WorldWideScience

Sample records for anomalous neutrino oscillations

  1. Neutrino oscillations

    International Nuclear Information System (INIS)

    Lecture notes on neutrino oscillations are given, including some background about neutrino mixing and masses, descriptions of flavour oscillations and experimental attempts to detect them, matter effects and neutrino-antineutrino oscillations. (U.K.)

  2. Oscillating neutrinos

    International Nuclear Information System (INIS)

    After a general introduction into the mixing of muon and electron neutrinos due to a possible mass difference between these particles some experiments for the study of neutrino oscillations are described. (HSI).

  3. Neutrino masses and oscillations

    International Nuclear Information System (INIS)

    New effects related to refraction of neutrinos in different media are reviewed and implication of the effects to neutrino mass and mixing are discussed. Patterns of neutrino masses and mixing implied by existing hints/bounds are described. Recent results on neutrino mass generation are presented. They include neutrino masses in SO(10) GUT's and models with anomalous U(1), generation of neutrino mass via neutrino-neutralino mixing, models of sterile neutrino. (author). 95 refs, 9 figs

  4. Atmospheric neutrinos and neutrino oscillations

    International Nuclear Information System (INIS)

    The results on the composition of atmospheric neutrinos interacting in underground detectors and on the rate of atmospheric muon neutrino interactions in the earth surrounding the detectors are reviewed. So far, systematic errors on the neutrino flux and on the electrons and muons neutrino interaction identifications are not yet reliable enough to prove that atmospheric neutrinos oscillate before being detected. (author) 22 refs., 5 figs

  5. Neutrino anomalies without oscillations

    Indian Academy of Sciences (India)

    Sandip Pakvasa

    2000-01-01

    I review explanations for the three neutrino anomalies (solar, atmospheric and LSND) which go beyond the `conventional' neutrino oscillations induced by mass-mixing. Several of these require non-zero neutrino masses as well.

  6. Status of Neutrino Oscillations

    OpenAIRE

    J.W.F. Valle

    2001-01-01

    Solar and atmospheric neutrino data require physics beyond the Standard Model of particle physics. The simplest, most generic, but not yet unique, interpretation of the data is in terms of neutrino oscillations. I summarize the results of the latest three-neutrino oscillation global fit of the data, in particular the bounds on the angle $\\theta_{13}$ probed in reactor experiments. Even though not implied by the data, bi-maximal neutrino mixing emerges as an attractive possibility either in hi...

  7. Neutrino Oscillations With Two Sterile Neutrinos

    CERN Document Server

    Kisslinger, Leonard S

    2016-01-01

    This work estimates the probability of $\\mu$ to $e$ neutrino oscillation with two sterile neutrinos using a 5x5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4x4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.

  8. Atmospheric neutrinos and discovery of neutrino oscillations

    International Nuclear Information System (INIS)

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

  9. Phenomenology of neutrino oscillations

    Indian Academy of Sciences (India)

    G Rajasekaran

    2000-07-01

    The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

  10. Solar neutrino oscillations

    International Nuclear Information System (INIS)

    The special properties of solar neutrinos that render this flux so uniquely important in searches for neutrino masses and flavor mixing are reviewed. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained through analogies with more familiar atomic physics phenomena

  11. Physics of Neutrino Oscillation

    CERN Document Server

    Mondal, Spandan

    2015-01-01

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

  12. Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

    OpenAIRE

    Albuquerque, Ivone F. M.; Smoot, George F.

    2001-01-01

    Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest ad...

  13. Solar neutrinos: Oscillations or No-oscillations?

    CERN Document Server

    Smirnov, A Yu

    2016-01-01

    The Nobel prize in physics 2015 has been awarded "... for the discovery of neutrino oscillations which show that neutrinos have mass". While SuperKamiokande (SK), indeed, has discovered oscillations, SNO observed effect of the adiabatic (almost non-oscillatory) flavor conversion of neutrinos in the matter of the Sun. Oscillations are irrelevant for solar neutrinos apart from small $\

  14. Neutrino Oscillation Experiments

    International Nuclear Information System (INIS)

    The current status and future propects for neutrino mass and oscillation experiments is summarized. An initial short summary of the direct neutrino mass measurements is given including double beta-decay and cosmological constraints. Next the current neutrino oscillations results are described for the solar, atmospheric, and LSND Δ m2 regions. This is followed by an overview of the expectations for the near-term reactor and long baseline experiments. Finally, the plans for the longer term oscillation program including the Hyper-K and LBNE experiments are described.

  15. Prospects for Detecting Supernova Neutrino Flavor Oscillations

    CERN Document Server

    Fuller, G M; McLaughlin, G C

    1999-01-01

    The neutrinos from a Type II supernova provide perhaps our best opportunity to probe cosmologically interesting muon and/or tauon neutrino masses. This is because matter enhanced neutrino oscillations can lead to an anomalously hot nu_e spectrum, and thus to enhanced charged current cross sections in terrestrial detectors. Two recently proposed supernova neutrino observatories, OMNIS and LAND, will detect neutrons spalled from target nuclei by neutral and charged current neutrino interactions. As this signal is not flavor specific, it is not immediately clear whether a convincing neutrino oscillation signal can be extracted from such experiments. To address this issue we examine the responses of a series of possible light and heavy mass targets, 9Be, 23Na, 35Cl, and 208Pb. We find that strategies for detecting oscillations which use only neutron count rates are problematic at best, even if cross sections are determined by ancillary experiments. Plausible uncertainties in supernova neutrino spectra tend to obs...

  16. Neutrino oscillations and supersymmetry

    International Nuclear Information System (INIS)

    The Super-Kamiokande experiment measured the atmospheric muon and electron neutrinos. The standard model predicts a ratio of 2, while Super-Kamiokande and others measure a much smaller value (1.30±0.02 for Super-Kamiokande). But Super-Kamiokande can also measure roughly the direction and the energy of the neutrinos. The zenith angle dependence for the muon neutrinos suggests that the muon neutrinos oscillate into a third neutrino species either into the τ neutrino or a sterile neutrino. This finding is investigated within the supersymmetric model. The neutrinos mix with the neutralinos, this means the wino, the bino and the two higgsinos. The 7 x 7 mass matrix is calculated on the tree level. One finds that the mass matrix has three linearly dependent rows which means, that two masses are zero. They are identified with the two lightest neutrino masses. The fit of the Super-Kamiokande data to oscillations between three neutrinos yields together with the result of supersymmetry that the third neutrino mass lies between 2 · 10-2 and 10-1 [eV]. The two lightest neutrino masses are in supersymmetry on the tree level zero. The averaged electron neutrino mass which is the essential parameter in the neutrinoless double beta decay νe> = mν3 · P3e ≤ 0.8 · 10-2 [eV] (95 % confidence limit). It is derived from the Super-Kamiokande data in this supersymmetric model to be two orders smaller than the best value (l[eV]) from the neutrinoless double beta decay. (author)

  17. Measuring atmospheric neutrino oscillations with neutrino telescopes

    International Nuclear Information System (INIS)

    Neutrino telescopes with large detection volumes can demonstrate whether the current indications of neutrino oscillation are correct or if a better description can be achieved with nonstandard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of nonstandard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely instrumented strings to the AMANDA II detector makes oscillation observations feasible. Such a configuration is competitive with current and proposed experiments

  18. Measuring atmospheric neutrino oscillations with neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Ivone F. M.; Smoot, George F.

    2001-09-01

    Neutrino telescopes with large detection volumes can demonstrate whether the current indications of neutrino oscillation are correct or if a better description can be achieved with nonstandard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of nonstandard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely instrumented strings to the AMANDA II detector makes oscillation observations feasible. Such a configuration is competitive with current and proposed experiments.

  19. Neutrino oscillations under gravity: mass independent oscillation

    OpenAIRE

    Mukhopadhyay, Banibrata

    2003-01-01

    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 the neutrino and anti-neutrino states comes out. Therefore I can conclude that under gravity neutrino oscillation tak...

  20. Neutrino oscillations refitted

    CERN Document Server

    Forero, D V; Valle, J W F

    2014-01-01

    Here we update our previous global fit of neutrino oscillations by including the recent results which have appeared since the Neutrino-2012 conference. These include the measurements of reactor anti-neutrino disappearance reported by Daya Bay and RENO, together with latest T2K and MINOS data including both disappearance and appearance channels. We also include the revised results from the third solar phase of Super-Kamiokande, SK-III, as well as new solar results from the fourth phase of Super-Kamiokande, SK-IV. We find that the preferred global determination of the atmospheric angle $\\theta_{23}$ is consistent with maximal mixing. We also determine the impact of the new data upon all the other neutrino oscillation parameters with emphasis on the increasing sensitivity to the CP phase, thanks to the interplay between accelerator and reactor data.

  1. Neutrino oscillations and dark matter

    OpenAIRE

    Zuber, K.

    1996-01-01

    The significance of light massive neutrinos as hot dark matter is outlined. The power of neutrino oscillation experiments with respect to detect such neutrinos in the eV-region is discussed. Present hints for neutrino oscillations in solar, atmospheric and LSND data are reviewed as well as future experiments and their potential.

  2. Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

    CERN Document Server

    Albuquerque, I F M; Albuquerque, Ivone F.M.; Smoot, George F.

    2001-01-01

    Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely-instrumented strings to the AMANDA II detector makes observations feasible. Such a configuration is competitive with current and proposed experiments.

  3. Entanglement in neutrino oscillations

    OpenAIRE

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

    2007-01-01

    Flavor oscillations in elementary particle physics are related to multi-mode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We disc...

  4. Entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

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

  5. Entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, M.; Dell' Anno, F.; De Siena, S.; Illuminati, F. [Universita degli Studi di Salerno Via Ponte don Melillon, Dipt. di Matematica e Informatica, Fisciano SA (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno - Baronissi SA (Italy); Dell' Anno, F.; De Siena, S.; Illuminati, F. [CNR-INFM Coherentia - Napoli (Italy); Blasone, M. [ISI Foundation for Scientific Interchange, Torino (Italy)

    2009-03-15

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

  6. Neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, L. [European Organization for Nuclear Research, Geneva (Switzerland)

    1996-11-01

    Neutrino oscillation experiments ({nu}{sub {mu}}{yields}{nu}{sub e} and {nu}{sub {mu}}{yields}{nu}{sub {tau}}) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs.

  7. Neutrino oscillations at LAMPF

    International Nuclear Information System (INIS)

    Work at Argonne continues on the construction of the neutrino oscillation experiment (E645). Construction of detector supports and active shield components were completed at the Provo plant of the principal contractor for the project (the Pittsburgh-Des Moines Corporation). Erection of the major experimental components was completed at the LAMPF experimental site in mid-March 1985. Work continues on the tunnel which will house the detector. Construction of detector components (scintillators and proportional drift tubes) is proceeding at Ohio State University and Louisiana State University. Consolidation of these components into the 20-ton neutrino detector is beginning at LAMPF

  8. Cosmological constraints on neutrino oscillations

    International Nuclear Information System (INIS)

    Solar, atmospheric and terrestrial neutrino experiments have provided evidence for neutrino oscillations. These neutrino anomalies were successfully explained in terms of neutrino oscillations, the dominant channels being flavour neutrino oscillations. The role of sterile neutrinos and the active-sterile subdominant channels are being explored presently. Therefore, we discuss all cosmological effects of active-sterile neutrino oscillations on the early Universe evolution, and particularly the effects on the nucleosynthesis epoch. Numerical analysis of the cosmological production of He-4, Yp in the presence of νe ↔ νs, effective after νe decoupling from the equilibrium, was provided for the full neutrino oscillations parameter range. These neutrino oscillations lead always to an overproduction of He-4. We have obtained isohelium contours corresponding to different levels of He-4 overproduction, δYp/Yp, for initial population of the sterile state in the range 0 ≤ δNs ≤ 0.5. Cosmological constraints on oscillation parameters, obtained on the base of the calculated isohelium contours and Yp observational data, are discussed. We present the constraints corresponding toδNs = 0.0 and 0.5, and helium overproduction δYp/Yp = 3%. These cosmological constraints, being more stringent than the ones provided from the neutrino experimental data, provide valuable information for the impact of sterile neutrino in the neutrino anomalies and for the neutrino physics in general. (author)

  9. Accelerator studies of neutrino oscillations

    CERN Document Server

    Ereditato, A

    2000-01-01

    The question of whether the neutrino has a non-vanishing mass plays acrucial role in particle physics. A massive neutrino would unambiguously reveal the existence of new physics beyond the Standard Model. In addition, it could have profound implications on astrophysics and cosmology, with effects on the evolution of the Universe. Experiments aiming at direct neutrino-mass measurements based on kinematics have not been able, so far, to measure the very small neutrino mass. Indirect measurements can be performed by exploiting reactions which may only occur for massive neutrinos. Neutrino oscillation is one of those processes. The mass difference between neutrino mass-eigenstates can be inferred from a phase measurement. This feature allows for high sensitivity experiments. Neutrinos from different sources can be used to search for oscillations: solar neutrinos, neutrinos produced in the interaction of cosmic rays with the atmosphere and artificially produced neutrinos from nuclear reactors and particle accelera...

  10. Neutrino Oscillation Studies with Reactors

    CERN Document Server

    Vogel, Petr; Zhang, Chao

    2015-01-01

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

  11. Search for neutrino oscillations

    International Nuclear Information System (INIS)

    The present paper reports on preliminary results from the E 816 experiment at Brookhaven National Laboratory. E 816 is the continuation of a 1984 experiment (PS 191) which was devoted to a neutrino decay search in the CERN PS neutrino beam. No candidate was seen, but a study of neutrino interactions in the calorimeter indicated an anomalous electron production. The statistics was too low and the experiment has been rerun in spring 86 at BNL to look specifically, with an improved detector for nu/sub e/ arising from a low energy nu/sub μ/ beam. The results presented here are preliminary for at least two reasons: first the collaboration is presently running a calibration test which results are not included here; second, only 1/3 of the neutrino data is used, and no mention will be made to antineutrino data for which the analysis is still going on. This report will directly start with a description of our apparatus, followed by the data analysis

  12. Neutrino Oscillations for Dummies

    OpenAIRE

    Waltham, Chris

    2003-01-01

    The reality of neutrino oscillations has not really sunk in yet. The phenomenon presents us with purely quantum mechanical effects over macroscopic time and distance scales (milliseconds and 1000s of km). In order to help with the pedagogical difficulties this poses, I attempt here to present the physics in words and pictures rather than math. No disrespect is implied by the title; I am merely borrowing a term used by a popular series of self-help books.

  13. Neutrino oscillation measurements with reactors

    OpenAIRE

    McKeown, R.D.

    2010-01-01

    Since the first direct observations of antineutrino events by Reines and Cowan in the 1950's, nuclear reactors have been an important tool in the study of neutrino properties. More recently, the study of neutrino oscillations has been a very active area of research. The pioneering observation of oscillations by the KamLAND experiment has provided important information on the neutrino masses and the neutrino mixing matrix. New experiments to study the remaining unknown mixing angle are current...

  14. Supernova neutrinos and their oscillations

    International Nuclear Information System (INIS)

    The recent observations of neutrinos from a supernova have many implications for astrophysics and particle physics. Besides containing information on the supernova, the signal depends on the properties of neutrinos. In order to interpret the recent observations, the uncertainties in supernova dynamics must be disentangled from the effects of neutrino propagation. The authors concentrate on the mixing of neutrino fluxes from neutrino oscillations, both in vacuum and in matter

  15. Neutrino Oscillations: Hierarchy Question

    CERN Document Server

    Ernst, D J; Burroughs, H R; Escamilla-Roa, J; Latimer, D C

    2013-01-01

    The only experimentally observed phenomenon that lies outside the standard model of the electroweak interaction is neutrino oscillations. A way to try to unify the extensive neutrino oscillation data is to add a phenomenological mass term to the Lagrangian that is not diagonal in the flavor basis. The goal is then to understand the world's data in terms of the parameters of the mixing matrix and the differences between the squares of the masses of the neutrinos. An outstanding question is what is the correct ordering of the masses, the hierarchy question. We point out a broken symmetry relevant to this question, the symmetry of the simultaneous interchange of hierarchy and the sign of $\\theta_{13}$. 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 $\\theta_{13} = 0.152\\pm 0.014$, $\\theta_{23} = 0.25^{+0.03}_{-0.05} \\pi$ and $\\Delta_{32} = 2.45\\pm 0.14 \\times 10^{-3}$ eV$^2$, results consistent with others. We...

