National Library of Energy BETA

Sample records for neutrino mass mixing

  1. Phenomenological relations for neutrino masses and mixing parameters

    SciTech Connect (OSTI)

    Khruschov, V. V.

    2013-11-15

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

  2. Leptonic mixing, family symmetries, and neutrino phenomenology

    SciTech Connect (OSTI)

    Medeiros Varzielas, I. de [Departamento de Fisica and Centro de Fisica Teorica de Particulas, Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Fakultaet fuer Physik, Technische Universitaet Dortmund D-44221 Dortmund (Germany); Gonzalez Felipe, R. [Departamento de Fisica and Centro de Fisica Teorica de Particulas, Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1959-007 Lisboa (Portugal); Serodio, H. [Departamento de Fisica and Centro de Fisica Teorica de Particulas, Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal)

    2011-02-01

    Tribimaximal leptonic mixing is a mass-independent mixing scheme consistent with the present solar and atmospheric neutrino data. By conveniently decomposing the effective neutrino mass matrix associated to it, we derive generic predictions in terms of the parameters governing the neutrino masses. We extend this phenomenological analysis to other mass-independent mixing schemes which are related to the tribimaximal form by a unitary transformation. We classify models that produce tribimaximal leptonic mixing through the group structure of their family symmetries in order to point out that there is often a direct connection between the group structure and the phenomenological analysis. The type of seesaw mechanism responsible for neutrino masses plays a role here, as it restricts the choices of family representations and affects the viability of leptogenesis. We also present a recipe to generalize a given tribimaximal model to an associated model with a different mass-independent mixing scheme, which preserves the connection between the group structure and phenomenology as in the original model. This procedure is explicitly illustrated by constructing toy models with the transpose tribimaximal, bimaximal, golden ratio, and hexagonal leptonic mixing patterns.

  3. Evidence for neutrino mass: A decade of discovery

    SciTech Connect (OSTI)

    Heeger, Karsten M.

    2004-12-08

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

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

    SciTech Connect (OSTI)

    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.

  5. Neutrino mixing and oscillations in astrophysical environments

    SciTech Connect (OSTI)

    Balantekin, A. B.

    2014-05-02

    A brief review of the current status of neutrino mixing and oscillations in astrophysical environments, with particular emphasis on the Sun and core-collapse supernovae, is given. Implications of the existence of sterile states which mix with the active neutrinos are discussed.

  6. Probing Late Neutrino Mass Properties With SupernovaNeutrinos...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Probing Late Neutrino Mass Properties With SupernovaNeutrinos Citation ... DOE Contract Number: DE-AC02-05CH11231 Resource Type: Journal Article Resource Relation: ...

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

    SciTech Connect (OSTI)

    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.

  8. Non-Oscillation Probes of Neutrino Masses

    SciTech Connect (OSTI)

    Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster Institut fuer Kernphysik, Wilhelm-Klemm-Str. 9, D-48149 Muenster (Germany)

    2010-03-30

    The absolute scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing statements on the neutrino mass from cosmological observations, two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double beta decay and the direct neutrino mass search. For both methods currently experiments with a sensitivity of O(100) meV are being set up or commissioned.

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

    SciTech Connect (OSTI)

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

    2015-12-01

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

  10. CP-phase effects on the effective neutrino mass m{sub ee} in the case of quasidegenerate neutrinos

    SciTech Connect (OSTI)

    Maalampi, J. [Department of Physics, P.O. Box 35, FIN-40014 University of Jyvaeskylae (Finland); Helsinki Institute of Physics, P.O. Box 64, FIN-00014 University of Helsinki (Finland); Riittinen, J. [Department of Physics, P.O. Box 35, FIN-40014 University of Jyvaeskylae (Finland)

    2010-02-01

    We study the possibility that the three mass states of the ordinary active neutrinos actually split into pairs of quasidegenerate states, with {Delta}m{sub kk}{sup '2{approx}}10{sup -12} eV{sup 2} or less, as a result of mixing of active neutrinos with sterile neutrinos. While in laboratory experiments these quasidegenerate pairs will look identical to single active states, the CP phase factors associated with active-sterile mixing might cause cancellations in the effective electron neutrino mass m{sub ee} measured in the neutrinoless double beta decay experiments thereby revealing the split nature of states.

  11. Constraining mass spectra with sterile neutrinos from neutrinoless double beta decay, tritium beta decay, and cosmology

    SciTech Connect (OSTI)

    Goswami, Srubabati [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

    2006-06-01

    We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that some of the allowed mass patterns are severely restricted by the current constraints, in particular, by the cosmological constraints on the total sum of neutrino masses and by the nonmaximality of the solar neutrino mixing angle. Furthermore, we estimate the form of the four neutrino mass matrices and also comment on the situation in scenarios with two additional sterile neutrinos.

  12. Neutrinoless double beta decay and neutrino masses

    SciTech Connect (OSTI)

    Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2012-07-27

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

  13. Double beta decay, Majorana neutrinos, and neutrino mass

    SciTech Connect (OSTI)

    Avignone, Frank T. III; Elliott, Steven R.; Engel, Jonathan [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599-3255 (United States)

    2008-04-15

    The theoretical and experimental issues relevant to neutrinoless double beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics, and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the nonobservation of neutrinoless double beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.

  14. Dirac or inverse seesaw neutrino masses with B L gauge symmetry and S? flavor symmetry

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ma, Ernest; Srivastava, Rahul

    2015-02-01

    Many studies have been made on extensions of the standard model with B L gauge symmetry. The addition of three singlet (right-handed) neutrinos renders it anomaly-free. It has always been assumed that the spontaneous breaking of B L is accomplished by a singlet scalar field carrying two units of B L charge. This results in a very natural implementation of the Majorana seesaw mechanism for neutrinos. However, there exists in fact another simple anomaly-free solution which allows Dirac or inverse seesaw neutrino masses. We show for the first time these new possibilities and discuss an application tomoreneutrino mixing with S? flavor symmetry.less

  15. Experimental Neutrino Physics: Final Report

    SciTech Connect (OSTI)

    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.

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

    SciTech Connect (OSTI)

    Antusch, S.; Spinrath, M. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, D-80805 Muenchen (Germany); King, Stephen F. [School of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton (United Kingdom)

    2011-01-01

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

  17. Neutrino mass, dark energy, and the linear growth factor (Journal...

    Office of Scientific and Technical Information (OSTI)

    dark energy, and the linear growth factor Citation Details In-Document Search Title: Neutrino mass, dark energy, and the linear growth factor We study the degeneracies between ...

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

    SciTech Connect (OSTI)

    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.

  19. Soft A4→Z3 symmetry breaking and cobimaximal neutrino mixing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ma, Ernest

    2016-03-28

    In this study, I propose a model of radiative charged-lepton and neutrino masses with A4 symmetry. The soft breaking of A4 to Z3 lepton triality is accomplished by dimension-three terms. The breaking of Z3 by dimension-two terms allows cobimaximal neutrino mixing (θ13 ≠ 0, θ23 = π/4, δcp=π/2) to be realized with only very small finite calculable deviations from the residual Z3 lepton triality. This construction solves a long-standing technical problem inherent in renormalizable A4 models since their inception.

  20. Majorana equations and the rest mass of neutrinos

    SciTech Connect (OSTI)

    von Borzeszkowski, H.; Treder, H.

    1985-02-01

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

  1. Renormalization of a two-loop neutrino mass model

    SciTech Connect (OSTI)

    Babu, K. S.; Julio, J.

    2014-01-01

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

  2. Neutrino oscillation studies with reactors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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.

  3. Unitarity and the three flavor neutrino mixing matrix

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Parke, Stephen; Ross-Lonergan, Mark

    2016-06-14

    Unitarity is a fundamental property of any theory required to ensure we work in a theoretically consistent framework. In comparison with the quark sector, experimental tests of unitarity for the 3x3 neutrino mixing matrix are considerably weaker. It must be remembered that the vast majority of our information on the neutrino mixing angles originates from v-e and vμ disappearance experiments, with the assumption of unitarity being invoked to constrain the remaining elements. New physics can invalidate this assumption for the 3x3 subset and thus modify our precision measurements. We also perform a reanalysis to see how global knowledge is alteredmore » when one refits oscillation results without assuming unitarity, and present 3σ ranges for allowed UPMNS elements consistent with all observed phenomena. We calculate the bounds on the closure of the six neutrino unitarity triangles, with the closure of the v-e and vμ triangle being constrained to be ≤0.03, while the remaining triangles are significantly less constrained to be ≤ 0.1 - 0.2. Similarly for the row and column normalization, we find their deviation from unity is constrained to be ≤ 0.2 - 0.4, for four out of six such normalizations, while for the vμ and ve row normalization the deviations are constrained to be ≤0.07, all at the 3σCL. Additionally, we emphasize that there is significant room for new low energy physics, especially in the vτ sector which very few current experiments constrain directly.« less

  4. Unitarity and the Three Flavour Neutrino Mixing Matrix

    SciTech Connect (OSTI)

    Parke, Stephen; Ross-Lonergan, Mark

    2015-08-20

    Unitarity is a fundamental property of any theory required to ensure we work in a theoretically consistent framework. In comparison with the quark sector, experimental tests of unitarity for the 3x3 neutrino mixing matrix are considerably weaker. It must be remembered that the vast majority of our information on the neutrino mixing angles originates from v-e and vμ disappearance experiments, with the assumption of unitarity being invoked to constrain the remaining elements. New physics can invalidate this assumption for the 3x3 subset and thus modify our precision measurements. We also perform a reanalysis to see how global knowledge is altered when one refits oscillation results without assuming unitarity, and present 3σ ranges for allowed UPMNS elements consistent with all observed phenomena. We calculate the bounds on the closure of the six neutrino unitarity triangles, with the closure of the v-e and vμ triangle being constrained to be ≤0.03, while the remaining triangles are significantly less constrained to be ≤ 0.1 - 0.2. Similarly for the row and column normalization, we find their deviation from unity is constrained to be ≤ 0.2 - 0.4, for four out of six such normalizations, while for the vμ and ve row normalization the deviations are constrained to be ≤0.07, all at the 3σCL. Additionally, we emphasize that there is significant room for new low energy physics, especially in the vτ sector which very few current experiments constrain directly.

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

    SciTech Connect (OSTI)

    BenTov, Yoni [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Zee, A. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)

    2011-10-01

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

  6. Neutrinoless double {beta}-decay and neutrino mass hierarchies

    SciTech Connect (OSTI)

    Bilenky, S. M. [Scuola Internazionale Superiore di Studi Avanzati, I-34014 Trieste (Italy); Faessler, Amand; Gutsche, Thomas; Simkovic, Fedor [Institute fuer Theoretische Physik der Universitaet Tuebingen, D-72076 Tuebingen (Germany)

    2005-09-01

    In the framework of the seesaw mechanism the normal hierarchy is favorable for the neutrino mass spectrum. For this spectrum we present a detailed calculation of the half-lives of neutrinoless double {beta}-decay for several nuclei of experimental interest. The half-lives are evaluated by considering the most comprehensive nuclear matrix elements, which were obtained within the renormalized quasiparticle random phase approximation by the Bratislava-Caltech-Tuebingen group. The dependence of the half-lives on sin{sup 2}{theta}{sub 13} and the lightest neutrino mass is studied. We present also the results of the calculations of the half-lives of neutrinoless double {beta}-decay in the case of the inverted hierarchy of neutrino masses.

  7. Probing the Dark Matter mass and nature with neutrinos

    SciTech Connect (OSTI)

    Blennow, Mattias; Carrigan, Marcus; Martinez, Enrique Fernandez E-mail: carri@kth.se

    2013-06-01

    We study the possible indirect neutrino signal from dark matter annihilations inside the Sun's core for relatively light dark matter masses in the O(10) GeV range. Due to their excellent energy reconstruction capabilities, we focus on the detection of this flux in liquid argon or magnetized iron calorimeter detectors, proposed for the next generation of far detectors of neutrino oscillation experiments and neutrino telescopes. The aim of the study is to probe the ability of these detectors to determine fundamental properties of the dark matter nature such as its mass or its relative annihilation branching fractions to different channels. We find that these detectors will be able to accurately measure the dark matter mass as long as the dark matter annihilations have a significant branching into the neutrino or at least the τ channel. We have also discovered degeneracies between different dark matter masses and annihilation channels, where a hard τ channel spectrum for a lower dark matter mass may mimic that of a softer quark channel spectrum for a larger dark matter mass. Finally, we discuss the sensitivity of the detectors to the different branching ratios and find that it is between one and two orders of magnitude better than the current bounds from those coming from analysis of Super-Kamiokande data.

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

    SciTech Connect (OSTI)

    Park, Wan-Il

    2014-06-01

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

  9. Tribimaximal neutrino mixing and neutrinoless double beta decay

    SciTech Connect (OSTI)

    Hirsch, M.; Morisi, S.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular-- C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

    2008-11-01

    We present a tribimaximal lepton mixing scheme where the neutrinoless double beta decay rate has a lower bound which correlates with the ratio {alpha}{identical_to}{delta}m{sub sol}{sup 2}/{delta}m{sub atm}{sup 2} well determined by current data, as well as with the unknown Majorana CP phase {phi}{sub 12} characterizing the solar neutrino subsystem. For the special value {phi}{sub 12}=({pi}/2) (opposite CP-sign neutrinos) the {beta}{beta}{sub 0{nu}} rate vanishes at tree level when {delta}m{sub sol}{sup 2}/{delta}m{sub atm}{sup 2}=3/80, only allowed at 3{sigma}. For all other cases the rate is nonzero, and lies within current and projected experimental sensitivities close to {phi}{sub 12}=0. We suggest two model realizations of this scheme in terms of A{sub 4}xZ{sub 2} and A{sub 4}xZ{sub 4} flavor symmetries.

  10. Embedding the Zee-Wolfenstein neutrino mass matrix in an SO(10)xA{sub 4} GUT scenario

    SciTech Connect (OSTI)

    Grimus, Walter; Kuehboeck, Helmut

    2008-03-01

    We consider renormalizable SO(10) Yukawa interactions and put the three fermionic 16-plets into the 3-dimensional irreducible A{sub 4} representation. Scanning the possible A{sub 4} representation assignments to the scalars, we find a unique case which allows one to accommodate the down-quark and charged-lepton masses. Assuming type II seesaw dominance, we obtain a viable scenario with the Zee-Wolfenstein neutrino mass matrix, i.e., the Majorana mass matrix with a vanishing diagonal. Contributions from the charged-lepton mass matrix resolve the well-known problems with lepton mixing arising from the vanishing diagonal. In our scenario, fermion masses and mixings are well reproduced for both normal and inverted neutrino mass spectra, and b-{tau} Yukawa unification and definite predictions for the effective mass in neutrinoless double-{beta} decay are obtained.

  11. A PRECISION MEASUREMENT OF THE NEUTRINO MIXING ANGLE THETA (SUB 13) USING REACTOR ANTINEUTRINOS AT DAYA BAY.

    SciTech Connect (OSTI)

    KETTELL, S.; ET AL.

    2006-10-16

    This document describes the design of the Daya Bay reactor neutrino experiment. Recent discoveries in neutrino physics have shown that the Standard Model of particle physics is incomplete. The observation of neutrino oscillations has unequivocally demonstrated that the masses of neutrinos are nonzero. The smallness of the neutrino masses (<2 eV) and the two surprisingly large mixing angles measured have thus far provided important clues and constraints to extensions of the Standard Model. The third mixing angle, {delta}{sub 13}, is small and has not yet been determined; the current experimental bound is sin{sup 2} 2{theta}{sub 13} < 0.17 at 90% confidence level (from Chooz) for {Delta}m{sub 31}{sup 2} = 2.5 x 10{sup -3} eV{sup 2}. It is important to measure this angle to provide further insight on how to extend the Standard Model. A precision measurement of sin{sup 2} 2{theta}{sub 13} using nuclear reactors has been recommended by the 2004 APS Multi-divisional Study on the Future of Neutrino Physics as well as a recent Neutrino Scientific Assessment Group (NUSAG) report. We propose to perform a precision measurement of this mixing angle by searching for the disappearance of electron antineutrinos from the nuclear reactor complex in Daya Bay, China. A reactor-based determination of sin{sup 2} 2{theta}{sub 13} will be vital in resolving the neutrino-mass hierarchy and future measurements of CP violation in the lepton sector because this technique cleanly separates {theta}{sub 13} from CP violation and effects of neutrino propagation in the earth. A reactor-based determination of sin{sup 2} 2{theta}{sub 13} will provide important, complementary information to that from long-baseline, accelerator-based experiments. The goal of the Daya Bay experiment is to reach a sensitivity of 0.01 or better in sin{sup 2} 2{theta}{sub 13} at 90% confidence level.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2015-12-23

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

  13. Nonzero {theta}{sub 13} for neutrino mixing in a supersymmetric B-L gauge model with T{sub 7} lepton flavor symmetry

    SciTech Connect (OSTI)

    Cao Qinghong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi

    2011-10-01

    We discuss how {theta}{sub 13}{ne}0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T{sub 7} in the context of a supersymmetric extension of the standard model with gauged U(1){sub B-L}. We predict a correlation between {theta}{sub 13} and {theta}{sub 23}, as well as the effective neutrino mass m{sub ee} in neutrinoless double beta decay.

  14. Los Alamos Science, Number 25 -- 1997: Celebrating the Neutrino

    DOE R&D Accomplishments [OSTI]

    Cooper, N. G. ed.

    1997-01-01

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

  15. Los Alamos Science, Number 25 -- 1997: Celebrating the neutrino

    SciTech Connect (OSTI)

    Cooper, N.G.

    1997-12-31

    This issue is devoted to the neutrino and its remaining mysteries. It is divided into the following areas: (1) The Reines-Cowan experiment -- detecting the poltergeist; (2) The oscillating neutrino -- an introduction to neutrino masses and mixing; (3) A brief history of neutrino experiments at LAMPF; (4) A thousand eyes -- the story of LSND (Los Alamos neutrino oscillation experiment); (5) The evidence for oscillations; (6) The nature of neutrinos in muon decay and physics beyond the Standard Model; (7) Exorcising ghosts -- in pursuit of the missing solar neutrinos; (8) MSW -- a possible solution to the solar neutrino problem; (8) Neutrinos and supernovae; and (9) Dark matter and massive neutrinos.

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

    SciTech Connect (OSTI)

    Faessler, A. [University of Tuebingen, Institute of Theoretical Physics (Germany)], E-mail: amand.faessler@uni-tuebingen.de

    2006-12-15

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

  17. Results from Neutrino Oscillations Experiments

    SciTech Connect (OSTI)

    Aguilar-Arevalo, Alexis

    2010-09-10

    The interpretation of the results of early solar and atmospheric neutrino experiments in terms of neutrino oscillations has been verified by several recent experiments using both, natural and man-made sources. The observations provide compelling evidence in favor of the existence of neutrino masses and mixings. These proceedings give a general description of the results from neutrino oscillation experiments, the current status of the field, and some possible future developments.

  18. Neutrino Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutrino Theory Neutrino Theory Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505) 667-5657 Email Neutrino Theory solar neutrino Figure 1: Impact of the solar neutrino mass splitting on collective oscillations of supernova neutrinos. Notice that while the strictly vanishing splitting gives the two-flavor result, even a tiny nonzero value qualitatively changes the answer. From [1]. Neutrino physics underwent

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

    SciTech Connect (OSTI)

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

    2013-07-01

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

  20. Neutrino Oscillation Physics

    SciTech Connect (OSTI)

    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.

  1. The fluxes of CN neutrinos from the Sun in case of mixing in a spherical layer in the solar core

    SciTech Connect (OSTI)

    Kopylov, Anatoly; Petukhov, Valery E-mail: beril@inr.ru

    2012-03-01

    The results of the calculation are presented for the fluxes of CN neutrinos from the Sun in case of mixing in a spherical layer in the solar core, consistent with the seismic data and with the measured solar neutrino fluxes. It is shown that a substantial increase of the flux of {sup 13}N neutrinos can be gained in this case. The possible implications for experiment are discussed.

  2. Matter effects in active-sterile solar neutrino oscillations

    SciTech Connect (OSTI)

    Giunti, C.; Li, Y. F.

