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Sample records for majorana neutrinos neutrino

  1. Searches for Majorana neutrinos in B- decays

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Abellan Beteta, C.; Adeva, B.; Adinolfi, M.; Adrover, C.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A., Jr.; Amato, S.; Amhis, Y.; Anderson, J.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Arrabito, L.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Bachmann, S.; Back, J. J.; Bailey, D. S.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Bates, A.; Bauer, C.; Bauer, Th.; Bay, A.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Benayoun, M.; Bencivenni, G.; Benson, S.; Benton, J.; Bernet, R.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjørnstad, P. M.; Blake, T.; Blanc, F.; Blanks, C.; Blouw, J.; Blusk, S.; Bobrov, A.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Bowcock, T. J. V.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brook, N. H.; Brown, H.; Büchler-Germann, A.; Burducea, I.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Callot, O.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cattaneo, M.; Cauet, Ch.; Charles, M.; Charpentier, Ph.; Chiapolini, N.; Ciba, K.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coca, C.; Coco, V.; Cogan, J.; Collins, P.; Comerma-Montells, A.; Constantin, F.; Contu, A.; Cook, A.; Coombes, M.; Corti, G.; Couturier, B.; Cowan, G. A.; Currie, R.; D'Ambrosio, C.; David, P.; David, P. N. Y.; De Bonis, I.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Lorenzi, F.; De Miranda, J. M.; De Paula, L.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Degaudenzi, H.; Del Buono, L.; Deplano, C.; Derkach, D.; Deschamps, O.; Dettori, F.; Dickens, J.; Dijkstra, H.; Diniz Batista, P.; Domingo Bonal, F.; Donleavy, S.; Dordei, F.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dupertuis, F.; Dzhelyadin, R.; Dziurda, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; van Eijk, D.; Eisele, F.; Eisenhardt, S.; Ekelhof, R.; Eklund, L.; Elsasser, Ch.; Elsby, D.; Esperante Pereira, D.; Falabella, A.; Fanchini, E.; Färber, C.; Fardell, G.; Farinelli, C.; Farry, S.; Fave, V.; Fernandez Albor, V.; Ferro-Luzzi, M.; Filippov, S.; Fitzpatrick, C.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Furcas, S.; Gallas Torreira, A.; Galli, D.; Gandelman, M.; Gandini, P.; Gao, Y.; Garnier, J.-C.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gauvin, N.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gibson, V.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hampson, T.; Hansmann-Menzemer, S.; Harji, R.; Harnew, N.; Harrison, J.; Harrison, P. F.; Hartmann, T.; He, J.; Heijne, V.; Hennessy, K.; Henrard, P.; Hernando Morata, J. A.; van Herwijnen, E.; Hicks, E.; Holubyev, K.; Hopchev, P.; Hulsbergen, W.; Hunt, P.; Huse, T.; Huston, R. S.; Hutchcroft, D.; Hynds, D.; Iakovenko, V.; Ilten, P.; Imong, J.; Jacobsson, R.; Jaeger, A.; Jahjah Hussein, M.; Jans, E.; Jansen, F.; Jaton, P.; Jean-Marie, B.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Jost, B.; Kaballo, M.; Kandybei, S.; Karacson, M.; Karbach, T. M.; Keaveney, J.; Kenyon, I. R.; Kerzel, U.; Ketel, T.; Keune, A.; Khanji, B.; Kim, Y. M.; Knecht, M.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kruzelecki, K.; Kucharczyk, M.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Li, L.; Li Gioi, L.; Lieng, M.; Liles, M.; Lindner, R.; Linn, C.; Liu, B.; Liu, G.; von Loeben, J.; Lopes, J. H.; Lopez Asamar, E.; Lopez-March, N.; Lu, H.; Luisier, J.; Mac Raighne, A.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Magnin, J.; Malde, S.; Mamunur, R. M. D.; Manca, G.; Mancinelli, G.; Mangiafave, N.; Marconi, U.; Märki, R.; Marks, J.; Martellotti, G.; Martens, A.; Martin, L.; Martín Sánchez, A.; Martinez Santos, D.; Massafferri, A.; Mathe, Z.; Matteuzzi, C.; Matveev, M.; Maurice, E.; Maynard, B.; Mazurov, A.; McGregor, G.; McNulty, R.; Meissner, M.; Merk, M.; Merkel, J.; Messi, R.; Miglioranzi, S.

    2012-06-01

    Searches for heavy Majorana neutrinos in B- decays in final states containing hadrons plus a ?-?- pair have been performed using 0.41fb-1 of data collected with the LHCb detector in proton-proton collisions at a center-of-mass energy of 7 TeV. The D+?-?- and D*+?-?- final states can arise from the presence of virtual Majorana neutrinos of any mass. Other final states containing ?+, Ds+, or D0?+ can be mediated by an on-shell Majorana neutrino. No signals are found and upper limits are set on Majorana neutrino production as a function of mass, and also on the B- decay branching fractions.

  2. Majorana neutrinos with point interactions

    E-print Network

    Chengfeng Cai; Hong-Hao Zhang

    2015-10-28

    We propose a realistic model with Majorana neutrinos in the framework of unifying the three generations of fermions by point interactions in an extra dimension. This model can simultaneously explain the origin of fermion generations, fermion masses and mixing, and the smallness of the masses of Majorana neutrinos. We show that there are two mechanisms working together to suppress the neutrino masses significantly, so we do not have to introduce a very large extra-dimension cut-off scale. One is the type-I seesaw mechanism and the other is the overlap integration of localized lepton wave functions. A singlet scalar with an exponential-like VEV plays a central role in these two mechanisms. For consistency in this model we introduce a $U(1)'$ gauge symmetry, which will be broken by the singlet scalar. Parameters of our model can fit the masses and flavor mixing data well. These parameters can also predict all CP violating phases including the Majorana ones and accidentally rescue the proton from decay.

  3. Neutrinos

    E-print Network

    J. Bernabeu

    2000-12-22

    In these lectures the following topics are considered: historical remarks and general properties, Dirac and Majorana neutrino masses, effective lagrangian approach, the seesaw mechanism, the number of active left-hauded neutrino species, the light neutrino mass matrix, the direct measurement of neutrino masses, double beta decay, neutrino oscillations in vacuum and neutrino oscillations in matter.

  4. Generating Majorana neutrino masses with loops

    NASA Astrophysics Data System (ADS)

    Geng, Chao-Qiang

    2015-08-01

    We give a review on neutrino models in which Majorana neutrino masses are generated radiatively through loop diagrams. In particular, we concentrate on the two-loop models which contain extra doubly charged singlet ? and triplet ? scalars beyond the Standard Model so that the new Yukawa ??¯Rc?R and effective ?±±W?W? couplings can be induced. In these two-loop models, we find that the neutrino mass spectrum is a normal hierarchy and the rate of the neutrinoless double beta decay (0???) can be large as it is dominated by the short-distance tree contribution. In addition, by using the neutrino oscillation data and comparing with the global fitting result in the literature, we find a unique neutrino mass matrix and predict the Dirac and two Majorana CP phases to be 3(? - ?)/2, ? + 3?/2 and (3? - ?)/2 with ? = 0.07?, respectively.

  5. Generating Majorana Neutrino Masses with Loops

    NASA Astrophysics Data System (ADS)

    Geng, Chao-Qiang

    We give a review on neutrino models in which Majorana neutrino masses are generated radiatively through loop diagrams. In particular, we concentrate on the two-loop models which contain extra doubly charged singlet ? and triplet ? scalars beyond the standard model so that the new Yukawa ? {bar{?}}_{R}^{c} ?_{R} and effective ?±±W?W? couplings can be induced. In these two-loop models, we find that the neutrino mass spectrum is a normal hierarchy and the rate of the neutrinoless double beta decay (0???) can be large as it is dominated by the short-distance tree contribution. In addition, by using the neutrino oscillation data and comparing with the global fitting result in the literature, we find a unique neutrino mass matrix and predict the Dirac and two Majorana CP phases to be 3(? - ?)/2, ? + 3?/2 and (3? - ?)/2 with ? = 0.07?, respectively.

  6. Majorana neutrino decay in an effective approach

    NASA Astrophysics Data System (ADS)

    Duarte, Lucía; Peressutti, Javier; Sampayo, Oscar A.

    2015-11-01

    The search strategy or the discovery of new effects for heavy neutrinos often rely on their different decay channels to detectable particles. In particular, in this work we study the decay of a Majorana neutrino with interactions obtained from an effective general theory modeling new physics at the scale ? . The results obtained are general because they are based in an effective theory and not in specific models. We are interested in relatively light-heavy Majorana neutrinos, with masses lower than the W mass (mNneutrino plus photon channel could account for different observations: we analyze the potentiality of the studied interactions to explain some neutrino-related problems like the MiniBooNE and SHALON anomalies. We show in different figures the dominant branching ratios and the decay length of the Majorana neutrino in this approach. These kinds of heavy neutral leptons could be searched for in the LHC with the use of displaced vertices techniques.

  7. Search for Majorana neutrinos in B- ? ?+ ?- ?- decays.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Bauer, T; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, C; Cenci, R; Charles, M; Charpentier, P; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dorosz, P; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, C; Falabella, A; Färber, C; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, P; Gianelle, A; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Y; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Hafkenscheid, T W; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Manzali, M; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morandin, M

    2014-04-01

    A search for heavy Majorana neutrinos produced in the B- ? ?+ ?- ?- decay mode is performed using 3??fb(-1) of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV at the LHC. Neutrinos with masses in the range 250 to 5000 MeV and lifetimes from zero to 1000 ps are probed. In the absence of a signal, upper limits are set on the branching fraction B(B- ? ?+ ?- ?-) as functions of neutrino mass and lifetime. These limits are on the order of 10(-9) for short neutrino lifetimes of 1 ps or less. Limits are also set on the coupling between the muon and a possible fourth-generation neutrino. PMID:24745405

  8. Geometry of Majorana neutrino and new symmetries

    E-print Network

    G. G. Volkov

    2006-07-30

    Experimental observation of Majorana fermion matter gives a new impetus to the understanding of the Lorentz symmetry and its extension, the geometrical properties of the ambient space-time structure, matter--antimatter symmetry and some new ways to understand the baryo-genesis problem in cosmology. Based on the primordial Majorana fermion matter assumption, we discuss a possibility to solve the baryo-genesis problem through the the Majorana-Diraco genesis in which we have a chance to understand creation of Q(em) charge and its conservation in our D=1+3 Universe after the Big Bang. In the Majorana-Diraco genesis approach there appears a possibility to check the proton and electron non-stability on the very low energy scale. In particle physics and in our space-time geometry, the Majorana nature of the neutrino can be related to new types of symmetries which are lying beyond the binary Cartan-Killing-Lie algebras/superalgebras. This can just support a conjecture about the non-completeness of the SM in terms of binary Cartan--Killing--Lie symmetries/supersymmetries. As one of the very important applications of such new ternary symmetries could be related with explanation of the nature of the three families and three colour symmetry. The Majorana neutrino can directly indicate the existence of a new extra-dimensional geometry and thanks to new ternary space-time symmetries, could lead at high energies to the unextraordinary phenomenological consequences.

  9. Triangle inequalities for Majorana-neutrino magnetic moments

    NASA Astrophysics Data System (ADS)

    Frère, Jean-Marie; Heeck, Julian; Mollet, Simon

    2015-09-01

    Electromagnetic properties of neutrinos, if ever observed, could help to decide the Dirac versus Majorana nature of neutrinos. We show that the magnetic moments of Majorana neutrinos have to fulfill triangle inequalities, |???|2?|???|2+|?? e|2 and cyclic permutations, which do not hold for Dirac neutrinos. Observing a violation of these inequalities, e.g., by measuring the magnetic moment of ?? at SHiP, would thus strongly hint either at the Dirac nature of neutrinos or at the presence of at least one extra light sterile mode.

  10. The Majorana neutrino mass matrix indicated by the current data

    NASA Astrophysics Data System (ADS)

    Zhang, XinYi; Ma, BoQiang

    2015-07-01

    The Majorana neutrino mass matrix combines information from the neutrino masses and the leptonic mixing in the flavor basis. Its invariance under some transformation matrices indicates the existence of certain residual symmetry. We offer an intuitive display of the structure of the Majorana neutrino mass matrix, using the whole set of the oscillation data. The structure is revealed depending on the lightest neutrino mass. We find that there are three regions with distinct characteristics of structure. A group effect and the µ- ? exchange symmetry are observed. Six types of texture non-zeros are shown. Implications for flavor models are discussed.

  11. Neutralino Induced Majorana Neutrino Transition Magnetic Moments

    E-print Network

    Gó?d?, Marek

    2012-01-01

    We calculate the effect of neutrino-neutralino mixing on the neutrino magnetic moment and compare it with the contribution of pure particle-sparticle loop. We have found that the dominated mechanism is still the bare loop, and that the bilinear insertions on the external neutrino lines contribute at least one order of magnitude weaker.

  12. Majorana Neutrino Magnetic Moment and Neutrino Decoupling in Big Bang Nucleosynthesis

    E-print Network

    N. Vassh; E. Grohs; A. B. Balantekin; G. M. Fuller

    2015-11-17

    We examine the physics of the early universe when Majorana neutrinos (electron neutrino, muon neutrino, tau neutrino) possess transition magnetic moments. These extra couplings beyond the usual weak interaction couplings alter the way neutrinos decouple from the plasma of electrons/positrons and photons. We calculate how transition magnetic moment couplings modify neutrino decoupling temperatures, and then use a full weak, strong, and electromagnetic reaction network to compute corresponding changes in Big Bang Nucleosynthesis abundance yields. We find that light element abundances and other cosmological parameters are sensitive to magnetic couplings on the order of 10^{-10} Bohr magnetons. Given the recent analysis of sub-MeV Borexino data which constrains Majorana moments to the order of 10^{-11} Bohr magnetons or less, we find that changes in cosmological parameters from magnetic contributions to neutrino decoupling temperatures are below the level of upcoming precision observations.

  13. Discriminating Majorana neutrino textures in light of the baryon asymmetry

    NASA Astrophysics Data System (ADS)

    Borah, Manikanta; Borah, Debasish; Das, Mrinal Kumar

    2015-06-01

    We study all possible texture zeros in the Majorana neutrino mass matrix which are allowed from neutrino oscillation as well as cosmology data when the charged lepton mass matrix is assumed to take the diagonal form. In the case of one-zero texture, we write down the Majorana phases which are assumed to be equal and the lightest neutrino mass as a function of the Dirac C P phase. In the case of two-zero texture, we numerically evaluate all the three C P phases and lightest neutrino mass by solving four real constraint equations. We then constrain texture zero mass matrices from the requirement of producing correct baryon asymmetry through the mechanism of leptogenesis by assuming the Dirac neutrino mass matrix to be diagonal. Adopting a type I seesaw framework, we consider the C P -violating out of equilibrium decay of the lightest right-handed neutrino as the source of lepton asymmetry. Apart from discriminating between the texture zero mass matrices and light neutrino mass hierarchy, we also constrain the Dirac and Majorana C P phases so that the observed baryon asymmetry can be produced. In two-zero texture, we further constrain the diagonal form of the Dirac neutrino mass matrix from the requirement of producing correct baryon asymmetry.

  14. Neutrinoless $??$ decay transition matrix elements within mechanisms involving light Majorana neutrinos, classical Majorons and sterile neutrinos

    E-print Network

    P. K. Rath; R. Chandra; K. Chaturvedi; P. Lohani; P. K. Raina; J. G. Hirsch

    2013-12-23

    In the PHFB model, uncertainties in the nuclear transition matrix elements for the neutrinoless double-$\\beta $ decay of $\\ ^{94,96}$Zr, $^{98,100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes within mechanisms involving light Majorana neutrinos, classical Majorons and sterile neutrinos are statistically estimated by considering sets of sixteen (twenty-four) matrix elements calculated with four different parametrization of the pairing plus multipolar type of effective two-body interaction, two sets of form factors and two (three) different parameterizations of Jastrow type of short range correlations. In the mechanisms involving the light Majorana neutrinos and classical Majorons, the maximum uncertainty is about 15% and in the scenario of sterile neutrinos, it varies in between approximately 4 (9)%--20 (36)% without(with) Jastrow short range correlations with Miller-Spencer parametrization, depending on the considered mass of the sterile neutrinos.

  15. New Stringy Instanton Effects And Neutrino Majorana Masses

    SciTech Connect

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

    2007-10-03

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

  16. On the Majorana Neutrinos and Neutrinoless Double Beta Decays

    NASA Astrophysics Data System (ADS)

    Xing, Zhi-Zhong; Zhou, Ye-Ling

    The neutrinoless double-beta (0???) decay is a lepton-number-violating process which is experimentally unique for identifying the Majorana nature of massive neutrinos. We give a brief overview of some theoretical aspects of this process. In particular, a novel "coupling-rod" diagram is introduced to describe the effective Majorana mass ee in the complex plane. Possible contributions of new physics to ee are also discussed.

  17. Multilepton collider signatures of heavy Dirac and Majorana neutrinos

    NASA Astrophysics Data System (ADS)

    Chen, Chien-Yi; Dev, P. S. Bhupal

    2012-05-01

    We discuss the possibility of observing multi-lepton signals at the Large Hadron Collider (LHC) from the production and decay of heavy standard model (SM) singlet neutrinos added in extensions of SM to explain the observed light neutrino masses by seesaw mechanism. In particular, we analyze two “smoking gun” signals depending on the Dirac or Majorana nature of the heavy neutrino: (i) for Majorana case, the same-sign di-lepton signal which can be used as a probe of lepton-number violation, and (ii) for Dirac case, the tri-lepton signal which conserves lepton number but may violate lepton flavor. Within a minimal Left-Right symmetric framework in which these additional neutrino states arise naturally, we find that in both cases, the signals can be identified with virtually no background beyond a TeV, and the heavy gauge boson WR can be discovered in this process. This analysis also provides a direct way to probe the nature of seesaw physics involving the SM singlets at TeV-scale, and in particular, to distinguish type-I seesaw with purely Majorana heavy neutrinos from inverse seesaw with pseudo-Dirac counterparts.

  18. Distinguishing between Dirac and Majorana neutrinos withtwo-particle interferometry

    SciTech Connect

    Gutierrez, Thomas D.

    2006-03-02

    Two-particle interferometry, a second-order interferenceeffect, is explored as another possible tool to distinguish betweenmassive Dirac and Majorana neutrinos. A simple theoretical framework isdiscussed in the context of several gedanken experiments. The method canin principle provide both the mass scale and the quantum nature of theneutrino for a certain class of incoherent left-handed sourcecurrents.

  19. Tachyonic Majorana neutrinos or neutrino spin-to-orbital angular momentum conversion in OPERA

    E-print Network

    M. Laveder; F. Tamburini

    2011-11-18

    The new data release of OPERA - CNGS experiment, obtained with a shorter spill of protons, confirms the tachyionic behavior expected from the phenomenological model of a Majorana neutrino with a fictitious imaginary mass term acquired during the propagation in the Earth's crust, recently presented by us. We performed numerical simulations of neutrino event detections to compare the properties of these Majorana tachyons with the new OPERA results, finding a good agreement. The possibility of spin-to orbital angular momentum conversion that is expected to give a negative squared mass in a medium, is also briefly discussed.

  20. Search for Majorana neutrinos with the SNO+ detector at SNOLAB

    NASA Astrophysics Data System (ADS)

    Maio, A.; SNO+ Collaboration

    2015-02-01

    The SNO+ experiment is adapting the Sudbury Neutrino Observatory (SNO) detector, in order to use isotope-loaded liquid scintillator as the active medium. SNO+ has multiple scientific goals, the main one being the search for neutrinoless double beta decay, the most promising signature for the possible Majorana character of neutrinos and for the absolute neutrino mass. Measurements of neutrinos from the Sun, the Earth, Supernovae and nuclear reactors are additional goals of the experiment. The detector consists of a 12m diameter spherical vessel, filled with 780 tonnes of Tellurium-loaded liquid scintillator, and surrounded by about 9500 PMTs. It is shielded by a large volume of ultra-pure water and the underground location at SNOLAB, Canada. This talk will review the Physics goals and current status of SNO+.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  2. Particle-Antiparticle Metamorphosis of Massive Majorana Neutrinos and Gauginos

    E-print Network

    Ahluwalia, D V

    2002-01-01

    Recent results on neutrinoless double beta decay, as reported by Klapdor-Kleingrothaus et al., take us for the first time into the realm of Majorana spacetime structure. However, this structure has either been treated as an afterthought to the Dirac construct; or, when it has been attended to in its own right, its physical and mathematical content was never fully unearthed. In this Letter,we undertake to remedy the existing situation. We present a detailed formalism required for the description of the non-trivial spacetime structure underlying the "nu-nubar" metamorphosis - where "nu" generically represents a massive Majorana neutrino, or a massive gaugino.

  3. Particle-Antiparticle Metamorphosis of Massive Majorana Neutrinos and Gauginos

    E-print Network

    D. V. Ahluwalia-Khalilova

    2003-06-13

    Recent results on neutrinoless double beta decay, as reported by Klapdor-Kleingrothaus et al., take us for the first time into the realm of Majorana spacetime structure. However, this structure has either been treated as an afterthought to the Dirac construct; or, when it has been attended to in its own right, its physical and mathematical content was never fully unearthed. In this Letter,we undertake to remedy the existing situation. We present a detailed formalism required for the description of the non-trivial spacetime structure underlying the "nu-nubar" metamorphosis - where "nu" generically represents a massive Majorana neutrino, or a massive gaugino.

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

    SciTech Connect

    Faessler, A.

    2006-12-15

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

  5. Ettore Majorana centennial and neutrino legacy

    NASA Astrophysics Data System (ADS)

    Esposito, Salvatore

    2007-06-01

    "In the world there are various categories of scientists: people of secondary or tertiary standing, who do their best but do not go very far. There are also those of high standing, who come to discoveries of great importance. But then there are geniuses like Galileo and Newton. Well, Ettore was one of them. Majorana had what no one else in the world has...". In this talk we try to put some light on this quite unusual statement by Enrico Fermi about Ettore Majorana, by exploring mainly personal notes left unpublished by the great sicilian physicist. Some emphasis is given on recent achievements about Majorana as a research scientist as well as a teacher in Theoretical Physics.

  6. Single atom tagging and the quest for Majorana Neutrinos

    NASA Astrophysics Data System (ADS)

    Gratta, Giorgio

    2015-05-01

    Elementary spin 1/2 particles (fermions) are generally described by a 4-component Dirac wavefunction. However Nature only needs to work this way for charged particles, where particles and antiparticles are distinguished by the charge state. A simpler 2-component Majorana wavefunction can be used to describe neutral spin 1/2 particles, in which case the particle-antiparticle and spin symmetries are related to each other. And indeed, Majorana particles have recently emerged in the condensed matter of topological materials. Within the Standard Model of elementary particle physics the neutrino is the only possible candidate for a Majorana particle. Dirac and Majorana behavior is only discernable for particles of finite mass, since in the massless case two of the Dirac states are impossible to reach. The recent discovery of finite neutrino masses has opened the question of whether neutrinos are elementary Majorana particles. In the affirmative case a new nuclear decay, the neutrinoless double-beta decay, is possible, albeit with a half-life that becomes infinite as the mass goes to zero. Present searches for neutrinoless double-beta decay have given negative results, with 90% CL half-lives in excess of 1025 yrs. The next generation of experiments will use tons of a specific isotope and search for a few nuclear decays in years of data. The challenge is, of course, to distinguish such decays from the unavoidable background due to trace amounts of natural radioactivity. In the nEXO project we will use tons of the isotope 136Xe , liquefied, in a Time Projection Chamber. In addition to more conventional (and essential) methods to suppress backgrounds, the nEXO collaboration is developing several techniques to recover and spectroscopically identify single atoms of the decay daughter, 136Ba, of the double-beta decay of 136Xe. These techniques can take advantage of ultrasensitive detection methods of atomic physics for a second phase of the nEXO program, with goals of improving the sensitivity to half-lives above 1028 yrs, corresponding to neutrino masses well below 10 meV. I will describe the general status of the field and the R&D in progress to detect a few atoms of Ba produced in a year in tons of Xe. On behalf of the nEXO collaboration.

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

    SciTech Connect

    Babi?, Andrej; Šimkovic, Fedor

    2013-12-30

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

  8. Connection between the neutrino seesaw mechanism and properties of the Majorana neutrino mass matrix

    SciTech Connect

    Ma, Ernest

    2005-06-01

    If it can be ascertained experimentally that the 3x3 Majorana neutrino mass matrix M{sub {nu}} has vanishing determinants for one or more of its 2x2 submatrices, it may be interpreted as supporting evidence for the theoretically well-known canonical seesaw mechanism. I show how these two things are connected and offer a realistic M{sub {nu}} with two zero subdeterminants as an example.

  9. Majorana neutrinos and photinos from kaon decay

    NASA Astrophysics Data System (ADS)

    Nieves, José F.; Pal, Palash B.

    1985-10-01

    We discuss the suggestion by Deshpande and Eilam of putting bounds on the ?? mass from the decay K+-->?+??¯. We show that the Dirac or Majorana nature of the ?? can make a significant difference in the pion energy spectrum. We also discuss the relative importance of the K+-->?+???? mode, ?? being the photino.

  10. Hunting for heavy composite Majorana neutrinos at the LHC

    E-print Network

    R. Leonardi; L. Alunni; F. Romeo; L. Fanò; O. Panella

    2015-10-27

    Motivated by the recent observation of an excess in the $eejj$ channel by the CMS collaboration we investigate the search for heavy Majorana neutrinos stemming from a composite model scenario at the upcoming LHC Run II at a center of mass energy of 13 TeV. While previous studies of the composite Majorana neutrino were focussed on gauge interactions via magnetic type transition coupling between ordinary and heavy fermions (with mass $m^*$) here we complement the composite model with contact interactions at the energy scale $\\Lambda$ and we find that the production cross sections are dominated by such contact interactions by roughly two/three orders of magnitude. This mechanism provides therefore very interesting rates at the prospected luminosities. We study the same sign di-lepton and di-jet signature ($pp \\to \\ell\\ell jj$) and we discuss how it can account for the excess in the $eejj$ invariant mass distribution, and perform a fast detector simulation based on DELPHES. We compute 3$\\sigma$ and 5$\\sigma$ contour plots of the statistical significance in the parameter space ($\\Lambda,m^*$). We find that the potentially excluded regions at $\\sqrt{s} =13$ TeV are quite larger than those excluded so far at Run I considering searches with other signatures.

  11. Radiatively induced neutrino masses and large Higgs-neutrino couplings in the Standard Model with Majorana fields

    NASA Astrophysics Data System (ADS)

    Pilaftsis, Apostolos

    1992-06-01

    The Higgs sector of the Standard Model (SM) with one right-handed neutrino per family is systematically analyzed. In a model with intergenerational independent mixings between families, we can account for very light neutrinos acquiring Majorana masses radiatively at the first electroweak loop level. We also find that in such a scenario the Higgs coupling to the light-heavy neutrinos and to the heavy-heavy ones may be remarkably enhanced with significant implications for the production of these heavy neutrinos at high energy colliders.

  12. The phenomenology of neutrinos with Majorana mass terms and standard-model interactions derived in the charge-parity basis

    E-print Network

    R. Plaga

    2012-12-14

    (abridged) The physical mechanisms that make a neutrino with standard-model (SM) weak interactions a "lepton-number conservation (LNC) violating" neutrino such as the Majorana neutrino are analysed in a basis of two Majorana states that have opposite charge-parity ("charge-parity basis"). A small Majorana mass that is larger than any Dirac mass makes the neutrino not a Majorana but a "pseudo-Majorana" particle that has no definite chirality and therefore has a different phenomenology than the physical neutrino. A combination of a large Majorana and Dirac mass of nearly equal value makes the neutrino a Majorana neutrino. However if this Majorana neutrino has SM interactions, its weak transition amplitudes squared are a factor 2 smaller than the ones observed for the physical neutrino. Only with a small Dirac mass that is larger than any Majorana mass (and in the massless case), the physical neutrino's phenomenology is correctly predicted by the SM. Such a mass combination makes the neutrino a Dirac- or (the most likely possibility for the physical neutrino) Pontecorvo's pseudo-Dirac particle which features neutrino-antineutrino oscillations, that violate LNC. Pseudo-Dirac neutrinos enable a completely negligible rate for neutrinoless double-beta decay if there is no Majorana-mass independent decay mechanism. Off-diagonal components of the mass matrix in the charge-parity basis make the neutrino a mixture of Dirac field with a different particle and anti-particle mass (i.e. a mass that violates CPT invariance) and a pseudo-Dirac field. Such a neutrino leads to a phenomenology similar to the one with additional generations of sterile neutrinos.

  13. Neutrinos

    NASA Astrophysics Data System (ADS)

    Winter, K.; Murdin, P.

    2000-11-01

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

  14. CP asymmetry in heavy Majorana neutrino decays at finite temperature: the nearly degenerate case

    E-print Network

    Biondini, Simone; Escobedo, Miguel Angel; Vairo, Antonio

    2015-01-01

    In a model where Majorana neutrinos heavier than the electroweak scale couple to Standard Model Higgs bosons and leptons, we compute systematically thermal corrections to the direct and indirect CP asymmetries in the Majorana neutrino decays. These are key ingredients entering the equations that describe the thermodynamic evolution of the induced lepton-number asymmetry eventually leading to the baryon asymmetry in the universe. We compute the thermal corrections in an effective field theory framework that assumes the temperature smaller than the masses of the Majorana neutrinos and larger than the electroweak scale, and we provide the leading corrections in an expansion of the temperature over the mass. In this work, we consider the case of two Majorana neutrinos with nearly degenerate masses.

  15. Search for Majorana Neutrinos in B[superscript ?] ? ?[superscript +]?[superscript ?]?[superscript ?] Decays

    E-print Network

    Counts, Ian Thomas Hunt

    A search for heavy Majorana neutrinos produced in the B[superscript ?] ? ?[superscript +]?[superscript ?]?[superscript ?] decay mode is performed using 3??fb[superscript ?1] of integrated luminosity collected with the LHCb ...

  16. Majorana Neutrino Magnetic Moment and Neutrino Decoupling in Big Bang Nucleosynthesis

    E-print Network

    Vassh, N; Balantekin, A B; Fuller, G M

    2015-01-01

    We examine the physics of the early universe when neutrinos (electron neutrino, muon neutrino, tau neutrino) possess transition magnetic moments. These extra couplings beyond the usual weak interaction couplings alter the way neutrinos decouple from the plasma of electrons/positrons and photons. We calculate how transition magnetic moment couplings modify neutrino decoupling temperatures, and then use a full weak, strong, and electromagnetic reaction network to compute corresponding changes in Big Bang Nucleosynthesis abundance yields. We find that light element observational constraints and other cosmological constraints may allow probes of neutrino transition magnetic moments which are not directly available in the laboratory.

  17. Arbitrary mass Majorana neutrinos in neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Faessler, Amand; González, Marcela; Kovalenko, Sergey; Šimkovic, Fedor

    2014-11-01

    We revisit the mechanism of neutrinoless double beta (0 ? ? ? ) decay mediated by the exchange with the heavy Majorana neutrino N of arbitrary mass mN , slightly mixed ˜UeN with the electron neutrino ?e . By assuming the dominance of this mechanism, we update the well-known 0 ? ? ? -decay exclusion plot in the mN-UeN plane taking into account recent progress in the calculation of nuclear matrix elements within quasiparticle random phase approximation and improved experimental bounds on the 0 ? ? ? -decay half-life of Ge 76 and Xe 136 . We also consider the known formula approximating the mN dependence of the 0 ? ? ? -decay nuclear matrix element in a simple explicit form. We analyze its accuracy and specify the corresponding parameters, allowing one to easily calculate the 0 ? ? ? -decay half-life for arbitrary mN for all the experimentally interesting isotopes without resorting to real nuclear structure calculations.

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

    SciTech Connect

    Bellini, F.

    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.

  19. Magnetic moment of the majorana neutrino in the left-right symmetric model

    SciTech Connect

    Boyarkin, O. M. Boyarkina, G. G.

    2013-04-15

    Corrections to the neutrino magnetic dipole moment from the singly charged Higgs bosons h{sup ({+-})} and {delta}-tilde{sup (}{+-}) were calculated within the left-right symmetric model involving Majorana neutrinos. It is shown that, if the h{sup ({+-})} and {delta}-tilde{sup (}{+-}) bosons lie at the electroweak scale, the contributions from Higgs sector are commensurate with the contribution of charged gauge bosons or may even exceed it. The behavior of the neutrino flux inmatter and in amagnetic field was studied. It was found that resonance transitions between light and heavy neutrinos are forbidden.

  20. Geometry of the effective Majorana neutrino mass in the 0??? decay

    NASA Astrophysics Data System (ADS)

    Xing, Zhi-zhong; Zhou, Ye-Ling

    2015-01-01

    The neutrinoless double-beta (0???) decay is a unique process used to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass ee. We put forward a novel ‘coupling-rod’ diagram to describe ee in the complex plane, by which the effects of the neutrino mass ordering and CP-violating phases on ee are intuitively understood. We show that this geometric language allows us to easily obtain the maximum and minimum of |ee|. It remains usable even if there is a kind of new physics contributing to ee, and it can also be extended to describe the effective Majorana masses e?, e?, ?? and ?? which may appear in some other lepton-number violating processes.

  1. Distinguishing between Dirac and Majorana neutrinos with two-particle interferometry.

    PubMed

    Gutierrez, Thomas D

    2006-03-31

    Two-particle interferometry, a second-order interference effect, is explored as another possible tool to distinguish between massive Dirac and Majorana neutrinos. A simple theoretical framework is discussed in the context of several gedanken experiments. The method can in principle provide both the mass scale and the quantum nature of the neutrino for a certain class of incoherent left-handed source currents. PMID:16605897

  2. Heavy Majorana Neutrinos in Dilepton Production in Deep-Inelastic Lepton-Proton Scattering

    SciTech Connect

    Ali, A.; Borisov, A.V.; Zhuridov, D.V.

    2005-12-01

    The cross section for the production of pairs of likely charged leptons in the deep-inelastic processes e{sup +}p {yields} {nu}-bar{sub e}l{sup +}l{sup '+}X (l, l{sup '} = e, {mu}, {tau}) induced by the exchange of heavy Majorana neutrinos is calculated. The effect of interference between different neutrino mass eigenstates is studied. The possibilities for observing this effect at future lepton-proton colliders are considered.

  3. Search for heavy Majorana neutrinos with the ATLAS detector in pp collisions at TeV

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Almond, J.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balestri, T.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansil, H. S.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boddy, C. R.; Boehler, M.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchholz, P.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Buehrer, F.; Bugge, L.

    2015-07-01

    A search for heavy Majorana neutrinos in events containing a pair of high- p T leptons of the same charge and high- p T 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 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 W R and Z'. [Figure not available: see fulltext.

  4. Majorana neutrino magnetic moments in the gauge-mediated supersymmetry breaking MSSM

    SciTech Connect

    Gozdz, Marek; Kaminski, Wieslaw A.

    2009-04-01

    Supersymmetric models with broken R parity provide mechanisms that allow to generate Majorana neutrino masses and magnetic moments through virtual particle-sparticle loops. This constitutes an attractive alternative to the seesaw mechanism. In this paper, we present a detailed calculation of the transition magnetic moments of a Majorana neutrino in gauge-mediated supersymmetry breaking minimal supersymmetric standard model (MSSM) without R parity. We base our analysis on the renormalization group evolution of the MSSM parameters, which are unified at the grand unified theory scale.

  5. The Majorana Zero-Neutrino Double-Beta Decay Experiment White Paper

    SciTech Connect

    Gaitskell, R.; Barabash, A.; Konovalov, S.; Stekhanov, V.; Umatov,, V.; Brudanin, V.; Egorov, S.; Webb, J.; Miley, Harry S.; Aalseth, Craig E.; Anderson, Dale N.; Bowyer, Ted W.; Brodzinski, Ronald L.; Jordan, David B.; Kouzes, Richard T.; Smith, Leon E.; Thompson, Robert C.; Warner, Ray A.; Tornow, W.; Young, A.; Collar, J. I.; Avignone, Frank T.; Palms, John M.; Doe, P. J.; Elliott, Steven R.; Kazkaz, K.; Robertson, Hamish; Wilkerson, John

    2002-03-07

    The goal of the Majorana Experiment is to determine the effective Majorana masss of the eletron neutrino. Detection of the neutrino mass implied by oscillation results in within our grasp. This exciting physics goal is best pursued using double-beta decay of germanium because of the historical and emerging advances in eliminating competing signals from radioactive backgrounds. The Majorana Experiment will consist of a large mass of 76Ge in the form of high-resolution detectors deep underground, searching for a sharp peak at the BB endpoint. We present here an overview of the entire project in order to help put in perspective the scope, the level and technial risk, and the readiness of the Collaboration to begin the undertaking.

  6. Search for Majorana neutrinos with the first two years of EXO-200 data.

    PubMed

    2014-06-12

    Many extensions of the standard model of particle physics suggest that neutrinos should be Majorana-type fermions-that is, that neutrinos are their own anti-particles-but this assumption is difficult to confirm. Observation of neutrinoless double-? decay (0???), a spontaneous transition that may occur in several candidate nuclei, would verify the Majorana nature of the neutrino and constrain the absolute scale of the neutrino mass spectrum. Recent searches carried out with (76)Ge (the GERDA experiment) and (136)Xe (the KamLAND-Zen and EXO (Enriched Xenon Observatory)-200 experiments) have established the lifetime of this decay to be longer than 10(25)?years, corresponding to a limit on the neutrino mass of 0.2-0.4?electronvolts. Here we report new results from EXO-200 based on a large (136)Xe exposure that represents an almost fourfold increase from our earlier published data sets. We have improved the detector resolution and revised the data analysis. The half-life sensitivity we obtain is 1.9?×?10(25)?years, an improvement by a factor of 2.7 on previous EXO-200 results. We find no statistically significant evidence for 0??? decay and set a half-life limit of 1.1?×?10(25)?years at the 90 per cent confidence level. The high sensitivity holds promise for further running of the EXO-200 detector and future 0??? decay searches with an improved Xe-based experiment, nEXO. PMID:24896189

  7. TeV Scale See-Saw Mechanisms of Neutrino Mass Generation, the Majorana Nature of the Heavy Singlet Neutrinos and $\\betabeta$-Decay

    E-print Network

    A. Ibarra; E. Molinaro; S. T. Petcov

    2010-07-14

    It is shown that the Majorana nature of the heavy neutrinos $N_j$ having masses in the range of $M_j \\sim (100 - 1000)$ GeV and present in the TeV scale type I and inverse see-saw scenarios of neutrino mass generation, is unlikely to be observable in the currently operating and future planned accelerator experiments (including LHC) due to the existence of very strong constraints on the parameters and couplings responsible for the corresponding $|\\Delta L| = 2$ processes, $L$ being the total lepton charge. If the heavy Majorana neutrinos $N_j$ are observed and they are associated only with the type I or inverse see-saw mechanisms and no additional TeV scale "new physics", they will behave like Dirac fermions to a relatively high level of precision, being actually pseudo-Dirac particles. The observation of effects proving the Majorana nature of $N_j$ would imply that these heavy neutrinos have additional relatively strong couplings to the Standard Model particles (as, e.g. in the type III see-saw scenario), or that light neutrino masses compatible with the observations are generated by a mechanism other than see-saw (e.g., radiatively at one or two loop level) in which the heavy Majorana neutrinos $N_j$ are nevertheless involved.

