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1

Fourth Generation Majorana Neutrinos  

Microsoft Academic Search

We investigate the possibility of a fourth sequential generation in the lepton sector. Assuming neutrinos to be Majorana particles and starting from a recent - albeit weak - evidence for a non-zero admixture of a fourth generation neutrino from fits to weak lepton and meson decays we discuss constraints from neutrinoless double beta decay, radiative lepton decay and like-sign dilepton

Alexander Lenz; Heinrich Päs; Dario Schalla

2011-01-01

2

The search for Majorana neutrinos  

NASA Astrophysics Data System (ADS)

In the Standard Model of strong and electroweak interactions, neutrinos are strictly massless due to the absence of the right-handed chiral states and the requirement of gauge invariance and renormalizability. However, recent neutrino oscillation experiments have provided strong evidence that neutrinos are massive and their flavors defined with respect to the charged leptons oscillate, presenting a pressing need for physics beyond the Standard Model. We do not know the nature of mass generation; in particular, we do not know if neutrinos are of Dirac or Majorana type-the former preserves lepton number and the latter violates it by two units. Although the prevailing theoretical prejudice prefers Majorana neutrinos, experimentally testing the Dirac or Majorana nature of neutrinos is of fundamental importance. The unambiguous proof of the existence of a Majorana neutrino is the observation of a lepton number violating process. Since neutrinos interact so weakly and leave no trace in ordinary detectors, the only appropriate signatures must involve two like-sign charged leptons for a process that violates lepton number by two units. To establish the Majorana nature of neutrinos definitively many low energy and collider processes that probe Majorana neutrino masses over many orders of magnitude, from sub-electron-volt to hundreds of giga-electron-volt have been studied.

Atre, Anupama

3

Majorana Neutrinos and Magnetic Fields.  

National Technical Information Service (NTIS)

It is stressed that if neutrinos are massive they are probably of Majorana type. This implies that their magnetic moment form factor vanishes identically so that the previously discussed phenomenon of spin rotation in a magnetic field would not appear to ...

J. Schechter J. W. F. Valle

1981-01-01

4

Majorana neutrino superfluidity and stability of neutrino dark energy  

SciTech Connect

We demonstrate that Majorana neutrinos can form Cooper pairs due to long-range attractive forces and show BCS superfluidity in a class of mass varying neutrino dark energy models. We describe the condensates for Majorana neutrinos and estimate the value of the gap, critical temperature, and Pippard coherence length for a simple neutrino dark energy model. In the strong coupling regime bosonic degree of freedom can become important, and Bose-Einstein condensate may govern the dynamics for the mass varying neutrino models. Formation of the condensates can significantly alter the instability scenario in the mass varying neutrino models.

Bhatt, Jitesh R.; Sarkar, Utpal [Physical Research Laboratory, Ahmedabad 380009 (India)

2009-08-15

5

Baryogenesis through mixing of heavy Majorana neutrinos  

Microsoft Academic Search

A mechanism is presented in which the mixing of right-handed heavy Majorana neutrinos creates a CP-asymmetric universe. When these Majorana neutrinos subsequently decay more leptons than anti leptons are produced. Due to a resonance phenomenon the lepton asymmetry created by this new mechanism can exceed by a few orders of magnitude any lepton asymmetry originating from direct decays. The asymmetry

Marion Flanz; Emmanuel A. Paschos; Utpal Sarkar; Jan Weiss

1996-01-01

6

Why do Majorana Neutrinos Run Faster than Dirac Neutrinos?  

NASA Astrophysics Data System (ADS)

The ?-lepton dominance in the one-loop renormalization-group equations (RGEs) of neutrinos sets a cute criterion to parametrize the 3x3 lepton flavor mixing matrix U: its elements U_{3i} (for i=1,2,3) should be as simple as possible. Such a novel parametrization is different from the ``standard" one used in the literature and can lead to greatly simplified RGEs for three mixing angles and the physical CP-violating phase(s), no matter whether neutrinos are Dirac or Majorana particles. We show that the RGEs of Dirac neutrinos are not identical with those of Majorana neutrinos even if two Majorana CP-violating phases vanish. As the latter can keep vanishing from the electroweak scale to the typical seesaw scale, it makes sense to explore the similarities and differences between the RGE running effects of Dirac and Majorana neutrinos. We conclude that Majorana neutrinos are in general expected to run faster (i.e., more significantly) than Dirac neutrinos.

Xing, Zhi-Zhong Zhang, He

2006-05-01

7

Baryogenesis through mixing of heavy Majorana neutrinos  

Microsoft Academic Search

We review the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy neutrinos. We pay special attention to the resonant phenomenon of CP violation through mixing of two nearly degenerate heavy Majorana neutrinos and show how unitarity and CPT invariance is maintained within the resummation approach. An important consequence of this is that the leptogenesis scale may

Apostolos Pilaftsis

1998-01-01

8

Constraints on fourth generation Majorana neutrinos  

Microsoft Academic Search

We investigate the possibility of a fourth sequential generation in the lepton sector. Assuming neutrinos to be Majorana particles and starting from a recent - albeit weak - evidence for a non-zero admixture of a fourth generation neutrino from fits to weak lepton and meson decays we discuss constraints from neutrinoless double beta decay, radiative lepton decay and like-sign di-lepton

Alexander Lenz; Heinrich Päs; Dario Schalla

2010-01-01

9

Search for Majorana Neutrinos in B-??+?-?- Decays  

NASA Astrophysics Data System (ADS)

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.

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, Th.; 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, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; 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, Ch.; 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, Ph.; 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, Yu.; 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.

2014-04-01

10

Majorana neutrinos production at NLC in an effective approach  

NASA Astrophysics Data System (ADS)

We investigate the possibility of detecting Majorana neutrinos at the e+e- Next Linear Collider (NLC). We study the lj?lk?+jets (lj?e, ?, ?) final states which are, due to leptonic number violation, a clear signature for intermediate Majorana neutrino contributions. Such signals (final leptons of the same sign) are not possible if the heavy neutrinos have Dirac nature. The interactions between Majorana neutrinos and the standard model particles are obtained from an effective Lagrangian approach. As for the background, we considered the standard model reaction e+e-?W+W+W-W-, with two W's decaying into jets and two W's decaying into l±+?(?¯), producing extra light neutrinos which avoid the detection. We present our results for the total cross section as a function of the neutrino mass and the center-of-mass energy. We also show the discovery region as a function of the Majorana neutrino mass and the effective coupling.

Peressutti, Javier; Romero, Ismael; Sampayo, Oscar A.

2011-12-01

11

nu-K0 Analogy, Dirac-Majorana Neutrino Duality and the Neutrino Oscillations  

Microsoft Academic Search

The intent of this paper is to convey a new primary physical idea of a Dirac-Majorana neutrino duality in relation to the topical problem of neutrino oscillations. In view of the new atmospheric, solar and the LSND neutrino oscillation data, the Pontecorvo nu - K0 oscillation analogy is generalized to the notion of neutrino duality with substantially different physical meaning

E. M. Lipmanov

2001-01-01

12

Majorana Zero-Neutrino Double-Beta Decay Experiment.  

National Technical Information Service (NTIS)

The goal of the Majorana Experiment is to determine the effective Majorana mass of the electron 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...

R. Gaitskell A. Barabash S. Konovalov V. Stekhanov V. Umatov

2002-01-01

13

Remark on Majorana CP phases in neutrino mixing and leptogenesis  

NASA Astrophysics Data System (ADS)

We estimate Majorana CP phases for a simple flavor neutrino mixing matrix which has been reported by Qu and Ma. Sizes of Majorana CP phases are evaluated in the study of the neutrinoless double beta decay and a particular leptogenesis scenario. We find the dependence of the physically relevant Majorana CP phase on the mass of lightest right-handed neutrino in the minimal seesaw model and the effective Majorana neutrino mass which is related with the half-life of the neutrinoless double beta decay.

Kitabayashi, Teruyuki; Koizumi, Naoto

2014-05-01

14

The Majorana project: 76Ge 0? ??-decay neutrino mass measurement  

Microsoft Academic Search

Interest in, and the relevance of, next-generation 0? ??-decay experiments is increasing. Even with nonzero neutrino mass strongly suggested by SNO, Super Kamiokande, and similar experiments sensitive to ?m2, 0? ??-decay experiments are still the only way to establish the Dirac or Majorana nature of neutrinos by measuring effective electron neutrino mass, ?m??. Various theorists have recently argued in favor

Craig E. Aalseth; Harry S. Miley

2002-01-01

15

CP violation and baryogenesis due to heavy Majorana neutrinos  

Microsoft Academic Search

We analyze the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy Majorana neutrinos and pay special attention to CP violation. Extending a recently proposed resummation formalism for two-fermion mixing to decay amplitudes, we calculate the resonant phenomenon of CP violation due to the mixing of two nearly degenerate heavy Majorana neutrinos. Solving numerically the relevant Boltzmann

Apostolos Pilaftsis

1997-01-01

16

Contributed report: Flavor anarchy for Majorana neutrinos  

NASA Astrophysics Data System (ADS)

We argue that neutrino flavor parameters may exhibit features that are very different from those of quarks and charged leptons. Specifically, within the Froggatt--Nielsen (FN) framework, charged fermion parameters depend on the ratio between two scales, while for neutrinos a third scale -- that of lepton number breaking -- is involved. Consequently, the selection rules for neutrinos may be different. In particular, if the scale of lepton number breaking is similar to the scale of horizontal symmetry breaking, neutrinos may become flavor-blind even if they carry different horizontal charges. This provides an attractive mechanism for neutrino flavor anarchy.

Nir, Yosef; Shadmi, Yael

2004-12-01

17

White Paper on the Majorana Zero-Neutrino Double-Beta Decay Experiment  

Microsoft Academic Search

The objective of the Majorana Experiment is to study neutrinoless double beta decay (0nbb) with an effective Majorana-neutrino mass sensitivity below 50 meV in order to characterize the Majorana nature of the neutrino, the Majorana mass spectrum, and the absolute mass scale. An experimental study of the neutrino mass scale implied by neutrino oscillation results is now technically within our

2003-01-01

18

Non-thermal leptogenesis from the heavier Majorana neutrinos  

NASA Astrophysics Data System (ADS)

We investigate a scheme for making leptogenesis by means of the /CP violating decays of the seesaw Majorana neutrinos proposed by Fukugita and Yanagida. However, in order to avoid the wash-out of the produced lepton number we propose the production of the Majorana neutrinos to occur non-thermally and sufficiently late. After this time, in consequence, the /B-L (baryon minus lepton) quantum number becomes a good ``accidental symmetry'' protecting the asymmetry produced. This non-thermal leptogenesis at late time is realized by a boson decaying into the Majorana neutrinos with a long lifetime. Suggestively this boson could correspond to a scalar field which causes the cosmic inflation, the inflaton, and thus its decay means really the reheating of the Universe. We find that this mechanism works well even if the lightest Majorana neutrinos are not produced sufficiently or not present, and the decays of the heavier seesaw Majorana neutrinos can be responsible to the baryon asymmetry in the present Universe, as we illustrate by the example of the family replicated gauge group model.

Asaka, T.; Nielsen, H. B.; Takanishi, Y.

2002-12-01

19

CP violation and baryogenesis due to heavy Majorana neutrinos  

NASA Astrophysics Data System (ADS)

We analyze the scenario of baryogenesis through leptogenesis induced by the out-of-equilibrium decays of heavy Majorana neutrinos and pay special attention to CP violation. Extending a recently proposed resummation formalism for two-fermion mixing to decay amplitudes, we calculate the resonant phenomenon of CP violation due to the mixing of two nearly degenerate heavy Majorana neutrinos. Solving numerically the relevant Boltzmann equations, we find that the isosinglet Majorana mass may range from 1 TeV up to the grand unification scale, depending on the mechanism of CP violation and/or the flavor structure of the neutrino mass matrix assumed. Finite temperature effects and possible constraints from the electric dipole moment of electron and other low-energy experiments are briefly discussed.

Pilaftsis, Apostolos

1997-11-01

20

Flavor structure in D-brane models: Majorana neutrino masses  

NASA Astrophysics Data System (ADS)

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

Hamada, Yuta; Kobayashi, Tatsuo; Uemura, Shohei

2014-05-01

21

Distinguishing between Dirac and Majorana neutrinos withtwo-particle interferometry  

SciTech Connect

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.

Gutierrez, Thomas D.

2006-03-02

22

Right-Handed Majorana Neutrino Mass Matrices for Generating Bimaximal Mixings in Degenerate and Inverted Models of Neutrinos  

NASA Astrophysics Data System (ADS)

An attempt is made to generate the bimaximal mixings of the three species of neutrinos from the textures of the right-handed Majorana neutrino mass matrices. We extend our earlier work in this paper for the generation of the nearly degenerate as well as the inverted hierarchical models of the left-handed Majorana neutrino mass matrices using the non-diagonal textures of the right-handed Majorana neutrino mass matrices and the diagonal form of Dirac neutrino mass matrices, within the framework of the see-saw mechanism in a model independent way. Such Majorana neutrino mass models are important in explaining the recently reported result on the neutrinoless double beta decay (0 ???) experiment, together with the earlier established data on LMA MSW solar and atmospheric neutrino oscillations.

Patgiri, Mahadev; Nimai Singh, N.

23

Model independent explorations of Majorana neutrino mass origins  

NASA Astrophysics Data System (ADS)

The recent observation of nonzero neutrino mass is the first concrete indication of physics beyond the Standard Model. Their properties, unique among the other fermions, leads naturally to the idea of a Majorana neutrino mass term. Despite the strong theoretical prejudice toward this concept, it must be tested experimentally. This is indeed possible in the context of next generation experiments. Unfortunately, the scale of neutrino mass generation may be too large to explore directly, but useful information may still be extracted from independent experimental channels. Here I survey various model independent probes of Majorana neutrino mass origins. A brief introduction to the concepts relevant to the analysis is followed by a discussion of the physical ranges of neutrino mass and mixing parameters within the context of standard and non-standard interactions. Armed with this, I move on to systematically analyze the properties of radiatively generated neutrino masses induced by nonrenormalizable lepton number violating effective operators of mass dimensions five through eleven. By fitting these to the observed light mass scale, I extract predictions for neutrino mixing as well as neutrinoless double beta decay, rare meson/tau decays and collider phenomenology. I find that many such models are already constrained by current data and many more will be probed in the near future. I then move on demonstrate the utility of a low scale see saw mechanism via a viable 3+2+1 sterile neutrino model that satisfies all oscillation data as well as solves problems associated with supernova kicks and heavy element nucleosynthesis. From this I extract predictions for tritium and neutrinoless double beta decay searches. This is supplemented throughout by descriptions of practical limitations in addition to suggestions for future work.

Jenkins, James Phearl, Jr.

24

Discriminating among the theoretical origins of new heavy Majorana neutrinos at CERN LHC  

SciTech Connect

A study on the possibility of distinguishing new heavy Majorana neutrino models at LHC energies is presented. The experimental confirmation of standard neutrinos with nonzero mass and the theoretical possibility of lepton number violation find a natural explanation when new heavy Majorana neutrinos exist. These new neutrinos appear in models with new right-handed singlets, in new doublets of some grand unified theories and left-right symmetrical models. It is expected that signals of new particles can be found at the CERN high-energy hadron collider (LHC). We present signatures and distributions that can indicate the theoretical origin of these new particles. The single and pair production of heavy Majorana neutrinos are calculated and the model dependence is discussed. Same-sign dileptons in the final state provide a clear signal for the Majorana nature of heavy neutrinos, since there is lepton number violation. Mass bounds on heavy Majorana neutrinos allowing model discrimination are estimated for three different LHC luminosities.

Almeida, F. M. L. de Jr.; Coutinho, Y. A.; Simoes, J. A. Martins; Ramalho, A. J.; Wulck, S.; Vale, M. A. B. do [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Departamento de Ciencias Naturais, Universidade Federal de Sao Joao del Rei, Sao Joao del Rei, MG (Brazil)

2007-04-01

25

Majorana neutrino masses and the neutrinoless double-beta decay  

SciTech Connect

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.

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

2006-12-15

26

Laser photons acquire circular polarization by interacting with a Dirac or Majorana neutrino beam  

NASA Astrophysics Data System (ADS)

It is shown that for the reason of neutrinos being left-handed and their gauge-couplings being parity-violated, linearly polarized photons acquire their circular polarization by interacting with neutrinos. Calculating the ratio of linear and circular polarizations of laser photons interacting with either Dirac or Majorana neutrino beam, we obtain this ratio for the Dirac neutrino case, which is about twice less than the ratio for the Majorana neutrino case. Based on this ratio, we discuss the possibility of using advanced laser facilities and the T2K neutrino experiment to measure the circular polarization of laser beams interacting with neutrino beams in ground laboratories. This could be an additional and useful way to gain some insight into the physics of neutrinos, for instance their Dirac or Majorana nature.

Mohammadi, Rohoollah; Xue, She-Sheng

2014-04-01

27

Effets de la nature de Dirac ou de Majorana, ainsi que de la masse, sur le comportement du neutrino. (Dirac or Majorana nature and mass effects on the neutrino behaviour).  

National Technical Information Service (NTIS)

This work deals with the Dirac or Majorana nature and mass effects on the neutrino behaviour. In the first part of this study are given the Dirac equation properties and the Majorana neutrino definition. As the difference between a Dirac and a Majorana ne...

J. E. Campagne

1995-01-01

28

Are massive Majorana neutrinos canceling each other in neutrinoless double-. beta. decay  

SciTech Connect

The possibility of various massive Majorana neutrinos canceling each other in neutrinoless double-..beta.. decay is examined. It is shown that if all neutrino eigenmasses are less than 10 MeV such a cancellation persists in the hadronic medium if initially present at the elementary (gauge) level. The same is true for neutrino mass greater than 10 GeV. In all other cases, such a cancellation will require a conspiracy between particle and nuclear physics.

Vergados, J.D.

1983-12-01

29

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

SciTech Connect

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.

Boyarkin, O. M., E-mail: oboyarkin@tut.by; Boyarkina, G. G. [Maxim Tank Belarusian State Pedagogical University (Belarus)] [Maxim Tank Belarusian State Pedagogical University (Belarus)

2013-04-15

30

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

NASA Astrophysics Data System (ADS)

The latest data from the ACME Collaboration have put a stringent constraint on the electric dipole moment de of the electron. Nevertheless, the standard model (SM) prediction for de 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 de 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 de crucially depends on whether neutrinos are Dirac or Majorana particles. In the Majorana case, de 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 de.

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

2014-05-01

31

Double-beta-decay suppression with three generations of Majorana neutrinos  

NASA Astrophysics Data System (ADS)

Rate suppression of double-beta decay with three generations of Majorana neutrinos is analyzed. It is shown that the physically attractive possibility of three equal masses and a relative CP eigenvalue of the first different from the other two can lead to complete cancellation in double-beta decay. An explanation in terms of pseudo-Dirac neutrinos is offered, and the process ?--->e+ is also examined.

Picciotto, Charles; Kopac, Julie

1985-09-01

32

GeV Majorana neutrinos in top-quark decay at the LHC  

SciTech Connect

We explore the {delta}L=2 same-sign dilepton signal from top-quark decay via a Majorana neutrino at the LHC in the top anti-top pair production samples. The signature is same-sign dilepton plus multijets with no significant missing energy. The most optimistic region lies where the Majorana neutrino mass is between 15-65 GeV. For 300 fb{sup -1} integrated luminosity, it is possible to probe S{sub ij}, the effective mixing parameter, to O(10{sup -5})

Si Zongguo [School of Physics, Shandong University, Jinan, Shandong 250100 (China); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Wang Kai [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China)

2009-01-01

33

Testing the realistic seesaw model with two heavy Majorana neutrinos at the CERN Large Hadron Collider  

NASA Astrophysics Data System (ADS)

In the conventional type-(I + II) seesaw model, the effective mass matrix of three known light neutrinos is given by M=M-MMR-1MDT in the leading-order approximation. We propose an intriguing scenario, in which the structural cancellation condition MMR-1MDT=0 is guaranteed by the A×Z flavor symmetry. As a consequence, neutrino masses are mainly generated by the Higgs triplet M=M, while the neutrino mixing matrix is non-unitary and takes on the nearly tri-bimaximal pattern. A discriminating feature of this scenario from the pure type-II seesaw model is that the lepton-number-violating signatures induced by the heavy Majorana neutrinos can be discovered at the CERN Large Hadron Collider. We calculate the total cross section of the same-sign dilepton events pp?l?±N?l?±l?±jj (for i=1,2 and ?,?=e,?,?), and emphasize the significant interference of the contributions from two different heavy Majorana neutrinos. The background from the standard model and the kinematic cuts used to reduce it have been considered. The possible way to distinguish between the signals from heavy Majorana neutrinos and those from doubly-charged Higgs bosons is briefly discussed.

Chao, Wei; Si, Zong-guo; Zheng, Ya-juan; Zhou, Shun

2010-01-01

34

Bimaximal Mixings from the Texture of the Right-Handed Majorana Neutrino Mass Matrix  

NASA Astrophysics Data System (ADS)

We study the origin of neutrino masses and mixing angles which can accommodate the LMA MSW solutions of the solar neutrino anomaly as well as the solution of the atmospheric neutrino problem, within the framework of the see-saw mechanism. We employ the diagonal form of the Dirac neutrino mass matrices with the physical masses as diagonal elements in the hierarchical order. Such a choice has been motivated from the fact that the known CKM angles for the quark sector, are relatively small. We consider both possibilities where the Dirac neutrino mass matrix is either the charged lepton or the up-quark mass matrix within the framework of SO(10) GUT with or without supersymmetry. The nonzero texture of the right-handed Majorana neutrino mass matrix MR is used for the generation of the desired bimaximal mixings in a model independent way. Both hierarchical and inverted hierarchical models of the left-handed Majorana neutrino mass matrices are generated and then discussed with examples. The see-saw mass scale which is kept as a free parameter, is predicted in all the examples.

Singh, N. Nimai; Patgiri, Mahadev

35

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

SciTech Connect

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.

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

36

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

PubMed

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

2014-06-12

37

Generation of small neutrino Majorana masses in a Randall-Sundrum model  

SciTech Connect

I propose a model, in the framework of five dimensions with warped geometry, in which small neutrino Majorana masses are generated by tree-level coupling of lepton doublets to a SU(2){sub L}-triplet scalar field, which is coupled to a bulk standard model singlet. The neutrino mass scale is determined by the bulk mass term ({alpha}{sub S}) of the singlet as ve{sup -2({alpha}{sub S}{sup -1){pi})}{sup kR}. This suppression is due to a small overlap between the profile of the singlet zero mode and the triplet, which is confined to the TeV brane. The generic form for the neutrino mass matrix due to the overlap between the fermions is not compatible with the large mixing angle solution. This is overcome by imposing a Z{sub 4} symmetry, which is softly broken by couplings of the triplet Higgs to the lepton doublets. This model successfully reproduces the observed masses and mixing angles in the charged lepton sector as well as in the neutrino sector, in addition to having a prediction of |U{sub e3}|{approx}O(0.01). The mass of the triplet is of the order of a TeV and could be produced at upcoming collider experiments. The doubly charged member of the triplet can decay into two same sign charged leptons, yielding the whole triplet coupling matrix which, in turn, gives the mixing matrix in the neutrino sector.

Chen, M.-C. [High Energy Theory Group, Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

2005-06-01

38

Neutrino interactions in matter  

SciTech Connect

If a fermion is travelling through a medium, it can have matter-induced magnetic and electric dipole moments. These contributions conserve chirality, and can be nonvanishing even for a Majorana neutrino. Several implications for neutrino physics are discussed.

Pal, P.B.

1993-03-01

39

Majorana CP-violating phases in neutrino-antineutrino oscillations and other lepton-number-violating processes  

NASA Astrophysics Data System (ADS)

If the massive neutrinos are identified to be the Majorana particles via a convincing measurement of the neutrinoless double beta (0???) decay, how to determine the Majorana CP-violating phases in the 3×3 lepton flavor mixing matrix U will become a desirable experimental question. The answer to this question is to explore all the possible lepton-number-violating (LNV) processes in which the Majorana phases really matter. In this paper we carry out a systematic study of CP violation in neutrino-antineutrino oscillations, whose CP-conserving parts involve six independent 0???-like mass terms ?m??? and CP-violating parts are associated with nine independent Jarlskog-like parameters V??ij (for ?, ?=e, ?, ? and i, j=1, 2, 3). With the help of current neutrino oscillation data, we analyze the sensitivities of |?m???| and V??ij to the three CP-violating phases of U, and illustrate the salient features of six independent CP-violating asymmetries between ????¯? and ?¯???? oscillations. As a by-product, the effects of the CP-violating phases on the LNV decays of doubly and singly charged Higgs bosons are reexamined by taking account of the unsuppressed value of ?13. Such CP-conserving LNV processes can be complementary to the possible measurements of neutrino-antineutrino oscillations in the distant future.

Xing, Zhi-zhong; Zhou, Ye-Ling

2013-08-01

40

Neutrinoless double electron capture: A tool to search for Majorana neutrinos  

NASA Astrophysics Data System (ADS)

The possibility of observing the neutrinoless double ? decay and thus proving the Majorana nature of neutrinos as well as providing a sensitive measure of its mass is a major challenge of today’s neutrino physics. As an attractive alternative, we propose to study the inverse process—the radiative neutrinoless double-electron capture (0?2EC) . The associated monoenergetic photon provides a convenient experimental signature. Other advantages include the favorable ratio of the 0?2EC to the competing 2?2EC capture rates and, very importantly, the existence of a coincidence trigger to suppress the random background. These advantages partly offset the expected longer lifetimes. Rates for the 0?2EC process are calculated. High Z atoms are strongly favored. A resonance enhancement of the capture rates is expected to occur at an energy release comparable to the 2P-1S atomic level difference. The resonance conditions are likely to be met for decays to excited states in final nuclei. Candidates for such studies are considered. The experimental feasibility is estimated and found encouraging.

Sujkowski, Z.; Wycech, S.

2004-11-01

41

The Importance of Being Majorana: Neutrinos versus Charged Fermions in Flavor Models  

NASA Astrophysics Data System (ADS)

We argue that neutrino flavor parameters may exhibit features that are very different from those of quarks and charged leptons. Specifically, within the Froggatt-Nielsen (FN) framework, charged fermion parameters depend on the ratio between two scales, while for neutrinos a third scale—that of lepton number breaking—is involved. Consequently, the selection rules for neutrinos may be different. In particular, if the scale of lepton number breaking is similar to the scale of horizontal symmetry breaking, neutrinos may become flavor-blind even if they carry different horizontal charges. This provides an attractive mechanism for neutrino flavor anarchy.

Nir, Yosef; Shadmi, Yael

2004-11-01

42

Neutrino Nuclear Responses For Neutrino Studies In Nuclear Femto Laboratories  

SciTech Connect

Neutrinos are key particles for particle and astro-nuclear physics. Majorana neutrino masses and phases, solar and supernova neutrino productions and oscillations, and neutrino nuclear synthesis and fundamental weak interactions are well studied in nuclei as femto laboratories. Here neutrino nuclear responses are crucial for the neutrino studies. This reports briefly experimental studies of neutrino nuclear responses, charge exchange reactions on Ga to study nuclear responses for solar and {sup 51}Cr neutrinos, and {beta}{sup +} neutrino responses for {beta}{beta}-{nu} matrix elements and astro {nu} interactions by photon and muon probes.

Ejiri, H. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047, Japan and Nuclear Science, Czech Technical University, Brehova, Prague (Czech Republic)

2011-12-16

43

Neutrino flavor conversion in random magnetic fields  

Microsoft Academic Search

If massive neutrinos possess magnetic moments, a magnetic field can cause a spin flip. In the case of Dirac neutrinos the spin flip converts an active neutrino into a sterile one and vice versa. By constrast, if neutrinos are Majorana particles, a spin flip converts them to a neutrino of a different flavor. We examine the behavior of neutrinos in

G. Domokos; S. Kovesi-Domokos

1997-01-01

44

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

NASA Astrophysics Data System (ADS)

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 ??0? events using 100-150 kg of xenon enriched in the isotope 136Xe. 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&aposaneo 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.

Gómez-Cadenas, J. J.; Martín-Albo, J.; Monrabal, F.

2012-11-01

45

Neutrino sector with Majorana mass terms and Friedberg-Lee symmetry  

SciTech Connect

We examine a recently proposed symmetry/condition by Friedberg and Lee in a framework where three right-handed neutrinos are added to the spectrum of the three-family minimal standard model. It is found that the right-handed neutrinos are very special, with respect to this symmetry. In the symmetry limit the neutrinos are massless, which could possibly be a hint about why they are light. Imposed as a condition and not as a full symmetry, we find that one of the three right-handed neutrinos simply decouples (has only gravitational interactions) and one of the interacting neutrinos is massless. The possible relation of the model to the seesaw mechanism is briefly discussed.

Jarlskog, C. [Division of Mathematical Physics, LTH, Lund University, Box 118, S-22100 Lund (Sweden)

2008-04-01

46

Constraints on TeV Scale Majorana Neutrino Phenomenology from the Vacuum Stability of the Higgs  

NASA Astrophysics Data System (ADS)

The vacuum stability condition of the Standard Model (SM) Higgs potential with mass in the range of 124-127 GeV puts an upper bound on the Dirac mass of the neutrinos. We study this constraint with the right-handed neutrino masses up to TeV scale. The heavy neutrinos contribute to ?L = 2 processes like neutrinoless double beta decay and same-sign-dilepton (SSD) production in the colliders. The vacuum stability criterion also restricts the light-heavy neutrino mixing and constrains the branching ratio (BR) of lepton flavor-violating process, like ??e? mediated by the heavy neutrinos. We show that neutrinoless double beta decay with a lifetime 1025 years can be observed if the lightest heavy neutrino mass is <4.5 TeV. We show that the vacuum stability condition and the experimental bound on ??e ? together put a constrain on heavy neutrino mass MR>3.3 TeV. Finally we show that the observation of SSDs associated with jets at the LHC needs much larger luminosity than available at present. We have estimated the possible maximum cross-section for this process at the LHC and show that with an integrated luminosity 100 fb-1 it may be possible to observe the SSD signals as long as MR < 400 GeV.

Chakrabortty, Joydeep; Das, Moumita; Mohanty, Subhendra

2013-04-01

47

Neutrinos Are Nearly Dirac Fermions  

Microsoft Academic Search

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 x_nu characterizes the kind of the neutrinos, with x_nu = 0 for Dirac neutrinos and x_nu = pi\\/2 for Majorana neutrinos. If x_nu = 0, then baryon-minus-lepton number is conserved. When x_nu is

Kevin Cahill

1999-01-01

48

Neutrino Mass MSW Oscillations & Seesaw Mechanism  

Microsoft Academic Search

In the Hugs 2002 student seminar sessions, I treat a number of topical issues in neutrino physics: the phenomenology of the MSW mechanism; a brief discussion of global analysis of atmospheric and solar neutrinos; Dirac and Majorana neutrino masses and the Seesaw mechanism as an explanation for the smallness of the neutrino mass. MSW model assumes that neutrinos are created

Hasan Yüksel

2004-01-01

49

Cosmic Neutrinos  

SciTech Connect

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.

Quigg, Chris; /Fermilab /CERN

2008-02-01

50

Precise Determination of the GERMANIUM-76-SELENIUM -76 Atomic Mass Difference and the Majorana Mass of the Electron Neutrino  

NASA Astrophysics Data System (ADS)

The double-beta decay process observed in ^{82}Se has been, until now, the rarest decay process ever observed in the laboratory. The lifetime has been measured to be of the order of 10 ^{21} years. The postulated form of the double-beta decay known as the zero-neutrino mode, or betabeta(0 nu), violates several of the principles of the Standard Model of physics. This decay form, applied to the candidate nucleus ^{76} Ge, would require the decay of two neutrons to two protons and the emission of only two electrons, violating conservation of lepton number and requiring the neutrino to be a Majorana particle. In addition, the neutrino would have to be massive and/or participate in a righthanded weak current process. Since this decay would emit only electrons, its signature would be a characteristic sharp spike at the Q-value for the decay. There are currently a number of research groups searching for evidence of the betabeta(0nu) decay of ^{76}Ge. Measurement by Ellis et al. in 1985 established the Q-value for the ^{76}Ge -^{76}Se decay. New measurements have cast some doubt on this determination, and, in the interests of resolving the controversy, a re-measurement has been made. The new results of mass measurements on mass doublets in this area will be given. In addition, the implication of this new Q-value to the mass of the neutrino will be discussed. New limits on the neutrino mass will be derived.

Hykawy, Jonathan Grant

51

The neutrino mass window for baryogenesis  

Microsoft Academic Search

Interactions of heavy Majorana neutrinos in the thermal phase of the early universe may be the origin of the cosmological matter–antimatter asymmetry. This mechanism of baryogenesis implies stringent constraints on light and heavy Majorana neutrino masses. We derive an improved upper bound on the CP asymmetry in heavy neutrino decays which, together with the kinetic equations, yields an upper bound

Wilfried Buchmüller; P. Di Bari; Michael Plümacher

2003-01-01

52

The Neutrino Mass Window for Baryogenesis  

Microsoft Academic Search

Interactions of heavy Majorana neutrinos in the thermal phase of the early universe may be the origin of the cosmological matter-antimatter asymmetry. This mech- anism of baryogenesis implies stringent constraints on light and heavy Majorana neutrino masses. We derive an improved upper bound on the CP asymmetry in heavy neutrino decays which, together with the kinetic equations, yields an upper

W. Buchmuller; P. Di Bari

53

THE SEARCH FOR MASSIVE NEUTRINOS - Short Contribution  

NASA Astrophysics Data System (ADS)

Double beta decay (DBD) has the potential to distinguish whether neutrinos are Majorana or Dirac particles. However, neutrinoless DBD (in violation of lepton number conservation) has not yet been observed. From the respective upper limits, limits on the neutrino restmass can be deduced if the neutrino is of Majorana type.

Kirsten, T.

54

Neutrinos:. Theory  

NASA Astrophysics Data System (ADS)

These lectures are a theoretical introduction to the phenomenology of massive neutrinos. First I will present the low energy formalism for adding neutrino masses to the Standard Model and the induced leptonic mixing, and then I will describe the phenomenology associated with neutrino oscillations in vacuum and in matter. I will also comment on the laboratory probes of the absolute neutrino mass scale. Finally I will briefly describe some possible collider signatures associated to neutrino mass models.

Gonzalez-Garcia, M. C.

2010-08-01

55

Neutrino tomography  

NASA Astrophysics Data System (ADS)

Neutrinos are produced in weak interactions as states with definite flavor--electron, muon, or tau--and these flavor states are superpositions of states of different mass. As a neutrino propagates through space, the different mass eigenstates interfere, resulting in time-dependent flavor oscillation. Though matter is transparent to neutrinos, the flavor oscillation probability is modified when neutrinos travel through matter. Herein, we present an introduction to neutrino propagation through matter in a manner accessible to advanced undergraduate students. As an interesting application, we consider neutrino propagation through matter with a piecewise-constant density profile. This scenario has relevance in neutrino tomography, in which the density profile of matter, like the Earth's interior, can be probed via a broad-spectrum neutrino beam. We provide an idealized example to demonstrate the principle of neutrino tomography.

Millhouse, Margaret A.; Latimer, David C.

2013-09-01

56

The Majorana Experiment: a Straightforward Neutrino Mass Experiment Using The Double-Beta Decay of Ge-76  

SciTech Connect

The Majorana Experiment proposes to measure the effective mass of the electron neutrino to as low as 0.02 eV using well-tested technology. A half life of about 4E27 y, corresponding to a mass range of [0.02 - 0.07] eV can be reached by operating 500 kg of germanium enriched to 86% in Ge-76 deep underground. Radiological backgrounds of cosmogenic or primordial origin will be greatly reduced by ultra-low background screening of detector, structural, and shielding materials, by chemical processing of materials, and by electronic rejection of multi-site events in the detector. Electronic background reduction is achieved with pulse shape analysis, detector segmentation, and detector-to detector coincidence rejection.

