupling constant α*, (δ) respectively gives prospective magnitudes of 0.808 meV and 27.68 meV for the rest masses mνe and mνμ of the electron (νe) and muon (νμ) neutrinos, (ɛ) specifies a symmetry condition that yields an exact predicted value for the Higgs particle mass that lies above 1018 GeV, and (ζ) enables the formulation of a direct physical connection between the anomalous flavor (νe/νμ) transforming propagation of solar neutrinos and the existence of a positive cosmological constant Λ. These results are uniformly in agreement with all corresponding

  9. Sudbury Neutrino Observatory

    SciTech Connect

    Beier, E.W.

    1992-03-01

    This document is a technical progress report on work performed at the University of Pennsylvania during the current year on the Sudbury Neutrino Observatory project. The motivation for the experiment is the measurement of neutrinos emitted by the sun. The Sudbury Neutrino Observatory (SNO) is a second generation dedicated solar neutrino experiment which will extend the results of our work with the Kamiokande II detector by measuring three reactions of neutrinos rather than the single reaction measured by the Kamiokande experiment. The collaborative project includes physicists from Canada, the United Kingdom, and the United States. Full funding for the construction of this facility was obtained in January 1990, and its construction is estimated to take five years. The motivation for the SNO experiment is to study the fundamental properties of neutrinos, in particular the mass and mixing parameters, which remain undetermined after decades of experiments in neutrino physics utilizing accelerators and reactors as sources of neutrinos. To continue the study of neutrino properties it is necessary to use the sun as a neutrino source. The long distance to the sun makes the search for neutrino mass sensitive to much smaller mass than can be studied with terrestrial sources. Furthermore, the matter density in the sun is sufficiently large to enhance the effects of small mixing between electron neutrinos and mu or tau neutrinos. This experiment, when combined with the results of the radiochemical {sup 37}Cl and {sup 71}Ga experiments and the Kamiokande II experiment, should extend our knowledge of these fundamental particles, and as a byproduct, improve our understanding of energy generation in the sun.

  10. Do observations prove that cosmological neutrinos are thermally distributed?

    SciTech Connect

    Cuoco, Alessandro; Lesgourgues, Julien; Mangano, Gianpiero; Pastor, Sergio

    2005-06-15

    It is usually assumed that relic neutrinos possess a Fermi-Dirac distribution, acquired during thermal equilibrium in the Early Universe. However, various mechanisms could introduce strong distortions in this distribution. We perform a Bayesian likelihood analysis including the first moments of the three active neutrino distributions as free parameters, and show that current cosmological observations of light element abundances, Cosmic Microwave Background anisotropies and Large Scale Structures are compatible with very large deviations from the standard picture. We also calculate the bounds on nonthermal distortions which can be expected from future observations, and stress that Cosmic Microwave Background and Large Scale Structures data alone will not be sensitive enough in order to distinguish between nonthermal distortions in the neutrino sector and extra relativistic degrees of freedom. This degeneracy could be removed by additional constraints from primordial nucleosynthesis or independent neutrino mass scale measurements.

  11. Status of High-Energy Neutrino Astronomy

    NASA Astrophysics Data System (ADS)

    Kowalski, Marek

    2015-08-01

    With the recent discovery of high-energy neutrinos of extra-terrestrial origin by the IceCube neutrino observatory, neutrino-astronomy is entering a new era. This review will cover currently operating open water/ice neutrino telescopes, the latest evidence for a flux of extra-terrestrial neutrinos and current efforts in the search for steady and transient neutrino point sources. Generalised constraints on potential astrophysical sources are presented, allowing to focus the hunt for the sources of the observed high-energy neutrinos.