  8. Large electron electric dipole moment in minimal flavor violation framework with Majorana neutrinos

    E-print Network

    Xiao-Gang He; Chao-Jung Lee; Siao-Fong Li; Jusak Tandean

    2014-06-04

    The latest data from the ACME Collaboration have put a stringent constraint on the electric dipole moment d_e of the electron. Nevertheless, the standard model (SM) prediction for d_e is many orders of magnitude below the new result, making this observable a powerful probe for physics beyond the SM. We carry out a model-independent study of d_e in the SM with right handed neutrinos and its extension with the neutrino seesaw mechanism under the framework of minimal flavor violation. We find that d_e crucially depends on whether neutrinos are Dirac or Majorana particles. In the Majorana case, d_e can reach its experimental bound, and it constrains the scale of minimal flavor violation to be above a few hundred GeV or more. We also explore extra CP-violating sources in the Yukawa couplings of the right-handed neutrinos. Such new sources can have important effects on d_e.

  9. Discriminating Majorana neutrino phases in the light of lepton flavor violation and leptogenesis in type I+II seesaw models

    NASA Astrophysics Data System (ADS)

    Kalita, Rupam; Borah, Debasish

    2015-07-01

    We study the effects of Majorana neutrino phases in lepton flavor violation and the origin of matter-antimatter asymmetry through the mechanism of leptogenesis within the framework of a model where both type I and type II seesaw mechanisms can contribute to tiny neutrino masses. We parametrize the type I seesaw mass matrix by assuming it to give rise to a tri-bimaximal (TBM) type neutrino mixing which predicts ?13 = 0. The type II seesaw mass matrix is then constructed in such a way that the necessary deviation from TBM mixing and the best fit values of neutrino parameters can be obtained when both type I and type II seesaw contributions are taken into account. Considering both subleading as well as equally dominating type II seesaw term, we first constrain the Majorana CP phases from the requirement of producing correct baryon asymmetry through leptogenesis and then incorporating the experimental bounds on lepton flavor violating decays ? ? e + ? and ? ? e + e + e.

  10. The contribution of light Majorana neutrinos to neutrinoless double beta decay and cosmology

    NASA Astrophysics Data System (ADS)

    Dell'Oro, S.; Marcocci, S.; Viel, M.; Vissani, F.

    2015-12-01

    Cosmology is making impressive progress and it is producing stringent bounds on the sum of the neutrino masses ?, a parameter of great importance for the current laboratory experiments. In this letter, we exploit the potential relevance of the analysis of Palanque-Delabrouille et al. [JCAP 02 (2015) 045] to the neutrinoless double beta decay (0? ? ?) search. This analysis indicates small values for the lightest neutrino mass, since the authors find ? < 84 meV at 1? C.L., and provides a 1? preference for the normal hierarchy. The allowed values for the Majorana effective mass, probed by 0? ? ?, turn out to be < 75 meV at 3? C.L. and lower down to less than 02 meV at 1? C.L. . If this indication is confirmed, the impact on the 0? ? ? experiments will be tremendous since the possibility of detecting a signal will be out of the reach of the next generation of experiments.

  11. Probing the Majorana neutrinos and their CP violation in decays of charged scalar mesons $?, K, D, D_s, B, B_c$

    E-print Network

    Gorazd Cvetic; Claudio Dib; C. S. Kim; Jilberto Zamora-Saa

    2015-05-26

    Some of the outstanding questions of particle physics today concern the neutrino sector, in particular whether there are more neutrinos than those already known and whether they are Dirac or Majorana particles.There are different ways to explore these issues. In this article we describe neutrino-mediated decays of charged pseudoscalar mesons such as $\\pi^{\\pm}$, $K^{\\pm}$ and $B^{\\pm}$, in scenarios where extra neutrinos are heavy and can be on their mass shell. We discuss semileptonic and leptonic decays of such kinds. We investigate possible ways of using these decays in order to distinguish between the Dirac and Majorana character of neutrinos. Further, we argue that there are significant possibilities of detecting CP violation in such decays when there are at least two almost degenerate Majorana neutrinos involved. This latter type of scenario fits well into the known neutrino minimal standard model ($\

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

    DOE PAGESBeta

    Aad, G.; et al.

    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

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

    SciTech Connect

    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'.

  14. Baryon number violation via Majorana neutrinos in the early Universe, at the LHC, and deep underground

    NASA Astrophysics Data System (ADS)

    Davoudiasl, Hooman; Zhang, Yue

    2015-07-01

    We propose and investigate a novel, minimal, and experimentally testable framework for baryogenesis, dubbed dexiogenesis, using baryon number violating effective interactions of right-handed Majorana neutrinos responsible for the seesaw mechanism. The distinct LHC signature of our framework is same-sign top quark final states, possibly originating from displaced vertices. The region of parameters relevant for LHC phenomenology can also yield concomitant signals in nucleon decay experiments. We provide a simple ultraviolet origin for our effective operators, by adding a color-triplet scalar, which could ultimately arise from a grand unified theory.

  15. Sterile neutrino states

    E-print Network

    Alexander Kusenko

    2006-09-17

    Neutrino masses are likely to be a manifestation of the right-handed, or sterile neutrinos. The number of sterile neutrinos and the scales of their Majorana masses are unknown. We explore theoretical arguments in favor of the high and low scale seesaw mechanisms, review the existing experimental results, and discuss the astrophysical hints regarding sterile neutrinos.

  16. Cosmic ray electron and positron excesses from a fourth generation heavy Majorana neutrino

    SciTech Connect

    Masina, Isabella; Sannino, Francesco E-mail: sannino@cp3-origins.net

    2011-08-01

    Unexpected features in the energy spectra of cosmic rays electrons and positrons have been recently observed by PAMELA and Fermi-LAT satellite experiments, opening to the exciting possibility of an indirect manifestation of new physics. A TeV-scale fourth lepton family is a natural extension of the Standard Model leptonic sector (also linked to the hierarchy problem in Minimal Walking Technicolor models). The heavy Majorana neutrino of this setup mixes with Standard Model charged leptons through a weak charged current interaction. Here, we first study analytically the energy spectrum of the electrons and positrons originated in the heavy Majorana neutrino decay modes, also including polarization effects. We then compare the prediction of this model with the experimental data, exploiting both the standard direct method and our recently proposed Sum Rules method. We find that the decay modes involving the tau and/or the muon charged leptons as primary decay products fit well the PAMELA and Fermi-LAT lepton excesses while there is tension with respect to the antiproton to proton fraction constrained by PAMELA.

  17. Nuclear-atomic state degeneracy in neutrinoless double-electron capture: A unique test for a Majorana-neutrino

    E-print Network

    D. Frekers

    2009-08-17

    There is a general consensus that detection of a double-beta decay without any neutrino involved would mark physics beyond the Standard Model. This is because in such decay modes lepton number conservation would be violated and the neutrino would reveal itself as being its own antiparticle, thereby of Majorana type. So far, the experimental focus has mostly been on the double beta minus decay variant, where one attempts to measure the spectrum of the two emitted electrons. A discrete line at the endpoint energy marks the unique signature for a Majorana neutrino. Little attention has been given to alternative decay modes in double-beta decay. In this note we show that there is at least one case in the periodic table, where the parent in the neutrinoless double-electron capture process is nearly degenerate with an excited state in the daughter, leading to a possible enhancement of the decay rate by several orders of magnitude. It is the nucleus 74-Se, which has this unique property. Furthermore, there is an easy to detect 2 gamma-ray decay cascade in 74-Ge, which follows the zero-neutrino double electron capture, and which by its mere detection provides unique signature of the Majorana neutrino.

  18. Search for heavy majorana neutrinos in ?[superscript ±]?[superscript ±] + jets events in proton–proton collisions at ?s = 8 TeV

    E-print Network

    Apyan, Aram

    A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two muons of the same charge and two jets (?[superscript ±]?[superscript ±]jj). The data correspond to an integrated luminosity of ...

  19. Neutrinos in Nuclear Physics

    E-print Network

    R. D. McKeown

    2014-12-03

    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.

  20. Neutrinos in Nuclear Physics

    SciTech Connect

    McKeown, Bob

    2015-06-01

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

  1. Pseudoscalar Fields in Torsionful Geometries of the Early Universe, the Baryon Asymmetry and Majorana Neutrino Mass Generation

    NASA Astrophysics Data System (ADS)

    Mavromatos, Nick E.

    2015-11-01

    We discuss here a specific field-theory model, inspired from string theory, in which the generation of a matter-antimatter asymmetry in the Cosmos is due to the propagation of fermions in a non-trivial, spherically asymmetric (and hence Lorentz violating) gravitational background that may characterise the epochs of the early universe. The background induces different dispersion relations, hence populations, between fermions and antifermions, and thus CPT Violation (CPTV) already in thermal equilibrium. Species populations may freeze out leading to leptogenesis and baryogenesis. More specifically, after reviewing some generic models of background-induced CPTV in early epochs of the Universe, we consider a string- inspired scenario, in which the CPTV is associated with a cosmological background with torsion provided by the Kalb-Ramond (KR) antisymemtric tensor field of the string gravitational multiplet. In a four-dimensional space time this field is dual to a pseudoscalar “axion-like” field. The thermalising processes in this model are (right-handed) Majorana neutrino-antineutrino oscillations, which are induced in the presence of the KR axion background. These processes freeze out at a (high) temperature Tc ? m, where m is the Majorana neutrino mass, at which the KR background goes to zero or is diminished significantly, through appropriate phase transitions of the (string) universe. An additional, but equally important, role, of the KR field is that its quantum fluctuations and mixing with an ordinary axion, which couples to the Majorana neutrinos via appropriate Yukawa couplings, can also lead to the generation of a Majorana neutrino mass through quantum anomalies. This provides a novel way for generating neutrino masses, independent of the traditional seesaw mechanism.

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

    PubMed

    Nemevšek, Miha; Senjanovi?, Goran; Tello, Vladimir

    2013-04-12

    Probing the origin of neutrino mass by disentangling the seesaw mechanism is one of the central issues of particle physics. We address it in the minimal left-right symmetric model and show how the knowledge of light and heavy neutrino masses and mixings suffices to determine their Dirac Yukawa couplings. This in turn allows one to make predictions for a number of high and low energy phenomena, such as decays of heavy neutrinos, neutrinoless double beta decay, electric dipole moments of charged leptons, and neutrino transition moments. We also discuss a way of reconstructing the neutrino Dirac Yukawa couplings at colliders such as the LHC. PMID:25167249

  3. A search for a heavy Majorana neutrino and a radiation damage simulation for the HF detector

    NASA Astrophysics Data System (ADS)

    Wetzel, James William

    A search for heavy Majorana neutrinos is performed using an event signature defined by two same-sign muons accompanied by two jets. This search is an extension of previous searches, (L3, DELPHI, CMS, ATLAS), using 19.7 fb -1 of data from the 2012 Large Hadron Collider experimental run collected by the Compact Muon Solenoid experiment. A mass window of 40-500 GeV/ c2 is explored. No excess events above Standard Model backgrounds is observed, and limits are set on the mixing element squared, |VmuN|2, as a function of Majorana neutFnrino mass. The Hadronic Forward (HF) Detector's performance will degrade as a function of the number of particles delivered to the detector over time, a quantity referred to as integrated luminosity and measured in inverse femtobarns (fb-1). In order to better plan detector upgrades, the CMS Forward Calorimetry Task Force (FCAL) group and the CMS Hadronic Calorimeter (HCAL) group have requested that radiation damage be simulated and the subsequent performance of the HF subdetector be studied. The simulation was implemented into both the CMS FastSim and CMS FullSim simulation packages. Standard calorimetry performance metrics were computed and are reported. The HF detector can expect to perform well through the planned delivery of 3000 fb-1.

  4. Are Neutrinos Their Own Antiparticles?

    E-print Network

    Boris Kayser

    2009-03-05

    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.

  5. Are neutrinos their own antiparticles?

    SciTech Connect

    Kayser, Boris; /Fermilab

    2009-03-01

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

  6. Search for heavy Majorana neutrinos in ?±?± + jets events in proton-proton collisions at ?{ s} = 8 TeV

    NASA Astrophysics Data System (ADS)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Daci, N.; Heracleous, N.; Keaveney, J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Randle-conde, A.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Nuttens, C.; Pagano, D.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Dos Reis Martins, T.; Molina, J.; Mora Herrera, C.; Pol, M. E.; Rebello Teles, P.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santaolalla, J.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Hadjiiska, R.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Tao, J.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zhang, F.; Zhang, L.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Busson, P.; Chapon, E.; Charlot, C.; Dahms, T.; Dobrzynski, L.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Bernet, C.; Boudoul, G.; Bouvier, E.; Brochet, S.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.

    2015-09-01

    A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two muons of the same charge and two jets (?±?± jj). The data correspond to an integrated luminosity of 19.7 fb-1 of proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No excess of events is observed beyond the expected standard model background and upper limits are set on |V?N | 2 as a function of Majorana neutrino mass mN for masses in the range of 40-500 GeV, where V?N is the mixing element of the heavy neutrino with the standard model muon neutrino. The limits obtained are |V?N | 2 < 0.00470 for mN = 90 GeV, |V?N | 2 < 0.0123 for mN = 200 GeV, and |V?N | 2 < 0.583 for mN = 500 GeV. These results extend considerably the regions excluded by previous direct searches.

  7. The Majorana Project: Ge-76 0 Nu Beta Beta Decay Neutrino Mass Measurement

    SciTech Connect

    Aalseth, Craig E. ); Miley, Harry S. )

    2001-12-01

    The analysis of recent results from solar and atmospheric neutrino experiments suggest next generation double-beta decay experiments sensitive to effective electron neutrino masses on the order of 0.05 eV could result in the direct observation of Ov double beta decay.

  8. NEXT, high-pressure xenon gas experiments for ultimate sensitivity to Majorana neutrinos

    E-print Network

    J. J. Gómez-Cadenas; J. Martín-Albo; F. Monrabal; for the NEXT Collaboration

    2012-11-21

    In this paper we describe an innovative type of Time Projection Chamber (TPC), which uses high-pressure xenon gas (HPXe) and electroluminescence amplification of the ionization charge as the basis of an apparatus capable of fully reconstructing the energy and topological signature of rare events. We will discuss a specific design of such HPXe TPC, the NEXT-100 detector, that will search for neutrinoless double beta decay events using 100-150 kg of xenon enriched in the isotope Xe-136. NEXT-100 is currently under construction, after completion of an accelerated and very successful R&D period. It will be installed at the Laboratorio Subterr\\'aneo de Canfranc (LSC), in Spain. The commissioning run is expected for late 2013 or early 2014. We will also present physics arguments that suggest that the HPXe technology can be extrapolated to the next-to-next generation (e.g, a fiducial mass of 1 ton of target), which will fully explore the Majorana nature of the neutrino if the mass hierarchy is inverse.

  9. Neutrino Experiments

    NASA Astrophysics Data System (ADS)

    McKeown, R. D.

    2010-08-01

    Recent studies of neutrino oscillations have established the existence of finite neutrino masses and mixing between generations of neutrinos [1]. The combined results from studies of atmospheric neutrinos, solar neutrinos, reactor antineutrinos and neutrinos produced at accelerators paint an intriguing picture that clearly requires modification of the standard model of particle physics. These results also provide clear motivation for future neutrino oscillation experiments as well as searches for direct neutrino mass and nuclear double-beta decay. I will discuss the program of new neutrino oscillation experiments aimed at completing our knowledge of the neutrino mixing matrix.

  10. Search for heavy Majorana neutrinos in ?±?± +jets and e±e± +jets events in pp collisions at ?{ s} = 7 TeV

    NASA Astrophysics Data System (ADS)

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Reis, T.; Thomas, L.; Vander Marcken, G.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins Junior, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Khalil, S.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Anagnostou, G.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.; Jussen, R.; Klein, K.

    2012-10-01

    A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two same-sign charged leptons of the same flavour and two jets. The data correspond to an integrated luminosity of 4.98 fb-1 of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events is observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing parameter, |V?N | 2, for ? = e , ?, as a function of heavy Majorana-neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for mN > 90 GeV.

  11. Relic Right-handed Dirac Neutrinos and Implications for Detection of Cosmic Neutrino Background

    E-print Network

    Jue Zhang; Shun Zhou

    2015-09-08

    It remains to be determined experimentally if massive neutrinos are Majorana or Dirac particles. In this connection, it has been recently suggested that the detection of cosmic neutrino background of left-handed neutrinos $\

  12. Relic Right-handed Dirac Neutrinos and Implications for Detection of Cosmic Neutrino Background

    E-print Network

    Jue Zhang; Shun Zhou

    2015-12-25

    It remains to be determined experimentally if massive neutrinos are Majorana or Dirac particles. In this connection, it has been recently suggested that the detection of cosmic neutrino background of left-handed neutrinos $\

  13. Relic Right-handed Dirac Neutrinos and Implications for Detection of Cosmic Neutrino Background

    E-print Network

    Zhang, Jue

    2015-01-01

    It remains to be determined experimentally if massive neutrinos are Majorana or Dirac particles. In this connection, it has been recently suggested that the detection of cosmic neutrino background of left-handed neutrinos $\

  14. Cosmic Neutrinos

    SciTech Connect

    Quigg, Chris; /Fermilab /CERN

    2008-02-01

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

  15. Neutrino Oscillations with Reactor Neutrinos

    E-print Network

    Anatael Cabrera

    2007-02-22

    Prospect measurements of neutrino oscillations with reactor neutrinos are reviewed in this document. The following items are described: neutrinos oscillations status, reactor neutrino experimental strategy, impact of uncertainties on the neutrino oscillation sensitivity and, finally, the experiments in the field. This is the synthesis of the talk delivered during the NOW2006 conference at Otranto (Italy) during September 2006.

  16. Search for Heavy Majorana Neutrinos in ?[superscript ±]?[superscript ±] + just and e[superscript ±]e[superscript ±] + jets events in pp collisions at ?s = 7 TeV

    E-print Network

    Apyan, Aram

    A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two same-sign charged leptons of the same flavour and two jets. The data correspond to an integrated luminosity of 4.98 fb[superscript ...

  17. B-L Neutrinos

    E-print Network

    Kevin Cahill

    2000-06-19

    Neutrino masses and mixings are analyzed in terms of left-handed fields and a 6x6 complex symmetric mass matrix whose singular values are the neutrino masses. An angle theta_nu characterizes the kind of the neutrinos, with theta_nu=0 for Dirac neutrinos and theta_nu=pi/2 for Majorana neutrinos. At theta_nu = 0 baryon-minus-lepton number is conserved. If theta_nu is approximately zero, the six neutrino masses coalesce into three nearly degenerate pairs. Thus the tiny mass differences exhibited in the solar and atmospheric neutrino experiments are naturally explained by the approximate conservation of B-L. Neutrinos are nearly Dirac fermions. This B-L model leads to these predictions: neutrinos oscillate mainly between flavor eigenfields and sterile eigenfields, and so the appearance of neutrinos and antineutrinos is suppressed; neutrinos may well be of cosmological importance; in principle the disappearance of the tau neutrino should be observable; and neutrinoless double-beta decay is suppressed by an extra factor of 10^(-5) and so will not be seen in the Heidelberg/Moscow, IGEX, GENIUS, or CUORE experiments.

  18. Neutrino propagation and quantum states in matter

    E-print Network

    Ivan Pivovarov; Alexander Studenikin

    2005-12-02

    We briefly review the matter effects in case of Dirac and Majorana neutrino propagation in medium. We develop the quantum treatment of neutrinos in matter: using the generalized Dirac equations for Dirac and Majorana neutrinos wave functions in matter we get the explicit expressions for the corresponding Green functions.

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

    SciTech Connect

    Rosen, S.P.

    1983-01-01

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

  20. Sterile neutrinos?

    E-print Network

    S. M. Bilenky; C. Giunti

    1999-05-05

    The notion of sterile neutrinos is discussed. The schemes of mixing of four massive neutrinos, which imply the existence of sterile neutrinos, are briefly considered. Several model independent methods that allow to reveal possible transitions of solar neutrinos into sterile states are presented.

  1. Solar Neutrinos

    E-print Network

    A. B. McDonald

    2002-09-21

    Present results and future measurements of solar neutrinos are discussed. The results to date indicate that solar electron neutrinos are changing to other active types and that transitions solely to sterile neutrinos are disfavored. The flux of $^{8}B$ solar neutrinos produced in the Sun, inferred assuming only active neutrino types, is found to be in very good agreement with solar model calculations. Future measurements will focus on greater accuracy for charged current and neutral current sensitive reactions to provide more accurate measurements of neutrino flavour change and further studies of day-night flux differences and spectral shape. Other experiments sensitive to lower energy solar neutrinos will be in operation soon.

  2. Tau Neutrino Appearance via Neutrino Oscillations in Atmospheric Neutrinos

    E-print Network

    Tokyo, University of

    Tau Neutrino Appearance via Neutrino Oscillations in Atmospheric Neutrinos A Dissertation Presented of the Dissertation Tau Neutrino Appearance via Neutrino Oscillations in Atmospheric Neutrinos by Tokufumi Kato Doctor of Philosophy in Physics Stony Brook University 2007 A search for the appearance of tau neutrinos from µ

  3. Neutrino Factories

    SciTech Connect

    Geer, Steve; /Fermilab

    2010-01-01

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

  4. Neutrino Interactions

    E-print Network

    Kevin McFarland

    2008-04-24

    This manuscript summarizes a series of three lectures on interactions of neutrinos . The lectures begin with a pedagogical foundation and then explore topics of interest to current and future neutrino oscillation and cross-section experiments.

  5. Neutrino physics

    SciTech Connect

    Kayser, Boris; /Fermilab

    2005-06-01

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

  6. Neutrino Experiments

    E-print Network

    J. M. Conrad

    2007-08-17

    This article is a summary of four introductory lectures on ``Neutrino Experiments,'' given at the 2006 TASI summer school. The purposes were to sketch out the present questions in neutrino physics and to discuss the experimental challenges in addressing them. This article concentrates on specific, illustrative examples rather than providing a complete overview of the field of neutrino physics. These lectures were meant to lay the ground-work for the talks which followed on specific, selected topics in neutrino physics.

  7. A new spin on neutrino quantum kinetics

    NASA Astrophysics Data System (ADS)

    Cirigliano, Vincenzo; Fuller, George M.; Vlasenko, Alexey

    2015-07-01

    Recent studies have demonstrated that in anisotropic environments a coherent spin-flip term arises in the Quantum Kinetic Equations (QKEs) which govern the evolution of neutrino flavor and spin in hot and dense media. This term can mediate neutrino-antineutrino transformation for Majorana neutrinos and active-sterile transformation for Dirac neutrinos. We discuss the physical origin of the coherent spin-flip term and provide explicit expressions for the QKEs in a two-flavor model with spherical geometry. In this context, we demonstrate that coherent neutrino spin transformation depends on the absolute neutrino mass and Majorana phases.

  8. Neutrino Detectors

    NASA Astrophysics Data System (ADS)

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

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

  9. Neutrino Telescopes

    SciTech Connect

    Hernandez-Rey, Juan Jose

    2006-11-28

    We review the present status of high energy neutrino astronomy. The advantages of neutrinos as extra-terrestrial messengers are recalled and their possible extra-terrestrial sources examined. We review as well the status of present and future neutrino telescopes and summarize the results obtained so far in this field.

  10. Solar neutrinos and neutrino physics

    E-print Network

    Michele Maltoni; Alexei Yu. Smirnov

    2015-08-11

    Solar neutrino studies triggered and largely motivated the major developments in neutrino physics in the last 50 years. Theory of neutrino propagation in different media with matter and fields has been elaborated. It includes oscillations in vacuum and matter, resonance flavor conversion and resonance oscillations, spin and spin-flavor precession, etc. LMA MSW has been established as the true solution of the solar neutrino problem. Parameters theta12 and Delta_m21^2 have been measured; theta13 extracted from the solar data is in agreement with results from reactor experiments. Solar neutrino studies provide a sensitive way to test theory of neutrino oscillations and conversion. Characterized by long baseline, huge fluxes and low energies they are a powerful set-up to search for new physics beyond the standard 3nu paradigm: new neutrino states, sterile neutrinos, non-standard neutrino interactions, effects of violation of fundamental symmetries, new dynamics of neutrino propagation, probes of space and time. These searches allow us to get stringent, and in some cases unique bounds on new physics. We summarize the results on physics of propagation, neutrino properties and physics beyond the standard model obtained from studies of solar neutrinos.

  11. Neutrino Lensing

    E-print Network

    Luo Xin-Lian

    2009-09-28

    Due to the intrinsic properties of neutrinos, the gravitational lens effect for neutrino should be more colorful and meaningful than the normal lens effect of photon. Other than the oscillation experiments operated at terrestrial laboratory, in principle, we can propose a completely new astrophysical method to determine not only the nature of gravity and spacetime of lens objects but also the mixing parameters of neutrinos by analyzing neutrino trajectories near the central objects. However, compared with the contemporaneous telescopes through the observation of the electromagnetic radiation, the angular, energy and time resolution of the neutrino telescopes are still comparatively poor, we just concentrate on the two classical tests of general relativity, i.e. the angular deflection and time delay of neutrino by a lens object as a preparative work in this paper. In addition, some simple properties of neutrino lensing are investigated.

  12. Neutrino factory

    DOE PAGESBeta

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

    2014-12-08

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

  13. Neutrino factory

    SciTech Connect

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

    2014-12-08

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

  14. Topics in Neutrino Astrophysics

    E-print Network

    W. C. Haxton

    1999-01-29

    These lectures cover three topics in neutrino astrophysics. The solar neutrino problem is reviewed, with particular emphasis on the microphysics of the standard solar model, detector responses, the quantum mechanics of the MSW mechanism, and the possibility of spin-flavor oscillations. In the second lecture the electromagnetic properties of Dirac and Majorana neutrinos are discussed. Two classic problems in red giant evolution - the triple alpha reaction and the delay of the He flash by anomalous cooling - are used to illustrate how stellar cooling arguments constrain neutrino properties. Axion and Dirac neutrino mass effects on supernova cooling are also discussed. The third lecture describes the supernova explosion mechanism and the associated nucleosynthesis. The neutrino process and r-process are discussed, including the "neutrino fingerprint" on the latter that supports earlier suggestions that the r-process site is near the mass cut of a type II supernova. The effects of tau neutrino oscillations on the r-process are described briefly. The material is presented at a level suitable for graduate students at the beginning of their research careers.

  15. Probing Late Neutrino Mass Properties With SupernovaNeutrinos

    SciTech Connect

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

    2007-08-08

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

  16. Neutrino factories

    NASA Astrophysics Data System (ADS)

    Soler, F. J. P.

    2015-07-01

    The Neutrino Factory is a facility that produces neutrino beams with a well-defined flavour content and energy spectrum from the decay of intense, high-energy, stored muon beams to establish CP violation in the neutrino sector. The International Design Study for the Neutrino Factory (the IDS-NF) is providing a Reference Design Report (RDR) for the facility. The present design is optimised for the recent measurements of ?13. The accelerator facility will deliver 1021 muon decays per year from 10 GeV stored muon beams. The straight sections of the storage ring point to a 100 kton Magnetised Iron Neutrino Detector (MIND) at a distance of 2000-2500 km from the source. The accuracy in the value of ?CP that a Neutrino Factory can achieve and the ?CP coverage is unrivalled by other future facilities. Staging scenarios for the Neutrino Factory deliver facilities that can carry out physics at each stage. In the context of Fermilab, such a scenario would imply in the first stage the construction of a small storage ring, nuSTORM, to carry out neutrino cross-section and sterile neutrino measurements and to perform a programme of 6D muon cooling R&D. The second stage is the construction of a 5 GeV Neutrino Factory (nuMAX) pointing to the Sanford Underground Research Facility at Homestake and the final stage would use many of the components of this facility to construct a Muon Collider, initially as a 126 GeV CM Higgs Factory, which may be upgraded to a multi-TeV Muon Collider if required.

  17. Neutrinos and Gauge Unification

    E-print Network

    J. A. Casas; J. R. Espinosa; A. Ibarra; I. Navarro

    2000-04-17

    The approximate unification of gauge couplings is the best indirect evidence for low-energy supersymmetry, although it is not perfect in its simplest realizations. Given the experimental evidence for small non-zero neutrino masses, it is plausible to extend the MSSM with three right-handed neutrino chiral multiplets, with large Majorana masses below the unification scale, so that a see-saw mechanism can be implemented. In this extended MSSM, the unification prediction for the strong gauge coupling constant at M_Z can be lowered by up to \\sim 5%, bringing it closer to the experimental value at 1\\sigma, therefore improving significantly the accuracy of gauge coupling unification.

  18. Radiative Emission of Neutrino Pairs in Atoms and Light Sterile Neutrinos

    E-print Network

    Dinh, D N

    2014-01-01

    The process of Radiative Emission of Neutrino Pair (RENP) in atoms is sensitive to the absolute neutrino mass scale, the type of spectrum neutrino masses obey and the nature - Dirac or Majorana - of massive neutrinos. We analyse the possibility to test the hypothesis of existence of neutrinos with masses at the eV scale coupled to the electron in the weak charged lepton current in an RENP experiment. The presence of eV scale neutrinos in the neutrino mixing is associated with the existence of sterile neutrinos which mix with the active flavour neutrinos. At present there are a number of hints for active-sterile neutrino oscillations driven by $\\Delta m^2 \\sim 1~{\\rm eV^2}$. We perform a detailed analysis of the RENP phenomenology within the "3 + 1" scheme with one sterile neutrino.

  19. Radiative Emission of Neutrino Pairs in Atoms and Light Sterile Neutrinos

    E-print Network

    D. N. Dinh; S. T. Petcov

    2015-01-22

    The process of Radiative Emission of Neutrino Pair (RENP) in atoms is sensitive to the absolute neutrino mass scale, the type of spectrum neutrino masses obey and the nature - Dirac or Majorana - of massive neutrinos. We analyse the possibility to test the hypothesis of existence of neutrinos with masses at the eV scale coupled to the electron in the weak charged lepton current in an RENP experiment. The presence of eV scale neutrinos in the neutrino mixing is associated with the existence of sterile neutrinos which mix with the active flavour neutrinos. At present there are a number of hints for active-sterile neutrino oscillations driven by $\\Delta m^2 \\sim 1~{\\rm eV^2}$. We perform a detailed analysis of the RENP phenomenology within the "3 + 1" scheme with one sterile neutrino.

  20. Gauge Trimming of Neutrino Masses

    SciTech Connect

    Chen, Mu-Chun; de Gouvea, Andre; Dobrescu, Bogdan A.; /Fermilab

    2006-12-01

    We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ''right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This ''Leptocratic'' Model predicts the existence of light quasi-sterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.

  1. Theoretical Results on Neutrinos

    E-print Network

    Shun Zhou

    2015-11-23

    In this talk, I first summarize our current knowledge about the fundamental properties of neutrinos and emphasize the remaining unsolved problems in neutrino physics. Then, recent theoretical results on neutrino mass models are introduced. Different approaches to understanding tiny neutrino masses, lepton flavor mixing and CP violation are presented. Finally, I report briefly some new progress in the studies of astrophysical neutrinos, including keV sterile neutrinos, supernova neutrinos and ultrahigh-energy cosmic neutrinos.

  2. Discovering sterile neutrinos lighter than MW at the LHC

    NASA Astrophysics Data System (ADS)

    Dib, Claudio O.; Kim, C. S.

    2015-11-01

    We study the purely leptonic W decays W+?e+?-e+?e and W+?e+e+?-?¯? (or their charge conjugates) produced at the LHC, induced by sterile neutrinos with mass below MW in the intermediate state. While the first mode is induced by both Dirac or Majorana neutrinos, the second mode is induced only by Majorana neutrinos, as it violates lepton number. We find that, even when the final (anti-)neutrino goes undetected, one could distinguish between these two processes, thus distinguishing the Dirac or Majorana character of the sterile neutrinos, by studying the muon spectrum in the decays.

  3. Neutrino Velocity and Neutrino Oscillations

    E-print Network

    H. Minakata; A. Yu. Smirnov

    2012-07-30

    We study distances of propagation and the group velocities of the muon neutrinos in the presence of mixing and oscillations assuming that Lorentz invariance holds. Oscillations lead to distortion of the $\

  4. GUT implications from neutrino mass

    SciTech Connect

    Carl H. Albright

    2001-06-26

    An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO (10) SUSY GUT model formulated by S.M. Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super beam and a neutrino factory for determining the small U{sub e3} mixing matrix element.

  5. Investigation of Neutrino Properties with Bolometric Detectors

    SciTech Connect

    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 (0???) is the only known mechanism to test whether neutrinos are their own antiparticles. The observation of 0??? 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 0??? 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.

  6. Neutrino Oscillations and the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Wark, David

    2001-04-01

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

  7. Solar Neutrinos and the Decaying Neutrino Hypothesis

    E-print Network

    Jeffrey M. Berryman; Andre de Gouvea; Daniel Hernandez

    2014-11-02

    We explore, mostly using data from solar neutrino experiments, the hypothesis that the neutrino mass eigenstates are unstable. We find that, by combining $^8$B solar neutrino data with those on $^7$Be and lower-energy solar neutrinos, one obtains a mostly model-independent bound on both the $\

  8. Solar Neutrinos

    E-print Network

    R. G. H. Robertson

    2006-02-05

    Experimental work with solar neutrinos has illuminated the properties of neutrinos and tested models of how the sun produces its energy. Three experiments continue to take data, and at least seven are in various stages of planning or construction. In this review, the current experimental status is summarized, and future directions explored with a focus on the effects of a non-zero theta-13 and the interesting possibility of directly testing the luminosity constraint. Such a confrontation at the few-percent level would provide a prediction of the solar irradiance tens of thousands of years in the future for comparison with the present-day irradiance. A model-independent analysis of existing low-energy data shows good agreement between the neutrino and electromagnetic luminosities at the +/- 20 % level.

  9. Neutrino masses, neutrino oscillations, and cosmological implications

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1982-01-01

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

  10. Supernova Neutrinos

    SciTech Connect

    Beacom, John

    2009-11-14

    Supernovae in our Galaxy probably occur about 3 times per century, though 90% of them are invisible optically because of obscuration by dust. However, present solar neutrino detectors are sensitive to core-collapse supernovae anywhere in our Galaxy, and would detect of order 10,000 events from a supernova at a distance of 10 kpc (roughly the distance to the Galactic center). I will describe how this data can be used to understand the supernova itself, as well as to test the properties of neutrinos.

  11. Supernova Neutrinos

    SciTech Connect

    Beacom, John

    2001-11-14

    Supernovae in our Galaxy probably occur about 3 times per century, though 90% of them are invisible optically because of obscuration by dust. However, present solar neutrino detectors are sensitive to core-collapse supernovae anywhere in our Galaxy, and would detect of order 10,000 events from a supernova at a distance of 10 kpc (roughly the distance to the Galactic center). I will describe how this data can be used to understand the supernova itself, as well as to test the properties of neutrinos.

  12. Secret of Neutrino Oscillations

    E-print Network

    Dmitry Zhuridov

    2012-03-08

    The new effect of partial and full destruction of the neutrino oscillation pattern due to the neutrino wave packets separation in the transverse plane to the direction of the neutrino propagation is investigated. It is shown that this effect is significant in the real oscillation data, in particular, for the solar neutrinos, and dramatically changes the extracted physical properties of neutrinos.

  13. Neutrinos and Symmetries

    E-print Network

    A. B. Balantekin

    2009-10-09

    Three facets of symmetries in neutrino physics are briefly reviewed: i) The SO(5) symmetry of the neutrino mass and and its connection to the see-saw mechanism; ii) Flavor SU(N) symmetries of dense, self-interacting neutrino gases in astrophysical settings; iii) The neutrino mixing angle theta13 and possible CP-violation in the neutrino sector.

  14. Solar Neutrinos Before and After Neutrino 2004

    E-print Network

    John N. Bahcall; M. C. Gonzalez-Garcia; Carlos Pena-Garay

    2004-09-02

    We compare, using a three neutrino analysis, the allowed neutrino oscillation parameters and solar neutrino fluxes determined by the experimental data available Before and After Neutrino 2004. New data available after Neutrino2004 include refined KamLAND and gallium measurements. We use six different approaches to analyzing the KamLAND data. We present detailed results using all the available neutrino and anti-neutrino data for Delta m^2_{12}, tan^2 theta_{12}, sin^2 theta_{13}, and sin^2 eta (sterile fraction). Using the same complete data sets, we also present Before and After determinations of all the solar neutrino fluxes, which are treated as free parameters, an upper limit to the luminosity fraction associated with CNO neutrinos, and the predicted rate for a 7Be solar neutrino experiment. The 1 sigma (3 sigma) allowed range of Delta m^2_{21} = (8.2 +- 0.3) (^+1.0_-0.8)times 10^{-5} eV^2 is decreased by a factor of 1.7 (5), but the allowed ranges of all other neutrino oscillation parameters and neutrino fluxes are not significantly changed. Maximal mixing is disfavored at 5.8 sigma and the bound on the mixing angle theta_{13} is slightly improved to sin^2 theta_{13}reactor anti-neutrino oscillation parameters with neutrino oscillation parameters. We also show that the recent data disfavor at 91 % CL a proposed non-standard interaction description of solar neutrino oscillations.

  15. Massive Neutrinos and the Higgs Mass Window

    E-print Network

    J. A. Casas; V. Di Clemente; A. Ibarra; M. Quiros

    1999-04-11

    If neutrino masses are produced by a see-saw mechanism the Standard Model prediction for the Higgs mass window (defined by upper (perturbativity) and lower (stability) bounds) can be substantially affected. Actually the Higgs mass window can close completely, which settles an upper bound on the Majorana mass for the right-handed neutrinos, $M$, ranging from $10^{13}$ GeV for three generations of quasi-degenerate massive neutrinos with $m_\

  16. Vanishing effective mass of the neutrinoless double beta decay including light sterile neutrinos

    E-print Network

    Y. F. Li; Si-shuo Liu

    2011-11-28

    Light sterile neutrinos with masses at the sub-eV or eV scale are hinted by current experimental and cosmological data. Assuming the Majorana nature of these hypothetical particles, we discuss their effects in the neutrinoless double beta decay by exploring the implications of a vanishing effective Majorana neutrino mass. Allowed ranges of neutrino masses, mixing angles and Majorana CP-violating phases are illustrated in some instructive cases for both normal and inverted mass hierarchies of three active neutrinos.

  17. Tachyonic neutrinos?

    E-print Network

    J. Rembielinski

    1994-12-05

    It is shown that tachyons are associated with unitary representations of Poincare mappings induced from SO(2) little group instead of SO(2,1) one. This allows us to treat more seriously possibility that neutrinos are fermionic tachyons according to the present experimental data.

  18. The Mystery of Neutrino Mixings

    E-print Network

    Guido Altarelli

    2011-11-28

    In the last years we have learnt a lot about neutrino masses and mixings. Neutrinos are not all massless but their masses are very small. Probably masses are small because neutrinos are Majorana particles with masses inversely proportional to the large scale M of lepton number (L) violation, which turns out to be compatible with the GUT scale. We have understood that there is no contradiction between large neutrino mixings and small quark mixings, even in the context of GUTs and that neutrino masses fit well in the SUSY GUT picture. Out of equilibrium decays with CP and L violation of heavy RH neutrinos can produce a B-L asymmetry, then converted near the weak scale by instantons into an amount of B asymmetry compatible with observations (baryogenesis via leptogenesis). It appears that active neutrinos are not a significant component of Dark Matter in the Universe. A long list of models have been formulated over the years to understand neutrino masses and mixings. With the continuous improvement of the data most of the models have been discarded by experiment. The surviving models still span a wide range going from a maximum of symmetry, with discrete non-abelian flavour groups, to the opposite extreme of anarchy.