Miley, Harry S.; Y Suzuki, M Nakahata, Y Itow, M Shiozawa & Y Obayashi

2004-08-01

57

Two Majorana Neutrino Mass Doublets with Thorough Maximal Doublet Mixing from an Analogy with the K^0Meson Oscillations  

Microsoft Academic Search

In the recent note we argued that most of the available positive and negative neutrino oscillation data can be incorporated in a four-neutrino weak interaction model with one physical condition: thorough maximal mixing of the neutrino components in each of the two mass doublets. On the level of CP-invariance an extended Pontecorvo analogy between the neutrino oscillations and the K^0-meson

E. M. Lipmanov

1999-01-01

58

Neutrino Telescopes  

SciTech Connect

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.

Hernandez-Rey, Juan Jose [IFIC - Instituto de Fisica Corpuscular, C.S.I.C. - Universitat de Valencia, E-46071, Valencia (Spain)

2006-11-28

59

Primordial Neutrinos  

NASA Astrophysics Data System (ADS)

This review discusses in detail the connection between cosmological observations and neutrino physics. Neutrinos decouple from thermal contact in the early universe at a temperature of order 1 MeV, which coincides with the temperature at which light-element synthesis occurs. Observations of light-element abundances therefore provide important information about properties such as neutrino energy density and chemical potential. Precision observations of the cosmic microwave background and large-scale structure of galaxies can be used to probe neutrino masses with greater precision than current laboratory experiments. This review discusses current cosmological bounds on neutrino properties, as well as possible bounds from upcoming measurements.

Hannestad, Steen

2006-11-01

60

Neutrino factories  

NASA Astrophysics Data System (ADS)

The discovery of neutrino oscillations marks a major milestone in the history of neutrino physics, and opens a window to what lies beyond the Standard Model. Many current and forthcoming experiments will answer open questions; however, a major step forward, up to and possibly including CP violation in the neutrino mixing matrix, will be offered by the neutrino beams from a neutrino factory. The neutrino factory is a new concept for producing neutrino beams of unprecedented quality in terms of intensity, flavour composition, and precision of the beam parameters. These beams enable the exploration of otherwise inaccessible domains in neutrino oscillation physics by exploiting baselines of planetary dimensions. Suitable detectors pose formidable challenges but seem within reach with only moderate extrapolations from existing technologies. Although the main physics attraction of the neutrino factory is in the area of neutrino oscillations, an interesting spectrum of further opportunities ranging from high-precision, high-rate neutrino scattering to physics with high-intensity stopped muons comes with it.

Dydak, F.

2002-07-01

61

Neutrino Mass MSW Oscillations & Seesaw Mechanism  

NASA Astrophysics Data System (ADS)

In the Hugs 2002 student seminar sessions, I treat a number of topical issues in neutrino physics: the phenomenology of the MSW mechanism; a brief discussion of global analysis of atmospheric and solar neutrinos; Dirac and Majorana neutrino masses and the Seesaw mechanism as an explanation for the smallness of the neutrino mass. MSW model assumes that neutrinos are created in flavor eigenstates without any definite mass but they evolve in mass eigenstates with definite mass. Latest experiments confirms the neutrino oscillations. Considering MSW oscillations in calculations provides an acceptable solution for measured neutrino flux deficiency in solar and atmospheric neutrinos. Neutrinos do not have mass in the standard model. Experimentally, it is known that neutrino mass is exceedingly small, if not zero. The seesaw mechanism predicts left handed light neutrinos with right handed heavy partners.

Yüksel, Hasan

2004-03-01

62

Neutrino mass  

SciTech Connect

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

Bowles, T.J.

1994-04-01

63

Neutrino Observatories  

NSDL National Science Digital Library

This online article, from Cosmic Horizons: Astronomy at the Cutting Edge, takes an in-depth look at the new generation of astronomy equipment. It provides an overview of the discovery of neutrinos, subatomic particles, and their role in the developing field of physics, studies that showed that nuclear reactions, including those that power the stars, produce an enormous number of neutrinos, the creation of neutrino observatories deep underground and the stunning and unexpected advances these observatories have already made.

64

Neutrino Telescopes  

SciTech Connect

Neutrino telescopes complement gamma ray telescopes in the observations of energetic astronomical sources as well as in searching for the dark matter. This paper gives the status of the current generation neutrino telescopes projects: Baikal, AMANDA, NESTOR, NEMO and ANTARES with particular emphasis on the ANTARES telescope in the Mediterranean Sea.

Carr, John [Centre de Physiques des Particules de Marseille, IN2P3/CNRS (France)

2005-02-21

65

Neutrino astronomy  

SciTech Connect

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

Schramm, D.N.

1980-01-01

66

Neutrino clouds.  

National Technical Information Service (NTIS)

We consider the possibility that neutrinos are coupled very weakly to an extremely light scalar boson. We first analyze the simple problem of one generation of neutrino and show that, for ranges of parameters that are allowed by existing data, such a syst...

G. J. Stephenson T. Goldman B. H. J. McKellar

1997-01-01

67

Neutrino mass  

SciTech Connect

Neutrinos play a dominant role in both particle physics, astrophysics, and cosmology. In the our present understanding of the strong, weak, and electromagnetic forces, the group structure of the Standard Model is SU(3){sub C} {circle_times} SU(2){sub L} {circle_times} U(I){sub EM}. In the Weinberg-Salam-Glashow Standard Electroweak Model, left-handed neutrinos sit in a doublet, while right-handed neutrinos are in a singlet, and therefore do not interact with the other known particles. Also in this model, the neutrinos are intrinsically massless. However, while the W-S-G model provides an amazingly accurate picture of our present cold Universe, It has a number of deficits. The Standard Model does not explain the origin of the group structure, It does not reduce the number of coupling constants required, nor does it offer any prediction for the physical masses of the particles. Thus, it is generally assumed that the Standard Model is but a subset of some larger gauge theory. A wide variety of Grand Unified field Theories (GUTs), Super Symmetric Models (SUSY), and Superstring models have been proposed as the model for this larger structure. In general, these models predict nonzero neutrino masses and contain mechanisms that provide for lepton-number violation. Thus, a variety of new phenomena are predicted, including finite neutrino masses and the possibility that neutrinos can oscillate from one type to another. This report looks at the possibility of detecting neutrino vat mass.

Bowles, T.J.

1993-04-01

68

Neutrino mass  

SciTech Connect

Neutrinos play a dominant role in both particle physics, astrophysics, and cosmology. In the our present understanding of the strong, weak, and electromagnetic forces, the group structure of the Standard Model is SU(3)[sub C] [circle times] SU(2)[sub L] [circle times] U(I)[sub EM]. In the Weinberg-Salam-Glashow Standard Electroweak Model, left-handed neutrinos sit in a doublet, while right-handed neutrinos are in a singlet, and therefore do not interact with the other known particles. Also in this model, the neutrinos are intrinsically massless. However, while the W-S-G model provides an amazingly accurate picture of our present cold Universe, It has a number of deficits. The Standard Model does not explain the origin of the group structure, It does not reduce the number of coupling constants required, nor does it offer any prediction for the physical masses of the particles. Thus, it is generally assumed that the Standard Model is but a subset of some larger gauge theory. A wide variety of Grand Unified field Theories (GUTs), Super Symmetric Models (SUSY), and Superstring models have been proposed as the model for this larger structure. In general, these models predict nonzero neutrino masses and contain mechanisms that provide for lepton-number violation. Thus, a variety of new phenomena are predicted, including finite neutrino masses and the possibility that neutrinos can oscillate from one type to another. This report looks at the possibility of detecting neutrino vat mass.

Bowles, T.J.

1993-01-01

69

Neutrinos Today.  

National Technical Information Service (NTIS)

After the famous 1983 discovery of intermediate W, Z/sup 0/ bosons, it may be stated with certainty that W, Z/sup 0/ are entirely responsible for the production of neutrinos and for their interactions. Neutrino physics notions are presented from this poin...

B. Pontecorvo S. Bilen'kij

1987-01-01

70

Two Majorana Neutrino Mass Doublets with Thorough Maximal Doublet Mixing from an Analogy with the K^0Meson Oscillations  

Microsoft Academic Search

In the recent note we argued that most of the available positive and negative\\u000aneutrino oscillation data can be incorporated in a four-neutrino weak\\u000ainteraction model with one physical condition: thorough maximal mixing of the\\u000aneutrino components in each of the two mass doublets. On the level of\\u000aCP-invariance an extended Pontecorvo analogy between the neutrino oscillations\\u000aand the K^0-meson

E. M. Lipmanov

1999-01-01

71

Underground Neutrino Astronomy.  

National Technical Information Service (NTIS)

A review is made of possible astronomical neutrino sources detectable with underground facilities. Comments are made about solar neutrinos and gravitational-collapse neutrinos, and particular emphasis is placed on ultra-high-energy astronomical neutrino s...

D. N. Schramm

1983-01-01

72

Ultrahigh Energy Tau Neutrinos  

NASA Astrophysics Data System (ADS)

We study ultrahigh energy astrophysical neutrinos and the contribution of tau neutrinos from neutrino oscillations, relative to the contribution of the other flavors. We show the effect of tau neutrino regeneration and tau energy loss as they propagate through the Earth. We consider a variety of neutrino fluxes, such as cosmogenic neutrinos and neutrinos that originate in Active Galactic Nuclei. We discuss signals of tau neutrinos in detectors such as IceCube, RICE and ANITA.

Jones, J.; Mocioiu, I.; Sarcevic, I.; Reno, M. H.

73

The Majorana 76 Ge neutrino less double-beta decay project: a brief update  

NASA Astrophysics Data System (ADS)

At present, Majorana is a research and development (R&D) project to investigate the feasibility and cost of constructing and operating a one ton 76Ge 0???-decay experiment with ~1000 kg of Ge detectors fabricated from germanium enriched to 86% in 76Ge. The study will include three separate cryostats with various types of detectors: un-segmented, un-segmented point-contact, minimally segmented, and highly segmented. One cryostat will contain at least 30 kg of enriched (preferably point-contact) detectors. The performance of the cryostats and detectors as well as background levels will be investigated. The goal of the demonstrator project is to reach a 3? discovery sensitivity of ~ 1026y.

Avignone, F. T., III

2008-07-01

74

Geometric phase of neutrino propagating through dissipative matter  

NASA Astrophysics Data System (ADS)

We study the geometric phase (GP) in neutrino oscillation for both Dirac and Majorana neutrinos. We apply the kinematic generalization of the GP to quantum open systems that take into account the coupling to a dissipative environment. In the dissipationless case, the GP does not depend on the Majorana angle. It is not the case in the presence of dissipation and hence the GP can serve as a tool determining the type of the Dirac vs the Majorana neutrino.

Dajka, J.; Syska, J.; ?uczka, J.

2011-05-01

75

Neutrino mixing effects, ? leptonic decays, and the solar-neutrino problem.  

NASA Astrophysics Data System (ADS)

It is assumed that a heavy right-handed Majorana neutrino which is a weak SU(2) singlet exists and its mixing with regular neutrinos causes a Cabibbo - Kobayashi - Maskawa - type matrix. This mixing effect may interpret some problems in ? leptonic decays. To be consistent with the requirements from both the seesaw mechanism and data on Z0 decay, the fourth generation with a heavy neutrino is needed. This also possibly provides a large destructive interference between contributions of magnetic moments of the electron neutrino and ? neutrino to explain away the puzzle about the deficiency of the solar neutrino flux.

Xu, Lieqian; Tao, Zhijian

1991-06-01

76

Neutrino mixing effects,. tau. leptonic decays, and the solar-neutrino problem  

SciTech Connect

It is assumed that a heavy right-handed Majorana neutrino (or more) which is a weak SU(2) singlet exists and its mixing with regular neutrinos causes a Cabibbo-Kobayashi-Maskawa-type matrix. This mixing effect may interpret some problems in {tau} leptonic decays. To be consistent with the requirements from both the seesaw mechanism and data on {ital Z}{sup 0} decay, the fourth generation with a heavy neutrino is needed. This also possibly provides a large destructive interference between contributions of magnetic moments of the electron neutrino and {tau} neutrino to explain away the puzzle about the deficiency of the solar-neutrino flux.

Li, X. (Center of Theoretical Physics, Chinese Center of Advanced Science Technology (World Laboratory), P.O. Box 8730, Beijing, China (CN) Physics Department, Nankai University, Tianjin, China); Tao Zhi-jian (Center of Theoretical Physics, Chinese Center of Advanced Science Technology (World Laboratory), P.O. Box 8730, Beijing, China Institute of Theoretical Physics, Academia Sinica, Beijing, China)

1991-06-01

77

Neutrino mixing effects, ? leptonic decays, and the solar-neutrino problem  

NASA Astrophysics Data System (ADS)

It is assumed that a heavy right-handed Majorana neutrino (or more) which is a weak SU(2) singlet exists and its mixing with regular neutrinos causes a Cabibbo-Kobayashi-Maskawa-type matrix. This mixing effect may interpret some problems in ? leptonic decays. To be consistent with the requirements from both the seesaw mechanism and data on Z0 decay, the fourth generation with a heavy neutrino is needed. This also possibly provides a large destructive interference between contributions of magnetic moments of the electron neutrino and ? neutrino to explain away the puzzle about the deficiency of the solar-neutrino flux.

Li, Xue-Qian; Zhi-Jian, Tao

1991-06-01

78

Neutrino mass matrices with a democratic texture  

SciTech Connect

The structure of the neutrino mass matrices is investigated, in a scheme where the minimal three-family Standard Model is extended by including right-handed neutrinos. No assumption is made about the presence of a large mass scale, like in the see-saw scheme. Certain peculiar features of the usual democratic mass matrix are investigated, and used to define matrices with a 'democratic texture'. By demanding that the neutrino mass matrices have a specific form with such a democratic texture, Majorana mass spectra with three massless (light) neutrinos and either two or three massive neutrinos, are obtained.

Kleppe, A. [Dep. of Mathematical Physics, LTH, Box 118, 22100 Lund (Sweden)

1997-06-15

79

Generic lepton mass matrices and neutrino oscillations  

NASA Astrophysics Data System (ADS)

Several intriguing aspects of neutrino oscillation phenomenology like the origin of small neutrino masses, the absolute neutrino mass scale, the neutrino mass hierarchy, i.e., normal or inverted, and the nature of neutrinos, i.e., Dirac or Majorana, etc. have been addressed from a general perspective. We show how the fundamental considerations of unitary transformations, naturalness, and the seesaw mechanism suffice to determine the texture structure of fermion Yukawa couplings and discuss the significance of the effective mass in 0??? decay for the texture structure of these couplings.

Verma, Rohit

2014-03-01

80

Neutrino masses, neutrino oscillations, and cosmological implications  

NASA Technical Reports Server (NTRS)

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.

Stecker, F. W.

1982-01-01

81

Supernova prompt neutronization neutrinos and neutrino magnetic moments  

Microsoft Academic Search

It is shown that the combined action of spin flavour conversions of supernova neutrinos due to the interactions of their Majorana-type transition magnetic moments with the supernova magnetic fields and flavour conversions due to the mass mixing can lead to the transformation of nue born in the neutronization process into their antiparticles bar nue. Such an effect would have a

Evgeny Kh Akhmedov; Takeshi Fukuyama

2003-01-01

82

Decaying Dirac neutrinos  

Microsoft Academic Search

Constraints on Dirac-neutrino decay into invisible particles are surveyed. Neutrino lifetimes short enough to explain the solar-neutrino problem are allowed by present terrestrial and cosmological measurements. A model in which Dirac neutrinos can have such short lifetimes is proposed. The recently resurrected 17-keV neutrino is incorporated into this model.

A. Acker; S. Pakvasa; J. Pantaleone

1992-01-01

83

A Bound on Neutrino Masses From Baryogenesis  

Microsoft Academic Search

Properties of neutrinos, the lightest of all elementary particles, may be the origin of the entire matter-antimatter asymmetry of the universe. This requires that neu- trinos are Majorana particles, which are equal to their antiparticles, and that their masses are sufficiently small. Leptogenesis, the theory explaining the cosmic matter- antimatter asymmetry, predicts that all neutrino masses are smaller than 0.2

W. Buchmuller; P. Di Bari; M. Plumacher

84

A bound on neutrino masses from baryogenesis  

Microsoft Academic Search

Properties of neutrinos, the lightest of all elementary particles, may be the origin of the entire matter–antimatter asymmetry of the universe. This requires that neutrinos are Majorana particles, which are equal to their antiparticles, and that their masses are sufficiently small. Leptogenesis, the theory explaining the cosmic matter–antimatter asymmetry, predicts that all neutrino masses are smaller than 0.2 eV, which will

W. Buchmuller; P. Di Bari; M. Plumacher

2002-01-01

85

Precise Determination of the GERMANIUM76SELENIUM -76 Atomic Mass Difference and the Majorana Mass of the Electron Neutrino  

Microsoft Academic Search

The double-beta decay process observed in ^{82}Se has been, until now, the rarest decay process ever observed in the laboratory. The lifetime has been measured to be of the order of 10 ^{21} years. The postulated form of the double-beta decay known as the zero-neutrino mode, or betabeta(0 nu), violates several of the principles of the Standard Model of physics.

Jonathan Grant Hykawy

1991-01-01

86

The Mystery of Neutrino Mixings  

NASA Astrophysics Data System (ADS)

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.

Altarelli, Guido

2013-07-01

87

Neutrino magnetic moment  

SciTech Connect

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

Chang, D. (Northwestern Univ., Evanston, IL (USA). Dept. of Physics and Astronomy Fermi National Accelerator Lab., Batavia, IL (USA)); Senjanovic, G. (Zagreb Univ. (Yugoslavia). Dept. of Theoretical Physics)

1990-01-01

88

Neutrinos: in and out of the standard model  

SciTech Connect

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.

Parke, Stephen; /Fermilab

2006-07-01

89

Neutrino masses and solar neutrinos.  

National Technical Information Service (NTIS)

It has been pointed out by Bahcall and Bethe and others that all solar neutrino data can be explained by MSW oscillations with m((nu)(sub (mu))) (approximately) 10(sup (minus)3) eV consistent with ideas grand unified theories (GUTS). There is a second pos...

L. Wolfenstein

1992-01-01

90

NEUTRINO FACTORIES - PHYSICS POTENTIALS.  

SciTech Connect

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

PARSA,Z.

2001-02-16

91

Neutrinos: Recent Developments  

SciTech Connect

Certainly one of the most exciting areas of research at present is neutrino physics. The neutrinos are fantastically numerous in the universe and as such they have bearing on our understanding of the universe. Therefore, we must understand the neutrinos, particularly their mass. There is compelling evidence from solar and atmospheric neutrinos and those from reactors for neutrino oscillations implying that neutrinos mix and have nonzero mass but without pinning down their absolute mass. This is reviewed. The implications of neutrino oscillations and mass squared splitting between neutrinos of different flavor on pattern of neutrino mass matrix is discussed. In particular, a neutrino mass matrix, which shows approximate flavor symmetry where the neutrino mass differences arise from flavor violation in off-diagonal Yukawa couplings is elaborated on. The implications in double beta decay are also discussed.

Riazuddin [National Center for Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2005-03-17

92

Sterile neutrinos as dark matter  

SciTech Connect

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

Dodelson, S. [Fermi National Accelerator Lab., Batavia, IL (United States); Widrow, L.M. [Queen`s Univ., Kingston, ON (Canada). Dept. of Physics]|[Toronto Univ., ON (Canada). Canadian Inst. for Theoretical Astrophysics

1993-03-01

93

Sterile neutrinos as dark matter  

SciTech Connect

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

Dodelson, S. (Fermi National Accelerator Lab., Batavia, IL (United States)); Widrow, L.M. (Queen's Univ., Kingston, ON (Canada). Dept. of Physics Toronto Univ., ON (Canada). Canadian Inst. for Theoretical Astrophysics)

1993-03-01

94

Massive neutrino in noncommutative space-time  

SciTech Connect

We consider the noncommutative standard model based on SU(3)xSU(2)xU(1). We study the gauge transformation of right-handed neutrinos and its direct interaction with photons in the noncommutative space-time. We show that the massive Dirac neutrinos, through the Higgs mechanism, cannot accommodate this extension of the standard model, while the massive Majorana neutrinos are consistent with the gauge symmetry of the model. The electromagnetic properties and the dispersion relations for the neutrino in the noncommutative standard model is examined. We also compare the results with the noncommutative standard model based on U(3)xU(2)xU(1)

Ettefaghi, M. M.; Haghighat, M. [Department of Physics, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

2008-03-01

95

Neutrino in Cosmology  

NASA Astrophysics Data System (ADS)

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

Kirilova, D.

2010-09-01

96

Nonaccelerator neutrino physics  

NASA Astrophysics Data System (ADS)

The subject of these lectures is experimental nonaccelerator neutrino physics. We discuss experiments on solar and atmospheric neutrino flux measurements, as well as experiments devoted to recording the antineutrino on nuclear reactors in the context of determining the parameters of neutrino oscillations. Neutrino geophysics, a new field of science, is overviewed.

Smirnov, O. Yu.

2012-12-01

97

Future Neutrino Experiments  

SciTech Connect

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.

Fleming, B. T. [Physics Department, Yale University, New Haven, CT 60510 (United States)

2009-12-17

98

The cosmic neutrino background  

NASA Technical Reports Server (NTRS)

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

Dar, Arnon

1991-01-01

99

Baryon asymmetry and neutrino mixing  

NASA Astrophysics Data System (ADS)

In theories where B - L is a spontaneously broken local symmetry, the cosmological baryon asymmetry can be generated by the out-of-equilibrium decay of heavy Majorana neutrinos. We study this mechanism assuming a similar pattern of mixings and masses for leptons and quarks, as suggested by SO(10) unification. This implies that B - L is broken at the unification scale ?GUT ~ 1016 GeV, if m?? ~ 3 . 10-3eV as preferred by the MSW explanation of the solar neutrino deficit. The observed value of the baryon asymmetry, nB/(s ~ 10-10), is then obtained without any fine tuning of parameters.

Buchmüller, W.; Plümacher, M.

1996-02-01

100

Tachyonic neutrinos and the neutrino masses  

NASA Astrophysics Data System (ADS)

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?2<0 having a much smaller magnitude than was implied by the original OPERA claim. One recently published non-standard analysis of SN 1987A neutrinos supports a tachyonic mass eigenstate, and here we show how it leads to 3 + 3 mirror neutrino model having an unconventional mass hierarchy. The model incorporates one superluminal active-sterile neutrino pair, and it is testable in numerous ways, including making a surprising prediction about an unpublished aspect of the SN 1987A neutrinos. Additional supporting evidence involving earlier analyses of cosmic rays is summarized to add credence to the tachyonic neutrino hypothesis.

Ehrlich, Robert

2013-01-01

101

Relic neutrino absorption spectroscopy  

NASA Astrophysics Data System (ADS)

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 1021 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 quasidegenerate to optimize the dip, which implies m??0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.

Eberle, Birgit; Ringwald, Andreas; Song, Liguo; Weiler, Thomas J.

2004-07-01

102

Discriminating neutrino see-saw models  

NASA Astrophysics Data System (ADS)

We consider how well current theories can predict neutrino mass and mixing parameters, and construct a statistical discriminator which allows us to compare different models to each other. As an example we consider see-saw models based on family symmetry, and single right-handed neutrino dominance, and compare them to each other and to the case of neutrino anarchy with random entries in the neutrino Yukawa and Majorana mass matrices. The predictions depend crucially on the range of the undetermined coefficients over which we scan, and we speculate on how future theories might lead to more precise predictions for the coefficients and hence for neutrino observables. Our results indicate how accurately neutrino masses and mixing angles need to be measured by future experiments in order to discriminate between current models.

Hirsch, M.; King, S. F.

2001-09-01

103

Neutrino masses and a TeV scale seesaw mechanism  

SciTech Connect

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.

Chao Wei [Center for High Energy Physics, Peking University, Beijing 100871 (China)

2010-07-01

104

Neutrino mass, a status report  

SciTech Connect

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.

Robertson, R.G.H.

1993-08-01

105

Experimental Neutrino Physics: Final Report  

SciTech Connect

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.

Lane, Charles E.; Maricic, Jelena

2012-09-05

106

Neutrino properties and puzzles  

SciTech Connect

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.

Bowles, T.J.

1990-01-01

107

Neutrinos from hell  

NASA Astrophysics Data System (ADS)

The detection of neutrinos is studied. The use of the Kamiokande II detector, which is a cylindrical tank holding about 3000 tons of highly purified water, for neutrino detection is examined. The operation and capabilities of the Kamiokande II detector are described. The Kamiokande II and Irvine-Michigan-Brookhaven detector observed the neutrinos from SN 1987A. The relation between the supernova and the neutrinos is analyzed. Particular consideration is given to the shock wave and the energies of the neutrinos. Additional data provided by the neutrino observations are discussed.

Schorn, Ronald A.

1987-05-01

108

Neutrino Physics at Fermilab  

ScienceCinema

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.

109

Neutrino Physics at Fermilab  

ScienceCinema

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.

Niki Saoulidou

2010-01-08

110

Neutrino Nucleosynthesis in Supernovae  

SciTech Connect

Neutrino nucleosynthesis is an important synthesis process for light elements in supernovae. One important physics input of neutrino nucleosynthesis is cross sections of neutrino-nucleus reactions. The cross sections of neutrino-{sup 12}C and {sup 4}He reactions are derived using new shell model Hamiltonians. With the new cross sections, light element synthesis of a supernova is investigated. The appropriate range of the neutrino temperature for supernovae is constrained to be between 4.3 MeV and 6.5 MeV from the {sup 11}B abundance in Galactic chemical evolution. Effects by neutrino oscillations are also discussed.

Yoshida, Takashi [Division of Theoretical Astronomy, National Astronomical Observatory of Japan (Japan); Suzuki, Toshio [Department of Physics, College of Humanities and Sciences, Nihon University (Japan); Chiba, Satoshi [Advanced Science Research Center, Japan Atomic Energy Agency (Japan); Kajino, Toshitaka [Division of Theoretical Astronomy, National Astronomical Observatory of Japan (Japan); Department of Astronomy, Graduate School of Science, University of Tokyo (Japan); Yokomakura, Hidekazu; Kimura, Keiichi [Department of Physics, Graduate School of Science, Nagoya University (Japan); Takamura, Akira [Department of Mathematics, Toyota National College of Technology (Japan); Hartmann, Dieter H. [Department of Physics and Astronomy, Clemson University (United States)

2009-05-04

111

PREFACE: Nobel Symposium 129 on Neutrino Physics  

NASA Astrophysics Data System (ADS)

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.

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

2005-01-01

112

Baryogenesis via neutrino oscillations.  

National Technical Information Service (NTIS)

We propose a new mechanism of leptogenesis in which the asymmetries in lepton numbers are produced through the CP-violating oscillations of ''sterile'' (electroweak singlet) neutrinos. The asymmetry is communicated from singlet neutrinos to ordinary lepto...

E. Akhmedov V. A. Rubakov A. Smirnov

1998-01-01

113

Birth of Neutrino Oscillation  

Microsoft Academic Search

This is a brief presentation of historical introduction to the theoretical concept of neutrino oscillation during the early stage up to 60's. (Openig address at the Europhysics NEUTRINO OSCILLATION WORKSHOP (NOW' 98), 7-9 Sept. 1998, Amsterdam.

M. Nakagawa

1998-01-01

114

Comparing Neutrino Event Generators  

SciTech Connect

This paper provides a description of a model of nucleon emission following nuclear pion absorption which has been developed for use with the NEUT Monte Carlo neutrino generator. It also discusses the comparison of several different neutrino event generators.

Tacik, Roman [Department of Physics, University of Regina, Regina, SK and TRIUMF, Vancouver, BC (Canada)

2011-11-23

115

High energy neutrino Astronomy  

NASA Astrophysics Data System (ADS)

Astrophysical candidate sources of ultra-high energy cosmic rays inevitably produce high-energy neutrinos in and/or around them. While cosmic rays are scattered in the inter-galactic magnetic fields, neutrinos point back to their origin. Hence neutrinos can be used to probe astrophysical sources just like in usual photon astronomy. Here we present the expected neutrino signals from different astrophysical objects and discuss their possible applications to study these intriguing sources.

Razzaque, Soebur

2011-12-01

116

Geo-neutrino Observation  

SciTech Connect

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.

Dye, S. T. [University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); Hawaii Pacific University, Kaneohe, Hawaii 96744 (United States); Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G. [University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); McDonough, W. F. [University of Maryland, College Park, Maryland 20742 (United States)

2009-12-17

117

Neutrino Oscillation Physics  

SciTech Connect

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.

Kayser, Boris

2012-06-01

118

The Sudbury Neutrino Observatory  

Microsoft Academic Search

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

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

2000-01-01

119

Solar neutrino experiments  

Microsoft Academic Search

Observational methods for detecting solar neutrinos are reviewed, and the current results presented. Four operating systems, the Homestake Mine Cl-37 radio-chemical method, the real-time neutrino scattering detector at Kamiokande II, in Japan, and two radiochemical gallium-germanium experiments are discussed in some detail. The results from these operating detectors are compared to solar model calculations and various neutrino neutrino oscillation processes

Raymond Davis Jr.; Arthur N. Cox

1991-01-01

120

Neutrinos in the early universe  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

121

Neutrino Factories - Physics Potentials.  

National Technical Information Service (NTIS)

The recent results from Super-Kamiolrande atmospheric and solar neutrino observations opens a new era in neutrino physics and has sparked a considerable interest in the physics possibilities with a Neutrino Factory based on the muon storage ring. We prese...

Z. Parsa

2001-01-01

122

Neutrino Cosmology - AN Update  

NASA Astrophysics Data System (ADS)

Present cosmological observations yield an upper bound on the neutrino mass which is significantly stronger than laboratory bounds. However, the exact value of the cosmological bound is model dependent and therefore less robust. Here, I review the current status of cosmological neutrino mass bounds and also discuss implications for sterile neutrinos and LSND in particular.

Hannestad, Steen

123

Molybdenum solar neutrino experiment  

Microsoft Academic Search

The molybdenum solar neutrino experiment goal is to deduce the (8)B solar neutrino flux, averaged over the past several million years, from the concentration of (98)Tc in a deeply buried molybdenum deposit. It is important because it will shed light on the reason for the discrepancy between theory and observation of the chlorine solar neutrino experiment. It is suggested that

K. Wolfsberg; G. A. Cowan; E. A. Bryant; K. S. Daniels; S. W. Downey; W. C. Haxton; V. G. Niesen; N. S. Nogar; C. M. Miller; D. J. Rokop

1984-01-01

124

Neutrino mass induced radiatively by supersymmetric leptoquarks  

NASA Astrophysics Data System (ADS)

We show how nonzero Majorana neutrino masses can be radiatively generated by extending the MSSM with leptoquark chiral multiplets without violating R-parity. It is found that, with these particles, the R-parity conservation does not imply lepton number conservation. Neutrino masses generated at a one-loop level are closely related to the down quark mass matrix. The ratio of neutrino mass-squared splittings ?m2?2- ?1/?m2?3- ?2 obtained is naturally close to ?m2s-d/?m2b- s~10-3 which is in the right region required to explain both the atmospheric neutrino data and the MSW solutions for the solar neutrino data.

Chua, C.-K.; He, X.-G.; Hwang, W.-Y. P.

2000-04-01

125

Neutrino masses, neutrino oscillations, double beta decay  

SciTech Connect

Experimental evidence for neutrino oscillations is so far inconclusive. Experimental data for the neutrino mass yields <5 eV from double beta decay and m<20 eV for the electron antineutrino. A review of these experimental data is given. (AIP)

Vuilleumier, J.h.

1984-05-01

126

Neutrino oscillations and neutrino-electron scattering  

SciTech Connect

Neutrino flavor oscillations can significantly alter the cross section for neutrino-electron scattering. As a result, such oscillations can affect the comparison between existing reactor data and theories of neutral-current processes. They may also lead to strikingly large effects in high-energy accelerator experiments.

Kayser, B.; Rosen, S.P.

1980-10-01

127

Solar neutrinos: Probing the sun or neutrinos.  

National Technical Information Service (NTIS)

The decade of the 1990's should prove to be a landmark period for the study of solar neutrino physics. Current observations show 2-3 times fewer neutrinos coming from the sun than are theoretically expected. As we enter the decade, new experiments are poi...

J. F. Wilkerson

1991-01-01

128

Testing neutrino flavor mixing plus decay with neutrino telescopes  

Microsoft Academic Search

We discuss the interplay of neutrino oscillation and decay properties at neutrino telescopes. Motivated by recent unparticle scenarios, which open the possibility of new neutrino decay modes over astrophysical distances, we perform a complete classification of possible decay schemes, and we illustrate how different scenarios can be identified. Moreover, we show that the sensitivity of neutrino telescopes to standard neutrino

Michele Maltoni; Walter Winter

2008-01-01

129

Mass determination of neutrinos  

NASA Technical Reports Server (NTRS)

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.

Chiu, Hong-Yee

1988-01-01

130

Neutrinos from AGN  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

131

The Neutrino Factory  

NASA Astrophysics Data System (ADS)

The discovery of neutrino oscillations marks a major milestone in the history of neutrino physics, and opens a window to what lies beyond the Standard Model. Many current and forthcoming experiments will answer open questions; however, a major step forward, up to and possibly including CP violation in the neutrino mixing matrix, will be offered by the neutrino beams from a neutrino factory. The neutrino factory is a new concept for producing neutrino beams of unprecedented quality in terms of intensity, flavour composition, and precision of the beam parameters. These beams enable the exploration of otherwise inaccessible domains in neutrino oscillation physics by exploiting baselines of planetary dimensions. Suitable detectors pose formidable challenges but seem within reach with only moderate extrapolations from existing technologies. Although the main physics' attraction of the neutrino factory is in the area of neutrino oscillations, an interesting spectrum of further opportunities ranging from high-precision, high-rate neutrino scattering to physics with high-intensity stopped muons comes with it.

Dydak, F.

132

Neutrinos from WIMP Annihilations  

NASA Astrophysics Data System (ADS)

In this talk, we make an improved analysis on the production of neutrinos coming from WIMP annihilations inside the Sun as well as the Earth. We treat both neutrino interaction and oscillation effects in a consistent three-flavor framework. Our numerical simulations are performed in an event-based setting, which is useful for both theoretical studies and creating neutrino telescope Monte Carlo simulations. We find that the yield of muon-type neutrinos is enhanced or suppressed depending on the dominant WIMP annihilation channel. In addition, we find that oscillations can significantly affect the neutrino yields from WIMP annihilations in the Sun. Effectively, the neutrino flavors are mixed. Finally, for the Earth, the oscillations have no large impact at energies for the new neutrino telescopes such as IceCube, ANTARES, and NESTOR.

Ohlsson, Tommy

2008-04-01

133

Molybdenum solar neutrino experiment  

NASA Astrophysics Data System (ADS)

The molybdenum solar neutrino experiment goal is to deduce the (8)B solar neutrino flux, averaged over the past several million years, from the concentration of (98)Tc in a deeply buried molybdenum deposit. It is important because it will shed light on the reason for the discrepancy between theory and observation of the chlorine solar neutrino experiment. It is suggested that possible reasons for the discrepancy lie in the properties of neutrinos or in deficiencies of the standard solar model. The chlorine experiment only measures the (8)B neutrino flux in current times. In the molybdenum experiments, (98)Tc (4.2 Myr) are measured, which are produced by (8)B neutrinos, and possibly (97)Tc (2.6 Myr), produced by lower energy neutrinos.

Wolfsberg, K.; Cowan, G. A.; Bryant, E. A.; Daniels, K. S.; Downey, S. W.; Haxton, W. C.; Niesen, V. G.; Nogar, N. S.; Miller, C. M.; Rokop, D. J.

134

Neutrino masses and electron-muon-?-lepton universality  

NASA Astrophysics Data System (ADS)

By a simple extension of the standard electroweak gauge group to SUL(2)×Ue(1)×U?(1)×U?(1), it is shown that it is possible to get light-neutrino masses in the range of a few electron volts. For this purpose it is necessary that MR, the mass scale associated with the masses of superheavy neutrinos which carries Ui(1) quantum numbers and which is related to the scale at which e-?-? universality is broken, is to be greater than 109 GeV. However, for the solar-neutrino problem MR should be in the range of 1011-1012 GeV. In particular, we obtain two Majorana neutrinos of almost equal mass and one Majorana neutrino (predominantly an electron neutrino) of almost zero mass.