  16. Solar neutrino oscillation phenomenology

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2004-02-01

    This article summarises the status of the solar neutrino oscillation phenomenology at the end of 2002 in the light of the SNO and KamLAND results. We first present the allowed areas obtained from global solar analysis and demonstrate the preference of the solar data towards the large-mixing-angle (LMA) MSW solution. A clear confirmation in favour of the LMA solution comes from the KamLAND reactor neutrino data. the KamLAND spectral data in conjunction with the global solar data further narrows down the allowed LMA region and splits it into two allowed zones - a low $ m^{2}$ region (low-LMA) and high $ m^{2}$ region (high-LMA). We demonstrate through a projected analysis that with an exposure of 3 kton-year (kTy) KamLAND can remove this ambiguity.

  17. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  18. Neutrino Oscillations with Nil Mass

    CERN Document Server

    Floyd, Edward R

    2016-01-01

    An alternative neutrino oscillation process is presented as a counterexample for which the neutrino may have nil mass consistent with the standard model. The process is developed in a quantum trajectories representation of quantum mechanics, which has a Hamilton-Jacobi foundation. This process has no need for mass differences between mass eigenstates. Flavor oscillations and $\\bar{\

  19. The Phase of Neutrino Oscillations

    OpenAIRE

    C. Giunti(INFN, Turin & Turin U)

    2002-01-01

    Using an analogy with the well-known double-slit experiment, we show that the standard phase of neutrino oscillations is correct, refuting recent claims of a factor of two correction. We also improve the wave packet treatment of neutrino oscillations taking into account explicitly the finite coherence time of the detection process.

  20. Transport Equations for Oscillating Neutrinos

    CERN Document Server

    Zhang, Yunfan

    2013-01-01

    We derive a suite of generalized Boltzmann equations, based on the density-matrix formalism, that incorporates the physics of neutrino oscillations for two- and three-flavor oscillations, matter refraction, and self-refraction. The resulting equations are straightforward extensions of the classical transport equations that nevertheless contain the full physics of quantum oscillation phenomena. In this way, our broadened formalism provides a bridge between the familiar neutrino transport algorithms employed by supernova modelers and the more quantum-heavy approaches frequently employed to illuminate the various neutrino oscillation effects. We also provide the corresponding angular-moment versions of this generalized equation set. Our goal is to make it easier for astrophysicists to address oscillation phenomena in a language with which they are familiar. The equations we derive are simple and practical, and are intended to facilitate progress concerning oscillation phenomena in the context of core-collapse su...

  1. Neutrino Masses and Flavor Oscillations

    CERN Document Server

    Wang, Yifang

    2015-01-01

    This essay is intended to provide a brief description of the peculiar properties of neutrinos within and beyond the standard theory of weak interactions. The focus is on the flavor oscillations of massive neutrinos, from which one has achieved some striking knowledge about their mass spectrum and flavor mixing pattern. The experimental prospects towards probing the absolute neutrino mass scale, possible Majorana nature and CP-violating effects will also be addressed.

  2. Damping signatures in future neutrino oscillation experiments

    OpenAIRE

    Blennow, Mattias; Ohlsson, Tommy; Winter, Walter

    2005-01-01

    We discuss the phenomenology of damping signatures in the neutrino oscillation probabilities, where either the oscillating terms or the probabilities can be damped. This approach is a possibility for tests of damping effects in future neutrino oscillation experiments, where we mainly focus on reactor and long-baseline experiments. We extensively motivate different damping signatures due to small corrections by neutrino decoherence, neutrino decay, oscillations into sterile neutrinos, or other...

  3. Parametric resonance in neutrino oscillations in matter

    Indian Academy of Sciences (India)

    E Kh Akhmedov

    2000-01-01

    Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we review the parametric resonance of neutrino oscillations in matter. In particular, physical interpretation of the effect and the prospects of its experimental observation in oscillations of solar and atmospheric neutrinos in the earth are discussed.

  4. Short distance neutrino oscillations with Borexino

    Directory of Open Access Journals (Sweden)

    Caminata A.

    2016-01-01

    Full Text Available The Borexino detector has convincingly shown its outstanding performances in the low energy, sub-MeV regime through its unprecedented accomplishments in the solar and geo-neutrinos detection. These performances make it the ideal tool to accomplish a state-of-the-art experiment able to test unambiguously the long-standing issue of the existence of a sterile neutrino, as suggested by the several anomalous results accumulated over the past two decades, i.e. the outputs of the LSND and Miniboone experiments, the results of the source calibration of the two Gallium solar neutrino experiments, and the recently hinted reactor anomaly. The SOX project will exploit two sources, based on Chromium and Cerium, respectively, which deployed under the experiment, in a location foreseen on purpose at the time of the construction of the detector, will emit two intense beams of neutrinos (Cr and anti-neutrinos (Ce. Interacting in the active volume of the liquid scintillator, each beam would create an unmistakable spatial wave pattern in case of oscillation of the νe (or ν̅e into the sterile state: such a pattern would be the smoking gun proving the existence of the new sterile member of the neutrino family. Otherwise, its absence will allow setting a very stringent limit on its existence.

  5. Neutrino production coherence and oscillation experiments

    CERN Document Server

    Akhmedov, Evgeny; Smirnov, Alexei

    2012-01-01

    Neutrino oscillations are only observable when the neutrino production, propagation and detection coherence conditions are satisfied. In this paper we consider in detail neutrino production coherence, taking \\pi\\to \\mu \

  6. Multipartite entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  7. Multipartite entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2009-06-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  8. Lepton asymmetries from neutrino oscillations

    CERN Document Server

    Volkas, R R

    2000-01-01

    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.

  9. Neutrino oscillation experiments at CERN

    International Nuclear Information System (INIS)

    Two proposals for neutrino oscillation experiments have been submitted at CERN at this time. A Padova-Pisa-Athens-Wisconsin group proposes to use BEBC to observe ν/sub e/ events in a nearly pure ν/sub μ/ beam, and the CERN-Dortmund-Heidelberg-Saclay group proposes to use the neutrino detector presently installed in the SPS high energy neutrino beam to look for the disappearance of ν/sub μ/. The main features of the two experiments are presented and discussed

  10. Pseudo-Dirac Scenario for Neutrino Oscillations

    OpenAIRE

    Kobayashi, Makoto; Lim, C. S.

    2000-01-01

    We argue how pseudo-Dirac scenario for neutrinos leads to rich neutrino oscillation phenomena, including oscillation inside each generation. The pseudo-Dirac scenario is generalized by incorporating generation mixings and formulae for the various neutrino oscillations are derived. As the application we compare the formulae with the corresponding data. We find that observed pattern of mixings, such as almost maximal mixing in the atmospheric neutrino oscillation, is naturally explained in the ...

  11. Studies of Neutrino Oscillations at Reactors

    OpenAIRE

    Boehm, Felix

    2000-01-01

    Experiments with reactor neutrinos continue to shed light on our understanding of neutrino oscillations. We review some of the early decisive experiments. We then turn to the recent long baseline oscillation experiments at Palo Verde and Chooz which are leading to the conclusion that the atmospheric neutrino anomaly if attributed to oscillations does not involve an appreciable mixing with the $\\bar\

  12. Neutrino Oscillation Experiment at JHF

    CERN Multimedia

    2002-01-01

    The first stage of a next-generation long baseline neutrino oscillation experiment is proposed to explore the physics beyond the Standard Model. The experiment will use the high intensity proton beam from the JHF 50 GeV proton synchrotron (JHF PS), and Super-Kamiokande as a far detector. The baseline length will be 295 km. The beam power of JHF PS is capable of delivering 3.3 x 10$^{14}$ 50 GeV protons every 3.5 seconds (0.75 MW). The experiment assumes 130 days of operation at full intensity for five years. The high intensity neutrino beam is produced in an off-axis configuration. The peak neutrino energy is tuned to the oscillation maximum of $\\sim$ 0.8 GeV to maximize the sensitivity to neutrino oscillations. The merits of this experiment can be summarized as follows: \\begin{itemize} \\item The off-axis beam can produce the highest possible intensity with a narrow energy spread. The oscillation maximum will be $\\sim$ 0.8 GeV for the distance of 295 km and $\\Delta m^{2} \\sim$ 3 x 10$^{-3}$eV$^{2}$. The corre...

  13. Field-theoretical treatment of neutrino oscillations

    OpenAIRE

    W. Grimus(University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Vienna, Austria); Mohanty, S.; Stockinger, P.

    1999-01-01

    We discuss the field-theoretical approach to neutrino oscillations. This approach includes the neutrino source and detector processes and allows to obtain the neutrino transition or survival probabilities as cross sections derived from the Feynman diagram of the combined source -- detection process. In this context, the neutrinos which are supposed to oscillate appear as propagators of the neutrino mass eigenfields, connecting the source and detection processes.

  14. Measuring neutrino oscillation parameters using $\

    Energy Technology Data Exchange (ETDEWEB)

    Backhouse, Christopher James [Oriel College, Oxford (United Kingdom)

    2011-01-01

    MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the 'atmospheric' neutrino oscillation parameters (Δmatm2 and sin2atm). The oscillation signal consists of an energy-dependent deficit of vμ interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the vμ-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the vμ-disappearance analysis, incorporating this new estimator were: Δm2 = 2.32-0.08+0.12 x 10-3 eV2, sin 2 2θ > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly $\\bar{v}$μ beam, yielded somewhat different best-fit parameters Δ$\\bar{m}${sup 2} = (3.36-0.40+0.46(stat.) ± 0.06(syst.)) x 10-3eV2, sin2 2$\\bar{θ}$ = 0.86-0.12_0

  15. Measuring neutrino oscillation parameters using $\

    Energy Technology Data Exchange (ETDEWEB)

    Backhouse, Christopher James; /Oxford U.

    2011-02-01

    MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the 'atmospheric' neutrino oscillation parameters ({Delta}m{sub atm}{sup 2} and sin{sup 2} 2{theta}{sub atm}). The oscillation signal consists of an energy-dependent deficit of {nu}{sub {mu}} interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the {nu}{sub {mu}}-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the {nu}{sub {mu}}-disappearance analysis, incorporating this new estimator were: {Delta}m{sup 2} = 2.32{sub -0.08}{sup +0.12} x 10{sup -3} eV{sup 2}, sin {sup 2} 2{theta} > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly {bar {nu}}{sub {mu}} beam, yielded somewhat different best-fit parameters {Delta}{bar m}{sup 2} = (3.36{sub -0.40}{sup +0.46}(stat.) {+-} 0.06(syst.)) x 10{sup -3}eV{sup 2}, sin{sup 2} 2{bar {theta}} = 0.86{sub -0.12}{sup _0.11}(stat.) {+-} 0.01(syst.). The tension between these

  16. Coherence and Wave Packets in Neutrino Oscillations

    OpenAIRE

    Giunti, Carlo

    2003-01-01

    General arguments in favor of the necessity of a wave packet description of neutrino oscillations are presented, drawing from analogies with other wave phenomena. We present a wave packet description of neutrino oscillations in stationary beams using the density matrix formalism. Recent claims of the necessity of an equal energy of different massive neutrinos are refuted.

  17. Neutrino oscillations in core-collapse supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Meng-Ru [TU Darmstadt (Germany); University of Minnesota, MN (United States); Huther, Lutz [TU Darmstadt (Germany); Fischer, Tobias; Martinez-Pinedo, Gabriel [TU Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Qian, Yong-Zhong [University of Minnesota, MN (United States)

    2013-07-01

    Neutrino oscillations play an important role in determining the spectra of neutrinos emitted from core-collapse supernova and must be considered in the analysis of supernova neutrino detection to understand both the supernova dynamics and the unknown neutrino mass hierarchy. We have studied neutrino oscillations in supernovae using the emission spectra of neutrinos and the dynamically evolving supernova density profile from a state-of-the-art supernova model. We find that in this model, different regions of neutrino oscillations are well separated. Collective neutrino oscillations happen at the innermost part such that the spectra of electron neutrinos and mu/tau neutrinos are partly swapped for the first few seconds in the cooling phase. Then, the high and low MSW resonances that occur after collective oscillations are both adiabatic. Using these results, we find that in this model, neutrino oscillations have little effect on the nucleosynthesis in the neutrino-driven winds. However, the detection of such a signal could possibly allow us to differentiate the neutrino mass hierarchy and to extract the shock revival time.

  18. Oscillation Parameters with forthcoming Reactor Neutrino Experiments

    CERN Document Server

    Lasserre, Thierry

    2010-01-01

    I review the status of the forthcoming reactor neutrino experiments that toe the cutting edge of neutrino oscillation research. Kilometer baseline oscillation experiments (Double Chooz, Daya Bay, and Reno) will soon play a relevant role providing clean information on the last undetermined neutrino mixing angle !13. A 50-70 km baseline reactor neutrino experiment could later provide the best sensitivity to the !12 mixing angle.

  19. Neutrino oscillations and the maximal mixing scenario

    International Nuclear Information System (INIS)

    The problem of neutrino oscillation is considered in the plane wave formalism, as well as in the full wave packet quantum mechanics language. It is shown that Lorentz invariance implies that in general, flavour neutrinos in oscillation experiments are superpositions of massive neutrinos with different energies and different momenta. The hypothesis of threefold-maximal neutrino mixing is investigated and the implications on the coherence of the states is analysed. (authors)

  20. Nuclear Physics and Astrophysics of Neutrino Oscillations

    CERN Document Server

    Balantekin, A B

    2016-01-01

    For a long time very little experimental information was available about neutrino properties, even though a minute neutrino mass has intriguing cosmological and astrophysical implications. This situation has changed in recent decades: intense experimental activity to measure many neutrino properties took place. Some of these developments and their implications for astrophysics and cosmology are briefly reviewed with a particular emphasis on neutrino magnetic moments and collective neutrino oscillations

  1. An introduction to neutrino oscillations and neutrino masses

    International Nuclear Information System (INIS)

    In these lectures we first summarize the general formalism of neutrino oscillations and treat the cases of two and three neutrino flavors in more detail. We then discuss some general experimental and numerical aspects and give a survey of the various types of experiments to look for neutrino oscillations. We describe the searches for oscillations carried out so far and present the experimental results. Finally we discuss the methods to determine the neutrino masses directly and give the present upper limits on these masses. (orig./HSI)

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

    CERN Document Server

    Adrian-Martinez, S; Albert, A; Andre, 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; Carloganu, 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; Enzenhoefer, A; Ernenwein, J -P; Escoffier, S; Fehn, K; Fermani, P; Ferri, M; Ferry, S; Flaminio, V; Folger, F; Fritsch, U; Fuda, J -L; Galata, S; Gay, P; Geyer, K; Giacomelli, G; Giordano, V; Gleixner, A; Gomez-Gonzalez, J P; Graf, K; Guillard, G; Hallewell, G; Hamal, M; van Haren, H; Heijboer, A J; Hello, Y; Hernandez-Rey, J J; Herold, B; Hoessl, 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; Lefevre, D; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Louis, F; Mangano, S; Marcelin, M; Margiotta, A; Martinez-Mora, J A; Meli, A; Montaruli, T; Morganti, M; Moscoso, L; Motz, H; Neff, M; Nezri, E; Palioselitis, D; Pavalas, G E; Payet, K; Petrovic, J; Piattelli, P; Popa, V; Pradier, T; Presani, E; Racca, C; Reed, C; Riccobene, G; Richardt, C; Richter, R; Riviere, C; Robert, A; Roensch, K; Rostovtsev, A; Ruiz-Rivas, J; Rujoiu, M; Russo, G V; Samtleben, D F E; Sanchez-Losa, A; Sapienza, P; Schmid, J; Schnabel, J; Schoeck, F; Schuller, J -P; Schuessler, 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; Vallee, 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; Zuniga, J

    2012-01-01

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

  3. Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Adrian-Martinez, S. [Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, 46730 Gandia (Spain); Al Samarai, I. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Albert, A. [GRPHE - Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit, BP 50568, 68008 Colmar (France); Andre, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Rambla Exposicio, 08800 Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M. [INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service d' Electronique des Detecteurs et d' Informatique, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Ardid, M. [Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, 46730 Gandia (Spain); Astraatmadja, T. [Nikhef, Science Park, Amsterdam (Netherlands); Aubert, J.-J. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); and others

    2012-08-14

    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 {Delta}m{sub 32}{sup 2}=(3.1{+-}0.9) Dot-Operator 10{sup -3} eV{sup 2} is obtained, in good agreement with the world average value.

  4. Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    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 Δm322=(3.1±0.9)⋅10-3 eV2 is obtained, in good agreement with the world average value.

