Constraints on Neutrino Mass from Galaxy Surveys
NASA Astrophysics Data System (ADS)
Cuesta, A. J.; Niro, V.; Verde, L.
2017-03-01
Modern large-scale galaxy surveys, combined with measurements of the cosmic microwave background, have managed to constrain the sum of neutrino masses to an order of magnitude below the limit placed by laboratory experiments. We discuss the signature of massive neutrinos in the distribution of galaxies and the current state of the art of neutrino mass constraints, focusing on parameter degeneracies that reveal how we can improve current constraints with next-generation galaxy surveys. We also comment on how the near future cosmology experiments are an opportunity for the first measurement of the value of the sum of neutrino masses, or alternatively, to find profound implications for neutrino physics extensions beyond the Standard Model.
Observational constraints on varying neutrino-mass cosmology
Geng, Chao-Qiang; Lee, Chung-Chi; Myrzakulov, R.; Sami, M.; Saridakis, Emmanuel N. E-mail: g9522545@oz.nthu.edu.tw E-mail: sami@iucaa.ernet.in
2016-01-01
We consider generic models of quintessence and we investigate the influence of massive neutrino matter with field-dependent masses on the matter power spectrum. In case of minimally coupled neutrino matter, we examine the effect in tracker models with inverse power-law and double exponential potentials. We present detailed investigations for the scaling field with a steep exponential potential, non-minimally coupled to massive neutrino matter, and we derive constraints on field-dependent neutrino masses from the observational data.
Global constraints on absolute neutrino masses and their ordering
NASA Astrophysics Data System (ADS)
Capozzi, Francesco; Di Valentino, Eleonora; Lisi, Eligio; Marrone, Antonio; Melchiorri, Alessandro; Palazzo, Antonio
2017-05-01
Within the standard three-neutrino framework, the absolute neutrino masses and their ordering (either normal, NO, or inverted, IO) are currently unknown. However, the combination of current data coming from oscillation experiments, neutrinoless double beta (0 ν β β ) decay searches, and cosmological surveys, can provide interesting constraints for such unknowns in the sub-eV mass range, down to O (10-1) eV in some cases. We discuss current limits on absolute neutrino mass observables by performing a global data analysis that includes the latest results from oscillation experiments, 0 ν β β decay bounds from the KamLAND-Zen experiment, and constraints from representative combinations of Planck measurements and other cosmological data sets. In general, NO appears to be somewhat favored with respect to IO at the level of ˜2 σ , mainly by neutrino oscillation data (especially atmospheric), corroborated by cosmological data in some cases. Detailed constraints are obtained via the χ2 method, by expanding the parameter space either around separate minima in NO and IO or around the absolute minimum in any ordering. Implications for upcoming oscillation and nonoscillation neutrino experiments, including β -decay searches, are also discussed.
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.
Supersymmetric inflation with constraints on superheavy neutrino masses
Lazarides, G.; Schaefer, R.K.; Shafi, Q.
1997-07-01
We consider a supersymmetric model of inflation in which the primordial density fluctuations are nearly scale invariant (spectral index n{approx}0.98) with an amplitude proportional to (M/M{sub Planck}){sup 2}, where M{approximately}10{sup 16} GeV denotes the scale of the gauge symmetry breaking associated with inflation. The 60 or so e foldings take place when all relevant scales are close to M, which helps suppress supergravity corrections. The gravitino and baryogenesis (via leptogenesis) constraints help determine the two heaviest right-handed neutrino masses to be {approx}2{times}10{sup 13} GeV and 6{times}10{sup 9} GeV. {copyright} {ital 1997} {ital The American Physical Society}
Neutrino mass constraint from CMB, BAO and SN
Ichikawa, Kazuhide
2007-11-20
We show that the cosmic microwave background (CMB) data of WMAP can give subelectronvolt limit on the neutrino mass. We investigate how much we can make it more stringent by using 'standard ruler' measurements such as baryon acoustic oscillation (BAO) and type Ia supernovae (SN)
Constraints on the relic neutrino abundance and implications for cosmological neutrino mass limits
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.
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.
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.
Robertson, R.G.H.
1992-01-01
Despite intensive experimental work since the neutrino's existence was proposed by Pauli 60 years ago, and its first observation by Reines and Cowan almost 40 years ago, the neutrino's fundamental properties remain elusive. Among those properties are the masses of the three known flavors, properties under charge conjugation, parity and time-reversal, and static and dynamic electromagnetic moments. Mass is perhaps the most fundamental, as it constrains the other properties. The present status of the search for neutrino mass is briefly reviewed.
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.
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.
Constraints on the {tau} neutrino mass and mixing from precise measurements of {tau} decay rates
Swain, J.; Taylor, L.
1997-01-01
We have derived constraints on the {tau} neutrino mass and fourth generation mixing from an analysis of the partial widths of {tau} lepton decays, in particular, {tau}{sup {minus}}{r_arrow}e{sup {minus}}{bar {nu}}{sub e}{nu}{sub {tau}}, {tau}{sup {minus}}{r_arrow}{mu}{sup {minus}}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {tau}{r_arrow}{pi}{sup {minus}}{nu}{sub {tau}}, and {tau}{r_arrow}K{sup {minus}}{nu}{sub {tau}}. We present predictions for the {tau} decay widths, allowing for a nonzero {tau} neutrino mass m{sub {nu}{sub {tau}}} and for mixing with a neutrino of mass m{sub {nu}{sub L}}{gt}M{sub Z}/2, which is parametrized using a Cabibbo-like mixing angle {theta}{sub L}. By comparison of these theoretical predictions with the experimental measurements, we obtain the following bounds at the 90{percent} confidence level: m{sub {nu}{sub {tau}}}{lt}42 MeV and sin{sup 2}{theta}{sub L}{lt}0.014. {copyright} {ital 1997} {ital The American Physical Society}
Yamazaki, Dai G.; Ichiki, Kiyotomo; Kajino, Toshitaka; Mathews, Grant J.
2010-05-15
We have made an analysis of limits on the neutrino mass based upon the formation of large-scale structure in the presence of a primordial magnetic field. We find that a new upper bound on the neutrino mass is possible based upon fits to the cosmic microwave background and matter power spectrum when the existing independent constraints on the matter density fluctuation parameter {sigma}{sub 8} and the primordial magnetic field are taken into account.
Constraints from unrealistic vacua in the supersymmetric standard model with neutrino mass operators
Kanehata, Yoshimi; Kobayashi, Tatsuo; Konishi, Yasufumi; Shimomura, Takashi
2010-10-01
We analyze a scalar potential of the minimal supersymmetric standard model (MSSM) with neutrino mass operators along unbounded-from-below and color and/or charged breaking directions. We show necessary conditions to avoid the potential minima which can be deeper than the realistic vacuum. These conditions would constrain more strongly than conditions in the MSSM without taking into account neutrino mass operators and can improve the predictive power of supersymmetric models with neutrino mass operators.
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.
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.
Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100
NASA Astrophysics Data System (ADS)
Yèche, Christophe; Palanque-Delabrouille, Nathalie; Baur, Julien; du Mas des Bourboux, Hélion
2017-06-01
We present constraints on masses of active and sterile neutrinos in the context of the ΛCDMν and ΛWDM models, respectively. We use the one-dimensional Lyα-forest power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III) measured by Palanque-Delabrouille et al. [1], and from the VLT/XSHOOTER legacy survey (XQ-100). In this paper, we present our own measurement of the publicly released XQ-100 quasar spectra, focusing in particular on an improved determination of the spectrograph resolution that allows us to push to smaller scales than the public release and reach k-modes of 0.070 s km-1. We compare the obtained 1D Lyα flux power spectrum to the one measured by Irsic et al. [2] to k-modes of 0.057 s km-1. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from Planck 2015 Cosmic Microwave Background (CMB) data. Combining BOSS and XQ-100 Lyα power spectra, we constrain the sum of neutrino masses to ∑ mν < 0.8 eV (95% C.L.) including all identified sources of systematic uncertainties. With the addition of CMB data, this bound is tightened to ∑ mν < 0.14 eV (95% C.L.). With their sensitivity to small scales, Lyα data are ideal to constrain ΛWDM models. Using XQ-100 alone, we issue lower bounds on pure dark matter particles: mX gtrsim 2.08 : keV (95% C.L.) for early decoupled thermal relics, and ms gtrsim 10.2 : keV (95% C.L.) for non-resonantly produced right-handed neutrinos. Combining the 1D Lyα-forest power spectrum measured by BOSS and XQ-100, we improve the two bounds to mX gtrsim 4.17 : keV and ms gtrsim 25.0 : keV (95% C.L.), slightly more constraining than what was achieved in Baur et al. 2015 [3] with BOSS data alone. The 3 σ bound shows a more significant improvement, increasing from mX gtrsim 2.74 : keV for BOSS alone to mX gtrsim 3.10 : keV for the combined BOSS+XQ-100 data set. Finally, we include in our analysis the
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).
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).
Review of direct neutrino mass experiments
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.
Constraints on texture zero and cofactor zero models for neutrino mass
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.
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.
Revised WMAP constraints on neutrino masses and other extensions of the minimal {lambda}CDM model
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.
Neutrino masses and family replication
Hung, P.Q.
1999-06-01
The issue of whether or not there is any link between the smallness of the neutrino mass (if present) and the odd or even nature of the number of families is investigated. It is found that, by assuming the existence of right-handed neutrinos (which would imply that neutrinos will have a mass) and a new chiral SU(2) gauge theory, a constraint on the nature of the number of families can be obtained. In addition, a model, based on that extra SU(2), is constructed where it is plausible to have one {open_quotes}very heavy{close_quotes} fourth neutrino and three almost degenerate light neutrinos whose masses are all of the Dirac type. {copyright} {ital 1999} {ital The American Physical Society}
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.
NASA Astrophysics Data System (ADS)
Capelli, Silvia; Di Bari, Pasquale
2013-04-01
Neutrino oscillation experiments firmly established non-vanishing neutrino masses, a result that can be regarded as a strong motivation to extend the Standard Model. In spite of being the lightest massive particles, neutrinos likely represent an important bridge to new physics at very high energies and offer new opportunities to address some of the current cosmological puzzles, such as the matter-antimatter asymmetry of the Universe and Dark Matter. In this context, the determination of the absolute neutrino mass scale is a key issue within modern High Energy Physics. The talks in this parallel session well describe the current exciting experimental activity aiming to determining the absolute neutrino mass scale and offer an overview of a few models beyond the Standard Model that have been proposed in order to explain the neutrino masses giving a prediction for the absolute neutrino mass scale and solving the cosmological puzzles.
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}}].
Wolfenstein, L.
1991-12-31
Theoretical prejudices, cosmology, and neutrino oscillation experiments all suggest neutrino mass are far below present direct experimental limits. Four interesting scenarios and their implications are discussed: (1) a 17 keV {nu}{sub {tau}}, (2) a 30 ev {nu}{sub {tau}} making up the dark matter, (3) a 10{sup {minus}3} ev {nu}{sub {mu}} to solve the solar neutrino problem, and (4) a three-neutrino MSW solution.
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.
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.
Saito, Shun; Takada, Masahiro; Taruya, Atsushi
2011-02-15
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{approx_equal}0.15 hMpc{sup -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{approx_equal}0.2 hMpc{sup -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=0.1 hMpc{sup -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 (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 if including the LRG spectrum up to k=0.2 hMpc{sup -1}, due to severe parameter degeneracies, although the constraint may be biased as
Direct neutrino mass measurements
NASA Astrophysics Data System (ADS)
Thümmler, T.
2011-07-01
The determination of the neutrino rest mass plays an important role at the intersections of cosmology, particle physics and astroparticle physics. This topic is currently being addressed by two complementary approaches in laboratory experiments. Neutrinoless double beta decay experiments probe whether neutrinos are Majorana particles and determine an effective neutrino mass value. Single beta decay experiments such as KATRIN and MARE investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Owing to neutrino flavour mixing, the neutrino mass parameter appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows β-spectroscopy close to the T 2 end-point with unprecedented precision and will reach a sensitivity of 200 meV/ c 2 (90% C.L.) on the neutrino rest mass.
Neutrino mass, a status report
Robertson, R.G.H.
1993-08-01
Experimental approaches to neutrino mass include kinematic mass measurements, neutrino oscillation searches at rectors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.
Cosmological constraints on R-parity violation from neutrino decay
NASA Astrophysics Data System (ADS)
Bhattacharyya, Gautam; Rakshit, Subhendu; Raychaudhuri, Amitava
2000-11-01
If the neutrino mass is nonzero, as hinted by several experiments, then R-parity-violating supersymmetric Yukawa couplings can drive a heavy neutrino decay into lighter states. The heavy neutrino may either decay radiatively into a lighter neutrino, or it may decay into three light neutrinos through a Z-mediated penguin diagram. For a given mass of the decaying neutrino, we calculate its lifetime for the various modes, each mode requiring certain pairs of R-parity-violating couplings to be nonzero. We then check whether the calculated lifetimes fall in zones allowed or excluded by cosmological requirements. For the latter case, we derive stringent new constraints on the corresponding products of R-parity-violating couplings for given values of the decaying neutrino mass.
Revisiting the texture zero neutrino mass matrices
NASA Astrophysics Data System (ADS)
Singh, Madan; Ahuja, Gulsheen; Gupta, Manmohan
2016-12-01
In the light of refined and large measurements of the reactor mixing angle θ, we have revisited the texture three- and two-zero neutrino mass matrices in the flavor basis. For Majorana neutrinos, it has been explicitly shown that all the texture three-zero mass matrices remain ruled out. Further, for both normal and inverted mass ordering, for the texture two-zero neutrino mass matrices one finds interesting constraints on the Dirac-like CP-violating phase δ and Majorana phases ρ and σ.
Neutrino masses and solar neutrinos
Wolfenstein, L.
1992-11-01
It has been pointed out by Bahcall and Bethe and others that all solar neutrino data can be explained by MSW oscillations with m({nu}{sub {mu}}) {approximately} 10{sup {minus}3} eV consistent with ideas grand unified theories (GUTS). There is a second possibility consistent with GUTS ideas with m({nu}{sub {tau}}) {approximately} 10{sup {minus}2} eV and m({nu} {sub {mu}}) {approximately} 10 {sup {minus}4} eV. The two cases can be distinguished by a measurement of the solar neutrinos from {sup {tau}}Be.
Direct neutrino mass measurements
NASA Astrophysics Data System (ADS)
Weinheimer, Christian
2013-03-01
Direct neutrino mass experiments are complementary to searches for neutrinoless double β-decay and to analyses of cosmological data. The previous tritium beta decay experiments at Mainz and at Troitsk have achieved upper limits on the neutrino mass of about 2 eV/c2 . The KATRIN experiment under construction will improve the neutrino mass sensitivity down to 200 meV/c2 by increasing strongly the statistics and—at the same time—reducing the systematic uncertainties. Huge improvements have been made to operate the system extremely stably and at very low background rate. The latter comprises new methods to reject secondary electrons from the walls as well as to avoid and to eject electrons stored in traps. As an alternative to tritium β-decay experiments cryo-bolometers investigating the endpoint region of 187Re β-decay or the electron capture of 163Ho are being developed. This article briefly reviews the current status of the direct neutrino mass measurements.
Determining the neutrino mass hierarchy with cosmology
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.
Neutrino Oscillations and Neutrino Masses
NASA Astrophysics Data System (ADS)
Fritzsch, Harald
In 1914 James Chadwick discovered that energy and momentum were not conserved in the beta decay of atomic nuclei. For the next 16 years this phenomenon was not understood. In 1930 Wolfgang Pauli suggested in a letter to the participants of a conference in Tuebingen, that in the beta decays not only an electron was emitted, but also a neutral particle, which could not be observed. The energy and momentum of this particle would be the observed missing energy and momentum. Enrico Fermi proposed a name for this hypothetical particle: neutrino...
Measuring the neutrino mass using intense photon and neutrino beams
NASA Astrophysics Data System (ADS)
Dicus, Duane A.; Repko, Wayne W.; Vega, Roberto
2000-11-01
We compute the cross section for neutrino-photon scattering taking into account a neutrino mass. We explore the possibility of using intense neutrino beams, such as those available at proposed muon colliders, together with high powered lasers to probe the neutrino mass in photon-neutrino collisions.
Neutrino oscillation constraints on neutrinoless double-beta decay
NASA Astrophysics Data System (ADS)
Bilenky, S. M.; Giunti, C.; Kim, C. W.; Monteno, M.
1998-06-01
We have studied the constraints imposed by the results of neutrino oscillation experiments on the effective Majorana mass \\|
Observables sensitive to absolute neutrino masses. II
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.
Possible cosmogenic neutrino constraints on Planck-scale Lorentz violation
Mattingly, David M.; Maccione, Luca; Galaverni, Matteo; Liberati, Stefano; Sigl, Günter E-mail: luca.maccione@desy.de E-mail: liberati@sissa.it
2010-02-01
We study, within an effective field theory framework, O(E{sup 2}M{sub Pl}{sup 2}) Planck-scale suppressed Lorentz invariance violation (LV) effects in the neutrino sector, whose size we parameterize by a dimensionless parameter η{sub ν}. We find deviations from predictions of Lorentz invariant physics in the cosmogenic neutrino spectrum. For positive O(1) coefficients no neutrino will survive above 10{sup 19}eV. The existence of this cutoff generates a bump in the neutrino spectrum at energies of 10{sup 17}eV. Although at present no constraint can be cast, as current experiments do not have enough sensitivity to detect ultra-high-energy neutrinos, we show that experiments in construction or being planned have the potential to cast limits as strong as η{sub ν}∼<10{sup −4} on the neutrino LV parameter, depending on how LV is distributed among neutrino mass states. Constraints on η{sub ν} < 0 can in principle be obtained with this strategy, but they require a more detailed modeling of how LV affects the neutrino sector.
Combining experimental and cosmological constraints on heavy neutrinos
NASA Astrophysics Data System (ADS)
Drewes, Marco; Garbrecht, Björn
2017-08-01
We study experimental and cosmological constraints on the extension of the Standard Model by three right handed neutrinos with masses between those of the pion and W boson. We combine for the first time direct, indirect and cosmological constraints in this mass range. This includes experimental constraints from neutrino oscillation data, neutrinoless double β decay, electroweak precision data, lepton universality, searches for rare lepton decays, tests of CKM unitarity and past direct searches at colliders or fixed target experiments. On the cosmological side, big bang nucleosynthesis has the most pronounced impact. Our results can be used to evaluate the discovery potential of searches for heavy neutrinos at LHCb, BELLE II, SHiP, ATLAS, CMS or a future lepton collider.
Direct neutrino mass measurements
NASA Astrophysics Data System (ADS)
Drexlin, G.
2008-11-01
Direct neutrino mass measurements are based on high precision spectroscopy studies close to the kinematic end-point of low-energy β-emitters such as 3H and 187Re. Relying only on energy-momentum conservation in β-decay, they offer the only model-independent method to measure the absolute ν-mass scale with sub-eV sensitivity. The two most sensitive detection principles, electrostatic retarding spectrometers and microbolometers, are complementary to each other, and two experiments are currently being prepared to explore ν-masses down to m(ν) = 200 meV. β-spectroscopy will thus allow to constrain the role of neutrino hot dark matter in structure formation, as well as to explore the parameter region of ν-mass scenarios with quasi-degenerate pattern. The MARE project will investigate the β-decay of 187Re with bolometers based on metallic Re and AgReO4 in a two-staged approach: in a phase-I set-up a sensitivity of m(ν) = 2 eV is expected, forming the basis for a later sub-eV phase-II. The Karlsruhe Tritium Neutrino (KATRIN) experiment is currently being set-up on the site of Tritium Laboratory at KIT. The experiment will combine an ultra-luminous windowless gaseous tritium source with a high resolution electrostatic spectrometer and offer an unprecedented precision in β-decay studies, pushing this technique to its technological limits. First KATRIN measurements with 3H after successful system integration are expected for mid-2011. This contribution gives a status report and outlook for both experiments and discusses the impact of direct ν-mass experiments on astroparticle physics.
Hannestad, Steen
2005-11-25
At present, cosmology provides the nominally strongest constraint on the masses of standard model neutrinos. However, this constraint is extremely dependent on the nature of the dark energy component of the Universe. When the dark energy equation of state parameter is taken as a free (but constant) parameter, the neutrino mass bound is sigma m(v) < or = 1.48 eV (95% C.L.), compared with sigma m(v) < or = 0.65 eV (95% C.L.) in the standard model where the dark energy is in the form of a cosmological constant. This has important consequences for future experiments aimed at the direct measurement of neutrino masses. We also discuss prospects for future cosmological measurements of neutrino masses.
Pair Production Constraints on Superluminal Neutrinos Revisited
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.
Gauge Trimming of Neutrino Masses
Chen, Mu-Chun; de Gouvea, Andre; Dobrescu, Bogdan A.; /Fermilab
2006-12-01
We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ''right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This ''Leptocratic'' Model predicts the existence of light quasi-sterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.
Ishikawa, K.; Tobita, Y.
2008-05-21
We report (1) the current status of neutrino parameters and (2) our recent work on implications of particle's coherence, which are weakly related each others. In the first part, current status of the neutrino parameters obtained from oscillation experiments and their prospects are briefly reviewed. From various oscillation experiments, existence of three mass scales have been confirmed. One value of the difference of mass squared is around 10{sup -3}eV{sup 2} and another is around 10{sup -5}eV{sup 2}. Although mixing angles are partly found, one important angle, {theta}{sub 13} is left unknown.In the second part, implications of coherence length of particles in the scattering of ultra-high energy cosmic rays (UHCR) with cosmic background radiations (CBR) is discussed. Although coherence length is regarded usually irrelevant to observations, its role is important in several situations of recent experiments which include that of the ultra-high energy charged particles. Here we discuss the scattering of UHCR with CBR.
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.
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.
The KATRIN Neutrino Mass Experiment
NASA Astrophysics Data System (ADS)
Parno, Diana; Katrin Collaboration
2017-01-01
While neutrino oscillation experiments have demonstrated that the particles have non-zero mass, the absolute neutrino mass scale is still unknown. The Karlsruhe Tritium Neutrino experiment (KATRIN) is designed to improve on previous laboratory limits by an order of magnitude, probing the effective neutrino mass with a sensitivity approaching 0.2 eV at 90% confidence via the kinematics of tritium beta decay. At the same time, KATRIN has the potential to scan for sterile neutrinos at eV and keV scales. After years of preparation, all major components are now on site and commissioning is underway. I will report on the current status of the experiment, including recent results and preparations for the introduction of tritium later this year. US participation in KATRIN is supported by the U.S. Department of Energy Office of Science, Office of Nuclear Physics under Award Number DE-FG02-97ER41020.
Experimental constraints on the neutrino oscillations and a simple model of three-flavor mixing
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.
Cosmological Neutrino Mass Detection: The Best Probe of Neutrino Lifetime
Serpico, Pasquale D.
2007-04-27
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 < or approx. 0.1 eV between cosmic neutrino bounds and lab data.
Cosmological neutrino mass detection: The Best probe of neutrino lifetime
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.
Neutrino mass models and CP violation
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.
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.
NASA Astrophysics Data System (ADS)
Feix, Martin; Zhao, Hongsheng; Fedeli, Cosimo; Pestaña, José Luis Garrido; Hoekstra, Henk
2010-12-01
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.
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.
Cosmological constraints on neutrinos with Planck data
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.
Cosmological constraints on a light nonthermal sterile neutrino
Acero, Mario A.
2009-02-15
Although the MiniBooNE experiment has severely restricted the possible existence of light sterile neutrinos, a few anomalies persist in oscillation data, and the possibility of extra light species contributing as a subdominant hot (or warm) component is still interesting. In many models, this species would be in thermal equilibrium in the early universe and share the same temperature as active neutrinos, but this is not necessarily the case. In this work, we fit up-to-date cosmological data with an extended {lambda}CDM model, including light relics with a mass typically in the range 0.1-10 eV. We provide, first, some nearly model-independent constraints on their current density and velocity dispersion, and second, some constraints on their mass, assuming that they consist either in early decoupled thermal relics, or in nonresonantly produced sterile neutrinos. Our results can be used for constraining most particle-physics-motivated models with three active neutrinos and one extra light species. For instance, we find that at the 3{sigma} confidence level, a sterile neutrino with mass m{sub s}=2 eV can be accommodated with the data provided that it is thermally distributed with T{sub s}/T{sub {nu}}{sup id} < or approx. 0.8 or nonresonantly produced with {delta}N{sub eff} < or approx. 0.5. The bounds become dramatically tighter when the mass increases. For m{sub s} < or approx. 0.9 eV and at the same confidence level, the data is still compatible with a standard thermalized neutrino.
Searching for radiative neutrino mass generation at the LHC
NASA Astrophysics Data System (ADS)
Volkas, Raymond R.
2015-04-01
In this talk (talk given at the International Conference on Massive Neutrinos, Singapore, 9-13 February 2015), I describe the general characteristics of radiative neutrino mass models that can be probed at the LHC. I then cover the specific constraints on a new, explicit model of this type.
Neutrino masses and scalar singlet dark matter
NASA Astrophysics Data System (ADS)
Bhattacharya, Subhaditya; Jana, Sudip; Nandi, S.
2017-03-01
We propose a simple extension of the Standard Model (SM) which has a viable dark matter (DM) candidate and can explain the generation of tiny neutrino masses. The DM is an electroweak (EW) singlet scalar S , odd under an imposed exact Z2 symmetry, that interacts with the SM through the "Higgs portal" coupling, while all other particles are even under Z2. The model also has an EW isospin 3 /2 scalar Δ and a pair of EW isospin vectors Σ and Σ ¯, which are responsible for generating tiny neutrino mass via the effective dimension-seven operator. Thanks to the additional interactions with Δ , the scalar singlet DM S survives a large region of parameter space by relic density constraints from WMAP/Planck and direct search bounds from updated LUX data. Constraints on the model from the LHC are also discussed.
Improvement of cosmological neutrino mass bounds
NASA Astrophysics Data System (ADS)
Giusarma, Elena; Gerbino, Martina; Mena, Olga; Vagnozzi, Sunny; Ho, Shirley; Freese, Katherine
2016-10-01
The most recent measurements of the temperature and low-multipole polarization anisotropies of the cosmic microwave background from the Planck satellite, when combined with galaxy clustering data from the Baryon Oscillation Spectroscopic Survey in the form of the full shape of the power spectrum, and with baryon acoustic oscillation measurements, provide a 95% confidence level (C.L.) upper bound on the sum of the three active neutrinos ∑mν<0.183 eV , among the tightest neutrino mass bounds in the literature, to date, when the same data sets are taken into account. This very same data combination is able to set, at ˜70 % C.L., an upper limit on ∑mν of 0.0968 eV, a value that approximately corresponds to the minimal mass expected in the inverted neutrino mass hierarchy scenario. If high-multipole polarization data from Planck is also considered, the 95% C.L. upper bound is tightened to ∑mν<0.176 eV . Further improvements are obtained by considering recent measurements of the Hubble parameter. These limits are obtained assuming a specific nondegenerate neutrino mass spectrum; they slightly worsen when considering other degenerate neutrino mass schemes. Low-redshift quantities, such as the Hubble constant or the reionization optical depth, play a very important role when setting the neutrino mass constraints. We also comment on the eventual shifts in the cosmological bounds on ∑mν when possible variations in the former two quantities are addressed.
Decaying majoron dark matter and neutrino masses
Lattanzi, Massimiliano
2008-01-03
We review our recent proposal of the majoron as a suitable warm dark matter candidate. The majoron is the Goldstone boson associated to the spontaneous breaking of ungauged lepton number, one of the mechanisms proposed to give rise to neutrino masses. The majoron can acquire a mass through quantum gravity effects, and can possibly account for the observed dark matter component of the Universe. We present constraints on the majoron lifetime, mass and abundance obtained by the analysis of the cosmic microwave background data. We find that, in the case of thermal production, the limits for the majoron mass read 0.12 keV
Neutrino mass from triton decay
NASA Astrophysics Data System (ADS)
Weinheimer, Christian
2006-07-01
Since the discovery of neutrino flavor oscillation in different fields and by many different experiments we believe that neutrinos have non-vanishing masses in contrast to their current description within the Standard Model of particle physics. However, the absolute values of the neutrino masses, which are as important for particle physics as they are for cosmology and astrophysics, cannot be determined by oscillation experiments alone. There are a few ways to determine the neutrino mass scale, but the only model-independent method is the investigation of the electron energy spectrum of a β decay near its endpoint with tritium being the ideal isotope for the classical spectrometer set-up. The tritium β decay experiments at Mainz and Troitsk have recently been finished. At Mainz all relevant systematic uncertainties have been investigated by dedicated experiments yielding an upper limit of m(ν)<2.3eV/c (90% C.L.). The new Karlsruhe Tritium Neutrino Experiment (KATRIN) will enhance the sensitivity on the neutrino mass by an ultra-precise measurement of the tritium β decay spectrum near the endpoint by another order of magnitude down to 0.2 eV/c2 by using a very strong windowless gaseous molecular tritium source and a huge ultra-high resolution electrostatic spectrometer of MAC-E-Filter type. The recent achievements in test experiments show, that this very challenging experiment is feasible.
Direct measurements of neutrino mass
Robertson, R.G.H.
1991-01-01
Some recent developments in the experimental search for neutrino mass are discussed. New data from Los Alamos on the electron neutrino mass as measured in tritium beta decay give an upper limit of 9.3 eV at the 95% confidence level. This result is not consistent with the long-standing ITEP result of 26(5) eV within a model-independent'' range of 17 to 40 eV. It now appears that the electron neutrino is not sufficiently massive to close the universe by itself. Hime and Jelley report finding new evidence for a 17-keV neutrino in the {Beta} decay of {sup 35}S and {sup 63}Ni. Many other experiments are being reported and the situation is still unresolved. 56 refs., 1 fig., 3 tabs.
Status of neutrino mass experiments
Fackler, O.
1985-12-01
In 1980 two experiments ignited a fertile field of research the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily I will discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. However, let me begin in Section I to discuss astronomical and terrestrial observations which motivated these experiments. In Section II, I will quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other papers. I will continue by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations will be reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks. 24 refs., 24 figs.
Constraints on secret neutrino interactions after Planck
Forastieri, Francesco; Lattanzi, Massimiliano; Natoli, Paolo E-mail: lattanzi@fe.infn.it
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 T≅ 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 γ{sub νν}{sup 4}, 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 γ{sub νν}{sup 4} ∼< 0.9× 10{sup −27} (95% C.L.), implying an upper limit on the redshift z{sub νrec} of neutrino recoupling 0∼< 850, leaving open the possibility that the latter occured well before hydrogen recombination. In the framework of Majoron models, the upper limit on γ{sub νν} roughly translates on a constraint g ∼< 8.2× 10{sup −7} on the Majoron-neutrino coupling constant g. In general, the data show a weak (∼ 1σ) but intriguing preference for non-zero values of γ{sub νν}{sup 4}, with best fits in the range γ{sub νν}{sup 4} = (0.15–0.35)× 10{sup −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+γ{sub νν} and including the Planck 2013, ACT and
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 .
Constraints and tests of the OPERA superluminal neutrinos.
Bi, Xiao-Jun; Yin, Peng-Fei; Yu, Zhao-Huan; Yuan, Qiang
2011-12-09
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.
Supernova constraints on neutrino oscillation and EoS for proto-neutron star
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.
Model of neutrino effective masses
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.
Supernova constraints on massive (pseudo)scalar coupling to neutrinos
NASA Astrophysics Data System (ADS)
Heurtier, Lucien; Zhang, Yongchao
2017-02-01
In this paper we derive constraints on the emission of a massive (pseudo)scalar S from annihilation of neutrinos in the core of supernovae through the dimension-4 coupling νν S, as well as the effective dimension-5 operator 1/Λ(νν)(SS). While most of earlier studies have focused on massless or ultralight scalars, our analysis involves scalar with masses of order eV–GeV which can be copiously produced during {the explosion of supernovae, whose core temperature is} generally of order T~ Script OO(10) MeV. From the luminosity and deleptonization arguments regarding the observation of SN1987A, we exclude a large range of couplings 10‑12 lesssim |gαβ|lesssim 10‑5 for the dimension-4 case, depending on the neutrino flavours involved and the scalar mass. In the case of dimension-5 operator, for a scalar mass from MeV to 100 MeV the coupling hαβ get constrained from 10‑6 to 10‑2, with the cutoff scale explicitly set Λ = 1 TeV. We finally show that if the neutrino burst of a nearby supernova explosion is detected by Super-Kamiokande and IceCube, the constraints will be largely reinforced.
Big bang nucleosynthesis constraints on massive, unstable neutrinos.
NASA Astrophysics Data System (ADS)
Steigman, G.
1995-01-01
The tau-neutrino, if sufficiently massive, must be unstable. Big bang nucleosynthesis (BBN) can provide constraints on the ντ mass and lifetime. The modification to the energy density of the early universe in the case of a massive τ-neutrino which decays via ντ→νμ+φ (where φ is a weakly coupled massless scalar) is described and the results of BBN production of the light elements is presented. Consistency with the primordial abundances of D, 3He, 7Li and, especially, 4He leads to constraints on the mass (mντ) and lifetime (τντ) of the tau-neutrino. Very massive ντ (mντ ≥ 5 - 10 MeV), up to the ARGUS bound of 31 MeV, are only allowed for short lifetimes (≤40 sec). Much lighter (mντ ≤ 0.01 MeV) ντ are permitted for lifetimes longer than ≡0.01 sec but, mντ(MeV) ≤ 10 τν(sec) for shorter lifetimes.
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.
Predictive models of radiative neutrino masses
Julio, J.
2016-06-21
We discuss two models of radiative neutrino mass generation. The first model features one–loop Zee model with Z{sub 4} 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.
Neutrino masses, mixing, moments, and matter
Marciano, W.J.
1988-01-01
The present status of neutrino masses, mixing, and electromagnetic moments is surveyed. Potential enhancements of neutrino oscillations, decay, and spin-flavor precession due to their interactions with matter are described.
Neutrino mass from M theory SO(10)
NASA Astrophysics Data System (ADS)
Acharya, Bobby S.; Bożek, Krzysztof; Romão, Miguel Crispim; King, Stephen F.; Pongkitivanichkul, Chakrit
2016-11-01
We study the origin of neutrino mass from SO(10) arising from M Theory compactified on a G 2-manifold. This is linked to the problem of the breaking of the extra U(1) gauge group, in the SU(5) × U(1) subgroup of SO(10), which we show can achieved via a (generalised) Kolda-Martin mechanism. The resulting neutrino masses arise from a combination of the seesaw mechanism and induced R-parity breaking contributions. The rather complicated neutrino mass matrix is analysed for one neutrino family and it is shown how phenomenologically acceptable neutrino masses can emerge.