Fayyazuddin; Riazuddin

1987-04-01

135

Neutrino masses from cosmological probes  

Microsoft Academic Search

There is a renewed interest in constraining the sum of the masses of the three neutrino flavours by using cosmological measurements. Solar, atmospheric, reactor and accelerator neutrino experiments have confirmed neutrino oscillations, implying that neutrinos have non-zero mass, but without pinning down their absolute masses. While it has been established that the effect of light neutrinos on the evolution of

Øystein Elgarøy; Ofer Lahav

2005-01-01

136

A New Neutrino Oscillation  

SciTech Connect

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.

Parke, Stephen J.; /Fermilab

2011-07-01

137

3-Neutrino mass spectrum from combining seesaw and radiative neutrino mass mechanisms  

NASA Astrophysics Data System (ADS)

We extend the Standard Model by adding a second Higgs doublet and a right-handed neutrino singlet with a heavy Majorana mass term. In this model, there are one heavy and three light Majorana neutrinos with a mass hierarchy m3>m2>m1 such that that only m3 is non-zero at the tree level and light because of the seesaw mechanism, m2 is generated at the one-loop and m1 at the two-loop level. We show that the atmospheric neutrino oscillations and large mixing MSW solar neutrino transitions with ?m2atm~=m32 and ?m2solar~=m22, respectively, are naturally accommodated in this model without employing any symmetry.

Grimus, W.; Neufeld, H.

2000-08-01

138

Neutrino dark energy and baryon asymmetry from Higgs sector  

NASA Astrophysics Data System (ADS)

We propose a new model to explain the neutrino masses, the dark energy and the baryon asymmetry altogether. In this model, neutrinos naturally acquire small Majorana masses via type-II seesaw mechanism, while the pseudo-Nambu-Goldstone bosons associated with the neutrino mass-generation mechanism provide attractive candidates for dark energy. The baryon asymmetry of the universe is produced from the Higgs triplets decay with CP-violation.

Gu, Pei-Hong; He, Hong-Jian; Sarkar, Utpal

2007-09-01

139

Neutrino mixing effects, tau leptonic decays, and the solar-neutrino problem  

Microsoft Academic Search

It is assumed that a heavy right-handed Majorana neutrino (or more) which is a weak SU(2) singlet exists and its mixing with regular neutrinos causes a Cabibbo-Kobayashi-Maskawa-type matrix. This mixing effect may interpret some problems in tau leptonic decays. To be consistent with the requirements from both the seesaw mechanism and data on Z0 decay, the fourth generation with a

Xue-Qian Li; Tao Zhi-Jian

1991-01-01

140

Neutrino helicity reversal and fundamental symmetries  

NASA Astrophysics Data System (ADS)

A rather elusive helicity reversal occurs in a gedanken experiment in which a massive left-handed Dirac neutrino, traveling at a velocity u < c, is overtaken on a highway by a speeding vehicle (traveling at velocity v with u < v < c). Namely, after passing the neutrino, looking back, one would see a right-handed neutrino (which has never been observed in nature). The Lorentz-invariant mass of the right-handed neutrino is still the same as before the passing. The gedanken experiment thus implies the existence of right-handed, light neutrinos, which are not completely sterile. Furthermore, overtaking a bunch of massive right-handed Dirac neutrinos leads to gradual de-sterilization. We discuss the helicity reversal and the concomitant sterilization and de-sterilization mechanisms by way of an illustrative example calculation, with a special emphasis on massive Dirac and Majorana neutrinos. We contrast the formalism with a modified Dirac neutrino described by a Dirac equation with a pseudoscalar mass term proportional to the fifth current.

Jentschura, U. D.; Wundt, B. J.

2014-07-01

141

Charged Cosmic Rays and Neutrinos  

NASA Astrophysics Data System (ADS)

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

Kachelrieß, M.

2013-04-01

142

Neutrino Oscillations in MINOS  

NASA Astrophysics Data System (ADS)

The MINOS experiment is a two detector experiment to study the phenomenon of neutrino oscillations, with the Near detector located at Fermilab, near Chicago and the Far detector located 734 km away, at the Soudan Underground Laboratory in Minnesota. A precision measurement of the neutrino oscillation parameters 2??23 and ?m32^2 can be accomplished using charged current neutrino events, which record both the neutrino flavor and energy. A deficit of events in the Far detector relative to that expected from the Near detector is seen, especially at low energy. In this talk we will discuss the neutrino oscillation measurement, the techniques utilized to select charged current events, as well as the expected backgrounds from neutral current neutrino scattering. Most recent results from a data set corresponding to 3.3x10^20 protons on target will be given.

Ma, Jasmine

2009-05-01

143

The neutrino telescope ANTARES  

NASA Astrophysics Data System (ADS)

The ANTARES neutrino telescope is currently the largest neutrino detector in the Northern Hemisphere. The detector consists of a three-dimensional array of 885 photomultiplier tubes, distributed along 12 lines, located at a depth of 2500 m in the Mediterranean Sea. The purpose of the experiment is the detection of high-energy cosmic neutrinos. The detection principle is based on the observation of Cherenkov-Light emitted by muons resulting from charged-current interactions of muon neutrinos in the vicinity of the detection volume. The main scientific targets of ANTARES include the search for astrophysical neutrino point sources, the measurement of the diffuse neutrino flux and the indirect search for dark matter.

Gleixner, Andreas

2014-04-01

144

Novel Ideas for Neutrino Beams  

SciTech Connect

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.

Peach, Ken [John Adams Institute for Accelerator Science, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Royal Holloway University of London, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom)

2007-04-23

145

Neutrino mass and leptogenesis  

NASA Astrophysics Data System (ADS)

We show that the seesaw mechanism may explain two independent physical parameters, small neutrino masses and universe's baryon-number asymmetry. The seesaw mechanism, thus, provides us with a big dream to relate the present baryon asymmetry to observables in neutrino physics. We show a simple model that can predict the sign of CP violation in low-energy neutrino oscillation provided that the baryon number in the present universe is positive.

Yanagida, T.

2003-04-01

146

Neutrino Mass Anarchy  

NASA Astrophysics Data System (ADS)

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.

Hall, Lawrence; Murayama, Hitoshi; Weiner, Neal

2000-03-01

147

Borexino and solar neutrinos  

Microsoft Academic Search

Borexino, a large volume detector for low energy neutrino spectroscopy, is currently running underground at the Laboratori Nazionali del Gran Sasso, Italy. The measured in- teraction rate of the 0.862 MeV 7Be neutrinos equals to 49 3stat 4syst counts\\/(day 100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with the Borexino measurement at the 4 C.L..

I. N. Machulina; C. Arpesella; M. Balata; G. Bellini; J. Benziger; S. Bonetti; A. Brigatti; B. Cac; L. Cadonati; F. Calaprice; C. Carraro; G. Cecchet; A. Chavarria; M. Chen; D. D'Angelo; A. de Bari; A. de Bellefon; A. Derbin; M. Deutsch; A. di Credico; R. Eisenstein; F. Elisei; A. Etenko; R. Fernholz; K. Fomenko; R. Ford; D. Franco; B. Freudiger; C. Galbiati; F. Gatti; S. Gazzana; M. Giammarchi; D. Giugni; M. Goeger; T. Goldbrunner; A. Goretti; C. Grieb; C. Hagner; W. Hampel; E. Harding; S. Hardy; F. X. Hartman; T. Hertrich; G. Heusser; Aldo Ianni; Andrea Ianni; M. Joyce; J. Kiko; T. Kirsten; V. Kobychev; G. Korga; G. Korschinek; D. Kryn; V. Lagomarsino; P. Lamarche; M. Lauben; C. Lendvai; M. Leung; T. Lewke; E. Litvinovich; B. Loer; P. Lombardi; L. Ludhova; I. Machulin; S. Malvezzi; S. Manecki; J. Maneira; W. Maneschg; I. Manno; D. Manuzio; G. Manuzio; A. Martemianov; F. Masetti; U. Mazzucato; K. McCarty; D. McKinsey; Q. Meindl; E. Meroni; L. Miramonti; M. Misiaszek; D. Montanari; M. E. Monzani; V. Muratova; P. Mu; H. Neder; A. Nelson; L. Niedermeier; L. Oberauer; M. Obolensky; M. Orsini; F. Ortica; M. Pallavicini; L. Papp; S. Parmeggiano; L. Perasso; A. Pocar; R. S. Raghavan; G. Ranucci; W. Rau; A. Razeto; E. Resconi; P. Risso; A. Romani; D. Rountree; A. Sabelnikov; R. Sal; C. Salvo; D. Schimizzi; S. Schonert; T. Shutt; H. Simgen; M. Skorokhvatov; O. Smirnov; A. Sonnenschein; A. Sotnikov; S. Sukhotin; Y. Suvorov; R. Tartaglia; G. Testera; D. Vignaud; S. Vitale; R. B. Vogelaar; F. von Feilitzsch; R. von Hentig; T. von Hentig; M. Wojcik; M. Wurm; O. Zaimidoroga; S. Zavatarelli; G. Zuzel

148

Neutrinos in the Electron  

SciTech Connect

I will show that one half of the rest mass of the electron consists of electron neutrinos and that the other half of the rest mass of the electron consists of the mass in the energy of electric oscillations. With this composition we can explain the rest mass of the electron, its charge, its spin and its magnetic moment We have also determined the rest masses of the muon neutrino and the electron neutrino.

Koschmieder, E. L. [Center for Statistical Mechanics, University of Texas at Austin, Austin TX 78712 (United States)

2007-04-28

149

Neutrino mass and unification  

SciTech Connect

In this talk a discussion of neutrino masses in grand unified theories is presented. Special care is paid to the question of intermediate mass scales and it is shown how they play a crucial role in the predictions for neutrino masses. SU(5) and SO(10) models are covered, with SO(10) offering a possibility of low energy parity restoration and appreciable neutrino masses and lepton number violation.

Senjanovic, G.

1981-01-01

150

Neutrinos in supernovae  

SciTech Connect

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.

Cooperstein, J.

1986-10-01

151

Neutrino-Nucleus Interactions  

NASA Astrophysics Data System (ADS)

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.

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

2011-11-01

152

Molybdenum solar neutrino experiment  

SciTech Connect

The goal of the molybdenum solar neutrino experiment is to deduce the /sup 8/B solar neutrino flux, averaged over the past several million years, from the concentration of /sup 98/Tc in a deeply buried molybdenum deposit. The experiment is important to an understanding of stellar processes because it will shed light on the reason for the discrepancy between theory and observation of the chlorine solar neutrino experiment. Possible reasons for the discrepancy may lie in the properties of neutrinos (neutrino oscillations or massive neutrinos) or in deficiencies of the standard solar model. The chlorine experiment only measures the /sup 8/B neutrino flux in current times and does not address possible temporal variations in the interior of the sun, which are also not considered in the standard model. In the molybdenum experiment, we plan to measure /sup 98/Tc (4.2 Myr), also produced by /sup 8/B neutrinos, and possibly /sup 97/Tc (2.6 Myr), produced by lower energy neutrinos.

Wolfsberg, K.; Cowan, G.A.; Bryant, E.A.; Daniels, K.S.; Downey, S.W.; Haxton, W.C.; Niesen, V.G.; Nogar, N.S.; Miller, C.M.; Rokop, D.J.

1984-01-01

153

Neutrino-nucleus interactions  

SciTech Connect

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.

Gallagher, H.; /Tufts U.; Garvey, G.; /Los Alamos; Zeller, G.P.; /Fermilab

2011-01-01

154

Bolometric detection of neutrinos  

NASA Technical Reports Server (NTRS)

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).

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

1985-01-01

155

Status and commissioning of the Karlsruhe tritium neutrino experiment KATRIN  

NASA Astrophysics Data System (ADS)

Neutrino properties, and especially the determination of the neutrino rest mass, play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double ? decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. Experiments based on single ? decay investigate electrons close to their kinematic endpoint in order to determine the neutrino mass by a modelindependent method. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows ? spectroscopy close to the tritium endpoint with unprecedented precision and will reach a sensitivity of 200 meV/c2 (90% C.L.) on the neutrino mass.

Thuemmler, Thomas; KATRIN Collaboration

2013-10-01

156

Diagnostic potential of cosmic-neutrino absorption spectroscopy  

SciTech Connect

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.

Barenboim, Gabriela; /Valencia U.; Mena Requejo, Olga; Quigg, Chris; /Fermilab

2004-12-01

157

High Energy Neutrinos with a Mediterranean Neutrino Telescope  

SciTech Connect

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

Borriello, E.; /Naples U. /INFN, Naples /Valencia U., IFIC; Cuoco, A.; /Aarhus U.; Mangano, G.; /Naples U. /INFN, Naples; Miele, G.; /Naples U. /INFN, Naples /Valencia U., IFIC; Pastor, Sergio; /Valencia U., IFIC; Pisanti, O.; /Naples U. /INFN, Naples; Serpico, Pasquale Dario; /Fermilab

2007-09-01

158

Neutrino mixing with nonzero ?13 in Zee-Babu model  

NASA Astrophysics Data System (ADS)

The exact solution for the neutrino mass matrix of the Zee-Babu model is derived. Tribimaximal mixing imposes conditions on the Yukawa couplings, from which the normal mass hierarchy is preferred. The derived conditions give a possibility of Majorana maximal CP violation in the neutrino sector. We have shown that nonzero ?13 is generated if Yukawa couplings between leptons almost equal to each other. The model gives some regions of the parameters where neutrino mixing angles and the normal neutrino mass hierarchy obtained are consistent with the recent experimental data.

Long, Hoang Ngoc; Vien, Vo Van

2014-05-01

159

Double Beta Decays and Neutrinos - Experiments and MOON  

SciTech Connect

This is a brief review of the present and future experiments of neutrino-less double beta decays (0{nu}{beta}{beta}) and the MOON (Mo Observatory Of Neutrinos) project. High sensitivity 0{nu}{beta}{beta} experiments are unique and realistic probes for studying the Majorana nature of neutrinos and the absolute mass scale as suggested by neutrino oscillation experiments. MOON aims at spectroscopic 0{nu}{beta}{beta} studies with the {nu}-mass sensitivity of 100-30 meV by means of a super ensemble of multilayer modules of scintillator plates and tracking detector planes.

Ejiri, H. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047, Japan, Nuclear Science, Czech Technical University, Brehova, Prague (Czech Republic); National Institute of Radiological Sciences, Chiba, 263-8555 (Japan)

2008-01-24

160

Dynamical electroweak symmetry breaking with top quark and neutrino condensates  

SciTech Connect

Recently it has been suggested that the electroweak symmetry is broken by a top quark vacuum condensate. In that model, the prediction for the top quark mass seems to be in conflict with indirect experimental upper bounds. We propose a new scenario in which the electroweak symmetry is broken by a combination of top quark and third generation neutrino condensates, involving a right- handed gauge singlet neutrino. We show that the top quark mass comes out smaller in this model and can easily lie in the experimentally favored window. The resulting neutrino spectrum is phenomenologically acceptable if we make the natural assumption that the right handed neutrino has a very large Majorana mass.

Martin, S.P.

1991-12-31

161

Dynamical electroweak symmetry breaking with top quark and neutrino condensates  

SciTech Connect

Recently it has been suggested that the electroweak symmetry is broken by a top quark vacuum condensate. In that model, the prediction for the top quark mass seems to be in conflict with indirect experimental upper bounds. We propose a new scenario in which the electroweak symmetry is broken by a combination of top quark and third generation neutrino condensates, involving a right- handed gauge singlet neutrino. We show that the top quark mass comes out smaller in this model and can easily lie in the experimentally favored window. The resulting neutrino spectrum is phenomenologically acceptable if we make the natural assumption that the right handed neutrino has a very large Majorana mass.

Martin, S.P.

1991-01-01

162

Neutrino Nuclear Responses for Neutrino Studies in Nuclear Femto Laboratories  

SciTech Connect

Fundamental properties of neutrinos and neutrino nuclear interactions are of great interest from particle and astro-nuclear physics view points. They are well studied in nuclear femto laboratories, where neutrino nuclear responses are crucial. Neutrino masses and neutrino natures are studied by neutrino-less double beta decays (0{nu}{beta}{beta}) in nuclei. Here neutrino nuclear responses are required to extract neutrino properties from 0{nu}{beta}{beta} rates. Neutrino nuclear responses are sensitive to nuclear spin isospin correlations and nuclear structures. They are experimentally studied by nuclear probes for charge exchange nuclear reactions, photon EM probes for photo-nuclear reactions, and lepton probes for muon and neutrino capture reactions.

Ejiri, Hiroyasu [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Nuclear Science, Czech Technical University, Brehova, Prague (Czech Republic)

2010-11-24

163

Ice fishing for neutrinos  

NASA Astrophysics Data System (ADS)

A new telescope, the Antarctic Muon and Neutrino Dtector Array (AMANDA), at the South Pole is attempting to collect 'ghost' particles from some of the highest energy sources in the universe. The goal is to transform a piece of the south-polar icecap into a telescope that will map the locations of high-energy neutrinos in the sky. Ten kilometer-long strings beaded with 20 multiplier tubes along their lower 200 meters make up AMANDA. Occasionally a neutrino, racing through the 3-km-thick Antarctic icecap, interacts with an atom and spawns a muon, which emits an expanding cone of Cherenkov light as it continues along nearly the same track as the neutrino itself. By timing when this light is detected by various photomultipliers, the neutrino's origin in the sky can be determined. AMANDA records light flashes from muons created by neutrinos that have passed through the Earth to arrive at the South Pole from the northern sky. If the neutrinos come from enduring sources, such as black holes, detections will cluster around 'hot spots' in the sky. Background 'noise' from neutrinos born in Northern Hemisphere cosmic-ray showers will be distributed randomly. Other aspects AMANDA are discussed.

Robinson, Lief J.

1994-07-01

164

The Baksan Neutrino Observatory  

NASA Astrophysics Data System (ADS)

An overall view of the history of the Baksan Neutrino Observatory INR RAS creation is presented. Ground-based and underground facilities used to study cosmic rays, rare nuclear reactions and decays, register solar neutrinos, observe various geophysical phenomena are described. Some main results obtained with these facilities are given.

Kuzminov, V. V.

2012-09-01

165

Neutrino astronomy: An update  

NASA Astrophysics Data System (ADS)

Detecting neutrinos associated with the still enigmatic sources of cosmic rays has reached a new watershed with the completion of IceCube, the first detector with sensitivity to the anticipated fluxes. In this review, we will briefly revisit the rationale for constructing kilometer-scale neutrino detectors and summarize the status of the field.

Halzen, Francis

2013-12-01

166

Neutrino astronomy: An update  

NASA Astrophysics Data System (ADS)

Detecting neutrinos associated with the still enigmatic sources of cosmic rays has reached a new watershed with the completion of IceCube, the first detector with sensitivity to the anticipated fluxes. In this review, we will briefly revisit the rationale for constructing kilometer-scale neutrino detectors and summarize the status of the field.

Halzen, Francis

2014-01-01

167

Neutrino Astronomy: An Update  

NASA Astrophysics Data System (ADS)

Detecting neutrinos associated with the still enigmatic sources of cosmic rays has reached a new watershed with the completion of IceCube, the first detector with sensitivity to the anticipated fluxes. In this review, we will briefly revisit the rationale for constructing kilometer-scale neutrino detectors and summarize the status of the field.

Halzen, Francis

2013-01-01

168

Theory of Neutrinos  

Microsoft Academic Search

After a brief overview of the present knowledge of neutrino masses and mixing, we summarize what can be learned about physics beyond the standard model from the various proposed neutrino experiments. We also comment on the impact of the experiments on our understanding of the origin of the matter-antimatter asymmetry of the Universe as well as what can be learned

R. N. Mohapatra; S. Antusch; K. S. Babu; G. Barenboim; Mu-Chun Chen; S. Davidson; A. de Gouvea; P. de Holanda; B. Dutta; Y. Grossman; A. Joshipura; J. Kersten; Y. Y. Keum; S. F. King; P. Langacker; M. Lindner; W. Loinaz; I. Masina; I. Mocioiu; S. Mohanty; H. Murayama; S. Pascoli; S. Petcov; A. Pilaftsis; P. Ramond; M. Ratz; W. Rodejohann; R. Shrock; T. Takeuchi; T. Underwood; F. Vissani; L. Wolfenstein

2004-01-01

169

Helioseismology and solar neutrinos  

Microsoft Academic Search

The manner by which helioseismic date are obtained and analysed to diagnose the interior structure and rotation of the Sun is briefly described. The principal results of the analysis pertinent to solar neutrino production are presented; they have constrained standard theoretical models of the Sun in such a way as to prevent them from explaining the neutrino flux measurements without

D. O. Gough

1999-01-01

170

Molybdenum Solar Neutrino Experiment.  

National Technical Information Service (NTIS)

The goal of the molybdenum solar neutrino experiment is to deduce the sup 8 B solar neutrino flux, averaged over the past several million years, from the concentration of sup 98 Tc in a deeply buried molybdenum deposit. The experiment is important to an u...

K. Wolfsberg G. A. Cowan E. A. Bryant K. S. Daniels S. W. Downey

1984-01-01

171

Helioseismology and solar neutrinos  

Microsoft Academic Search

The manner by which helioseismic data are obtained and analysed to diagnose the interior structure and rotation of the Sun is briefly described. The principal results of the analysis pertinent to solar neutrino production are presented; they have constrained standard theoretical models of the Sun in such a way as to prevent them from explaining the neutrino flux measurements without

D. O. Gough

1999-01-01

172

Reactor neutrino anomaly and sterile neutrinos revisited  

NASA Astrophysics Data System (ADS)

In this contribution we will present results from two separate experiments dealing with the neutrino response on 71Ga. Both experiments provide input to the calibration of the SAGE and GALLEX solar neutrino detectors and address a long-standing discrepancy between the measured and evaluated capture rates from the 51Cr and 37Ar neutrino calibration sources. The first is a 71Ga(3He,t)71Ge charge-exchange experiment performed at RCNP, Osaka, which allows to extract with high precision the Gamow-Teller transition strengths to the three lowest-lying states in 71Ge, i.e., the ground state (1/2-), the 175 (5/2-) and the 500 keV (3/2-) excited states. These are the states, which are populated via a charged-current reaction induced by neutrinos from reactor produced 51Cr and 37Ar sources. In the second part we present a new precision Q-value measurement for the 71Ga(nu,e-)71Ge reaction using the TITAN mass measurement facility at TRIUMF. From the results of the two experiments we now conclude that there are no further unknowns in the nuclear structure, which could remove the persistent discrepancy in the SAGE and GALLEX calibration measurement performed with neutrinos from 51Cr and 37Ar sources.

Lennarz, Annika

2012-10-01

173

On the nature of the fourth generation neutrino and its implications  

NASA Astrophysics Data System (ADS)

We consider the neutrino sector of a Standard Model with four generations. While the three light neutrinos can obtain their masses from a variety of mechanisms with or without new neutral fermions, fourth-generation neutrinos need at least one new relatively light right-handed neutrino. If lepton number is not conserved this neutrino must have a Majorana mass term whose size depends on the underlying mechanism for lepton number violation. Majorana masses for the fourth-generation neutrinos induce relative large two-loop contributions to the light neutrino masses which could be even larger than the cosmological bounds. This sets strong limits on the mass parameters and mixings of the fourth-generation neutrinos.

Aparici, Alberto; Herrero-García, Juan; Rius, Nuria; Santamaria, Arcadi

2012-07-01

174

Neutrino Astronomy and Intermediate Bosons.  

National Technical Information Service (NTIS)

Neutrino fluxes from strong radio sources are estimated, assuming the neutrino-production mechanism: p+p yields nucleons+mesons yields nucleons+electrons, gamma rays, and neutrinos. The neutrino fluxes calculated on the basis of this mechanism are too sma...

J. N. Bahcall S. C. Frautschi

1964-01-01

175

Neutrino mass bounds from cosmology  

NASA Astrophysics Data System (ADS)

Cosmology is at present one of the most powerful probes of neutrino properties. The advent of precision data from the cosmic microwave background and large scale structure has allowed for a very strong bound on the neutrino mass. Here, I review the status of cosmological bounds on neutrino properties with emphasis on mass bounds on light neutrinos.

Hannestad, Steen

2005-08-01

176

Summary: Neutrinos and nonaccelerator physics  

SciTech Connect

This paper contains brief synopsis of the following major topics discussed in the neutrino and nonaccelerator parallel sessions: dark matter; neutrino oscillations at accelerators and reactors; gamma-ray astronomy; double beta decay; solar neutrinos; and the possible existence of a 17-KeV neutrino. (LSP)

Hoffman, C.M.

1991-01-01

177

Muon neutrino to electron neutrino oscillations in the MINOS experiment  

NASA Astrophysics Data System (ADS)

MINOS is a long-baseline neutrino oscillation experiment situated along Fermilab's high-intensity NuMI neutrino beam. MINOS has completed an updated search for muon neutrino to electron neutrino transitions, observation of which would indicate a non-zero value for the neutrino mixing angle ?13. The present 7×1020 protons-on-target data set represents more than double the exposure used in the previous analysis. The new results are presented.

Toner, R.; Pawloski, G.; Whitehead, L.; Minos Collaboration

2012-08-01

178

Neutrino Oscillations, Masses and Mixing  

Microsoft Academic Search

The original B. Pontecorvo idea of neutrino oscillations is discussed.\\u000aNeutrino mixing and basics of neutrino oscillations in vacuum and in matter are\\u000aconsidered. Recent evidences in favour of neutrino oscillations, obtained in\\u000aSuper-Kamiokande, SNO, KamLAND and other neutrino experiments are discussed.\\u000aNeutrino oscillations in the solar and atmospheric ranges of the neutrino\\u000amass-squared differences are considered in the framework

W. M. Alberico; S. M. Bilenky

2003-01-01

179

Solar neutrinos: Probing the sun or neutrinos  

SciTech Connect

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

Wilkerson, J.F.

1991-01-01

180

Zero minors of the neutrino mass matrix  

SciTech Connect

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.

Lashin, E. I. [Abdus Salam ICTP, P.O. Box 586, 34100 Trieste (Italy); Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Department of Physics and Astronomy, College of Science, King Saud University, Riyadh (Saudi Arabia); Chamoun, N. [Abdus Salam ICTP, P.O. Box 586, 34100 Trieste (Italy); Physics Department, HIAST, P.O. Box 31983, Damascus (Syrian Arab Republic)

2008-10-01

181

Sterile neutrinos in neutrinoless double beta decay  

SciTech Connect

We study possible contribution of the Majorana neutrino mass eigenstate {nu}{sub h}, dominated by a sterile neutrino component, to neutrinoless double beta (0{nu}{beta}{beta}) decay. A special emphasis is made on accurate calculation of the corresponding nuclear matrix elements. From the current experimental lower bound on the 0{nu}{beta}{beta}-decay half-life of 76 Ge we derive stringent constraints on the {nu}{sub h}-{nu}{sub e} mixing in a wide region of the values of {nu}{sub h} mass. We discuss cosmological and astrophysical status of {nu}{sub h} in this mass region.

Benes, P.; Faessler, Amand; Simkovic, F. [Institute fuer Theoretische Physik der Univesitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany); Kovalenko, S. [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)

2005-04-01

182

Tau Neutrinos Favored over Sterile Neutrinos in Atmospheric Muon Neutrino Oscillations  

Microsoft Academic Search

The previously published atmospheric neutrino data did not distinguish whether muon neutrinos were oscillating into tau neutrinos or sterile neutrinos, as both hypotheses fit the data. Using data recorded in 1100 live days of the Super-Kamiokande detector, we use three complementary data samples to study the difference in zenith angle distribution due to neutral currents and matter effects. We find

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

2000-01-01

183

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

SciTech Connect

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.

Dighe, Amol [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

2011-11-23

184

Neutrino oscillations: theory and phenomenology  

NASA Astrophysics Data System (ADS)

A brief overview of selected topics in the theory and phenomenology of neutrino oscillations is given. These include: oscillations in vacuum and in matter; phenomenology of 3-flavour neutrino oscillations; CP and T violation in neutrino oscillations in vacuum and in matter; matter effects on ????? oscillations; parametric resonance in neutrino oscillations inside the earth; oscillations below and above the MSW resonance; unsettled issues in the theory of neutrino oscillations.

Akhmedov, E. K.

2011-12-01

185

Coherent scattering of cosmic neutrinos  

NASA Technical Reports Server (NTRS)

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.

Opher, R.

1974-01-01

186

Presupernovae as Powerful Neutrino Sources  

NASA Astrophysics Data System (ADS)

In this report, some research results of the neutrino astrophysics group at the Institute of Physics of Jagellonian University are presented http://ribes.if.uj.edu.pl/psns . It is shown that neutrinos emitted by presupernovae located within a few kpc from Earth could be detected by new generation of neutrino detectors. We encourage planners of the future neutrino experiments to include presupernova neutrino measurements on their agenda.

Kutschera, M.; Odrzywo?ek, A.; Misiaszek, M.

2009-11-01

187

Topics in neutrino astrophysics  

NASA Astrophysics Data System (ADS)

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.

Chan, Man Ho

2009-06-01

188

Neutrino cosmology and Planck  

NASA Astrophysics Data System (ADS)

Relic neutrinos play an important role in the evolution of the Universe, modifying some of the cosmological observables. We summarize the main aspects of cosmological neutrinos and describe how the precision of present cosmological data can be used to learn about neutrino properties. In particular, we discuss how cosmology provides information on the absolute scale of neutrino masses, complementary to beta decay and neutrinoless double-beta decay experiments. We explain why the combination of Planck temperature data with measurements of the baryon acoustic oscillation angular scale provides a strong bound on the sum of neutrino masses, 0.23 eV at the 95% confidence level, while the lensing potential spectrum and the cluster mass function measured by Planck are compatible with larger values. We also review the constraints from current data on other neutrino properties. Finally, we describe the very good perspectives from future cosmological measurements, which are expected to be sensitive to neutrino masses close to the minimum values guaranteed by flavour oscillations.

Lesgourgues, Julien; Pastor, Sergio

2014-06-01

189

Nonzero ?13 and Neutrino Masses from Modified Neutrino Mixing Matrix  

NASA Astrophysics Data System (ADS)

The nonzero and relatively large ?13 have been reported by Daya Bay, T2K, MINOS and Double Chooz Collaborations. In order to accommodate the nonzero ?13, we modified the tribimaximal (TB), bimaxima (BM) and democratic (DC) neutrino mixing matrices. From three modified neutrino mixing matrices, two of them (the modified BM and DC mixing matrices) can give nonzero ?13 which is compatible with the result of the Daya Bay and T2K experiments. The modified TB neutrino mixing matrix predicts the value of ?13 which is greater than the upper bound value of the latest experimental results. By using the modified neutrino mixing matrices and imposing an additional assumption that neutrino mass matrices have two zeros texture, we then obtain the neutrino mass in normal hierarchy when (M?)22 = (M?)33 = 0 for the neutrino mass matrix from the modified TB neutrino mixing matrix and (M?)11 = (M?)13 = 0 for the neutrino mass matrix from the modified DC neutrino mixing matrix. For these two patterns of neutrino mass matrices, either the atmospheric mass squared difference or the solar mass squared difference can be obtained, but not both of them simultaneously. From four patterns of two zeros texture to be considered on the obtained neutrino mass matrix from the modified BM neutrino mixing matrix, none of them can correctly predict the neutrino mass spectrum (normal or inverted hierarchy).

Damanik, Asan

2012-06-01

190

Neutrino Propagation in Nuclear Medium and Neutrinoless Double-? Decay  

NASA Astrophysics Data System (ADS)

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.

Kovalenko, S.; Krivoruchenko, M. I.; Šimkovic, F.

2014-04-01

191

Neutrino masses and non-abelian horizontal symmetries  

NASA Astrophysics Data System (ADS)

Recently neutrino experiments have made very significant progresses and our knowledge of neutrino masses and mixing has considerably improved. In a model-independent Monte Carlo approach, we have examined a very large class of textures, in the context of non-abelian horizontal symmetries; we have found that neutrino data select only those charged lepton matrices with left-right asymmetric texture. The large atmospheric mixing angle needs m23? m33. This result, if combined with similar recent findings for the quark sector in the B oscillations, can be interpreted as a hint for SU(5) unification. In the neutrino sector strict neutrino anarchy is disfavored by data, and at least a factor 2 of suppression in the first row and column of the neutrino Majorana mass matrix is required.

Antonelli, V.; Caravaglios, F.; Ferrari, R.; Picariello, M.

2002-12-01

192

Bounds on neutrino masses from leptogenesis in type-II seesaw models  

SciTech Connect

The presence of the triplet {delta}{sub L} in left-right symmetric theories leads to type-II seesaw mechanism for the neutrino masses. In these models, assuming a normal mass hierarchy for the heavy Majorana neutrinos, we derive a lower bound on the mass of the lightest of heavy Majorana neutrinos from the leptogenesis constraint. From this bound we establish a consistent picture for the hierarchy of heavy Majorana neutrinos in a class of left-right symmetric models in which we identify the neutrino Dirac mass matrix with that of Fritzsch type charged lepton mass matrix. It is shown that these values are compatible with the current neutrino oscillation data.

Sahu, Narendra; Sankar, S. Uma [Department of Physics, Indian Institute of Technology, Bombay, Mumbai 400076 (India)

2005-01-01

193

Review of Recent Neutrino Physics Research  

NASA Astrophysics Data System (ADS)

We review recent research in neutrino physics, including neutrino oscillations to test time reversal and CP symmetry violations, the measurement of parameters in the U matrix, sterile neutrino emission causing pulsar kicks, and neutrino energies in the neutrinosphere.

Kisslinger, Leonard S.

2013-09-01

194

Neutrinos: Nature's Identity Thieves?  

ScienceCinema

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.

Dr. Don Lincoln

2013-07-22

195

Neutrinos from neutron stars  

NASA Technical Reports Server (NTRS)

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.

Helfand, D. J.

1979-01-01

196

Solar-neutrino oscillations  

NASA Technical Reports Server (NTRS)

The theory of oscillations of solar neutrinos is developed as it applies to the electron-recoil spectrum in neutrino-electron scattering. The spectral information obtained by such measurements (as opposed to counting total event rates) is crucial for allowing observation of neutrino oscillations for masses down to 500 neV. In this regard, the effects of different masses and mixing angles, as well as such subtleties as thermal and pressure broadening, finite solar-core size, and variable indices of refraction are investigated.

Krauss, L.; Wilczek, F.

1985-01-01

197

Neutrinos: Nature's Identity Thieves?  

SciTech Connect

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.

Dr. Don Lincoln

2013-07-11

198

Observational Neutrino Astronomy.  

National Technical Information Service (NTIS)

Experiments to be performed in 1965 involving neutrinos from the sun, from the decay of cosmic-ray secondaries, and from strong radio sources are discussed. The foundations of the theoretical predictions and the significance of the experiments are emphasi...

J. N. Bahcall

1964-01-01

199

Sterile neutrino anarchy  

NASA Astrophysics Data System (ADS)

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.

Heeck, Julian; Rodejohann, Werner

2013-02-01

200

The ANTARES neutrino telescope  

NASA Astrophysics Data System (ADS)

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.

Zornoza, J. D.; Zúñiga, J.

2013-05-01

201

Helioseismology and solar neutrinos  

NASA Astrophysics Data System (ADS)

The manner by which helioseismic data are obtained and analysed to diagnose the interior structure and rotation of the Sun is briefly described. The principal results of the analysis pertinent to solar neutrino production are presented; they have constrained standard theoretical models of the Sun in such a way as to prevent them from explaining the neutrino flux measurements without recourse to neutrino transitions. However, standard solar models do not represent the entire class of plausible models, and indeed they suffer the deficiency of being unstable. Models in which the products of the nuclear reactions are redistributed in the core may represent the Sun more closely, and should at least be considered and tested further in the process of developing a reliable model of the neutrino source.