  19. Neutrino refraction by the cosmic neutrino background

    E-print Network

    Diaz, J S

    2015-01-01

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

  20. Neutrino refraction by the cosmic neutrino background

    E-print Network

    J. S. Diaz; F. R. Klinkhamer

    2015-12-07

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

  1. Electromagnetic properties of neutrinos

    E-print Network

    Carlo Giunti; Alexander Studenikin

    2010-06-08

    A short review on electromagnetic properties of neutrinos is presented. In spite of many efforts in the theoretical and experimental studies of neutrino electromagnetic properties, they still remain one of the main puzzles related to neutrinos.

  2. Neutrinos: in and out of the standard model

    SciTech Connect

    Parke, Stephen; /Fermilab

    2006-07-01

    The particle physics Standard Model has been tremendously successful in predicting the outcome of a large number of experiments. In this model Neutrinos are massless. Yet recent evidence points to the fact that neutrinos are massive particles with tiny masses compared to the other particles in the Standard Model. These tiny masses allow the neutrinos to change flavor and oscillate. In this series of Lectures, I will review the properties of Neutrinos In the Standard Model and then discuss the physics of Neutrinos Beyond the Standard Model. Topics to be covered include Neutrino Flavor Transformations and Oscillations, Majorana versus Dirac Neutrino Masses, the Seesaw Mechanism and Leptogenesis.

  3. Neutrino Mass Seesaw Version 3: Recent Developments

    SciTech Connect

    Ma, Ernest

    2009-04-20

    The origin of neutrino mass is usually attributed to a seesaw mechanism, either through a heavy Majorana fermion singlet (version 1) or a heavy scalar triplet (version 2). Recently, the idea of using a heavy Majorana fermion triplet (version 3) has gained some attention. This is a review of the basic idea involved, its U(1) gauge extension, and some recent developments.

  4. Gravity triggered neutrino condensates

    SciTech Connect

    Barenboim, Gabriela

    2010-11-01

    In this work we use the Schwinger-Dyson equations to study the possibility that an enhanced gravitational attraction triggers the formation of a right-handed neutrino condensate, inducing dynamical symmetry breaking and generating a Majorana mass for the right-handed neutrino at a scale appropriate for the seesaw mechanism. The composite field formed by the condensate phase could drive an early epoch of inflation. We find that to the lowest order, the theory does not allow dynamical symmetry breaking. Nevertheless, thanks to the large number of matter fields in the model, the suppression by additional powers in G of higher order terms can be compensated, boosting them up to their lowest order counterparts. This way chiral symmetry can be broken dynamically and the infrared mass generated turns out to be in the expected range for a successful seesaw scenario.

  5. Neutrinos: Theory and Phenomenology

    SciTech Connect

    Parke, Stephen

    2013-10-22

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

  6. Light Sterile Neutrinos and Short Baseline Neutrino Oscillation Anomalies

    E-print Network

    JiJi Fan; Paul Langacker

    2012-01-31

    We study two possible explanations for short baseline neutrino oscillation anomalies, such as the LSND and MiniBooNE anti-neutrino data, and for the reactor anomaly. The first scenario is the mini-seesaw mechanism with two eV-scale sterile neutrinos. We present both analytic formulas and numerical results showing that this scenario could account for the short baseline and reactor anomalies and is consistent with the observed masses and mixings of the three active neutrinos. We also show that this scenario could arise naturally from an effective theory containing a TeV-scale VEV, which could be related to other TeV-scale physics. The minimal version of the mini-seesaw relates the active-sterile mixings to five real parameters and favors an inverted hierarchy. It has the interesting property that the effective Majorana mass for neutrinoless double beta decay vanishes, while the effective masses relevant to tritium beta decay and to cosmology are respectively around 0.2 and 2.4 eV. The second scenario contains only one eV-scale sterile neutrino but with an effective non-unitary mixing matrix between the light sterile and active neutrinos. We find that though this may explain the anomalies, if the non-unitarity originates from a heavy sterile neutrino with a large (fine-tuned) mixing angle, this scenario is highly constrained by cosmological and laboratory observations.

  7. The Intermediate Neutrino Program

    E-print Network

    C. Adams; J. R. Alonso; A. M. Ankowski; J. A. Asaadi; J. Ashenfelter; S. N. Axani; K. Babu; C. Backhouse; H. R. Band; P. S. Barbeau; N. Barros; A. Bernstein; M. Betancourt; M. Bishai; E. Blucher; J. Bouffard; N. Bowden; S. Brice; C. Bryan; L. Camilleri; J. Cao; J. Carlson; R. E. Carr; A. Chatterjee; M. Chen; S. Chen; M. Chiu; E. D. Church; J. I. Collar; G. Collin; J. M. Conrad; M. R. Convery; R. L. Cooper; D. Cowen; H. Davoudiasl; A. De Gouvea; D. J. Dean; G. Deichert; F. Descamps; T. DeYoung; M. V. Diwan; Z. Djurcic; M. J. Dolinski; J. Dolph; B. Donnelly; D. A. Dwyer; S. Dytman; Y. Efremenko; L. L. Everett; A. Fava; E. Figueroa-Feliciano; B. Fleming; A. Friedland; B. K. Fujikawa; T. K. Gaisser; M. Galeazzi; D. C. Galehouse; A. Galindo-Uribarri; G. T. Garvey; S. Gautam; K. E. Gilje; M. Gonzalez-Garcia; M. C. Goodman; H. Gordon; E. Gramellini; M. P. Green; A. Guglielmi; R. W. Hackenburg; A. Hackenburg; F. Halzen; K. Han; S. Hans; D. Harris; K. M. Heeger; M. Herman; R. Hill; A. Holin; P. Huber; D. E. Jaffe; R. A. Johnson; J. Joshi; G. Karagiorgi; L. J. Kaufman; B. Kayser; S. H. Kettell; B. J. Kirby; J. R. Klein; Yu. G. Kolomensky; R. M. Kriske; C. E. Lane; T. J. Langford; A. Lankford; K. Lau; J. G. Learned; J. Ling; J. M. Link; D. Lissauer; L. Littenberg; B. R. Littlejohn; S. Lockwitz; M. Lokajicek; W. C. Louis; K. Luk; J. Lykken; W. J. Marciano; J. Maricic; D. M. Markoff; D. A. Martinez Caicedo; C. Mauger; K. Mavrokoridis; E. McCluskey; D. McKeen; R. McKeown; G. Mills; I. Mocioiu; B. Monreal; M. R. Mooney; J. G. Morfin; P. Mumm; J. Napolitano; R. Neilson; J. K. Nelson; M. Nessi; D. Norcini; F. Nova; D. R. Nygren; G. D. Orebi Gann; O. Palamara; Z. Parsa; R. Patterson; P. Paul; A. Pocar; X. Qian; J. L. Raaf; R. Rameika; G. Ranucci; H. Ray; D. Reyna; G. C. Rich; P. Rodrigues; E. Romero Romero; R. Rosero; S. D. Rountree; B. Rybolt; M. C. Sanchez; G. Santucci; D. Schmitz; K. Scholberg; D. Seckel; M. Shaevitz; R. Shrock; M. B. Smy; M. Soderberg; A. Sonzogni; A. B. Sousa; J. Spitz; J. M. St. John; J. Stewart; J. B. Strait; G. Sullivan; R. Svoboda; A. M. Szelc; R. Tayloe; M. A. Thomson; M. Toups; A. Vacheret; M. Vagins; R. G. Van de Water; R. B. Vogelaar; M. Weber; W. Weng; M. Wetstein; C. White; B. R. White; L. Whitehead; D. W. Whittington; M. J. Wilking; R. J. Wilson; P. Wilson; D. Winklehner; D. R. Winn; E. Worcester; L. Yang; M. Yeh; Z. W. Yokley; J. Yoo; B. Yu; J. Yu; C. Zhang

    2015-04-01

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

  8. The Intermediate Neutrino Program

    E-print Network

    Adams, C; Ankowski, A M; Asaadi, J A; Ashenfelter, J; Axani, S N; Babu, K; Backhouse, C; Band, H R; Barbeau, P S; Barros, N; Bernstein, A; Betancourt, M; Bishai, M; Blucher, E; Bouffard, J; Bowden, N; Brice, S; Bryan, C; Camilleri, L; Cao, J; Carlson, J; Carr, R E; Chatterjee, A; Chen, M; Chen, S; Chiu, M; Church, E D; Collar, J I; Collin, G; Conrad, J M; Convery, M R; Cooper, R L; Cowen, D; Davoudiasl, H; De Gouvea, A; Dean, D J; Deichert, G; Descamps, F; DeYoung, T; Diwan, M V; Djurcic, Z; Dolinski, M J; Dolph, J; Donnelly, B; Dwyer, D A; Dytman, S; Efremenko, Y; Everett, L L; Fava, A; Figueroa-Feliciano, E; Fleming, B; Friedland, A; Fujikawa, B K; Gaisser, T K; Galeazzi, M; Galehouse, D C; Galindo-Uribarri, A; Garvey, G T; Gautam, S; Gilje, K E; Gonzalez-Garcia, M; Goodman, M C; Gordon, H; Gramellini, E; Green, M P; Guglielmi, A; Hackenburg, R W; Hackenburg, A; Halzen, F; Han, K; Hans, S; Harris, D; Heeger, K M; Herman, M; Hill, R; Holin, A; Huber, P; Jaffe, D E; Johnson, R A; Joshi, J; Karagiorgi, G; Kaufman, L J; Kayser, B; Kettell, S H; Kirby, B J; Klein, J R; Kolomensky, Yu G; Kriske, R M; Lane, C E; Langford, T J; Lankford, A; Lau, K; Learned, J G; Ling, J; Link, J M; Lissauer, D; Littenberg, L; Littlejohn, B R; Lockwitz, S; Lokajicek, M; Louis, W C; Luk, K; Lykken, J; Marciano, W J; Maricic, J; Markoff, D M; Caicedo, D A Martinez; Mauger, C; Mavrokoridis, K; McCluskey, E; McKeen, D; McKeown, R; Mills, G; Mocioiu, I; Monreal, B; Mooney, M R; Morfin, J G; Mumm, P; Napolitano, J; Neilson, R; Nelson, J K; Nessi, M; Norcini, D; Nova, F; Nygren, D R; Gann, G D Orebi; Palamara, O; Parsa, Z; Patterson, R; Paul, P; Pocar, A; Qian, X; Raaf, J L; Rameika, R; Ranucci, G; Ray, H; Reyna, D; Rich, G C; Rodrigues, P; Romero, E Romero; Rosero, R; Rountree, S D; Rybolt, B; Sanchez, M C; Santucci, G; Schmitz, D; Scholberg, K; Seckel, D; Shaevitz, M; Shrock, R; Smy, M B; Soderberg, M; Sonzogni, A; Sousa, A B; Spitz, J; John, J M St; Stewart, J; Strait, J B; Sullivan, G; Svoboda, R; Szelc, A M; Tayloe, R; Thomson, M A; Toups, M; Vacheret, A; Vagins, M; Van de Water, R G; Vogelaar, R B; Weber, M; Weng, W; Wetstein, M; White, C; White, B R; Whitehead, L; Whittington, D W; Wilking, M J; Wilson, R J; Wilson, P; Winklehner, D; Winn, D R; Worcester, E; Yang, L; Yeh, M; Yokley, Z W; Yoo, J; Yu, B; Yu, J; Zhang, C

    2015-01-01

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summ...

  9. Atmospheric neutrino and Long Baseline neutrino experiments

    E-print Network

    Giorgio Giacomelli

    2007-12-13

    The results obtained by several experiments on atmospheric neutrino oscillations are summarized and discussed. Then the results obtained by different long baseline neutrino experiments are considered. Finally conclusions and perspectives are made.

  10. Non standard neutrino interactions: current status and future prospects

    NASA Astrophysics Data System (ADS)

    Miranda, O. G.; Nunokawa, H.

    2015-09-01

    Neutrino oscillations have become well-known phenomena; the measurements of neutrino mixing angles and mass squared differences are continuously improving. Future oscillation experiments will eventually determine the remaining unknown neutrino parameters, namely, the mass ordering, normal or inverted, and the CP-violating phase. On the other hand, the absolute mass scale of neutrinos could be probed by cosmological observations, single beta decay as well as by neutrinoless double beta decay experiments. Furthermore, the last one may shed light on the nature of neutrinos, Dirac or Majorana, by measuring the effective Majorana mass of neutrinos. However, the neutrino mass generation mechanism remains unknown. A well-motivated phenomenological approach to search for new physics, in the neutrino sector, is that of non-standard interactions. In this short review, the current constraints in this picture, as well as the perspectives from future experiments, are discussed.

  11. Neutrino Mass Phenomenology

    SciTech Connect

    Marrone, A.

    2005-10-12

    The present knowledge about neutrino mass and mixing, in the framework of three active neutrino mixing, is reviewed. All available data on solar, atmospheric, reactor, and accelerator oscillation neutrino experiments are analysed and combined with data on absolute neutrino masses, coming from beta decay and neutrinoless double beta decay experiments and astrophysical and cosmological researches.

  12. New Neutrinos Algal Biofuels

    E-print Network

    New Neutrinos Algal Biofuels Charged-Particle Vision Primordial Soup LOS ALAMOS SCIENCE in Illinois, a beam of neutrino particles streams through the MiniBooNE detector. This experiment tests the degree to which neutrinos shift from one "flavor" to another. Each neutrino normally travels as a mixture

  13. Tachyonic neutrinos Gillian Lustermans

    E-print Network

    van Suijlekom, Walter

    Tachyonic neutrinos Gillian Lustermans July 11, 2012 #12;Abstract In this paper, the possibility neutrino and an electron antineutrino. By substituting the two neutrinos by tachyonic neu- trinos for the subject of tachyons came from the results of the OPERA experiment, where tachyonic neutrinos were thought

  14. Muons and Neutrinos 2007

    E-print Network

    Thomas K. Gaisser

    2008-01-29

    This paper is the written version of the rapporteur talk on Section HE-2, muons and neutrinos, presented at the 30th International Cosmic Ray Conference, Merida, Yucatan, July 11, 2007. Topics include atmospheric muons and neutrinos, solar neutrinos and astrophysical neutrinos as well as calculations and instrumentation related to these topics.

  15. Future Neutrino Experiments

    SciTech Connect

    Fleming, B. T.

    2009-12-17

    There are a number of future neutrino experiments addressing fundamental questions about the neutrino and about what the neutrino can tell us about the universe. A class of these experiments are long baseline neutrino oscillation v{sub e} appearance searches which can measure the final unknowns of the 3x3 neutrino mixing matrix and look for CP violation in the neutrino sector. The massive detectors needed for these experiments can also search for proton decay and measure extra-terrestrial neutrino sources. There are a number of efforts worldwide to launch these experiments. These efforts, with a focus on US plans, are described.

  16. Neutrino Physics with JUNO

    E-print Network

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

    2015-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter, sterile neutrinos, etc. We present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. By detecting reactor antineutrinos from two power plants at 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4 sigma significance with six years of running. The measurement of antineutrino spectrum will also lead to the precise determination of three out of the six oscillation parameters to an accuracy of better than 1\\%. Neutrino burst from a typical cor...

  17. Lunar neutrino physics

    SciTech Connect

    Learned, J.G. Department of Astronomy, University of Hawaii, Manoa, 2505 Correa Road, Honolulu, HI )

    1990-03-15

    The possibilities of the use of the moon as a base for conducting neutrino physics are examined, exphasizing neutrino astronomy. The principle advantage of the moon for this research is freedom from the atmospheric layer of the earth: cosmic rays hitting the atmosphere generate a rather copious source of neutrinos, which are a terrestrially inescapable diffuse background to neutrino astronomy. The cosmic ray generated neutrinos on earth are also a limiting background for other sensitive particle physics experiments, typically those performed underground.

  18. Relic Neutrino Absorption Spectroscopy

    SciTech Connect

    Eberle, b

    2004-01-28

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

  19. Measuring anisotropies in the cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Lisanti, Mariangela; Safdi, Benjamin R.; Tully, Christopher G.

    2014-10-01

    Neutrino capture on tritium has emerged as a promising method for detecting the cosmic neutrino background (C ? B ). We show that relic neutrinos are captured most readily when their spin vectors are antialigned with the polarization axis of the tritium nuclei and when they approach along the direction of polarization. As a result, C ? B observatories may measure anisotropies in the cosmic neutrino velocity and spin distributions by polarizing the tritium targets. A small dipole anisotropy in the C ? B is expected due to the peculiar velocity of the lab frame with respect to the cosmic frame and due to late-time gravitational effects. The PTOLEMY experiment, a tritium observatory currently under construction, should observe a nearly isotropic background. This would serve as a strong test of the cosmological origin of a potential signal. The polarized-target measurements may also constrain nonstandard neutrino interactions that would induce larger anisotropies and help discriminate between Majorana versus Dirac neutrinos.

  20. Neutrino masses and a TeV scale seesaw mechanism

    SciTech Connect

    Chao Wei

    2010-07-01

    A simple extension of the standard model providing a TeV-scale seesaw mechanism is presented. Beside the standard model particles and right-handed Majorana neutrinos, the model contains a singly charged scalar, an extra Higgs doublet, and three vectorlike singly charged fermions. In our model, Dirac neutrino mass matrix raises only at the loop level. Small but nonzero Majorana neutrino masses come from integrating out heavy Majorana neutrinos, which can be at the TeV-scale. The phenomenologies of the model are investigated, including scalar mass spectrum, neutrino masses and mixings, lepton flavor violations, heavy neutrino magnetic moments as well as possible collider signatures of the model at the LHC.

  1. Neutrino magnetic moments, flavor mixing, and the SuperKamiokande solar data

    E-print Network

    J. F. Beacom; P. Vogel

    1999-10-25

    We find that magnetic neutrino-electron scattering is unaffected by oscillations for vacuum mixing of Dirac neutrinos with only diagonal moments and for Majorana neutrinos with two flavors. For MSW mixing, these cases again obtain, though the effective moments can depend on the neutrino energy. Thus, e.g., the magnetic moments measured with $\\bar{\

  2. STERILE NEUTRINOS IN E6 International Conference on Massive Neutrinos

    E-print Network

    Rosner, Jonathan L.

    1/17 STERILE NEUTRINOS IN E6 International Conference on Massive Neutrinos J. Rosner ­ Singapore ­ Feb. 11, 2015 What are sterile neutrinos and why do we need them? Weak isosinglet neutrinos, visible that the three active neutrinos aren't enough to fit all oscillation data; sterile neutrinos are invoked Data

  3. The Measurement of Neutrino Properties with Atmospheric Neutrinos

    NASA Astrophysics Data System (ADS)

    Kajita, Takaaki

    2014-10-01

    Atmospheric neutrinos are produced by cosmic-ray interactions in the atmosphere. Atmospheric neutrino experiments typically observe zenith-angle and energy dependences of [Formula: see text] and ?e events. Through these experiments, neutrino oscillation was discovered. Since then, various studies have been performed to further our understanding of neutrino properties. This article discusses experimental studies of neutrino oscillations with atmospheric neutrinos.

  4. Future solar neutrino experiments and neutrino spin-flavour precession

    E-print Network

    Bilenky, S M

    1993-01-01

    The main features of the observables in the SNO and Super-Kamiokande solar neutrino experiments in the case of neutrino spin and/or spin-flavour precession in the magnetic field of the sun are discussed. It is shown without any model dependent assumption that in the case of Majorana transition magnetic moments the NC event rate $N^{\\mathrm{NC}}$ does not depend on time and a measurement of $N^{\\mathrm{NC}}$ will allow to determine the initial flux of $^8\\mathrm{B}$ neutrinos with a theoretical uncertainty of a few \\%. In the case of Dirac magnetic moments the NC event rate will depend on time and we obtain a model independent lower bound for the transition probability of initial $\

  5. Neutrino Shortcuts in Spacetime

    E-print Network

    A. Nicolaidis

    2012-07-03

    Theories with large extra dimensions may be tested using sterile neutrinos living in the bulk. A bulk neutrino can mix with a ?a- vor neutrino localized in the brane leading to unconventional patterns of neutrino oscillations. A resonance phenomenon, strong mixing be- tween the ?avor and the sterile neutrino, allows to determine the radius of the large extra dimension. If our brane is curved, then the sterile neutrino can take a shortcut through the bulk, leading to an appar- ent superluminal neutrino speed. The amount of ?superluminality? is directly connected to parameters determining the shape of the brane. On the experimental side, we suggest that a long baseline neutrino beam from CERN to NESTOR neutrino telescope will help to clarify these important issues.

  6. Neutrino properties from Yukawa structure

    E-print Network

    A. Ibarra; G. G. Ross

    2003-12-10

    We discuss the implications for lepton mixing and CP violation of structure in the lepton mass matrices, for the case that neutrino masses are generated by the see-saw mechanism with an hierarchical structure for the Majorana masses. For a particularly interesting case with enhanced symmetry in which the lepton Dirac mass matrices are related to those in the quark sector, the CHOOZ angle is near the present limit and the CP violating phase relevant to thermal leptogenesis and to $\

  7. Neutrino mass, a status report

    SciTech Connect

    Robertson, R.G.H.

    1993-08-01

    Experimental approaches to neutrino mass include kinematic mass measurements, neutrino oscillation searches at rectors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.

  8. Experimental Neutrino Physics: Final Report

    SciTech Connect

    Lane, Charles E.; Maricic, Jelena

    2012-09-05

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

  9. A Compromise between Neutrino Masses and Collider Signatures in the Type-II Seesaw Model

    E-print Network

    Wei Chao; Shu Luo; Zhi-zhong Xing; Shun Zhou

    2007-09-07

    A natural extension of the standard $SU(2)_{\\rm L} \\times U(1)_{\\rm Y}$ gauge model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a $6\\times 6$ neutrino mass matrix which contains three $3\\times 3$ sub-matrices $M_{\\rm L}$, $M_{\\rm D}$ and $M_{\\rm R}$. We show that three light Majorana neutrinos (i.e., the mass eigenstates of $\

  10. Neutrinos in a Sterile Throat

    E-print Network

    Ben Gripaios

    2009-12-16

    We consider field-theoretic models of a warped extra dimension with multiple throats, in which fermions that are singlets of the Standard Model gauge group propagate in a separate throat from the Standard Model fields, which we call the sterile throat. The singlets mix with Standard Model fields via interactions localized on the UV brane that connects the two throats. This leads to three, light, mostly-active, Majorana neutrinos via a higher-dimensional see-saw mechanism, together with Kaluza-Klein towers of mostly-sterile neutrinos, whose scale is set by the warp factor in the sterile throat and can be very low if the throat is deep. We suggest that a model of this kind may explain all the neutrino data, reconciling the LSND result with astrophysical constraints.

  11. Neutrino-axion-dilaton interconnection

    E-print Network

    Bertolini, Stefano; Kolešová, Helena; Malinský, Michal; Vasquez, Juan Carlos

    2015-01-01

    We show that a recently proposed framework that provides a simple connection between Majorana neutrinos and an invisible axion in minimal scalar extensions of the standard electroweak model can be naturally embedded in a classically scale-invariant setup. The explicit breaking of the scale invariance \\`a la Coleman-Weinberg generates the Peccei-Quinn and electroweak scales. The spontaneous breaking of the chiral $U(1)_{PQ}$ triggers the generation of neutrino masses via Type-II seesaw and, at the same time, provides a dynamical solution to the strong CP problem as well as the axion as a dark matter candidate. The electroweak and neutrino mass scales are obtained via a technically natural ultraweak limit of the singlet scalar interactions. Accordingly, a realistic and perturbatively stable scalar spectrum, possibly in the reach of the LHC, is naturally obtained. A very light pseudo-dilaton characterizes such a setting. The vacuum stability of the extended setup is discussed.

  12. Neutrino properties and puzzles

    SciTech Connect

    Bowles, T.J.

    1990-01-01

    Sixty years after the existence of the neutrino was first postulated, we are still lacking in information on the fundamental properties of neutrinos. Measurements have consistently pushed the limits on the mass, magnetic moment, and possible mixing down. Solar neutrino experiments are now shedding more light on the solar neutrino problem'' and are starting to give a hint that perhaps these quantities are nonzero. The present status of our knowledge of neutrino properties, the newest experimental data on the solar neutrino problem,'' and future plans will be presented. 27 refs.

  13. Neutrino Physics at Fermilab

    ScienceCinema

    Saoulidou, Niki

    2010-01-08

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

  14. Neutrino Physics at Fermilab

    SciTech Connect

    Saoulidou, Niki

    2008-04-09

    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.

  15. PREFACE: Nobel Symposium 129 on Neutrino Physics

    NASA Astrophysics Data System (ADS)

    Bergström, Lars; Botner, Olga; Carlson, Per; Hulth, Per Olof; Ohlsson, Tommy

    2005-01-01

    Nobel Symposium 129 on Neutrino Physics was held at Haga Slott in Enköping, Sweden during August 19 24, 2004. Invited to the symposium were around 40 globally leading researchers in the field of neutrino physics, both experimental and theoretical. In addition to these participants, some 30 local researchers and graduate students participated in the symposium. The dominant theme of the lectures was neutrino oscillations, which after several years were recently verified by results from the Super-Kamiokande detector in Kamioka, Japan and the SNO detector in Sudbury, Canada. Discussion focused especially on effects of neutrino oscillations derived from the presence of matter and the fact that three different neutrinos exist. Since neutrino oscillations imply that neutrinos have mass, this is the first experimental observation that fundamentally deviates from the standard model of particle physics. This is a challenge to both theoretical and experimental physics. The various oscillation parameters will be determined with increased precision in new, specially designed experiments. Theoretical physics is working intensively to insert the knowledge that neutrinos have mass into the theoretical models that describe particle physics. It will probably turn out that the discovery of neutrino oscillations signifies a breakthrough in the description of the very smallest constituents of matter. The lectures provided a very good description of the intensive situation in the field right now. The topics discussed also included mass models for neutrinos, neutrinos in extra dimensions as well as the `seesaw mechanism', which provides a good description of why neutrino masses are so small. Also discussed, besides neutrino oscillations, was the new field of neutrino astronomy. Among the questions that neutrino astronomy hopes to answer are what the dark matter in the Universe consists of and where cosmic radiation at extremely high energies comes from. For this purpose, large neutrino telescopes are built deep in the Antarctic ice, in the Baikal Lake, and in the Mediterranean Sea. Among prominent unanswered questions, highlighted as one of the most important, was whether neutrinos are Dirac or Majorana particles. By studying neutrino double beta decay, researchers hope to answer this question, but it will put very large demands on detectors. The programme also included ample time for lively and valuable discussions, which cannot normally be held at ordinary conferences. The symposium concluded with a round-table discussion, where participants discussed the future of neutrino physics.Without a doubt, neutrino physics today is moving toward a very exciting and interesting period. An important contribution to the success of the symposium was the wonderful setting that the Haga Slott manor house hotel and conference center offered to the participants.

  16. Neutrino properties from high energy astrophysical neutrinos

    E-print Network

    Sandip Pakvasa

    2004-05-19

    It is shown how high energy neutrino beams from very distant sources can be utilised to learn about some properties of neutrinos such as lifetimes, mass hierarchy etc. Furthemore, even mixing elements such as U_e3 and the CPV phase in the neutrino mixing matrix can be measured in principle. Pseudo-Dirac mass differences as small as 10^-18 eV^2 can be probed as well.

  17. Neutrino Physics with JUNO

    E-print Network

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

    2015-10-18

    The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy as a primary physics goal. It is also capable of observing neutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, solar neutrinos, as well as exotic searches such as nucleon decays, dark matter, sterile neutrinos, etc. We present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. By detecting reactor antineutrinos from two power plants at 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4 sigma significance with six years of running. The measurement of antineutrino spectrum will also lead to the precise determination of three out of the six oscillation parameters to an accuracy of better than 1\\%. Neutrino burst from a typical core-collapse supernova at 10 kpc would lead to ~5000 inverse-beta-decay events and ~2000 all-flavor neutrino-proton elastic scattering events in JUNO. Detection of DSNB would provide valuable information on the cosmic star-formation rate and the average core-collapsed neutrino energy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400 events per year, significantly improving the statistics of existing geoneutrino samples. The JUNO detector is sensitive to several exotic searches, e.g. proton decay via the $p\\to K^++\\bar\

  18. Neutrino mixing and CP phase correlations

    NASA Astrophysics Data System (ADS)

    Ma, Ernest; Natale, Alexander; Popov, Oleg

    2015-06-01

    A special form of the 3 × 3 Majorana neutrino mass matrix derivable from ?- ? interchange symmetry accompanied by a generalized CP transformation was obtained many years ago. It predicts ?23 = ? / 4 as well as ?CP = ± ? / 2, with ?13 ? 0. Whereas this is consistent with present data, we explore a deviation of this result which occurs naturally in a recent proposed model of radiative inverse seesaw neutrino mass.

  19. Seesaw Neutrinos from the Heterotic String

    E-print Network

    Wilfried Buchmuller; Koichi Hamaguchi; Oleg Lebedev; Saul Ramos-Sanchez; Michael Ratz

    2007-06-27

    We study the possibility of realizing the neutrino seesaw mechanism in the E8XE8 heterotic string. In particular, we consider its Z_6 orbifold compactifications leading to the supersymmetric standard model gauge group and matter content. We find that these models possess all the necessary ingredients for the seesaw mechanism, including the required Dirac Yukawa couplings and large Majorana mass terms. We argue that this situation is quite common in heterotic orbifolds. In contrast to the conventional seesaw of grand unified theories (GUTs), no large GUT representations are needed to generate the Majorana mass terms. The total number of right--handed neutrinos can be very large, up to O(100).

  20. Oscillations of neutrino velocity

    E-print Network

    Branislav Sazdovi?; Milovan Vasili?

    2012-10-12

    In this paper, we consider the problem of quantum measurement of neutrino velocity. We show, that the well known neutrino flavor oscillations are always accompanied by the oscillations of neutrino velocity. In particular, the velocity of a freely moving neutrino is demonstrated to periodically exceed the speed of light. Unfortunately, the superluminal effect turns out to be too small to be experimentally detected. It is also shown that neutrino velocity significantly depends on the energy, size and shape of the neutrino wave packet. Owing to the big experimental error of the recent experiments, these dependences remained unnoticeable. Finally, we have shown that the recent claims that superluminal neutrinos should loose energy during their flight is not true. Instead, our formula suggests the approximate conservation of energy along neutrino trajectory. All these results have been obtained without violation of special theory of relativity.

  1. Solar neutrinos - Eclipse effect

    E-print Network

    Mohan Narayan; G. Rajasekaran; Rahul Sinha

    1997-03-12

    It is pointed out that the enhancement of the solar neutrino rate in a real time detector like Super-Kamioka, SNO or Borexino due to neutrino oscillations in the moon during a partial or total solar eclipse may be observable. The enhancement is calculated as a function of the neutrino parameters in the case of three flavor mixing. This enhancement if seen, can further help to determine the neutrino parameters.

  2. Neutrino masses and mixings

    SciTech Connect

    Wolfenstein, L.

    1991-12-31

    Theoretical prejudices, cosmology, and neutrino oscillation experiments all suggest neutrino mass are far below present direct experimental limits. Four interesting scenarios and their implications are discussed: (1) a 17 keV {nu}{sub {tau}}, (2) a 30 ev {nu}{sub {tau}} making up the dark matter, (3) a 10{sup {minus}3} ev {nu}{sub {mu}} to solve the solar neutrino problem, and (4) a three-neutrino MSW solution.

  3. Geo-neutrino Observation

    SciTech Connect

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

    2009-12-17

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

  4. Neutrinos from WIMP annihilations

    E-print Network

    Mattias Blennow

    2007-10-08

    We make an improved analysis on the flow of neutrinos originating from WIMP annihilations inside the Sun and the Earth. We treat both neutrino interaction and oscillation effects in a consistent framework. Our numerical simulations are performed in an event based setting, which is useful for both theoretical studies and for creating neutrino telescope Monte Carlos. We find that the flow of muon-type neutrinos is enhanced or suppressed depending on the dominant WIMP annihilation channel.

  5. Neutrino Oscillation Physics

    SciTech Connect

    Kayser, Boris

    2012-06-01

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

  6. Neutrinos in the early universe

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  7. Neutrinos as cosmic messengers

    SciTech Connect

    Valle, J. W. F.

    2009-04-17

    I briefly review the current status of neutrino oscillation parameters and discuss the role of neutrinos as cosmological probes, that could possibly induce the baryon asymmetry as well as the dark matter in the Universe. I comment on the origin of neutrino masses in seesaw-type and low-scale models and mention some of their laboratory signals.

  8. Neutrino Astronomy Scott Wilbur

    E-print Network

    Golwala, Sunil

    V protons, which should be created with neutrinos, have been seen Can be used to observe possible dark Particle Physics Extremely long baseline for neutrino oscillation studies Dark Matter Searches Many dark Detector Picture from AMANDA II Web Site: http://www.amanda.uci.edu #12;Advantages of Neutrino Astronomy

  9. Neutrino Magnetic Moment

    E-print Network

    A. B. Balantekin

    2006-01-13

    Current experimental and observational limits on the neutrino magnetic moment are reviewed. Implications of the recent results from the solar and reactor neutrino experiments for the value of the neutrino magnetic moment are discussed. It is shown that spin-flavor precession in the Sun is suppressed.

  10. Solar Neutrinos Kamioka Observatory

    E-print Network

    Tokyo, University of

    Solar Neutrinos Y. Suzuki Kamioka Observatory Institute for Cosmic Ray Research University of Tokyo Higashi-Mozumi, Kamioka Gifu 506-1205, Japan 1 Introduction We now recognize that neutrinos have #12;nite masses. In 1998, the Super-Kamiokande experiment found evidence for the atmospheric neutrino oscillation

  11. Neutrino seesaw mechanism with texture zeros

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    In the context of the Type I seesaw mechanism, we carry out a systematic study of the constraints that result from zeros in both the Dirac and right-handed Majorana neutrino mass matrices. We find that most constraints can be expressed in the standard form with one or two element/cofactor zeros alone, while there are 9 classes of nonstandard constraints. We show that all the constraints are stable under one-loop renormalization group running from the lightest right-handed neutrino mass scale to the electroweak scale. We study the predictions of the nonstandard constraints for the lightest neutrino mass, Dirac CP phase and neutrinoless double beta decay.

  12. Neutrino seesaw mechanism with texture zeros

    E-print Network

    Liao, Jiajun; Whisnant, K

    2015-01-01

    In the context of the Type I seesaw mechanism, we carry out a systematic study of the constraints that result from zeros in both the Dirac and right-handed Majorana neutrino mass matrices. We find that most constraints can be expressed in the standard form with one or two element/cofactor zeros alone, while there are 9 classes of nonstandard constraints. We show that all the constraints are stable under renormalization group running from the lightest right-handed neutrino mass scale to the electroweak scale. We study the predictions of the nonstandard constraints for the lightest neutrino mass, Dirac CP phase and neutrinoless double beta decay.

  13. Possible deviation from the tri-bimaximal neutrino mixing in a seesaw model

    SciTech Connect

    Kang, Sin Kyu; Xing Zhizhong; Zhou Shun

    2006-01-01

    We propose a simple but suggestive seesaw model with two phenomenological conjectures: three heavy (right-handed) Majorana neutrinos are degenerate in mass in the symmetry limit and three light Majorana neutrinos have the tri-bimaximal mixing pattern V{sub 0}. We show that a small mass splitting between the first generation and the other two generations of heavy Majorana neutrinos is responsible for the deviation of the solar neutrino mixing angle {theta}{sub 12} from its initial value 35.3 deg. given by V{sub 0}, and the slight breaking of the mass degeneracy between the second and third generations of heavy Majorana neutrinos results in a small mixing angle {theta}{sub 13} and a tiny departure of the atmospheric neutrino mixing angle {theta}{sub 23} from 45 deg. It turns out that a normal hierarchy of the light neutrino mass spectrum is favored in this seesaw scenario.

  14. Nearly degenerate neutrinos, Supersymmetry and radiative corrections

    E-print Network

    J. A. Casas; J. R. Espinosa; A. Ibarra; I. Navarro

    1999-05-18

    If neutrinos are to play a relevant cosmological role, they must be essentially degenerate with a mass matrix of the bimaximal mixing type. We study this scenario in the MSSM framework, finding that if neutrino masses are produced by a see-saw mechanism, the radiative corrections give rise to mass splittings and mixing angles that can accommodate the atmospheric and the (large angle MSW) solar neutrino oscillations. This provides a natural origin for the $\\Delta m^2_{sol} << \\Delta m^2_{atm}$ hierarchy. On the other hand, the vacuum oscillation solution to the solar neutrino problem is always excluded. We discuss also in the SUSY scenario other possible effects of radiative corrections involving the new neutrino Yukawa couplings, including implications for triviality limits on the Majorana mass, the infrared fixed point value of the top Yukawa coupling, and gauge coupling and bottom-tau unification.

  15. Tachyonic neutrinos and the neutrino masses

    E-print Network

    Robert Ehrlich

    2012-12-05

    With a recent claim of superluminal neutrinos shown to be in error, 2012 may not be a propitious time to consider the evidence that one or more neutrinos may indeed be tachyons. Nevertheless, there are a growing number of observations that continue to suggest this possibility -- albeit with an $m_{\

  16. Neutrino observations from the Sudbury Neutrino Observatory

    SciTech Connect

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

    2001-09-24

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

  17. Neutrino pair and gamma beams from circulating excited ions

    E-print Network

    Yoshimura, M

    2015-01-01

    We propose a new method of producing neutrino pair beam that consists of an equal mixture of neutrinos and anti-neutrinos of all flavors. The idea is based on a coherent neutrino pair emission from excited ions in circular motion. The proposed beam may provide an excellent opportunity of performing comprehensive CP violation experiments including measurement of all Majorana phases, test of CPT theorem, search for the sterile neutrino. High energy gamma ray much beyond the keV range may also be produced by a different choice of excited level.

  18. Scalar sextet in the 331 model with right-handed neutrinos

    SciTech Connect

    Nguyen Anh Ky; Nguyen Thi Hong Van

    2005-12-01

    A Higgs sextet is introduced in order to generate Dirac and Majorana neutrino masses in the 331 model with right-handed neutrinos. As will be seen the present sextet introduction leads to a rich neutrino mass structure. The smallness of neutrino masses can be achieved via, for example, a seesaw limit. The fact that the masses of the charged leptons are not effected by their new Yukawa couplings to the sextet is convenient for generating small neutrino masses.