NASA Astrophysics Data System (ADS)
Lu, Jianbo; Liu, Molin; Wu, Yabo; Wang, Yan; Yang, Weiqiang
2016-12-01
Tensions between several cosmic observations were found recently, such as the inconsistent values of H0 (or σ 8) were indicated by the different cosmic observations. Introducing the massive neutrinos in Λ CDM could potentially solve the tensions. Viable f( R) gravity producing Λ CDM background expansion with massive neutrinos is investigated in this paper. We fit the current observational data: Planck-2015 CMB, RSD, BAO, and SNIa to constrain the mass of neutrinos in viable f( R) theory. The constraint results at 95% confidence level are: Σ m_ν <0.202 eV for the active-neutrino case, m_{ν , sterile}^eff<0.757 eV with N_eff<3.22 for the sterile neutrino case. For the effects due to the mass of the neutrinos, the constraint results on model parameter at 95% confidence level become f_{R0}× 10^{-6}> -1.89 and f_{R0}× 10^{-6}> -2.02 for two cases, respectively. It is also shown that the fitting values of several parameters much depend on the neutrino properties, such as the cold dark matter density, the cosmological quantities at matter-radiation equality, the neutrino density and the fraction of baryonic mass in helium. Finally, the constraint result shows that the tension between direct and CMB measurements of H_0 gets slightly weaker in the viable f( R) model than that in the base Λ CDM model.
Neutrino constraints on inelastic dark matter after CDMS II results
NASA Astrophysics Data System (ADS)
Shu, Jing; Yin, Peng-Fei; Zhu, Shou-Hua
2010-06-01
We discuss the neutrino constraints from solar and terrestrial dark matter (DM) annihilations in the inelastic dark matter (iDM) scenario after the recent CDMS II results. To reconcile the DAMA/LIBRA data with constraints from all other direct experiments, the iDM needs to be light (mχ<100GeV) and have a large DM-nucleon cross section (σn˜10-4pb in the spin-independent (SI) scattering and σn˜10pb in the spin-dependent (SD) scattering). The dominant contribution to the iDM capture in the Sun is from scattering off Fe/Al in the SI/SD case. Current bounds from Super-Kamiokande exclude the hard DM annihilation channels, such as W+W-, ZZ, tt¯, and τ+τ-. For soft channels such as bb¯ and cc¯, the limits are loose, but could be tested or further constrained by future IceCube plus DeepCore. For neutrino constraints from the DM annihilation in the Earth, due to the weaker gravitational effect of the Earth and inelastic capture condition, the constraint exists only for small mass splitting δ<40keV and mχ˜(10,50)GeV even in the τ+τ- channel.
Neutrino constraints on inelastic dark matter after CDMS II results
Shu Jing; Yin Pengfei; Zhu Shouhua
2010-06-15
We discuss the neutrino constraints from solar and terrestrial dark matter (DM) annihilations in the inelastic dark matter (iDM) scenario after the recent CDMS II results. To reconcile the DAMA/LIBRA data with constraints from all other direct experiments, the iDM needs to be light (m{sub {chi}}<100 GeV) and have a large DM-nucleon cross section ({sigma}{sub n{approx}}10{sup -4} pb in the spin-independent (SI) scattering and {sigma}{sub n{approx}}10 pb in the spin-dependent (SD) scattering). The dominant contribution to the iDM capture in the Sun is from scattering off Fe/Al in the SI/SD case. Current bounds from Super-Kamiokande exclude the hard DM annihilation channels, such as W{sup +}W{sup -}, ZZ, tt, and {tau}{sup +{tau}-}. For soft channels such as bb and cc, the limits are loose, but could be tested or further constrained by future IceCube plus DeepCore. For neutrino constraints from the DM annihilation in the Earth, due to the weaker gravitational effect of the Earth and inelastic capture condition, the constraint exists only for small mass splitting {delta}<40 keV and m{sub {chi}}{approx}(10,50) GeV even in the {tau}{sup +{tau}-} channel.
A combined view of sterile-neutrino constraints from CMB and neutrino oscillation measurements
NASA Astrophysics Data System (ADS)
Bridle, Sarah; Elvin-Poole, Jack; Evans, Justin; Fernandez, Susana; Guzowski, Pawel; Söldner-Rembold, Stefan
2017-01-01
We perform a comparative analysis of constraints on sterile neutrinos from the Planck experiment and from current and future neutrino oscillation experiments (MINOS, IceCube, SBN). For the first time, we express joint constraints on Neff and meffsterile from the CMB in the Δm2, sin2 2 θ parameter space used by oscillation experiments. We also show constraints from oscillation experiments in the Neff, meffsterile cosmology parameter space. In a model with a single sterile neutrino species and using standard assumptions, we find that the Planck 2015 data and the oscillation experiments measuring muon-neutrino (νμ) disappearance have similar sensitivity.
Radiative neutrino mass model with degenerate right-handed neutrinos
NASA Astrophysics Data System (ADS)
Kashiwase, Shoichi; Suematsu, Daijiro
2016-03-01
The radiative neutrino mass model can relate neutrino masses and dark matter at a TeV scale. If we apply this model to thermal leptogenesis, we need to consider resonant leptogenesis at that scale. It requires both finely degenerate masses for the right-handed neutrinos and a tiny neutrino Yukawa coupling. We propose an extension of the model with a U(1) gauge symmetry, in which these conditions are shown to be simultaneously realized through a TeV scale symmetry breaking. Moreover, this extension can bring about a small quartic scalar coupling between the Higgs doublet scalar and an inert doublet scalar which characterizes the radiative neutrino mass generation. It also is the origin of the Z_2 symmetry which guarantees the stability of dark matter. Several assumptions which are independently supposed in the original model are closely connected through this extension.
Renormalization of a two-loop neutrino mass model
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.
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.
Observational constraints on cosmic neutrinos and dark energy revisited
Wang, Xin; Meng, Xiao-Lei; Zhang, Tong-Jie; Shan, HuanYuan; Tao, Charling; Gong, Yan; Chen, Xuelei; Huang, Y.F. E-mail: mlwx@mail.bnu.edu.cn E-mail: shanhuany@gmail.com E-mail: tao@cppm.in2p3.fr E-mail: hyf@nju.edu.cn
2012-11-01
Using several cosmological observations, i.e. the cosmic microwave background anisotropies (WMAP), the weak gravitational lensing (CFHTLS), the measurements of baryon acoustic oscillations (SDSS+WiggleZ), the most recent observational Hubble parameter data, the Union2.1 compilation of type Ia supernovae, and the HST prior, we impose constraints on the sum of neutrino masses (m{sub ν}), the effective number of neutrino species (N{sub eff}) and dark energy equation of state (w), individually and collectively. We find that a tight upper limit on m{sub ν} can be extracted from the full data combination, if N{sub eff} and w are fixed. However this upper bound is severely weakened if N{sub eff} and w are allowed to vary. This result naturally raises questions on the robustness of previous strict upper bounds on m{sub ν}, ever reported in the literature. The best-fit values from our most generalized constraint read m{sub ν} = 0.556{sup +0.231}{sub −0.288} eV, N{sub eff} = 3.839±0.452, and w = −1.058±0.088 at 68% confidence level, which shows a firm lower limit on total neutrino mass, favors an extra light degree of freedom, and supports the cosmological constant model. The current weak lensing data are already helpful in constraining cosmological model parameters for fixed w. The dataset of Hubble parameter gains numerous advantages over supernovae when w = −1, particularly its illuminating power in constraining N{sub eff}. As long as w is included as a free parameter, it is still the standardizable candles of type Ia supernovae that play the most dominant role in the parameter constraints.
NASA Astrophysics Data System (ADS)
Schönert, S.; Oberauer, L.; Hagner, C.; Feilitzsch, F. v.; Schreckenbach, K.; Declais, Y.; Mayerhofer, U.
1996-05-01
From cosmological constraints, the requirement for stable neutrinos is to have masses less than 30 eV. In the case that neutrino masses exceed this bound, neutrinos must decay sufficiently fast in order to satisfy the presently observed energy density of the universe. The experiments presented in this contribution consist of the complementary search for heavy neutrino admixture in nuclear beta decay of 177Lu and of the search for a radiative neutrino decay mode at the nuclear power station in Bugey, France. The data obtained from the 177Lu beta decay restrict the mixing probability of a heavy neutrino to the electron | U eh| 2 < 0.2 - 0.3% (90% Cl) for neutrino masses between 10 and 95 keV. The radiative lifetime is constrained to exceed t/ m > 180 × | U eh| 2 sec/eV which is one order of magnitude more restrictive than previous laboratory limits.
Neutrino masses from a pseudo-Dirac bino
Coloma, Pilar; Ipek, Seyda
2016-09-09
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 “bi νo.” An inverse seesaw texture is generated for the neutrino-biνo sector, and the lightest neutrino is predicted to be massless. Lastly, unlike in most models with heavy right-handed neutrinos, the bi νo 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.
Neutrino masses from a pseudo-Dirac bino
Coloma, Pilar; Ipek, Seyda
2016-09-09
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 “bi νo.” An inverse seesaw texture is generated for the neutrino-biνo sector, and the lightest neutrino is predicted to be massless. Lastly, unlike in most models with heavy right-handed neutrinos, the bi νo 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.
Neutrino masses from a pseudo-Dirac bino
Coloma, Pilar; Ipek, Seyda
2016-09-09
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 “bi νo.” An inverse seesaw texture is generated for the neutrino-biνo sector, and the lightest neutrino is predicted to be massless. Lastly, unlike in most models with heavy right-handed neutrinos, the bi νo can be sizably produced at the LHC through its interactions with colored particles, while respecting low energy constraints frommore » neutrinoless double-beta decay and charged lepton flavor violation.« less
Neutrino Masses from a Pseudo-Dirac Bino
NASA Astrophysics Data System (ADS)
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 "bi ν o ." An inverse seesaw texture is generated for the neutrino-bi ν o sector, and the lightest neutrino is predicted to be massless. Unlike in most models with heavy right-handed neutrinos, the bi ν o 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.
Neutrino Masses from a Pseudo-Dirac Bino.
Coloma, Pilar; Ipek, Seyda
2016-09-09
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.
Neutrino mass and mixing: Summary of the neutrino sessions
Bowles, T.J.
1993-01-01
A great deal of experimental and theoretical effort is underway to use neutrinos as a probe for Physics Beyond the Standard Model. Most of these efforts center on the questions of the possible existence of non zero neutrino mass and mixing. Sessions at the Moriond conferences have dealt with these questions at most of the meetings during the last several years and this year was no exception. Presentations covering most of the current and planned research in this field were presented and discussed. Although there is, at present, no definitive evidence for a non zero neutrino mass and mixing, several unresolved problems (in particular solar neutrinos) do seem to be indicating the likely existence of new neutrino properties. It is likely that before the end of this decade, efforts now being initiated will be able to determine whether or not the hints we are now seeing are really due to new physics.
Neutrino oscillations from Dirac and Majorana masses
Ring, D.
1997-05-01
We present a scenario of neutrino masses and mixing angles. Each generation includes a sterile right-handed neutrino in addition to the usual left-handed one. We assume a hierarchy in their Dirac masses similar to, but much larger than, the hierarchies in the quarks and charged leptons. In addition, we include a Majorana mass term for the sterile neutrinos only. These assumptions prove sufficient to accommodate scales of mass differences and mixing angles consistent with all existing neutrino oscillation data. {copyright} {ital 1997} {ital The American Physical Society}
Probing the Absolute Mass Scale of Neutrinos
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.
Experimental Constraints on Neutrino Spectra Following Fission
NASA Astrophysics Data System (ADS)
Napolitano, Jim; Daya Bay Collaboration
2016-09-01
We discuss new initiatives to constrain predictions of fission neutrino spectra from nuclear reactors. These predictions are germane to the understanding of reactor flux anomalies; are needed to reduce systematic uncertainty in neutrino oscillation spectra; and inform searches for the diffuse supernova neutrino background. The initiatives include a search for very high- Q beta decay components to the neutrino spectrum from the Daya Bay power plant; plans for a measurement of the β- spectrum from 252Cf fission products; and precision measurements of the 235U fission neutrino spectrum from PROSPECT and other very short baseline reactor experiments.
Neutrino mass and dark energy from weak lensing.
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.
The modified correlation mass method for detecting neutrino mass from astrophysical neutrino bursts
NASA Technical Reports Server (NTRS)
Chan, Kwing L.; Chiu, Hong-Yee; Kondo, Yoji
1989-01-01
A modified correlation mass method for calculating the value of a possible neutrino mass from neutrino bursts of astrophysical origin is proposed which can more sensitively detect small neutrino masses than previous methods. Application of the method to the neutrinos detected from SN 1987 A yields a value of 3.6 + or - 0.3 eV for the neutrino mass energy with a confidence level of 97 percent. Assuming a neutrino mass of 3.6 eV, and transforming all of the detected neutrino events back to the point of emission, it is shown that bursts are composed of a short initial pulse (which lasts for about 0.1 sec and contains 30-40 percent of the total neutrinos) and an extended emission lasting for about 10 sec.
Predictivity of neutrino mass sum rules
NASA Astrophysics Data System (ADS)
Gehrlein, Julia; Merle, Alexander; Spinrath, Martin
2016-11-01
Correlations between light neutrino observables are arguably the strongest predictions of lepton flavor models based on (discrete) symmetries, except for the very few cases which unambiguously predict the full set of leptonic mixing angles. A subclass of these correlations is neutrino mass sum rules, which connect the three (complex) light neutrino mass eigenvalues among each other. This connection constrains both the light neutrino mass scale and the Majorana phases, so that mass sum rules generically lead to a nonzero value of the lightest neutrino mass and to distinct predictions for the effective mass probed in neutrinoless double beta decay. However, in nearly all cases known, the neutrino mass sum rules are not exact and receive corrections from various sources. We introduce a formalism to handle these corrections perturbatively in a model-independent manner, which overcomes issues present in earlier approaches. Our ansatz allows us to quantify the modification of the predictions derived from neutrino mass sum rules. We show that, in most cases, the predictions are fairly stable: while small quantitative changes can appear, they are generally rather mild. We therefore establish the predictivity of neutrino mass sum rules on a level far more general than previously known.
Higgs mass from neutrino-messenger mixing
NASA Astrophysics Data System (ADS)
Byakti, Pritibhajan; Khosa, Charanjit K.; Mummidi, V. S.; Vempati, Sudhir K.
2017-03-01
The discovery of the Higgs particle at 125 GeV has put strong constraints on minimal messenger models of gauge mediation, pushing the stop masses into the multi-TeV regime. Extensions of these models with matter-messenger mixing terms have been proposed to generate a large trilinear parameter, A t , relaxing these constraints. The detailed survey of these models [1, 2] so far considered messenger mixings with only MSSM superfields. In the present work, we extend the survey to MSSM with inverse-seesaw mechanism. The neutrino-sneutrino corrections to the Higgs mass in the inverse seesaw model are not significant in the minimal gauge mediation model, unless one considers messenger-matter interaction terms. We classify all possible models with messenger-matter interactions and perform thorough numerical analysis to find out the promising models. We found that out of the 17 possible models 9 of them can lead to Higgs mass within the observed value without raising the sfermion masses significantly. The successful models have stop masses ˜1.5 TeV with small or negligible mixing and yet a light CP even Higgs at 125 GeV.
Radiative neutrino mass, dark matter, and leptogenesis
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.
The experimental status of neutrino masses and mixings
Robertson, R.G.H.
1992-01-01
We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.
Neutrino mass and mixing, and non-accelerator experiments
Robertson, R.G.H.
1992-01-01
We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.
The Higgs seesaw induced neutrino masses and dark matter
Cai, Yi; Chao, Wei
2015-08-12
In this study we propose a possible explanation of the active neutrino Majorana masses with the TeV scale new physics which also provide a dark matter candidate. We extend the Standard Model (SM) with a local U(1)' symmetry and introduce a seesaw relation for the vacuum expectation values (VEVs) of the exotic scalar singlets, which break the U(1)' spontaneously. The larger VEV is responsible for generating the Dirac mass term of the heavy neutrinos, while the smaller for the Majorana mass term. As a result active neutrino masses are generated via the modified inverse seesaw mechanism. The lightest of themore » new fermion singlets, which are introduced to cancel the U(1)' anomalies, can be a stable particle with ultra flavor symmetry and thus a plausible dark matter candidate. We explore the parameter space with constraints from the dark matter relic abundance and dark matter direct detection.« less
PINGU sensitivity to neutrino mass hierarchy
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.
The KATRIN neutrino mass experiment
NASA Astrophysics Data System (ADS)
Wolf, Joachim; Katrin Collaboration
2010-11-01
The Karlsruhe Tritium Neutrino experiment (KATRIN) aims to determine the electron neutrino mass from tritium decay in a model-independent way, by a kinematic measurement of the energy of β-electrons. The unprecedented sensitivity of 0.2 eV/c2 will improve present limits by one order of magnitude. The decay electrons will originate from a 10 m long windowless gaseous tritium source. Super-conducting magnets will guide the electrons through a differential and cryogenic pumping section to the electro-static tandem spectrometer (MAG-E-filter), where the kinetic energy will be measured. The experiment is presently being built at the Forschungszentrum Karlsruhe by an international collaboration of more than 120 scientists. The largest component, the 1240 m3 main spectrometer, was delivered end of 2006 and first commissioning tests have been performed. This paper gives an overview of the goals and technological challenges of the experiment and reports on the progress in commissioning first major components. The start of first measurements is expected in 2012.
Decaying warm dark matter and neutrino masses.
Lattanzi, M; Valle, J W F
2007-09-21
Neutrino masses may arise from spontaneous breaking of ungauged lepton number. Because of quantum gravity effects the associated Goldstone boson - the majoron - will pick up a mass. We determine the lifetime and mass required by cosmic microwave background observations so that the massive majoron provides the observed dark matter of the Universe. The majoron decaying dark matter scenario fits nicely in models where neutrino masses arise via the seesaw mechanism, and may lead to other possible cosmological implications.
Decaying Warm Dark Matter and Neutrino Masses
Lattanzi, M.; Valle, J. W. F.
2007-09-21
Neutrino masses may arise from spontaneous breaking of ungauged lepton number. Because of quantum gravity effects the associated Goldstone boson--the majoron--will pick up a mass. We determine the lifetime and mass required by cosmic microwave background observations so that the massive majoron provides the observed dark matter of the Universe. The majoron decaying dark matter scenario fits nicely in models where neutrino masses arise via the seesaw mechanism, and may lead to other possible cosmological implications.
Constraining bilinear R-parity violation from neutrino masses
NASA Astrophysics Data System (ADS)
Góźdź, Marek; Kamiński, Wiesław 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.
Neutrino masses, leptogenesis, and sterile neutrino dark matter
NASA Astrophysics Data System (ADS)
Tsuyuki, Takanao
2014-07-01
We analyze a scenario in which the lightest heavy neutrino N1 is a dark matter candidate and the second-heaviest neutrino N2 decays producing a lepton number. If N1 were in thermal equilibrium, its energy density today would be much larger than that of the observed dark matter, so we consider energy injection by the decay of N2. In this paper, we show the parameters of this scenario that give the correct abundances of dark matter and baryonic matter and also induce the observed neutrino masses. This model can explain a possible sterile neutrino dark matter signal of M1=7 keV in the x-ray observation of x-ray multi-mirror mission.
Hiding neutrino mass in modified gravity cosmologies
NASA Astrophysics Data System (ADS)
Bellomo, Nicola; Bellini, Emilio; Hu, Bin; Jimenez, Raul; Pena-Garay, Carlos; Verde, Licia
2017-02-01
Cosmological observables show a dependence with the neutrino mass, which is partially degenerate with parameters of extended models of gravity. We study and explore this degeneracy in Horndeski generalized scalar-tensor theories of gravity. Using forecasted cosmic microwave background and galaxy power spectrum datasets, we find that a single parameter in the linear regime of the effective theory dominates the correlation with the total neutrino mass. For any given mass, a particular value of this parameter approximately cancels the power suppression due to the neutrino mass at a given redshift. The extent of the cancellation of this degeneracy depends on the cosmological large-scale structure data used at different redshifts. We constrain the parameters and functions of the effective gravity theory and determine the influence of gravity on the determination of the neutrino mass from present and future surveys.
Neutrino mass hierarchy and octant determination with atmospheric neutrinos.
Barger, Vernon; Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Marfatia, Danny; Prakash, Suprabh; Raut, Sushant K; Sankar, S Uma
2012-08-31
The recent discovery by the Daya-Bay and RENO experiments, that θ(13) is nonzero and relatively large, significantly impacts existing experiments and the planning of future facilities. In many scenarios, the nonzero value of θ(13) implies that θ(23) is likely to be different from π/4. Additionally, large detectors will be sensitive to matter effects on the oscillations of atmospheric neutrinos, making it possible to determine the neutrino mass hierarchy and the octant of θ(23). We show that a 50 kT magnetized liquid argon neutrino detector can ascertain the mass hierarchy with a significance larger than 4σ with moderate exposure times, and the octant at the level of 2-3σ with greater exposure.
Neff versus the lightest neutrino mass
NASA Astrophysics Data System (ADS)
Kekic, Marija
2016-04-01
Within the framework of low-scale Type I seesaw models with two and three extra sterile neutrinos we evaluate the production of the sterile states in the Early Universe. We explore the full parameter space and find that in the model with two extra states both of them reach thermal equilibrium with the primordial plasma. In the model with three sterile neutrinos, if the lightest active neutrino mass is below O (10-3eV) one sterile neutrino might not thermalize, while the other two always reach thermalization. Applying constrains from both extra radiation at BBN and CMB, and the dark matter allowed abundance, we show that the spectra of heavier states are severely restricted in the mass range 1eV-100MeV. The possible impact of extra sterile neutrinos on neutrinoless double beta decay is also discussed.
Late Time Neutrino Masses, the LSND Experiment and the Cosmic Microwave Background
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.
Impacts of dark energy on weighing neutrinos: Mass hierarchies considered
NASA Astrophysics Data System (ADS)
Wang, Sai; Wang, Yi-Fan; Xia, Dong-Mei; Zhang, Xin
2016-10-01
Taking into account the mass splittings between three active neutrinos, we investigate the impacts of dark energy on constraining the total neutrino mass ∑mν by using recent cosmological observations. We consider two typical dark energy models, namely, the w CDM model and the holographic dark energy (HDE) model, which both have an additional free parameter compared with the Λ CDM model. We employ the Planck 2015 data of CMB temperature and polarization anisotropies, combined with low-redshift measurements on BAO distance scales, type Ia supernovae, the Hubble constant, and Planck lensing. Compared to the Λ CDM model, our study shows that the upper limit on ∑mν becomes much looser in the w CDM model but much tighter in the HDE model. In the HDE model, we obtain the 95% confidence level upper limit ∑mν<0.105 eV for three degenerate neutrinos. This might be the most stringent constraint on ∑mν by far, and it is on the verge of diagnosing the neutrino mass hierarchies in the HDE model. However, the difference of χ2 is still not significant enough to distinguish the neutrino mass hierarchies, even though the minimal χ2 of the normal hierarchy is slightly smaller than that of the inverted hierarchy.
Lepton mass hierarchy and neutrino oscillations
NASA Astrophysics Data System (ADS)
Fritzsch, Harald; Zhi-Zhong, Xing
1996-02-01
Starting from the symmetry of lepton flavor democracy, we propose and discuss a simple pattern for the mass generation and flavor mixing of the charged leptons and neutrinos. The three neutrino masses are nearly degenerate, and the flavor mixing angles can be calculated. The observed deficit of solar and atmospheric neutrinos can be interpreted as a consequence of the near degeneracy and large oscillations of νe, νμ and ντ in the vacuum. Our ansatz can also accommodate the cosmological requirement for hot dark matter and the current data on neutrinoless ββ-decay.
First Constraints on the Complete Neutrino Mixing Matrix with a Sterile Neutrino.
Collin, G H; Argüelles, C A; Conrad, J M; Shaevitz, M H
2016-11-25
Neutrino oscillation models involving one extra mass eigenstate beyond the standard three (3+1) are fit to global short baseline experimental data and the recent IceCube ν_{μ}+ν[over ¯]_{μ} disappearance search result. We find a best fit of Δm_{41}^{2}=1.75 eV^{2} with Δχ_{null-min}^{2}/d.o.f. of 50.61/4. We find that the combined IceCube and short baseline data constrain θ_{34} to <80°(<6°) at 90% C.L. for Δm_{41}^{2}≈2(6) eV^{2}, which is improved over present limits. Incorporating the IceCube information provides the first constraints on all entries of the 3+1 mixing matrix.
NASA Astrophysics Data System (ADS)
Mastbaum, Andrew; SNO Collaboration
2017-01-01
The Sudbury Neutrino Observatory (SNO) has demonstrated that the apparent deficit in solar neutrinos observed on Earth is due to matter-enhanced flavor transitions and provided precise measurements of the relevant model parameters. The low backgrounds and large, spectral νe - d cross section that enabled this program also give SNO unique sensitivity to two yet-unobserved neutrino signals of interest: hep solar neutrinos and the νe component of the diffuse supernova neutrino background (DSNB). We have developed a combined hep and DSNB search making use of the full SNO dataset. We perform both a cut-and-count analysis and a multidimensional spectral fit, improving upon previously reported constraints based on the initial phase of SNO running only.
Pathways to naturally small Dirac neutrino masses
NASA Astrophysics Data System (ADS)
Ma, Ernest; Popov, Oleg
2017-01-01
If neutrinos are truly Dirac fermions, the smallness of their masses may still be natural if certain symmetries exist beyond those of the standard model of quarks and leptons. We perform a systematic study of how this may occur at tree level and in one loop. We also propose a scotogenic version of the left-right gauge model with naturally small Dirac neutrino masses in one loop.
Splitting Neutrino masses and Showering into Sky
NASA Astrophysics Data System (ADS)
Fargion, D.; D'Armiento, D.; Lanciano, O.; Oliva, P.; Iacobelli, M.; de Sanctis Lucentini, P. G.; Grossi, M.; de Santis, M.
2007-06-01
Neutrino masses might be as light as a few time the atmospheric neutrino mass splitting. The relic cosmic neutrinos may cluster in wide Dark Hot Local Group Halo. High Energy ZeV cosmic neutrinos (in Z-Showering model) might hit relic ones at each mass in different resonance energies in our nearby Universe. This non-degenerated density and energy must split UHE Z-boson secondaries (in Z-Burst model) leading to multi injection of UHECR nucleons within future extreme AUGER energy. Secondaries of Z-Burst as neutral gamma, below a few tens EeV are better surviving local GZK cut-off and they might explain recent Hires BL-Lac UHECR correlations at small angles. A different high energy resonance must lead to Glashow's anti-neutrino showers while hitting electrons in matter. In water and ice it leads to isotropic light explosions. In air, Glashow's anti-neutrino showers lead to collimated and directional air-showers offering a new Neutrino Astronomy. Because of neutrino flavor mixing, astrophysical energetic tau neutrino above tens GeV must arise over atmospheric background. At TeV range is difficult to disentangle tau neutrinos from other atmospheric flavors. At greater energy around PeV, Tau escaping mountains and Earth and decaying in flight are effectively showering in air sky. These Horizontal showering is splitting by geomagnetic field in forked shapes. Such air-showers secondaries release amplified and beamed gamma bursts (like observed TGF), made also by muon and electron pair bundles, with their accompanying rich Cherenkov flashes. Also planet's largest (Saturn, Jupiter) atmosphere limbs offer an ideal screen for UHE GZK and Z-burst tau neutrino, because their largest sizes. Titan thick atmosphere and small radius are optimal for discovering up-going resonant Glashow resonant anti-neutrino electron showers. Detection from Earth of Tau, anti-Tau, anti-electron neutrino induced Air-showers by twin Magic Telescopes on top mountains, or space based detection on
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.
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.
Minimal supergravity scalar neutrino dark matter and inverse seesaw neutrino masses.
Arina, C; Bazzocchi, F; Fornengo, N; Romao, J C; Valle, J W F
2008-10-17
We show that within the inverse seesaw mechanism for generating neutrino masses, minimal supergravity naturally provides the scalar neutrino as the lightest superparticle. We also demonstrate that such schemes naturally reconcile the small neutrino masses with the correct relic scalar neutrino dark matter abundance and accessible direct detection rates in nuclear recoil experiments. This way, inverse seesaw minimal supergravity offers a common solution to the generation of the neutrino mass and to the origin of dark matter.
Neutrino Masses and Mixing from Supersymmetric Inflation
NASA Astrophysics Data System (ADS)
Lazarides, G.
A supersymmetric model based on a l-right symmetric gauge group is proposed where hybrid inflation, baryogenesis and neutrino oscillations are linked.This scheme, supplemented by a familiar ansatz for the neutrino Dirac masses and mixing of the two heaviest families and with the MSW resolution of the solar neutrino puzzle, implies that 1
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.
Measurement of neutrino masses from relative velocities.
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.
Tomographic Constraints on High-Energy Neutrinos of Hadronuclear Origin
NASA Astrophysics Data System (ADS)
Ando, Shin'ichiro; Tamborra, Irene; Zandanel, Fabio
2015-11-01
Mounting evidence suggests that the TeV-PeV neutrino flux detected by the IceCube telescope has mainly an extragalactic origin. If such neutrinos are primarily produced by a single class of astrophysical sources via hadronuclear (p p ) interactions, a similar flux of gamma-ray photons is expected. For the first time, we employ tomographic constraints to pinpoint the origin of the IceCube neutrino events by analyzing recent measurements of the cross correlation between the distribution of GeV gamma rays, detected by the Fermi satellite, and several galaxy catalogs in different redshift ranges. We find that the corresponding bounds on the neutrino luminosity density are up to 1 order of magnitude tighter than those obtained by using only the spectrum of the gamma-ray background, especially for sources with mild redshift evolution. In particular, our method excludes any hadronuclear source with a spectrum softer than E-2.1 as a main component of the neutrino background, if its evolution is slower than (1 +z )3. Starburst galaxies, if able to accelerate and confine cosmic rays efficiently, satisfy both spectral and tomographic constraints.
Tomographic Constraints on High-Energy Neutrinos of Hadronuclear Origin.
Ando, Shin'ichiro; Tamborra, Irene; Zandanel, Fabio
2015-11-27
Mounting evidence suggests that the TeV-PeV neutrino flux detected by the IceCube telescope has mainly an extragalactic origin. If such neutrinos are primarily produced by a single class of astrophysical sources via hadronuclear (pp) interactions, a similar flux of gamma-ray photons is expected. For the first time, we employ tomographic constraints to pinpoint the origin of the IceCube neutrino events by analyzing recent measurements of the cross correlation between the distribution of GeV gamma rays, detected by the Fermi satellite, and several galaxy catalogs in different redshift ranges. We find that the corresponding bounds on the neutrino luminosity density are up to 1 order of magnitude tighter than those obtained by using only the spectrum of the gamma-ray background, especially for sources with mild redshift evolution. In particular, our method excludes any hadronuclear source with a spectrum softer than E^{-2.1} as a main component of the neutrino background, if its evolution is slower than (1+z)^{3}. Starburst galaxies, if able to accelerate and confine cosmic rays efficiently, satisfy both spectral and tomographic constraints.
Comments on the determination of the neutrino mass ordering in reactor neutrino experiments
NASA Astrophysics Data System (ADS)
Bilenky, S. M.
2017-05-01
We consider the problem of determination of the neutrino mass ordering via precise study of the vacuum neutrino oscillations in the JUNO and other future medium baseline reactor neutrino experiments. We are proposing to resolve neutrino mass ordering by determination of the neutrino oscillation parameters from analysis of the data of the reactor experiments and comparison them with the oscillation parameters obtained from analysis of the solar and KamLAND experiments.
Evidence for neutrino mass: A decade of discovery
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.
Zero minors of the neutrino mass matrix
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.
Neutrino mass implications for muon decay parameters
Erwin, Rebecca J.; Kile, Jennifer; Ramsey-Musolf, Michael J.; Wang Peng
2007-02-01
We use the scale of neutrino mass and naturalness considerations to obtain model-independent expectations for the magnitude of possible contributions to muon decay Michel parameters from new physics above the electroweak symmetry-breaking scale. Focusing on Dirac neutrinos, we obtain a complete basis of dimension four and dimension six effective operators that are invariant under the gauge symmetry of the standard model and that contribute to both muon decay and neutrino mass. We show that - in the absence of fine tuning - the most stringent neutrino-mass naturalness bounds on chirality-changing vector operators relevant to muon decay arise from one-loop operator mixing. The bounds we obtain on their contributions to the Michel parameters are 2 orders of magnitude stronger than bounds previously obtained in the literature. In addition, we analyze the implications of one-loop matching considerations and find that the expectations for the size of various scalar and tensor contributions to the Michel parameters are considerably smaller than derived from previous estimates of two-loop operator mixing. We also show, however, that there exist gauge-invariant operators that generate scalar and tensor contributions to muon decay but whose flavor structure allows them to evade neutrino-mass naturalness bounds. We discuss the implications of our analysis for the interpretation of muon-decay experiments.
Small Neutrino Masses from Supersymmetry Breaking
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.
Supernova heavy element nucleosynthesis: Can it tell us about neutrino masses?
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)
Neutrino mass as the probe of intermediate mass scales
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.
Neutrino mass hierarchy determination using reactor antineutrinos
NASA Astrophysics Data System (ADS)
Ghoshal, Pomita; Petcov, S. T.
2011-03-01
Building on earlier studies, we investigate the possibility to determine the type of neutrino mass spectrum (i.e., "the neutrino mass hierarchy") in a high statistics reactor {bar{ν }_e} experiment with a relatively large KamLAND-like detector and an optimal baseline of 60 Km. We analyze systematically the Fourier Sine and Cosine Transforms (FST and FCT) of simulated reactor antineutrino data with reference to their specific mass hierarchy-dependent features discussed earlier in the literature. We perform also a binned χ 2 analysis of the sensitivity of simulated reactor {bar{ν }_e} event spectrum data to the neutrino mass hierarchy, and determine, in particular, the characteristics of the detector and the experiment (energy resolution, visible energy threshold, exposure, systematic errors, binning of data, etc.), which would allow us to get significant information on, or even determine, the type of the neutrino mass spectrum. We find that if sin2 2 θ 13 is sufficiently large, sin2 2 θ 13 ≳ 0 .02, the requirements on the set-up of interest are very challenging, but not impossible to realize.