Gough, D. O.

1999-05-01

202

Very high energy neutrinos  

NASA Astrophysics Data System (ADS)

A sky survey with neutrinos may considerably extend our understanding of cosmic phenomena. Due to the low interaction cross section of neutrinos with matter and due to the high cosmic ray background the detector must be very large (of the order of 1 km 3) and must be shielded. These new devices consist of a network of photo-tubes which are deployed in the depth of the ocean, of a lake or of the ice of South Pole. The detection of the Cherenkov light emitted by muons produced in muon neutrino interactions with the matter surrounding the detector will allow the reconstruction of the neutrino direction with an angular resolution of the order or lower than one degree. Several projects are underway. Their status will be reviewed in this paper.

Moscoso, Luciano; Spiering, Christian

2000-03-01

203

Neutrino electron plasma instability  

NASA Astrophysics Data System (ADS)

Weak interactions play an important role in early universe plasma collection, especially on neutrinos and the corresponding leptons. It also has important effects on the detail balance of the primordial nucleosynthesis, especially on the production of He and light elements. At around T = 300 GeV, the primordial plasma undergone electroweak spontaneous symmetry breaking (SSB) phase transition. Some of the gauge bosons and other particles gain mass via Higgs mechanism. Deduced from Weinberg-Salam electroweak theory, a Boltzmann equation and subsequent fluid equations are derived for the primordial electron-positron-neutrino- photon plasma. A collective instability that separates the phases of electrons (and positrons) and neutrinos (and anti-neutrinos) is discussed. We also discussed the application of the fluctuation-dissipation theory in this system of plasma. An approach with Hubble expansion included in Boltzmann equation is also discussed. Astrophysical applications and implications are explored, particularly in supernovae.

Lai, Chi-Hsuan

1999-03-01

204

Neutrino Masses, Where Do We Stand?  

Microsoft Academic Search

I review the status of neutrino physics post-Neutrino~98, including the implications of solar and atmospheric neutrino data, which strongly indicate nonzero neutrino masses. LSND and the possible role of neutrinos as hot dark matter (HDM) are also mentioned. The simplest schemes proposed to reconcile these requirements invoke a light sterile neutrino in addition to the three active ones, two of

J. W. F. Valle

1999-01-01

205

Neutrino Flavor Tagging in a Four-Neutrino Mixing and Oscillation Model  

Microsoft Academic Search

A neutrino mass dominance quantity is introduced for tagging the neutrino flavor in the phenomenological two-parameter four neutrino mixing matrix with two neutrino mass doublets and thorough maximal neutrino doublet mixing. While there is no hierarchy of the neutrino masses in the neutrino flavor eigenstates of this model, it may rather be a special hierarchy of the mass dominance ratios

E. M. Lipmanov

1999-01-01

206

Neutrino oscillation based on the mixings with a heavy right-handed neutrino  

Microsoft Academic Search

We study a consistent explanation for both deficits of solar neutrino and atmospheric neutrino due to the neutrino oscillation induced by the mixing of light neutrinos with a heavy right-handed neutrino. We propose such a phenomenological neutrino mass matrix that realizes this scenario in the simple three generation left- and right- handed neutrino framework. Although this model contains only one

Daijiro Suematsu

1997-01-01

207

Small Neutrino Masses from Supersymmetry Breaking  

SciTech Connect

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

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

2000-06-27

208

GUT, neutrinos, and baryogenesis  

NASA Astrophysics Data System (ADS)

It is an exciting time for flavor physics. In this talk, I discuss recent topics in baryogenesis and leptogenesis in light of new data, and implications in B and neutrino physics. I also discuss current situation of grand unified theories concerning coupling unification, proton decay, and indirect consequences in lepton flavor violation and B physics. I explain attempts to understand the origin of flavor based on flavor symmetry, in particular "anarchy" in neutrinos.

Murayama, Hitoshi

2002-11-01

209

Radiochemical solar neutrino experiments  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

210

Boxing with Neutrino Oscillations  

NASA Astrophysics Data System (ADS)

We have developed a model-independent ``box'' parameterization of neutrino oscillations. Oscillation probabilities are linear in these new parameters, so measurements can straighforwardly determine the box parameters which can then be manipulated to yield magnitudes of mixing matrix elements. We will present these new parameters and examine the effects of unitarity which reduce the number of independent parameters to the minimum set. The framework presented here will facilitate general analyses of neutrino oscillations among n >= 3 flavors.

Wagner, Dj; Weiler, Thomas J.

1998-03-01

211

Neutrinos beyond the Standard Model  

SciTech Connect

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.

Valle, J.W.F.

1989-08-01

212

Experimental High Energy Neutrino Astrophysics  

SciTech Connect

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.

Distefano, Carla [Laboratori Nazionali del Sud, Catania (Italy)

2005-10-12

213

Frontiers of neutrino astrophysics. Proceedings.  

NASA Astrophysics Data System (ADS)

This symposium highlighted the recent developments and the future direction of neutrino astrophysics and related topics. The results from on-going solar neutrino experiments as well as detailed discussions on the possible solutions to the solar neutrino problems were presented, including the observed deficit of the atmospheric muon neutrinos. The status of many new solar neutrino experiments were reported, and topics from grand unified theories, big bang cosmology, and dark matter were presented. Discussions were also held on radiation from supernovae and compact astrophysical objects, not just with regard to neutrinos, but also X-rays, ?-rays, and gravitational waves.

Suzuki, Y.; Nakamura, K.

214

Electromagnetic properties of massive neutrinos  

SciTech Connect

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.

Dobrynina, A. A., E-mail: aleksandradobrynina@rambler.ru; Mikheev, N. V.; Narynskaya, E. N. [Demidov Yaroslavl State University (Russian Federation)] [Demidov Yaroslavl State University (Russian Federation)

2013-10-15

215

Neutrino Detectors: Challenges and Opportunities  

SciTech Connect

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.

Soler, F. J. P. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2011-10-06

216

Neutrino quantum kinetics  

NASA Astrophysics Data System (ADS)

We present a formulation of the quantum kinetic equations (QKEs), which govern the evolution of neutrino flavor at high density and temperature. Here, the structure of the QKEs is derived from the ground up, using fundamental neutrino interactions and quantum field theory. We show that the resulting QKEs describe coherent flavor evolution with an effective mass when inelastic scattering is negligible. The QKEs also contain a collision term. This term can reduce to the collision term in the Boltzmann equation when scattering is dominant and the neutrino effective masses and density matrices become diagonal in the interaction basis. We also find that the QKEs include equations of motion for a new dynamical quantity related to neutrino spin. This quantity decouples from the equations of motion for the density matrices at low densities or in isotropic conditions. However, the spin equations of motion allow for the possibility of coherent transformation between neutrinos and antineutrinos at high densities and in the presence of anisotropy. Although the requisite conditions for this exist in the core collapse supernova and compact object merger environments, it is likely that only a self-consistent incorporation of the QKEs in a sufficiently realistic model could establish whether or not significant neutrino-antineutrino conversion occurs.

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

2014-05-01

217

MINOS neutrino oscillation results  

NASA Astrophysics Data System (ADS)

Neutrinos interact only weakly with other matter and had been thought to be massless. However, if their mass is non-zero, they could change flavors as they propagate. Recent results from observations of atmospheric, solar, and reactor neutrinos indicate that they do change flavor and these observations have provided measurements of two of the three possible mixings. The MINOS experiment is now making precise measurements of the ??? oscillations seen in atmospheric neutrinos, and extends our reach towards the so far unseen angle ?3 by looking for ? appearance from the ? beam. It does so by using the intense, well-understood NuMI neutrino beam created at Fermilab and observing it 735 km away at the Soudan Mine in Northeast Minnesota. This combination also allows investigation of the oscillation properties of anti-neutrinos, as the NuMI beam can focus opposite-charged pions to produce the anti-neutrinos, and the MINOS detectors are magnetized, allowing event-by-event discrimination of the resulting muon charge-sign.

Habig, A.; Minos Collaboration

218

Prospect for Relic Neutrino Searches  

NASA Astrophysics Data System (ADS)

Neutrinos from the Big Bang are theoretically expected to be the most abundant particles in the Universe after the photons of the Cosmic Microwave Background (CMB). Unlike the relic photons, relic neutrinos have not so far been observed. The Cosmic Neutrino Background (C?B) is the oldest relic from the Big Bang, produced a few seconds after the Bang itself. Due to their impact in cosmology, relic neutrinos may be revealed indirectly in the near future through cosmological observations. In this talk we concentrate on other proposals, made in the last 30 years, to try to detect the C?B directly, either in laboratory searches (through tiny accelerations they produce on macroscopic targets) or through astrophysical observations (looking for absorption dips in the flux of Ultra-High Energy (UHE) neutrinos, due to the annihilation of these neutrinos with relic neutrinos at the Z-resonance). We concentrate mainly on the first possibility. We show that, given present bounds on neutrino masses, lepton number in the Universe and gravitational clustering of neutrinos, all expected laboratory effects of relic neutrinos are far from observability, awaiting future technological advances to reach the necessary sensitivity. The problem for astrophysical searches is that sources of UHE neutrinos at the extreme energies required may not exist. If they do exist, we could reveal the existence, and possibly the mass spectrum, of relic neutrinos, with detectors of UHE neutrinos (such as ANITA, Auger, EUSO, OWL, RICE and SalSA).

Gelmini, Graciela B.

2006-03-01

219

Prospect for Relic Neutrino Searches  

NASA Astrophysics Data System (ADS)

Neutrinos from the Big Bang are theoretically expected to be the most abundant particles in the Universe after the photons of the Cosmic Microwave Background (CMB). Unlike the relic photons, relic neutrinos have not so far been observed. The Cosmic Neutrino Background (C?B) is the oldest relic from the Big Bang, produced a few seconds after the Bang itself. Due to their impact in cosmology, relic neutrinos may be revealed indirectly in the near future through cosmological observations. In this talk we concentrate on other proposals, made in the last 30 years, to try to detect the C?B directly, either in laboratory searches (through tiny accelerations they produce on macroscopic targets) or through astrophysical observations (looking for absorption dips in the flux of Ultra-High Energy (UHE) neutrinos, due to the annihilation of these neutrinos with relic neutrinos at the Z-resonance). We concentrate mainly on the first possibility. We show that, given present bounds on neutrino masses, lepton number in the Universe and gravitational clustering of neutrinos, all expected laboratory effects of relic neutrinos are far from observability, awaiting future technological advances to reach the necessary sensitivity. The problem for astrophysical searches is that sources of UHE neutrinos at the extreme energies required may not exist. If they do exist, we could reveal the existence, and possibly the mass spectrum, of relic neutrinos, with detectors of UHE neutrinos (such as ANITA, Auger, EUSO, OWL, RICE and SalSA).

Gelmini, Graciela B.

2005-01-01

220

Astrophysical tau neutrinos and their detection by large neutrino telescopes  

SciTech Connect

We present results of the detailed Monte Carlo calculation of the rates of double-bang events in a 1-km{sup 3} underwater neutrino telescope taking into account the effects of {tau}-neutrino propagation through the Earth. As an input, the moderately optimistic theoretical predictions for diffuse neutrino spectra of AGN jets are used.

Bugaev, E.V. [Institute for Nuclear Research, Russian Academy of Sciences, Moscow (Russian Federation); Montaruli, T. [Physics Department, Bari University (Italy); INFN/Bari (Italy); Sokalski, I.A. [INFN/Bari (Italy)

2004-06-01

221

Effects of Spin-Flavor Conversion in Supernova Neutrino Signal  

SciTech Connect

Majorana neutrinos with a finite transition magnetic moment are expected to convert their flavors by spin precession in a strong magnetic field of a supernova. We investigate detailed dependence of the resonant spin-flavor conversions on electron fraction Y{sub e} in the innermost region of the supernova assuming the inverted mass hierarchy. The observed supernova v-bar{sub e} spectrum is expected to be larger in Y{sub e}>0.5 than that in Y{sub e}<0.5. Therefore, the time variation of supernova v-bar{sub e} signal would indicate Majorana neutrinos with a finite transition magnetic moment.

Yoshida, Takashi [Division of Theoretical Astronomy, National Astronomical Observatory of Japan (Japan); Takamura, Akira [Department of Mathematics, Toyota National College of Technology (Japan); Kimura, Keiichi; Yokomakura, Hidekazu [Department of Physics, Graduate School of Science, Nagoya University (Japan); Kawagoe, Shiou [Department of Astronomy, Graduate School of Science, University of Tokyo (Japan); Kajino, Toshitaka [Division of Theoretical Astronomy, National Astronomical Observatory of Japan (Japan); Department of Astronomy, Graduate School of Science, University of Tokyo (Japan)

2009-05-04

222

Neutrino masses: evidences and implications  

NASA Astrophysics Data System (ADS)

I give an overview of the evidences for neutrino masses and mixing, the associated neutrino mass generation schemes, as well as the resulting implications in particle physics experiments and cosmology.

Valle, J. W. F.

2014-03-01

223

Cosmology of "visible" Sterile Neutrinos  

NASA Astrophysics Data System (ADS)

We point out that in scenarios with a low reheating temperature TR << 100 MeV at the end of (the last episode of) inflation or entropy production, the abundance of sterile neutrinos becomes largely independent of their coupling to active neutrinos. Thus, cosmological bounds become less stringent than usually assumed, allowing sterile neutrinos to be "visible" in future experiments. For example, the sterile neutrino required by the LSND result does not have any cosmological problem within these scenarios.

Gelmini, Graciela B.

224

Neutrino Masses and Flavor Mixing  

NASA Astrophysics Data System (ADS)

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

Xing, Zhi-zhong

2010-06-01

225

Observation of geo-neutrinos  

Microsoft Academic Search

Geo-neutrinos, electron anti-neutrinos produced in ? 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? C.L. of geo-neutrinos, performed with the Borexino detector at Laboratori Nazionali del Gran Sasso. Anti-neutrinos are detected through the neutron inverse ? decay reaction. With a 252.6

G. Bellini; J. Benziger; S. Bonetti; M. Buizza Avanzini; B. Caccianiga; L. Cadonati; F. Calaprice; C. Carraro; A. Chavarria; F. Dalnoki-Veress; D. D'Angelo; S. Davini; H. de Kerret; A. Derbin; A. Etenko; G. Fiorentini; K. Fomenko; D. Franco; C. Galbiati; S. Gazzana; C. Ghiano; M. Giammarchi; A. Goretti; E. Guardincerri; S. Hardy; Aldo Ianni; Andrea Ianni; M. Joyce; V. V. Kobychev; Y. Koshio; G. Korga; D. Kryn; M. Laubenstein; T. Lewke; E. Litvinovich; B. Loer; P. Lombardi; L. Ludhova; I. Machulin; S. Manecki; W. Maneschg; G. Manuzio; Q. Meindl; E. Meroni; L. Miramonti; M. Misiaszek; D. Montanari; V. Muratova; L. Oberauer; M. Obolensky; F. Ortica; M. Pallavicini; L. Papp; L. Perasso; S. Perasso; A. Pocar; R. S. Raghavan; G. Ranucci; A. Razeto; B. Ricci; P. Risso; A. Romani; D. Rountree; A. Sabelnikov; R. Saldanha; C. Salvo; S. Schönert; H. Simgen; M. Skorokhvatov; O. Smirnov; A. Sotnikov; S. Sukhotin; Y. Suvorov; R. Tartaglia; G. Testera; D. Vignaud; R. B. Vogelaar; F. von Feilitzsch; J. Winter; M. Wojcik; A. Wright; M. Wurm; J. Xu; O. Zaimidoroga; S. Zavatarelli; G. Zuzel

2010-01-01

226

Neutrino Mixing in the ??SSM  

NASA Astrophysics Data System (ADS)

Recently, several reactor oscillation experiments have successively measured a nonzero value for the neutrino mixing angle ?13, which is greater than five standard deviations. Within framework of the ? from ? Supersymmetric Standard Model (??SSM), three tiny neutrino masses are generated at the tree level through TeV scale seesaw mechanism. In this work, we analyze the neutrino masses and mixing in the ??SSM with a "top-down" method, assuming neutrino mass spectrum with normal ordering or inverted ordering.

Zhang, Hai-Bin; Feng, Tai-Fu; Kou, Li-Na; Zhao, Shu-Min

2013-09-01

227

AGS Broad Band Neutrino Beam.  

National Technical Information Service (NTIS)

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 w...

D. H. White

1985-01-01

228

Gravitational Lensing of Supernova Neutrinos  

SciTech Connect

The black hole at the center of the galaxy is a powerful lens for supernova neutrinos. In the very special circumstance of a supernova near the extended line of sight from Earth to the galactic center, lensing could dramatically enhance the neutrino flux at Earth and stretch the neutrino pulse.

Mena, Olga; /Fermilab /Rome U.; Mocioiu, Irina; /Penn State U.; Quigg, Chris; /Fermilab

2006-10-01

229

Physics in Action: Neutrino Astrophysics  

NSDL National Science Digital Library

This site provides information about the importance of neutrinos in stellar astronomy. It uses the famous supernova 1987A as an example of the energy carried by neutrinos. More information on supernovae and the solar neutrino question are provided, along with links to research.

Central, Physics

2004-04-08

230

Is Neutrino a Superluminal Particle?  

Microsoft Academic Search

Based on the experimental discovery that the mass-square of neutrino is negative, a quantum theory for superluminal neutrino is proposed. Two Weyl equations coupled together via a mass term respecting the maximum parity violation lead to a new equation which describes the superluminal motion of neutrino with permanent helicity. Various strange features of subluminal and superluminal particles can be ascribed

Guang-jiong Ni; Tsao Chang

2001-01-01

231

Tau events in neutrino telescopes  

Microsoft Academic Search

We discuss the propagation of muon and tauon neutrinos through the inner Earth. In particular, we investigate the effects of crossing the Earth on the spectra of high-energy tauon neutrinos and on generic neutrino flux limits. Finally, we comment on the possibility of carrying out a tomography of the Earth using total event rates.

Christian Hettlage; Karl Mannheim

2001-01-01

232

Physics at a Neutrino Factory  

Microsoft Academic Search

In response to the growing interest in building a Neutrino Factory to produce high intensity beams of electron- and muon-neutrinos and antineutrinos, in October 1999 the Fermilab Directorate initiated two six-month studies. The first study, organized by N. Holtkamp and D. Finley, was to investigate the technical feasibility of an intense neutrino source based on a muon storage ring. This

C. Albright; G. Anderson; V. Barger; R. Bernstein; G. Blazey; A. Bodek; E. Buckley-Geer; A. Bueno; M. Campanelli; D. Carey; D. Casper; A. Cervera; C. Crisan; F. DeJongh; S. Eichblatt; A. Erner; R. Fernow; D. Finley; J. Formaggio; J. Gallardo; S. Geer; M. Goodman; D. Harris; E. Hawker; J. Hill; R. Johnson; D. Kaplan; S. Kahn; B. Kayser; E. Kearns; B. J. King; H. Kirk; J. Krane; D. Krop; Z. Ligeti; J. Lykken; K. McDonald; K. McFarland; I. Mocioiu; J. Morfin; H. Murayama; J. Nelson; D. Neuffer; P. Nienaber; R. Palmer; S. Parke; Z. Parsa; R. Plunkett; E. Prebys; C. Quigg; R. Raja; S. Rigolin; A. Rubbia; H. Schellman; M. Shaevitz; P. Shanahan; R. Shrock; P. Spentzouris; R. Stefanski; J. Stone; L. Sulak; G. Unel; M. Velasco; K. Whisnant; J. Yu; E. D. Zimmerman

2000-01-01

233

Neutrino Mass and New Physics  

Microsoft Academic Search

Reconstruction of the neutrino mass and flavor spectrum is described. Essentially two processes are relevant for interpretation of the neutrino results which were used in determination of neutrino parameters: oscillations (averaged and non-averaged) in vacuum and matter and the adiabatic flavor conversion in matter (the MSW-effect). Detailed physics picture of these processes is elaborated and their realizations in solar and

A. Yu. Smirnov

2006-01-01

234

Neutrino Masses in Superstring Theories  

NASA Astrophysics Data System (ADS)

The author discusses the problems associated with generating small masses for the left-handed physical neutrinos in the superstring E6 theories. He then proposes a solution to this problem, in the context of the intermediate scale scenario. The ranges of the neutrino masses obtained in this way are compatible with those needed for the MSW explanation of the solar neutrino problem.

Nandi, S.

235

Neutrinos from Inert Doublet dark matter  

SciTech Connect

We investigate the signatures of neutrinos produced in the annihilation of WIMP dark matter in the Earth, the Sun and at the Galactic centre within the framework of the Inert Doublet Model and extensions. We consider a dark matter candidate, that we take to be one of the neutral components of an extra Higgs doublet, in three distinct mass ranges, which have all been shown previously to be consistent with both WMAP abundance and direct detection experiments exclusion limits. Specifically, we consider a light WIMP with mass between 4 and 8 GeV (low), a WIMP with mass around 60-70 GeV (middle) and a heavy WIMP with mass above 500 GeV (high). In the first case, we show that capture in the Sun may be constrained using Super-Kamiokande data. In the last two cases, we argue that indirect detection through neutrinos is challenging but not altogether excluded. For middle masses, we try to make the most benefit of the proximity of the so-called 'iron resonance' that might enhance the capture of the dark matter candidate by the Earth. The signal from the Earth is further enhanced if light right-handed Majorana neutrinos are introduced, in which case the scalar dark matter candidate may annihilate into pairs of mono-energetic neutrinos. In the case of high masses, detection of neutrinos from the Galactic centre might be possible, provided the dark matter abundance is substantially boosted.

Andreas, Sarah; Tytgat, Michel H.G.; Swillens, Quentin, E-mail: Sarah.Andreas@rwth-aachen.de, E-mail: mtytgat@ulb.ac.be, E-mail: qswillen@ulb.ac.be [Service de Physique Theorique, Universite Libre de Bruxelles, CP225, Bld du Triomphe, B-1050 Brussels (Belgium)] [Service de Physique Theorique, Universite Libre de Bruxelles, CP225, Bld du Triomphe, B-1050 Brussels (Belgium)

2009-04-15

236

CP violation in bipair neutrino mixing  

NASA Astrophysics Data System (ADS)

There are experimentally determined two best-fit points for the atmospheric neutrino mixing angle ?23: sin2 ?23=0.413 (case A) and sin2 ?23=0.594 (case B). In the bipair neutrino mixing scheme, we predict sin2 ?23=?{2}-1 (case 1) to be consistent with the case A and sin2 ?23=2-?{2} (case 2) to be consistent with the case B. If the case B is realized in nature, the bipair neutrino mixing provides a unique neutrino model consistent with the observation sin2 ?23=0.594. However, the reactor neutrino mixing angle ?13 is predicted to be sin2 ?13=0, which is inconsistent with the observation. We propose a new modification scheme to yield sin2 ?13?0 utilizing the charged lepton contribution and study its effect on both of CP-violating Dirac and Majorana phases, which is numerically estimated. It is found that there appear striking differences between the case 1 and the case 2 in their phase structure.

Kitabayashi, Teruyuki; Yasuè, Masaki

2013-10-01

237

Teeny, tiny dirac neutrino masses: an unorthodox point of view  

NASA Astrophysics Data System (ADS)

There are now strong hints suggesting that neutrinos do have a mass after all. If they do have a mass, it would have to be tiny. Why is it so? Is it Dirac or Majorana? Can one build a model in which a teeny, tiny Dirac neutrino mass arises in a natural way? Can one learn something else other than just neutrino masses? What are the extra phenomenological consequences of such a model? These are the questions that I will try to focus on in this talk. .

Hung, D. Q.

2000-10-01

238

Common Origin for Neutrino Anarchy and Charged Hierarchies  

NASA Astrophysics Data System (ADS)

The generation of exponential flavor hierarchies from extra-dimensional wave function overlaps is reexamined. We find, surprisingly, that the coexistence of anarchic fermion mass matrices with such hierarchies is intrinsic and natural to this setting. The salient features of charged fermion and neutrino masses and mixings can thereby be captured within a single framework. Both Dirac and Majorana neutrinos can be realized. Implications for a variety of weak-scale scenarios, including warped compactification and supersymmetry, are discussed. When the new weak-scale physics is sensitive to the origin of flavor structure, Dirac neutrinos are preferred.

Agashe, Kaustubh; Okui, Takemichi; Sundrum, Raman

2009-03-01

239

Supernova Neutrino-Process and Implication in Neutrino Oscillation  

NASA Astrophysics Data System (ADS)

We studied the supernova nucleosynthesis induced by neutrino interactions and found that several isotopes of rare elements like 7Li, 11B, 138La, 180Ta and many others are predominantly produced by the neutrino-process in core-collapse supernovae. These isotopes are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect. We here propose a new novel method to determine the unknown neutrino oscillation parameters, ?13 and mass hierarchy simultaneously from the supernova neutrino-process, combined with the r-process for heavy-element synthsis and the Galactic chemical evolution on light nuclei.

Kajino, T.; Aoki, W.; Fujiya, W.; Mathews, G. J.; Yoshida, T.; Shaku, K.; Nakamura, K.; Hayakawa, T.

2012-08-01

240

Search for the Neutrino Mass and Low Energy Neutrino Astronomy  

NASA Astrophysics Data System (ADS)

The history of neutrinos is strongly coupled with the understanding of weak interactions, which in turn rules energy production in stars. Thus there is a important interplay of nuclear-, particle and astrophysics to explain stellar energy production and to disentangle neutrino properties. In addition to terrestrial searches for neutrino masses the article focuses on the discovery and solution of solar neutrinos, a mystery for decades in the field of particle astrophysics. Furthermore, the first detection of supernova neutrinos is described. A discussion of open issues and an outlook into future activities is given.

Zuber, Kai

241

Neutrino dark energy with more than one neutrino species  

SciTech Connect

The mass varying neutrino scenario is a model that successfully explains the origin of dark energy while at the same time solves the coincidence problem. The model is, however, heavily constrained by its stability towards the formation of neutrino bound states when the neutrinos become nonrelativistic. We discuss these constraints and find that natural, adiabatic, stable models with the right amount of dark energy today do not exist. Second, we explain why using the lightest neutrino, which is still relativistic, as an explanation for dark energy does not work because of a feedback mechanism from the heavier neutrinos.

Bjaelde, Ole Eggers; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark and Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, New York 10003 (United States); Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C (Denmark)

2010-03-15

242

Magnetic moments of active and sterile neutrinos  

NASA Astrophysics Data System (ADS)

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.

Balantekin, A. B.; Vassh, N.

2014-04-01

243

Neutrino magnetic moments and the solar neutrino problem  

SciTech Connect

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2{theta}{sub o} {approx_gt} 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar {bar {nu}}{sub e}`s.

Akhmedov, E.Kh. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory]|[Valencia Univ. (Spain). Dept. de Fisica Teorica

1994-08-01

244

The neutrino signal at HALO: learning about the primary supernova neutrino fluxes and neutrino properties  

NASA Astrophysics Data System (ADS)

Core-collapse supernova neutrinos undergo a variety of phenomena when they travel from the high neutrino density region and large matter densities to the Earth. We perform analytical calculations of the supernova neutrino fluxes including collective effects due to the neutrino-neutrino interactions, the Mikheev-Smirnov-Wolfenstein (MSW) effect due to the neutrino interactions with the background matter and decoherence of the wave packets as they propagate in space. We predict the numbers of one- and two-neutron charged and neutral-current electron-neutrino scattering on lead events. We show that, due to the energy thresholds, the ratios of one- to two-neutron events are sensitive to the pinching parameters of neutrino fluxes at the neutrinosphere, almost independently of the presently unknown neutrino properties. Besides, such events have an interesting sensitivity to the spectral split features that depend upon the presence/absence of energy equipartition among neutrino flavors. Our calculations show that a lead-based observatory like the Helium And Lead Observatory (HALO) has the potential to pin down important characteristics of the neutrino fluxes at the neutrinosphere, and provide us with information on the neutrino transport in the supernova core.

Väänänen, Daavid; Volpe, Cristina

2011-10-01

245

High Energy Neutrino Astronomy  

NASA Astrophysics Data System (ADS)

The short review of theoretical aspects of ultra high energy (UHE) neutrinos. The accelerator sources, such as Supernovae remnants, Gamma Ray Bursts, AGN etc are discussed. The top-down sources include Topological Defects (TDs), Superheavy Dark Matter (SHDM) and Mirror Matter. The diffuse fluxes are considered accordingly as that of cosmogenic and top-down neutrinos. Much attention is given to the cascade upper limit to the diffuse neutrino fluxes in the light of Fermi-LAT data on diffuse high energy gamma radiation. This is most general and rigorous upper limit, valid for both cosmogenic and top-down models. At present upper limits from many detectors are close to the cascade upper limit, and 5 yr IceCube upper limit will be well below it.

Berezinsky, V.

2012-08-01

246

Neutrino Astronomy with Icecube  

NASA Astrophysics Data System (ADS)

IceCube is a kilometer-scale high energy neutrino telescope under construction at the South Pole, a second-generation instrument expanding the capabilities of the AMANDA telescope. The scientific portfolio of IceCube includes the detection of neutrinos from astrophysical objects such as the sources of the cosmic rays, the search for dark matter, and fundamental physics using a very large data set of atmospheric neutrinos. The design and status of IceCube are briefly reviewed, followed by a summary of results to date from AMANDA and initial IceCube results from the 2007 run, with 22 of a planned 86 strings operational. The new infill array known as Deep Core, which will extend IceCube's capabilities to energies as low as 10 GeV, is also described.

Deyoung, Tyce

247

Neutrino physics: Summary talk  

SciTech Connect

This paper is organized as follows: First, I describe the state of neutrino phenomenology. Emphasis is placed on sin/sup 2/ /theta//sub W/, its present status and future prospects. In addition, some signatures of ''new physics'' are described. Then, kaon physics at Fermilab is briefly discussed. I concentrate on the interesting rare decay K/sub L/ /yields/ /pi//sup 0/e/sup +/e/sup /minus// which may be a clean probe direct CP violation. Neutrino mass, mixing, and electromagnetic moments are surveyed. There, I describe the present state and future direction of accelerator based experiments. Finally, I conclude with an outlook on the future. Throughout this summary, I have drawn from and incorporated ideas discussed by other speakers at this workshop. However, I have tried to combine their ideas with my own perspective on neutrino physics and where it is headed. 49 refs., 3 figs., 4 tabs.

Marciano, W.J.

1989-04-01

248

Sterile Neutrinos and Supernova Nucleosynthesis  

NASA Astrophysics Data System (ADS)

Neutrinos play an important role in the core-collapse supernova environment, from facilitating the explosion mechanism to influencing the outflow's elemental composition. Traditional heavy element nucleosynthesis, the r-process, are stifled by electron neutrinos during the alpha particle formation epoch. Introduction of a sterile neutrino species can temper this alpha effect as well as generate an environment sufficiently neutron-rich for fission cycling to occur. Fission cycling in the r-process produces abundance patterns similar to the halo star data. Here we examine reductions in the neutrino flux necessary to achieve fission cycling; sterile neutrinos or other new physics may realize these reductions.

Beun, Joshua; McLaughlin, Gail; Surman, Rebecca; Hix, Raph

2006-10-01

249

Supernova nucleosynthesis and neutrino oscillation  

NASA Astrophysics Data System (ADS)

Neutrinos play the critical roles in nucleosynthesis of light-to-heavy mass nuclei like 7Li, 11B, 138La and 180Ta in core-collapse supernovae. We find average neutrino temperatures of three flavor neutrinos so that the supernova nucleosynthesis models of the neutrino-process and the r-process can explain the observed solar-system abundance and Galactic chemical evolution of these isotopes. We propose a method to determine the unknown neutrino oscillation parameters ?13 and mass hierarchy by the use of the MSW effects on the supernova nucleosynthesis.

Kajino, T.; Aoki, W.; Cheoun, M.-K.; Chiba, S.; Fujiya, W.; Hayakawa, T.; Mathews, G. J.; Nakamura, K.; Shaku, K.; Yoshida, T.

2012-04-01

250

Testing CPT invariance with neutrinos  

NASA Astrophysics Data System (ADS)

We investigate possible tests of CPT invariance on the level of event rates at neutrino factories. We do not assume any specific model, but phenomenological differences in the neutrino-antineutrino masses and mixing angles in a Lorentz invariance preserving context, which could be induced by physics beyond the Standard Model. We especially focus on the muon neutrino and antineutrino disappearance channels in order to obtain constraints on the neutrino-antineutrino mass and mixing angle differences. In a typical neutrino factory setup simulation, we find, for example, that |m 3 - overlinem3| $?1.9 · 10 -4eV and |? 23 - overline?23|? 2° .

Ohlsson, Tommy

2003-04-01

251

Double-Chooz Neutrino Experiment  

NASA Astrophysics Data System (ADS)

The Double Chooz experiment will use the electron anti-neutrinos produced by the Chooz nuclear power station to search for a non-vanishing value of the ?13 neutrino mixing angle. Double Chooz will be the first of a new generation of neutrino experiments using identical detectors at different distances from the neutrino source to reduce the systematic errors due to the uncertainties on the neutrino flux and to the detector acceptance. The far detector will be operative by the beginning of 2011. Installation of the near detector will occur in 2012.

Palomares, Carmen; Double Chooz Collaboration

2011-12-01

252

Flavor oscillations of supernova neutrinos  

NASA Astrophysics Data System (ADS)

Neutrinos emitted by core-collapse supernovae (SNe) represent an important laboratory for both particle physics and astrophysics. While propagating in the dense SN environment, they can feel not only the presence of background matter (via ordinary Mikheev-Smirnov-Wolfenstein effects) but also of the gas of neutrinos and antineutrinos (via neutrino-neutrino interaction effects). The MSW effect would imprint on SN neutrinos a track of the shock-wave propagation and of the matter turbulences in the stellar envelope. Moreover, the neutrino-neutrino interactions appear to modify the flavor evolution of SN neutrinos in a collective way, completely different from the ordinary matter effects. In these conditions, the flavor evolution equations become highly nonlinear, sometimes resulting in surprising phenomena when the entire neutrino system oscillates coherently as a single collective mode. In this talk, I will present the recent results on supernova neutrino flavor conversions and I will discuss about the sensitivity of these effects to the ordering of the neutrino mass spectrum.

Mirizzi, Alessandro

2012-08-01

253

Neutrino Oscillation Results from MINOS  

NASA Astrophysics Data System (ADS)

The Main Injector Neutrino Oscillation Search (MINOS) long baseline experiment has been actively taking beam data since 2005, having already accumulated 2.6E20 protons-on-target. MINOS uses the most powerful neutrino beam currently in operation 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 make the most precise measurement of the mass-square difference neutrino mixing parameter in the atmospheric sector. In this talk, The latest MINOS neutrino oscillation results are presented, along with a discussion of the MINOS sensitivity to other neutrino oscillation phenomena, such as the nu_mu into nu_e subdominant oscillation mode and oscillations into sterile neutrinos.

Sousa, Alexandre

254

A two parameter four neutrino mixing model with an exchange symmetry of the mass doublet neutrinos  

Microsoft Academic Search

In a model with four neutrino mass eigenstates grouping in two narrow doublets the condition of maximal mixing of the doublet neutrino components leads to a simple 4-neutrino mixing matrix which is related to two connected effective two-neutrino mixing patterns. As a result, large values of the neutrino oscillation amplitudes for both the solar and atmospheric neutrino anomalies appear quite

E. M. Lipmanov

1998-01-01

255

Resonant neutrino activation and neutrino oscillations  

NASA Astrophysics Data System (ADS)

Low Q value weak nuclear decays are considered which have two body final states (electron captures and bound state beta decays, BSD). This permits an analogy with the Mössbauer effect, where the emitted (anti) neutrinos will resonantly activate daughter nuclei in a suitable absorber. Candidates for such a process are examined and the relevant solid state host problems are discussed. We point out that resonant line widths as large as the narrowest observed in Mössbauer spectroscopy suffice to greatly extend the sensitivity of ? [disappearance] oscillation experiments.

Kells, William P.