    2009-12-01

    The matter effects for solar neutrino oscillations are studied in a general scheme with an arbitrary number of sterile neutrinos, without any constraint on the mixing, assuming only a realistic hierarchy of neutrino squared-mass differences in which the smallest squared-mass difference is effective in solar neutrino oscillations. The validity of the analytic results are illustrated with a numerical solution of the evolution equation in three examples of the possible mixing matrix in the simplest case of four-neutrino mixing.

  3. neutrinos matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nu0001 PDF full text version nu0001 HTML full text version nu0002 Credits nu0003 Contents nu0004 Introduction nu0005 Neutrinos are Everywhere nu0006 What are neutrinos? nu0007 A new particle? nu0008 Origins nu0009 Making neutrinos nu0010 Seeing neutrinos nu0011 Big detector nu0012 Neutrinos are there nu0013 Loners of the universe nu0014 The neutrino family nu0015 Neutrino tracks nu0016 Do they have mass? nu0017 What if they do? nu0018 Oscillations nu0019 Seeing the invisible nu0020 Neutrinos

  4. Neutrino masses in SU(4){sub L}⊗U(1){sub X} gauge models

    SciTech Connect (OSTI)

    Palcu, Adrian

    2013-11-13

    Neutrino masses are obtained within SU(4){sub L}⊗U(1){sub X} electroweak gauge models with spontaneous symmetry breaking by simply exploiting the tree level realization of certain dimension-five effective operators. The scalar sector needs not to be enlarged, since these operators are constructed as direct products among scalar multiplets already existing in the model. There is a unique generic matrix for Yukawa couplings in the neutrino sector, while the charged leptons are already in their diagonal basis. The experimentally observed phenomenology in the neutrino sector is obtained as a natural consequence of this particular approach.

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

    SciTech Connect (OSTI)

    Wagner, Christian; Verde, Licia; Jimenez, Raul [Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E08028 Barcelona (Spain)

    2012-06-20

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

  6. Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology

    SciTech Connect (OSTI)

    Lindner, Manfred; Merle, Alexander; Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

    2006-03-01

    We analyze the impact of a measurement, or of an improved bound, on {theta}{sub 13} for the determination of the effective neutrino mass in neutrinoless double beta decay and cosmology. In particular, we discuss how an improved limit on (or a specific value of) {theta}{sub 13} can influence the determination of the neutrino mass spectrum via neutrinoless double beta decay. We also discuss the interplay with improved cosmological neutrino mass searches.

  7. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high sourcemore » luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.« less

  8. Status of the KATRIN experiment and prospects to search for keV-mass sterile neutrinos in tritium β-decay

    SciTech Connect (OSTI)

    Mertens, Susanne

    2015-03-24

    In this contribution the current status and future perspectives of the Karlsruhe Tritium Neutrino (KATRIN) Experiment are presented. The prime goal of this single β-decay experiment is to probe the absolute neutrino mass scale with a sensitivity of 200 meV (90% CL). We discuss first results of the recent main spectrometer commissioning measurements, successfully verifying the spectrometer’s basic vacuum, transmission and background properties. We also discuss the prospects of making use of the KATRIN tritium source, to search for sterile neutrinos in the multi-keV mass range constituting a classical candidate for Warm Dark Matter. Due to the very high source luminosity, a statistical sensitivity down to active-sterile mixing angles of sin² θ < 1 · 10⁻⁷ (90% CL) could be reached.

  9. Mass varying neutrinos, quintessence, and the accelerating expansion of the Universe

    SciTech Connect (OSTI)

    Chitov, Gennady Y.; August, Tyler [Department of Physics, Laurentian University, Ramsey Lake Road, Sudbury, ON, P3E 2C6 (Canada); Natarajan, Aravind [McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Kahniashvili, Tina [McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Department of Physics, Laurentian University, Ramsey Lake Road, Sudbury, ON, P3E 2C6 (Canada); National Abastumani Astrophysical Observatory, Ilia Chavchavadze State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia)

    2011-02-15

    We analyze the mass varying neutrino scenario. We consider a minimal model of massless Dirac fermions coupled to a scalar field, mainly in the framework of finite-temperature quantum field theory. We demonstrate that the mass equation we find has nontrivial solutions only for special classes of potentials, and only within certain temperature intervals. We give most of our results for the Ratra-Peebles dark energy (DE) potential. The thermal (temporal) evolution of the model is analyzed. Following the time arrow, the stable, metastable, and unstable phases are predicted. The model predicts that the present Universe is below its critical temperature and accelerates. At the critical point, the Universe undergoes a first-order phase transition from the (meta)stable oscillatory regime to the unstable rolling regime of the DE field. This conclusion agrees with the original idea of quintessence as a force making the Universe roll towards its true vacuum with a zero {Lambda} term. The present mass varying neutrino scenario is free from the coincidence problem, since both the DE density and the neutrino mass are determined by the scale M of the potential. Choosing M{approx}10{sup -3} eV to match the present DE density, we can obtain the present neutrino mass in the range m{approx}10{sup -2}-1 eV and consistent estimates for other parameters of the Universe.

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

    SciTech Connect (OSTI)

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

    2014-05-01

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

  11. On the minimum dark matter mass testable by neutrinos from the Sun

    SciTech Connect (OSTI)

    Busoni, Giorgio; Simone, Andrea De; Huang, Wei-Chih E-mail: andrea.desimone@sissa.it

    2013-07-01

    We discuss a limitation on extracting bounds on the scattering cross section of dark matter with nucleons, using neutrinos from the Sun. If the dark matter particle is sufficiently light (less than about 4 GeV), the effect of evaporation is not negligible and the capture process goes in equilibrium with the evaporation. In this regime, the flux of solar neutrinos of dark matter origin becomes independent of the scattering cross section and therefore no constraint can be placed on it. We find the minimum values of dark matter masses for which the scattering cross section on nucleons can be probed using neutrinos from the Sun. We also provide simple and accurate fitting functions for all the relevant processes of GeV-scale dark matter in the Sun.

  12. Investigation of Neutrino Properties with Bolometric Detectors

    SciTech Connect (OSTI)

    Heeger, Karsten M

    2014-11-01

    Neutrino mass and mixing are amongst the major discoveries of the past decade. The particle nature of neutrinos and the hierarchy of mass eigenstates, however, are unknown. Neutrinoless double beta-decay (0νββ) is the only known mechanism to test whether neutrinos are their own antiparticles. The observation of 0νββ would imply lepton number violation and show that neutrinos have Majorana mass. This report describes research activities performed at the University of Wisconsin in 2011-2014 aimed at the search for 0νββ with CUORE-0 and CUORE with the goal of exploring the inverted mass hierarchy region and probing an effective neutrino mass of ~40- 120 meV.

  13. Dirac neutrino in warped extra dimensions

    SciTech Connect (OSTI)

    Chang, W.-F.; Ng, John N.; Wu, Jackson M. S.

    2009-12-01

    We implement Dirac neutrinos in the minimal custodial Randall-Sundrum setting via the Krauss-Wilczek mechanism. We demonstrate by giving explicit lepton mass matrices that with neutrinos in the normal hierarchy, lepton mass and mixing patterns can be naturally reproduced at the scale set by the constraints from electroweak precision measurements, and at the same time without violating bounds set by lepton flavor violations. Our scenario generically predicts a nonzero neutrino mixing angle {theta}{sub 13}, as well as the existence of sub-TeV right-handed Kaluza-Klein neutrinos, which partner the right-handed standard model charged leptons. These relatively light KK neutrinos may be searched for at the LHC.

  14. Precision Measurements of Long-Baseline Neutrino Oscillation at LBNF

    SciTech Connect (OSTI)

    Worcester, Elizabeth

    2015-08-06

    In a long-baseline neutrino oscillation experiment, the primary physics objectives are to determine the neutrino mass hierarchy, to determine the octant of the neutrino mixing angle θ23, to search for CP violation in neutrino oscillation, and to precisely measure the size of any CP-violating effect that is discovered. This presentation provides a brief introduction to these measurements and reports on efforts to optimize the design of a long-baseline neutrino oscillation experiment, the status of LBNE, and the transition to an international collaboration at LBNF.

  15. Precision Measurements of Long-Baseline Neutrino Oscillation at LBNF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Worcester, Elizabeth

    2015-08-06

    In a long-baseline neutrino oscillation experiment, the primary physics objectives are to determine the neutrino mass hierarchy, to determine the octant of the neutrino mixing angle θ23, to search for CP violation in neutrino oscillation, and to precisely measure the size of any CP-violating effect that is discovered. This presentation provides a brief introduction to these measurements and reports on efforts to optimize the design of a long-baseline neutrino oscillation experiment, the status of LBNE, and the transition to an international collaboration at LBNF.

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

    SciTech Connect (OSTI)

    Rodriguez, J-Alexis; Duarte, J.

    2008-11-23

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

  17. Neutrinos in Nuclear Physics

    SciTech Connect (OSTI)

    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.

  18. An SO(10) × SO(10)' model for common origin of neutrino masses, ordinary and dark matter-antimatter asymmetries

    SciTech Connect (OSTI)

    Gu, Pei-Hong

    2014-12-01

    We propose an SO(10) × SO(10)' model to simultaneously realize a seesaw for Dirac neutrino masses and a leptogenesis for ordinary and dark matter-antimatter asymmetries. A (16 × 1-bar 6-bar '){sub H} scalar crossing the SO(10) and SO(10)' sectors plays an essential role in this seesaw-leptogenesis scenario. As a result of lepton number conservation, the lightest dark nucleon as the dark matter particle should have a determined mass around 15 GeV to explain the comparable fractions of ordinary and dark matter in the present universe. The (16 × 1-bar 6-bar '){sub H} scalar also mediates a U(1){sub em} × U(1)'{sub em} kinetic mixing after the ordinary and dark left-right symmetry breaking so that we can expect a dark nucleon scattering in direct detection experiments and/or a dark nucleon decay in indirect detection experiments. Furthermore, we can impose a softly broken mirror symmetry to simplify the parameter choice.

  19. Long Baseline Neutrino Beams and Large Detectors

    SciTech Connect (OSTI)

    Samios,N.P.

    2008-10-27

    It is amazing to acknowledge that in roughly 70 years from when the existence of the neutrino was postulated, we are now contemplating investigating the mysteries of this particle (or particles) requiring and utilizing detectors of 300 ktons , distances of 1,000-2,000 kilometers, beam intensities of megawatts and underground depth of 5,000 feet. This evolution has evolved slowly, from the experimental discovery of the neutrino in 1956, to the demonstration that there were two neutrinos in 1962 and three and only three by 1991. The great excitement occurred in the 2000's coming from the study of solar and atmospheric neutrinos in which neutrinos were observed to oscillate and therefore have mass. Although the absolute mass of any of the neutrinos has yet to be determined (the upper limit is less than I electron volt) the difference in this square of these masses has been measured, yielding a value of (2.3 {+-} .2) 10{sup -3} ev{sup 2} for atmospheric neutrinos and (7.6 {+-} .2) 10{sup -5} ev{sup 2} for solar neutrinos. In addition their mixing angles were found to be 45{sup o} for atmospheric neutrinos and 34{sup o} for solar neutrinos. This present state of knowledge on neutrinos is pictorially displayed in Fig. 1. Of course, mixing between flavors had already been observed in the quark sector as exemplified by the Cabbibo-Kobayashi-Meskawa Matrix. It was therefore natural to extend this formalism to the lepton sector involving unitary 3 x 3 matrices and one CP violating phase. This is shown in Fig. 2 for the two sectors, quark and leptons including the Jarlskog invariant (J).

  20. Conversion of experimental half-life to effective electron neutrino mass in 0nubetabeta decay

    SciTech Connect (OSTI)

    Smolnikov, Anatoly; Grabmayr, Peter [Joint Institute for Nuclear Research, Dubna, Russia, and Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Kepler Center for Astro and Particle Physics, Eberhard Karls Universitaet Tuebingen (Germany)

    2010-02-15

    The Germanium Detector Array (GERDA) collaboration will be searching for neutrinoless double beta decay of {sup 76}Ge. As a result it will measure the half-life T{sub 1/2} of this rare process; or at least a new value for the lower limit for T{sub 1/2} will be derived. The sensitivity of the GERDA experiment on the effective electron neutrino mass depends on the theoretical value for the nuclear matrix element M and the kinematical phase space factor G.In this Brief Report we focus on existing difficulties in applying the dimensionless values of M calculated by various theoretical groups, which use different methods and parametrizations. The implicit radius dependencies in M and G are discussed. Resulting values of the neutrino mass are tabulated for various representative half-lives T{sub 1/2} representing the sensitivity of the various phases of the GERDA experiment.

  1. A measurement of neutrino oscillations with muon neutrinos in the MINOS experiment

    SciTech Connect (OSTI)

    Coleman, Stephen James; /William-Mary Coll.

    2011-01-01

    Experimental evidence has established that neutrino flavor states evolve over time. A neutrino of a particular flavor that travels some distance can be detected in a different neutrino flavor state. The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline experiment that is designed to study this phenomenon, called neutrino oscillations. MINOS is based at Fermilab near Chicago, IL, and consists of two detectors: the Near Detector located at Fermilab, and the Far Detector, which is located in an old iron mine in Soudan, MN. Both detectors are exposed to a beam of muon neutrinos from the NuMI beamline, and MINOS measures the fraction of muon neutrinos that disappear after traveling the 734 km between the two detectors. One can measure the atmospheric neutrino mass splitting and mixing angle by observing the energy-dependence of this muon neutrino disappearance. MINOS has made several prior measurements of these parameters. Here I describe recently-developed techniques used to enhance our sensitivity to the oscillation parameters, and I present the results obtained when they are applied to a dataset that is twice as large as has been previously analyzed. We measure the mass splitting {Delta}m{sub 23}{sup 2} = (2.32{sub -0.08}{sup +0.12}) x 10{sup -3} eV{sup 2}/c{sup 4} and the mixing angle sin{sup 2}(2{theta}{sub 32}) > 0.90 at 90% C.L. These results comprise the world's best measurement of the atmospheric neutrino mass splitting. Alternative disappearance models are also tested. The neutrino decay hypothesis is disfavored at 7.2{sigma} and the neutrino quantum decoherence hypothesis is disfavored at 9.0{sigma}.

  2. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    SciTech Connect (OSTI)

    Abazov, Victor Mukhamedovich

    2015-11-11

    We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at √s= 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. Furthermore, we improve the calibration of jet energies using the calibration determined in tt¯ → lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. As a result, the measured top quark mass is mt = 173.32±1.36(stat)±0.85(syst) GeV.

  3. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich

    2015-11-11

    We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at √s= 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. Furthermore, we improve the calibration of jet energies using the calibration determined in tt¯ → lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. As a result, the measured top quark mass is mt = 173.32±1.36(stat)±0.85(syst) GeV.

  4. Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass

    SciTech Connect (OSTI)

    Vergados, J. D. [Physics Department, University of Ioannina, Ioannina, GR 451 10, Greece and Theory Division, CERN 1211, Geneva 23 (Greece)

    2011-12-16

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0{nu}{beta}{beta}-decay in three different nuclei, e.g. {sup 76}Ge, {sup 100}Mo and {sup 130}Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.

  5. BooNE: Booster Neutrino Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    BooNE will investigate the question of neutrino mass by searching for oscillations of muon neutrinos into electron neutrinos. This will be done by directing a muon neutrino beam...

  6. FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.

    SciTech Connect (OSTI)

    GALLARDO,J.C.; OZAKI,S.; PALMER,R.B.; ZISMAN,M.

    2001-06-30

    The concept of using a muon storage ring to provide a well characterized beam of muon and electron neutrinos (a Neutrino Factory) has been under study for a number of years now at various laboratories throughout the world. The physics program of a Neutrino Factoryis focused on the relatively unexplored neutrino sector. In conjunction with a detector located a suitable distance from the neutrino source, the facility would make valuable contributions to the study of neutrino masses and lepton mixing. A Neutrino Factory is expected to improve the measurement accuracy of sin{sup 2}(2{theta}{sub 23}) and {Delta}m{sup 2}{sub 32} and provide measurements of sin{sup 2}(2{theta}{sub 13}) and the sign of {Delta}m{sup 2}{sub 32}. It may also be able to measure CP violation in the lepton sector.

  7. Accelerator-based neutrino oscillation searches

    SciTech Connect (OSTI)

    Whitehouse, D.A.; Rameika, R.; Stanton, N.

    1993-10-01

    This paper attempts to summarize the neutrino oscillation section of the Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Beam Facilities. There were very lively discussions about the merits of the different oscillation channels, experiments, and facilities, but we believe a substantial consensus emerged. First, the next decade is one of great potential for discovery in neutrino physics, but it is also one of great peril. The possibility that neutrino oscillations explain the solar neutrino and atmospheric neutrino experiments, and the indirect evidence that Hot Dark Matter (HDM) in the form of light neutrinos might make up 30% of the mass of the universe, point to areas where accelerator-based experiments could play a crucial role in piecing together the puzzle. At the same time, the field faces a very uncertain future. The LSND experiment at LAMPF is the only funded neutrino oscillation experiment in the United States and it is threatened by the abrupt shutdown of LAMPF proposed for fiscal 1994. The future of neutrino physics at the Brookhaven National Laboratory AGS depends the continuation of High Energy Physics (HEP) funding after the RHIC startup. Most proposed neutrino oscillation searches at Fermilab depend on the completion of the Main Injector project and on the construction of a new neutrino beamline, which is uncertain at this point. The proposed KAON facility at TRIUMF would provide a neutrino beam similar to that at the AGS but with a much increase intensity. The future of KAON is also uncertain. Despite the difficult obstacles present, there is a real possibility that we are on the verge of understanding the masses and mixings of the neutrinos. The physics importance of such a discovery can not be overstated. The current experimental status and future possibilities are discussed below.

  8. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters

    SciTech Connect (OSTI)

    Prasai, K.; Yanardag, S. Basak; Galeazzi, M.; Uprety, Y.; Alves, E.; Rocha, J.; Bagliani, D.; Biasotti, M.; Gatti, F.; Gomes, M. Ribeiro

    2013-08-15

    In a microcalorimetric neutrino mass experiment using the radioactive decay of {sup 163}Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the {sup 163}Ho fabrication), in the temperature range 70 mK–300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

  9. A study of muon neutrino disappearance in the MINOS detectors and the NuMI beam

    SciTech Connect (OSTI)

    Ling, Jiajie; /South Carolina U.

    2010-07-01

    There is now substantial evidence that the proper description of neutrino involves two representations related by the 3 x 3 PMNS matrix characterized by either distinct mass or flavor. The parameters of this mixing matrix, three angles and a phase, as well as the mass differences between the three mass eigenstates must be determined experimentally. The Main Injector Neutrino Oscillation Search experiment is designed to study the flavor composition of a beam of muon neutrinos as it travels between the Near Detector at Fermi National Accelerator Laboratory at 1 km from the target, and the Far Detector in the Soudan iron mine in Minnesota at 735 km from the target. From the comparison of reconstructed neutrino energy spectra at the near and far location, precise measurements of neutrino oscillation parameters from muon neutrino disappearance and electron neutrino appearance are expected. It is very important to know the neutrino flux coming from the source in order to achieve the main goal of the MINOS experiment: precise measurements of the atmospheric mass splitting |{Delta}m{sub 23}{sup 2}|, sin{sup 2} {theta}{sub 23}. The goal of my thesis is to accurately predict the neutrino flux for the MINOS experiment and measure the neutrino mixing angle and atmospheric mass splitting.

  10. Scientific Opportunities with the Long-Baseline Neutrino Experiment

    SciTech Connect (OSTI)

    Adams, C.; et al.,

    2013-07-28

    In this document, we describe the wealth of science opportunities and capabilities of LBNE, the Long-Baseline Neutrino Experiment. LBNE has been developed to provide a unique and compelling program for the exploration of key questions at the forefront of particle physics. Chief among the discovery opportunities are observation of CP symmetry violation in neutrino mixing, resolution of the neutrino mass hierarchy, determination of maximal or near-maximal mixing in neutrinos, searches for nucleon decay signatures, and detailed studies of neutrino bursts from galactic supernovae. To fulfill these and other goals as a world-class facility, LBNE is conceived around four central components: (1) a new, intense wide-band neutrino source at Fermilab, (2) a fine-grained `near' neutrino detector just downstream of the source, (3) the Sanford Underground Research Facility (SURF) in Lead, South Dakota at an optimal distance (~1300 km) from the neutrino source, and (4) a massive liquid argon time-projection chamber (LArTPC) deployed there as a 'far' detector. The facilities envisioned are expected to enable many other science opportunities due to the high event rates and excellent detector resolution from beam neutrinos in the near detector and atmospheric neutrinos in the far detector. This is a mature, well developed, world class experiment whose relevance, importance, and probability of unearthing critical and exciting physics has increased with time.