  5. Another look at synchronized neutrino oscillations

    CERN Document Server

    Akhmedov, Evgeny

    2016-01-01

    In dense neutrino backgrounds present in supernovae and in the early Universe neutrino oscillations may exhibit complex collective phenomena, such as synchronized oscillations, bipolar oscillations and spectral splits and swaps. We consider in detail possible decoherence effects on the simplest of these phenomena -- synchronized neutrino oscillations that can occur in a uniform and isotropic neutrino gas. We develop an exact formalism of spectral moments of the flavour spin vectors describing such a system and then apply it to find analytical approaches that allow one to study decoherence effects on its late-time evolution. This turns out to be possible in part due to the existence of the (previously unknown) exact conservation law satisfied by the quantities describing the considered neutrino system. Interpretation of the decoherence effects in terms of neutrino wave packet separation is also given, both in the adiabatic and non-adiabatic regimes of neutrino flavour evolution.

  6. Another look at synchronized neutrino oscillations

    Science.gov (United States)

    Akhmedov, Evgeny; Mirizzi, Alessandro

    2016-07-01

    In dense neutrino backgrounds present in supernovae and in the early Universe neutrino oscillations may exhibit complex collective phenomena, such as synchronized oscillations, bipolar oscillations and spectral splits and swaps. We consider in detail possible decoherence effects on the simplest of these phenomena - synchronized neutrino oscillations that can occur in a uniform and isotropic neutrino gas. We develop an exact formalism of spectral moments of the flavour spin vectors describing such a system and then apply it to find analytical approaches that allow one to study decoherence effects on its late-time evolution. This turns out to be possible in part due to the existence of the (previously unknown) exact conservation law satisfied by the quantities describing the considered neutrino system. Interpretation of the decoherence effects in terms of neutrino wave packet separation is also given, both in the adiabatic and non-adiabatic regimes of neutrino flavour evolution.

  7. Recherche des oscillations de Neutrinos $\

    CERN Document Server

    Gangler, E

    1997-01-01

    Le detecteur nomad, place sur le faisceau de neutrinos wide-band-beam du sps, de contamination en neutrino tau marginale, permet de rechercher des oscillations neutrino muon - tau dans la region de pertinence cosmologique et de distinguer statistiquement les courants charges des neutrinos tau essentiellement par leur mesure cinematique. Une large part du travail de these a donc ete consacree a la reconstruction des evenements dans les chambres a derive, cible instrumentee et cur de l'experience, dont la physique de detection est decrite. Une methode de recherche de traces fut developpee, utilisant certaines informations d'un autre sous-detecteur de nomad, le trd. Pour combler une perte d'efficacite de reconstruction, une methode de recherche de traces courtes s'appuyant sur des vertex deja constitues fut developpee en exploitant les potentialites du filtre de kalman, algorithme iteratif d'ajustement de traces. Ces methodes sont utilisees en production par la collaboration. Cette these porte sur la recherche d...

  8. Relic neutrino decoupling including flavour oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Mangano, Gianpiero [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II and INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Naples (Italy); Department of Physics, Syracuse University, Syracuse, NY 13244-1130 (United States); Miele, Gennaro [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II and INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Naples (Italy); Pastor, Sergio [Instituto de Fisica Corpuscular (CSIC-Universitat de Valencia), Ed. Institutos de Investigacion, Apdo. 22085, E-46071 Valencia (Spain)]. E-mail: pastor@ific.uv.es; Pinto, Teguayco [Instituto de Fisica Corpuscular (CSIC-Universitat de Valencia), Ed. Institutos de Investigacion, Apdo. 22085, E-46071 Valencia (Spain); Pisanti, Ofelia [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II and INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Naples (Italy); Serpico, Pasquale D. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, D-80805 Munich (Germany)

    2005-11-21

    In the early universe, neutrinos are slightly coupled when electron-positron pairs annihilate transferring their entropy to photons. This process originates non-thermal distortions on the neutrino spectra which depend on neutrino flavour, larger for {nu}{sub e} than for {nu}{sub {mu}} or {nu}{sub {tau}}. We study the effect of three-neutrino flavour oscillations on the process of neutrino decoupling by solving the momentum-dependent kinetic equations for the neutrino spectra. We find that oscillations do not essentially modify the total change in the neutrino energy density, giving N{sub eff}=3.046 in terms of the effective number of neutrinos, while the small effect over the production of primordial {sup 4}He is increased by O(20%), up to 2.1x10{sup -4}. These results are stable within the presently favoured region of neutrino mixing parameters.

  9. Solar models and solar neutrino oscillations

    OpenAIRE

    Bahcall, John N.; Peña Garay, Carlos

    2004-01-01

    We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.

  10. Status of the OPERA Neutrino Oscillation Experiment

    International Nuclear Information System (INIS)

    The OPERA neutrino detector at the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode through the study of νμ → ντ oscillations. The apparatus consists of a lead/emulsion-film target complemented by electronic detectors. It is placed in the high-energy, long-baseline CERN neutrino beam (CNGS) 730 km away from the neutrino source. Runs with CNGS neutrinos were successfully carried out in 2008-2009 with the detector fully operational with its related facilities for the emulsion handling and analysis. (author)

  11. Neutrino Mixing and Leptonic CP Phase in Neutrino Oscillations

    OpenAIRE

    Ryzhikh, D. A.; Ter-Martirosyan, K. A.

    2001-01-01

    Oscillations of the Dirac neutrinos of three generations in vacuum are considered with allowance made for the effect of the CP-violating leptonic phase (analogue of the quark CP phase) in the lepton mixing matrix. The general formulas for the probabilities of neutrino transition from one sort to another in oscillations are obtained as functions of three mixing angles and the CP phase. It is found that the leptonic CP phase can, in principle, be reconstructed by measuring the oscillation-avera...

  12. Quantum decoherence effect and neutrino oscillation

    CERN Document Server

    Sun, C P

    1998-01-01

    In the view of the quantum dynamic theory of measurement developed from the Hepp-Colemen (HC) model (K. Hepp, Hev.Phys.Acta, {\\bf 45}, 237 (1972)), the quantum decoherence in neutrino flavor oscillation caused by an environment surrounding neutrinos is generally considered in this paper. The Ellis, Hagelin, Nanopoulos and Srednicki (EHNS) mechanism for solving the solar neutrino problem can be comprehended in a framework of the ordinary quantum mechanics. In the weak- coupling limit, a microscopic model is proposed to describe the transition of two neutrino system from a pure state to a mixed state. It gives the modified formula of survival probability of neutrino oscillation with two additional time-dependent parameters. For specified environments, this result shows that the oscillating phenomena of neutrino still exist even without a mass difference in free neutrino.

  13. Neutrino oscillations: Present status and outlook

    Indian Academy of Sciences (India)

    Thomas Schwetz

    2009-01-01

    The status of neutrino oscillations from global data is summarized, with the focus on the three-flavour picture. The status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results is also discussed. Further-more, an outlook on the measurement of the mixing angle 13 in the near term future, as well as prospects to discover CP violation in neutrino oscillations and to determine the type of the neutrino mass ordering by long-baseline experiments in the long term future are given.

  14. Measuring Neutrino Oscillations with Nuclear Reactors

    OpenAIRE

    McKeown, R.D.

    2007-01-01

    Since the first direct observations of antineutrino events by Reines and Cowan in the 1950's [1], nuclear reactors have been an important tool in the study of neutrino properties. More recently, the study of neutrino oscillations has been a very active area of research. The pioneering observation of oscillations by the KamLAND experiment has provided crucial information on the neutrino mixing matrix. New experiments to study the remaining unknown mixing angle are currently under development. ...

  15. Neutrino mass and oscillation: An introductory review

    Indian Academy of Sciences (India)

    D P Roy

    2000-01-01

    After a brief introduction to neutrino mass via the see-saw model I discuss neutrinomixing and oscillation, first in vacuum and then its matter enhancement. Then the solar and atmospheric neutrino oscillation data are briefly reviewed. Finally I discuss the problem of reconciling hierarchical neutrino masses with at least one large mixing, as implied by these data. A minimal see-saw model for reconciling the two is discussed.

  16. Neutrino oscillations: Recent results and future directions

    Indian Academy of Sciences (India)

    Amitava Raychaudhuri

    2000-01-01

    A brief introduction to the phenomena of vacuum neutrino oscillations and resonant flavour conversion is presented with a heavy pedagogic leaning. Variants of these ideas, e.g., neutrino helicity flip in a magnetic field, violation of the equivalence principle, etc. are outlined. A few vexing issues pertaining to the quantum mechanics of neutrino oscillations are discussed. Expectations from some of the future experiments are summarized.

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

    Directory of Open Access Journals (Sweden)

    Z.S. Wang

    2015-11-01

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

  18. Pseudoscalar - sterile neutrino interactions: reconciling the cosmos with neutrino oscillations

    CERN Document Server

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

    2016-01-01

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

  19. Neutrino oscillations: From a historical perspective to the present status

    Science.gov (United States)

    Bilenky, S.

    2016-07-01

    The history of neutrino mixing and oscillations is briefly presented. Basics of neutrino mixing and oscillations and convenient formalism of neutrino oscillations in vacuum are given. The role of neutrino in the Standard Model and the Weinberg mechanism of the generation of the Majorana neutrino masses are discussed.

  20. Searching for neutrino oscillation parameters in long baseline experiments

    CERN Document Server

    Vihonen, Sampsa

    2016-01-01

    Developing neutrino astronomy requires a good understanding of the neutrino oscillations mechanism. The European strategy for neutrino oscillation physics sets a high priority on future long baseline neutrino experiments with the aim to measure the intrinsic parameters that govern the neutrino oscillations. In this work we take a look at the next generation of long baseline experiments and discuss their prospects in future research.

  1. Neutrino oscillations: from an historical perspective to the present status

    CERN Document Server

    Bilenky, S

    2016-01-01

    The history of neutrino mixing and oscillations is briefly presented. Basics of neutrino mixing and oscillations and convenient formalism of neutrino oscillations in vacuum is given. The role of neutrino in the Standard Model and the Weinberg mechanism of the generation of the Majorana neutrino masses are discussed.

  2. Neutrino oscillations in strong magnetic fields

    International Nuclear Information System (INIS)

    Neutrino conversion processes between two neutrino species and the corresponding oscillations induced by strong magnetic fields are considered. The value of the critical strength of magnetic field Bcr as a function of characteristics of neutrinos in vacuum (Δm2ν, mixing angle θ), effective particle density of matter neff, neutrino (transition) magnetic moment μ-tilde and energy E is introduced. It is shown that the neutrino conversion and oscillations effects induced by magnetic fields B ≥ Bcr are important and may result in the depletion of the initial type of ν's in the bunch. A possible increase of these effects in the case when neutrinos pass through a sudden decrease of density of matter (''cross-boundary effect'') and applications to neutrinos from neutron stars and supernova are discussed. (author). 25 refs

  3. Possible consequences for neutrino oscillations of a tachyonic muon neutrino

    International Nuclear Information System (INIS)

    Some papers appeared recently, which are noticeable since they call attention to interesting experimental results referring to the old-dated question whether neutrinos are Superluminal (or not): but they diregarded most of the previous theoretical literature. We complement them, therefore, from the theoretical point of view; and add some experimental predictions that could be tested, especially in connection with neutrino oscillations

  4. Helicity oscillations of Dirac and Majorana neutrinos

    CERN Document Server

    Dobrynina, Alexandra; Raffelt, Georg

    2016-01-01

    The helicity of a Dirac neutrino with mass $m$ evolves under the influence of a $B$-field because it has a magnetic dipole moment proportional to $m$. Moreover, it was recently shown that a polarized or anisotropic medium engenders the same effect for both Dirac and Majorana neutrinos. Because a $B$-field polarizes a background medium, it instigates helicity oscillations even for Majorana neutrinos unless the medium is symmetric between matter and antimatter. Motivated by these observations, we review the impact of a $B$-field and of an anisotropic or polarized medium on helicity oscillations for Dirac and Majorana neutrinos from the common perspective of in-medium dispersion.

  5. Atmospheric neutrino oscillations for earth tomography

    International Nuclear Information System (INIS)

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can measure the lower mantle density of the earth with a precision at the level of a few percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  6. Atmospheric neutrino oscillations for earth tomography

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Walter

    2016-04-05

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can measure the lower mantle density of the earth with a precision at the level of a few percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  7. Atmospheric Neutrino Oscillations for Earth Tomography

    CERN Document Server

    Winter, Walter

    2015-01-01

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can robustly measure the lower mantle density of the earth with a precision at the level of 4-5 percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  8. Atmospheric neutrino oscillations for Earth tomography

    Science.gov (United States)

    Winter, Walter

    2016-07-01

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can measure the lower mantle density of the earth with a precision at the level of a few percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  9. Solar neutrino observations and neutrino oscillations

    International Nuclear Information System (INIS)

    The results of recent Kamiokande-II and 37Cl solar-neutrino experiments are quantitatively analyzed assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar-neutrino problem. It is found that the parameter region known as the ''large mass'' solution to the solar-neutrino problem is disfavored by a little more than 1 σ while the ''small mass'' and ''large angle'' solutions are in good agreement at this level. The implications on this analysis from time variations in the data are discussed

  10. The Unruh effect and oscillating neutrinos

    CERN Document Server

    Ahluwalia, Dharam Vir; Torrieri, Giorgio

    2015-01-01

    We point out that neutrino oscillations imply an ambiguity in the definition of the vacuum and the coupling to gravity, with experimentally observable consequences due to the Unruh effect. In an accelerating frame, the detector should see a bath of mass Eigenstates neutrinos. In inertial processes, neutrinos are produced and absorbed as charge Eigenstates. The two cannot be reconciled by a spacetime coordinate transformation. This makes manifestations of the Unruh effect in neutrino physics a promising probe of both neutrinos and fundamental quantum field theory. In this respect, we suggest $p\\rightarrow n +\\ell^+ + {\

  11. A study of neutrino oscillations in MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Raufer, Tobias Martin; /Oxford U.

    2007-06-01

    MINOS is a long-baseline neutrino oscillations experiment located at Fermi National Accelerator Laboratory (FNAL), USA. It makes use of the NuMI neutrino beamline and two functionally identical detectors located at distances of {approx}1km and {approx}735km from the neutrino production target respectively. The Near Detector measures the composition and energy spectrum of the neutrino beam with high precision while the Far Detector looks for evidence of neutrino oscillations. This thesis presents work conducted in two distinct areas of the MINOS experiment: analysis of neutral current and charged current interactions. While charged current events are only sensitive to muon neutrino disappearance, neutral current events can be used to distinguish oscillations into sterile neutrinos from those involving only active neutrino species. A complete, preliminary neutral current study is performed on simulated data. This is followed by a more detailed investigation of neutral current neutrino interactions in the MINOS Near Detector. A procedure identifying neutral current interactions and rejecting backgrounds due to reconstruction failures is developed. Two distinct event classification methods are investigated. The selected neutral current events in the Near Detector are used to extract corrections to the neutral current cross-section in the MINOS Monte Carlo simulation as a function of energy. The resulting correction factors are consistent with unity. The main MINOS charged current neutrino disappearance analysis is described. We present the Monte Carlo tuning procedure, event selection, extrapolation from Near to Far Detector and fit for neutrino oscillations. Systematic errors on this measurement are evaluated and discussed in detail. The data are consistent with neutrino oscillations with the following parameters: 2.74 {sup +0.44}{sub -0.26} x 10{sup -3} eV{sup 2} and sin{sup 2}(2{theta}{sub 23}) > 0.87 at 68% confidence level.

  12. Squeezed neutrino oscillations in quantum field theory

    CERN Document Server

    Alfinito, E; Iorio, A; Vitiello, G

    1995-01-01

    By resorting to recent results on fermion mixing which show that the Fock space of definite flavor states is unitarily inequivalent to the Fock space of definite mass states, we discuss the phenomenological implications on the neutrino oscillation formula. For finite momentum the oscillation amplitude is depressed, or "squeezed", by a momentum dependent factor. In the relativistic limit the conventional oscillation formula is recovered.