1983-06-01

256

Resonant neutrino activation and neutrino oscillations  

SciTech Connect

Low Q value weak nuclear decays are considered which have two body final states (electron captures and bound state ..beta.. decays, BSD). This permits an analogy with the Moessbauer effect, where the emitted (anti)neutrinos will resonantly activate daughter nuclei in a suitable absorber. Candidates for such a process are examined and the relevant solid state host problems are discussed. The authors point out that resonant line widths as large as the narrowest observed in Moessbauer spectroscopy suffice to greatly extend the sensitivity of nu (disappearance) oscillation experiments.

Kells, W.P.

1983-01-01

257

Neutrinos from a core collapse supernova  

SciTech Connect

The neutrino burst from a galactic supernova can help determine the neutrino mass hierarchy and {theta}{sub 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.

Dighe, Amol [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

2008-02-21

258

Review of the physics of the neutrino  

SciTech Connect

The status of knowledge with respect to neutrinos is reviewed. Questions covered briefly include whether or not a neutrino is its own antiparticle and neutrino mass. Experimental studies are also considered, including neutrino oscillations, double beta decay, and direct neutrino mass measurements. (LEW)

Robertson, R.G.H.

1986-01-01

259

Decaying Dirac neutrinos. [SN1987a  

SciTech Connect

Constraints on Dirac-neutrino decay into invisible particles are surveyed. Neutrino lifetimes short enough to explain the solar-neutrino problem are allowed by present terrestrial and cosmological measurements. A model in which Dirac neutrinos can have such short lifetimes is proposed. The recently resurrected 17-keV neutrino is incorporated into this model.

Acker, A.; Pakvasa, S. (Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States)); Pantaleone, J. (Department of Physics, University of California, Riverside, California 92521 (United States))

1992-01-01

260

Neutrino mass hierarchy and the origin of leptonic flavor mixing from the right-handed sector  

Microsoft Academic Search

We consider a neutrino mass model where all leptonic mixing is induced by a heavy Majorana sector through the seesaw type I mechanism, while the Dirac mass matrices are diagonal. Such a pattern occurs naturally in grand unified theories. Constraints on the parameters of the models are considered and it is shown that a normal neutrino mass hierarchy is preferred.

P. Leser; H. Päs

2011-01-01

261

Neutrino spectroscopy with atoms and molecules  

NASA Astrophysics Data System (ADS)

We systematically investigate the new experimental method of using atoms or molecules to measure the important parameters of neutrinos that are still to be determined: the absolute mass scale, the mass hierarchy pattern (normal or inverted), the neutrino mass type (Majorana or Dirac), and the CP-violating phases, including Majorana phases. Most of these observables are difficult to measure in neutrino oscillation experiments. There are advantages to using atomic targets, such as the closeness of available atomic energies to anticipated neutrino masses, over nuclear target experiments such as the end point spectrum of ? decay and two-electron line spectrum in the neutrinoless double ? decay, both of which address some of the overlapping objectives with atomic/molecular experiments. A disadvantage of using atomic targets, the smallness of rates, is overcome by the macro-coherent amplification mechanism. The atomic or molecular process we use is a cooperative deexcitation of a collective body of atoms in a metastable level |e> emitting a neutrino pair and a photon: |erangle rArr |grangle + ? + ? _i ? _j, where ?is are neutrino mass eigenstates. The macro-coherence is developed by trigger-laser irradiation of two colors, which frequently causes the two-photon process |erangle leftrArr |grangle + ? +? , |erangle + ? leftrArr |g rangle + ? inside the target. We discuss important aspects of the macro-coherence development in detail, by setting up the master equation for the target Bloch vector (whose components are population difference and medium polarization) and the propagating electric field. Our master equation includes the effects of phase decoherence of medium polarization and decay of population difference. The spectral rate (the number of events per unit time) of macro-coherent radiative emission of a neutrino pair has three parts, and is given by a factorized formula of the form (overall ?-independent rate denoted by ?0) × (spectral shape function denoted by I(?)) × (time-evolving dynamical factor), where ? is the photon energy. The constant factor ?0 determines the overall rate in the unit of 1/time, and for Xe it is of the order of 1 Hz(n/1022 cm-3)3 (V/102 cm3). The dynamical factor is time dependent and is given by the space integrated quantity, over the entire target, of the product of the magnitude squared of the coherent polarization and the field strength (in the units of the maximally extractable energy density) stored inside the target. The asymptotic value of the time-evolving dynamical factor is given by the contribution of the field condensate accompanied by macroscopic coherence, which is calculated using the static limit of the master equation. With an appropriate choice of heavy target atoms or molecules such as Xe and I2 that have a large M1 × E1 matrix element between |e> and |g>, we show that one can determine three neutrino masses along with distinction of the mass hierarchy pattern (normal or inverted) by measuring the spectral shape I(?). If one uses a target of available energy of a fraction of 1 eV, the most experimentally challenging observable, the Majorana CP phases may be determined, comparing the detected rate with differences of theoretical expectations which exist at the level of several percent. The Majorana CP-violating phase is expected to be crucial to the understanding of the matter-antimatter imbalance in our universe. Our master equation, when applied to E1 × E1 transitions such as pH2 vibrational Xv = 1 rArr 0, can describe explosive paired superradiance events in which most of the energy stored in |e> is released in the order of a few nanoseconds. The present paper is intended to be self-contained, explaining some details of related theoretical works in the past, and reports on new simulations and the ongoing experimental efforts of the project to realize neutrino mass spectroscopy using atoms/molecules.

Fukumi, Atsushi; Kuma, Susumu; Miyamoto, Yuki; Nakajima, Kyo; Nakano, Itsuo; Nanjo, Hajime; Ohae, Chiaki; Sasao, Noboru; Tanaka, Minoru; Taniguchi, Takashi; Uetake, Satoshi; Wakabayashi, Tomonari; Yamaguchi, Takuya; Yoshimi, Akihiro; Yoshimura, Motohiko

2012-12-01

262

New segmented p-type germanium detector for neutrino-less double-beta decay  

Microsoft Academic Search

Neutrino-less double-beta decay (0nubetabetabeta - decay) has been selected by the American Physical Society Joint Study of Neutrino Physics, and by the Neutrino Science Advisory Group (NUSAG) as a top priority for consideration by the National Science Foundation and the US Department of Energy. The proposed Majorana 76Ge experiment was recommended as one of the two top projects in the

George Savage King III

2006-01-01

263

High energy neutrino astrophysics  

NASA Astrophysics Data System (ADS)

Astroparticle physics is a field rich in perspectives in investigating the ultra high energy region which will never be accessible to man-made machines. Many efforts are underway in order to detect the first cosmic neutrinos, messengers of the unobserved universe. The motivations of this field of research, and the current and next future experimental status are reviewed.

Montaruli, Teresa

2005-01-01

264

Experimental Neutrino Physics  

ScienceCinema

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.

Chris Walter

2010-01-08

265

Low energy neutrinos  

NASA Astrophysics Data System (ADS)

Low energy neutrino investigation has been one of the most active fields of particle physics research over the past decades, accumulating important and sometimes unexpected achievements. In this work some of the most recent impressive successes will be reviewed, as well as the future perspectives of this exciting area of study.

Ranucci, G.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Buizza Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Empl, A.; Etenko, A.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Grandi, L.; Hagner, C.; Hungenford, E.; Ianni, Al.; Ianni, An.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lewke, T.; Litvinovich, E.; Loer, B.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Meindl, Q.; Meroni, E.; Miramonti, L.; Misiaszek, M.; Mllenberg, R.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Pallavicini, M.; Papp, L.; Perasso, L.; Perasso, S.; Pocar, A.; Raghavan, R. S.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Winter, J.; Wojcik, M.; Wright, A.; Wurm, M.; Xu, J.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.

2014-05-01

266

Laboratory Limits on Neutrino Masses  

NASA Astrophysics Data System (ADS)

The recent neutrino oscillation experiments have obtained nonzero differences of squared neutrino masses and therefore proven that neutrinos are massive particles. The values of the neutrino masses have to be determined in a different way. There are two classes of laboratory experiments, both of which have yielded up to now only upper limits on neutrino masses. The direct mass experiments investigate the kinematics of weak decays, obtaining information about the neutrino mass without further requirements. Here, the tritium ? decay experiments give the most stringent results. The search for neutrinoless double ? decay is also very sensitive to the neutrino mass states. However, this search is complementary to direct neutrino mass experiments, since it requires neutrinos to be identical to their antiparticles and probes a linear combination of neutrino masses including complex phases. This chapter is structured as follows. After an introduction in Sect. 2.1, the two approaches are discussed together with the current experimental results in Sects. 2.2 and 2.3, followed by consideration of the outlook for future activities in Sect. 2.4.

Weinheimer, Christian

267

Heavy neutrinos and lepton number violation in ?p colliders  

NASA Astrophysics Data System (ADS)

We discuss the prospects of studying lepton number violating processes in order to identify Majorana neutrinos from low scale seesaw mechanisms at lepton-proton colliders. In particular, we consider the scenarios of colliding electrons with LHC energy protons and, motivated by the efforts towards the construction of a muon collider, the prospects of muon-proton collisions. We find that present constraints on the mixing of the Majorana neutrinos still allow for a detectable signal at these kind of facilities given the smallness of the Standard Model background. We discuss possible cuts in order to further increase the signal over background ratio and the prospects of reconstructing the neutrino mass from the kinematics of the final state particles.

Blaksley, Carl; Blennow, Mattias; Bonnet, Florian; Coloma, Pilar; Fernandez-Martinez, Enrique

2011-11-01

268

Neutrino Masses, Cosmological Bound and Four Zero Yukawa Textures  

NASA Astrophysics Data System (ADS)

Four zero neutrino Yukawa textures in a specified weak basis, combined with ?? symmetry and type-I seesaw, yield a highly constrained and predictive scheme. Two alternately viable 3×3 light neutrino Majorana mass matrices m?A/m?B result with inverted/normal mass ordering. Neutrino masses, Majorana in character and predicted within definite ranges with laboratory and cosmological inputs, will have their sum probed cosmologically. The rate for 0??? decay, though generally below the reach of planned experiments, could approach it in some parameter region. Departure from ?? symmetry due to RG evolution from a high scale and consequent CP violation, with a Jarlskog invariant whose magnitude could almost reach 6×10-3, are explored.

Adhikary, Biswajit; Ghosal, Ambar; Roy, Probir

269

Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope  

NASA Astrophysics Data System (ADS)

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 maximal mixing, a mass difference of ?m322=(3.1±0.9)?10-3 eV is obtained, in good agreement with the world average value.

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

2012-08-01

270

Global status of neutrino oscillation parameters after Neutrino-2012  

NASA Astrophysics Data System (ADS)

Here we update the global fit of neutrino oscillations in Refs. [T. Schwetz, M. Tortola, and J. W. F. Valle, New J. Phys. 13, 063004 (2011); T. Schwetz, M. Tortola, and J. W. F. Valle, New J. Phys. 13, 109401 (2011)] including the recent measurements of reactor antineutrino disappearance reported by the Double Chooz, Daya Bay, and RENO experiments, together with latest MINOS and T2K appearance and disappearance results, as presented at the Neutrino-2012 conference. We find that the preferred global fit value of ?13 is quite large: sin?2?13?0.025 for normal and inverted neutrino mass ordering, with ?13=0 now excluded at more than 10?. The impact of the new ?13 measurements over the other neutrino oscillation parameters is discussed as well as the role of the new long-baseline neutrino data and the atmospheric neutrino analysis in the determination of a non-maximal atmospheric angle ?23.

Forero, D. V.; Tórtola, M.; Valle, J. W. F.

2012-10-01

271

Neutrino mass as the probe of intermediate mass scales  

SciTech Connect

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.

Senjanovic, G.

1980-01-01

272

Four-neutrino oscillations and the solar neutrino problem  

NASA Astrophysics Data System (ADS)

We perform a fit of solar neutrino data in the framework of the two four-neutrino schemes that are compatible with the results of all neutrino oscillation experiments. These schemes allow simultaneous transitions of solar ? e's into active ? ?'s, ? ?'s and sterile ? s. The data imply that the SMA solution is valid for any combination of ? e? active and ? e? sterile transitions, whereas the LMA, LOW and VO solutions disappear when ? e?? s transitions are dominant.

Giunti, C.; Gonzalez-Garcia, M. C.; Peña-Garay, C.

2001-10-01

273

Neutrino Masses, where do we stand?  

Microsoft Academic Search

I review the status of neutrino physics post-Neutrino~98, including the\\u000aimplications of solar and atmospheric neutrino data, which strongly indicate\\u000anonzero neutrino masses. LSND and the possible role of neutrinos as hot dark\\u000amatter (HDM) are also mentioned. The simplest schemes proposed to reconcile\\u000athese requirements invoke a light sterile neutrino in addition to the three\\u000aactive ones, two of

E W. F. VALLE

1998-01-01

274

When neutrinos attack - the impact of agressive neutrinos in astrophysics.  

NASA Astrophysics Data System (ADS)

Of all the constituents within the standard model of particle physics our understanding of the neutrino has benefited the most from the interaction of astrophysics and `terraphysics'. Much has been learned about the properties of the neutrino from each: experiments here on Earth temper our appreciation of the role that neutrinos play in the cosmos while astrophysics can provide the densities and temperatures in which the neutrinos do more than simply flee. But their reluctance to interact means that it is not until we venture into the most extreme environments of astrophysics that we observe neutrinos pushing back' as hard as they are being pushed'. We review two sites where this occurs: the early Universe and the accretion disk, engines' of gamma ray bursts. Neutrinos play an important role in the evolution of the early Universe with a particular focus upon the electron neutrino in determining the primordial elemental composition via its participation in the most important reaction at that time. Within gamma ray burst accretion disks we again see the electron neutrinos at work in the nuclear reactions and through their function as the coolant' for the disk. Removal of the disk energy, and its deposition into the remnants of the massive star surrounding the disk, may lead to the formation of highly relativistic jets that will later be observed as the burst. We show what has been learned so far about the neutrino and its properties from the study of such environments and discuss where future research is heading.

Kneller, James

2004-11-01

275

Decaying neutrinos and implications from the supernova relic neutrino observation  

NASA Astrophysics Data System (ADS)

We propose that supernova relic neutrino (SRN) observation can be used to set constraints on the neutrino decay models. Because of the long distance scale from cosmological supernovae to the Earth, SRN have possibility to provide much stronger limit than the present one obtained from solar neutrino observation. Since the currently available data are only the upper limit on the flux integrated over E?¯e>19.3 MeV, the decay models on which we can set constraints is quite restricted; they must satisfy specific conditions such that the daughter neutrinos are active species, the neutrino mass spectrum is quasi-degenerate, and the neutrino mass hierarchy is normal. Our numerical calculation clearly indicates that the neutrino decay model with (?2/m,?3/m)<~(1010,1010) [s//eV], where ?i represents the lifetime of mass eigenstates ?¯i, appears to give the SRN flux that is larger than the current upper limit. However, since the theoretical SRN prediction contains many uncertainties concerning a supernova rate in the universe or simulation of supernova explosions, we cannot conclude that there exists the excluded parameter region of the neutrino lifetime. In the near future, further reduced upper limit is actually expected, and it will provide more severe constraints on the neutrino decay models.

Ando, Shin'ichiro

2003-09-01

276

Electron-neutrino survival probability from solar-neutrino data  

NASA Astrophysics Data System (ADS)

With SNO data [SNO Collaboration, nucl-ex/0106015] on electron-neutrino flux from the sun, it is possible to derive the ?e survival probability Pee(E) from existing experimental data of Super-Kamiokande, gallium experiments and Homestake. The combined data of SNO and Super-Kamiokande provide boron ?e flux and the total flux of all active boron neutrinos, giving thus Pee(E) for boron neutrinos. The Homestake detector, after subtraction of the signal from boron neutrinos, gives the flux of Be/+CNO neutrinos, and Pee for the corresponding energy interval, if the produced flux is taken from the Standard Solar Model (SSM). Gallium detectors, GALLEX, SAGE and GNO, detect additionally /pp-neutrinos. The /pp flux can be calculated subtracting from the gallium signal the rate due to boron, beryllium and CNO neutrinos. The ratio of the measured /pp-neutrino flux to that predicted by the SSM gives the survival probability for /pp-neutrinos. Comparison with theoretical survival probabilities shows that the best (among known models) fit is given by LMA and LOW solutions.

Berezinsky, V.; Lissia, M.

2001-11-01

277

Small neutrino mass from large compactification volumes.  

PubMed

We present an argument in which the scale approximately 0.1 eV associated with neutrino masses naturally appears in a class of (very) large volume compactifications, being tied to a supersymmetry scale of 10(3) GeV and a string scale of 10(11) GeV. The masses are of the Majorana type, and there is no right-handed neutrino within the low-energy field theory. The suppression scale 10(14) GeV is independent of the masses of the heavy states that are integrated out. These kinds of constructions appear naturally in type IIB flux compactifications. However, the arguments that lead to this result rely only on a few geometrical features of the compactification manifold and, hence, can be used independently of string theory. PMID:17678352

Conlon, Joseph P; Cremades, Daniel

2007-07-27

278

Low Energy Neutrino Cross Sections  

NASA Astrophysics Data System (ADS)

Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ~ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies. Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy.

Zeller, G. P.

2004-10-01

279

Astrophysical and cosmological constraints to neutrino properties  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

280

The number of neutrino species  

Microsoft Academic Search

The authors review the methods used before the operation of the high energy Stanford and CERN e+e- colliders to determine the number of neutrino species Nnu, or an upper limit on this number, within the framework of the Standard Model of light stable neutrinos interacting according to the SU(2)×U(1) universal couplings. The astrophysical limit based on the neutrino burst from

Daniel Denegri; Bernard Sadoulet; Michel Spiro

1990-01-01

281

Muon colliders and neutrino factories  

SciTech Connect

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.

Geer, S.; /Fermilab

2010-09-01

282

An Overview of Neutrino Mixing  

NASA Astrophysics Data System (ADS)

We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large ?13, possible non maximal ?23, approaching sensitivity on ?) and their implications on models of neutrino mixing. The new data disfavour many models but the surviving ones still span a wide range going from Anarchy (no structure, no symmetry in the lepton sector) to a maximum of symmetry, as for the models based on discrete non-abelian flavour groups.

Altarelli, G.

2013-08-01

283

Neutrino emission from neutron stars  

Microsoft Academic Search

We review the main neutrino emission mechanisms in neutron star crusts and cores. Among them are the well-known reactions such as the electron–positron annihilation, plasmon decay, neutrino bremsstrahlung of electrons colliding with atomic nuclei in the crust, as well as the Urca processes and neutrino bremsstrahlung in nucleon–nucleon collisions in the core. We emphasize recent theoretical achievements, for instance, band

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

2001-01-01

284

Quantum coherence of relic neutrinos.  

PubMed

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

Fuller, George M; Kishimoto, Chad T

2009-05-22

285

Neutrino Flavor Tagging in a Four-Neutrino Mixing and Oscillation Model  

Microsoft Academic Search

A neutrino mass dominance quantity is introduced for tagging the neutrino\\u000aflavor in the phenomenological two-parameter four neutrino mixing matrix with\\u000atwo neutrino mass doublets and thorough maximal neutrino doublet mixing. While\\u000athere is no hierarchy of the neutrino masses in the neutrino flavor eigenstates\\u000aof this model, it may rather be a special hierarchy of the mass dominance\\u000aratios

E. M. Lipmanov

1999-01-01

286

MINOS atmospheric neutrino contained events  

SciTech Connect

The Main Injector Neutrino Oscillation Search (MINOS) experiment has continued to collect atmospheric neutrino events while doing a precision measurement of NuMI beam {nu}{sub {mu}} disappearance oscillations. The 5.4 kton iron calorimeter is magnetized to provide the unique capability of discriminating between {nu}{sub {mu}} and {bar {nu}}{sub {mu}} interactions on an event-by-event basis and has been collecting atmospheric neutrino data since July 2003. An analysis of the neutrino events with interaction vertices contained inside the detector will be presented.

Habig, A.; /Minnesota U.

2007-10-01

287

Supernova neutrinos and explosive nucleosynthesis  

NASA Astrophysics Data System (ADS)

Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes 7Li, 11B, 92Nb, 138La and 180Ta 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 ?13, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements 11B and 7Li encapsulated in the presolar grains. Combining the recent experimental constraints on ?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.

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

2014-05-01

288

Solar Neutrino Results from Sage  

NASA Astrophysics Data System (ADS)

Since January of 1990, the Russian-American Solar neutrino Experiment has carried out measurements of the capture rate of solar neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory. The measured capture rate from the 71Ge K- and L-peak counting data through December 2000 is 77.0 +7.1/-6.9 SNU, where the uncertainties statistical and systematic, respectively. This result represents a 6 depression in the neutrino flux compared with predicted Standard Solar Model rates. The experimental procedures and data analysis are presented.

Gavrin, Vladimir N.

2003-02-01

289

Review of Neutrino Mass Measurements  

SciTech Connect

After a brief summary of the recent achievements of neutrino physics, the concept of neutrino mass scale is clarified. The methods for the determination of the neutrino mass values are summarized and critically compared, in particular in the different and complementary contexts of cosmology, double and single beta decay. The attention is then focussed on the laboratory approaches to investigate neutrino mass. The role of neutrinoless double beta decay is explained and a short review of the present and most promising future experiments in this field is given. Single beta decay sensitivity is discussed, with brief descriptions of the KATRIN tritium experiment and of the recently proposed MARE rhenium project.

Giuliani, A. [Universita dell' Insubria, Via Valleggio 11, I-22100 Como (Italy); INFN-Milano, Via Valleggio 11, I-22100 Como (Italy)

2006-02-08

290

Phenomenology of pseudo Dirac neutrinos  

NASA Astrophysics Data System (ADS)

We formulate general conditions on /3×3 neutrino mass matrices under which a degenerate pair of neutrinos at a high scale would split at low scale by radiative corrections involving only the standard model fields. This generalizes the original observations of Wolfenstein on pseudo Dirac neutrinos to three generations. A specific model involving partially broken discrete symmetry and solving the solar and atmospheric anomalies is proposed. The symmetry pattern of the model naturally generates two large angles one of which can account for the large angle MSW solution to the solar neutrino problem.

Joshipura, A. S.; Rindani, S. D.

2000-11-01

291

Birth of Neutrino Astrophysics  

SciTech Connect

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.

None

2010-05-07

292

Birth of Neutrino Astrophysics  

ScienceCinema

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.

None

2011-10-06

293

Coherent Neutrino Scattering  

NASA Astrophysics Data System (ADS)

We present a microscopic model for coherent pion production off nuclei induced by neutrinos. This model is built upon a model for single nucleon processes that goes beyond the usual Delta dominance by including non resonant background contributions. We include nuclear medium effects: medium corrections to Delta properties and outgoing pion absorption via an optical potential. This results in major modifications to cross-sections for low energy experiments when compared with phenomenological models like Rein-Sehgal's.

Valverde, M.; Amaro, J. E.; Hernandez, E.; Nieves, J.

2009-09-01

294

Baryogenesis via Neutrino Oscillations  

Microsoft Academic Search

We propose a new mechanism of leptogenesis in which the asymmetries in lepton\\u000anumbers are produced through the CP-violating oscillations of ``sterile''\\u000a(electroweak singlet) neutrinos. The asymmetry is communicated from singlet\\u000aneutrinos to ordinary leptons through their Yukawa couplings. The lepton\\u000aasymmetry is then reprocessed into baryon asymmetry by electroweak sphalerons.\\u000aWe show that the observed value of baryon asymmetry

E. Kh; V. A. Rubakov; A. Yu. Smirnov

1998-01-01

295

Natural Neutrino Dark Energy  

SciTech Connect

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.

Gurwich, Ilya [Physics Department, Ben-Gurion University, Beer-Sheva 84105 (Israel)

2010-06-23

296

Neutrino physics at LAMPF  

SciTech Connect

There are three neutrino experiments at LAMPF in various stages of completion or development. E225, the study of electron-neutrino electron scattering, which completed data taking in December 1986 and has just about completed all its analysis. E645, a search for /bar /nu///sub ..mu../ ..-->.. /bar /nu///sub e/ oscillation, is in its third and final year of data taking. The Large Cerenkov Detector (LCD), associated with E1015, has undergone extensive scientific and technical review and we are presently trying to obtain the necessary funds to build the detector, beam line, and target. In the following, each of these experiments will be briefly discussed. Before doing so, it is useful to show the characteristics of the neutrino spectrum resulting from the decay of ..pi../sup +/ at rest. It is also useful to realize that, on average, an 800-MeV proton from LAMPF produces about 0.1 ..pi../sup +/ decaying at rest. 16 refs., 5 figs., 4 tabs.

Garvey, G.T.

1989-01-01

297

Neutrino Oscillations:. Hierarchy Question  

NASA Astrophysics Data System (ADS)

The only experimentally observed phenomenon that lies outside the standard model of the electroweak interaction is neutrino oscillations. A way to try to unify the extensive neutrino oscillation data is to add a phenomenological mass term to the Lagrangian that is not diagonal in the flavor basis. The goal is then to understand the world's data in terms of the parameters of the mixing matrix and the differences between the squares of the masses of the neutrinos. An outstanding question is what is the correct ordering of the masses, the hierarchy question. We point out a broken symmetry relevant to this question, the symmetry of the simultaneous interchange of hierarchy and the sign of ?13. We first present the results of an analysis of data that well determine the phenomenological parameters but are not sensitive to the hierarchy. We find ?13 = 0.152±0.014, ? 23 = 0.25{ - 0.05}{ + 0.03} ? and ?32 = 2.45±0.14×10-3 eV2, results consistent with others. We then include data that are sensitive to the hierarchy and the sign of ?13. We find, unlike others, four isolated minimum in the ?2-space as predicted by the symmetry. Now that Daya Bay and RENO have determined ?13 to be surprisingly large, the Super-K atmospheric data produce meaningful symmetry breaking such that the inverse hierarchy is preferred at the 97.2 % level.

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

2014-09-01

298

Boxing with neutrino oscillations  

NASA Astrophysics Data System (ADS)

We develop a characterization of neutrino oscillations based on the coefficients of the oscillating terms. These coefficients are individually observable; although they are quartic in the elements of the unitary mixing matrix, they are independent of the conventions chosen for the angle and phase parametrization of the mixing matrix. We call these reparametrization-invariant observables ``boxes'' because of their geometric relation to the mixing matrix, and because of their association with the Feynman box diagram that describes oscillations in field theory. The real parts of the boxes are the coefficients for the CP- or T-even oscillation modes, while the imaginary parts are the coefficients for the CP- or T-odd oscillation modes. Oscillation probabilities are linear in the boxes, so measurements can straightforwardly determine values for the boxes (which can then be manipulated to yield magnitudes of mixing matrix elements). We examine the effects of unitarity on the boxes and discuss the reduction of the number of boxes to a minimum basis set. For the three-generation case, we explicitly construct the basis. Using the box algebra, we show that CP violation may be inferred from measurements of neutrino flavor mixing even when the oscillatory factors have averaged. The framework presented here will facilitate general analyses of neutrino oscillations among n>=3 flavors.

Wagner, D. J.; Weiler, Thomas J.

1999-06-01

299

Neutrino self-energy operator and neutrino magnetic moment  

SciTech Connect

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.

Dobrynina, A. A., E-mail: elenan@uniyar.ac.ru; Mikheev, N. V.; Narynskaya, E. N. [Yaroslavl State University (Russian Federation)] [Yaroslavl State University (Russian Federation)

2013-11-15

300

Neutrino Oscillations and the Anomalous Atmospheric Neutrino Flux.  

National Technical Information Service (NTIS)

We re-analyze the constraints on atmospheric nu /sub e/ and nu /sub mu / fluxes due to three-neutrino oscillations and investigate the anomalous neutrino fluxes recently observed at Kamiokande. We find that it is difficult to explain the data by nu /sub e...

K. Hidaka M. Honda S. Midorikawa

1988-01-01

301

Neutrino self-energy operator and neutrino magnetic moment  

NASA Astrophysics Data System (ADS)

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 ? gauge for the case of an arbitrary ratio of the lepton and W-boson masses.

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

2013-11-01

302

Resonant solar neutrino oscillation versus laboratory neutrino oscillation experiments  

SciTech Connect

The interplay between resonant solar neutrino oscillations and neutrino oscillations in laboratory experiments is investigated in a 3 generation model. Due to the assumed hierarchy of neutrino masses, together with our choice of a convenient parameterization of the 3 generation mixing matrix, we can derive a simple analytic formula which reduces the solar neutrino problem to an effective 2 generation problem. The reduction makes it apparent that the allowed range of mixing and mass parameters crucially depend on whether the survival probability of solar neutrinos S satisfies S greater than or equal to 1/3 or not. The formulae for probabilities of laboratory neutrino oscillations are also greatly simplified. We argue that a combination of the observed solar neutrino depletion and data obtained from reactor experiments seems to rule out some range of neutrino masses. If a sizable nu/sub ..mu../ ..-->.. nu/sub e/ oscillation is observed at accelerators, as suggested at this Workshop, it severely restricts the range of 2 mixing angles.

Lim, Chong-Sa

1987-02-01

303

Excited neutrino production by ultrahigh energy neutrinos traversing the Earth  

NASA Astrophysics Data System (ADS)

We focus on the production of excited neutrinos by ultra high energy (UHE, E?>104GeV) neutrinos traversing the Earth. The surviving neutrino fluxes are calculated using the complete system of transport equations for ordinary neutrinos and their excited states, and we compare these results with the obtained using only Standard Model (SM) interactions. We extend the analysis by including the neutral current (NC) and decay regeneration effects, and computing the surviving flux for different values of f/?, where ? is the compositeness scale and f a coupling factor representing non-perturbative physics. Finally, we analyze the possibilities of detecting such fluxes in a neutrino telescope such as IceCube showing the allowed regions in the (m*,f/?) plane for two possible initial fluxes. We have considered the IC80 configuration of IceCube for an operation time of ten years.

Reynoso, Matías M.; Romero, Ismael; Sampayo, Oscar A.

2012-12-01

304

Overview of neutrino mixing results from accelerator-based neutrino experiments  

NASA Astrophysics Data System (ADS)

Over the past fifteen years, many experiments have provided definitive evidence for neutrino flavor change. This talk briefly highlighted the experimental results and what constraints they place on neutrino masses and mixing. While the observed effects can often be described by mixing between two neutrino flavors, the current generation neutrino oscillation experiments are becoming increasingly sensitive to the mixing between all three neutrino flavors.

Marino, A. D.

2013-10-01

305

NESTOR: Deep underwater neutrino astronomy.  

National Technical Information Service (NTIS)

NESTOR is the first step toward the construction of a neutrino telescope using the depth of the sea both as a shield against atmospheric muons and as detector material. The experiment is based on the detection of Cerenkov radiation produced by neutrino mu...

L. Trasatti

1997-01-01

306

The emergence of neutrino astronomy  

NASA Astrophysics Data System (ADS)

This paper is a brief historical review of the quest to find neutrinos of extraterrestrial origin. In the context of the Victor Hess centenary, it is interesting to consider how the development of detectors for neutrinos from space relates to developments in cosmic-ray and particle physics over the same time span.

Gaisser, Thomas K.

2013-02-01

307

Is There a Massive Neutrino?  

ERIC Educational Resources Information Center

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)

Selvin, Paul

1991-01-01

308

Neutrino astronomy: Present and future  

NASA Astrophysics Data System (ADS)

I briefly review the present and future status of the burgeoning field of neutrino astronomy. I outline the astrophysics and particle physics goals, design, and performance of the various current and proposed neutrino telescopes. Also described are present results and future expectations.

McCauley, Thomas

2006-10-01

309

Coherent lunar effect on solar neutrino  

Microsoft Academic Search

Coherent interaction of solar neutrino with the moon and its implication are investigated. We solve the Dirac equation with the moon potential and show that a phase shift of the neutrino wave function becomes almost one unit if the neutrino penetrates the moon. Spatial interference is generated for the neutrino wave packets during eclipse and possibility of observing interference effect

K. Ishikawa; T. Shimomura

2005-01-01

310

Probing thermonuclear supernova explosions with neutrinos  

Microsoft Academic Search

Aims: We present neutrino light curves and energy spectra for two representative type Ia supernova explosion models: a pure deflagration and a delayed detonation. Methods: We calculate the neutrino flux from beta processes using nuclear statistical equilibrium abundances convoluted with approximate neutrino spectra of the individual nuclei and the thermal neutrino spectrum (pair+plasma). Results: Although the two considered thermonuclear supernova

A. Odrzywolek; T. Plewa

2011-01-01

311

Neutrino-helium ionizing collisions: Electromagnetic contribution  

NASA Astrophysics Data System (ADS)

In terrestrial experiments searching for neutrino magnetic moments one investigates the ionization channel in the neutrino-atom scattering. We present numerical calculations that disprove the recent theoretical claim about large enhancement of the electromagnetic-interaction contribution to the neutrino impact ionization of helium relative to the case of the neutrino scattering on free electrons.

Kouzakov, Konstantin A.; Rodina, Yulia A.; Studenikin, Alexander I.

2014-04-01

312

Neutrino mass models and CP violation  

SciTech Connect

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.

Joshipura, Anjan S. [Physical Research Laboratory, Navarangpura, Ahmedabad, 380 009 (India)

2011-10-06

313

Neutrino oscillation results from MINOS  

SciTech Connect

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.

Sousa, Alexandre; /Oxford U.

2007-08-01

314

Neutrinos Get Under Your Skin  

SciTech Connect

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.

Kayser, Boris

2005-08-30

315

Review of Reactor Neutrino Oscillation Experiments  

NASA Astrophysics Data System (ADS)

In this document we will review the current status of reactor neutrino oscillation experiments and present their physics potentials for measuring the ?13 neutrino mixing angle. The neutrino mixing angle ?13 is currently a high-priority topic in the field of neutrino physics. There are currently three different reactor neutrino experiments, DOUBLE CHOOZ, DAYA BAY and RENO and a few accelerator neutrino experiments searching for neutrino oscillations induced by this angle. A description of the reactor experiments searching for a nonzero value of ?13 is given, along with a discussion of the sensitivities that these experiments can reach in the near future.

Mariani, C.

316

Supernova observations for neutrino mixing parameters  

SciTech Connect

The neutrino spectra from a future galactic core collapse supernova could reveal information on the neutrino mixing pattern, especially on {theta}{sub 13} and the mass hierarchy. I briefly outline our current understanding of neutrino flavor conversions inside a supernova, and point out possible signatures of various neutrino mixing scenarios that the neutrino detectors should look for. Supernova neutrinos provide a probe for {theta}{sub 13} and mass hierarchy that is complementary to, and sometimes even better than, the current and proposed terrestrial neutrino oscillation experiments.

Dighe, Amol [Department of Theoretical Physics, Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

2011-10-06

317

Collective neutrino oscillations in turbulent backgrounds  

SciTech Connect

Using a Kolmogorov turbulence model, we investigate the effects of fluctuations in matter and neutrino density in the region near a supernova core on the flavor oscillations of neutrinos emitted in the core collapse in a single-angle, two-flavor approximation. Deviation from a smooth background neutrino density causes significant alterations in the final flavor state of the neutrino ensemble after 400 km, but even very large fluctuations in the matter density do not strongly affect the state of the neutrinos after the collective phase. In both cases, there is a strong effect on the neutrino flavor evolution at intermediate radii, with the flavor evolution becoming much more chaotic. The effect of fluctuations also depends strongly on the initial neutrino spectra. We conclude that the true neutrino fluxes arriving at Earth from core-collapse supernova could differ considerably from predictions of neutrino fluxes based on approximate models with smoothly decreasing matter and neutrino densities.