  12. Direct Exoplanet Imaging with JWST NIRCam: Low-Mass Stars, Low-Mass Planets, and Critical Constraints on Planet Formation

    NASA Astrophysics Data System (ADS)

    Schlieder, Joshua E.; Meyer, Michael; Reggiani, Maddalena; Quanz, Sascha; Beichman, Charles A.; Greene, Thomas P.; Burrows, Adam Seth

    2016-01-01

    As next generation exoplanet imagers are making their first discoveries, the largest population of stars in the Galaxy, the M dwarfs, are largely unaccounted for in their surveys. However, RV trends and micro lensing have revealed that M dwarfs host a substantial population of Neptune to Jupiter mass planets between ~1-10 AU. The unprecedented sensitivity of NIRCam on the JWST provides direct access to this population of gas-giants. A NIRCam 3 - 5 μm survey for such planets will place critical constraints on planet formation by: 1) measuring the luminosities of young, sub-Jupiter mass planets, 2) providing constraints on the peak in the companion surface density vs. separation distribution, and 3) measuring the frequency of ≤Jupiter mass giants in the outskirts of these systems (>10 AU). We have carefully constructed a sample of nearby, young, late-type stars, performed NIRCam survey simulations, and will report on the expected yield and advantages of JWST compared to current ground based capabilities.

  13. An Assessment of Dynamical Mass Constraints on Pre-Main-Sequence Evolutionary Tracks

    NASA Astrophysics Data System (ADS)

    Hillenbrand, Lynne A.; White, Russel J.

    2004-04-01

    We have assembled a database of stars having both masses determined from measured orbital dynamics and sufficient spectral and photometric information for their placement on a theoretical H-R diagram. Our sample consists of 115 low-mass (M<2.0 Msolar) stars, 27 pre-main-sequence and 88 main-sequence. We use a variety of available pre-main-sequence evolutionary calculations to test the consistency of predicted stellar masses with dynamically determined masses. Despite substantial improvements in model physics over the past decade, large systematic discrepancies still exist between empirical and theoretically derived masses. For main-sequence stars, all models considered predict masses consistent with dynamical values above 1.2 Msolar and some models predict consistent masses at solar or slightly lower masses, but no models predict consistent masses below 0.5 Msolar, with all models systematically underpredicting such low masses by 5%-20%. The failure at low masses stems from the poor match of most models to the empirical main sequence below temperatures of 3800 K, at which molecules become the dominant source of opacity and convection is the dominant mode of energy transport. For the pre-main-sequence sample we find similar trends. There is generally good agreement between predicted and dynamical masses above 1.2 Msolar for all models. Below 1.2 Msolar and down to 0.3 Msolar (the lowest mass testable), most evolutionary models systematically underpredict the dynamically determined masses by 10%-30%, on average, with the Lyon group models predicting marginally consistent masses in the mean, although with large scatter. Over all mass ranges, the usefulness of dynamical mass constraints for pre-main-sequence stars is in many cases limited by the random errors caused by poorly determined luminosities and especially temperatures of young stars. Adopting a warmer-than-dwarf temperature scale would help reconcile the systematic pre-main-sequence offset at the lowest masses

  14. Neutrinos in Cosmology

    SciTech Connect

    Wong, Yvonne Y. Y.

    2008-01-24

    I give an overview of the effects of neutrinos on cosmology, focussing in particular on the role played by neutrinos in the evolution of cosmological perturbations. I discuss how recent observations of the cosmic microwave background and the large-scale structure of galaxies can probe neutrino masses with greater precision than current laboratory experiments. I describe several new techniques that will be used to probe cosmology in the future.

  15. Neutrino Physics at Fermilab

    SciTech Connect

    Federspiel, F.; Garvey, G.; Louis, W.C.; Mills, G.B.; Tayloe, R.; Sandberg, V.; Sapp, B.; White, D.H.

    1999-07-09

    The Liquid Scintillator Neutrino Detector (LSND), located at the LANSCE (formerly LAMPF) linear accelerator at Los Alamos National Laboratory, has seen evidence for the oscillation of neutrinos, and hence neutrino mass. That discovery was the impetus for this LDRD project, begun in 1996. The goal of this project was to define the appropriate technologies to use in a follow up experiment and to set in place the requirements for such an experiment.