  13. (g-2)μ anomaly and neutrino oscillations within the left-right model

    International Nuclear Information System (INIS)

    The Higgs sector structure of the left right model is investigated. The coupling constants of the physical Higgs bosons are expressed in terms of the oscillation parameters of the heavy neutrinos. The electroweak corrections to the value of the anomalous magnetic moment of the muon coming from the Higgs bosons axe found. It is shown that in the LRM the motion of the light neutrino flux in matter is described within the hybrid three-neutrino scheme, namely, the neutrino oscillations and the non standard neutrino interactions, caused by the Higgs sector. These non standard contributions may considerably change the matter potential compared with the SM prediction. Therefore, the analysis of the (g-2)μ, anomaly and the oscillations of the light neutrinos in matter could be used to constrain the parameters of the heavy neutrinos. (author)

  14. Four-Neutrino Oscillation Solutions of the Solar Neutrino Problem

    CERN Document Server

    Giunti, C; Peña-Garay, C

    2000-01-01

    We present an analysis of the neutrino oscillation solutions of the solar neutrino problem in the framework of four-neutrino mixing where a sterile neutrino is added to the three standard ones. We perform a fit to the full data set corresponding to the 825-day Super-Kamiokande data sample as well as to Chlorine, GALLEX and SAGE and Kamiokande experiments. In our analysis we use all measured total event rates as well as all Super-Kamiokande data on the zenith angle dependence and the recoil electron energy spectrum. We consider both transitions via the Mikheyev-Smirnov-Wolfenstein (MSW) mechanism as well as oscillations in vacuum (just-so) and find the allowed solutions for different values of the additional mixing angles. This framework permits transitions into active or sterile neutrinos controlled by the additional parameter $\\cos^2(\\vartheta_{23}) \\cos^2(\\vartheta_{24})$ . We discuss the maximum allowed values of this additional mixing parameter for the different solutions.

  15. Neutrino mixing and lepton CP-phase in neutrino oscillations

    International Nuclear Information System (INIS)

    One studied oscillations of the Dirac neutrinos belonging to three generations in vacuum with regard to the effect of the lepton CP-breaking phase on them in the matrix of lepton mixing (analogue of the quark CP-phase). In the general form one obtained formulae for probabilities of transition of neutrino of one kind to another at oscillations depending on three angles of mixing and on CP-phase. It was pointed that when measuring oscillation average probabilities of transition of neutrino of one kind to another one might in principle, restore the value of lepton CP-phase. Manifestation of CP-phase in the form of deviation of the values of probabilities of direct neutrino transition from reverse one is the effect practically escaping observation

  16. Supernova Neutrino Nucleosynthesis of Light Elements with Neutrino Oscillations

    CERN Document Server

    Yoshida, T; Yokomakura, H; Kimura, K; Takamura, A; Hartmann, D H

    2006-01-01

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

  17. CP Violation in Vacuum Neutrino Oscillation Experiments

    CERN Document Server

    Gago, A M; Zukanovich-Funchal, R

    2000-01-01

    We discuss the use of the CP asymmetry parameter (Acp) as a possible observable of CP violation in the leptonic sector. In order to do this, we study for a wide range of values of L/E the behavior of this asymmetry for the corresponding maximal value of the CP violation factor allowed by all present experimental limits on neutrino oscillations in vacuum and the recent Super-Kamiokande atmospheric neutrino result. We work in the three neutrino flavor framework.

  18. Oscillations of solar and atmospheric neutrinos

    OpenAIRE

    Barbieri, R; Hall, L. J.; Smith, D.; A. Strumia; Weiner, N

    1998-01-01

    Motivated by recent results from SuperKamiokande, we study both solar and atmospheric neutrino fluxes in the context of oscillations of the three known neutrinos. We aim at a global view which identifies the various possibilities, rather than attempting the most accurate determination of the parameters of each scenario. For solar neutrinos we emphasise the importance of performing a general analysis, independent of any particular solar model and we consider the possibility that any one of the...

  19. Neutrino Oscillation Induced by Chiral Phase Transition

    Institute of Scientific and Technical Information of China (English)

    MU Cheng-Fu; SUN Gao-Feng; ZHUANG Peng-Fei

    2009-01-01

    Electric charge neutrality provides a relationship between chiral dynamics and neutrino propagation in compact stars.Due to the sudden drop of the electron density at the first-order chiral phase transition,the oscillation for low energy neutrinos is significant and can be regarded as a signature of chiral symmetry restoration in the core of compact stars.

  20. Long-Baseline Neutrino Oscillation Experiments

    OpenAIRE

    Feldman, G J; Hartnell, J.; T. Kobayashi

    2013-01-01

    A review of accelerator long-baseline neutrino oscillation experiments is provided, including all experiments performed to date and the projected sensitivity of those currently in progress. Accelerator experiments have played a crucial role in the confirmation of the neutrino oscillation phenomenon and in precision measurements of the parameters. With a fixed baseline and detectors providing good energy resolution, precise measurements of the ratio of distance/energy (L/E) on the scale of ind...

  1. Neutrino Oscillations Present Status and Future Plans

    CERN Document Server

    Thomas, Jennifer

    2008-01-01

    This book reviews the status of a very exciting field - neutrino oscillations - at a very important time. The fact that neutrinos have mass has only been proved in the last few years and the acceptance of that fact has opened up a whole new area of study to understand the fundamental parameters of the mixing matrix. The book summarizes the results from all the experiments which have played a role in the measurement of neutrino oscillations and briefly describes the scope of some new planned experiments. Contributions include a theoretical introduction by Stephen Parke from FNAL, as well as art

  2. Evidence for Oscillation of Atmospheric Neutrinos

    International Nuclear Information System (INIS)

    We present an analysis of atmospheric neutrino data from a 33.0thinspthinspktonthinspthinspyr (535-day) exposure of the Super-Kamiokande detector. The data exhibit a zenith angle dependent deficit of muon neutrinos which is inconsistent with expectations based on calculations of the atmospheric neutrino flux. Experimental biases and uncertainties in the prediction of neutrino fluxes and cross sections are unable to explain our observation. The data are consistent, however, with two-flavor νμ↔ντ oscillations with sin22θ >0.82 and 5x10-42-3 eV2 at 90% confidence level. copyright 1998 The American Physical Society

  3. Spectrometry of the Earth using neutrino oscillations

    Science.gov (United States)

    Taketa, Akimichi; Rott, Carsten

    2016-04-01

    Neutrinos have favorable properties for measuring the elemental composition deep inside the earth's interior. First, they propagate a long distance almost undisturbed through the earth due to their weak interactions with matter. Secondly, neutrino oscillations in matter are sensitive to the electron density of the medium traversed by them. Therefore, neutrinos can be used for a probe to determine the average atomic mass ratio Z/A of the earth's core by comparing with the earth's nucleus density distribution that is inferred from seismic observations. There is a little uncertainty in densities of the earth's core, but our knowledge of its main light element is still not fixed. With the advent of the new-generation megaton neutrino detectors, neutrino oscillation mass spectrometry will allow us to constrain directly the light elements in the earth's outer core. We report the detail of this novel technic and the sensitivity study.

  4. Some Unsettled Questions in the Problem of Neutrino Oscillations

    OpenAIRE

    Beshtoev, Kh. M.

    2002-01-01

    It is noted that the theory of neutrino oscillations can be constructed only in the framework of the particle physics theory, where is a mass shell conception and then transitions (oscillations) between neutrinos with equal masses are real and between neutrinos with different masses are virtual. It is necessary to solve the question: which type of neutrino transitions (oscillations) is realized in nature? There can be three types of neutrino transitions (oscillations). At present it is consid...

  5. Neutrino oscillation above a black hole accretion disk

    International Nuclear Information System (INIS)

    We examine neutrino oscillations in the context of an accretion disk surrounding a black hole. Because accretion disks produce large quantities of neutrinos, they may be home to interesting neutrino oscillation as well. We model accretion disks associated with stellar collapse for the sake of understanding neutrino oscillations. We find that the neutrino oscillations include phenomena seen in the protoneutron star setting as well as phenomena not seen elsewhere

  6. Neutrino oscillation above a black hole accretion disk

    Energy Technology Data Exchange (ETDEWEB)

    Malkus, A.; Kneller, J. P.; McLaughlin, G. C. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Surman, R. [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States)

    2015-05-15

    We examine neutrino oscillations in the context of an accretion disk surrounding a black hole. Because accretion disks produce large quantities of neutrinos, they may be home to interesting neutrino oscillation as well. We model accretion disks associated with stellar collapse for the sake of understanding neutrino oscillations. We find that the neutrino oscillations include phenomena seen in the protoneutron star setting as well as phenomena not seen elsewhere.

  7. When do neutrinos cease to oscillate?

    CERN Document Server

    Giunti, C; Lee, U W

    1998-01-01

    In order to investigate when neutrinos cease to oscillate in the framework of quantum field theory, we have reexamined the wave packet treatment of neutrino oscillations by taking different sizes of the wave packets of the particles involved in the production and detection processes. The treatment is shown to be considerably simplified by using the Grimus-Stockinger theorem which enables us to carry out the integration over the momentum of the propagating neutrino. Our new results confirm the recent observation by Kiers, Nussinov and Weiss that a precise measurement of the energies of the particles involved in the detection process would increase the coherence length. We also present a precise definition of the coherence length beyond which neutrinos cease to oscillate.

  8. Sterile neutrino analysis of reactor-neutrino oscillation

    CERN Document Server

    Kang, S K; Ko, Y; Siyeon, K

    2013-01-01

    Sterile neutrinos are one candidate to explain anomalies in neutrino oscillations. The mass-difference-driving oscillation between flavors can be probed only within specific combinations of baseline and flight energy. For a neutrino whose mass is completely unknown, it is necessary to scan all available ranges in spectrum and all accessible baselines. Here, we present four-neutrino analysis of the results announced by RENO and Daya Bay, which performed the definitive measurements of $\\theta_{13}$ based on the disappearance of the inverse-beta-decay antineutrino at km-order baselines. Our results within 3+1 scheme include the exclusion curve of $\\Delta m_{41}$ vs. $\\theta_{14}$, and the adjustment of $\\theta_{13}$ due to the contribution of $\\theta_{14}$ to the disappearance of electron antineutrinos.

  9. Progress in neutrino oscillation searches and their implications

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2003-02-01

    Neutrino oscillation, in which a given flavor of neutrino transforms into another is a powerful tool for probing small neutrino masses. The intrinsic neutrino properties involved are neutrino mass squared difference 2 and the mixing angle in vacuum . In this paper I will summarize the progress that we have achieved in our search for neutrino oscillation with special emphasis on the recent results from the Sudbury Neutrino Observatory (SNO) on the measurement of solar neutrino fluxes. I will outline the current bounds on the neutrino masses and mixing parameters and discuss the major physics goals of future neutrino experiments in the context of the present picture.

  10. Spontaneous breaking of spatial symmetries in collective neutrino oscillations

    CERN Document Server

    Duan, Huaiyu

    2014-01-01

    A dense neutrino medium can experience collective oscillations or self-induced flavor transformation through nonlinear neutrino-neutrino refraction. To make the problem of collective neutrino oscillations more tractable, all previous studies on this subject have assumed some spatial symmetry or symmetries in the neutrino medium (e.g., translation symmetries in the early universe and spherical symmetry in core-collapse supernovae). We point out that the collective oscillation modes studied in such models are very special. Using a simple toy model we show that spatial symmetries can be broken spontaneously in collective neutrino oscillations. We also show that the spatial-symmetry-breaking (SSB) modes of neutrino oscillations can exist for both neutrino mass hierarchies and even in the regimes where collective neutrino oscillations were previously thought to be suppressed. This finding calls for study of collective neutrino oscillations in multi-dimensional models.

  11. Massive neutrinos flavor mixing of leptons and neutrino oscillations

    CERN Document Server

    2015-01-01

    Since the discovery of neutrino oscillations neutrino physics has become an interesting field of research in physics. They imply that neutrino must have a small mass and that the neutrinos, coupled to the charged leptons, are mixtures of the mass eigenstates, analogous to the flavor mixing of the quarks. The mixing angles for the quarks are small, but for the leptons two of the mixing angles are large. The masses of the three neutrinos must be very small, less than 1 eV, but from the oscillation experiments we only know the mass differences — the absolute masses are still unknown. Also we do not know, if the masses of the neutrinos are Dirac masses, as the masses of the charged leptons and of the quarks, or whether they are Majorana masses. In this volume, an overview of the present state of research in neutrino physics is given by well-known experimentalists and theorists. The contents — originated from talks and discussions at a recent conference addressing some of the most pressing open questions in n...

  12. Accelerator-based neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Deborah A.; /Fermilab

    2007-12-01

    Neutrino oscillations were first discovered by experiments looking at neutrinos coming from extra-terrestrial sources, namely the sun and the atmosphere, but we will be depending on earth-based sources to take many of the next steps in this field. This article describes what has been learned so far from accelerator-based neutrino oscillation experiments, and then describe very generally what the next accelerator-based steps are. In section 2 the article discusses how one uses an accelerator to make a neutrino beam, in particular, one made from decays in flight of charged pions. There are several different neutrino detection methods currently in use, or under development. In section 3 these are presented, with a description of the general concept, an example of such a detector, and then a brief discussion of the outstanding issues associated with this detection technique. Finally, section 4 describes how the measurements of oscillation probabilities are made. This includes a description of the near detector technique and how it can be used to make the most precise measurements of neutrino oscillations.

  13. Resurrection of large lepton number asymmetries from neutrino flavor oscillations

    CERN Document Server

    Barenboim, Gabriela; Park, Wan-Il

    2016-01-01

    We numerically solve the evolution equations of neutrino three-flavor density matrices, and show that, even if neutrino oscillations mix neutrino flavors, large lepton number asymmetries are still allowed in certain limits by Big Bang Nucleosynthesis (BBN).

  14. Present Aspects and Future Prospects of Neutrino Mass and Oscillation

    CERN Document Server

    Ghosh, Monojit

    2016-01-01

    Neutrinos are neutral, spin-$\\frac{1}{2}$ particles which undergo only weak interactions. The experimentally observed phenomenon of neutrino oscillation establishes the fact that neutrinos are massive and there is mixing between different neutrino flavours. This constitutes the first unambiguous hint towards the physics Beyond Standard Model (BSM). In the BSM theories, the neutrino mass terms in the Lagrangian lead to the non-diagonal neutrino mass matrix in the flavour basis which depends on neutrino mass and mixing parameters. Thus knowledge of the neutrino oscillation parameters and understanding the underlying symmetries of the neutrino mass matrix are very important as they can give an insight to the new physics beyond Standard Model. Therefore the measurement of different oscillation parameters and studying the structure of the neutrino mass matrix are some of the main goals in neutrino physics at present. In this thesis we have studied the potential of present/future neutrino oscillation experiments an...

  15. Relic neutrino decoupling with flavour oscillations revisited

    CERN Document Server

    de Salas, Pablo F

    2016-01-01

    We study the decoupling process of neutrinos in the early universe in the presence of three-flavour oscillations. The evolution of the neutrino spectra is found by solving the corresponding momentum-dependent kinetic equations for the neutrino density matrix, including for the first time the proper collision integrals for both diagonal and off-diagonal elements. This improved calculation modifies the evolution of the off-diagonal elements of the neutrino density matrix and changes the deviation from equilibrium of the frozen neutrino spectra. However, it does not vary the contribution of neutrinos to the cosmological energy density in the form of radiation, usually expressed in terms of the effective number of neutrinos, N_eff. We find a value of N_eff=3.045, in agreement with previous theoretical calculations and consistent with the latest analysis of Planck data. This result does not depend on the ordering of neutrino masses. We also consider the effect of non-standard neutrino-electron interactions (NSI), ...

  16. Spectrometry of the Earth using Neutrino Oscillations

    OpenAIRE

    Rott, C.; Taketa, A.; Bose, D

    2015-01-01

    The unknown constituents of the interior of our home planet have provoked the human imagination and driven scientific exploration. We herein demonstrate that large neutrino detectors could be used in the near future to significantly improve our understanding of the Earth's inner chemical composition. Neutrinos, which are naturally produced in the atmosphere, traverse the Earth and undergo oscillations that depend on the Earth's electron density. The Earth's chemical composition can be determi...

  17. More general BBN constraints on neutrino oscillations

    International Nuclear Information System (INIS)

    Stringent constraints on active-sterile neutrino oscillations were obtained from cosmology. However, mainly the case of initially zero νs state δNs = 0 was considered. We study cosmological constraints on νe ↔ νs oscillations for the case when νe is partially filled initially, i.e. 0 2 4He, in the presence of νe ↔ νs oscillations, effective after neutrino decoupling. We account for all known oscillations effects on cosmological nucleosynthesis. We calculate the cosmological constraints on oscillation parameters corresponding to non-zero initial population of the sterile state and 5% 4He overproduction. These generalized cosmological constraints corresponding to δN2 > 0 are relaxed in comparison to the δN2 = 0 case and the relaxation is proportional to δN2. (author)

  18. Neutrino oscillations in magnetically driven supernova explosions

    CERN Document Server

    Kawagoe, Shio; Kotake, Kei

    2009-01-01

    We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarcy with a relatively large theta_(13), we show that survival probabilities of electron type neutrinos and antineutrinos seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of electron type antineutrinos observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which lea...