Reid, Giles; Adams, Jenni; Seunarine, Suruj [University of Canterbury, Christchurch (New Zealand); University of the West Indies, Bridgetown (Barbados)

2011-10-15

318

A search for supernova neutrinos with the Sudbury Neutrino Observatory  

NASA Astrophysics Data System (ADS)

The Sudbury Neutrino Observatory (SNO) is an underground Cerenkov detector designed to detect neutrinos from astrophysical sources. The fiducial mass of the detector consists of 1000 tonnes of D2O, which provides sensitivity to all neutrino flavours. Since much of the energy released in the supernova burst is expected to be carried by the muon and tau neutrinos, the supernova signal recorded by the SNO detector is of particular importance. In addition, SNO is also sensitive to the prompt electron neutrino signal expected from capture processes during core collapse. Various supernova models are investigated and predictions of the SNO supernova signal are studied using simulated Monte Carlo data. A data analysis program to identify neutrinos from a galactic supernova burst has been installed in the online system at SNO. The program automatically analyzes burst data and it is anticipated that a manual alert to the Supernova Early Warning System could be issued within 20--30 minutes with negligible possibility of a false alarm. The burst identification algorithm currently in use both online and offline provides detection sensitivity beyond the far edge of our galaxy. A search for supernova neutrinos was performed using 241.0 days of data collected over the time period between November 2, 1999 and January 4, 2001. No candidate bursts were observed over this period, which places a 90% confidence level upper limit of <3.5 galactic supernovae per year.

Heise, Jaret Curt

319

Neutrino-induced muons observed with MINOS  

SciTech Connect

The Main Injector Neutrino Oscillation Search (MINOS) experiment's Far Detector has been operational since July 2003, taking cosmic ray and atmospheric neutrino data from its location in the Soudan Mine Underground Lab. Numerous neutrino-induced muons have been observed. The detector's magnetic field allows the first determination by a large underground detector of muon charge and thus neutrino versus anti-neutrino on an event by event basis.

Habig, A.; /Minnesota U., Duluth

2005-07-01

320

Theory Predictions for Inclusive atmospheric Neutrino flux  

NASA Astrophysics Data System (ADS)

We describe the history of theory prediction of inclusive atmospheric neutrino flux shortly, then the 3-dimensional calculation of atmospheric neutrino flux in some detail. With the calculated atmospheric neutrino flux for INO and South Pole, we discuss on the relation of atmospheric neutrino flux and geomagnetic field. We find the full 3-dimensional scheme calculation is necessary for the theory prediction of the atmospheric neutrino flux.

Honda, Morihiro

2013-06-01

321

Neutrino-nucleus interactions  

NASA Astrophysics Data System (ADS)

Inclusive electron scattering cross-sections in the quasielastic and resonance regions for few GeV electrons are well represented in terms of scaling functions and scaling variables, the so-called superscaling analysis (SuSA). The concepts of scaling of the first and second kinds and superscaling are discussed, as are several mechanisms which are known to yield scaling violations. Given the high quality of scaling for cross-sections at appropriate kinematics, it is shown how the ideas can be turned around to provide predictions for both charge-changing and neutral current neutrino reactions with nuclei at comparable kinematics.

Donnelly, T. W.

2007-03-01

322

Neutrino and Anti-neutrino Cross Sections at MiniBooNE  

SciTech Connect

The MiniBooNE experiment has reported a number of high statistics neutrino and anti-neutrino cross sections -among which are the charged current quasi-elastic (CCQE) and neutral current elastic (NCE) neutrino scattering on mineral oil (CH{sub 2}). Recently a study of the neutrino contamination of the anti-neutrino beam has concluded and the analysis of the anti-neutrino CCQE and NCE scattering is ongoing.

Dharmapalan, Ranjan [University of Alabama Department of Physics and Astronomy, Tuscaloosa, AL-35487 (United States)

2011-10-06

323

Neutrino oscillation based on the mixings with a heavy right-handed neutrino  

NASA Astrophysics Data System (ADS)

We study a consistent explanation for both deficits of solar neutrino and atmospheric neutrino due to the neutrino oscillation induced by the mixing of light neutrinos with a heavy right-handed neutrino. We propose such a phenomenological neutrino mass matrix that realizes this scenario in the simple three generation left- and right- handed neutrino framework. Although this model contains only one nonzero mass eigenvalue ~ 10 eV for these light neutrino states at the first approximation level, it can be expected to explain consistently both deficiencies due to the appropriate higher order corrections. A suitable hot dark matter candidate is naturally included in it as its own feature.

Suematsu, Daijiro

1997-02-01

324

MUON STORAGE RINGS - NEUTRINO FACTORIES  

SciTech Connect

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.

PARSA,Z.

2000-05-30

325

Dissertation Award in Nuclear Physics Lecture: New Germanium Detectors for Neutrino Research and Dark Matter Searches  

NASA Astrophysics Data System (ADS)

The recent development of large mass, low noise P-Type point contact (PPC) germanium detectors has opened up new opportunities for experiments in neutrino and astroparticle physics. Several of these experiments have been performed with the earliest prototypes. As part of a campaign to measure coherent neutrino-nucles scattering (CoGeNT), and assessment of the low energy backgrounds at a nuclear power reactor are presented. Using the exposure of the detector to this high flux of neutrinos, a search for a neutrino magnetic moment is demonstrated and a projected limit from a more complete experiment is discussed. A limit is also placed on the magnitude of a continuous energy deposition by reactor neutrinos. Searches for signatures of light WIMPs and dark galactic pseudoscalars using these detectors are highlighted. Finally, the role that the PPC detectors play in searches for zero neutrino double beta decay, specifically within the MAJORANA collaboration, is also discussed.

Barbeau, Phillip

2012-03-01

326

LSND neutrino oscillation results  

SciTech Connect

The LSND (Liquid Scintillator Neutrino Detector) experiment at Los Alamos has conducted a search for muon antineutrino {r_arrow} electron antineutrino oscillations using muon neutrinos from antimuon decay at rest. The electron antineutrinos are detected via the reaction electron antineutrino + proton {r_arrow} positron + neutron, correlated with the 2.2-MeV gamma from neutron + proton {r_arrow} deuteron + gamma. The use of tight cuts to identify positron events with correlated gamma rays yields 22 events with positron energy between 36 and 60 MeV and only 4.6 {+-} 0.6 background events. The probability that this excess is due entirely to a statistical fluctuation is 4.1 {times} 10{sup -8}. A chi-squared fit to the entire positron sample results in a total excess of 51.8 {sup +18.7}{sub -16.9} {+-} 8.0 events with positron energy between 20 and 60 MeV. If attributed to muon antineutrino {r_arrow} electron antineutrino oscillations, this corresponds to an oscillation probability (averaged over the experimental energy and spatial acceptance) of (0.31 {+-} 0.12 {+-} 0.05){percent}. 10 refs., 7 figs., 1 tab.

Louis, W.C.; LSND Collaboration

1996-10-01

327

Report on solar neutrino experiments  

SciTech Connect

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. 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.

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

1984-11-15

328

Status of solar neutrino experiments  

SciTech Connect

A summary of the status of four solar neutrino experiments is presented. The Homestake {sup 37}Cl data are presented and the possible time dependence of the data is addressed. Data from 1040 days of operation of the Kamiokande II detector are presented next. The status of the {sup 71}Ga experiment in the Baksan Neutrino Observatory, which has operated for a short time, is discussed. The summary concludes with a discussion of the status of the Sudbury Neutrino Observatory, which has been under construction since the beginning of 1990. 7 refs., 6 figs.

Beier, E.W.; Davis, R. Jr.; Kim, S.B. (Pennsylvania Univ., Philadelphia, PA (USA). Dept. of Physics); Elliott, S.R. (Los Alamos National Lab., NM (USA)); Jelley, N. (Oxford Univ. (UK))

1990-01-01

329

Neutrino interactions in neutron matter  

NASA Astrophysics Data System (ADS)

Neutrino flow is the dominant mechanism of energy transfer in the latest stages of supernovae explosions and in compact stars. The Standard Model of particle physics and accelerator data, provide a satisfactory description of neutrino physics in vacuum up to TeV scale. Nevertheless modeling the dynamics of neutrino interaction in the nuclear environment involves severe difficulties. This thesis in mainly aimed at obtaining the weak response of infinite matter, using both the Correlated Basis Function theory and Landau Theory of Fermi liquid to take into account properly nucleon-nucleon hard core potential and long range correlation (quasi-particle, collective modes, ecc.)

Cipollone, Andrea

2012-12-01

330

Neutrinos:. Windows to Planck Physics  

NASA Astrophysics Data System (ADS)

After recalling some elegant contributions of the late Freydoon Mansouri, we turn to neutrino physics and use a modicum of grand unification to relate quark and lepton mixing matrices. We advocate an expansion for the MNS matrix, à la Wolfenstein, and argue that in a wide class of models, ?13 is a Cabibbo mixing effect. Also the large neutrino mixing angles reflect the mass patterns of the right-handed neutrinos near the Planck scale, and provide evidence for family structure at that scale.

Ramond, P.

2004-10-01

331

Current MINOS neutrino oscillation results  

NASA Astrophysics Data System (ADS)

The MINOS experiment is now making precise measurements of the ?? disappearance oscillations seen in atmospheric neutrinos, tests possible disappearance to sterile ? by measuring the neutral current flux, and has extended our reach towards the so far unseen ?13 by looking for ?e appearance in the ?? beam. It does so by using the intense, well-understood NuMI neutrino beam created at Fermilab and observing it 735km away at the Soudan Mine in Northeast Minnesota. High-statistics studies of the neutrino interactions themselves and the cosmic rays seen by the MINOS detectors have also been made. Results from MINOS' first three years of operations will be presented.

Habig, Alec; Minos Collaboration

2010-01-01

332

Study of Salt Neutrino Detector  

NASA Astrophysics Data System (ADS)

Rock salt is studied as a radio wave transmission medium in an ultra high energy (UHE) cosmic neutrino detector. The radio wave would be generated by Askar'yan effect (coherent Chrenkov radiation from negative excess charges in the electromagnetic shower) in the UHE neutrino interaction in the rock salt. We collected the samples of the rock salts from various rock salt mines in order to investigate whether they have a possibility as a Salt Neutrino Detector (SND) sites or not. As a tentative result, the absorption length of the rock salt samples was measured to be between 40 m and400 m at 1 GHz. .

Chiba, Masami; Kamijo, Toshio; Kawaki, Miho; Husain, Athar; Inuzuka, Masahide; Ikeda, Maho; Yasuda, Osamu

2001-07-01

333

Sterile Neutrinos in a 6x6 Matrix  

NASA Astrophysics Data System (ADS)

An early study of neutrino mixing within the see-saw framework considered random mass matrices in what is now known as the sterile sector[1]. The mixing angles in the lepton sector were found to be closely distributed about the CKM angles that were assumed. In that work, rank 3 was assumed for the weak isospin zero Majorana mass matrix in the sterile neutrino sector. We report here on the character of new results using a reduced rank (``singular'') sterile matrix. We find that an additional flavor misalignment in the sterile sector can produce several interesting effects, including: 1) mass eigenstates that lead to very large flavor mixing among active neutrinos, and 2) small values for the 1-3 mixing angle parameter[2]. We also discuss the limits that current observations place on the mass scale of light sterile neutrinos in this model. [1]T. Goldman and G. J. Stephenson, Jr., ``How Large Are the Neutrino Mixing Angles?'' Phys. Rev. D 24, 236 (1981). [2]G. J. Stephenson, Jr. , T. Goldman, B. H. J. McKellar and M. Garbutt, ``Large Mixing from Small: Pseudo-Dirac Neutrinos and the Singular Seesaw,'' Int. J.Mod.Phys.A20 (2005) 6373; [hep-ph/0404015].

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

2006-10-01

334

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

PubMed

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

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

2014-04-11

335

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory  

SciTech Connect

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.

Marino, Alysia Diane

2004-08-10

336

An Analysis of Recent Solar Neutrino Data  

NASA Astrophysics Data System (ADS)

Recent solar neutrino data from the Sudbury Neutrino Observatory (SNO) and from the Borexino experiment reach relatively low neutrino energies of several MeV. At these energies, the matter-enhanced neutrino oscillations via the so-called Mikheev-Smirnov-Wolfenstein (MSW) resonance manifest. Neutrinos originating near the center of the sun will feel this resonance as they propagate at these energies, modifying their oscillation away from the standard MSW effect. We examine these solar data in the context of effects that could be larger at the resonance than elsewhere in the solar neutrino spectrum. We explore the potential for the electron neutrino survival probability measured by these experiments to reveal those effects. We look for evidence of nonzero values for the neutrino mixing angle ?13, for evidence of sterile neutrinos and for interactions beyond the Standard Model of particle physics among these data

Malkus, Annelise

337

The many aspects of neutrino physics  

SciTech Connect

In mid-November, over seventy physicists gathered at Fermilab for an informal workshop on the Many Aspects of Neutrino Physics, which dovetailed with and also helped lay the groundwork for the succeeding more narrowly focused conference on Long Baseline Neutrino Oscillations. The workshop indeed covered many of the interrelated aspects of neutrino physics: 17 keV neutrinos (experiments, theoretical models, and astrophysical constraints), neutrino properties (double beta decay experiments, neutrino magnetic moments), neutrinos from/as weakly interacting massive particles (WIMPs) in cosmology and astrophysics, atmospheric neutrinos, and solar neutrinos. In the following, I provide a brief and thoroughly biased account of only some of the many interesting developments discussed at the workshop.

Frieman, J.A.

1992-01-01

338

Electron Neutrino Appearance in the MINOS Experiment  

SciTech Connect

MINOS is a long-baseline neutrino oscillation experiment tasked to make a precision measurement of the neutrino mixing parameters associated with the atmospheric neutrino mass splitting. Using a high powered neutrino beam from the Main Injector (NuMI) facility at Fermilab, it compares the neutrino energy spectrum for neutrino interactions observed in two large detectors located at Fermilab and in the Soudan mine in northern Minnesota at a distance of 735 km. We have recently presented muon-neutrino disappearance results after two years of data taking. Beyond those results there is the possibility that for a mixing angle related to electron-neutrino appearance in the vicinity of the current experimental limit, MINOS could make an initial measurement of this parameter. We present a method for particle identification of electron neutrinos and show several techniques being used to study the background contributions for this analysis in the non-oscillated data at the Near Detector.

Sanchez, Mayly C. [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)

2008-02-21

339

Electron Neutrino Appearance in the MINOS Experiment  

NASA Astrophysics Data System (ADS)

MINOS is a long-baseline neutrino oscillation experiment tasked to make a precision measurement of the neutrino mixing parameters associated with the atmospheric neutrino mass splitting. Using a high powered neutrino beam from the Main Injector (NuMI) facility at Fermilab, it compares the neutrino energy spectrum for neutrino interactions observed in two large detectors located at Fermilab and in the Soudan mine in northern Minnesota at a distance of 735 km. We have recently presented muon-neutrino disappearance results after two years of data taking. Beyond those results there is the possibility that for a mixing angle related to electron-neutrino appearance in the vicinity of the current experimental limit, MINOS could make an initial measurement of this parameter. We present a method for particle identification of electron neutrinos and show several techniques being used to study the background contributions for this analysis in the non-oscillated data at the Near Detector.

Sanchez, Mayly C.

2008-02-01

340

Neutrino Experiments at the SNS  

SciTech Connect

This talk describes planned neutrino physics experiments at the Spallation Neutron Source in Oak Ridge, Tennessee, with a focus on the proposed CLEAR (Coherent Low Energy Nuclear(A) Recoils) experiment.

Scholberg, Kate [Duke University Physics Department, Durham, NC, 27708 (United States)

2009-12-17

341

The Diffuse Supernova Neutrino Background  

NASA Astrophysics Data System (ADS)

The diffuse supernova neutrino background (DSNB) is the weak glow of megaelectronvolt neutrinos and antineutrinos from distant core-collapse supernovae. The DSNB has not been detected yet, but the Super-Kamiokande (SK) 2003 upper limit on the [Formula: see text] flux is close to predictions, now quite precise, that are based on astrophysical data. If SK is modified with dissolved gadolinium to reduce detector backgrounds and increase the energy range for analysis, then it should detect the DSNB at a rate of a few events per year, providing a new probe of supernova neutrino emission and the cosmic core-collapse rate. If the DSNB is not detected, then new physics will be required. Neutrino astronomy, although uniquely powerful, has proven extremely difficult—only the Sun and the nearby Supernova 1987A have been detected to date—so the promise of detecting new sources soon is exciting indeed.

Beacom, John F.

2010-11-01

342

LENA: Low Energy Neutrino Astronomy  

NASA Astrophysics Data System (ADS)

We focus on the physics potential of a large liquid scintillation detector in the field of low energy neutrino astrophysics. Proton decay search and long baseline oscillations will be discussed briefly at the end.

Oberauer, L.; Hellgartner, D.; Lewke, T.; Marrodán Undagoitia, T.; Meindl, Q.; Möllenstedt, R.; Potzel, W.; Tippmann, M.; von Feilitzsch, F.; Winter, J.; Wurm, M.

2011-08-01

343

AMANDA and ICECUBE Neutrino Telescopes  

Microsoft Academic Search

However, also particle physics proper may profit, e.g. in the area of neutrino properties and ultra-high energy cross section, in the search for supersymmetric particles that may constitute part of the \\

J. Ahrens; T. Becka; T. Feser; O. Franzen; R. Gozzini; M. Hellwig; L. Kopke; T. Kowarik; T. Neunhoffer; A. Piegsa; H. G. Sander; U. Schafer; N. Sidro; J. Stegmeier

344

The effective neutrino charge radius  

NASA Astrophysics Data System (ADS)

It is shown that at one-loop order a neutrino charge radius (NCR) may be defined, which is ultraviolet finite, does not depend on the gauge-fixing parameter, nor on properties of the target other than its electric charge. This is accomplished through the systematic decomposition of physical amplitudes into effective self-energies, vertices, and boxes, which separately respect electroweak gauge invariance. In this way the NCR stems solely from an effective proper photon-neutrino one-loop vertex, which satisfies a naive, QED-like Ward identity. The NCR so defined may be extracted from experiment, at least in principle, by expressing a set of experimental electron-neutrino cross-sections in terms of the finite NCR and two additional gauge- and renormalization-group-invariant quantities, corresponding to the electroweak effective charge and mixing angle. PACS: 13.15.+g Neutrino interactions - 13.40.Gp Electromagnetic form factors

Papavassiliou, J.; Bernabéu, J.; Binosi, D.; Vidal, J.

345

Unparticle effects in neutrino telescopes  

SciTech Connect

Recently H. Georgi has introduced the concept of unparticles in order to describe the low energy physics of a nontrivial scale invariant sector of an effective theory. We investigate its physical effects on the neutrino flux to be detected in a kilometer cubic neutrino telescope such as IceCube. We study the effects, on different observables, of the survival neutrino flux after through the Earth, and the regeneration originated in the neutral currents. We calculate the contribution of unparticle physics to the neutrino-nucleon interaction and, then, to the observables in order to evaluate detectable effects in IceCUbe. Our results are compared with the bounds obtained by other nonunderground experiments. Finally, the results are presented as an exclusion plot in the relevant parameters of the new physics stuff.

Gonzalez-Sprinberg, G.; Martinez, R.; Sampayo, Oscar A. [Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, Igua 4225, 11400 Montevideo (Uruguay); Departamento de Fisica, Universidad Nacional, Bogota (Colombia); Departamento de Fisica, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina)

2009-03-01

346

Neutrino mass and mixing, and non-accelerator experiments  

SciTech Connect

We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.

Robertson, R.G.H.

1992-10-01

347

Neutrino mass and mixing, and non-accelerator experiments  

SciTech Connect

We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.

Robertson, R.G.H.

1992-01-01

348

Seesaw model in SO(10) with an upper limit on right-handed neutrino masses  

NASA Astrophysics Data System (ADS)

In the framework of SO(10) gauge unification and the seesaw mechanism, we show that the upper bound on the mass of the heaviest right-handed neutrino MR3<3×1011GeV, given by the Pati-Salam intermediate scale of B-L spontaneous symmetry breaking, constrains the observables related to the left-handed light neutrino mass matrix. We assume such an upper limit on the masses of right-handed neutrinos and, as a first approximation, a Cabibbo form for the matrix VL that diagonalizes the Dirac neutrino matrix mD. Using the inverse seesaw formula, we show that our hypotheses imply a triangular relation in the complex plane of the light neutrino masses with the Majorana phases. We obtain normal hierarchy with an absolute scale for the light neutrino spectrum. Two regions are allowed for the lightest neutrino mass m1 and for the Majorana phases, implying predictions for the neutrino mass measured in Tritium decay and for the double beta decay effective mass |?mee?|.

Abud, M.; Buccella, F.; Falcone, D.; Oliver, L.

2012-08-01

349

Cosmological Bounds on Masses of Neutrinos and Other Thermal Relics  

NASA Astrophysics Data System (ADS)

With the advent of precision data, cosmology has become an extremely powerful tool for probing particle physics. The prime example of this is the cosmological bound on light neutrino masses. Here I review the current status of cosmological neutrino mass bounds as well as the various uncertainties involved in deriving them. From WMAP, SDSS, and Lyman-? forest data an upper bound on the sum of neutrino masses of 0.65 eV (95% C.L.) can be derived without any assumptions about bias. I also present new limits on other light, thermally produced particles. For example, a hypothetical new Majorana fermion decoupling around the electroweak phase transition must have m ? 5 eV.

Hannestad, Steen

2005-04-01

350

N Resonances in Neutrino Interactions  

NASA Astrophysics Data System (ADS)

The role of N* resonances in neutrino interactions with nucleons is discussed, stressing the relevance for neutrino cross-section and oscillation experiments. The cross section for single N* weak excitation is expressed in terms of vector and axial transition form factors, which can be partially constrained using the available experimental information from photon, electron and pion reactions on the nucleon. New measurements on hydrogen and deuterium are necessary to reduce further the uncertainties.

Alvarez-Ruso, L.

2014-01-01

351

The Antares Undersea Neutrino Telescope  

NASA Astrophysics Data System (ADS)

Neutrino astronomy is a very promising field of investigation representing a complementary source of information with respect to photon-astronomy. ANTARES, operating off the French Mediterranean coast, is the worlds largest operational underwater neutrino telescope. In these proceedings, in addition to a short detector description, the results of recent analysis will be discussed. The ANTARES project is an important physics experiment but also represents a bench mark for a future large detector of the km3 scale.

Anghinolfi, Marco

2013-11-01

352

Family Symmetry and Neutrino Mixing  

Microsoft Academic Search

The observed quark hierarchies suggest a simple family symmetry. Generalized to leptons through grand-unified quantum numbers, it produces a neutrino mixing matrix with order-1 numu-nutau mixing, and order- lambda3 nue-numu and nue-nutau mixings. The intrafamily hierarchy and observed neutrino mass differences together require this symmetry to be anomalous, suggesting through the Green-Schwarz mechanism a string or M-theory origin for the

John K. Elwood; Nikolaos Irges; Pierre Ramond

1998-01-01

353

Daya Bay Reactor Neutrino Experiment  

Microsoft Academic Search

The Daya Bay reactor neutrino experiment, currently under construction in China, will be the most sensitive experiments in the world searching for the yet unknown neutrino mixing parameters, theta-13(theta13). With a thermal power of 17.4GW by 2011, the Daya Bay site provides an intense electron antineutrino flux, which together with 3 years of data taking from 4 pairs of identical

Yuenkeung Hor

2009-01-01

354

Detection of massive supernova neutrinos  

Microsoft Academic Search

Neutrinos and antineutrinos of all three flavours are emitted during the post bounce phase of a core collapse supernova with numu\\/nutau(nu¯mu\\/nu¯tau) having average energies more than that of nue(nu¯e). The author presents the effect of flavour oscillations on the neutrino flux and their expected number of events at the detector. The author performs a three-generation analysis and for the mass

S. Choubey

1999-01-01

355

Solar Neutrinos: Status and Prospects  

NASA Astrophysics Data System (ADS)

We describe the current status of solar neutrino measurements and of the theory—both neutrino physics and solar astrophysics—employed in interpreting measurements. Important recent developments include Super-Kamiokande's determination of the ?-e elastic scattering rate for 8B neutrinos to 3%; the latest Sudbury Neutrino Observatory (SNO) global analysis in which the inclusion of low-energy data from SNO I and II significantly narrowed the range of allowed values for the neutrino mixing angle ?12; Borexino results for both the 7Be and proton-electron-proton (pep) neutrino fluxes, the first direct measurements constraining the rate of proton-proton (pp) I and pp II burning in the Sun; global reanalyses of solar neutrino data that take into account new reactor results on ?13; a new decadal evaluation of the nuclear physics of the pp chain and CNO cycle defining best values and uncertainties in the nuclear microphysics input to solar models; recognition of an emerging discrepancy between two tests of solar metallicity, helioseismological mappings of the sound speed in the solar interior, and analyses of the metal photoabsorption lines based on our best current description of the Sun's photosphere; a new round of standard solar model calculations optimized to agree either with helioseismology or with the new photospheric analysis; and, motivated by the solar abundance problem, the development of nonstandard, accreting solar models, in order to investigate possible consequences of the metal segregation that occurred in the proto-solar disk. We review this progress and describe how new experiments such as SNO+ could help us further exploit neutrinos as a unique probe of stellar interiors.

Haxton, W. C.; Hamish Robertson, R. G.; Serenelli, Aldo M.

2013-08-01

356

Lepton asymmetries from neutrino oscillations  

NASA Astrophysics Data System (ADS)

Reasonably large relic neutrino asymmetries can be generated by active-sterile neutrino oscillations. After briefly discussing possible applications, I describe the Quantum Kinetic Equation formalism used to compute the asymmetry growth curves. I then show how the basic features of these curves can be understood on the basis of the adiabatic limit approximation in the collision dominated epoch, and the pure MSW effect at lower temperatures.

Volkas, R. R.

357

New ideas in neutrino detection  

Microsoft Academic Search

What is new in the field of neutrino detection? In addition to new projects probing both the low and high ends of the neutrino\\u000a energy scale, an inexpensive, effective technique is being developed to allow tagging of antineutrinos in water Cherenkov\\u000a (WC) detectors via the addition to water of a solute with a large neutron cross-section and energetic ? daughters.

M. R. Vagins

2006-01-01

358

Invariants of collective neutrino oscillations  

NASA Astrophysics Data System (ADS)

We consider the flavor evolution of a dense neutrino gas by taking into account both vacuum oscillations and self-interactions of neutrinos. We examine the system from a many-body perspective as well as from the point of view of an effective one-body description formulated in terms of the neutrino polarization vectors. We show that, in the single angle approximation, both the many-body picture and the effective one-particle picture possess several constants of motion. We write down these constants of motion explicitly in terms of the neutrino isospin operators for the many-body case and in terms of the polarization vectors for the effective one-body case. The existence of these constants of motion is a direct consequence of the fact that the collective neutrino oscillation Hamiltonian belongs to the class of Gaudin Hamiltonians. This class of Hamiltonians also includes the (reduced) BCS pairing Hamiltonian describing superconductivity. We point out the similarity between the collective neutrino oscillation Hamiltonian and the BCS pairing Hamiltonian. The constants of motion manifest the exact solvability of the system. Borrowing the well established techniques of calculating the exact BCS spectrum, we present exact eigenstates and eigenvalues of both the many-body and the effective one-particle Hamiltonians describing the collective neutrino oscillations. For the effective one-body case, we show that spectral splits of neutrinos can be understood in terms of the adiabatic evolution of some quasiparticle degrees of freedom from a high-density region where they coincide with flavor eigenstates to the vacuum where they coincide with mass eigenstates. We write down the most general consistency equations which should be satisfied by the effective one-body eigenstates and show that they reduce to the spectral split consistency equations for the appropriate initial conditions.

Pehlivan, Y.; Balantekin, A. B.; Kajino, Toshitaka; Yoshida, Takashi

2011-09-01

359

Neutrinos from hell. [Detected from supernova  

SciTech Connect

The detection of neutrinos is studied. The use of the Kamiokande II detector, which is a cylindrical tank holding about 3000 tons of highly purified water, for neutrino detection is examined. The operation and capabilities of the Kamiokande II detector are described. The Kamiokande II and Irvine-Michigan-Brookhaven detector observed the neutrinos from SN 1987A. The relation between the supernova and the neutrinos is analyzed. Particular consideration is given to the shock wave and the energies of the neutrinos. Additional data provided by the neutrino observations are discussed.

Schorn, R.A.

1987-05-01

360

Supernova neutrino observations: What can we learn?  

NASA Astrophysics Data System (ADS)

Twenty years after SN 1987A, the vast international programme of experimental neutrino physics and neutrino astronomy suggests that large detectors will operate for a long time. It is realistic that a high-statistics neutrino signal from a galactic SN will be observed. I review some of the generic lessons from such an observation where neutrinos largely play the role of astrophysical messengers. In principle, the signal also holds valuable information about neutrino mixing parameters. I explain some recent developments about the crucial importance of collective neutrino oscillations in the SN environment.

Raffelt, Georg G.

2011-12-01

361

Quantum Gravity Effect on Neutrino Oscillation  

NASA Astrophysics Data System (ADS)

The quantum gravity may have strong consequence for neutrino oscillation phenemomenon over a large distance.We found a significant modification of neutrino oscillation due to quantum gravity effects. Quantum gravity (Planck scale effects) leads to an effective S U(2) L ×U(1) invariant dimension-5 Lagrangian involving, neutrino and Higgs fields. On symmetry breaking, this operator gives rise to correction to the neutrino masses and mixing. The gravitational interaction (M X =M p l ) demands that the element of this perturbation matrix should be independent of flavor indices. In this paper, we study the quantum gravity effects on neutrino oscillation, namely modified dispersion relation for neutrino oscillations parameter.

Koranga, Bipin Singh; Narayan, Mohan

2014-05-01

362

Solar mass-varying neutrino oscillations.  

PubMed

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. PMID:16384133

Barger, V; Huber, Patrick; Marfatia, Danny

2005-11-18

363

High-energy neutrino astronomy  

NASA Astrophysics Data System (ADS)

Neutrino astronomy, conceptually conceived four decades ago, has entered an exciting phase for providing results on the quest for the sources of the observed highest energy particles. IceCube and ANTARES are now completed and are scanning in space and time possible signals of high energy neutrinos indicating the existence of such sources. DeepCore, inside IceCube, is a playground for vetoed neutrino measurement with better potential below 1 TeV. A larger and denser detector is now being discussed. ARA, now in test phase, will be composed by radio stations that could cover up to ~ 100 km2 and aims at the highest energy region of cosmogenic neutrinos. The non observation of cosmic events is on one side a source of disappointment, on the other it represents by itself an important result. If seen in the context of a multi-messenger science, the combination of photon and cosmic ray experiment results brings invaluable information. The experimental upper bounds of the cubic-kilometer telescope IceCube are now below the theoretical upper bounds for extragalactic fluxes of neutrinos from optically thin sources. These are responsible for accelerating the extragalactic cosmic rays. Such limits constrain the role of gamma-ray bursts, described by the fireball picture, as sources of ultra-high energy cosmic rays. Neutrino telescopes are exciting running multi-task experiments that produce astrophysics and particle physics results some of which have been illustrated at this conference and are summarized in this report.

Montaruli, Teresa

2012-07-01

364

Extraterrestrial high energy neutrino fluxes  

NASA Technical Reports Server (NTRS)

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.

Stecker, F. W.

1979-01-01

365

Beta Beams for Neutrino Production  

NASA Astrophysics Data System (ADS)

To use accelerated beta active radioactive ions to produce collimated high energy neutrino beams was proposed by P. Zuchelli in 2002. Since then, several ideas related to how to design Beta Beam facilities have been studied. Design studies of an accelerator complex, based on CERN accelerators, have been supported by research programs within the European Commisison FP6 and FP7 frameworks (EURISOL Design Study and EUROnu). In these studies 6He and 18Ne are used as beta emitters to produce antineutrinos and neutrinos respectively. Alternative isotopes for neutrino beam production, 8Li and 8B, are investigated in the now ongoing study, EUROnu. Due to the higher reaction Q-value of these ions, the resulting neutrino energies are higher. The isotopes we need for neutrino beams have to be produced in large quantities using non conventional methods. Latest research on production of isotopes that are presently considered for Beta Beams will be discussed. The work achieved gives a good ground to propose the Beta Beam, which is based on known technology, for neutrino production. In this status review we concentrate on technical issues related to a possible Beta Beam facility using the CERN infrastructure.

Wildner, E.

2012-08-01

366

Neutrino masses in the economical 3-3-1 model  

SciTech Connect

We show that in the framework of the economical 3-3-1 model, the suitable pattern of neutrino masses arises from three quite different sources - the lepton-number conserving, the spontaneous lepton-number breaking, and the explicit lepton-number violating, widely ranging over mass scales including the GUT one: u{approx}O(1) GeV, v{approx_equal}246 GeV, {omega}{approx}O(1) TeV, and M{approx}O(10{sup 16}) GeV. At the tree level, the model contains three Dirac neutrinos: one massless, and two large with degenerate masses in the range of the electron mass. At the one-loop level, the left-handed and right-handed neutrinos obtain Majorana masses M{sub L,R} in orders of 10{sup -2}-10{sup -3} eV and degenerate in M{sub R}=-M{sub L}, while the Dirac masses get a large reduction down to eV scale through a finite mass renormalization. In this model, the contributions of new physics are strongly signified, the degenerations in the masses and the last hierarchy between the Majorana and Dirac masses can be completely removed by heavy particles. All the neutrinos get mass and can fit the data. The acceptable set of the input data does not induce the large lepton flavor violating branching ratios such as Br({mu}{yields}e{gamma})

Dong, P. V.; Long, H. N.; Soa, D. V. [Department of Physics and NCTS, National Tsing Hua University, Hsinchu, Taiwan (China); Department of Physics, Kobe University, Nada, Kobe 657-8501 (Japan); Department of Physics, Hanoi University of Education, Hanoi (Viet Nam)

2007-04-01

367

Dark energy from mass varying neutrinos  

NASA Astrophysics Data System (ADS)

We show that mass varying neutrinos (MaVaNs) can behave as a negative pressure fluid which could be the origin of the cosmic acceleration. We derive a model independent relation between the neutrino mass and the equation of state parameter of the neutrino dark energy, which is applicable for general theories of mass varying particles. The neutrino mass depends on the local neutrino density and the observed neutrino mass can exceed the cosmological bound on a constant neutrino mass. We discuss microscopic realizations of the MaVaN acceleration scenario, which involve a sterile neutrino. We consider naturalness constraints for mass varying particles, and find that both eV cut-offs and eV mass particles are needed to avoid fine-tuning. In microscopic realizations of this scenario with a sterile neutrino, these considerations give the sterile neutrino a maximum mass today of order an eV, which could be detectable at MiniBooNE. Because the sterile neutrino was much heavier at earlier times, constraints from big bang nucleosynthesis on additional states are not problematic. We consider regions of high neutrino density and find that the most likely place today to find neutrino masses which are significantly different from the neutrino masses in our solar system is in a supernova. The possibility of different neutrino mass in different regions of the galaxy and the local group could be significant for Z-burst models of ultra-high energy cosmic rays. We also consider the cosmology of and the constraints on the 'acceleron', the scalar field which is responsible for the varying neutrino mass, and briefly discuss neutrino density dependent variations in other constants, such as the fine structure constant.

Fardon, Rob; Nelson, Ann E.; Weiner, Neal

2004-10-01

368

Neutrino factories: Realization and physics potential  

NASA Astrophysics Data System (ADS)

Neutrino Factories offer an exciting option for the long-term neutrino physics program. This new type of neutrino facility will provide beams with unique properties. Low systematic uncertainties at a Neutrino Factory, together with a unique and precisely known neutrino flavor content, will enable neutrino oscillation measurements to be made with unprecedented sensitivity and precision. Over recent years, the resulting neutrino factory physics potential has been discussed extensively in the literature. In addition, over the last six years the R&D necessary to realize a Neutrino Factory has been progressing, and has developed into a significant international activity. It is expected that, within about five more years, the initial phase of this R&D program will be complete and, if the community chooses to build this new type of neutrino source within the following decade, neutrino factory technology will be ready for the final R&D phase prior to construction. In this paper (i) an overview is given of the technical ingredients needed for a Neutrino Factory, (ii) beam properties are described, (iii) the resulting neutrino oscillation physics potential is summarized, (iv) a more detailed description is given for one representative Neutrino Factory design, and (v) the ongoing R&D program is summarized, and future plans briefly described.