  11. CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy

    SciTech Connect (OSTI)

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Cai, X. Z.; Camacho, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Dafinei, I.; Dally, A.; Datskov, V.; De Biasi, A.; Deninno, M. M.; Di Domizio, S.; di Vacri, M. L.; Ejzak, L.; Fang, D. Q.; Farach, H. A.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Goett, J.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Hennings-Yeomans, R.; Huang, H. Z.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kolomensky, Yu. G.; Li, Y. L.; Ligi, C.; Liu, X.; Ma, Y. G.; Maiano, C.; Maino, M.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Napolitano, T.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; O’Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Wielgus, L.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhu, B. X.; Zucchelli, S.

    2015-03-24

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130Te. With 741 kg of TeO2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6 × 1026 y at 1σ (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with 130Te and possibly other double beta decay candidate nuclei.

  12. CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; et al

    2015-03-24

    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130Te. With 741 kg of TeO2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6 × 1026 y at 1σ (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meVmore » (50–130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with 130Te and possibly other double beta decay candidate nuclei.« less

  13. Future Long-Baseline Neutrino Oscillations: View from North America

    SciTech Connect (OSTI)

    Wilson, R. J.

    2015-06-01

    In late 2012 the US Department of Energy gave approval for the first phase of the Long-Baseline Neutrino Experiment (LBNE), that will conduct a broad scientific program including neutrino oscillations, neutrino scattering physics, search for baryon violation, supernova burst neutrinos and other related astrophysical phenomena. The project is now being reformulated as an international facility hosted by the United States. The facility will consist of an intense neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), a highly capable set of neutrino detectors on the Fermilab campus, and a large underground liquid argon time projection chamber at Sanford Underground Research Facility (SURF) in South Dakota 1300 km from Fermilab. With an intense beam and massive far detector, the experimental program at the facility will make detailed studies of neutrino oscillations, including measurements of the neutrino mass hierarchy and Charge-Parity symmetry violation, by measuring neutrino and anti-neutrino mixing separately. At the near site, the high-statistics neutrino scattering data will allow for many cross section measurements and precision tests of the Standard Model. This presentation will describe the configuration developed by the LBNE collaboration, the broad physics program, and the status of the formation of the international facility.

  14. Neutrino Physics | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutrino Physics Neutrino Physics Experimental neutrino physics is focused on the measurements of mass and other properties of neutrinos that may have profound consequences for understanding the evolution of the universe. Over the last few decades, particle physicists have accumulated experimental evidence on the properties of major constituents of matter, including neutrinos, to explain how neutrinos interact with matter and how these ghostly particles propagate over long distances. We have

  15. Isolation of 163Ho from dysprosium target material by HPLC for neutrino mass measurements

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mocko, Veronika; Taylor, Wayne  A.; Nortier, Francois M.; Engle, Jonathan  W.; Barnhart, Todd  E.; Nickles, Robert  J.; Pollington, Anthony  D.; Kunde, Gerd  J.; Rabin, Michael  W.; Birnbaum, Eva  R.

    2015-04-29

    The rare earth isotope 163Ho is of interest for neutrino mass measurements. This report describes the isolation of 163Ho from a proton-irradiated dysprosium target and its purification. A Dy metal target was irradiated with 16 MeV protons for 10 h. After target dissolution, 163Ho was separated from the bulk Dy via cation-exchange high performance liquid chromatography using 70 mmol dm–3 α-hydroxyisobutyric acid as the mobile phase. Subsequent purification of the collected Ho fraction was performed to remove the α-hydroxyisobutyrate chelating agent and to concentrate the Ho in a low ionic strength aqueous matrix. The final solution was characterized by MC-ICP-MSmore » to determine the 163Ho/165Ho ratio, 163Ho and the residual Dy content. The HPLC purification process resulted in a decontamination factor 1.4E5 for Dy. As a result, the isolated Ho fraction contained 24.8 ±1.3 ng of 163Ho corresponding to holmium recovery of 72 ± 3%.« less

  16. Neutrino Physics at Fermilab

    ScienceCinema (OSTI)

    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.

  17. Booster Neutrino Experiment - About Neutrinos

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from major neutrino experiments and important results in neutrino physics. Includes java applets. Janet's Neutrino Oscillation Page More extensive material about neutrino...

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

    SciTech Connect (OSTI)

    Babi?, Andrej; imkovic, 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.

  19. EFFECTS OF A DEEP MIXED SHELL ON SOLAR g-MODES, p-MODES, AND NEUTRINO FLUX

    SciTech Connect (OSTI)

    Wolff, Charles L.

    2009-08-10

    A mixed-shell model that reflects g-modes away from the Sun's center is developed further by calibrating its parameters and evaluating a mixing mechanism: buoyancy. The shell roughly doubles g-mode oscillation periods and would explain why there is no definitive detection of their periods. But the shell has only minor effects on most p-modes. The model provides a mechanism for causing short-term fluctuations in neutrino flux and makes plausible the correlations between this flux and solar activity levels. Relations are derived for a shell heated asymmetrically by transient increases in nuclear burning in small 'hot spots'. The size of these spots and the timing of a heating event are governed by sets(l) of standing asymptotic g-modes, coupled by a maximal principle that greatly enhances their excitation and concentrates power toward the equator, assisting the detection of higher-l sets. Signals from all sets, except one, in the range 2 {<=} l {<=} 8 are identified by difference periods between consecutive radial states using the method of Garcia et al. and reinterpreting their latest spectrum. This confirms two detections of sets in a similar range of l by their rotation rates. The mean radius of shell mixing is r{sub m} = 0.16 R{sub sun}, which improves an earlier independent estimate of 0.18 by the author. The shell may cause the unexplained dip in measured sound speed at its location. Another sound speed error, centered near 0.67 R{sub sun}, and reversing flows in the same place with a period originally near 1.3 yr suggest that the g-modes are depositing there about 3% of the solar luminosity. That implies the shell at r{sub m} is receiving a similar magnitude of power, which would be enough energy to mix the corresponding shell in a standard solar model in <<10{sup 7} yr.

  20. Observing Muon Neutrino to Electron Neutrino Oscillations in the NOνA Experiment

    SciTech Connect (OSTI)

    Xin, Tian

    2016-01-01

    Neutrino oscillations offers an insight on new physics beyond the Standard Model. The three mixing angles (θ12, θ13 and θ23) and the two mass splittings (Δm2 and Αm2 ) have been measured by different neutrino oscillation experiments. Some other parameters including the mass ordering of different neutrino mass eigenstates and the CP violation phase are still unknown. NOνA is a long-baseline accelerator neutrino experiment, using neutrinos from the NuMI beam at Fermilab. The experiment is equipped with two functionally identical detectors about 810 kilometers apart and 14 mrad off the beam axis. In this configuration, the muon neutrinos from the NuMI beam reach the disappearance maximum in the far detector and a small fraction of that oscillates into electron neutrinos. The sensitivity to the mass ordering and CP viola- tion phase determination is greately enhanced. This thesis presents the νeappearance analysis using the neutrino data collected with the NOνA experiment between February 2014 and May 2015, which corresponds to 3.45 ×1020 protons-on-target (POT). The νe appearance analysis is performed by comparing the observed νe CC-like events to the estimated background at the far detector. The total background is predicted to be 0.95 events with 0.89 originated from beam events and 0.06 from cosmic ray events. The beam background is obtained by extrapolating near detector data through different oscillation channels, while the cosmic ray background is calculated based on out-of-time NuMI trigger data. A total of 6 electron neutrino candidates are observed in the end at the far detector which represents 3.3 σ excess over the predicted background. The NOνA result disfavors inverted mass hierarchy for δcp ϵ [0, 0.6π] at 90% C.L.

  1. Neutrinoless double beta decay and future neutrino oscillation precision experiments

    SciTech Connect (OSTI)

    Choubey, Sandhya [Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

    2005-08-01

    We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the {delta}m{sup 2} corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter {theta}{sub 12} will govern a large part of the uncertainty. We focus, in particular, on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses which allow to distinguish the normal from the inverted hierarchy. All aspects are discussed as a function of the uncertainty stemming from the involved nuclear matrix elements. The implications of a vanishing, or extremely small, effective mass are also investigated. By giving a large list of possible neutrino mass matrices and their predictions for the observables, we finally explore how a measurement of (or an improved limit on) neutrinoless double beta decay can help to identify the neutrino mass matrix if more precise values of the relevant parameters are known.

  2. Cosmic Neutrinos Scott Dodelson Fermilab/UChicago

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    matter particles with the smallest mass, neutrinos, are also the most abundant in the Universe. Large cosmic surveys can not only detect these neutrinos, produced when the Universe...

  3. Subgrid models for mass and thermal diffusion in turbulent mixing

    SciTech Connect (OSTI)

    Sharp, David H; Lim, Hyunkyung; Li, Xiao - Lin; Gilmm, James G

    2008-01-01

    We are concerned with the chaotic flow fields of turbulent mixing. Chaotic flow is found in an extreme form in multiply shocked Richtmyer-Meshkov unstable flows. The goal of a converged simulation for this problem is twofold: to obtain converged solutions for macro solution features, such as the trajectories of the principal shock waves, mixing zone edges, and mean densities and velocities within each phase, and also for such micro solution features as the joint probability distributions of the temperature and species concentration. We introduce parameterized subgrid models of mass and thermal diffusion, to define large eddy simulations (LES) that replicate the micro features observed in the direct numerical simulation (DNS). The Schmidt numbers and Prandtl numbers are chosen to represent typical liquid, gas and plasma parameter values. Our main result is to explore the variation of the Schmidt, Prandtl and Reynolds numbers by three orders of magnitude, and the mesh by a factor of 8 per linear dimension (up to 3200 cells per dimension), to allow exploration of both DNS and LES regimes and verification of the simulations for both macro and micro observables. We find mesh convergence for key properties describing the molecular level of mixing, including chemical reaction rates between the distinct fluid species. We find results nearly independent of Reynolds number for Re 300, 6000, 600K . Methodologically, the results are also new. In common with the shock capturing community, we allow and maintain sharp solution gradients, and we enhance these gradients through use of front tracking. In common with the turbulence modeling community, we include subgrid scale models with no adjustable parameters for LES. To the authors' knowledge, these two methodologies have not been previously combined. In contrast to both of these methodologies, our use of Front Tracking, with DNS or LES resolution of the momentum equation at or near the Kolmogorov scale, but without resolving the

  4. Subpanel on accelerator-based neutrino oscillation experiments

    SciTech Connect (OSTI)

    1995-09-01

    Neutrinos are among nature`s fundamental constituents, and they are also the ones about which we know least. Their role in the universe is widespread, ranging from the radioactive decay of a single atom to the explosions of supernovae and the formation of ordinary matter. Neutrinos might exhibit a striking property that has not yet been observed. Like the back-and-forth swing of a pendulum, neutrinos can oscillate to-and-from among their three types (or flavors) if nature provides certain conditions. These conditions include neutrinos having mass and a property called {open_quotes}mixing.{close_quotes} The phenomenon is referred to as neutrino oscillations. The questions of the origin of neutrino mass and mixing among the neutrino flavors are unsolved problems for which the Standard Model of particle physics holds few clues. It is likely that the next critical step in answering these questions will result from the experimental observation of neutrino oscillations. The High Energy Physics Advisory Panel (HEPAP) Subpanel on Accelerator-Based Neutrino Oscillation Experiments was charged to review the status and discovery potential of ongoing and proposed accelerator experiments on neutrino oscillations, to evaluate the opportunities for the U.S. in this area of physics, and to recommend a cost-effective plan for pursuing this physics, as appropriate. The complete charge is provided in Appendix A. The Subpanel studied these issues over several months and reviewed all the relevant and available information on the subject. In particular, the Subpanel reviewed the two proposed neutrino oscillation programs at Fermi National Accelerator Laboratory (Fermilab) and at Brookhaven National Laboratory (BNL). The conclusions of this review are enumerated in detail in Chapter 7 of this report. The recommendations given in Chapter 7 are also reproduced in this summary.

  5. No-neutrino double beta decay: more than one neutrino

    SciTech Connect (OSTI)

    Rosen, S.P.

    1983-01-01

    Interference effects between light and heavy Majorana neutrinos in the amplitude for no-neutrino double beta decay are discussed. The effects include an upper bound on the heavy neutrino mass, and an A dependence for the effective mass extracted from double beta decay. Thus the search for the no-neutrino decay mode should be pursued in several nuclei, and particularly in Ca/sup 48/, where the effective mass may be quite large.

  6. Study of muon neutrino and muon antineutrino disappearance with the NOvA neutrino oscillation experiment

    SciTech Connect (OSTI)

    Pawloski, Gregory

    2014-06-30

    The primary goal of this working group is to study the disappearance rate of νμ charged current events in order to measure the mixing angle θ23 and the magnitude of the neutrino mass square splitting Δm 232.

  7. Independent measurement of the neutrino mixing angle θ13 via neutron capture on hydrogen at Daya Bay

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jaffe, D. E.

    2014-10-03

    A new measurement of the θ13 mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of the θ13 measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GWth reactors, the rate deficit observed at the far hall is interpreted as sin22θ13=0.083±0.018 in the three-flavor oscillationmore » model. When combined with the gadolinium-capture result from Daya Bay, we obtain sin22θ13=0.089±0.008 as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.« less

  8. Independent measurement of the neutrino mixing angle ?13 via neutron capture on hydrogen at Daya Bay

    SciTech Connect (OSTI)

    Jaffe, D. E.

    2014-10-03

    A new measurement of the ?13 mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of the ?13 measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GWth reactors, the rate deficit observed at the far hall is interpreted as sin22?13=0.0830.018 in the three-flavor oscillation model. When combined with the gadolinium-capture result from Daya Bay, we obtain sin22?13=0.0890.008 as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.

  9. Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

    SciTech Connect (OSTI)

    He, Yudong |

    1995-07-01

    This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled `Neutrino Mass and Oscillation`, `High Energy Neutrino Astrophysics`, `Detection of Dark Matter`, `Search for Strange Quark Matter`, and `Magnetic Monopole Searches`. The report is introduced by a survey of the field and a brief description of each of the author`s papers.

  10. Are neutrinos their own antiparticles?

    SciTech Connect (OSTI)

    Kayser, Boris; /Fermilab

    2009-03-01

    We explain the relationship between Majorana neutrinos, which are their own antiparticles, and Majorana neutrino masses. We point out that Majorana masses would make the neutrinos very distinctive particles, and explain why many theorists strongly suspect that neutrinos do have Majorana masses. The promising approach to confirming this suspicion is to seek neutrinoless double beta decay. We introduce a toy model that illustrates why this decay requires nonzero neutrino masses, even when there are both right-handed and left-handed weak currents.

  11. 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 (OSTI)

    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 ?} ? 10{sup 54} erg s{sup 1}), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution.

  12. Low Energy Neutrino Oscillations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Low Energy Neutrino Oscillations Žarko Pavlović Los Alamos National Laboratory APS April Meeting, May 1 2011 Standard Model & Neutrino Oscillations ● 3 neutrinos ● Initially assumed massless ● Mixing matrix: ● Oscillation Probability:   e      =  U e1 U e2 U e3 U 1 U 2 U 3 U  1 U  2 U  3    1  2  3  Neutrino Oscillations ● Lot of experimental evidence ● L/E dependence ● Precise measurement of atmospheric and solar

  13. Right-Handed Neutrinos and the 2 TeV $W'$ Boson

    SciTech Connect (OSTI)

    Coloma, Pilar; Dobrescu, Bogdan A.; Lopez-Pavon, Jacobo

    2015-12-30

    The CMS e+e-jj events of invariant mass near 2 TeV are consistent with a W' boson decaying into an electron and a right-handed neutrino whose TeV-scale mass is of the Dirac type. We show that the Dirac partner of the right-handed electron-neutrino can be the right-handed tau-neutrino. Furthermore, a prediction of this model is that the sum of the τ+e+jj and τ-e-jj signal cross sections equals twice that for e+e-jj. The Standard Model neutrinos acquire Majorana masses and mixings compatible with neutrino oscillation data.

  14. Sterile Neutrino Searches in MINOS and MINOS+ Experiments

    SciTech Connect (OSTI)

    Huang, Junting

    2015-05-01

    This dissertation presents the searches on sterile neutrinos using the data collected in MINOS+ Experiment from September 2013 to September 2014, and the full data set of MINOS Experiment collected from 2005 to 2012. Anomalies in short baseline experiments, such as LSND and MiniBooNE, showed hints of sterile neutrinos, a type of neutrino that does not interact with the Standard Model particles. In this work, two models are considered: 3+1 and large extra dimension (LED). In the 3+1 model, one sterile neutrino state is added into the standard oscillation scheme consisting of three known active neutrino states ve, vμ and vτ. In the LED model, sterile neutrinos arise as Kaluza-Klein (KK) states due to assumed large extra dimensions. Mixing between sterile and active neutrino states may modify the oscillation patterns observed in the MINOS detectors. Both searches yield null results. For 3+1, a combined fit of MINOS and MINOS+ data gives a stronger limit on θ24 in the range of 10-2 eV2 < Δm412 < 1 eV2 than previous experiments. For LED, with the complete MINOS data set, the size of extra dimensions is constrained to be smaller than ~ 0.35 μm at 90% C.L. in the limit of a vanishing lightest neutrino mass.

  15. Neutrinos from WIMP annihilations obtained using a full three-flavor Monte Carlo approach

    SciTech Connect (OSTI)

    Blennow, Mattias; Ohlsson, Tommy; Edsjoe, Joakim E-mail: edsjo@physto.se

    2008-01-15

    Weakly interacting massive particles (WIMPs) are one of the main candidates for making up the dark matter in the Universe. If these particles make up the dark matter, then they can be captured by the Sun or the Earth, sink to the respective cores, annihilate, and produce neutrinos. Thus, these neutrinos can be a striking dark matter signature at neutrino telescopes looking towards the Sun and/or the Earth. Here, we improve previous analyses on computing the neutrino yields from WIMP annihilations in several respects. We include neutrino oscillations in a full three-flavor framework as well as all effects from neutrino interactions on the way through the Sun (absorption, energy loss, and regeneration from tau decays). In addition, we study the effects of non-zero values of the mixing angle {theta}{sub 13} as well as the normal and inverted neutrino mass hierarchies. Our study is performed in an event-based setting which makes these results very useful both for theoretical analyses and for building a neutrino telescope Monte Carlo code. All our results for the neutrino yields, as well as our Monte Carlo code, are publicly available. We find that the yield of muon-type neutrinos from WIMP annihilations in the Sun is enhanced or suppressed, depending on the dominant WIMP annihilation channel. This effect is due to an effective flavor mixing caused by neutrino oscillations. For WIMP annihilations inside the Earth, the distance from source to detector is too small to allow for any significant amount of oscillations at the neutrino energies relevant for neutrino telescopes.

  16. Impact of semi-annihilation of ℤ{sub 3} symmetric dark matter with radiative neutrino masses

    SciTech Connect (OSTI)

    Aoki, Mayumi; Toma, Takashi

    2014-09-08

    We investigate a ℤ{sub 3} symmetric model with two-loop radiative neutrino masses. Dark matter in the model is either a Dirac fermion or a complex scalar as a result of an unbroken ℤ{sub 3} symmetry. In addition to standard annihilation processes, semi-annihilation of the dark matter contributes to the relic density. We study the effect of the semi-annihilation in the model and find that those contributions are important to obtain the observed relic density. The experimental signatures in dark matter searches are also discussed, where some of them are expected to be different from the signatures of dark matter in ℤ{sub 2} symmetric models.

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

    SciTech Connect (OSTI)

    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.

  18. Low-mass helium star models for type Ib supernovae - Light curves, mixing, and nucleosynthesis

    SciTech Connect (OSTI)

    Shigeyama, Toshikazu; Nomoto, Kenichi; Tsujimoto, Takuji; Hashimoto, Masaki (Tokyo Univ. (Japan) Kyushu Univ., Fukuoka (Japan))

    1990-09-01

    The applicability of theoretical models of He-star explosions to type Ib SN explosions is explored. Particular attention is given to light curves and mixing, Rayleigh-Taylor instabilities and mixing, and nucleosynthesis and the mass of Ni-56. Typical numerical results are presented in graphs, and it is concluded that the explosions of SN 1983N and SN 1983I can be accurately represented in terms of explosions of He stars with M(alpha) of 3-4 solar mass. A strong M(alpha) dependence of light-curve shape, photospheric velocity, and Ni-56 mass is found. 44 refs.

