Science.gov

Sample records for ev neutrino hot

  1. BEST sensitivity to O(1) eV sterile neutrino

    NASA Astrophysics Data System (ADS)

    Barinov, Vladislav; Gavrin, Vladimir; Gorbunov, Dmitry; Ibragimova, Tatiana

    2016-04-01

    Numerous anomalous results in neutrino oscillation experiments can be attributed to the interference of an ˜1 eV sterile neutrino. The Baksan Experiment on Sterile Transitions (BEST), specially designed to fully explore the Gallium anomaly, starts next year. We investigate the sensitivity of BEST in search of a sterile neutrino mixed with an electron neutrino. Then, performing the combined analysis of all the Gallium experiments (SAGE, GALLEX, BEST), we find the region in the model parameter space (sterile neutrino mass and mixing angle) which will be excluded if BEST agrees with no sterile neutrino hypothesis. For the opposite case, if BEST observes the signal as it follows from the sterile neutrino explanation of the Gallium (SAGE and GALLEX) anomaly, we show how BEST will improve upon the present estimates of the model parameters.

  2. Neutrino and axion hot dark matter bounds after WMAP-7

    SciTech Connect

    Hannestad, Steen; Mirizzi, Alessandro; Raffelt, Georg G.; Wong, Yvonne Y.Y. E-mail: alessandro.mirizzi@desy.de E-mail: yvonne.wong@physik.rwth-aachen.de

    2010-08-01

    We update cosmological hot dark matter constraints on neutrinos and hadronic axions. Our most restrictive limits use 7-year data from the Wilkinson Microwave Anisotropy Probe for the cosmic microwave background anisotropies, the halo power spectrum (HPS) from the 7th data release of the Sloan Digital Sky Survey, and the Hubble constant from Hubble Space Telescope observations. We find 95% CL upper limits of Σm{sub ν} < 0.44 eV (no axions), m{sub a} < 0.91 eV (assuming Σm{sub ν} = 0), and Σm{sub ν} < 0.41 eV and m{sub a} < 0.72 eV for two hot dark matter components after marginalising over the respective other mass. CMB data alone yield Σm{sub ν} < 1.19 eV (no axions), while for axions the HPS is crucial for deriving m{sub a} constraints. This difference can be traced to the fact that for a given hot dark matter fraction axions are much more massive than neutrinos.

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

    PubMed

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

    2013-03-22

    It is shown that the tension between recent neutrino oscillation experiments, favoring sterile neutrinos with masses of the order of 1 eV, and cosmological data which impose stringent constraints on neutrino masses from the free streaming suppression of density fluctuations, can be resolved in models of the present accelerated expansion of the Universe based on f(R) gravity. PMID:25166788

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

    SciTech Connect

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

    2008-04-15

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

  5. Propagation of neutrinos in hot and dense media

    NASA Astrophysics Data System (ADS)

    Masood, Samina

    2016-03-01

    We study the propagation of neutrinos in hot and dense media of stellar systems as well as in the very early universe. Our emphasis is on the study of the basic properties of neutrinos with tiny mass and their interactions with the hot and dense media. We also discuss the relevance of our results to astrophysics and cosmology.

  6. 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.

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

    SciTech Connect

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

    2011-09-01

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

  8. Search for eV sterile neutrinos at a nuclear reactor — the Stereo project

    NASA Astrophysics Data System (ADS)

    Haser, J.; Stereo Collaboration

    2016-05-01

    The re-analyses of the reference spectra of reactor antineutrinos together with a revised neutrino interaction cross section enlarged the absolute normalization of the predicted neutrino flux. The tension between previous reactor measurements and the new prediction is significant at 2.7 σ and is known as “reactor antineutrino anomaly”. In combination with other anomalies encountered in neutrino oscillation measurements, this observation revived speculations about the existence of a sterile neutrino in the eV mass range. Mixing of this light sterile neutrino with the active flavours would lead to a modification of the detected antineutrino flux. An oscillation pattern in energy and space could be resolved by a detector at a distance of few meters from a reactor core: the neutrino detector of the Stereo project will be located at about 10 m distance from the ILL research reactor in Grenoble, France. Lengthwise separated in six target cells filled with 2 m3 Gd-loaded liquid scintillator in total, the experiment will search for a position-dependent distortion in the energy spectrum.

  9. Collaborative Research: Neutrinos & Nucleosynthesis in Hot Dense Matter

    SciTech Connect

    Reddy, Sanjay

    2013-09-06

    It is now firmly established that neutrinos, which are copiously produced in the hot and dense core of the supernova, play a role in the supernova explosion mechanism and in the synthesis of heavy elements through a phenomena known as r-process nucleosynthesis. They are also detectable in terrestrial neutrino experiments, and serve as a probe of the extreme environment and complex dynamics encountered in the supernova. The major goal of the UW research activity relevant to this project was to calculate the neutrino interaction rates in hot and dense matter of relevance to core collapse supernova. These serve as key input physics in large scale computer simulations of the supernova dynamics and nucleosynthesis being pursued at national laboratories here in the United States and by other groups in Europe and Japan. Our calculations show that neutrino production and scattering rate are altered by the nuclear interactions and that these modifications have important implications for nucleosynthesis and terrestrial neutrino detection. The calculation of neutrino rates in dense matter are difficult because nucleons in the dense matter are strongly coupled. A neutrino interacts with several nucleons and the quantum interference between scattering off different nucleons depends on the nature of correlations between them in dense matter. To describe these correlations we used analytic methods based on mean field theory and hydrodynamics, and computational methods such as Quantum Monte Carlo. We found that due to nuclear effects neutrino production rates at relevant temperatures are enhanced, and that electron neutrinos are more easily absorbed than anti-electron neutrinos in dense matter. The latter, was shown to favor synthesis of heavy neutron-rich elements in the supernova.

  10. A new life for sterile neutrinos: resolving inconsistencies using hot dark matter

    SciTech Connect

    Hamann, Jan; Hasenkamp, Jasper E-mail: jasper.hasenkamp@nyu.edu

    2013-10-01

    Within the standard ΛCDM model of cosmology, the recent Planck measurements have shown discrepancies with other observations, e.g., measurements of the current expansion rate H{sub 0}, the galaxy shear power spectrum and counts of galaxy clusters. We show that if ΛCDM is extended by a hot dark matter component, which could be interpreted as a sterile neutrino, the data sets can be combined consistently. A combination of Planck data, WMAP-9 polarisation data, measurements of the BAO scale, the HST measurement of H{sub 0}, Planck galaxy cluster counts and galaxy shear data from the CFHTLens survey yields ΔN{sub eff} = 0.61±0.30 and m{sub s}{sup eff} = (0.41±0.13)eV at 1σ. The former is driven mainly by the large H{sub 0} of the HST measurement, while the latter is driven by cluster data. CFHTLens galaxy shear data prefer ΔN{sub eff}> 0 and a non-zero mass. Taken together, we find hints for the presence of a hot dark matter component at 3σ. A sterile neutrino motivated by the reactor and gallium anomalies appears rejected at even higher significance and an accelerator anomaly sterile neutrino is found in tension at 2σ.

  11. Topical Collaboration "Neutrinos and Nucleosynthesis in Hot and Dense Matter"

    SciTech Connect

    Allahverdi, Rouzbeh

    2015-09-18

    This is the final technical report describing contributions from the University of New Mexico to Topical Collaboration on "Neutrinos and Nucleosynthesis in Hot and Dense Matter" in the period June 2010 through May 2015. During the funding period, the University of New Mexico successfully hired Huaiyu Duan as a new faculty member with the support from DOE, who has contributed to the Topical Collaboration through his research and collaborations.

  12. Neutrinos of energy approximately 10(16) eV from gamma-ray bursts in pulsar wind bubbles.

    PubMed

    Guetta, Dafne; Granot, Jonathan

    2003-05-23

    The supranova model for gamma-ray bursts (GRBs) is becoming increasingly more popular. In this scenario the GRB occurs weeks to years after a supernova explosion, and is located inside a pulsar wind bubble (PWB). Protons accelerated in the internal shocks that emit the GRB may interact with the external PWB photons producing pions which decay into approximately 10(16) eV neutrinos. A km(2) neutrino detector would observe several events per year correlated with the GRBs. PMID:12785881

  13. Dual baseline search for muon neutrino disappearance at 0.5 eV2 < Delta m2 < 40 eV2

    DOE PAGESBeta

    Mahn, K B.M.

    2011-06-01

    The SciBooNE and MiniBooNE collaborations report the results of a νμ disappearance search in the Δ'm2 region of 0.5-40 eV2. The neutrino rate as measured by the SciBooNE tracking detectors is used to constrain the rate at the MiniBooNE Cherenkov detector in the first joint analysis of data from both collaborations. Two separate analyses of the combined data samples set 90% confidence level (CL) limits on νμ disappearance in the 0.5-40 eV2 Δm2 region, with an improvement over previous experimental constraints between 10 and 30 eV2

  14. From eV to EeV: Neutrino cross sections across energy scales

    NASA Astrophysics Data System (ADS)

    Formaggio, J. A.; Zeller, G. P.

    2012-07-01

    Since its original postulation by Wolfgang Pauli in 1930, the neutrino has played a prominent role in our understanding of nuclear and particle physics. In the intervening 80 years, scientists have detected and measured neutrinos from a variety of sources, both man made and natural. Underlying all of these observations, and any inferences we may have made from them, is an understanding of how neutrinos interact with matter. Knowledge of neutrino interaction cross sections is an important and necessary ingredient in any neutrino measurement. With the advent of new precision experiments, the demands on our understanding of neutrino interactions is becoming even greater. The purpose of this article is to survey our current knowledge of neutrino cross sections across all known energy scales: from the very lowest energies to the highest that we hope to observe. The article covers a wide range of neutrino interactions including coherent scattering, neutrino capture, inverse beta decay, low-energy nuclear interactions, quasielastic scattering, resonant pion production, kaon production, deep inelastic scattering, and ultrahigh energy interactions. Strong emphasis is placed on experimental data whenever such measurements are available.

  15. IceCube astrophysical neutrinos without a spectral cutoff and 1015-1017 eV cosmic gamma radiation

    NASA Astrophysics Data System (ADS)

    Kalashev, O.; Troitsky, S.

    2015-02-01

    We present a range of unbroken power-law fits to the astrophysical-neutrino spectrum consistent with the most recent published IceCube data at the 68% confidence level. Assuming that the neutrinos originate in decays of π mesons, we estimate accompanying gamma-ray fluxes for various distributions of sources, taking propagation effects into account. We then briefly discuss existing experimental results constraining PeV to EeV diffuse gamma-ray flux and their systematic uncertainties. Several scenarios are marginally consistent both with the KASKADE and CASA-MIA upper limits at 10152-1016 eV and with the EAS-MSU tentative detection at ˜1017 eV, given large systematic errors of the measurements. Future searches for the diffuse gamma-ray background at sub-PeV to sub-EeV energies just below present upper limits will give a crucial diagnostic tool for distinguishing between the Galactic and extragalactic models of the origin of the IceCube events.

  16. Improved flux limits for neutrinos with energies above 10(22) eV from observations with the Westerbork Synthesis Radio Telescope.

    PubMed

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

    2009-11-01

    Particle cascades initiated by ultrahigh energy neutrinos in the lunar regolith will emit an electromagnetic pulse with a time duration of the order of nanoseconds through a process known as the Askaryan effect. It has been shown that in an observing window around 150 MHz there is a maximum chance for detecting this radiation with radio telescopes commonly used in astronomy. In 50 h of observation time with the Westerbork Synthesis Radio Telescope array we have set a new limit on the flux of neutrinos, summed over all flavors, with energies in excess of 4x10(22) eV. PMID:20365914

  17. Resurrecting hot dark matter - Large-scale structure from cosmic strings and massive neutrinos

    NASA Technical Reports Server (NTRS)

    Scherrer, Robert J.

    1988-01-01

    These are the results of a numerical simulation of the formation of large-scale structure from cosmic-string loops in a universe dominated by massive neutrinos (hot dark matter). This model has several desirable features. The final matter distribution contains isolated density peaks embedded in a smooth background, producing a natural bias in the distribution of luminous matter. Because baryons can accrete onto the cosmic strings before the neutrinos, the galaxies will have baryon cores and dark neutrino halos. Galaxy formation in this model begins much earlier than in random-phase models. On large scales the distribution of clustered matter visually resembles the CfA survey, with large voids and filaments.

  18. Acceptances for space-based and ground-based fluorescence detectors, and inference of the neutrino-nucleon cross-section above 10{sup 19} eV

    SciTech Connect

    Palomares-Ruiz, Sergio; Irimia, Andrei; Weiler, Thomas J.

    2006-04-15

    Detection of ultrahigh energy neutrinos will be useful for unraveling the dynamics of the most violent sources in the cosmos and for revealing the neutrino cross-section at extreme energy. If there exists a Greisen-Zatsepin-Kuz'min (GZK) suppression of cosmic-ray events above E{sub GZK}{approx}5x10{sup 19} eV, as predicted by theory, then the only messengers of energies beyond E{sub GZK} are neutrinos. Cosmic neutrino fluxes can initiate air-showers through interaction in the atmosphere, or in the Earth. Neutrino trajectories will be downgoing to nearly horizontal in the former case, and 'Earth-skimming' in the latter case. Thus it is important to know the acceptances (event rate/flux) of proposed air-shower experiments for detecting both types of neutrino-initiated events. We calculate these acceptances for fluorescence detectors, both space-based as with the EUSO and OWL proposals, and ground-based, as with Auger, HiRes and Telescope Array. The neutrino cross-section {sigma}{sub {nu}}{sub N}{sup CC} is unknown at energies above 5.2x10{sup 13} eV. Although the popular QCD extrapolation of lower-energy physics offers the cross-section value of 0.54x10{sup -31}(E{sub {nu}}/10{sup 20} eV){sup 0.36} cm{sup 2}, new physics could raise or lower this value. Therefore, we present the acceptances of horizontal (HAS) and upgoing (UAS) air-showers as a function of {sigma}{sub {nu}}{sub N}{sup CC} over the range 10{sup -34} to 10{sup -30} cm{sup 2}. The dependences of acceptances on neutrino energy, shower-threshold energy, shower length, and shower column density are also studied. We introduce a cloud layer, and study its effect on rates as viewed from space and from the ground. For UAS, we present acceptances for events over land (rock), and over the ocean (water). Acceptances over water are larger by about an order of magnitude, thus favoring space-based detectors. We revisit the idea of Kusenko and Weiler [Phys. Rev. Lett. 88, 161101 (2002)] to infer {sigma}{sub {nu

  19. Can neutrino decay-driven mock gravity save hot dark matter?

    NASA Technical Reports Server (NTRS)

    Splinter, Randall J.; Melott, Adrian L.

    1992-01-01

    The radiative decay of a 30 eV neutrino with a lifetime of order 10 exp 23-24 s has recently been shown to yield a satisfactory explanation of a wide range of problems in astrophysics. In this paper, it is investigated whether the photon flux generated by the radiative decay of a massive neutrino is capable of generating sufficient radiation pressure to cause a 'mock gravitational' collapse of primordial hydrogen clouds. It is shown that when using neutral hydrogen as a source of opacity for mock gravity the time scale for mock gravitational collapse is significantly larger than the expansion time scale. Thus, the model fails as a source of galactic seed perturbations. Furthermore, it is argued that nonlinear feedback mechanisms will be unable to increase the collapse rate of the cloud under mock gravity.

  20. A search for muon neutrino to electron neutrino oscillations at delta(m^2)>0.1 eV^2

    SciTech Connect

    Patterson, Ryan Benton; /Princeton U.

    2007-11-01

    The evidence is compelling that neutrinos undergo flavor change as they propagate. In recent years, experiments have observed this phenomenon of neutrino oscillations using disparate neutrino sources: the sun, fission reactors, accelerators, and secondary cosmic rays. The standard model of particle physics needs only simple extensions - neutrino masses and mixing - to accommodate all neutrino oscillation results to date, save one. The 3.8{sigma}-significant {bar {nu}}{sub e} excess reported by the LSND collaboration is consistent with {bar {nu}}{sub {mu}} {yields}{bar {nu}}{sub e} oscillations with a mass-squared splitting of {Delta}m{sup 2} {approx} 1 eV{sup 2}. This signal, which has not been independently verified, is inconsistent with other oscillation evidence unless more daring standard model extensions (e.g. sterile neutrinos) are considered.

  1. A Search for electron neutrino appearance at the Delta m**2 ~ 1- eV**2 scale

    SciTech Connect

    Aguilar-Arevalo, A.A.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; Djurcic, Z.; /Columbia U. /Fermilab

    2007-04-01

    The MiniBooNE Collaboration reports first results of a search for {upsilon}{sub e} appearance in a {upsilon}{sub {mu}} beam. With two largely independent analyses, we observe no significant excess of events above background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two neutrino appearance-only oscillation model.

  2. Black hole-neutron star mergers with a hot equation of state and neutrino cooling

    NASA Astrophysics Data System (ADS)

    Foucart, Francois

    2014-03-01

    Black hole-neutron star (BHNS) and neutron star-neutron star mergers will be prime candidates for the joint detection of gravitational wave and electromagnetic (EM) signals once the Advanced LIGO/VIRGO/KAGRA detectors come online. For BHNS binaries, the result of the merger strongly depends on the parameters of the system. EM emissions from a post-merger disk (e.g. gamma-ray bursts) are only possible for low mass or high spin black holes. The amount of ejected neutron-rich material, which has important consequences for the emission of more isotropic EM signals and the production of r-process elements, can also vary by a few orders of magnitudes - with high mass, high spin black holes ejecting more than 0 . 1M⊙ of unbound material. I will describe recent simulations of BHNS mergers performed by the SXS collaboration, which explore the parameter space dependence of these mergers while using a hot nuclear equation of state (LS220) and approximate neutrino cooling of the post-merger accretion disk. I will discuss the qualitative differences between these mergers and earlier simulations performed with polytropic equations of state, as well as the effect of neutrino cooling on the post-merger evolution and the general properties of the neutrino radiation.

  3. Neutrinos

    PubMed Central

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

    1999-01-01

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

  4. Neutrino emissivity from e sup minus e+ annihilation in a strong magnetic field: Hot, nondegenerate plasma

    SciTech Connect

    Kaminker, A.D.; Gnedin, O.Y.; Yakovlev, D.G. ); Amsterdamski, P.; Haensel, P. )

    1992-11-15

    The neutrino emissivity from {ital e}{sup {minus}}{ital e+} pair annihilation is calculated for a hot, nondegenerate plasma, {ital T}{much gt}{ital T}{sub {ital F}} ({ital T}{sub {ital F}} is the electron degeneracy temperature), in a magnetic field {bold B} of arbitrary strength. The results are fitted by an analytic expression. A not-very-strong magnetic field, {ital b}={ital B}/{ital B}{sub {ital c}}{much lt}1 ({ital B}{sub {ital c}}=4.41{times}10{sup 13} G), enhances the emissivity of a nonrelativistic plasma, {ital t}={ital T}/{ital T}{sub {ital c}}{approx lt}{ital b} ({ital T}{sub {ital c}}=6{times}10{sup 9} K), and does not affect the emissivity at higher {ital T}. Stronger fields, {ital b}{much gt}1, influence the pair annihilation if {ital t}{approx lt} {radical}{ital b} . At {ital t}{approx gt}{ital b}{sup 1/4} they suppress the process, and at {ital t}{much lt}{ital b}{sup 1/4} they enhance it. As a rule the pair annihilation dominates over other neutrino production mechanisms in a hot plasma of neutron-star envelopes.

  5. Upper Bound of 0.28 eV on Neutrino Masses from the Largest Photometric Redshift Survey

    SciTech Connect

    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 0.45neutrino 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.

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

    PubMed

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

    2010-07-16

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

  7. Unified model for cosmic rays above 1017 eV and the diffuse gamma-ray and neutrino backgrounds

    NASA Astrophysics Data System (ADS)

    Giacinti, G.; Kachelrieß, M.; Kalashev, O.; Neronov, A.; Semikoz, D. V.

    2015-10-01

    We investigate how the extragalactic proton component derived within the "escape model" can be explained by astrophysical sources. We consider as possible cosmic ray (CR) sources normal or starburst galaxies and radio-loud active galactic nuclei (AGN). We find that the contribution to the total extragalactic proton flux from normal and starburst galaxies is only subdominant and does not fit the spectral shape deduced in the escape model. In the case of radio-loud AGN, we show that the complete extragalactic proton spectrum can be explained by a single source population, BL Lac/FR I, for any of the potential acceleration sites in these sources. We calculate the diffuse neutrino and γ -ray fluxes produced by these CR protons interacting with gas inside their sources. For a spectral slope of CRs close to α =2.1 - 2.2 as suggested by shock acceleration, we find that these UHECR sources contribute the dominant fraction of both the isotropic γ -ray background and of the extragalactic part of the astrophysical neutrino signal observed by IceCube.

  8. Neutrino emissivity from electron-positron annihilation in hot matter in a strong magnetic field

    SciTech Connect

    Amsterdamski, P.; Haensel, P. )

    1990-10-15

    The neutrino emissivity due to electron-positron annihilation in a strong magnetic field is computed. A strong magnetic field can significantly increase the neutrino emissivity at {ital T}{similar to}10{sup 9} K.

  9. Neutrinos

    NASA Astrophysics Data System (ADS)

    Winter, K.; Murdin, P.

    2000-11-01

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

  10. Charged-current weak interaction processes in hot and dense matter and its impact on the spectra of neutrinos emitted from protoneutron star cooling.

    PubMed

    Martínez-Pinedo, G; Fischer, T; Lohs, A; Huther, L

    2012-12-21

    We perform three-flavor Boltzmann neutrino transport radiation hydrodynamics simulations covering a period of 3 s after the formation of a protoneutron star in a core-collapse supernova explosion. Our results show that a treatment of charged-current neutrino interactions in hot and dense matter as suggested by Reddy et al. [Phys. Rev. D 58, 013009 (1998)] has a strong impact on the luminosities and spectra of the emitted neutrinos. When compared with simulations that neglect mean-field effects on the neutrino opacities, we find that the luminosities of all neutrino flavors are reduced while the spectral differences between electron neutrinos and antineutrinos are increased. Their magnitude depends on the equation of state and in particular on the symmetry energy at subnuclear densities. These modifications reduce the proton-to-nucleon ratio of the outflow, increasing slightly their entropy. They are expected to have a substantial impact on nucleosynthesis in neutrino-driven winds, even though they do not result in conditions that favor an r process. Contrary to previous findings, our results show that the spectra of electron neutrinos remain substantially different from those of other (anti)neutrino flavors during the entire deleptonization phase of the protoneutron star. The obtained luminosity and spectral changes are also expected to have important consequences for neutrino flavor oscillations and neutrino detection on Earth. PMID:23368446

  11. Neutrino

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-04-01

    The most basic Quantum are the particles who mutual rotation, quantum is composed of basic quantum.Quantum convergence or divergence is conditional, the faster the particle rotates, the smaller the orbiting radius will be, the greater quality is, the more density will be. The orbiting radius of less than 10-15 meters in the order of convergence, convergence of neutron, proton, and then they are in the formation of the nucleus, and the convergence of quantum can make extra nuclear electron and the formation of atomic; if rotation radius is more than 10-15 meters of magnitude, the internal quantum atoms diverge to outer space in the form of electromagnetic waves. The quality of magnetic wave particle is composed of the rotation speed of the particle which is internal of the electromagnetic, it doesn't matter about the electromagnetic wave propagation velocity of particles. Neutrinos are orbiting particles, the orbiting radius is about 10-15 meters, is a special kind of radiation. Neutrino is between the virtual particles (according to modern science, the electromagnetic wave doesn't have quality) and modern scientific (the particle who has quality) special particles

  12. Why Are Neutrinos Light? -- An Alternative

    SciTech Connect

    Hall, Lawrence J.; Oliver, Steven J.

    2004-09-23

    We review the recent proposal that neutrinos are light because their masses are proportional to a low scale, f, of lepton flavor symmetry breaking. This mechanism is testable because the resulting pseudo-Goldstone bosons, of mass m_G, couple strongly with the neutrinos, affecting the acoustic oscillations during the eV era of the early universe that generate the peaks in the CMB radiation. Characteristic signals result over a very wide range of (f, m_G) because of a change in the total relativistic energy density and because the neutrinos scatter rather than free-stream. Thermodynamics allows a precise calculation of the signal, so that observations would not only confirm the late-time neutrino mass mechanism, but could also determine whether the neutrino spectrum is degenerate, inverted or hierarchical and whether the neutrinos are Dirac or Majorana. The flavor symmetries could also give light sterile states. If the masses of the sterile neutrinos turn on after the MeV era, the LSND oscillations can be explained without upsetting big bang nucleosynthesis, and, since the sterile states decay to lighter neutrinos and pseudo-Goldstones, without giving too much hot dark matter.

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

    SciTech Connect

    Serpico, Pasquale D.; /Fermilab

    2007-01-01

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

  14. Cosmological Neutrino Mass Detection: The Best Probe of Neutrino Lifetime

    SciTech Connect

    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.

  15. BLACK HOLE-NEUTRON STAR MERGERS WITH A HOT NUCLEAR EQUATION OF STATE: OUTFLOW AND NEUTRINO-COOLED DISK FOR A LOW-MASS, HIGH-SPIN CASE

    SciTech Connect

    Deaton, M. Brett; Duez, Matthew D.; Foucart, Francois; O'Connor, Evan; Ott, Christian D.; Scheel, Mark A.; Szilagyi, Bela; Kidder, Lawrence E.; Muhlberger, Curran D. E-mail: m.duez@wsu.edu

    2013-10-10

    Neutrino emission significantly affects the evolution of the accretion tori formed in black hole-neutron star mergers. It removes energy from the disk, alters its composition, and provides a potential power source for a gamma-ray burst. To study these effects, simulations in general relativity with a hot microphysical equation of state (EOS) and neutrino feedback are needed. We present the first such simulation, using a neutrino leakage scheme for cooling to capture the most essential effects and considering a moderate mass (1.4 M{sub ☉} neutron star, 5.6 M{sub ☉} black hole), high-spin (black hole J/M {sup 2} = 0.9) system with the K{sub 0} = 220 MeV Lattimer-Swesty EOS. We find that about 0.08 M{sub ☉} of nuclear matter is ejected from the system, while another 0.3 M{sub ☉} forms a hot, compact accretion disk. The primary effects of the escaping neutrinos are (1) to make the disk much denser and more compact, (2) to cause the average electron fraction Y{sub e} of the disk to rise to about 0.2 and then gradually decrease again, and (3) to gradually cool the disk. The disk is initially hot (T ∼ 6 MeV) and luminous in neutrinos (L{sub ν} ∼ 10{sup 54} erg s{sup –1}), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution.