Geer, S.; Zisman, M. S.

2007-10-01

369

Atmospheric Neutrinos in the MINOS Far Detector  

SciTech Connect

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

Howcroft, Caius L.F.; /Cambridge U.

2004-12-01

370

Supernova neutrinos: Earth matter effects and neutrino mass spectrum  

NASA Astrophysics Data System (ADS)

We perform a detailed study of the Earth matter effects on supernova neutrinos. The dependences of these effects on the properties of the original neutrino fluxes, on the trajectory of the neutrinos inside the Earth and on the oscillation parameters are described. We show that, for a large fraction (/~60%) of the possible arrival times of the signal, the neutrino flux crosses a substantial amount of the matter of the Earth at least for one of the existing detectors. For oscillation parameters from the LMA solution of the solar neutrino problem the Earth matter effect consists in an oscillatory modulation of the ?¯e and/or ?e energy spectra. The relative deviation with respect to the undistorted spectra can be as large as 20-30% for /E>~20 MeV and 70-100% for /E>~40 MeV. For parameters from the SMA and LOW solutions the effect is localized at low energies (/E<~10 MeV) and is not larger than /~10%. The Earth matter effects can be revealed (i) by the observation of oscillatory distortions of the energy spectra in a single experiment and (ii) by the comparison between the spectra at different detectors. For a supernova at distance /D=10 Kpc, comparing the results of SuperKamiokande (SK), SNO and LVD experiments one can establish the effect at (2-3)/? level, whereas larger statistical significance ((4-5)/?) is obtained if two experiments of SK-size or larger are available. Studies of the Earth matter effect will select or confirm the solution of the solar neutrino problem, probe the mixing Ue3 and identify the hierarchy of the neutrino mass spectrum.

Lunardini, C.; Smirnov, A. Yu.

2001-11-01

371

Quantum corrections to the effective neutrino mass operator in a 5D MSSM  

SciTech Connect

We discuss in detail a five-dimensional minimal supersymmetric standard model compactified on S{sup 1}/Z{sub 2} extended by the effective Majorana neutrino mass operator. We study the evolution of neutrino masses and mixings. Masses and angles, in particular, the atmospheric mixing angle {theta}{sub 23}, can be significantly lowered at high energies with respect to their value at low energy.

Deandrea, Aldo; Welzel, Julien [Universite de Lyon 1, Institut de Physique Nucleaire, 4 rue E. Fermi, 69622 Villeurbanne Cedex (France); Hosteins, Pierre [SPhT, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France); Oertel, Micaela [LUTH, Observatoire de Paris, CNRS, Universite Paris Diderot, 5 place Jules Janssen, 92195 Meudon (France)

2007-06-01

372

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

SciTech Connect

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

Cooper, N.G. [ed.] [ed.

1997-12-31

373

Detecting thermal neutrinos from supernovae with DUMAND  

SciTech Connect

The Deep Underwater Muon and Neutrino Detector (DUMAND) could be made sensitive to the thermal (about 10-MeV) neutrinos from a supernova, as well as the TeV neutrinos for which it was originally designed, by clustering the photomultiplier tubes used to detect the Cerenkov light produced by neutrino interactions into nodes of four tubes. Requiring coincident counts from three or four of the tubes at a node would reduce the background from bioluminescence enough to allow the detection of the neutrinos from a supernova. A modified DUMAND using quadruple coincidence would have detected roughly eight neutrinos from SN 1987A and would detect about 280 neutrinos from a Galactic supernova at a distance of 9 kpc. Triple coincidence could be used with a Galactic supernova and would detect about 1500 neutrinos. 26 references.

Pryor, C.; Roos, C.E.; Webster, M.S.

1988-06-01

374

The neutrino sky at very high energies  

NASA Astrophysics Data System (ADS)

Neutrino astronomy opens a new window for the observation and study of high-energy phenomena in our Universe. The emission of high-energy neutrinos in extragalactic sources or the cosmic environment is intimately related to that of ?-rays and cosmic rays. We will review the various indirect neutrino limits that arise from this cosmic connection and compare this to the present direct limits of neutrino observatories. Specific models of extragalactic TeV to PeV neutrino sources are already testable by large volume neutrino observatories like IceCube. At the EeV energy scale the flux of cosmogenic neutrinos associated with the propagation of ultra-high energy cosmic rays in the cosmic radiation background seems to be the most promising contribution to the diffuse neutrino background. We will discuss its model dependence w.r.t. chemical composition and evolution of the sources and provide simple bolometric scaling relations.

Ahlers, Markus

2013-10-01

375

Reactor neutrino experiments: ?13 and beyond  

NASA Astrophysics Data System (ADS)

We review the current-generation short-baseline reactor neutrino experiments that have firmly established the third neutrino mixing angle ?13 to be nonzero. The relative large value of ?13 (around 9°) has opened many new and exciting opportunities for future neutrino experiments. Daya Bay experiment with the first measurement of ? m2ee is aiming for a precision measurement of this atmospheric mass-squared splitting with a comparable precision as ? m2? ? from accelerator muon neutrino experiments. JUNO, a next-generation reactor neutrino experiment, is targeting to determine the neutrino mass hierarchy (MH) with medium baselines ( 50 km). Beside these opportunities enabled by the large ?13, the current-generation (Daya Bay, Double Chooz, and RENO) and the next-generation (JUNO, RENO-50, and PROSPECT) reactor experiments, with their unprecedented statistics, are also leading the precision era of the three-flavor neutrino oscillation physics as well as constraining new physics beyond the neutrino Standard Model.

Qian, Xin; Wang, Wei

2014-05-01

376

Observation of Electron Neutrino Appearance in a Muon Neutrino Beam  

NASA Astrophysics Data System (ADS)

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3? when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles ?12, ?23, ?13, a mass difference ?m322 and a CP violating phase ?CP. In this neutrino oscillation scenario, assuming |?m322|=2.4×10-3 eV2, sin2?23=0.5, and ?m322>0 (?m322<0), a best-fit value of sin22?13=0.140-0.032+0.038 (0.170-0.037+0.045) is obtained at ?CP=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of ?13 from reactor experiments, some values of ?CP are disfavored at the 90% C.L.

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

2014-02-01

377

Evidence of electron neutrino appearance in a muon neutrino beam  

NASA Astrophysics Data System (ADS)

The T2K Collaboration reports evidence for electron neutrino appearance at the atmospheric mass splitting, |?m322|?2.4×10-3eV2. An excess of electron neutrino interactions over background is observed from a muon neutrino beam with a peak energy of 0.6 GeV at the Super-Kamiokande (SK) detector 295 km from the beam’s origin. Signal and background predictions are constrained by data from near detectors located 280 m from the neutrino production target. We observe 11 electron neutrino candidate events at the SK detector when a background of 3.3±0.4(syst) events is expected. The background-only hypothesis is rejected with a p value of 0.0009 (3.1?), and a fit assuming ????e oscillations with sin?22?23=1, ?CP=0 and |?m322|=2.4×10-3eV2 yields sin?22?13=0.088-0.039+0.049(stat+syst).

Abe, K.; Abgrall, N.; Aihara, H.; Akiri, T.; Albert, J. B.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Ariga, T.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Bentham, S. W.; Berardi, V.; Berger, B. E.; Berkman, S.; Bertram, I.; Beznosko, D.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; Boyd, S.; Brailsford, D.; Bravar, A.; Bronner, C.; Brook-Roberge, D. G.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Curioni, A.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; Day, M.; de André, J. P. A. M.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S.; Densham, C.; Di Lodovico, F.; Di Luise, S.; Dobson, J.; Drapier, O.; Duboyski, T.; Dufour, F.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Dziomba, M.; Emery, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Frank, E.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A.; Galymov, V.; Gaudin, A.; Giffin, S.; Giganti, C.; Gilje, K.; Golan, T.; Gomez-Cadenas, J. J.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Ives, S. J.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; Jo, J. H.; Jonsson, P.; Joo, K. K.; Jung, C. K.; Kaboth, A.; Kaji, H.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Kearns, E.; Khabibullin, M.; Khanam, F.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J. Y.; Kim, J.; Kim, S. B.; Kirby, B.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Kogan, G.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koseki, K.; Koshio, Y.; Kowalik, K.; Kreslo, I.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kumaratunga, S.; Kurjata, R.; Kutter, T.; Lagoda, J.; Laihem, K.; Laing, A.; Laveder, M.; Lawe, M.; Lazos, M.; Lee, K. P.; Licciardi, C.; Lim, I. T.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Lopez, G. D.; Ludovici, L.; Macaire, M.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marchionni, A.; Marino, A. D.; Marteau, J.; Martin, J. F.; Maruyama, T.; Marzec, J.; Masliah, P.; Mathie, E. L.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCauley, N.; McFarland, K. S.; McGrew, C.; McLachlan, T.; Messina, M.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Monfregola, L.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nagasaki, T.; Nakadaira, T.; Nakahata, M.; Nakai, T.; Nakajima, K.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Naples, D.; Nicholls, T. C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; O'Keeffe, H. M.; Obayashi, Y.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Otani, M.; Owen, R. A.; Oyama, Y.; Pac, M. Y.; Palladino, V.; Paolone, V.; Payne, D.; Pearce, G. F.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pinzon Guerra, E. S.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Reeves, M.; Reinherz-Aronis, E.; Retiere, F.; Robert, A.; Rodrigues, P. A.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Sacco, R.; Sakashita, K.; Sánchez, F.; Scantamburlo, E.; Scholberg, K.; Schwehr, J.; Scott, M.; Scully, D. I.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shibata, M.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smith, R. J.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Szeglowski, T.; Szeptycka, M.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. A.; Tanaka, M. M.; Tanaka, M.; Taylor, I. J.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Ueno, K.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Zalewska, A.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.

2013-08-01

378

Observation of electron neutrino appearance in a muon neutrino beam.  

PubMed

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3? when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles ?12, ?23, ?13, a mass difference ?m(32)(2) and a CP violating phase ?(CP). In this neutrino oscillation scenario, assuming |?m(32)(2)|=2.4×10(-3)??eV(2), sin(2)?(23)=0.5, and ?m322>0 (?m(32)(2)<0), a best-fit value of sin(2)2?(13)=0.140(-0.032)(+0.038) (0.170(-0.037)(+0.045)) is obtained at ?(CP)=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of ?(13) from reactor experiments, some values of ?(CP) are disfavored at the 90% C.L. PMID:24580687

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

2014-02-14

379

Supersymmetric Seesaw without Singlet Neutrinos: Neutrino Masses and Lepton-Flavour Violation  

Microsoft Academic Search

We consider the supersymmetric seesaw mechanism induced by the exchange of\\u000aheavy SU(2)_W triplet states, rather than `right-handed' neutrino singlets, to\\u000agenerate neutrino masses. We show that in this scenario the neutrino flavour\\u000astructure tested at low-energy in the atmospheric and solar neutrino\\u000aexperiments is directly inherited from the neutrino Yukawa couplings to the\\u000atriplets. This allows us to predict

Anna Rossi; G. Galilei

2002-01-01

380

From Neutrino Factory to Muon Collider  

SciTech Connect

Both Muon Colliders and Neutrino Factories require a muon source capable of producing and capturing {Omicron}(10{sup 21}) muons/year. This paper reviews the similarities and differences between Neutrino Factory and Muon Collider accelerator complexes, the ongoing R&D needed for a Muon Collider that goes beyond Neutrino Factory R&D, and some thoughts about how a Neutrino Factory on the CERN site might eventually be upgraded to a Muon Collider.

Geer, S.; /Fermilab

2010-01-01

381

Have massive cosmological neutrinos already been detected  

NASA Technical Reports Server (NTRS)

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

Stecker, F. W.

1980-01-01

382

Neutrino oscillations under gravity: mass independent oscillation  

Microsoft Academic Search

I discuss the possibility of neutrino oscillation in presence of gravity. In this respect I consider the propagation of neutrinos in the early phase of universe and around black holes. It is seen that whether the rest masses of a neutrino and corresponding anti-neutrino are considered to be same or not due to space-time curvature effect non-zero oscillation probability between

Banibrata Mukhopadhyay

2003-01-01

383

Atmospheric neutrino flux at INO site  

SciTech Connect

To illustrate the calculation of the atmospheric neutrino flux, we briefly explain our calculation scheme and important components, such as primary cosmic ray spectra, interaction model, and geomagnetic model. Then, we calculate the atmospheric neutrino flux at INO site in our calculation scheme. We compare the calculated atmospheric neutrino fluxes predicted at INO with those at other major neutrino detector sites, especially that at SK site.

Honda, Morihiro [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8582 (Japan)

2011-11-23

384

Atmospheric neutrino flux at INO site  

NASA Astrophysics Data System (ADS)

To illustrate the calculation of the atmospheric neutrino flux, we briefly explain our calculation scheme and important components, such as primary cosmic ray spectra, interaction model, and geomagnetic model. Then, we calculate the atmospheric neutrino flux at INO site in our calculation scheme. We compare the calculated atmospheric neutrino fluxes predicted at INO with those at other major neutrino detector sites, especially that at SK site.

Honda, Morihiro

2011-11-01

385

Studying Possibilities of the IHEP Neutrino Channel.  

National Technical Information Service (NTIS)

Given are the results of investigation of operating regimes of the IHEP neutrino channel which can ensure to conduct experiments with the required parameters of neutrino spectra. The muon distributions in the neutrino channel shield, where pi - and K-meso...

A. P. Bugorskii S. A. Knyazev V. I. Kotov V. I. Kochetkov V. I. Kurbakov

1980-01-01

386

Velocity and Distribution of Primordial Neutrinos  

Microsoft Academic Search

The cosmic neutrinos background (CNB) comprises primordial neutrinos that were decoupled when the Universe was very young. Its detection is complicated, especially if we take into account neutrino mass and a possible breaking of Lorentz invariance at high energy, but has a fundamental relevance to studying the Big Bang. In this paper, we will see that a Lorentz violation does

Jorge Alfaro; Pablo González

2008-01-01

387

Family hierarchy and large neutrino mixings  

Microsoft Academic Search

The recent neutrino data seem to favor two large and one small mixing angles and a hierarchy of their squared mass differences. We discuss these within the context of hierarchical neutrino masses. We show that this scheme suggests a specific neutrino mass matrix with mild fine-tuning. We then present a Froggatt–Nielsen model that reproduces this matrix.

Fu-Sin Ling; Pierre Ramond

2002-01-01

388

Cosmology and neutrino masses - An update  

NASA Astrophysics Data System (ADS)

Present cosmological observations yield an upper bound on the neutrino mass which is significantly stronger than laboratory bounds. However, the exact value of the cosmological bound is model dependent and therefore less robust. Here, I review the current status of cosmological neutrino mass bounds and also discuss implications for sterile neutrinos and LSND in particular.

Hannestad, Steen

389

Quantum Gravity on Neutrino Mass Square Difference  

Microsoft Academic Search

We consider the non-renormalizable interaction term as a perturbation of the neutrino mass matrix. We assume that the neutrino masses and mixing arise through physics at a scale intermediate between Planck scale and the electroweak breaking scale. We also assume that, just above the electroweak breaking scale, neutrino masses are nearly degenerate and their mixing is bi-maximal. Quantum gravity (Planck

Bipin Singh Koranga

2010-01-01

390

Neutrino phenomenology of very low-energy seesaw scenarios  

NASA Astrophysics Data System (ADS)

The standard model augmented by the presence of gauge-singlet right-handed neutrinos proves to be an ideal scenario for accommodating nonzero neutrino masses. Among the new parameters of this “new standard model” are right-handed neutrino Majorana masses M. Theoretical prejudice points to M much larger than the electroweak symmetry breaking scale, but it has recently been emphasized that all M values are technically natural and should be explored. Indeed, M around 1 10eV can accommodate an elegant oscillation solution to the liquid scintillator neutrino detector (LSND) anomaly, while other M values lead to several observable consequences. We consider the phenomenology of low-energy (M?1keV) seesaw scenarios. By exploring such a framework with three right-handed neutrinos, we can consistently fit all oscillation data—including those from LSND—while partially addressing several astrophysical puzzles, including anomalous pulsar kicks, heavy element nucleosynthesis in supernovae, and the existence of warm dark matter. In order to accomplish all of this, we find that a nonstandard cosmological scenario is required. Finally, low-energy seesaws—regardless of their relation to the LSND anomaly—can also be tested by future tritium beta-decay experiments, neutrinoless double-beta decay searches, and other observables. We estimate the sensitivity of such probes to M.

de Gouvêa, André; Jenkins, James; Vasudevan, Nirmala

2007-01-01

391

Neutrinos in the simplest little Higgs scenario and TeV leptogenesis  

SciTech Connect

The little Higgs scenario may provide an interesting framework to accommodate TeV scale leptogenesis, because a TeV Majorana mass of the right-handed neutrino that we employ for the latter may find a natural place near the ultraviolet cutoff of the former. In this work we study how a light neutrino spectrum, generated radiatively, and TeV scale leptogenesis can be embedded in the simplest little Higgs framework. Alternatively, we highlight how the neutrino Yukawa textures of the latter are constrained.

Abada, Asmaa [LPT, Universite de Paris-Sud XI, Batiment 210, 91405 Orsay Cedex (France); Bhattacharyya, Gautam [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700064 (India); Losada, Marta [Centro de Investigaciones, Universidad Antonio Narino, Cll. 58A No. 37-94, Santa Fe de Bogota (Colombia)

2006-02-01

392

Flipped heavy neutrinos. From the solar neutrino problem to baryogenesis  

NASA Astrophysics Data System (ADS)

We discuss baryogenesis using the flipped SU(5) model for lepton mass matrices. We show that the generalized see-saw mechanism in this model cannot only provide MSW neutrino mixing suitable for solving the solar neutrino problem, and supply a hot dark matter candidate (v?) with mass O(10)eV as indicated by recent COBE results, but can also naturally account for the baryon asymmetry of the universe. Heavy singlet neutrino decay generates a net lepton asymmetry which is subsequently reprocessed by non-perturbative electroweak interactions. We evaluate the baryon asymmetry so produced in light of the constraints that the COBE observations put on inflationary cosmologies, finding it comfortably consistent with observation.

Ellis, John; Nanopoulos, D. V.; Olive, Keith A.

1993-02-01

393

Muon neutrino disappearance at MINOS  

SciTech Connect

A strong case has been made by several experiments that neutrinos oscillate, although important questions remain as to the mechanisms and precise values of the parameters. In the standard picture, two parameters describe the nature of how the neutrinos oscillate: the mass-squared difference between states and the mixing angle. The purpose of this thesis is to use data from the MINOS experiment to precisely measure the parameters associated with oscillations first observed in studies of atmospheric neutrinos. MINOS utilizes two similar detectors to observe the oscillatory nature of neutrinos. The Near Detector, located 1 km from the source, observes the unoscillated energy spectrum while the Far Detector, located 735 km away, is positioned to see the oscillation signal. Using the data in the Near Detector, a prediction of the expected neutrino spectrum at the Far Detector assuming no oscillations is made. By comparing this prediction with the MINOS data, the atmospheric mixing parameters are measured to be {Delta}m{sub 32}{sup 2} = 2.45{sub +0.12}{sup -0.12} x 10{sub -3} eV{sup 2} and sin{sup 2}(2{theta}{sub 32}) = 1.00{sub -0.04}{sup +0.00} (> 0.90 at 90% confidence level).

Armstrong, R.; /Indiana U.

2009-08-01

394

Solar neutrinos: Interpretation of results  

NASA Astrophysics Data System (ADS)

Recent SNO results give strong evidence that the solar neutrinos undergo flavor conversion. The main issue now is the identification of the mechanism of conversion. The LMA MSW solution with ?m2 = (5-7)·10 -5 eV 2, tan 2? = 0.35-0.45 looks rather plausible: it fits well the experimental data and our new theoretical prejudices. In the LMA case, KamLAND should see (0.5 - 0.7) reduced signal. VAC-QVO and LOW are accepted at about 3?-level. The SMA solution is practically excluded. No sub-leading effects produced by Ue3 and admixture of sterile neutrino have been found. The fit becomes worse with an increase of Ue3 (for LMA) and a ?s admixture. Still a (30 - 50)% presence of the sterile neutrino is allowed. Solutions based on the neutrino spin-flip in the magnetic fields of the Sun as well as on non-standard neutrino interactions give a good fit of the data. If KamLAND confirms LMA MSW, the spin-flip and non-standard interactions can be considered (and will be searched for) as sub-leading effects.

Smirnov, A. Yu.

2003-04-01

395

Black holes at neutrino telescopes  

NASA Astrophysics Data System (ADS)

In scenarios with extra dimensions and TeV-scale quantum gravity, black holes are expected to be produced in the collision of light particles at center-of-mass energies above the fundamental Planck scale with small impact parameters. Black hole production and evaporation may thus be studied in detail at the Large Hadron Collider (LHC). But even before the LHC starts operating, neutrino telescopes such as AMANDA/IceCube, ANTARES, Baikal, and RICE have an opportunity to search for black hole signatures. Black hole production in the scattering of ultrahigh energy cosmic neutrinos on nucleons in the ice or water may initiate cascades and through-going muons with distinct characteristics above the Standard Model rate. In this Letter, we investigate the sensitivity of neutrino telescopes to black hole production and compare it to the one expected at the Pierre Auger Observatory, an air shower array currently under construction, and at the LHC. We find that, already with the currently available data, AMANDA and RICE should be able to place sensible constraints in black hole production parameter space, which are competitive with the present ones from the air shower facilities Fly's Eye and AGASA. In the optimistic case that a ultrahigh energy cosmic neutrino flux significantly higher than the one expected from cosmic ray interactions with the cosmic microwave background radiation is realized in nature, one even has discovery potential for black holes at neutrino telescopes beyond the reach of LHC.

Kowalski, M.; Ringwald, A.; Tu, H.

2002-03-01

396

Tracing very high energy neutrinos from cosmological distances in ice  

NASA Astrophysics Data System (ADS)

Astrophysical sources of ultrahigh energy neutrinos yield tau neutrino fluxes due to neutrino oscillations. We study in detail the contribution of tau neutrinos with energies above 106 GeV relative to the contribution of the other flavors. We consider several different initial neutrino fluxes and include tau neutrino regeneration in transit through the Earth and the energy loss of charged leptons. We discuss the signals of tau neutrinos in detectors such as IceCube, RICE, and ANITA.

Jones, J.; Mocioiu, I.; Reno, M. H.; Sarcevic, I.

2004-02-01

397

Neutrino mass and dark matter from gauged U(1)B-L breaking  

NASA Astrophysics Data System (ADS)

We propose a new model where the Dirac mass term for neutrinos, the Majorana mass term for right-handed neutrinos, and the other new fermion masses arise via the spontaneous breakdown of the U(1)B-L gauge symmetry. The anomaly-free condition gives four sets of assignment of the B-L charge to new particles, and three of these sets have an associated global U(1)DM symmetry which stabilizes dark matter candidates. The dark matter candidates contribute to generating the Dirac mass term for neutrinos at the one-loop level. Consequently, tiny neutrino masses are generated at the two-loop level via a type-I-seesaw-like mechanism. We show that this model can satisfy current bounds from neutrino oscillation data, the lepton flavor violation, the relic abundance of the dark matter, and the direct search for the dark matter. This model would be tested at future collider experiments and dark matter experiments.

Kanemura, Shinya; Matsui, Toshinori; Sugiyama, Hiroaki

2014-07-01

398

The Low Energy Neutrino Factory  

SciTech Connect

We show that a low energy neutrino factory with a baseline of 1300 km and muon energy of 4.5 GeV has an excellent physics reach. The results of our optimisation studies demonstrate that such a setup can have remarkable sensitivity to theta{sub 13} and delta for sin{sup 2}(2theta{sub 13})>10{sup -4}, and to the mass hierarchy for sin{sup 2}(2theta{sub 13})>10{sup -3}. We also illustrate the power of the unique combination of golden and platinum channels accessible to the low energy neutrino factory. We have considered both a 20 kton totally active scintillating detector and a 100 kton liquid argon detector as possible detector technologies, finding that a liquid argon detector with very good background rejection can produce sensitivity to theta{sub 13} and delta with that of the International Design Study neutrino factory.

Bross, Alan; Geer, Steve [Fermi National Accelerator Laboratory, Batavia (United States); Ellis, Malcolm [Brunel University, London (United Kingdom); Fernandez Martinez, Enrique [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Li, Tracey; Pascoli, Silvia [Institute for Particle Physics Phenomenology, Durham University (United Kingdom); Mena, Olga [Instituto de Fisica Corpuscular, IFIC CSIC and Universidad de Valencia (Spain)

2010-03-30

399

Status of neutrino mass experiments  

SciTech Connect

In 1980 two experiments ignited a fertile field of research the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily I will discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. However, let me begin in Section I to discuss astronomical and terrestrial observations which motivated these experiments. In Section II, I will quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other papers. I will continue by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations will be reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks. 24 refs., 24 figs.

Fackler, O.

1985-12-01

400

Decaying neutrinos in galaxy clusters  

NASA Technical Reports Server (NTRS)

The DM profile in clusters of galaxies was studied and simulated using the Harrison-Zel'dovich spectrum of density fluctuations, and an amplitude previously derived from numerical simulations and in agreement with microwave background fluctuations. Neutrino DM densities, with this amplitude normalization cluster, are comparable to observed cluster DM values. It was concluded that given this normalization, the cluster DM should be al least largely composed of neutrinos. The constraint of Davidson et al., who argued that the failure to detect uv photons from the dark matter (DM) in cluster A665 excludes the decaying neutrino hypothesis, could be somewhat weakened by the presence of baryonic DM; but it cannot be eliminated given our assumptions.

Melott, Adrian L.; Splinter, Randall J.; Persic, Massimo; Salucci, Paolo

1993-01-01

401

Stimulated neutrino transformation through turbulence  

NASA Astrophysics Data System (ADS)

We derive an analytical solution for the flavor evolution of a neutrino through a turbulent density profile which is found to accurately predict the amplitude and transition wavelength of numerical solutions on a case-by-case basis. The evolution is seen to strongly depend upon those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues. Transitions are strongly enhanced by those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues. We also find a suppression of transitions due to the long wavelength modes when the ratio of their amplitude and the wave number is of order, or greater than, the first root of the Bessel function J0.

Patton, Kelly M.; Kneller, James P.; McLaughlin, Gail C.

2014-04-01

402

Recent developments in neutrino physics  

SciTech Connect

I shall attempt to summarize recent developments in the experimental situation in neutrino physics. The paper will deal with recent results, drawing on either published work or research that has been presented in preprint form, as there is an adequate supply of interesting and controversial data restricting oneself to these generally more reliable sources. The discussion of the theoretical implication of these experimental results will be presented in the following paper by Boris Kayser. The topics to be covered in this presentation are: direct measurements of {bar {nu}}{sub e} mass via beta endpoint studies; status of solar neutrino observations; status of 17-keV neutrino'' reports; and the use of {nu}p elastic scattering to determine the strange quark'' content of the proton. 2 refs., 15 figs., 9 tabs.

Garvey, G.T.

1991-01-01

403

The antares neutrino detector instrumentation  

NASA Astrophysics Data System (ADS)

ANTARES is actually the fully operational and the largest neutrino telescope in the Northern hemisphere. Located in the Mediterranean Sea, it consists of a 3D array of 885 photomultiplier tubes (PMTs) arranged in 12 detection lines (25 storeys each), able to detect the Cherenkov light induced by upgoing relativistic muons produced in the interaction of high energy cosmic neutrinos with the detector surroundings. Among its physics goals, the search for neutrino astrophysical sources and the indirect detection of dark matter particles coming from the sun are of particular interest. To reach these goals, good accuracy in track reconstruction is mandatory, so several calibration systems for timing and positioning have been developed. In this contribution we will present the design of the detector, calibration systems, associated equipment and its performance on track reconstruction.

Yepes-Ramírez, H.

2012-01-01

404

Decaying neutrinos in galaxy clusters  

NASA Technical Reports Server (NTRS)

Davidsen et al. (1991) have argued that the failure to detect UV photons from the dark matter (DM) in cluster A665 excludes the decaying neutrino hypothesis. Sciama et al. (1993) argued that because of high central concentration the DM in that cluster must be baryonic. We study the DM profile in clusters of galaxies simulated using the Harrison-Zel'dovich spectrum of density fluctuations, and an amplitude previously derived from numerical simulations (Melott 1984b; Anninos et al. 1991) and in agreement with microwave background fluctuations (Smoot et al. 1992). We find that with this amplitude normalization cluster neutrino DM densities are comparable to observed cluster DM values. We conclude that given this normalization, the cluster DM should be at least largely composed of neutrinos. The constraint of Davidsen et al. can be somewhat weakened by the presence of baryonic DM; but it cannot be eliminated given our assumptions.

Melott, Adrian L.; Splinter, Randall J.; Persic, Massimo; Salucci, Paolo

1994-01-01

405

Neutrino oscillations in noisy media  

SciTech Connect

The authors develop the Redfield equation for delta-correlated gaussian noise and apply it to the case of two neutrino flavor or spin precession in the presence of a noisy matter density or magnetic field, respectively. The criteria under which physical fluctuations can be well approximated by the delta-correlated gaussian noise for the above cases are examined. Current limits on the possible neutrino magnetic moment and solar magnetic field suggest that a reasonably noisy solar magnetic field would not appreciably affect the solar electron neutrino flux. However, if the solar electron density has fluctuations of a few percent of the local density and a small enough correlation length, the MSW effect is suppressed for a range of parameters.

Loreti, F.N.; Balantekin, A.B.

1994-05-27

406

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

National Technical Information Service (NTIS)

In this talk, we discuss the possibility of determining the neutrino mass hierarchy by comparing the two effective atmospheric neutrino mass squared differences measured, respectively, in electron, and in muon neutrino disappearance oscillation experiment...

H. Minakata H. Nunokawa R. Z. Funchal S. Parke

2006-01-01

407

Measuring Neutrinos with the ANTARES Telescope  

SciTech Connect

The ANTARES underwater neutrino telescope has been taking data since construction began in 2006. The telescope, completed in May of 2008, detects the Cerenkov radiation of charged leptons produced by high energy neutrinos interacting in or around the detector. The lepton trajectory is reconstructed with high precision, revealing the direction of the incoming neutrino. The performance of the detector will be discussed and recent data showing muons, electromagnetic showers and atmospheric neutrinos will be presented. Studies have been underway to search for neutrino point sources in the ANTARES data since 2007. Results from these studies will be presented, and the sensitivity of the telescope will be discussed.

Reed, Corey [National Institute for Subatomic Physics (Nikhef), Amsterdam (Netherlands)

2009-12-17

408

Neutrino mass from beta decay  

NASA Astrophysics Data System (ADS)

The investigation of the endpoint spectrum of the tritium ? decay is still the most sensitive direct method to determine the neutrino mass scale. The KATRIN experiment currently being set up at the Forschungszentrum Karlsruhe will improve the neutrino mass sensitivity compared to the previous Mainz and Troitsk experiments by one order of magnitude down to 0.2 eV/c 2. The first generation of cryobolometric experiments at Genova and Milan using the isotope 187Re will be followed up by the MARE experiment which aims to eventually reach a similar sensitivity.

Weinheimer, Ch.

2007-06-01

409

Hierarchical neutrinos and supersymmetric inflation  

NASA Astrophysics Data System (ADS)

A moderate extension of MSSM based on a left-right symmetric gauge group, within which hybrid inflation is `naturally' realized, is discussed. The ? problem is solved via a Peccei-Quinn symmetry. Light neutrinos acquire hierarchical masses by the seesaw mechanism. They are taken from the small angle MSW resolution of the solar neutrino puzzle and the SuperKamiokande data. The range of parameters consistent with maximal ??-?? mixing and the gravitino constraint is determined. The baryon asymmetry of the universe is generated through a primordial leptogenesis. The subrange of parameters, where the baryogenesis constraint is also met, is specified. The required values of parameters are more or less `natural'.

Lazarides, G.; Vlachos, N. D.

1999-07-01

410

Neutrino radiation hazards: A paper tiger  

SciTech Connect

Neutrinos are present in the natural environment due to terrestrial, solar, and cosmic sources and are also produced at accelerators both incidentally and intentionally as part of physics research programs. Progress in fundamental physics research has led to the creation of beams of neutrinos of ever-increasing intensity and/or energy. The large size and cost associated with these beams attracts, and indeed requires, public interest, support, and some understanding of the `exotic` particles produced, including the neutrinos. Furthermore, the very word neutrino (`little neutral one`, as coined by Enrico Fermi) can lead to public concern due to confusion with `neutron`, a word widely associated with radiological hazards. Adding to such possible concerns is a recent assertion, widely publicized, that neutrinos from astronomical events may have led to the extinction of some biological species. Presented here are methods for conservatively estimating the dose equivalent due to neutrinos as well as an assessment of the possible role of neutrinos in biological extinction processes. It is found that neutrinos produced by the sun and modern particle accelerators produce inconsequential dose equivalent rates. Examining recent calculations concerning neutrinos incident upon the earth due to stellar collapse, it is concluded that it is highly unlikely that these neutrinos caused the mass extinctions of species found in the paleontological record. Neutrino radiation hazards are, then, truly a `paper tiger`. 14 refs., 1 fig., 1 tab.

Cossairt, J.D.; Grossman, N.L.; Marshall, E.T.

1996-09-01

411

Mass freezing in growing neutrino quintessence  

SciTech Connect

Growing neutrino quintessence solves the coincidence problem for dark energy by a growing cosmological value of the neutrino mass which emerges from a cosmon-neutrino interaction stronger than gravity. The cosmon-mediated attraction between neutrinos induces the formation of large-scale neutrino lumps in a recent cosmological epoch. We argue that the nonlinearities in the cosmon field equations stop the further increase of the neutrino mass within sufficiently dense and large lumps. As a result, we find the neutrino-induced gravitational potential to be substantially reduced when compared to linear extrapolations. We furthermore demonstrate that inside a lump the possible time variation of fundamental constants is much smaller than their cosmological evolution. This feature may reconcile current geophysical bounds with claimed cosmological variations of the fine structure constant.

Nunes, Nelson J.; Schrempp, Lily; Wetterich, Christof [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)

2011-04-15

412

A cosmological bound on radiative neutrino lifetime  

NASA Astrophysics Data System (ADS)

Neutrino oscillation experiments and direct bounds on absolute masses constrain neutrino mass differences to fall into the microwave energy range, for most of the allowed parameter space. As a consequence of these recent phenomenological advances, older constraints on radiative neutrino decays based on diffuse background radiations and assuming strongly hierarchical masses in the eV range are now outdated. We thus derive new bounds on the radiative neutrino lifetime using the high precision cosmic microwave background spectral data collected by the FIRAS instrument on board of COBE. The lower bound on neutrino lifetime is between a few ×1019 s and ~ 5 × 1020 s, depending on the neutrino mass ordering and on the absolute neutrino mass scale. However, due to phase space limitations, the upper bound on the effective magnetic moment mediating the decay is not better than ~10-8 ?B. We also comment about possible improvements of these limits, by means of recent diffuse infrared photon background data.

Mirizzi, A.; Montanino, D.; Serpico, P. D.

2008-07-01

413

Analysis of the solar neutrino data  

NASA Astrophysics Data System (ADS)

We analyse the solar neutrino data (pre-SNO) in the framework of two-neutrino, three-neutrino and four-neutrino schemes. We discuss the status of the different regimes that remain allowed (LMA, SMA and LOW-QVO). The solar and the atmospheric data are in good agreement with the CHOOZ data showing a preference for small ?13, where the stronger bound comes from the CHOOZ data. Also, we discuss the oscillations to active and sterile neutrinos in a unified picture: four-neutrino oscillations. Using the predictions for the next solar neutrino experiment, SNO, we discuss the questions that could be solved in the different frameworks. The data will be able to disfavour some of the solar regimes and also will be able to prove (or disprove) the 2+2 scenarios.

Peña-Garay, C.