  19. The Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Boger, J.; Hahn, R. L.; Rowley, J. K.; Carter, A. L.; Hollebone, B.; Kessler, D.; Blevis, I.; Dalnoki-Veress, F.; DeKok, A.; Farine, J.; Grant, D. R.; Hargrove, C. K.; Laberge, G.; Levine, I.; McFarlane, K.; Mes, H.; Noble, A. T.; Novikov, V. M.; O'Neill, M.; Shatkay, M.; Shewchuk, C.; Sinclair, D.; Clifford, E. T. H.; Deal, R.; Earle, E. D.; Gaudette, E.; Milton, G.; Sur, B.; Bigu, J.; Cowan, J. H. M.; Cluff, D. L.; Hallman, E. D.; Haq, R. U.; Hewett, J.; Hykawy, J. G.; Jonkmans, G.; Michaud, R.; Roberge, A.; Roberts, J.; Saettler, E.; Schwendener, M. H.; Seifert, H.; Sweezey, D.; Tafirout, R.; Virtue, C. J.; Beck, D. N.; Chan, Y. D.; Chen, X.; Dragowsky, M. R.; Dycus, F. W.; Gonzalez, J.; Isaac, M. C. P.; Kajiyama, Y.; Koehler, G. W.; Lesko, K. T.; Moebus, M. C.; Norman, E. B.; Okada, C. E.; Poon, A. W. P.; Purgalis, P.; Schuelke, A.; Smith, A. R.; Stokstad, R. G.; Turner, S.; Zlimen, I.; Anaya, J. M.; Bowles, T. J.; Brice, S. J.; Esch, E.-I.; Fowler, M. M.; Goldschmidt, A.; Hime, A.; McGirt, A. F.; Miller, G. G.; Teasdale, W. A.; Wilhelmy, J. B.; Wouters, J. M.; Anglin, J. D.; Bercovitch, M.; Davidson, W. F.; Storey, R. S.; Biller, S.; Black, R. A.; Boardman, R. J.; Bowler, M. G.; Cameron, J.; Cleveland, B.; Ferraris, A. P.; Doucas, G.; Heron, H.; Howard, C.; Jelley, N. A.; Knox, A. B.; Lay, M.; Locke, W.; Lyon, J.; Majerus, S.; Moorhead, M.; Omori, M.; Tanner, N. W.; Taplin, R. K.; Thorman, M.; Wark, D. L.; West, N.; Barton, J. C.; Trent, P. T.; Kouzes, R.; Lowry, M. M.; Bell, A. L.; Bonvin, E.; Boulay, M.; Dayon, M.; Duncan, F.; Erhardt, L. S.; Evans, H. C.; Ewan, G. T.; Ford, R.; Hallin, A.; Hamer, A.; Hart, P. M.; Harvey, P. J.; Haslip, D.; Hearns, C. A. W.; Heaton, R.; Hepburn, J. D.; Jillings, C. J.; Korpach, E. P.; Lee, H. W.; Leslie, J. R.; Liu, M.-Q.; Mak, H. B.; McDonald, A. B.; MacArthur, J. D.; McLatchie, W.; Moffat, B. A.; Noel, S.; Radcliffe, T. J.; Robertson, B. C.; Skensved, P.; Stevenson, R. L.; Zhu, X.; Gil, S.; Heise, J.; Helmer, R. L.; Komar, R. J.; Nally, C. W.; Ng, H. S.; Waltham, C. E.; Allen, R. C.; Bühler, G.; Chen, H. H.; Aardsma, G.; Andersen, T.; Cameron, K.; Chon, M. C.; Hanson, R. H.; Jagam, P.; Karn, J.; Law, J.; Ollerhead, R. W.; Simpson, J. J.; Tagg, N.; Wang, J.-X.; Alexander, C.; Beier, E. W.; Cook, J. C.; Cowen, D. F.; Frank, E. D.; Frati, W.; Keener, P. T.; Klein, J. R.; Mayers, G.; McDonald, D. S.; Neubauer, M. S.; Newcomer, F. M.; Pearce, R. J.; de Water, R. G. V.; Berg, R. V.; Wittich, P.; Ahmad, Q. R.; Beck, J. M.; Browne, M. C.; Burritt, T. H.; Doe, P. J.; Duba, C. A.; Elliott, S. R.; Franklin, J. E.; Germani, J. V.; Green, P.; Hamian, A. A.; Heeger, K. M.; Howe, M.; Drees, R. M.; Myers, A.; Robertson, R. G. H.; Smith, M. W. E.; Steiger, T. D.; Wechel, T. V.; Wilkerson, J. F.

    2000-07-01

    The Sudbury Neutrino Observatory is a second-generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.

  20. Nucleosynthesis and Neutrinos

    SciTech Connect

    Kajino, Toshitaka

    2011-05-06

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

  1. Mass determination of neutrinos

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1988-01-01

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

  2. Neutrinos from AGN

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  3. Neutrino Mass and Mixing in the Seesaw Playground

    E-print Network

    Stephen F. King

    2015-11-12

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

  4. Physics of Neutrino Oscillation

    E-print Network

    Mondal, Spandan

    2015-01-01

    The Standard Model of particle physics describes neutrinos as massless, chargeless elementary particles that come in three different flavours. However, recent experiments indicate that neutrinos not only have mass, but also have multiple mass eigenstates that are not identical to the flavour states, thereby indicating mixing. As an evidence of mixing, neutrinos have been observed to change from one flavour to another during their propagation, a phenomenon called neutrino oscillation. We have studied the reasons and derived the probabilities of neutrino flavour change, both in vacuum and in matter. We have also studied the parameters affecting this probability. We have discussed the special case of two-neutrino oscillations. Lastly, we have discussed some basic properties of neutrinos that are reflected in the previous derivations and highlighted a few relevant open problems. To begin with, we have also studied the relevant topics in introductory High Energy Physics and Quantum Mechanics to familiarize with th...

  5. Collective neutrino oscillations in supernovae

    SciTech Connect

    Duan, Huaiyu

    2014-06-24

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

  6. Phenomenology of Light Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Giunti, Carlo

    We consider the extension of standard three-neutrino mixing with the addition of one or two light sterile neutrinos which can explain the anomalies found in short-baseline neutrino oscillation experiments. We review the results of the global analyses of short-baseline neutrino oscillation data in 3 + 1, 3 + 2 and 3 + 1 + 1 neutrino mixing schemes.

  7. A New Neutrino Oscillation

    SciTech Connect

    Parke, Stephen J.; /Fermilab

    2011-07-01

    Starting in the late 1960s, neutrino detectors began to see signs that neutrinos, now known to come in the flavors electron ({nu}{sub e}), muon ({nu}{sub {mu}}), and tau ({nu}{sub {tau}}), could transform from one flavor to another. The findings implied that neutrinos must have mass, since massless particles travel at the speed of light and their clocks, so to speak, don't tick, thus they cannot change. What has since been discovered is that neutrinos oscillate at two distinct scales, 500 km/GeV and 15,000 km/GeV, which are defined by the baseline (L) of the experiment (the distance the neutrino travels) divided by the neutrino energy (E). Neutrinos of one flavor can oscillate into neutrinos of another flavor at both L/E scales, but the amplitude of these oscillations is different for the two scales and depends on the initial and final flavor of the neutrinos. The neutrino states that propogate unchanged in time, the mass eigenstates {nu}1, {nu}2, {nu}3, are quantum mechanical mixtures of the electron, muon, and tau neutrino flavors, and the fraction of each flavor in a given mass eigenstate is controlled by three mixing angles and a complex phase. Two of these mixing angles are known with reasonable precision. An upper bound exists for the third angle, called {theta}{sub 13}, which controls the size of the muon neutrino to electron neutrino oscillation at an L/E of 500 km/GeV. The phase is completely unknown. The existence of this phase has important implications for the asymmetry between matter and antimatter we observe in the universe today. Experiments around the world have steadily assembled this picture of neutrino oscillation, but evidence of muon neutrino to electron neutrino oscillation at 500 km/GeV has remained elusive. Now, a paper from the T2K (Tokai to Kamioka) experiment in Japan, reports the first possible observation of muon neutrinos oscillating into electron neutrinos at 500 km/GeV. They see 6 candidate signal events, above an expected background of 1.5 events. The probability that the 6 events are all background is only about 0.7%. Stated differently, this is a 2.7{sigma} indication that the parameter that controls the oscillation, the neutrino mixing angle {theta}{sub 13}, is nonzero, just shy of the 3{sigma} requirement to claim 'evidence for.' Nevertheless, this experiment provides the strongest indication to date that this oscillation actually occurs in nature.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  9. Effective Theories of Neutrino Masses

    NASA Astrophysics Data System (ADS)

    Gavela, M. B.

    2013-02-01

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

  10. High Energy Neutrino Astronomy and Neutrino Telescopes

    NASA Astrophysics Data System (ADS)

    Kouchner, A.

    2015-04-01

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

  11. Perspectives in Neutrino Physics: Monochromatic Neutrino Beams

    E-print Network

    J. Bernabeu; J. Burguet-Castell; C. Espinoza; M. Lindroos

    2005-12-22

    In the last few years spectacular results have been achieved with the demonstration of non vanishing neutrino masses and flavour mixing. The ultimate goal is the understanding of the origin of these properties from new physics. In this road, the last unknown mixing $[U_{e3}]$ must be determined. If it is proved to be non-zero, the possibility is open for Charge Conjugation-Parity (CP) violation in the lepton sector. This will require precision experiments with a very intense neutrino source. Here a novel method to create a monochromatic neutrino beam, an old dream for neutrino physics, is proposed based on the recent discovery of nuclei that decay fast through electron capture. Such nuclei will generate a monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We also show that the capacity of such a facility to discover new physics is impressive, so that fine tuning of the boosted neutrino energy allows precision measurements of the oscillation parameters even for a $[U_{e3}]$ mixing as small as 1 degree. We can thus open a window to the discovery of CP violation in neutrino oscillations.

  12. Neutrino masses, Majorons, and muon decay

    SciTech Connect

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

    1987-09-01

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

  13. Effects of degenerate sterile neutrinos on the supernova neutrino flux

    E-print Network

    P. Keranen; J. Maalampi; M. Myyrylainen; J. Riittinen

    2004-08-11

    We consider the possibility that there exist sterile neutrinos which are closely degenerate in mass with the active neutrinos and mixed with them. We investigate the effects of this kind of active-sterile neutrino mixing on the composition of supernova neutrino flux at the Earth. If an adiabatic MSW-transition between active and sterile neutrinos takes place, it could dramatically diminish the electron neutrino flux.

  14. MINOS Sterile Neutrino Search

    SciTech Connect

    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.

  15. SuperGZK neutrinos

    E-print Network

    V. Berezinsky

    2005-09-22

    The sources and fluxes of superGZK neutrinos, $E>10^{20}$ eV, are discussed. The fluxes of {\\em cosmogenic neutrinos}, i.e. those produced by ultra-high energy cosmic rays (UHECR) interacting with CMB photons, are calculated in the models, which give the good fit to the observed flux of UHECR. The best fit given in no-evolutionary model with maximum acceleration energy $E_{\\rm max}=1\\times 10^{21}$ eV results in very low flux of superGZK neutrinos an order of magnitude lower than the observed flux of UHECR. The predicted neutrino flux becomes larger and observable by next generation detectors at energies $10^{20} - 10^{21}$ eV in the evolutionary models with $E_{\\rm max}=1\\times 10^{23}$ eV. The largest cosmogenic neutrino flux is given in models with very flat generation spectrum, e.g. $\\propto E^{-2}$. The neutrino energies are naturally high in the models of {\\em superheavy dark matter and topological defects}. Their fluxes can also be higher than those of cosmogenic neutrinos. The largest fluxes are given by {\\em mirror neutrinos}, oscillating into ordinary neutrinos. Their fluxes obey some theoretical upper limit which is very weak, and in practice these fluxes are most efficiently limited now by observations of radio emission from neutrino-induced showers.

  16. Why Are Neutrinos Light? -- An Alternative

    SciTech Connect

    Hall, Lawrence J.; Oliver, Steven J.

    2004-09-23

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

  17. Majorana-Fermions, Their-Own Antiparticles, Following Non-Abelian Anyon/Semion Quantum-Statistics : Solid-State MEETS Particle Physics Neutrinos: Spin-Orbit-Coupled Superconductors and/or Superfluids to Neutrinos; Insulator-Heisenberg-Antiferromagnet MnF2 Majorana-Siegel-Birgenau-Keimer - Effect

    NASA Astrophysics Data System (ADS)

    Majorana-Fermi-Segre, E.-L.; Antonoff-Overhauser-Salam, Marvin-Albert-Abdus; Siegel, Edward Carl-Ludwig

    2013-03-01

    Majorana-fermions, being their own antiparticles, following non-Abelian anyon/semion quantum-statistics: in Zhang et.al.-...-Detwiler et.al.-...``Worlds-in-Collision'': solid-state/condensed-matter - physics spin-orbit - coupled topological-excitations in superconductors and/or superfluids -to- particle-physics neutrinos: ``When `Worlds' Collide'', analysis via Siegel[Schrodinger Centenary Symp., Imperial College, London (1987); in The Copenhagen-Interpretation Fifty-Years After the Como-Lecture, Symp. Fdns. Mod.-Phys., Joensu(1987); Symp. on Fractals, MRS Fall-Mtg., Boston(1989)-5-papers!!!] ``complex quantum-statistics in fractal-dimensions'', which explains hidden-dark-matter(HDM) IN Siegel ``Sephirot'' scenario for The Creation, uses Takagi[Prog.Theo.Phys. Suppl.88,1(86)]-Ooguri[PR D33,357(85)] - Picard-Lefschetz-Arnol'd-Vassil'ev[``Principia Read After 300 Years'', Not.AMS(1989); quantum-theory caveats comment-letters(1990); Applied Picard-Lefschetz Theory, AMS(2006)] - theorem quantum-statistics, which via Euler- formula becomes which via de Moivre- -formula further becomes which on unit-circle is only real for only, i.e, for, versus complex with imaginary-damping denominator for, i.e, for, such that Fermi-Dirac quantum-statistics for

  18. Neutrinos and collider physics

    NASA Astrophysics Data System (ADS)

    Deppisch, Frank F.; Bhupal Dev, P. S.; Pilaftsis, Apostolos

    2015-07-01

    We review the collider phenomenology of neutrino physics and the synergetic aspects at energy, intensity and cosmic frontiers to test the new physics behind the neutrino mass mechanism. In particular, we focus on seesaw models within the minimal setup as well as with extended gauge and/or Higgs sectors, and on supersymmetric neutrino mass models with seesaw mechanism and with R-parity violation. In the simplest type-I seesaw scenario with sterile neutrinos, we summarize and update the current experimental constraints on the sterile neutrino mass and its mixing with the active neutrinos. We also discuss the future experimental prospects of testing the seesaw mechanism at colliders and in related low-energy searches for rare processes, such as lepton flavor violation and neutrinoless double beta decay. The implications of the discovery of lepton number violation at the Large Hadron Collider for leptogenesis are also studied.

  19. Solar neutrino detection

    E-print Network

    Lino Miramonti

    2009-01-22

    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.

  20. Neutrino mass measurements.

    PubMed

    Wark, D L

    2003-11-15

    Before we can be sure we have a dark-matter problem we have to first be certain that no known particle can account for the missing matter. The last possibility has long been the neutrino, which, while massless in the Standard Model of particle physics, is the second most numerous particle in the Universe (after the photon) and thus (if massive) a potential source of substantial unaccounted for mass. Recent neutrino oscillation measurements have, in fact, confirmed that the Standard Model is incomplete and that neutrinos have mass. However, recent measurements have confirmed that the resulting mass is insufficient for neutrinos to make up the bulk of the dark matter. In fact, observations of the matter distribution in the Universe are now competing with laboratory measurements in their sensitivity to the absolute masses of neutrinos. The article discusses all these measurements and gives some guesses about where we may get in our measurements of neutrino masses in the future. PMID:14667316

  1. Spectroscopy of Solar Neutrinos

    E-print Network

    Michael Wurm; Franz von Feilitzsch; Marianne Goeger-Neff; Tobias Lachenmaier; Timo Lewke; Quirin Meindl; Randoplh Moellenberg; Lothar Oberauer; Walter Potzel; Marc Tippmann; Christoph Traunsteiner; Juergen Winter

    2010-04-06

    In the last years, liquid-scintillator detectors have opened a new window for the observation of low-energetic astrophysical neutrino sources. In 2007, the solar neutrino experiment Borexino began its data-taking in the Gran Sasso underground laboratory. High energy resolution and excellent radioactive background conditions in the detector allow the first-time spectroscopic measurement of solar neutrinos in the sub-MeV energy regime. The experimental results of the Beryllium-7 neutrino flux measurements as well as the prospects for the detection of solar Boron-8, pep and CNO neutrinos are presented in the context of the currently discussed ambiguities in solar metallicity. In addition, the potential of the future SNO+ and LENA experiments for high-precision solar neutrino spectroscopy will be outlined.

  2. Paradoxes of neutrino oscillations

    SciTech Connect

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

    2009-08-15

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

  3. Neutrino Oscillation Studies with Reactors

    E-print Network

    Petr Vogel; Liangjian Wen; Chao Zhang

    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 flavors 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 $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  4. Novel Ideas for Neutrino Beams

    SciTech Connect

    Peach, Ken

    2007-04-23

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

  5. Neutrino oscillation studies with reactors

    PubMed Central

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

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle ?13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  6. Neutrino Oscillation Studies with Reactors

    E-print Network

    Vogel, Petr; Zhang, Chao

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors 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 $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  7. Neutrino oscillation studies with reactors

    SciTech Connect

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

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle ?13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  8. Neutrino oscillation studies with reactors

    DOE PAGESBeta

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

    2015-04-27

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle ?13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  9. Neutrino oscillation studies with reactors.

    PubMed

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

    2015-01-01

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle ?13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819

  10. Neutrinos in Cosmology

    SciTech Connect

    Wong, Yvonne Y. Y.

    2008-01-24

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

  11. Neutrino mass anarchy

    PubMed

    Hall; Murayama; Weiner

    2000-03-20

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

  12. Neutrino Mass Anarchy

    NASA Astrophysics Data System (ADS)

    Hall, Lawrence; Murayama, Hitoshi; Weiner, Neal

    2000-03-01

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

  13. Neutrinos: Nature's Ghosts?

    ScienceCinema

    Lincoln, Don

    2014-08-12

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

  14. Neutrinos: Nature's Ghosts?

    SciTech Connect

    Lincoln, Don

    2013-06-18

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

  15. High intensity neutrino beams

    NASA Astrophysics Data System (ADS)

    Ichikawa, A. K.

    2015-07-01

    High-intensity proton accelerator complex enabled long baseline neutrino oscillation experiments with a precisely controlled neutrino beam. The beam power so far achieved is a few hundred kW with enourmorous efforts of accelerator physicists and engineers. However, to fully understand the lepton mixing structure, MW-class accelerators are desired. We describe the current intensity-frontier high-energy proton accelerators, their plans to go beyond and technical challenges in the neutrino beamline facilities.

  16. Nucleosynthesis Limits on the Mass of Long Lived Tau and Muon Neutrinos

    E-print Network

    Brian D. Fields; Kimmo Kainulainen; Keith A. Olive

    1995-12-15

    We compute the nucleosynthesis bounds on the masses of stable Dirac and Majorana neutrinos by solving an evolution equation network comprising of all neutrino species which in the Dirac case includes different helicity states as separate species. We will not commit ourselves to any particular value of the nucleosynthesis bound on effective number of light neutrino degrees of freedom $N_\

  17. Short review on solar neutrinos experiments and search for sterile neutrinos with solar neutrino detectors

    NASA Astrophysics Data System (ADS)

    Pallavicini, Marco

    2015-05-01

    The spectroscopy of solar neutrinos is now entering the precision era, after a golden age which has led to the discovery of neutrino oscillations and the MSW effect. In this paper we summarise the current experimental knowledge in the field and its future perspectives, showing that solar neutrino detectors are and will remain a crucial tool for a deeper understanding of stars, neutrinos, and fundamental physics. We also show that solar neutrinos may become pivotal for the search of sterile neutrinos.

  18. Compact neutrino source

    NASA Astrophysics Data System (ADS)

    LoSecco, John

    2015-08-01

    Some evidence for sterile neutrinos has been found in short baseline observations where the measured neutrino flux did not agree with expectations. Systematic uncertainties from the expected values have limited the sensitivity of this approach. Observation at multiple distances can remove the normalization uncertainty by isolating the distance dependence. This does not work for high-? m2 sterile neutrinos since they are fully mixed at most observation distances and only shift the normalization of the flux. A compact intense source of neutrinos based on a subcritical fission reactor would permit observation of oscillations on submeter distance scales and clearly distinguish between a systematic normalization and the L /E dependence expected from oscillations.

  19. Atmospheric Sterile Neutrinos

    E-print Network

    Takehiko Asaka; Atsushi Watanabe

    2012-07-17

    We study production of sterile neutrinos in the atmosphere and their detection at Super-Kamiokande. A sterile neutrino in the mass range $1\\,{\\rm MeV} \\lesssim M_N \\lesssim 105\\,{\\rm MeV}$ is produced by muon or pion decay, and decays to an electron-positron pair and an active neutrino. Such a decay of the sterile neutrino leaves two electron-like Cherenkov rings in the detector. We estimate the sterile neutrino flux from the well-established active neutrino fluxes and study the number of the decay events in the detector. The upper bounds for the active-sterile mixings are obtained by comparing the $2e$-like events from the sterile neutrino decays and the observed data by Super-Kamiokande. The upper bound for the muon type mixing $\\Theta_\\mu$ is found to be $|\\Theta_\\mu|^2 \\lesssim 5 \\times 10^{-5}$ for $20 \\,{\\rm MeV} \\lesssim M_N \\lesssim 80\\,{\\rm MeV}$, which is significantly loosened compared to the previous estimation. We demonstrate that the opening angle and the total energy of the rings may serve as diagnostic tools to discover the sterile neutrinos in further data accumulation and future upgraded facilities. The directional asymmetry of the events is a sensitive measure of the diminishment of the sterile neutrino flux due to the decays on the way to the detector.

  20. Neutrino-nucleus interactions

    SciTech Connect

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

    2011-01-01

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

  1. Neutrinos in supernovae

    SciTech Connect

    Cooperstein, J.

    1986-10-01

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

  2. Bolometric detection of neutrinos

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  3. Generating $?_{13}$ from sterile neutrinos in $?- ?$ symmetric models

    E-print Network

    Diana C. Rivera-Agudelo; Abdel Pérez-Lorenzana

    2015-10-07

    The smallness of the $\\theta_{13}$ mixing angle as observed in neutrino oscillation experiments can be understood through an approximated $\\mu - \\tau$ exchange symmetry in the neutrino mass matrix. Using recent oscillation neutrino data, but assuming no \\textit{CP} violation, we study $\\mu-\\tau$ breaking parameter space to establish the conditions under which such a breaking could have a perturbative origin. According to the so-obtained conditions, we suggest that a sterile neutrino, matching LSND/MiniBooNE neutrino oscillation results, could provide the necessary ingredients to properly fix atmospheric and $\\theta_{13}$ mixing angles to observable values, without exceeding the sterile neutrino fraction bound in solar oscillations. In such a scenario, we analyze the general effect of a fourth neutrino on the prediction for the effective $m_{ee}$ majorana mass parameter.

  4. Generating ?13 from sterile neutrinos in ? -? symmetric models

    NASA Astrophysics Data System (ADS)

    Rivera-Agudelo, Diana C.; Pérez-Lorenzana, Abdel

    2015-10-01

    The smallness of the ?13 mixing angle as observed in neutrino oscillation experiments can be understood through an approximated ? -? exchange symmetry in the neutrino mass matrix. Using recent oscillation neutrino data, but assuming no C P violation, we study ? -? breaking parameter space to establish the conditions under which such a breaking could have a perturbative origin. According to the so-obtained conditions, we suggest that a sterile neutrino, matching LSND/MiniBooNE neutrino oscillation results, could provide the necessary ingredients to properly fix atmospheric and ?13 mixing angles to observable values, without exceeding the sterile neutrino fraction bound in solar oscillations. In such a scenario, we analyze the general effect of a fourth neutrino on the prediction for the effective me e majorana mass parameter.

  5. Simplest Neutrino Mixing from S4 Symmetry

    E-print Network

    R. Krishnan; P. F. Harrison; W. G. Scott

    2013-03-28

    In 2004, two of us proposed a texture, the "Simplest" neutrino mass matrix, which predicted sin(theta13)=sqrt((2 Solar-Delta m^2)/(3 Atm-Delta m^2)) and delta_CP=90 degrees. Using today's measured values for neutrino mass-squared differences, this prediction gives sin^2(theta13)~0.086+0.003-0.006, compared with a measured value, found by averaging the results of the Daya Bay and RENO experiments, of sin^2(theta13)=0.093+0.010-0.010. Here we present a specific model based on S4 symmetry leading to this successful texture in the context of the type-1 see-saw mechanism, assuming Majorana neutrinos. In this case, slightly different predictions are obtained relating theta13 to the light neutrino masses, which are in accord with current experimental limits and testable at future experiments. Large CP asymmetries remain a generic prediction of the texture.

  6. Diagnostic potential of cosmic-neutrino absorption spectroscopy

    SciTech Connect

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

    2004-12-01

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

  7. Constraint on the heavy sterile neutrino mixing angles in the SO(10) model with double see-saw mechanism

    E-print Network

    Takeshi Fukuyama; Tatsuru Kikuchi; Koichi Matsuda

    2008-04-22

    Constraints on the heavy sterile neutrino mixing angles are studied in the framework of a minimal supersymmetric ${\\rm SO}(10)$ model with {\\it double see-saw mechanism}. A new singlet matter in addition to the right-handed neutrinos is introduced to realize the double see-saw mechanism. The minimal ${\\rm SO}(10)$ model gives an unambiguous Dirac neutrino mass matrix, which enables us to predict the masses and the mixing angles in the enlarged $9 \\times 9$ neutrino mass matrix. Mixing angles between the light Majorana neutrinos and the heavy sterile neutrinos are shown to be within the LEP experimental bound on all ranges of the Majorana phases.

  8. Extremely high energy cosmic neutrinos and relic neutrinos

    SciTech Connect

    Quigg, Chris; /Fermilab /CERN

    2006-03-01

    I review the essentials of ultrahigh-energy neutrino interactions, show how neutral-current detection and flavor tagging can enhance the scientific potential of neutrino telescopes, and sketch new studies on neutrino encounters with dark matter relics and on gravitational lensing of neutrinos.

  9. Neutrino propagation in media: Flavor-, helicity-, and pair correlations

    E-print Network

    A. Kartavtsev; G. Raffelt; H. Vogel

    2015-06-17

    Neutrinos propagating in media (matter and electromagnetic fields) undergo flavor and helicity oscillations, where helicity transitions are instigated both by electromagnetic fields and matter currents. In addition, it has been shown that correlations between neutrinos and antineutrinos of opposite momentum can build up in anisotropic media. We re-derive the neutrino equations of motion in the mean-field approximation for homogeneous yet anisotropic media, confirming previous results except for a small correction in the Majorana case. Furthermore, we derive the mean-field Hamiltonian induced by neutrino electromagnetic interactions. We also provide a phenomenological discussion of pair correlations in comparison with helicity correlations.

  10. Neutrino-antineutrino correlations in dense anisotropic media

    E-print Network

    Julien Serreau; Cristina Volpe

    2015-01-08

    We derive the most general evolution equations describing in-medium (anti)neutrino propagation in the mean-field approximation. In particular, we consider various types of neutrino-antineutrino mixing, for both Dirac and Majorana fields, resulting either from nontrivial pair correlations or from helicity coherence due to the nonvanishing neutrino masses. We show that, unless the medium is spatially homogeneous and isotropic, these correlations are sourced by the usual neutrino and antineutrino densities. This may be of importance in astrophysical environments such as core-collapse supernovae.

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

    SciTech Connect

    Serpico, Pasquale D.; /Fermilab

    2007-01-01

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

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

    SciTech Connect

    Serpico, Pasquale D.

    2007-04-27

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

  13. Physics of neutrino flavor transformation through matter-neutrino resonances

    NASA Astrophysics Data System (ADS)

    Wu, Meng-Ru; Duan, Huaiyu; Qian, Yong-Zhong

    2016-01-01

    In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.

  14. Neutrino Counter Nuclear Weapon

    E-print Network

    Tang, Alfred

    2008-01-01

    Radiations produced by neutrino-antineutrino annihilation at the Z0 pole can be used to heat up the primary stage of a thermonuclear warhead and can in principle detonate the device remotely. Neutrino-antineutrino annihilation can also be used as a tactical assault weapon to target hideouts that are unreachable by conventional means.

  15. Neutrino Counter Nuclear Weapon

    E-print Network

    Alfred Tang

    2013-06-25

    Radiations produced by neutrino-antineutrino annihilation at the Z0 pole can be used to heat up the primary stage of a thermonuclear warhead and can in principle detonate the device remotely. Neutrino-antineutrino annihilation can also be used as a tactical assault weapon to target hideouts that are unreachable by conventional means.

  16. Update on Atmospheric Neutrinos

    E-print Network

    M. C. Gonzalez-Garcia; H. Nunokawa; O. L. G. Peres; T. Stanev; J. W. F. Valle

    1998-01-20

    We discuss the impact of recent experimental results on the determination of atmospheric neutrino oscillation parameters. We use all published results on atmospheric neutrinos, including the preliminary large statistics data of Super-Kamiokande. We re-analyze the data in terms of both $\

  17. Hierarchically Acting Sterile Neutrinos

    E-print Network

    Chian-Shu Chen; Ryo Takahashi

    2011-12-09

    We propose that a hierarchical spectrum of sterile neutrinos (eV, keV, $10^{13-15}$ GeV) is considered to as the explanations for MiniBooNE and LSND oscillation anomalies, dark matter, and baryon asymmetry of the universe (BAU) respectively. The scenario can also realize the smallness of active neutrino masses by seesaw mechanism.

  18. Neutrinos for Peace

    NASA Astrophysics Data System (ADS)

    Cribier, M.

    2015-04-01

    The fundamental knowledge on neutrinos acquired in the recent years open the possibility of applied neutrino physics. Among it the automatic and non intrusive monitoring of nuclear reactor by its antineutrino signal could be very valuable to IAEA in charge of the control of nuclear power plants. Several efforts worldwide have already started.

  19. The Sudbury Neutrino Observatory

    SciTech Connect

    Hime, A.

    1996-09-01

    A report is given on the status of the Sudbury Neutrino Observatory, presently under construction in the Creighton nickel mine near Sudbury, Ontario in Canada. Focus is upon the technical factors involving a measurement of the charged-current and neutral-current interactions of solar neutrinos on deuterium.

  20. Neutrino quantum kinetic equations

    NASA Astrophysics Data System (ADS)

    Volpe, Cristina

    2015-09-01

    Neutrinos propagate in astrophysical and cosmological environments modifying their flavor in intriguing ways. The study of neutrino propagation in media is based on the mean-field, extended mean-field and Boltzmann equations. We summarize salient features of these evolution equations and the methods employed so far to derive them. We emphasize applications to situations of observational interest.

  1. Muon and neutrino fluxes

    NASA Technical Reports Server (NTRS)

    Edwards, P. G.; Protheroe, R. J.

    1985-01-01

    The result of a new calculation of the atmospheric muon and neutrino fluxes and the energy spectrum of muon-neutrinos produced in individual extensive air showers (EAS) initiated by proton and gamma-ray primaries is reported. Also explained is the possibility of detecting atmospheric nu sub mu's due to gamma-rays from these sources.

  2. Reactor Monitoring with Neutrinos

    E-print Network

    M. Cribier

    2007-04-06

    The fundamental knowledge on neutrinos acquired in the recent years open the possibility of applied neutrino physics. Among it the automatic and non intrusive monitoring of nuclear reactor by its antineutrino signal could be very valuable to IAEA in charge of the control of nuclear power plants. Several efforts worldwide have already started.

  3. Interplay between neutrino magnetic moments and $CP$ violating phases in left-right models

    E-print Network

    D. Delepine; H. Novales-Sánchez

    2015-11-18

    We revisit the neutrino magnetic moments (MMs) in the left-right model with non-manifest symmetry. After deriving an expression in terms of the Dirac and Majorana phases, we analyze the sensitivity of neutrino MMs to these $CP$-violating phases in two scenarios: 1) a maximal right mixing in which left- and right-handed neutrinos are mixed by the same matrix; and 2) a right-handed neutrino mixing whose off-diagonal entries are much smaller than the elements in the diagonal, but where the $CP$ phases remain general. Our results show that, even though certain values of the Majorana phases can eliminate neutrino MMs, the presence of a maximal $CP$-violating phase in neutrino mixing matrix, as favored by the discrepancy between T2K results and reactor measurements in neutrino oscillations, requires that at least one neutrino have a large nonzero MM.

  4. Interplay between neutrino magnetic moments and C P violating phases in left-right models

    NASA Astrophysics Data System (ADS)

    Delepine, D.; Novales-Sánchez, H.

    2015-11-01

    We revisit the neutrino magnetic moments (MMs) in the left-right model with nonmanifest symmetry. After deriving an expression in terms of the Dirac and Majorana phases, we analyze the sensitivity of neutrino MMs to these C P -violating phases in two scenarios: (1) a maximal right mixing in which left- and right-handed neutrinos are mixed by the same matrix, and (2) a right-handed neutrino mixing whose off diagonal entries are much smaller than the elements in the diagonal, but where the C P phases remain general. Our results show that, even though certain values of the Majorana phases can eliminate neutrino MMs, the presence of a maximal C P -violating phase in neutrino mixing matrix, as favored by the discrepancy between T2K results and reactor measurements in neutrino oscillations, requires that at least one neutrino have a large nonzero MM.

  5. Sterile neutrino signals from supernovae

    E-print Network

    P. Keränen; J. Maalampi; M. Myyryläinen; J. Riittinen

    2007-11-22

    We investigate the effects of a mixing of active and sterile neutrinos on the ratios of supernova electron neutrino flux ($F_e$) and antineutrino flux ($F_{\\bar e}$) to the total flux of the other neutrino and antineutrino flavours ($F_a$). We assume that the heaviest (in the normal hierarchy) Standard Model neutrino $\

  6. Neutrino in standard model and beyond

    NASA Astrophysics Data System (ADS)

    Bilenky, S. M.

    2015-07-01

    After discovery of the Higgs boson at CERN the Standard Model acquired a status of the theory of the elementary particles in the electroweak range (up to about 300 GeV). What general conclusions can be inferred from the Standard Model? It looks that the Standard Model teaches us that in the framework of such general principles as local gauge symmetry, unification of weak and electromagnetic interactions and Brout-Englert-Higgs spontaneous breaking of the electroweak symmetry nature chooses the simplest possibilities. Two-component left-handed massless neutrino fields play crucial role in the determination of the charged current structure of the Standard Model. The absence of the right-handed neutrino fields in the Standard Model is the simplest, most economical possibility. In such a scenario Majorana mass term is the only possibility for neutrinos to be massive and mixed. Such mass term is generated by the lepton-number violating Weinberg effective Lagrangian. In this approach three Majorana neutrino masses are suppressed with respect to the masses of other fundamental fermions by the ratio of the electroweak scale and a scale of a lepton-number violating physics. The discovery of the neutrinoless double ?-decay and absence of transitions of flavor neutrinos into sterile states would be evidence in favor of the minimal scenario we advocate here.

  7. Neutrinos, WMAP, and BBN

    E-print Network

    Lawrence M. Krauss; Cecilia Lunardini; Christel Smith

    2010-11-18

    New data from WMAP have appeared, related to both the fractional energy density in relativistic species at decoupling and also the primordial helium abundance, at the same time as other independent observational estimates suggest a higher value of the latter than previously estimated. All the data are consistent with the possibility that the effective number of relativistic species in the radiation gas at the time of Big Bang Nucleosynthesis may exceed the value of 3, as expected from a CP-symmetric population of the known neutrino species. Here we explore the possibility that new neutrino physics accounts for such an excess. We explore different realizations, including neutrino asymmetry and new neutrino species, as well as their combination, and describe how existing constraints on neutrino physics would need to be relaxed as a result of the new data, as well as possible experimental tests of these possibilities.

  8. Solar Neutrino Physics

    SciTech Connect

    Bowles, T.J.; Brice, S.J.; Esch, E.-I.; Fowler, M.M.; Goldschmidt, A.; Hime, A.; McGirt, F.; Miller, G.G.; Thornewell, P.M.; Wilhelmy, J.B.; Wouters, J.M.

    1999-07-15

    With its heavy water target, the Sudbury Neutrino Observatory (SNO) offers the unique opportunity to measure both the 8B flux of electron neutrinos from the Sun and, independently, the flux of all active neutrino species reaching the Earth. A model-independent test of the hypothesis that neutrino oscillations are responsible for the observed solar neutrino deficit can be made by comparing the charged-current (CC) and neutral-current (NC) rates. This LDRD proposal supported the research and development necessary for an assessment of backgrounds and performance of the SNO detector and the ability to extract the NC/CC-Ratio. Particular emphasis is put upon the criteria for deployment and signal extraction from a discrete NC detector array based upon ultra-low background 3He proportional counters.

  9. Neutrinos and dark matter

    NASA Astrophysics Data System (ADS)

    Ibarra, Alejandro

    2015-07-01

    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.

  10. Neutrino Mixing from CP Symmetry

    E-print Network

    Peng Chen; Chang-Yuan Yao; Gui-Jun Ding

    2015-07-13

    The neutrino mass matrix has remnant CP symmetry expressed in terms of the lepton mixing matrix, and vice versa the remnant CP transformations allow us to reconstruct the mixing matrix. We study the scenario that all the four remnant CP transformations are preserved by the neutrino mass matrix. The most general parameterization of remnant CP transformations is presented. The lepton mixing matrix is completely fixed by the remnant CP, and its explicit form is derived. The necessary and sufficient condition for conserved Dirac CP violating phase is found. If the Klein four flavor symmetry generated by the postulated remnant CP transformations arises from a finite flavor symmetry group, the phenomenologically viable lepton flavor mixing would be the trimaximal pattern, both Dirac CP phase $\\delta_{CP}$ and Majorana phase $\\alpha_{31}$ are either $0$ or $\\pi$ while another Majorana phase $\\alpha_{21}$ is a rational multiple of $\\pi$. These general results are confirmed to be true in the case that the finite flavor symmetry group is $\\Delta(6n^2)$.

  11. Neutrinoless double beta decay and neutrino masses

    SciTech Connect

    Duerr, Michael

    2012-07-27

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

  12. Electromagnetic properties of neutrinos in a medium

    SciTech Connect

    Nieves, J.F. ); Pal, P.B.

    1989-09-01

    We show that, contrary to the situation in the vacuum, a Majorana neutrino can have electric and magnetic dipole moments in a medium. This is because of new contributions, equal for a particle and its antiparticle, that can arise only in a material background. For Dirac neutrinos, these contributions make the magnitudes of the dipole moments of the particle and the antiparticle unequal. We discuss the conditions which give rise to such effects, with particular attention to the role played by the discrete symmetries {ital C}, {ital P}, and {ital T}.

  13. Zero minors of the neutrino mass matrix

    SciTech Connect

    Lashin, E. I.; Chamoun, N.

    2008-10-01

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

  14. Neutrino-neutrino interactions in a supernova and their effect on neutrino flavor conversions

    SciTech Connect

    Dighe, Amol

    2011-11-23

    The neutrino-neutrino interactions inside a supernova core give rise to nonlinear collective effects that significantly influence the neutrino flavor conversions inside the star. I shall describe these interactions, the new oscillation phenomena they generate, and their effect on the neutrino fluxes arriving at the earth.

  15. New Physics and Neutrino Oscillation

    NASA Astrophysics Data System (ADS)

    Ochman, M.; Szafron, R.; Zralek, M.

    2011-08-01

    Description of neutrino oscillation in the case of Non-Standard neutrino Interaction (NSI) is briefly presented. The NSI causes the entanglement between internal degrees of freedom of neutrinos (mass, spin, flavour) and other accompanying particles in the production and detection processes. In such case neutrinos are mostly in the mixed states. Role of the density matrix in description of neutrino oscillation process is shortly explained.