Towards a cosmological neutrino mass detection
NASA Astrophysics Data System (ADS)
Allison, R.; Caucal, P.; Calabrese, E.; Dunkley, J.; Louis, T.
2015-12-01
Future cosmological measurements should enable the sum of neutrino masses to be determined indirectly through their effects on the expansion rate of the Universe and the clustering of matter. We consider prospects for the gravitationally lensed cosmic microwave background (CMB) anisotropies and baryon acoustic oscillations (BAOs) in the galaxy distribution, examining how the projected uncertainty of ≈15 meV on the neutrino mass sum (a 4 σ detection of the minimal mass) might be reached over the next decade. The current 1 σ uncertainty of ≈103 meV (Planck-2015 +BAO -15 ) will be improved by upcoming "Stage-3" (S3) CMB experiments (S 3 +BAO -15 : 44 meV ), then upcoming BAO measurements (S 3 +DESI : 22 meV ), and planned next-generation "Stage 4" (S4) CMB experiments (S 4 +DESI : 15 - 19 meV , depending on angular range). An improved optical depth measurement is important: the projected neutrino mass uncertainty increases to 26 meV if S4 is limited to ℓ>20 and combined with current large-scale polarization data. Looking beyond Λ CDM , including curvature uncertainty increases the forecast mass error by ≈50 % for S 4 +DESI , and more than doubles the error with a two-parameter dark-energy equation of state. Complementary low-redshift probes including galaxy lensing will play a role in distinguishing between massive neutrinos and a departure from a w =-1 , flat geometry.
Limits on neutrino masses from neutrinoless double-β decay.
Barea, J; Kotila, J; Iachello, F
2012-07-27
Neutrinoless double-β decay is of fundamental importance for the determining neutrino mass. By combining a calculation of nuclear matrix elements within the framework of the microscopic interacting boson model with an improved calculation of phase space factors, we set limits on the average light neutrino mass and on the average inverse heavy neutrino mass (flavor-violating parameter).
Murase, Kohta; Beacom, John F. E-mail: beacom.7@osu.edu
2013-02-01
Galaxy Clusters (GCs) are the largest reservoirs of both dark matter and cosmic rays (CRs). Dark matter self-annihilation can lead to a high luminosity in gamma rays and neutrinos, enhanced by a strong degree of clustering in dark matter substructures. Hadronic CR interactions can also lead to a high luminosity in gamma rays and neutrinos, enhanced by the confinement of CRs from cluster accretion/merger shocks and active galactic nuclei. We show that IceCube/KM3Net observations of high-energy neutrinos can probe the nature of GCs and the separate dark matter and CR emission processes, taking into account how the results depend on the still-substantial uncertainties. Neutrino observations are relevant at high energies, especially at ∼>10 TeV. Our results should be useful for improving experimental searches for high-energy neutrino emission. Neutrino telescopes are sensitive to extended sources formed by dark matter substructures and CRs distributed over large scales. Recent observations by Fermi and imaging atmospheric Cherenkov telescopes have placed interesting constraints on the gamma-ray emission from GCs. We also provide calculations of the gamma-ray fluxes, taking into account electromagnetic cascades inside GCs, which can be important for injections at sufficiently high energies. This also allows us to extend previous gamma-ray constraints to very high dark matter masses and significant CR injections at very high energies. Using both neutrinos and gamma rays, which can lead to comparable constraints, will allow more complete understandings of GCs. Neutrinos are essential for dark matter annihilation channels like χχ→μ{sup +}μ{sup −}, where the neutrino signals are larger than the gamma-ray signals, and for hadronic instead of electronic CRs, because only the first leads to neutrinos. Our results suggest that the multi-messenger observations of GCs will be able to give useful constraints on specific models of dark matter and CRs.
Cosmological constraints on neutrino plus axion hot dark matter: update after WMAP-5
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.)
Neutrino masses and absence of flavor changing interactions in the 2HDM from gauge principles
NASA Astrophysics Data System (ADS)
Campos, Miguel D.; Cogollo, D.; Lindner, Manfred; Melo, T.; Queiroz, Farinaldo S.; Rodejohann, Werner
2017-08-01
We propose several Two Higgs Doublet Models with the addition of an Abelian gauge group which free the usual framework from flavor changing neutral interactions and explain neutrino masses through the seesaw mechanism. We discuss the kinetic and mass-mixing gripping phenomenology which encompass several constraints coming from atomic parity violation, the muon anomalous magnetic moment, rare meson decays, Higgs physics, LEP precision data, neutrino-electron scattering, low energy accelerators and LHC probes.
Strong thermal leptogenesis and the absolute neutrino mass scale
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.
Direct determination of neutrino mass parameters at future colliders
Kadastik, M.; Raidal, M.; Rebane, L.
2008-06-01
If the observed light neutrino masses are induced by their Yukawa couplings to singlet right-handed neutrinos, the natural smallness of those makes direct collider tests of the electroweak scale neutrino mass mechanisms difficult in the simplest models. In the triplet Higgs seesaw scenario the smallness of light neutrino masses may come from the smallness of B-L breaking parameters, allowing sizable Yukawa couplings even for a TeV scale triplet. We show that, in this scenario, measuring the branching fractions of doubly charged Higgs to different same-charged lepton flavors at CERN LHC and/or ILC experiments will allow one to measure the neutrino mass parameters that neutrino oscillation experiments are insensitive to, including the neutrino mass hierarchy, lightest neutrino mass, and Majorana phases.
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.
Higgs Boson Mass, Neutrino Oscillations and Inflation
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.
Neutrino Mass Seesaw Version 3: Recent Developments
Ma, Ernest
2009-04-20
The origin of neutrino mass is usually attributed to a seesaw mechanism, either through a heavy Majorana fermion singlet (version 1) or a heavy scalar triplet (version 2). Recently, the idea of using a heavy Majorana fermion triplet (version 3) has gained some attention. This is a review of the basic idea involved, its U(1) gauge extension, and some recent developments.
Neutrino masses, Majorons, and muon decay
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.
11B and constraints on neutrino oscillations and spectra from neutrino nucleosynthesis.
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.
Right-handed neutrinos at CERN LHC and the mechanism of neutrino mass generation
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.
Unique forbidden beta decays and neutrino mass
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.
New model for the neutrino mass matrix
NASA Astrophysics Data System (ADS)
Lavoura, L.
2000-11-01
I suggest a model based on a softly broken symmetry Le-Lμ-Lτ and on Babu's mechanism for the two-loop radiative generation of neutrino masses. The model predicts that one of the physical neutrinos (ν3) is massless and that its component along the νe direction (Ue3) is zero. Moreover, if the soft-breaking term is assumed to be very small, then the vacuum oscillations of νe have almost maximal amplitude and solve the solar-neutrino problem. New scalars are predicted in the 10 TeV energy range, and a breakdown of e-μ-τ universality should not be far from existing experimental bounds.
QLC relation and neutrino mass hierarchy
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.
Constraints on sterile neutrino oscillations using DUNE near detector
NASA Astrophysics Data System (ADS)
Choubey, Sandhya; Pramanik, Dipyaman
2017-01-01
DUNE (Deep Underground Neutrino Experiment) is a proposed long-baseline neutrino experiment in the US with a baseline of 1300 km from Fermi National Accelerator Laboratory (Fermilab) to Sanford Underground Research Facility, which will house a 40 kt Liquid Argon Time Projection Chamber (LArTPC) as the far detector. The experiment will also have a fine grained near detector for accurately measuring the initial fluxes. We show that the energy range of the fluxes and baseline of the DUNE near detector is conducive for observing νμ →νe oscillations of Δm2 ∼ eV2 scale sterile neutrinos, and hence can be effectively used for testing to very high accuracy the reported oscillation signal seen by the LSND and MiniBooNE experiments. We study the sensitivity of the DUNE near detector to sterile neutrino oscillations by varying the baseline, detector fiducial mass and systematic uncertainties. We find that the detector mass and baseline of the currently proposed near detector at DUNE will be able to test the entire LSND parameter region with good precision. The dependence of sensitivity on baseline and detector mass is seen to give interesting results, while dependence on systematic uncertainties is seen to be small.
Generalized mass ordering degeneracy in neutrino oscillation experiments
Coloma, Pilar; Schwetz, Thomas
2016-09-07
Here, 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 θ_{12} 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.
Generalized mass ordering degeneracy in neutrino oscillation experiments
Coloma, Pilar; Schwetz, Thomas
2016-09-07
Here, 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 θ_{12} 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.
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.
NASA Astrophysics Data System (ADS)
Kang, Kyungsik; Shin, Michael
1987-02-01
The light neutrino masses and their mixing angles are investigated in a class of SO(10) models with the GRSY seesaw mechanism. The models are motivated by a recent proposal on the structure of the Yukawa couplings postulated from the observed K-M angles and the strong-CP problem. The scale of the seesaw mechanism is found to be bounded from above by the invisible axion scale, leading to a lower bound on the light neutrino masses. The main results are: 0.18eV<=mv3<=100eV, mv1/mv2=O(mu/mc), and mv2/mv3=O((mc/mt)(√mumc/mt)) for the non-hierarchical structure of the right-handed neutrino mass matrix (MN), and mv2/mv3=O(mc/mt) for the hierarchical structure of MN, θeμ≅√me/mμ+exp(iηl')O(√mu/mc), θμt≅√mμ/mt-exp(iη2)O(√mc/mt), and θe/mtθμt, where η1' and η2 are some phases. With present experimental constraints on the mixing angles, νμ-ντ and νe-νμ oscillations may be observable in the next generation of experiments. Regarding the solution to the solar neutrino problem with the MSW amplification mechanism, we find that the relevant neutrino oscillation in the sun should be in the νe-νμ channel, instead of the νe-νt channel which the ``naive seesaw'' model at the GUT scale predicts. Moreover, we also find that, for the structure of MN similar to those of quarks, the existence of a light fourth generation neutrino is inevitable, if the cosmological mass density bound is to be saturated by the light neutrino masses and the solar neutrino problem is solved by the MSW mechanism.
Seesaw neutrino masses and mixing with extended democracy
NASA Astrophysics Data System (ADS)
Joaquim, F. R.
2001-05-01
In the context of a minimal extension of the Standard Model with three extra heavy right-handed neutrinos, we propose a model for neutrino masses and mixing based on the hipothesis of a complete alignment of the lepton mass matrices in flavour space. Considering a uniform quasi-democratic structure for these matrices, we show that, in the presence of a highly hierarchical right-handed neutrino mass spectrum, the effective neutrino mass matrix, obtained through the seesaw mechanism, can reproduce all the solutions of the solar neutrino problem.
Implications of 4 texture zeros mass matrices for neutrino anomalies
NASA Astrophysics Data System (ADS)
Gill, P. S.; Gupta, Manmohan
1998-04-01
Phenomenological 4 texture zeros mass matrices, successful in accommodating the CKM phenomenology, are used to simultaneously explain the three neutrino anomalies: the solar neutrino problem (SNP), the atmospheric neutrino problem (ANP), and the LSND anomaly. When the SNP is resolved through vacuum oscillations, we obtain a solution implying large mixing. In case the SNP is resolved through the MSW mechanism, the neutrino masses follow a ``natural'' hierarchy.
Cosmic microwave background constraints on secret interactions among sterile neutrinos
NASA Astrophysics Data System (ADS)
Forastieri, Francesco; Lattanzi, Massimiliano; Mangano, Gianpiero; Mirizzi, Alessandro; Natoli, Paolo; Saviano, Ninetta
2017-07-01
Secret contact interactions among eV sterile neutrinos, mediated by a massive gauge boson X (with MX ll MW), and characterized by a gauge coupling gX, have been proposed as a mean to reconcile cosmological observations and short-baseline laboratory anomalies. We constrain this scenario using the latest Planck data on Cosmic Microwave Background anisotropies, and measurements of baryon acoustic oscillations (BAO). We consistently include the effect of secret interactions on cosmological perturbations, namely the increased density and pressure fluctuations in the neutrino fluid, and still find a severe tension between the secret interaction framework and cosmology. In fact, taking into account neutrino scattering via secret interactions, we derive our own mass bound on sterile neutrinos and find (at 95 % CL) ms < 0.82 eV or ms < 0.29 eV from Planck alone or in combination with BAO, respectively. These limits confirm the discrepancy with the laboratory anomalies. Moreover, we constrain, in the limit of contact interaction, the effective strength GX to be < 2.8 (2.0) × 1010 GF from Planck (Planck+BAO). This result, together with the mass bound, strongly disfavours the region with MX ~ 0.1 MeV and relatively large coupling gX~ 10-1, previously indicated as a possible solution to the small scale dark matter problem.
Neutrino mass hierarchy and stepwise spectral swapping of supernova neutrino flavors.
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.
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
Measuring neutrino masses with weak lensing
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.
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.
Constraints on the neutrino flux in NOvA using the near detector data
Maan, Kuldeep K.
2016-12-19
NOvA, a long-baseline neutrino oscillation experiment at Fermilab, is designed to measure electron-neutrino appearance and muon-neutrino disappearance in the NuMI beam. NOvA comprises of two finely segmented liquid scintillator detectors at 14 mrad off-axis in the NuMI beam. An accurate prediction of the neutrino flux is needed for precision oscillation and cross-section measurements. Data from the hadron-production experiments and, importantly, from the NOvA Near Detector provide powerful constraints on the muon-neutrino and electron-neutrino fluxes. In particular, the measurement of the neutrino-electron elastic scattering provides an in situ constraint on the absolute flux. Lastly, this poster presents the data-driven predictions of the NOvA muonneutrino and electron-neutrino flux, and outlines future improvements in the flux determination.
Constraints on the neutrino flux in NOvA using the near detector data
Maan, Kuldeep K.
2016-12-19
NOvA, a long-baseline neutrino oscillation experiment at Fermilab, is designed to measure electron-neutrino appearance and muon-neutrino disappearance in the NuMI beam. NOvA comprises of two finely segmented liquid scintillator detectors at 14 mrad off-axis in the NuMI beam. An accurate prediction of the neutrino flux is needed for precision oscillation and cross-section measurements. Data from the hadron-production experiments and, importantly, from the NOvA Near Detector provide powerful constraints on the muon-neutrino and electron-neutrino fluxes. In particular, the measurement of the neutrino-electron elastic scattering provides an in situ constraint on the absolute flux. Lastly, this poster presents the data-driven predictions ofmore » the NOvA muonneutrino and electron-neutrino flux, and outlines future improvements in the flux determination.« less
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.
Cosmology of mass-varying neutrinos driven by quintessence: Theory and observations
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.
Constraining dynamical neutrino mass generation with cosmological data
NASA Astrophysics Data System (ADS)
Koksbang, S. M.; Hannestad, S.
2017-09-01
We study models in which neutrino masses are generated dynamically at cosmologically late times. Our study is purely phenomenological and parameterized in terms of three effective parameters characterizing the redshift of mass generation, the width of the transition region, and the present day neutrino mass. We also study the possibility that neutrinos become strongly self-interacting at the time where the mass is generated. We find that in a number of cases, models with large present day neutrino masses are allowed by current CMB, BAO and supernova data. The increase in the allowed mass range makes it possible that a non-zero neutrino mass could be measured in direct detection experiments such as KATRIN. Intriguingly we also find that there are allowed models in which neutrinos become strongly self-interacting around the epoch of recombination.
Supernovae, neutrino rest mass, and the middle-energy neutrino background in the universe
NASA Astrophysics Data System (ADS)
Bisnovatyi-Kogan, G. S.; Seidov, Z. F.
Neutrinos emitted during the formation of the neutron stars and black holes form, together with relict microwave radiation and relict neutrinos, a background for the present universe. The energy of the kind of neutrino emitted in neutron star formation, at 3-30 MeV, is much greater than that of relict neutrinos and much smaller than that of the cosmic ray neutrinos; they are accordingly designated 'middle energy neutrinos' (MENs). It is presently shown that the MEN background's density, at 2-10 x 10 to the -33rd gm/cu cm, is greater than the density of relict microwave radiation and less than the density of matter. The MEN spectra presently calculated yield 0.002 to 0.008 solar neutrino units in the solar chlorine-argon detector. Possible neutrino rest mass effects are discussed for the cases of expanding universe propagation and MEN background spatial structure.
Status of the neutrino mass experiment KATRIN
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.
Neutrino mass and mixing with discrete symmetry.
King, Stephen F; Luhn, Christoph
2013-05-01
This is a review paper about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of see-saw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mechanisms for flavon vacuum alignment and different model building strategies that have been proposed to generate the reactor angle. We then briefly review grand unified theories (GUTs) and how they may be combined with discrete family symmetry to describe all quark and lepton masses and mixing. Finally, we discuss three model examples which combine an SU(5) GUT with the discrete family symmetries A₄, S₄ and Δ(96).
Neutrinoless double beta decay and neutrino mass
NASA Astrophysics Data System (ADS)
Vergados, J. D.; Ejiri, H.; Šimkovic, F.
2016-11-01
The observation of neutrinoless double beta decay (DBD) will have important consequences. First it will signal that lepton number is not conserved and the neutrinos are Majorana particles. Second, it represents our best hope for determining the absolute neutrino mass scale at the level of a few tens of meV. To achieve the last goal, however, certain hurdles have to be overcome involving particle, nuclear and experimental physics. Particle physics is important since it provides the mechanisms for neutrinoless DBD. In this review, we emphasize the light neutrino mass mechanism. Nuclear physics is important for extracting the useful information from the data. One must accurately evaluate the relevant nuclear matrix elements (NMEs), a formidable task. To this end, we review the recently developed sophisticated nuclear structure approaches, employing different methods and techniques of calculation. We also examine the question of quenching of the axial vector coupling constant, which may have important consequences on the size of the NMEs. From an experimental point of view it is challenging, since the life times are extremely long and one has to fight against formidable backgrounds. One needs large isotopically enriched sources and detectors with good energy resolution and very low background.
Supersymmetric model with Dirac neutrino masses
Marshall, Gardner; McCaskey, Mathew; Sher, Marc
2010-03-01
New models have recently been proposed in which a second Higgs doublet couples only to the lepton doublets and right-handed neutrinos, yielding Dirac neutrino masses. The vacuum value of this second 'nu-Higgs' doublet is made very small by means of a very softly-broken Z{sub 2} or U(1) symmetry. The latter is technically natural and avoids fine-tuning and very light scalars. We consider a supersymmetric version of this model, in which two additional doublets are added to the minimal supersymmetric standard model (MSSM). If kinematically allowed, the decay of the heavy MSSM scalar into charged nu-Higgs scalars will yield dilepton events which can be separated from the W-pair background. In addition, the nu-Higgsinos can lead to very dramatic tetralepton, pentalepton, and hexalepton events which have negligible background and can be detected at the LHC and the Tevatron.
Status of the KATRIN neutrino mass experiment
NASA Astrophysics Data System (ADS)
Martin, Eric; Katrin Collaboration
2016-09-01
The upcoming Karlsruhe Tritium Neutrino (KATRIN) experiment aims to explore neutrino mass down to 0.2 eV/c2 (90% CL) by measuring the shape of the tritium beta decay spectrum. Using magnetic adiabatic collimation with an electrostatic filter (MAC-E filter) KATRIN will measure the electron kinetic energy spectrum with a resolution better than one part in 104. All major components are on site and commissioning is underway, with first tritium data currently scheduled for 2017. The measurement technique will be explained along with an update on commissioning progress. This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Nuclear Physics under Award Number DE-FG02-97ER41020.
Predictive minimal model for neutrino masses and mixings
NASA Astrophysics Data System (ADS)
Stech, Berthold
2000-11-01
A model is considered in which the scale of the heavy singlet neutrinos is a few orders of magnitude below the grand unification scale and where right-handed vector bosons still play a negligible role. In a basis with diagonal up-quark and Dirac-neutrino mass matrices it is assumed that the heavy neutrino mass matrix has only zero elements in its diagonal, in analogy with the light neutrino mass matrix in the Zee model. Connecting then the remaining matrix elements with the small parameter describing the hierarchy of quark masses and mixings and by assuming commutativity of the charged lepton with the down-quark mass matrix, the calculation of all neutrino properties can be performed in terms of the two mass differences relevant for atmospheric and solar neutrino oscillations. CP violation is directly related to CP violation in the quark sector.
Assess the neutrino mass with micro and macro calorimeter approach
NASA Astrophysics Data System (ADS)
Giachero, A.
2017-05-01
Thanks to oscillation experiments it is now an established fact that neutrinos are massive particles. Yet, the assessment of neutrinos absolute mass scale is still an outstanding challenge in particle physics and cosmology as oscillation experiments are sensitive only to the squared mass differences of the three neutrino mass eigenstates. The mass hierarchy is not the only missing piece in the puzzle. Theories of neutrino mass generation call into play Majorana neutrinos and there are experimental observations pointing toward the existence of sterile neutrinos in addition to the three weakly interacting ones. Three experimental approaches are currently pursued: an indirect neutrino mass determination via cosmological observables, the search for neutrinoless double β-decay, and a direct measurement based on the kinematics of single β or electron capture decays. Bolometers and calorimeters are low temperature detectors used in many applications, such as astrophysics, fast spectroscopy and particle physics. In particular, sensitive calorimeters play an important role in the neutrino mass measurement and in the search for the neutrinoless double β-decay. There has been great technical progress on low temperature detectors since they were proposed for neutrino physics experiments in 1984. This general detector paradigm can be implemented in devices as small as a micrometer for sub eV radiation or as large as 1 kg for MeV scale particles. Today this technique offers the high energy resolution and scalability required for leading edges and competitive experiments addressing the still open questions in neutrino physics.
Measuring neutrino mass imprinted on the anisotropic galaxy clustering
NASA Astrophysics Data System (ADS)
Oh, Minji; Song, Yong-Seon
2017-04-01
The anisotropic galaxy clustering of large scale structure observed by the Baryon Oscillation Spectroscopic Survey Data Release 11 is analyzed to probe the sum of neutrino masses in the small mν lesssim 1 eV limit in which the early broadband shape determined before the last scattering surface is immune from the variation of mν. The signature of mν is imprinted on the altered shape of the power spectrum at later epoch, which provides an opportunity to access the non-trivial mν through the measured anisotropic correlation function in redshift space (hereafter RSD instead of Redshift Space Distortion). The non-linear RSD corrections with massive neutrinos in the quasi linear regime are approximately estimated using one-loop order terms. We suggest an approach to probe mν simultaneously with all other distance measures and coherent growth functions, exploiting this deformation of the early broadband shape of the spectrum at later epoch. If the origin of cosmic acceleration is unknown, mν is poorly determined after marginalizing over all other observables. However, we find that the measured distances and coherent growth functions are minimally affected by the presence of mild neutrino mass. Although the standard model of cosmic acceleration is assumed to be the cosmological constant, the constraint on mν is little improved. Interestingly, the measured Cosmic Microwave Background (hereafter CMB) distance to the last scattering surface sharply slices the degeneracy between the matter content and mν, and the mν is observed to be mν = 0.19+0.28-0.17 eV which is different from massless neutrino at 68% confidence.
Neutrino Mass from Beta Decay of the Free Neutron
NASA Astrophysics Data System (ADS)
Tegen, R.; Miller, H. G.
We calculate the beta decay rate of the free neutron including effects due to (i) a neutrino mass around 1 eV, (ii) deviations from the leptonic V-A structure, (iii) nucleon form factors F1,2V (q2), GA(q2), and (iv) W- propagation. At the end-point energies linear neutrino mass effects in n -> p + e- + ¯ {ν }e are almost exclusively kinematical. If the neutrino spectrum is (almost) degenerate, neutrino oscillations cannot uniquely determine the mass of the neutrino, and direct mass determinations become necessary. The traditional Kurie plot and a partially integrated decay rate are found to be sensitive to a neutrino mass between 1 eV and 3 eV.
Leptoquark mechanism of neutrino masses within the grand unification framework
NASA Astrophysics Data System (ADS)
Doršner, Ilja; Fajfer, Svjetlana; Košnik, Nejc
2017-06-01
We demonstrate the viability of the one-loop neutrino mass mechanism within the framework of grand unification when the loop particles comprise scalar leptoquarks (LQs) and quarks of the matching electric charge. This mechanism can be implemented in both supersymmetric and non-supersymmetric models and requires the presence of at least one LQ pair. The appropriate pairs for the neutrino mass generation via the up-type and down-type quark loops are S_3-R_2 and S_{1, 3}-\\tilde{R}_2, respectively. We consider two distinct regimes for the LQ masses in our analysis. The first regime calls for very heavy LQs in the loop. It can be naturally realized with the S_{1, 3}-\\tilde{R}_2 scenarios when the LQ masses are roughly between 10^{12} and 5 × 10^{13} GeV. These lower and upper bounds originate from experimental limits on partial proton decay lifetimes and perturbativity constraints, respectively. Second regime corresponds to the collider accessible LQs in the neutrino mass loop. That option is viable for the S_3-\\tilde{R}_2 scenario in the models of unification that we discuss. If one furthermore assumes the presence of the type II see-saw mechanism there is an additional contribution from the S_3-R_2 scenario that needs to be taken into account beside the type II see-saw contribution itself. We provide a complete list of renormalizable operators that yield necessary mixing of all aforementioned LQ pairs using the language of SU(5). We furthermore discuss several possible embeddings of this mechanism in SU(5) and SO(10) gauge groups.
Introduction to direct neutrino mass measurements and KATRIN
NASA Astrophysics Data System (ADS)
Thümmler, T.; Katrin Collaboration
2012-08-01
The properties of neutrinos and especially their rest mass play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double beta decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. On the other hand experiments such as MARE, KATRIN and the recently proposed Project 8 will investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Here, because of neutrino flavour mixing, the neutrino mass appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. It combines an ultra-luminous molecular windowless gaseous tritium source with an integrating high-resolution spectrometer of MAC-E filter type. It will investigate the neutrino rest mass with 0.2 eV/c (90% C.L.) sensitivity and allow β spectroscopy close to the T endpoint at 18.6 keV with unprecedented precision.
IceCube constraints on fast-spinning pulsars as high-energy neutrino sources
Fang, Ke; Kotera, Kumiko; Murase, Kohta; Olinto, Angela V. E-mail: kotera@iap.fr E-mail: olinto@kicp.uchicago.edu
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 10{sup 18} 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.
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.
Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO
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.
Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO
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.
Sterile neutrinos with eV masses in cosmology — How disfavoured exactly?
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.
Challenging the Neutrino Mass with Cuore
NASA Astrophysics Data System (ADS)
Ferroni, F.
2008-06-01
One of the fundamental questions still open in elementary particle is the nature of the neutrino mass. Whether Dirac or Majorana, its knowledge would deeply impact the development of the field. Double Beta Decay experiments are, although extremely challenging, the only way known that might give an answer to the question. In this paper one of the second generation experiment that aims to get the sensitivity for probing the inverted hierarchy will be discussed. It is CUORE, in preparation at the Gran Sasso underground laboratories of INFN.
Degeneracy effects of neutrino mass ejection in supernovae
NASA Technical Reports Server (NTRS)
Mazurek, T. J.
1974-01-01
A neutrino mechanism is discussed in order to explain supernovae in massive stars. An argument is presented for supernova mass ejection through leptonic neutrino transport characteristics suppressed by the arbitrary zero chemical potential condition. Results show that lepton conservation effects may be important in supernova neutrino transport. At low temperature and density the diffusion approximation becomes less precise because of the long mean free paths of low energy neutrinos. The amount of equilibrium neutrino spectrum affected here is small over most of the collapsing supernova structure.
Constraints on dark photon from neutrino-electron scattering experiments
NASA Astrophysics Data System (ADS)
Bilmiş, S.; Turan, I.; Aliev, T. M.; Deniz, M.; Singh, L.; Wong, H. T.
2015-08-01
A possible manifestation of an additional light gauge boson A', named a dark photon, associated with a group U (1 )B -L , is studied in neutrino-electron scattering experiments. The exclusion plot on the coupling constant gB -L and the dark photon mass MA' is obtained. It is shown that the contributions of interference terms between the dark photon and the Standard Model are important. The interference effects are studied and compared with data sets from TEXONO, GEMMA, BOREXINO, and LSND, as well as CHARM II experiments. Our results provide more stringent bounds to some regions of parameter space.
DESI and other Dark Energy experiments in the era of neutrino mass measurements
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.
DESI and other Dark Energy experiments in the era of neutrino mass measurements
Font-Ribera, Andreu; McDonald, Patrick; Mostek, Nick; Reid, Beth A.; Seo, Hee-Jong; Slosar, Anže
2014-05-19
Here 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. Finally, 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.
DESI and other Dark Energy experiments in the era of neutrino mass measurements
Font-Ribera, Andreu; McDonald, Patrick; Mostek, Nick; ...
2014-05-19
Here 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 measuremore » 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. Finally, 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.« less
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.
NASA Astrophysics Data System (ADS)
Kopp, Joachim; Welter, Johannes
2014-12-01
Sterile neutrino models with new gauge interactions in the sterile sector are phenomenologically interesting since they can lead to novel effects in neutrino oscillation experiments, in cosmology and in dark matter detectors, possibly even explaining some of the observed anomalies in these experiments. Here, we use data from neutrino oscillation experiments, in particular from MiniBooNE, MINOS and solar neutrino experiments, to constrain such models. We focus in particular on the case where the sterile sector gauge boson A ' couples also to Standard Model particles (for instance to the baryon number current) and thus induces a large Mikheyev-Smirnov-Wolfenstein potential. For eV-scale sterile neutrinos, we obtain strong constraints especially from MINOS, which restricts the strength of the new interaction to be less than ˜ 10 times that of the Standard Model weak interaction unless active-sterile neutrino mixing is very small (sin2 θ 24 ≲ 10-3). This rules out gauge forces large enough to affect short-baseline experiments like MiniBooNE and it imposes nontrivial constraints on signals from sterile neutrino scattering in dark matter experiments.
Hybrid method to resolve the neutrino mass hierarchy by supernova (anti)neutrino induced reactions
Vale, D.; Rauscher, T.; Paar, N. E-mail: Thomas.Rauscher@unibas.ch
2016-02-01
We introduce a hybrid method to determine the neutrino mass hierarchy by simultaneous measurements of responses of at least two detectors to antineutrino and neutrino fluxes from accretion and cooling phases of core-collapse supernovae. The (anti)neutrino-nucleus cross sections for {sup 56}Fe and {sup 208}Pb are calculated in the framework of the relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons p(ν-bar {sub e},e{sup +})n are obtained using heavy-baryon chiral perturbation theory. The modelling of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside the exploding star. The particle emission rates from the elementary decay modes of the daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material allows to determine the neutrino mass hierarchy from the ratios of ν{sub e}- and ν-bar {sub e}-induced particle emissions. This hybrid method favors neutrinos from the supernova cooling phase and the implementation of detectors with heavier target nuclei ({sup 208}Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil or water is the appropriate choice.
Stringent neutrino flux constraints on antiquark nugget dark matter
NASA Astrophysics Data System (ADS)
Gorham, P. W.; Rotter, B. J.
2017-05-01
Strongly interacting matter in the form of nuggets of nuclear-density material is not currently excluded as a dark matter candidate in the ten gram to hundreds of kilogram mass range. A recent variation on quark nugget dark matter models postulates that a first-order imbalance between matter and antimatter at the quark-gluon phase transition in the early Universe could lead to most of the dark matter bound into heavy (baryon number B ˜1 025) antiquark nuggets in the current epoch, explaining both the dark matter preponderance and the matter-antimatter asymmetry. Interactions of these massive objects with normal matter in the Earth and Sun lead to annihilation and an associated neutrino flux in the ˜30 MeV range. We calculate these fluxes for antiquark nuggets of sufficient flux to account for the dark matter and find that current neutrino flux limits from Super-Kamiokande (SuperK) exclude these objects as major dark matter candidates at a high confidence level. Antiquark nuggets in the previously allowed mass range cannot account for more than ˜15 % of the dark matter flux.
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.
Probing neutrino masses with CMB lensing extraction
Lesgourgues, Julien; Perotto, Laurence; Pastor, Sergio; Piat, Michel
2006-02-15
We evaluate the ability of future cosmic microwave background (CMB) experiments to measure the power spectrum of large scale structure using quadratic estimators of the weak lensing deflection field. We calculate the sensitivity of upcoming CMB experiments such as BICEP, QUaD, BRAIN, ClOVER and Planck to the nonzero total neutrino mass M{sub {nu}} indicated by current neutrino oscillation data. We find that these experiments greatly benefit from lensing extraction techniques, improving their one-sigma sensitivity to M{sub {nu}} by a factor of order four. The combination of data from Planck and the SAMPAN mini-satellite project would lead to {sigma}(M{sub {nu}}){approx}0.1 eV, while a value as small as {sigma}(M{sub {nu}}){approx}0.035 eV is within the reach of a space mission based on bolometers with a passively cooled 3-4 m aperture telescope, representative of the most ambitious projects currently under investigation. We show that our results are robust not only considering possible difficulties in subtracting astrophysical foregrounds from the primary CMB signal but also when the minimal cosmological model ({lambda} Mixed Dark Matter) is generalized in order to include a possible scalar tilt running, a constant equation-of-state parameter for the dark energy and/or extra relativistic degrees of freedom.
Neutrino mass effects on the CMB polarization with PMF
Kojima, Kazuhiko; Kajino, Toshitaka; Mathews, Grant J.
2009-05-04
Our previous work showed that if a primordial magnetic field (PMF) was present during photon decoupling and afterward, massive neutrinos affect all modes of the CMB. This is because of the compensation of anisotropic stress between the neutrinos and the PMF. In order to study the observability of this new effect, we need careful analysis of the passive mode generated by the PMF. Here, we focus on the polarization of the CMB and study the observability of the finite neutrino mass effect.
Active and sterile neutrino mass effects on beta decay spectra
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.
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.
Masses, mixing angles and phases of general Majorana neutrino mass matrix
NASA Astrophysics Data System (ADS)
Adhikary, Biswajit; Chakraborty, Mainak; Ghosal, Ambar
2013-10-01
General Majorana neutrino mass matrix is complex symmetric and for three generations of neutrinos it contains 12 real parameters. We diagonalize this general neutrino mass matrix and express the three neutrino masses, three mixing angles, one Dirac CP phase and two Majorana phases (removing three unphysical phases) in terms of the neutrino mass matrix elements. We apply the results in the context of a neutrino mass matrix derived from a broken cyclic symmetry invoking type-I seesaw mechanism. Phenomenological study of the above mass matrix allows enough parameter space to satisfy the neutrino oscillation data with only 10% breaking of this symmetry. In this model only normal mass hierarchy is allowed. In addition, the Dirac CP phase and the Majorana phases are numerically estimated. Σ m i and | m νee | are also calculated.