  19. Neutrino oscillations in strong gravitational fields

    CERN Document Server

    Roy, M F; Roy, Mou; Wudka, Jose

    1996-01-01

    Neutrino oscillations in the presence of strong gravitational fields are studied. We look at very high energy neutrinos (\\sim 1 TeV) emanating from Active Galactic Nuclei (AGN). It is observed that spin flavor resonant transitions of such neutrinos may occur in the vicinity of AGN due to {\\it gravitational} effects and due to the presence of a large magnetic field (\\sim 1 Tesla). A point to note is that matter effects (normal MSW transitions) become negligible in comparison o gravitational effects in our scenario.

  20. Future reactor neutrino oscillation experiments at Krasnoyarsk

    International Nuclear Information System (INIS)

    Recent studies of atmospheric neutrinos and the results from CHOOZ and Palo-Verde experiment call for new and more sensitive searches for neutrino oscillations at reactors. The main goal of the project considered here is to look for very small mixing angle oscillations of electron neutrinos in the atmospheric neutrino mass parameter region around Δm2 ∼ 3 x 10-3eV2 and to define the element Ue3 of the neutrino mixing matrix (Ue3 is the contribution of the mass-3 state to the electron neutrino flavor state). The practical goal of the project is to decrease, relative to the CHOOZ, the statistic and systematic errors as much as possible. To achieve this we plan to use two identical antineutrino detectors each with a ∼ 50-ton liquid scintillator target located at ∼1100 m and ∼250 m from the underground reactor (∼ 600 mwe). Much attention is given to the detector calibration and monitoring procedures. As a first step we consider two much smaller pilot detectors each of ∼ a 3 ton target mass stationed at ∼20 m and 35-60 m from the reactor. The goals of this first stage are: (i) to accumulate necessary experience and (ii) to investigate with electron neutrinos the LSND mass parameter region

  1. OPERA neutrino oscillation search: Status and perspectives

    Science.gov (United States)

    Gornushkin, Yu.

    2016-07-01

    OPERA is a long-baseline neutrino experiment at the Gran Sasso laboratory (LNGS) designed to search for ν_{{μ}}^{} → ν_{{τ}}^{} oscillations in a direct appearance mode on an event by event basis. OPERA took data in 2008-2012 with the CNGS neutrino beam from CERN. The data analysis is ongoing, with the goal of establishing ν_{{τ}}^{} appearance with a high significance. Complementary studies of the ν_{{μ}}^{} → ν_{{e}}^{} oscillations and atmospheric muons fluxes were performed as well. Current results of the experiment are presented and perspectives discussed.

  2. Neutrino oscillation study in the muon neutrino → electron neutrino channel at the Brookhaven accelerator

    International Nuclear Information System (INIS)

    The E816 experiment described in this thesis is devoted to a neutrino oscillation search at the Brookhaven AGS. The method used here is to look with a fine grained calorimeter for the appearence of electron neutrino in a muon neutrino beam. After recalling the theoretical treatment of the neutrino mass problem, the experimental phenomenology of massive neutrinos and more specifically neutrino oscillations is reviewed. The experiment itself is then extensively described, both on the technical side (detector, beam, simulation) and on the analysis side. In particular the statistical separation of the electromagnetic showers from electrons - our signal - and from photons - our background - treated in detail. The present analysis is based on 2/3 of the final statistics and it leads to the - preliminary - observation of an electron excess in the neutrino interactions yielding 19 ± 15.6 (stat) ± 7 (syst)

  3. The OPERA long baseline neutrino oscillation experiment

    International Nuclear Information System (INIS)

    OPERA is a long baseline neutrino oscillation experiment designed to observe the appearance of vτ in a pure vμ beam in the parameter space indicated by the atmospheric neutrinos oscillation signal. The detector is situated in the underground LNGS laboratory under 3 800 water meter equivalent at a distance of 730 km from CERN where the CNGS neutrino beam to which it is exposed originates. It consists of two identical 0.68 kilotons lead/nuclear emulsion targets, each instrumented with a tracking device and complemented by a muon spectrometer. The concept and the status of the detector are described and the first results obtained with cosmic rays and during two weeks of beam commissioning in 2006 are reported

  4. Spectrometry of the Earth using Neutrino Oscillations

    CERN Document Server

    Rott, Carsten; Bose, Debanjan

    2015-01-01

    The unknown constituents of the interior of our home planet have provoked the human imagination and driven scientific exploration. We herein demonstrate that large neutrino detectors could be used in the near future to significantly improve our understanding of the Earth's inner chemical composition. Neutrinos, which are naturally produced in the atmosphere, traverse the Earth and undergo oscillations that depend on the Earth's electron density. The Earth's chemical composition can be determined by combining observations from large neutrino detectors with seismic measurements of the Earth's matter density. We present a method that will allow us to perform a measurement that can distinguish between composition models of the outer core. We show that the next-generation large-volume neutrino detectors can provide sufficient sensitivity to reject outer core models with large hydrogen content and thereby demonstrate the potential of this novel method. In the future, dedicated instruments could be capable of distin...

  5. Collective neutrino oscillations in nonspherical geometry

    International Nuclear Information System (INIS)

    The rich phenomenology of collective neutrino oscillations has been studied only in one-dimensional or spherically symmetric systems. Motivated by the nonspherical example of coalescing neutron stars, presumably the central engines of short gamma-ray bursts, we use the Liouville equation to formulate the problem for general source geometries. Assuming the neutrino ensemble displays self-maintained coherence, the problem once more becomes effectively one-dimensional along the streamlines of the overall neutrino flux. This approach for the first time provides a formal definition of the 'single-angle approximation' frequently used for supernova neutrinos and allows for a natural generalization to nonspherical geometries. We study the explicit example of a disk-shaped source as a proxy for coalescing neutron stars.

  6. On entanglement in neutrino mixing and oscillations

    International Nuclear Information System (INIS)

    We report on recent results about entanglement in the context of particle mixing and oscillations. We study in detail single-particle entanglement arising in two-flavor neutrino mixing. The analysis is performed first in the context of Quantum Mechanics, and then for the case of Quantum Field Theory.

  7. On entanglement in neutrino mixing and oscillations

    OpenAIRE

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

    2010-01-01

    We report on recent results about entanglement in the context of particle mixing and oscillations. We study in detail single-particle entanglement arising in two-flavor neutrino mixing. The analysis is performed first in the context of Quantum Mechanics, and then for the case of Quantum Field Theory.

  8. On entanglement in neutrino mixing and oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2010-06-01

    We report on recent results about entanglement in the context of particle mixing and oscillations. We study in detail single-particle entanglement arising in two-flavor neutrino mixing. The analysis is performed first in the context of Quantum Mechanics, and then for the case of Quantum Field Theory.

  9. Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Marino, Alysia Diane

    2004-08-10

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

  10. Evidence for neutrino oscillations in the Sudbury Neutrino Observatory

    International Nuclear Information System (INIS)

    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 ∼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.)±0.0680.065(sys.)±0.02(theor.)] x 106cm-2s-1, via the elastic-scattering interaction is [2.21±0.22(stat.)±0.120.11(sys.)±0.01(theor.)] x 106cm-2s-1, and via the neutral-current interaction is [5.05±0.23(stat.)±0.370.31(sys.)±0.06(theor.)] x 106cm-2s-1. The electron-only flux seen via the charged-current interaction is more than 7σ 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

  11. Neutrino Oscillations, Lorentz/CPT Violation, and Dark Energy

    CERN Document Server

    Ando, Shin'ichiro; Mocioiu, Irina

    2009-01-01

    If dark energy (DE) couples to neutrinos, then there may be apparent violations of Lorentz/CPT invariance in neutrino oscillations. The DE-induced Lorentz/CPT violation takes a specific form that introduces neutrino oscillations that are energy independent, differ for particles and antiparticles, and can lead to novel effects for neutrinos propagating through matter. We show that ultra-high-energy neutrinos may provide one avenue to seek this type of Lorentz/CPT violation in \

  12. A Novel Approach In The Detection Of Muon Neutrino To Tau Neutrino Oscillation From Extragalactic Neutrinos

    CERN Document Server

    Iyer, S R

    2001-01-01

    A novel approach is proposed for studying the νμ → ν τ oscillation and detection of extragalactic neutrinos. Active Galactic Nuclei (AGN), Gamma Ray Bursters (GRB) and Topological Defects are believed to be sources of ultrahigh energy νμ and ντ. These astrophysical sources provide a long baseline of 100Mpc, or more, for possible detection of νμ → ντ oscillation with mixing parameter Δm2 down to 10 −17 eV2, many orders of magnitude below the current accelerator experiments. The propagation characteristics of upward going muon and tau neutrinos is studied to show that high energy tau neutrinos cascade down in energy as they propagate through the Earth, producing an enhancement of the incoming tau neutrino flux in the low energy region. By contrast, high energy muon neutrinos get attenuated as they traverse the Earth. It is observed that the relative steepness of the incoming neutrino flux...

  13. Phenomenology of neutrino oscillations at the neutrino factory

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jian

    2011-12-19

    We consider the prospects for a neutrino factory measuring mixing angles, the CP violating phase and mass-squared differences by detecting wrong-charge muons arising from the chain {mu}{sup +} {yields} {nu}{sub e} {yields} {nu}{sub {mu}} {yields} {mu}{sup -} and the right-charge muons coming from the chain {mu}{sup +} {yields} anti {nu}{sub {mu}} {yields} anti {nu}{sub {mu}} {yields} {mu}{sup -} (similar to {mu}{sup -} chains), where {nu}{sub e} {yields} {nu}{sub {mu}} and anti {nu}{sub {mu}} {yields} anti {nu}{sub {mu}} are neutrino oscillation channels through a long baseline. First, we study physics with near detectors and consider the treatment of systematic errors including cross section errors, flux errors, and background uncertainties. We illustrate for which measurements near detectors are required, discuss how many are needed, and what the role of the flux monitoring is. We demonstrate that near detectors are mandatory for the leading atmospheric parameter measurements if the neutrino factory has only one baseline, whereas systematic errors partially cancel if the neutrino factory complex includes the magic baseline. Second, we perform the baseline and energy optimization of the neutrino factory including the latest simulation results from the magnetized iron neutrino detector (MIND). We also consider the impact of {tau} decays, generated by appearance channels {nu}{sub {mu}} {yields} {nu}{sub {tau}} and {nu}{sub e} {yields} {nu}{sub {tau}}, on the discovery reaches of the mass orderings, the leptonic CP violation, and the non-zero {theta}{sub 13}, which we find to be negligible for the considered detector. Third, we make a comparison of a high energy neutrino factory to a low energy neutrino factory and find that they are just two versions of the same experiment optimized for different regions of the parameter space. In addition, we briefly comment on whether it is useful to build the bi-magic baseline at the low energy neutrino factory. Finally, the

  14. Aspects of Neutrino Oscillation in Alternative Gravity Theories

    CERN Document Server

    Chakraborty, Sumanta

    2015-01-01

    Neutrino spin and flavour oscillation in curved spacetime have been studied for the most general static spherically symmetric configuration. Using the symmetry properties we have derived spin oscillation frequency for neutrino moving along a geodesic or in a circular orbit. Starting from the expression of neutrino spin oscillation frequency we have shown that even in this general context, in high energy limit the spin oscillation frequency for neutrino moving along circular orbit vanishes. This finally lends itself to non-zero probability of neutrino helicity flip. While for neutrino flavour oscillation we have derived general results for oscillation phase, which subsequently have been applied to different gravity theories. These include dilaton field coupled to Maxwell field tensor, generalization of Schwarzschild solution by introduction of quadratic curvature terms of all possible form to the Einstein-Hilbert action and finally regular black hole solutions. In all these cases using the solar neutrino oscil...

  15. Sterile Neutrino Fits to Short Baseline Neutrino Oscillation Measurements

    CERN Document Server

    Conrad, J M; Karagiorgi, G; Shaevitz, M H; Spitz, J

    2012-01-01

    This paper reviews short baseline oscillation experiments as interpreted within the context of one, two, and three sterile neutrino models associated with additional neutrino mass states in the ~1 eV range. Appearance and disappearance signals and limits are considered. We show that fitting short baseline data sets to a (3+3) model, defined by three active and three sterile neutrinos, results in an overall goodness of fit of 67%, and a compatibility of 90% among all data sets -- to be compared to the compatibility of 0.043% and 13% for a (3+1) and a (3+2) model, respectively. While the (3+3) fit yields the highest quality overall, it still finds inconsistencies with the MiniBooNE appearance data sets; in particular, the global fit fails to account for the observed MiniBooNE low-energy excess. Given the overall improvement, we recommend using the results of (3+2) and (3+3) fits, rather than (3+1) fits, for future neutrino oscillation phenomenology. These results motivate the pursuit of further short baseline e...

  16. Global three-neutrino oscillation analysis of neutrino data

    CERN Document Server

    González-Garciá, M Concepción; Peña-Garay, C; Valle, José W F

    2001-01-01

    A global analysis of the solar, atmospheric and reactor neutrino data is presented in terms of three-neutrino oscillations. We include the most recent solar neutrino rates of Homestake, SAGE, GALLEX and GNO, as well as the recent 1117 day Super-Kamiokande data sample, including the recoil electron energy spectrum both for day and night periods, and we treat in a unified way the full parameter space for oscillations, correctly accounting for the transition from the matter enhanced to the vacuum oscillations regime. Likewise, we include in our description conversions with theta /sub 12/> pi /4. For the atmospheric data we perform our analysis of the contained events and the upward-going nu -induced muon fluxes, including the previous data samples of Frejus, IMB, Nusex, and Kamioka experiments as well as the full 71 kton yr (1144 days) Super-Kamiokande data set, the recent 5.1 kton yr contained events of Soudan2 and the results on upgoing muons from the MACRO detector. We first present the allowed regions of sol...

  17. High intensity neutrino oscillation facilities in Europe

    CERN Document Server

    Edgecock, T R; Davenne, T; Densham, C; Fitton, M; Kelliher, D; Loveridge, P; Machida, S; Prior, C; Rogers, C; Rooney, M; Thomason, J; Wilcox, D; Wildner, E; Efthymiopoulos, I; Garoby, R; Gilardoni, S; Hansen, C; Benedetto, E; Jensen, E; Kosmicki, A; Martini, M; Osborne, J; Prior, G; Stora, T; Melo-Mendonca, T; Vlachoudis, V; Waaijer, C; Cupial, P; Chancé, A; Longhin, A; Payet, J; Zito, M; Baussan, E; Bobeth, C; Bouquerel, E; Dracos, M; Gaudiot, G; Lepers, B; Osswald, F; Poussot, P; Vassilopoulos, N; Wurtz, J; Zeter, V; Bielski, J; Kozien, M; Lacny, L; Skoczen, B; Szybinski, B; Ustrycka, A; Wroblewski, A; Marie-Jeanne, M; Balint, P; Fourel, C; Giraud, J; Jacob, J; Lamy, T; Latrasse, L; Sortais, P; Thuillier, T; Mitrofanov, S; Loiselet, M; Keutgen, Th; Delbar, Th; Debray, F; Trophine, C; Veys, S; Daversin, C; Zorin, V; Izotov, I; Skalyga, V; Burt, G; Dexter, A C; Kravchuk, V L; Marchi, T; Cinausero, M; Gramegna, F; De Angelis, G; Prete, G; Collazuol, G; Laveder, M; Mazzocco, M; Mezzetto, M; Signorini, C; Vardaci, E; Di Nitto, A; Brondi, A; La Rana, G; Migliozzi, P; Moro, R; Palladino, V; Gelli, N; Berkovits, D; Hass, M; Hirsh, T Y; Schaumann, M; Stahl, A; Wehner, J; Bross, A; Kopp, J; Neuffer, D; Wands, R; Bayes, R; Laing, A; Soler, P; Agarwalla, S K; Villanueva, A Cervera; Donini, A; Ghosh, T; Cadenas, J J Gómez; Hernández, P; Martín-Albo, J; Mena, O; Burguet-Castell, J; Agostino, L; Buizza-Avanzini, M; Marafini, M; Patzak, T; Tonazzo, A; Duchesneau, D; Mosca, L; Bogomilov, M; Karadzhov, Y; Matev, R; Tsenov, R; Akhmedov, E; Blennow, M; Lindner, M; Schwetz, T; Martinez, E Fernández; Maltoni, M; Menéndez, J; Giunti, C; García, M C González; Salvado, J; Coloma, P; Huber, P; Li, T; López-Pavón, J; Orme, C; Pascoli, S; Meloni, D; Tang, J; Winter, W; Ohlsson, T; Zhang, H; Scotto-Lavina, L; Terranova, F; Bonesini, M; Tortora, L; Alekou, A; Aslaninejad, M; Bontoiu, C; Kurup, A; Jenner, L J; Long, K; Pasternak, J; Pozimski, J; Back, J J; Harrison, P; Beard, K; Bogacz, A; Berg, J S; Stratakis, D; Witte, H; Snopok, P; Bliss, N; Cordwell, M; Moss, A; Pattalwar, S; Apollonio, M

    2013-01-01

    The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fr\\'ejus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of {\\mu}+ and {\\mu}- beams in a storage ring. The far detector in this case is a 100 kt Magnetised Iron Neutrino Detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular 6He and 18Ne, also stored in a ring. The far detector is also the MEMPHYS detector in the Fr\\'ejus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the ph...