  16. Relic Neutrino Absorption Spectroscopy

    SciTech Connect

    Eberle, b

    2004-01-28

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

  17. Neutrino refraction by the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Díaz, J. S.; Klinkhamer, F. R.

    2016-03-01

    We have determined the dispersion relation of a neutrino test particle propagating in the cosmic neutrino background. Describing the relic neutrinos and antineutrinos from the hot big bang as a dense medium, a matter potential or refractive index is obtained. The vacuum neutrino mixing angles are unchanged, but the energy of each mass state is modified. Using a matrix in the space of neutrino species, the induced potential is decomposed into a part which produces signatures in beta-decay experiments and another part which modifies neutrino oscillations. The low temperature of the relic neutrinos makes a direct detection extremely challenging. From a different point of view, the identified refractive effects of the cosmic neutrino background constitute an ultralow background for future experimental studies of nonvanishing Lorentz violation in the neutrino sector.

  18. Initial Results from a Search for Lunar Radio Emission from Interactions of >= 10(exp 19) eV Neutrinos and Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Gorham, P. W.; Liewer, K. M.; Naudet, C. J.

    2000-01-01

    Using the NASA Goldstone 70m antenna DSS 14 both singly and in coincidence with the 34 m antenna DSS 13 (21.7 km to the southeast), we have acquired approximately 12 hrs of livetime in a search for predicted pulsed radio emission from extremely-high energy cascades induced by neutrinos or cosmic rays in the lunar regolith. In about 4 hrs of single antenna observations, we reduced our sensitivity to impulsive terrestrial interference to a negligible level by use of a veto afforded by the unique capability of DSS 14. In the 8 hrs of dual-antenna observations, terrestrial interference is eliminated as a background. In both observing modes the thermal noise floor limits the sensitivity. We detected no events above statistical background. We report here initial limits based on these data which begin to constrain several predictions of the flux of EHE neutrinos.

  19. 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.

  20. Neutrino fluctuat nec mercitur: are fossil neutrinos detectable

    SciTech Connect

    De Rujula, A

    1980-04-01

    A brief report is presented on the question whether light (few eV to approx. 100 eV) neutrinos left over from the big bang are detectable. The answer is perhaps. If the weak current of leptons, like those of quarks, are not diagonal in mass eigenstates, a neutrino will decay into a lighter neutrino and a monochromatic photon. The corresponding photon line may be detectable provided: neutrinos are heavy enough to participate in galaxy clustering and neutrino lifetimes are, as in some weak interaction models, short enough.

  1. Light sterile neutrinos: Status and perspectives

    NASA Astrophysics Data System (ADS)

    Giunti, Carlo

    2016-07-01

    The indications in favor of the existence of light sterile neutrinos at the eV scale found in short-baseline neutrino oscillation experiments is reviewed. The future perspectives of short-baseline neutrino oscillation experiments and the connections with β-decay measurements of the neutrino masses and with neutrinoless double-β decay experiments are discussed.

  2. 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.

  3. Daughters mimic sterile neutrinos (almost!) perfectly

    NASA Astrophysics Data System (ADS)

    Hasenkamp, Jasper

    2014-09-01

    Since only recently, cosmological observations are sensitive to hot dark matter (HDM) admixtures with sub-eV mass, mhdmeff < eV, that are not fully-thermalised, Δ Neff < 1. We argue that their almost automatic interpretation as a sterile neutrino species is neither from theoretical nor practical parsimony principles preferred over HDM formed by decay products (daughters) of an out-of-equilibrium particle decay. While daughters mimic sterile neutrinos in Neff and mhdmeff, there are opportunities to assess this possibility in likelihood analyses. Connecting cosmological parameters and moments of momentum distribution functions, we show that—also in the case of mass-degenerate daughters with indistinguishable main physical effects—the mimicry breaks down when the next moment, the skewness, is considered. Predicted differences of order one in the root-mean-squares of absolute momenta are too small for current sensitivities.

  4. Axion hot dark matter bounds after Planck

    SciTech Connect

    Archidiacono, Maria; Hannestad, Steen; Mirizzi, Alessandro; Raffelt, Georg; Wong, Yvonne Y.Y. E-mail: sth@phys.au.dk E-mail: raffelt@mpp.mpg.de

    2013-10-01

    We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m{sub a} < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H{sub 0} released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H{sub 0} measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m{sub a} has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H{sub 0} and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from Σ m{sub ν} < 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.

  5. Cosmological constraints on a light nonthermal sterile neutrino

    SciTech Connect

    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.

  6. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

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

  7. Absolute neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Wolf, Joachim

    2011-10-01

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2β) searches, single β-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy. Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium β-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R&D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2β decay and single β-decay.

  8. Neutrino physics with JUNO

    NASA Astrophysics Data System (ADS)

    An, Fengpeng; An, Guangpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Buizza Avanzini, Margherita; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio; Cao, Guofu; Cao, Jun; Chang, Yun; Chen, Shaomin; Chen, Shenjian; Chen, Yixue; Chiesa, Davide; Clemenza, Massimiliano; Clerbaux, Barbara; Conrad, Janet; D'Angelo, Davide; De Kerret, Hervé; Deng, Zhi; Deng, Ziyan; Ding, Yayun; Djurcic, Zelimir; Dornic, Damien; Dracos, Marcos; Drapier, Olivier; Dusini, Stefano; Dye, Stephen; Enqvist, Timo; Fan, Donghua; Fang, Jian; Favart, Laurent; Ford, Richard; Göger-Neff, Marianne; Gan, Haonan; Garfagnini, Alberto; Giammarchi, Marco; Gonchar, Maxim; Gong, Guanghua; Gong, Hui; Gonin, Michel; Grassi, Marco; Grewing, Christian; Guan, Mengyun; Guarino, Vic; Guo, Gang; Guo, Wanlei; Guo, Xin-Heng; Hagner, Caren; Han, Ran; He, Miao; Heng, Yuekun; Hsiung, Yee; Hu, Jun; Hu, Shouyang; Hu, Tao; Huang, Hanxiong; Huang, Xingtao; Huo, Lei; Ioannisian, Ara; Jeitler, Manfred; Ji, Xiangdong; Jiang, Xiaoshan; Jollet, Cécile; Kang, Li; Karagounis, Michael; Kazarian, Narine; Krumshteyn, Zinovy; Kruth, Andre; Kuusiniemi, Pasi; Lachenmaier, Tobias; Leitner, Rupert; Li, Chao; Li, Jiaxing; Li, Weidong; Li, Weiguo; Li, Xiaomei; Li, Xiaonan; Li, Yi; Li, Yufeng; Li, Zhi-Bing; Liang, Hao; Lin, Guey-Lin; Lin, Tao; Lin, Yen-Hsun; Ling, Jiajie; Lippi, Ivano; Liu, Dawei; Liu, Hongbang; Liu, Hu; Liu, Jianglai; Liu, Jianli; Liu, Jinchang; Liu, Qian; Liu, Shubin; Liu, Shulin; Lombardi, Paolo; Long, Yongbing; Lu, Haoqi; Lu, Jiashu; Lu, Jingbin; Lu, Junguang; Lubsandorzhiev, Bayarto; Ludhova, Livia; Luo, Shu; Lyashuk, Vladimir; Möllenberg, Randolph; Ma, Xubo; Mantovani, Fabio; Mao, Yajun; Mari, Stefano M.; McDonough, William F.; Meng, Guang; Meregaglia, Anselmo; Meroni, Emanuela; Mezzetto, Mauro; Miramonti, Lino; Mueller, Thomas; Naumov, Dmitry; Oberauer, Lothar; Ochoa-Ricoux, Juan Pedro; Olshevskiy, Alexander; Ortica, Fausto; Paoloni, Alessandro; Peng, Haiping; Peng, Jen-Chieh; Previtali, Ezio; Qi, Ming; Qian, Sen; Qian, Xin; Qian, Yongzhong; Qin, Zhonghua; Raffelt, Georg; Ranucci, Gioacchino; Ricci, Barbara; Robens, Markus; Romani, Aldo; Ruan, Xiangdong; Ruan, Xichao; Salamanna, Giuseppe; Shaevitz, Mike; Sinev, Valery; Sirignano, Chiara; Sisti, Monica; Smirnov, Oleg; Soiron, Michael; Stahl, Achim; Stanco, Luca; Steinmann, Jochen; Sun, Xilei; Sun, Yongjie; Taichenachev, Dmitriy; Tang, Jian; Tkachev, Igor; Trzaska, Wladyslaw; van Waasen, Stefan; Volpe, Cristina; Vorobel, Vit; Votano, Lucia; Wang, Chung-Hsiang; Wang, Guoli; Wang, Hao; Wang, Meng; Wang, Ruiguang; Wang, Siguang; Wang, Wei; Wang, Yi; Wang, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Björn; Wu, Qun; Wulz, Claudia-Elisabeth; Wurm, Michael; Xi, Yufei; Xia, Dongmei; Xie, Yuguang; Xing, Zhi-zhong; Xu, Jilei; Yan, Baojun; Yang, Changgen; Yang, Chaowen; Yang, Guang; Yang, Lei; Yang, Yifan; Yao, Yu; Yegin, Ugur; Yermia, Frédéric; You, Zhengyun; Yu, Boxiang; Yu, Chunxu; Yu, Zeyuan; Zavatarelli, Sandra; Zhan, Liang; Zhang, Chao; Zhang, Hong-Hao; Zhang, Jiawen; Zhang, Jingbo; Zhang, Qingmin; Zhang, Yu-Mei; Zhang, Zhenyu; Zhao, Zhenghua; Zheng, Yangheng; Zhong, Weili; Zhou, Guorong; Zhou, Jing; Zhou, Li; Zhou, Rong; Zhou, Shun; Zhou, Wenxiong; Zhou, Xiang; Zhou, Yeling; Zhou, Yufeng; Zou, Jiaheng

    2016-03-01

    . Detection of neutrinos from all past core-collapse supernova explosions in the visible universe with JUNO would further provide valuable information on the cosmic star-formation rate and the average core-collapse neutrino energy spectrum. Antineutrinos originating from the radioactive decay of uranium and thorium in the Earth can be detected in JUNO with a rate of ˜400 events per year, significantly improving the statistics of existing geoneutrino event samples. Atmospheric neutrino events collected in JUNO can provide independent inputs for determining the MH and the octant of the {θ }23 mixing angle. Detection of the 7Be and 8B solar neutrino events at JUNO would shed new light on the solar metallicity problem and examine the transition region between the vacuum and matter dominated neutrino oscillations. Regarding light sterile neutrino topics, sterile neutrinos with {10}-5 {{{eV}}}2\\lt {{Δ }}{m}412\\lt {10}-2 {{{eV}}}2 and a sufficiently large mixing angle {θ }14 could be identified through a precise measurement of the reactor antineutrino energy spectrum. Meanwhile, JUNO can also provide us excellent opportunities to test the eV-scale sterile neutrino hypothesis, using either the radioactive neutrino sources or a cyclotron-produced neutrino beam. The JUNO detector is also sensitive to several other beyondthe-standard-model physics. Examples include the search for proton decay via the p\\to {K}++\\bar{ν } decay channel, search for neutrinos resulting from dark-matter annihilation in the Sun, search for violation of Lorentz invariance via the sidereal modulation of the reactor neutrino event rate, and search for the effects of non-standard interactions. The proposed construction of the JUNO detector will provide a unique facility to address many outstanding crucial questions in particle and astrophysics in a timely and cost-effective fashion. It holds the great potential for further advancing our quest to understanding the fundamental properties of neutrinos, one

  9. Pseudo-dirac neutrinos: a challenge for neutrino telescopes.

    PubMed

    Beacom, John F; Bell, Nicole F; Hooper, Dan; Learned, John G; Pakvasa, Sandip; Weiler, Thomas J

    2004-01-01

    Neutrinos may be pseudo-Dirac states, such that each generation is actually composed of two maximally mixed Majorana neutrinos separated by a tiny mass difference. The usual active neutrino oscillation phenomenology would be unaltered if the pseudo-Dirac splittings are deltam(2) less, similar 10(-12) eV(2); in addition, neutrinoless double beta decay would be highly suppressed. However, it may be possible to distinguish pseudo-Dirac from Dirac neutrinos using high-energy astrophysical neutrinos. By measuring flavor ratios as a function of L/E, mass-squared differences down to deltam(2) approximately 10(-18) eV(2) can be reached. We comment on the possibility of probing cosmological parameters with neutrinos. PMID:14753977

  10. Nonlinear growing neutrino cosmology

    NASA Astrophysics Data System (ADS)

    Ayaita, Youness; Baldi, Marco; Führer, Florian; Puchwein, Ewald; Wetterich, Christof

    2016-03-01

    The energy scale of dark energy, ˜2 ×10-3 eV , is a long way off compared to all known fundamental scales—except for the neutrino masses. If dark energy is dynamical and couples to neutrinos, this is no longer a coincidence. The time at which dark energy starts to behave as an effective cosmological constant can be linked to the time at which the cosmic neutrinos become nonrelativistic. This naturally places the onset of the Universe's accelerated expansion in recent cosmic history, addressing the why-now problem of dark energy. We show that these mechanisms indeed work in the growing neutrino quintessence model—even if the fully nonlinear structure formation and backreaction are taken into account, which were previously suspected of spoiling the cosmological evolution. The attractive force between neutrinos arising from their coupling to dark energy grows as large as 106 times the gravitational strength. This induces very rapid dynamics of neutrino fluctuations which are nonlinear at redshift z ≈2 . Nevertheless, a nonlinear stabilization phenomenon ensures only mildly nonlinear oscillating neutrino overdensities with a large-scale gravitational potential substantially smaller than that of cold dark matter perturbations. Depending on model parameters, the signals of large-scale neutrino lumps may render the cosmic neutrino background observable.

  11. Democratic Neutrino Paradigm

    NASA Astrophysics Data System (ADS)

    Zhuridov, Dmitry

    2014-03-01

    I will introduce a democratic neutrino theory, which sets the absolute scale of the neutrino masses at about 0.03 eV, and has only one free parameter in contrast to 7 (9) free parameters in the conventional model of Dirac (Majorana) neutrino masses and mixing. Taking into account the incoherence and matter effects, this democratic theory agrees with the atmospheric and solar neutrino data. Moreover the results of the reactor neutrino experiments with the baselines around 100 m can be better explained. I will also discuss the predictions of this theory for low energy beta decays, magnetic moments, and neutrinoless double beta decays. Supported in part by the U.S. Department of Energy under contract DE-FG02-12ER41825.

  12. Have massive cosmological neutrinos already been detected

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1980-01-01

    The possibility is investigated that the decay of massive cosmological neutrinos may have produced a spectral signature which has already been detected in observations of the ultraviolet background radiation. Various implications are discussed including a possible implied neutrino mass of 13.8-14.8 eV. A lower limit is also placed on the lifetime of heavy neutrinos with respect to decay into light neutrinos and gamma rays based on the cosmic UV observations.

  13. Direct measurements of neutrino mass

    SciTech Connect

    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.

  14. Neutrino Experiments

    SciTech Connect

    McKeown, R. D.

    2010-08-04

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

  15. New constraints on neutrino masses from cosmology

    SciTech Connect

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

    2006-01-01

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

  16. Hydrologic data collected in the vicinity of the proposed gamma-ray and neutrino detector site, Hot Spring County, Arkansas, 1988-89

    USGS Publications Warehouse

    Fitzpatrick, D.J.; Westerfield, P.W.

    1990-01-01

    An abandoned barite mine in Hot Spring County, Arkansas, has been selected as the location for a proposed gamma-ray and neutrino detector site. As part of the hydrologic evaluation of the site, the U.S. Geological Survey in cooperation with the Arkansas Geological Commission collected hydrologic data at selected locations in the vicinity of the abandoned barite mine. Data collected as part of the project included water quality, pond-evaluation, and precipitation data within the abandoned barite mine and flow and water quality data at selected sites in the vicinity of the mine. Water quality samples from within the abandoned mine were collected at three locations in the pond at selected depths. These data included field measurements of specific conductance, pH, water temperature, dissolved oxygen, major ions, and trace metals. Major ion and trace-metal samples were collected at six stream sites, one lake site, and two wastewater pond sites. Pond elevation and precipitation data from within the abandoned barite mine were measured during the period between July 1, 1988 and June 30, 1989. Twevle discharge measurements during the period between June 21, 1988, and June 26, 1989, were collected at six sites in the vicinity of the abandoned barite mine. (USGS)

  17. Light sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Gariazzo, S.; Giunti, C.; Laveder, M.; Li, Y. F.; Zavanin, E. M.

    2016-03-01

    The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, gallium and Liquid Scintillator Neutrino Detector anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3 + 1 and 3 + 2 schemes are discussed, together with the implications for β-decay and neutrinoless double-β decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives. This review is dedicated to the memory of Hai-Wei Long, our dear friend and collaborator, who passed away on 29 May 2015. He was an exceptionally kind person and an enthusiastic physicist. We deeply miss him.

  18. Light sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Gariazzo, S.; Giunti, C.; Laveder, M.; Li, Y. F.; Zavanin, E. M.

    2015-03-01

    The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, gallium and Liquid Scintillator Neutrino Detector anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3 + 1 and 3 + 2 schemes are discussed, together with the implications for β-decay and neutrinoless double-β decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives. This review is dedicated to the memory of Hai-Wei Long, our dear friend and collaborator, who passed away on 29 May 2015. He was an exceptionally kind person and an enthusiastic physicist. We deeply miss him.

  19. Sterile Neutrino Search with MINOS

    NASA Astrophysics Data System (ADS)

    Devan, Alena V.

    MINOS, Main Injector Neutrino Oscillation Search, is a long-baseline neutrino oscillation experiment in the NuMI muon neutrino beam at the Fermi National Accelerator Laboratory in Batavia, IL. It consists of two detectors, a near detector positioned 1 km from the source of the beam and a far detector 734 km away in Minnesota. MINOS is primarily designed to observe muon neutrino disappearance resulting from three flavor oscillations. The Standard Model of Particle Physics predicts that neutrinos oscillate between three active flavors as they propagate through space. This means that a muon type neutrino has a certain probability to later interact as a different type of neutrino. In the standard picture, the neutrino oscillation probabilities depend only on three neutrino flavors and two mass splittings, Amt. An anomaly was observed by the LSND and MiniBooNE experiments that suggests the existence of a fourth, sterile neutrino flavor that does not interact through any of the known Standard Model interactions. Oscillations into a theoretical sterile flavor may be observed by a deficit in neutral current interactions in the MINOS detectors. A distortion in the charged current energy spectrum might also be visible if oscillations into the sterile flavor are driven by a large mass-squared difference, Delta m2s 1 eV2. The results of the 2013 sterile neutrino search are presented here.

  20. Secret neutrino interactions: a pseudoscalar model

    NASA Astrophysics Data System (ADS)

    Archidiacono, Maria; Hannestad, Steen; Sloth Hansen, Rasmus; Tram, Thomas

    2016-05-01

    Neutrino oscillation experiments point towards the existence of additional mostly sterile neutrino mass eigenstates in the eV mass range. At the same time, such sterile neutrinos are disfavoured by cosmology (Big Bang Nucleosynthesis, Cosmic Microwave Background and Large Scale Structure), unless they can be prevented from being thermalised in the early Universe. To this aim, we introduce a model of sterile neutrino secret interactions mediated by a new light pseudoscalar: The new interactions can accomodate sterile neutrinos in the early Universe, providing a good fit to all the up to date cosmological data.

  1. Neutrinos and cosmology: a lifetime relationship

    SciTech Connect

    Serpico, Pasquale D.; /Fermilab

    2008-06-01

    We consider the example of neutrino decays to illustrate the profound relation between laboratory neutrino physics and cosmology. Two case studies are presented: In the first one, we show how the high precision cosmic microwave background spectral data collected by the FIRAS instrument on board of COBE, when combined with Lab data, have greatly changed bounds on the radiative neutrino lifetime. In the second case, we speculate on the consequence for neutrino physics of the cosmological detection of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a detection at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on some models of neutrino secret interactions.

  2. Probing Neutrino Hierarchy and Chirality via Wakes

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    The relic neutrinos are expected to acquire a bulk relative velocity with respect to the dark matter at low redshifts, and neutrino wakes are expected to develop downstream of the dark matter halos. We propose a method of measuring the neutrino mass based on this mechanism. This neutrino wake will cause a dipole distortion of the galaxy-galaxy lensing pattern. This effect could be detected by combining upcoming lensing surveys with a low redshift galaxy survey or a 21 cm intensity mapping survey, which can map the neutrino flow field. The data obtained with LSST and Euclid should enable us to make a positive detection if the three neutrino masses are quasidegenerate with each neutrino mass of ˜0.1 eV , and a future high precision 21 cm lensing survey would allow the normal hierarchy and inverted hierarchy cases to be distinguished, and even the right-handed Dirac neutrinos may be detectable.

  3. Topics in neutrino astroparticle physics

    NASA Astrophysics Data System (ADS)

    Hong, Woopyo

    1993-01-01

    In the first part of the dissertation, two neutrino properties such as neutrino mass measurement and neutrino dipole moment, in the terrestrial experiments, are examined with particular attention to exotic phenomena that may be observed for theories beyond the Standard Model. In the second part, we study a method for measuring the neutrino mass from a galactic supernova neutrino burst using an innovated detector concept. The neutral current based SNBO (Supernova Neutrino Burst Observatory) detector concept is discussed. We show that it is possible to measure a cosmologically significant neutrino mass, i.e., 5-50 eV directly from the flight time difference between the massive and massless neutrino using the SNBO detector concept. In the third part, very heavy unstable particles from the Big Bang decaying into neutrinos at cosmological epochs is discussed. In particular, we focus on a detection of such relic neutrinos from the decays in the neutrino window on earth, in the energy ranges 10-100 MeV, where the neutrino background is expected to be lowest. In the fourth part, neutrino emission from the explosion of Primordial Black Holes in the context of the Hawking radiation is presented. We suggest a new explosion mechanism inspired by new data from gamma ray bursts that might occur when the Primordial Black Hole reaches a certain surface temperature. We propose some observational tests that use a satellite detector and the proposed SNBO detector. In the last chapter, we examine a possible connection between the baryogenesis in the early universe and the lepton number violation processes.

  4. Ultrahigh-energy neutrino flux as a probe of large extra-dimensions

    SciTech Connect

    Lykken, Joseph; Mena, Olga; Razzaque, Soebur; /Penn State U., Astron. Astrophys. /Penn State U.

    2007-05-01

    A suppression in the spectrum of ultrahigh-energy (UHE, {ge} 10{sup 18} eV) neutrinos will be present in extra-dimensional scenarios, due to enhanced neutrino-antineutrino annihilation processes with the supernova relic neutrinos. In this scenario, neutrinos can not be responsible for the highest energy events observed in the UHE cosmic ray spectrum. A direct implication of these extra-dimensional interactions would be the absence of UHE neutrinos in ongoing and future neutrino telescopes.

  5. Is cosmology compatible with sterile neutrinos?

    SciTech Connect

    Dodelson, Scott; Melchiorri, Alessandro; Slosar, Anze; /Ljubljana U.

    2005-11-01

    By combining data from cosmic microwave background (CMB) experiments (including the recent BOOMERANG-2K2 results), large scale structure (LSS) and Lyman-{alpha} forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless + 1 massive neutrino case we bound the mass of the sterile neutrino to m{sub s} < 0.55eV at 95% c.l.. These results exclude at high significance the sterile neutrino hypothesis as an explanation of the LSND anomaly. We then generalize the analysis to account for active neutrino masses (which tightens the limit to m{sub s} < 0.51eV) and the possibility that the sterile abundance is not thermal. In the latter case, the constraints in the (mass, density) plane are non-trivial. For a mass of > 1eV or < 0.05eV the cosmological energy density in sterile neutrinos is always constrained to be {omega}{sub {nu}} < 0.005 at 95% c.l.. However, for a sterile neutrino mass of {approx} 0.25 eV, {omega}{sub {nu}} can be as large as 0.015.

  6. Neutrino Physics

    DOE R&D Accomplishments Database

    Lederman, L. M.

    1963-01-09

    The prediction and verification of the neutrino are reviewed, together with the V A theory for its interactions (particularly the difficulties with the apparent existence of two neutrinos and the high energy cross section). The Brookhaven experiment confirming the existence of two neutrinos and the cross section increase with momentum is then described, and future neutrino experiments are considered. (D.C.W.)

  7. Neutrino physics

    SciTech Connect

    Harris, Deborah A.; /Fermilab

    2008-09-01

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

  8. Sterile neutrinos as dark matter

    SciTech Connect

    Dodelson, S.; Widrow, L.M. |

    1993-03-01

    The simplest model that can accommodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed or sterile neutrinos. This model has been studied extensively in the context of the hot dark matter scenario. We reexamine this model and find that hot, warm, and cold dark matter are all possibilities. We focus on the case where sterile neutrinos are the dark matter. Since their only direct coupling is to left-handed or active neutrinos, the most efficient production mechanism is via neutrino oscillations. If the production rate is always less than the expansion rate, then these neutrinos will never be in thermal equilibrium. However, they may still play a significant role in the dynamics of the Universe and possibly provide the missing mass necessary for closure. We consider a single generation of neutrino fields ({nu}{sub L}, {nu}{sub R}) with a Dirac mass, {mu}, and a Majorana mass for the right-handed components only, M. For M {much_gt} {mu} we show that the number density of sterile neutrinos is proportional to {mu}{sup 2}/M so that the energy density today is independent of M. However M is crucial in determining the large scale structure of the Universe. In particular, M {approx_equal} 0.1--1.0 key leads to warm dark matter and a structure formation scenario that may have some advantages over both the standard hot and cold dark matter scenarios.