Leptogenesis, neutrino masses and gauge unification
NASA Astrophysics Data System (ADS)
Cosme, N.
2004-08-01
Leptogenesis is considered in its natural context where Majorana neutrinos fit in a gauge unification scheme and therefore couple to some extra gauge bosons. The masses of some of these gauge bosons are expected to be similar to those of the heavy Majorana particles, and this can have important consequences for leptogenesis. In fact, the effect can go both ways. Stricter bounds are obtained on one hand due to the dilution of the CP-violating effect by new decay and scattering channels, while, in a re-heating scheme, the presence of gauge couplings facilitates the re-population of the Majorana states. The latter effect allows in particular for smaller Dirac couplings.
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.
Statistical Evaluation of Experimental Determinations of Neutrino Mass Hierarchy
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}|.
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.
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.
Probing the origins of neutrino mass with supernova data.
Davoudiasl, Hooman; Huber, Patrick
2005-11-04
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.
Probability densities of the effective neutrino masses mβ and mββ
NASA Astrophysics Data System (ADS)
Di Iura, Andrea; Meloni, Davide
2017-08-01
We compute the probability densities of the effective neutrino masses mβ and mββ using the Kernel Density Estimate (KDE) approach applied to a distribution of points in the (mmin ,mββ) and (mβ ,mββ) planes, obtained using the available Probability Distribution Functions (PDFs) of the neutrino mixing angles and mass differences, with the additional constraints coming from cosmological data on the sum of the neutrino masses. We show that the reconstructed probability densities strongly depend on the assumed set of cosmological data: for ∑jmj ≤ 0.68 eV at 95% CL a sensitive portion of the allowed values are already excluded by null results of experiments searching for mββ and mβ, whereas in the case ∑jmj ≤ 0.23 eV at 95% CL the bulk of the probability densities are below the current bounds.
NASA Astrophysics Data System (ADS)
Kirilova, D. P.; Chizhov, M. V.
2000-12-01
We have provided a numerical study of the influence of the resonant active-sterile neutrino oscillations νe↔ νs, on the primordial production of helium-4. The evolution of the neutrino ensembles was followed selfconsistently with the evolution of the nucleons, using exact kinetic equations for the neutrino density matrix and the nucleon number densities in momentum space, from the time of neutrino decoupling till the freeze-out of nucleons at 0.3 MeV. The exact kinetic approach enabled us to study precisely the neutrino depletion, spectrum distortion and neutrino mixing generated asymmetry due to oscillations at each momentum mode, and to prove that their effect on nucleosynthesis is considerable. We have calculated the dependence of the primordially produced helium-4 on the oscillation parameters Yp( δm2, ϑ) for the full range of mixing parameters of the model of oscillations with small mass differences δm2≤10 -7 eV 2. We have obtained iso-helium contours on the δm2- ϑ plane. Cosmological constraints on oscillation parameters, more precise than the existing ones were extracted, due to the exact kinetic approach and the proper account for the neutrino spectrum distortion and the oscillations generated asymmetry.
Neutrino mass spectrum and future beta decay experiments
NASA Astrophysics Data System (ADS)
Farzan, Y.; Peres, O. L. G.; Smirnov, A. Yu.
2001-09-01
We study the discovery potential of future beta decay experiments on searches for the neutrino mass in the sub-eV range, and, in particular, KATRIN experiment with sensitivity m>0.3 eV. Effects of neutrino mass and mixing on the beta decay spectrum in the neutrino schemes which explain the solar and atmospheric neutrino data are discussed. The schemes which lead to observable effects contain one or two sets of quasi-degenerate states. Future beta decay measurements will allow to check the three-neutrino scheme with mass degeneracy, moreover, the possibility appears to measure the CP-violating Majorana phase. Effects in the four-neutrino schemes which can also explain the LSND data are strongly restricted by the results of Bugey and CHOOZ oscillation experiments: apart from bending of the spectrum and the shift of the end point one expects appearance of small kink of (<2%) size or suppressed tail after bending of the spectrum with rate below 2% of the expected rate for zero neutrino mass. We consider possible implications of future beta decay experiments for the neutrino mass spectrum, the determination of the absolute scale of neutrino mass and for establishing the nature of neutrinos. We show that beta decay measurements in combination with data from the oscillation and double beta decay experiments will allow to establish the structure of the scheme (hierarchical or non-hierarchical), the type of the hierarchy or ordering of states (normal or inverted) and to measure the relative CP-violating phase in the solar pair of states.
An alternative method of determining the neutrino mass ordering in reactor neutrino experiments
NASA Astrophysics Data System (ADS)
Bilenky, S. M.; Capozzi, F.; Petcov, S. T.
2017-09-01
We discuss a novel alternative method of determining the neutrino mass ordering in medium baseline experiments with reactor antineutrinos. Results on the potential sensitivity of the new method are also presented.
New constraints on muon-neutrino to electron-neutrino transitions in MINOS
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).
Constraints on very light sterile neutrinos from θ 13-sensitive reactor experiments
NASA Astrophysics Data System (ADS)
Palazzo, Antonio
2013-10-01
Three dedicated reactor experiments, Double Chooz, RENO and Daya Bay, have recently performed a precision measurement of the third standard mixing angle θ 13 exploiting a multiple baseline comparison of ν e → ν e disappearance driven by the atmospheric mass-squared splitting. In this paper we show how the same technique can be used to put stringent limits on the oscillations of the electron neutrino into a fourth very light sterile species (VLS ν) characterized by a mass-squared difference lying in the range [10-3 - 10-1] eV2. We present accurate constraints on the admixture | U e4|2 obtained by a 4-flavor analysis of the publicly available reactor data. In addition, we show that the estimate of θ 13 obtained by the combination of the three reactor experiments is rather robust and substantially independent of the 4-flavor-induced perturbations provided that the new mass-squared splitting is not too low (≳ 6 × 10-3 eV2). We briefly comment on the possible impact of VLS ν's on the rest of the neutrino oscillation phenomenology and emphasize their potential role in the cosmological "dark radiation" anomaly.
Constraints on nonstandard intermediate boson exchange models from neutrino-electron scattering
NASA Astrophysics Data System (ADS)
Sevda, B.; Şen, A.; Demirci, M.; Deniz, M.; Agartioglu, M.; Ajjaq, A.; Kerman, S.; Singh, L.; Sonay, A.; Wong, H. T.; Zeyrek, M.
2017-08-01
Constraints on couplings of several beyond-Standard-Model-physics scenarios, mediated by massive intermediate particles including (1) an extra Z-prime, (2) a new light spin-1 boson, and (3) a charged Higgs boson, are placed via the neutrino-electron scattering channel to test the Standard Model at a low energy-momentum transfer regime. Data on ν¯e-e and νe-e scattering from the TEXONO and LSND, respectively, are used. Upper bounds to coupling constants of the flavor-conserving and flavor-violating new light spin-1 boson and the charged Higgs boson with respect to different mediator masses are determined. The relevant parameter spaces are extended by allowing light mediators. New lower mass limits for extra Z-prime gauge boson models are also placed.
Oyama, Yoshihiko; Kohri, Kazunori; Hazumi, Masashi E-mail: kohri@post.kek.jp
2016-02-01
Observations of the 21 cm line radiation coming from the epoch of reionization have a great capacity to study the cosmological growth of the Universe. Besides, CMB polarization produced by gravitational lensing has a large amount of information about the growth of matter fluctuations at late time. In this paper, we investigate their sensitivities to the impact of neutrino property on the growth of density fluctuations, such as the total neutrino mass, the effective number of neutrino species (extra radiation), and the neutrino mass hierarchy. We show that by combining a precise CMB polarization observation such as Simons Array with a 21 cm line observation such as Square kilometer Array (SKA) phase 1 and a baryon acoustic oscillation observation (Dark Energy Spectroscopic Instrument:DESI) we can measure effects of non-zero neutrino mass on the growth of density fluctuation if the total neutrino mass is larger than 0.1 eV. Additionally, the combinations can strongly improve errors of the bounds on the effective number of neutrino species σ (N{sub ν}) ∼ 0.06−0.09 at 95 % C.L.. Finally, by using SKA phase 2, we can determine the neutrino mass hierarchy at 95 % C.L. if the total neutrino mass is similar to or smaller than 0.1 eV.
Generalized mass ordering degeneracy in neutrino oscillation experiments
Coloma, Pilar; Schwetz, Thomas
2016-09-07
Here, 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 neutrinomore » NC scattering experiments.« less
Robust neutrino constraints by combining low redshift observations with the CMB
Reid, Beth A.; Verde, Licia; Jimenez, Raul; Mena, Olga E-mail: liciaverde@icc.ub.edu E-mail: omena@ific.uv.es
2010-01-01
We illustrate how recently improved low-redshift cosmological measurements can tighten constraints on neutrino properties. In particular we examine the impact of the assumed cosmological model on the constraints. We first consider the new HST H{sub 0} = 74.2±3.6 measurement by Riess et al. (2009) and the σ{sub 8}(Ω{sub m}/0.25){sup 0.41} = 0.832±0.033 constraint from Rozo et al. (2009) derived from the SDSS maxBCG Cluster Catalog. In a ΛCDM model and when combined with WMAP5 constraints, these low-redshift measurements constrain Σm{sub ν} < 0.4 eV at the 95% confidence level. This bound does not relax when allowing for the running of the spectral index or for primordial tensor perturbations. When adding also Supernovae and BAO constraints, we obtain a 95% upper limit of Σm{sub ν} < 0.3eV. We test the sensitivity of the neutrino mass constraint to the assumed expansion history by both allowing a dark energy equation of state parameter w≠−1 and by studying a model with coupling between dark energy and dark matter, which allows for variation in w, Ω{sub k}, and dark coupling strength ξ. When combining CMB, H{sub 0} and the SDSS LRG halo power spectrum from Reid et al. 2009, we find that in this very general model, Σm{sub ν} < 0.51 eV with 95% confidence. If we allow the number of relativistic species N{sub rel} to vary in a ΛCDM model with Σm{sub ν} = 0, we find N{sub rel} = 3.76{sup +0.63}{sub −0.68}({sup +1.38}{sub −1.21}) for the 68% and 95% confidence intervals. We also report prior-independent constraints, which are in excellent agreement with the Bayesian constraints.
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.
Neutrino beam constraints on flavor-diagonal Lorentz violation
NASA Astrophysics Data System (ADS)
Altschul, Brett
2013-05-01
Breaking of isotropy and Lorentz boost invariance in the dynamics of second-generation leptons would lead to direction-dependent changes in the lifetimes of charged pions. This would make the intensity of a neutrino beam produced via pion decay a function of the beam orientation. The experimental signature of this phenomenon—sidereal variations in the event rate at a downstream neutrino detector—has already been studied, in searches for Lorentz-violating neutrino oscillations. Existing analyses of MINOS near detector data can be used to constrain the flavor-diagonal Lorentz violation coefficients affecting muon neutrino speeds at roughly the 10-5 level.
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.
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.
Neutrino masses in lepton number violating mSUGRA
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.
Mass varying neutrinos, symmetry breaking, and cosmic acceleration
NASA Astrophysics Data System (ADS)
Sadjadi, H. Mohseni; Anari, V.
2017-06-01
We introduce a new proposal for the onset of cosmic acceleration based on mass varying neutrinos. When massive neutrinos become nonrelativistic, the Z2 symmetry breaks, and the quintessence potential becomes positive from its initially zero value. This positive potential behaves like a cosmological constant at the present era and drives the Universe's acceleration during the slow roll evolution of the quintessence. In contrast to Λ CDM model, the dark energy in our model is dynamical, and the acceleration is not persistent. Contrary to some of the previous models of dark energy with mass varying neutrinos, we do not use the adiabaticity condition, which leads to instability.
Cosmology in Mirror Twin Higgs and neutrino masses
Chacko, Zackaria; Craig, Nathaniel; Fox, Patrick J.; ...
2017-07-06
We explore a simple solution to the cosmological challenges of the original Mirror Twin Higgs (MTH) model that leads to interesting implications for experiment. We consider theories in which both the standard model and mirror neutrinos acquire masses through the familiar seesaw mechanism, but with a low right-handed neutrino mass scale of order a few GeV. In thesemore » $$\
Model independent explorations of Majorana neutrino mass origins
NASA Astrophysics Data System (ADS)
Jenkins, James Phearl, Jr.
The recent observation of nonzero neutrino mass is the first concrete indication of physics beyond the Standard Model. Their properties, unique among the other fermions, leads naturally to the idea of a Majorana neutrino mass term. Despite the strong theoretical prejudice toward this concept, it must be tested experimentally. This is indeed possible in the context of next generation experiments. Unfortunately, the scale of neutrino mass generation may be too large to explore directly, but useful information may still be extracted from independent experimental channels. Here I survey various model independent probes of Majorana neutrino mass origins. A brief introduction to the concepts relevant to the analysis is followed by a discussion of the physical ranges of neutrino mass and mixing parameters within the context of standard and non-standard interactions. Armed with this, I move on to systematically analyze the properties of radiatively generated neutrino masses induced by nonrenormalizable lepton number violating effective operators of mass dimensions five through eleven. By fitting these to the observed light mass scale, I extract predictions for neutrino mixing as well as neutrinoless double beta decay, rare meson/tau decays and collider phenomenology. I find that many such models are already constrained by current data and many more will be probed in the near future. I then move on demonstrate the utility of a low scale see saw mechanism via a viable 3+2+1 sterile neutrino model that satisfies all oscillation data as well as solves problems associated with supernova kicks and heavy element nucleosynthesis. From this I extract predictions for tritium and neutrinoless double beta decay searches. This is supplemented throughout by descriptions of practical limitations in addition to suggestions for future work.
Forbidden unique beta-decays and neutrino mass
NASA Astrophysics Data System (ADS)
Dvornický, Rastislav; Šimkovic, Fedor
2013-12-01
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 79Se, 107Pd and 187Re. It is found that the p3/2-wave emission dominates over the s1/2-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 3H.
SIMULTANEOUS CONSTRAINTS ON THE NUMBER AND MASS OF RELATIVISTIC SPECIES
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.
Radiative model of neutrino mass with neutrino interacting MeV dark matter
Arhrib, Abdesslam; Boehm, Céline; Ma, Ernest; Yuan, Tzu-Chiang
2016-04-26
We consider the radiative generation of neutrino mass through the interactions of neutrinos with MeV dark matter. We construct a realistic renormalizable model with one scalar doublet (in additional to the standard model doublet) and one complex singlet together with three light singlet Majorana fermions, all transforming under a dark U(1){sub D} symmetry which breaks softly to Z{sub 2}. We study in detail the scalar sector which supports this specific scenario and its rich phenomenology.
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.
Neutrino mass hierarchy and three-flavor spectral splits of supernova neutrinos
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.
Gauged U(1) Lμ -Lτ model in light of muon g - 2 anomaly, neutrino mass and dark matter phenomenology
NASA Astrophysics Data System (ADS)
Patra, Sudhanwa; Rao, Soumya; Sahoo, Nirakar; Sahu, Narendra
2017-04-01
Gauged U(1) Lμ -Lτ model has been advocated for a long time in light of muon g - 2 anomaly, which is a more than 3σ discrepancy between the experimental measurement and the standard model prediction. We augment this model with three right-handed neutrinos (Ne ,Nμ ,Nτ) and a vector-like singlet fermion (χ) to explain simultaneously the non-zero neutrino masses and dark matter content of the Universe, while satisfying the anomalous muon g - 2 constraints. We find that the model suffers stringent constraints from the simultaneous explanation of neutrino trident production and muon g - 2 anomaly. In a large region of the parameter space, where contribution to muon g - 2 anomaly comes partially and yet not ruled out by neutrino trident production, the model can explain the positron excess, observed at PAMELA, Fermi-LAT and AMS-02 through dark matter annihilation, while satisfying the relic density and direct detection limits.
Neutrino masses and oscillations in an unconventional model of lepton number violation
NASA Astrophysics Data System (ADS)
Tamvakis, K.; Vergados, J. D.
1985-06-01
Radiatively generated neutrino masses are studied in the framework of a simple model which predicts large mixings for neutrinos independently of the actual value of neutrino masses. The associated phenomenology of neutrino oscillations is analysed in detail. Other lepton violating processes are also discussed.
A tight SO(10) connection between leptogenesis and neutrino masses
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.
Relic Neutrino Absorption Spectroscopy
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.
Neutrino mass and the origin of galactic magnetic fields
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
NASA Astrophysics Data System (ADS)
Mathews, G. J.; Kajino, T.; Aoki, W.; Fujiya, W.; Pitts, J. B.
2012-05-01
There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced ν-process B11 and or Li7 encapsulated in the grains. The synthesis of B11 and Li7 via neutrino-induced nucleon emission (the ν process) in supernovas is sensitive to the neutrino mass hierarchy for finite sin22θ13>0.001. This sensitivity arises because, when there is 13 mixing, the average electron neutrino energy for charged-current neutrino reactions is larger for a normal mass hierarchy than for an inverted hierarchy. Recent constraints on θ13 from the Daya Bay, Double Chooz, MINOS, RENO, and T2K collaborations all suggest that indeed sin22θ13>0.001. We examine the possible implications of these new results based upon a Bayesian analysis of the uncertainties in the measured meteoritic material and the associated supernova nucleosynthesis models. We show that although the uncertainties are large, they hint at a marginal preference for an inverted neutrino mass hierarchy. We discuss the possibility that an analysis of more X grains enriched in Li and B along with a better understanding of the relevant stellar nuclear and neutrino reactions could eventually reveal the neutrino mass hierarchy.
Neutrino masses and mixings in non-factorizable geometry
Grossman, Y.
2000-01-07
The authors study bulk fermion fields in the localized gravity model with non-factorizable metric recently proposed by Randall and Sundrum, and Gogberashvili. In addition to a tower of weak-scale Kaluza-Klein states the authors find a zero mode for any value of the fundamental fermion mass. If the fermion mass is larger than half the curvature of the compact dimension, the zero mode can be localized on the ``hidden'' 3-brane in the Randall-Sundrum model. Identifying this mode with a right-handed neutrino provides a new way for obtaining small Dirac neutrino masses without invoking a see-saw mechanism. Cancellation of the parity anomaly requires introducing an even number of bulk fermions. This naturally leads to a strong hierarchy of neutrino masses and generically large mixing angles.
Unification of gauge couplings in radiative neutrino mass models
NASA Astrophysics Data System (ADS)
Hagedorn, Claudia; Ohlsson, Tommy; Riad, Stella; Schmidt, Michael A.
2016-09-01
We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level. Renormalization group running of gauge couplings is performed analytically and numerically at one- and two-loop order, respectively. We study three representative classes of radiative neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 Δ L = 2 operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino masses at one-loop level and (III) models with particles in the adjoint representation of SU(3). In class (I), gauge couplings unify in a few models and adding dark matter amplifies the chances for unification. In class (II), about a quarter of the models admits gauge coupling unification. In class (III), none of the models leads to gauge coupling unification. Regarding the scale of unification, we find values between 1014 GeV and 1016 GeV for models belonging to class (I) without dark matter, whereas models in class (I) with dark matter as well as models of class (II) prefer values in the range 5·1010 - 5·1014 GeV.
Dark matter, {mu} problem, and neutrino mass with gauged R symmetry
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.
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.
Shedding light on neutrino masses with dark forces
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
Shedding light on neutrino masses with dark forces
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 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. 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.
The seesaw portal in testable models of neutrino masses
NASA Astrophysics Data System (ADS)
Caputo, A.; Hernández, P.; López-Pavón, J.; Salvado, J.
2017-06-01
A Standard Model extension with two Majorana neutrinos can explain the measured neutrino masses and mixings, and also account for the matter-antimatter asymmetry in a region of parameter space that could be testable in future experiments. The testability of the model relies to some extent on its minimality. In this paper we address the possibility that the model might be extended by extra generic new physics which we parametrize in terms of a low-energy effective theory. We consider the effects of the operators of the lowest dimensionality, d = 5, and evaluate the upper bounds on the coefficients so that the predictions of the minimal model are robust. One of the operators gives a new production mechanism for the heavy neutrinos at LHC via higgs decays. The higgs can decay to a pair of such neutrinos that, being long-lived, leave a powerful signal of two displaced vertices. We estimate the LHC reach to this process.
New Constraints on Neutrino Physics from BOOMERANG Data
NASA Astrophysics Data System (ADS)
Hannestad, Steen
2000-11-01
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 2σ bound is Nν<=13. This bound is not flavor sensitive. It also applies to the Universe at a much later epoch, and as such places severe limits on scenarios with decaying neutrinos. The bound also yields a firm upper limit on the lepton asymmetry in the Universe.
Neutrinos and the origin of fermion mass structure
Ross, Graham G.
2007-11-20
The pattern of neutrino masses and mixings is characteristically different from those observed in the quark sector. I discuss why this should be the case and what implications this has for the origin of quark and lepton masses, mixings and CP violation.
Predictive model for radiatively induced neutrino masses and mixings with dark matter.
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.
NASA Astrophysics Data System (ADS)
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.; Cowan, J. H.; 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.; 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.; 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.; Radcliffe, T. J.; Roberge, A.; Robertson, B. C.; Robertson, R. G.; Rosendahl, S. S.; 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.; 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 (sup 8)B spectrum, the night minus day rate is 14.0%[plus-or-minus]6.3%(sup +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%[plus-or-minus]4.9%(sup +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.
Neutrino Masses, Cosmological Bound and Four Zero Yukawa Textures
NASA Astrophysics Data System (ADS)
Adhikary, Biswajit; Ghosal, Ambar; Roy, Probir
Four zero neutrino Yukawa textures in a specified weak basis, combined with μτ symmetry and type-I seesaw, yield a highly constrained and predictive scheme. Two alternately viable 3×3 light neutrino Majorana mass matrices mνA/mνB result with inverted/normal mass ordering. Neutrino masses, Majorana in character and predicted within definite ranges with laboratory and cosmological inputs, will have their sum probed cosmologically. The rate for 0νββ decay, though generally below the reach of planned experiments, could approach it in some parameter region. Departure from μτ symmetry due to RG evolution from a high scale and consequent CP violation, with a Jarlskog invariant whose magnitude could almost reach 6×10-3, are explored.
Doublet-triplet dark matter with neutrino masses
NASA Astrophysics Data System (ADS)
Betancur, Amalia; Longas, Robinson; Zapata, Oscar
2017-08-01
We consider a dark matter (DM) model that arises from the interplay of two renormalizable dark matter models, namely, the doublet-triplet fermion model and the doublet-triplet scalar model. Despite being excellent exponents of the weakly interacting massive particle paradigm, the physics related to DM in each of these models fails at the same time to account for neutrino masses. It turns out that from the combination of these two models it is possible to generate neutrino masses at one-loop level in the four topologies that are realizations of the Weinberg operator for neutrino masses at one loop. In this work, we combine both models focusing mostly on fermionic dark matter lying at the electroweak scale. We analyze the impact of the extra charged fields on the Higgs diphoton decay and find that, thanks to the presence of the charged scalars, it is possible to have a viable DM region at the electroweak scale.
Constraints on cosmic ray and PeV neutrino production in blazars
NASA Astrophysics Data System (ADS)
Zhang, B. Theodore; Li, Zhuo
2017-03-01
IceCube has detected a cumulative flux of PeV neutrinos, which origin is unknown. Blazars, active galactic nuclei with relativistic jets pointing to us, are long and widely expected to be one of the strong candidates of high energy neutrino sources. The neutrino production depends strongly on the cosmic ray power of blazar jets, which is largely unknown. The recent null results in stacking searches of neutrinos for several blazar samples by IceCube put upper limits on the neutrino fluxes from these blazars. Here we compute the cosmic ray power and PeV neutrino flux of Fermi-LAT blazars, and find that the upper limits for known blazar sources give stringent constraint on the cosmic ray loading factor of blazar jets (i.e., the ratio of the cosmic ray to bolometric radiation luminosity of blazar jets), ξcr lesssim (2–10)ζ‑1 (with ζ lesssim 1 the remained fraction of cosmic ray energy when propagate into the blazar broad line region) for flat cosmic ray spectrum, and that the cumulative PeV neutrino flux contributed by all-sky blazars is a fraction lesssim (10–50)% of the IceCube detected flux.
Physical effects involved in the measurements of neutrino masses with future cosmological data
NASA Astrophysics Data System (ADS)
Archidiacono, Maria; Brinckmann, Thejs; Lesgourgues, Julien; Poulin, Vivian
2017-02-01
Future Cosmic Microwave Background experiments together with upcoming galaxy and 21-cm surveys will provide extremely accurate measurements of different cosmological observables located at different epochs of the cosmic history. The new data will be able to constrain the neutrino mass sum with the best precision ever. In order to exploit the complementarity of the different redshift probes, a deep understanding of the physical effects driving the impact of massive neutrinos on CMB and large scale structures is required. The goal of this work is to describe these effects, assuming a summed neutrino mass close to its minimum allowed value. We find that parameter degeneracies can be removed by appropriate combinations, leading to robust and model independent constraints. A joint forecast of the sensitivity of Euclid and DESI surveys together with a CORE-like CMB experiment leads to a 1σ uncertainty of 14 meV on the summed neutrino mass. Finally the degeneracy between Mν and the optical depth at reionization τreio, originating in the combination of CMB and low redshift galaxy probes, might be broken by future 21-cm surveys, thus further decreasing the uncertainty on Mν. For instance, an independent determination of the optical depth with an accuracy of σ(τreio)=0.001 (which might be achievable, although this is subject to astrophysical uncertainties) would decrease the uncertainty down to σ(Mν)=12 meV.
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.
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.
Two-loop Dirac neutrino mass and WIMP dark matter
NASA Astrophysics Data System (ADS)
Bonilla, Cesar; Ma, Ernest; Peinado, Eduardo; Valle, Jose W. F.
2016-11-01
We propose a "scotogenic" mechanism relating small neutrino mass and cosmological dark matter. Neutrinos are Dirac fermions with masses arising only in two-loop order through the sector responsible for dark matter. Two triality symmetries ensure both dark matter stability and strict lepton number conservation at higher orders. A global spontaneously broken U(1) symmetry leads to a physical Diracon that induces invisible Higgs decays which add up to the Higgs to dark matter mode. This enhances sensitivities to spin-independent WIMP dark matter search below mh / 2.
Magic neutrino mass matrix and the Bjorken Harrison Scott parameterization
NASA Astrophysics Data System (ADS)
Lam, C. S.
2006-09-01
Observed neutrino mixing can be described by a tribimaximal MNS matrix. The resulting neutrino mass matrix in the basis of a diagonal charged lepton mass matrix is both 2-3 symmetric and magic. By a magic matrix, I mean one whose row sums and column sums are all identical. I study what happens if 2-3 symmetry is broken but the magic symmetry is kept intact. In that case, the mixing matrix is parameterized by a single complex parameter Ue 3, in a form discussed recently by Bjorken, Harrison, and Scott.
Cosmology in Mirror Twin Higgs and neutrino masses
NASA Astrophysics Data System (ADS)
Chacko, Zackaria; Craig, Nathaniel; Fox, Patrick J.; Harnik, Roni
2017-07-01
We explore a simple solution to the cosmological challenges of the original Mirror Twin Higgs (MTH) model that leads to interesting implications for experiment. We consider theories in which both the standard model and mirror neutrinos acquire masses through the familiar seesaw mechanism, but with a low right-handed neutrino mass scale of order a few GeV. In these νMTH models, the right-handed neutrinos leave the thermal bath while still relativistic. As the universe expands, these particles eventually become nonrelativistic, and come to dominate the energy density of the universe before decaying. Decays to standard model states are preferred, with the result that the visible sector is left at a higher temperature than the twin sector. Consequently the contribution of the twin sector to the radiation density in the early universe is suppressed, allowing the current bounds on this scenario to be satisfied. However, the energy density in twin radiation remains large enough to be discovered in future cosmic microwave background experiments. In addition, the twin neutrinos are significantly heavier than their standard model counterparts, resulting in a sizable contribution to the overall mass density in neutrinos that can be detected in upcoming experiments designed to probe the large scale structure of the universe.
Maccione, Luca; Liberati, Stefano; Mattingly, David M. E-mail: liberati@sissa.it
2013-03-01
Recently there has been a renewed activity in the physics of violations of Lorentz invariance in the neutrino sector. Flavor dependent Lorentz violation, which generically changes the pattern of neutrino oscillations, is extremely tightly constrained by oscillation experiments. Flavor independent Lorentz violation, which does not introduce new oscillation phenomena, is much more weakly constrained with constraints coming from time of flight and anomalous threshold analyses. We use a simplified rotationally invariant model to investigate the effects of finite baselines and energy dependent dispersion on anomalous reaction rates in long baseline experiments and show numerically that anomalous reactions do not necessarily cut off the spectrum quite as sharply as currently assumed. We also present a revised analysis of how anomalous reactions can be used to cast constraints from the observed atmospheric high energy neutrinos and the expected cosmogenic ones.
Measuring neutrino masses with a future galaxy survey
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)
NASA Astrophysics Data System (ADS)
Liu, Zhen; Gu, Pei-Hong
2017-02-01
We extend some two Higgs doublet models, where the Yukawa couplings for the charged fermion mass generation only involve one Higgs doublet, by two singlet scalars respectively carrying a singly electric charge and a doubly electric charge. The doublet and singlet scalars together can mediate a two-loop diagram to generate a tiny Majorana mass matrix of the standard model neutrinos. Remarkably, the structure of the neutrino mass matrix is fully determined by the symmetric Yukawa couplings of the doubly charged scalar to the right-handed leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can arrive at a testable level even if the electron neutrino has an extremely small Majorana mass. We also study other experimental constraints and implications including some rare processes and Higgs phenomenology.
Reconstructing SUSY and R-Neutrino Masses in SO(10)
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.
NASA Astrophysics Data System (ADS)
Jinnouchi, O.; Homma, K.
1998-09-01
The unphysical result of the negative mass square of the electron neutrinos recently reported in several tritium β-decay experiments, is one of the most attractive subjects among remaining physical problems. As a possible scenario to explain the anomaly, we have assumed a reaction with relic neutrinos which are predicted by the standard big bang cosmology. If such neutrinos could exist, the interaction of the relic neutrinos with the target tritium, νe+3H-->3He+e- could be laid under the large amount of the β-decay process, 3H-->3He+e-+νē, which would cause a peak-like structure beyond the end-point in the Kurie plot. Based on the assumption, we evaluated the cross section from the event rate found in the peak by re-fitting to the 1991 data published by the Mainz Group. In this letter we will provide a scenario that can account for the evaluated cross section by introducing a spatially inhomogeneous neutrino degeneration, which would result much lower temperature than the prediction from the standard big bang cosmology.
Neutrino masses in the left right supersymmetric model
NASA Astrophysics Data System (ADS)
Frank, M.
2002-08-01
We show that in a left-right supersymmetric model with a Higgs structure that supports the see-saw mechanism, the neutrinos get additional contributions to their masses at one loop level. The mechanism responsible is analogous to the Grossman-Haber see-saw mechanism, but the additional mass terms are proportional to the mass difference of the right-handed sneutrinos. We show that the data on both the solar and the atmospheric neutrinos can be accommodated by either two almost degenerate right-handed sneutrinos, or two heavy sneutrino with different, but still relatively small, mass splittings. We discuss the implications of this result for the masses and mixings of the heavy sneutrinos, and the soft-breaking parameters of the left-right supersymmetric model.
Distinguishing neutrino mass hierarchies using dark matter annihilation signals at IceCube
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.
False Vacuum in the Supersymmetric Mass Varying Neutrino Model
Tanimoto, Morimitsu
2009-04-17
We discuss the vacuum structure of the scalar potential in a supersymmetric Mass Varying Neutrinos model. The observed dark energy density is identified with the false vacuum energy and the dark energy scale of order (10{sup -3} eV){sup 4} is understood by gravitationally suppressed supersymmetry breaking scale, F(TeV{sup 2})/M{sub pl}.
NEW NEUTRINO MASS BOUNDS FROM SDSS-III DATA RELEASE 8 PHOTOMETRIC LUMINOUS GALAXIES
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
New Neutrino Mass Bounds from SDSS-III Data Release 8 Photometric Luminous Galaxies
NASA Astrophysics Data System (ADS)
de Putter, Roland; Mena, Olga; Giusarma, Elena; Ho, Shirley; Cuesta, Antonio; Seo, Hee-Jong; Ross, Ashley J.; White, Martin; Bizyaev, Dmitry; Brewington, Howard; Kirkby, David; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Percival, Will J.; Ross, Nicholas P.; Schneider, Donald P.; Shelden, Alaina; Simmons, Audrey; Snedden, Stephanie
2012-12-01
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 deg2, thus probing a volume of 3 h -3 Gpc3 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 ∑m ν < 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 (~1σ-1.5σ) bias in ΩDM h 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., ∑m ν < 0.38 eV (95% CL) for WMAP+HST+CMASS (lmax = 200). We also study the dependence of the neutrino bound on the multipole range (lmax = 150 versus lmax = 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 Ω K , while a second companion paper presents a measurement of the scale of baryon acoustic oscillations from
False vacuum in the supersymmetric mass varying neutrinos model
Takahashi, Ryo; Tanimoto, Morimitsu
2008-02-15
We present detailed analyses of the vacuum structure of the scalar potential in a supersymmetric mass varying neutrinos model. The observed dark energy density is identified with false vacuum energy and the dark energy scale of order (10{sup -3} eV){sup 4} is understood by the gravitationally suppressed supersymmetry breaking scale, F(TeV){sup 2}/M{sub Pl}, in the model. The vacuum expectation values of sneutrinos should be tiny in order that the model works. Some decay processes of superparticles into an acceleron and sterile neutrino are also discussed in the model.
NASA Astrophysics Data System (ADS)
Hirsch, M.; Díaz, M. A.; Porod, W.; Romão, J. C.; Valle, J. W. F.
2000-12-01
The simplest unified extension of the minimal supersymmetric standard model with bilinear R-parity violation naturally predicts a hierarchical neutrino mass spectrum, in which one neutrino acquires mass by mixing with neutralinos, while the other two get mass radiatively. We have performed a full one-loop calculation of the neutralino-neutrino mass matrix in the bilinear R/p minimal supersymmetric standard model, taking special care to achieve a manifestly gauge invariant calculation. Moreover we have performed the renormalization of the heaviest neutrino, needed in order to get meaningful results. The atmospheric mass scale and maximal mixing angle arise from tree-level physics, while solar neutrino scale and oscillations follow from calculable one-loop corrections. If universal supergravity assumptions are made on the soft-supersymmetry breaking terms then the atmospheric scale is calculable as a function of a single R/p violating parameter by the renormalization group evolution due to the nonzero bottom quark Yukawa coupling. The solar neutrino problem must be accounted for by the small mixing angle Mikheyev-Smirnov-Wolfenstein (MSW) solution. If these assumptions are relaxed then one can implement large mixing angle solutions. The theory predicts the lightest supersymmetic particle decay to be observable at high-energy colliders, despite the smallness of neutrino masses indicated by experiment. This provides an independent way to test this solution of the atmospheric and solar neutrino anomalies.