  18. Structures of neutrino flavor mixing matrix and neutrino oscillations at CHORUS and NOMAD

    International Nuclear Information System (INIS)

    We study structures of the neutrino flavor mixing matrix focusing on the neutrino oscillations at CHORUS and NOMAD as well as the one at LSND (or KARMEN). We assume two typical neutrino mass hierarchies m3≅m2>m1 and m3>m2>m1 (or ≅m1). Taking into account the seesaw mechanism of neutrino masses, reasonable neutrino flavor mixing patterns are discussed. The observation of the neutrino oscillation at CHORUS and NOMAD presents an important constraint for the structure of the neutrino flavor mixing matrix. The atmospheric neutrino anomaly is discussed in relation to the CHORUS and NOMAD experiments. copyright 1996 The American Physical Society

  19. Sterile neutrino oscillations in core-collapse supernova simulations

    CERN Document Server

    Warren, MacKenzie L; Mathews, Grant; Hidaka, Jun; Kajino, Toshitaka

    2014-01-01

    We have made core-collapse supernova simulations that allow oscillations between electron neutrinos (or their anti particles) with right-handed sterile neutrinos. We have considered a range of mixing angles and sterile neutrino masses including those consistent with sterile neutrinos as a dark matter candidate. We examine whether such oscillations can impact the core bounce and shock reheating in supernovae. We identify the optimum ranges of mixing angles and masses that can dramatically enhance the supernova explosion by efficiently transporting electron anti-neutrinos from the core to behind the shock where they provide additional heating leading to much larger explosion kinetic energies. We show that an interesting oscillation in the neutrino luminosity develops due to a cycle of depletion of the neutrino density by conversion to sterile neutrinos that shuts off the conversion, followed by a replenished neutrino density as neutrinos transport through the core.

  20. Quantum correlations in terms of neutrino oscillation probabilities

    Science.gov (United States)

    Alok, Ashutosh Kumar; Banerjee, Subhashish; Uma Sankar, S.

    2016-08-01

    Neutrino oscillations provide evidence for the mode entanglement of neutrino mass eigenstates in a given flavour eigenstate. Given this mode entanglement, it is pertinent to consider the relation between the oscillation probabilities and other quantum correlations. In this work, we show that all the well-known quantum correlations, such as the Bell's inequality, are directly related to the neutrino oscillation probabilities. The results of the neutrino oscillation experiments, which measure the neutrino survival probability to be less than unity, imply Bell's inequality violation.

  1. Non-standard Interactions, Density Matrix and Neutrino Oscillations

    International Nuclear Information System (INIS)

    We present an analysis of a neutrino production and detection processes, necessary in order to describe the oscillation phenomena in any model of neutrino interaction. We derive an oscillation probability in the presence of neutrino non-standard interactions and compare the result with the standard approach. Our results are applicable in a very wide class of New Physics models. (authors)

  2. Oscillating Flavors in Massless Neutrinos

    CERN Document Server

    Welch, Lester C

    2016-01-01

    By considering Dirac's equation using quaternions ($\\mathbb{H}$) with their greater degree of freedom in imaginaries, it is shown that a model can be created with oscillations among flavors even if the particles, are massless. Furthermore the solutions are spin $\\frac{1}{2}$ and have helicities depending on whether their energy is positive or negative.

  3. Analysis of solar models - neutrinos and oscillations

    International Nuclear Information System (INIS)

    The theory of stellar structure and evolution is used to calculate the properties of a variety of objects from red giants and supernova precursors to white dwarfs and neutron stars. Accurate tests of the theory in the context of these applications are generally not available. The sun as the nearest star provides a unique example of a star which can be subjected to a variety of precise tests not possible with remote stars. We will concentrate on two of these tests - solar neutrinos and solar oscillations - which currently indicate that there is something seriously wrong with our standard solar model. Although we do not yet known what the source of the error is, it is quite possible that the correction of this error will require some modification of the results of other applications of stellar structure theory. It now seems unlikely that the difficulty with the solar neutrino experiment lies in the experiment itself. The combination of the difficulty with the solar neutrino flux and the difficulty with the solar oscillation frequencies suggests that the solar neutrino problem is a failure of stellar structure theory rather than a failure of weak interaction theory, although this latter possibility cannot yet be firmly ruled out

  4. Quantum gravity signals in neutrino oscillations

    International Nuclear Information System (INIS)

    We investigate the effect of a Quantum Gravity-induced minimal length on neutrino oscillations. The minimal length is implemented in a phenomenological framework, allowing us to make predictions independently of any fundamental approach. We obtain clear minimal length signatures and discuss their observability in current and future experiments. We present an overview over other scenarios in which the minimal length leaves its signature and show new results concerning minimal length thermodynamics. (author)

  5. Noncyclic geometric phase for neutrino oscillation

    CERN Document Server

    Wang, X B; Liu, Y; Oh, C H; Wang, Xiang-Bin; Liu, Yong

    2001-01-01

    We provide explicit formulae for the noncyclic geometric phases or Pancharatnam phases of neutrino oscillations. Since Pancharatnam phase is a generalization of the Berry phase, our results generalize the previous findings for Berry phase in a recent paper [Phys. Lett. B, 466 (1999) 262]. Unlike the Berry phase, the noncyclic geometric phase offers distinctive advantage in terms of measurement and prediction. In particular, for three-flavor mixing, our explicit formula offers an alternative means of determining the CP-violating phase. Our results can also be extended easily to explore geometric phase associated with neutron-antineutron oscillations.

  6. Anomalous vector-boson couplings in Majorana neutrino models

    CERN Document Server

    Burgess, C P

    1994-01-01

    We examine the contributions of Majorana neutrinos to CP-violating WWZ and ZZZ self-couplings, using a model in which sterile neutrinos couple to the W and Z by mixing with a fourth-generation heavy lepton. We find that the induced form factors can be as large as 0.5%. The model satisfies all phenomenological bounds in a natural way, including those due to the strong limits on the neutron and electron electric dipole moments. Anomalous CP-odd couplings of this size are unlikely to be observed at LEP200, but might be detectable at NLC.

  7. Theory of oscillations and sterile neutrinos

    International Nuclear Information System (INIS)

    We present a concise review of the theoretical status of neutrino oscillations within the (standard) 3-flavor framework and the (non-standard) 4-flavor scheme endowed with one additional sterile species (the so-called 3+1 scheme). We emphasize the slight overall preference that recently emerged for CP-violation in the 3-flavor analysis and highlight the unique role of the global data combination in the near future. After a brief introduction of the motivations for light (eV) sterile neutrinos, we discuss the bounds on their mixing with the electron neutrinos, attainable from the solar sector. The upper limit so obtained is independent of the reactor neutrino fluxes, whose calculations are affected by systematic uncertainties not completely under control. Finally, we highlight the possibility to explore sub-eV ''super-light'' sterile neutrinos exploiting the θ13-dedicated reactor experiments also commenting on the robustness of the 3- flavor results within the enlarged 3+1 scheme

  8. Systematic uncertainties in long-baseline neutrino-oscillation experiments

    CERN Document Server

    Ankowski, Artur M

    2016-01-01

    Thanks to global efforts over the past two decades, the phenomenon of neutrino oscillations is now well established. In ongoing experiments, the parameters driving the oscillations are being determined with rapidly increasing precision. Yet there still are open issues that have implications going well beyond neutrino physics. The next two decades are expected to bring definite answers to the neutrino-mass hierarchy and violation of charge-particle (CP) symmetry in neutrino oscillations. The question of the mass hierarchy---whether the neutrino masses follow the pattern of the charged-lepton masses---is relevant for cosmology, astrophysics and unification theories. On the other hand, CP violating oscillations have the potential to give an important, or event dominant, contribution to the matter-antimatter asymmetry in the Universe. For the success of future neutrino-oscillation studies it is, however, necessary to ensure a significant reduction of uncertainties, particularly those related to neutrino-energy re...

  9. Neutrino spin-flavor oscillations derived from the mass basis

    CERN Document Server

    Fabbricatore, Riccardo; Studenikin, Alexander

    2016-01-01

    We consider neutrino mixing and oscillations in presence of an arbitrary constant magnetic field with nonzero transversal $B_{\\perp}$ and longitudinal $B_{\\parallel}$ components with respect to the direction of neutrino propagation. The electromagnetic interaction of neutrinos is determined by diagonal and transition neutrino magnetic moments that are introduced for the neutrino mass states. Explicit expressions for the effective neutrino diagonal and transition magnetic moments for the flavor basis in terms of these values for the mass states are obtained. The effective evolution Hamiltonian for the flavor neutrino and the corresponding oscillation probability are derived. The role of the longitudinal magnetic field component is examined. In particular, it is shown that: 1) $B_{\\parallel}$ coupled to the corresponding magnetic moments shifts the neutrino energy, and 2) in case of nonvanishing neutrino transition magnetic moments $B_{\\parallel}$ produces an additional mixing between neutrino states, both in t...

  10. Constraints on neutrino oscillations from big bang nucleosynthesis

    International Nuclear Information System (INIS)

    We discuss in detail the effect of neutrino oscillations in Big Bang nucleosynthesis between active and sterile neutrinos as well as between active and active neutrinos. We calculate the constraints on mixings between active and sterile neutrinos from the present observation of the primordial helium abundance and discuss the potential implications on various astrophysical and cosmological problems of such oscillations. In particular, we show that large-angle sterile neutrino mixing seems to be excluded as a MSW solution to the solar neutrino situation or a solution to the atmospheric neutrino mixing hinted at in some underground experiments. We show how, with this constraint, the next generation of solar neutrino experiments should be able to determine the resolution of the solar neutrino problem. It is also shown how sterile neutrinos remain a viable dark matter candidate

  11. Neutrino Oscillations as a Probe of Light Scalar Dark Matter

    OpenAIRE

    Berlin, Asher

    2016-01-01

    We consider a class of models involving interactions between ultra-light scalar dark matter and Standard Model neutrinos. Such couplings modify the neutrino mass splittings and mixing angles to include additional components that vary in time periodically with a frequency and amplitude set by the mass and energy density of the dark matter. Null results from recent searches for anomalous periodicities in the solar neutrino flux strongly constrain the dark matter-neutrino coupling to be orders o...

  12. Time-Energy Uncertainty Relations for Neutrino Oscillation and M\\"Ossbauer Neutrino Experiment

    CERN Document Server

    Bilenky, S M; Potzel, W

    2008-01-01

    Using the Mandelstam-Tamm method we derive time-energy uncertainty relations for neutrino oscillations. We demonstrate that the small energy uncertainty of antineutrinos in a recently considered experiment with recoilless resonant (M\\"ossbauer) production and absorption of tritium antineutrinos is in conflict with the energy uncertainty which, according to the time-energy uncertainty relation, is necessary for neutrino oscillations to happen. A M\\"ossbauer neutrino experiment could provide a unique possibility to test the applicability of the time-energy uncertainty relation to neutrino oscillations and to reveal the true nature of neutrino oscillations.

  13. Detecting dark energy in long baseline neutrino oscillations

    Institute of Scientific and Technical Information of China (English)

    GU Pei-Hong; BI Xiao-Jun; FENG Bo; YOUNG Bing-Lin; ZHANG Xin-Min

    2008-01-01

    In this paper, we discuss a possibility of studying properties of dark energy in long baseline neutrino oscillation experiments. We consider two types of models of neutrino dark energy. For one type of models the scalar field is taken to be quintessence-like and for the other phantom-like. In these models the scalar fields couple to the neutrinos to give rise to spatially varying neutrino masses. We will show that the two types of models predict different behaviors of the spatial variation of the neutrino masses inside the Earth and consequently result in different signals in long baseline neutrino oscillation experiments.

  14. Pseudo-Dirac neutrinos as a potential complete solution to the neutrino oscillation puzzle

    CERN Document Server

    Geiser, A

    1998-01-01

    A solution for the neutrino mass and mixing pattern is proposed which is compatible with all available experimental data on neutrino oscillations. This solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. $m_{\\rm Majorana} \\ll m_{\\rm Dirac}$. The solar and atmospheric neutrino observations are mainly explained as $\

  15. Expectation values of flavor-neutrino numbers with respect to neutrino-source hadron states --Neutrino oscillations and decay probabilities--

    CERN Document Server

    Fujii, Kanji

    2014-01-01

    On the basis of quantum field theory, we consider a unified description of various processes accompanied by neutrinos, namely weak decays and oscillation processes. The structures of the expectation values of flavor-neutrino numbers with respect to neutrino-source hadron state are investigated. Due to the smallness of neutrino masses, we naturally obtain the old (i.e. pre-mixing) formulas of decay probabilities. Together, it is shown that the oscillation formulas, similar to the usual ones, are applied irrespectively of the details of neutrino-producing processes. The derived oscillation formulas are the same in form as the usually used ones except for the oscillation length.

  16. Field-Theoretical Treatment of Neutrino Oscillations: The Strength of the Canonical Oscillation Formula

    OpenAIRE

    W. Grimus(University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Vienna, Austria); Mohanty, S.; Stockinger, P.

    1999-01-01

    We discuss conceptual aspects of neutrino oscillations with the main emphasis on the field-theoretical approach. This approach includes the neutrino source and detector processes and allows to obtain the neutrino transition or survival probabilities as cross sections derived from the Feynman diagram of the combined source - detection process. In this context, the neutrinos which are supposed to oscillate appear as propagators of the neutrino mass eigenfields, connecting the source and detecti...

  17. Simulation of neutrino oscillations using discrete-time quantum walk

    CERN Document Server

    Mallick, Arindam; Chandrashekar, C M

    2016-01-01

    Neutrino oscillation is a well-known phenomenon observed in high energy physics. Here starting from a one-spatial dimensional discrete-time quantum walk we present a method to simulate neutrino oscillation. We present the set of walk parameters with which we can obtain the same oscillation probability profile obtained in both, long range and short range neutrino experiment. Our scheme to simulate three-generation neutrino oscillation from quantum walk evolution operators can be physically realized in any low energy experimental setup with access to control a single six-level system, a multiparticle three-qubits or a qubit-qutrit system.

  18. Beyond the New Standard Model in neutrino oscillations

    Indian Academy of Sciences (India)

    M Zralek

    2006-11-01

    We discuss effects of new physics (NP) in neutrino oscillation experiments. Such effects can modify a production neutrino flux, a detection cross-section and a matter transition. As a result, the NP effects change neutrino oscillations both in vacuum and in matter. A relation between the small effects of NP and the oscillation parameters is discussed. It is shown for which parameters the NP effects are suppressed and when they are potentially large. Oscillations of non-unitary mixed neutrinos are presented in more details.

  19. The OPERA experiment - Neutrino oscillation search

    International Nuclear Information System (INIS)

    The primary goal of the OPERA long-baseline neutrino oscillation experiment is the first direct detection of νμ →ντ oscillations. The hybrid OPERA detector consists of a target made from lead and photo emulsions, providing micrometric resolution, and electronic detector parts for on-line readout. It is located in the LNGS underground laboratory, at a baseline of 730 km from the SPS at CERN, where the νμ CNGS beam is produced. The measurement of ντ appearance relies on the detection of the decay of τ leptons which are created in ντ charged current reactions. Data acquisition started in 2008, and numerous beam-induced events have been recorded, including the observation of a first ντ candidate event in 2009. In this talk, the current status of the oscillation analysis is presented.