  16. Phenomenology of Light Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Laveder, Marco; Giunti, Carlo

    2015-07-01

    After a short review of the current status of standard three-neutrino mixing, we consider its extension with the addition of one or two light sterile neutrinos which can explain the anomalies found in short-baseline neutrino oscillation experiments. We review the results of the global analyses of short-baseline neutrino oscillation data in 3+1, 3+2 and 3+1+1 neutrino mixing schemes.

  17. Coherent scattering of cosmic neutrinos

    NASA Technical Reports Server (NTRS)

    Opher, R.

    1974-01-01

    It is shown that cosmic neutrino scattering can be non-negligible when coherence effects previously neglected are taken into account. The coherent neutrino scattering cross section is derived and the neutrino index of refraction evaluated. As an example of coherent neutrino scattering, a detector using critical reflection is described which in principle can detect the low energy cosmic neutrino background allowed by the measured cosmological red shift.

  18. Topics in neutrino astrophysics

    NASA Astrophysics Data System (ADS)

    Chan, Man Ho

    2009-06-01

    In this thesis, we investigate observable consequences of active and sterile neutrinos, in galactic, cluster, and cosmological scales. We assume that sterile neutrinos with masses of order 10's eV, 10's keV, and MeV were formed by oscillation of active neutrinos in the early universe. If sterile neutrinos with mass ~ 30 eV exist, they affect the structure of galaxies and explain the flatness of their rotation curves. Also, the existence of decaying sterile neutrinos with mass 16 -- 18 keV and decay rate G = (5 ± 1) × 10^-17 s -1 can simultaneously be the cause of heating at the Milky Way center, the supermassive blackhole mass and velocity dispersion relation, the lack of cooling flow in clusters, and reionization in the universe. Lastly, we make of the observed 511 keV annihilation flux line at the Milky Way center to constrain properties of sterile neutrinos of MeV mass scale. We also derive a relation among several cluster observables assuming the existence of an active neutrino halo, which agrees with the observational data in 103 clusters.

  19. Physics of Neutrino Oscillation

    E-print Network

    Spandan Mondal

    2015-11-20

    The Standard Model of particle physics describes neutrinos as massless, chargeless elementary particles that come in three different flavours. However, recent experiments indicate that neutrinos not only have mass, but also have multiple mass eigenstates that are not identical to the flavour states, thereby indicating mixing. As an evidence of mixing, neutrinos have been observed to change from one flavour to another during their propagation, a phenomenon called neutrino oscillation. We have studied the reasons and derived the probabilities of neutrino flavour change, both in vacuum and in matter. We have also studied the parameters affecting this probability. We have discussed the special case of two-neutrino oscillations. Lastly, we have discussed some basic properties of neutrinos that are reflected in the previous derivations and highlighted a few relevant open problems. To begin with, we have also studied the relevant topics in introductory High Energy Physics and Quantum Mechanics to familiarize with the notations, units and methodologies that would be required for the subsequent topics.

  20. Conformal Neutrinos: an Alternative to the See-saw Mechanism

    E-print Network

    Gero von Gersdorff; Mariano Quiros

    2009-02-19

    We analyze a scenario where the right-handed neutrinos make part of a strongly coupled conformal field theory and acquire an anomalous dimension \\gammaconformal invariance. We derive an upper bound on \\gamma from loop-induced flavor changing neutral currents. Neutrino Yukawa couplings can be sizable at electroweak scales and therefore the invisible decay of the Higgs in the neutrino channel can be comparable to the c\\bar c and \\tau\\bar\\tau modes and predict interesting Higgs phenomenology. If lepton number is violated in the conformal theory an irrelevant Majorana mass operator for right-handed neutrinos appears for \\gamma>1/2 giving rise to an inverse see-saw mechanism. In this case light sterile neutrinos do appear and neutrino oscillation experiments are able to probe our model.

  1. Thermal and non-thermal leptogenesis in different neutrino mass models with tribimaximal mixings

    E-print Network

    N. Nimai Singh; H. Zeen Devi; Amal Kr Sarma

    2008-07-15

    In the present work we study both thermal and non-thermal leptogenesis in all neutrino mass models describing the presently available neutrino mass patterns. We consider the Majorana CP violating phases coming from right-handed Majorana mass matrices to estimate the baryon asymmetry of the universe, for different neutrino mass models namely degenerate, inverted hierarchical and normal hierarchical models, with tribimaximal mixings. Considering two possible diagonal forms of Dirac neutrino mass matrix as either charged lepton or up-quark mass matrix, the right-handed Majorana mass matrices are constructed from the light neutrino mass matrix through the inverse seesaw formula. Only the normal hierarchical model leads to the best predictions for baryon asymmetry of the universe, consistent with observations in both thermal and non-thermal leptogenesis scenario. The analysis though phenomenological may serve as an additional information in the discrimination among the presently available neutrino mass models.

  2. Solar mass-varying neutrino oscillations

    E-print Network

    Marfatia, Danny; Huber, P.; Barger, V.

    2005-11-18

    We propose that the solar neutrino deficit may be due to oscillations of mass-varying neutrinos (MaVaNs). This scenario elucidates solar neutrino data beautifully while remaining comfortably compatible with atmospheric neutrino and K2K data...

  3. Neutrino time travel

    E-print Network

    James Dent; Heinrich Päs; Sandip Pakvasa; Thomas J. Weiler

    2007-12-09

    We discuss causality properties of extra-dimensional theories allowing for effectively superluminal bulk shortcuts. Such shortcuts for sterile neutrinos have been discussed as a solution to the puzzling LSND and MiniBooNE neutrino oscillation results. We focus here on the sub-category of asymmetrically warped brane spacetimes and argue that scenarios with two extra dimensions may allow for timelike curves which can be closed via paths in the extra-dimensional bulk. In principle sterile neutrinos propagating in the extra dimension may be manipulated in a way to test the chronology protection conjecture experimentally.

  4. Low Energy Neutrino Measurements

    E-print Network

    D'Angelo, Davide

    2012-01-01

    Low Energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND experiments as well as from upcoming (SNO+) and planned (LENA) experiments. Scintillator neutrino detectors are also powerful antineutrino detectors such as those emitted by the Earth crust and mantle. First measurements of geo-neutrinos have occurred and can bring fundamental contribution in understanding the geophysics of the planet.

  5. Low Energy Neutrino Measurements

    E-print Network

    Davide D'Angelo

    2012-11-22

    Low Energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND experiments as well as from upcoming (SNO+) and planned (LENA) experiments. Scintillator neutrino detectors are also powerful antineutrino detectors such as those emitted by the Earth crust and mantle. First measurements of geo-neutrinos have occurred and can bring fundamental contribution in understanding the geophysics of the planet.

  6. Submarine neutrino communication

    E-print Network

    Patrick Huber

    2010-08-20

    We discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

  7. Submarine neutrino communication

    E-print Network

    Huber, Patrick

    2009-01-01

    We discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

  8. The AMANDA Neutrino Telescope

    E-print Network

    F. Halzen; for the AMANDA Collaboration

    1998-09-23

    With an effective telescope area of order $10^4$ m$^2$ for TeV neutrinos, a threshold near $\\sim$50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.

  9. Neutrinos: Nature's Identity Thieves?

    SciTech Connect

    Dr. Don Lincoln

    2013-07-11

    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.

  10. Neutrinos from neutron stars

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.

    1979-01-01

    A calculation of the flux of ultra-high energy neutrinos from galactic neutron stars is presented. The calculation is used to determine the number of point sources detectable at the sensitivity threshold of a proposed deep underwater muon and neutrino detector array. The detector array would have a point source detection threshold of about 100 eV/sq cm-sec. Analysis of neutrino luminosities and the number of detectable sources suggests that the deep underwater detector may make a few discoveries. In particular, a suspected neutron star in the Cyg X-3 source seems a promising target for the deep underwater array.

  11. Neutrinos: Nature's Identity Thieves?

    ScienceCinema

    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.

  12. Neutrinos: Nature's Identity Thieves?

    ScienceCinema

    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.

  13. Probing nonstandard neutrino interactions with supernova neutrinos

    NASA Astrophysics Data System (ADS)

    Esteban-Pretel, A.; Tomàs, R.; Valle, J. W. F.

    2007-09-01

    We analyze the possibility of probing nonstandard neutrino interactions (NSI, for short) through the detection of neutrinos produced in a future galactic supernova (SN). We consider the effect of NSI on the neutrino propagation through the SN envelope within a three-neutrino framework, paying special attention to the inclusion of NSI-induced resonant conversions, which may take place in the most deleptonized inner layers. We study the possibility of detecting NSI effects in a Megaton water Cherenkov detector, either through modulation effects in the ?¯e spectrum due to (i) the passage of shock waves through the SN envelope, (ii) the time dependence of the electron fraction, and (iii) the Earth matter effects; or, finally, through the possible detectability of the neutronization ?e burst. We find that the ?¯e spectrum can exhibit dramatic features due to the internal NSI-induced resonant conversion. This occurs for nonuniversal NSI strengths of a few %, and for very small flavor-changing NSI above a few×10-5.

  14. Probing nonstandard neutrino interactions with supernova neutrinos

    SciTech Connect

    Esteban-Pretel, A.; Tomas, R.; Valle, J. W. F.

    2007-09-01

    We analyze the possibility of probing nonstandard neutrino interactions (NSI, for short) through the detection of neutrinos produced in a future galactic supernova (SN). We consider the effect of NSI on the neutrino propagation through the SN envelope within a three-neutrino framework, paying special attention to the inclusion of NSI-induced resonant conversions, which may take place in the most deleptonized inner layers. We study the possibility of detecting NSI effects in a Megaton water Cherenkov detector, either through modulation effects in the {nu}{sub e} spectrum due to (i) the passage of shock waves through the SN envelope, (ii) the time dependence of the electron fraction, and (iii) the Earth matter effects; or, finally, through the possible detectability of the neutronization {nu}{sub e} burst. We find that the {nu}{sub e} spectrum can exhibit dramatic features due to the internal NSI-induced resonant conversion. This occurs for nonuniversal NSI strengths of a few %, and for very small flavor-changing NSI above a fewx10{sup -5}.

  15. Light WIMPs And Equivalent Neutrinos

    E-print Network

    Gary Steigman; Kenneth M. Nollett

    2014-02-21

    Very light WIMPs (chi), thermal relics that annihilate late in the early Universe, change the energy and entropy densities at BBN and at recombination. BBN, in combination with the CMB, can remove some of the degeneracies among light WIMPs and equivalent neutrinos, constraining the existence and properties of each. Depending on the nature of the light WIMP (Majorana or Dirac fermion, real or complex scalar) the joint BBN + CMB analyses set lower bounds to m_chi in the range 0.5 - 5 MeV (m_chi/m_e > 1 - 10), and they identify best fit values for m_chi in the range 5 - 10 MeV. The joint BBN + CMB analysis finds a best fit value for the number of equivalent neutrinos, Delta N_nu ~ 0.65, nearly independent of the nature of the WIMP. In the absence of a light WIMP (m_chi > 20 MeV), N_eff = 3.05(1 + Delta N_nu /3). In this case, there is excellent agreement between BBN and the CMB, but the joint fit reveals Delta N_nu = 0.40+-0.17, disfavoring standard big bang nucleosynthesis (SBBN) (Delta N_nu = 0) at ~ 2.4 sigma, as well as a sterile neutrino (Delta N_nu = 1) at ~ 3.5 sigma. The best BBN + CMB joint fit disfavors the absence of dark radiation (Delta N_nu = 0 at ~ 95% confidence), while allowing for the presence of a sterile neutrino (Delta N_nu = 1 at ~ 1 sigma). For all cases considered here, the lithium problem persists. These results, presented at the TAUP 2013 Conference, are based on Nollett & Steigman (2013).

  16. Atmospheric neutrino oscillations and tau neutrinos in ice

    SciTech Connect

    Giordano, Gerardo; Mocioiu, Irina; Mena, Olga

    2010-06-01

    The main goal of the IceCube Deep Core Array is to search for neutrinos of astrophysical origins. Atmospheric neutrinos are commonly considered as a background for these searches. We show here that cascade measurements in the Ice Cube Deep Core Array can provide strong evidence for tau neutrino appearance in atmospheric neutrino oscillations. Controlling systematic uncertainties will be the limiting factor in the analysis. A careful study of these tau neutrinos is crucial, since they constitute an irreducible background for astrophysical neutrino detection.

  17. Double beta decay and neutrino mass models

    E-print Network

    J. C. Helo; M. Hirsch; T. Ota; F. A. Pereira dos Santos

    2015-05-21

    Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori guaranteed to be the dominant contribution in all models. Here, we discuss whether the mass mechanism dominates or not from the theory point of view. We classify all possible (scalar-mediated) short-range contributions to the decay rate according to the loop level, at which the corresponding models will generate Majorana neutrino masses, and discuss the expected relative size of the different contributions to the decay rate in each class. Our discussion is general for models based on the SM group but does not cover models with an extended gauge. We also work out the phenomenology of one concrete 2-loop model in which both, mass mechanism and short-range diagram, might lead to competitive contributions, in some detail.

  18. Double beta decay and neutrino mass models

    NASA Astrophysics Data System (ADS)

    Helo, J. C.; Hirsch, M.; Ota, T.; dos Santos, F. A. Pereira

    2015-05-01

    Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori guaranteed to be the dominant contribution in all models. Here, we discuss whether the mass mechanism dominates or not from the theory point of view. We classify all possible (scalar-mediated) short-range contributions to the decay rate according to the loop level, at which the corresponding models will generate Majorana neutrino masses, and discuss the expected relative size of the different contributions to the decay rate in each class. Our discussion is general for models based on the SM group but does not cover models with an extended gauge. We also work out the phenomenology of one concrete 2-loop model in which both, mass mechanism and short-range diagram, might lead to competitive contributions, in some detail.

  19. Double beta decay and neutrino mass models

    E-print Network

    Helo, J C; Ota, T; Santos, F A Pereira dos

    2015-01-01

    Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori guaranteed to be the dominant contribution in all models. Here, we discuss whether the mass mechanism dominates or not from the theory point of view. We classify all possible (scalar-mediated) short-range contributions to the decay rate according to the loop level, at which the corresponding models will generate Majorana neutrino masses, and discuss the expected relative size of the different contributions to the decay rate in each class. We also work out the phenomenology of one concrete 2-loop model in which both, mass mechanism and short-range diagram, might lead to competitive contributions, in some detail.

  20. Seesaw Neutrinos from the Heterotic String

    SciTech Connect

    Buchmueller, Wilfried; Hamaguchi, Koichi; Lebedev, Oleg; Ramos-Sanchez, Saul; Ratz, Michael

    2007-07-13

    We study the possibility of realizing the neutrino seesaw mechanism in the E{sub 8}xE{sub 8} heterotic string. In particular, we consider its Z{sub 6} orbifold compactifications leading to the supersymmetric standard model gauge group and matter content. We find that these models possess all the necessary ingredients for the seesaw mechanism, including the required Dirac Yukawa couplings and large Majorana mass terms. We argue that this situation is quite common in heterotic orbifolds. In contrast with the conventional seesaw of grand unified theories (GUTs), no large GUT representations are needed to generate the Majorana mass terms. The total number of right-handed neutrinos can be very large, up to O(100)

  1. Neutrino masses from fine tuning

    NASA Astrophysics Data System (ADS)

    Grossmann, B. N.; Murdock, Z.; Nandi, S.

    2010-10-01

    We present a new approach for generating tiny neutrino masses. The Dirac neutrino mass matrix gets contributions from two new Higgs doublets with their vevs at the electroweak (EW) scale. Neutrino masses are tiny not because of tiny Yukawa couplings, or very heavy ( ?10 GeV) right-handed neutrinos. They are tiny because of a cancellation in the Dirac neutrino mass matrix (fine tuning). After fine tuning to make the Dirac neutrino mass matrix at the 10 GeV scale, light neutrino masses are obtained in the correct scale via the see-saw mechanism with the right-handed neutrino at the EW scale. The proposal links neutrino physics to collider physics. The Higgs search strategy is completely altered. For a wide range of Higgs masses, the Standard Model Higgs decays dominantly to ?N mode giving rise to the final state ?bar?bbarb, or ?bar???. This can be tested at the LHC, and possibly at the Tevatron.

  2. The Science of NOA Neutrinos are everywhere!

    E-print Network

    Quigg, Chris

    The Science of NOA Neutrinos are everywhere! Neutrinos are among the most abundant particles. Unimaginably large numbers of neutrinos from the first moments of the universe are still present today. Neutrinos help to shape our universe Nuclear reactions make the sun shine, producing neutrinos. Neutrinos

  3. WMAPping out neutrino masses

    SciTech Connect

    Pierce, Aaron; Murayama, Hitoshi

    2003-10-28

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

  4. Detecting the Neutrino

    NASA Astrophysics Data System (ADS)

    Arns, Robert G.

    In 1930 Wolfgang Pauli suggested that a new particle might be required to make sense of the radioactive-disintegration mode known as beta decay. This conjecture initially seemed impossible to verify since the new particle, which became known as the neutrino, was uncharged, had zero or small mass, and interacted only insignificantly with other matter. In 1951 Frederick Reines and Clyde L. Cowan, Jr., of the Los Alamos Scientific Laboratory undertook the difficult task of detecting the free neutrino by observing its inverse beta-decay interaction with matter. They succeeded in 1956. The neutrino was accepted rapidly as a fundamental particle despite discrepancies in reported details of the experiments and despite the absence of independent verification of the result. This paper describes the experiments, examines the nature of the discrepancies, and discusses the circumstances of the acceptance of the neutrino's detection by the physics community.

  5. Sterile Neutrino Anarchy

    E-print Network

    Julian Heeck; Werner Rodejohann

    2013-02-07

    Lepton mixing, which requires physics beyond the Standard Model, is surprisingly compatible with a minimal, symmetryless and unbiased approach, called anarchy. This contrasts with highly involved flavor symmetry models. On the other hand, hints for light sterile neutrinos have emerged from a variety of independent experiments and observations. If confirmed, their existence would represent a groundbreaking discovery, calling for a theoretical interpretation. We discuss anarchy in the two-neutrino eV-scale seesaw framework. The distributions of mixing angles and masses according to anarchy are in agreement with global fits for the active and sterile neutrino parameters. Our minimal and economical scenario predicts the absence of neutrinoless double beta decay and one vanishing neutrino mass, and can therefore be tested in future experiments.

  6. Precision Neutrino Counting

    E-print Network

    Gary Steigman

    2001-08-08

    In the framework of the standard, hot big bang cosmological model the dynamics of the early evolution of the universe is controlled by the energy density of relativistic particles, among which neutrinos play an important role. In equilibrium, the energy density contributed by one flavor of relativistic neutrinos is 7/8 of that of the cosmic background radiation (CBR) photons. As the universe expands and cools, neutrinos decouple and their subsequent contribution to the energy density is modified by the relative heating of the CBR photons when electron-positron pairs annihilate. The small corrections to the post-annihilation energy density of the standard model neutrinos due to incomplete decoupling and finite-temperature QED effects are reviewed (correcting an error in the literature) and extended to account for possible additional relativistic degrees of freedom whose presence might modify the predictions of primordial nucleosynthesis and of the predicted CBR anisotropies.

  7. Ultrahigh energy neutrino interactions

    NASA Astrophysics Data System (ADS)

    Domokos, G.; Elliot, B.; Kovesi-Domokos, S.; Mrenna, S.

    1990-03-01

    Ultrahigh energy neutrinos are valuable probes of physics beyond the Standard Model. Neutrinos of the highest energies are emitted by point sources in the sky. We review briefly the predictions of the Standard Model concerning neutrino interactions. We further argue that a number of preon models designed to overcome some difficulties of the Standard Model leads to a blurring of the distinction between leptons and quarks. As a consequence, at sufficiently high energies neutrinos acquire ``anomalous'' interactions. While this phenomenon can probably explain the observed muon excess in extensive air showers (EAS), it can be also tested by studying the absorption of the primaries on the cosmic microwave background. We discuss some observations to be performed in the search of such ``new physics'' beyond the Standard Model.

  8. The ANTARES neutrino telescope

    E-print Network

    Juan de Dios Zornoza; Juan Zúñiga

    2012-10-10

    The ANTARES collaboration completed the installation of the first neutrino detector in the sea in 2008. It consists of a three dimensional array of 885 photomultipliers to gather the Cherenkov photons induced by relativistic muons produced in charged-current interactions of high energy neutrinos close to/in the detector. The scientific scope of neutrino telescopes is very broad: the origin of cosmic rays, the origin of the TeV photons observed in many astrophysical sources or the nature of dark matter. The data collected up to now have allowed us to produce a rich output of physics results, including the map of the neutrino sky of the Southern hemisphere, search for correlations with GRBs, flaring sources, gravitational waves, limits on the flux produced by dark matter self-annihilations, etc. In this paper a review of these results is presented.

  9. ICFA neutrino panel report

    NASA Astrophysics Data System (ADS)

    Long, K.

    2015-07-01

    In the summer of 2013 the International Committee on Future Accelerators (ICFA) established a Neutrino Panel with the mandate: "To promote international cooperation in the development of the accelerator-based neutrino-oscillation program and to promote international collaboration in the development of a neutrino factory as a future intense source of neutrinos for particle physics experiments." In its first year the Panel organised a series of regional Town Meetings to collect input from the community and to receive reports from the regional planning exercises. The Panel distilled its findings and presented them in a report to ICFA [1]. In this contribution the formation and composition of the Panel are presented together with a summary of the Panel's findings from the three Regional Town Meetings. The Panel's initial conclusions are then articulated and the steps that the Panel seeks to take are outlined.

  10. Neutrinos estériles en nucleosíntesis primordial

    NASA Astrophysics Data System (ADS)

    Sáez, M. M.; Mosquera, M. E.; Civitarese, O.

    2015-08-01

    We have studied the effect of the inclusion of massive sterile neutrinos upon primordial abundances of the elements produced during the stage of primordial nucleosynthesis (Big Bang Nucleosynthesis). We calculate the new active neutrino number densities by taking into account the interactions between active neutrinos (effective potential), the active neutrino oscillations, the active-sterile neutrino oscillations and a damping factor for active neutrinos. We computed the primordial abundances as functions of the active-sterile mixing parameters. Finally, we compared the abundances calculated theoretically with the observations to set constraints for the free parameters.

  11. Solar Neutrinos: Present and Future

    SciTech Connect

    Ianni, A.

    2005-10-12

    In this paper, present and future experimental techniques to search for solar neutrinos are discussed. A number of reasons to measure sub-MeV solar neutrinos in the future are presented. This opportunity offers a unique possibility to search for a new physics case, besides neutrino oscillations and mixing, which may play a sub-dominant role in the solar neutrino phenomenology, in particular below 1 MeV. On one side non-standard neutrino interactions can be probed through sub-MeV solar neutrinos; on the other, the astrophysics of the sun can be studied at the level of a few %'s.

  12. Experimental High Energy Neutrino Astrophysics

    SciTech Connect

    Distefano, Carla

    2005-10-12

    Neutrinos are considered promising probes for high energy astrophysics. More than four decades after deep water Cerenkov technique was proposed to detect high energy neutrinos. Two detectors of this type are successfully taking data: BAIKAL and AMANDA. They have demonstrated the feasibility of the high energy neutrino detection and have set first constraints on TeV neutrino production astrophysical models. The quest for the construction of km3 size detectors have already started: in the South Pole, the IceCube neutrino telescope is under construction; the ANTARES, NEMO and NESTOR Collaborations are working towards the installation of a neutrino telescope in the Mediterranean Sea.

  13. Neutrinos beyond the Standard Model

    SciTech Connect

    Valle, J.W.F.

    1989-08-01

    I review some basic aspects of neutrino physics beyond the Standard Model such as neutrino mixing and neutrino non-orthogonality, universality and CP violation in the lepton sector, total lepton number and lepton flavor violation, etc.. These may lead to neutrino decays and oscillations, exotic weak decay processes, neutrinoless double /beta/ decay, etc.. Particle physics models are discussed where some of these processes can be sizable even in the absence of measurable neutrino masses. These may also substantially affect the propagation properties of solar and astrophysical neutrinos. 39 refs., 4 figs.

  14. Neutrino Detectors: Challenges and Opportunities

    SciTech Connect

    Soler, F. J. P.

    2011-10-06

    This paper covers possible detector options suitable at future neutrino facilities, such as Neutrino Factories, Super Beams and Beta Beams. The Magnetised Iron Neutrino Detector (MIND), which is the baseline detector at a Neutrino Factory, will be described and a new analysis which improves the efficiency of this detector at low energies will be shown. Other detectors covered include the Totally Active Scintillating Detectors (TASD), particularly relevant for a low energy Neutrino Factory, emulsion detectors for tau detection, liquid argon detectors and megaton scale water Cherenkov detectors. Finally the requirements of near detectors for long-baseline neutrino experiments will be demonstrated.

  15. Electromagnetic properties of massive neutrinos

    SciTech Connect

    Dobrynina, A. A. Mikheev, N. V.; Narynskaya, E. N.

    2013-10-15

    The vertex function for a virtual massive neutrino is calculated in the limit of soft real photons. A method based on employing the neutrino self-energy operator in a weak external electromagnetic field in the approximation linear in the field is developed in order to render this calculation of the vertex function convenient. It is shown that the electric charge and the electric dipole moment of the real neutrino are zero; only the magnetic moment is nonzero for massive neutrinos. A fourth-generation heavy neutrino of mass not less than half of the Z-boson mass is considered as a massive neutrino.

  16. Cosmological and supernova neutrinos

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  17. Radiochemical solar neutrino experiments

    E-print Network

    V. N. Gavrin; B. T. Cleveland

    2007-03-06

    Radiochemical experiments have been crucial to solar neutrino research. Even today, they provide the only direct measurement of the rate of the proton-proton fusion reaction, p + p --> d + e^+ + nu_e, which generates most of the Sun's energy. We first give a little history of radiochemical solar neutrino experiments with emphasis on the gallium experiment SAGE -- the only currently operating detector of this type. The combined result of all data from the Ga experiments is a capture rate of 67.6 +/- 3.7 SNU. For comparison to theory, we use the calculated flux at the Sun from a standard solar model, take into account neutrino propagation from the Sun to the Earth and the results of neutrino source experiments with Ga, and obtain 67.3 ^{+3.9}_{-3.5} SNU. Using the data from all solar neutrino experiments we calculate an electron neutrino pp flux at the earth of (3.41 ^{+0.76}_{-0.77}) x 10^{10}/(cm^2-s), which agrees well with the prediction from a detailed solar model of (3.30 ^{+0.13} _{-0.14}) x 10^{10}/(cm^2-s). Four tests of the Ga experiments have been carried out with very intense reactor-produced neutrino sources and the ratio of observed to calculated rates is 0.88 +/- 0.05. One explanation for this unexpectedly low result is that the cross section for neutrino capture by the two lowest-lying excited states in 71Ge has been overestimated. We end with consideration of possible time variation in the Ga experiments and an enumeration of other possible radiochemical experiments that might have been.

  18. THE SOLAR NEUTRINO PROBLEM

    E-print Network

    W. Haxton

    1995-03-24

    The solar neutrino problem has persisted for almost three decades. Recent results from Kamiokande, SAGE, and GALLEX indicate a pattern of neutrino fluxes that is very difficult to reconcile with plausible variations in standard solar models. This situation is reviewed and suggested particle physics solutions are discussed. A summary is given of the important physics expected from SNO, SuperKamiokande, and other future experiments.

  19. Radiochemical solar neutrino experiments

    NASA Astrophysics Data System (ADS)

    Gavrin, V. N.; Cleveland, B. T.

    2011-12-01

    Radiochemical experiments have been crucial to solar neutrino research. Even today, they provide the only direct measurement of the rate of the proton-proton fusion reaction, p+p?d+e++?e, which generates most of the Sun's energy. We first give a little history of radiochemical solar neutrino experiments with emphasis on the gallium experiment SAGE - the only currently operating detector of this type. The combined result of all data from the Ga experiments is a capture rate of 67.6±3.7 SNU. For comparison to theory, we use the calculated flux at the Sun from a standard solar model, take into account neutrino propagation from the Sun to the Earth and the results of neutrino source experiments with Ga, and obtain 67.3-3.5+3.9 SNU. Using the data from all solar neutrino experiments we calculate an electron neutrino pp flux of ?pp?=(3.41-0.77+0.76)×1010/(cm-s), which agrees well with the prediction from a detailed solar model of ?pp?=(3.30-0.14+0.13)×1010/(cm-s). Four tests of the Ga experiments have been carried out with very intense reactor-produced neutrino sources and the ratio of observed to calculated rates is 0.88±0.05. One explanation for this unexpectedly low result is that the cross section for neutrino capture by the two lowest-lying excited states in 71Ge has been overestimated. We end with consideration of possible time variation in the Ga experiments and an enumeration of other possible radiochemical experiments that might have been.

  20. Cosmological and supernova neutrinos

    SciTech Connect

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

    2014-06-24

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

  1. Oscillation of heavy sterile neutrino in decay of B ?? e ?

    NASA Astrophysics Data System (ADS)

    Cveti?, Gorazd; Kim, C. S.; Kögerler, Reinhart; Zamora-Saá, Jilberto

    2015-07-01

    In a scenario with two almost mass degenerate heavy sterile Majorana neutrinos with a mass ˜1 GeV , we present the semileptonic decay widths of heavy charged pseudoscalars such as B mesons, either lepton number violating (B±??±e±?? ), or lepton number conserving (B±??±e??± ), mediated by such on-shell neutrinos. It had been explained in the literature that such decays may be eventually detected, and that they can present even detectable C P violation effects. In this work we point out that, in addition, such decays may present detectable effects of heavy neutrino oscillation, allowing us to extract the oscillation length and thus the heavy neutrino mass difference ? MN , as well as a C P -violating Majorana phase.

  2. Top quark as a dark portal and neutrino mass generation

    NASA Astrophysics Data System (ADS)

    Ng, John N.; de la Puente, Alejandro

    2013-11-01

    We present a new model for radiatively generating Majorana active neutrino masses while incorporating a viable dark matter candidate. This is possible by extending the Standard Model with a single Majorana neutrino endowed with a dark parity, a coloured electroweak-singlet scalar, as well as a coloured electroweak-triplet scalar. Within this framework, the up-type quarks play a special role, serving as a portal for dark matter, and a messenger for neutrino mass generation. We consider three benchmark scenarios where the abundance of dark matter can match the latest experimental results, while generating neutrino masses in the milli-electronvolt range. We show how constraints from lepton flavor violation, in particular the branching fraction of ??e?, can place lower bounds on the coupling between our dark matter candidate and top quarks. Furthermore, we show that this coupling can also be constrained using collider data from the Tevatron and the LHC.

  3. Minimal seesaw textures with two heavy neutrinos

    SciTech Connect

    Goswami, Srubabati; Watanabe, Atsushi

    2009-02-01

    We systematically analyze the Dirac and the Majorana mass matrices in seesaw models with two heavy right-handed neutrinos. We perform thorough classification of the vanishing matrix elements which are compatible with the results from the current neutrino oscillation experiments. We include the possibility of a nondiagonal Majorana mass matrix which leads to new solutions viable with data. In a basis where the Majorana mass matrix is diagonal, these solutions imply a Dirac matrix with specific relationships amongst its elements. We find that at the level of total four zeros together in m{sub D} and M{sub R} the mass matrices are almost consistent with the data but one mixing angle is predicted to be unsuitable. At the next level, i.e. with total three zeros, only seven patterns of mass matrices describe the experimental data well. The seven solutions have testable predictions for the future neutrino experiments. In particular, each solution has definite predictions about the observation of the 1-3 leptonic mixing angle and the effective mass measured in neutrinoless double beta decay. The solutions of the mass matrices contain novel texture forms and provide new insights into the lepton-generation structure. We also discuss possible connections between these textures and the tri-bimaximal mixing to search for symmetry principles behind the mass matrix structure.

  4. Probing Non-Standard Neutrino Interactions with Neutrino Factories

    E-print Network

    N. Cipriano Ribeiro; H. Minakata; H. Nunokawa; S. Uchinami; R. Zukanovich Funchal

    2007-12-14

    We discuss the sensitivity reach of a neutrino factory measurement to non-standard neutrino interactions (NSI), which may exist as a low-energy manifestation of physics beyond the Standard Model. We use the muon appearance mode \

  5. Probing Non-Standard Neutrino Interactions with Neutrino Factories

    E-print Network

    Ribeiro, N C; Nunokawa, H; Uchinami, S; Funchal, R Zukanovich

    2007-01-01

    We discuss the sensitivity reach of a neutrino factory measurement to non-standard neutrino interactions (NSI), which may exist as a low-energy manifestation of physics beyond the Standard Model. We use the muon appearance mode \

  6. Sterile Neutrino Fits to Short-Baseline Neutrino Oscillation Measurements

    E-print Network

    Conrad, Janet

    2013-01-01

    This paper reviews short-baseline oscillation experiments as interpreted within the context of one, two, and three sterile neutrino models associated with additional neutrino mass states in the ~1?eV range. Appearance and ...

  7. GENIUS project, neutrino oscillations and Cosmology: neutrinos reveal their nature?

    E-print Network

    M. Czakon; J. Studnik; M. Zralek; J. Gluza

    2000-05-17

    The neutrinoless double beta decay as well as any other laboratory experiment has not been able to answer the question of the neutrino's nature. Hints on the answer are available when neutrino oscillations and $(\\beta\\beta)_{0 \

  8. GENIUS project, neutrino oscillations and Cosmology neutrinos reveal their nature?

    E-print Network

    Czakon, M; Zralek, M; Gluza, J

    2000-01-01

    The neutrinoless double beta decay as well as any other laboratory experiment has not been able to answer the question of the neutrino's nature. Hints on the answer are available when neutrino oscillations and $(\\beta\\beta)_{0 \

  9. Trapped ionic simulation of neutrino electromagnetic properties in neutrino oscillation

    NASA Astrophysics Data System (ADS)

    Wang, Z. S.; Cai, Xiaoya; Pan, Hui

    2015-11-01

    We present an approach to study neutrino electromagnetic properties by simulating neutrino oscillation in both dense background matter and external electromagnetic field in terms of trapped coupling ions. We find that the neutrino and anti-neutrino productions can be simulated by using large enough diagonal matter potentials and external magnetic field. We further show that the transition probabilities of flavor neutrino have rich features and time scales corresponding to the neutrino magnetic moments and electric millicharges. Especially, such features and scales can be achieved by tuning the laser parameters. At last, we show that the millicharge and magnetic moments can be detected in terms of flavor neutrino transition probabilities in the trapped ion system. Our approach provides a useful clue to measure the neutrino electromagnetic properties for experimental realization.

  10. Measurement of Atmospheric Neutrinos at the Sudbury Neutrino Observatory

    E-print Network

    Formaggio, Joseph A.

    The Sudbury Neutrino Observatory consists of a 1 kiloton heavy water Cherenkov detector able to detect and reconstruct high-energy muons created from cosmic ray showers and atmospheric neutrino interactions. By measuring ...

  11. Core-collapse supernova neutrinos and neutrino properties

    E-print Network

    J. Gava; C. Volpe

    2008-05-18

    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.

  12. Confronting Recent Neutrino Oscillation Data with Sterile Neutrinos

    E-print Network

    G. Karagiorgi

    2011-10-17

    Recent neutrino oscillation results have evoked renewed interest in sterile neutrino oscillation models. This paper reviews the data from MiniBooNE and short-baseline reactor antineutrino experiments within the context of sterile neutrinos. The results are incorporated into combined fits to test the viability of sterile neutrino oscillation models, which are later expanded to address matter effects. Finally, future experiments that can resolve the questions that have been raised are discussed.

  13. Neutrino Matter Effect Invariants and the Observables of Neutrino Oscillations

    E-print Network

    P. F. Harrison; W. G. Scott

    2002-04-29

    We generalise our previous observation on the invariance of the Jarlskog determinant to matter effects in neutrino oscillations. Within the context of standard neutrino oscillation theory with matter effects, we present the complete set of (five) matter invariant observables for neutrino propagation in matter. We give some examples of their application.

  14. Atmospheric neutrinos in ice and measurement of neutrino oscillation parameters

    SciTech Connect

    Fernandez-Martinez, Enrique; Giordano, Gerardo; Mocioiu, Irina; Mena, Olga

    2010-11-01

    The main goal of the IceCube Deep Core array is to search for neutrinos of astrophysical origins. Atmospheric neutrinos are commonly considered as a background for these searches. We show that the very high statistics atmospheric neutrino data can be used to obtain precise measurements of the main oscillation parameters.

  15. Detecting Neutrinos from AGNs and Topological Defects with Neutrino Telescopes

    E-print Network

    Raj Gandhi; Chris Quigg; M. H. Reno; Ina Sarcevic

    1996-09-29

    We evaluate neutrino-nucleon cross section for energies up to $10^{21} eV$ in light of new information on the small-$x$ behavior of parton distributions. We give predictions for large underground neutrino telescope event rates for ultrahigh-energy neutrinos from Active Galactic Nuclei and from the decay of topological defects formed in the early Universe.

  16. Neutrino Phenomenology -- the case of two right handed neutrinos

    E-print Network

    A. Ibarra; G. G. Ross

    2004-01-23

    We make a general analysis of neutrino phenomenology for the case neutrino masses are generated by the see-saw mechanism with just two right handed neutrinos. We find general constraints on leptogenesis and lepton flavour violating processes. We also analyse the predictions following from a nontrivial texture zero structure.

  17. Vetoing atmospheric neutrinos in a high energy neutrino telescope

    E-print Network

    Stefan Schönert; Thomas K. Gaisser; Elisa Resconi; Olaf Schulz

    2008-12-22

    We discuss the possibility to suppress downward atmospheric neutrinos in a high energy neutrino telescope. This can be achieved by vetoing the muon which is produced by the same parent meson decaying in the atmosphere. In principle, atmospheric neutrinos with energies $E_\

  18. Formation of Neutrino Stars from Cosmological Background Neutrinos

    E-print Network

    M. H. Chan; M. -C. Chu

    2006-09-20

    We study hydrodynamic evolution of cosmological background neutrinos. By using a spherically symmetric Newtonian hydrodynamic code, we calculate the time evolution of the density profiles of neutrino matter in cluster and galactic scales. We discuss the possible observational consequences of such evolution and the resulting density profiles of the degenerate neutrino `stars' in galaxies and clusters.

  19. Lorentz violation and neutrino oscillations

    E-print Network

    Matthew Mewes

    2007-03-23

    Lorentz violation naturally leads to neutrino oscillations and provides an alternative mechanism that may explain current data. In this work, we discuss possible signals of Lorentz violation in neutrino-oscillation experiments.

  20. Hadronization processes in neutrino interactions

    NASA Astrophysics Data System (ADS)

    Katori, Teppei; Mandalia, Shivesh

    2015-10-01

    Next generation neutrino oscillation experiments utilize details of hadronic final states to improve the precision of neutrino interaction measurements. The hadronic system was often neglected or poorly modelled in the past, but they have significant effects on high precision neutrino oscillation and cross-section measurements. Among the physics of hadronic systems in neutrino interactions, the hadronization model controls multiplicities and kinematics of final state hadrons from the primary interaction vertex. For relatively high invariant mass events, many neutrino experiments rely on the PYTHIA program. Here, we show a possible improvement of this process in neutrino event generators, by utilizing expertise from the HERMES experiment. Finally, we estimate the impact on the systematics of hadronization models for neutrino mass hierarchy analysis using atmospheric neutrinos such as the PINGU experiment.