Mass hierarchy determination via future atmospheric neutrino detectors
NASA Astrophysics Data System (ADS)
Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Mehta, Poonam; Uma Sankar, S.; Shalgar, Shashank
2007-10-01
We study the problem of determination of the sign of Δm312, or the neutrino mass hierarchy, through observations of atmospheric neutrinos in future detectors. We consider two proposed detector types: (a) Megaton sized water C̆erenkov detectors, which can measure the event rates of νμ+ν¯μ and νe+ν¯e and (b) 100 kton sized magnetized iron detectors, which can measure the event rates of νμ and ν¯μ. For energies and path lengths relevant to atmospheric neutrinos, these rates obtain significant matter contributions from Pμe, Pμμ and Pee, leading to an appreciable sensitivity to the hierarchy. We do a binned χ2 analysis of simulated data in these two types of detectors which includes the effect of smearing in neutrino energy and direction and incorporates detector efficiencies and relevant statistical, theoretical and systematic errors. We also marginalize the χ2 over the allowed ranges of neutrino parameters in order to accurately account for their uncertainties. Finally, we compare the performance of both types of detectors vis a vis the hierarchy determination.
Low Temperature Magnetic Calorimeters For Neutrino Mass Direct Measurement
NASA Astrophysics Data System (ADS)
Gastaldo, L.; Porst, J. P.; von Seggern, F.; Kirsch, A.; Ranitzsch, P.; Fleischmann, A.; Enss, C.; Seidel, G. M.
2009-12-01
In the last years the mixing of the three neutrino flavor eigenstates through a unitary matrix has been experimentally proved. Presently one of the greatest challenges in neutrino physics is to establish the absolute value of the masses of the three neutrino mass eigenstates. The kinematic determination of electron neutrino and antineutrino mass by means of the analysis of calorimetric spectra of isotopes which undergo a beta or electron-capture decay, with especially low energy available for the decay itself, represents an interesting method. In fact this method is less affected by theoretical models defining branching ratio among different decay modes. For the beta decay the isotope with the lowest Q-value present in nature is the 187Re (Q about 2.5 keV) while for the electron capture decay the best candidate known is the 163Ho (Q about 2.5 keV). Since those experiments need to be extremely precise, they might suffer from unexpected systematic errors. It is therefore important to investigate in detail the performance of the detectors and the calorimetric spectrum. We present our results obtained with low temperature magnetic calorimeters designed for measuring low energy beta and electron capture spectra. We also discuss problematic and the possibly present systematic uncertainties using this kind of detectors.
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.
Phenomenology of "bimaximal + Democratic" Type Neutrino Mass Matrix
NASA Astrophysics Data System (ADS)
Ghosal, Ambar; Majumdar, Debasish
We demonstrate that "Bimaximal + Democratic" type neutrino mass matrix can accommodate the deviation of θ⊙ from its maximal value along with the other present-day neutrino experimental results, namely, atmospheric, CHOOZ, neutrinoless double beta decay (ββ0ν) and result obtained from WMAP experiment. We define a function χp in terms of solar and atmospheric neutrino mass squared differences and solar neutrino mixing angle (obtained from different experiments and our proposed texture). The masses and mixing angles are expressed in terms of three parameters in our proposed texture. The allowed region of the texture parameters is obtained through minimization of the above function. The proposed texture crucially depends on the value of the experimental results of ββ0ν experiment among all other above-mentioned experiments. If, in future, ββ0ν experiments, namely, MOON, EXO, GENIUS shift the lower bound on
Forbidden unique beta-decays and neutrino mass
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.
One vanishing minor in the neutrino mass matrix
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.
Sterile neutrinos in the early universe
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.
Study of radiative neutrino mass generation and physics beyond the Standard Model
NASA Astrophysics Data System (ADS)
Julio, Julio
Scope and methods. In this dissertation I propose a new class of models of radiative neutrino mass generation induced by leptoquarks. These models generate neutrino mass at two-loop level. Chapter 2 and Chapter 3 are devoted to discuss such models. In Chapter 4, I study the perturbative unitarity constraints on class of W' models attempting to explain the Tevatron top quark asymmetry and CDF Wjj anomaly. Findings and conclusions. In one model discussed in Chapter 2, it is shown that all of neutrino oscillation data can be explained consistently. The lightest of neutrinos is predicted to be massless with the hierarchy of neutrino mass being normal. The oscillation parameters are linked to leptoquark branching ratios. Neutrinoless double beta decay might be observed through vector-scalar exchange. New contribution to CP violation in B0s system arises from leptoquark box diagrams, which can explain the apparent anomaly observed in experiments. In Chapter 3, I propose a model of two-loop neutrino mass involving a charge 2/3 vectorlike particle and a doublet of leptoquark scalar. This model predicts one of the neutrinos to be massless and admits both the normal and inverted neutrino mass hierarchies with correlated predictions for ℓi → ℓ j + gamma branching ratios. New contributions to CP violation in B0s-B0s mixing arise in the model through leptoquark box diagrams and through mixing of quarks with vectorlike quark. These can explain the anomalous dimuon events reported by the D0 Collaboration. These leptoquarks, with masses below 500 GeV, also provide a natural resolution to the apparent discrepancy in the measured values of the CP violation parameters sin 2beta and epsilonK. In Chapter 4, I study perturbative unitarity constraints on general W' models by considering the high energy behavior of fermion scattering into gauge bosons. In most cases that are surveyed, a Z' boson with a comparable mass must be present for the theory to be consistent, with fixed
Gravity effects on neutrino masses in split supersymmetry
Diaz, Marco Aurelio; Koch, Benjamin; Panes, Boris
2009-06-01
The mass differences and mixing angles of neutrinos can neither be explained by R-parity violating split supersymmetry nor by flavor blind quantum gravity alone. It is shown that combining both effects leads, within the allowed parameter range, to good agreement with the experimental results. The atmospheric mass is generated by supersymmetry through mixing between neutrinos and neutralinos, while the solar mass is generated by gravity through flavor blind dimension five operators. Maximal atmospheric mixing forces the tangent squared of the solar angle to be equal to 1/2. The scale of the quantum gravity operator is predicted within a 5% error, implying that the reduced Planck scale should lie around the grand unified theory scale. In this way, the model is very predictive and can be tested at future experiments.
Textures with two traceless submatrices of the neutrino mass matrix
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.
Effect of neutrino rest mass on ionization equilibrium freeze-out
Grohs, Evan Bradley; Fuller, George M.; Kishimoto, Chad T.; ...
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.
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.
Effect of neutrino rest mass on ionization equilibrium freeze-out
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.
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.
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.
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.
Models of Neutrino Masses: Anarchy versus Hierarchy
NASA Astrophysics Data System (ADS)
Altarelli, Guido; Feruglio, Ferruccio; Masina, Isabella
2003-01-01
We present a quantitative study of the ability of models with different levels of hierarchy to reproduce the solar neutrino solutions, in particular the LA solution. As a flexible testing ground we consider models based on SU(5) × U(1)F. In this context, we have made statistical simulations of models with different patterns from anarchy to various types of hierarchy: normal hierarchical models with and without automatic suppression of the 23 (sub)determinant and inverse hierarchy models. We find that, not only for the LOW or VO solutions, but even in the LA case, the hierarchical models have a significantly better success rate than those based on anarchy. The normal hierarchy and the inverse hierarchy models have comparable performances in models with see-saw dominance, while the inverse hierarchy models are particularly good in the no see-saw versions. As a possible distinction between these categories of models, the inverse hierarchy models favour a maximal solar mixing angle and their rate of success drops dramatically as the mixing angle decreases, while normal hierarchy models are far more stable in this respect.
Common origin of neutrino mass, dark matter and Dirac leptogenesis
NASA Astrophysics Data System (ADS)
Borah, Debasish; Dasgupta, Arnab
2016-12-01
We study the possibility of generating tiny Dirac neutrino masses at one loop level through the scotogenic mechanism such that one of the particles going inside the loop can be a stable cold dark matter (DM) candidate. Majorana mass terms of singlet fermions as well as tree level Dirac neutrino masses are prevented by incorporating the presence of additional discrete symmetries in a minimal fashion, which also guarantee the stability of the dark matter candidate. Due to the absence of total lepton number violation, the observed baryon asymmetry of the Universe is generated through the mechanism of Dirac leptogenesis where an equal and opposite amount of leptonic asymmetry is generated in the left and right handed sectors which are prevented from equilibration due to tiny Dirac Yukawa couplings. Dark matter relic abundance is generated through its usual freeze-out at a temperature much below the scale of leptogenesis. We constrain the relevant parameter space from neutrino mass, baryon asymmetry, Planck bound on dark matter relic abundance, and latest LUX bound on spin independent DM-nucleon scattering cross section. We also discuss the charged lepton flavour violation (μ → e γ) and electric dipole moment of electron in this model in the light of the latest experimental data and constrain the parameter space of the model.
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.
Cosmology with massive neutrinos III: the halo mass function and an application to galaxy clusters
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.
A radiative neutrino mass model with SIMP dark matter
NASA Astrophysics Data System (ADS)
Ho, Shu-Yu; Toma, Takashi; Tsumura, Koji
2017-07-01
We propose the first viable radiative seesaw model, in which the neutrino masses are induced radiatively via the two-loop Feynman diagram involving Strongly Interacting Massive Particles (SIMP). The stability of SIMP dark matter (DM) is ensured by a ℤ 5 discrete symmetry, through which the DM annihilation rate is dominated by the 3 → 2 self-annihilating processes. The right amount of thermal relic abundance can be obtained with perturbative couplings in the resonant SIMP scenario, while the astrophysical bounds inferred from the Bullet cluster and spherical halo shapes can be satisfied. We show that SIMP DM is able to maintain kinetic equilibrium with thermal plasma until the freeze-out temperature via the Yukawa interactions associated with neutrino mass generation.
Lai, Kwang-Chang; Lee, Fei-Fan; Lee, Feng-Shiuh; Lin, Guey-Lin; Liu, Tsung-Che; Yang, Yi
2016-07-22
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(ν-bar)+p→ν(ν-bar)+p, and inverse beta decays (IBD), ν-bar{sub e}+p→n+e{sup +}, 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 ν-bar{sub e} flux with the ν-bar{sub x} (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.
NASA Astrophysics Data System (ADS)
Dermíšek, Radovan
2004-08-01
We show that both small mixing in the quark sector and large mixing in the lepton sector can be obtained from a simple assumption of universality of Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading order. We discuss conditions under which bilarge mixing in the lepton sector is achieved with a minimal amount of fine-tuning requirements for possible models. From knowledge of the solar and atmospheric mixing angles we determine the allowed values of sin θ13. If embedded into grand unified theories, the third generation Yukawa coupling unification is a generic feature while masses of the first two generations of charged fermions depend on small perturbations. In the neutrino sector, the heavier two neutrinos are model dependent, while the mass of the lightest neutrino in this approach does not depend on perturbations in the leading order. The right-handed neutrino mass scale can be identified with the GUT scale in which case the mass of the lightest neutrino is given as (m2top/MGUT)sin2 θ23 sin2 θ12 in the limit sin θ13≃0. Discussing symmetries we make a connection with hierarchical models and show that the basis independent characteristic of this scenario is a strong dominance of the third generation right-handed neutrino, M1,M2<10-4M3, M3=MGUT.
Peccei-Quinn symmetry, dark matter, and neutrino mass
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.
Neutrino mass, electron capture, and the shake-off contributions
NASA Astrophysics Data System (ADS)
Faessler, Amand; Gastaldo, Loredana; Šimkovic, Fedor
2017-04-01
Electron capture can determine the electron neutrino mass, while the β decay of tritium measures the electron antineutrino mass and the neutrinoless double β decay observes the Majorana neutrino mass. In electron capture, e.g., Ho16367+e-→Dy16366*+νe , one can determine the electron neutrino mass from the upper end of the decay spectrum of the excited Dy, which is given by the Q value minus the neutrino mass. The excitation of Dy is described by one, two, and even three hole excitations limited by the Q value. These states decay by x-ray and Auger electron emissions. The total decay energy is measured in a bolometer. These excitations have been studied by Robertson and by Faessler et al. In addition the daughter atom Dy can also be excited by moving in the capture process one (or more) electrons into the continuum. The escape of these continuum electrons is automatically included in the experimental bolometer spectrum. Recently a method developed by Intemann and Pollock was used by DeRujula and Lusignoli for a rough estimate of this shake-off process for "s " wave electrons in capture on 163Ho. The purpose of the present work is to give a more reliable description of "s " wave shake-off in electron capture on holmium. One uses the sudden approximation to calculate the spectrum of the decay of Dy16366* after electron capture on Ho16367. For that one needs very accurate atomic wave functions of Ho in its ground state and excited atomic wave functions of Dy including a description of the continuum electrons. DeRujula and Lusignoli use screened nonrelativistic Coulomb wave functions for the Ho electrons 3 s and 4 s and calculate the Dy* states by first-order perturbation theory based on Ho. In the present approach the wave functions of Ho and Dy* are determined self-consistently with the antisymmetrized relativistic Dirac-Hartree-Fock approach. The relativistic continuum electron wave functions for the ionized Dy* are obtained in the corresponding self
NEUTRINO CONSTRAINTS TO THE DIFFUSE GAMMA-RAY EMISSION FROM ACCRETION SHOCKS
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.
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.
NASA Astrophysics Data System (ADS)
Murthy, P. V. R.
The astrophysics and high energy physics of neutrinos are discussed. The former includes the topics of solar neutrinos, gravitational stellar collapses, neutrinos at high and superhigh energies, and DUMAND and related topics. Experimental results from the Homestake mine chlorine-37 experiment on solar neutrinos are shown. The solar neutrino puzzle is assessed, the economic aspects of DUMAND are discussed, and expectations for related projects are examined. For high energy physics, the discussion includes DUMAND and related projects, neutrino oscillations, the resolution of the puzzles of the measurement of the stopping muon flux and of the cosmic ray event time intervals, and the proton decay experiments.
Connecting Dirac and Majorana neutrino mass matrices in the minimal left-right symmetric model.
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.
Neutrino masses, leptogenesis, and dark matter in a hybrid seesaw model
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.
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.
Measurement of the Top Quark Mass in Dilepton Final States with the Neutrino Weighting Method
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 m_{t} = 174.0± 2.4 (stat.) ±1.4 (syst.) GeV.
Neutrino mass model with S3 symmetry and seesaw interplay
NASA Astrophysics Data System (ADS)
Pramanick, Soumita; Raychaudhuri, Amitava
2016-12-01
We develop a seesaw model for neutrino masses and mixing with an S3×Z3 symmetry. It involves an interplay of type-I and type-II seesaw contributions of which the former is subdominant. The S3×Z3 quantum numbers of the fermion and scalar fields are chosen such that the type-II seesaw generates a mass matrix which incorporates the atmospheric mass splitting and sets θ23=π /4 . The solar splitting and θ13 are absent, while the third mixing angle can achieve any value, θ120. Specific choices of θ120 are of interest, e.g., 35.3° (tribimaximal), 45.0° (bimaximal), 31.7° (golden ratio), and 0° (no solar mixing). The role of the type-I seesaw is to nudge all the above into the range indicated by the data. The model results in novel interrelationships between these quantities due to their common origin, making it readily falsifiable. For example, normal (inverted) ordering is associated with θ23 in the first (second) octant. C P violation is controlled by phases in the right-handed neutrino Majorana mass matrix, Mν R . In their absence, only normal ordering is admissible. When Mν R is complex, the Dirac C P phase, δ , can be large, i.e., ˜±π /2 , and inverted ordering is also allowed. The preliminary results from T2K and NOVA which favor normal ordering and δ ˜-π /2 are indicative, in this model, of a lightest neutrino mass of 0.05 eV or more.
Explaining solar neutrinos with heavy Higgs masses in partial split supersymmetry
Diaz, Marco Aurelio; Garay, Francisca; Koch, Benjamin
2009-12-01
Partial Split Supersymmetry with violation of R-parity as a model for neutrino masses is explored. It is shown that at the one-loop level the model can give predictions that are in agreement with all present experimental values for the neutrino sector. An analytical result is that the small solar neutrino mass difference can be naturally explained in the decoupling limit for the heavy Higgs mass eigenstates.
Upper Bound of 0.28 eV on Neutrino Masses from the Largest Photometric Redshift Survey
Thomas, Shaun A.; Abdalla, Filipe B.; Lahav, Ofer
2010-07-16
We present a new limit of (95% CL) on the sum of the neutrino masses assuming a flat {Lambda}CDM cosmology. This relaxes slightly to and when quasinonlinear scales are removed and w{ne}-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{sup -1}){sup 3} and redshift range 0.45
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.
Neutrino mass matrix with the seesaw mechanism and two-loop mass splitting
NASA Astrophysics Data System (ADS)
Grimus, W.; Lavoura, L.
2000-11-01
We propose a model which uses the seesaw mechanism and the lepton number L¯=Le-Lμ-Lτ to achieve the neutrino mass spectrum m1=m2 and m3=0, together with a lepton mixing matrix U with Ue3=0. In this way, we accommodate atmospheric neutrino oscillations. A small mass splitting m1>m2 is generated by breaking L¯ spontaneously and using Babu's two-loop mechanism. This allows us to incorporate either the ``just so'' or the LOW solution of the solar-neutrino problem, with maximal mixing, into the model. The resulting mass matrix has three parameters only, since L¯ breaking leads exclusively to a non-zero ee matrix element.
COSMOLOGICAL CONSTRAINTS ON THE HIGGS BOSON MASS
Popa, L. A.; Caramete, A.
2010-11-01
For a robust interpretation of upcoming observations from PLANCK and Large Hadron Collider experiments it is imperative to understand how the inflationary dynamics of a non-minimally coupled Higgs scalar field with gravity may affect the determination of the inflationary observables. We make a full proper analysis of the Wilkinson Microwave Anisotropy Probe, Type Ia supernova distance-redshift relation, and the baryon acoustic oscillations data sets in a context of the non-minimally coupled Higgs inflation field with gravity. For the central value of the top quark pole mass m{sub T} = 171.3 GeV, the fit of the inflation model with a non-minimally coupled Higgs scalar field leads to a Higgs boson mass in the range 143.7 GeV {<=} m{sub H} {<=} 167 GeV (95% CL). We show that the inflation driven by a non-minimally coupled scalar field to the Einstein gravity leads to significant constraints on the scalar spectral index n{sub S} and the tensor-to-scalar ratio R when compared with a tensor with similar constraints to form the standard inflation with a minimally coupled scalar field. We also show that an accurate reconstruction of the Higgs potential in terms of inflationary observables requires an improved accuracy of other parameters of the standard model of particle physics such as the top quark mass and the effective QCD coupling constant.
NASA Astrophysics Data System (ADS)
Chang, Xiao-Chuan; Liu, Ruo-Yu; Wang, Xiang-Yu
2016-07-01
The nearly isotropic distribution of teraelectronvolt to petaelectronvolt neutrinos recently detected by the IceCube Collaboration suggests that they come from sources at a distance beyond our Galaxy, but how far away they are is largely unknown because of a lack of any associations with known sources. In this paper, we propose that the cumulative TeV gamma-ray emission accompanying the production of neutrinos can be used to constrain the distance of these neutrino sources, since the opacity of TeV gamma rays due to absorption by the extragalactic background light depends on the distance these TeV gamma rays have traveled. As the diffuse extragalactic TeV background measured by Fermi is much weaker than the expected cumulative flux associated with IceCube neutrinos, the majority of IceCube neutrinos, if their sources are transparent to TeV gamma rays, must come from distances larger than the horizon of TeV gamma rays. We find that above 80% of the IceCube neutrinos should come from sources at redshift z > 0.5. Thus, the chance of finding nearby sources correlated with IceCube neutrinos would be small. We also find that, to explain the flux of neutrinos under the TeV gamma-ray emission constraint, the redshift evolution of neutrino source density must be at least as fast as the cosmic star formation rate.
Form invariance and symmetry in the neutrino mass matrix
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.
Effect of atmospheric flux uncertainties on the determination of the neutrino mass hierarchy
NASA Astrophysics Data System (ADS)
Sandroos, Joakim; Erhardt, Thomas; Arlen, Tim; Böser, Sebastian
2016-04-01
The next generation of large-volume neutrino telescopes will include low-energy subarrays which will be able to measure neutrinos with energies of a few GeV. In this energy range the primary signal below the horizon is neutrinos created by cosmic ray interactions in the atmosphere. The measured event rate will depend on the neutrino mass hierarchy, allowing determination of this quantity to a significance level of about 3.5 sigma within a 5-year period, mostly limited by systematic uncertainties. We present here the impact of the uncertainties on the atmospheric neutrino flux normalization on the determination of the neutrino mass hierarchy. We suggest constraining the systematic uncertainties by including the downgoing neutrino sample, which will increase the significance. This work was performed using simulation data from the low-energy extension to the IceCube detector located at the geographic south pole, PINGU, and is relevant to a wide range of other experiments.
Neutrino masses and mixing with seesaw mechanism and universal breaking of extended democracy
NASA Astrophysics Data System (ADS)
Akhmedov, E. K.; Branco, G. C.; Joaquim, F. R.; Silva-Marcos, J. I.
2001-01-01
In the framework of a minimal extension of the SM, where the only additional fields are three right-handed neutrinos, we suggest that the charged lepton, the Dirac neutrino and the right-handed Majorana neutrino mass matrices are all, to leading approximation, proportional to the democratic matrix. With the further assumption that the breaking of this extended democracy is universal for all leptonic mass matrices, a large mixing in the 2-3 sector can be obtained and is linked to the seesaw mechanism, together with the existence of a strong hierarchy in the masses of right-handed neutrinos. The structure of the resulting effective mass matrix of light neutrinos is stable against the RGE evolution, and a good fit to all solar and atmospheric neutrino data is obtained.
Unifying inflation and dark matter with neutrino masses.
Allahverdi, Rouzbeh; Dutta, Bhaskar; Mazumdar, Anupam
2007-12-31
We propose a simple model where a gauge-invariant inflaton is responsible for cosmic inflation and generates the seed for structure formation, while its relic thermal abundance explains the missing matter of the Universe in the form of cold dark matter. The inflaton self-coupling also explains the observed neutrino masses. All the virtues can be attained in a minimal extension of the standard model gauge group around the TeV scale. We can also unveil these properties of an inflaton in forthcoming space and ground based experiments.
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.
A neutrino mass-mixing sum rule from SO(10) and neutrinoless double beta decay
NASA Astrophysics Data System (ADS)
Buccella, F.; Chianese, M.; Mangano, G.; Miele, G.; Morisi, S.; Santorelli, P.
2017-04-01
Minimal SO(10) grand unified models provide phenomenological predictions for neutrino mass patterns and mixing. These are the outcome of the interplay of several features, namely: i) the seesaw mechanism; ii) the presence of an intermediate scale where B-L gauge symmetry is broken and the right-handed neutrinos acquire a Majorana mass; iii) a symmetric Dirac neutrino mass matrix whose pattern is close to the up-type quark one. In this framework two natural characteristics emerge. Normal neutrino mass hierarchy is the only allowed, and there is an approximate relation involving both light-neutrino masses and mixing parameters. This differs from what occurring when horizontal flavour symmetries are invoked. In this case, in fact, neutrino mixing or mass relations have been separately obtained in literature. In this paper we discuss an example of such comprehensive mixing-mass relation in a specific realization of SO(10) and, in particular, analyse its impact on the expected neutrinoless double beta decay effective mass parameter < m ee >, and on the neutrino mass scale. Remarkably a lower limit for the lightest neutrino mass is obtained ( m lightest ≳ 7 .5 × 10 -4 eV, at 3 σ level).
NASA Astrophysics Data System (ADS)
Fukugita, Masataka; Kaneta, Yuya; Shimizu, Yusuke; Tanimoto, Morimitsu; Yanagida, Tsutomu T.
2017-01-01
The model of neutrino mass matrix with minimal texture is now tightly constrained by experiment so that it can yield a prediction for the phase of CP violation. This phase is predicted to lie in the range δCP = 0.77 π- 1.24 π. If neutrino oscillation experiment would find the CP violation phase outside this range, this means that the minimal-texture neutrino mass matrix, the element of which is all real, fails and the neutrino mass matrix must be complex, i.e., the phase must be present that is responsible for leptogenesis.
Constraints on nucleon decay via invisible modes from the Sudbury Neutrino Observatory.
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.
Updated constraints on the light-neutrino exchange mechanisms of the 0νββ-decay
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.
NASA Technical Reports Server (NTRS)
Raffelt, Georg G.
1990-01-01
Existing measurements of the bolometric magnitudes of the brightest red giants in 26 globular clusters are used to determine the brightness difference between the tip of the red giant branch (on average found to be 0.1 mag brighter than the brightest red giant) and RR Lyrae stars. The metallicity variation of the result agrees perfectly with theoretical predictions. In conjunction with previous determinations of the number ratio of horizontal-branch versus red giant stars, with statistical parallax determinations of RR Lyrae absolute luminosities, and with theoretical predictions based on the Sweigart and Gross evolutionary sequences, this result yields an allowed range for a hypothetical core mass variation relative to the standard results of (0.009 + or - 0.012) solar mass. If neutrinos had anomalous electromagnetic dipole moments, the increased energy loss near the helium flash would lead to an increased core mass. Constraints on neutrino electromagnetic properties are determined from the color-magnitude diagrams of the globular clusters.
NASA Technical Reports Server (NTRS)
Raffelt, Georg G.
1990-01-01
Existing measurements of the bolometric magnitudes of the brightest red giants in 26 globular clusters are used to determine the brightness difference between the tip of the red giant branch (on average found to be 0.1 mag brighter than the brightest red giant) and RR Lyrae stars. The metallicity variation of the result agrees perfectly with theoretical predictions. In conjunction with previous determinations of the number ratio of horizontal-branch versus red giant stars, with statistical parallax determinations of RR Lyrae absolute luminosities, and with theoretical predictions based on the Sweigart and Gross evolutionary sequences, this result yields an allowed range for a hypothetical core mass variation relative to the standard results of (0.009 + or - 0.012) solar mass. If neutrinos had anomalous electromagnetic dipole moments, the increased energy loss near the helium flash would lead to an increased core mass. Constraints on neutrino electromagnetic properties are determined from the color-magnitude diagrams of the globular clusters.
NASA Astrophysics Data System (ADS)
Dutta, Rupak; Ch, Upender; Giri, Anjan K.; Sahu, Narendra
2014-08-01
We discuss the role of lightest neutrino mass (m0) in the neutrino mass matrix, defined in a flavor basis, through a bottom-up approach using the current neutrino oscillation data. We find that if m0 < 10-3eV, then the deviation δMν in the neutrino mass matrix from a tree-level, say tribimaximal neutrino mass matrix, does not depend on m0. As a result δMν's are exactly predicted in terms of the experimentally determined quantities such as solar and atmospheric mass squared differences and the mixing angles. On the other hand for m0 ≳10-3eV, δMν strongly depends on m0 and hence cannot be determined within the knowledge of oscillation parameters alone. In this limit, we provide an exponential parametrization for δMν for all values of m0 such that it can factorize the m0 dependency of δMν from rest of the oscillation parameters. This helps us in finding δMν as a function of the solar and atmospheric mass squared differences and the mixing angles for all values of m0. We use this information to build up a model of neutrino masses and mixings in a top-down scenario which can predict large θ13 perturbatively.
Peccei, R. D.
1999-10-25
These lectures describe some aspects of the physics of massive neutrinos. After a brief introduction of neutrinos in the Standard Model, I discuss possible patterns for their masses. In particular, I show how the presence of a large Majorana mass term for the right-handed neutrinos can engender tiny neutrino masses for the observed neutrinos. If neutrinos have mass, different flavors of neutrinos can oscillate into one another. To analyze this phenomena, I develop the relevant formalism for neutrino oscillations, both in vacuum and in matter. After reviewing the existing (negative) evidence for neutrino masses coming from direct searches, I discuss evidence for, and hints of, neutrino oscillations in the atmosphere, the sun, and at accelerators. Some of the theoretical implications of these results are emphasized. I close these lectures by briefly outlining future experiments which will shed further light on atmospheric, accelerator and solar neutrino oscillations. A pedagogical discussion of Dirac and Majorana masses is contained in an appendix.
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
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}.
Seesaw model in SO(10) with an upper limit on right-handed neutrino masses
NASA Astrophysics Data System (ADS)
Abud, M.; Buccella, F.; Falcone, D.; Oliver, L.
2012-08-01
In the framework of SO(10) gauge unification and the seesaw mechanism, we show that the upper bound on the mass of the heaviest right-handed neutrino MR3<3×1011GeV, given by the Pati-Salam intermediate scale of B-L spontaneous symmetry breaking, constrains the observables related to the left-handed light neutrino mass matrix. We assume such an upper limit on the masses of right-handed neutrinos and, as a first approximation, a Cabibbo form for the matrix VL that diagonalizes the Dirac neutrino matrix mD. Using the inverse seesaw formula, we show that our hypotheses imply a triangular relation in the complex plane of the light neutrino masses with the Majorana phases. We obtain normal hierarchy with an absolute scale for the light neutrino spectrum. Two regions are allowed for the lightest neutrino mass m1 and for the Majorana phases, implying predictions for the neutrino mass measured in Tritium decay and for the double beta decay effective mass |⟨mee⟩|.
More is different: Reconciling eV sterile neutrinos with cosmological mass bounds
NASA Astrophysics Data System (ADS)
Tang, Yong
2015-11-01
It is generally expected that adding light sterile species would increase the effective number of neutrinos, Neff. In this paper we discuss a scenario that Neff can actually decrease due to the neutrino oscillation effect if sterile neutrinos have self-interactions. We specifically focus on the eV mass range, as suggested by the neutrino anomalies. With large self-interactions, sterile neutrinos are not fully thermalized in the early Universe because of the suppressed effective mixing angle or matter effect. As the Universe cools down, flavor equilibrium between active and sterile species can be reached after big bang nucleosynthesis (BBN) epoch, but leading to a decrease of Neff. In such a scenario, we also show that the conflict with cosmological mass bounds on the additional sterile neutrinos can be relaxed further when more light species are introduced. To be consistent with the latest Planck results, at least 3 sterile species are needed.
Probing neutrino mass with displaced vertices at the Fermilab Tevatron
Campos, F. de; Eboli, O.J.P.; Magro, M.B.; Porod, W.; Restrepo, D.; Valle, J.W.F.
2005-04-01
Supersymmetric extensions of the standard model exhibiting bilinear R-parity violation can generate naturally the observed neutrino mass spectrum as well as mixings. One interesting feature of these scenarios is that the lightest supersymmetric particle (LSP) is unstable, with several of its decay properties predicted in terms of neutrino mixing angles. A smoking gun of this model in colliders is the presence of displaced vertices due to LSP decays in large parts of the parameter space. In this work we focus on the simplest model of this type that comes from minimal supergravity with universal R-parity conserving soft breaking of supersymmetry augmented with bilinear R-parity breaking terms at the electroweak scale (RmSUGRA). We evaluate the potential of the Fermilab Tevatron to probe the RmSUGRA parameters through the analysis of events possessing two displaced vertices stemming from LSP decays. We show that requiring two displaced vertices in the events leads to a reach in m{sub 1/2} twice the one in the usual multilepton signals in a large fraction of the parameter space.
Beacom, J.F.; Vogel, P.
1998-11-01
Core-collapse supernovae emit of order 10{sup 58} neutrinos and antineutrinos of all flavors over several seconds, with average energies of 10{endash}25 MeV. In the Sudbury Neutrino Observatory (SNO), which begins operation this year, neutrinos and antineutrinos of all flavors can be detected by reactions which break up the deuteron. For a future Galactic supernova at a distance of 10 kpc, several hundred events will be observed in SNO. The {nu}{sub {mu}} and {nu}{sub {tau}} neutrinos and antineutrinos are of particular interest, as a test of the supernova mechanism. In addition, it is possible to measure or limit their masses by their delay (determined from neutral-current events) relative to the {bar {nu}}{sub e} neutrinos (determined from charged-current events). Numerical results are presented for such a future supernova as seen in SNO. Under reasonable assumptions, and in the presence of the expected counting statistics, a {nu}{sub {mu}} or {nu}{sub {tau}} mass down to about 30 eV can be simply and robustly determined. If zero delay is measured, then the mass limit is {ital independent} of the distance D. At present, this seems to be the best possibility for direct determination of a {nu}{sub {mu}} or {nu}{sub {tau}} mass within the cosmologically interesting range. We also show how to separately study the supernova and neutrino physics, and how changes in the assumed supernova parameters would affect the mass sensitivity. {copyright} {ital 1998} {ital The American Physical Society}
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.
NASA Astrophysics Data System (ADS)
Allison, P.; Auffenberg, J.; Bard, R.; Beatty, J. J.; Besson, D. Z.; Bora, C.; Chen, C.-C.; Chen, P.; Connolly, A.; Davies, J. P.; DuVernois, M. A.; Fox, B.; Gorham, P. W.; Hanson, K.; Hill, B.; Hoffman, K. D.; Hong, E.; Hu, L.-C.; Ishihara, A.; Karle, A.; Kelley, J.; Kravchenko, I.; Landsman, H.; Laundrie, A.; Li, C.-J.; Liu, T.; Lu, M.-Y.; Maunu, R.; Mase, K.; Meures, T.; Miki, C.; Nam, J.; Nichol, R. J.; Nir, G.; O'Murchadha, A.; Pfendner, C. G.; Ratzlaff, K.; Richman, M.; Rotter, B.; Sandstrom, P.; Seckel, D.; Shultz, A.; Stockham, J.; Stockham, M.; Sullivan, M.; Touart, J.; Tu, H.-Y.; Varner, G. S.; Yoshida, S.; Young, R.
2015-10-01
The Askaryan Radio Array (ARA) is an ultra-high energy (>1017 eV) cosmic neutrino detector in phased construction near the south pole. ARA searches for radio Cherenkov emission from particle cascades induced by neutrino interactions in the ice using radio frequency antennas (∼ 150 - 800 MHz) deployed at a design depth of 200 m in the Antarctic ice. A prototype ARA Testbed station was deployed at ∼ 30 m depth in the 2010-2011 season and the first three full ARA stations were deployed in the 2011-2012 and 2012-2013 seasons. We present the first neutrino search with ARA using data taken in 2011 and 2012 with the ARA Testbed and the resulting constraints on the neutrino flux from 1017 -1021 eV.