  19. Neutrino Physics

    DOE R&D Accomplishments [OSTI]

    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.)

  20. Isolation of 163Ho from dysprosium target material by HPLC for neutrino mass measurements

    SciTech Connect (OSTI)

    Mocko, Veronika; Taylor, Wayne  A.; Nortier, Francois M.; Engle, Jonathan  W.; Barnhart, Todd  E.; Nickles, Robert  J.; Pollington, Anthony  D.; Kunde, Gerd  J.; Rabin, Michael  W.; Birnbaum, Eva  R.

    2015-04-29

    The rare earth isotope 163Ho is of interest for neutrino mass measurements. This report describes the isolation of 163Ho from a proton-irradiated dysprosium target and its purification. A Dy metal target was irradiated with 16 MeV protons for 10 h. After target dissolution, 163Ho was separated from the bulk Dy via cation-exchange high performance liquid chromatography using 70 mmol dm–3 α-hydroxyisobutyric acid as the mobile phase. Subsequent purification of the collected Ho fraction was performed to remove the α-hydroxyisobutyrate chelating agent and to concentrate the Ho in a low ionic strength aqueous matrix. The final solution was characterized by MC-ICP-MS to determine the 163Ho/165Ho ratio, 163Ho and the residual Dy content. The HPLC purification process resulted in a decontamination factor 1.4E5 for Dy. As a result, the isolated Ho fraction contained 24.8 ±1.3 ng of 163Ho corresponding to holmium recovery of 72 ± 3%.

  1. Sterile Neutrino Search with MINOS

    SciTech Connect (OSTI)

    Devan, Alena V.

    2015-08-01

    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 1km from the source of the beam and a far detector 734km away in Minnesota. MINOS is primarily designed to observe muon neutrino disappearance resulting from three avor oscillations. The Standard Model of Particle Physics predicts that neutrinos oscillate between three active avors as they propagate through space. This means that a muon type neutrino has a certain probability to later interact as a di erent type of neutrino. In the standard picture, the neutrino oscillation probabilities depend only on three neutrino avors and two mass splittings, Δm2. An anomaly was observed by the LSND and MiniBooNE experiments that suggests the existence of a fourth, sterile neutrino avor that does not interact through any of the known Standard Model interactions. Oscillations into a theoretical sterile avor may be observed by a de cit 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 avor are driven by a large mass-squared di erence, m2s 1 eV2. The results of the 2013 sterile neutrino search are presented here.

  2. Direct probes of neutrino properties using solar-neutrino lines

    SciTech Connect (OSTI)

    Pakvasa, S.; Pantaleone, J. )

    1990-11-12

    The spectrum of neutrinos from the Sun contains large fluxes of monoenergetic neutrinos which could be observed in the next generation of solar-neutrino detectors. Such observations directly probe neutrino parameters independent of uncertainties in the standard solar model. Small neutrino mass differences, 10{sup {minus}11}{lt}{ital m}{sub 2}{sup 2}{minus}{ital m}{sub 1}{sup 2}{lt}10{sup {minus}8} eV{sup 2}, would cause the measured flux of {sup 7}Be-line neutrinos to oscillate with a period in the range of a week up to a year. A neutrino magnetic moment comparable to the present laboratory bound would produce large distortions in the spectrum of scattered electrons.

  3. Is the tribimaximal mixing accidental?

    SciTech Connect (OSTI)

    Abbas, Mohammed; Smirnov, A. Yu.

    2010-07-01

    The tribimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on the structure of the neutrino mass matrix and on the underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM-mass relations. As a result, the mass matrix may have an 'anarchical' structure with random values of elements or it may have some symmetry that differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain 'flavor alignment' as well as hierarchical matrices with a two-component structure, where the dominant and subdominant contributions have different symmetries. This opens up new approaches to understanding the lepton mixing.

  4. Neutrinos: Nature's Identity Thieves?

    ScienceCinema (OSTI)

    Dr. Don Lincoln

    2013-07-22

    The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.

  5. Neutrinos: Nature's Identity Thieves?

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07

    The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.

  6. Neutrino Physics AAPT Strand Day

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics AAPT Strand Day NSTA Regional, 2005 Jocelyn Monroe, Columbia University 1. What Is a Neutrino Anyway? 2. The Question Of Neutrino Mass 3. Searching For Neutrino Oscillations 4. Where Are We Now? ν Neutrinos, they are very small. They have no charge and have no mass And do not interact at all. The earth is just a silly ball To them, through which they simply pass... ...And pierce the lover and his lass From underneath the bed- you call It wonderful; I call it crass. J from ``Cosmic

  7. Mass and mixing angle patterns in the Standard Model and its material Supersymmetric Extension

    SciTech Connect (OSTI)

    Ramond, P.

    1992-01-01

    Using renormalization group techniques, we examine several interesting relations among masses and mixing angles of quarks and lepton in the Standard Model of Elementary Particle Interactions as a functionof scale. We extend the analysis to the minimal Supersymmetric Extension to determine its effect on these mass relations. For a heavy to quark, and minimal supersymmetry, most of these relations, can be made to agree at one unification scale.

  8. Fermilab | Science | Particle Physics | Neutrinos

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutrinos photo Our universe is permeated with neutrinos - nearly massless, neutral particles that interact so rarely with other matter that trillions of them pass through our bodies each second without leaving a trace. These tiny particles, studied in world-leading Fermilab experiments, could be key to a deeper understanding of our universe. Neutrinos, first discovered in 1956, have some mysterious characteristics. They have puzzlingly low masses, compared to other elementary particles, and

  9. Neutrino Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interactions, Phys.Lett. B 594, 347 (2004). A. Friedland and C. Lunardini, A Test of tau neutrino interactions with atmospheric neutrinos and K2K, Phys.Rev. D 72, 053009...

  10. Neutrino Observations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Observations from the Sudbury Neutrino Observatory A.W.P. Poon 1 Institute for Nuclear and Particle Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA, USA Abstract. The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D 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 ν e flux and the total flux of all active neutrino

  11. Two loop neutrino model and dark matter particles with global B?L symmetry

    SciTech Connect (OSTI)

    Baek, Seungwon; Okada, Hiroshi; Toma, Takashi E-mail: hokada@kias.re.kr

    2014-06-01

    We study a two loop induced seesaw model with global U(1){sub B?L} symmetry, in which we consider two component dark matter particles. The dark matter properties are investigated together with some phenomenological constraints such as electroweak precision test, neutrino masses and mixing and lepton flavor violation. In particular, the mixing angle between the Standard Model like Higgs and an extra Higgs is extremely restricted by the direct detection experiment of dark matter. We also discuss the contribution of Goldstone boson to the effective number of neutrino species ?N{sub eff} ? 0.39 which has been reported by several experiments.

  12. Solar and supernova neutrino interactions

    SciTech Connect (OSTI)

    Haxton, W.C.

    1990-11-01

    Two topics are addressed, the interactions of neutrinos during a type II supernova and the effect of current eddies on solar neutrino oscillations. The supernova discussion focuses on the nucleosynthesis that accompanies inelastic neutral current interactions of neutrinos in the mantle of a collapsing star, and on the effect of neutrino down-scattering'' and preheating on the explosion mechanism. The second half of the talk deals with the influence of solar turbulence (or density fluctuations) on the neutrino effective mass and the possibility that a time-varying neutrino flux could result. The effects of harmonic density or three-current perturbations on the oscillation probability are explored analytically and numerically. 15 refs., 5 figs.

  13. Supernova neutrinos and explosive nucleosynthesis

    SciTech Connect (OSTI)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-05-09

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

  14. Neutrino factory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    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

  15. Neutrino factory

    SciTech Connect (OSTI)

    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.

  16. Anti-Neutrino Charged Current Quasi-Elastic Scattering in MINER$\

    SciTech Connect (OSTI)

    Chvojka, Jesse John

    2012-01-01

    The phenomenon of neutrino oscillation is becoming increasingly understood with results from accelerator-based and reactor-based experiments, but unanswered questions remain. The proper ordering of the neutrino mass eigenstates that compose the neutrino avor eigenstates is not completely known. We have yet to detect CP violation in neutrino mixing, which if present could help explain the asymmetry between matter and anti-matter in the universe. We also have not resolved whether sterile neutrinos, which do not interact in any Standard Model interaction, exist. Accelerator-based experiments appear to be the most promising candidates for resolving these questions; however, the ability of present and future experiments to provide answers is likely to be limited by systematic errors. A significant source of this systematic error comes from limitations in our knowledge of neutrino-nucleus interactions. Errors on cross-sections for such interactions are large, existing data is sometimes contradictory, and knowledge of nuclear effects is incomplete. One type of neutrino interaction of particular interest is charged current quasi-elastic (CCQE) scattering, which yields a final state consisting of a charged lepton and nucleon. This process, which is the dominant interaction near energies of 1 GeV, is of great utility to neutrino oscillation experiments since the incoming neutrino energy and the square of the momentum transferred to the final state nucleon, Q2, can be reconstructed using the final state lepton kinematics. To address the uncertainty in our knowledge of neutrino interactions, many experiments have begun making dedicated measurements. In particular, the MINER A experiment is studying neutrino-nucleus interactions in the few GeV region. MINERvA is a fine-grained, high precision, high statistics neutrino scattering experiment that will greatly improve our understanding of neutrino cross-sections and nuclear effects that affect the final state particles

  17. Light mixed sneutrinos as thermal dark matter

    SciTech Connect (OSTI)

    Bélanger, G.; Kakizaki, M.; Park, E.K.; Kraml, S.

    2010-11-01

    In supersymmetric models with Dirac neutrino masses, a left-right mixed sneutrino can be a viable dark matter candidate. We examine the MSSM+ν-tilde {sub R} parameter space where this is the case with particular emphasis on light sneutrinos with masses below 10 GeV. We discuss implications for direct and indirect dark matter searches, including the relevant uncertainties, as well as consequences for collider phenomenology.

  18. Search for heavy Majorana neutrinos in e$$^{±}$$e$$^{±}$$+jets and e$$^{±}$$$$\\mu^{±}$$+jets events in proton-proton collisions at $$ \\sqrt{s}=8 $$ TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan

    2016-04-27

    In this study, a search is performed for heavy Majorana neutrinos (N) decaying into a W boson and a lepton using the CMS detector at the Large Hadron Collider. A signature of two jets and either two same sign electrons or a same sign electron-muon pair is searched for using 19.7 inverse femtobarns of data collected during 2012 in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data are found to be consistent with the expected standard model (SM) background and, in the context of a Type-1 seesaw mechanism, upper limits are set on the cross section timesmore » branching fraction for production of heavy Majorana neutrinos in the mass range between 40 and 500 GeV. The results are additionally interpreted as limits on the mixing between the heavy Majorana neutrinos and the SM neutrinos. In the mass range considered, the upper limits range between 0.00015 - 0.72 for |VeN|2 and 6.6x10-5 - 0.47 for |VeN V*μN|2 / ( |VeN|2 + |VμN|2), where VlN is the mixing element describing the mixing of the heavy neutrino with the SM neutrino of flavour l. These limits are the most restrictive direct limits for heavy Majorana neutrino masses above 200 GeV.« less

  19. Cosmological and supernova neutrinos

    SciTech Connect (OSTI)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GS, Department of Physics, ?i?li, ?stanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-06-24

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

  20. Solar Neutrinos

    DOE R&D Accomplishments [OSTI]

    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.

  1. Measurement of the top quark mass at CDF using the `neutrino phi weighting' template method on a lepton plus isolated track sample

    SciTech Connect (OSTI)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-01-01

    We present a measurement of the top quark mass with t{bar t} dilepton events produced in p{bar p} collisions at the Fermilab Tevatron ({radical}s = 1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb{sup -1}, are selected as t{bar t} candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles ({phi}{sub {nu}1}, {phi}{sub {nu}2}) of neutrinos and reconstruct the top quark mass for each {phi}{sub {nu}1}, {phi}{sub {nu}2} pair by minimizing a {chi}{sup 2} function in the t{bar t} dilepton hypothesis. We assign {chi}{sup 2}-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t{bar t} and background events, and parameterized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5{sub -3.3}{sup +3.4}(stat.){+-}3.1(syst.) GeV/c{sup 2}.

  2. Neutrinos and cosmology: a lifetime relationship

    SciTech Connect (OSTI)

    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.

  3. Neutrino Physics with Thermal Detectors

    SciTech Connect (OSTI)

    Nucciotti, A. [Dipartimento di Fisica, Universita di Milano Bicocca and INFN Sezione di Milano-Bicocca Piazza della Scienza, 3, 20126 Milano (Italy)

    2009-11-09

    The investigation of fundamental neutrino properties like its mass and its nature calls for the design of a new generation of experiments. High sensitivity, high energy resolution, and versatility together with the possibility of a simple multiplexing scheme are the key features of future detectors for these experiments. Thermal detectors can combine all these features. This paper reviews the status and the perspectives for what concerns the application of this type of detectors to neutrino physics, focusing on direct neutrino mass measurements and neutrinoless double beta decay searches.

  4. Neutrino Oscillations with the MINOS, MINOS+, T2K, and NOvA Experiments

    SciTech Connect (OSTI)

    Nakaya, Tsuyoshi; Plunkett, Robert K.

    2015-07-29

    Our paper discusses results and near-term prospects of the long-baseline neutrino experiments MINOS, MONOS+, T2K and NOvA. The non-zero value of the third neutrino mixing angle θ13 allows experimental analysis in a manner which explicitly exhibits appearance and disappearance dependencies on additional parameters associated with mass-hierarchy, CP violation, and any non-maximal θ23. Our current and near-future experiments begin the era of precision accelerator long-baseline measurements and lay the framework within which future experimental results will be interpreted.

  5. Sterile Neutrinos in Cold Climates

    SciTech Connect (OSTI)

    Jones, Benjamin J.P.

    2015-09-01

    Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system; test-stand measurements of liquid argon optical properties with dissolved impurities; optimization of wavelength-shifting coatings for liquid argon scintillation light detection; testing and deployment of high-voltage surge arrestors to protect TPC field cages; and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin224 ≤ 0.02 at m2 ~ 0.3 eV2, and the LSND and Mini

  6. Long-Baseline Neutrino Facility / Deep Underground Neutrino Project...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Long-Baseline Neutrino Facility Deep Underground Neutrino Project (LBNF-DUNE) Long-Baseline Neutrino Facility Deep Underground Neutrino Project (LBNF-DUNE) Long-Baseline ...

  7. Multipartite entangled states in particle mixing

    SciTech Connect (OSTI)

    Blasone, M.; Dell'Anno, F.; De Siena, S.; Di Mauro, M.; Illuminati, F.

    2008-05-01

    In the physics of flavor mixing, the flavor states are given by superpositions of mass eigenstates. By using the occupation number to define a multiqubit space, the flavor states can be interpreted as multipartite mode-entangled states. By exploiting a suitable global measure of entanglement, based on the entropies related to all possible bipartitions of the system, we analyze the correlation properties of such states in the instances of three- and four-flavor mixing. Depending on the mixing parameters, and, in particular, on the values taken by the free phases, responsible for the CP-violation, entanglement concentrates in certain bipartitions. We quantify in detail the amount and the distribution of entanglement in the physically relevant cases of flavor mixing in quark and neutrino systems. By using the wave packet description for localized particles, we use the global measure of entanglement, suitably adapted for the instance of multipartite mixed states, to analyze the decoherence, induced by the free evolution dynamics, on the quantum correlations of stationary neutrino beams. We define a decoherence length as the distance associated with the vanishing of the coherent interference effects among massive neutrino states. We investigate the role of the CP-violating phase in the decoherence process.

  8. Measuring Neutrino Oscillations with Nuclear Reactors

    SciTech Connect (OSTI)

    McKeown, R. D.

    2007-10-26

    Since the first direct observations of antineutrino events by Reines and Cowan in the 1950's, nuclear reactors have been an important tool in the study of neutrino properties. More recently, the study of neutrino oscillations has been a very active area of research. The pioneering observation of oscillations by the KamLAND experiment has provided crucial information on the neutrino mixing matrix. New experiments to study the remaining unknown mixing angle are currently under development. These recent studies and potential future developments will be discussed.

  9. The neutrino portal to new physics

    SciTech Connect (OSTI)

    Ma, Ernest

    2014-06-24

    Neutrinos may have interactions beyond those of the standard model. They may be responsible for neutrino mass and provide a link to other fundamental issues of particle physics such as dark matter. A brief incomplete survey of some of the theoretical ideas along this direction is offered.

  10. Lepton number violating processes mediated by Majorana neutrinos at hadron colliders

    SciTech Connect (OSTI)

    Kovalenko, Sergey; Lu Zhun; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico, Santa Maria, Casilla 110-V, Valparaiso (Chile) and Center of Subatomic Physics, Valparaiso (Chile)

    2009-10-01

    We study the lepton number violating like-sign dilepton processes h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}jjX and h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}W{sup {+-}}X, mediated by heavy GeV scale Majorana neutrinos. We focus on the resonantly enhanced contributions with a nearly on-mass-shell Majorana neutrino in the s channel. We study the constraints on like-sign dilepton production at the Tevatron and the LHC on the basis of the existing experimental limits on the masses of heavy neutrinos and their mixings U{sub {alpha}}{sub N} with {alpha}={nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}. Special attention is paid to the constraints from neutrinoless double beta decay. We note that searches for like-sign e{sup {+-}}e{sup {+-}} events at Tevatron and LHC may provide evidence of CP violation in the neutrino sector. We also discuss the conditions under which it is possible to extract individual constraints on the mixing matrix elements in a model independent way.

  11. SAGE: Solar Neutrino Data from SAGE, the Russian-American Gallium Solar Neutrino Experiment

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    SAGE Collaboration

    SAGE is a solar neutrino experiment based on the reaction 71Ga + n goes to 71Ge + e-. The 71Ge atoms are chemically extracted from a 50-metric ton target of Ga metal and concentrated in a sample of germane gas mixed with xenon. The atoms are then individually counted by observing their decay back to 71Ga in a small proportional counter. The distinguishing feature of the experiment is its ability to detect the low-energy neutrinos from proton-proton fusion. These neutrinos, which are made in the primary reaction that provides the Sun's energy, are the major component of the solar neutrino flux and have not been observed in any other way. To shield the experiment from cosmic rays, it is located deep underground in a specially built facility at the Baksan Neutrino Observatory in the northern Caucasus mountains of Russia. Nearly 100 measurements of the solar neutrino flux have been made during 1990-2000, and their combined result is a neutrino capture rate that is well below the prediction of the Standard Solar Model. The significant suppression of the solar neutrino flux that SAGE and other solar neutrino experiments have observed gives a strong indication for the existence of neutrino oscillations. [copied from the SAGE homepage at http://ewi.npl.washington.edu/SAGE/SAGE.html

  12. Arthur B. McDonald and Oscillating Neutrinos

    Office of Scientific and Technical Information (OSTI)

    detector in Japan. This "metamorphosis" requires that neutrinos have mass.'1 'For particle physics this was a historic discovery. Its Standard Model of the innermost...

  13. Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

    SciTech Connect (OSTI)

    Anderson, Colin E.

    2011-05-01

    Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for νμ → νe oscillation - a channel that may yield insight into the vanishingly small mixing parameter θ13, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single π0 (NC 1π0) production. Unfortunately, the available data concerning NC 1π0 production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1π0 production yield substantially differing predictions in the critical Eν ~ 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data (~ 106 neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns the measurement of both neutrino and antineutrino NC 1π0 production cross sections at MiniBooNE. The size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the first measurements of the absolute NC 1π0 cross section as well as the first differential cross sections in both neutrino and antineutrino mode. Specifically, we measure single differential cross sections with respect to pion momentum and pion angle. We find the

  14. Search for heavy Majorana neutrinos with the ATLAS detector in pp collisions at √s = 8 TeV

    SciTech Connect (OSTI)

    Aad, G.