  9. Sterile neutrinos as dark matter

    SciTech Connect

    Dodelson, S. ); Widrow, L.M. . Dept. of Physics Toronto Univ., ON . Canadian Inst. for Theoretical Astrophysics)

    1993-03-01

    The simplest model that can accommodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed or sterile neutrinos. This model has been studied extensively in the context of the hot dark matter scenario. We reexamine this model and find that hot, warm, and cold dark matter are all possibilities. We focus on the case where sterile neutrinos are the dark matter. Since their only direct coupling is to left-handed or active neutrinos, the most efficient production mechanism is via neutrino oscillations. If the production rate is always less than the expansion rate, then these neutrinos will never be in thermal equilibrium. However, they may still play a significant role in the dynamics of the Universe and possibly provide the missing mass necessary for closure. We consider a single generation of neutrino fields ([nu][sub L], [nu][sub R]) with a Dirac mass, [mu], and a Majorana mass for the right-handed components only, M. For M [much gt] [mu] we show that the number density of sterile neutrinos is proportional to [mu][sup 2]/M so that the energy density today is independent of M. However M is crucial in determining the large scale structure of the Universe. In particular, M [approx equal] 0.1--1.0 key leads to warm dark matter and a structure formation scenario that may have some advantages over both the standard hot and cold dark matter scenarios.

  10. Pseudoscalar—sterile neutrino interactions: reconciling the cosmos with neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Archidiacono, Maria; Gariazzo, Stefano; Giunti, Carlo; Hannestad, Steen; Hansen, Rasmus; Laveder, Marco; Tram, Thomas

    2016-08-01

    The Short BaseLine (SBL) neutrino oscillation anomalies hint at the presence of a sterile neutrino with a mass of around 1 eV. However, such a neutrino is incompatible with cosmological data, in particular observations of the Cosmic Microwave Background (CMB) anisotropies. However, this conclusion can change by invoking new physics. One possibility is to introduce a secret interaction in the sterile neutrino sector mediated by a light pseudoscalar. In this pseudoscalar model, CMB data prefer a sterile neutrino mass that is fully compatible with the mass ranges suggested by SBL anomalies. In addition, this model predicts a value of the Hubble parameter which is completely consistent with local measurements.

  11. The Giant Radio Array for Neutrino Detection

    NASA Astrophysics Data System (ADS)

    Martineau-Huynh, Olivier; Kotera, Kumiko; Bustamente, Mauricio; Charrier, Didier; De Jong, Sijbrand; de Vries, Krijn D.; Fang, Ke; Feng, Zhaoyang; Finley, Chad; Gou, Quanbu; Gu, Junhua; Hanson, Jordan C.; Hu, Hongbo; Murase, Kohta; Niess, Valentin; Oikonomou, Foteini; Renault-Tinacci, Nicolas; Schmid, Julia; Timmermans, Charles; Wang, Zhen; Wu, Xiangping; Zhang, Jianli; Zhang, Yi

    2016-04-01

    High-energy neutrino astronomy will probe the working of the most violent phenomena in the Universe. The Giant Radio Array for Neutrino Detection (GRAND) project consists of an array of ˜ 105 radio antennas deployed over ˜ 200 000 km2 in a mountainous site. It aims at detecting high-energy neutrinos via the measurement of air showers induced by the decay in the atmosphere of τ leptons produced by the interaction of cosmic neutrinos under the Earth surface. Our objective with GRAND is to reach a neutrino sensitivity of 5 × 10-11E-2 GeV-1 cm-2 s-1 sr-1 above 3 × 1016 eV. This sensitivity ensures the detection of cosmogenic neutrinos in the most pessimistic source models, and up to 100 events per year are expected for the standard models. GRAND would also probe the neutrino signals produced at the potential sources of UHECRs.

  12. KATRIN: Measuring the Mass Scale of Neutrinos

    NASA Astrophysics Data System (ADS)

    Oblath, Noah; Katrin Collaboration

    2011-10-01

    Over the past decade, experiments studying neutrinos from atmospheric, solar, and reactor sources have shown conclusively that neutrinos change flavor and, as a consequence, have a small but finite mass. However, the scale of neutrino masses remains an open question that is of great importance for many areas of physics. The most direct method to measure the neutrino mass scale is still via beta decay. The talk will focus primarily on the status of the KArlsruhe TRItium Neutrino experiment (KATRIN), currently under construction. KATRIN combines an ultra-luminous molecular windowless gaseous tritium source with a high-resolution integrating spectrometer to gain sensitivity to the absolute mass scale of neutrinos. The projected sensitivity of the experiment on the neutrino mass is 0.2 eV at 90% C.L. In this talk I will discuss the status of the KATRIN experiment.

  13. How self-interactions can reconcile sterile neutrinos with cosmology.

    PubMed

    Hannestad, Steen; Hansen, Rasmus Sloth; Tram, Thomas

    2014-01-24

    Short baseline neutrino oscillation experiments have shown hints of the existence of additional sterile neutrinos in the eV mass range. However, such neutrinos seem incompatible with cosmology because they have too large of an impact on cosmic structure formation. Here we show that new interactions in the sterile neutrino sector can prevent their production in the early Universe and reconcile short baseline oscillation experiments with cosmology. PMID:24484130

  14. Coherent development of neutrino flavor in the supernova environment.

    PubMed

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

    2006-12-15

    We calculate coherent neutrino and antineutrino flavor transformation in the supernova environment, for the first time including self-consistent coupling of intersecting neutrino and antineutrino trajectories. For neutrino mass-squared difference /deltam2/ = 3 x 10(-3) eV2 we find that in the normal (inverted) mass hierarchy the more tangentially-propagating (radially-propagating) neutrinos and antineutrinos can initiate collective, simultaneous medium-enhanced flavor conversion of these particles across broad ranges of energy and propagation direction. Accompanying alterations in neutrino and antineutrino energy spectra and fluxes could affect supernova nucleosynthesis and the expected neutrino signal. PMID:17280265

  15. Neutrino Factories

    SciTech Connect

    Geer, Steve; /Fermilab

    2010-01-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(10{sup 21}) muons/year. This prepares the way for a Neutrino Factory (NF) in which high energy muons decay within the straight sections of a storage ring to produce a beam of neutrinos and anti-neutrinos. The NF concept was proposed in 1997 at a time when the discovery that the three known types of neutrino ({nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}) can change their flavor as they propagate through space (neutrino oscillations) was providing a first glimpse of physics beyond the Standard Model. This development prepares the way for a new type of neutrino source: a Neutrino Factory. This article reviews the motivation, design and R&D for a Neutrino Factory.

  16. Neutrino physics

    SciTech Connect

    Kayser, Boris; /Fermilab

    2005-06-01

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

  17. Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    von Feilitzsch, Franz; Lanfranchi, Jean-Côme; Wurm, Michael

    The neutrino was postulated by Wolfgang Pauli in the early 1930s, but could only be detected for the first time in the 1950s. Ever since scientists all around the world have worked on the detection and understanding of this particle which so scarcely interacts with matter. Depending on the origin and nature of the neutrino, various types of experiments have been developed and operated. In this entry, we will review neutrino detectors in terms of neutrino energy and associated detection technique as well as the scientific outcome of some selected examples. After a brief historical introduction, the detection of low-energy neutrinos originating from nuclear reactors or from the Earth is used to illustrate the principles and difficulties which are encountered in detecting neutrinos. In the context of solar neutrino spectroscopy, where the neutrino is used as a probe for astrophysics, three different types of neutrino detectors are presented - water Čerenkov, radiochemical, and liquid-scintillator detectors. Moving to higher neutrino energies, we discuss neutrinos produced by astrophysical sources and from accelerators. The entry concludes with an overview of a selection of future neutrino experiments and their scientific goals.

  18. Neutrino Factories

    NASA Astrophysics Data System (ADS)

    Geer, Steve

    2010-06-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(1021) muons/year. This development prepares the way for a new type of neutrino source : a Neutrino Factory. This article reviews the motivation, design and R&D for a Neutrino Factory.

  19. Possible explanation of the solar-neutrino puzzle

    NASA Technical Reports Server (NTRS)

    Bethe, H. A.

    1986-01-01

    A new derivation of the Mikheyev and Smirnov (1985) mechanism for the conversion of electron neutrinos into mu neutrinos when traversing the sun is presented, and various hypotheses set forth. It is assumed that this process is responsible for the detection of fewer solar neutrinos than expected, with neutrinos below a minimum energy, E(m), being undetectable. E(m) is found to be about 6 MeV, and the difference of the squares of the respective neutrino masses is calculated to be 6 X 10 to the - 5th sq eV. A restriction on the neutrino mixing angle is assumed such that the change of density near the crossing point is adiabatic. It is predicted that no resonance conversion of neutrinos will occur in the dense core of supernovae, but conversion of electron neutrinos to mu neutrinos will occur as they escape outward through a density region around 100.

  20. Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Palazzo, Antonio

    2016-05-01

    Several anomalies recorded in short-baseline neutrino experiments suggest the possibility that the standard 3-flavor framework may be incomplete and point towards a manifestation of new physics. Light sterile neutrinos provide a credible solution to these puzzling results. Here, we present a concise review of the status of the neutrino oscillations within the 3+1 scheme, the minimal extension of the standard 3-flavor framework endowed with one sterile neutrino species. We emphasize the potential role of LBL experiments in the searches of CP violation related to sterile neutrinos and their complementarity with the SBL experiments.

  1. Solar neutrinos and neutrino physics

    NASA Astrophysics Data System (ADS)

    Maltoni, Michele; Smirnov, Alexei Yu.

    2016-04-01

    Solar neutrino studies triggered and largely motivated the major developments in neutrino physics in the last 50 years. The theory of neutrino propagation in different media with matter and fields has been elaborated. It includes oscillations in vacuum and matter, resonance flavor conversion and resonance oscillations, spin and spin-flavor precession, etc. LMA MSW has been established as the true solution of the solar neutrino problem. Parameters θ_{12} and Δ m 2 21 have been measured; θ_{13} extracted from the solar data is in agreement with results from reactor experiments. Solar neutrino studies provide a sensitive way to test theory of neutrino oscillations and conversion. Characterized by long baseline, huge fluxes and low energies they are a powerful set-up to search for new physics beyond the standard 3 ν paradigm: new neutrino states, sterile neutrinos, non-standard neutrino interactions, effects of violation of fundamental symmetries, new dynamics of neutrino propagation, probes of space and time. These searches allow us to get stringent, and in some cases unique bounds on new physics. We summarize the results on physics of propagation, neutrino properties and physics beyond the standard model obtained from studies of solar neutrinos.

  2. Active-sterile neutrino oscillations in the early universe with dynamical neutrino asymmetries

    NASA Astrophysics Data System (ADS)

    Saviano, Ninetta

    2013-04-01

    In the last recent years different anomalies observed in short-baseline neutrino oscillation experiments seem to point towards the existence of light sterile neutrinos. These sterile neutrinos can also be produced in the early universe by oscillations of the active neutrinos and can affect different cosmological observables. In order to quantify the abundance of sterile neutrinos, we perform a detailed study of the flavor evolution in (3+1) and (2+1) oscillation schemes, in presence of dynamical primordial neutrino asymmetries L. We find that for |L|≲10-4 eV sterile neutrinos would be completely thermalized creating a tension with the cosmological data. An asymmetry of |L|≳10-3 is then required in order to suppress the sterile production and to reconcile them with cosmology.

  3. Light sterile neutrinos after BICEP-2

    SciTech Connect

    Archidiacono, Maria; Hannestad, Steen; Fornengo, Nicolao; Gariazzo, Stefano; Giunti, Carlo; Laveder, Marco E-mail: fornengo@to.infn.it E-mail: giunti@to.infn.it E-mail: marco.laveder@pd.infn.it

    2014-06-01

    The recent discovery of B-modes in the polarization pattern of the Cosmic Microwave Background by the BICEP2 experiment has important implications for neutrino physics. We revisit cosmological bounds on light sterile neutrinos and show that they are compatible with all current cosmological data provided that the mass is relatively low. Using CMB data, including BICEP-2, we find an upper bound of m{sub s} < 0.85 eV (2σ Confidence Level). This bound is strengthened to 0.48 eV when HST measurements of H{sub 0} are included. However, the inclusion of SZ cluster data from the Planck mission and weak gravitational measurements from the CFHTLenS project favours a non-zero sterile neutrino mass of 0.44{sup +0.11}{sub −0.16} eV. Short baseline neutrino oscillations, on the other hand, indicate a new mass state around 1.2 eV. This mass is highly incompatible with cosmological data if the sterile neutrino is fully thermalised (Δχ{sup 2} > 10). However, if the sterile neutrino only partly thermalises it can be compatible with all current data, both cosmological and terrestrial.

  4. Planck scale effects in neutrino physics

    NASA Astrophysics Data System (ADS)

    Akhmedov, E. K.; Senjanovic, G.; Tao, Zhi-Jan; Berezhiani, Z. G.

    1992-08-01

    We study the phenomenology and cosmology of the Majoron (flavon) models of one inert neutrino and three active ones. We pay special attention to the possible (almost) conserved generalization of the Zeldovich-Konopinski-Mahmoud lepton charge. Using Planck scale physics effects, which provide the breaking of the lepton charge, we show how, in this picture, one can incorporate the solutions to some of the central issues in neutrino physics, such as the solar and atmospheric neutrino puzzles, dark matter, and a 17 keV neutrino. These gravitation effects induce tiny Majorana mass terms for neutrinos and considerable masses for flavons. The cosmological demand for the sufficiently fast decay of flavons implies a lower limit on the electron neutrino mass in the range of 0.1-1 eV.

  5. Planck scale effects in neutrino physics

    NASA Astrophysics Data System (ADS)

    Akhmedov, Eugeni Kh.; Berezhiani, Zurab G.; Senjanović, Goran; Tao, Zhijian

    1993-04-01

    We study the phenomenology and cosmology of the Majoron (flavon) models of three active and one inert neutrino paying special attention to the possible (almost) conserved generalization of the Zeldovich-Konopinski-Mahmoud lepton charge. Using Planck scale physics effects which provide the breaking of the lepton charge, we show how in this picture one can incorporate the solutions to some of the central issues in neutrino physics such as the solar and atmospheric neutrino puzzles and the dark matter problem with the possible existence of a heavy (1-10 keV) neutrino. These gravitational effects induce tiny Majorana mass terms for neutrinos and considerable masses for flavons. The cosmological demand for the sufficiently fast decay of flavons implies a lower limit on the electron-neutrino mass in the range of 0.1-1 eV.

  6. Resolving the reactor neutrino anomaly with the KATRIN neutrino experiment

    NASA Astrophysics Data System (ADS)

    Formaggio, J. A.; Barrett, J.

    2011-11-01

    The KArlsruhe TRItium Neutrino experiment (KATRIN) combines an ultra-luminous molecular tritium source with an integrating high-resolution spectrometer to gain sensitivity to the absolute mass scale of neutrinos. The projected sensitivity of the experiment on the electron neutrino mass is 200 meV at 90% C.L. With such unprecedented resolution, the experiment is also sensitive to physics beyond the Standard Model, particularly to the existence of additional sterile neutrinos at the eV mass scale. A recent analysis of available reactor data appears to favor the existence of such a sterile neutrino with a mass splitting of | Δmsterile | 2 ⩾ 1.5eV2 and mixing strength of sin2 2θsterile = 0.17 ± 0.08 at 95% C.L. Upcoming tritium beta decay experiments should be able to rule out or confirm the presence of the new phenomenon for a substantial fraction of the allowed parameter space.

  7. Neutrino factory

    SciTech Connect

    Bogomilov, M.; Matev, R.; Tsenov, R.; Dracos, M.; Bonesini, M.; Palladino, V.; Tortora, L.; Mori, Y.; Planche, T.; Lagrange, J. B.; Kuno, Y.; Benedetto, E.; Efthymiopoulos, I.; Garoby, R.; Gilardoini, S.; Martini, M.; Wildner, E.; Prior, G.; Blondel, A.; Karadzhow, Y.; Ellis, M.; Kyberd, P.; Bayes, R.; Laing, A.; Soler, F. J. P.; Alekou, A.; Apollonio, M.; Aslaninejad, M.; Bontoiu, C.; Jenner, L. J.; Kurup, A.; Long, K.; Pasternak, J.; Zarrebini, A.; Poslimski, J.; Blackmore, V.; Cobb, J.; Tunnell, C.; Andreopoulos, C.; Bennett, J. R.J.; Brooks, S.; Caretta, O.; Davenne, T.; Densham, C.; Edgecock, T. R.; Fitton, M.; Kelliher, D.; Loveridge, P.; McFarland, A.; Machida, S.; Prior, C.; Rees, G.; Rogers, C.; Rooney, M.; Thomason, J.; Wilcox, D.; Booth, C.; Skoro, G.; Back, J. J.; Harrison, P.; Berg, J. S.; Fernow, R.; Gallardo, J. C.; Gupta, R.; Kirk, H.; Simos, N.; Stratakis, D.; Souchlas, N.; Witte, H.; Bross, A.; Geer, S.; Johnstone, C.; Makhov, N.; Neuffer, D.; Popovic, M.; Strait, J.; Striganov, S.; Morfín, J. G.; Wands, R.; Snopok, P.; Bagacz, S. A.; Morozov, V.; Roblin, Y.; Cline, D.; Ding, X.; Bromberg, C.; Hart, T.; Abrams, R. J.; Ankenbrandt, C. M.; Beard, K. B.; Cummings, M. A.C.; Flanagan, G.; Johnson, R. P.; Roberts, T. J.; Yoshikawa, C. Y.; Graves, V. B.; McDonald, K. T.; Coney, L.; Hanson, G.

    2014-12-08

    The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that theta(13) > 0. The measured value of theta(13) is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti) neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO nu. Design Study consortium. EURO nu coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO nu baseline accelerator facility will provide 10(21) muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.

  8. Neutrino factory

    DOE PAGESBeta

    Bogomilov, M.; Matev, R.; Tsenov, R.; Dracos, M.; Bonesini, M.; Palladino, V.; Tortora, L.; Mori, Y.; Planche, T.; Lagrange, J. B.; et al

    2014-12-08

    The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that theta(13) > 0. The measured value of theta(13) is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable ofmore » making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti) neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO nu. Design Study consortium. EURO nu coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO nu baseline accelerator facility will provide 10(21) muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.« less

  9. Neutrino Oscillations With Two Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Kisslinger, Leonard S.

    2016-06-01

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

  10. Solar Neutrinos

    DOE R&D Accomplishments Database

    Davis, R. Jr.; Harmer, D. S.

    1964-12-01

    The prospect of studying the solar energy generation process directly by observing the solar neutrino radiation has been discussed for many years. The main difficulty with this approach is that the sun emits predominantly low energy neutrinos, and detectors for observing low fluxes of low energy neutrinos have not been developed. However, experimental techniques have been developed for observing neutrinos, and one can foresee that in the near future these techniques will be improved sufficiently in sensitivity to observe solar neutrinos. At the present several experiments are being designed and hopefully will be operating in the next year or so. We will discuss an experiment based upon a neutrino capture reaction that is the inverse of the electron-capture radioactive decay of argon-37. The method depends upon exposing a large volume of a chlorine compound, removing the radioactive argon-37 and observing the characteristic decay in a small low-level counter.

  11. Atmospheric neutrinos

    NASA Astrophysics Data System (ADS)

    Gaisser, Thomas K.

    2016-05-01

    In view of the observation by IceCube of high-energy astrophysical neutrinos, it is important to quantify the uncertainty in the background of atmospheric neutrinos. There are two sources of uncertainty, the imperfect knowledge of the spectrum and composition of the primary cosmic rays that produce the neutrinos and the limited understanding of hadron production, including charm, at high energy. This paper is an overview of both aspects.

  12. OscSNS: A Precision Short-Baseline Neutrino Oscillation Experiment

    NASA Astrophysics Data System (ADS)

    Louis, William

    2012-03-01

    Short baseline neutrino experiments are consistent with neutrino oscillations at a δm^2 of approximately 1 eV^2, and world neutrino and antineutrino data fit reasonably well to a 3+2 (active+sterile) neutrino oscillation model with CP violation. The OscSNS experiment at ORNL would be able to make precision short-baseline neutrino oscillation measurements and prove that sterile neutrinos exist. The OscSNS experiment will be described and the corresponding neutrino oscillation sensitivities will be discussed.

  13. Atmospheric neutrinos and discovery of neutrino oscillations

    PubMed Central

    Kajita, Takaaki

    2010-01-01

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

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

    SciTech Connect

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

    2015-05-26

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

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

    NASA Astrophysics Data System (ADS)

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

    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 mν 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 mν < (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 mν < (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.

  16. Nonstandard neutrino-neutrino refractive effects in dense neutrino gases

    SciTech Connect

    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.

  17. Extraterrestrial high energy neutrino fluxes

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1979-01-01

    Using the most recent cosmic ray spectra up to 2x10 to the 20th power eV, production spectra of high energy neutrinos from cosmic ray interactions with interstellar gas and extragalactic interactions of ultrahigh energy cosmic rays with 3K universal background photons are presented and discussed. Estimates of the fluxes from cosmic diffuse sources and the nearby quasar 3C273 are made using the generic relationship between secondary neutrinos and gammas and using recent gamma ray satellite data. These gamma ray data provide important upper limits on cosmological neutrinos. Quantitative estimates of the observability of high energy neutrinos from the inner galaxy and 3C273 above atmospheric background for a DUMAND type detector are discussed in the context of the Weinberg-Salam model with sq sin theta omega = 0.2 and including the atmospheric background from the decay of charmed mesons. Constraints on cosmological high energy neutrino production models are also discussed. It appears that important high energy neutrino astronomy may be possible with DUMAND, but very long observing times are required.

  18. Neutrino astronomy

    SciTech Connect

    Schramm, D.N.

    1980-01-01

    Current knowledge and proposed experiments in the field of neutrino astronomy are reviewed, with particular emphasis on expected sources and existing and proposed detectors for intermediate-energy (10 to 50 MeV) and ultrahigh energy (greater than 10 GeV) neutrinos. Following a brief discussion of the counting rate obtained in the solar neutrino experiment of Davis (1978) and possible statistical sources for the discrepancy between the expected and observed rates, consideration is given to the physics of neutrino ejection in stellar gravitational collapse and sources of high-energy proton collisions giving rise to ultrahigh energy neutrinos. The capabilities of operating Cerenkov detectors at the Homestake Gold Mine, the Mt. Blanc Tunnel and in the Soviet Caucasus are considered in relation to the detection of gravitational collapse in the center of the galaxy, and it is pointed out that neutrino detectors offer a more reliable means of detecting collapses in the Galaxy than do gravitational wave detectors. The possibility of using Cerenkov detectors for ultrahigh energy neutrino detection is also indicated, and applications of large neutrino detectors such as the proposed DUMAND array to measure the lifetime of the proton are discussed.

  19. Neutrino telescopes

    SciTech Connect

    Costantini, H.

    2012-09-15

    Neutrino astrophysics offers a new possibility to observe our Universe: high-energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos: this young discipline extends in fact the conventional astronomy beyond the usual electromagnetic probe. The weak interaction of neutrinos with matter allows them to escape from the core of astrophysical objects and in this sense they represent a complementary messenger with respect to photons. However, their detection on Earth due to the small interaction cross section requires a large target mass. The aim of this article is to review the scientific motivations of the high-energy neutrino astrophysics, the detection principles together with the description of a running apparatus, the experiment ANTARES, the performance of this detector with some results, and the presentation of other neutrino telescope projects.

  20. Neutrinos Matter

    NASA Astrophysics Data System (ADS)

    Freedman, Stuart

    2003-04-01

    The excitement about neutrinos is all about mass. Recent experiments have established that neutrino have mass and that the familiar weak interaction states ν_e, ν_μ, and ν_τ are not the states the quantum states with definite mass. These new discoveries require a major reassessment of the role of neutrinos in the universe and the first reformulation of the Standard Model of particle physics since the discovery of the third generation of quarks and leptons. Neutrino experiments are poised to answer many of the new questions raised by the recent discoveries. I will review the current status of the field and discuss what experiment is teaching us about neutrino mass and mixing.

  1. Neutrino factories

    NASA Astrophysics Data System (ADS)

    Soler, F. J. P.

    2015-07-01

    The Neutrino Factory is a facility that produces neutrino beams with a well-defined flavour content and energy spectrum from the decay of intense, high-energy, stored muon beams to establish CP violation in the neutrino sector. The International Design Study for the Neutrino Factory (the IDS-NF) is providing a Reference Design Report (RDR) for the facility. The present design is optimised for the recent measurements of θ13. The accelerator facility will deliver 1021 muon decays per year from 10 GeV stored muon beams. The straight sections of the storage ring point to a 100 kton Magnetised Iron Neutrino Detector (MIND) at a distance of 2000-2500 km from the source. The accuracy in the value of δCP that a Neutrino Factory can achieve and the δCP coverage is unrivalled by other future facilities. Staging scenarios for the Neutrino Factory deliver facilities that can carry out physics at each stage. In the context of Fermilab, such a scenario would imply in the first stage the construction of a small storage ring, nuSTORM, to carry out neutrino cross-section and sterile neutrino measurements and to perform a programme of 6D muon cooling R&D. The second stage is the construction of a 5 GeV Neutrino Factory (nuMAX) pointing to the Sanford Underground Research Facility at Homestake and the final stage would use many of the components of this facility to construct a Muon Collider, initially as a 126 GeV CM Higgs Factory, which may be upgraded to a multi-TeV Muon Collider if required.

  2. Neutrino factories

    SciTech Connect

    Soler, F. J. P.

    2015-07-15

    The Neutrino Factory is a facility that produces neutrino beams with a well-defined flavour content and energy spectrum from the decay of intense, high-energy, stored muon beams to establish CP violation in the neutrino sector. The International Design Study for the Neutrino Factory (the IDS-NF) is providing a Reference Design Report (RDR) for the facility. The present design is optimised for the recent measurements of θ{sub 13}. The accelerator facility will deliver 10{sup 21} muon decays per year from 10 GeV stored muon beams. The straight sections of the storage ring point to a 100 kton Magnetised Iron Neutrino Detector (MIND) at a distance of 2000-2500 km from the source. The accuracy in the value of δ{sub CP} that a Neutrino Factory can achieve and the δ{sub CP} coverage is unrivalled by other future facilities. Staging scenarios for the Neutrino Factory deliver facilities that can carry out physics at each stage. In the context of Fermilab, such a scenario would imply in the first stage the construction of a small storage ring, nuSTORM, to carry out neutrino cross-section and sterile neutrino measurements and to perform a programme of 6D muon cooling R&D. The second stage is the construction of a 5 GeV Neutrino Factory (nuMAX) pointing to the Sanford Underground Research Facility at Homestake and the final stage would use many of the components of this facility to construct a Muon Collider, initially as a 126 GeV CM Higgs Factory, which may be upgraded to a multi-TeV Muon Collider if required.