Fermion Masses from Six Dimensions and Implications for Majorana Neutrinos
NASA Astrophysics Data System (ADS)
Frère, J.-M.; Libanov, M.; Mollet, S.; Troitsky, S.
2015-06-01
In these notes, we review the main results of our approach to fermion masses. The marge mass ratios between fermions, confronted with a unique breaking mechanism leading to vector bosons masses, led us to consider the possibility that they result from the overlap of fermion wave functions. Such overlaps vary indeed very strongly if the observed fermion families in 4 dimensions originate in a single family in 6 dimensions, through localized wave functions. This framework leads in a natural way to large mass ratios and small mixing angles between quarks. What came as a surprise is that if we impose that neutrinos behave as 2- component (“Majorana”) particles in 4D, a completely different situation is obtained for them. Instead of diagonal mass matrices, anti-diagonal ones emerge and lead to a generic prediction of combined inverted hierarchy, large mixing angles in the leptonicsector, and a suppression of neutrinoless-double beta decay placing it at the lower limit of the inverted hierarchy branch, a challenging situation for on-going and planned experiments. Our approach predicted the size of the θ13 mixing angle before its actual measurement. Possible signals at colliders are only briefly evoked.
Neutrino oscillation, finite self-mass and general Yang-Mills symmetry
NASA Astrophysics Data System (ADS)
Hsu, Jong-Ping
2016-10-01
The conservation of lepton number is assumed to be associated with a general Yang-Mills (gYM) symmetry. New transformations involve (Lorentz) vector gauge functions and characteristic phase functions, and they form a group. General Yang-Mills fields are associated with new fourth-order equations and linear potentials. Lepton self-masses turn out to be finite and proportional to the inverse of lepton masses, which implies that neutrinos should have nonzero masses. Thus, gYM symmetry could provide an understanding of neutrino oscillations and suggests that neutrinos with masses and very weak leptonic force may play a role in dark matter.
Prospects for constraining neutrino mass using Planck and Lyman-{alpha} forest data
Gratton, Steven; Lewis, Antony; Efstathiou, George
2008-04-15
In this paper we investigate how well Planck and Lyman-{alpha} forest data will be able to constrain the sum of the neutrino masses, and thus, in conjunction with flavor oscillation experiments, be able to determine the absolute masses of the neutrinos. It seems possible that Planck, together with a Lyman-{alpha} survey, will be able to put pressure on an inverted hierarchial model for the neutrino masses. However, even for optimistic assumptions of the precision of future Lyman-{alpha} data sets, it will not be possible to confirm a minimal-mass normal hierarchy.
Correction to Neutrino Mass Square Difference in the Co-Bimaximal Mixings due to Quantum Gravity
NASA Astrophysics Data System (ADS)
Koranga, Bipin Singh; Narayan, Mohan
2017-08-01
We consider non-renormalizable interaction term as a perturbation of the neutrino mass matrix. We assume that the neutrino masses and mixing arise through physics at a scale intermediate between Planck scale and the electroweak breaking scale. We also assume that, just above the electroweak breaking scale, neutrino masses are nearly degenerate and their mixing is Co-bimaximal mixing by assumming mixing angle θ _{13}≠ 0=10°,θ _{23}={π}/{4}, tanθ _{12}2={1-3sinθ_{13}2}/{2}=34° and Dirac phase δ =± {π}/{2}. . Quantum gravity (Planck scale effects) lead to an effective S U(2) L × U(1) invariant dimension-5 Lagrangian involving neutrino and Higgs fields. On symmetry breaking, this operator gives rise to correction to the above masses and mixing. The gravitational interaction M X = M p l , we find that for degenerate neutrino mass spectrum, the considered perturbation term change the {Δ }_{21}^' } by 12% and {Δ }_{31}^' } mass square difference is unchanged above GUT scale. The nature of gravitational interaction demands that the element of this perturbation matrix should be independent of flavor indices. In this paper, we study the quantum gravity effects on neutrino mass square difference, namely modified dispersion relation for neutrino mass square differences.
4-Neutrino mass schemes and the likelihood of (3+1)-mass spectra
NASA Astrophysics Data System (ADS)
Grimus, W.; Schwetz, T.
2001-04-01
We examine the (3+1)-class of 4-neutrino mass spectra within a rigorous statistical analysis based on the Bayesian approach to probability. The data of the Bugey, CDHS and KARMEN experiments are combined by using a likelihood function. Our statistical approach allows us to incorporate solar and atmospheric neutrino data and also the result of the CHOOZ experiment via inequalities which involve elements of the neutrino mixing matrix and are derived from these data. For any short-baseline Δ m^2 we calculate a bound on the LSND transition amplitude A_{μ;e} and find that, in the Δ m^2 A_{μ;e} plane, there is no overlap between the 99% CL region allowed by the latest LSND analysis and the region allowed by our bound on A_{μ;e} at 95% CL; there are some small overlap regions if we take the bound at 99% CL. Therefore, we conclude that, with the existing data, the (3+1)-neutrino mass spectra are not very likely. However, treating the (2+2)-spectra with our method, we find that they are well compatible with all data.
Leptogenesis, radiative neutrino masses and inert Higgs triplet dark matter
Lu, Wen-Bin; Gu, Pei-Hong
2016-05-18
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 Z{sub 2} 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.
Neutrino masses and cosmology with Lyman-alpha forest power spectrum
NASA Astrophysics Data System (ADS)
Palanque-Delabrouille, Nathalie; Yèche, Christophe; Baur, Julien; Magneville, Christophe; Rossi, Graziano; Lesgourgues, Julien; Borde, Arnaud; Burtin, Etienne; LeGoff, Jean-Marc; Rich, James; Viel, Matteo; Weinberg, David
2015-11-01
We present constraints on neutrino masses, the primordial fluctuation spectrum from inflation, and other parameters of the ΛCDM model, using the one-dimensional Lyα-forest power spectrum measured by [1] from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III), complemented by Planck 2015 cosmic microwave background (CMB) data and other cosmological probes. This paper improves on the previous analysis by [2] by using a more powerful set of calibrating hydrodynamical simulations that reduces uncertainties associated with resolution and box size, by adopting a more flexible set of nuisance parameters for describing the evolution of the intergalactic medium, by including additional freedom to account for systematic uncertainties, and by using Planck 2015 constraints in place of Planck 2013. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from CMB data, except for a weak tension on the scalar index ns. Combining BOSS Lyα with Planck CMB constrains the sum of neutrino masses to ∑ mν < 0.12 eV (95% C.L.) including all identified systematic uncertainties, tighter than our previous limit (0.15 eV) and more robust. Adding Lyα data to CMB data reduces the uncertainties on the optical depth to reionization τ, through the correlation of τ with σ8. Similarly, correlations between cosmological parameters help in constraining the tensor-to-scalar ratio of primordial fluctuations r. The tension on ns can be accommodated by allowing for a running dns/d ln k. Allowing running as a free parameter in the fits does not change the limit on ∑ mν. We discuss possible interpretations of these results in the context of slow-roll inflation.
Neutrino masses and cosmology with Lyman-alpha forest power spectrum
Palanque-Delabrouille, Nathalie; Yèche, Christophe; Baur, Julien; Magneville, Christophe; Borde, Arnaud; Burtin, Etienne; LeGoff, Jean-Marc; Rich, James; Lesgourgues, Julien; Viel, Matteo; Weinberg, David E-mail: christophe.yeche@cea.fr E-mail: christophe.magneville@cea.fr E-mail: Julien.Lesgourgues@cern.ch
2015-11-01
We present constraints on neutrino masses, the primordial fluctuation spectrum from inflation, and other parameters of the ΛCDM model, using the one-dimensional Lyα-forest power spectrum measured by [1] from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III), complemented by Planck 2015 cosmic microwave background (CMB) data and other cosmological probes. This paper improves on the previous analysis by [2] by using a more powerful set of calibrating hydrodynamical simulations that reduces uncertainties associated with resolution and box size, by adopting a more flexible set of nuisance parameters for describing the evolution of the intergalactic medium, by including additional freedom to account for systematic uncertainties, and by using Planck 2015 constraints in place of Planck 2013. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from CMB data, except for a weak tension on the scalar index n{sub s}. Combining BOSS Lyα with Planck CMB constrains the sum of neutrino masses to ∑ m{sub ν} < 0.12 eV (95% C.L.) including all identified systematic uncertainties, tighter than our previous limit (0.15 eV) and more robust. Adding Lyα data to CMB data reduces the uncertainties on the optical depth to reionization τ, through the correlation of τ with σ{sub 8}. Similarly, correlations between cosmological parameters help in constraining the tensor-to-scalar ratio of primordial fluctuations r. The tension on n{sub s} can be accommodated by allowing for a running dn{sub s}/d ln k. Allowing running as a free parameter in the fits does not change the limit on ∑ m{sub ν}. We discuss possible interpretations of these results in the context of slow-roll inflation.
NASA Astrophysics Data System (ADS)
Fogli, G. L.; Lisi, E.; Marrone, A.; Montanino, D.; Palazzo, A.; Rotunno, A. M.
2012-07-01
We perform a global analysis of neutrino oscillation data, including high-precision measurements of the neutrino mixing angle θ13 at reactor experiments, which have confirmed previous indications in favor of θ13>0. Recent data presented at the Neutrino 2012 conference are also included. We focus on the correlations between θ13 and the mixing angle θ23, as well as between θ13 and the neutrino CP-violation phase δ. We find interesting indications for θ23<π/4 and possible hints for δ˜π, with no significant difference between normal and inverted mass hierarchy.
Measurable neutrino mass scale in A{sub 4}xSU(5)
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.
Dark matter and strong electroweak phase transition in a radiative neutrino mass model
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.
Diffuse supernova neutrinos: oscillation effects, stellar cooling and progenitor mass dependence
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.
Bartos, Imre; Finley, Chad; Corsi, Alessandra; Márka, Szabolcs
2011-12-16
Many astronomical sources of intense bursts of photons are also predicted to be strong emitters of gravitational waves (GWs) and high-energy neutrinos (HENs). Moreover some suspected classes, e.g., choked gamma-ray bursts, may only be identifiable via nonphoton messengers. Here we explore the reach of current and planned experiments to address this question. We derive constraints on the rate of GW and HEN bursts based on independent observations by the initial LIGO and Virgo GW detectors and the partially completed IceCube (40-string) HEN detector. We then estimate the reach of joint GW+HEN searches using advanced GW detectors and the completed km(3) IceCube detector to probe the joint parameter space. We show that searches undertaken by advanced detectors will be capable of detecting, constraining, or excluding, several existing models with 1 yr of observation. © 2011 American Physical Society
Very low energy supernovae from neutrino mass loss
Lovegrove, Elizabeth; Woosley, S. E.
2013-06-01
It now seems likely that some percentage of more massive supernova progenitors do not explode by any of the currently discussed explosion mechanisms. This has led to speculation concerning the observable transients that might be produced if such a supernova fails. Even if a prompt outgoing shock fails to form in a collapsing presupernova star, one must still consider the hydrodynamic response of the star to the abrupt loss of mass via neutrinos as the core forms a protoneutron star. Following a suggestion by Nadezhin, we calculate the hydrodynamical responses of typical supernova progenitor stars to the rapid loss of approximately 0.2-0.5 M {sub ☉} of gravitational mass from their centers. In a red supergiant star, a very weak supernova with total kinetic energy ∼10{sup 47} erg results. The binding energy of a large fraction of the hydrogen envelope before the explosion is of the same order and, depending upon assumptions regarding the maximum mass of a neutron star, most of it is ejected. Ejection speeds are ∼100 km s{sup –1} and luminosities ∼10{sup 39} erg s{sup –1} 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 'luminous red novae', but have much lower speeds.
Very Low Energy Supernovae from Neutrino Mass Loss
NASA Astrophysics Data System (ADS)
Lovegrove, Elizabeth; Woosley, S. E.
2013-06-01
It now seems likely that some percentage of more massive supernova progenitors do not explode by any of the currently discussed explosion mechanisms. This has led to speculation concerning the observable transients that might be produced if such a supernova fails. Even if a prompt outgoing shock fails to form in a collapsing presupernova star, one must still consider the hydrodynamic response of the star to the abrupt loss of mass via neutrinos as the core forms a protoneutron star. Following a suggestion by Nadezhin, we calculate the hydrodynamical responses of typical supernova progenitor stars to the rapid loss of approximately 0.2-0.5 M ⊙ of gravitational mass from their centers. In a red supergiant star, a very weak supernova with total kinetic energy ~1047 erg results. The binding energy of a large fraction of the hydrogen envelope before the explosion is of the same order and, depending upon assumptions regarding the maximum mass of a neutron star, most of it is ejected. Ejection speeds are ~100 km s-1 and luminosities ~1039 erg s-1 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 "luminous red novae," but have much lower speeds.
TRIMS: Validating T2 Molecular Effects for Neutrino Mass Experiments
NASA Astrophysics Data System (ADS)
Lin, Ying-Ting; Bodine, Laura; Enomoto, Sanshiro; Kallander, Matthew; Machado, Eric; Parno, Diana; Robertson, Hamish; Trims Collaboration
2017-01-01
The upcoming KATRIN and Project 8 experiments will measure the model-independent effective neutrino mass through the kinematics near the endpoint of tritium beta-decay. A critical systematic, however, is the understanding of the molecular final-state distribution populated by tritium decay. In fact, the current theory incorporated in the KATRIN analysis framework predicts an observable that disagrees with an experimental result from the 1950s. The Tritium Recoil-Ion Mass Spectrometer (TRIMS) experiment will reexamine branching ratio of the molecular tritium (T2) beta decay to the bound state (3HeT+). TRIMS consists of a magnet-guided time-of-flight mass spectrometer with a detector located on each end. By measuring the kinetic energy and time-of-flight difference of the ions and beta particles reaching the detectors, we will be able to distinguish molecular ions from atomic ones and hence derive the ratio in question.We will give an update on simulation software, analysis tools, and the apparatus, including early commissioning results. U.S. Department of Energy Office of Science, Office of Nuclear Physics, Award Number DE-FG02-97ER41020.
Constraining neutrino decays with CMBR data
NASA Astrophysics Data System (ADS)
Hannestad, Steen
1998-07-01
The decay of massive neutrinos to final states containing only invisible particles is poorly constrained experimentally. In this letter we describe the constraints that can be put on neutrino mass and lifetime using CMBR measurements. We find that very tight lifetime limits on neutrinos in the mass range 10 eV - 100 keV can be derived using CMBR data from upcoming satellite measurements.
NASA Astrophysics Data System (ADS)
Homma, Kensuke; Jinnouchi, Osamu
2003-04-01
The unphysical result of the negative mass square of the electron neutrinos recently reported in several tritium β-decay experiments, is one of the most attractive subjects. As a possible scenario to explain the anomaly, we have assumed a reaction with relic neutrinos which are predicted by the standard big bang cosmology. If such neutrinos could exist, the interaction of the relic neutrinos with the target tritium, νe + 3H → 3He + e- could be laid under the large amount of the β-decay process, H- > He + e- + bar ν e, which would cause a peak-like structure beyond the end-point in the Kurie plot. Based on the assumption, we evaluated the cross section from the event rate found in the peak by re-fitting to the 1991 data published by Mainz Group. In this talk we will provide a scenario that could account for the evaluated cross section by assuming a coherent state of the neutrino sea, which would result much lower temperature than the prediction from the standard big bang cosmology.
NOvA and T2K: The Race for the neutrino mass hierarchy
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
Impact of eV-mass sterile neutrinos on neutrino-driven supernova outflows
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.
Neutrino mass and mixing: from theory to experiment
NASA Astrophysics Data System (ADS)
King, Stephen F.; Merle, Alexander; Morisi, Stefano; Shimizu, Yusuke; Tanimoto, Morimitsu
2014-04-01
The origin of fermion mass hierarchies and mixings is one of the unresolved and most difficult problems in high-energy physics. One possibility to address the flavour problems is by extending the standard model to include a family symmetry. In the recent years it has become very popular to use non-Abelian discrete flavour symmetries because of their power in the prediction of the large leptonic mixing angles relevant for neutrino oscillation experiments. Here we give an introduction to the flavour problem and to discrete groups that have been used to attempt a solution for it. We review the current status of models in light of the recent measurement of the reactor angle, and we consider different model-building directions taken. The use of the flavons or multi-Higgs scalars in model building is discussed as well as the direct versus indirect approaches. We also focus on the possibility of experimentally distinguishing flavour symmetry models by means of mixing sum rules and mass sum rules. In fact, we illustrate in this review the complete path from mathematics, via model building, to experiments, so that any reader interested in starting work in the field could use this text as a starting point in order to obtain a broad overview of the different subject areas.
Particle-physics constraints from the globular cluster M5: neutrino dipole moments
NASA Astrophysics Data System (ADS)
Viaux, N.; Catelan, M.; Stetson, P. B.; Raffelt, G. G.; Redondo, J.; Valcarce, A. A. R.; Weiss, A.
2013-10-01
Stellar evolution is modified if energy is lost in a "dark channel" similar to neutrino emission. Comparing modified stellar evolution sequences with observations provides some of the most restrictive limits on axions and other hypothetical low-mass particles and on non-standard neutrino properties. In particular, a putative neutrino magnetic dipole moment μν enhances the plasmon decay process, postpones helium ignition in low-mass stars, and therefore extends the red giant branch (RGB) in globular clusters (GCs). The brightness of the tip of the RGB (TRGB) remains the most sensitive probe for μν and we revisit this argument from a modern perspective. Based on a large set of archival observations, we provide high-precision photometry for the Galactic GC M5 (NGC 5904) and carefully determine its TRGB position. On the theoretical side, we add the extra plasmon decay rate brought about by μν to the Princeton-Goddard-PUC (PGPUC) stellar evolution code. Different sources of uncertainty are critically examined. The main source of systematic uncertainty is the bolometric correction and the main statistical uncertainty derives from the distance modulus based on main-sequence fitting. (Other measures of distance, e.g., the brightness of RR Lyrae stars, are influenced by the energy loss that we wish to constrain.) The statistical uncertainty of the TRGB position relative to the brightest RGB star is less important because the RGB is well populated. We infer an absolute I-band brightness of MI = -4.17 ± 0.13 mag for the TRGB compared with the theoretical prediction of - 3.99 ± 0.07 mag, in reasonable agreement with each other. A significant brightness increase caused by neutrino dipole moments is constrained such that μν < 2.6 × 10-12 μB (68% CL), where μB ≡ e/2me is the Bohr magneton, and μν < 4.5 × 10-12 μB (95% CL). In these results, statistical and systematic errors have been combined in quadrature. The photometric catalog is only available at the CDS
NASA Astrophysics Data System (ADS)
Aoki, Mayumi; Kanemura, Shinya; Sakurai, Kodai; Sugiyama, Hiroaki
2016-12-01
We investigate how observations of the lepton flavor violating decay of the Higgs boson (h → ℓℓ‧) can narrow down models of neutrino mass generation mechanisms, which were systematically studied in Refs. [1,2] by focusing on the combination of new Yukawa coupling matrices with leptons. We find that a wide class of models for neutrino masses can be excluded if evidence for h → ℓℓ‧ is really obtained in the current or future collider experiments. In particular, simple models of Majorana neutrino masses cannot be compatible with the observation of h → ℓℓ‧. It is also found that some of the simple models to generate masses of Dirac neutrinos radiatively can be compatible with a significant rate of the h → ℓℓ‧ process.
Effects of Non-Standard Neutrino Emission on the Evolution of Low-Mass Stars
NASA Astrophysics Data System (ADS)
Arceo-Díaz, S.; Schrüder, K. P.; Zuber, K.
2013-04-01
In this work we use models created with the Eggleton stellar evolution code, with near solar mass and metallicity, and determine which are the parameters sensitive to an enhanced neutrino emission. We analyze the changes in stellar evolution, through alterations in the HR-Diagram and internal structure, when the existence of a non-zero magnetic dipole moment causes an increased plasmon decay rate and an enhanced neutrino cooling flux in the stellar core. We also study the apparent connection between the mass-loss rate during the RGB branch, by the Reimers mechanism, and the enhanced neutrino emission by their magnetic dipole moment.
New U(1) gauge model of radiative lepton masses with sterile neutrino and dark matter
Adhikari, Rathin; Borah, Debasish; Ma, Ernest
2016-02-23
Here, an anomaly-free U(1) gauge extension of the standard model (SM) is presented. Only one Higgs doublet with a nonzero vacuum expectation is required as in the SM. New fermions and scalars as well as all SM particles transform nontrivially under this U(1), resulting in a model of three active neutrinos and one sterile neutrino, all acquiring radiative masses. Charged-lepton masses are also radiative as well as the mixing between active and sterile neutrinos. At the same time, a residual Z2 symmetry of the U(1) gauge symmetry remains exact, allowing for the existence of dark matter.
Molecular effects in the neutrino mass determination from beta-decay of the tritium molecule
Fackler, O.; Jeziorski, B.; Kolos, W.; Szalewicz, K.; Monkhorst, H.J.; Mugge, M.
1986-03-01
Molecular final state energies and transition probabilities have been computed for beta-decay of the tritium molecule. The results are of sufficient accuracy to make a determination of the electron neutrino rest mass with an error not exceeding a few tenths of an electron volt. Effects of approximate models of tritium beta-decay on the neutrino mass determination are discussed. 14 refs., 3 figs., 1 tab.
Baryon asymmetry via leptogenesis in a neutrino mass model with complex scaling
NASA Astrophysics Data System (ADS)
Samanta, Rome; Chakraborty, Mainak; Roy, Probir; Ghosal, Ambar
2017-03-01
Baryogenesis via leptogenesis is investigated in a specific model of light neutrino masses and mixing angles. The latter was proposed on the basis of an assumed complex-extended scaling property of the neutrino Majorana mass matrix Mν, derived with a type-1 seesaw from a Dirac mass matrix mD and a heavy singlet neutrino Majorana mass matrix MR. One of its important features, highlighted here, is that there is a common source of the origin of a nonzero θ13 and the CP violating lepton asymmetry through the imaginary part of mD. The model predicted CP violation to be maximal for the Dirac type and vanishing for the Majorana type. We assume strongly hierarchical mass eigenvalues for MR. The leptonic CP asymmetry parameter εα1 mm with lepton flavor α, originating from the decays of the lightest of the heavy neutrinos N1 (of mass M1) at a temperature T ~ M1, is what matters here with the lepton asymmetries, originating from the decays of N2,3, being washed out. The light leptonic and heavy neutrino number densities (normalized to the entropy density) are evolved via Boltzmann equations down to electroweak temperatures to yield a baryon asymmetry through sphaleronic transitions. The effects of flavored vs. unflavored leptogenesis in the three mass regimes (1) M1 < 109 GeV, (2) 109 GeV < M1 < 1012 GeV and (3) M1 > 1012 GeV are numerically worked out for both a normal and an inverted mass ordering of the light neutrinos. Corresponding results on the baryon asymmetry of the universe are obtained, displayed and discussed. For values close to the best-fit points of the input neutrino mass and mixing parameters, obtained from neutrino oscillation experiments, successful baryogenesis is achieved for the mass regime (2) and a normal mass ordering of the light neutrinos with a nonzero θ13 playing a crucial role. However, the other possibility of an inverted mass ordering for the same mass regime, though disfavored, cannot be excluded. A discussion is also given on the
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).
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...
Cosmology based on f(R) gravity admits 1 eV sterile neutrinos.
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.
Measurement of the neutrino mass splitting and flavor mixing by MINOS.
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
2011-05-06
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.
Measurement of the Neutrino Mass Splitting and Flavor Mixing by MINOS
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.
Assessment of molecular effects on neutrino mass measurements from tritium β decay
NASA Astrophysics Data System (ADS)
Bodine, L. I.; Parno, D. Â. S.; Robertson, R. Â. G. Â. H.
2015-03-01
The β decay of molecular tritium currently provides the highest sensitivity in laboratory-based neutrino mass measurements. The upcoming Karlsruhe Tritium Neutrino (KATRIN) experiment will improve the sensitivity to 0.2 eV, making a percent-level quantitative understanding of molecular effects essential. The modern theoretical calculations available for neutrino mass experiments agree with spectroscopic data. Moreover, when neutrino mass experiments performed in the 1980s with gaseous tritium are reevaluated using these modern calculations, the extracted neutrino mass squared values are consistent with zero instead of being significantly negative. However, the calculated molecular final-state branching ratios are in conflict with dissociation experiments performed in the 1950s. We reexamine the theory of the final-state spectrum of molecular-tritium decay and its effect on the determination of the neutrino mass, with an emphasis on the role of the vibrational- and rotational-state distribution in the ground electronic state. General features can be reproduced quantitatively from considerations of kinematics and zero-point motion. We summarize the status of validation efforts and suggest means for resolving the apparent discrepancy in dissociation rates.
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.
NASA Astrophysics Data System (ADS)
Huang, Yong-Chang; Tehreem Iqbal, Syeda; Lei, Zhen; Wang, Wen-Yu
2017-04-01
The masses of the three generations of charged leptons are known to completely satisfy Koide’s mass relation, but the question remains of whether such a relation exists for neutrinos. In this paper, by considering the seesaw mechanism as the mechanism generating tiny neutrino masses, we show how neutrinos satisfy Koide’s mass relation, on the basis of which we systematically give exact values of both left- and right-handed neutrino masses. Supported by National Natural Science Foundation of China (11275017, 11172008, 11173028). STI has the financial support from Chinese Scholarship Council
Atmospheric neutrinos and discovery of neutrino oscillations
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
Atmospheric neutrinos and discovery of neutrino oscillations.
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.
Joint short- and long-baseline constraints on light sterile neutrinos
NASA Astrophysics Data System (ADS)
Capozzi, F.; Giunti, C.; Laveder, M.; Palazzo, A.
2017-02-01
Recent studies provide evidence that long-baseline (LBL) experiments are sensitive to the extra C P phases involved with light sterile neutrinos, whose existence is suggested by several anomalous short-baseline (SBL) results. We show that, within the 3 +1 scheme, the combination of the existing SBL data with the LBL results coming from the two currently running experiments, NO ν A and T2K, enables us to simultaneously constrain two active-sterile mixing angles, θ14 and θ24, and two C P phases, δ13≡δ and δ14, although the information on the second C P phase is still weak. The two mixing angles are basically determined by the SBL data, while the two C P phases are constrained by the LBL experiments, once the information coming from the SBL setups is taken into account. We also assess the robustness or fragility of the estimates of the standard 3-flavor parameters in the more general 3 +1 scheme. To this regard we find that (i) the indication of C P violation found in the 3-flavor analyses persists also in the 3 +1 scheme, with δ13≡δ having still its best-fit value around -π /2 , (ii) the 3-flavor weak hint in favor of the normal hierarchy becomes even less significant when sterile neutrinos come into play, (iii) the weak indication of nonmaximal θ23 (driven by NO ν A disappearance data) persists in the 3 +1 scheme, where maximal mixing is disfavored at almost the 90% C.L. in both normal and inverted mass hierarchy, and (iv) the preference in favor of one of the two octants of θ23 found in the 3-flavor framework (higher octant for inverted mass hierarchy) is completely washed out in the 3 +1 scheme.
Neutrino mixing, CP and T violation, and textures in four-neutrino models
Barger, V.; Dai, Y.; Whisnant, K.; Young, B.
1999-06-01
We examine the prospects for determining the neutrino mixing matrix and for observing CP and T violation in neutrino oscillations in four-neutrino models. We focus on a general class of four-neutrino models with two pairs of nearly degenerate mass eigenstates separated by approximately 1 eV, which can describe the solar, atmospheric and LSND neutrino data. We present a general parametrization of these models and discuss in detail the determination of the mixing parameters and the mass matrix texture from current and future neutrino data in the case where {nu}{sub e} and {nu}{sub {mu}} each mix primarily with one other neutrino. We find that measurable CP or T violation in long-baseline experiments, with amplitude at the level of the LSND signal, is possible given current experimental constraints. Also, additional oscillation effects in short- and long-baseline experiments may be measurable in many cases. We point out that, given separate scales for the mass-squared differences of the solar and atmospheric oscillations, observable CP or T violation effects in neutrino oscillations signal the existence of a sterile neutrino. We examine several textures of the neutrino mass matrix and determine which textures can have measurable CP or T violation in neutrino oscillations in long-baseline experiments. We also briefly discuss some possible origins of the neutrino mass terms in straightforward extensions of the standard model. {copyright} {ital 1999} {ital The American Physical Society}
Experimental conditions for determination of the neutrino mass hierarchy with reactor antineutrinos
NASA Astrophysics Data System (ADS)
Pac, Myoung Youl
2016-01-01
This article reports the optimized experimental requirements to determine neutrino mass hierarchy using electron antineutrinos (νbare) generated in a nuclear reactor. The features of the neutrino mass hierarchy can be extracted from the | Δ m312 | and | Δ m322 | oscillations by applying the Fourier sine and cosine transforms to the L / E spectrum. To determine the neutrino mass hierarchy above 90% probability, the requirements on the energy resolution as a function of the baseline are studied at sin2 2θ13 = 0.1. If the energy resolution of the neutrino detector is less than 0.04 /√{Eν} and the determination probability obtained from Bayes' theorem is above 90%, the detector needs to be located around 48-53 km from the reactor(s) to measure the energy spectrum of νbare. These results will be helpful for setting up an experiment to determine the neutrino mass hierarchy, which is an important problem in neutrino physics.
Extended scaling and residual flavor symmetry in the neutrino Majorana mass matrix
NASA Astrophysics Data System (ADS)
Samanta, Rome; Roy, Probir; Ghosal, Ambar
2016-12-01
The residual symmetry approach, along with a complex extension for some flavor invariance, is a powerful tool to uncover the flavor structure of the 3 × 3 neutrino Majorana mass matrix M_ν toward gaining insights into neutrino mixing. We utilize this to propose a complex extension of the real scaling ansatz for M_ν which was introduced some years ago. Unlike the latter, our proposal allows a nonzero mass for each of the three light neutrinos as well as a nonvanishing θ _{13}. The generation of light neutrino masses via the type-I seesaw mechanism is also demonstrated. A major result of this scheme is that leptonic Dirac CP-violation must be maximal while atmospheric neutrino mixing does not need to be exactly maximal. Moreover, each of the two allowed Majorana phases, to be probed by the search for nuclear 0ν β β decay, has to be at one of its two CP-conserving values. There are other interesting consequences such as the allowed occurrence of a normal mass ordering which is not favored by the real scaling ansatz. Our predictions will be tested in ongoing and future neutrino oscillation experiments at T2K, NOν A and DUNE.
KM3NeT - ORCA: measuring the neutrino mass ordering in the Mediterranean
NASA Astrophysics Data System (ADS)
Kouchner, Antoine
2016-05-01
ORCA (Oscillations Research with Cosmics in the Abyss) is the low-energy branch of KM3NeT, the underwater Cherenkov neutrino detector in the Mediterranean. Its primary goal is to resolve the long-standing unsolved question of the neutrino mass ordering by measuring matter oscillation effects in atmospheric neutrinos. To be deployed at the French KM3NeT site, ORCA’s multi-PMT optical modules will exploit the excellent optical properties of deep seawater to reconstruct cascade and track events with a few GeV of energy. This contribution reviews the methods and technology, and discusses the current expected performances.
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.
Cosmology favoring extra radiation and sub-eV mass sterile neutrinos as an option.
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.
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.
TRITIUM-β-DECAY Experiments - the Direct way to the Absolute Neutrino Mass
NASA Astrophysics Data System (ADS)
Bornschein, Lutz
2013-11-01
Tritium-β-decay experiments provide the most sensitive approach to measure the absolute neutrino mass in a model independent way. The Karlsruhe Tritium Neutrino experiment KATRIN will measure the neutrino mass scale with an expected sensitivity of 0.2 eV/c2 (90% C.L.) and so will help to clarify the roles of neutrinos in the early universe. KATRIN investigates spectroscopically the electron spectrum from tritium β-decay 3 H -> 3 {He} + {e}^ - + bar ν e close to the kinematic endpoint of 18.6 keV. It will use a windowless gaseous tritium source in combination with an electrostatic filter for energy analysis. KATRIN is currently under construction at the Karlsruhe Institute of Technology (KIT) Campus North. This proceeding will give an overview of the status of the main components of the KATRIN experiment.
Status and prospects of global analyses of neutrino mass-mixing parameters
NASA Astrophysics Data System (ADS)
Capozzi, F.; Lisi, E.; Marrone, A.; Montanino, D.; Palazzo, A.
2017-09-01
We discuss the present knowledge of the neutrino oscillation parameters, the two mass squared differences (δm 2, Δm 2), the three mixing angles (θ 12, θ 13, θ 23) and one phase δ. While five out of these six parameters have been measured, the CP-violating phase δ remains unknown. Moreover, the octant of the mixing angle θ 23 and the neutrino mass ordering are still undetermined. We update our previous analysis, by adding to the global fit the recent results presented at The XXVII International Conference on Neutrino Physics and Astrophysics (Neutrino 2016) by the experiments T2K, NOνA, Super-Kamiokande, Daya Bay and RENO.
Absolute mass of neutrinos and the first unique forbidden β decay of Re187
NASA Astrophysics Data System (ADS)
Dvornický, Rastislav; Muto, Kazuo; Šimkovic, Fedor; Faessler, Amand
2011-04-01
The planned rhenium β-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 β decay of Re187. 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 β 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 β decay of H3.
Absolute mass of neutrinos and the first unique forbidden {beta} decay of {sup 187}Re
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.
Cosmology Favoring Extra Radiation and Sub-eV Mass Sterile Neutrinos as an Option
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.
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.
Tritium beta decay, neutrino mass matrices, and interactions beyond the standard model
NASA Astrophysics Data System (ADS)
Stephenson, G. J., Jr.; Goldman, T.; McKellar, B. H. J.
2000-11-01
The interference of charge changing interactions, weaker than the V-A standard model (SM) interaction and having a different Lorentz structure, with that SM interaction, can, in principle, produce effects near the end point of the tritium beta decay spectrum which are of a different character from those produced by the purely kinematic effect of neutrino mass expected in the simplest extension of the SM. We show that the existence of more than one mass eigenstate can lead to interference effects at the end point that are stronger than those occurring over the entire spectrum. We discuss these effects both for the special case of Dirac neutrinos and the more general case of Majorana neutrinos and show that, for the present precision of the experiments, one formula should suffice to express the interference effects in all cases. Implications for ``sterile'' neutrinos are noted.