    2015-07-29

    A search for heavy Majorana neutrinos in events containing a pair of high-pT leptons of the same charge and high-pT jets is presented. The search uses 20.3 fb-1 of pp collision data collected with the ATLAS detector at the CERN Large Hadron Collider with a centre-of-mass energy of √s = 8 TeV. The data are found to be consistent with the background-only hypothesis based on the Standard Model expectation. In the context of a Type-I seesaw mechanism, limits are set on the production cross-section times branching ratio for production of heavy Majorana neutrinos in the mass range between 100 and 500 GeV. The limits are subsequently interpreted as limits on the mixing between the heavy Majorana neutrinos and the Standard Model neutrinos. In the context of a left-right symmetric model, limits on the production cross-section times branching ratio are set with respect to the masses of heavy Majorana neutrinos and heavy gauge bosons WR and Z'.

  15. Search for heavy Majorana neutrinos with the ATLAS detector in pp collisions at √s = 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.

    2015-07-29

    A search for heavy Majorana neutrinos in events containing a pair of high-pT leptons of the same charge and high-pT jets is presented. The search uses 20.3 fb-1 of pp collision data collected with the ATLAS detector at the CERN Large Hadron Collider with a centre-of-mass energy of √s = 8 TeV. The data are found to be consistent with the background-only hypothesis based on the Standard Model expectation. In the context of a Type-I seesaw mechanism, limits are set on the production cross-section times branching ratio for production of heavy Majorana neutrinos in the mass range between 100 andmore » 500 GeV. The limits are subsequently interpreted as limits on the mixing between the heavy Majorana neutrinos and the Standard Model neutrinos. In the context of a left-right symmetric model, limits on the production cross-section times branching ratio are set with respect to the masses of heavy Majorana neutrinos and heavy gauge bosons WR and Z'.« less

  16. The neutrino turns 60

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The neutrino turns 60 The neutrino turns 60 Although neutrinos are extremely abundant, it took 26 years for scientists to confirm their existence. In the 60 years since the neutrino's discovery, we've slowly learned about this intriguing particle. June 20, 2016 Although neutrinos are extremely abundant, it took 26 years for scientists to confirm their existence. In the 60 years since the neutrino's discovery, we've slowly learned about this intriguing particle. Artwork by Sandbox Studio, Chicago

  17. Inverse neutrinoless double beta decay revisited: Neutrinos, Higgs triplets, and a muon collider

    SciTech Connect (OSTI)

    Rodejohann, Werner [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany)

    2010-06-01

    We revisit the process of inverse neutrinoless double beta decay (e{sup -}e{sup -{yields}}W{sup -}W{sup -}) at future linear colliders. The cases of Majorana neutrino and Higgs triplet exchange are considered. We also discuss the processes e{sup -{mu}-{yields}}W{sup -}W{sup -} and {mu}{sup -{mu}-{yields}}W{sup -}W{sup -}, which are motivated by the possibility of muon colliders. For heavy neutrino exchange, we show that masses up to 10{sup 6} (10{sup 5}) GeV could be probed for ee and e{mu} machines, respectively. The stringent limits for mixing of heavy neutrinos with muons render {mu}{sup -{mu}-{yields}}W{sup -}W{sup -} less promising, even though this process is not constrained by limits from neutrinoless double beta decay. If Higgs triplets are responsible for inverse neutrinoless double beta decay, observable signals are only possible if a very narrow resonance is met. We also consider unitarity aspects of the process in case both Higgs triplets and neutrinos are exchanged. An exact seesaw relation connecting low energy data with heavy neutrino and triplet parameters is found.

  18. Testing quantum gravity via cosmogenic neutrino oscillations

    SciTech Connect (OSTI)

    Christian, Joy

    2005-01-15

    Implications of some proposed theories of quantum gravity for neutrino flavor oscillations are explored within the context of modified dispersion relations of special relativity. In particular, approximate expressions for Planck scale-induced deviations from the standard oscillation length are obtained as functions of neutrino mass, energy, and propagation distance. Grounding on these expressions, it is pointed out that, in general, even those deviations that are suppressed by the second power of the Planck energy may be observable for ultra-high-energy neutrinos, provided they originate at cosmological distances. In fact, for neutrinos in the highest energy range of EeV to ZeV, deviations that are suppressed by as much as the seventh power of the Planck energy may become observable. Accordingly, realistic possibilities of experimentally verifying these deviations by means of the next generation neutrino detectors--such as IceCube and ANITA--are investigated.

  19. Why study neutrinos?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Why study neutrinos? Neutrinos are by far the most abundant particles in the universe. About 100 trillion neutrinos pass through your body every second without interacting with any of the particles in your body. You never notice them. The combination of that ghostly presence and the important role neutrinos play in the universe captivates physicists. Neutrinos play a role in many fundamental aspects of our lives; they are produced in nuclear fusion processes that power the sun and stars, they

  20. Neutrino Fluxes from NUHM LSP Annihilations in the Sun

    SciTech Connect (OSTI)

    Olive, Keith

    2011-08-12

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

  1. Light sterile neutrinos after BICEP-2

    SciTech Connect (OSTI)

    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.

  2. Sterile neutrinos and indirect dark matter searches in IceCube

    SciTech Connect (OSTI)

    Argüelles, Carlos A.; Kopp, Joachim E-mail: jkopp@fnal.gov

    2012-07-01

    If light sterile neutrinos exist and mix with the active neutrino flavors, this mixing will affect the propagation of high-energy neutrinos from dark matter annihilation in the Sun. In particular, new Mikheyev-Smirnov-Wolfenstein resonances can occur, leading to almost complete conversion of some active neutrino flavors into sterile states. We demonstrate how this can weaken IceCube limits on neutrino capture and annihilation in the Sun and how potential future conflicts between IceCube constraints and direct detection or collider data might be resolved by invoking sterile neutrinos. We also point out that, if the dark matter-nucleon scattering cross section and the allowed annihilation channels are precisely measured in direct detection and collider experiments in the future, IceCube can be used to constrain sterile neutrino models using neutrinos from the dark matter annihilation.

  3. Dark matter vs. neutrinos: the effect of astrophysical uncertainties and timing information on the neutrino floor

    SciTech Connect (OSTI)

    Davis, Jonathan H.

    2015-03-09

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments are said to run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that, using only spectral information, the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions it can still be surpassed using timing information, and so the neutrino floor is not an absolute limit on the sensitivity of Direct Detection experiments.

  4. Short-baseline electron neutrino disappearance, tritium beta decay, and neutrinoless double-beta decay

    SciTech Connect (OSTI)

    Giunti, Carlo; Laveder, Marco [INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Dipartimento di Fisica G. Galilei, Universita di Padova, and INFN, Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy)

    2010-09-01

    We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of 3+1 four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}. The combined fit gives {Delta}m{sup 2}(greater-or-similar sign)0.1 eV{sup 2} and 0.11(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.48 at 2{sigma}. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in {beta} decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of sin{sup 2}2{theta} below 0.10 at 2{sigma}. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives {Delta}m{sup 2}{approx_equal}2 eV and 0.01(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.13 at 2{sigma}. Assuming a hierarchy of masses m{sub 1}, m{sub 2}, m{sub 3}<neutrino masses in {beta} decay and neutrinoless double-{beta} decay are, respectively, between about 0.06 and 0.49 and between about 0.003 and 0.07 eV at 2{sigma}. We also consider the possibility of reconciling the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data with different mixings in the neutrino and antineutrino sectors. We find a 2.6{sigma} indication of a mixing angle asymmetry.

  5. Protoneutron star evolution and the neutrino-driven wind in general relativistic neutrino radiation hydrodynamics simulations

    SciTech Connect (OSTI)

    Fischer, T.; Mezzacappa, Anthony; Thielemann, F.-K.; Liebendoerfer, M.; Whitehouse, S.

    2010-01-01

    Massive stars end their lives in explosions with kinetic energies on the order of 10{sup 51} erg. Immediately after the explosion has been launched, a region of low density and high entropy forms behind the ejecta, which is continuously subject to neutrino heating. The neutrinos emitted from the remnant at the center, the protoneutron star (PNS), heat the material above the PNS surface. This heat is partly converted into kinetic energy, and the material accelerates to an outflow that is known as the neutrino-driven wind. For the first time we simulate the collapse, bounce, explosion, and the neutrino-driven wind phases consistently over more than 20 s. Our numerical model is based on spherically symmetric general relativistic radiation hydrodynamics using spectral three-flavor Boltzmann neutrino transport. In simulations where no explosions are obtained naturally, we model neutrino-driven explosions for low- and intermediate-mass Fe-core progenitor stars by enhancing the charged current reaction rates. In the case of a special progenitor star, the 8.8 M{circle_dot} O-Ne-Mg-core, the explosion in spherical symmetry was obtained without enhanced opacities. The post-explosion evolution is in qualitative agreement with static steady-state and parametrized dynamic models of the neutrino-driven wind. On the other hand, we generally find lower neutrino luminosities and mean neutrino energies, as well as a different evolutionary behavior of the neutrino luminosities and mean neutrino energies. The neutrino-driven wind is proton-rich for more than 10 s and the contraction of the PNS differs from the assumptions made for the conditions at the inner boundary in previous neutrino-driven wind studies. Despite the moderately high entropies of about 100 k{sub B}/baryon and the fast expansion timescales, the conditions found in our models are unlikely to favor r-process nucleosynthesis. The simulations are carried out until the neutrino-driven wind settles down to a quasi

  6. Quark and lepton mixing as manifestations of violated mirror symmetry

    SciTech Connect (OSTI)

    Dyatlov, I. T.

    2015-06-15

    The existence of heavy mirror analogs of ordinary fermions would provide deeper insight into the gedanken paradox appearing in the Standard Model upon direct parity violation and consisting in a physical distinguishability of left- and right-hand coordinate frames. Arguments are presented in support of the statement that such mirror states may also be involved in the formation of observed properties of the system of Standard Model quarks and leptons—that is, their mass spectra and their weak-mixing matrices: (i) In the case of the involvement of mirror generations, the quark mixing matrix assumes the experimentally observed form. It is determined by the constraints imposed by weak SU(2) symmetry and by the quark-mass hierarchy. (ii) Under the same conditions and upon the involvement of mirror particles, the lepton mixing matrix (neutrino mixing) may become drastically different from its quark analog—the Cabibbo-Kobayashi-Maskawa matrix; that is, it may acquire properties suggested by experimental data. This character of mixing is also indicative of an inverse mass spectrum of Standard Model neutrinos and their Dirac (not Majorana) nature.

  7. BooNE: Booster Neutrino Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Some neutrino interactions produce the neutrino's namesake lepton (electron, muon, or tau); this allows the type of neutrino to be tagged. Since neutrino oscillation searches...

  8. BooNE: Booster Neutrino Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from major neutrino experiments and important results in neutrino physics. Includes java applets. Janet's Neutrino Oscillation Page More extensive material about neutrino...

  9. Short Baseline Neutrino

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    decay region is followed by an absorber and 450 m of dirt, beyond which only the neutrino component of the beam survives. e ? The MiniBooNE Neutrino Beam March 10, 2003...

  10. Solar Neutrino Problem

    DOE R&D Accomplishments [OSTI]

    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.

  11. Introduction to Neutrino Physics

    SciTech Connect (OSTI)

    Linares, Edgar Casimiro

    2009-04-30

    I present a basic introduction to the physics of the neutrino, with emphasis on experimental results and developments.

  12. Geo-neutrino Observation

    SciTech Connect (OSTI)

    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.

  13. Measuring Neutrino Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measuring Neutrino Interactions with MiniBooNE R. Tayloe for the MiniBooNE collaboration Physics Department, Indiana University Bloomington, IN 47405, USA Abstract. The MiniBooNE neutrino oscillation experiment has collected a large sample of charged- and neutral-current neutrino interaction events. These samples are important to understand the normalization and backgrounds in neutrino oscillation searches. They also reveal insight into the structure of the nucleus and nucleon. The MiniBooNE

  14. The halo model in a massive neutrino cosmology

    SciTech Connect (OSTI)

    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=0.51 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.

  15. Neutrino oscillations with IceCube DeepCore and PINGU

    SciTech Connect (OSTI)

    DeYoung, T.; Collaboration: IceCube-PINGU Collaboration

    2014-11-18

    The IceCube neutrino telescope was augmented with the DeepCore infill array, completed in the 2010/11 austral summer, to enhance its response to neutrinos below 100 GeV. At these energies, neutrino oscillation effects are visible in the flux of atmospheric neutrinos traversing path lengths comparable to the Earth's diameter. Initial measurements of muon neutrino disappearance parameters using data from DeepCore are presented, as well as an estimate of potential future precision. In addition, plans for a Precision IceCube Next Generation Upgrade (PINGU), which could permit determination of the neutrino mass hierarchy within the coming decade, are discussed.

  16. THE BNL SUPER NEUTRINO BEAM PROJECT

    SciTech Connect (OSTI)

    WENG,W-T.; RAPARIA,D.

    2004-12-02

    To determine the neutrino mixing amplitudes and phase accurately, as well as the CP violation parameters, a very long base line super neutrino beam facility is needed. This is possible due to the long distance and wideband nature of the neutrino beam for the observation of several oscillations from one species of the neutrino to the other [1,2]. BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW and beyond for such a neutrino facility which consists of three major subsystems. First is a 1.5 GeV superconducting linac to replace the booster as injector for the AGS, second is the performance upgrade for the AGS itself for the higher intensity and repetition rate, and finally is target and horn system for the neutrino production. The major contribution for the higher power is from the increase of the repetition rate of the AGS form 0.3 Hz to 2.5 Hz, with moderate increase from the intensity [3]. The design consideration to achieve high intensity and low losses for the linac and the AGS will be reviewed. The target horn design for high power operation and easy maintenance will also be presented.

  17. Collective neutrino oscillations in supernovae

    SciTech Connect (OSTI)

    Duan, Huaiyu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)

    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.

  18. MINOS Sterile Neutrino Search

    SciTech Connect (OSTI)

    Koskinen, David Jason; /University Coll. London

    2009-09-01

    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 {nu}{sub {mu}} {yields} V{sub {tau}} 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 {approx}2.5 x 10{sup 20} 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.

  19. Long-Baseline Neutrino Facility / Deep Underground Neutrino Project

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    (LBNF-DUNE) | Department of Energy Long-Baseline Neutrino Facility / Deep Underground Neutrino Project (LBNF-DUNE) Long-Baseline Neutrino Facility / Deep Underground Neutrino Project (LBNF-DUNE) Long-Baseline Neutrino Facility / Deep Underground Neutrino Project (LBNF-DUNE) Chris Mossey, Deputy Lab Director (Fermi) and Project Director for LBNF-DUNE March 23, 2016 Presentation (5.94 MB) Key Resources PMCDP EVMS PARS IIe FPD Resource Center PM Newsletter Forms and Templates More Documents

  20. EA-1943: Long Baseline Neutrino Facility/Deep Underground Neutrino...

    Broader source: Energy.gov (indexed) [DOE]

    May 27, 2015 EA-1943: Draft Environmental Assessment Long Baseline Neutrino FacilityDeep Underground Neutrino Experiment (LBNFDUNE) at Fermilab, Batavia, Illinois and the...

  1. Muon Neutrino to Electron Neutrino Oscillation in NO$\

    SciTech Connect (OSTI)

    Sachdev, Kanika

    2015-08-01

    NOvA is a long-baseline neutrino oscillation experiment optimized for electron neu- trino ( e) appearance in the NuMI beam, a muon neutrino ( $\

  2. Solar neutrino detection

    SciTech Connect (OSTI)

    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.

  3. Deviations from tribimaximal mixing due to the vacuum expectation value misalignment in A{sub 4} models

    SciTech Connect (OSTI)

    Barry, James; Rodejohann, Werner

    2010-05-01

    The addition of an A{sub 4} family symmetry and extended Higgs sector to the standard model can generate the tribimaximal mixing pattern for leptons, assuming the correct vacuum expectation value alignment of the Higgs scalars. Deviating this alignment affects the predictions for the neutrino oscillation and neutrino mass observables. An attempt is made to classify the plethora of models in the literature, with respect to the chosen A{sub 4} particle assignments. Of these models, two particularly popular examples have been analyzed for deviations from tribimaximal mixing by perturbing the vacuum expectation value alignments. The effect of perturbations on the mixing angle observables is studied. However, it is only investigation of the mass-related observables (the effective mass for neutrinoless double beta decay and the sum of masses from cosmology) that can lead to the exclusion of particular models by constraints from future data, which indicates the importance of neutrino mass in disentangling models. The models have also been tested for fine-tuning of the parameters. Furthermore, a well-known seesaw model is generalized to include additional scalars, which transform as representations of A{sub 4} not included in the original model.

  4. Neutrinos: Nature's Ghosts?

    ScienceCinema (OSTI)

    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.

  5. Booster Neutrino Experiment - Introduction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    back The MiniBooNE Experiment next The Oscillating Neutrino Normal matter is made of atoms. Atoms are also composite objects, made up in turn of protons and neutrons (in the nucleus) and the lightweight and familiar electrons. Electrons belong to a class of particles called leptons, the same family to which neutrinos belong. Neutrinos are the very lightweight (originally thought massless) neutral partners of the electrically charged electron and its more exotic cousins the muon and the tau.

  6. Booster Neutrino Experiment - Introduction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    close The MiniBooNE Experiment next The Oscillating Neutrino The first phase of the Booster Neutrino Experiment (BooNE) at the Fermi National Accelerator Laboratory is a smaller version of the final planned experiment, and has been dubbed "MiniBooNE." The physicists working on MiniBooNE are trying to find out more about the fundamental properties of neutrinos. But, what exactly is a neutrino? To answer that question, we need to look at what's called the Standard Model of particles and

  7. Neutrino-nucleus interactions

    SciTech Connect (OSTI)

    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.

  8. Collection efficiency of the soot-particle aerosol mass spectrometer (SP-AMS) for internally mixed particulate black carbon

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Willis, M. D.; Lee, A. K. Y.; Onasch, T. B.; Fortner, E. C.; Williams, L. R.; Lambe, A. T.; Worsnop, D. R.; Abbatt, J. P. D.

    2014-12-18

    The soot-particle aerosol mass spectrometer (SP-AMS) uses an intra-cavity infrared laser to vaporize refractory black carbon (rBC) containing particles, making the particle beam–laser beam overlap critical in determining the collection efficiency (CE) for rBC and associated non-refractory particulate matter (NR-PM). This work evaluates the ability of the SP-AMS to quantify rBC and NR-PM mass in internally mixed particles with different thicknesses of organic coating. Using apparent relative ionization efficiencies for uncoated and thickly coated rBC particles, we report measurements of SP-AMS sensitivity to NR-PM and rBC, for Regal Black, the recommended particulate calibration material. Beam width probe (BWP) measurements aremore » used to illustrate an increase in sensitivity for highly coated particles due to narrowing of the particle beam, which enhances the CE of the SP-AMS by increasing the laser beam–particle beam overlap. Assuming complete overlap for thick coatings, we estimate CE for bare Regal Black particles of 0.6 ± 0.1, which suggests that previously measured SP-AMS sensitivities to Regal Black were underestimated by up to a factor of 2. The efficacy of the BWP measurements is highlighted by studies at a busy road in downtown Toronto and at a non-roadside location, which show particle beam widths similar to, but greater than that of bare Regal Black and coated Regal Black, respectively. Further BWP measurements at field locations will help to constrain the range of CE for fresh and aged rBC-containing particles. The ability of the SP-AMS to quantitatively assess the composition of internally mixed particles is validated through measurements of laboratory-generated organic coated particles, which demonstrate that the SP-AMS can quantify rBC and NR-PM over a wide range of particle compositions and rBC core sizes.« less

  9. Collection efficiency of the Soot-Particle Aerosol Mass Spectrometer (SP-AMS) for internally mixed particulate black carbon

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Willis, M. D.; Lee, A. K. Y.; Onasch, T. B.; Fortner, E. C.; Williams, L. R.; Lambe, A. T.; Worsnop, D. R.; Abbatt, J. P. D.