  3. Limits on sterile neutrino contributions to neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Barea, J.; Kotila, J.; Iachello, F.

    2015-11-01

    Nuclear matrix elements (NME) for exchange of arbitrary mass neutrinos are calculated in the interacting boson model (IBM-2). By combining the NME with the phase space factors (PSF), expected half-lives for neutrinos of mass mN and coupling Ue N are estimated. Limits on sterile neutrinos with masses in the eV, keV, MeV-GeV, and TeV range are given.

  4. f(R) Cosmology and Massive Neutrinos

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    f(R) gravity provides viable cosmology alternative to the ΛCDM model. We discuss the effect of massive neutrinos on matter power spectrum in this theory, to show that the anomalous growth of density fluctuations on small scales due to the scalaron force can be compensated by free streaming of neutrinos. As a result, models which predict observable deviation of the equation-of-state parameter wDE from wDE = -1 may be reconciled with observations of matter clustering if the total neutrino mass is O(0.5 eV).

  5. Software for neutrino acoustic detection and localization

    NASA Astrophysics Data System (ADS)

    Bouhadef, B.

    2009-06-01

    The evidence of the existing of UHE (E>10eV) cosmic rays and its possible connection to UHE neutrino suggests the building of an acoustic telescope for neutrino, exploiting thermo-acoustic effect. We present software for neutrino acoustic signal detection and localization. The main points discussed here are the sea noise model, the determination of time differences of arrival (TDOA) between hydrophones signals, the source localization algorithm, and the telescope geometry effect. The effect of TDOAs errors and telescope geometry on the localization accuracy is also discussed.

  6. Coronal Neutrino Emission in Hypercritical Accretion Flows

    NASA Astrophysics Data System (ADS)

    Kawabata, R.; Mineshige, S.; Kawanaka, N.

    2008-03-01

    Hypercritical accretion flows onto stellar mass black holes (BHs) are commonly believed to be as a promising model of central engines of gamma-ray bursts (GRBs). In this model a certain fraction of the gravitational binding energy of accreting matter is deposited to the energy of relativistic jets via neutrino annihilation and/or magnetic fields. However, some recent studies have indicated that the energy deposition rate by neutrino annihilation is somewhat smaller than that needed to power a GRB. To overcome this difficulty, Ramirez-Ruiz and Socrates proposed that high-energy neutrinos from the hot corona above the accretion disk might enhance the efficiency of the energy deposition. We elucidate the disk corona model in the context of hypercritical accretion flows. From the energy balance in the disk and the corona, we can calculate the disk and coronal temperature, Td and Tc, and neutrino spectra, taking into account the neutrino cooling processes by neutrino-electron scatterings and neutrino pair productions. The calculated neutrino spectra consist of two peaks: one by the neutrino emission from the disk and the other by that from the corona. We find that the disk corona can enhance the efficiency of energy release but only by a factor of 1.5 or so, unless the height of the corona is very small, Hll r. This is because the neutrino emission is very sensitive to the temperature of the emitting region, and then the ratio Tc/Td cannot be very large.

  7. Neutrino Oscillations:. Hierarchy Question

    NASA Astrophysics Data System (ADS)

    Ernst, D. J.; Cogswell, B. K.; Burroughs, H. R.; Escamilla-Roa, J.; Latimer, D. L.

    2014-09-01

    The only experimentally observed phenomenon that lies outside the standard model of the electroweak interaction is neutrino oscillations. A way to try to unify the extensive neutrino oscillation data is to add a phenomenological mass term to the Lagrangian that is not diagonal in the flavor basis. The goal is then to understand the world's data in terms of the parameters of the mixing matrix and the differences between the squares of the masses of the neutrinos. An outstanding question is what is the correct ordering of the masses, the hierarchy question. We point out a broken symmetry relevant to this question, the symmetry of the simultaneous interchange of hierarchy and the sign of θ13. We first present the results of an analysis of data that well determine the phenomenological parameters but are not sensitive to the hierarchy. We find θ13 = 0.152±0.014, θ 23 = 0.25{ - 0.05}{ + 0.03} π and Δ32 = 2.45±0.14×10-3 eV2, results consistent with others. We then include data that are sensitive to the hierarchy and the sign of θ13. We find, unlike others, four isolated minimum in the χ2-space as predicted by the symmetry. Now that Daya Bay and RENO have determined θ13 to be surprisingly large, the Super-K atmospheric data produce meaningful symmetry breaking such that the inverse hierarchy is preferred at the 97.2 % level.

  8. A Lead Astronomical Neutrino Detector: LAND

    NASA Astrophysics Data System (ADS)

    Hargrove, C. K.; Batkin, I.; Sundaresan, M. K.; Dubeau, J.

    1996-08-01

    The development of a sensitive detector for neutrinos of astronomical origin (simply called astronomical neutrinos hereafter) would make possible detailed investigation of supernovae (SN) and open the way for the discovery of new astronomical phenomena. The neutrino weak interaction cross section at energies less than 100 MeV increases with Z due to correlated nucleon effects and the nuclear Coulomb factor (Fermi function). Therefore neutrino detection based on high Z materials will give the largest possible cross sections and best possible neutrino detection efficiency. This physics argument motivated us to study lead as a detector of SN. The neutrino cross section for neutron production on lead through the reaction Pb(νe,μ,τ, ln)X is ≈ 10-40 cm2, for energies up to 50 MeV, where X refers to Pb, Bi or Tl, the product nuclei of the reactions, l refers to the scattered lepton, and n refers to neutrons. Neutron production will occur for all types of neutrinos and the neutrons can be detected easily and efficiently. The detector is uniquely sensitive to all neutrinos but #x003BD;e. We show that a SN at the centre of the galaxy produces about 1000 neutrons in a 1 kiloton detector. This large number will make it possible to measure the mass of νμ and ντ neutrinos between 10 and 100 eV with a precision of 10 eV. Further, we describe a possible detector in which one also detects the associated electromagnetic energy in coincidence with the neutrons. The coincidence makes this detector essentially background free. It is possible to expand such a detector to a size which will reach SN well beyond our galaxy. We calculate the ν-Pb cross section, discuss the design, neutrino mass resolution, neutron detection efficiency and signal to noise ratio aspects of these detectors.

  9. Limits on sterile neutrino mixing using atmospheric neutrinos in Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Abe, K.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakano, Y.; Nakayama, S.; Sekiya, H.; Shiozawa, M.; Suzuki, Y.; Takeda, A.; Tanaka, H.; Tomura, T.; Ueno, K.; Wendell, R. A.; Yokozawa, T.; Irvine, T.; Kajita, T.; Kametani, I.; Kaneyuki, K.; Lee, K. P.; McLachlan, T.; Nishimura, Y.; Richard, E.; Okumura, K.; Labarga, L.; Fernandez, P.; Gustafson, J.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tanaka, H. A.; Tobayama, S.; Goldhaber, M.; Carminati, G.; Kropp, W. R.; Mine, S.; Weatherly, P.; Renshaw, A.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Keig, W. E.; Hong, N.; Kim, J. Y.; Lim, I. T.; Akiri, T.; Himmel, A.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Tasaka, S.; Jang, J. S.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Suzuki, A. T.; Takeuchi, Y.; Bronner, C.; Hirota, S.; Huang, K.; Ieki, K.; Kikawa, T.; Minamino, A.; Murakami, A.; Nakaya, T.; Suzuki, K.; Takahashi, S.; Tateishi, K.; Fukuda, Y.; Choi, K.; Itow, Y.; Mitsuka, G.; Mijakowski, P.; Hignight, J.; Imber, J.; Jung, C. K.; Yanagisawa, C.; Ishino, H.; Kibayashi, A.; Koshio, Y.; Mori, T.; Sakuda, M.; Yamaguchi, R.; Yano, T.; Kuno, Y.; Tacik, R.; Kim, S. B.; Okazawa, H.; Choi, Y.; Nishijima, K.; Koshiba, M.; Suda, Y.; Totsuka, Y.; Yokoyama, M.; Martens, K.; Marti, Ll.; Vagins, M. R.; Martin, J. F.; de Perio, P.; Konaka, A.; Wilking, M. J.; Chen, S.; Zhang, Y.; Connolly, K.; Wilkes, R. J.; Super-Kamiokande Collaboration

    2015-03-01

    We present limits on sterile neutrino mixing using 4,438 live-days of atmospheric neutrino data from the Super-Kamiokande experiment. We search for fast oscillations driven by an eV2 -scale mass splitting and for oscillations into sterile neutrinos instead of tau neutrinos at the atmospheric mass splitting. When performing both of these searches we assume that the sterile mass splitting is large, allowing sin2(Δ m2L /4 E ) to be approximated as 0.5, and we assume that there is no mixing between electron neutrinos and sterile neutrinos (|Ue 4|2=0 ). No evidence of sterile oscillations is seen and we limit |Uμ 4|2 to less than 0.041 and |Uτ 4|2 to less than 0.18 for Δ m2>0.1 eV2 at the 90% C.L. in a 3 +1 framework. The approximations that can be made with atmospheric neutrinos allow these limits to be easily applied to 3 +N models, and we provide our results in a generic format to allow comparisons with other sterile neutrino models.

  10. NEUTRINO SPECTRA FROM ACCRETION DISKS: NEUTRINO GENERAL RELATIVISTIC EFFECTS AND THE CONSEQUENCES FOR NUCLEOSYNTHESIS

    SciTech Connect

    Caballero, O. L.; McLaughlin, G. C.; Surman, R. E-mail: olcaball@ncsu.edu E-mail: surmanr@union.edu

    2012-02-01

    Black hole (BH) accretion disks have been proposed as good candidates for a range of interesting nucleosynthesis, including the r-process. The presence of the BH influences the neutrino fluxes and affects the nucleosynthesis resulting from the interaction of the emitted neutrinos and hot outflowing material ejected from the disk. We study the impact of general relativistic effects on the neutrinos emitted from BH accretion disks. We present abundances obtained by considering null geodesics and energy shifts for two different disk models. We find that both the bending of the neutrino trajectories and the energy shifts have important consequences for the nucleosynthetic outcome.

  11. Observation of Electron Neutrino Appearance in a Muon Neutrino Beam

    NASA Astrophysics Data System (ADS)

    Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Ariga, T.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Bentham, S. W.; Berardi, V.; Berger, B. E.; Berkman, S.; Bertram, I.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; 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.; 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.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dufour, F.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Floetotto, L.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Gaudin, A.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gomez-Cadenas, J. J.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Ives, S. J.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koseki, K.; Koshio, Y.; Kreslo, I.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kumaratunga, S.; Kurjata, R.; Kutter, T.; Lagoda, J.; Laihem, K.; Lamont, I.; Laveder, M.; Lawe, M.; Lazos, M.; Lee, K. P.; Licciardi, C.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Ludovici, L.; Macaire, M.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Maruyama, T.; Marzec, J.; Mathie, E. L.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Monfregola, L.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nagasaki, T.; Nakadaira, T.; Nakahata, M.; Nakai, T.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Naples, D.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Owen, R. A.; Oyama, Y.; Palladino, V.; Paolone, V.; Payne, D.; Pearce, G. F.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L. J.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala, 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.; Retiere, F.; Robert, A.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smith, R. J.; 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.; Szeglowski, T.; 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.; Ueno, K.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; 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.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

    2014-02-01

    The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3σ when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles θ12, θ23, θ13, a mass difference Δm322 and a CP violating phase δCP. In this neutrino oscillation scenario, assuming |Δm322|=2.4×10-3 eV2, sin2θ23=0.5, and Δm322>0 (Δm322<0), a best-fit value of sin22θ13=0.140-0.032+0.038 (0.170-0.037+0.045) is obtained at δCP=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of θ13 from reactor experiments, some values of δCP are disfavored at the 90% C.L.

  12. Constraining invisible neutrino decays with the cosmic microwave background

    SciTech Connect

    Hannestad, Steen; Raffelt, Georg G.

    2005-11-15

    Precision measurements of the acoustic peaks of the cosmic microwave background indicate that neutrinos must be freely streaming at the photon decoupling epoch when T{approx_equal}0.3 eV. This requirement implies restrictive limits on 'secret neutrino interactions', notably on neutrino Yukawa couplings with hypothetical low-mass (pseudo)scalars {phi}. For diagonal couplings in the neutrino mass basis we find g < or approx. 1x10{sup -7}, comparable to limits from supernova 1987A. For the off-diagonal couplings and assuming hierarchical neutrino masses we find g < or approx. 1x10{sup -11}(0.05 eV/m){sup 2} where m is the heavier mass of a given neutrino pair connected by g. This stringent limit excludes that the flavor content of high-energy neutrinos from cosmic-ray sources is modified by {nu}{yields}{nu}{sup '}+{phi} decays on their way to Earth.

  13. The early universe and clustering of the relic neutrinos

    SciTech Connect

    Sato, H.

    1981-12-29

    The astronomical consequences of a neutrino mass on the order of 10 eV are assessed. According to big bang cosmology, the neutrino blackbody radiation was excited in the early universe and, in the case of a neutrino mass of less than 1 MeV, would remain until now in the form of relic neutrinos without undergoing pair annihilation. These neutrinos may contribute to the average density of the universe, and may also be the main source of gravity in astronomical objects such as galactic clusters. While it is understood that neutrino-bound systems with masses on the order of galactic clusters are formed through a growth of the primordial density fluctuation in the relic neutrino distribution, there is as yet no explanation of how the protocluster fragments form individual galaxies and the massive halos of neutrinos around them. If the neutrino mass is larger than 10 eV, the missing mass in those galactic systems could be explained by the rest mass of the neutrino.

  14. Sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Kopp, J.; Machado, P. A. N.; Maltoni, M.; Schwetz, T.

    2016-06-01

    We characterize statistically the indications of a presence of one or more light sterile neutrinos from MiniBooNE and LSND data, together with the reactor and gallium anomalies, in the global context. The compatibility of the aforementioned signals with null results from solar, atmospheric, reactor, and accelerator experiments is evaluated. We conclude that a severe tension is present in the global fit, and therefore the addition of eV-scale sterile neutrinos does not satisfactorily explain the anomalies.

  15. Neutrino-atom collisions

    NASA Astrophysics Data System (ADS)

    Kouzakov, Konstantin A.; Studenikin, Alexander I.

    2016-05-01

    Neutrino-atom scattering provides a sensitive tool for probing nonstandard interactions of massive neutrinos in laboratory measurements. The ionization channel of this collision process plays an important role in experiments searching for neutrino magnetic moments. We discuss some theoretical aspects of atomic ionization by massive neutrinos. We also outline possible manifestations of neutrino electromagnetic properties in coherent elastic neutrino-nucleus scattering.

  16. Diagnostic potential of cosmic-neutrino absorption spectroscopy

    SciTech Connect

    Barenboim, Gabriela; Mena Requejo, Olga; Quigg, Chris; /Fermilab

    2004-12-01

    Annihilation of extremely energetic cosmic neutrinos on the relic-neutrino background can give rise to absorption lines at energies corresponding to formation of the electroweak gauge boson Z{sup 0}. The positions of the absorption dips are set by the masses of the relic neutrinos. Suitably intense sources of extremely energetic (10{sup 21} - 10{sup 25}-eV) cosmic neutrinos might therefore enable the determination of the absolute neutrino masses and the flavor composition of the mass eigenstates. Several factors--other than neutrino mass and composition--distort the absorption lines, however. We analyze the influence of the time-evolution of the relic-neutrino density and the consequences of neutrino decay. We consider the sensitivity of the lineshape to the age and character of extremely energetic neutrino sources, and to the thermal history of the Universe, reflected in the expansion rate. We take into account Fermi motion arising from the thermal distribution of the relic-neutrino gas. We also note the implications of Dirac vs. Majorana relics, and briefly consider unconventional neutrino histories. We ask what kinds of external information would enhance the potential of cosmic-neutrino absorption spectroscopy, and estimate the sensitivity required to make the technique a reality.

  17. Surface morphology changes and damage in hot tungsten by impact of 80 eV - 12 keV He-ions and keV-energy self-atoms

    NASA Astrophysics Data System (ADS)

    Hijazi, Hussein; Bannister, Mark E.; Krstic, Predrag S.; Parish, Chad M.; Meyer, Harry M., III; Meyer, Fred M.

    2013-10-01

    We report on measurements of interactions of 50 - 12,000 eV He ions with heated tungsten surfaces performed at the ORNL MIRF. Surface morphology changes, as well as nano-fuzz formation were investigated as function of flux and total fluence, for both virgin and pre-damaged W-targets. At low fluences, ordered surface structures are observed, with great grain-to-grain variability, together with blisters and pinholes, whose density and size increase with increasing fluence. At larger fluences, individual grain characteristics disappear, and the entire surface assumes a frothy appearance in FIB/SEM, with a multitude of near-surface bubbles with a broad range of sizes, and disordered whisker growth, while in SEM imaging the surface is indistinguishable from nano-fuzz produced on linear plasma devices. These features are evident at progressively lower fluences as the He-ion energy is increased, particularly above 1 keV, where the He beam serves not only to load the near-surface region with He to saturation, but to produce significant near-surface damage sites that can trap He. We also report on observations of the effects on surface morphology changes and nano-fuzz formation of pre-damage created by self-ion impact, and on MD simulations of near-surface damage using self-atoms. Research sponsored by the LDRD Program of ORNL, managed by UT-Battelle, LLC, for the US DOE.

  18. 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.

  19. SOX: Short distance neutrino Oscillations with BoreXino

    NASA Astrophysics Data System (ADS)

    Bellini, G.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Etenko, A.; Fernandes, G.; Fomenko, K.; Franco, D.; Galbiati, C.; Ghiano, C.; Göger-Neff, M.; Goretti, A.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Kobychev, V.; Korablev, D.; Korga, G.; Krasnicky, D.; Kryn, D.; Laubenstein, M.; Link, J. M.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Pallavicini, M.; Pantic, E.; Papp, L.; Perasso, S.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Saldanha, R.; Salvo, C.; Schönert, S.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Unzhakov, E.; Vogelaar, R. B.; Wang, H.; Wojcik, M.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.

    2013-08-01

    The very low radioactive background of the Borexino detector, its large size, and the well proved capability to detect both low energy electron neutrinos and antineutrinos make an ideal case for the study of short distance neutrino oscillations with artificial sources at Gran Sasso. This paper describes the possible layouts of 51Cr ( ν e ) and 144Ce-144Pr source experiments in Borexino and shows the expected sensitivity to eV mass sterile neutrinos for three possible different phases of the experiment. Expected results on neutrino magnetic moment, electroweak mixing angle, and couplings to axial and vector currents are shown too.

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

    SciTech Connect

    Blennow, Mattias

    2008-06-01

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

  1. Limits on deeply penetrating particles in the 10(17) eV cosmic ray flux

    NASA Technical Reports Server (NTRS)

    Baltrusaitis, R. M.; Gerhardy, J. W.; Mizumoto, Y.; Cassiday, G. L.; Cooper, R.; Elbert, J. W.; Loh, P. R.; Sokolsky, P.; Sommers, P.; Steck, D.

    1985-01-01

    Deeply penetrating particles in the 10 to the 17th power eV cosmic ray flux were investigated. No such events were found in 8.2 x 10 to the 6th power sec of running time. Limits were set on the following: quark-matter in the primary cosmic ray flux; long-lived, weakly interacting particles produced in p-air collisions; the astrophysical neutrino flux. In particular, the neutrino flux limit at 10 to the 17th power eV implies that z, the red shift of maximum activity is 10 in the model of Hill and Schramm.

  2. On the Proof of Dark Matter, the Law of Gravity, and the Mass of Neutrinos

    NASA Astrophysics Data System (ADS)

    Angus, Garry W.; Shan, Huan Yuan; Zhao, Hong Sheng; Famaey, Benoit

    2007-01-01

    We develop a new method to predict the density associated with weak-lensing maps of (un)relaxed clusters in a range of theories interpolating between general relativity (GR) and modified Newtonian dynamics (MOND). We apply it to fit the lensing map of the Bullet merging cluster 1E 0657-56, in order to constrain more robustly the nature and amount of collisionless matter in clusters beyond the usual assumption of spherical equilibrium (Pointecouteau & Silk) and the validity of GR on cluster scales (Clowe et al.). Strengthening the proposal of previous authors, we show that the Bullet Cluster is dominated by a collisionless-most probably nonbaryonic-component in GR as well as in MOND, a result consistent with the dynamics of many X-ray clusters. Our findings add to the number of known pathologies for a purely baryonic MOND, including its inability to fit the latest data from the Wilkinson Microwave Anisotropy Probe. A plausible resolution of all these issues and standard issues of cold dark matter (CDM) with galaxy rotation curves is the ``marriage'' of MOND with ordinary hot neutrinos of 2 eV. This prediction is just within the GR-independent maximum of neutrino mass from current β-decay experiments and will be falsifiable by the Karlsruhe Tritium Neutrino (KATRIN) experiment by 2009. Issues of consistency with strong-lensing arcs and the large relative velocity of the two clusters comprising the Bullet Cluster are also addressed.

  3. The halo model in a massive neutrino cosmology

    SciTech Connect

    Massara, Elena; Villaescusa-Navarro, Francisco; Viel, Matteo E-mail: villaescusa@oats.inaf.it

    2014-12-01

    We provide a quantitative analysis of the halo model in the context of massive neutrino cosmologies. We discuss all the ingredients necessary to model the non-linear matter and cold dark matter power spectra and compare with the results of N-body simulations that incorporate massive neutrinos. Our neutrino halo model is able to capture the non-linear behavior of matter clustering with a ∼20% accuracy up to very non-linear scales of k = 10 h/Mpc (which would be affected by baryon physics). The largest discrepancies arise in the range k = 0.5 – 1 h/Mpc where the 1-halo and 2-halo terms are comparable and are present also in a massless neutrino cosmology. However, at scales k < 0.2 h/Mpc our neutrino halo model agrees with the results of N-body simulations at the level of 8% for total neutrino masses of < 0.3 eV. We also model the neutrino non-linear density field as a sum of a linear and clustered component and predict the neutrino power spectrum and the cold dark matter-neutrino cross-power spectrum up to k = 1 h/Mpc with ∼30% accuracy. For masses below 0.15 eV the neutrino halo model captures the neutrino induced suppression, casted in terms of matter power ratios between massive and massless scenarios, with a 2% agreement with the results of N-body/neutrino simulations. Finally, we provide a simple application of the halo model: the computation of the clustering of galaxies, in massless and massive neutrinos cosmologies, using a simple Halo Occupation Distribution scheme and our halo model extension.

  4. Propagation of high-energy neutrinos in a background of ultralight scalar dark matter

    NASA Astrophysics Data System (ADS)

    Reynoso, Matías M.; Sampayo, Oscar A.

    2016-09-01

    If high-energy neutrinos propagate in a background of ultralight scalar field particles of dark matter (mφ ∼10-23 eV), neutrino-dark matter interactions can play a role and affect the neutrino flux. In this work we analyse this effect using transport equations that account for the neutrino regeneration as well as absorption, and we consider the neutrino flux propagation in the extragalactic medium and also through the galactic halo of dark matter. We show the results for the final flux to arrive on Earth for different cases of point and diffuse neutrino fluxes. We conclude that this type of neutrino interactions with ultralight scalar particles as dark matter can yield very different results in the neutrino flux and in the flavor ratios that can be measured in neutrino detectors such as IceCube.

  5. Neutrino Oscillations and the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Wark, David

    2001-04-01

    When the existence of the neutrino was almost apologetically first proposed by Wolfgang Pauli it was intended to explain the mysterious apparent absence of energy and momentum in beta decay. 70 years later the neutrino has indeed solved that mystery, but it has generated still more of its own. Are neutrinos massive? Is it possible to create a neutrino with its spin in the same direction as its momentum? What fraction of the mass of the Universe is made up of neutrinos? Are the flavour labels which we put on neutrinos, like electron and muon, really fixed or can they change? Why does no experiment see the predicted flux of neutrinos from the Sun? Why do there appear to be roughly equal numbers of muon and electron neutrinos created in our atmosphere, rather than the 2:1 ratio we would expect? Many of these questions were coupled when Bruno Pontecorvo first suggested that the shortfall in solar neutrino measurements were caused by neutrino oscillations - neutrinos spontaneously changing flavour as they travel from the Sun. 30 years later we still await definitive proof of that conjecture, and providing that proof is the reason for the Sudbury Neutrino Observatory. The talk will discuss the current state of neutrino oscillations studies, and show how the unique capabilities of the Sudbury Neutrino Observatory can provide definitive proof of whether neutrino oscillations are the long-sought answer to the solar neutrino problem.

  6. Neutrino dynamics below the electroweak crossover

    NASA Astrophysics Data System (ADS)

    Ghiglieri, J.; Laine, M.

    2016-07-01

    We estimate the thermal masses and damping rates of active (m < eV) and sterile (M ~ GeV) neutrinos with thermal momenta k~ 3T at temperatures below the electroweak crossover (5 GeV < T < 160 GeV) . These quantities fix the equilibration or ``washout'' rates of Standard Model lepton number densities. Sterile neutrinos interact via direct scatterings mediated by Yukawa couplings, and via their overlap with active neutrinos. Including all leading-order reactions we find that the washout rate generally exceeds the Hubble rate for 5 GeV < T < 30 GeV . Therefore it is challenging to generate a large lepton asymmetry facilitating dark matter computations operating at T < 5 GeV, whereas the generation of a baryon asymmetry at T > 130 GeV remains an option. Our differential rates are tabulated in a form suitable for studies of specific scenarios with given neutrino Yukawa matrices.

  7. Cosmological bounds on active-sterile neutrino mixing after Planck data

    NASA Astrophysics Data System (ADS)

    Saviano, Ninetta

    2015-04-01

    Light sterile neutrinos can be produced by oscillations with active neutrinos in the early universe. Their properties can be constrained by their contribution as extra-radiation, parametrized in terms of the effective number of neutrino species Neff, and to the universe energy density today Ωvh2. Both these parameters have been measured to quite a good precision by the Planck satellite experiment. We use these results to update the bounds on the parameter space of (3+1) sterile neutrino scenarios, with an active-sterile neutrino mass squared splitting in the range (10-5 — 102)eV2. For the first time we take into account the possibility of two non-vanishing active-sterile mixing angles. We find that the mass and mixing parameter space is severely constrained. In particular sterile neutrinos with m ˜ O(1) eV are strongly disfavoured by neutrino mass bound.