  1. Neutrino oscillations in nuclear media

    E-print Network

    Iman Motie; She-Sheng Xue

    2011-04-14

    On basis of effective interactions of charged lepton and hadron currents, we obtain an effective interacting Hamiltonian of neutrinos in nuclear media up to the leading order. Using this effective Hamiltonian, we study neutrino mixing and oscillations in nuclear media and strong magnetic fields. We compute neutrino mixing angle and mass squared difference, and find the pattern of vacuum neutrino oscillations is modified in magnetized nuclear media. Comparing with the vacuum neutrino oscillation, we find that for high-energy neutrinos, neutrino oscillations are suppressed in the presence of nuclear media. In the general case of neutral nuclear media with the presence of electrons, we calculate the mixing angle and mass squared difference, and discuss the resonance and level-crossing in neutrino oscillations.

  2. Neutrino Experiments and Their Implications

    E-print Network

    A. B. Balantekin

    2004-03-11

    Recent developments in solar, reactor, and accelerator neutrino physics are reviewed. Implications for neutrino physics, solar physics, nuclear two-body physics, and r-process nucleosynthesis are briefly discussed.

  3. Neutrino production states and NSI

    E-print Network

    Robert Szafron; Marek Zralek

    2010-10-28

    The problems of neutrino production states, prepared to the oscillation process, in the case of non standard interactions, are briefly discussed. Quantum neutrino states are determined from the dynamics of a production process. We show, that even in models where only left-handed neutrinos are introduced, the standard adopted procedure is valid only approximately. Entanglement between neutrino masses or between masses, flavour and spins cause, that their quantum states are mixed.

  4. Neutrino production states and NSI

    E-print Network

    Szafron, Robert

    2010-01-01

    The problems of neutrino production states, prepared to the oscillation process, in the case of non standard interactions, are briefly discussed. Quantum neutrino states are determined from the dynamics of a production process. We show, that even in models where only left-handed neutrinos are introduced, the standard adopted procedure is valid only approximately. Entanglement between neutrino masses or between masses, flavour and spins cause, that their quantum states are mixed.

  5. Neutrino dispersion in magnetized plasma

    E-print Network

    N. V. Mikheev; E. N. Narynskaya

    2008-12-02

    The neutrino dispersion in the charge symmetric magnetized plasma is investigated. We have studied the plasma contribution into the additional energy of neutrino and obtained the simple expression for it. We consider in detail the neutrino self-energy under physical conditions of weak field, moderate field and strong field limits. It is shown that our result for neutrino dispersion in moderate magnetic field differ substantially from the previous one in the literature.

  6. Supernova Neutrinos Detection On Earth

    E-print Network

    Xin-Heng Guo; Ming-Yang Huang; Bing-Lin Young

    2009-05-12

    In this paper, we first discuss the detection of supernova neutrino on Earth. Then we propose a possible method to acquire information about $\\theta_{13}$ smaller than $1.5^\\circ$ by detecting the ratio of the event numbers of different flavor supernova neutrinos. Such an sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment.

  7. Solar Neutrino Matter Effects Redux

    E-print Network

    A. B. Balantekin; A. Malkus

    2011-12-19

    Following recent low-threshold analysis of the Sudbury Neutrino Observatory and asymmetry measurements of the BOREXINO Collaboration of the solar neutrino flux, we revisit the analysis of the matter effects in the Sun. We show that solar neutrino data constrains the mixing angle $\\theta_{13}$ poorly and that subdominant Standard Model effects can mimic the effects of the physics beyond the Standard Model.

  8. Heavy neutrinos in particle physics and cosmology

    E-print Network

    Marco Drewes

    2015-10-27

    Neutrinos are the only particles in the Standard Model of particle physics that have only been observed with left handed chirality to date. If right handed neutrinos exist, they would not only explain the observed neutrino oscillations, but could also be responsible for several phenomena in cosmology, including the baryon asymmetry of the universe, dark matter and dark radiation. A crucial parameter in this context is their Majorana mass, which in principle could lie anywhere between the eV scale and GUT scale. The implications for experiments and cosmology strongly depend on the choice of the mass scale. We review recent progress in the phenomenology of right handed neutrinos with different masses, focusing on scenarios in which the mass is at least a keV. We emphasise the possibility to discover heavy neutrinos that are responsible for the baryon asymmetry of the universe via low scale leptogenesis in near future experiments, such as LHC, BELLE II, SHiP, FCC-ee or CEPC.

  9. Yukawa couplings and seesaw neutrino masses in noncommutative gauge theory

    E-print Network

    Raul Horvat; Amon Ilakovac; Peter Schupp; Josip Trampetic; Jiangyang You

    2012-07-21

    We consider Yukawa couplings in a theta-exact approach to noncommutative gauge field theory and show that both Dirac and singlet Majorana neutrino mass terms can be consistently accommodated. This shows that in fact the whole neutrino-mass extended standard model on noncommutative spacetime can the formulated in the new nonperturbative (in theta) approach which eliminates the previous restriction of Seiberg-Witten map based theories to low-energy phenomena. Spacetime noncommutativity induced couplings between neutrinos and photons as well as Z-bosons appear quite naturally in the model. We derive relevant Feynman rules for the type I seesaw mechanism.

  10. Neutrino Scattering Physics at Superbeams and Neutrino Factories

    E-print Network

    S. Kumano

    2003-10-14

    Neutrino scattering physics is discussed for investigating internal structure of the nucleon and nuclei at future neutrino facilities. We explain structure functions in neutrino scattering. In particular, there are new polarized functions g_3, g_4, and g_5, and they should provide us important information for determining internal nucleon spin structure. Next, nuclear structure functions are discussed. From F_3 structure function measurements, valence-quark shadowing should be clarified. Nuclear effects on the NuTeV sin^2\\theta_W anomaly are explained. We also comment on low-energy neutrino scattering, which is relevant to current long-baseline neutrino oscillation experiments.

  11. Magnetic moments of active and sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Balantekin, A. B.; Vassh, N.

    2014-04-01

    Since most of the neutrino parameters are well measured, we illustrate precisely the prediction of the Standard Model, minimally extended to allow massive neutrinos, for the electron neutrino magnetic moment. We elaborate on the effects of light sterile neutrinos on the effective electron neutrino magnetic moment measured at the reactors. We explicitly show that the kinematical effects of the neutrino masses are negligible even for light sterile neutrinos.

  12. Extraterrestrial Solar Neutrino Physics

    E-print Network

    W-Y. Pauchy Hwang; Jen-Chieh Peng

    2011-07-26

    We advocate the extraterrestrial solar neutrino physics (etSNP) as a means of investigating solar neutrino physics (SNP). As we already know, the dominant and subdominant (vacuum) oscillation lengths would be approximately one kilometer and one hundred kilometers. On the other hand, we know so far that the matter-enhanced oscillations take place only in the core of the Sun. Thus, the etSNP, i.e. solar neutrino physics that could be extracted outside the Earth, would assume a special unique role. The etSNP experiments include (1) a satellite (detector) around the Earth or around the Jupiter or others (to provide the shadow, for the matter-enhanced neutrino oscillations), (2) during the Sun-Venus-Earth eclipse or similar, and (3) the chemical compositions of the geology type (as in the Jupiter or in the Venus, to study the origins of these planets). To be specific, we note that the reactions induced by the ^8B solar neutrinos, in view of the sole high energy nature (E_\

  13. Probing neutrino magnetic moments at Spallation Neutron Source facilities

    E-print Network

    T. S. Kosmas; O. G. Miranda; D. K. Papoulias; M. Tortola; J. W. F. Valle

    2015-07-15

    Majorana neutrino electromagnetic properties are studied through neutral current coherent neutrino-nucleus scattering. We focus on the potential of the recently planned COHERENT experiment at the Spallation Neutron Source to probe muon-neutrino magnetic moments. The resulting sensitivities are determined on the basis of a chi^2 analysis employing realistic nuclear structure calculations in the context of the quasi-particle random phase approximation. We find that they can improve existing limits by half an order of magnitude. In addition, we show that these facilities allow for Standard Model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. Finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge-radius. We illustrate our results for various choices of experimental setup and target material.

  14. Probing neutrino magnetic moments at Spallation Neutron Source facilities

    E-print Network

    Kosmas, T S; Papoulias, D K; Tortola, M; Valle, J W F

    2015-01-01

    Majorana neutrino electromagnetic properties are studied through neutral current coherent neutrino-nucleus scattering. We focus on the potential of the recently planned COHERENT experiment at the Spallation Neutron Source to probe muon-neutrino magnetic moments. The resulting sensitivities are determined on the basis of a $\\chi^2$ analysis employing realistic nuclear structure calculations in the context of the quasi-particle random phase approximation (QRPA). We find that they can improve existing limits by half an order of magnitude. In addition, we show that these facilities allow for Standard Model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. Finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge-radius. We illustrate our results for various choices of experimental setup and target material.

  15. Probing neutrino magnetic moments at the Spallation Neutron Source facility

    NASA Astrophysics Data System (ADS)

    Kosmas, T. S.; Miranda, O. G.; Papoulias, D. K.; Tórtola, M.; Valle, J. W. F.

    2015-07-01

    Majorana neutrino electromagnetic properties are studied through neutral current coherent neutrino-nucleus scattering. We focus on the potential of the recently planned COHERENT experiment at the Spallation Neutron Source to probe muon-neutrino magnetic moments. The resulting sensitivities are determined on the basis of a ?2 analysis employing realistic nuclear structure calculations in the context of the quasiparticle random phase approximation. We find that they can improve existing limits by half an order of magnitude. In addition, we show that these facilities allow for standard model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. Finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge radius. We illustrate our results for various choices of experimental setup and target material.

  16. Sterile neutrinos: direct mixing effects versus induced mass matrix of active neutrinos

    E-print Network

    Alexei Yu. Smirnov; Renata Zukanovich Funchal

    2006-06-14

    Mixing of active neutrinos with sterile ones generate ``induced'' contributions to the mass matrix of active neutrinos $\\sim m_S \\sin^2\\theta_{aS}$, where $m_S$ is the Majorana mass of the sterile neutrino and $\\theta_{aS}$ is the active-sterile mixing angle. We study possible effects of the induced matrix which can modify substantially the implications of neutrino oscillation results. We have identified the regions of $m_S$ and $\\sin^2\\theta_{aS}$ where the induced matrix (i) provides the dominant structures, (ii) gives the sub-dominant effects and (iii) where its effects can be neglected. The induced matrix can be responsible for peculiar properties of the lepton mixing and neutrino mass spectrum, in particular, it can generate the tri-bimaximal mixing. We update and discuss bounds on the induced masses from laboratory measurements, astrophysics and cosmology. We find that substantial impact of the induced matrix is possible if $m_S \\sim 0.1-1$ eV and $\\sin^2\\theta_{aS} \\sim 10^{-3} - 10^{-2}$ or $m_S \\geq 200$ MeV and $\\sin^2\\theta_{aS} \\leq 10^{-9}$. The bounds can be relaxed in cosmological scenarios with low reheating temperature, if sterile neutrinos decay sufficiently fast, or their masses change with time.

  17. Entanglement in neutrino oscillations

    E-print Network

    Massimo Blasone; Fabio Dell'Anno; Silvio De Siena; Fabrizio Illuminati

    2009-04-17

    Flavor oscillations in elementary particle physics are related to multi-mode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks.

  18. Cosmology and neutrino physics

    SciTech Connect

    Steigman, G.

    1982-01-01

    Constraints on cosmology and on neutrino physics are provided by the abundances of the light elements produced during the early evolution of the universe. The predictions of primordial nucleosynthesis depend on the nucleon to photon ratio eta and on the number of types of two component neutrinos N/sub nu/. A comparison between the big bang predictions and the observed abundances of D, /sup 3/He, /sup 4/He and /sup 7/Li shows that eta is constrained to a narrow range around 4 x 10/sup -10/ and N/sub nu/ approx.< 4. An important consequence of the derived value of eta is that the universal density of nucleons is small, raising the possibility that our Universe may be dominated by massive relic neutrinos. The constraint on N/sub nu/ suggests that (almost) all lepton species are now known.

  19. Cosmological Constraints on Neutrinos

    NASA Astrophysics Data System (ADS)

    Millea, Marius

    2015-04-01

    The cosmic background of neutrinos (the CNB) created during the big bang has been definitively detected via its gravitational influence. Ongoing measurements are now giving increasingly precise answers to questions such as 1) what is the energy density contained in the CNB? 2) what are the masses of the particles making up the CNB? and 3) are these particles really neutrinos, e.g. do they free-stream like neutrinos? I will discuss answers to these questions from cosmological probes such as baryon acoustic oscillations or local Hubble constant measurements, and with particular focus on the Planck 2015 cosmic microwave background results. One possibility I will explore is if axions of axion-like particles can be masquerading as a component of the CNB. Recent improvements from Planck and from big bang nucleosynthesis measurements have been placing increasingly tight constraints on this scenario.

  20. Short Baseline Neutrino Oscillation Experiments

    NASA Astrophysics Data System (ADS)

    Katori, Teppei

    2015-04-01

    Series of short baseline neutrino oscillation experiments provided unexpected results, and now they are called short baseline anomalies, and all indicates an existence of sterile neutrinos with a mass scale around 1 eV. The signals of short baseline anomalies are reported from 4 different classes of experiments. However, at this moment, there is no convincing theoretical model to explain such sterile neutrinos, and a single experiment to confirm 1 eV sterile neutrinos may be challenging. In this short note, we describe classes of short baseline neutrino oscillation experiments and their goals.

  1. Neutrino quantum states in matter

    E-print Network

    Alexander Studenikin; Alexei Ternov

    2004-10-21

    We propose a modified Dirac equation for a massive neutrino moving in the presence of the background matter. The effects of the charged and neutral-current interactions with the matter as well as the matter motion and polarization are accounted for. In the particular case of the matter with a constant density the exact solutions of this equation are found, the neutrino energy spectrum in the matter is also determined. On this basis the effects of the neutrino trapping and reflection, the neutrino-antineutrino pair annihilation and creation in a medium are studied. The quantum theory of the spin light of neutrino in matter ($SL\

  2. A hypothesis on neutrino helicity

    E-print Network

    Sahin, I

    2016-01-01

    It is firmly established by experimental results that neutrinos are almost 100\\% longitudinally polarized and left-handed. It is also confirmed by neutrino oscillation experiments that neutrinos have tiny but non-zero masses. Since the helicity is not a Lorentz invariant quantity for massive particles, neutrinos can not be strictly left-handed. On the other hand, it is generally assumed that ultrarelativistic massive fermions can be described well enough by the Weyl equations. We discuss the validity of this assumption and propose a new hypothesis according to which neutrinos can be described by pure helicity states although they are not massless.

  3. Panel Discussion v: Neutrino Physics

    NASA Astrophysics Data System (ADS)

    Obraztsov, Vladimir; Konaka, Akira; Ikeda, Motoyasu; Jediny, Filip; Shirokov, Evgeny; Kalekin, Oleg; Palomares-Ruiz, Sergio

    2015-06-01

    Questions to discuss: * Can sidereal time analysis of the long time neutrino observations give information about the galaxy distribution in the Local Universe? * How well do we need to know the PMNS matrix elements? * Is the existence of MSW effect proved experimentally? * Are there new species of neutrino (e.g. the sterile one)? * What are other most important problems in neutrino physics (CP-violation)? * Can sidereal time analysis of the long time neutrino observations give information about the galaxy distribution in the Local Universe? * Perspectives of existing and future neutrino experiments (LNBF, LAGUNA, ICARUS, SHIP ...)

  4. Simulating nonlinear neutrino flavor evolution

    E-print Network

    Duan, Huaiyu; Carlson, J

    2008-01-01

    We discuss a new kind of astrophysical transport problem: the coherent evolution of neutrino flavor in core collapse supernovae. Solution of this problem requires a numerical approach which can simulate accurately the quantum mechanical coupling of intersecting neutrino trajectories and the associated nonlinearity which characterizes neutrino flavor conversion. We describe here the two codes developed to attack this problem. We also describe the surprising phenomena revealed by these numerical calculations. Chief among these is that the nonlinearities in the problem can engineer neutrino flavor transformation which is dramatically different than in standard Mikheyev-Smirnov-Wolfenstein treatments. This happens even though the neutrino mass-squared differences are measured to be small, and even when neutrino self-coupling is sub-dominant. Our numerical work has revealed potential signatures which, if detected in the neutrino burst from a Galactic core collapse event, could reveal heretofore unmeasurable proper...

  5. New Results on Solar Neutrinos

    E-print Network

    Alain Bellerive

    2010-12-11

    This paper reviews the constraints on the solar neutrino mixing parameters with data collected by the Homestake, SAGE, GALLEX, Kamiokande, SuperKamiokande, Borexino and SNO experiments. An emphasis will be given to the global solar neutrino analyses in terms of matter-enhanced oscillation of two and three active flavors. The results to-date, including both solar model dependent and independent measurements, indicate that electron neutrinos are changing to other active types on route to the Earth from the Sun. The total flux of solar neutrinos is found to be in very good agreement with solar model calculations. Today, solar neutrino measurements focus on greater accuracy for mixing parameters and on better sensitivity to low neutrino energies. This article also summarizes near future prospects in the field of solar neutrino physics.

  6. Neutrino flux predictions for cross section measurements

    SciTech Connect

    Hartz, Mark

    2015-05-15

    Experiments that measure neutrino interaction cross sections using accelerator neutrino sources require a prediction of the neutrino flux to extract the interaction cross section from the measured neutrino interaction rate. This article summarizes methods of estimating the neutrino flux using in-situ and ex-situ measurements. The application of these methods by current and recent experiments is discussed.

  7. Status of neutrino-quark NSI parameters

    NASA Astrophysics Data System (ADS)

    Escrihuela, Francisco J.

    2012-07-01

    Experimental observations, as neutrino oscillations, require neutrinos as massive particles. Most neutrino mass generation mechanisms imply the existence of non-standard neutrino interactions (NSI). In order to grant the relevance that it deserves, here we will see a review of neutrino NSI with quark parameters using the most recent solar, reactor, accelerator and atmospheric data.

  8. Neutrinos from a core collapse supernova

    E-print Network

    Amol Dighe

    2007-12-28

    The neutrino burst from a galactic supernova can help determine the neutrino mass hierarchy and $\\theta_{13}$, and provide crucial information about supernova astrophysics. Here we review our current understanding of the neutrino burst, flavor conversions of these neutrinos, and model independent signatures of various neutrino mixing scenarios.

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

    SciTech Connect

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

    2004-12-01

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

  10. Compromise between neutrino masses and collider signatures in the type-II seesaw model

    SciTech Connect

    Chao Wei; Luo Shu; Xing Zhizhong; Zhou Shun

    2008-01-01

    A natural extension of the standard SU(2){sub L}xU(1){sub Y} gauge model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6x6 neutrino mass matrix which contains three 3x3 submatrices, M{sub L}, M{sub D} and M{sub R}. We show that three light Majorana neutrinos (i.e., the mass eigenstates of {nu}{sub e}, {nu}{sub {mu}}, and {nu}{sub {tau}}) are exactly massless in this model, if and only if M{sub L}=M{sub D}M{sub R}{sup -1}M{sub D}{sup T} exactly holds. This no-go theorem implies that small but nonvanishing neutrino masses may result from a significant but incomplete cancellation between M{sub L} and M{sub D}M{sub R}{sup -1}M{sub D}{sup T} terms in the Type-II seesaw formula, provided three right-handed Majorana neutrinos are of O(1) TeV and experimentally detectable at the LHC. We propose three simple Type-II seesaw scenarios with the A{sub 4}xU(1){sub X} flavor symmetry and its explicit breaking to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the 3x3 neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.

  11. Effective theory approach to portly neutrinos: theory and application

    SciTech Connect

    Wudka, Jose

    2009-04-20

    I will discuss the effects of heavy Majorana neutrinos with sub-TeV masses. I will argue that the mere presence of these particles would be a signal of physics beyond the minimal seesaw mechanism. Using an effective Lagrangian approach I will describe the most important interactions of these particles and discuss to what extent these interactions can be probed at the LHC.

  12. Neutrino Factory Target Vessel

    E-print Network

    McDonald, Kirk

    Neutrino Factory Target Vessel Concept V. Graves Target Studies EVO April 11, 2012 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Concept 11 Apr 2012 Target Vessel;3 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Concept 11 Apr 2012 Starting Point

  13. Neutrino Factory Target Vessel

    E-print Network

    McDonald, Kirk

    Neutrino Factory Target Vessel Concept Update V. Graves T. Lessard Target Studies EVO June 26, 2012 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Update 26 June 2012 of Energy Target Vessel Update 26 June 2012 Review - Mercury Module Extraction #12;4 Managed by UT

  14. Neutrino Factory Target Vessel

    E-print Network

    McDonald, Kirk

    Neutrino Factory Target Vessel Concepts Updated 4/16/12 V. Graves Target Studies EVO April 11, 2012 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Concept 16 Apr 2012 Target Vessel Requirements · Accurate jet placement · Jet/beam dump pool · Double containment of mercury

  15. Neutrino Factory Target Vessel

    E-print Network

    McDonald, Kirk

    Neutrino Factory Target Vessel Concept Update V. Graves Target Studies EVO June 12, 2012 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Update 12 June 2012 Review ­ IPAC #12;3 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Update 12 June 2012 Inner

  16. Physical flavor neutrino states

    E-print Network

    Blasone, Massimo

    2011-01-01

    The problem of representation for flavor states of mixed neutrinos is discussed. By resorting to recent results, it is shown that a specific representation exists in which a number of conceptual problems are resolved. Phenomenological consequences of our analysis are explored.

  17. Experimental Neutrino Physics

    ScienceCinema

    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.

  18. Neutrino and Extra World

    E-print Network

    Baranov, D S

    2012-01-01

    The neutrino speed measurement experiments are the continuations of the classic light speed measurement experiments have been done in range of the solar planet system (Ole Roemer, 1676), in star system (James Braidely, 1728) and, at last, on the Earth (Lois Fizeau, 1849),.... The finite light speed measurement has led to the revolution in the humanity consciousness and eventually led to a new understanding of the visible universe. In 1998-2005, we had a lot of excited discussions at CERN about the possibilities to perform the neutrino experiments to test the superluminal neutrino hypothesis and to find new phenomena beyond the SM. From one hand the idea of such experiments was associated with the hope to understand the role of the V-A- weak interactions, the quark-lepton family symmetry, the neutrino space-time properties and to observe some indications on a new vacuum structure existence outside of the Weak Scale, i.e. in the region 1/R ~ (0.1-20) TeV. From another hand the general trends of this idea has be...

  19. Neutrino Trapped Stellar Matter

    SciTech Connect

    Panda, P.K.; Menezes, D.P.; Providencia, C.

    2004-12-02

    The equation of state for hybrid stars with trapped neutrinos is studied. We use the quark meson coupling model for the hadron matter and two possibilities for the quark matter phase, namely, the unpaired quark phase and the color-flavor locked phase. A comparison with other relativistic equation of state is done.

  20. Neutrino and it's lepton

    E-print Network

    G. Quznetsov

    2008-11-10

    In this paper I cite p.p. 100-117 of book G. Quznetsov, Probabilistic Treatment of Gauge Theories, in series Contemporary Fundamental Physics,ed. V. Dvoeglazov, Nova Sci. Publ., NY (2007). There I research a bound between neutrino and it's lepton.

  1. The Higgs Seesaw Induced Neutrino Masses and Dark Matter

    E-print Network

    Yi Cai; Wei Chao

    2014-08-26

    In this paper we propose a possible explanation of the active neutrino Majorana masses with the TeV scale new physics which also provide a dark matter candidate. We extend the Standard Model (SM) with a local U(1)' symmetry and introduce a seesaw relation for the vacuum expectation values (VEVs) of the exotic scalar singlets, which break the U(1)' spontaneously. The larger VEV is responsible for generating the Dirac mass term of the heavy neutrinos, while the smaller for the Majorana mass term. As a result active neutrino masses are generated via the modified inverse seesaw mechanism. The lightest of the new fermion singlets, which are introduced to cancel the U(1)' anomalies, can be a stable particle with ultra flavor symmetry and thus a plausible dark matter candidate. We explore the parameter space with constraints from the dark matter relic abundance and dark matter direct detection.

  2. Flavour-dependent radiative correction to neutrino-neutrino refraction

    E-print Network

    Alessandro Mirizzi; Stefano Pozzorini; Georg G. Raffelt; Pasquale D. Serpico

    2009-10-08

    In the framework of the Standard Model we calculate the flavour non-universal correction for neutrino refraction in a neutrino background and verify a similar previous result for the case of ordinary-matter background. The dominant term arises at loop level and involves tau leptons circulating in the loop. These O(G_F m_tau^2) corrections to the tree-level potential provide the dominant refractive difference between nu_mu and nu_tau unless the medium contains mu or tau leptons. Our results affect the flavour evolution of dense neutrino gases and may be of interest for collective three-flavour oscillations of supernova neutrinos. We spell out explicitly how these non-universal neutrino-neutrino interactions enter the flavour oscillation equations.

  3. Measurement of Atmospheric Neutrino Oscillations with the ANTARES Neutrino Telescope

    E-print Network

    ANTARES collaboration; S. Adrian-Martinez; I. Al Samarai; A. Albert; M. Andre; M. Anghinolfi; G. Anton; S. Anvar; M. Ardid; T. Astraatmadja; J. -J. Aubert; B. Baret; S. Basa; V. Bertin; S. Biagi; C. Bigongiari; C. Bogazzi; M. Bou-Cabo; B. Bouhou; M. C. Bouwhuis; J. Brunner; J. Busto; A. Capone; C. Carloganu; J. Carr; S. Cecchini; Z. Charif; Ph. Charvis; T. Chiarusi; M. Circella; R. Coniglione; L. Core; H. Costantini; P. Coyle; A. Creusot; C. Curtil; G. De Bonis; M. P. Decowski; I. Dekeyser; A. Deschamps; C. Distefano; C. Donzaud; D. Dornic; Q. Dorosti; D. Drouhin; T. Eberl; U. Emanuele; A. Enzenhoefer; J. -P. Ernenwein; S. Escoffier; K. Fehn; P. Fermani; M. Ferri; S. Ferry; V. Flaminio; F. Folger; U. Fritsch; J. -L. Fuda; S. Galata; P. Gay; K. Geyer; G. Giacomelli; V. Giordano; A. Gleixner; J. P. Gomez-Gonzalez; K. Graf; G. Guillard; G. Hallewell; M. Hamal; H. van Haren; A. J. Heijboer; Y. Hello; J. J. Hernandez-Rey; B. Herold; J. Hoessl; C. C. Hsu; M. de Jong; M. Kadler; O. Kalekin; A. Kappes; U. Katz; O. Kavatsyuk; P. Kooijman; C. Kopper; A. Kouchner; I. Kreykenbohm; V. Kulikovskiy; R. Lahmann; G. Lambard; G. Larosa; D. Lattuada; D. Lefevre; G. Lim; D. Lo Presti; H. Loehner; S. Loucatos; F. Louis; S. Mangano; M. Marcelin; A. Margiotta; J. A. Martinez-Mora; A. Meli; T. Montaruli; M. Morganti; L. Moscoso; H. Motz; M. Neff; E. Nezri; D. Palioselitis; G. E. Pavalas; K. Payet; J. Petrovic; P. Piattelli; V. Popa; T. Pradier; E. Presani; C. Racca; C. Reed; G. Riccobene; C. Richardt; R. Richter; C. Riviere; A. Robert; K. Roensch; A. Rostovtsev; J. Ruiz-Rivas; M. Rujoiu; G. V. Russo; D. F. E. Samtleben; A. Sanchez-Losa; P. Sapienza; J. Schmid; J. Schnabel; F. Schoeck; J. -P. Schuller; F. Schuessler; T. Seitz; R. Shanidze; F. Simeone; A. Spies; M. Spurio; J. J. M. Steijger; Th. Stolarczyk; M. Taiuti; C. Tamburini; A. Trovato; B. Vallage; C. Vallee; V. Van Elewyck; M. Vecchi; P. Vernin; E. Visser; S. Wagner; G. Wijnker; J. Wilms; E. de Wolf; H. Yepes; D. Zaborov; J. D. Zornoza; J. Zuniga

    2012-07-02

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximum mixing, a mass difference of $\\Delta m_{32}^2=(3.1\\pm 0.9)\\cdot 10^{-3}$ eV$^2$ is obtained, in good agreement with the world average value.

  4. Brief introduction of the neutrino event generators

    SciTech Connect

    Hayato, Yoshinari

    2015-05-15

    The neutrino interaction simulation programs (event generators) play an important role in the neutrino experiments. This article briefly explains what is the neutrino event generator and how it works.

  5. Neutrino mass as the probe of intermediate mass scales

    SciTech Connect

    Senjanovic, G.

    1980-01-01

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

  6. Loop level constraints on Seesaw neutrino mixing

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    We perform a detailed study of the importance of loop corrections when deriving bounds on heavy-active neutrino mixing in the context of general Seesaw mechanisms with extra heavy right-handed neutrinos. We find that, for low-scale Seesaws with an approximate B - L symmetry characterized by electroweak scale Majorana masses and large Yukawas, loop corrections could indeed become relevant in a small part of the parameter space. Previous results in the literature showed that a partial cancellation between these important loop corrections and the tree level contributions could relax some constraints and lead to qualitatively different results upon their inclusion. However, we find that this cancellation can only take place in presence of large violations of the B - L symmetry, that lead to unacceptably large contributions to the light neutrino masses at loop level. Thus, when we restrict our analysis of the key observables to an approximate B - L symmetry so as to recover the correct values for neutrino masses, we always find loop corrections to be negligible in the regions of the parameter space preferred by data.

  7. Heavy sterile neutrinos and supernova explosions

    E-print Network

    George M. Fuller; Alexander Kusenko; Kalliopi Petraki

    2008-10-01

    We consider sterile neutrinos with rest masses ~0.2 GeV. Such sterile neutrinos could augment core collapse supernova shock energies by enhancing energy transport from the core to the vicinity of the shock front. The decay of these neutrinos could produce a flux of very energetic active neutrinos, detectable by future neutrino observations from a galactic supernova. The relevant range of sterile neutrino masses and mixing angles can be probed in future laboratory experiments.

  8. Probing non-standard neutrino interactions with supernova neutrinos

    E-print Network

    Esteban-Pretel, A; Valle, J W F

    2007-01-01

    We analyze the possibility of probing non-standard neutrino interactions (NSI, for short) through the detection of neutrinos produced in a future galactic supernova (SN).We consider the effect of NSI on the neutrino propagation through the SN envelope within a three-neutrino framework, paying special attention to the inclusion of NSI-induced resonant conversions, which may take place in the most deleptonised inner layers. We study the possibility of detecting NSI effects in a Megaton water Cherenkov detector, either through modulation effects in the $\\bar\

  9. Probing non-standard neutrino interactions with supernova neutrinos

    E-print Network

    A. Esteban-Pretel; R. Tomàs; J. W. F. Valle

    2007-04-02

    We analyze the possibility of probing non-standard neutrino interactions (NSI, for short) through the detection of neutrinos produced in a future galactic supernova (SN).We consider the effect of NSI on the neutrino propagation through the SN envelope within a three-neutrino framework, paying special attention to the inclusion of NSI-induced resonant conversions, which may take place in the most deleptonised inner layers. We study the possibility of detecting NSI effects in a Megaton water Cherenkov detector, either through modulation effects in the $\\bar\

  10. Searching for hep Neutrinos using the Sudbury Neutrino Observatory

    E-print Network

    Howard, Chris

    2009-01-01

    The Sudbury Neutrino Observatory has recently finished its third and final phase, and has accumulated over 1082 days of neutrino data, spanning the energy range from approximately 5-20 MeV. Almost all the observed neutrinos are due to the 8B reaction in the Sun. The so-called hep process (3He + p -> 4He + e + nu_e) also occurs in the Sun, but has not yet been observed. hep neutrino energy endpoint extends above the 8B spectrum. This paper describes the three phase analysis that will ultimately be the most sensitive to this reaction.

  11. Constraints on Neutrino-Neutrino Interactions from Primordial Nucleosynthesis

    E-print Network

    Eduard Massó; Ramon Toldrà

    1994-04-26

    We use the constraints arising from primordial nucleosynthesis to bound the strength $F$ of non-standard neutrino-neutrino interactions, when the right-handed neutrinos participate in the interaction. We find $F < 3 \\times 10^{-3}\\ G_F$, which is five orders of magnitude more stringent than the limit obtained using LEP data. We also show that secret interactions of neutrinos mediated by massless particles must have a coupling $f$ less than $2 \\times 10^{-5}$. This also ameliorates previous limits in the literature.

  12. Searching for hep Neutrinos using the Sudbury Neutrino Observatory

    E-print Network

    Chris Howard; for the SNO Collaboration

    2009-05-29

    The Sudbury Neutrino Observatory has recently finished its third and final phase, and has accumulated over 1082 days of neutrino data, spanning the energy range from approximately 5-20 MeV. Almost all the observed neutrinos are due to the 8B reaction in the Sun. The so-called hep process (3He + p -> 4He + e + nu_e) also occurs in the Sun, but has not yet been observed. hep neutrino energy endpoint extends above the 8B spectrum. This paper describes the three phase analysis that will ultimately be the most sensitive to this reaction.

  13. Neutrino symmetries from high to low scales

    SciTech Connect

    Roy, Probir

    2007-10-03

    Proposed symmetry relations, e.g., quark-lepton complementarity (QLC) or tribimaximal mixing (TBM), need to be imposed at a high scale and {approx}10{sup 12} GeV characterising the large masses of right-handed neutrinos required to implement the seesaw mechanism. RG evolution down to the laboratory scale {lambda}{approx}10{sup 3} GeV, generically prone to spoil these relations and their predicted neutrino mixing patterns, can be made to preserve them by appropriately constraining the Majorana phases {alpha}{sub 2,3}. This is explicitly demonstrated in the MSSM for two versions of QLC and two versions of TBM. A preference for {alpha}{sub 2}{approx_equal}{pi} (i.e. m{sub 1}{approx_equal}-m{sub 2}) emerges in each case. Discrimination among the four cases is shown to be possible by future measurements of {theta}{sub 13}.

  14. Neutrino Mixing from ?(6n2) Groups

    NASA Astrophysics Data System (ADS)

    Neder, Thomas

    2015-04-01

    Experimentally viable lepton mixing parameters can be predicted in so-called direct flavour models with Majorana neutrinos using ?(6n2) groups as a flavour group. In direct models, in which the flavour group is broken to a Z2 × Z2 subgroup in the neutrino sector, mixing angles and Dirac CP phase are purely predicted from symmetry. General predictions of direct models with ?(6n2) flavour groups are that all mixing angles are fixed up to a discrete choice and that the Dirac CP phase is 0 or ? Furthermore, the middle column of the mixing matrix is trimaximal which yields the sum rule ?23 = 45° ± ?13/?2 depending on the Dirac phase. These predictions of lepton mixing parameters are compatible with recent global fit results or will be tested experimentally in the near future. It is the first time that such predictions have been obtained model-independently for an infinite series of groups.

  15. Discrete symmetries and mixing of Dirac neutrinos

    NASA Astrophysics Data System (ADS)

    Esmaili, Arman; Smirnov, Alexei Yu.

    2015-11-01

    We study the mixing of the Dirac neutrinos in the residual symmetries approach. The key difference from the Majorana case is that the Dirac mass matrix may have larger symmetries: G?=Zn with n ?3 . The symmetry group relations have been generalized to the case of Dirac neutrinos. Using them, we have found all new relations between mixing parameters and corresponding symmetry assignments, which are in agreement with the present data. The viable relations exist only for the charged lepton residual symmetry G?=Z2. The relations involve elements of the rows of the Pontecorvo-Maki-Nakagawa-Sakata matrix and lead to precise predictions of the 2-3 mixing angle and certain ranges of the C P violation phase. For larger symmetries G?, an agreement with the data can be achieved if ˜10 % corrections related to breaking of G? and G? are included.

  16. Unparticle physics and neutrino phenomenology

    SciTech Connect

    Barranco, J.; Bolanos, A.; Miranda, O. G.; Moura, C. A.; Rashba, T. I.

    2009-04-01

    We have constrained unparticle interactions with neutrinos and electrons using available data on neutrino-electron elastic scattering and the four CERN LEP experiments data on mono photon production. We have found that, for neutrino-electron elastic scattering, the MUNU experiment gives better constraints than previous reported limits in the region d>1.5. The results are compared with the current astrophysical limits, pointing out the cases where these limits may or may not apply. We also discuss the sensitivity of future experiments to unparticle physics. In particular, we show that the measurement of coherent reactor neutrino scattering off nuclei could provide a good sensitivity to the couplings of unparticle interaction with neutrinos and quarks. We also discuss the case of future neutrino-electron experiments as well as the International Linear Collider.

  17. Probing Superluminal Neutrinos Via Refraction

    E-print Network

    Albert Stebbins

    2011-10-12

    One phenomenological explanation of superluminal propagation of neutrinos, which may have been observed by OPERA and MINOS, is that neutrinos travel faster inside of matter than in vacuum. If so neutrinos exhibit refraction inside matter and should exhibit other manifestations of refraction, such as deflection and reflection. Such refraction would be easily detectable through the momentum imparted to appropriately shaped refractive material inserted into the neutrino beam. For NuMI this could be as large as ~10g cm/s. If these effect were found, they would provide new ways of manipulating and detecting neutrinos. Reasons why this scenario seems implausible are given, however it is still worthwhile to conduct simple searches for differential refraction of neutrinos.

  18. Neutrinos And Big Bang Nucleosynthesis

    E-print Network

    Steigman, Gary

    2012-01-01

    According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders this neutrino background undetectable with current technology. The cosmic neutrino background can, however, be probed indirectly through its cosmological effects on big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) radiation. In this BBN review, focused on neutrinos and, more generally on dark radiation, the BBN constraints on the number of "equivalent neutrinos" (dark radiation), on the baryon asymmetry (baryon density), and on a possible lepton asymmetry (neutrino degeneracy) are reviewed and updated. The BBN constraints on dark radiation and on the baryon density following from considerations of the primordial abundances of deuterium and helium-4 are in excellent agreement with the complementary results from the CMB, providing a suggestive, but curr...

  19. Solar neutrino experiments: An update

    SciTech Connect

    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.

  20. Astrophysical and cosmological constraints to neutrino properties

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  1. Muon colliders and neutrino factories

    SciTech Connect

    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.

  2. Muon Colliders and Neutrino Factories

    SciTech Connect

    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.

  3. Advancements in Solar Neutrino Physics

    NASA Astrophysics Data System (ADS)

    Miramonti, Lino; Antonelli, Vito

    2013-05-01

    We review the results of solar neutrino physics, with particular attention to the data obtained and the analyses performed in the last decades, which were determinant to solve the solar neutrino problem (SNP), proving that neutrinos are massive and oscillating particles and contributing to refine the solar models. We also discuss the perspectives of the presently running experiments in this sector and of the ones planned for the near future and the impact they can have on elementary particle physics and astrophysics.

  4. Quantum coherence of relic neutrinos.

    PubMed

    Fuller, George M; Kishimoto, Chad T

    2009-05-22

    We argue that in at least a portion of the history of the Universe the relic background neutrinos are spatially extended, coherent superpositions of mass states. We show that an appropriate quantum mechanical treatment affects the neutrino mass values derived from cosmological data. The coherence scale of these neutrino flavor wave packets can be an appreciable fraction of the causal horizon size, raising the possibility of spacetime curvature-induced decoherence. PMID:19519016

  5. Neutrino Masses and Flavor Mixing

    NASA Astrophysics Data System (ADS)

    Fritzsch, Harald

    We discuss the neutrino oscillations, using texture zero mass matrices for the leptons. The reactor mixing angle ?l is calculated. The ratio of the masses of two neutrinos is determined by the solar mixing angle. We can calculate the masses of the three neutrinos: m1 ? 0.003 eV, m2 ? 0.012 eV, m3 ? 0.048 eV.