  20. Study of the atmospheric neutrino oscillations in the Frejus experiment

    International Nuclear Information System (INIS)

    The behavior of atmospheric neutrinos is investigated. It is a zero mass, zero charge and weak interacting particle. The aim of the investigation is to search for non standard phenomena, such as neutrino oscillations. The neutrino theoretical properties are discussed and the physical parameters experimental limits are recalled. The analysis of the approximately 200 events from atmospheric neutrinos observed in Frejus detector is carried out. The results and simulation of neutrino interactions are presented. The data analysis induces to the exclusion of neutrino oscillation hypothesis from some models. Three cases of oscillations involving two neutrino flavors are analyzed. The effect of a third flavor is also taken into account. The present data and those from IMB and Kamiokande experiments are compared. Topics involving investigations on the superposition of a signal and the atmospheric neutrinos are included

  1. Neutrino Oscillations with MINOS and MINOS+

    CERN Document Server

    Whitehead, Leigh H

    2016-01-01

    The MINOS experiment ran from 2003 until 2012 and collected a data sample including 10.71x10^20 protons-on-target (POT) of beam neutrinos, 3.36x10^20 POT of beam antineutrinos and an atmospheric neutrino exposure of 37.88 kt-yrs. The final measurement of the atmospheric neutrino oscillation parameters, dm^2_32 and theta_23, came from a full three flavour oscillation analysis of the combined CC nu_mu and CC anti-nu_mu beam and atmospheric samples and the CC nu_e and CC anti-nu_e appearance samples. This analysis yielded the most precise measurement of the atmospheric mass splitting dm^2_32 performed to date. The results are |dm^2_32|=[2.28 - 2.46]x10^-3 eV^2 (68\\%) and sin^{2}theta_23=0.35-0.65$ (90\\%) in the normal hierarchy, and |dm^2_32|=[2.32 - 2.53]x10^-3 eV^2 (68\\%) and sin^{2}theta_23=0.34-0.67 (90\\%) in the inverted hierarchy. The successor to MINOS in the NOvA era at FNAL, MINOS+, is now collecting data mostly in the 3-10 GeV region, and an analysis of nu_mu disappearance using the first 2.99x10^20 PO...

  2. Some unsettled questions in the problem of neutrino oscillations

    International Nuclear Information System (INIS)

    It is noted that the theory of neutrino oscillations can be constructed only in the framework of the particle physics theory where a mass shell conception is presented and then transitions (oscillations) between neutrinos with equal masses are real and between neutrinos with different masses are virtual. There can be three types of neutrino transitions. In the experiments it is necessary to decide the question: which type of neutrino transitions is realized in nature? At present it is supposed that Dirac and Majorana neutrino oscillations can be realized. It is shown that we cannot put Majorana neutrinos in the standard weak interaction theory without violation of the gauge invariance. If we use the Majorana neutrinos then we come to contradiction with the existing experimental data. Then it is obvious that there can be only realized transitions between Dirac neutrinos with different flavors. It is also shown that the mechanism of resonance enhancement of neutrino oscillations in matter cannot be realized without violation of the law of energy-momentum conservation. Though it is supposed that in experiments we see neutrino oscillations, indeed only transitions between neutrinos are registered.To register neutrino oscillations, it is necessary to see second or even higher neutrino oscillation modes in experiments. For this purpose we can use the elliptic character of the Earth orbit at registrations of sun neutrinos. The analysis shows that the SNO experimental results do not confirm smallness of νe → ντ transition angle mixing, which was obtained in the CHOOZ experiment. It is also noted that there is contradiction between the SNO, Super-Kamiokande, Homestake and SAGE, and GNO (GALLEX) data. (author)

  3. The Palo Verde Neutrino Oscillation Experiment

    CERN Document Server

    Miller, L H

    2001-01-01

    The n&d1;e flux and spectrum have been measured at a distance of about 800 m from the reactors of the Palo Verde Nuclear Generating Station using a segmented Gd- loaded liquid scintillator detector. Correlated positron- neutron events from the reaction n&d1;e p→e+n were recorded for a period of 353 d including 110 d with one of the three reactors off for refueling. Backgrounds were accounted for by making use of the reactor-on and reactor-off cycles, and also with a technique based on the differences between signal and background under reversal of the e +-type and n-type portions of the events. Results from the experiment show no evidence for neutrino oscillation. n&d1;e→ n&d1;x oscillation was excluded at 90% CL for Δm 2 > 1.28 × 10−3 eV2 for full mixing, and sin2 2&thetas; > 0.22 for large Δ m2. These results support the conclusion that the observed atmospheric neutrino oscillation predominantly does not involve ne .

  4. Geometric Solutions for the Neutrino Oscillation Length Resonance

    CERN Document Server

    Pruet, J; Pruet, Jason; Fuller, George M.

    1999-01-01

    We give a geometric interpretation of the neutrino 'oscillation length resonance' recently discovered by Petcov. We use this picture to identify two new solutions for oscillation length resonances in a 3-layer earth model.

  5. Velocity Induced Neutrino Oscillation and its Possible Implications for Long Baseline Neutrinos

    CERN Document Server

    Banik, Amit Dutta

    2014-01-01

    If the three types of active neutrinos possess different maximum attainable velocities and the neutrino eigenstates in the velocity basis are different from those in the flavour (and mass) basis then this will induce a flavour oscillation in addition to the normal mass flavour oscillation. Here we study such an oscillation scenario in three neutrino framework including also the matter effect and apply our results to demonstrate its consequences for long baseline neutrinos. We also predict the possible signatures in terms of yields in a possible long baseline neutrino experiment.

  6. Measurement of the Solar Neutrino Capture Rate by SAGE and Implications for Neutrino Oscillations in Vacuum

    International Nuclear Information System (INIS)

    The Russian-American solar neutrino experiment has measured the capture rate of neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory. Eight years of measurement give the result 67.2+7.2+3.5-7.0-3.0 solar neutrino units, where the uncertainties are statistical and systematic, respectively. The restrictions these results impose on vacuum neutrino oscillation parameters are given. (c) 1999 The American Physical Society

  7. Tri-Bimaximal Mixing and the Neutrino Oscillation Data

    CERN Document Server

    Harrison, P F; Scott, W G

    2002-01-01

    Following recent results from the SNO solar neutrino experiment and the K2K long-baseline neutrino experiment, the combined existing data on neutrino oscillations now point strongly to a specific form for the lepton mixing matrix, with effective bimaximal mixing of $\

  8. Exercices with the neutrino oscillation length

    CERN Document Server

    Lévy, J M

    2000-01-01

    Forsaking the traditionnal hand-waving in the treatment of the motion allows to show that the ultra-relativistic approximation and the equality of kinematical variables are unnecessary ingredients in the derivation of the oscillation length using plane waves, at least in a two flavor world. It ensues that the formula is valid as it is in the non relativistic regime, provided one uses the correct variable which is found to be momentum, not energy, and that the precise production kinematics is irrelevant. Applications to more realistic three neutrino cases are briefly discussed.

  9. Future long-baseline neutrino oscillations: View from Asia

    International Nuclear Information System (INIS)

    Accelerator based long-baseline neutrino oscillation experiments have been playing important roles in revealing the nature of neutrinos. However, it turned out that the current experiments are not sufficient to study two major remaining problems, the CP violation in the lepton sector and the mass hierarchy of neutrinos. Therefore, several new experiments have been proposed. Among of them, two accelerator based long-baseline neutrino oscillation experiments, the J-PARC neutrino beam and Hyper-Kamiokande, and MOMENT, have been proposed in Asia. These two projects are reviewed in this article

  10. Introduction to a field-theoretical treatment of neutrino oscillations

    Indian Academy of Sciences (India)

    P Stockinger

    2000-01-01

    We discuss the main features of the field-theoretical approach to neutrino oscillations where one combines neutrino production and detection processes in a single Feynman graph. The ‘oscillating neutrinos’ are represented by inner lines of this graph and appear in the calculation of the cross section of the total process as propagators of the neutrino mass eigenfields. We show that this field-theoretical approach leads to a transparent treatment of neutrino oscillations without ambiguities and provides the correct answer in cases where the standard approach fails.

  11. On a theory of neutrino oscillations with entanglement

    International Nuclear Information System (INIS)

    We show that the standard expression for the neutrino oscillation length can be confirmed even in theoretical approaches that take into account entanglement between the neutrino and its interaction partners. We show this in particular for the formalism developed in arXiv:1004.1847. Finally, we shed some light on the question why plane-wave approaches to the neutrino oscillation problem can yield the correct result for the oscillation length even though they do not explicitly account for the localization of the neutrino source and the detector.

  12. Linking neutrino oscillations to the nucleosynthesis of elements

    CERN Document Server

    Wu, Meng-Ru; Qian, Yong-Zhong

    2015-01-01

    Neutrino interactions with matter play an important role in determining the nucleosynthesis outcome in explosive astrophysical environments such as core-collapse supernovae or mergers of compact objects. In this article, we first discuss our recent work on the importance of studying the time evolution of collective neutrino oscillations among active flavors in determining their effects on nucleosynthesis. We then consider the possible active-sterile neutrino mixing and demonstrate the need of a consistent approach to evolve neutrino flavor oscillations, matter composition, and the hydrodynamics when flavor oscillations can happen very deep inside the supernovae.

  13. Atmospheric neutrinos, nu_e-nu_s oscillations, and a novel neutrino evolution equation

    CERN Document Server

    Akhmedov, Evgeny

    2016-01-01

    If a sterile neutrino nu_s with an eV-scale mass and a sizeable mixing to the electron neutrino exists, as indicated by the reactor and gallium neutrino anomalies, a strong resonance enhancement of nu_e-nu_s oscillations of atmospheric neutrinos should occur in the TeV energy range. At these energies neutrino flavour transitions in the 3+1 scheme depend on just one neutrino mass squared difference and are fully described within a 3-flavour oscillation framework. We demonstrate that the flavour transitions of atmospheric nu_e can actually be very accurately described in a 2-flavour framework, with neutrino flavour evolution governed by an inhomogeneous Schroedinger-like equation. Evolution equations of this type have not been previously considered in the theory of neutrino oscillations.

  14. Neutrino oscillations in MHD supernova explosions

    International Nuclear Information System (INIS)

    We calculate the neutrino oscillations numerically in magnetohydrodynamic (MHD) explosion models to see how asphericity has impacts on neutrino spectra. Magneto-driven explosions are one of the most attracting scenarios for producing large scale departures from spherical symmetric geometry, that are reported by many observational data. We find that the event rates at Super-Kamiokande (SK) seen from the polar direction (e.g., the rotational axis of the supernovae) decrease when the shock wave is propagating through H-resonance. In addition, we find that L-resonance in this situation becomes non-adiabatic, and the effect of L-resonance appears in the neutrino signal, because the MHD shock can propagate to the stellar surface without shock-stall after core bounce, and the shock reaches the L-resonance at earlier stage than the conventional spherical supernova explosion models. Our results suggest that we may obtain the observational signatures of the two resonances in SK for Galactic supernova.

  15. Generalized mass ordering degeneracy in neutrino oscillation experiments

    CERN Document Server

    Coloma, Pilar

    2016-01-01

    We consider the impact of neutral-current (NC) non-standard neutrino interactions (NSI) on the determination of the neutrino mass ordering. We show that in presence of NSI there is an exact degeneracy which makes it impossible to determine the neutrino mass ordering and the octant of the solar mixing angle $\\theta_{12}$ at oscillation experiments. The degeneracy holds at the probability level and for arbitrary matter density profiles, and hence, solar, atmospheric, reactor, and accelerator neutrino experiments are affected simultaneously. The degeneracy requires order-one corrections from NSI to the NC electron neutrino--quark interaction and can be tested in electron neutrino NC scattering experiments.

  16. Untangling supernova-neutrino oscillations with beta-beam data

    OpenAIRE

    Jachowicz, Natalie; McLaughlin, Gail; Volpe, Cristina

    2008-01-01

    Recently, we suggested that low-energy beta-beam neutrinos can be very useful for the study of supernova neutrino interactions. In this paper, we examine the use of a such experiment for the analysis of a supernova neutrino signal. Since supernova neutrinos are oscillating, it is very likely that the terrestrial spectrum of supernova neutrinos of a given flavor will not be the same as the energy distribution with which these neutrinos were first emitted. We demonstrate the efficacy of the pro...

  17. A 3 X 2 texture for neutrino oscillations and leptogenesis

    OpenAIRE

    Brahmachari, Biswajoy; Okada, Nobuchika

    2006-01-01

    In an economical system with only two heavy right handed neutrinos, we postulate a new texture for $3 \\times 2$ Dirac mass matrix $m_D$. This model implies one massless light neutrino and thus displays only two patterns of mass spectrum for light neutrinos, namely hierarchical or inverse-hierarchical. Both the cases can correctly reproduce all the current neutrino oscillation data with a unique prediction $m_{\

  18. Obtaining supernova directional information using the neutrino matter oscillation pattern

    CERN Document Server

    Scholberg, Kate; Wendell, Roger

    2009-01-01

    A nearby core collapse supernova will produce a burst of neutrinos in several detectors worldwide. With reasonably high probability, the Earth will shadow the neutrino flux in one or more detectors. In such a case, for allowed oscillation parameter scenarios, the observed neutrino energy spectrum will bear the signature of oscillations in Earth matter. Because the frequency of the oscillations in energy depends on the pathlength traveled by the neutrinos in the Earth, an observed spectrum contains also information about the direction to the supernova. We explore here the possibility of constraining the supernova location using matter oscillation patterns observed in a detector. Good energy resolution (typical of scintillator detectors), well known oscillation parameters, and optimistically large (but conceivable) statistics are required. Pointing by this method can be significantly improved using multiple detectors located around the globe. Although it is not competitive with neutrino-electron elastic scatter...

  19. Oscillations in neutrino beams: status and possibilities of observation

    International Nuclear Information System (INIS)

    The possibility to observe neutrino oscillations between different states in reactor, accelerator and solar neutrino experiments is discussed. In principle there are two ways of looking experimentally for the effects. If M=√/m12-m22/ (m1 and m2 - masses of initial and final neutrino states) is relatively large, say more than 0.2 eV, the first way is to measure neutrino beam intensity oscillations or the ratio of the intensities of electron and muon neutrinos as a function of their momentum at an accelerator. At reactor facilities one might observe relative effects of oscillations by measuring the antineutrino spectrum. As far as neutrino astronomy is concerned, the possibilities of doing relative measurements are very remote. If M< 0.1 eV the only hope of seeing oscillation effects is based on cosmic ray neutrino and especially on neutrino solar experiments: to compare the observed and theoretical absolute intensities of a given type of neutrinos. The effects of ''sterile'' (undetectable) neutrinos and neutrino mixing are also shortly discussed

  20. Global analyses of neutrino oscillation experiments

    Science.gov (United States)

    Gonzalez-Garcia, M. C.; Maltoni, Michele; Schwetz, Thomas

    2016-07-01

    We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions.

  1. Chaotic amplification of neutrino chemical potentials by neutrino oscillations in big bang nucleosynthesis

    International Nuclear Information System (INIS)

    We investigate in detail the parameter space of active-sterile neutrino oscillations that amplifies neutrino chemical potentials at the epoch of big bang nucleosynthesis. We calculate the magnitude of the amplification and show evidence of chaos in the amplification process. We also discuss the implications of the neutrino chemical potential amplification in big bang nucleosynthesis. It is shown that with a ∼1 eV νe, the amplification of its chemical potential by active-sterile neutrino oscillations can lower the effective number of neutrino species at big bang nucleosynthesis to significantly below three. copyright 1996 The American Physical Society

  2. A Combined View of Sterile-Neutrino Constraints from CMB and Neutrino Oscillation Measurements

    CERN Document Server

    Bridle, Sarah; Evans, Justin; Fernandez, Susana; Guzowski, Pawel; Soldner-Rembold, Stefan

    2016-01-01

    We perform a comparative analysis of constraints on sterile neutrinos from the Planck experiment and from current and future neutrino oscillation experiments (MINOS, IceCube, SBN). For the first time, we express the Planck constraints on $N_{\\rm eff}$ and $m_{\\rm eff}^{\\rm sterile}$ from the Cosmic Microwave Background in the parameter space used by oscillation experiments using both mass-squared differences and mixing angles. In a model with a single sterile neutrino species and using standard assumptions, we find that the Planck data and the oscillation experiments measuring muon-neutrino disappearance have similar sensitivity.