  8. Ultra high energy neutrinos: absorption, thermal effects and signatures

    SciTech Connect

    Lunardini, Cecilia; Sabancilar, Eray; Yang, Lili E-mail: Eray.Sabancilar@asu.edu

    2013-08-01

    We study absorption of ultra high energy neutrinos by the cosmic neutrino background, with full inclusion of the effect of the thermal distribution of the background on the resonant annihilation channel. For a hierarchical neutrino mass spectrum (with at least one neutrino with mass below ∼ 10{sup −2} eV), thermal effects are important for ultra high energy neutrino sources at z∼>16. The neutrino transmission probability shows no more than two separate suppression dips since the two lightest mass eigenstates contribute as a single species when thermal effects are included. Results are applied to a number of models of ultra high energy neutrino emission. Suppression effects are strong for sources that extend beyond z ∼ 10, which can be realized for certain top down scenarios, such as superheavy dark matter decays, cosmic strings and cosmic necklaces. For these, a broad suppression valley should affect the neutrino spectrum at least in the energy interval 10{sup 12}−10{sup 13} GeV — which therefore is disfavored for ultra high energy neutrino searches — with only a mild dependence on the neutrino mass spectrum and hierarchy. The observation of absorption effects would indicate a population of sources beyond z ∼ 10, and favor top-down mechanisms; it would also be an interesting probe of the physics of the relic neutrino background in the unexplored redshift interval z ∼ 10–100.

  9. 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.

  10. Prospects for detecting supernova neutrino flavor oscillations

    NASA Astrophysics Data System (ADS)

    Fuller, George M.; Haxton, Wick C.; McLaughlin, Gail C.

    1999-04-01

    The neutrinos from a type II supernova provide perhaps our best opportunity to probe cosmologically interesting muon and/or tauon neutrino masses. This is because matter enhanced neutrino oscillations can lead to an anomalously hot νe spectrum, and thus to enhanced charged current cross sections in terrestrial detectors. Two recently proposed supernova neutrino observatories, OMNIS and LAND, will detect neutrons spalled from target nuclei by neutral and charged current neutrino interactions. As this signal is not flavor specific, it is not immediately clear whether a convincing neutrino oscillation signal can be extracted from such experiments. To address this issue we examine the responses of a series of possible light and heavy mass targets, 9Be,23Na,35Cl, and 208Pb. We find that strategies for detecting oscillations which use only neutron count rates are problematic at best, even if cross sections are determined by ancillary experiments. Plausible uncertainties in supernova neutrino spectra tend to obscure rate enhancements due to oscillations. However, in the case of 208Pb, a signal emerges that is largely flavor specific and extraordinarily sensitive to the νe temperature, the emission of two neutrons. This signal and its flavor specificity are associated with the strength and location of the first-forbidden responses for neutral and charge current reactions, aspects of the 208Pb neutrino cross section that have not been discussed previously. Hadronic spin transfer experiments might be helpful in confirming some of the nuclear structure physics underlying our conclusions.

  11. Tau neutrino component to tritium beta decay

    SciTech Connect

    Snyderman, N.J.

    1995-06-01

    A framework is given for explaining anomalous results of neutrino mass experiments that measure the high energy electron spectrum of tritium {beta} decay. The experimental results have been fit to a negative neutrino mass square. We show that there is a consistent phenomenological interpretation due to a positive mass tau neutrino component of the {beta} decay spectrum, with strong near threshold final state interactions with the He nucleus. If this enhancement is due to new interactions between low energy tau neutrinos and nuclei, then the tritium 0 decay experiments could be used as detectors for cosmic background tau neutrinos. The model predicts a distinctive spectrum shape that is consistent with a recent high statistics LLNL experiment. A fit to the experiment gives a tau neutrino mass of 23 eV. Tau neutrinos of this mass would dominate the mass of the universe. Requirements for a theoretical model are given, as well as models that realize different aspects of these requirements. While qualitatively successful, the theoretical models have such severe quantitative difficulties that the accuracy of the molecular physics of the T-{sup 3}He ion, assumed in the analysis of the experimental data, is called into question.

  12. Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam.

    PubMed

    Abe, K; Adam, J; Aihara, H; Akiri, T; Andreopoulos, C; Aoki, S; Ariga, A; Ariga, T; Assylbekov, S; Autiero, D; Barbi, M; Barker, G J; Barr, G; Bass, M; Batkiewicz, M; Bay, F; Bentham, S W; Berardi, V; Berger, B E; Berkman, S; Bertram, I; Bhadra, S; Blaszczyk, F D M; Blondel, A; Bojechko, C; 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; Christodoulou, G; Clifton, A; Coleman, J; Coleman, S J; Collazuol, G; Connolly, K; Cremonesi, L; Curioni, A; Dabrowska, A; Danko, I; Das, R; Davis, S; de Perio, P; De Rosa, G; Dealtry, T; Dennis, S R; Densham, C; Di Lodovico, F; Di Luise, S; Drapier, O; Duboyski, T; Duffy, K; Dufour, F; Dumarchez, J; Dytman, S; Dziewiecki, M; Emery, S; Ereditato, A; Escudero, L; Finch, A J; Frank, E; Friend, M; Fujii, Y; Fukuda, Y; Furmanski, A P; Galymov, V; Gaudin, A; Giffin, S; Giganti, C; Gilje, K; Golan, T; Gomez-Cadenas, J J; Gonin, M; Grant, N; Gudin, D; Hadley, D R; Haesler, A; Haigh, M D; Hamilton, P; Hansen, D; Hara, T; Hartz, M; Hasegawa, T; Hastings, N C; Hayato, Y; Hearty, C; Helmer, R L; Hierholzer, M; Hignight, J; Hillairet, A; Himmel, A; Hiraki, T; Hirota, S; Holeczek, J; Horikawa, S; Huang, K; Ichikawa, A K; Ieki, K; Ieva, M; Ikeda, M; Imber, J; Insler, J; Irvine, T J; Ishida, T; Ishii, T; Ives, S J; Iyogi, K; Izmaylov, A; Jacob, A; Jamieson, B; Johnson, R A; Jo, J H; Jonsson, P; Joo, K K; Jung, C K; Kaboth, A C; Kajita, T; Kakuno, H; Kameda, J; Kanazawa, Y; Karlen, D; Karpikov, I; Kearns, E; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kikawa, T; Kilinski, A; Kim, J; Kim, S B; Kisiel, J; Kitching, P; Kobayashi, T; Kogan, G; Kolaceke, A; Konaka, A; Kormos, L L; Korzenev, A; Koseki, K; Koshio, Y; Kreslo, I; Kropp, W; Kubo, H; Kudenko, Y; Kumaratunga, S; Kurjata, R; Kutter, T; Lagoda, J; Laihem, K; Laveder, M; Lawe, M; Lazos, M; Lee, K P; Licciardi, C; Lim, I T; Lindner, T; Lister, C; Litchfield, R P; Longhin, A; Lopez, G D; Ludovici, L; Macaire, M; Magaletti, L; Mahn, K; Malek, M; Manly, S; Marino, A D; Marteau, J; Martin, J F; Maruyama, T; Marzec, J; Masliah, P; Mathie, E L; Matveev, V; Mavrokoridis, K; Mazzucato, E; McCarthy, M; McCauley, N; McFarland, K S; McGrew, C; Metelko, C; Mijakowski, P; Miller, C A; Minamino, A; Mineev, O; Mine, S; Missert, A; Miura, M; Monfregola, L; Moriyama, S; Mueller, Th A; Murakami, A; Murdoch, M; Murphy, S; Myslik, J; Nagasaki, T; Nakadaira, T; Nakahata, M; Nakai, T; Nakamura, K; Nakayama, S; Nakaya, T; Nakayoshi, K; Naples, D; Nielsen, C; Nirkko, M; Nishikawa, K; Nishimura, Y; O'Keeffe, H M; Ohta, R; Okumura, K; Okusawa, T; Oryszczak, W; Oser, S M; Otani, M; Owen, R A; Oyama, Y; Pac, M Y; Palladino, V; Paolone, V; Payne, D; Pearce, G F; Perevozchikov, O; Perkin, J D; Petrov, Y; Pinzon Guerra, E S; Pistillo, C; Plonski, P; Poplawska, E; Popov, B; Posiadala, 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; Retiere, F; Robert, A; Rodrigues, P A; Rondio, E; Roth, S; Rubbia, A; Ruterbories, D; Sacco, R; Sakashita, K; Sánchez, F; Sato, F; Scantamburlo, E; Scholberg, K; Schwehr, J; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Sgalaberna, D; Shiozawa, M; Short, S; Shustrov, Y; Sinclair, P; Smith, B; Smith, R J; 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; Szeglowski, T; Tacik, R; Tada, M; Takahashi, S; Takeda, A; Takeuchi, Y; Tanaka, H K; Tanaka, H A; Tanaka, M M; Taylor, I J; 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; Ueno, K; Vacheret, A; Vagins, M; Vasseur, G; Wachala, T; Waldron, A V; Walter, C W; Wark, D; 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; Yen, S; Yershov, N; Yokoyama, M; Yuan, T; Zalewska, A; Zalipska, J; Zambelli, L; Zaremba, K; Ziembicki, M; Zimmerman, E D; Zito, M; Zmuda, J

    2013-11-22

    The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×10(20) protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(θ23)=0.514±0.082 and mass splitting |Δm(32)(2)|=2.44(-0.15)(+0.17)×10(-3) eV2/c4. Our result corresponds to the maximal oscillation disappearance probability. PMID:24313479

  13. Neutrino floor at ultralow threshold

    NASA Astrophysics Data System (ADS)

    Strigari, Louis E.

    2016-05-01

    By lowering their energy threshold, direct dark matter searches can reach the neutrino floor with experimental technology that is now in development. The 7Be flux can be detected with ˜10 eV nuclear recoil energy threshold and 50 kg/yr exposure. The p e p flux can be detected with ˜3 ton/yr exposure, and the first detection of the CNO flux is possible with similar exposure. The p p flux can be detected with threshold of ˜eV and only ˜ kg /yr exposure. These can be the first pure neutral current measurements of the low-energy solar neutrino flux. Measuring this flux is important for low mass dark matter searches and for understanding the solar interior.

  14. Neutrino magnetic moment

    SciTech Connect

    Chang, D. . Dept. of Physics and Astronomy Fermi National Accelerator Lab., Batavia, IL ); Senjanovic, G. . Dept. of Theoretical Physics)

    1990-01-01

    We review attempts to achieve a large neutrino magnetic moment ({mu}{sub {nu}} {le} 10{sup {minus}11}{mu}{sub B}), while keeping neutrino light or massless. The application to the solar neutrino puzzle is discussed. 24 refs.

  15. Chiral transport of neutrinos in supernovae: Neutrino-induced fluid helicity and helical plasma instability

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naoki

    2016-03-01

    Chirality of neutrinos modifies the conventional kinetic theory and hydrodynamics, leading to unusual chiral transport related to quantum anomalies in field theory. We argue that these corrections have new phenomenological consequences for hot and dense neutrino gases, especially in core-collapse supernovae. We find that the neutrino density can be converted to the fluid helicity through the chiral vortical effect. This fluid helicity effectively acts as a chiral chemical potential for electrons via the momentum exchange with neutrinos and induces a "helical plasma instability" that generates a strong helical magnetic field. This provides a new mechanism for converting the gravitational energy released by the core collapse to the electromagnetic energy and potentially explains the origin of magnetars. The other possible applications of the neutrino chiral transport theory are also discussed.

  16. Probing neutrinos from Planck and forthcoming galaxy redshift surveys

    NASA Astrophysics Data System (ADS)

    Takeuchi, Yoshitaka; Kadota, Kenji

    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 Script 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 lesssim0.005 eV with the predicted 1-σ uncertainties taken into account.

  17. Observation of high energy neutrinos with IceCube

    NASA Astrophysics Data System (ADS)

    Karle, Albrecht

    2015-04-01

    High energy cosmic rays have been observed up to extremely high energies of more than 1020 eV. The mechanism of their acceleration and their sources are, however, still largely unknown. Numerous scenarios suggest that neutrinos are produced in collisions of cosmic rays with matter or radiation fields in the source region. Because neutrinos are neither absorbed nor deflected, they will point directly back to their sources making them a unique tool for high energy particle astronomy. The IceCube neutrino detector at the South Pole, in full operation since 2011, uses more than a billion tons of natural ice as a target for neutrino detection. More than 50,000 atmospheric neutrinos at the TeV energy scale are being detected per year. The first several years of data have provided compelling evidence for a flux of neutrinos of astrophysical origin. The data include the detection of tens of neutrinos per year with energies above 1014 eV - the highest energy leptons ever observed. The data are consistent with expectations from an extragalactic neutrino flux, however a galactic contribution cannot be excluded with current data. I will review the recent findings obtained with IceCube and compare data with expectations. New strategies such as multimessenger approaches where data from IceCube are correlated with observations of gamma rays and other telescope data will be discussed.

  18. Probing neutrinos from Planck and forthcoming galaxy redshift surveys

    SciTech Connect

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

    2014-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  20. Ultra-high Energy Neutrinos from Gamma-Ray Burst Afterglows Using the Swift-UVOT Data

    NASA Astrophysics Data System (ADS)

    Nir, Guy; Guetta, Dafne; Landsman, Hagar; Behar, Ehud

    2016-02-01

    We consider a sample of 107 gamma-ray bursts (GRBs) for which early ultra-violet emission was measured by Swift and extrapolate the photon intensity to lower energies. Protons accelerated in the GRB jet may interact with such photons to produce charged pions and subsequently ultra high energy neutrinos {\\varepsilon }ν ≥slant {10}16 eV. We use simple energy conversion efficiency arguments to predict the maximal neutrino flux expected from each GRB. We estimate the neutrino detection rate at large area radio based neutrino detectors and conclude that the early afterglow neutrino emission is too weak to be detected even by next generation neutrino observatories.

  1. NEUTRINO FACTORIES - PHYSICS POTENTIALS.

    SciTech Connect

    PARSA,Z.

    2001-02-16

    The recent results from Super-Kamiokande atmospheric and solar neutrino observations opens a new era in neutrino physics and has sparked a considerable interest in the physics possibilities with a Neutrino Factory based on the muon storage ring. We present physics opportunities at a Neutrino Factory, and prospects of Neutrino oscillation experiments. Using the precisely known flavor composition of the beam, one could envision an extensive program to measure the neutrino oscillation mixing matrix, including possible CP violating effects. These and Neutrino Interaction Rates for examples of a Neutrino Factory at BNL (and FNAL) with detectors at Gran Sasso, SLAC and Sudan are also presented.

  2. Neutrinos: Theory and Phenomenology

    SciTech Connect

    Parke, Stephen

    2013-10-22

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

  3. Direct detection of relic active and sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Li, Yu-Feng

    2016-05-01

    Both active and sterile sub-eV neutrinos can form the cosmic neutrino background in the early Universe. We consider the beta-decaying (e.g., 3H) and EC-decaying (e.g., 163Ho) nuclei as the promising targets to capture relic neutrinos in the laboratory. We calculate the capture rates of relic electron neutrinos and antineutrinos against the corresponding beta decay or electron capture (EC) decay backgrounds in the (3+Ns) flavor mixing scheme, and discuss the future prospect in terms of the PTOLEMY project. We stress that such direct measurements of hot DM might not be hopeless in the long term.

  4. Searches for massive neutrinos in nuclear beta decay

    SciTech Connect

    Jaros, J.A.

    1992-10-01

    The status of searches for massive neutrinos in nuclear beta decay is reviewed. The claim by an ITEP group that the electron antineutrino mass > 17eV has been disputed by all the subsequent experiments. Current measurements of the tritium beta spectrum limit m{sub {bar {nu}}e} < 10 eV. The status of the 17 keV neutrino is reviewed. The strong null results from INS Tokyo and Argonne, and deficiencies in the experiments which reported positive effects, make it unreasonable to ascribe the spectral distortions seen by Simpson, Hime, and others to a 17keV neutrino. Several new ideas on how to search for massive neutrinos in nuclear beta decay are discussed.

  5. Constraints on neutrino masses from future cosmological observations

    SciTech Connect

    Hirano, Koichi

    2014-05-02

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

  6. Calculating Neutrino Oscillations with Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Linehan, Bryan

    2014-09-01

    In particle physics, it is currently known that three types of neutrinos exist that interact via the weak force. Referred to as ``flavors,'' they are distinguishable and named for the lepton they produce through charged current interactions: electron, muon, and tau. In a process called neutrino oscillation, one flavor of neutrino can change into another flavor as it propagates through space. At the moment, mild discrepancies between expected and measured neutrino oscillations suggest that more types of neutrinos that do not interact via the weak force exist: sterile neutrinos. The goal of this project was to calculate non-sterile flavor oscillation probabilities when 1, 2 or 3 sterile neutrinos were assumed to exist. An application has been written in Mathematica that calculates these probabilities with the neutrino masses, linear relationships between mass and flavor states, values of CP symmetry violating constants, and constant densities of media in which the neutrinos propagate set as parameters. The application was published online for researchers to use as a tool when considering the existence of sterile neutrinos. In the immediate future, the insights this application gives into neutrino oscillations will be studied and reported. In particle physics, it is currently known that three types of neutrinos exist that interact via the weak force. Referred to as ``flavors,'' they are distinguishable and named for the lepton they produce through charged current interactions: electron, muon, and tau. In a process called neutrino oscillation, one flavor of neutrino can change into another flavor as it propagates through space. At the moment, mild discrepancies between expected and measured neutrino oscillations suggest that more types of neutrinos that do not interact via the weak force exist: sterile neutrinos. The goal of this project was to calculate non-sterile flavor oscillation probabilities when 1, 2 or 3 sterile neutrinos were assumed to exist. An application

  7. Enhanced tau neutrino appearance through invisible decay

    NASA Astrophysics Data System (ADS)

    Pagliaroli, Giulia; Di Marco, Natalia; Mannarelli, Massimo

    2016-06-01

    The decay of neutrino mass eigenstates leads to a change of the conversion and survival probability of neutrino flavor eigenstates. Exploiting the recent results released by the long-baseline OPERA experiment we perform the statistical investigation of the neutrino invisible decay hypothesis in the νμ→ντ appearance channel. We find that the neutrino decay provides an enhancement of the expected tau appearance signal with respect to the standard oscillation scenario for the long-baseline OPERA experiment. The increase of the νμ→ντ conversion probability by the decay of one of the mass eigenstates is due to a reduction of the "destructive interference" among the different massive neutrino components. Despite data showing a very mild preference for invisible decays with respect to the oscillations only hypothesis, we provide an upper limit for the neutrino decay lifetime in this channel of τ3/m3≳1.3 ×10-13 s /eV at the 90% confidence level.

  8. Collisional production of sterile neutrinos via secret interactions and cosmological implications

    NASA Astrophysics Data System (ADS)

    Mirizzi, Alessandro; Mangano, Gianpiero; Pisanti, Ofelia; Saviano, Ninetta

    2015-01-01

    Secret interactions among sterile neutrinos have been recently proposed as an escape route to reconcile eV sterile neutrino hints from short-baseline anomalies with cosmological observations. In particular models with coupling gX≳1 0-2 and gauge boson mediators X with MX≲10 MeV lead to large matter potential suppressing the sterile neutrino production before the neutrino decoupling. With this choice of parameter ranges, big-bang nucleosynthesis is left unchanged and gives no bound on the model. However, we show that at lower temperatures when active-sterile oscillations are no longer matter suppressed, sterile neutrinos are still in a collisional regime, due to their secret self-interactions. The interplay between vacuum oscillations and collisions leads to a scattering-induced decoherent production of sterile neutrinos with a fast rate. This process is responsible for a flavor equilibration among the different neutrino species. We explore the effect of this large sterile neutrino population on cosmological observables. We find that a signature of strong secret interactions would be a reduction of the effective number of neutrinos Neff at matter radiation equality down to 2.7. Moreover, for MX≳gX MeV sterile neutrinos would be free-streaming before becoming nonrelativistic and they would affect the large-scale structure power spectrum. As a consequence, for this range of parameters we find a tension of an eV mass sterile state with cosmological neutrino mass bounds.

  9. Impact of Neutrino Flavor Oscillations on the Neutrino-Driven Wind Nucleosynthesis of an Electron-Capture Supernova

    NASA Astrophysics Data System (ADS)

    Pllumbi, Else; Tamborra, Irene; Wanajo, Shinya; Janka, Hans-Thomas; Hüdepohl, Lorenz

    2015-08-01

    Neutrino oscillations, especially to light sterile states, can affect nucleosynthesis yields because of their possible feedback effect on the electron fraction (Ye). For the first time, we perform nucleosynthesis calculations for neutrino-driven wind trajectories from the neutrino-cooling phase of an 8.8 {M}⊙ electron-capture supernova (SN), whose hydrodynamic evolution was computed in spherical symmetry with sophisticated neutrino transport and whose Ye evolution was post-processed by including neutrino oscillations between both active and active-sterile flavors. We also take into account the α-effect as well as weak magnetism and recoil corrections in the neutrino absorption and emission processes. We observe effects on the Ye evolution that depend in a subtle way on the relative radial positions of the sterile Mikheyev-Smirnov-Wolfenstein resonances, on collective flavor transformations, and on the formation of α particles. For the adopted SN progenitor, we find that neutrino oscillations, also to a sterile state with eV mass, do not significantly affect the element formation and in particular cannot make the post-explosion wind outflow neutron-rich enough to activate a strong r-process. Our conclusions become even more robust when, in order to mimic equation-of-state-dependent corrections due to nucleon potential effects in the dense-medium neutrino opacities, six cases with reduced Ye in the wind are considered. In these cases, despite the conversion of active neutrinos to sterile neutrinos, Ye increases or is not significantly lowered compared to the values obtained without oscillations and active flavor transformations. This is a consequence of a complicated interplay between sterile-neutrino production, neutrino-neutrino interactions, and α-effect.

  10. The cosmic neutrino background

    NASA Technical Reports Server (NTRS)

    Dar, Arnon

    1991-01-01

    The cosmic neutrino background is expected to consist of relic neutrinos from the big bang, of neutrinos produced during nuclear burning in stars, of neutrinos released by gravitational stellar collapse, and of neutrinos produced by cosmic ray interactions with matter and radiation in the interstellar and intergalactic medium. Formation of baryonic dark matter in the early universe, matter-antimatter annihilation in a baryonic symmetric universe, and dark matter annihilation could have also contributed significantly to the cosmic neutrino background. The purpose of this paper is to review the properties of these cosmic neutrino backgrounds, the indirect evidence for their existence, and the prospects for their detection.

  11. Low-energy neutrinos

    NASA Astrophysics Data System (ADS)

    Ludhova, Livia

    2016-05-01

    There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the field of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artificial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three fields, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.

  12. Neutrinos in Nuclear Physics

    SciTech Connect

    McKeown, Bob

    2015-06-01

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

  13. Experimental limit on the cosmic diffuse ultrahigh energy neutrino flux.

    PubMed

    Gorham, P W; Hebert, C L; Liewer, K M; Naudet, C J; Saltzberg, D; Williams, D

    2004-07-23

    We report results from 120 h of live time with the Goldstone lunar ultrahigh energy neutrino experiment (GLUE). The experiment searches for < or = 10 ns microwave pulses from the lunar regolith, appearing in coincidence at two large radio telescopes separated by 22 km and linked by optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of > or = 100 EeV (1 EeV = 10(18) eV neutrinos in the lunar regolith. No candidates are yet seen, and the implied limits constrain several current models for ultrahigh energy neutrino fluxes. PMID:15323748

  14. Constraints on the mass of unstable neutrinos from the supernova

    NASA Astrophysics Data System (ADS)

    Liu, Jiang

    1987-11-01

    The cosmological constraint together with the information obtained from the supernova could be used to give a lower bound on the mass of unstable neutrinos. It is shown that if the only viable channel for the unstable neutrino decay is through three lighter neutrinos, the mass of this particle should be heavier than about 500 eV. I wish to thank Professor Ling-Fong Li and Professor Lincoln Wolfenstein for valuable discussions. This work was supported in part by the US Department of Energy.

  15. Simple neutrino mass matrix with only two free parameters

    NASA Astrophysics Data System (ADS)

    Nishiura, Hiroyuki; Fukuyama, Takeshi

    2014-09-01

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

  16. Experimental Limit on the Cosmic Diffuse Ultrahigh Energy Neutrino Flux

    NASA Astrophysics Data System (ADS)

    Gorham, P. W.; Hebert, C. L.; Liewer, K. M.; Naudet, C. J.; Saltzberg, D.; Williams, D.

    2004-07-01

    We report results from 120h of live time with the Goldstone lunar ultrahigh energy neutrino experiment (GLUE). The experiment searches for ≤10 ns microwave pulses from the lunar regolith, appearing in coincidence at two large radio telescopes separated by 22km and linked by optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of ≥100 EeV (1 EeV=1018 eV neutrinos in the lunar regolith. No candidates are yet seen, and the implied limits constrain several current models for ultrahigh energy neutrino fluxes.

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

    SciTech Connect

    Boillos, Juan Manuel; Moya de Guerra, Elvira

    2013-06-10

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

  18. SalSA: A Teraton UHE Neutrino Detector

    SciTech Connect

    Reil, Kevin; /SLAC

    2006-04-19

    The observed spectrum of ultra-high energy cosmic rays virtually guarantees the presence of ultra-high energy neutrinos due to their interaction with the cosmic microwave background. Unlike cosmic rays, each of these neutrinos will point back directly to its source and will arrive at the Earth unattenuated, from sources perhaps as distant as z = 20. The neutrino telescopes currently under construction, should discover a handful of these events, probably too few for detailed study. This paper describes how an array of VHF and UHF antennas embedded in a large salt dome, SalSA (Salt dome Shower Array) promises to yield a teraton detector (> 500 km{sup 3 sr}) for contained neutrino events with energies above 10{sup 17} eV. Our simulations show that such a detector may observe several hundreds of these neutrinos over its lifetime with excellent angular resolution providing source locations.

  19. Radio detection of ultra-high energy cosmic neutrinos

    SciTech Connect

    Vieregg, Abigail G.

    2015-07-15

    Ultra-high energy (UHE) neutrino astronomy constitutes a new window of observation onto the UHE universe. The detection and characterization of astrophysical neutrinos at the highest energies (E> 10{sup 18} eV) would reveal the sources of high-energy cosmic rays, the highest energy particles ever seen, and would constrain the evolution of such sources over time. UHE neutrino astrophysics also allows us to probe weak interaction couplings at energies much greater than those available at particle colliders. One promising way of detecting the highest energy neutrinos is through the radio emission created when they interact in a large volume of dielectric, such as ice. Here I discuss current results and future efforts to instrument large volumes of detector material with radio antennas to detect, point back, and characterize the energy of UHE astrophysical neutrinos.