  6. Challenging the Neutrino Mass with Cuore

    NASA Astrophysics Data System (ADS)

    Ferroni, F.

    2008-06-01

    One of the fundamental questions still open in elementary particle is the nature of the neutrino mass. Whether Dirac or Majorana, its knowledge would deeply impact the development of the field. Double Beta Decay experiments are, although extremely challenging, the only way known that might give an answer to the question. In this paper one of the second generation experiment that aims to get the sensitivity for probing the inverted hierarchy will be discussed. It is CUORE, in preparation at the Gran Sasso underground laboratories of INFN.

  7. Supernova neutrinos and explosive nucleosynthesis

    SciTech Connect

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

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and ?{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.

  8. Neutrino clouds and dark matter

    SciTech Connect

    Goldman, T.; McKellar, B.H.J.; Stephenson, G.J. Jr.

    1996-12-31

    We have examined the consequences of assuming the existence of a light scalar boson, weakly coupled to neutrinos, and not coupled to any other light fermions. For a range of parameters, we find that this hypothesis leads to the development of neutrino clusters which form in the early Universe and which provide gravitational fluctuations on scales small compared to a parsec (i.e., the scale of solar systems). Under some conditions, this can produce anomalous gravitational acceleration within solar systems and lead to a vanishing of neutrino mass-squared differences, giving rise to strong neutrino oscillation effects.

  9. Magnetic Dipole Moment of Neutrino

    E-print Network

    Samina S. Masood

    2015-06-03

    We recalculate the magnetic moment of neutrinos in a hot and dense medium. The magnetic dipole moment of neutrinos is modified at high temperature and chemical potential. We show that the magnetic dipole moment of electron neutrino does not get a significant contribution from thermal background to meet the cosmological bound. However, chemical potential contribution to the magnetic moment is non-ignorable even when chemical potential is an order of magnitude greater than the electron mass. It is demonstrated that this effect is more significant in the models with an extended Higgs sector through neutrino mixing.

  10. Proton and Neutrino Extragalactic Astronomy

    E-print Network

    Paolo Lipari

    2008-08-04

    The study of extragalactic sources of high energy radiation via the direct measurement of the proton and neutrino fluxes that they are likely to emit is one of the main goals for the future observations of the recently developed air showers detectors and neutrino telescopes. In this work we discuss the relation between the inclusive proton and neutrino signals from the ensemble of all sources in the universe, and the resolved signals from the closest and brightest objects. We also compare the sensitivities of proton and neutrino telescopes and comment on the relation between these two new astronomies.

  11. MINOS Search for Sterile Neutrinos

    E-print Network

    Alexandre Sousa; on behalf of the MINOS Collaboration

    2011-10-16

    Using a NuMI beam exposure of 7.1 /times 10^20 protons-on-target, the MINOS long-baseline experiment has performed a search for active to sterile neutrino mixing over a distance of 735 km. Details of the analysis are provided, along with results from comparisons with standard three neutrino oscillations and fits to a 3+1 model including oscillations into one sterile neutrino. An outlook on the future sterile neutrino related contributions from MINOS and the proposed MINOS+ project is also presented.

  12. Generating $\\theta_{13}$ from sterile neutrinos in $\\mu - \\tau$ symmetric models

    E-print Network

    Rivera-Agudelo, Diana C

    2015-01-01

    Smallness of $\\theta_{13}$ mixing angle as observed in neutrino oscillation experiments can be understood through an approximated $\\mu - \\tau$ exchange symmetry in the neutrino mass matrix. Using recent oscillation neutrino data, but assuming no CP violation, we study $\\mu-\\tau$ breaking parameter space to establish the conditions under which such a breaking could have a perturbative origin. According to the so obtained conditions, we suggest that a sterile neutrino, matching LSND/MiniBooNE neutrino oscillation results, could provide the necessary ingredients to properly fix atmospheric and $\\theta_{13}$ mixing angles to observable values, without exceeding the sterile neutrino fraction bound in solar oscillations. In such a scenario, we analyze the general effect of a fourth neutrino on the prediction for the effective $m_{ee}$ majorana mass parameter.

  13. Sneutrino dark matter in gauged inverse seesaw models for neutrinos.

    PubMed

    An, Haipeng; Dev, P S Bhupal; Cai, Yi; Mohapatra, R N

    2012-02-24

    Extending the minimal supersymmetric standard model to explain small neutrino masses via the inverse seesaw mechanism can lead to a new light supersymmetric scalar partner which can play the role of inelastic dark matter (IDM). It is a linear combination of the superpartners of the neutral fermions in the theory (the light left-handed neutrino and two heavy standard model singlet neutrinos) which can be very light with mass in ~5-20 GeV range, as suggested by some current direct detection experiments. The IDM in this class of models has keV-scale mass splitting, which is intimately connected to the small Majorana masses of neutrinos. We predict the differential scattering rate and annual modulation of the IDM signal which can be testable at future germanium- and xenon-based detectors. PMID:22463522

  14. Lepton generation-weighting factors and neutrino mass formula

    E-print Network

    Wojciech Krolikowski

    2005-03-08

    A candidate for the simple empirical neutrino mass formula is found, predicting the mass proportion m_1:m_2:m_3 = 0:4:24 and so, the mass ratio Delta m^2_{32}/Delta m^2_{21} = 35 not inconsistent with its experimental estimate. It involves only one free parameter and three generation-weighting factors suggested by the successful mass formula found previously for charged leptons (the simplest neutrino mass formula would predict m_1:m_2:m_3 = 1:4:24 and thus, Delta m^2_{32}/Delta m^2_{21} \\simeq 37). A more involved variation of this equation follows from a special seesaw neutrino model with specifically "conspiring" Dirac and Majorana neutrino mass matrices. In this variation m_1:m_2:m_3 \\simeq \\epsilon^{(\

  15. The Enigmatic Neutrino

    NASA Astrophysics Data System (ADS)

    Lincoln, Don; Miceli, Tia

    2015-09-01

    Through a century of work, physicists have refined a model to describe all fundamental particles, the forces they share, and their interactions on a microscopic scale. This masterpiece of science is called the Standard Model. While this theory is incredibly powerful, we know of at least one particle that exhibits behaviors that are outside of its scope and remain unexplained. These particles are called neutrinos and they are the enigmatic ghosts of the quantum world. Interacting only via the weak nuclear force, literally billions of them pass through you undetected every second. While we understand that particular spooky behavior, we do not understand in any fundamental way how it is that neutrinos can literally change their identity, much as if a house cat could turn into a lion and then a tiger before transitioning back into a house cat again.

  16. Helioseismology and Beryllium neutrino

    E-print Network

    B. Ricci; F. L. Villante; M. Lissia

    1999-04-06

    We derive a lower limit on the Beryllium neutrino flux on earth, $\\Phi(Be)_{min} = 1\\cdot 10^9 cm^{-2} s^{-1}$, in the absence of oscillations, by using helioseismic data, the B-neutrino flux measured by Superkamiokande and the hydrogen abundance at the solar center predicted by Standard Solar Model (SSM) calculations. We emphasize that this abundance is the only result of SSMs needed for getting $\\Phi(Be)_{min}$. We also derive lower bounds for the Gallium signal, $G_{min}=(91 \\pm 3) $ SNU, and for the Chlorine signal, $C_{min}=(3.24\\pm 0.14)$ SNU, which are about $3\\sigma$ above their corresponding experimental values, $G_{exp}= (72\\pm 6)$ SNU and $C_{exp}= (2.56\\pm 0.22) $ SNU.

  17. Superbeams versus Neutrino Factories

    E-print Network

    Huber, P; Winter, W; Huber, Patrick; Lindner, Manfred; Winter, Walter

    2002-01-01

    We compare the physics potential of planned superbeams with the one of neutrino factories. Therefore, the experimental setups as well as the most relevant uncertainties and errors are considered on the same footing as much as possible. We use an improved analysis including the full parameter correlations, as well as statistical, systematical, and degeneracy errors. Especially, degeneracies have so far not been taken into account in a numerical analysis. We furthermore include external input, such as improved knowledge of the solar oscillation parameters from the KamLAND experiment. This allows us to determine the limiting uncertainties in all cases. For a specific comparison, we choose two representatives of each class: For the superbeam, we take the first conceivable setup, namely the JHF to SuperKamiokande experiment, as well as, on a longer time scale, the JHF to HyperKamiokande experiment. For the neutrino factory, we choose an initially conceivable setup and an advanced machine. We determine the potentia...

  18. Neutrino Factory Target Vessel

    E-print Network

    McDonald, Kirk

    Neutrino Factory Target Vessel Concept V. Graves Target Studies EVO May 1, 2012 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Concept 1 May 2012 Review ­ Two Target Vessel Ideas · Solid-Battelle for the U.S. Department of Energy Target Vessel Concept 1 May 2012 #12;4 Managed by UT-Battelle for the U

  19. Birth of Neutrino Astrophysics

    SciTech Connect

    2010-05-07

    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.

  20. Natural Neutrino Dark Energy

    SciTech Connect

    Gurwich, Ilya

    2010-06-23

    1 construct a general description for neutrino dark energy models, that do not require exotic particles or strange couplings. With the help of the above, this class of models is reduced to a single function with several constraints. It is shown that these models lead to some concrete predictions that can be verified (or disproved) within the next decade, using results from PLANK, EUCLID and JDEM.

  1. Neutrino and Extra World

    E-print Network

    D. S. Baranov; G. G. Volkov

    2012-11-20

    The neutrino speed measurement experiments are the continuations of the classic light speed measurement experiments have been done in range of the solar planet system (Ole Roemer, 1676), in star system (James Braidely, 1728) and, at last, on the Earth (Lois Fizeau, 1849),.... The finite light speed measurement has led to the revolution in the humanity consciousness and eventually led to a new understanding of the visible universe. In 1998-2005, we had a lot of excited discussions at CERN about the possibilities to perform the neutrino experiments to test the superluminal neutrino hypothesis and to find new phenomena beyond the SM. From one hand the idea of such experiments was associated with the hope to understand the role of the V-A- weak interactions, the quark-lepton family symmetry, the neutrino space-time properties and to observe some indications on a new vacuum structure existence outside of the Weak Scale, i.e. in the region 1/R ~ (0.1-20) TeV. From another hand the general trends of this idea has been related to the possible existence some extra space-time noncompact dimensions of the universe. In this context it would be first serious encounter with the dual conception between the physical phenomena of microcosmos and of universe. One of the main goals is to find some new space-time peculiarities and structures that might explain the formation of our visible D=(3+1)-universe with all its space-time and internal symmetries which could be only a part of a vast Universe filled with other kinds of matter. The main difficulties of such experiments related to the possible relativity principle paradoxes have been discussed.

  2. Neutrinos in the Electron

    E-print Network

    E. L. Koschmieder

    2006-09-26

    We will show that one half of the rest mass of the electron is equal to the sum of the rest masses of electron neutrinos and that the other half of the rest mass of the electron is given by the energy in the sum of electric oscillations. With this composition we can explain the rest mass, the electric charge, the spin and the magnetic moment of the electron.

  3. Birth of Neutrino Astrophysics

    ScienceCinema

    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.

  4. Neutrino Anisotropies after Planck

    E-print Network

    Gerbino, Martina; Said, Najla

    2013-01-01

    We present new constraints on the rest-frame sound speed, c_eff^2, and the viscosity parameter, c_vis^2, of the Cosmic Neutrino Background from the recent measurements of the Cosmic Microwave Background anisotropies provided by the Planck satellite. While broadly consistent with the ex- pectations of c_eff^2 = c_vis^2 = 1/3 in the standard scenario, the Planck dataset hints for a higher value of the viscosity parameter, with c_vis^2 = 0.60 +/- 0.18 at 68% c.l., and a lower value of the sound speed, with c_eff^2 = 0.304 +/- 0.013 at 68% c.l.. We find a correlation between the neutrino parameters and the lensing amplitude of the temperature power spectrum A_L. When the latter parameter is allowed to vary, we find a better consistency with the standard model with c_vis^2 = 0.51 +/- 0.22, c_eff^2 = 0.311 +/- 0.019 and A_L = 1.08 +/- 0.18 at 68% c.l.. This result indicates that the anomalous large value of A_L measured by Planck could be connected to non-standard neutrino properties. Including additional datasets ...

  5. Sterile neutrino at the Deep Underground Neutrino Experiment

    NASA Astrophysics Data System (ADS)

    Berryman, Jeffrey M.; de Gouvêa, André; Kelly, Kevin J.; Kobach, Andrew

    2015-10-01

    We investigate the potential for the Deep Underground Neutrino Experiment (DUNE) to probe the existence and effects of a fourth neutrino mass eigenstate. We study the mixing of the fourth mass eigenstate with the three active neutrinos of the Standard Model, including the effects of new sources of C P -invariance violation, for a wide range of new mass-squared differences, from lower than 10-5 eV2 to higher than 1 eV2 . DUNE is sensitive to previously unexplored regions of the mixing angle-mass-squared difference parameter space. If there is a fourth neutrino, in some regions of the parameter space, DUNE is able to measure the new oscillation parameters (some very precisely) and clearly identify two independent sources of C P -invariance violation. Finally, we use the hypothesis that there are four neutrino mass eigenstates in order to ascertain how well DUNE can test the limits of the three-massive-neutrinos paradigm. In this way, we briefly explore whether light sterile neutrinos can serve as proxies for other, in principle unknown, phenomena that might manifest themselves in long-baseline neutrino oscillation experiments.

  6. Neutrino self-energy operator and neutrino magnetic moment

    SciTech Connect

    Dobrynina, A. A. Mikheev, N. V.; Narynskaya, E. N.

    2013-11-15

    A simple method for calculating the magnetic moment of a massive neutrino on the basis of its self-energy operator is presented. An expression for the magnetic moment of a massive neutrino in an external electromagnetic field is obtained in the R{sub {xi}} gauge for the case of an arbitrary ratio of the lepton and W-boson masses.

  7. Sensitivity of neutrino mass experiments to the cosmic neutrino background

    E-print Network

    Formaggio, Joseph A.

    The KATRIN neutrino experiment is a next-generation tritium beta decay experiment aimed at measuring the mass of the electron neutrino to better than 200 meV at 90% C.L. Because of its intense tritium source, KATRIN can ...

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  9. Neutrinos from the Early Universe and physics beyond standard models

    NASA Astrophysics Data System (ADS)

    Kirilova, Daniela

    2015-01-01

    Neutrino oscillations present the only robust example of experimentally detected physics beyond the standard model. This review discusses the established and several hypothetical beyond standard models neutrino characteristics and their cosmological effects and constraints. Particularly, the contemporary cosmological constraints on the number of neutrino families, neutrino mass differences and mixing, lepton asymmetry in the neutrino sector, neutrino masses, light sterile neutrino are briefly reviewed.

  10. Three loop neutrino model with isolated k±±

    NASA Astrophysics Data System (ADS)

    Nishiwaki, Kenji; Okada, Hiroshi; Orikasa, Yuta

    2015-11-01

    We propose a three loop radiative neutrino mass scenario with an isolated doubly charged singlet scalar k±± without couplings to the charged leptons, while two other singly charged scalars h1± and h2± attach to them. In this setup, the lepton flavor violation originating from k±± exchanges is suppressed and the model is less constrained, where some couplings can take sizable values. As reported in our previous work [1], the loop suppression factor at the three loop level would be too strong and realized neutrino masses in a three loop scenario could be smaller than the observed minuscule values. The sizable couplings can help us to enhance neutrino masses without drastically large scalar trilinear couplings appearing in a neutrino mass matrix, which tends to drive the vacuum stability to become jeopardized at the one loop level. Now the doubly charged scalar k±± has less constraint via lepton flavor violation and the vacuum can be quite stable, and thus a few hundred GeV mass in k±± is possible, which is within the LHC reach and this model can be tested in the near future. Note that the other h1± and h2± should be heavy at least around a few TeV. We suitably arrange the charges of an additional global U (1 ) symmetry, where the decay constant of the associated Nambu-Goldstone boson can be around a TeV scale consistently. Also, this model is indirectly limited through a global analysis on results of the LHC Higgs search and issues on a dark matter candidate, the lightest Majorana neutrino. After h1± and h2± are decoupled, this particle couples to the standard model particles only through two charge parity even scalars in theory and thus information on this scalar sector is important. Consistent solutions are found, but a part of them is now on the edge.

  11. Detailed Studies of neutrino oscillations with atmospheric neutrinos of wide energy range from 100

    E-print Network

    Tokyo, University of

    Detailed Studies of neutrino oscillations with atmospheric neutrinos of wide energy range from 100; #12; Abstract An experimental study on the neutrino oscillations with atmospheric neutrinos of wide;cit of the upward-going #23; #22; 's, and it implies neutrino oscillation. Several theories predict

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

    DOE PAGESBeta

    Ma, Ernest; Srivastava, Rahul

    2015-02-01

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

  13. An Anatomy of Neutrino Oscillations

    E-print Network

    W-Y. Pauchy Hwang

    2015-11-03

    We ponder about neutrino oscillations; a particle without a clear identity, a neutrino of a given flavor in fact does not satisfy the Dirac equation (which is used to define the mass eigen-states and mass eigen-values). This alters the basic treatment of neutrino oscillations, in that the Dirac spinors are defined as the mass eigen-states while the flavor states can only be given as linear combinations of the mass eigen-states (of Dirac equations). Even though neutrino masses are tiny, the impacts of several neutrino masses in a single reaction or a single decay, such as possible violation of the energy-momentum conservation, should not be overlooked. Among those sources of oscillating neutrinos, we point out that the ultra high energy cosmic rays (UHECR's) such as the proton of energy $10^{18}\\, eV$ or higher, used to think of being rather stable, can capture, in the matter media, an electron to convert into an electron-like neutrino and a spectator neutron. This would be the most important neutrino source of the UHECR origin.

  14. Neutrino Mysteries OLLI UC Irvine

    E-print Network

    Grossman, Emily

    of interactions: Creation: e ve + W Disappearance: ve e + W Scattering: ve ve via exchange of a Z The ve with the tau. These are called the flavor neutrino states. #12;Now Enters Quantum Mechanics The ve , v with the catchy names v , v , and v . These are called the neutrino mass states. For example, ve is a sum of v1

  15. Neutrino Physics and Astrophysics : Highlights

    E-print Network

    Henry Tsz-King Wong

    2007-02-28

    This article presents an overview of neutrino physics research, with highlights on the physics goals, results and interpretations of the current neutrino experiments and future directions and program. It is not meant to be a comprehensive account or detailed review article. Interested readers can pursue the details via the listed references.

  16. Observation of Geo-Neutrinos

    E-print Network

    Borexino Collaboration

    2010-03-20

    Geo-neutrinos, electron anti-neutrinos produced in beta decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. We report the first observation at more than 3$\\sigma$ C.L. of geo-neutrinos, performed with the Borexino detector at Laboratori Nazionali del Gran Sasso. Anti-neutrinos are detected through the neutron inverse beta decay reaction. With a 252.6 ton-yr fiducial exposure after all selection cuts, we detected 9.9^{+4.1}_{-3.4}(^{+14.6}_{-8.2}) geo-neutrino events, with errors corresponding to a 68.3%(99.73%) C.L. From the $\\ln{\\cal{L}}$ profile, the statistical significance of the Borexino geo-neutrino observation corresponds to a 99.997% C.L. Our measurement of the geo-neutrinos rate is 3.9^{+1.6}_{-1.3}(^{+5.8}_{-3.2}) events/(100ton-yr). This measurement rejects the hypothesis of an active geo-reactor in the Earth's core with a power above 3 TW at 95% C.L. The observed prompt positron spectrum above 2.6 MeV is compatible with that expected from european nuclear reactors (mean base line of approximately 1000 km). Our measurement of reactor anti-neutrinos excludes the non-oscillation hypothesis at 99.60% C.L.

  17. The Mass of the Neutrinos

    E-print Network

    Burra G. Sidharth

    2009-04-30

    In the theory of the Dirac equation and in the standard model, the neutrino is massless. Both these theories use Lorentz invariance. In modern approaches however, spacetime is no longer smooth, and this modifies special relativity. We show how such a modification throws up the mass of the neutrino.

  18. Is There a Massive Neutrino?

    ERIC Educational Resources Information Center

    Selvin, Paul

    1991-01-01

    Discussed is the question of whether "heavy" neutrinos really do exist based on the evidence supplied by four research groups. The implications of its existence on the disciplines of particle physics, astrophsyics, and cosmology are discussed. Background information on the different types of neutrinos is provided. (KR)

  19. Heavy Neutrinos at Future Colliders

    E-print Network

    Dev, P S Bhupal

    2016-01-01

    We discuss the current status and future prospects of heavy neutrino searches at the energy frontier, which might play an important role in vindicating the simplest seesaw paradigm as the new physics responsible for neutrino mass generation. After summarizing the current search limits and potential improvements at hadron colliders, we highlight the unparalleled sensitivities achievable in the clean environment of future lepton colliders.

  20. The Higgs seesaw induced neutrino masses and dark matter

    NASA Astrophysics Data System (ADS)

    Cai, Yi; Chao, Wei

    2015-10-01

    In this paper we propose a possible explanation of the active neutrino Majorana masses with the TeV scale new physics which also provide a dark matter candidate. We extend the Standard Model (SM) with a local U(1) ? symmetry and introduce a seesaw relation for the vacuum expectation values (VEVs) of the exotic scalar singlets, which break the U(1) ? spontaneously. The larger VEV is responsible for generating the Dirac mass term of the heavy neutrinos, while the smaller for the Majorana mass term. As a result active neutrino masses are generated via the modified inverse seesaw mechanism. The lightest of the new fermion singlets, which are introduced to cancel the U(1) ? anomalies, can be a stable particle with ultra flavor symmetry and thus a plausible dark matter candidate. We explore the parameter space with constraints from the dark matter relic abundance and dark matter direct detection. All the mass terms (Dirac and Majorana mass terms) originate from the spontaneous breaking of local gauge symmetries in our model. The smallness of the Majorana mass term (? term in the traditional inverse seesaw model) is naturally explained by the so-called Higgs seesaw mechanism. The dark matter phenomenology is closely correlated with the neutrino physics via the U(1) ? gauge symmetry in our model. We study constraints on the parameter space of this model from astrophysical observation and dark matter direct detections.The paper is organized as follows. In Section 2 we describe our model, including the full Lagrangian, Higgs VEVs and mass spectrum. In Section 3 we study the neutrino masses and the effective lepton mixing matrix of the model. Section 4 is devoted to the study of the dark matter phenomenology. We summarize in Section 5.

  1. Solar neutrinos: experimental review and prospectives

    NASA Astrophysics Data System (ADS)

    Pallavicini, Marco

    2015-04-01

    Solar neutrino physics, after the golden age which led to the discovery of neutrino oscillations, is about to enter the precision era. We summarise here the current experimental knowledge in the field and the future perspectives, showing that solar neutrino detectors are and will remain in the near future a fundamental tool for a deeper understanding of stars, neutrinos, and fundamental physics.

  2. Solar Neutrinos and the Eclipse Effect

    E-print Network

    Mohan Narayan; G. Rajasekaran; Rahul Sinha; C. P. Burgess

    1999-09-01

    The solar neutrino counting rate in a real time detector like Super--Kamiokanda, SNO, or Borexino is enhanced due to neutrino oscillations in the Moon during a partial or total solar eclipse. The enhancement is calculated as a function of the neutrino parameters in the case of three flavor mixing. This enhancement, if seen, can further help to determine the neutrino parameters.

  3. Hyperon Production from Neutrino-Nucleon Reaction

    NASA Astrophysics Data System (ADS)

    Wu, Jia-Jun; Zou, Bing-Song

    2015-05-01

    The neutrino induced hyperon production processes may provide a unique clean place for studying low energy interaction and hyperon resonances below KN threshold. The production rates for some neutrino induced hyperon production processes are estimated with theoretical models. Suggestions are made for the study of hyperon production from neutrino-nucleon reaction at present and future neutrino facilities.

  4. Neutrino mass models and CP violation

    SciTech Connect

    Joshipura, Anjan S.

    2011-10-06

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

  5. Electromagnetic neutrinos in laboratory experiments and astrophysics

    E-print Network

    Carlo Giunti; Konstantin A. Kouzakov; Yu-Feng Li; Alexey V. Lokhov; Alexander I. Studenikin; Shun Zhou

    2015-11-12

    An overview of neutrino electromagnetic properties, which open a door to the new physics beyond the Standard Model, is given. The effects of neutrino electromagnetic interactions both in terrestrial experiments and in astrophysical environments are discussed. The experimental bounds on neutrino electromagnetic characteristics are summarized. Future astrophysical probes of electromagnetic neutrinos are outlined.

  6. Thermodynamic Laws of Neutrino and Photon Emission.

    ERIC Educational Resources Information Center

    Walsh, P. J.; Gallo, C. F.

    1980-01-01

    Compares neutrino and photon emissions, develops the thermodynamic blackbody laws of neutrino emission analogous to laws governing photon emission, points out that combined radiation from a "true blackbody" consists of both photon and neutrino emissions of comparable magnitude, and speculates upon the existence of blackbody neutrino emitters in…

  7. Big World of Small Neutrinos Hitoshi Murayama

    E-print Network

    Murayama, Hitoshi

    Big World of Small Neutrinos Hitoshi Murayama UC Berkeley / LBNL Harvard, Dec 9, 2002 #12;Harvard colloquium 2 Neutrinos are Everywhere #12;Harvard colloquium 3 "Wimpy and Abundant" Neutrinos are Everywhere · They come from the Big Bang: ­ When the Universe was hot, neutrinos were created equally with any other

  8. Lepton flavor violating Higgs boson decays from massive seesaw neutrinos

    SciTech Connect

    Arganda, Ernesto; Curiel, Ana M.; Herrero, Maria J.; Temes, David

    2005-02-01

    Lepton flavor violating Higgs boson decays are studied within the context of seesaw models with Majorana massive neutrinos. Two models are considered: the SM-seesaw, with the standard model particle content plus three right-handed neutrinos, and the MSSM-seesaw, with the minimal supersymmetric standard model particle content plus three right-handed neutrinos and their supersymmetric partners. The widths for these decays are derived from a full one-loop diagrammatic computation in both models, and they are analyzed numerically in terms of the seesaw parameters, namely, the Dirac and Majorana mass matrices. Several possible scenarios for these mass matrices that are compatible with neutrino data are considered. In the SM-seesaw case, very small branching ratios are found for all studied scenarios. These ratios are explained as a consequence of the decoupling behavior of the heavy right-handed neutrinos. In contrast, in the MSSM-seesaw case, sizable branching ratios are found for some of the leptonic flavor violating decays of the MSSM neutral Higgs bosons and for some choices of the seesaw matrices and MSSM parameters. The relevance of the two competing sources of lepton flavor changing interactions in the MSSM-seesaw case is also discussed. The nondecoupling behavior of the supersymmetric particles contributing in the loop diagrams is finally shown.

  9. Oscillations of solar atmosphere neutrinos

    SciTech Connect

    Fogli, G. L.; Lisi, E.; Mirizzi, A.; Montanino, D.; Serpico, P. D.

    2006-11-01

    The Sun is a source of high-energy neutrinos (E(greater-or-similar sign)10 GeV) produced by cosmic ray interactions in the solar atmosphere. We study the impact of three-flavor oscillations (in vacuum and in matter) on solar atmosphere neutrinos, and calculate their observable fluxes at Earth, as well as their event rates in a kilometer-scale detector in water or ice. We find that peculiar three-flavor oscillation effects in matter, which can occur in the energy range probed by solar atmosphere neutrinos, are significantly suppressed by averaging over the production region and over the neutrino and antineutrino components. In particular, we find that the relation between the neutrino fluxes at the Sun and at the Earth can be approximately expressed in terms of phase-averaged vacuum oscillations, dominated by a single mixing parameter (the angle {theta}{sub 23})

  10. Reactor Monitoring with Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    Casimiro Linares, Edgar

    2011-09-01

    The study of the use of neutrino detectors to monitor nuclear reactors is currently a very active field of research. While neutrino detectors located close to reactors have been used to provide information about the global performance of the reactors, a general improvement of the technique is needed in order to use it in a practical way to monitor the fissile contents of the fuel of the nuclear reactors or the thermal power delivered. I describe the current status of the Angra Neutrino Project, aimed to building a low-mass neutrino detector to monitor the Angra II reactor of the Brazilian nuclear power plant Almirante Alvaro Ramos in order to explore new approaches to reactor monitoring with neutrino detectors.

  11. Neutrino oscillation results from MINOS

    SciTech Connect

    Sousa, Alexandre; /Oxford U.

    2007-08-01

    The Main Injector Neutrino Oscillation Search (MINOS) long-baseline experiment has been actively collecting beam data since 2005, having already accumulated 3 x 10{sup 20} protons-on-target (POT). MINOS uses the Neutrinos at the Main Injector (NuMI) neutrino beam measured in two locations: at Fermilab, close to beam production, and 735 km downstream, in Northern Minnesota. By observing the oscillatory structure in the neutrino energy spectrum, MINOS can precisely measure the neutrino oscillation parameters in the atmospheric sector. These parameters were determined to be |{Delta}m{sub 32}{sup 2}| = 2.74{sub -0.26}{sup +0.44} x 10{sup -3} eV{sup 2}/c{sup 4} and sin{sup 2}(2{theta}{sub 23}) > 0.87 (68% C.L.) from analysis of the first year of data, corresponding to 1.27 x 10{sup 20} POT.

  12. Neutrinos Get Under Your Skin

    SciTech Connect

    Kayser, Boris

    2005-08-30

    The enigmatic neutrinos are among the most abundant of the tiny particles that make up our universe. They are a billion times more abundant than the particles of which the earth and we humans are made. Thus, to understand the universe, we must understand the neutrinos. Moving ghostlike, almost invisibly, through matter, these particles are very hard to pin down and study. However, dramatic progress has recently been made. In this lecture, the neutrinos will be introduced. Their behavior, so different from that of everyday objects, will be explained, and recent discoveries will be described. The open questions about neutrinos, forthcoming attempts to answer these questions, and the role of neutrinos in shaping the universe and making human life possible, will all be explained.

  13. Status of High-Energy Neutrino Astronomy

    NASA Astrophysics Data System (ADS)

    Kowalski, Marek

    2015-08-01

    With the recent discovery of high-energy neutrinos of extra-terrestrial origin by the IceCube neutrino observatory, neutrino-astronomy is entering a new era. This review will cover currently operating open water/ice neutrino telescopes, the latest evidence for a flux of extra-terrestrial neutrinos and current efforts in the search for steady and transient neutrino point sources. Generalised constraints on potential astrophysical sources are presented, allowing to focus the hunt for the sources of the observed high-energy neutrinos.

  14. Neutrino flux in the rotating reference frame

    E-print Network

    D. L. Khokhlov

    2000-11-06

    It is considered neutrino flux in the rotating reference frame. Due to the rotation of the frame, neutrino is observed as a superposition of two states P-transformed one from another. Since P-transformation is forbidden for neutrino, in the rotating reference frame one can detect a half of neutrino flux. Due to the rotation of the earth, the detector of neutrinos can measure a half of the solar neutrino flux predicted by the SSM that may provide a solution for the solar neutrino puzzle.

  15. ANTARES deep sea neutrino telescope results

    SciTech Connect

    Mangano, Salvatore; 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.

  16. Neutrino mixing from C P symmetry

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Yao, Chang-Yuan; Ding, Gui-Jun

    2015-10-01

    The neutrino mass matrix has remnant C P symmetry expressed in terms of the lepton mixing matrix, and vice versa the remnant C P transformations allow us to reconstruct the mixing matrix. We study the scenario that all four remnant C P transformations are preserved by the neutrino mass matrix. The most general parametrization of remnant C P transformations is presented. The lepton mixing matrix is completely fixed by the remnant C P , and its explicit form is derived. The necessary and sufficient condition for conserved Dirac C P violating phase is found. If the Klein four flavor symmetry generated by the postulated remnant C P transformations arises from a finite flavor symmetry group, the phenomenologically viable lepton flavor mixing would be the trimaximal pattern, both Dirac C P phase ?C P and Majorana phase ?31 are either 0 or ? while another Majorana phase ?21 is a rational multiple of ? . These general results are confirmed to be true in the case that the finite flavor symmetry group is ? (6 n2).

  17. Beaming Neutrinos and Anti-neutrinos across the Earth to Disentangle Neutrino Mixing Parameters

    NASA Astrophysics Data System (ADS)

    Fargion, Daniele; D'Armiento, Daniele; Desiati, Paolo; Paggi, Paolo

    2012-10-01

    A result from MINOS seemed to indicate that the mass splitting and mixing angle of anti-neutrinos is different from that of neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector. However, more recent MINOS data reduced the ??-\\bar{\

  18. Neutrino minimal standard model predictions for neutrinoless double beta decay

    SciTech Connect

    Bezrukov, F.

    2005-10-01

    Prediction of the effective Majorana mass for neutrinoless double {beta} decay in a simple extension of the standard model ({nu}MSM) is given. The model adds three right-handed neutrinos with masses smaller than the electroweak scale and explains dark matter of the Universe. This leads to constraints 1.3neutrino mass hierarchy and 13

  19. Geometry-free neutrino masses in curved spacetime

    E-print Network

    Atsushi Watanabe; Koichi Yoshioka

    2009-10-05

    The seesaw-induced neutrino mass is discussed in a generic class of curved spacetime, including the flat and warped extra dimensions. For Majorana masses in the bulk and on the boundary, the exact forms of seesaw-induced masses are derived by using the Kaluza-Klein mode expansion and the lepton number violating correlator for bulk fermion. It is found that the neutrino mass is determined without the knowledge of wave functions and whole background geometry when the metric factor is fixed on the boundary, e.g. by solving the hierarchy problem.

  20. Energy Dependence of Solar Neutrino Suppression and Bounds on the Neutrino Magnetic Moment

    E-print Network

    Joao Pulido; Ana M. Mourao

    1998-03-02

    An analysis of neutrino electron scattering as applied to the SuperKamiokande solar neutrino experiment with the data from the Homestake experiment leads to an upper bound on the neutrino magnetic moment in the range $\\mu_{\

  1. An angle to tackle the neutrinos

    E-print Network

    G. Rajasekaran

    2012-06-01

    A brief history of the discovery of neutrino oscillations and neutrino mass is presented highlighting the recent breakthrough in the determination of a crucial neutrino parameter by the Daya Bay and RENO reactor experiments. The importance of this parameter in the context of one of the goals of the India-based Neutrino Observatory (INO) project and also in advancing the frontier of neutrino physics is explained.

  2. Radiative corrections to light neutrino masses in low scale type I seesaw scenarios and neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Lopez-Pavon, J.; Molinaro, E.; Petcov, S. T.

    2015-11-01

    We perform a detailed analysis of the one-loop corrections to the light neutrino mass matrix within low scale type I seesaw extensions of the Standard Model and their implications in experimental searches for neutrinoless double beta decay. We show that a sizable contribution to the effective Majorana neutrino mass from the exchange of heavy Majorana neutrinos is always possible, provided one requires a fine-tuned cancellation between the tree-level and one-loop contribution to the light neutrino masses. We quantify the level of fine-tuning as a function of the seesaw parameters and introduce a generalisation of the Casas-Ibarra parametrization of the neutrino Yukawa matrix, which easily allows to include the one-loop corrections to the light neutrino masses.

  3. Radiative Corrections to Light Neutrino Masses in Low Scale Type I Seesaw Scenarios and Neutrinoless Double Beta Decay

    E-print Network

    J. Lopez-Pavon; E. Molinaro; S. T. Petcov

    2015-10-20

    We perform a detailed analysis of the one-loop corrections to the light neutrino mass matrix within low scale type I seesaw extensions of the Standard Model and their implications in experimental searches for neutrinoless double beta decay. We show that a sizable contribution to the effective Majorana neutrino mass from the exchange of heavy Majorana neutrinos is always possible, provided one requires a fine-tuned cancellation between the tree-level and one-loop contribution to the light neutrino masses. We quantify the level of fine-tuning as a function of the seesaw parameters and introduce a generalisation of the Casas-Ibarra parametrization of the neutrino Yukawa matrix, which easily allows to include the one-loop corrections to the light neutrino masses.

  4. Challenging Lorentz noninvariant neutrino oscillations without neutrino masses

    E-print Network

    V. Barger; D. Marfatia; K. Whisnant

    2007-07-25

    We show that the combined data from solar, long-baseline and reactor neutrino experiments can exclude the generalized bicycle model of Lorentz noninvariant direction-dependent and/or direction-independent oscillations of massless neutrinos. This model has five parameters, which is more than is needed in standard oscillation phenomenology with neutrino masses. Solar data alone are sufficient to exclude the pure direction-dependent case. The combination of solar and long-baseline data rules out the pure direction-independent case. With the addition of KamLAND data, a mixture of direction-dependent and direction-independent terms in the effective Hamiltonian is also excluded.

  5. MOON for a next-generation neutrino-less double-beta decay experiment: Present status and perspective

    SciTech Connect

    Shima, T.; Doe, P.J.; Ejiri, H.; Elliot, S.R.; Engel, J.; Finger, M.; Finger, M.; Fushimi, K.; Gehman, V.M.; Greenfield, M.B.; Hazama, R.; /Hiroshima U. /NIRS, Chiba

    2008-01-01

    The performance of the MOON detector for a next-generation neutrino-less double-beta decay experiment was evaluated by means of the Monte Carlo method. The MOON detector was found to be a feasible solution for the future experiment to search for the Majorana neutrino mass in the range of 100-30 meV.

  6. KARMEN: neutrino physics at ISIS

    NASA Astrophysics Data System (ADS)

    Zeitnitz, B.

    The KARMEN experiment at the pulsed spallation neutron facility ISIS is investigating neutrino properties and interactions by measuring neutrino-induced charged current 12C(??,e-)12N and, for the first time, neutral current 12C(?,?')12C* excitations of nuclei. Neutrino-nucleus interactions in the energy range up to 50 MeV are detected by a 56 ton high resolution liquid scintillation calorimeter with spectroscopic quality. Efficient background rejection results in clear neutrino signatures and allows reliable cross section measurements down to 10-42 cm2. After its first three years of data taking the experiment has identified and analysed more than 1000 neutrino-nucleus interactions. We present cross section results for neutrino-induced nuclear reactions with special emphasis on their implications for neutrino astrophysics, weak nuclear form factors and ?-e universality of neutral currents. KARMEN Collaboration: B. Armbruster, G. Drexlin, V. Eberhard, C. Eichner, K. Eitel, H. Gemmeke, W. Grandegger, D. Hunkel, T. Jannakos, M. Kleifges, J. Kleinfeller, P. Plischke, J. Rapp, J. Weber, J. Wochele, J. Wolf, S. Wölfle: Kernforschungszentrum Karlsruhe and Universität Karlsruhe. B. Bodmann, M. Ferstl, E. Finckh, T. Hanika, M. Hehle, J. Hößl, W. Kretschmer, H. Schmidt, O. Stumm: Universität Erlangen-Nürnberg. R. Maschuw: Universität Bonn. J.A. Edgington, B. Seligmann: Queen Mary and Westfield College, London. A.C. Dodd: Rutherford Appleton Laboratory. N.E. Booth: Oxford University.