2003-05-01

414

PREFACE: Neutrino physics at spallation neutron sources  

NASA Astrophysics Data System (ADS)

Unique because of their super-light masses and tiny interaction cross sections, neutrinos combine fundamental physics on the scale of the miniscule with macroscopic physics on the scale of the cosmos. Starting from the ignition of the primal p-p chain of stellar and solar fusion reactions that signal star-birth, these elementary leptons (neutrinos) are also critical players in the life-cycles and explosive deaths of massive stars and the production and disbursement of heavy elements. Stepping beyond their importance in solar, stellar and supernova astrophysics, neutrino interactions and properties influence the evolution, dynamics and symmetries of the cosmos as a whole. Further, they serve as valuable probes of its material content at various levels of structure from atoms and nuclei to valence and sea quarks. In the light of the multitude of physics phenomena that neutrinos influence, it is imperative to enhance our understanding of neutrino interactions and properties to the maximum. This is accentuated by the recent evidence of finite neutrino mass and flavour mixing between generations that reverberates on the plethora of physics that neutrinos influence. Laboratory experiments using intense neutrino fluxes would allow precision measurements and determination of important neutrino reaction rates. These can then complement atmospheric, solar and reactor experiments that have enriched so valuably our understanding of the neutrino and its repertoire of physics applications. In particular, intermediate energy neutrino experiments can provide critical information on stellar and solar astrophysical processes, along with advancing our knowledge of nuclear structure, sub-nuclear physics and fundamental symmetries. So where should we look for such intense neutrino sources? Spallation neutron facilities by their design are sources of intense neutrino pulses that are produced as a by-product of neutron spallation. These neutrino sources could serve as unique laboratories to enrich our knowledge of neutrino physics and the multifaceted science it interfaces. In fact, the neutrino energy spectra expected at spallation neutron facilities overlap remarkably with those emanating from distant supernovae and these sources seem `made to order' for terrestrial studies of supernova reactions. They are also in a suitable energy regime to pursue neutrino-mediated studies of nuclear structure, fundamental symmetries and solar reactions. Recent research indicates neutrino-nuclear reactions may be even more influential in supernova dynamics and detection than hitherto believed. The need for in-depth understanding of the individual neutrino-nuclear reactions that collectively have dramatic effects on the large-scale dynamics of evolving stars points to laboratory measurements of neutrino reactions on various nuclei as a premier requirement of neutrino-nuclear astrophysics. Such experimental data can improve our input to the extensive modelling projects that investigate the evolutionary stages of exploding supernovae and further our understanding of their internal physics. State-of-the-art simulations exploring the neutrino-reheating phases fail to produce explosions---yet clearly nature explodes her supernovae. Matters pertaining to the galactic abundance of very p-rich nuclei and the various isotope ratios are by no means well defined and demand further research, as do the intricacies of the nucleo-synthesis channels. Neutrino-nuclear experiments are also essential for proper development and calibration of appropriate supernova detectors. Solar neutrino research and detection have contributed vastly to our current understanding of neutrino science and have helped to validate the standard solar model. The chapter is by no means closed and experiments with intense neutrino fluxes could enrich valuably our understanding of both neutrino and solar physics. Neutrino nuclear reactions are not only important for their role in nuclear astrophysics, but also for the insight they provide on nuclear structure and the theoretical models used to calculat

Avignone, F. T.; Chatterjee, L.; Efremenko, Y. V.; Strayer, M.

2003-11-01

415

Neutrino Charm Production and a Limit to Neutrino Oscillations  

Microsoft Academic Search

The production of charmed particles and a limit to tau lepton production have been measured using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative cross section for charged current charmed particle production is. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). and the energy dependence of the cross section and the kinematic distributions of the charm events

David Charles Bailey

1983-01-01

416

Charmed hadron production by neutrinos  

Microsoft Academic Search

Charmed hadron production has been studied using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative rates of D0, D+, F+, and Lambda+c production have been measured - the fraction of D mesons is 69 +\\/- 810%. Momentum, transverse momentum, Feynman X, and fragmentation (Z) distributions are presented. The mean Z for charmed hadrons is 0.59 +\\/-

N. Ushida; T. Kondo; F. Fujioka; H. Fukushima; Y. Takahashi; S. Tatsumi; C. Yokohama; Y. Homma; Y. Tsuzuki; S. Bahk; C. Kim; J. Song; D. Bailey; S. Conetti; J. Fischer; J. Trischuk; H. Fuchi; K. Hoshino; M. Miyanashi; K. Niu; K. Niwa; H. Shibuya; Y. Yanagisawa; S. Errede; M. Gutzwiller; S. Kuramata; N. W. Reay; K. Reibel; T. A. Romanowski; R. Sidwell; N. R. Stanton; K. Moriyama; H. Shibata; T. Hara; O. Kusumoto; Y. Noguchi; M. Teranaka; H. Okabe; J. Yokota; J. Harnois; C. Hébert; J. Hébert; S. Lokanathan; B. McLeod; S. Tasaka; P. Davis; J. Martin; D. Pitman; J. D. Prentice; P. Sinervo; T. S. Yoon; H. Kimura; Y. Maeda

1983-01-01

417

The Case for Neutrino Oscillations  

Microsoft Academic Search

No abstract appeared in the Proceedings, but I am adding the following summary at the request of the X^3 people: The idea of neutrino masses is discussed in the context of grand unified theories., and various scenarios are presented, including the seesaw mechanism. At the end, preference is stated for maximal mixing between $\\\

P. Ramond

2000-01-01

418

A new solar neutrino detector  

Microsoft Academic Search

This paper describes the main features of the proposed low energy solar neutrino detector Borexino, planned to be installed at the Gran Sasso Laboratory. This real time detector is based on a massive, calorimetric, liquid scintillation spectroscopy technique, whose high luminosity is the base for the attempt to achieve a low signal detection threshold. After a description of the main

G. Alimonti; B. Alpat; C. Arpesella; G. Bellini; P. Benetti; S. Bonetti; F. P. Calaprice; M. Campanella; G. Cecchet; A. de Bari; M. Deutsch; A. Donati; F. Elisei; F. von Feilitzsch; D. Franciotti; M. G. Giammarchi; D. Giugni; A. Golubchikov; G. Husser; T. Kovacs; I. Manno; G. Mantovani; G. Manuzio; F. Masetti; U. Mazzucato; E. Meroni; J. Mitchell; L. Oberauer; S. Pakvasa; A. Perotti; A. Preda; P. Raghavan; R. S. Raghavan; F. Ragusa; G. Ranucci; R. Scardaoni; S. Schonert; O. Smirnov; R. Tartaglia; G. Testera; P. Ullucci; S. Vitale; O. Zaimidoroga

1993-01-01

419

Medium-energy neutrino physics  

SciTech Connect

A selection of opportunities for neutrino physics from a source generated from pions that decay in flight and at rest is described. The present source at LAMPF has a duty factor of about 6%; improvements in opportunities that emerge from a source using a pulse 0.25 {mu}sec long from a proton storage ring are also described. 7 refs., 9 figs.

White, D.H.

1991-11-22

420

Neutrino Event Generators: A Review  

SciTech Connect

Event generators play an important role in the design, optimization, and execution of neutrino experiments. In this paper I will review the status of event generators used in this field, focusing on advances since the start of the NuINT conference series in 2001.

Gallagher, Hugh R. [Tufts University, Medford, Massachusetts (United States)

2009-11-25

421

AMANDA South Pole neutrino detector.  

NASA Astrophysics Data System (ADS)

It is proposed to instrument the polar ice cap as a low-noise particle detector sensing the Cherenkov light from neutrino-induced muons. This paper describes the successful operation of a prototype string of optical modules that where deployed on January 17, 1992 at the South Pole.

Barwick, S. W.; Lynch, J.; Porrata, R.; Yodh, G.; Lowder, D.; Miller, T.; Price, B.; Richards, A.; Snowden-Ifft, D.; Westphal, A.; Halzen, F.; Jacobsen, J.; Kandhadai, V.; Liubarsky, I.; Morse, R.; Tilav, S.

422

New ideas in neutrino detection  

NASA Astrophysics Data System (ADS)

What is new in the field of neutrino detection? In addition to new projects probing both the low and high ends of the neutrino energy scale, an inexpensive, effective technique is being developed to allow tagging of antineutrinos in water Cherenkov (WC) detectors via the addition to water of a solute with a large neutron cross-section and energetic ? daughters. Gadolinium is an excellent candidate since in recent years it has become very inexpensive, now less than 8 per kilogram in the form of commercially available gadolinium trichloride. This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields an 8.0~MeV gamma cascade easily seen in detectors like Super-Kamiokande. The uses of GdCl_3 as a possible upgrade for the Super-Kamiokande detector -- with a view toward improving its performance as an antineutrino detector for supernova neutrinos and reactor neutrinos -- are discussed, as are the ongoing R&D efforts which aim to make this dream a reality within the next two years.

Vagins, M. R.

2006-10-01

423

Neutrino radiography of the Earth with the IceCube Neutrino Observatory  

NASA Astrophysics Data System (ADS)

Probing interior structures of the Earth with neutrinos has been discussed for more than 30 years. Unlike muons, neutrinos are chargeless particles and have very small cross-sections. They normally penetrate the Earth without any interaction, and from the rare interactions that do occur we obtain information on the density profile of the Earth's interior. Since this method is independent of any geophysical models, it has been expected to complement indirect physical methods such as seismic wave propagation analysis. However, the elusive characteristic of neutrinos poses a challenge for detecting them at experimental sites. To compensate for the small interaction cross-section, one needs a large volume neutrino detector. In the spring of 2011, IceCube, the world's largest neutrino observatory, was completed within deep glacial ice at the South Pole. IceCube is designed to detect Cherenkov light emitted by secondary charged particles generated from high-energy neutrinos. The primary mission of IceCube is to discover the origin of cosmic neutrinos. Toward that end, detailed studies of the atmospheric neutrino background have been performed in the last six years. Using these atmospheric neutrino events, we started a practical application of "neutrino radiography" which used to be known as "neutrino absorption tomography." In this talk we present a review of neutrino radiography including history from past decades and recent progress with the IceCube Neutrino Observatory.lt;img border=0 src="images/P23D-03_B.jpg">

Hoshina, K.; Tanaka, H.

2012-12-01

424

Recent progress in neutrino - astrophysics connections  

NASA Astrophysics Data System (ADS)

Of all the constituents within the standard model of particle physics our understanding of the neutrino has benefited the most from the interaction of astrophysics and `terraphysics.' Much has been learned about the properties of the neutrino from each: experiments here on Earth temper our appreciation of the role that neutrinos play in the cosmos while astrophysics can provide the densities and temperatures in which the neutrinos do more than simply flee. But the reluctance of neutrinos to interact means that it is not until we venture into the most extreme environments of astrophysics that we observe neutrinos `pushing back' as hard as they are being `pushed'. We review two sites where this occurs: the early Universe and the accretion disk `engines' of gamma ray bursts. Neutrinos play an important role in the evolution of the early Universe with a particular focus upon the electron neutrino in determining the primordial elemental composition via its participation in the most important reaction at that time. Within gamma ray burst accretion disks we again see the electron neutrinos at work in the nuclear reactions and through their function as the `coolant' for the disk. Removal of the disk energy, and its deposition into the remnants of the massive star surrounding the disk, may lead to the formation of highly relativistic jets that will later be observed as the burst. We show what has been learned so far about the neutrino and its properties from the study of such environments.

Kneller, James

2005-04-01

425

Status of global fits to neutrino oscillations  

NASA Astrophysics Data System (ADS)

We review the present status of global analyses of neutrino oscillations, taking into account the most recent neutrino data including the latest KamLAND and K2K updates presented at Neutrino 2004, as well as state-of-the-art solar and atmospheric neutrino flux calculations. We give the two-neutrino solar + KamLAND results, and the two-neutrino atmospheric + K2K oscillation regions, discussing in each case the robustness of the oscillation interpretation against departures from the Standard Solar Model and the possible existence of non-standard neutrino physics. Furthermore, we give the best-fit values and allowed ranges of the three-flavour oscillation parameters from the current worlds' global neutrino data sample and discuss in detail the status of the small parameters agr equiv DgrmSOL2/DgrmATM2 as well as sin2 thgr13, which characterize the strength of CP violating effects in neutrino oscillations. We also update the degree of rejection of four-neutrino interpretations of the LSND evidence in view of the most recent developments.

Maltoni, Michele; Schwetz, Thomas; Tórtola, Mariam; Valle, José W. F.

2004-09-01

426

Soft breaking of L{sub {mu}}-L{sub {tau}} symmetry: Light neutrino spectrum and leptogenesis  

SciTech Connect

Continuous U(1){sub {mu}}-L{sub {tau}} symmetry can generate quasidegenerate mass spectrum for both left handed light and right handed heavy Majorana neutrinos assuming that the symmetry preserving nonzero parameters are nearly same. There is an accidental {mu}{tau} exchange symmetry in the light and heavy neutrino Majorana mass terms. This implies {theta}{sub 13}=0 and {theta}{sub 23}=({pi}/4). In addition it generates another zero mixing angle and one zero mass difference. We restrict ourselves to type-I See-Saw mechanism for generation of light neutrino mass. We have found that under U(1){sub L{sub {mu}}-L{sub {tau}}} symmetry cosmological lepton asymmetry vanishes. We break U(1){sub L{sub {mu}}-L{sub {tau}}} such a way that the {mu}{tau} exchange symmetry preserves in the neutrino sector. We have seen that light neutrino phenomenology can be explained under soft breaking of this symmetry. We have observed that softness of this symmetry breaking depends on the degeneracy of the light neutrino mass spectrum. Quasidegeneracy of right handed neutrino mass spectrum opens an option for resonant leptogenesis. The degeneracy of the right handed neutrino mass spectrum is restricted through light neutrino data. We observed that for generation of right sized baryon asymmetry common neutrino mass scale m{sub 0} have to be of the order of {radical}({delta}m{sub atm}{sup 2}) and corresponding right handed neutrino mass scale have to be nearly 10{sup 13} GeV. We also have discussed the effect of RG evolution on light neutrino spectrum and also on baryon asymmetry.

Adhikary, Biswajit [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700064 (India)

2006-08-01

427

Effect of the neutrino magnetic moment on the properties of the muon  

NASA Astrophysics Data System (ADS)

The effect of the neutrino dipole magnetic moment on the properties of the muon is investigated within the standard model of electroweak interactions and a model based on the SU(2) L × SU(2) R × U(1) B-L gauge group (left-right model). In the case of the Dirac neutrino, muon decay through the channel µ- ? e -? is studied with allowance for the neutrino dipole magnetic moment. It is shown that, both in the standard model supplemented with an SU(2) L right-handed neutrino singlet and in the standard model featuring two doublets of Higgs fields, radiative muon decay is unobservable. In the left-right model, the contributions of diagrams associated with the neutrino dipole magnetic moment become significant only in the case of a mutual compensation of the contributions of diagrams involving the electromagnetic vertices of charged gauge bosons and singly charged Higgs bosons. At specific values of the parameters of the left-right model, one can then obtain an experimental upper limit on the branching fraction of this reaction. The contributions of the neutrino dipole magnetic moment to the muon anomalous magnetic moment are found for the Dirac and the Majorana neutrino. It is established that, both in the standard model and in the left-right model, values of the neutrino anomalous magnetic moment that are required for explaining the ( g - 2)µ anomaly are in excess of the theoretical predictions for this moment.

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

2009-04-01

428

Towards the resolution of the solar neutrino problem.  

National Technical Information Service (NTIS)

A number of experiments have accumulated over the years a large amount of solar neutrino data. The data indicate that the observed solar neutrino flux is significantly smaller than expected and, furthermore, that the electron neutrino survival probability...

A. Friedland

2000-01-01

429

Massive neutrinos in the standard model and beyond  

NASA Astrophysics Data System (ADS)

The generation of the fermion mass hierarchy in the standard model of particle physics is a long-standing puzzle. The recent discoveries from neutrino physics suggests that the mixing in the lepton sector is large compared to the quark mixings. To understand this asymmetry between the quark and lepton mixings is an important aim for particle physics. In this regard, two promising approaches from the theoretical side are grand unified theories and family symmetries. In the first part of my thesis we try to understand certain general features of grand unified theories with Abelian family symmetries by taking the simplest SU(5) grand unified theory as a prototype. We construct an SU(5) toy model with U(1) F ?Z'2 ?Z'' 2?Z''' 2 family symmetry that, in a natural way, duplicates the observed mass hierarchy and mixing matrices to lowest approximation. The system for generating the mass hierarchy is through a Froggatt-Nielsen type mechanism. One idea that we use in the model is that the quark and charged lepton sectors are hierarchical with small mixing angles while the light neutrino sector is democratic with larger mixing angles. We also discuss some of the difficulties in incorporating finer details into the model without making further assumptions or adding a large scalar sector. In the second part of my thesis, the interaction of high energy neutrinos with weak gravitational fields is explored. The form of the graviton-neutrino vertex is motivated from Lorentz and gauge invariance and the non-relativistic interpretations of the neutrino gravitational form factors are obtained. We comment on the renormalization conditions, the preservation of the weak equivalence principle and the definition of the neutrino mass radius. We associate the neutrino gravitational form factors with specific angular momentum states. Based on Feynman diagrams, spin-statistics, CP invariance and symmetries of the angular momentum states in the neutrino-graviton vertex, we deduce differences between the Majorana and Dirac cases. It is then proved that in spite of the theoretical differences between the two cases, as far as experiments are considered, they would be virtually indistinguishable for any space-time geometry satisfying the weak field condition. We then calculate the transition gravitational form factors for the neutrino by evaluating the relevant Feynman diagrams at 1-loop and estimate a neutrino transition mass radius. The form factor is seen to depend on the momentum transfer very weakly. It is also seen that the neutrino transition mass radius is smaller than the typical neutrino charge radius by a couple of orders of magnitude. In the final part of my thesis, some of the recent neutrino observations and anomalies are revisited, in the context of sterile neutrinos. Among our aims is to understand more clearly some of the analytic implications of the current global neutrino fits from short baseline experiments. Of particular interest to us are the neutrino disappearance measurements from MINOS and the recent indications of a possibly non-vanishing angle, theta13 , from T2K, MINOS and Double-CHOOZ. Based on a general parametrization motivated in the presence of sterile neutrinos, the consistency of the MINOS disappearance data with additional sterile neutrinos is discussed. We also explore the implications of sterile neutrinos for the measurement of | Umu3| in this case. We then turn our attention to the study of |Ue3| extraction in electron neutrino disappearance and appearance measurements. In particular, we study the effects of some of the additional CP phases that appear when there are sterile neutrinos. We observe that the existence of sterile neutrinos may induce a significant modification of the theta13 angle in neutrino appearance experiments like T2K and MINOS, over and above the ambiguities and degeneracies that are already present in 3-neutrino parameter extractions. There are reactor experiments, for instance those measuring nu e disappearance like Double-CHOOZ, Daya Bay and RENO, where this modification is less signific

Thalapillil, Arun Madhav

430

Measurement of Neutrino Oscillation Parameters from Muon Neutrino Disappearance with an Off-Axis Beam  

NASA Astrophysics Data System (ADS)

The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×1020 protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin?2(?23)=0.514±0.082 and mass splitting |?m322|=2.44-0.15+0.17×10-3eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.

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

2013-11-01

431

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

SciTech Connect

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

Kersten, Joern [Abdus Salam ICTP, Strada Costiera 11, 34014 Trieste (Italy); Smirnov, Alexei Yu. [Abdus Salam ICTP, Strada Costiera 11, 34014 Trieste (Italy); Institute for Nuclear Research, Russian Academy of Sciences, 60th October Anniversary Prospect 7A, 117 312 Moscow (Russian Federation)

2007-10-01

432

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

PubMed

The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×10(20) protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(?23)=0.514±0.082 and mass splitting |?m(32)(2)|=2.44(-0.15)(+0.17)×10(-3) eV2/c4. Our result corresponds to the maximal oscillation disappearance probability. PMID:24313479

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

2013-11-22

433

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

SciTech Connect

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

Bell, Nicole F.; /Fermilab

2004-01-01

434

The modified correlation mass method for detecting neutrino mass from astrophysical neutrino bursts  

NASA Technical Reports Server (NTRS)

A modified correlation mass method for calculating the value of a possible neutrino mass from neutrino bursts of astrophysical origin is proposed which can more sensitively detect small neutrino masses than previous methods. Application of the method to the neutrinos detected from SN 1987 A yields a value of 3.6 + or - 0.3 eV for the neutrino mass energy with a confidence level of 97 percent. Assuming a neutrino mass of 3.6 eV, and transforming all of the detected neutrino events back to the point of emission, it is shown that bursts are composed of a short initial pulse (which lasts for about 0.1 sec and contains 30-40 percent of the total neutrinos) and an extended emission lasting for about 10 sec.

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

1989-01-01

435

Flavor composition of ultrahigh energy neutrinos at source and at neutrino telescopes  

SciTech Connect

We parametrize the initial flux composition of high energy astrophysical neutrinos as ({phi}{sub e}{sup 0} ratio {phi}{sub {mu}}{sup 0} ratio {phi}{sub {tau}}{sup 0})=(1 ratio n ratio 0), where n characterizes the source. All usually assumed neutrino sources appear as limits of this simple parametrization. We investigate how precise neutrino telescopes can pin down the value of n. We furthermore show that there is a neutrino mixing scenario in which the ratio of muon neutrinos to the other neutrinos takes a constant value regardless of the initial flux composition. This occurs when the muon neutrino survival probability takes its minimal allowed value. The phenomenological consequences of this very predictive neutrino mixing scenario are given.

Choubey, Sandhya [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, 211019 Allahabad (India); Rodejohann, Werner [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany)

2009-12-01

436

Constraints on Neutrino Oscillations Using 1258 Days of Super-Kamiokande Solar Neutrino Data  

Microsoft Academic Search

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

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

2001-01-01

437

Constraints on Neutrino Oscillations Using 1258 Days of Super-Kamiokande Solar Neutrino Data  

NASA Astrophysics Data System (ADS)

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

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

2001-06-01

438

Solar-neutrino problem: Some old solutions reexamined  

SciTech Connect

Recent experimental data confirm the solar-neutrino problem and imply new neutrino physics. We review some of the less discussed proposals to solve this problem: (1) maximal vacuum mixing of three neutrino flavors, (2) vacuum oscillation of two neutrino flavors, and (3) neutrino decay. Each of these three solutions can fit the {sup 37}Cl and Kamiokande-II solar-neutrino flux measurements. Their implications for the continuing {sup 71}Ga experiments and for other, future experiments are discussed.

Acker, A.; Pakvasa, S. (Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822 (USA)); Pantaleone, J. (Department of Physics, University of California, Riverside, California 92521 (USA))

1991-03-15

439

Neutrino mixing in a left-right model  

NASA Astrophysics Data System (ADS)

We study the mixing among different generations of massive neutrino fields in a Majorana and Dirac mass terms in the Yukawa sector. Parity can be spontaneously broken at a scale neutrino oscillations. The left and right sectors can be connected by a new neutral current. PACS: 12.60.-i, 14.60.St, 14.60.Pq

Martins Simões, J. A.; Ponciano, J. A.

440

CP violation in modified bipair neutrino mixing and leptogenesis  

NASA Astrophysics Data System (ADS)

We study effects of CP violation in a modified bipair neutrino mixing scheme predicting sin2?23 near both 0.4 and 0.6 currently consistent with experimentally allowed values. The source of CP violation is supplied by charged lepton mixing accompanied by a single phase, whose mixing size is assumed to be less than that of the Wolfenstein parameter for the quark mixing. Including results of leptogenesis, which is based on the minimal seesaw model, we obtain the allowed region of CP-violating Dirac and Majorana phases, which provides the observed baryon asymmetry of the universe in the case of the Dirac neutrino mass matrix subject to one zero texture.

Iizuka, Jun; Kaneko, Yoshikazu; Kitabayashi, Teruyuki; Koizumi, Naoto; Yasuè, Masaki

2014-05-01

441

Burst Neutrinos from the Nitrogen Flash  

NASA Astrophysics Data System (ADS)

Neutrinos provide us with a novel probe in which to explore the deep interior of astrophysical objects that otherwise would not be accessible with optical observations; among the notable examples are solar and supernova neutrinos. We show that there is a new class of strong neutrino emission from helium burning, 14N + ? --> 18F + ? followed by beta decay 18F --> 18O + e+ + ?e, that gives a maximum neutrino luminosity of 108 times the solar bolometric luminosity at the helium-core flash of a 1 Msolar star, whereas the flash is not observable by optical means. This means that the neutrino flux, with an average energy of 0.382 MeV, will be 10% the solar CNO neutrino flux on Earth if the star is located at 10 pc.

Serenelli, A. M.; Fukugita, M.

2005-10-01

442

Massive Stars and High-Energy Neutrinos  

NASA Astrophysics Data System (ADS)

Massive stars have been associated with the production of high-energy neutrinos since the early claims of detection of very high-energy gamma rays from Cygnus X-3 in the 1970s and early 1980s. Although such claims are now discredited, many thoretical models were developed predicting significant neutrino fluxes from binary systems with massive stars. With the discovery of microquasars, new, improved models appeared. The large neutrino telescopes currently under construction (IceCube, Antares) and the detection of gamma-ray sources of likely hadronic origin associated with massive binaries and star forming regions make the prospects for high-energy neutrino astronomy quite promising. In this paper I will review the basic features of neutrino production in stellar systems and I will discuss the physical implications of a positive neutrino detection from such systems for our view of the stellar evolution and comsic ray origin.

Romero, G. E.

2010-05-01

443

Dynamical collective calculation of supernova neutrino signals.  

PubMed

We present the first calculations with three flavors of collective and shock wave effects for neutrino propagation in core-collapse supernovae using hydrodynamical density profiles and the S matrix formalism. We explore the interplay between the neutrino-neutrino interaction and the effects of multiple resonances upon the time signal of positrons in supernova observatories. A specific signature is found for the inverted hierarchy and a large third neutrino mixing angle and we predict, in this case, a dearth of lower energy positrons in Cherenkov detectors midway through the neutrino signal and the simultaneous revelation of valuable information about the original fluxes. We show that this feature is also observable with current generation neutrino detectors at the level of several sigmas. PMID:19792628

Gava, Jérôme; Kneller, James; Volpe, Cristina; McLaughlin, G C

2009-08-14

444

Neutrino masses twenty-five years later  

NASA Astrophysics Data System (ADS)

The discovery of neutrino mass marks a turning point in elementaary particle physics, with important implications for nuclear and astroparticle physics. Here I give a brief update, where I summarize the current status of three-neutrino oscillation parameters from current solar, atmospheric, reactor and accelerator neutrino data, discuss the case for sterile neutrinos and LSND, and also the importance of tritium and double beta decay experiments probing the absolute scale of neutrino mass. In this opininated look at the present of neutrino physics, I keep an eye in the future, and a perspective of the past, taking the oportunity to highlight Joe Schechter's pioneering contribution, which I have had the fortune to share, as his PhD student back in the early eighties.

Valle, J. W. F.

2003-11-01

445

Measurement of Neutrino-Nucleus Cross Sections  

NASA Astrophysics Data System (ADS)

For more than 50 years, neutrinos have surprised us: not only by their mere presence, but by the recent revelation that these ghostlike particles can oscillate from one type to another. This stunning discovery has opened up a host of new questions about neutrinos and their properties; questions which we are currently in a global race to answer. The results inherently hinge upon knowledge of neutrino interaction cross sections. Such cross sections are generally poorly known and have not been updated for decades. With the advent of intense man-made neutrino beams, this situation is quickly changing. Detailed studies of low energy neutrino-nucleus interactions are now being made and revealing surprises of their own. Recent neutrino scattering measurements from a variety of experiments will be presented along with a projection for what the future holds.

Zeller, Geralyn

2011-04-01

446

The NO?A Neutrino Calorimeter  

NASA Astrophysics Data System (ADS)

The NO?A experiment is a long baseline neutrino detector designed to 1) observe oscillations of muon neutrinos to electron neutrinos, 2) determine the ordering of the neutrino mass states, and 3) observe CP violation in neutrinos if it exists. To accomplish this, the NO?A detector is a unique low-Z, high sampling fraction calorimeter capable of precise measurements of the particles produced in a neutrino interaction while also being able to reject particles from background cosmic rays. Some experience has already been obtained with the operation of a prototype near detector on the Fermilab site, and construction of the far detector is just beginning in northern Minnesota. The calorimetric properties of the NO?A detector will be described with emphasis on relevance to the overall experimental goals.

Magill, Stephen

2012-12-01

447

Detection methods at reactor neutrino experiments  

NASA Astrophysics Data System (ADS)

In 2011 and 2012, the smallest neutrino mixing angle ?13 was determined to be unexpected large by reactor neutrino experiments Daya Bay, Double Chooz, and RENO, and accelerator experiments T2K and MINOS. The most precise measurement is sin22?13=0.089±0.010(stat.)±0.005(syst.), provided by Daya Bay. The measurement of ?13 opened the gateway to the mass hierarchy and CP phase measurements. It also marked the beginning of precision measurements in neutrino studies. With near-far relative measurement and improvements in detector design, the relative precision of neutrino detectors reached 0.2%. Detection methods for reactor neutrinos are reviewed. The highlighted techniques include gadolinium-doped liquid scintillator, three-layer detectors, functionally identical detectors, reflective panel, background shielding, etc. The next generation reactor neutrino experiment Daya Bay II and its technical challenges are briefly described.

Cao, Jun

2013-12-01

448

Early Neutrino Data in the NO$\  

SciTech Connect

NO{nu}A is a long-baseline neutrino experiment using an off-axis neutrino beam produced by the NuMI neutrino beam at Fermilab. The NO{nu}A experiment will study neutrino {nu}{sub {mu}} {yields} {nu}{sub e} oscillations. A short term goal for the NO{nu}A experiment is to develop a good understanding of the response of the detector. These studies are being carried out with the full Near Detector installed on the surface (NDOS) at Fermilab. This detector is currently running and will acquire neutrino data for a year. Using beam muon neutrino data, quasi-elastic charged-current interactions will be studied. Status of the NDOS running and early data will be shown.

Betancourt, M.; /Minnesota U.

2011-09-01

449

Can cosmic neutrinos be detected with superconductors  

SciTech Connect

The development of techniques for the experimental detection of cosmic neutrinos would be of great importance the both astrophysics and particle physics. In this paper ideas based on the coherent response of conducting materials to long-wavelength cosmic or galactic neutrinos, via the weak neutral current interaction are discussed. The necessity to consider the refraction of neutrino waves by the conduction electrons as an independent process leads to the absence of recoil electric currents to first order in G for a uniform neutrino flux. As a result of this, a recently-published suggestion (Opher, 1982) for the detection of cosmic (and also solar) neutrinos with small volumes of superconducting material is shown to be fallacious. Superconducting detectors based on the very small forces of order G2 would be possible in principle, but no practically feasible scheme has yet been suggested. Some basic questions concerning the interaction of neutrinos with a closed superconducting circuit also require more detailed study. 15 references.

Lewin, J.D.; Smith, P.F.

1984-01-01

450

Large extra dimensions, sterile neutrinos and solar neutrino data.  

PubMed

Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, nu(B), which can exist in the bulk of extra dimensions. Solar nu(e), confined to the brane, can oscillate in the vacuum to the zero mode of nu(B) and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of nu(B). This new way to fit solar data is provided by both low and intermediate string scale models. From average rates seen in the three types of solar experiments, the Super-Kamiokande spectrum is predicted with 73% probability, but dips characteristic of the 0.06 mm extra dimension should be seen in the SNO spectrum. PMID:11461607

Caldwell, D O; Mohapatra, R N; Yellin, S J

2001-07-23

451

Prospects for measuring coherent neutrino-nucleus elastic scattering at a stopped-pion neutrino source  

SciTech Connect

Rates of coherent neutrino-nucleus elastic scattering at a high-intensity stopped-pion neutrino source in various detector materials (relevant for novel low-threshold detectors) are calculated. Sensitivity of a coherent neutrino-nucleus elastic scattering experiment to new physics is also explored.

Scholberg, Kate [Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

2006-02-01

452

Report of the Solar and Atmospheric Neutrino Experiments Working Group of the APS Multidivisional Neutrino Study  

Microsoft Academic Search

Both the first evidence and the first discoveries of neutrino flavor transformation have come from experiments which use neutrino beams provided by Nature. These discoveries were remarkable not only because they were unexpected--they were discoveries in the purest sense--but that they were made initially by experiments whose primary goals were aimed at other physics. Future solar and atmospheric neutrino experiments

J. N. Bahcall; J. Bernabeu; M. G. Boulay; T. Bowles; F. Calaprice; A. Champagne; M. Gai; C. Galbiati; H. Gallagher; C. Gonzalez-Garcia; R. L. Hahn; K. M. Heeger; A. Hime; C. K. Jung; J. R. Klein; M. Koike; R. Lanou; J. G. Learned; K. T. Lesko; J. Losecco; M. Maltoni; A. Mann; D. McKinsey; S. Palomares-Ruiz; C. Pena-Garay; S. T. Petcov; A. Piepke; M. Pitt; R. Raghavan; R. G. H. Robertson; K. Scholberg; H. W. Sobel; T. Takeuchi; R. Vogelaar; L. Wolfenstein

2004-01-01

453

Study of muon neutrino disappearance using the Fermilab Main Injector neutrino beam  

Microsoft Academic Search

We report the results of a search for {sub } disappearance by the Main Injector Neutrino Oscillation Search [D. G. Michael et al. (MINOS), Phys. Rev. Lett. 97, 191801 (2006).]. The experiment uses two detectors separated by 734 km to observe a beam of neutrinos created by the Neutrinos at the Main Injector facility at Fermi National Accelerator Laboratory. The

P. Adamson; C. Andreopoulos; A. Belias; T. Durkin; J. Hartnell; C. J. Metelko; T. C. Nicholls; G. F. Pearce; K. E. Arms; B. R. Becker; P. M. Border; J. Gogos; K. Heller; S. M. S. Kasahara; S. Kumaratunga; P. J. Litchfield; M. L. Marshak; J. R. Meier; W. H. Miller; E. A. Peterson

2008-01-01

454

Testing neutrino magnetic moment in ionization of atoms by neutrino impact  

Microsoft Academic Search

The atomic ionization processes induced by scattering of neutrinos play key roles in the experimental searches for a neutrino magnetic moment. Current experiments with reactor (anti)neutrinos employ germanium detectors having energy threshold comparable to typical binding energies of atomic electrons, which fact must be taken into account in the interpretation of the data. Our theoretical analysis shows that the so-called

K. A. Kouzakov; A. I. Studenikin; M. B. Voloshin

2011-01-01

455

On neutrino-atom scattering in searches for neutrino magnetic moments  

Microsoft Academic Search

In the experimental searches for neutrino magnetic moments using germanium detectors one studies the ionization channel in the neutrino-atom scattering. We find that the so-called stepping approximation to the neutrino-impact ionization is exact in the semiclassical limit, and that the deviations from this approximation are very small.

Konstantin A. Kouzakov; Alexander I. Studenikin; Mikhail B. Voloshin

2011-01-01

456

On neutrino-atom scattering in searches for neutrino magnetic moments  

NASA Astrophysics Data System (ADS)

In the experimental searches for neutrino magnetic moments using germanium detectors one studies the ionization channel in the neutrino-atom scattering. We find that the so-called stepping approximation to the neutrino-impact ionization is exact in the semiclassical limit, and that the deviations from this approximation are very small.

Kouzakov, Konstantin A.; Studenikin, Alexander I.; Voloshin, Mikhail B.

2012-08-01

457

Neutrino Astronomy with the IceCube Observatory  

NASA Astrophysics Data System (ADS)

IceCube is the first representative of the km3 class of neutrino telescopes and currently the most sensitive detector to high-energy neutrinos. Its main mission is to search for Galactic and extragalactic sources of high-energy neutrinos, but it is also an excellent detector for the investigation of a variety of other highly topical astrophysics and particle physics topics like supernovae, dark matter and neutrino oscillations. After an introduction to neutrino astronomy and neutrino telescopes, this article presents a selection of latest results from the IceCube neutrino detector with respect to searches for cosmic high-energy neutrino sources.

Kappes, A.; IceCube Collaboration

2013-02-01