  20. Search for a light sterile neutrino at Daya Bay.

    PubMed

    An, F P; Balantekin, A B; Band, H R; Beriguete, W; Bishai, M; Blyth, S; Butorov, I; Cao, G F; Cao, J; Chan, Y L; Chang, J F; Chang, L C; Chang, Y; Chasman, C; Chen, H; Chen, Q Y; Chen, S M; Chen, X; Chen, X; Chen, Y X; Chen, Y; Cheng, Y P; Cherwinka, J J; Chu, M C; Cummings, J P; de Arcos, J; Deng, Z Y; Ding, Y Y; Diwan, M V; Draeger, E; Du, X F; Dwyer, D A; Edwards, W R; Ely, S R; Fu, J Y; Ge, L Q; Gill, R; Gonchar, M; Gong, G H; Gong, H; Grassi, M; Gu, W Q; Guan, M Y; Guo, X H; Hackenburg, R W; Han, G H; Hans, S; He, M; Heeger, K M; Heng, Y K; Hinrichs, P; Hor, Y K; Hsiung, Y B; Hu, B Z; Hu, L M; Hu, L J; Hu, T; Hu, W; Huang, E C; Huang, H; Huang, X T; Huber, P; Hussain, G; Isvan, Z; Jaffe, D E; Jaffke, P; Jen, K L; Jetter, S; Ji, X P; Ji, X L; Jiang, H J; Jiao, J B; Johnson, R A; Kang, L; Kettell, S H; Kramer, M; Kwan, K K; Kwok, M W; Kwok, T; Lai, W C; Lau, K; Lebanowski, L; Lee, J; Lei, R T; Leitner, R; Leung, A; Leung, J K C; Lewis, C A; Li, D J; Li, F; Li, G S; Li, Q J; Li, W D; Li, X N; Li, X Q; Li, Y F; Li, Z B; Liang, H; Lin, C J; Lin, G L; Lin, P Y; Lin, S K; Lin, Y C; Ling, J J; Link, J M; Littenberg, L; Littlejohn, B R; Liu, D W; Liu, H; Liu, J L; Liu, J C; Liu, S S; Liu, Y B; Lu, C; Lu, H Q; Luk, K B; Ma, Q M; Ma, X Y; Ma, X B; Ma, Y Q; McDonald, K T; McFarlane, M C; McKeown, R D; Meng, Y; Mitchell, I; Monari Kebwaro, J; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Nemchenok, I; Ngai, H Y; Ning, Z; Ochoa-Ricoux, J P; Olshevski, A; Patton, S; Pec, V; Peng, J C; Piilonen, L E; Pinsky, L; Pun, C S J; Qi, F Z; Qi, M; Qian, X; Raper, N; Ren, B; Ren, J; Rosero, R; Roskovec, B; Ruan, X C; Shao, B B; Steiner, H; Sun, G X; Sun, J L; Tam, Y H; Tang, X; Themann, H; Tsang, K V; Tsang, R H M; Tull, C E; Tung, Y C; Viren, B; Vorobel, V; Wang, C H; Wang, L S; Wang, L Y; Wang, M; Wang, N Y; Wang, R G; Wang, W; Wang, W W; Wang, X; Wang, Y F; Wang, Z; Wang, Z; Wang, Z M; Webber, D M; Wei, H Y; Wei, Y D; Wen, L J; Whisnant, K; White, C G; Whitehead, L; Wise, T; Wong, H L H; Wong, S C F; Worcester, E; Wu, Q; Xia, D M; Xia, J K; Xia, X; Xing, Z Z; Xu, J Y; Xu, J L; Xu, J; Xu, Y; Xue, T; Yan, J; Yang, C C; Yang, L; Yang, M S; Yang, M T; Ye, M; Yeh, M; Yeh, Y S; Young, B L; Yu, G Y; Yu, J Y; Yu, Z Y; Zang, S L; Zeng, B; Zhan, L; Zhang, C; Zhang, F H; Zhang, J W; Zhang, Q M; Zhang, Q; Zhang, S H; Zhang, Y C; Zhang, Y M; Zhang, Y H; Zhang, Y X; Zhang, Z J; Zhang, Z Y; Zhang, Z P; Zhao, J; Zhao, Q W; Zhao, Y; Zhao, Y B; Zheng, L; Zhong, W L; Zhou, L; Zhou, Z Y; Zhuang, H L; Zou, J H

    2014-10-01

    A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored. PMID:25325631

  1. Inflationary freedom and cosmological neutrino constraints

    NASA Astrophysics Data System (ADS)

    de Putter, Roland; Linder, Eric V.; Mishra, Abhilash

    2014-05-01

    The most stringent bounds on the absolute neutrino mass scale come from cosmological data. These bounds are made possible because massive relic neutrinos affect the expansion history of the universe and lead to a suppression of matter clustering on scales smaller than the associated free streaming length. However, the resulting effect on cosmological perturbations is relative to the primordial power spectrum of density perturbations from inflation, so freedom in the primordial power spectrum affects neutrino mass constraints. Using measurements of the cosmic microwave background (CMB), the galaxy power spectrum and the Hubble constant, we constrain neutrino mass and number of species for a model-independent primordial power spectrum. Describing the primordial power spectrum by a 20-node spline, we find that the neutrino mass upper limit is a factor 3 weaker than when a power law form is imposed, if only CMB data are used. The primordial power spectrum itself is constrained to better than 10% in the wave vector range k ≈0.01-0.25 Mpc-1. Galaxy clustering data and a determination of the Hubble constant play a key role in reining in the effects of inflationary freedom on neutrino constraints. The inclusion of both eliminates the inflationary freedom degradation of the neutrino mass bound, giving for the sum of neutrino masses Σmν<0.18 eV (at 95% confidence level, Planck+BOSS+H0), approximately independent of the assumed primordial power spectrum model. When allowing for a free effective number of species, Neff, the joint constraints on Σmν and Neff are loosened by a factor 1.7 when the power law form of the primordial power spectrum is abandoned in favor of the spline parametrization.

  2. Extremely high energy neutrinos from cosmic strings

    SciTech Connect

    Berezinsky, Veniamin; Sabancilar, Eray; Vilenkin, Alexander

    2011-10-15

    Superstring theory and other supersymmetric theories predict the existence of relatively light, weakly interacting scalar particles, called moduli, with a universal form of coupling to matter. Such particles can be emitted from cusps of cosmic strings, where extremely large Lorentz factors are achieved momentarily. Highly boosted modulus bursts emanating from cusps subsequently decay into gluons; they generate parton cascades which in turn produce large numbers of pions and then neutrinos. Because of very large Lorentz factors, extremely high energy neutrinos, up to the Planck scale and above, are produced. For some model parameters, the predicted flux of neutrinos with energies > or approx. 10{sup 21} eV is observable by JEM-EUSO and by the future large radio detectors LOFAR and SKA.

  3. Tachyonic neutrinos and the neutrino masses

    NASA Astrophysics Data System (ADS)

    Ehrlich, Robert

    2013-01-01

    With a recent claim of superluminal neutrinos shown to be in error, 2012 may not be a propitious time to consider the evidence that one or more neutrinos may indeed be tachyons. Nevertheless, there are a growing number of observations that continue to suggest this possibility - albeit with an mν2<0 having a much smaller magnitude than was implied by the original OPERA claim. One recently published non-standard analysis of SN 1987A neutrinos supports a tachyonic mass eigenstate, and here we show how it leads to 3 + 3 mirror neutrino model having an unconventional mass hierarchy. The model incorporates one superluminal active-sterile neutrino pair, and it is testable in numerous ways, including making a surprising prediction about an unpublished aspect of the SN 1987A neutrinos. Additional supporting evidence involving earlier analyses of cosmic rays is summarized to add credence to the tachyonic neutrino hypothesis.

  4. Measuring neutrino masses with weak lensing

    SciTech Connect

    Wong, Yvonne Y. Y.

    2006-11-17

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

  5. Neutrino Oscillations with Three Active and Three Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Kisslinger, Leonard S.

    2016-07-01

    This is an extension of estimates of the probability of μ to e neutrino oscillation with one sterile neutrino to three sterile neutrinos, using a 6x6 matrix. Since the mixing angle for only one sterile neutrino has been experimentally determined, we estimate the μ to e neutrino oscillation probability with different mixing angles for two of the sterile neutrinos.

  6. How Do The EV Project Participants Feel About Their EVS?

    SciTech Connect

    Francfort, James E.

    2015-02-01

    The EV Project is an infrastructure study that enrolled over 8,000 residential participants. These participants purchased or leased a Nissan Leaf battery electric vehicle (BEV) or Chevrolet Volt extended range electric vehicle (EREV) and were among the first to explore this new electric drive technology. Collectively, BEV, EREV, and plug-in hybrid electric vehicles (PHEVs) are called plug-in electric vehicles (PEVs). The EV Project participants were very cooperative and enthusiastic about their participation in the project and very supportive in providing feedback and information. The information and attitudes of these participants concerning their experience with their PEVs were solicited using a survey in June 2013. At that time, some had up to 3 years of experience with their PEVs.

  7. Neutrino Physics at Fermilab

    ScienceCinema

    Saoulidou, Niki

    2010-01-08

    Neutrino oscillations provide the first evidence for physics beyond the Standard Model. I will briefly overview the neutrino "hi-story", describing key discoveries over the past decades that shaped our understanding of neutrinos and their behavior. Fermilab was, is and hopefully will be at the forefront of the accelerator neutrino experiments.  NuMI, the most powerful accelerator neutrino beam in the world has ushered us into the era of precise measurements. Its further upgrades may give a chance to tackle the remaining mysteries of the neutrino mass hierarchy and possible CP violation.

  8. Experimental Neutrino Physics: Final Report

    SciTech Connect

    Lane, Charles E.; Maricic, Jelena

    2012-09-05

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

  9. Measuring Active-Sterile Neutrino Oscillations with a Stopped Pion Neutrino Source

    NASA Astrophysics Data System (ADS)

    van de Water, Richard; Louis, Bill; Mills, Geoff

    2007-04-01

    The question of the existence of light sterile neutrinos is of great interest in many areas of particle physics, astrophysics, and cosmology. Furthermore, should the MiniBooNE experiment at Fermilab confirm the LSND oscillation signal, then new measurements are required to identify the mechanism responsible for these oscillations. Possibilities include sterile neutrinos, CP or CPT violation, variable mass neutrinos, and Lorentz violation. Here we consider an experiment at a stopped pion neutrino source (the Spallation Neutron Source at ORNL) to determine if active-sterile neutrino oscillations with δm ^2 greater than 0.1 eV^2 can account for the signal. By exploiting stopped +circ decay to produce a monoenergetic νμ source, and measuring the rate of the neutral current reaction νx0.05in ^12C ->νx0.05in ^12C^*(15.11) as a function of distance from the source, we show that a convincing test for active-sterile neutrino oscillations can be performed.

  10. Constraints on neutrino masses from weak lensing

    SciTech Connect

    Ichiki, Kiyotomo; Takada, Masahiro; Takahashi, Tomo

    2009-01-15

    Weak lensing (WL) distortions of distant galaxy images are sensitive to neutrino masses by probing the suppression effect on clustering strengths of total matter in large-scale structure. We use the latest measurements of WL correlations, the Canada-France-Hawaii Telescope Legacy Survey data, to explore constraints on neutrino masses. We find that, while the WL data alone cannot place a stringent limit on neutrino masses due to parameter degeneracies, the constraint can be significantly improved when combined with other cosmological probes, such as the WMAP 5-year data (WMAP5) and the distance measurements of type-Ia supernovae (SNe) and baryon acoustic oscillations (BAO). The upper bounds on the sum of neutrino masses are , 0.76, and 0.54 eV (95% CL) for WL+WMAP5, WMAP5+SNe+BAO, and WL+WMAP5+SNe+BAO, respectively, assuming a flat {lambda}CDM model with finite-mass neutrinos. In deriving these constraints, our analysis includes the non-Gaussian covariances of the WL correlation functions to properly take into account significant correlations between different angles.

  11. Revisiting cosmological bounds on radiative neutrino lifetime

    SciTech Connect

    Mirizzi, Alessandro; Montanino, Daniele; Serpico, Pasquale D.

    2007-09-01

    Neutrino oscillation experiments and direct bounds on absolute masses constrain neutrino mass differences to fall into the microwave energy range, for most of the allowed parameter space. As a consequence of these recent phenomenological advances, older constraints on radiative neutrino decays based on diffuse background radiations and assuming strongly hierarchical masses in the eV range are now outdated. We thus derive new bounds on the radiative neutrino lifetime using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board the Cosmic Background Explorer. The lower bound on the lifetime is between a fewx10{sup 19} s and {approx}5x10{sup 20} s, depending on the neutrino mass ordering and on the absolute mass scale. However, due to phase space limitations, the upper bound in terms of the effective magnetic moment mediating the decay is not better than {approx}10{sup -8} Bohr magnetons. We also comment about possible improvements of these limits, by means of recent diffuse infrared photon background data. We compare these bounds with preexisting limits coming from laboratory or astrophysical arguments. We emphasize the complementarity of our results with others available in the literature.

  12. Searches for muon-to-electron (anti) neutrino flavor change

    NASA Astrophysics Data System (ADS)

    Louis, W. C.

    2009-07-01

    Employing an 800 MeV, high-intensity proton beam, the LSND experiment performed a sensitive search for neutrino oscillations and obtained evidence for ν→ν flavor change. Although the KARMEN experiment observed no such evidence, a joint analysis of the two experiments shows that the data sets are compatible with neutrino oscillations occurring either in a band from 0.2 to 1 eV 2 or in a region around 7 eV 2. The MiniBooNE experiment at Fermilab was designed to test the LSND evidence for neutrino oscillations [C. Athanassopoulos et al., Phys. Rev. Lett. 75, 2650 (1995); 77, 3082 (1996); 81, 1774 (1998); A. Aguilar et al., Phys. Rev. D 64, 112007 (2001)]. The MiniBooNE oscillation result in neutrino mode [A. Aguilar-Arevalo et al., Phys. Rev. Lett. 98, 231801 (2007); A. Aguilar-Arevalo et al. arXiv:0812.2243] shows no significant excess of events at higher energies ( Eν>475 MeV), although a sizeable excess is observed at lower energies ( Eν<475 MeV). The lack of a significant excess at higher energies allows MiniBooNE to rule out simple 2-ν oscillations as an explanation of the LSND signal. However, the low-energy excess is presently unexplained. Additional antineutrino data and NuMI data may allow the collaboration to determine whether the excess is due, for example, to a neutrino neutral-current radiative interaction or to neutrino oscillations involving sterile neutrinos and whether the excess is related to the LSND signal. If the excess is consistent with being due to sterile neutrinos or other new physics, then future experiments at FNAL (MicroBooNE & BooNE) or ORNL (OscSNS) or with the Low-Energy Neutrino Spectrometer (LENS) detector could confirm their existence.

  13. Searches for massive neutrinos in nuclear beta decay

    SciTech Connect

    Jaros, J.A.

    1992-10-01

    The status of searches for massive neutrinos in nuclear beta decay is reviewed. The claim by an ITEP group that the electron antineutrino mass > 17eV has been disputed by all the subsequent experiments. Current measurements of the tritium beta spectrum limit m[sub [bar [nu

  14. Supernova neutrino detection

    SciTech Connect

    Scholberg, K.

    2015-07-15

    In this presentation I summarize the main detection channels for neutrinos from core-collapse supernovae, and describe current status of and future prospects for supernova-neutrino-sensitive detectors worldwide.

  15. Solar Neutrino Problem

    DOE R&D Accomplishments Database

    Davis, R. Jr.; Evans, J. C.; Cleveland, B. T.

    1978-04-28

    A summary of the results of the Brookhaven solar neutrino experiment is given and discussed in relation to solar model calculations. A review is given of the merits of various new solar neutrino detectors that were proposed.

  16. Majorana phases, CP violation, sterile neutrinos and neutrinoless double-beta decay

    SciTech Connect

    Babič, Andrej; Šimkovic, Fedor

    2013-12-30

    CP violation plays a crucial role in the generation of the baryon asymmetry in the Universe. Within this context we investigate the possibility of CP violation in the lepton sector caused by Majorana neutrino mixing. Focus is put on the model including 1 sterile neutrino. Both cases of normal and inverted neutrino mass spectrum are considered. We address the question whether the Majorana phases can be measured in the neutrinoless double-beta decay experiments with sensitivity to the effective Majorana neutrino mass of the order of 10{sup −2} eV.

  17. SOX: search for short baseline neutrino oscillations with Borexino

    NASA Astrophysics Data System (ADS)

    Vivier, M.; Agostini, M.; Altenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; Choi, K.; Cribier, M.; D’Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Durero, M.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffliot, J.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, T.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jonquàres, N.; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kornoukhov, V.; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, B.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Scola, L.; Semenov, D.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Veyssiére, C.; Unzhakov, E.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.; Borexino collaboration

    2016-05-01

    The Borexino detector has convincingly shown its outstanding performances in the low energy regime through its accomplishments in the observation and study of the solar and geo neutrinos. It is then an ideal tool to perform a state of the art source-based experiment for testing the longstanding hypothesis of a fourth sterile neutrino with ~ eV2 mass, as suggested by several anomalies accumulated over the past three decades in source, reactor, and accelerator-based experiments. The SOX project aims at successively deploying two intense radioactive sources, made of Cerium (antineutrino) and Chromium (neutrino), respectively, in a dedicated pit located beneath the detector. The existence of such an ~ eV2 sterile neutrino would then show up as an unambiguous spatial and energy distortion in the count rate of neutrinos interacting within the active detector volume. This article reports on the latest developments about the first phase of the SOX experiment, namely CeSOX, and gives a realistic projection of CeSOX sensitivity to light sterile neutrinos in a simple (3+1) model.

  18. First indication of terrestrial matter effects on solar neutrino oscillation.

    PubMed

    Renshaw, A; Abe, K; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Tomura, T; Ueno, K; Yokozawa, T; Wendell, R A; Irvine, T; Kajita, T; Kaneyuki, K; Lee, K P; Nishimura, Y; Okumura, K; McLachlan, T; Labarga, L; Berkman, S; Tanaka, H A; Tobayama, S; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Goldhabar, M; Bays, K; Carminati, G; Kropp, W R; Mine, S; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Bronner, C; Hirota, S; Huang, K; Ieki, K; Ikeda, M; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Choi, K; Itow, Y; Mitsuka, G; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Yanagisawa, C; Ishino, H; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Yano, T; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Martens, K; Marti, Ll; Vagins, M R; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J

    2014-03-01

    We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2 ± 1.1(stat) ± 0.5(syst)]%, which deviates from zero by 2.7 σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4 × 10(-5)  eV(2) ≤ Δm 2(21) ≤ 7 × 10(-5) eV(2) and large mixing values of θ12, at the 68% C.L. PMID:24655245

  19. Neutrino Oscillation Physics

    SciTech Connect

    Kayser, Boris

    2012-06-01

    To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures. Neutrinos and photons are by far the most abundant elementary particles in the universe. Thus, if we would like to comprehend the universe, we must understand the neutrinos. Of course, studying the neutrinos is challenging, since the only known forces through which these electrically-neutral leptons interact are the weak force and gravity. Consequently, interactions of neutrinos in a detector are very rare events, so that very large detectors and intense neutrino sources are needed to make experiments feasible. Nevertheless, we have confirmed that the weak interactions of neutrinos are correctly described by the Standard Model (SM) of elementary particle physics. Moreover, in the last 14 years, we have discovered that neutrinos have nonzero masses, and that leptons mix. These discoveries have been based on the observation that neutrinos can change from one 'flavor' to another - the phenomenon known as neutrino oscillation. We shall explain the physics of neutrino oscillation, deriving the probability of oscillation in a new way. We shall also provide a very brief guide to references that can be used to study some major neutrino-physics topics other than neutrino oscillation.

  20. Leptogenesis with many neutrinos

    SciTech Connect

    Eisele, Marc-Thomas

    2008-02-15

    We consider leptogenesis in scenarios with many neutrino singlets. We find that the lower bound for the reheating temperature can be significantly relaxed with respect to the hierarchical three neutrino case. We further argue that the upper bound for the neutrino mass scale from leptogenesis gets significantly lifted in these scenarios. As a specific realization, we then discuss an extradimensional model, where the large number of neutrinos is provided by Kaluza-Klein excitations.

  1. Geo-neutrino Observation

    SciTech Connect

    Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.

    2009-12-17

    Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

  2. Sensitivity to Z -prime and nonstandard neutrino interactions from ultralow threshold neutrino-nucleus coherent scattering

    NASA Astrophysics Data System (ADS)

    Dutta, Bhaskar; Mahapatra, Rupak; Strigari, Louis E.; Walker, Joel W.

    2016-01-01

    We discuss prospects for probing Z -prime and nonstandard neutrino interactions using neutrino-nucleus coherent scattering with ultralow energy (˜10 eV ) threshold Si and Ge detectors. The analysis is performed in the context of a specific and contemporary reactor-based experimental proposal, developed in cooperation with the Nuclear Science Center at Texas A&M University, and referencing available technology based upon economical and scalable detector arrays. For expected exposures, we show that sensitivity to the Z -prime mass is on the order of several TeV and is complementary to the LHC search with low-mass detectors in the near term. This technology is also shown to provide sensitivity to the neutrino magnetic moment, at a level that surpasses terrestrial limits, and is competitive with more stringent astrophysical bounds. We demonstrate the benefits of combining silicon and germanium detectors for distinguishing between classes of models of new physics and for suppressing correlated systematic uncertainties.

  3. Neutrino oscillations with MINOS and MINOS+

    NASA Astrophysics Data System (ADS)

    Whitehead, L. H.

    2016-07-01

    The MINOS experiment ran from 2003 until 2012 and collected a data sample including 10.71 ×1020 protons-on-target (POT) of beam neutrinos, 3.36 ×1020 POT of beam antineutrinos and an atmospheric neutrino exposure of 37.88 kt yrs. The final measurement of the atmospheric neutrino oscillation parameters, Δ m322 and θ23, came from a full three flavour oscillation analysis of the combined CC νμ and CC ν‾μ beam and atmospheric samples and the CC νe and CC ν‾e appearance samples. This analysis yielded the most precise measurement of the atmospheric mass splitting Δ m322 performed to date. The results are | Δ m322 | = [ 2.28- 2.46 ] ×10-3 eV2 (68%) and sin2 ⁡θ23 = 0.35- 0.65 (90%) in the normal hierarchy, and | Δ m322 | = [ 2.32- 2.53 ] ×10-3 eV2 (68%) and sin2 ⁡θ23 = 0.34- 0.67 (90%) in the inverted hierarchy. The successor to MINOS in the NOνA era at FNAL, MINOS+, is now collecting data mostly in the 3- 10 GeV region, and an analysis of νμ disappearance using the first 2.99 ×1020 POT of data produced results very consistent with those from MINOS. Future data will further test the standard neutrino oscillation paradigm and allow for improved searches for exotic phenomena including sterile neutrinos, large extra dimensions and non-standard interactions.

  4. Neutrino Physics with Opera

    NASA Astrophysics Data System (ADS)

    Bertolin, Alessandro

    2011-10-01

    Neutrino physics with the OPERA experiment will be discussed in this paper. First the OPERA physic goal will be presented. A description of the neutrino beam and of the detector will follow. The analysis of the beam induced neutrino interactions will then be presented.

  5. Neutrino Detectors Review

    SciTech Connect

    D'Ambrosio, Nicola

    2005-10-12

    The neutrino physics is one of the most important research field and there are several experiments made and under construction focused on it. This paper will present a review on some detectors used for Solar Neutrinos detection, Atmospheric Neutrinos detection and in Long Baseline Experiments.

  6. Neutrino observations from the Sudbury Neutrino Observatory

    SciTech Connect

    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.; Buhler, 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.; 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,D.S.; McDonald, A.B.; McFarlane, K.; McGregor, G.; Meijer, 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.; Schulke, A.; Seifert, H.; Shatkay, M.; Simpson, J.J.; Sims, C.J.; et al.

    2001-09-24

    The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

  7. Neutrino Observations from the Sudbury Neutrino Observatory

    DOE R&D Accomplishments Database

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

    2001-09-24

    The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.

  8. Tight bonds between sterile neutrinos and dark matter

    SciTech Connect

    Bringmann, Torsten; Hasenkamp, Jasper; Kersten, Jörn E-mail: Jasper.Hasenkamp@nyu.edu

    2014-07-01

    Despite the astonishing success of standard ΛCDM cosmology, there is mounting evidence for a tension with observations at small and intermediate scales. We introduce a simple model where both cold dark matter (DM) and sterile neutrinos are charged under a new U(1){sub X} gauge interaction. The resulting DM self-interactions resolve the tension with the observed abundances and internal density structures of dwarf galaxies. At the same time, the sterile neutrinos can account for both the small hot DM component favored by cosmological observations and the neutrino anomalies found in short-baseline experiments.

  9. High-energy neutrinos from photomeson processes in blazars.

    PubMed

    Atoyan, A; Dermer, C D

    2001-11-26

    An important radiation field for photomeson neutrino production in blazars is shown to be the radiation field external to the jet. Assuming that protons are accelerated with the same power as electrons and injected with a -2 number spectrum, we predict that km(2) neutrino telescopes will > or similar to 1 neutrinos per year from flat spectrum radio quasars such as 3C 279. The escaping high-energy neutron and photon beams transport inner jet energy far from the black-hole engine, and could power synchrotron x-ray jets and FR II hot spots and lobes. PMID:11736392

  10. Finding evidence for massive neutrinos using 3D weak lensing

    SciTech Connect

    Kitching, T. D.; Heavens, A. F.; Verde, L.; Serra, P.; Melchiorri, A.