    2014-05-26

    The soot-particle aerosol mass spectrometer (SP-AMS) uses an intra-cavity infrared laser to vaporize refractory black carbon (rBC) containing particles, making the particle beam–laser beam overlap critical in determining the collection efficiency (CE) for rBC and associated non-refractory particulate matter (NR-PM). This work evaluates the ability of the SP-AMS to quantify rBC and NR-PM mass in internally mixed particles with different thicknesses of organic coating. Using apparent relative ionization efficiencies for uncoated and thickly coated rBC particles, we report measurements of SP-AMS sensitivity to NR-PM and rBC, for Regal Black, the recommended particulate calibration material. Beam width probe (BWP) measurements aremore » used to illustrate an increase in sensitivity for highly coated particles due to narrowing of the particle beam, which enhances the CE of the SP-AMS by increasing the laser beam–particle beam overlap. Assuming complete overlap for thick coatings, we estimate CE for bare Regal Black particles of 0.6 ± 0.1, which suggests that previously measured SP-AMS sensitivities to Regal Black were underestimated by up to a factor of two. The efficacy of the BWP measurements is highlighted by studies at a busy road in downtown Toronto and at a non-roadside location, which show particle beam widths similar to, but greater than that of bare Regal Black and coated Regal Black, respectively. Further BWP measurements at field locations will help to constrain the range of CE for fresh and aged rBC-containing particles. The ability of the SP-AMS to quantitatively assess the composition of internally mixed particles is validated through measurements of laboratory-generated organic coated particles, which demonstrate that the SP-AMS can quantify rBC and NR-PM over a wide range of particle compositions and rBC core sizes.« less

  10. Symmetrical parametrizations of the lepton mixing matrix

    SciTech Connect (OSTI)

    Rodejohann, W. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, 69029 Heidelberg (Germany); Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

    2011-10-01

    Advantages of the original symmetrical form of the parametrization of the lepton mixing matrix are discussed. It provides a conceptually more transparent description of neutrino oscillations and lepton number violating processes like neutrinoless double beta decay, clarifying the significance of Dirac and Majorana phases. It is also ideal for parametrizing scenarios with light sterile neutrinos.

  11. NOvA: Exploring Neutrino Mysteries

    ScienceCinema (OSTI)

    Vahle, Tricia; Messier, Mark

    2014-08-12

    Neutrinos are a mystery to physicists. They exist in three different flavors and mass states and may be able to give hints about the origins of the matter-dominated universe. A new long-baseline experiment led by Fermilab called NOvA may provide some answers.

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

    SciTech Connect (OSTI)

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

    2014-05-02

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

  13. Search for neutrino oscillations by detecting UNK-1 600-GeV neutrino beams at Gran Sasso (Italy)

    SciTech Connect (OSTI)

    Vasil`ev, P.S.; Kuznetsov, A.E.; Kuznetsov, E.P.

    1995-12-01

    The possibility of formation of neutrino beams from the 600-GeV UNK-1 accelerator toward Gran Sasso (Italy) and of study neutrino oscillations with the ICARUS detector is demonstrated. The proposed experiment is sensitive to {Delta}m{sup 2} values down to 10{sup -3} eV{sup 2} at maximum neutrino mixing and to sin{sup 2}2{theta} values down to 6 x 10{sup -3} at {Delta}m{sup 2} {approximately} 2 x 10{sup -2} eV{sup 2}. 21 refs., 6 figs., 3 tabs.

  14. Neutrinos and dark matter

    SciTech Connect (OSTI)

    Ibarra, Alejandro

    2015-07-15

    Neutrinos could be key particles to unravel the nature of the dark matter of the Universe. On the one hand, sterile neutrinos in minimal extensions of the Standard Model are excellent dark matter candidates, producing potentially observable signals in the form of a line in the X-ray sky. On the other hand, the annihilation or the decay of dark matter particles produces, in many plausible dark matter scenarios, a neutrino flux that could be detected at neutrino telescopes, thus providing non-gravitational evidence for dark matter. More conservatively, the non-observation of a significant excess in the neutrino fluxes with respect to the expected astrophysical backgrounds can be used to constrain dark matter properties, such as the self-annihilation cross section, the scattering cross section with nucleons and the lifetime.

  15. Solar neutrinos: Probing the sun or neutrinos

    SciTech Connect (OSTI)

    Wilkerson, J.F.

    1991-01-01

    The decade of the 1990's should prove to be a landmark period for the study of solar neutrino physics. Current observations show 2-3 times fewer neutrinos coming from the sun than are theoretically expected. As we enter the decade, new experiments are poised to attempt and discover whether this deficit is a problem with our understanding of how the sun works, is a hint of new neutrino properties beyond those predicted by the standard model of particle physics, or perhaps a combination of both. This paper will review the current status of the field and point out how future measurements should help solve this interesting puzzle. 11 refs., 3 figs., 1 tab.

  16. BooNE: Booster Neutrino Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Booster Neutrino Experiment (BooNE) Goals of BooNE BooNE in a Nutshell Making Neutrinos Detecting Neutrinos

  17. Possible cosmogenic neutrino constraints on Planck-scale Lorentz violation

    SciTech Connect (OSTI)

    Mattingly, David M.; Maccione, Luca; Galaverni, Matteo; Liberati, Stefano; Sigl, Günter E-mail: luca.maccione@desy.de E-mail: liberati@sissa.it

    2010-02-01

    We study, within an effective field theory framework, O(E{sup 2}M{sub Pl}{sup 2}) Planck-scale suppressed Lorentz invariance violation (LV) effects in the neutrino sector, whose size we parameterize by a dimensionless parameter η{sub ν}. We find deviations from predictions of Lorentz invariant physics in the cosmogenic neutrino spectrum. For positive O(1) coefficients no neutrino will survive above 10{sup 19}eV. The existence of this cutoff generates a bump in the neutrino spectrum at energies of 10{sup 17}eV. Although at present no constraint can be cast, as current experiments do not have enough sensitivity to detect ultra-high-energy neutrinos, we show that experiments in construction or being planned have the potential to cast limits as strong as η{sub ν}∼<10{sup −4} on the neutrino LV parameter, depending on how LV is distributed among neutrino mass states. Constraints on η{sub ν} < 0 can in principle be obtained with this strategy, but they require a more detailed modeling of how LV affects the neutrino sector.

  18. The accretion of solar material onto white dwarfs: No mixing with core material implies that the mass of the white dwarf is increasing

    SciTech Connect (OSTI)

    Starrfield, Sumner

    2014-04-15

    Cataclysmic Variables (CVs) are close binary star systems with one component a white dwarf (WD) and the other a larger cooler star that fills its Roche Lobe. The cooler star is losing mass through the inner Lagrangian point of the binary and some unknown fraction of this material is accreted by the WD. One consequence of the WDs accreting material, is the possibility that they are growing in mass and will eventually reach the Chandrasekhar Limit. This evolution could result in a Supernova Ia (SN Ia) explosion and is designated the Single Degenerate Progenitor (SD) scenario. This paper is concerned with the SD scenario for SN Ia progenitors. One problem with the single degenerate scenario is that it is generally assumed that the accreting material mixes with WD core material at some time during the accretion phase of evolution and, since the typical WD has a carbon-oxygen CO core, the mixing results in large amounts of carbon and oxygen being brought up into the accreted layers. The presence of enriched carbon causes enhanced nuclear fusion and a Classical Nova explosion. Both observations and theoretical studies of these explosions imply that more mass is ejected than is accreted. Thus, the WD in a Classical Nova system is losing mass and cannot be a SN Ia progenitor. However, the composition in the nuclear burning region is important and, in new calculations reported here, the consequences to the WD of no mixing of accreted material with core material have been investigated so that the material involved in the explosion has only a Solar composition. WDs with a large range in initial masses and mass accretion rates have been evolved. I find that once sufficient material has been accreted, nuclear burning occurs in all evolutionary sequences and continues until a thermonuclear runaway (TNR) occurs and the WD either ejects a small amount of material or its radius grows to about 10{sup 12} cm and the evolution is ended. In all cases where mass ejection occurs, the

  19. Solar neutrinos: Theoretical status

    SciTech Connect (OSTI)

    Haxton, W.C.

    1991-01-01

    I review the standard solar model, the disparities between its predictions an the solar neutrino flux measurements of the Homestake and Kamioka 2 collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained by building analogies with more familiar atomic physics phenomena. These and other mechanisms are considered as possible explanations for time variations in the solar neutrino flux. Finally, I consider possible outcomes and implications of the SAGE/GALLEX gallium experiments.

  20. Leptogenesis via neutrino production during Higgs condensate...

    Office of Scientific and Technical Information (OSTI)

    Leptogenesis via neutrino production during Higgs condensate relaxation Title: Leptogenesis via neutrino production during Higgs condensate relaxation Authors: Pearce, Lauren ; ...

  1. Neutrino properties deduced from the study of lepton number violating processes at low and high energies

    SciTech Connect (OSTI)

    Stoica, Sabin

    2012-11-20

    There is nowadays a significant progress in understanding the neutrino properties. The results of the neutrino oscillation experiments have convincingly showed that neutrinos have mass and oscillate, in contradiction with the Standard Model (SM) assumptions, and these are the first evidences of beyond SM physics. However, fundamental properties of the neutrinos like their absolute mass, their character (are they Dirac or Majorana particles?), their mass hierarchy, the number of neutrino flavors, etc., still remain unknown. In this context there is an increased interest in the study of the lepton number violating (LNV) processes, since they could complete our understanding on the neutrino properties. Since recently, the neutrinoless double beta decay was considered the only process able to distinguish between Dirac or Majorana neutrinos and to give a hint on the absolute mass of the electron neutrino. At present, the increased luminosity of the LHC experiments makes feasible the search of LNV processes at high energy as well. In this lecture I will make a brief review on our present knowledge of the neutrino properties, on the present status of the double-beta decay studies and on the first attempts to search LNV processes at LHC.

  2. Core-collapse supernova neutrinos and neutrino properties

    SciTech Connect (OSTI)

    Gava, J.; Volpe, C.

    2008-08-29

    Core-collapse supernovae are powerful neutrino sources. The observation of a future (extra-)galactic supernova explosion or of the relic supernova neutrinos might provide important information on the supernova dynamics, on the supernova formation rate and on neutrino properties. One might learn more about unknown neutrino properties either from indirect effects in the supernova (e.g. on the explosion or on in the r-process) or from modifications of the neutrino time or energy distributions in a detector on Earth. Here we will discuss in particular possible effects of CP violation in the lepton sector. We will also mention the interest of future neutrino-nucleus interaction measurements for the precise knowledge of supernova neutrino detector response to electron neutrinos.

  3. Neutrino physics with multi-ton scale liquid xenon detectors

    SciTech Connect (OSTI)

    Baudis, L.; Ferella, A.; Kish, A.; Manalaysay, A.; Undagoitia, T. Marrodn; Schumann, M., E-mail: laura.baudis@physik.uzh.ch, E-mail: alfredo.ferella@lngs.infn.it, E-mail: alexkish@physik.uzh.ch, E-mail: aaronm@ucdavis.edu, E-mail: marrodan@mpi-hd.mpg.de, E-mail: marc.schumann@lhep.unibe.ch [Physik Institut, University of Zrich, Winterthurerstrasse 190, Zrich, CH-8057 (Switzerland)

    2014-01-01

    We study the sensitivity of large-scale xenon detectors to low-energy solar neutrinos, to coherent neutrino-nucleus scattering and to neutrinoless double beta decay. As a concrete example, we consider the xenon part of the proposed DARWIN (Dark Matter WIMP Search with Noble Liquids) experiment. We perform detailed Monte Carlo simulations of the expected backgrounds, considering realistic energy resolutions and thresholds in the detector. In a low-energy window of 230 keV, where the sensitivity to solar pp and {sup 7}Be-neutrinos is highest, an integrated pp-neutrino rate of 5900 events can be reached in a fiducial mass of 14 tons of natural xenon, after 5 years of data. The pp-neutrino flux could thus be measured with a statistical uncertainty around 1%, reaching the precision of solar model predictions. These low-energy solar neutrinos will be the limiting background to the dark matter search channel for WIMP-nucleon cross sections below ? 2 10{sup ?48} cm{sup 2} and WIMP masses around 50 GeV?c{sup ?2}, for an assumed 99.5% rejection of electronic recoils due to elastic neutrino-electron scatters. Nuclear recoils from coherent scattering of solar neutrinos will limit the sensitivity to WIMP masses below ? 6 GeV?c{sup ?2} to cross sections above ? 4 10{sup ?45}cm{sup 2}. DARWIN could reach a competitive half-life sensitivity of 5.6 10{sup 26} y to the neutrinoless double beta decay of {sup 136}Xe after 5 years of data, using 6 tons of natural xenon in the central detector region.

  4. Neutrino Oscillation Parameter Sensitivity in Future Long-Baseline Experiments

    SciTech Connect (OSTI)

    Bass, Matthew

    2014-01-01

    The study of neutrino interactions and propagation has produced evidence for physics beyond the standard model and promises to continue to shed light on rare phenomena. Since the discovery of neutrino oscillations in the late 1990s there have been rapid advances in establishing the three flavor paradigm of neutrino oscillations. The 2012 discovery of a large value for the last unmeasured missing angle has opened the way for future experiments to search for charge-parity symmetry violation in the lepton sector. This thesis presents an analysis of the future sensitivity to neutrino oscillations in the three flavor paradigm for the T2K, NO A, LBNE, and T2HK experiments. The theory of the three flavor paradigm is explained and the methods to use these theoretical predictions to design long baseline neutrino experiments are described. The sensitivity to the oscillation parameters for each experiment is presented with a particular focus on the search for CP violation and the measurement of the neutrino mass hierarchy. The variations of these sensitivities with statistical considerations and experimental design optimizations taken into account are explored. The effects of systematic uncertainties in the neutrino flux, interaction, and detection predictions are also considered by incorporating more advanced simulations inputs from the LBNE experiment.

  5. Frederick Reines and the Neutrino

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frederick Reines and the Detection of the Neutrino Resources with Additional Information '[Frederick] Reines - known among scientists as the "father of neutrino physics" - won the Nobel Prize for physics in 1995 ["for the detection of the neutrino"], nearly 40 years after his neutrino experiments changed the world of physics and set in motion a new way of looking at the universe. ... Frederick Reines Courtesy University of California Irvine Until Reines's discovery,

  6. Perspectives on neutrino telescopes 2009

    SciTech Connect (OSTI)

    Quigg, Chris; /Fermilab /Karlsruhe U., TTP

    2009-04-01

    Remarks at the roundtable on plans for the future at the XIII International Workshop on Neutrino Telescopes.

  7. What is a Neutrino Horn?

    Office of Energy Efficiency and Renewable Energy (EERE)

    Find out how scientists at Fermilab scientists study some of the most elusive particles in our universe: neutrinos.

  8. Dark photons as fractional cosmic neutrino masquerader

    SciTech Connect (OSTI)

    Ng, Kin-Wang; Tu, Huitzu; Yuan, Tzu-Chiang E-mail: huitzu@phys.sinica.edu.tw

    2014-09-01

    Recently, Weinberg proposed a Higgs portal model with a spontaneously broken global U(1) symmetry in which Goldstone bosons may be masquerading as fractional cosmic neutrinos. We extend the model by gauging the U(1) symmetry. This gives rise to the so-called dark photon and dark Higgs. The dark photons can constitute about 0.912 (0.167) to the effective number of light neutrino species if they decouple from the thermal bath before the pions become non-relativistic and after (before) the QCD transition. Restriction on the parameter space of the portal coupling and the dark Higgs mass is obtained from the freeze-out condition of the dark photons. Combining with the collider data constraints on the invisible width of the standard model Higgs requires the dark Higgs mass to be less than a few GeV.

  9. Dirac neutrinos from a second Higgs doublet

    SciTech Connect (OSTI)

    Davidson, Shainen M.; Logan, Heather E. [Ottawa-Carleton Institute for Physics, Carleton University, Ottawa K1S 5B6 (Canada)

    2009-11-01

    We propose a minimal extension of the standard model in which neutrinos are Dirac particles and their tiny masses are explained without requiring tiny Yukawa couplings. A second Higgs doublet with a tiny vacuum expectation value provides neutrino masses while simultaneously improving the naturalness of the model by allowing a heavier standard-model-like Higgs boson consistent with electroweak precision data. The model predicts a {mu}{yields}e{gamma} rate potentially detectable in the current round of experiments, as well as distinctive signatures in the production and decay of the charged Higgs H{sup +} of the second doublet which can be tested at future colliders. Neutrinoless double beta decay is absent.

  10. High-precision Penning trap mass measurements for tests of the Standard Model

    SciTech Connect (OSTI)

    Blaum, Klaus; Eliseev, Sergey; Nagy, Szilard

    2010-08-04

    With the nowadays achievable accuracy in Penning trap mass spectrometry on short-lived exotic nuclides as well as stable atoms, precision fundamental tests can be performed, among them a test of the Standard Model, in particular with regard to the weak interaction, the CPT symmetry conservation, and the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. In addition, accurate mass values of specific nuclides are important for neutrino physics. The presently best tests of the Standard Model with high-precision Penning trap mass spectrometry will be reviewed.

  11. Searches for massive neutrinos in nuclear beta decay

    SciTech Connect (OSTI)

    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.

  12. Solar Neutrinos. II. Experimental

    DOE R&D Accomplishments [OSTI]

    Davis, Raymond Jr.

    1964-01-01

    A method is described for observing solar neutrinos from the reaction Cl{sup 37}(nu,e{sup -})Ar{sup 37} in C{sub 2}Cl{sub 4}. Two 5 00-gal tanks of C{sub 2}Cl{sub 4} were placed in a limestone mine (1800 m.w.e.) and the resulting Ar{sup 37} activity induced by cosmic mesons( mu ) was measured to determine the necessary conditions for solar neutrino observations. (R.E.U.)

  13. The Final Results from the Sudbury Neutrino Observatory

    ScienceCinema (OSTI)

    None

    2011-04-25

    The Sudbury Neutrino Observatory (SNO) was a water Cherenkov detector dedicated to investigate elementary particles called neutrinos. It successfully took data between 1999 and 2006. The detector was unique in its use of heavy water as a detection medium, permitting it to make a solar model-independent test of solar neutrino mixing. In fact, SNO conclusively showed that solar neutrinos oscillate on their way from the core of the Sun to the Earth. This groundbreaking observation was made during three independent phases of the experiment. Even if data taking ended, SNO is still in a mode of precise determination of the solar neutrino oscillation parameters because all along SNO had developed several methods to tell charged-current events apart from neutral-current events. This ability is crucial for the final and ultimate data analysis of all the phases. The physics reach of a combined three-phase solar analysis will be reviewed together with results and subtleties about solar neutrino physics.

  14. The detector system of the Daya Bay reactor neutrino experiment

    SciTech Connect (OSTI)

    An, F. P.

    2015-12-15

    The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of ν¯e oscillations over km-baselines. Subsequent data has provided the world's most precise measurement of sin 213 and the effective mass splitting Δm2ee. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world's most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes, the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors’ baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This study describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking.

  15. Intensity of Upward Muon Flux Due to Cosmic-Ray Neutrinos Produced in the Atmosphere

    DOE R&D Accomplishments [OSTI]

    Lee, T. D.; Robinson, H.; Schwartz, M.; Cool, R.

    1963-06-01

    Calculations were performed to determine the upward going muon flux leaving the earth's surface after production by cosmic-ray neutrinos in the crust. Only neutrinos produced in the earth's atmosphere are considered. Rates of the order of one per 100 sq m/day might be expected if an intermediate boson exists and has a mass less than 2 Bev. (auth)

  16. The search for Majorana neutrinos with neutrinoless double beta decays: From CUORICINO to LUCIFER experiment

    SciTech Connect (OSTI)

    Bellini, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma I-00185 (Italy) and INFN - Sezione di Roma, Roma I-00185 (Italy)

    2012-11-20

    The study of neutrino properties is one of the fundamental challenges in particle physics nowadays. Fifty years of investigations established that neutrinos are massive but the absolute mass scale has not yet been measured. Moreover its true nature is still unknown. Is the neutrino its own antiparticle (thus violating the lepton number) as proposed by Majorana in 1937? The only way to probe the neutrino nature is through the observation of Neutrinoless Double Beta Decay (0{nu}{beta}{beta}), a very rare spontaneous nuclear transition which emits two electrons and no neutrinos. In this paper, after a brief introduction to the theoretical framework of Majorana's neutrino, a presentation of experimental challenges posed by 0{nu}{beta}{beta} search will be given as well as an overview of present status and future perpectives of experiments.

  17. The Neutrino Signal from Protoneutron Star Accretion and Black Hole Formation

    SciTech Connect (OSTI)

    Fischer, T.; Whitehouse, S.; Mezzacappa, Anthony; Thielemann, F.-K.; Liebendoerfer, M.