  16. Precise measurements of the $W$ mass at the Tevatron and indirect constraints on the Higgs mass

    SciTech Connect

    Lopes de Sa, Rafael

    2012-04-01

    I describe the latest D0 and CDF W boson mass measurements. The D0 measurement is performed with 4.3 fb{sup -1} of integrated luminosity in the electron decay channel with a data set of 1.68 x 10{sup 8} W candidates. The value of the W boson mass measured by D0 is M{sub W} = 80.375 {+-} 0.023 GeV when combined with the previously analyzed 1 fb{sup -1} of integrated luminosity. The CDF measurement uses 2.2 fb{sup -1} of integrated luminosity in both electron and muon decay channels with a total of 1.1 x 10{sup 8} W candidates. The value of the W boson mass measured by CDF is M{sub W} = 80.387 {+-} 0.019 GeV. I report the combination of these two measurements with previous Tevatron measurements and with the LEP measurements of the W boson mass. The new world average is M{sub W} = 80.385 {+-} 0.015GeV. I discuss the implications of the new measurement to the indirect measurement of the Standard Model Higgs boson mass.

  17. The mass-hierarchy and CP-violation discovery reach of the LBNO long-baseline neutrino experiment

    NASA Astrophysics Data System (ADS)

    Agarwalla, S. K.; Agostino, L.; Aittola, M.; Alekou, A.; Andrieu, B.; Angus, D.; Antoniou, F.; Ariga, A.; Ariga, T.; Asfandiyarov, R.; Autiero, D.; Ballett, P.; Bandac, I.; Banerjee, D.; Barker, G. J.; Barr, G.; Bartmann, W.; Bay, F.; Berardi, V.; Bertram, I.; Bésida, O.; Blebea-Apostu, A. M.; Blondel, A.; Bogomilov, M.; Borriello, E.; Boyd, S.; Brancus, I.; Bravar, A.; Buizza-Avanzini, M.; Cafagna, F.; Calin, M.; Calviani, M.; Campanelli, M.; Cantini, C.; Caretta, O.; Cata-Danil, G.; Catanesi, M. G.; Cervera, A.; Chakraborty, S.; Chaussard, L.; Chesneanu, D.; Chipesiu, F.; Christodoulou, G.; Coleman, J.; Crivelli, P.; Davenne, T.; Dawson, J.; De Bonis, I.; De Jong, J.; Déclais, Y.; Del Amo Sanchez, P.; Delbart, A.; Densham, C.; Di Lodovico, F.; Di Luise, S.; Duchesneau, D.; Dumarchez, J.; Efthymiopoulos, I.; Eliseev, A.; Emery, S.; Enqvist, K.; Enqvist, T.; Epprecht, L.; Ereditato, A.; Erykalov, A. N.; Esanu, T.; Finch, A. J.; Fitton, M. D.; Franco, D.; Galymov, V.; Gavrilov, G.; Gendotti, A.; Giganti, C.; Goddard, B.; Gomez, J. J.; Gomoiu, C. M.; Gornushkin, Y. A.; Gorodetzky, P.; Grant, N.; Haesler, A.; Haigh, M. D.; Hasegawa, T.; Haug, S.; Hierholzer, M.; Hissa, J.; Horikawa, S.; Huitu, K.; Ilic, J.; Ioannisian, A. N.; Izmaylov, A.; Jipa, A.; Kainulainen, K.; Kalliokoski, T.; Karadzhov, Y.; Kawada, J.; Khabibullin, M.; Khotjantsev, A.; Kokko, E.; Kopylov, A. N.; Kormos, L. L.; Korzenev, A.; Kosyanenko, S.; Kreslo, I.; Kryn, D.; Kudenko, Y.; Kudryavtsev, V. A.; Kumpulainen, J.; Kuusiniemi, P.; Lagoda, J.; Lazanu, I.; Levy, J.-M.; Litchfield, R. P.; Loo, K.; Loveridge, P.; Maalampi, J.; Magaletti, L.; Margineanu, R. M.; Marteau, J.; Martin-Mari, C.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCauley, N.; Mercadante, A.; Mineev, O.; Mirizzi, A.; Mitrica, B.; Morgan, B.; Murdoch, M.; Murphy, S.; Mursula, K.; Narita, S.; Nesterenko, D. A.; Nguyen, K.; Nikolics, K.; Noah, E.; Novikov, Yu.; O'Keeffe, H.; Odell, J.; Oprima, A.; Palladino, V.; Papaphilippou, Y.; Pascoli, S.; Patzak, T.; Payne, D.; Pectu, M.; Pennacchio, E.; Periale, L.; Pessard, H.; Pistillo, C.; Popov, B.; Przewlocki, P.; Quinto, M.; Radicioni, E.; Ramachers, Y.; Ratoff, P. N.; Ravonel, M.; Rayner, M.; Resnati, F.; Ristea, O.; Robert, A.; Rondio, E.; Rubbia, A.; Rummukainen, K.; Sacco, R.; Saftoiu, A.; Sakashita, K.; Sarkamo, J.; Sato, F.; Saviano, N.; Scantamburlo, E.; Sergiampietri, F.; Sgalaberna, D.; Shaposhnikova, E.; Slupecki, M.; Sorel, M.; Spooner, N. J. C.; Stahl, A.; Stanca, D.; Steerenberg, R.; Sterian, A. R.; Sterian, P.; Still, B.; Stoica, S.; Strauss, T.; Suhonen, J.; Suvorov, V.; Szeptycka, M.; Terri, R.; Thompson, L. F.; Toma, G.; Tonazzo, A.; Touramanis, C.; Trzaska, W. H.; Tsenov, R.; Tuominen, K.; Vacheret, A.; Valram, M.; Vankova-Kirilova, G.; Vanucci, F.; Vasseur, G.; Velotti, F.; Velten, P.; Viant, T.; Vincke, H.; Virtanen, A.; Vorobyev, A.; Wark, D.; Weber, A.; Weber, M.; Wiebusch, C.; Wilson, J. R.; Wu, S.; Yershov, N.; Zalipska, J.; Zito, M.