EFFECTS OF THE NEUTRINO MASS SPLITTING ON THE NONLINEAR MATTER POWER SPECTRUM
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.
Precision electron-capture energy in 202Pb and its relevance for neutrino mass determination
NASA Astrophysics Data System (ADS)
Welker, A.; Filianin, P.; Althubiti, N. A. S.; Atanasov, D.; Blaum, K.; Cocolios, T. E.; Eliseev, S.; Herfurth, F.; Kreim, S.; Lunney, D.; Manea, V.; Neidherr, D.; Novikov, Yu.; Rosenbusch, M.; Schweikhard, L.; Wienholtz, F.; Wolf, R. N.; Zuber, K.
2017-07-01
Within the framework of an extensive programme devoted to the search for alternative candidates for the neutrino mass determination, the atomic mass difference between 202Pb and 202Tl has been measured with the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN. The obtained value Q_{EC} = 38.8(43) keV is three times more precise than the AME2012 value. While it will probably not lead to a replacement of 163Ho in modern experiments on the determination of the electron-neutrino mass, the electron capture in 202Pb would however allow a determination of the electron-neutrino mass on the few-eV level using a cryogenic micro-calorimeter.
Grand unification and low scale implications: D₂ parity for unification and neutrino masses
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.
Primordial black hole constraints for extended mass functions
NASA Astrophysics Data System (ADS)
Carr, Bernard; Raidal, Martti; Tenkanen, Tommi; Vaskonen, Ville; Veermäe, Hardi
2017-07-01
We revisit the cosmological and astrophysical constraints on the fraction of the dark matter in primordial black holes (PBHs) with an extended mass function. We consider a variety of mass functions, all of which are described by three parameters: a characteristic mass and width and a dark matter fraction. Various observations then impose constraints on the dark matter fraction as a function of the first two parameters. We show how these constraints relate to those for a monochromatic mass function, demonstrating that they usually become more stringent in the extended case than the monochromatic one. Considering only the well-established bounds, and neglecting the ones that depend on additional astrophysical assumptions, we find that there are three mass windows, around 5 ×10-16M⊙ , 2 ×10-14M⊙ and 25 - 100 M⊙ , where PBHs can constitute all the dark matter. However, if one includes all the bounds, PBHs can only constitute of order 10% of the dark matter.
Grohs, E.; Fuller, George M.; Kishimoto, Chad T.; Paris, Mark W. E-mail: gfuller@ucsd.edu E-mail: mparis@lanl.gov
2015-05-01
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.
Upper bound of 0.28 eV on neutrino masses from the largest photometric redshift survey.
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.
Avignone, F.T. III; Brodzinski, R.L.; Brown, D.P.; Evans, J.C. Jr.; Hensley, W.K.; Reeves, J.H.; Wogman, N.A.
1983-03-07
A continuing search for the no-neutrino mode of the double beta decay of /sup 76/Ge has resulted in a new lower limit T/sub 1/2//sup 0nu/ > or =1.7 x 10/sup 22/ yr. This value corresponds to a 90% confidence level determined with a maximum-likelihood analysis of the energy interval 2041 +- 2 keV. Combined with recent shell-model calculations, the data imply m/sub ..nu../< or =10 eV and a limit on lepton nonconservation Vertical BaretaVertical Bar< or =2.4 x 10/sup -5/. In the context of the shell model, the data imply that the electron neutrino is not a Majorana mass eigenstate.
Is the Zee model the model of neutrino masses?
Smirnov, A.Y.; Tanimoto, M.
1997-02-01
The Zee model predicts naturally two heavy, strongly degenerate and almost maximally mixed neutrinos and one light neutrino with small mixing. This pattern coincides with the one needed for a solution of the atmospheric neutrino problem by {nu}{sub {mu}}{r_arrow}{nu}{sub {tau}} oscillations and for existence of the two component hot dark matter in the Universe. Furthermore, the oscillations {bar {nu}}{sub {mu}}{r_arrow}{bar {nu}}{sub e} can be in the range of sensitivity of KARMEN, LSND experiments. The phenomenology of this scenario is considered and the possibility to check it in the forthcoming experiments is discussed. The scenario implies large values and inverse flavor hierarchy of couplings of the Zee boson with fermions: f{sub e{tau}}{lt}f{sub {mu}{tau}}{le}f{sub e{mu}}{approximately}0.1. The main signatures of the scenario are a strongly suppressed signal of {nu}{sub {mu}}{r_arrow}{nu}{sub {tau}} oscillation in CHORUS and NOMAD experiments, so that a positive result from these experiments will rule out the scenario, the possibility of the observation of {nu}{sub e}{r_arrow}{nu}{sub {tau}} oscillations by CHORUS and NOMAD, the corrections to the muon decay and neutrino-electron scattering at the level of experimental errors, and a branching ratio B({mu}{r_arrow}e{gamma}) bigger than 10{sup {minus}13}. The solar neutrino problem can be solved by the introduction of an additional very light singlet fermion without appreciable modification of the active neutrino pattern. {copyright} {ital 1997} {ital The American Physical Society}
Maximum Entropy Inferences on the Axion Mass in Models with Axion-Neutrino Interaction
NASA Astrophysics Data System (ADS)
Alves, Alexandre; Dias, Alex Gomes; da Silva, Roberto
2017-08-01
In this work, we use the maximum entropy principle (MEP) to infer the mass of an axion which interacts to photons and neutrinos in an effective low energy theory. The Shannon entropy function to be maximized is defined in terms of the axion branching ratios. We show that MEP strongly constrains the axion mass taking into account the current experimental bounds on the neutrinos masses. Assuming that the axion is massive enough to decay into all the three neutrinos and that MEP fixes all the free parameters of the model, the inferred axion mass is in the interval 0.1 eV < m A < 0.2 eV, which can be tested by forthcoming experiments such as IAXO. However, even in the case where MEP fixes just the axion mass and no other parameter, we found that 0.1 eV < m A < 6.3 eV in the DFSZ model with right-handed neutrinos. Moreover, a light axion, allowed to decay to photons and the lightest neutrino only, is determined by MEP as a viable dark matter candidate.
Testing keV sterile neutrino dark matter in future direct detection experiments
NASA Astrophysics Data System (ADS)
Campos, Miguel D.; Rodejohann, Werner
2016-11-01
We determine constraints on sterile neutrino warm dark matter through direct detection experiments, taking XENON100, XENON1T, and DARWIN as examples. If keV-scale sterile neutrinos scatter inelastically with bound electrons of the target material, an electron recoil signal is generated. This can be used to set limits on the sterile neutrino mass and its mixing with the active sector. While not competitive with astrophysical constraints from x-ray data, the constraints are the first direct laboratory bounds on sterile neutrino warm dark matter and will be in some parts of parameter space the strongest limits on keV-scale neutrinos.
Dirac or Inverse Seesaw Neutrino Masses from Gauged B - L Symmetry
NASA Astrophysics Data System (ADS)
Ma, Ernest; Srivastava, Rahul
The gauged B - L symmetry is one of the simplest and well studied extension of standard model. In the conventional case, addition of three singlet right-handed neutrinos each transforming as -1 under the B - L symmetry renders it anomaly free. It is usually assumed that the B - L symmetry is spontaneously broken by a singlet scalar having two units of B - L charge, resulting in a natural implementation of Majorana seesaw mechanism for neutrinos. However, as we discuss in this proceeding, there is another simple anomaly free solution which leads to Dirac or inverse seesaw masses for neutrinos. These new possibilities are explored along with an application to neutrino mixing with S3 flavour symmetry.
Dirac or inverse seesaw neutrino masses with B – L gauge symmetry and S₃ flavor symmetry
Ma, Ernest; Srivastava, Rahul
2015-02-01
Many studies have been made on extensions of the standard model with B – L gauge symmetry. The addition of three singlet (right-handed) neutrinos renders it anomaly-free. It has always been assumed that the spontaneous breaking of B – L is accomplished by a singlet scalar field carrying two units of B – L charge. This results in a very natural implementation of the Majorana seesaw mechanism for neutrinos. However, there exists in fact another simple anomaly-free solution which allows Dirac or inverse seesaw neutrino masses. We show for the first time these new possibilities and discuss an application tomore » neutrino mixing with S₃ flavor symmetry.« less
NASA Astrophysics Data System (ADS)
Schneps, J.; Kafka, T.; Mann, W. A.; Nath, P.
Contents: 1. Neutrino mass. 2. Neutrino oscillations. 3. Double beta decay. 4. Solar neutrinos. 5. Neutrinos from supernovae. 6. Neutrino interactions at accelerators. 7. New detectors for neutrino processes. 8. Neutrino interactions at accelerators II. 9. W, Z, and the standard model. 10. "Fred Reines at 70" Fest. 11. Nucleon decay, the standard model, and beyond. 12. Neutrinos: Earth, atmosphere, Sun, and galaxies. 13. Dark matter and cosmology. 14. Theoretical topics. 15. Future prospects.
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.
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.
Few active mechanisms of the 0νββ decay and effective mass of Majorana neutrinos
NASA Astrophysics Data System (ADS)
Šimkovic, Fedor; Vergados, John; Faessler, Amand
2010-12-01
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, assuming the observation of the 0νββ decay in three different nuclei, e.g., Ge76, Mo100, and Te130, and just three lepton number violating mechanisms (light- and heavy-neutrino mass mechanisms as well as the R-parity breaking supersymmetry mechanism) being active, there are only four different solutions for the lepton violating parameters, provided that they are relatively real. In particular, our analysis shows that the effective neutrino Majorana mass |mββ| can be almost uniquely extracted by utilizing other existing constraints (cosmological observations and tritium β-decay experiments). We also point out the possibility that the nonobservation of the 0νββ decay for some isotopes could be in agreement with a value of |mββ| in the sub-eV region. We thus suggest that it is important to have at least two different 0νββ-decay experiments for a given nucleus. We note that obtained results are sensitive to the accuracy of measured half-lives and to uncertainties in calculated nuclear matrix elements.
Nonstandard neutrino-neutrino refractive effects in dense neutrino gases
Blennow, Mattias; Mirizzi, Alessandro; Serpico, Pasquale D.; /CERN /Fermilab
2008-10-01
We investigate the effects of nonstandard four-fermion neutrino-neutrino interactions on the flavor evolution of dense neutrino gases. We find that in the regions where the neutrino-neutrino refractive index leads to collective flavor oscillations, the presence of new neutrino interactions can produce flavor equilibration in both normal and inverted neutrino mass hierarchy. In realistic supernova environments, these effects are significant if the nonstandard neutrino-neutrino interaction strength is comparable to the one expected in the standard case, dominating the ordinary matter potential. However, very small nonstandard neutrino-neutrino couplings are enough to trigger the usual collective neutrino flavor transformations in the inverted neutrino mass hierarchy, even if the mixing angle vanishes exactly.
Higgs portal dark matter and neutrino mass and mixing with a doubly charged scalar
NASA Astrophysics Data System (ADS)
Hierro, I. M.; King, S. F.; Rigolin, S.
2017-06-01
We consider an extension of the Standard Model involving two new scalar particles around the TeV scale: a singlet neutral scalar ϕ, to be eventually identified as the Dark Matter candidate, plus a doubly charged SU(2)L singlet scalar, S++, that can be the source for the non-vanishing neutrino masses and mixings. Assuming an unbroken Z2 symmetry in the scalar sector, under which only the additional neutral scalar ϕ is odd, we write the most general (renormalizable) scalar potential. The model may be regarded as a possible extension of the conventional Higgs portal Dark Matter scenario which also accounts for neutrino mass and mixing. This framework cannot completely explain the observed positron excess. However a softening of the discrepancy observed in conventional Higgs portal framework can be obtained, especially when the scale of new physics responsible for generating neutrino masses and lepton number violating processes is around 2 TeV.
Beta Decay in the Field of an Electromagnetic Wave and Experiments on Measuring the Neutrino Mass
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'.
Geometry of the effective Majorana neutrino mass in the 0νββ decay
NASA Astrophysics Data System (ADS)
Xing, Zhi-zhong; Zhou, Ye-Ling
2015-01-01
The neutrinoless double-beta (0νββ) decay is a unique process used to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass
Neutrino seesaw mechanism with texture zeros
Liao, Jiajun; Marfatia, D.; Whisnant, K.
2015-09-26
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 andmore » neutrinoless double beta decay.« less
Supernova neutrinos and explosive nucleosynthesis
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.
Neutrino physics, superbeams and the neutrino factory
Boris Kayser
2003-10-14
We summarize what has been learned about the neutrino mass spectrum and neutrino mixing, identify interesting open questions that can be answered by accelerator neutrino facilities of the future, and discuss the importance and physics of answering them.
Neutrino mass matrices from two zero 3 × 2 Yukawa textures and minimal d = 5 entries
NASA Astrophysics Data System (ADS)
Achelashvili, Avtandil; Tavartkiladze, Zurab
2016-05-01
Aiming to relate leptonic CP violating phase δ to the cosmological CP asymmetry, we study the extension of MSSM by two quasi-degenerate (strictly degenerate at tree level) right-handed neutrinos and consider all possible two texture zero 3 × 2 Yukawa matrices plus one ΔL = 2 dimension five (d = 5) operator contributing to the light neutrino mass matrix. We classify all experimentally viable mass matrices, leading to several predictions, and analytically derive predictive relations. We also relate the CP violating δ phase to the CP phase of the thermal leptogenesis.
Solar neutrino limit on axions and keV-mass bosons
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.
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.
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.
New constraints on all flavor Galactic diffuse neutrino emission with the ANTARES telescope
NASA Astrophysics Data System (ADS)
Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Belhorma, B.; Bertin, V.; Biagi, S.; Bormuth, R.; Bourret, S.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Cherkaoui El Moursli, R.; Chiarusi, T.; Circella, M.; Coelho, J. A. B.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Díaz, A. F.; Deschamps, A.; de Bonis, G.; Distefano, C.; di Palma, I.; Domi, A.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; El Khayati, N.; Elsässer, D.; Enzenhöfer, A.; Ettahiri, A.; Fassi, F.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Giordano, V.; Glotin, H.; Grégoire, T.; 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.; Jongen, 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.; Lotze, M.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mele, R.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Navas, S.; Nezri, E.; Organokov, M.; Pǎvǎlaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Quinn, L.; Racca, C.; Riccobene, G.; Sánchez-Losa, A.; Saldaña, M.; Salvadori, I.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schüssler, F.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Taiuti, M.; Tayalati, Y.; Trovato, A.; Turpin, D.; Tönnis, C.; Vallage, B.; van Elewyck, V.; Versari, F.; Vivolo, D.; Vizzoca, A.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; Gaggero, D.; Grasso, D.; ANTARES Collaboration
2017-09-01
The flux of very high-energy neutrinos produced in our Galaxy by the interaction of accelerated cosmic rays with the interstellar medium is not yet determined. The characterization of this flux will shed light on Galactic accelerator features, gas distribution morphology and Galactic cosmic ray transport. The central Galactic plane can be the site of an enhanced neutrino production, thus leading to anisotropies in the extraterrestrial neutrino signal as measured by the IceCube Collaboration. The ANTARES neutrino telescope, located in the Mediterranean Sea, offers a favorable view of this part of the sky, thereby allowing for a contribution to the determination of this flux. The expected diffuse Galactic neutrino emission can be obtained, linking a model of generation and propagation of cosmic rays with the morphology of the gas distribution in the Milky Way. In this paper, the so-called "gamma model" introduced recently to explain the high-energy gamma-ray diffuse Galactic emission is assumed as reference. The neutrino flux predicted by the "gamma model" depends on the assumed primary cosmic ray spectrum cutoff. Considering a radially dependent diffusion coefficient, this proposed scenario is able to account for the local cosmic ray measurements, as well as for the Galactic gamma-ray observations. Nine years of ANTARES data are used in this work to search for a possible Galactic contribution according to this scenario. All flavor neutrino interactions are considered. No excess of events is observed, and an upper limit is set on the neutrino flux of 1.1 (1.2) times the prediction of the "gamma model," assuming the primary cosmic ray spectrum cutoff at 5 (50) PeV. This limit excludes the diffuse Galactic neutrino emission as the major cause of the "spectral anomaly" between the two hemispheres measured by IceCube.
Possible implications of the atmospheric, the Bugey, and the Los Alamos neutrino experiments
NASA Astrophysics Data System (ADS)
Minakata, Hisakazu
1995-12-01
A combined analysis of the terrestrial neutrino experiments and the Kamiokande observation of the atmospheric neutrino anomaly is performed under the assumption of the existence of dark-matter-mass neutrinos, as suggested by the recent Los Alamos experiment. In the three-flavor mixing scheme of neutrinos it is shown that the constraints from these experiments are so strong that the patterns of mass hierarchy and flavor mixing of neutrinos are determined almost uniquely depending upon the interpretation of the atmospheric neutrino anomaly.
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.
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.
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
Unification of gauge couplings and the tau-neutrino mass in supergravity without R parity
NASA Astrophysics Data System (ADS)
Díaz, M. A.; Ferrandis, J.; Romão, J. C.; Valle, J. W. F.
2000-12-01
Minimal R-parity violating supergravity predicts a value for αs(M Z) smaller than in the case with conserved R-parity, and therefore closer to the experimental world average. We show that the R-parity violating effect on the αs prediction comes from the larger two-loop b-quark Yukawa contribution to the renormalization group evolution of the gauge couplings which characterizes R-parity violating supergravity. The effect is related to the tau neutrino mass and is sensitive to the initial conditions on the soft supersymmetry breaking parameters at the unification scale. We show how a few percent effect on αs(M Z) may occur even with ντ masses as small as indicated by the simplest neutrino oscillation interpretation of the atmospheric neutrino data from Super-Kamiokande.
Can sterile neutrinos be the dark matter?
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.
Mass varying neutrinos, quintessence, and the accelerating expansion of the Universe
Chitov, Gennady Y.; August, Tyler; Natarajan, Aravind; Kahniashvili, Tina
2011-02-15
We analyze the mass varying neutrino scenario. We consider a minimal model of massless Dirac fermions coupled to a scalar field, mainly in the framework of finite-temperature quantum field theory. We demonstrate that the mass equation we find has nontrivial solutions only for special classes of potentials, and only within certain temperature intervals. We give most of our results for the Ratra-Peebles dark energy (DE) potential. The thermal (temporal) evolution of the model is analyzed. Following the time arrow, the stable, metastable, and unstable phases are predicted. The model predicts that the present Universe is below its critical temperature and accelerates. At the critical point, the Universe undergoes a first-order phase transition from the (meta)stable oscillatory regime to the unstable rolling regime of the DE field. This conclusion agrees with the original idea of quintessence as a force making the Universe roll towards its true vacuum with a zero {Lambda} term. The present mass varying neutrino scenario is free from the coincidence problem, since both the DE density and the neutrino mass are determined by the scale M of the potential. Choosing M{approx}10{sup -3} eV to match the present DE density, we can obtain the present neutrino mass in the range m{approx}10{sup -2}-1 eV and consistent estimates for other parameters of the Universe.
NASA Astrophysics Data System (ADS)
Borgohain, Happy; Das, Mrinal Kumar
2017-09-01
We have studied neutrinoless double beta decay and charged lepton flavour violation in broken μ - τ symmetric neutrino masses in a generic left-right symmetric model (LRSM). The leading order μ - τ symmetric mass matrix originates from the type I (II) seesaw mechanism, whereas the perturbations to μ - τ symmetry in order for generation of non-zero reactor mixing angle 𝜃 13, as required by latest neutrino oscillation data, originates from the type II (I) seesaw mechanism. In our work, we considered four different realizations of μ - τ symmetry, viz. Tribimaximal Mixing (TBM), Bimaximal Mixing (BM), Hexagonal Mixing (HM) and Golden Ratio Mixing (GRM). We then studied the new physics contributions to neutrinoless double beta decay (NDBD) ignoring the left-right gauge boson mixing and the heavy-light neutrino mixing within the framework of LRSM. We have considered the mass of the gauge bosons and scalars to be around TeV and studied the effects of the new physics contributions on the effective mass and the NDBD half life and compared with the current experimental limit imposed by KamLAND-Zen. We further extended our analysis by correlating the lepton flavour violation of the decay processes, ( μ → 3 e) and ( μ → e γ) with the lightest neutrino mass and atmospheric mixing angle 𝜃 23 respectively.
NASA Astrophysics Data System (ADS)
Borgohain, Happy; Das, Mrinal Kumar
2017-06-01
We have studied neutrinoless double beta decay and charged lepton flavour violation in broken μ - τ symmetric neutrino masses in a generic left-right symmetric model (LRSM). The leading order μ - τ symmetric mass matrix originates from the type I (II) seesaw mechanism, whereas the perturbations to μ - τ symmetry in order for generation of non-zero reactor mixing angle 𝜃 13, as required by latest neutrino oscillation data, originates from the type II (I) seesaw mechanism. In our work, we considered four different realizations of μ - τ symmetry, viz. Tribimaximal Mixing (TBM), Bimaximal Mixing (BM), Hexagonal Mixing (HM) and Golden Ratio Mixing (GRM). We then studied the new physics contributions to neutrinoless double beta decay (NDBD) ignoring the left-right gauge boson mixing and the heavy-light neutrino mixing within the framework of LRSM. We have considered the mass of the gauge bosons and scalars to be around TeV and studied the effects of the new physics contributions on the effective mass and the NDBD half life and compared with the current experimental limit imposed by KamLAND-Zen. We further extended our analysis by correlating the lepton flavour violation of the decay processes, (μ → 3e) and (μ → e γ) with the lightest neutrino mass and atmospheric mixing angle 𝜃 23 respectively.
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.
Cosmological constraints on the graviton mass in RTG
NASA Astrophysics Data System (ADS)
Chugreev, Yu. V.
2017-07-01
The Friedmann cosmological scenario in RTG (without inflation) is considered. The joint maximum-likelihood analysis of data on type Ia supernovae, the shift parameter of microwave radiation, and baryon acoustic oscillations from the Sloan catalogue of red galaxies provided tight fit constraints on the graviton mass and the space curvature in GR. It is demonstrated that the confidence interval for the graviton mass extends indefinitely if the quintessence parameter tends to zero. These conclusions are valid if the present scale factor a 0 >(2)-1/6= 0.89. At a 0 <(2)-1/6, a tight constraint on the graviton mass was derived from these observational data: m < 10-83 g. This implies that terms with the graviton mass may be neglected (with the exception of solutions of the black-hole type) in the gravitational field equations in a broad range of redshifts (0 < z < 1015).
Coloma, Pilar
2016-11-21
Neutrino oscillations have demonstrated that neutrinos have mass and, by now, oscillation experiments have been able to determine most of the parameters in the leptonic mixing matrix with a very good accuracy. Nevertheless, there are still many open questions in the neutrino sector. As a result, I will briefly discuss some of these questions, pointing out possible experimental avenues to address them.
Coloma, Pilar
2016-11-21
Neutrino oscillations have demonstrated that neutrinos have mass and, by now, oscillation experiments have been able to determine most of the parameters in the leptonic mixing matrix with a very good accuracy. Nevertheless, there are still many open questions in the neutrino sector. As a result, I will briefly discuss some of these questions, pointing out possible experimental avenues to address them.
Measuring the mass of a sterile neutrino with a very short baseline reactor experiment
NASA Astrophysics Data System (ADS)
Latimer, D. C.; Escamilla, J.; Ernst, D. J.
2007-04-01
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 Δm2≅0.9eV2. We trace its origin to harmonic oscillations in the electron survival probability Pee 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 Δm2≅1.9eV2. We point out that the phenomenon of harmonic oscillations of Pee 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 eV2 to several eV2 (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.
Measuring the mass of a sterile neutrino with a very short baseline reactor experiment
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.
Neutrino mass hierarchy, vacuum oscillations, and vanishing |U(e3)|
de Gouvea, Andre; Jenkins, James; Kayser, Boris; /Fermilab
2005-03-01
Is the relatively isolated member of the neutrino mass spectrum heavier or lighter than the two closely-spaced members? This question--the character of the neutrino mass hierarchy--is of great theoretical interest. All previously identified experiments for addressing it via neutrino oscillations require that the currently unknown size of the U{sub e3} element of the leptonic mixing matrix (parameterized by the unknown {theta}{sub 13} mixing angle) be sufficiently large, and will utterly fail in the limit {theta}{sub 13} {yields} 0. For this reason, we explore alternative oscillation approaches that would still succeed even if {theta}{sub 13} vanishes. We identify several alternatives that require neither a nonzero |U{sub e3}| nor the presence of significant matter effects. All include multiple percent-level neutrino oscillation measurements, usually involving muon-neutrino (or antineutrino) disappearance and very long baselines. We comment on the degree of promise that these alternative approaches show.
Neutrino mass hierarchy, vacuum oscillations, and vanishing vertical bar U{sub e3} vertical bar
Gouvea, Andre de; Jenkins, James; Kayser, Boris
2005-06-01
Is the relatively isolated member of the neutrino mass spectrum heavier or lighter than the two closely-spaced members? This question--the character of the neutrino mass hierarchy--is of great theoretical interest. All previously identified experiments for addressing it via neutrino oscillations require that the currently unknown size of the U{sub e3} element of the leptonic mixing matrix (parameterized by the unknown {theta}{sub 13} mixing angle) be sufficiently large, and will utterly fail in the limit {theta}{sub 13}{yields}0. For this reason, we explore alternative oscillation approaches that would still succeed even if {theta}{sub 13} vanishes. We identify several alternatives that require neither a nonzero vertical bar U{sub e3} vertical bar nor the presence of significant matter effects (even if the latter are unavoidable in the case of long-baseline, Earth-based experiments). All include multiple percent-level neutrino oscillation measurements, usually involving muon-neutrino (or antineutrino) disappearance and very long baselines. We comment on the degree of promise that these alternative approaches show.
Sterile Neutrino Experiments I: Accelerator-based
NASA Astrophysics Data System (ADS)
Toups, Matthew
2017-01-01
The Standard Model is the theory that describes the fundamental constituents of matter and their interactions. Despite its great success, there still exists evidence for a wide range of phenomena, which lie outside the framework of the Standard Model. Among these, neutrino flavor oscillations hold great promise to bring insight to the field towards a theory that transcends the Standard Model. The discovery of light, sterile neutrinos that mix with the three active neutrino flavors and modify the standard three-neutrino oscillation probabilities in vacuum and matter would be a major breakthrough for the field and contribute to our overall understanding of neutrino mass and mixing. Current indications for light sterile neutrinos come from a variety of experiments reporting anomalies. The accelerator-based LSND and MiniBooNE experiments, for example, reported an excess of electron-type neutrinos over short baselines, which if interpreted as due to νμ ->νe (or νμ ->νe) oscillations, would imply the existence of a fourth light neutrino mass state. On the other hand, null results from other accelerator-based neutrino oscillation experiments searching for sterile neutrinos have put constraints on the possible existence of these particles. This talk will review the accelerator-based searches for light, sterile neutrinos as well as the prospects for confirming or refuting their existence in the coming years.
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_(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(2)theta_(13) < or approximately 10(-5), where long baseline neutrino experiments would be ineffectual.
Zhang, Jing-Fei; Zhao, Ming-Ming; Li, Yun-He; Zhang, Xin E-mail: zhaomingmingsp@163.com E-mail: zhangxin@mail.neu.edu.cn
2015-04-01
The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter w evolving across the phantom divide w=−1 in the HDE model with c<1. We thus derive the evolutions of density perturbations of various components and metric fluctuations in the HDE model. The impacts of massive neutrino and dark radiation on the CMB anisotropy power spectrum and the matter power spectrum in the HDE scenario are discussed. Furthermore, we constrain the models of HDE with massive neutrinos and/or dark radiation by using the latest measurements of expansion history and growth of structure, including the Planck CMB temperature data, the baryon acoustic oscillation data, the JLA supernova data, the Hubble constant direct measurement, the cosmic shear data of weak lensing, the Planck CMB lensing data, and the redshift space distortions data. We find that ∑ m{sub ν}<0.186 eV (95% CL) and N{sub eff}=3.75{sup +0.28}{sub −0.32} in the HDE model from the constraints of these data.
NASA Astrophysics Data System (ADS)
Gu, Pei-Hong; Ma, Ernest; Sarkar, Utpal
2016-12-01
The scotogenic mechanism for radiative neutrino mass is generalized to include neutron-antineutron oscillation as well as proton decay. Dark matter is stabilized by extending the notion of lepton parity to matter parity. Leptogenesis is also a possible byproduct. This framework unifies the description of all these important topics in physics beyond the standard model of particle interactions.
What neutrinoless double beta decay would tell us about neutrino mass
Kayser, B. )
1992-02-01
We identify several types of gauge theories, which together comprise a very broad range, in which the observation of neutrinoless double beta decay would imply a significant lower bound on neutrino mass. We explain why these gauge theories have this property.
Determining the neutrino mass with cyclotron radiation emission spectroscopy—Project 8
NASA Astrophysics Data System (ADS)
Ashtari Esfahani, Ali; Asner, David M.; Böser, Sebastian; Cervantes, Raphael; Claessens, Christine; de Viveiros, Luiz; Doe, Peter J.; Doeleman, Shepard; Fernandes, Justin L.; Fertl, Martin; Finn, Erin C.; Formaggio, Joseph A.; Furse, Daniel; Guigue, Mathieu; Heeger, Karsten M.; Jones, A. Mark; Kazkaz, Kareem; Kofron, Jared A.; Lamb, Callum; LaRoque, Benjamin H.; Machado, Eric; McBride, Elizabeth L.; Miller, Michael L.; Monreal, Benjamin; Mohanmurthy, Prajwal; Nikkel, James A.; Oblath, Noah S.; Pettus, Walter C.; Hamish Robertson, R. G.; Rosenberg, Leslie J.; Rybka, Gray; Rysewyk, Devyn; Saldaña, Luis; Slocum, Penny L.; Sternberg, Matthew G.; Tedeschi, Jonathan R.; Thümmler, Thomas; VanDevender, Brent A.; E Vertatschitsch, Laura; Wachtendonk, Megan; Weintroub, Jonathan; Woods, Natasha L.; Young, André; Zayas, Evan M.
2017-05-01
The most sensitive direct method to establish the absolute neutrino mass is observation of the endpoint of the tritium beta-decay spectrum. Cyclotron radiation emission spectroscopy (CRES) is a precision spectrographic technique that can probe much of the unexplored neutrino mass range with { O }({eV}) resolution. A lower bound of m({ν }e)≳ 9(0.1) {meV} is set by observations of neutrino oscillations, while the KATRIN experiment—the current-generation tritium beta-decay experiment that is based on magnetic adiabatic collimation with an electrostatic (MAC-E) filter—will achieve a sensitivity of m({ν }e)≲ 0.2 {eV}. The CRES technique aims to avoid the difficulties in scaling up a MAC-E filter-based experiment to achieve a lower mass sensitivity. In this paper we review the current status of the CRES technique and describe Project 8, a phased absolute neutrino mass experiment that has the potential to reach sensitivities down to m({ν }e)≲ 40 {meV} using an atomic tritium source.
Neutrino mass^2 inferred from the cosmic ray spectrum and tritium beta decay
NASA Astrophysics Data System (ADS)
Ehrlich, R.
2000-11-01
An earlier prediction of a cosmic ray neutron line right at the energy of the knee of the cosmic ray spectrum was based on the speculation that the electron neutrino is a tachyon whose mass is reciprocally related to the energy of the knee, $E_k$. Given the large uncertainty in $E_k$, the values of ${m_\
Status report on the Livermore-Rockefeller-Fermilab neutrino mass experiment
Fackler, O.; Mugge, M.; Sticker, H.; White, R.M.; Woerner, R.
1986-03-01
An experiment is being performed to determine the electron neutrino mass with the precision of a few eV by measuring the tritium beta decay energy distribution near the endpoint. Key features of the experiment are a 2 eV resolution electrostatic spectrometer and a high-activity frozen tritium source.
AN OVERVIEW OF NEUTRINO MASSES AND MIXING IN SO(10) MODELS.
CHEN,M.C.MAHANTHAPPA,K.T.
2003-06-05
We review in this talk various SUSY SO(10) models. Specifically, we discuss how small neutrino masses are generated in and generic predictions of different SO(10) models. A comparison of the predictions of these models for sin{sup 2} {theta}{sub 13}is given.
A realistic model of neutrino masses with a large neutrinoless double beta decay rate
NASA Astrophysics Data System (ADS)
del Aguila, Francisco; Aparici, Alberto; Bhattacharya, Subhaditya; Santamaria, Arcadi; Wudka, Jose
2012-05-01
The minimal Standard Model extension with the Weinberg operator does accommodate the observed neutrino masses and mixing, but predicts a neutrinoless double beta (0 νββ) decay rate proportional to the effective electron neutrino mass, which can be then arbitrarily small within present experimental limits. However, in general 0 νββ decay can have an independent origin and be near its present experimental bound; whereas neutrino masses are generated radiatively, contributing negligibly to 0 νββ decay. We provide a realization of this scenario in a simple, well defined and testable model, with potential LHC effects and calculable neutrino masses, whose two-loop expression we derive exactly. We also discuss the connection of this model to others that have appeared in the literature, and remark on the significant differences that result from various choices of quantum number assignments and symmetry assumptions. In this type of models lepton flavor violating rates are also preferred to be relatively large, at the reach of foreseen experiments. Interestingly enough, in our model this stands for a large third mixing angle, {{si}}{{{n}}^{{2}}}{θ_{{{13}}}}{˜}}}{ > }}0.00{8} , when μ→ eee is required to lie below its present experimental limit.
Constraints on high-energy neutrino emission from SN 2008D
NASA Astrophysics Data System (ADS)
IceCube Collaboration; Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Ben Zvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Davis, J. C.; De Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Grant, D.; Griesel, T.; Gro, A.; Grullon, S.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hül, J. P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K. H.; Kappes A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Köhne, J. H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lehmann, R.; Lünemann, J.; Madsen, J.; Majumdar, P.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Matusik, M.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Ono, M.; Panknin, S.; Paul, L.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Singh, K.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; van Santen, J.; Voge, M.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.