    2009-01-01

    We discuss the formation of stellar mass black holes via protoneutron star (PNS) collapse. In the absence of an earlier explosion, the PNS collapses to a black hole due to the continued mass accretion onto the PNS. We present an analysis of the emitted neutrino spectra of all three flavors during the PNS contraction. Special attention is given to the physical conditions which depend on the input physics, e.g. the equation of state (EoS) and the progenitor model. The PNSs are modeled as the central object in core collapse simulations using general relativistic three-flavor Boltzmann neutrino transport in spherical symmetry. The simulations are launched from several massive progenitors of 40 M{omicron} and 50 M{omicron}. We analyze the electron-neutrino luminosity dependencies and construct a simple approximation for the electron-neutrino luminosity, which depends only on the physical conditions at the electron-neutrinosphere. In addition, we analyze different ({mu}, {tau})-neutrino pair-reactions separately and compare the differences during the post-bounce phases of failed core collapse supernova explosions of massive progenitors. We also investigate the connection between the increasing {mu},{tau}-neutrino luminosity and the PNS contraction during the accretion phase before black hole formation. Comparing the different post bounce phases of the progenitor models under investigation, we find large differences in the emitted neutrino spectra. These differences and the analysis of the electron-neutrino luminosity indicate a strong progenitor model dependency of the emitted neutrino signal.

  18. Atmospheric electron neutrinos in the MINOS far detector

    SciTech Connect (OSTI)

    Speakman, Benjamin Phillip; /Minnesota U.

    2007-01-01

    Neutrinos produced as a result of cosmic-ray interactions in the earth's atmosphere offer a powerful probe into the nature of this three-membered family of low-mass, weakly-interacting particles. Ten years ago, the Super-Kamiokande Experiment has confirmed earlier indications that neutrinos undergo lepton-flavor oscillations during propagation, proving that they are massive contrary to the previous Standard Model assumptions. The Soudan Underground Laboratory, located in northern Minnesota, was host to the Soudan2 Experiment, which has made important contributions to atmospheric neutrino research. This same lab has more recently been host to the MINOS far detector, a neutrino detector which serves as the downstream element of an accelerator-based long-baseline neutrino-oscillation experiment. This thesis has examined 418.5 live days of atmospheric neutrino data (fiducial exposure of 4.18 kton-years) collected in the MINOS far detector prior to the activation of the NuMI neutrino beam, with a specific emphasis on the investigation of electron-type neutrino interactions. Atmospheric neutrino interaction candidates have been selected and separated into showering or track-like events. The showering sample consists of 89 observed events, while the track-like sample consists of 112 observed events. Based on the Bartol atmospheric neutrino flux model of Barr et al. plus a Monte Carlo (MC) simulation of interactions in the MINOS detector, the expected yields of showering and track-like events in the absence of neutrino oscillations are 88.0 {+-} 1.0 and 149.1 {+-} 1.0 respectively (where the uncertainties reflect only the limited MC statistics). Major systematic uncertainties, especially those associated with the flux model, are cancelled by forming a double ratio of these observed and expected yields: R{sup data}{sub trk/shw}/R{sup MC}{sub trk/shw} = 0.74{sup +0.12}{sub -01.0}(stat.) {+-} 0.04 (syst.) This double ratio should be equal to unity in the absence of

  19. Neutrino Factory Downstream Systems

    SciTech Connect (OSTI)

    Zisman, Michael S.

    2009-12-23

    We describe the Neutrino Factory accelerator systems downstream from the target and capture area. These include the bunching and phase rotation, cooling, acceleration, and decay ring systems. We also briefly discuss the R&D program under way to develop these systems, and indicate areas where help from CERN would be invaluable.

  20. Observation of Electron Neutrino Appearance in the NuMI Beam with the NOvA Experiment

    SciTech Connect (OSTI)

    Niner, Evan David

    2015-01-01

    NOvA is a long-baseline neutrino oscillation experiment that uses two functionally identical detectors separated by 810 kilometers at locations 14 milliradians off-axis from the NuMI muon neutrino beam at Fermilab. At these locations the beam energy peaks at 2 GeV. This baseline is the longest in the world for an accelerator-based neutrino oscillation experiment, which enhances the sensitivity to the neutrino mass ordering. The experiment studies oscillations of the muon neutrino and anti-neutrino beam that is produced. Both detectors completed commissioning in the summer of 2014 and continue to collect data. One of the primary physics goals of the experiment is the measurement of electron neutrino appearance in the muon neutrino beam which yields measurements of the oscillation parameters sin213, δ , and the neutrino mass ordering within the standard model of neutrino oscillations. This thesis presents the analysis of data collected between February 2014 and May 2015, corresponding to 3.52 X 1020 protons-on-target. In this first analysis NOvA recorded 6 electron neutrino candidates, which is a 3.3σ observation of electron neutrino appearance. The T2K experiment performs the same measurement on a baseline of 295 kilometers and has a 1 σ preference for the normal mass ordering over the inverted ordering over the phase space of the CP violating parameter δ, which is also weakly seen in the NOvA result. By the summer of 2016 NOvA will triple its statistics due to increased beam power and a completed detector. If electron neutrinos continue to be observed at the current rate NOvA will be able to establish a mass ordering preference at a similar confidence level to T2K.

  1. Precision Solar Neutrino Measurements with the Sudbury Neutrino Observatory

    SciTech Connect (OSTI)

    Oblath, Noah

    2007-10-26

    The Sudbury Neutrino Observatory (SNO) is the first experiment to measure the total flux of active, high-energy neutrinos from the sun. Results from SNO have solved the long-standing 'Solar Neutrino Problem' by demonstrating that neutrinos change flavor. SNO measured the total neutrino flux with the neutral-current interaction of solar neutrinos with 1000 tonnes of D{sub 2}O. In the first two phases of the experiment we detected the neutron from that interaction by capture on deuterium and capture on chlorine, respectively. In the third phase an array of {sup 3}He proportional counters was deployed in the detector. This allows a measurement of the neutral-current neutrons that is independent of the Cherenkov light detected by the PMT array. We are currently developing a unique, detailed simulation of the current pulses from the proportional-counter array that will be used to help distinguish signal and background pulses.

  2. Raymond Davis Jr., Solar Neutrinos, and the Solar Neutrino Problems

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Raymond Davis, Jr., Solar Neutrinos, and the Solar Neutrino Problem Resources with Additional Information Raymond Davis, Jr. Photo Courtesy of Brookhaven National Laboratory (BNL) Raymond Davis, Jr., who conducted research in the Chemistry Department at Brookhaven National Laboratory (BNL) from 1948 through 1984, was awarded the 2002 Nobel Prize in Physics "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos." Dr. Davis is also a recipient

  3. BooNE: Booster Neutrino Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Posters What's a Neutrino? How neutrinos fit into our understanding of the universe. Recipe for a Neutrino Beam Start with some protons... concocting the MiniBooNE beam. The...

  4. Energy Neutrinos Ever Lisa Gerhardt, LBNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    IceCube and the Highest Energy Neutrinos Ever Lisa Gerhardt, LBNL NUG 2014 February 5, 2014 2 Neutrinos Neutrinos are produced locally in Sun, nuclear reactors, and cosmic ray ...

  5. On the Detection of the Free Neutrino

    DOE R&D Accomplishments [OSTI]

    Reines, F.; Cowan, C. L., Jr.

    1953-08-06

    The experiment previously proposed [to Detect the Free Neutrino] has been initiated, with a Hanford pile as a neutrino source. It appears probable that neutrino detection has been accomplished, and confirmatory work is in progress. (K.S.)

  6. Raymond Davis Jr., Solar Neutrinos, and the Solar Neutrino Problems

    Office of Scientific and Technical Information (OSTI)

    discrepancy. While at Brookhaven, Ray Davis conducted research and experiments in solar neutrinos at Homestake Gold Mine in South Dakota. This research was funded by the...

  7. Solar neutrino experiments: An update

    SciTech Connect (OSTI)

    Hahn, R.L.

    1993-12-31

    The situation in solar neutrino physics has changed drastically in the past few years, so that now there are four neutrino experiments in operation, using different methods to look at different regions of the solar neutrino energy spectrum. These experiments are the radiochemical {sup 37}Cl Homestake detector, the realtime Kamiokande detector, and the different forms of radiochemical {sup 71}Ga detectors used in the GALLEX and SAGE projects. It is noteworthy that all of these experiments report a deficit of observed neutrinos relative to the predictions of standard solar models (although in the case of the gallium detectors, the statistical errors are still relatively large). This paper reviews the basic principles of operation of these neutrino detectors, reports their latest results and discusses some theoretical interpretations. The progress of three realtime neutrino detectors that are currently under construction, SuperKamiok, SNO and Borexino, is also discussed.

  8. Flavor changing neutral currents in the 3-3-1 model with right-handed neutrinos

    SciTech Connect (OSTI)

    Benavides, Richard H.; Giraldo, Yithsbey; Ponce, William A.

    2009-12-01

    Flavor changing neutral currents coming from a new nonuniversal neutral gauge boson and from the nonunitary quark mixing matrix for the SU(3){sub c} x SU(3){sub L} x U(1){sub X} model with right-handed neutrinos are studied. By imposing as experimental constraints the measured values of the 3x3 quark mixing matrix, the neutral meson mixing, and bounds and measured values for direct flavor changing neutral current processes, the largest mixing of the known quarks with the exotic ones can be established, with new sources of flavor changing neutral currents being identified. Our main result is that for a |V{sub tb}| value smaller than 1, large rates of rare top decays such as t{yields}c{gamma}, t{yields}cZ, and t{yields}cg (where g stands for the gluon field) are obtained; but if |V{sub tb}|{approx}1 the model can survive present experimental limits only if the mass of the new neutral gauge bosons becomes larger that 10 TeV.

  9. Active-sterile neutrino oscillations in the early Universe with full collision terms

    SciTech Connect (OSTI)

    Hannestad, Steen; Hansen, Rasmus Sloth; Tram, Thomas; Wong, Yvonne Y.Y.

    2015-08-11

    Sterile neutrinos are thermalised in the early Universe via oscillations with the active neutrinos for certain mixing parameters. The most detailed calculation of this thermalisation process involves the solution of the momentum-dependent quantum kinetic equations, which track the evolution of the neutrino phase space distributions. Until now the collision terms in the quantum kinetic equations have always been approximated using equilibrium distributions, but this approximation has never been checked numerically. In this work we revisit the sterile neutrino thermalisation calculation using the full collision term, and compare the results with various existing approximations in the literature. We find a better agreement than would naively be expected, but also identify some issues with these approximations that have not been appreciated previously. These include an unphysical production of neutrinos via scattering and the importance of redistributing momentum through scattering, as well as details of Pauli blocking. Finally, we devise a new approximation scheme, which improves upon some of the shortcomings of previous schemes.

  10. Muon Colliders and Neutrino Factories

    SciTech Connect (OSTI)

    Geer, Steve; /Fermilab

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate {Omicron}(10{sup 21}) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  11. Muon colliders and neutrino factories

    SciTech Connect (OSTI)

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  12. Solar neutrinos: theory vs experiment

    SciTech Connect (OSTI)

    Haxton, W.C.

    1991-01-01

    I review the standard solar model, the disparities between its predictions and the solar neutrino flux measurements of the Homestake and Kamioka II collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are reviewed, including possibilities for generating time variations in the solar neutrino flux. Finally, I consider possible outcomes and implications of the SAGE/GALLEX gallium experiments.

  13. Masatoshi Koshiba and Cosmic Neutrinos

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Masatoshi Koshiba and Cosmic Neutrinos Resources with Additional Information Masatoshi Koshiba Courtesy of Sebastian Brandt 'The 2002 Nobel Prize in Physics has been awarded to ... Masatoshi Koshiba of the International Center for Elementary Particle Physics at the University of Tokyo in Japan, ... "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos." ... Neutrinos are important in astrophysics since they might have played a considerable

  14. A search for muon neutrino to electron neutrino oscillations in the MINOS Experiment

    SciTech Connect (OSTI)

    Ochoa Ricoux, Juan Pedro; /Caltech

    2009-10-01

    We perform a search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, a process which would manifest a nonzero value of the {theta}{sub 13} mixing angle, in the MINOS long-baseline neutrino oscillation experiment. The analysis consists of searching for an excess of {nu}{sub e} charged-current candidate events over the predicted backgrounds, made mostly of neutral-current events with high electromagnetic content. A novel technique to select electron neutrino events is developed, which achieves an improved separation between the signal and the backgrounds, and which consequently yields a better reach in {theta}{sub 13}. The backgrounds are predicted in the Far Detector from Near Detector measurements. An excess is observed in the Far Detector data over the predicted backgrounds, which is consistent with the background-only hypothesis at 1.2 standard deviations.

  15. A new multi-dimensional general relativistic neutrino hydrodynamics code for core-collapse supernovae. IV. The neutrino signal

    SciTech Connect (OSTI)

    Mller, Bernhard [Monash Center for Astrophysics, School of Mathematical Sciences, Building 28, Monash University, Victoria 3800 (Australia); Janka, Hans-Thomas, E-mail: bernhard.mueller@monash.edu, E-mail: bjmuellr@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

    2014-06-10

    Considering six general relativistic, two-dimensional (2D) supernova (SN) explosion models of progenitor stars between 8.1 and 27 M {sub ?}, we systematically analyze the properties of the neutrino emission from core collapse and bounce to the post-explosion phase. The models were computed with the VERTEX-COCONUT code, using three-flavor, energy-dependent neutrino transport in the ray-by-ray-plus approximation. Our results confirm the close similarity of the mean energies, (E), of ?-bar {sub e} and heavy-lepton neutrinos and even their crossing during the accretion phase for stars with M ? 10 M {sub ?} as observed in previous 1D and 2D simulations with state-of-the-art neutrino transport. We establish a roughly linear scaling of ?E{sub ?-bar{sub e}}? with the proto-neutron star (PNS) mass, which holds in time as well as for different progenitors. Convection inside the PNS affects the neutrino emission on the 10%-20% level, and accretion continuing beyond the onset of the explosion prevents the abrupt drop of the neutrino luminosities seen in artificially exploded 1D models. We demonstrate that a wavelet-based time-frequency analysis of SN neutrino signals in IceCube will offer sensitive diagnostics for the SN core dynamics up to at least ?10 kpc distance. Strong, narrow-band signal modulations indicate quasi-periodic shock sloshing motions due to the standing accretion shock instability (SASI), and the frequency evolution of such 'SASI neutrino chirps' reveals shock expansion or contraction. The onset of the explosion is accompanied by a shift of the modulation frequency below 40-50 Hz, and post-explosion, episodic accretion downflows will be signaled by activity intervals stretching over an extended frequency range in the wavelet spectrogram.

  16. Fermilab | Inquiring Minds | Neutrino | Discovery | Particles...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | theory | astrophysics | discoveries at Fermilab Discoveries at Fermilab - The Tau Neutrino Neutrino Symbol An international collaboration of scientists at the Department...

  17. Leptogenesis via neutrino production during Higgs condensate...

    Office of Scientific and Technical Information (OSTI)

    Leptogenesis via neutrino production during Higgs condensate relaxation Citation Details In-Document Search Title: Leptogenesis via neutrino production during Higgs condensate ...

  18. Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs

    SciTech Connect (OSTI)

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

    2015-05-11

    In this study, we show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and Cosmic Microwave Background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, and scenarios for light and heavy sterile neutrinos.

  19. Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2015-05-11

    In this study, we show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and Cosmic Microwave Background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, andmore » scenarios for light and heavy sterile neutrinos.« less

  20. The neutrino yesterday and today

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The neutrino yesterday and today The neutrino yesterday and today WHEN: Aug 18, 2016 5:30 PM - 7:00 PM WHERE: UnQuarked Wine Room 145 Central Park Square, Los Alamos, NM 87544, USA CONTACT: Linda Anderman (505) 665-9196 CATEGORY: Bradbury INTERNAL: Calendar Login Event Description The event is open to those of all ages! The neutrino yesterday and today Keith Rielage, a neutrino physicist with the Lab's Neutron Science & Technology group, will share a brief tale of the discovery and study of

  1. Neutrino CCQE Data Release Page

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutrino CCQE Data Release Page "Measurement of Muon Neutrino Quasi-Elastic Scattering on a Hydrocarbon Target at Ev ~ 3.5 GeV" Phys. Rev. Lett. 111 (2013) 022502, hep-ex/1305.2243 Data Ancillary data files for this result are given here, and supercede the ones originally associated with the arXiv entry: they have been updated with MINERvA's best estimate of the NuMI neutrino flux. The available data files have the following format: The columns are Q2 bins, first the 8 neutrino and

  2. zeller-neutrino08.ppt

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutrino 08 1 Low Energy ν Cross Sections Sam Zeller LANL Neutrino 08 May 28, 2008 * review of experimental programs at K2K, MiniBooNE, SciBooNE, and MINERνA Sam Zeller, Neutrino 08 2 Neutrino Cross Sections * over the past ~5 years, renewed interest in low energy ν cross sections for two reasons: * advent of new high intensity ν sources has brought with it a host of new ν cross section measurement opportunities - taking a giant leap forward (both in terms of precision & sample sizes) -

  3. Frederick Reines and the Neutrino

    Office of Scientific and Technical Information (OSTI)

    of California Irvine Until Reines's discovery, physicists had only theorized the existence of the neutrino - and physicists believed the tiny particles would never be...

  4. Birth of Neutrino Astrophysics

    ScienceCinema (OSTI)

    None

    2011-10-06

    Based mainly on the results of two experiments, KamiokaNDE and Super-KamiokaNDE, the birth of neutrino astrophysics will be described. At the end, the result of the third generation Kamioka experiment, KamLAND, will be discussed together with the future possibilities.Organiser(s): Daniel Treille / EP DivisionNote: * Tea & coffee will be served at 16:00 hrs. Please note unusual day.

  5. Experimental Neutrino Physics

    ScienceCinema (OSTI)

    Walter, Chris [Duke University, Durham, North Carolina, United States

    2010-01-08

    In this talk, I will review how a set of experiments in the last decade has given us our current understanding of neutrino properties.  I will show how experiments in the last year or two have clarified this picture, and will discuss how new experiments about to start will address remaining questions.  I will particularly emphasize the relationship between various experimental techniques.

  6. {mu}-{tau} symmetry, sterile right-handed neutrinos, and leptogenesis

    SciTech Connect (OSTI)

    Riazuddin [National Centre for Physics, Quaid-i-Azam University, Islamabad (Pakistan)

    2008-01-01

    Leptogenesis is studied in a seesaw model with {mu}-{tau} symmetry for SU{sub L}(2)-singlet right-handed neutrinos. It is shown that lepton asymmetry is not zero and is given by the square of the solar neutrino mass difference and can be of the right order of magnitude. Further it involves the same Majorana phase which appears in the neutrinoless double {beta}-decay. In this framework one of the right-handed seesaw partners of light neutrinos can be made massless. This can be identified with a sterile neutrino, once it acquires a tiny mass ({approx_equal}1 eV) when {mu}-{tau} symmetry is broken in the right-handed neutrino sector. The above mentioned sterile neutrino together with another one can be identified to explain the MiniBooNE and LSND results. The light 5x5 neutrino mass matrix is completely fixed if CP is conserved and so is the effective mass for neutrinoless double {beta}-decay.

  7. Compact perturbative expressions for neutrino oscillations in matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Denton, Peter B.; Minakata, Hisakazu; Parke, Stephen J.