    2014-05-01

    The next generation neutrino observatory proposed by the LBNO collaboration will address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, in its first stage a 20 kt LAr double phase TPC and a magnetised iron calorimeter, situated at 2300 km from CERN and a near detector based on a highpressure argon gas TPC. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the L/E behaviour, and distinguishing effects arising from δ CP and matter. In this paper we have reevaluated the physics potential of this setup for determining the mass hierarchy (MH) and discovering CP-violation (CPV), using a conventional neutrino beam from the CERN SPS with a power of 750 kW. We use conservative assumptions on the knowledge of oscillation parameter priors and systematic uncertainties. The impact of each systematic error and the precision of oscillation prior is shown. We demonstrate that the first stage of LBNO can determine unambiguously the MH to > 5 σ C.L. over the whole phase space. We show that the statistical treatment of the experiment is of very high importance, resulting in the conclusion that LBNO has ~ 100% probability to determine the MH in at most 4-5 years of running. Since the knowledge of MH is indispensable to extract δ CP from the data, the first LBNO phase can convincingly give evidence for CPV on the 3 σ C.L. using today's knowledge on oscillation parameters and realistic assumptions on the systematic uncertainties.

  18. Revisiting XENON100's constraints (and signals?) for low-mass dark matter

    SciTech Connect

    Hooper, Dan

    2013-09-01

    Although observations made with the CoGeNT and CDMS experiments have been interpreted as possible signals of low-mass ( ∼ 7–10 GeV) dark matter particles, constraints from the XENON100 collaboration appear to be incompatible with this hypothesis, at least at face value. In this paper, we revisit XENON100's constraint on dark matter in this mass range, and consider how various uncertainties and assumptions made might alter this conclusion. We also note that while XENON100's two nuclear recoil candidates each exhibit very low ratios of ionization-to-scintillation signals, making them difficult to attribute to known electronic or neutron backgrounds, they are consistent with originating from dark matter particles in the mass range favored by CoGeNT and CDMS. We argue that with lower, but not implausible, values for the relative scintillation efficiency of liquid xenon (L{sub eff}), and the suppression of the scintillation signal in liquid xenon at XENON100's electric field (S{sub nr}), these two events could consistently arise from dark matter particles with a mass and cross section in the range favored by CoGeNT and CDMS. If this interpretation is correct, we predict that the LUX experiment, with a significantly higher light yield than XENON100, should observe dark matter induced events at an observable rate of ∼ 3–24 per month.

  19. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    SciTech Connect

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high source luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.

  20. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    DOE PAGES

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high sourcemore » luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.« less