2011-03-01
SN 2008D, a core collapse supernova at a distance of 27 Mpc, was serendipitously discovered by the Swift satellite through an associated X-ray flash. Core collapse supernovae have been observed in association with long gamma-ray bursts and X-ray flashes and a physical connection is widely assumed. This connection could imply that some core collapse supernovae possess mildly relativistic jets in which high-energy neutrinos are produced through proton-proton collisions. The predicted neutrino spectra would be detectable by Cherenkov neutrino detectors like IceCube. A search for a neutrino signal in temporal and spatial correlation with the observed X-ray flash of SN 2008D was conducted using data taken in 2007-2008 with 22 strings of the IceCube detector. Events were selected based on a boosted decision tree classifier trained with simulated signal and experimental background data. The classifier was optimized to the position and a "soft jet" neutrino spectrum assumed for SN 2008D. Using three search windows placed around the X-ray peak, emission time scales from 100-10 000 s were probed. No events passing the cuts were observed in agreement with the signal expectation of 0.13 events. Upper limits on the muon neutrino flux from core collapse supernovae were derived for different emission time scales and the principal model parameters were constrained. While no meaningful limits can be given in the case of an isotropic neutrino emission, the parameter space for a jetted emission can be constrained. Future analyses with the full 86 string IceCube detector could detect up to ~100 events for a core-collapse supernova at 10 Mpc according to the soft jet model.
NASA Astrophysics Data System (ADS)
Cheung, Kingman; Nomura, Takaaki; Okada, Hiroshi
2016-12-01
We propose a one-loop radiative Majorana-type neutrino-mass matrix without any kind of additional symmetries by introducing two leptoquark-like bosons only. In this scenario, we show that the anomaly appearing in the process b →s ℓℓ ¯ can be explained without any conflicts against various constraints such as lepton-flavor violations, flavor-changing neutral currents, oblique parameters Δ S , Δ T , and the Drell-Yan process. We make the predictions for the flavor-violating lepton-pair production (e μ , e τ , and μ τ ) at the LHC, as well as the cross sections for pair production of these leptoquark-like bosons.
Effect of the charged-lepton's mass on the quasielastic neutrino cross sections
NASA Astrophysics Data System (ADS)
Ankowski, Artur M.
2017-09-01
Martini et al. [Phys. Rev. C 94, 015501 (2016), 10.1103/PhysRevC.94.015501] recently observed that when the produced-lepton's mass plays an important role, the charged-current quasielastic cross section for muon neutrinos can be higher than that for electron neutrinos. Here I argue that this effect appears solely in the theoretical descriptions of nuclear effects in which nucleon knockout requires the energy and momentum transfers to lie in a narrow range of the kinematically allowed values.
Thermal vacuum, cosmic microwave radiation, neutrino masses and fractal-like self-similar structure
NASA Astrophysics Data System (ADS)
Capolupo, Antonio; Lambiase, Gaetano; Vitiello, Giuseppe
2017-08-01
The behavior of thermal vacuum condensates of scalar and fermion fields is analyzed and it is shown that the condensate of Maxwell fields reproduces the characteristics of the cosmic microwave radiation. By studying fermion thermal states with the temperature of the cosmic neutrino background, we derive a value of the sum of the active neutrino masses which is compatible with its estimated lower bound. Moreover, we reveal the fractal self-similar structure of the thermal radiation and we relate it to the coherent structure of the thermal vacuum.
X. Qian, D. A. Dwyer, R. D. McKeown, P. Vogel, W. Wang, C. Zhang`
2013-02-01
Determination of the neutrino mass hierarchy using a reactor neutrino experiment at ∼60 km is analyzed. Such a measurement is challenging due to the finite detector resolution, the absolute energy scale calibration, and the degeneracies caused by current experimental uncertainty of |Δm{sub 32}{sup 2}|. The standard {chi}{sup 2} method is compared with a proposed Fourier transformation method. In addition, we show that for such a measurement to succeed, one must understand the nonlinearity of the detector energy scale at the level of a few tenths of percent.
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.
Cosmological and supernova neutrinos
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.
The Absolute Mass of Neutrino and the First Unique Forbidden β-DECAY of 187Re
NASA Astrophysics Data System (ADS)
Dvornický, Rastislav; Šimkovic, Fedor; Muto, Kazuo
2011-10-01
The planned rhenium β-decay experiment MARE might probe the absolute mass scale of neutrinos with the same sensitivity as the tritium β-decay experiment KATRIN, which will start data taking in 2011 and will proceed for five years. We present the energy distribution of emitted electrons for the first unique forbidden β-decay of 187Re. 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 β-decay is derived. It is shown that the Kurie plot near the endpoint is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed βof 3H.
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.
Lepton jets and low-mass sterile neutrinos at hadron colliders
NASA Astrophysics Data System (ADS)
Dube, Sourabh; Gadkari, Divya; Thalapillil, Arun M.
2017-09-01
Sterile neutrinos, if they exist, are potential harbingers for physics beyond the Standard Model. They have the capacity to shed light on our flavor sector, grand unification frameworks, dark matter sector and origins of baryon antibaryon asymmetry. There have been a few seminal studies that have broached the subject of sterile neutrinos with low, electroweak-scale masses (i.e. ΛQCD≪mNR≪mW± ) and investigated their reach at hadron colliders using lepton jets. These preliminary studies nevertheless assume background-free scenarios after certain selection criteria which are overly optimistic and untenable in realistic situations. These lead to incorrect projections. The unique signal topology and challenging hadronic environment also make this mass-scale regime ripe for a careful investigation. With the above motivations, we attempt to perform the first systematic study of low, electroweak-scale, right-handed neutrinos at hadron colliders, in this unique signal topology. There are currently no active searches at hadron colliders for sterile neutrino states in this mass range, and we frame the study in the context of the 13 TeV high-luminosity Large Hadron Collider and the proposed FCC-hh/SppC 100 TeV p p -collider.
Search for sterile neutrino oscillations in muon neutrino disappearance at MINOS/MINOS+
NASA Astrophysics Data System (ADS)
Todd, Jacob; Minos+ Collaboration
2017-01-01
A wide variety of neutrino oscillation phenomena are well-described by the standard three-flavour neutrino model, but some anomalies exist. The LSND and MiniBooNE experiments have measured electron antineutrino appearance in excess of standard oscillation predictions, which points to the possibility of a sterile neutrino with higher mass than the presently known states. MINOS, a two-detector, long-baseline neutrino oscillation experiment, was optimized for the measurement of muon neutrino disappearance in the NuMI neutrino beam. A sterile neutrino responsible for the LSND and MiniBooNE excesses would cause distortions in the charged current and neutral current MINOS spectra, which permits the search for sterile neutrinos at MINOS. In close collaboration with the Daya Bay reactor neutrino experiment, MINOS has placed strong constraints on the sterile neutrino parameter space for a model with one additional sterile neutrino. Further, the extension of data collection with MINOS+, which samples the NuMI beam in a medium energy configuration, markedly increases the sensitivity of the combined MINOS and MINOS+ sample to a 3+1-flavour sterile neutrino model.
NASA Astrophysics Data System (ADS)
Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Argüelles, C.; Auffenberg, J.; Axani, S.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blot, S.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Burgman, A.; Carver, T.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cross, R.; Day, M.; de André, J. P. A. M.; De Clercq, C.; del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Eller, P.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Franckowiak, A.; Friedman, E.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Gladstone, L.; Glagla, M.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Grant, D.; Griffith, Z.; Haack, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, B.; Hansmann, T.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfel, K.; Hoshina, K.; Huang, F.; Huber, M.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Jurkovic, M.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kim, M.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krückl, G.; Krüger, C.; Kunnen, J.; Kunwar, S.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lauber, F.; Lennarz, D.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mancina, S.; Mandelartz, M.; Maruyama, R.; Mase, K.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Mohrmann, L.; Montaruli, T.; Moulai, M.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Penek, Ö.; Pepper, J. A.; Pérez de los Heros, C.; Pieloth, D.; Pinat, E.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relethford, B.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Rysewyk, D.; Sabbatini, L.; Sanchez Herrera, S. E.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Satalecka, K.; Schimp, M.; Schlunder, P.; Schmidt, T.; Schoenen, S.; Schöneberg, S.; Schumacher, L.; Seckel, D.; Seunarine, S.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stahlberg, M.; Stanev, T.; Stasik, A.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Tatar, J.; Tenholt, F.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Turcati, A.; Unger, E.; Usner, M.; Vandenbroucke, J.; van Eijndhoven, N.; Vanheule, S.; van Rossem, M.; van Santen, J.; Veenkamp, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Weaver, Ch.; Weiss, M. J.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wickmann, S.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wolf, M.; Wood, T. R.; Woolsey, E.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.; IceCube Collaboration
2016-12-01
We report constraints on the sources of ultrahigh-energy cosmic rays (UHECRs) above 1 09 GeV , based on an analysis of seven years of IceCube data. This analysis efficiently selects very high- energy neutrino-induced events which have deposited energies from 5 ×1 05 GeV to above 1 011 GeV . Two neutrino-induced events with an estimated deposited energy of (2.6 ±0.3 )×1 06 GeV , the highest neutrino energy observed so far, and (7.7 ±2.0 )×1 05 GeV were detected. The atmospheric background-only hypothesis of detecting these events is rejected at 3.6 σ . The hypothesis that the observed events are of cosmogenic origin is also rejected at >99 % CL because of the limited deposited energy and the nonobservation of events at higher energy, while their observation is consistent with an astrophysical origin. Our limits on cosmogenic neutrino fluxes disfavor the UHECR sources having a cosmological evolution stronger than the star formation rate, e.g., active galactic nuclei and γ -ray bursts, assuming proton-dominated UHECRs. Constraints on UHECR sources including mixed and heavy UHECR compositions are obtained for models of neutrino production within UHECR sources. Our limit disfavors a significant part of parameter space for active galactic nuclei and new-born pulsar models. These limits on the ultrahigh-energy neutrino flux models are the most stringent to date.
Supernova bound on keV-mass sterile neutrinos reexamined
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.
Nomura, Takaaki; Okada, Hiroshi; Okada, Nobuchika
2016-09-22
Here, we propose a radiative seesaw model at the three-loop level, in which quarks, leptons, leptoquark bosons, and a Majorana fermion of dark matter candidate are involved in the neutrino loop. When analyzing neutrino oscillation data includes all possible constraints such as flavor changing neutral currents, lepton flavor violations, upper/lower bound on the mass of leptoquark from the collider physics, and the measured relic density of the dark matter, we show the allowed region to satisfy all the data/constraints.
Neutrino mass, dark matter, and Baryon asymmetry via TeV-scale physics without fine-tuning.
Aoki, Mayumi; Kanemura, Shinya; Seto, Osamu
2009-02-06
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.
Two-loop neutrino model with exotic leptons
NASA Astrophysics Data System (ADS)
Okada, Hiroshi; Orikasa, Yuta
2016-01-01
We propose a two-loop induced neutrino mass model, in which we show some bench mark points to satisfy the observed neutrino oscillation, the constraints of lepton flavor violations, and the relic density in the coannihilation system satisfying the current upper bound on the spin independent scattering cross section with nuclei. We also discuss new sources of muon anomalous magnetic moments.
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
Majorana Neutrino Masses by Spectroscopic Studies of Double Beta Decays and Moon
NASA Astrophysics Data System (ADS)
Ejiri, Hiroyasu
This is a brief review of spectroscopic studies of neutrino-less double beta decays (0νββ) and the MOON (Mo Observatory Of Neutrinos) project. It aims at studying the Majorana nature of neutrinos and the mass spectrum by spectroscopic studies of 0νββ with ν-mass sensitivity of
Resolving the mass hierarchy with atmospheric neutrinos using a liquid argon detector
Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Sankar, S. Uma
2008-10-01
We explore the potential offered by large-mass liquid argon detectors for determination of the sign of {delta}m{sub 31}{sup 2}, or the neutrino mass hierarchy, through interactions of atmospheric neutrinos. We give results for a 100 kT sized magnetized detector which provides separate sensitivity to {nu}{sub {mu}}, {nu}{sub {mu}} and, over a limited energy range, to {nu}{sub e}, {nu}{sub e}. We also discuss the sensitivity for the unmagnetized version of such a detector. After including the effect of smearing in neutrino energy and direction and incorporating the relevant statistical, theoretical, and systematic errors, we perform a binned {chi}{sup 2} analysis of simulated data. The {chi}{sup 2} is marginalized over the presently allowed ranges of neutrino parameters and determined as a function of {theta}{sub 13}. We find that such a detector offers superior capabilities for hierarchy resolution, allowing a >4{sigma} determination for a 100 kT detector over a 10-year running period for values of sin{sup 2}2{theta}{sub 13}{>=}0.05. For an unmagnetized detector, a 2.5{sigma} hierarchy sensitivity is possible for sin{sup 2}2{theta}{sub 13}=0.04.
High-scale leptogenesis with three-loop neutrino mass generation and dark matter
NASA Astrophysics Data System (ADS)
Gu, Pei-Hong
2017-04-01
We demonstrate a common origin for high-scale leptogenesis and three-loop neutrino mass generation. Specifically we extend the standard model by two real singlet scalars, two singly charged scalars carrying different quantum numbers under certain global symmetry and two or more singlet fermions with Majorana masses. This global symmetry is only allowed to be softly or spontaneously broken. Our model also respects an exactly conserved Z 2 discrete symmetry. Through the real scalar decays and then the charged scalar decays, we can obtain a lepton asymmetry stored in the standard model leptons. This lepton asymmetry can be partially converted to a baryon asymmetry by the sphaleron processes. The interactions for this leptogenesis can also result in a three-loop diagram to generate the neutrino masses. The lightest singlet fermion can keep stable to serve as a dark matter particle.
Model for neutrino masses and dark matter with a discrete gauge symmetry
NASA Astrophysics Data System (ADS)
Chang, We-Fu; Wong, Chi-Fong
2012-01-01
A simple renormalizable U(1) gauge model is constructed to explain the smallness of the active neutrino masses and provide the stable cold dark matter candidate simultaneously. The local U(1) symmetry is assumed to be spontaneously broken by a scalar field around the TeV scale. The active neutrino masses are then generated at one-loop level. This model contains several cold dark matter candidates whose stability is guaranteed by a residual discrete gauge Z2 symmetry à la the Krauss-Wilczek mechanism. Unlike the other dark matter models, no further global discrete or continuous symmetry is introduced. Moreover, the masses of all fermionic degrees of freedom beyond the standard model are closely related to the scale of spontaneous breaking of U(1); thus they could be probed at or below the TeV scale. The possible cosmological and phenomenological consequences are briefly discussed.
Oscillating decay rate in electron capture and the neutrino mass difference
NASA Astrophysics Data System (ADS)
Peshkin, Murray
2015-04-01
Reported oscillations in the rate of decay of certain ions by K -electron capture have raised questions about whether and how such oscillations can arise in quantum-mechanical theory and whether they can measure the neutrino mass difference. Here I show that simple principles of quantum mechanics answer some questions and clarify what must be performed theoretically or experimentally to answer some others. The principal result is that quantum mechanics does allow mass-difference-dependent oscillations in principle, but it imposes conditions not obeyed by the approximate dynamical models that have been put forth up to now. In particular, indirect coupling between two neutrino mass channels must be taken into account. What needs to be done experimentally and theoretically is discussed.
Final scientific and technical report: New experiments to measure the neutrino mass scale
Monreal, Benjamin
2016-11-19
In this work, we made material progress towards future measurements of the mass of the neutrino. The neutrino is a fundamental particle, first observed in the 1950s and subjected to particularly intense study over the past 20 years. It is now known to have some, non-zero mass, but we are in an unusual situation of knowing the mass exists but not knowing what value it takes. The mass may be determined by precise measurements of certain radioactive decay distributions, particularly the beta decay of tritium. The KATRIN experiment is an international project which is nearing the beginning of a tritium measurement campaign using a large electrostatic spectrumeter. This research included participation in KATRIN, including construction and delivery of a key calibration subsystem, the ``Rear Section''. To obtain sensitivity beyond KATRIN's, new techniques are required; this work included R\\&D on a new technique we call CRES (Cyclotron Resonance Electron Spectroscopy) which has promise to enable even-more-sensitive tritium decay measurements. We successfully carried out CRES spectroscopy in a model system in 2014, making an important step towards the design of a next-generation tritium experiment with new neutrino mass measurement abilities.
NASA Astrophysics Data System (ADS)
Xing, Zhi-Zhong; Zhang, He; Zhou, Shun
Assuming the Majorana nature of massive neutrinos, we generalize the Friedberg-Lee neutrino mass model to include CP violation in the neutrino mass matrix Mν. The most general case with all the free parameters of Mν being complex is discussed. We show that a favorable neutrino mixing pattern (with θ12 ≈ 35.3°, θ23 = 45°, θ13 ≠ 0° and δ = 90°) can naturally be derived from Mν, if it has an approximate or softly-broken μ-τ symmetry. We also point out a different way to obtain the nearly tri-bimaximal neutrino mixing pattern with δ = 0° and non-vanishing Majorana phases.
Validity of quasi-degenerate neutrino mass models and their predictions on baryogenesis
NASA Astrophysics Data System (ADS)
Francis, Ng. K.; Nimai Singh, N.
2012-10-01
Quasi-degenerate neutrino mass models (QDN) which can explain the current data on neutrino masses and mixings, are studied. In the first part, we study the effect of CP-phases on QDN mass matrix (mLL) obeying μ-τ symmetry in normal hierarchical (QD-NH) and inverted hierarchical (QD-IH) patterns. The numerical predictions are consistent with observed data on (i) solar mixing angle (θ12) which lies below tri-bimaximal (TBM) value, (ii) absolute neutrino masses consistent with 0νββ decay mass parameter (mee) and (iii) cosmological upper bound ∑i3mi. mLL is parameterized using only two unknown parameters (ɛ,η) within μ-τ symmetry. The second part deals with the estimation of observed baryon asymmetry of the universe (BAU) where we consider the Majorana CP violating phases (α,β) and the Dirac neutrino mass matrix (mLR). mLR is taken as either the charged lepton or the up quark mass matrix. α, β is derived from the heavy right-handed Majorana mass matrix MRR. MRR is generated from mLL and mLR through inversion of Type-I seesaw formula. The predictions for BAU are nearly consistent with observations for flavoured thermal leptogenesis scenario for Type-IA in both QD-NH and QD-IH models. We also observe some enhancement effects in flavour leptogenesis compared to non-flavour leptogenesis by a magnitude of order one. In non-thermal leptogenesis QD-NH Type-IA is the only model consistent with observed data on baryon asymmetry. QD-NH model appears to be more favourable than those of QD-IH. The predicted inflaton mass needed to produce the BAU is found to be Mϕ˜1010 GeV corresponding to the reheating temperature TR=106 GeV. The present analysis shows that the three absolute neutrino masses may exhibit quasi-degenerate pattern in nature.
NASA Astrophysics Data System (ADS)
Borah, Debasish
2017-02-01
We revisit the possibility of generating a nonzero reactor mixing angle in a scenario where there is a sterile neutrino at the eV scale apart from the usual three sub-eV scale active neutrinos. We show that the 3 ×3 active neutrino mass matrix can possess a μ -τ symmetry and can still be consistent with the nonzero value of the reactor mixing angle θ13 if this μ -τ symmetry is broken in the sterile neutrino sector. We first propose a simple model based on the discrete flavor symmetry A4×Z3×Z3' to realize such a scenario and then numerically evaluate the complete 3 +1 neutrino parameter space that allows such a possibility. We show that the possibility of generating a nonzero θ13 can, in general, remain valid even if the present 3 +1 neutrino global fit data get ruled out by future experiments. We also discuss the possible implications at neutrinoless double beta decay (0 ν β β ) experiments in view of the latest results from the KamLAND-Zen experiment.
Cosmology and neutrino properties
Dolgov, A. D.
2008-12-15
A brief review for particle physicists on the cosmological impact of neutrinos and on restrictions on neutrino properties from cosmology is given. The paper includes a discussion of upper bounds on neutrino mass and possible ways to relax them, methods to observe the cosmic-neutrino background, bounds on the cosmological lepton asymmetry which are strongly improved by neutrino oscillations, cosmological effects of breaking of the spin-statistics theorem for neutrinos, bounds on mixing parameters of active and possible sterile neutrinos with account of active-neutrino oscillations, bounds on right-handed currents and neutrino magnetic moments, and some more.
Effect of non-unitarity on neutrino mass hierarchy determination at DUNE, NOνA and T2K
NASA Astrophysics Data System (ADS)
Dutta, Debajyoti; Ghoshal, Pomita; Roy, Samiran
2017-07-01
The neutrino mass ordering is one of the principal unknowns in the neutrino sector. Long baseline neutrino experiments have the potential of resolving this issue as they are sensitive to large matter effects. The superbeam experiment DUNE is one of the most promising candidates to study the neutrino mass hierarchy, along with NOνA and T2K. But in the presence of non-unitarity of the leptonic mixing matrix, the capability of such experiments to discriminate between the two hierarchies gets suppressed. The mass hierarchy sensitivity of DUNE decreases in the presence of new physics. In this paper we analyze the origin and extent of this loss of sensitivity at the level of oscillation probabilities, events, mass hierarchy sensitivity and the discovery reach of DUNE, NOνA and T2K.
MASS CONSTRAINTS FROM ECLIPSE TIMING IN DOUBLE WHITE DWARF BINARIES
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.
Constraints to a Galactic component of the Ice Cube cosmic neutrino flux from ANTARES
NASA Astrophysics Data System (ADS)
Spurio, M.
2014-11-01
The IceCube evidence for cosmic neutrinos in the high-energy starting events (HESE) sample has inspired a large number of hypotheses on their origin, mainly due to the poor precision on the measurement of the direction of showering events. The fact that most HESE are downward going suggests a possible Galactic component. This could be originated either by a single pointlike source or to a directional excess from an extended Galactic region. These hypotheses are reviewed and constrained, using the present available upper limits from the ANTARES neutrino telescope. ANTARES detects νμ from sources in the Southern sky with an effective area larger than that providing the IceCube HESE for Eν<60 TeV and a factor of about two smaller at 1 PeV. The use of the νμ signal enables an accurate measurement of the incoming neutrino direction. The Galactic signal allowed by the IceCube HESE and the corresponding ANTARES limits are studied in terms of a power law flux E-Γ, with spectral index Γ ranging from 2.0 to 2.5 to cover most astrophysical models.
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.
Gamma-ray constraints on maximum cosmogenic neutrino fluxes and UHECR source evolution models
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.
Gamma-ray constraints on maximum cosmogenic neutrino fluxes and UHECR source evolution models
NASA Astrophysics Data System (ADS)
Gelmini, Graciela B.; Kalashev, Oleg; Semikoz, Dmitri V.
2012-01-01
The dip model assumes that the ultra-high energy cosmic rays (UHECRs) above 1018 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 1019 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.
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.
Radiofrequency instruments to search for new particles and measure neutrino mass
NASA Astrophysics Data System (ADS)
Rybka, Gray
2016-09-01
The smallness of the neutrino mass scale and renewed interest in sub-eV particles to explain dark matter and dark energy suggest that physics beyond the standard model may be found by looking at energies much lower than those traditionally associated with nuclear physics. Fortuitously, recent advances in microwave and radiofrequency electronics from fields such as radio astronomy and quantum computing offer the ability to access these energy scales with unprecedented sensitivity. I will discuss the application of these advances to nuclear physics, highlighting experiments using microwave technology to probe the neutrino mass scale and experiments using of quantum radiofrequency electronics to search for sub-eV particles such as axions.
Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen
Gando, A.; Gando, Y.; Hachiya, T.; ...
2016-08-16
Here, we present an improved search for neutrinoless double-beta (0νββ) decay of Xe136 in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the Ag110m 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 Tmore » $$0v\\atop{1/2}$$ > 1.07×1026 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. Finally, for the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.« less
Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen.
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.
Calculation of molecular final states and their effect on a precision neutrino mass experiment
Fackler, O.; Mugge, M.; Sticker, H.; Winter, N.; Woerner, R.
1984-02-01
An experiment to determine the electron neutrino mass is being performed with the precision of a few electron volts by measuring the tritium beta decay energy distribution near the endpoint. At the few electron volt level, a major consideration in the choice of a tritium source is the effect of excited final atomic or molecular states on the beta decay distribution. It is important to choose a source for which the initial and final states can be accurately calculated. Frozen tritium was chosen as the source since the states of molecular tritium and those of the HeT/sup +/ daughter ion have electronic wavefunctions that can be calculated with high accuracy. The effects of final excited states on the neutrino mass determination and the results of these calculations are described.
Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen
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.
2016-08-16
Here, we present an improved search for neutrinoless double-beta (0νββ) decay of Xe^{136} in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the Ag^{110m} 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$0v\\atop{1/2}$ > 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. Finally, for the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.
Experimental Neutrino Physics: Final Report
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.
Constraints on the Dark Matter Particle Mass from the Number of Milky Way Satellites
2010-04-12
neutrino produced by the Dodelson &Widrow mechanism andmWDM > 2.1 keV for a thermal dark matter particle. The recent discovery of many new dark matter...conventionally set to the value for a light neutrino species: gX = 1.5. The parameter k is the spatial wavenumber in Mpc−1 and mWDM is the mass of the...it decoupled. This is the case for a sterile neutrino (see [17] and references therein), a theoretical particle added to standard electroweak the- ory
Sterile neutrinos beyond LSND at the neutrino factory
Meloni, Davide; Tang Jian; Winter, Walter
2010-11-01
We discuss the effects of one additional sterile neutrino at the Neutrino Factory. Compared to earlier analyses, which have been motivated by Liquid Scintillator Neutrino Detector (LSND) results, we do not impose any constraint on the additional mass squared splitting. This means that the additional mass eigenstate could, with small mixings, be located among the known ones, as it is suggested by the recent analysis of cosmological data. We use a self-consistent framework at the Neutrino Factory without any constraints on the new parameters. We demonstrate for a combined short and long baseline setup that near detectors can provide the expected sensitivity at the LSND-motivated {Delta}m{sub 41}{sup 2}-range, while some sensitivity can also be obtained in the region of the atmospheric mass splitting from the long baselines. We point out that limits on such very light sterile neutrinos may also be obtained from a reanalysis of atmospheric and solar neutrino oscillation data, as well as from supernova neutrino observations. In the second part of the analysis, we compare our sensitivity with the existing literature using additional assumptions, such as |{Delta}m{sub 41}{sup 2}|>>|{Delta}m{sub 31}{sup 2}|, leading to averaging of the fast oscillations in the far detectors. We demonstrate that while the Neutrino Factory has excellent sensitivity compared to existing studies using similar assumptions, one has to be very careful interpreting these results for a combined short and long baseline setup where oscillations could occur in the near detectors. We also test the impact of additional {nu}{sub {tau}} detectors at the short and long baselines, and we do not find a substantial improvement of the sensitivities.
Neutrinos: Theory and Phenomenology
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.
Starobinsky-like inflation and neutrino masses in a no-scale SO(10) model
NASA Astrophysics Data System (ADS)
Ellis, John; Garcia, Marcos A. G.; Nagata, Natsumi; Nanopoulos, Dimitri V.; Olive, Keith A.
2016-11-01
Using a no-scale supergravity framework, we construct an SO(10) model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology. We pay particular attention to the behaviour of the scalar fields during inflation and the subsequent reheating.
Starobinsky-like inflation and neutrino masses in a no-scale SO(10) model
Ellis, John; Garcia, Marcos A.G.; Nagata, Natsumi; Nanopoulos, Dimitri V.; Olive, Keith A.
2016-11-08
Using a no-scale supergravity framework, we construct an SO(10) model that makes predictions for cosmic microwave background observables similar to those of the Starobinsky model of inflation, and incorporates a double-seesaw model for neutrino masses consistent with oscillation experiments and late-time cosmology. We pay particular attention to the behaviour of the scalar fields during inflation and the subsequent reheating.
Soft see-saw: Radiative origin of neutrino masses in SUSY theories
NASA Astrophysics Data System (ADS)
Megrelidze, Luka; Tavartkiladze, Zurab
2017-01-01
Radiative neutrino mass generation within supersymmetric (SUSY) construction is studied. The mechanism is considered where the lepton number violation is originating from the soft SUSY breaking terms. This requires MSSM extensions with states around the TeV scale. We present several explicit realizations based on extensions either by MSSM singlet or SU(2)w triplet states. Besides some novelties of the proposed scenarios, various phenomenological implications are also discussed.
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.
Dirac neutrino in warped extra dimensions
NASA Astrophysics Data System (ADS)
Chang, We-Fu; Ng, John N.; Wu, Jackson M. S.
2009-12-01
We implement Dirac neutrinos in the minimal custodial Randall-Sundrum setting via the Krauss-Wilczek mechanism. We demonstrate by giving explicit lepton mass matrices that with neutrinos in the normal hierarchy, lepton mass and mixing patterns can be naturally reproduced at the scale set by the constraints from electroweak precision measurements, and at the same time without violating bounds set by lepton flavor violations. Our scenario generically predicts a nonzero neutrino mixing angle θ13, as well as the existence of sub-TeV right-handed Kaluza-Klein neutrinos, which partner the right-handed standard model charged leptons. These relatively light KK neutrinos may be searched for at the LHC.
Probing neutrinos from Planck and forthcoming galaxy redshift surveys
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.
NASA Astrophysics Data System (ADS)
Soni, Sanjeev Kant
An important constraint on Grand Unified Theories (GUTs) is the correct estimate of Baryon Asymmetry of the Universe (BAU), in the standard scenario and with a conventional energy-temperature behavior. This is proportional to the intrinsic maximal CP-violation at superhigh energies, which as the lore goes barely accounts for the observed baryon -to-entropy ratio. This is further controlled by some global features: a global symmetry, if broken inadequately, can unduely suppress our estimate and the problem is how to overwhelm the suppression. Illustrated variously, this possibility of the group-theoretical constraint is also contrasted with that of a dynamical constraint. We focus our attention on a specific constraint, that arising from the broken group-C invariance (C = Charge-conjugation), note its implications on neutrino mass and examine, in particular, how to overwhelm the resulting suppression by splitting the mass of the decaying scalar X from its charge conjugate X('c) in an SO(10) theory with Witten's mechanism for neutrino mass. This possibility of X-X('c) mass-splitting was envisaged in our previous general study (with Haber and Segre) whose important conclusions are reviewed: some general observations on spontaneously unbroken C-invariance and a solution to the problem of BAU, in spontaneously broken C-invariant theories, by allowing no overlap between the contributions form the free-decays of X-X(' )and X('c) -X('c) pairs through (nu)-N('c) mass splitting >(, )10('10) GeV, or/and, when X X('c), through X-X('c) mass splitting >(, )m (X). Only the following details are now added. As examples of GUTs with uniquely defined C, we give the maximal and the minimal (single-family) unification schemes based on SU(16) and SO(10) respectively. We discuss in detail the X-X('c) mass splitting scenario with(' )X-X(X('c)-X('c)) belonging to the (6, 3, 1)(,+2) ((6, 1, 3)(,-2)) subcomponent of the 120 of SO(10). In addition to explicitizing the mass-splitting, we
OBSERVATIONAL CONSTRAINTS ON THE DEGENERATE MASS-RADIUS RELATION
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.
Scales of mass generation for quarks, leptons, and majorana neutrinos.
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.
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.
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.
Constraints in measuring body mass during simulated microgravity
NASA Astrophysics Data System (ADS)
Shimada, Kazuhito; Fujii, Yusaku
2008-12-01
The authors proposed "Space Scale" concept for measuring astronaut body mass in spacecraft on orbit. For the development of the flight hardware, accuracy/precision/operability verification tests under simulated microgravity are mandatory. We tested our device on a business jet flying parabolas to simulate microgravity. In addition to design constraints from microgravity, human factor engineering aspects also had to be dealt with. Methods (1) Mass was calculated based on (Mass) = (Force) x (Acceleration). (2) For Flight Test Series #1, a metal dummy mass of 9.37kg was used on parabolic flight tests. (3)For Flight Test Series #2, human subject mass was measured. (4) To eliminate acceleration noise from cabin vibration and air turbulence, data were rigorously filtered post-flight. Results With Flight Test Series #1, mass of the dummy was successfully derived with the standard uncertainty of 2.1 % for single measurement, and 0.7 % for the mean value of 12 measurements. Each measurement duration was less than 3sec., with rubber cord length reduction of 1 m. Conclusion The parabolic flight environment was a noisy acceleration field. Future studies should look more into human factor engineering aspects.
Arbitrarily massive sterile neutrinos at the neutrino factory
Meloni, Davide; Tang Jian; Winter, Walter
2011-10-06
We study the effects of one additional sterile neutrino at the Neutrino Factory. On the one hand, we do not impose any constraint on the additional mass squared splitting, which is different from earlier discussions where LSND motivated Q(1)eV{sup 2} is always assumed. We find that a combination of near detectors and long baselines is good at searching for arbitrarily massive sterile neutrinos at the neutrino factory. On the other hand, we compare our sensitivities of mixing angles with the MINOS results where |{Delta}m{sub 41}{sup 2}|>>{Delta}m{sub 31}{sup 2}| is assumed and the fast oscillations in the far detectors are averaged out.
Low-energy sterile neutrinos: Theory
NASA Astrophysics Data System (ADS)
Palazzo, Antonio
2013-04-01
Several experimental anomalies seem to point towards the existence of light sterile neutrinos. We focus on the low-energy anomalous results (the so-called gallium and reactor anomalies), which indicate a non-zero admixture U of the electron neutrino with a fourth (mostly) sterile mass eigenstate ν4. We point out that solar sector data, in combination with the precision measurement of θ13, provide the constraint |<0.041 (90% C.L.), independent of the reactor flux determinations.
Very low-energy neutrino interactions
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.
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.
NASA Astrophysics Data System (ADS)
Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brown, A. M.; Buitink, S.; Caballero-Mora, K. S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Daughhetee, J.; Davis, J. C.; De Clercq, C.; Demirörs, L.; Denger, T.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; DeYoung, T.; Díaz-Vélez, J. C.; Dierckxsens, M.; Dreyer, J.; Dumm, J. P.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Gora, D.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gurtner, M.; Ha, C.; Hajismail, A.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Heinen, D.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Larson, M. J.; Lauer, R.; Lünemann, J.; Madsen, J.; Majumdar, P.; Marotta, A.; Maruyama, R.; Mase, K.; Matis, H. S.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miller, J.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; O'Murchadha, A.; Ono, M.; Panknin, S.; Paul, L.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Schmidt, T.; Schönwald, A.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stössl, A.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Stür, M.; Sullivan, G. W.; Swillens, Q.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Toscano, S.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Zoll, M.
2012-01-01
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 γ-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 -2 ν 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 γ-rays. The 90% confidence level (CL) best upper limits on the Crab flux during the 10 day flare are 4.73 × 10-11 cm-2 s-1 TeV-1 for an E -2 ν neutrino spectrum and 2.50 × 10-10 cm-2 s-1 TeV-1 for a softer neutrino spectra of E -2.7 ν, 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.
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).
WEIGHING NEUTRINOS WITH COSMIC NEUTRAL HYDROGEN
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)