    2016-06-08

    We further develop and extend a recent perturbative framework for neutrino oscillations in uniform matter density so that the resulting oscillation probabilities are accurate for the complete matter potential versus baseline divided by neutrino energy plane. This extension also gives the exact oscillation probabilities in vacuum for all values of baseline divided by neutrino energy. The expansion parameter used is related to the ratio of the solar to the atmosphericmore » $$\\Delta m^2$$ scales but with a unique choice of the atmospheric $$\\Delta m^2$$ such that certain first-order effects are taken into account in the zeroth-order Hamiltonian. Using a mixing matrix formulation, this framework has the exceptional feature that the neutrino oscillation probability in matter has the same structure as in vacuum, to all orders in the expansion parameter. It also contains all orders in the matter potential and $$\\sin\\theta_{13}$$. It facilitates immediate physical interpretation of the analytic results, and makes the expressions for the neutrino oscillation probabilities extremely compact and very accurate even at zeroth order in our perturbative expansion. Furthermore, the first and second order results are also given which improve the precision by approximately two or more orders of magnitude per perturbative order.« less

  8. Searches for massive neutrinos in nuclear beta decay

    SciTech Connect (OSTI)

    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

  9. Measurement of neutrino flux from neutrino-electron elastic scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Park, J.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; et al

    2016-06-10

    In muon-neutrino elastic scattering on electrons is an observable neutrino process whose cross section is precisely known. Consequently a measurement of this process in an accelerator-based νμ beam can improve the knowledge of the absolute neutrino flux impinging upon the detector; typically this knowledge is limited to ~10% due to uncertainties in hadron production and focusing. We also isolated a sample of 135±17 neutrino-electron elastic scattering candidates in the segmented scintillator detector of MINERvA, after subtracting backgrounds and correcting for efficiency. We show how this sample can be used to reduce the total uncertainty on the NuMI νμ flux frommore » 9% to 6%. Finally, our measurement provides a flux constraint that is useful to other experiments using the NuMI beam, and this technique is applicable to future neutrino beams operating at multi-GeV energies.« less

  10. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    SciTech Connect (OSTI)

    Asner, David M.; Burns, Kimberly A.; Campbell, Luke W.; Greenfield, Bryce A.; Kos, Marek S.; Orrell, John L.; Schram, Malachi; VanDevender, Brent A.; Wood, Lynn S.; Wootan, David W.

    2015-03-01

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

  11. ANTARES deep sea neutrino telescope results

    SciTech Connect (OSTI)

    Mangano, Salvatore [IFIC - Instituto de Fsica Corpuscular, Edificio Institutos de Investigatin, 46071 Valencia (Spain); Collaboration: ANTARES Collaboration

    2014-01-01

    The ANTARES experiment is currently the largest underwater neutrino telescope in the Northern Hemisphere. It is taking high quality data since 2007. Its main scientific goal is to search for high energy neutrinos that are expected from the acceleration of cosmic rays from astrophysical sources. This contribution reviews the status of the detector and presents several analyses carried out on atmospheric muons and neutrinos. For example it shows the results from the measurement of atmospheric muon neutrino spectrum and of atmospheric neutrino oscillation parameters as well as searches for neutrinos from steady cosmic point-like sources, for neutrinos from gamma ray bursts and for relativistic magnetic monopoles.

  12. Prospects for Relic Neutrino Detection at PTOLEMY: Princeton...

    Office of Environmental Management (EM)

    Prospects for Relic Neutrino Detection at PTOLEMY: Princeton Tritium Observatory for Light, Early-Universe, Massive-Neutrino Yield Prospects for Relic Neutrino Detection at...

  13. Improved search for muon-neutrino to electron-neutrino oscillations in MINOS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adamson, P.

    2011-10-27

    The authors report the results of a search for νe appearance in νμ beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 x 1020 protons on the NuMI target at Fermilab, they find that 2 sin2 (θ23 sin2 (θ13) < 0.12 (0.20) at 90% confidence level for δ = 0 and the normal (inverted) neutrino mass hierarchy, with a best fit of 2 sin2θ23) sin 2 (2θ13) = 0.041-0.031 +0.047 (0.079-0.053 +0.071). The θ13= 0 hypothesis is disfavored by the MINOS data at the 89% confidence level.

  14. Big Bang Day: 5 Particles - 4. The Neutrino

    ScienceCinema (OSTI)

    None

    2011-04-25

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". It's the most populous particle in the universe. Millions of these subatomic particles are passing through each one of us. With no charge and virtually no mass they can penetrate vast thicknesses of matter without any interaction - indeed the sun emits huge numbers that pass through earth at the speed of light. Neutrinos are similar to the more familiar electron, with one crucial difference: neutrinos do not carry electric charge. As a result they're extremely difficult to detect . But like HG Wells' invisible man they can give themselves away by bumping into things at high energy and detectors hidden in mines are exploiting this to observe these rare interactions.

  15. Analyzing Atmospheric Neutrino Oscillations

    SciTech Connect (OSTI)

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

    2007-10-26

    We provide a pedagogic derivation of the formula needed to analyze atmospheric data and then derive, for the subset of the data that are fully-contained events, an analysis tool that is quantitative and numerically efficient. Results for the full set of neutrino oscillation data are then presented. We find the following preliminary results: 1.) the sub-dominant approximation provides reasonable values for the best fit parameters for {delta}{sub 32}, {theta}{sub 23}, and {theta}{sub 13} but does not quantitatively provide the errors for these three parameters; 2.) the size of the MSW effect is suppressed in the sub-dominant approximation; 3.) the MSW effect reduces somewhat the extracted error for {delta}{sub 32}, more so for {theta}{sub 23} and {theta}{sub 13}; 4.) atmospheric data alone constrains the allowed values of {theta}{sub 13} only in the sub-dominant approximation, the full three neutrino calculations requires CHOOZ to get a clean constraint; 5.) the linear in {theta}{sub 13} terms are not negligible; and 6.) the minimum value of {theta}{sub 13} is found to be negative, but at a statistically insignificant level.

  16. Enhanced sensitivity to dark matter self-annihilations in the Sun using neutrino spectral information

    SciTech Connect (OSTI)

    Rott, C.; Tanaka, T.; Itow, Y. E-mail: ttanaka@stelab.nagoya-u.ac.jp

    2011-09-01

    Self-annihilating dark matter gravitationally captured by the Sun could yield observable neutrino signals at current and next generation neutrino detectors. By exploiting such signals, neutrino detectors can probe the spin-dependent scattering of weakly interacting massive particles (WIMPs) with nucleons in the Sun. We describe a method how to convert constraints on neutrino fluxes to a limit on the WIMP-nucleon scattering cross section. In this method all neutrino flavors can be treated in a very similar way. We study the sensitivity of neutrino telescopes for Solar WIMP signals using vertex contained events and find that this detection channel is of particular importance in the search for low mass WIMPs. We obtain highly competitive sensitivities with all neutrino flavor channels for a Megaton sized detector through the application of basic spectral selection criteria. Best results are obtained with the electron neutrino channel. We discuss associated uncertainties and provide a procedure how to treat them for analyses in a consistent way.

  17. Partial Quark-Lepton Universality and Neutrino CP Violation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2015-01-01

    We smore » tudy a model with partial quark-lepton universality that can naturally arise in grand unified theories. We find that constraints on the model can be reduced to a single condition on the Dirac CP phase δ in the neutrino sector. Using our current knowledge of the CKM and PMNS mixing matrices, we predict - 32 . 4 ° ≤ δ ≤ 32 . 0 ° at 2 σ .« less

  18. Raymond Davis Jr., Solar Neutrinos, and the Solar Neutrino Problems

    Office of Scientific and Technical Information (OSTI)

    Davis is also a recipient of the 2003 Fermi Award. He was the first scientist to detect solar neutrinos, ghostlike particles produced in the nuclear reactions that power the sun. ...

  19. Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazajian, K. N.; Arnold, K.; Austermann, J.; Benson, B. A.; Bischoff, C.; Bock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; et al

    2014-03-15

    This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve σ (σmv) = 16 meV and σ (Neff)(Neff) = 0.020.more » Such a mass measurement will produce a high significance detection of non-zero σmνσmν, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics — the origin of mass. This precise a measurement of Neff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that Neff = 3.046.« less

  20. Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure

    SciTech Connect (OSTI)

    Abazajian, K. N.; Arnold, K.; Austermann, J.; Benson, B. A.; Bischoff, C.; Bock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; Carvalho, C. S.; Chang, C. L.; Chiang, H. C.; Church, S.; Cooray, A.; Crawford, T. M.; Dawson, K. S.; Das, S.; Devlin, M. J.; Dobbs, M.; Dodelson, S.; Dore, O.; Dunkley, J.; Errard, J.; Fraisse, A.; Gallicchio, J.; Halverson, N. W.; Hanany, S.; Hildebrandt, S. R.; Hincks, A.; Hlozek, R.; Holder, G.; Holzapfel, W. L.; Honscheid, K.; Hu, W.; Hubmayr, J.; Irwin, K.; Jones, W. C.; Kamionkowski, M.; Keating, B.; Keisler, R.; Knox, L.; Komatsu, E.; Kovac, J.; Kuo, C. -L.; Lawrence, C.; Lee, A. T.; Leitch, E.; Linder, E.; Lubin, P.; McMahon, J.; Miller, A.; Newburgh, L.; Niemack, M. D.; Nguyen, H.; Nguyen, H. T.; Page, L.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sehgal, N.; Seljak, U.; Sievers, J.; Silverstein, E.; Slosar, A.; Smith, K. M.; Spergel, D.; Staggs, S. T.; Stark, A.; Stompor, R.; Wang, G.; Watson, S.; Wollack, E. J.; Wu, W. L.K.; Yoon, K. W.; Zahn, O.

    2014-03-15

    This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve ? (?mv) = 16 meV and ? (Neff)(Neff) = 0.020. Such a mass measurement will produce a high significance detection of non-zero ?m??m?, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics the origin of mass. This precise a measurement of Neff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that Neff = 3.046.

  1. Neutrino physics from the cosmic microwave background and large scale structure

    SciTech Connect (OSTI)

    Abazajian, K. N.; Arnold, K.; Austermann, J. E.; Benson, B. A.; Bischoff, C.; Brock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; Chang, C. L.

    2015-03-15

    This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve σ (σmν)(σmν) = 16 meV and σ (Neff)(Neff) = 0.020. Such a mass measurement will produce a high significance detection of non-zero σmνσmν, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics — the origin of mass. This precise a measurement of NeffNeff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that View the MathML sourceNeff=3.046.

  2. Collective flavor oscillations of supernova neutrinos and r-process nucleosynthesis

    SciTech Connect (OSTI)

    Chakraborty, Sovan; Kar, Kamales; Goswami, Srubabati E-mail: sandhya@hri.res.in E-mail: kamales.kar@saha.ac.in

    2010-06-01

    Neutrino-neutrino interactions inside core-collapse supernovae may give rise to collective flavor oscillations resulting in swap between flavors. These oscillations depend on the initial energy spectra, and relative fluxes or relative luminosities of the neutrinos. It has been observed that departure from energy equipartition among different flavors can give rise to one or more sharp spectral swap over energy, termed as splits. We study the occurrence of splits in the neutrino and antineutrino spectra, varying the initial relative fluxes for different models of initial energy spectrum, in both normal and inverted hierarchy. These initial relative flux variations give rise to several possible split patterns whereas variation over different models of energy spectra give similar results. We explore the effect of these spectral splits on the electron fraction, Y{sub e}, that governs r-process nucleosynthesis inside supernovae. Since spectral splits modify the electron neutrino and antineutrino spectra in the region where r-process is postulated to happen, and since the pattern of spectral splits depends on the initial conditions of the spectra and the neutrino mass hierarchy, we show that the condition Y{sub e} < 0.5 required for successful r-process nucleosynthesis will lead to constraints on the initial spectral conditions, for a given neutrino mass hierarchy.

  3. Neutrino probe comparisons of supernovae as a function of redshift

    SciTech Connect (OSTI)

    Fryer, Christopher Lee

    2009-01-01

    We compare aspects of supernova explosions produced in the current epoch against those produced in the first round of star formation. Although the total final mass of stars can change dramatically between these two epochs due to different mass-loss rates from winds, their cores remam very similar. The core structure is more sensitive to the stellar evolution code than it is to the amount of metals. As such, current stellar models produce supernovae from first stars that look very similar to that of stars produced in the current epoch. The neutrino signal, a powerful probe of the inner core, is identical to the few percent level for both star formation epochs. A change in the neutrino signal in the supernova population between these two star formation epochs will only arise if the initial mass function is altered.

  4. Research in Neutrino Physics

    SciTech Connect (OSTI)

    Busenitz, Jerome

    2014-09-30

    Research in Neutrino Physics We describe here the recent activities of our two groups over the first year of this award (effectively November 2010 through January 2012) and our proposed activities and associated budgets for the coming grant year. Both of our groups are collaborating on the Double Chooz reactor neutrino experiment and are playing major roles in calibration and analysis. A major milestone was reached recently: the collaboration obtained the first result on the search for 13 based on 100 days of data from the far detector. Our data indicates that 13 is not zero; specifically the best fit of the neutrino oscillation hypothesis to our data gives sin2 (2 13) = 0.086 ± 0.041 (stat) ± 0.030 (syst) The null oscillation hypothesis is excluded at the 94.6% C.L. This result1 has been submitted to Physical Review Letters. As we continue to take data with the far detector in the coming year, in parallel with completing the construction of the near lab and installing the near detector, we expect the precision of our measurement to improve as we gather significantly more statistics, gain better control of backgrounds through use of partial power data and improved event selection, and better understand the detector energy scale and detection efficiency from calibration data. With both detectors taking data starting in the second half of 2013, we expect to further drive down the uncertainty on our measurement of sin2 (2 13) to less than 0.02. Stancu’s group is also collaborating on the MiniBooNE experiment. Data taking is scheduled to continue through April, by which time 1.18 × 1021 POT is projected. The UA group is playing a leading role in the measurement of antineutrino cross sections, which should be the subject of a publication later this year as well as of Ranjan Dharmapalan’s Ph.D. thesis, which he is expected to defend by the end of this year. It is time to begin working on projects which will eventually succeed Double Chooz and MiniBooNE as the main

  5. On the dynamics of non-relativistic flavor-mixed particles

    SciTech Connect (OSTI)

    Medvedev, Mikhail V.

    2014-06-01

    Evolution of a system of interacting non-relativistic quantum flavor-mixed particles is considered both theoretically and numerically. It was shown that collisions of mixed particles not only scatter them elastically, but can also change their mass eigenstates thus affecting particles' flavor composition and kinetic energy. The mass eigenstate conversions and elastic scattering are related but different processes, hence the conversion S-matrix elements can be arbitrarily large even when the elastic scattering S-matrix elements vanish. The conversions are efficient when the mass eigenstates are well-separated in space but suppressed if their wave-packets overlap; the suppression is most severe for mass-degenerate eigenstates in flat space-time. The mass eigenstate conversions can lead to an interesting process, called ''quantum evaporation'', in which mixed particles, initially confined deep inside a gravitational potential well and scattering only off each other, can escape from it without extra energy supply leaving nothing behind inside the potential at t ? ?. Implications for the cosmic neutrino background and the two-component dark matter model are discussed and a prediction for the direct detection dark matter experiments is made.

  6. The Fermilab neutrino beam program

    SciTech Connect (OSTI)

    Rameika, Regina A.; /Fermilab

    2007-01-01

    This talk presents an overview of the Fermilab Neutrino Beam Program. Results from completed experiments as well as the status and outlook for current experiments is given. Emphasis is given to current activities towards planning for a future program.

  7. 7Be Solar Neutrino Measurement with KamLAND

    SciTech Connect (OSTI)

    The KamLAND Collaboration; Gando, A.; Gando, Y.; Hanakago, H.; Ikeda, H.; Inoue, K.; Ishidoshiro, K.; Ishikawa, H.; Kishimoto, Y.; Koga, M.; Matsuda, R.; Matsuda, S.; Mitsui, T.; Motoki, D.; Nakajima, K.; Nakamura, K.; Obata, A.; Oki, A.; Oki, Y.; Otani, M.; Shimizu, I.; Shirai, J.; Suzuki, A.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yamada, S.; Yamauchi, Y.; Yoshida, H.; Kozlov, A.; Takemoto, Y.; Yoshida, S.; Grant, C.; Keefer, G.; McKee, D. W.; Piepke, A.; Banks, T. I.; Bloxham, T.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Hsu, L.; Ichimura, K.; Murayama, H.; O'Donnell, T.; Steiner, H. M.; Winslow, L. A.; Dwyer, D.; Mauger, C.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Learned, J. G.; Sakai, M.; Horton-Smith, G. A.; Tang, A.; Downum, K. E.; Tolich, K.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Detwiler, J. A.; Enomoto, S.; Heeger, K.; Decowski, M. P.

    2014-05-26

    We report a measurement of the neutrino-electron elastic scattering rate of 862 keV {sup 7}Be solar neutrinos based on a 165.4 kton-day exposure of KamLAND. The observed rate is 582{+-}90 (kton#1;day){sup -1}, which corresponds to a 862 keV {sup 7}Be solar neutrino flux of (3.26{+-}0.50) #2;x 10{sup 9} cm{sup -2}s{sup -1}, assuming a pure electron flavor flux. Comparing this flux with the standard solar model prediction and further assuming three flavor mixing, a #23;e survival probability of 0.66{+-}0.14 is determined from the KamLAND data. Utilizing a global three flavor oscillation analysis, we obtain a total {sup 7}Be solar neutrino flux of (5.82{+-}0.98) x 10{sup 9} cm{sup -2}s{sup -1}, which is consistent with the standard solar model predictions.

  8. BooNE: Booster Neutrino Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Flux The MiniBooNE neutrino flux calculations are described in detail in PRD 79, 072002 (2009) and arXiv:0806.1449 General neutrino fluxes vs true neutrino energy, for MiniBooNE: image:muon neutrino flux image:electron neutrino flux image:final muon and electron neutrino fluxes π+ production Data sets: M.G. Catanesi et al. [HARP Collaboration], ``Measurement of the production cross-section of positive pions in the collision of 8.9-GeV/c protons on beryllium,'', arXiv:hep-ex/0702024 E910

  9. Environmental assessment -- Proposed neutrino beams at the Main Injector project

    SciTech Connect (OSTI)

    1997-12-01

    The US Department of Energy (DOE) proposes to build a beamline on the Fermi National Accelerator Laboratory (Fermilab) site to accommodate an experimental research program in neutrino physics. The proposed action, called Neutrino Beams at the Main Injector (NuMI), is to design, construct, operate and decommission a facility for producing and studying a high flux beam of neutrinos in the energy range of 1 to 40 GeV (1 GeV is one billion or 10{sup 9} electron volts). The proposed facility would initially be dedicated to two experiments, COSMOS (Cosmologically Significant Mass Oscillations) and MINOS (Main Injector Neutrino Oscillation Search). The neutrino beam would pass underground from Fermilab to northern Minnesota. A tunnel would not be built in this intervening region because the neutrinos easily pass through the earth, not interacting, similar to the way that light passes through a pane of glass. The beam is pointed towards the MINOS detector in the Soudan Underground Laboratory in Minnesota. Thus, the proposed project also includes construction, operation and decommissioning of the facility located in the Soudan Underground Laboratory in Minnesota that houses this MINOS detector. This environmental assessment (EA) has been prepared by the US Department of Energy (DOE) in accordance with the DOE`s National Environmental Policy Act (NEPA) Implementing Procedures (10 CFR 1021). This EA documents DOE`s evaluation of potential environmental impacts associated with the proposed construction and operation of NuMI at Fermilab and its far detector facility located in the Soudan Underground Laboratory in Minnesota. Any future use of the facilities on the Fermilab site would require the administrative approval of the Director of Fermilab and would undergo a separate NEPA review. Fermilab is a Federal high-energy physics research laboratory in Batavia, Illinois operated on behalf of the DOE by Universities Research Association, Inc.

  10. Atmospheric Neutrinos in the MINOS Far Detector

    SciTech Connect (OSTI)

    Howcroft, Caius L.F.

    2004-12-01

    The phenomenon of flavour oscillations of neutrinos created in the atmosphere was first reported by the Super-Kamiokande collaboration in 1998 and since then has been confirmed by Soudan 2 and MACRO. The MINOS Far Detector is the first magnetized neutrino detector able to study atmospheric neutrino oscillations. Although it was designed to detect neutrinos from the NuMI beam, it provides a unique opportunity to measure the oscillation parameters for neutrinos and anti-neutrinos independently. The MINOS Far Detector was completed in August 2003 and since then has collected 2.52 kton-years of atmospheric data. Atmospheric neutrino interactions contained within the volume of the detector are separated from the dominant background from cosmic ray muons. Thirty seven events are selected with an estimated background contamination of less than 10%. Using the detector's magnetic field, 17 neutrino events and 6 anti-neutrino events are identified, 14 events have ambiguous charge. The neutrino oscillation parameters for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} are studied using a maximum likelihood analysis. The measurement does not place constraining limits on the neutrino oscillation parameters due to the limited statistics of the data set analysed. However, this thesis represents the first observation of charge separated atmospheric neutrino interactions. It also details the techniques developed to perform atmospheric neutrino analyses in the MINOS Far Detector.