    2008-05-15

    In this paper we investigate the potential of 3D cosmic shear to constrain massive neutrino parameters. We find that if the total mass is substantial (near the upper limits from large scale structure, but setting aside the Ly alpha limit for now), then 3D cosmic shear+Planck is very sensitive to neutrino mass and one may expect that a next generation photometric redshift survey could constrain the number of neutrinos N{sub {nu}} and the sum of their masses m{sub {nu}}=im{sub i} to an accuracy of {delta}N{sub {nu}}{approx}0.08 and {delta}m{sub {nu}}{approx}0.03 eV, respectively. If in fact the masses are close to zero, then the errors weaken to {delta}N{sub {nu}}{approx}0.10 and {delta}m{sub {nu}}{approx}0.07 eV. In either case there is a factor 4 improvement over Planck alone. We use a Bayesian evidence method to predict joint expected evidence for N{sub {nu}} and m{sub {nu}}. We find that 3D cosmic shear combined with a Planck prior could provide 'substantial' evidence for massive neutrinos and be able to distinguish 'decisively' between many competing massive neutrino models. This technique should 'decisively' distinguish between models in which there are no massive neutrinos and models in which there are massive neutrinos with |N{sub {nu}}-3| > or approx. 0.35 and m{sub {nu}} > or approx. 0.25 eV. We introduce the notion of marginalized and conditional evidence when considering evidence for individual parameter values within a multiparameter model.

  11. Overcoming the high cost of EV batteries

    SciTech Connect

    Wright, S.R.

    1995-07-01

    Electric Vehicles (EV`s) are a solution to three major problems facing the US today. The commercialization of EV`s will reduce the growing trade deficit, provide economic gains from a new electric automobile industry, and help alleviate the air pollution problems encountered in many of America`s largest cities. The existence of EV`s is not the answer; their increasing use is. This increase in deployment will largely depend on vehicle price and not range limitations as many would have you believe. The price of an EV will be determined by the auto makers with their economics determining the ultimate price to the consumer. The cost of EV batteries is considered to be a major hurdle in achieving an affordable EV. Prices of EV batteries at this time cannot be controlled by the auto manufacturers. How high is this cost hurdle and what measures can be taken to reduce this obstacle and facilitate the successful commercialization of EV`s? This paper discusses a variety of alternatives. Each sector of industry may favor a particular solution, but, in order for the EV industry to thrive, all sectors must agree to work together to provide for customer needs.

  12. Neutrinos from AGN

    NASA Technical Reports Server (NTRS)

    Kazanas, Demosthenes; White, Nicholas E. (Technical Monitor)

    2000-01-01

    The great penetrating power of neutrinos makes them ideal probe of astrophysical sites and conditions inaccessible to other forms of radiation. These are the centers of stars (collapsing or not) and the centers of Active Galactic Nuclei (AGN). It has been suggested that AGN presented a very promising source of high energy neutrinos, possibly detectable by underwater neutrino detectors. This paper reviews the evolution of ideas concerning the emission of neutrinos from AGN in view of the more recent developments in gamma-ray astronomy and their implications for the neutrino emission from these class of objects.

  13. Nucleosynthesis and Neutrinos

    SciTech Connect

    Kajino, Toshitaka

    2011-05-06

    Neutrinos play the critical roles in nucleosynthesis of light-to-heavy mass nuclei in core-collapse supernovae. We study the nucleosynthesis induced by neutrino interactions and find suitable average neutrino temperatures in order to explain the observed solar system abundances of several isotopes {sup 7}Li, {sup 11}B, {sup 138}La and {sup 180}Ta. These isotopes are predominantly synthesized by the supernova {nu}-process. We also study the neutrino oscillation effects on their abundances and propose a method to determine the unknown neutrino oscillation parameters, i.e. {theta}{sub 13} and mass hierarchy.

  14. Direct Neutrino Mass Searches

    NASA Astrophysics Data System (ADS)

    VanDevender, B. A.

    2009-12-01

    Neutrino flavor oscillation experiments have demonstrated that the three Standard Model neutrino flavor eigenstates are mixed with three mass eigenstates whose mass eigenvalues are nondegenerate. The oscillation experiments measure the differences between the squares of the mass eigenvalues but tell us nothing about their absolute values. The unknown absolute neutrino mass scale has important implications in particle physics and cosmology. Beta decay endpoint measurements are presented as a model-independent method to measure the absolute neutrino mass. The Karlsruhe Tritium Neutrino Experiment (KATRIN) is explored in detail.

  15. Radiative decay of massious neutrinos: Implications for physics and astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1981-01-01

    The radiative lifetime tau for the decay of massious neutrinos is calculated using various physical models for neutrino decay. The results are related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data are used to place lower limits on tau. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models. It is considered that this may be an important test for substructure in leptons and quarks.

  16. Latest progress from the Daya Bay reactor neutrino experiment

    NASA Astrophysics Data System (ADS)

    Wang, Zhe; Daya Bay Collaboration

    2016-05-01

    Recently the Daya Bay reactor neutrino experiment has presented several new results about neutrino and reactor physics after acquiring a large data sample and after gaining a more sophisticated understanding of the experiment. In this talk I will introduce the latest progress made by the experiment including a three-flavor neutrino oscillation analysis using neutron capture on gadolinium, which gave sin2 2θ 13 = 0.084 ± 0.005 and |Δm2 ee| = (2.42 ±0.11) × 10-3 eV2, an independent θ 13 measurement using neutron capture on hydrogen, a search for a light sterile neutrino, and a measurement of the reactor antineutrino flux and spectrum.

  17. Minimal 3 +2 sterile neutrino model at LBNE

    NASA Astrophysics Data System (ADS)

    Hollander, D.; Mocioiu, I.

    2015-01-01

    In this paper we examine the sensitivity of the Long Baseline Neutrino Oscillation Experiment to the inclusion of two new sterile neutrino flavors with masses in the eV range. We implement a model with a modified Casas-Ibarra parametrization which can accommodate medium scale mass eigenstates and introduce a new complex mixing angle. We explore the new mixing angle parameter space and demonstrate how LBNE can be used to either provide evidence for or rule out a particular model of sterile neutrinos. Certain three-flavor C P -violation scenarios cannot be distinguished from the sterile neutrinos. Constraints from the Daya Bay reactor experiment and T2K are used to help lift this degeneracy.

  18. Implications of Fermi-LAT observations on the origin of IceCube neutrinos

    SciTech Connect

    Wang, Bin; Li, Zhuo; Zhao, Xiaohong E-mail: zhaoxh@ynao.ac.cn

    2014-11-01

    The IceCube (IC) collaboration recently reported the detection of TeV-PeV extraterrestrial neutrinos whose origin is yet unknown. By the photon-neutrino connection in pp and pγ interactions, we use the Fermi-LAT observations to constrain the origin of the IC detected neutrinos. We find that Galactic origins, i.e., the diffuse Galactic neutrinos due to cosmic ray (CR) propagation in the Milky Way, and the neutrinos from the Galactic point sources, may not produce the IC neutrino flux, thus these neutrinos should be of extragalactic origin. Moreover, the extragalactic gamma-ray bursts (GRBs) may not account for the IC neutrino flux, the jets of active galactic nuclei may not produce the IC neutrino spectrum, but the starburst galaxies (SBGs) may be promising sources. As suggested by the consistency between the IC detected neutrino flux and the Waxman-Bahcall bound, GRBs in SBGs may be the sources of both the ultrahigh energy, ∼> 10{sup 19}eV, CRs and the 1–100 PeV CRs that produce the IC detected TeV-PeV neutrinos.

  19. Non-linear evolution of the cosmic neutrino background

    SciTech Connect

    Villaescusa-Navarro, Francisco; Viel, Matteo; Peña-Garay, Carlos E-mail: spb@ias.edu E-mail: viel@oats.inaf.it

    2013-03-01

    We investigate the non-linear evolution of the relic cosmic neutrino background by running large box-size, high resolution N-body simulations which incorporate cold dark matter (CDM) and neutrinos as independent particle species. Our set of simulations explore the properties of neutrinos in a reference ΛCDM model with total neutrino masses between 0.05-0.60 eV in cold dark matter haloes of mass 10{sup 11}−10{sup 15} h{sup −1}M{sub s}un, over a redshift range z = 0−2. We compute the halo mass function and show that it is reasonably well fitted by the Sheth-Tormen formula, once the neutrino contribution to the total matter is removed. More importantly, we focus on the CDM and neutrino properties of the density and peculiar velocity fields in the cosmological volume, inside and in the outskirts of virialized haloes. The dynamical state of the neutrino particles depends strongly on their momentum: whereas neutrinos in the low velocity tail behave similarly to CDM particles, neutrinos in the high velocity tail are not affected by the clustering of the underlying CDM component. We find that the neutrino (linear) unperturbed momentum distribution is modified and mass and redshift dependent deviations from the expected Fermi-Dirac distribution are in place both in the cosmological volume and inside haloes. The neutrino density profiles around virialized haloes have been carefully investigated and a simple fitting formula is provided. The neutrino profile, unlike the cold dark matter one, is found to be cored with core size and central density that depend on the neutrino mass, redshift and mass of the halo, for halos of masses larger than ∼ 10{sup 13.5}h{sup −1}M{sub s}un. For lower masses the neutrino profile is best fitted by a simple power-law relation in the range probed by the simulations. The results we obtain are numerically converged in terms of neutrino profiles at the 10% level for scales above ∼ 200 h{sup −1}kpc at z = 0, and are stable with

  20. Cosmic string with a light massive neutrino

    NASA Technical Reports Server (NTRS)

    Albrecht, Andreas; Stebbins, Albert

    1992-01-01

    We have estimated the power spectra of density fluctuations produced by cosmic strings with neutrino hot dark matter (HDM). Normalizing at 8/h Mpc, we find that the spectrum has more power on small scales than HDM + inflation, less than cold dark matter (CDM) + inflation, and significantly less the CDM + strings. With HDM, large wakes give significant contribution to the power on the galaxy scale and may give rise to large sheets of galaxies.

  1. Solar neutrinos and the influence of radiative opacities on solar models

    NASA Technical Reports Server (NTRS)

    Carson, T. R.; Ezer, D.; Stothers, R.

    1973-01-01

    Use of new radiative opacities based on the hot Thomas-Fermi model of the atom yields a predicted solar neutrino flux which is still considerably larger than the flux observed in Davis's Cl-37 experiment.

  2. A New Neutrino Oscillation

    SciTech Connect

    Parke, Stephen J.; /Fermilab

    2011-07-01

    Starting in the late 1960s, neutrino detectors began to see signs that neutrinos, now known to come in the flavors electron ({nu}{sub e}), muon ({nu}{sub {mu}}), and tau ({nu}{sub {tau}}), could transform from one flavor to another. The findings implied that neutrinos must have mass, since massless particles travel at the speed of light and their clocks, so to speak, don't tick, thus they cannot change. What has since been discovered is that neutrinos oscillate at two distinct scales, 500 km/GeV and 15,000 km/GeV, which are defined by the baseline (L) of the experiment (the distance the neutrino travels) divided by the neutrino energy (E). Neutrinos of one flavor can oscillate into neutrinos of another flavor at both L/E scales, but the amplitude of these oscillations is different for the two scales and depends on the initial and final flavor of the neutrinos. The neutrino states that propogate unchanged in time, the mass eigenstates {nu}1, {nu}2, {nu}3, are quantum mechanical mixtures of the electron, muon, and tau neutrino flavors, and the fraction of each flavor in a given mass eigenstate is controlled by three mixing angles and a complex phase. Two of these mixing angles are known with reasonable precision. An upper bound exists for the third angle, called {theta}{sub 13}, which controls the size of the muon neutrino to electron neutrino oscillation at an L/E of 500 km/GeV. The phase is completely unknown. The existence of this phase has important implications for the asymmetry between matter and antimatter we observe in the universe today. Experiments around the world have steadily assembled this picture of neutrino oscillation, but evidence of muon neutrino to electron neutrino oscillation at 500 km/GeV has remained elusive. Now, a paper from the T2K (Tokai to Kamioka) experiment in Japan, reports the first possible observation of muon neutrinos oscillating into electron neutrinos at 500 km/GeV. They see 6 candidate signal events, above an expected background

  3. High Energy Neutrino Astronomy and Neutrino Telescopes

    NASA Astrophysics Data System (ADS)

    Kouchner, A.

    2015-04-01

    Neutrinos constitute a unique probe since they escape from their sources, travel undisturbed on cosmological distances and are produced in high-energy (HE) hadronic processes. In particular they would allow a direct detection and unambiguous identification of the acceleration sites of HE baryonic cosmic rays (CR), which remain unknown. Recent results from the ICECUBE collaboration present the first highly significant indication for the detection of high-energy extraterrestrial neutrinos, after several decades of instrumental efforts. We briefly report on this important results which open the route for the high-energy neutrino astronomy era. We then focus on the ANTARES detector, which despite its modest size with respect to ICECUBE is the largest deep-sea neutrino telescope in the world. The primary goal is to search for astrophysical neutrinos in the TeV-PeV range. This comprises generic searches for any diffuse cosmic neutrino flux as well as more specific searches for astrophysical sources such as active galactic nuclei or Galactic sources. The search program also includes multi-messenger analyses based on time and/or space coincidences with other cosmic probes. The ANTARES observatory is sensitive to a wide-range of other phenomena, from atmospheric neutrino oscillations to dark matter annihilation or potential exotics such as nuclearites and magnetic monopoles. The most recent results are reported.

  4. Collective neutrino oscillations in supernovae

    SciTech Connect

    Duan, Huaiyu

    2014-06-24

    In a dense neutrino medium neutrinos can experience collective flavor transformation through the neutrino-neutrino forward scattering. In this talk we present some basic features of collective neutrino flavor transformation in the context in core-collapse supernovae. We also give some qualitative arguments for why and when this interesting phenomenon may occur and how it may affect supernova nucleosynthesis.

  5. A search for oscillation of atmospheric neutrinos with the IMB detector

    NASA Astrophysics Data System (ADS)

    Gajewski, W.

    1992-07-01

    Neutrino oscillations have been studied using a flux of atmospheric neutrinos and the IMB water C¯erenkov detector. The study is based on: 1) a sample of 935 events in the detector volume during 7.7 kton-yrs exposure. About 70% of events have a single track which allows identification of the parent neutrino flavor. 2) a sample of 593 up-going muon tracks from neutrino interactions in rock below the detector. These studies are sensitive to δm2 down to 10-4eV2 and sin2(2θ) > 0.4, a region unexplored in previous experiments. Future plans of long baseline neutrino oscillation studies using the IMB detector and neutrinos from artificial sources are described. They include νe from a power reactor 13 km from the detector and νμ produced by the Main Injector at Fermilab at a distance of 570 km.

  6. Maki-Nakagawa-Sakata parameters from neutrino oscillations, single beta decay, and double beta decay

    SciTech Connect

    Matsuda, K.; Takeda, N.; Fukuyama, T.; Nishiura, H.

    2001-07-01

    We examine the constraints on the Maki-Nakagawa-Sakata lepton mixing matrix from the present and future experimental data of neutrino oscillation, tritium beta decay, and neutrinoless double beta decay for the Majorana neutrinos. We show that the small mixing angle solutions for solar neutrino problem are disfavored for small averaged mass ({l_angle}m{sub {nu}}{r_angle}) of neutrinoless double beta decay ({le}0.01 eV) in the inverse neutrino mass hierarchy scenario. This is the case even in the normal mass hierarchy scenario except for a very restrictive value of the averaged neutrino mass ({ovr m{sub {nu}}}) of single beta decay. The lower mass bound for {ovr m{sub {nu}}} is given from the present neutrino oscillation data. We obtain some relations between {l_angle}m{sub {nu}}{r_angle} and {ovr m{sub {nu}}}. The constraints on the Majorana CP violating phases are also given.

  7. Neutrino and Superluminal Limiting Velocity

    NASA Astrophysics Data System (ADS)

    Soln, Josip

    2013-04-01

    From the relativistic kinematics one derives the relativistic bicubic equation for the particle limiting velocity in the arbitrary reference frame. The three solutions, in quadratic forms, depending on the particle mass, m, energy, E, and the ordinary velocity, v, are all given in exact forms. In a frame where mv^2/E is very small, the solutions are given as Taylor series from which one recognizes just one solution as physically acceptable and denoting it as C. For a massless particle, m=o, C=v, the particle velocity,while for a photon C becomes luminal, C=c, with c the light velocity. In the OPERA experiment [1], one measures the muon neutrino velocity with E=17GeV at a distance of 730 km. The mass of the neutrino pushes the C values upward from c which, however is neutralized by a large value of E and could be neglected. Restricting ourselves to the OPERA results for which v >,=c,and for the sake of completeness, assuming m=0.05eV, the solution for C turns out to be slightly larger than c, C >,=c, with the largest value C=1.000002c.[4pt] [1] T. Adam et al., arXiv:1212.1276

  8. Measurement of atmospheric neutrino oscillations with IceCube.

    PubMed

    Aartsen, M G; Abbasi, R; Abdou, Y; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Beatty, J J; Bechet, S; Becker Tjus, J; Becker, K-H; Bell, M; Benabderrahmane, M L; Benzvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bernhard, A; Bertrand, D; Besson, D Z; Binder, G; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohaichuk, S; Bohm, C; Bose, D; Böser, S; Botner, O; Brayeur, L; Bretz, H-P; Brown, A M; Bruijn, R; Brunner, J; Carson, M; Casey, J; Casier, M; Chirkin, D; Christov, A; Christy, B; Clark, K; Clevermann, F; Coenders, S; Cohen, S; Cowen, D F; Cruz Silva, A H; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; De Ridder, S; Desiati, P; de With, M; DeYoung, T; Díaz-Vélez, J C; Dunkman, M; Eagan, R; Eberhardt, B; Eisch, J; Ellsworth, R W; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Franckowiak, A; Franke, R; Frantzen, K; Fuchs, T; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Goodman, J A; Góra, D; Grandmont, D T; Grant, D; Groß, A; Ha, C; Haj Ismail, A; Hallen, P; Hallgren, A; Halzen, F; Hanson, K; Heereman, D; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, R; Homeier, A; Hoshina, K; Huelsnitz, W; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Jagielski, K; Japaridze, G S; Jero, K; Jlelati, O; Kaminsky, B; Kappes, A; Karg, T; Karle, A; Kelley, J L; Kiryluk, J; Kislat, F; Kläs, J; Klein, S R; Köhne, J-H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krasberg, M; Krings, K; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Landsman, H; Larson, M J; Lesiak-Bzdak, M; Leuermann, M; Leute, J; Lünemann, J; Madsen, J; Maruyama, R; Mase, K; Matis, H S; McNally, F; Meagher, K; Merck, M; Mészáros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Niederhausen, H; Nowicki, S C; Nygren, D R; Obertacke, A; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Palazzo, A; Paul, L; Pepper, J A; Pérez de los Heros, C; Pfendner, C; Pieloth, D; Pinat, E; Pirk, N; Posselt, J; Price, P B; Przybylski, G T; Rädel, L; Rameez, M; Rawlins, K; Redl, P; Reimann, R; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rodrigues, J P; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Salameh, T; Sander, H-G; Santander, M; Sarkar, S; Schatto, K; Scheel, M; Scheriau, F; Schmidt, T; Schmitz, M; Schoenen, S; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Schulz, O; Seckel, D; Sestayo, Y; Seunarine, S; Sheremata, C; Smith, M W E; Soldin, D; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stasik, A; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Tepe, A; Ter-Antonyan, S; Tešić, G; Tilav, S; Toale, P A; Toscano, S; Usner, M; van der Drift, D; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Vraeghe, M; Walck, C; Waldenmaier, T; Wallraff, M; Wasserman, R; Weaver, Ch; Wellons, M; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Ziemann, J; Zierke, S; Zoll, M

    2013-08-23

    We present the first statistically significant detection of neutrino oscillations in the high-energy regime (>20 GeV) from an analysis of IceCube Neutrino Observatory data collected in 2010 and 2011. This measurement is made possible by the low-energy threshold of the DeepCore detector (~20 GeV) and benefits from the use of the IceCube detector as a veto against cosmic-ray-induced muon background. The oscillation signal was detected within a low-energy muon neutrino sample (20-100 GeV) extracted from data collected by DeepCore. A high-energy muon neutrino sample (100 GeV-10 TeV) was extracted from IceCube data to constrain systematic uncertainties. The disappearance of low-energy upward-going muon neutrinos was observed, and the nonoscillation hypothesis is rejected with more than 5σ significance. In a two-neutrino flavor formalism, our data are best described by the atmospheric neutrino oscillation parameters |Δm(32)(2)|=(2.3(-0.5)(+0.6))×10(-3) eV(2) and sin(2)(2θ(23))>0.93, and maximum mixing is favored. PMID:24010427

  9. Sterile neutrinos with secret interactions — lasting friendship with cosmology

    SciTech Connect

    Chu, Xiaoyong; Dasgupta, Basudeb; Kopp, Joachim

    2015-10-06

    Sterile neutrinos with mass ≃1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these constraints are avoided if sterile neutrinos couple to a new MeV-scale gauge boson A{sup ′}. However, even this scenario is restricted by structure formation constraints when A{sup ′}-mediated collisional processes lead to efficient active-to-sterile neutrino conversion after neutrinos have decoupled. In view of this, we reevaluate in this paper the viability of sterile neutrinos with such “secret” interactions. We carefully dissect their evolution in the early Universe, including the various production channels and the expected modifications to large scale structure formation. We argue that there are two regions in parameter space — one at very small A{sup ′} coupling, one at relatively large A{sup ′} coupling — where all constraints from big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and large scale structure (LSS) data are satisfied. Interestingly, the large A{sup ′} coupling region is precisely the region that was previously shown to have potentially important consequences for the small scale structure of dark matter halos if the A{sup ′} boson couples also to the dark matter in the Universe.

  10. Sterile neutrinos with secret interactions—lasting friendship with cosmology

    NASA Astrophysics Data System (ADS)

    Chu, Xiaoyong; Dasgupta, Basudeb; Kopp, Joachim

    2015-10-01

    Sterile neutrinos with mass simeq 1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these constraints are avoided if sterile neutrinos couple to a new MeV-scale gauge boson A'. However, even this scenario is restricted by structure formation constraints when A'-mediated collisional processes lead to efficient active-to-sterile neutrino conversion after neutrinos have decoupled. In view of this, we reevaluate in this paper the viability of sterile neutrinos with such ``secret'' interactions. We carefully dissect their evolution in the early Universe, including the various production channels and the expected modifications to large scale structure formation. We argue that there are two regions in parameter space—one at very small A' coupling, one at relatively large A' coupling—where all constraints from big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and large scale structure (LSS) data are satisfied. Interestingly, the large A' coupling region is precisely the region that was previously shown to have potentially important consequences for the small scale structure of dark matter halos if the A' boson couples also to the dark matter in the Universe.

  11. EV space suit gloves (passive)

    NASA Technical Reports Server (NTRS)

    Fletcher, E. G.; Dodson, J. D.; Elkins, W.; Tickner, E. G.

    1975-01-01

    A pair of pressure and thermal insulating overgloves to be used with an Extravehicular (EV) suit assembly was designed, developed, fabricated, and tested. The design features extensive use of Nomex felt materials in lieu of the multiple layer insulation formerly used with the Apollo thermal glove. The glove theoretically satisfies all of the thermal requirements. The presence of the thermal glove does not degrade pressure glove tactility by more than the acceptable 10% value. On the other hand, the thermal glove generally degrades pressure glove mobility by more than the acceptable 10% value, primarily in the area of the fingers. Life cycling tests were completed with minimal problems. The thermal glove/pressure glove ensemble was also tested for comfort; the test subjects found no problems with the thermal glove although they did report difficulties with pressure points on the pressure glove which were independent of the thermal glove.

  12. Determining neutrino oscillation parameters from atmospheric muon neutrino disappearance with three years of IceCube DeepCore data

    NASA Astrophysics Data System (ADS)

    Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; 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.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Brayeur, L.; Bretz, H.-P.; Brown, A. M.; Brunner, J.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Christy, B.; Clark, K.; Classen, L.; Clevermann, F.; Coenders, S.; Cowen, D. F.; Cruz Silva, A. H.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; Dunkman, M.; Eagan, R.; Eberhardt, B.; Eichmann, B.; Eisch, J.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Felde, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Gier, D.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Goodman, J. A.; Góra, D.; Grant, D.; Gretskov, P.; Groh, J. C.; Groß, A.; Ha, C.; Haack, C.; Haj Ismail, A.; Hallen, P.; Hallgren, A.; Halzen, F.; Hanson, K.; Hebecker, D.; Heereman, D.; Heinen, D.; Helbing, K.; Hellauer, R.; Hellwig, D.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huang, F.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Jagielski, K.; Japaridze, G. S.; Jero, K.; Jlelati, O.; Jurkovic, M.; Kaminsky, B.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kiryluk, J.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Koob, A.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Kriesten, A.; Krings, K.; Kroll, G.; Kroll, M.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larsen, D. T.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Lünemann, J.; Madsen, J.; Maggi, G.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meli, A.; Meures, T.; Miarecki, S.; Middell, E.; Middlemas, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Paul, L.; Penek, Ö.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Pütz, J.; Quinnan, M.; Rädel, L.; Rameez, M.; Rawlins, K.; Redl, P.; Rees, I.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rodrigues, J. P.; Rongen, M.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Sander, H.-G.; Sandroos, J.; Santander, M.; Sarkar, S.; Schatto, K.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Sestayo, Y.; Seunarine, S.; Shanidze, R.; Smith, M. W. E.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stanisha, N. A.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Tosi, D.; Tselengidou, M.; Unger, E.; Usner, M.; Vallecorsa, S.; van Eijndhoven, N.; Vandenbroucke, J.; van Santen, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallraff, M.; Weaver, Ch.; Wellons, M.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Whitehorn, N.; Wichary, C.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zierke, S.; Zoll, M.; IceCube Collaboration

    2015-04-01

    We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser IceCube instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 and 100 GeV, where a strong disappearance signal is expected. The IceCube detector volume surrounding DeepCore is used as a veto region to suppress the atmospheric muon background. Neutrino events are selected where the detected Cherenkov photons of the secondary particles minimally scatter, and the neutrino energy and arrival direction are reconstructed. Both variables are used to obtain the neutrino oscillation parameters from the data, with the best fit given by Δ m322=2.72-0.20+0.19×10-3 eV2 and sin2θ23=0.53-0.12+0.09 (normal mass ordering assumed). The results are compatible, and comparable in precision, to those of dedicated oscillation experiments.

  13. MINOS Sterile Neutrino Search

    SciTech Connect

    Koskinen, David Jason

    2009-02-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the v μ→ Vτ transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling ~2.5 x 1020 protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.

  14. 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.