  7. General RG Equations for Physical Neutrino Parameters and their Phenomenological Implications

    E-print Network

    J. A. Casas; J. R. Espinosa; A. Ibarra; I. Navarro

    1999-10-20

    The neutral leptonic sector of the Standard Model presumably consists of three neutrinos with non-zero Majorana masses with properties further determined by three mixing angles and three CP-violating phases. We derive the general renormalization group equations for these physical parameters and apply them to study the impact of radiative effects on neutrino physics. In particular, we examine the existing solutions to the solar and atmospheric neutrino problems, derive conclusions on their theoretical naturalness, and show how some of the measured neutrino parameters could be determined by purely radiative effects. For example, the mass splitting and mixing angle suggested by solar neutrino data could be entirely explained as a radiative effect if the small angle MSW solution is realized. On the other hand, the mass splitting required by atmospheric neutrino data is probably determined by unknown physics at a high energy scale. We also discuss the effect of non-zero CP-violating phases on radiative corrections.

  8. High-energy atmospheric neutrinos

    E-print Network

    S. I. Sinegovsky; A. A. Kochanov; T. S. Sinegovskaya

    2010-10-12

    High-energy neutrinos, arising from decays of mesons that were produced through the cosmic rays collisions with air nuclei, form unavoidable background noise in the astrophysical neutrino detection problem. The atmospheric neutrino flux above 1 PeV should be supposedly dominated by the contribution of charmed particle decays. These (prompt) neutrinos originated from decays of massive and shortlived particles, $D^\\pm$, $D^0$, $\\bar{D}{}^0$, $D_s^\\pm$, $\\Lambda^+_c$, form the most uncertain fraction of the high-energy atmospheric neutrino flux because of poor explored processes of the charm production. Besides, an ambiguity in high-energy behavior of pion and especially kaon production cross sections for nucleon-nucleus collisions may affect essentially the calculated neutrino flux. There is the energy region where above flux uncertainties superimpose. A new calculation presented here reveals sizable differences, up to the factor of 1.8 above 1 TeV, in muon neutrino flux predictions obtained with usage of known hadronic models, SIBYLL 2.1 and QGSJET-II. The atmospheric neutrino flux in the energy range $10-10^7$ GeV was computed within the 1D approach to solve nuclear cascade equations in the atmosphere, which takes into account non-scaling behavior of the inclusive cross-sections for the particle production, the rise of total inelastic hadron-nucleus cross-sections and nonpower-law character of the primary cosmic ray spectrum. This approach was recently tested in the atmospheric muon flux calculations [1]. The results of the neutrino flux calculations are compared with the Frejus, AMANDA-II and IceCube measurement data.

  9. MUON STORAGE RINGS - NEUTRINO FACTORIES

    SciTech Connect

    PARSA,Z.

    2000-05-30

    The concept of a muon storage ring based Neutrino Source (Neutrino Factory) has sparked considerable interest in the High Energy Physics community. Besides providing a first phase of a muon collider facility, it would generate more intense and well collimated neutrino beams than currently available. The BNL-AGS or some other proton driver would provide an intense proton beam that hits a target, produces pions that decay into muons. The muons must be cooled, accelerated and injected into a storage ring with a long straight section where they decay. The decays occurring in the straight sections of the ring would generate neutrino beams that could be directed to detectors located thousands of kilometers away, allowing studies of neutrino oscillations with precisions not currently accessible. For example, with the neutrino source at BNL, detectors at Soudan, Minnesota (1,715 km), and Gran Sasso, Italy (6,527 km) become very interesting possibilities. The feasibility of constructing and operating such a muon-storage-ring based Neutrino-Factory, including geotechnical questions related to building non-planar storage rings (e.g. at 8{degree} angle for BNL-Soudan, and 3{degree} angle for BNL-Gran Sasso) along with the design of the muon capture, cooling, acceleration, and storage ring for such a facility is being explored by the growing Neutrino Factory and Muon Collider Collaboration (NFMCC). The authors present overview of Neutrino Factory concept based on a muon storage ring, its components, physics opportunities, possible upgrade to a full muon collider, latest simulations of front-end, and a new bowtie-muon storage ring design.

  10. Superbeams vs. neutrino factories

    NASA Astrophysics Data System (ADS)

    Huber, P.; Lindner, M.; Winter, W.

    2002-11-01

    We compare the physics potential of planned superbeams with the one of neutrino factories. Therefore, the experimental setups as well as the most relevant uncertainties and errors are considered on the same footing as much as possible. We use an improved analysis including the full parameter correlations, as well as statistical, systematical, and degeneracy errors. Especially, degeneracies have so far not been taken into account in a numerical analysis. We furthermore include external input, such as improved knowledge of the solar oscillation parameters from the KamLAND experiment. This allows us to determine the limiting uncertainties in all cases. For a specific comparison, we choose two representatives of each class: for the superbeam, we take the first conceivable setup, namely, the JHF to SuperKamiokande experiment, as well as, on a longer time scale, the JHF to HyperKamiokande experiment. For the neutrino factory, we choose an initially conceivable setup and an advanced machine. We determine the potential to measure the small mixing angle sin 22 ?13, the sign of ?m231, and the leptonic CP phase ?CP, which also implies that we compare the limitations of the different setups. We find interesting results, such as the complete loss of the sensitivity to the sign of ?m231 due to degeneracies in many cases.

  11. Supernova neutrinos and nucleosynthesis

    E-print Network

    G. Martínez-Pinedo; T. Fischer; L. Huther

    2013-09-21

    Observations of metal-poor stars indicate that at least two different nucleosynthesis sites contribute to the production of r-process elements. One site is responsible for the production of light r-process elements ZFe. It suggest that neutrino-driven winds from core-collapse supernova are the main site for the production of these elements. We explore this possibility by performing nucleosynthesis calculations based on long term Boltzmann neutrino transport simulations. They are based on an Equation of State that reproduces recent constrains on the nuclear symmetry energy. We predict that the early ejecta is neutron-rich with Ye ~ 0.48, it becomes proton rich around 4 s and reaches Ye = 0.586 at 9 s when our simulation stops. The nucleosynthesis in this model produces elements between Zn and Mo, including 92Mo. The elemental abundances are consistent with the observations of the metal-poor star HD 12263. For the elements between Ge and Mo, we produce mainly the neutron-deficient isotopes. This prediction can be confirmed by observations of isotopic abundances in metal-poor stars. No elements heavier than Mo (Z=42) and no heavy r-process elements are produced in our calculations.

  12. Superbeams versus Neutrino Factories

    E-print Network

    Patrick Huber; Manfred Lindner; Walter Winter

    2002-07-30

    We compare the physics potential of planned superbeams with the one of neutrino factories. Therefore, the experimental setups as well as the most relevant uncertainties and errors are considered on the same footing as much as possible. We use an improved analysis including the full parameter correlations, as well as statistical, systematical, and degeneracy errors. Especially, degeneracies have so far not been taken into account in a numerical analysis. We furthermore include external input, such as improved knowledge of the solar oscillation parameters from the KamLAND experiment. This allows us to determine the limiting uncertainties in all cases. For a specific comparison, we choose two representatives of each class: For the superbeam, we take the first conceivable setup, namely the JHF to SuperKamiokande experiment, as well as, on a longer time scale, the JHF to HyperKamiokande experiment. For the neutrino factory, we choose an initially conceivable setup and an advanced machine. We determine the potential to measure the small mixing angle sin^2 2 theta_{13}, the sign of Delta m^2_{31}, and the leptonic CP phase $\\deltacp$, which also implies that we compare the limitations of the different setups. We find interesting results, such as the complete loss of the sensitivity to the sign of Delta m^2_{31} due to degeneracies in many cases.

  13. Report on solar neutrino experiments

    SciTech Connect

    Davis, R. Jr.; Cleveland, B.T.; Rowley, J.K.

    1984-01-01

    A summary is given of the status of solar neutrino research that includes results of the Brookhaven chlorine detector, a discussion of the development of the gallium, bromine, and lithium radiochemical detectors, and some proposals for direct counting detectors. The gallium and bromine radiochemical detectors are developed and are capable of giving critical information of interest about neutrino physics and the fusion reactions in the interior of the sun. A plan for building these detectors is outlined and a rough cost estimate is given. A review is given of the plans in the Soviet Union in solar neutrino research.

  14. Some remarks on solar neutrinos

    NASA Astrophysics Data System (ADS)

    Gough, D.

    2003-07-01

    In 1970 Fred Hoyle encouraged a study of solar neutrino production which led to along-term investigation of the influence of what have become known as `non-standard' processes (i.e. processes that are not accounted for in the relatively naively constructed so-called `standard' theoretical solar models). The outcome is a very much sounder understanding of the structure and dynamics of the Sun, which has yielded a knowledge of conditions in the energy-generating core so precise that one can set quite tight reliable constraints on neutrino-producing nuclear reactions, and thereby provide an important contribution to the study of neutrino transitions.

  15. Solar monopoles and terrestrial neutrinos

    SciTech Connect

    Frieman, J.

    1988-04-01

    Magnetic monopoles captured in the core of the sun may give rise to a substantial flux of energetic neutrinos by catalyzing the decay of solar hydrogen. We discuss the expected neutrino flux in underground detectors under different assumptions about solar interior conditions. Although a monopole flux as low as F/sub M/ /approximately/ 10/sup /minus/24/ cm/sup /minus/2/ sec/sup /minus/1/ sr/sup /minus/1/ could give rise to a neutrino flux above atmospheric background, due to M/bar M/ annihilation, this does not translate into a reliable monopole flux bound stronger than the Parker limit. 8 refs., 1 fig.

  16. An Anatomy of Neutrino Oscillations

    E-print Network

    Hwang, W-Y Pauchy

    2012-01-01

    To understand neutrino oscillations in the sense of quantum mechanics or quantum field theory, we describe how to use an off-diagonal (cross-generation) neutrino-Higgs(mass) interaction to simulate oscillations in a natural way. This results in an extra orthogonal SU_f (3) family gauge theory, which may help us to resolve a few outstanding puzzles - the question of why there are only three generations, the question of why the masses of neutrinos are so tiny, and the question of why the dark-matter world is so huge (25%) as compared to the visible ordinary-matter world (5%).

  17. Problems with Atmospheric Neutrino Oscillations

    E-print Network

    J. M. LoSecco

    1998-07-13

    The neutrino oscillation hypothesis does a poor job of representing the atmospheric neutrino anomaly. The anomaly is observed over 4 decades in path length and at least a factor of 30 in energy. This restricts the potential oscillation solutions to those with large amplitudes and mixing mass differences that are ruled out by other observations. The $\\Delta m^{2}$ region in the range $10^{-4} - 10^{-2}$ leads to inconsistencies within the atmospheric neutrino data itself. The observed value of $R$ seems to be incompatible with the $\\Delta m^{2}$ implied by recent results

  18. Neutrinos in Cosmology and Astrophysics

    E-print Network

    A. B. Balantekin; G. M. Fuller

    2013-03-15

    We briefly review the recent developments in neutrino physics and astrophysics which have import for frontline research in nuclear physics. These developments, we argue, tie nuclear physics to exciting developments in observational cosmology and astrophysics in new ways. Moreover, the behavior of neutrinos in dense matter is itself a fundamental problem in many-body quantum mechanics, in some ways akin to well-known issues in nuclear matter and nuclei, and in some ways radically different, especially because of nonlinearity and quantum de-coherence. The self-interacting neutrino gas is the only many body system driven by the weak interactions.

  19. Supernova neutrino nucleosynthesis of light elements with neutrino oscillations.

    PubMed

    Yoshida, Takashi; Kajino, Toshitaka; Yokomakura, Hidekazu; Kimura, Keiichi; Takamura, Akira; Hartmann, Dieter H

    2006-03-10

    Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the v process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current -process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a nonadiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations of the 7Li/11B ratio in stars showing signs of supernova enrichment could thus provide a unique test of neutrino oscillations and constrain their parameters and the mass hierarchy. PMID:16606251

  20. Presymmetry in the Standard Model with adulterated Dirac neutrinos

    NASA Astrophysics Data System (ADS)

    Matute, Ernesto A.

    2015-08-01

    Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the ’t Hooft’s naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.

  1. Presymmetry in the Standard Model with adulterated Dirac neutrinos

    E-print Network

    Ernesto A. Matute

    2015-10-21

    Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the 't Hooft's naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.

  2. Neutrino propagation in nuclear medium and neutrinoless double-? decay.

    PubMed

    Kovalenko, S; Krivoruchenko, M I; Simkovic, F

    2014-04-11

    We discuss a novel effect in neutrinoless double-? (0???) decay related with the fact that its underlying mechanisms take place in the nuclear matter environment. We study the neutrino exchange mechanism and demonstrate the possible impact of nuclear medium via lepton-number-violating (LNV) four-fermion interactions of neutrinos with quarks from a decaying nucleus. The net effect of these interactions is the generation of an effective in-medium Majorana neutrino mass matrix. The enhanced rate of the 0??? decay can lead to the apparent incompatibility of observations of the 0??? decay with the value of the neutrino mass determined or restricted by the ?-decay and cosmological data. The effective neutrino masses and mixing are calculated for the complete set of the relevant four-fermion neutrino-quark operators. Using experimental data on the 0??? decay in combination with the ?-decay and cosmological data, we evaluate the characteristic scales of these operators: ?LNV?2.4??TeV. PMID:24765948

  3. Perturbation Theory of Neutrino Oscillation with Nonstandard Neutrino Interactions

    E-print Network

    Takashi Kikuchi; Hisakazu Minakata; Shoichi Uchinami

    2009-02-06

    We discuss various physics aspects of neutrino oscillation with non-standard interactions (NSI). We formulate a perturbative framework by taking \\Delta m^2_{21} / \\Delta m^2_{31}, s_{13}, and the NSI elements \\epsilon_{\\alpha \\beta} (\\alpha, \\beta = e, \\mu, \\tau) as small expansion parameters of the same order \\epsilon. Within the \\epsilon perturbation theory we obtain the S matrix elements and the neutrino oscillation probability formula to second order (third order in \

  4. Perturbation Theory of Neutrino Oscillation with Nonstandard Neutrino Interactions

    E-print Network

    Kikuchi, Takashi; Uchinami, Shoichi

    2009-01-01

    We discuss various physics aspects of neutrino oscillation with non-standard interactions (NSI). We formulate a perturbative framework by taking \\Delta m^2_{21} / \\Delta m^2_{31}, s_{13}, and the NSI elements \\varepsilon_{\\alpha \\beta} (\\alpha, \\beta = e, \\mu, \\tau) as small expansion parameters of the same order \\epsilon. Within the \\epsilon perturbation theory we obtain the S matrix elements and the neutrino oscillation probability formulas to second order (third order in \

  5. Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

    SciTech Connect

    Marino, Alysia Diane

    2004-08-10

    The Sudbury Neutrino Observatory (SNO) is a large-volume heavy water Cerenkov detector designed to resolve the solar neutrino problem. SNO observes charged-current interactions with electron neutrinos, neutral-current interactions with all active neutrinos, and elastic-scattering interactions primarily with electron neutrinos with some sensitivity to other flavors. This dissertation presents an analysis of the solar neutrino flux observed in SNO in the second phase of operation, while {approx}2 tonnes of salt (NaCl) were dissolved in the heavy water. The dataset here represents 391 live days of data. Only the events above a visible energy threshold of 5.5 MeV and inside a fiducial volume within 550 cm of the center of the detector are studied. The neutrino flux observed via the charged-current interaction is [1.71 {+-} 0.065(stat.){+-}{sub 0.068}{sup 0.065}(sys.){+-}0.02(theor.)] x 10{sup 6}cm{sup -2}s{sup -1}, via the elastic-scattering interaction is [2.21{+-}0.22(stat.){+-}{sub 0.12}{sup 0.11}(sys.){+-}0.01(theor.)] x 10{sup 6}cm{sup -2}s{sup -1}, and via the neutral-current interaction is [5.05{+-}0.23(stat.){+-}{sub 0.37}{sup 0.31}(sys.){+-}0.06(theor.)] x 10{sup 6}cm{sup -2}s{sup -1}. The electron-only flux seen via the charged-current interaction is more than 7{sigma} below the total active flux seen via the neutral-current interaction, providing strong evidence that neutrinos are undergoing flavor transformation as they travel from the core of the Sun to the Earth. The most likely origin of the flavor transformation is matter-induced flavor oscillation.

  6. Sterile Neutrinos and IceCube

    E-print Network

    Francis Halzen

    2011-11-03

    Although the framework for oscillations of the three neutrino flavors in the Standard Model has been convincingly established, indications persist that it may be incomplete. Challenges are coming from the LSND and MiniBooNe short-baseline experiments, from the neutrino sources used in the Gallex and Sage solar neutrino experiments and, more recently,from an a-posteriori analysis of reactor neutrino experiments. One way to accommodate the reported "anomalies", if real, is to introduce one or more sterile neutrinos in the mass range $\\delta m^2 \\sim 1 eV^2$. TeV atmospheric neutrinos propagating through the Earth undergo resonant oscillations in the presence of sterile neutrinos; a clear signature in a neutrino telescope like IceCube is the the change in shape of the zenith-energy distribution of the atmospheric neutrinos.

  7. First measurement of the flux of solar neutrinos from the sun at the Sudbury Neutrino Observatory

    NASA Astrophysics Data System (ADS)

    Wittich, Peter

    2000-12-01

    The Sudbury Neutrino Observatory (SNO) is a second generation solar neutrino detector. SNO is the first experiment that is able to measure both the electron neutrino flux and a flavor-blind flux of all active neutrino types, allowing a model-independent determination if the deficit of solar neutrinos known as the solar neutrino problem is due to neutrino oscillation. The Sudbury Neutrino Observatory started taking production data in November, 1999. A measurement of the charged current rate will be the first indication if SNO too sees a suppression of the solar neutrino signal relative to the theoretical predictions. Such a confirmation is the first step in SNO's ambitious science program. In this thesis, we present evidence that SNO is seeing solar neutrinos and a preliminary ratio of the measured vs predicted rate of electrons as induced by 8B neutrinos in the ?e, + d --> p + p + e charged-current (CC) reaction.

  8. MeV neutrinos in double {beta} decay

    SciTech Connect

    Zuber, K.

    1997-08-01

    The effect of Majorana neutrinos in the MeV mass range on the double {beta} decay of various isotopes is studied on pure phenomenological arguments. By using only experimental half-life data, limits on the mixing parameter U{sub eh}{sup 2} of the order 10{sup {minus}7} can be derived. Also the possible achievements of upcoming experiments and some consequences are outlined. {copyright} {ital 1997} {ital The American Physical Society}

  9. An expansion for Neutrino Phenomenology

    E-print Network

    Benjamin Grinstein; Michael Trott

    2012-08-24

    We develop a formalism for constructing the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix and neutrino masses using an expansion that originates when a sequence of heavy right handed neutrinos are integrated out, assuming a seesaw mechanism for the origin of neutrino masses. The expansion establishes relationships between the structure of the PMNS matrix and the mass differences of neutrinos, and allows symmetry implications for measured deviations from tri-bimaximal form to be studied systematically. Our approach does not depend on choosing the rotation between the weak and mass eigenstates of the charged lepton fields to be diagonal. We comment on using this expansion to examine the symmetry implications of the recent results from the Daya-Bay collaboration reporting the discovery of a non zero value for theta_{13}, indicating a deviation from tri-bimaximal form, with a significance of 5.2 sigma.

  10. On the muon neutrino mass

    E-print Network

    N. Angelov; F. Balestra; Yu. Batusov; A. Bianconi; M. P. Bussa; L. Busso; L. Ferrero; R. Garfagnini; I. Gnesi; E. Lodi Rizzini; A. Maggiora; D. Panzieri; G. Piragino; G. Pontecorvo; F. Tosello; L. Venturelli

    2006-05-03

    During the runs of the PS 179 experiment at LEAR of CERN, we photographed an event of antiproton-Ne absorption, with a complete pi+ -> mu+ ->e+ chain. From the vertex of the reaction a very slow energy pi+ was emitted. The pi+ decays into a mu+ and subsequently the mu+ decays into a positron. At the first decay vertex a muon neutrino was emitted and at the second decay vertex an electron neutrino and a muon antineutrino. Measuring the pion and muon tracks and applying the momentum and energy conservation and using a classical statistical interval estimator, we obtained an experimental upper limit for the muon neutrino mass: m_nu < 2.2 MeV at a 90% confidence level. A statistical analysis has been performed of the factors contributing to the square value of the neutrino mass limit.

  11. Neutrinos and Cosmology: An Update

    SciTech Connect

    Pisanti, Ofelia; Serpico, Pasquale D.

    2005-10-12

    We review the current cosmological status of neutrinos, with particular emphasis on their effects on Big Bang Nucleosynthesis, Large Scale Structure of the universe and Cosmic Microwave Background Radiation measurements.

  12. Neutrino capital of the world

    E-print Network

    Johnson, Carolyn Y., 1980-

    2004-01-01

    Neutrinos are ubiquitous particles, but they don't like to mingle. Each second, billions of them pass through our bodies, slicing imperceptibly through our delicate internal organs. They can barrel through the sun, stars, ...

  13. MEASUREMENT OF NEUTRINO OSCILLATION PARAMETERS

    E-print Network

    Gratta, Giorgio

    #12;iv #12;Abstract The Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) was designed the Pgeo flux. Ara^ and 812 are two of the fundamental constants of nature, whose values are not currently

  14. Quasidegenerate neutrinos in SO(10)

    SciTech Connect

    Joshipura, Anjan S.; Patel, Ketan M.

    2010-08-01

    We propose a specific ansatz for the structure of Yukawa matrices in SO(10) models that lead to quasidegenerate neutrinos through the type-I seesaw mechanism. Consistency of this ansatz is demonstrated through detailed fits to fermion masses and mixing angles, all of which can be explained with reasonable accuracy in a model that uses the Higgs fields transforming as 10, 120, and 126 representations of SO(10). The proposed ansatz is shown to follow from an extended model based on the three generations of the vectorlike fermions and an O(3) flavor symmetry. Successful numerical fits are also discussed in earlier proposed models, which used a combination of the type-I and type-II seesaw mechanisms for obtaining quasidegenerate neutrinos. Large neutrino mixing angles emerge as a consequence of neutrino mass degeneracy in both these cases.

  15. AGS broad band neutrino beam

    SciTech Connect

    White, D.H.

    1985-02-27

    We describe the broad band neutrino beam in the north area of the AGS and discuss the calculation of the neutrino flux. The horns were initially designed by Robert Palmer and this beam has been used for almost all neutrino running at the AGS. All of the wide band running for E734 has been done in the beam we discuss. E734 is an experiment designed to measure elastic scattering of neutrinos and antineutrinos on electrons and protons. The detector is sufficiently large (approx. =170 tons) that enough events can be detected to make precision measurements of cross sections. In particular, the reaction nu/sub ..mu../ + e ..-->.. nu/sub ..mu../ + e has been detected with more than 100 events, requiring a detailed understanding of the beam characteristics for normalization.

  16. The Fermilab neutrino beam program

    SciTech Connect

    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.

  17. Quasidegenerate neutrinos in SO(10)

    NASA Astrophysics Data System (ADS)

    Joshipura, Anjan S.; Patel, Ketan M.

    2010-08-01

    We propose a specific ansatz for the structure of Yukawa matrices in SO(10) models that lead to quasidegenerate neutrinos through the type-I seesaw mechanism. Consistency of this ansatz is demonstrated through detailed fits to fermion masses and mixing angles, all of which can be explained with reasonable accuracy in a model that uses the Higgs fields transforming as 10, 120, and 126¯ representations of SO(10). The proposed ansatz is shown to follow from an extended model based on the three generations of the vectorlike fermions and an O(3) flavor symmetry. Successful numerical fits are also discussed in earlier proposed models, which used a combination of the type-I and type-II seesaw mechanisms for obtaining quasidegenerate neutrinos. Large neutrino mixing angles emerge as a consequence of neutrino mass degeneracy in both these cases.

  18. Neutrinos And Big Bang Nucleosynthesis

    E-print Network

    Steigman, G

    2005-01-01

    The early universe provides a unique laboratory for probing the frontiers of particle physics in general and neutrino physics in particular. The primordial abundances of the relic nuclei produced during the first few minutes of the evolution of the Universe depend on the electron neutrinos through the charged-current weak interactions among neutrons and protons (and electrons and positrons and neutrinos), and on all flavors of neutrinos through their contributions to the total energy density which regulates the universal expansion rate. The latter contribution also plays a role in determining the spectrum of the temperature fluctuations imprinted on the Cosmic Background Radiation (CBR) some 400 thousand years later. Using deuterium as a baryometer and helium-4 as a chronometer, the predictions of BBN and the CBR are compared to observations. The successes of, as well as challenges to the standard models of particle physics and cosmology are identified. While systematic uncertainties may be the source of some...

  19. Neutrino Masses, Lepton Flavor Mixing and Leptogenesis in the Minimal Seesaw Model

    E-print Network

    Wan-lei Guo; Zhi-zhong Xing; Shun Zhou

    2006-12-05

    We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as $\\mu \\to e + \\gamma$, are also discussed in the supersymmetric extension of the MSM.

  20. Research in Neutrino Physics

    SciTech Connect

    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 foci of our efforts. The Stancu group plans to become re–involved in LBNE and possibly also to join NO A, and the Busenitz group has begun to explore joining a direct dark matter search.

  1. Large invisible decay of a Higgs boson to neutrinos

    NASA Astrophysics Data System (ADS)

    Seto, Osamu

    2015-10-01

    We show that the standard model (SM)-like Higgs boson may decay into neutrinos with a sizable decay branching ratio in one well-known two Higgs doublet model, so-called neutrinophilic Higgs model. This could happen if the mass of the lighter extra neutral Higgs boson is smaller than one half of the SM-like Higgs boson mass. The definite prediction of this scenario is that the rate of the SM-like Higgs boson decay into diphoton normalized by the SM value is about 0.9. In the case that a neutrino is Majorana particle, a displaced vertex of right-handed neutrino decay would be additionally observed. This example indicates that a large invisible Higgs boson decay could be irrelevant to dark matter.

  2. Baryon asymmetry from leptogenesis with four zero neutrino Yukawa textures

    SciTech Connect

    Adhikary, Biswajit; Ghosal, Ambar; Roy, Probir E-mail: ambar.ghosal@saha.ac.in

    2011-01-01

    The generation of the right amount of baryon asymmetry ? of the Universe from supersymmetric leptogenesis is studied within the type-I seesaw framework with three heavy singlet Majorana neutrinos N{sub i} (i = 1,2,3) and their superpartners. We assume the occurrence of four zeroes in the neutrino Yukawa coupling matrix Y{sub ?}, taken to be ?? symmetric, in the weak basis where N{sub i} (with real masses M{sub i} > 0) and the charged leptons l{sub ?} (? = e,?,?) are mass diagonal. The quadrant of the single nontrivial phase, allowed in the corresponding light neutrino mass matrix m{sub ?}, gets fixed and additional constraints ensue from the requirement of matching ? with its observed value. Special attention is paid to flavor effects in the washout of the lepton asymmetry. We also comment on the role of small departures from high scale ?? symmetry due to RG evolution.

  3. Solar mass-varying neutrino oscillations

    E-print Network

    V. Barger; Patrick Huber; Danny Marfatia

    2005-09-30

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

  4. Dark matter origins of neutrino masses

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Chih; Deppisch, Frank F.

    2015-05-01

    We propose a simple scenario that directly connects the dark matter (DM) and neutrino mass scales. Based on an interaction between the DM particle ? and the neutrino ? of the form ? ? ? ? /?2, the DM annihilation cross section into the neutrino is determined and a neutrino mass is radiatively induced. Using the observed neutrino mass scale and the DM relic density, the DM mass and the effective scale ? are found to be of the order MeV and GeV, respectively. We construct an ultraviolet-complete toy model based on the inverse seesaw mechanism which realizes this potential connection between DM and neutrino physics.

  5. MONOLITH: a high resolution neutrino oscillation experiment

    E-print Network

    Tommaso Tabarelli de Fatis

    2001-06-22

    MONOLITH is a proposed massive magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon neutrinos. The main goal is to test the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The sensitivity range for this measurement comfortably covers the entire Super-Kamiokande allowed region. Other measurements include studies of matter effects, the NC/CC and neutrino/anti-neutrino ratio with atmospheric neutrinos and auxiliary measurements from the CERN to Gran Sasso neutrino beam. Depending on approval, data taking with part of the detector could start in 2005. The MONOLITH detector and its performance are described.

  6. Topological phase in two flavor neutrino oscillations

    SciTech Connect

    Mehta, Poonam

    2009-05-01

    We show that the phase appearing in neutrino flavor oscillation formulae has a geometric and topological contribution. We identify a topological phase appearing in the two flavor neutrino oscillation formula using Pancharatnam's prescription of quantum collapses between nonorthogonal states. Such quantum collapses appear naturally in the expression for appearance and survival probabilities of neutrinos. Our analysis applies to neutrinos propagating in vacuum or through matter. For the minimal case of two flavors with CP conservation, our study shows for the first time that there is a geometric interpretation of the neutrino oscillation formulae for the detection probability of neutrino species.

  7. Topological phase in two flavor neutrino oscillations

    E-print Network

    Poonam Mehta

    2009-05-20

    We show that the phase appearing in neutrino flavor oscillation formulae has a geometric and topological contribution. We identify a topological phase appearing in the two flavor neutrino oscillation formula using Pancharatnam's prescription of quantum collapses between non-orthogonal states. Such quantum collapses appear naturally in the expression for appearance and survival probabilities of neutrinos. Our analysis applies to neutrinos propagating in vacuum or through matter. For the minimal case of two flavors with CP conservation, our study shows for the first time that there is a geometric interpretation of the neutrino oscillation formulae for the detection probability of neutrino species.

  8. Status of non-standard neutrino interactions.

    PubMed

    Ohlsson, Tommy

    2013-04-01

    The phenomenon of neutrino oscillations has been established as the leading mechanism behind neutrino flavor transitions, providing solid experimental evidence that neutrinos are massive and lepton flavors are mixed. Here we review sub-leading effects in neutrino flavor transitions known as non-standard neutrino interactions (NSIs), which is currently the most explored description for effects beyond the standard paradigm of neutrino oscillations. In particular, we report on the phenomenology of NSIs and their experimental and phenomenological bounds as well as an outlook for future sensitivity and discovery reach. PMID:23481442

  9. Neutrino scattering and flavor transformation in supernovae.

    PubMed

    Cherry, John F; Carlson, J; Friedland, Alexander; Fuller, George M; Vlasenko, Alexey

    2012-06-29

    We argue that the small fraction of neutrinos that undergo direction-changing scattering outside of the neutrinosphere could have significant influence on neutrino flavor transformation in core-collapse supernova environments. We show that the standard treatment for collective neutrino flavor transformation is adequate at late times but could be inadequate in early epochs of core-collapse supernovae, where the potentials that govern neutrino flavor evolution are affected by the scattered neutrinos. Taking account of this effect, and the way it couples to entropy and composition, will require a new approach in neutrino flavor transformation modeling. PMID:23004955

  10. Standard and non-standard primordial neutrinos

    E-print Network

    P. D. Serpico

    2006-08-14

    The standard cosmological model predicts the existence of a cosmic neutrino background with a present density of about 110 cm^{-3} per flavour, which affects big-bang nucleosynthesis, cosmic microwave background anisotropies, and the evolution of large scale structures. We report on a precision calculation of the cosmic neutrino background properties including the modification introduced by neutrino oscillations. The role of a possible neutrino-antineutrino asymmetry and the impact of non-standard neutrino-electron interactions on the relic neutrinos are also briefly discussed.

  11. Neutrinos in an expanding Universe

    NASA Astrophysics Data System (ADS)

    Wigmans, Richard

    2015-09-01

    The Universe contains several billion neutrinos for each nucleon. In this paper, we follow the history of these relic neutrinos as the Universe expanded. At present, their typical velocity is a few hundred km/s and, therefore, their spectra are affected by gravitational forces. This may have led to a phenomenon that could explain two of todays great mysteries: The large-scale structure of the Universe and the increasing rate at which it expands.

  12. Are solar neutrino oscillations robust?

    NASA Astrophysics Data System (ADS)

    Miranda, Omar G.; Amparo Tórtola, Maria; Valle, José W. F.

    2006-10-01

    The robustness of the large mixing angle (LMA) oscillation (OSC) interpretation of the solar neutrino data is considered in a more general framework where non-standard neutrino interactions (NSI) are present. Such interactions may be regarded as a generic feature of models of neutrino mass. The 766.3 ton-yr data sample of the KamLAND collaboration are included in the analysis, paying attention to the background from the reaction 13C(?,n)16O. Similarly, the latest solar neutrino fluxes from the SNO collaboration are included. In addition to the solution which holds in the absence of NSI (LMA-I) there is a ``dark-side'' solution (LMA-D) with sin 2?odot = 0.70, essentially degenerate with the former, and another light-side solution (LMA-0) allowed only at 97% CL. More precise KamLAND reactor measurements will not resolve the ambiguity in the determination of the solar neutrino mixing angle ?odot, as they are expected to constrain mainly ?m2sol. We comment on the complementary role of atmospheric, laboratory (e.g. CHARM) and future solar neutrino experiments in lifting the degeneracy between the LMA-I and LMA-D solutions. In particular, we show how the LMA-D solution induced by the simplest NSI between neutrinos and down-type-quarks-only is in conflict with the combination of current atmospheric data and data of the CHARM experiment. We also mention that establishing the issue of robustness of the oscillation picture in the most general case will require further experiments, such as those involving low energy solar neutrinos.

  13. Are solar neutrino oscillations robust?

    E-print Network

    O. G. Miranda; M. A. Tortola; J. W. F. Valle

    2006-09-07

    The robustness of the large mixing angle (LMA) oscillation (OSC) interpretation of the solar neutrino data is considered in a more general framework where non-standard neutrino interactions (NSI) are present. Such interactions may be regarded as a generic feature of models of neutrino mass. The 766.3 ton-yr data sample of the KamLAND collaboration are included in the analysis, paying attention to the background from the reaction ^13C(\\alpha,n) ^16O. Similarly, the latest solar neutrino fluxes from the SNO collaboration are included. In addition to the solution which holds in the absence of NSI (LMA-I) there is a 'dark-side' solution (LMA-D) with sin^2 theta_Sol = 0.70, essentially degenerate with the former, and another light-side solution (LMA-0) allowed only at 97% CL. More precise KamLAND reactor measurements will not resolve the ambiguity in the determination of the solar neutrino mixing angle theta_Sol, as they are expected to constrain mainly Delta m^2. We comment on the complementary role of atmospheric, laboratory (e.g. CHARM) and future solar neutrino experiments in lifting the degeneracy between the LMA-I and LMA-D solutions. In particular, we show how the LMA-D solution induced by the simplest NSI between neutrinos and down-type-quarks-only is in conflict with the combination of current atmospheric data and data of the CHARM experiment. We also mention that establishing the issue of robustness of the oscillation picture in the most general case will require further experiments, such as those involving low energy solar neutrinos.

  14. Quantum Entanglement of Neutrino Pairs

    E-print Network

    Junli Li; Cong-Feng Qiao

    2014-02-19

    It is practically shown that a pair of neutrinos from tau decay can form a flavor entangled state. With this kind of state we show that the locality constrains imposed by Bell inequality are violated by the quantum mechanics, and an experimental test of this effect is feasible within the earth's length scale. Theoretically, the quantum entanglement of neutrino pairs can be employed to the use of long distance cryptography distribution in a protocol similar to the BB84.

  15. 40 years of neutrino physics

    NASA Astrophysics Data System (ADS)

    Reines, Frederick

    Wolfgang Pauli and Enrico Fermi pioneered the hypothesis and characteristics of the weak interaction and the elementary particle called the neutrino. Since its discovery some forty years ago the neutrino has been shown to be a fundamental constituent of matter with a surprisingly rich, and in very many ways unexpected, set of characteristics ranging from basic roles in the generation of energy in the sun to supernovæ.

  16. Quasidegenerate neutrinos and tribimaximal mixing

    SciTech Connect

    Medeiros Varzielas, Ivo de; Ross, Graham G.; Serna, Mario

    2009-10-01

    We consider how, for quasidegenerate neutrinos with tribimaximal mixing at a high-energy scale, the mixing angles are affected by radiative running from high- to low-energy scales in a supersymmetric theory. The limits on the high-energy scale that follow from consistency with the observed mixing are determined. We construct a model in which a non-Abelian discrete family symmetry leads to both a quasidegenerate neutrino-mass spectrum and to near tribimaximal mixing.

  17. Probing Heavy-Light Neutrino Mixing in Left-Right Seesaw Models at the LHC

    E-print Network

    Chien-Yi Chen; P. S. Bhupal Dev; R. N. Mohapatra

    2013-08-14

    We show that in TeV-scale left-right (L-R) symmetric seesaw models, there are new dominant contributions to the collider signals of heavy Majorana neutrinos arising from the heavy-light neutrino mixing, which directly probe the seesaw matrix in a certain class of models. We propose a way to distinguish this contribution from the widely discussed one that only probes the Majorana nature of the heavy right-handed neutrinos, by analyzing some simple kinematical variables. We find that in this class of L-R seesaw models the existing LHC data already yield slightly stronger constraints on the heavy-light neutrino mixing than those derived for standard seesaw models, and the improvement will be significant as more data are collected.

  18. Neutrinos And Big Bang Nucleosynthesis

    E-print Network

    Gary Steigman

    2012-07-31

    According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders this neutrino background undetectable with current technology. The cosmic neutrino background can, however, be probed indirectly through its cosmological effects on big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) radiation. In this BBN review, focused on neutrinos and, more generally on dark radiation, the BBN constraints on the number of "equivalent neutrinos" (dark radiation), on the baryon asymmetry (baryon density), and on a possible lepton asymmetry (neutrino degeneracy) are reviewed and updated. The BBN constraints on dark radiation and on the baryon density following from considerations of the primordial abundances of deuterium and helium-4 are in excellent agreement with the complementary results from the CMB, providing a suggestive, but currently inconclusive, hint of the presence of dark radiation and, they constrain any lepton asymmetry. For all the cases considered here there is a "lithium problem": the BBN-predicted lithium abundance exceeds the observationally inferred primordial value by a factor of ~3.

  19. Neutrinos And Big Bang Nucleosynthesis

    E-print Network

    Gary Steigman

    2005-01-12

    The early universe provides a unique laboratory for probing the frontiers of particle physics in general and neutrino physics in particular. The primordial abundances of the relic nuclei produced during the first few minutes of the evolution of the Universe depend on the electron neutrinos through the charged-current weak interactions among neutrons and protons (and electrons and positrons and neutrinos), and on all flavors of neutrinos through their contributions to the total energy density which regulates the universal expansion rate. The latter contribution also plays a role in determining the spectrum of the temperature fluctuations imprinted on the Cosmic Background Radiation (CBR) some 400 thousand years later. Using deuterium as a baryometer and helium-4 as a chronometer, the predictions of BBN and the CBR are compared to observations. The successes of, as well as challenges to the standard models of particle physics and cosmology are identified. While systematic uncertainties may be the source of some of the current tensions, it could be that the data are pointing the way to new physics. In particular, BBN and the CBR are used to address the questions of whether or not the relic neutrinos were fully populated in the early universe and, to limit the magnitude of any lepton asymmetry which may be concealed in the neutrinos.

  20. Extraterrestrial high energy neutrino fluxes

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1979-01-01

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