  15. Detecting non-relativistic cosmic neutrinos by capture on tritium: phenomenology and physics potential

    NASA Astrophysics Data System (ADS)

    Long, Andrew J.; Lunardini, Cecilia; Sabancilar, Eray

    2014-08-01

    We study the physics potential of the detection of the Cosmic Neutrino Background via neutrino capture on tritium, taking the proposed PTOLEMY experiment as a case study. With the projected energy resolution of Δ ~ 0.15 eV, the experiment will be sensitive to neutrino masses with degenerate spectrum, m1 simeq m2 simeq m3 = mν gtrsim 0.1 eV. These neutrinos are non-relativistic today; detecting them would be a unique opportunity to probe this unexplored kinematical regime. The signature of neutrino capture is a peak in the electron spectrum that is displaced by 2 mν above the beta decay endpoint. The signal would exceed the background from beta decay if the energy resolution is Δ lesssim 0.7 mν . Interestingly, the total capture rate depends on the origin of the neutrino mass, being ΓD simeq 4 and ΓM simeq 8 events per year (for a 100 g tritium target) for unclustered Dirac and Majorana neutrinos, respectively. An enhancement of the rate of up to Script O(1) is expected due to gravitational clustering, with the unique potential to probe the local overdensity of neutrinos. Turning to more exotic neutrino physics, PTOLEMY could be sensitive to a lepton asymmetry, and reveal the eV-scale sterile neutrino that is favored by short baseline oscillation searches. The experiment would also be sensitive to a neutrino lifetime on the order of the age of the universe and break the degeneracy between neutrino mass and lifetime which affects existing bounds.

  16. Detecting non-relativistic cosmic neutrinos by capture on tritium: phenomenology and physics potential

    SciTech Connect

    Long, Andrew J.; Lunardini, Cecilia; Sabancilar, Eray E-mail: Cecilia.Lunardini@asu.edu

    2014-08-01

    We study the physics potential of the detection of the Cosmic Neutrino Background via neutrino capture on tritium, taking the proposed PTOLEMY experiment as a case study. With the projected energy resolution of Δ ∼ 0.15 eV, the experiment will be sensitive to neutrino masses with degenerate spectrum, m{sub 1} ≅ m{sub 2} ≅ m{sub 3} = m{sub ν} ∼> 0.1 eV. These neutrinos are non-relativistic today; detecting them would be a unique opportunity to probe this unexplored kinematical regime. The signature of neutrino capture is a peak in the electron spectrum that is displaced by 2 m{sub ν} above the beta decay endpoint. The signal would exceed the background from beta decay if the energy resolution is Δ ∼< 0.7 m{sub ν} . Interestingly, the total capture rate depends on the origin of the neutrino mass, being Γ{sup D} ≅ 4 and Γ{sup M} ≅ 8 events per year (for a 100 g tritium target) for unclustered Dirac and Majorana neutrinos, respectively. An enhancement of the rate of up to O(1) is expected due to gravitational clustering, with the unique potential to probe the local overdensity of neutrinos. Turning to more exotic neutrino physics, PTOLEMY could be sensitive to a lepton asymmetry, and reveal the eV-scale sterile neutrino that is favored by short baseline oscillation searches. The experiment would also be sensitive to a neutrino lifetime on the order of the age of the universe and break the degeneracy between neutrino mass and lifetime which affects existing bounds.

  17. Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Beier, E. W.

    1992-03-01

    This document is a technical progress report on work performed at the University of Pennsylvania during the current year on the Sudbury Neutrino Observatory project. The motivation for the experiment is the measurement of neutrinos emitted by the sun. The Sudbury Neutrino Observatory (SNO) is a second generation dedicated solar neutrino experiment which will extend the results of our work with the Kamiokande II detector by measuring three reactions of neutrinos rather than the single reaction measured by the Kamiokande experiment. The collaborative project includes physicists from Canada, the United Kingdom, and the United States. Full funding for the construction of this facility was obtained in Jan. 1990, and its construction is estimated to take five years. The motivation for the SNO experiment is to study the fundamental properties of neutrinos, in particular the mass and mixing parameters, which remain undetermined after decades of experiments in neutrino physics utilizing accelerators and reactors as sources of neutrinos. To continue the study of neutrino properties it is necessary to use the sun as a neutrino source. The long distance to the sun makes the search for neutrino mass sensitive to much smaller mass than can be studied with terrestrial sources. Furthermore, the matter density in the sun is sufficiently large to enhance the effects of small mixing between electron neutrinos and mu or tau neutrinos. This experiment, when combined with the results of the radiochemical Cl-37 and Ga-71 experiments and the Kamiokande II experiment, should extend our knowledge of these fundamental particles, and as a byproduct, improve our understanding of energy generation in the sun.

  18. Sterile neutrino fits to short baseline data

    NASA Astrophysics Data System (ADS)

    Collin, G. H.; Argüelles, C. A.; Conrad, J. M.; Shaevitz, M. H.

    2016-07-01

    Neutrino oscillation models involving extra mass eigenstates beyond the standard three (3 + N) are fit to global short baseline experimental data. We find that 3 + 1 has a best fit of Δ m412 = 1.75 eV2 with a Δ χnull-min2 (dof) of 52.34 (3). The 3 + 2 fit has a Δ χnull-min2 (dof) of 56.99 (7). For the first time, we show Bayesian credible intervals for a 3 + 1 model. These are found to be in agreement with frequentist intervals. The results of these new fits favor a higher Δm2 value than previous studies, which may have an impact on future sterile neutrino searches such as the Fermilab SBN program.

  19. Status of the KATRIN Neutrino Mass Experiment

    NASA Astrophysics Data System (ADS)

    Parno, Diana; Katrin Collaboration

    2015-04-01

    The Karlsruhe Tritium Neutrino experiment (KATRIN), presently under construction in Germany, will probe the absolute mass scale of the neutrino through the kinematics of tritium beta decay, a nearly model-independent approach. To achieve the projected sensitivity of 0.2 eV at the 90% confidence level, KATRIN will use a windowless, gaseous tritium source and a large magnetic adiabatic collimation-electrostatic filter. The collaboration has now completed a second commissioning phase of the spectrometer and detector section, and construction of the tritium sections is proceeding well. We will report on the current status of the experiment and the outlook for data-taking with tritium. 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.

  20. Relic neutrinos, thermal axions, and cosmology in early 2014

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We present up-to-date cosmological bounds on the sum of active neutrino masses as well as on extended cosmological scenarios with additional thermal relics, as thermal axions or sterile neutrino species. Our analyses consider all the current available cosmological data in the beginning of year 2014, including the very recent and most precise baryon acoustic oscillation measurements from the Baryon Oscillation Spectroscopic Survey. In the minimal three-active-neutrino scenario, we find ∑mν<0.22 eV at 95% C.L. from the combination of cosmic microwave background (CMB), baryon acoustic oscillation, and Hubble Space Telescope measurements of the Hubble constant. A nonzero value for the sum of the three active neutrino masses of ˜0.3 eV is significantly favored at more than three standard deviations when adding the constraints on σ8 and Ωm from the Planck cluster catalog on galaxy number counts. This preference for nonzero thermal relic masses disappears almost completely in both the thermal axion and massive sterile neutrino schemes. Extra light species contribute to the effective number of relativistic degrees of freedom, parametrized via Neff. We found that when the recent detection of B mode polarization from the BICEP2 experiment is considered, an analysis of the combined CMB data in the framework of LCDM +r models gives Neff=3.90±0.42, suggesting the presence of an extra relativistic relic at more than 95% C.L. from CMB-only data.

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

    NASA Astrophysics Data System (ADS)

    Archidiacono, Maria; Hannestad, Steen

    2014-07-01

    We provide updated bounds on non-standard neutrino interactions based on data from the Planck satellite as well as auxiliary cosmological measurements. Two types of models are studied - A Fermi-like 4-point interaction and an interaction mediated by a light pseudoscalar - and we show that these two models are representative of models in which neutrinos either decouple or recouple in the early Universe. Current cosmological data constrain the effective 4-point coupling to be GX <= (0.06 GeV)-2, corresponding to GX <= 2.5 × 107 GF. For non-standard pseudoscalar interactions we set a limit on the diagonal elements of the dimensionless coupling matrix, gij, of gii <= 1.2 × 10-7. For the off-diagonal elements which induce neutrino decay the bound is significantly stronger, corresponding to gij <= 2.3 × 10-11(m/0.05 eV)-2, or a lifetime constraint of τ >= 1.2 × 109 s (m/0.05 eV)3 . This is currently the strongest known bound on this particular type of neutrino decay. We finally note that extremely strong neutrino self-interactions which completely suppress anisotropic stress over all of cosmic history are very highly disfavored by current data Δ χ2 ~ 104).

  2. Paradoxes of neutrino oscillations

    SciTech Connect

    Akhmedov, E. Kh.; Smirnov, A. Yu.

    2009-08-15

    Despite the theory of neutrino oscillations being rather old, some of its basic issues are still being debated in the literature. We discuss a number of such issues, including the relevance of the 'same energy' and 'same momentum' assumptions, the role of quantum-mechanical uncertainty relations in neutrino oscillations, the dependence of the coherence and localization conditions that ensure the observability of neutrino oscillations on neutrino energy and momentum uncertainties, the question of (in)dependence of the oscillation probabilities on the neutrino production and detection processes, and the applicability limits of the stationary-source approximation. We also develop a novel approach to calculation of the oscillation probability in the wave-packet approach, based on the summation/integration conventions different from the standard one, which allows a new insight into the 'same energy' vs. 'same momentum' problem. We also discuss a number of apparently paradoxical features of the theory of neutrino oscillations.

  3. Solar neutrino detection

    SciTech Connect

    Miramonti, Lino

    2009-04-30

    More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.

  4. Charged Cosmic Rays and Neutrinos

    NASA Astrophysics Data System (ADS)

    Kachelrieß, M.

    2013-04-01

    High-energy neutrino astronomy has grown up, with IceCube as one of its main experiments having sufficient sensitivity to test "vanilla" models of astrophysical neutrinos. I review predictions of neutrino fluxes as well as the status of cosmic ray physics. I comment also briefly on an improvement of the Fermi-LAT limit for cosmogenic neutrinos and on the two neutrino events presented by IceCube first at "Neutrino 2012".

  5. Neutrinos: Nature's Ghosts?

    SciTech Connect

    Lincoln, Don

    2013-06-18

    Dr. Don Lincoln introduces one of the most fascinating inhabitants of the subatomic realm: the neutrino. Neutrinos are ghosts of the microworld, almost not interacting at all. In this video, he describes some of their properties and how they were discovered. Studies of neutrinos are expected to be performed at many laboratories across the world and to form one of the cornerstones of the Fermilab research program for the next decade or more.

  6. Neutrino Mass Anarchy

    NASA Astrophysics Data System (ADS)

    Hall, Lawrence; Murayama, Hitoshi; Weiner, Neal

    2000-03-01

    What is the form of the neutrino mass matrix which governs the oscillations of the atmospheric and solar neutrinos? Features of the data have led to a dominant viewpoint where the mass matrix has an ordered, regulated pattern, perhaps dictated by a flavor symmetry. We challenge this viewpoint and demonstrate that the data are well accounted for by a neutrino mass matrix which appears to have random entries.

  7. Neutrino mass anarchy

    PubMed

    Hall; Murayama; Weiner

    2000-03-20

    What is the form of the neutrino mass matrix which governs the oscillations of the atmospheric and solar neutrinos? Features of the data have led to a dominant viewpoint where the mass matrix has an ordered, regulated pattern, perhaps dictated by a flavor symmetry. We challenge this viewpoint and demonstrate that the data are well accounted for by a neutrino mass matrix which appears to have random entries. PMID:11017272

  8. Neutrinos in Cosmology

    SciTech Connect

    Wong, Yvonne Y. Y.

    2008-01-24

    I give an overview of the effects of neutrinos on cosmology, focussing in particular on the role played by neutrinos in the evolution of cosmological perturbations. I discuss how recent observations of the cosmic microwave background and the large-scale structure of galaxies can probe neutrino masses with greater precision than current laboratory experiments. I describe several new techniques that will be used to probe cosmology in the future.

  9. Neutrinos: Nature's Ghosts?

    ScienceCinema

    Lincoln, Don

    2014-08-12

    Dr. Don Lincoln introduces one of the most fascinating inhabitants of the subatomic realm: the neutrino. Neutrinos are ghosts of the microworld, almost not interacting at all. In this video, he describes some of their properties and how they were discovered. Studies of neutrinos are expected to be performed at many laboratories across the world and to form one of the cornerstones of the Fermilab research program for the next decade or more.

  10. Precise Measurement of the Neutrino Mixing Parameter θ23 from Muon Neutrino Disappearance in an Off-Axis Beam

    NASA Astrophysics Data System (ADS)

    Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Ariga, T.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Bentham, S. W.; Berardi, V.; Berger, B. E.; Berkman, S.; Bertram, I.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; 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.; 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.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dufour, F.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Floetotto, L.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Ives, S. J.; Iwai, E.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; 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.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koseki, K.; Koshio, Y.; Kreslo, I.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kumaratunga, S.; Kurjata, R.; Kutter, T.; Lagoda, J.; Laihem, K.; Lamont, I.; Laveder, M.; Lawe, M.; Lazos, M.; Lee, K. P.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Ludovici, L.; Macaire, M.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Maruyama, T.; Marzec, J.; Mathie, E. L.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Monfregola, L.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nagasaki, T.; Nakadaira, T.; Nakahata, M.; Nakai, T.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Naples, D.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J.; 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, 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.; Retiere, F.; Robert, A.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; 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.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smith, R. J.; 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.; Szeglowski, T.; 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.; Ueno, K.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; 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.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

    2014-05-01

    New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter θ23. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57×1020 protons on target, T2K has fit the energy-dependent νμ oscillation probability to determine oscillation parameters. The 68% confidence limit on sin2(θ23) is 0.514-0.056+0.055 (0.511±0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Δm322=(2.51±0.10)×10-3 eV2/c4 (inverted hierarchy: Δm132=(2.48±0.10)×10-3 eV2/c4). Adding a model of multinucleon interactions that affect neutrino energy reconstruction is found to produce only small biases in neutrino oscillation parameter extraction at current levels of statistical uncertainty.

  11. Serological detection and analysis of anti-VP1 responses against various enteroviruses (EV) (EV-A, EV-B and EV-C) in Chinese individuals.

    PubMed

    Gao, Caixia; Ding, Yingying; Zhou, Peng; Feng, Jiaojiao; Qian, Baohua; Lin, Ziyu; Wang, Lili; Wang, Jinhong; Zhao, Chunyan; Li, Xiangyu; Cao, Mingmei; Peng, Heng; Rui, Bing; Pan, Wei

    2016-01-01

    The overall serological prevalence of EV infections based on ELISA remains unknown. In the present study, the antibody responses against VP1 of the EV-A species (enterovirus 71 (EV71), Coxsackievirus A16 (CA16), Coxsackievirus A5 (CA5) and Coxsackievirus A6 (CA6)), of the EV-B species (Coxsackievirus B3 (CB3)), and of the EV-C species (Poliovirus 1 (PV1)) were detected and analyzed by a NEIBM (novel evolved immunoglobulin-binding molecule)-based ELISA in Shanghai blood donors. The serological prevalence of anti-CB3 VP1 antibodies was demonstrated to show the highest level, with anti-PV1 VP1 antibodies at the second highest level, and anti-CA5, CA6, CA16 and EV71 VP1 antibodies at a comparatively low level. All reactions were significantly correlated at different levels, which were approximately proportional to their sequence similarities. Antibody responses against EV71 VP1 showed obvious differences with responses against other EV-A viruses. Obvious differences in antibody responses between August 2013 and May 2014 were revealed. These findings are the first to describe the detailed information of the serological prevalence of human antibody responses against the VP1 of EV-A, B and C viruses, and could be helpful for understanding of the ubiquity of EV infections and for identifying an effective approach for seroepidemiological surveillance based on ELISA. PMID:26917423

  12. Serological detection and analysis of anti-VP1 responses against various enteroviruses (EV) (EV-A, EV-B and EV-C) in Chinese individuals

    PubMed Central

    Gao, Caixia; Ding, Yingying; Zhou, Peng; Feng, Jiaojiao; Qian, Baohua; Lin, Ziyu; Wang, Lili; Wang, Jinhong; Zhao, Chunyan; Li, Xiangyu; Cao, Mingmei; Peng, Heng; Rui, Bing; Pan, Wei

    2016-01-01

    The overall serological prevalence of EV infections based on ELISA remains unknown. In the present study, the antibody responses against VP1 of the EV-A species (enterovirus 71 (EV71), Coxsackievirus A16 (CA16), Coxsackievirus A5 (CA5) and Coxsackievirus A6 (CA6)), of the EV-B species (Coxsackievirus B3 (CB3)), and of the EV-C species (Poliovirus 1 (PV1)) were detected and analyzed by a NEIBM (novel evolved immunoglobulin-binding molecule)-based ELISA in Shanghai blood donors. The serological prevalence of anti-CB3 VP1 antibodies was demonstrated to show the highest level, with anti-PV1 VP1 antibodies at the second highest level, and anti-CA5, CA6, CA16 and EV71 VP1 antibodies at a comparatively low level. All reactions were significantly correlated at different levels, which were approximately proportional to their sequence similarities. Antibody responses against EV71 VP1 showed obvious differences with responses against other EV-A viruses. Obvious differences in antibody responses between August 2013 and May 2014 were revealed. These findings are the first to describe the detailed information of the serological prevalence of human antibody responses against the VP1 of EV-A, B and C viruses, and could be helpful for understanding of the ubiquity of EV infections and for identifying an effective approach for seroepidemiological surveillance based on ELISA. PMID:26917423

  13. Novel Ideas for Neutrino Beams

    SciTech Connect

    Peach, Ken

    2007-04-23

    Recent developments in neutrino physics, primarily the demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The simplest phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or {pi}, contribute to the otherwise unexplained baryon asymmetry observed in the universe. Exploring the neutrino sector will require very intense beams of neutrinos, and will need novel solutions.

  14. Neutrino oscillation studies with reactors.

    PubMed

    Vogel, P; Wen, L J; Zhang, C

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  15. Neutrino oscillation studies with reactors

    DOE PAGESBeta

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  16. Neutrino oscillation studies with reactors

    PubMed Central

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  17. Neutrino oscillation studies with reactors

    SciTech Connect

    Vogel, P.; Wen, L.J.; Zhang, C.

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  18. Accelerator neutrino program at Fermilab

    SciTech Connect

    Parke, Stephen J.; /Fermilab

    2010-05-01

    The accelerator neutrino programme in the USA consists primarily of the Fermilab neutrino programme. Currently, Fermilab operates two neutrino beamlines, the Booster neutrino beamline and the NuMI neutrino beamline and is the planning stages for a third neutrino beam to send neutrinos to DUSEL. The experiments in the Booster neutrino beamline are miniBooNE, SciBooNE and in the future microBooNE, whereas in the NuMI beamline we have MINOS, ArgoNut, MINERVA and coming soon NOvA. The major experiment in the beamline to DUSEL will be LBNE.

  19. Bolometric detection of neutrinos

    NASA Technical Reports Server (NTRS)

    Cabrera, B.; Krauss, L. M.; Wilczek, F.

    1985-01-01

    Elastic neutrino scattering off electrons in crystalline silicon at 1-10 mK results in measurable temperature changes in macroscopic amounts of material, even for low-energy (less than 0.41-MeV) pp neutrinos from the sun. New detectors for bolometric measurement of low-energy neutrino interactions, including coherent nuclear elastic scattering, are proposed. A new and more sensitive search for oscillations of reactor antineutrinos is practical (about 100 kg of Si), and would lay the groundwork for a more ambitious measurement of the spectrum of pp, Be-7, and B-8 solar neutrinos, and of supernovae anywhere in the Galaxy (about 10 tons of Si).

  20. Neutrino-nucleus interactions

    SciTech Connect

    Gallagher, H.; Garvey, G.; Zeller, G.P.; /Fermilab

    2011-01-01

    The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

  1. Muons and neutrinos

    NASA Technical Reports Server (NTRS)

    Stanev, T.

    1986-01-01

    The first generation of large and precise detectors, some initially dedicated to search for nucleon decay has accumulated significant statistics on neutrinos and high-energy muons. A second generation of even better and bigger detectors are already in operation or in advanced construction stage. The present set of experimental data on muon groups and neutrinos is qualitatively better than several years ago and the expectations for the following years are high. Composition studies with underground muon groups, neutrino detection, and expected extraterrestrial neutrino fluxes are discussed.

  2. Neutrinos in supernovae

    SciTech Connect

    Cooperstein, J.

    1986-10-01

    The role of neutrinos in Type II supernovae is discussed. An overall view of the neutrino luminosity as expected theoretically is presented. The different weak interactions involved are assessed from the standpoint of how they exchange energy, momentum, and lepton number. Particular attention is paid to entropy generation and the path to thermal and chemical equilibration, and to the phenomenon of trapping. Various methods used to calculate the neutrino flows are considered. These include trapping and leakage schemes, distribution-averaged transfer, and multi-energy group methods. The information obtained from the neutrinos caught from Supernova 1987a is briefly evaluated. 55 refs., 7 figs.

  3. Bounds on sterile neutrino parameters from reactor experiments

    NASA Astrophysics Data System (ADS)

    Bora, Kalpana

    2014-03-01

    In this work, we present a realistic analysis of the potential of the present-day reactor experiments Double Chooz, Daya Bay and RENO for probing the existence of sterile neutrinos. We present exclusion regions for sterile oscillation parameters and find that these experimental set-ups give significant bounds on the parameter Θee especially in the low sterile oscillation region 0.01 < Δm241 < 0.05 eV2. These bounds can add to our understanding of the sterile neutrino sector since there is still a tension in the allowed regions from different experiments for sterile parameters.

  4. Neutrino mass and dark energy from weak lensing.

    PubMed

    Abazajian, Kevork N; Dodelson, Scott

    2003-07-25

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

  5. Low Energy Neutrino and Dark Matter Physics with sub-keV Germanium Detectors

    SciTech Connect

    Singh, L.; Singh, V.; Soma, A. K.; Singh, M. K.; Wong, H. T.

    2011-10-06

    A TEXONO collaboration research program on low energy neutrino and dark matter physics is going on at the Kuo-Sheng Neutrino Laboratory (KSNL). Collaboration main goals are to measure the neutrino-nucleus coherent scattering cross section, neutrino magnetic moments, and the searches of WIMP dark matter. To achieve these goals various prototype detectors and their sub-keV background are under study. A threshold of 220 eV was achieved with prototype detectors at the KSNL. New limits were set for WIMPs with mass between 3-6 GeV. Data are being taken with a 500 g Point Contact Germanium detector, where a threshold of {approx}350 eV was demonstrated. A 20 g ULEGe detector is taking data at CJPL in Sichuan, China.

  6. 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.

  7. Search for the Cosmic Neutrino Background

    NASA Astrophysics Data System (ADS)

    Faessler, A.; Hodak, R.; Kovalenko, S.; Simkovic, F.

    2015-02-01

    One expects three Cosmic Backgrounds: (1) The Cosmic Microwave Background (CMB) originated 380000 years after the Big Bang (BB). (2) The Neutrino Background decoupled about one second after the BB, while (3) the Cosmic Gravitational Wave Background created by the inflationary expansion decoupled directly after the BB. Only the Cosmic Microwave Background (CMB) has been detected and is well studied. Its spectrum follows Planck's black body radiation formula and shows a remarkable constant temperature of T0γ ≈ 2.7 K independent of the direction. The present photon density is about 370 photons per cm3. The size of the hot spots, which deviates only in the fifth decimal of the temperature from the average value, tells us, that the universe is flat. About 380 000 years after the Big Bang at a temperature of T0γ = 3000 K already in the matter dominated era the electrons combine with the protons and 4He and the photons move freely in the neutral universe and form the CMB. So the temperature and distribution of the photons give us information of the universe 380 000 years after the Big Bang. The Cosmic Neutrino Background (CνB) decoupled from matter already one second after the BB at a temperature of about 1010 K. Today their temperature is ~ 1.95 K and the average density is 56 electron-neutrinos and the total density of all neutrinos about 336 per cm3. Measurement of these neutrinos is an extremely challenging experimental problem which can hardly be solved with the present technologies. On the other hand it represents a tempting opportunity to check one of the key elements of the Big Bang Cosmology and to probe the early stages of the universe. The search for the CνB with the induced beta decay νe+3H → 3He + e- using KATRIN (KArlsruhe TRItium Neutrino experiment) is the topic of this contribution.

  8. Neutrinos from collapsars

    NASA Astrophysics Data System (ADS)

    Vieyro, F. L.; Romero, G. E.; Peres, O. L. G.

    2013-10-01

    Context. Long gamma-ray bursts (GRBs) are associated with the gravitational collapse of very massive stars. The central engine of a GRB can collimate relativistic jets that propagate inside the stellar envelope. The shock waves produced when the jet disrupts the stellar surface are capable of accelerating particles up to very high energies. Aims: If the jet has hadronic content, neutrinos will be produced via charged pion decays. The main goal of this work is to estimate the neutrino emission produced in the region close to the surface of the star, taking pion and muon cooling into account, along with subtle effects arising from neutrino production in a highly magnetized medium. Methods: We estimate the maximum energies of the different kinds of particles and solve the coupled transport equations for each species. Once the particle distributions are known, we calculate the intensity of neutrinos. We study the different effects on the neutrinos that can change the relative weight of different flavors. In particular, we consider the effects of neutrino oscillations, and of neutrino spin precession caused by strong magnetic fields. Results: The expected neutrino signals from the shocks in the uncorking regions of Population III events is very weak, but the neutrino signal produced by Wolf-Rayet GRBs with z < 0.5 is not far from the level of the atmospheric background. Conclusions: The IceCube experiment does not have the sensitivity to detect neutrinos from the implosion of the earliest stars, but a number of high-energy neutrinos may be detected from nearby long GRBs. The cumulative signal should be detectable over several years (~10 yr) of integration with the full 86-string configuration.

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

    NASA Astrophysics Data System (ADS)

    Fujikawa, Kazuo; Tureanu, Anca

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

  10. High Energy Neutrinos with a Mediterranean Neutrino Telescope

    SciTech Connect

    Borriello, E.; Cuoco, A.; Mangano, G.; Miele, G.; Pastor, Sergio; Pisanti, O.; Serpico, Pasquale Dario; /Fermilab

    2007-09-01

    The high energy neutrino detection by a km{sup 3} Neutrino Telescope placed in the Mediterranean sea provides a unique tool to both determine the diffuse astrophysical neutrino flux and the neutrino nucleon cross section in the extreme kinematical region, which could unveil the presence of new physics. Here is performed a brief analysis of possible NEMO site performances.