  3. Oscillation and Mixing Among the Three Neutrino Flavors

    CERN Document Server

    Weiler, Thomas J

    2013-01-01

    With the educated, interested non-specialist as the target audience, we overview what is known and not known about contemporary neutrino physics. Theory tells us that neutrinos are the second-most common particle in the Universe, behind only the quanta of radiation called photons. Almost a trillion neutrinos per second enter each human eyeball, and yet we do not see them; these neutrinos, in roughly equal numbers, are emanations from our Sun and relics of the hot "big bang" era of the early Universe. Much of what we know about neutrinos, and hope to learn in the future, is derived from a unique feature of neutrinos -- "oscillation" among neutrino "flavor" types. An initial neutrino flavor will in general oscillate into another flavor as the neutrino propagates in space and time. Oscillations are a quantum mechanical phenomenon. One of the wonders of neutrinos is that their quantum mechanics may be observed over large distances, even astronomically large. We begin this article with neutrino phenomenology in te...

  4. Neutrino mass spectrum with υμ → υs oscillations of atmospheric neutrinos

    International Nuclear Information System (INIS)

    We consider the ''standard'' spectrum of the active neutrinos (characterized by strong mass hierarchy and small mixing) with additional sterile, υs. The sterile neutrino mixes strongly with the muon neutrino, so that υμ ↔ υs oscillations solve the atmospheric neutrino problem. We show that the parametric enhancement of the υμ ↔ υs oscillations occurs for the high energy atmospheric neutrinos which cross the core of the Earth. This can be relevant for the anomaly observed by the MACRO experiment. Solar neutrinos are converted both to υμ and υs. The heaviest neutrino (approx. υτ) may compose the hot dark matter of the Universe. Phenomenology of this scenario is elaborated and crucial experimental signatures are identified. We also discuss properties of the underlying neutrino mass matrix. (author)

  5. Schemes and Mechanisms of Neutrino Mixings (Oscillations) and a Solution of the Sun Neutrinos Deficit Problem

    OpenAIRE

    Beshtoev, Kh. M.

    2004-01-01

    Three schemes of neutrino mixings (oscillations) are proposed. The problems of origin of angle mixings, with the law of energy-momentum conservation and disintegration of neutrino as wave pocket are solved. These two schemes belong to mass mixings schemes, where mixing angles and oscillation lengths are expressed via elements of mass matrix. The third scheme belongs to the charge mixings scheme, where mixing parameters are expressed via neutrino weak charges, as it takes place in the vector d...

  6. Time-Energy Uncertainty Relations for Neutrino Oscillation and M\\"Ossbauer Neutrino Experiment

    OpenAIRE

    Bilenky, S. M.; von Feilitzsch, F.; Potzel, W.

    2008-01-01

    Using the Mandelstam-Tamm method we derive time-energy uncertainty relations for neutrino oscillations. We demonstrate that the small energy uncertainty of antineutrinos in a recently considered experiment with recoilless resonant (M\\"ossbauer) production and absorption of tritium antineutrinos is in conflict with the energy uncertainty which, according to the time-energy uncertainty relation, is necessary for neutrino oscillations to happen. A M\\"ossbauer neutrino experiment could provide a ...

  7. Measurement of the solar neutrino capture rate by SAGE and implications for neutrino oscillations in vacuum

    CERN Document Server

    Abdurashitov, J N; Cherry, M L; Cleveland, B T; Davis, R; Elliott, S R; Gavrin, V N; Girin, S V; Gorbachev, V V; Ibragimova, T V; Kalikhov, A V; Knodel, T V; Lande, K; Mirmov, I N; Nico, J S; Shikhin, A A; Teasdale, W A; Veretenkin, E P; Vermul, V M; Wark, D L; Wildenhain, P S; Yants, V E; Zatsepin, G T; Khairnasov, N G; Wilkerson, J F

    1999-01-01

    The Russian-American solar neutrino experiment has measured the capture rate of neutrinos on metallic gallium in a radiochemical experiment at the Baksan Neutrino Observatory. Eight years of measurement give the result 67.2 (+7.2,-7.0) (+3.5,-3.0) SNU, where the uncertainties are statistical and systematic, respectively. The restrictions these results impose on vacuum neutrino oscillation parameters are given.

  8. Neutrino mass hierarchy determination and other physics potential of medium-baseline reactor neutrino oscillation experiments

    CERN Document Server

    Kettell, Steve; Qian, Xin; Yeh, Minfang; Zhang, Chao; Lin, Cheng-Ju; Luk, Kam-Biu; Johnson, Randy; Littlejohn, Bryce; Learned, John; Maricic, Jelena; Peng, Jen-Chieh; Betts, Russell; White, Chrisopher; Dye, Stephen; Lau, Kwong; Liu, Dawei; McDonald, Kirk; Napolitano, Jim; Detwiler, Jason; Tolich, Nikolai; Zhao, Tianchi; McKeown, Robert D; Wang, Wei; Balantekin, A B; Band, Henry; Cherwinka, Jeff; Heeger, Karsten M

    2013-01-01

    Medium-baseline reactor neutrino oscillation experiments (MBRO) have been proposed to determine the neutrino mass hierarchy (MH) and to make precise measurements of the neutrino oscillation parameters. With sufficient statistics, better than $\\sim 3% / \\sqrt{E(MeV)}$ energy resolution and well understood energy non-linearity, MH can be determined by analyzing oscillation signals driven by the atmospheric mass-squared difference in the survival spectrum of reactor antineutrinos. With such high performance MBRO detectors, oscillation parameters, such as $\\sin^22\\theta_{12}$, $\\Delta m^2_{21}$, and $\\Delta m^2_{32}$, can be measured to sub-percent level, which enables a future test of the PMNS matrix unitarity to $\\sim$1% level and helps the forthcoming neutrinoless double beta decay experiments to constrain the allowed $\\langle m_{\\beta \\beta} \\rangle$ values. Combined with results from the next generation long-baseline beam neutrino and atmospheric neutrino oscillation experiments, the MH determination sensiti...

  9. Neutrino Oscillations as a Probe of Light Scalar Dark Matter

    CERN Document Server

    Berlin, Asher

    2016-01-01

    We consider a class of models involving interactions between ultra-light scalar dark matter and Standard Model neutrinos. Such couplings modify the neutrino mass splittings and mixing angles to include additional components that vary in time periodically with a frequency and amplitude set by the mass and energy density of the dark matter. Null results from recent searches for anomalous periodicities in the solar neutrino flux strongly constrain the dark matter-neutrino coupling to be orders of magnitude below current and projected limits derived from observations of the cosmic microwave background.

  10. Silicon detectors for neutrino oscillation experiments

    CERN Document Server

    do Couto e Silva, E

    1998-01-01

    This note describes the technique of using a target equipped with high resolution silicon microstrip detectors for the detection of the topological signature of decays in neutrino oscillation ex periments. Two detectors are presented. The first detector is installed in the NOMAD spectrometer at the CERN SPS neutrino beam. The target consists of four layers passive boron carbide plate s (total mass of 45 kg) interleaved with five layers of silicon microstrip detectors. A total of 600 single--sided silicon microstrip detectors are used amounting to a total area of 1.14 m$^2$. The silicon tracker is made with the longest ladders built to date (72 cm). During the 1997 run about 8000 charged current interactions were estimated to have occurred in the target and data tak ing will continue in 1998. For these events it will be possible to perform a precise measurement of both vertex and kinematical variables. The second detector was installed in September 1997 in a CERN PS pion beam to investigate the possibility of ...

  11. Future long-baseline neutrino oscillations: View from Europe

    International Nuclear Information System (INIS)

    Since about a decade the european physics community interested in neutrino and neutrino-astrophysics develops a plan to conceive the next generation large underground neutrino observatory. Recently, the LAGUNA-LBNO collaboration made the outcome of the FP7 design study public which shows a clear path for the realization of such experiment. In this paper the LAGUNA and LAGUNA-LBNO Design studies, resulting in a proposal for the LBNO experiment, will be discussed. The author will focus on the long baseline neutrino oscillation search, especially on the potential to discover the neutrino mass ordering and the search for CP violation in the lepton sector

  12. Subpanel on accelerator-based neutrino oscillation experiments

    International Nuclear Information System (INIS)

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

  13. The minimal 3+2 neutrino model versus oscillation anomalies

    CERN Document Server

    Donini, A; Lopez-Pavon, J; Maltoni, M; Schwetz, T

    2012-01-01

    We study the constraints imposed by neutrino oscillation experiments on the minimal extension of the Standard Model that can explain neutrino masses, which requires the addition of just two singlet Weyl fermions. The most general renormalizable couplings of this model imply generically four massive neutrino mass eigenstates while one remains massless: it is therefore a minimal 3+2 model. The possibility to account for the confirmed solar, atmospheric and long-baseline oscillations, together with the LSND/MiniBooNE and reactor anomalies is addressed. We find that the minimal model can fit oscillation data including the anomalies better than the standard $3\

  14. Solar Neutrino Data, Solar Model Uncertainties and Neutrino Oscillations

    OpenAIRE

    Krauss, Lawrence M.; Gates, Evalyn; White, Martin

    1992-01-01

    We incorporate all existing solar neutrino flux measurements and take solar model flux uncertainties into account in deriving global fits to parameter space for the MSW and vacuum solutions of the solar neutrino problem.

  15. Study of neutrino interaction in the K2K and the JHF-Kamioka long baseline neutrino oscillation experiments

    International Nuclear Information System (INIS)

    Neutrino oscillation discovered in 1998 by Super-Kamiokande opened a new field of neutrino flavor physics. Long baseline neutrino oscillation experiments aiming for precision study of oscillations will require much accurate knowledge on neutrino-nucleus interactions. These experiments also will provide new reaction data with much higher accuracy than before. Neutrino interaction study in the K2K and JHF-Kamioka experiments is discussed

  16. Future long-baseline neutrino oscillations: View from North America

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R. J.

    2015-06-01

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

  18. Future long-baseline neutrino oscillations: View from North America

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Robert J., E-mail: wilson@colostate.edu [Department of Physics, Colorado State University, Fort Collins, CO 80523-1875 (United States)

    2015-07-15

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

  19. Discussion on Neutrino Oscillation and CPT/Lorentz Invariance Violation

    CERN Document Server

    Luo, Cui-Bai; Du, Yi-Lun; Wang, Yong-Long; Zong, Hong-Shi

    2016-01-01

    Depending on deformed canonical anticommutation relations, massless neutrino oscillation based on CPT /Lorentz invariance viol ation is discussed. It is found that the deformed canonical anti-commutation relations should satisfy the condition of new Moy al product and new non standard commutation relations. Furthermore, by comparing the neutrino experimental data and the above relations, we find that the orders of magnitude of noncommutative parameters or Lorentz invariant Violation parameters $\\mathi t{A}$ is not self-consistent. This means that the previous studies about Lorentz invariance violation in noncommutative field theory may not naturally explain massless neutrino oscillation. In other words, it should be impossible to explain neutrino os cillation by lorentz invariance violation. This conclusion is supported by the latest atmospheric neutrinos experimental resul ts from Super-Kamiokande Collaboration, which show that no evidence of Lorentz invariance violation on atmospheric neutrinos w as observe...

  20. Leptogenesis from Oscillations of Heavy Neutrinos with Large Mixing Angles

    CERN Document Server

    Drewes, Marco; Gueter, Dario; Klaric, Juraj

    2016-01-01

    The extension of the Standard Model by heavy right-handed neutrinos can simultaneously explain the observed neutrino masses via the seesaw mechanism and the baryon asymmetry of the Universe via leptogenesis. If the mass of the heavy neutrinos is below the electroweak scale, they may be found at LHCb, BELLE II, the proposed SHiP experiment or a future high-energy collider. In this mass range, the baryon asymmetry is generated via $CP$-violating oscillations of the heavy neutrinos during their production. We study the generation of the baryon asymmetry of the Universe in this scenario from first principles of non-equilibrium quantum field theory, including spectator processes and feedback effects. We eliminate several uncertainties from previous calculations and find that the baryon asymmetry of the Universe can be explained with larger heavy neutrino mixing angles, increasing the chance for an experimental discovery. For the limiting cases of fast and strongly overdamped oscillations of right-handed neutrinos,...

  1. Implications of Fermionic Dark Matter on recent neutrino oscillation data

    CERN Document Server

    Singirala, Shivaramakrishna

    2016-01-01

    We investigate flavor phenomenology and dark matter in the context of scotogenic model. In this model, the neutrino masses are generated through radiative corrections at one-loop level. Considering the neutrino mixing matrix to be of tri-bimaximal form with additional perturbations to accommodate the recently observed non-zero value of reactor mixing angle $\\theta_{13}$, we obtain the relation between various neutrino oscillation parameters and the model parameters. Working in degenerate heavy neutrino mass spectrum, we obtain light neutrino masses obeying normal heirarchy and also study the relic abundance of fermionic dark matter candidate including coannihilation effects. A viable parameter space is thus obtained, consistent with neutrino oscillation data, relic abundance and various lepton flavor violating decays such as $\\ell_\\alpha\\to\\ell_\\beta\\gamma$ and $\\ell_\\alpha \\to 3 \\, \\ell_\\beta$.

  2. Non-standard Hamiltonian effects on neutrino oscillations

    CERN Document Server

    Blennow, M; Winter, W

    2005-01-01

    We investigate non-standard Hamiltonian effects on neutrino oscillations which are effective additional contributions to the vacuum Hamiltonian similar to the Mikheyev-Smirnov-Wolfenstein matter potential. In this context, we develop a general framework for such effects with two neutrino flavors and discuss the extension to three neutrino flavors. The effects are classified as either flavor or mass effects, which both can be conserving or violating (changing). In both flavor and mass bases, we derive the effective neutrino oscillation parameters due to these effects. In addition, we find that the resonance condition is modified for flavor conserving effects as well as for both mass conserving and violating effects. The non-standard Hamiltonian effects on the effective mixing and the two-flavor appearance probability are visualized and described in detail. Furthermore, we point out the difference of non-standard Hamiltonian effects from so-called "damping effects" on neutrino oscillations probabilities, which ...

  3. Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Damjanovic, S; Payet, J; Chancé, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, V; Gramegna, F; Marchi, T; Collazuol, G; Mezzetto, M; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Burt, G; Dexter, A; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A; Vardaci, E; Di Nitto, A; Brondi, A; La Rana, G; Moro, R; De Rosa, G; Palladino, V

    2012-01-01

    Neutrino oscillations have implications for the Standard Model of particle physics. The CERN Beta Beam has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration EUROnu (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make decisions on future European neutrino oscillation facilities. ”Beta Beams” produce collimated pure electron (anti)neutrinos by accelerating beta active ions to high energies and having them decay in a storage ring. Using existing machines and infrastructure is an advantage for the cost evaluation; however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integratio...

  4. Simplified Theory of Neutrino Oscillations in Matter with CP violation

    CERN Document Server

    Johnson, Mikkel B

    2016-01-01

    We obtain approximate analytical expressions for the observable oscillation probabilities characterizing three coupled Dirac neutrinos described by the Standard Neutrino Model. Our expressions are slightly more complicated than the familiar ones, but they are vastly more accurate throughout the entire region of interest at present and envisioned future neutrino facilities. The methods we develop here are applied to the flavor-changing transitions of the $(\

  5. Search for atmospheric neutrino oscillations with the Soudan 2 detector

    International Nuclear Information System (INIS)

    Underground proton decay detectors record a sizeable number of atmospheric neutrino-induced events. These neutrinos come primarily from the decay of pions and muons produced in cosmic ray showers in the earth's atmosphere. The expected flux ratio of muon neutrinos to electron neutrinos traversing an underground detector, νμ/νe, is about 2. The combined effects of detector systematics and nuclear cross section differences between νmu and νe interactions typically reduce the measured νmu/ν3 event ratio to about 1. Over the last decade, both the Kamioka detector in Japan and the IMB detector in the United States have made high-statistics measurements of the atmospheric neutrino event ratio. Both groups have presented strong experimental evidence that the underground νmu/νe event ratio is substantially smaller than predicted. In both cases, a statistically significant deficit of muon neutrino-induced events is measured. One possible explanation of the muon neutrino deficit is that these neutrinos are undergoing flavor oscillations between their production points in the atmosphere and their interaction points in underground detectors. An MSW effect interpretation of solar neutrino experiments implies a νe → νmu oscillation region in δm2-sin2(2θ) space at least two orders of magnitude lower in δm2 than the best fit point of the Kamioka result. It is therefore usually assumed that the relevant flavor oscillation for atmospheric muon neutrinos would be νmu → νr. The Soudan 2 nucleon decay detector is now approaching completion and collecting data. It will be able to make low-background measurements of atmospheric neutrinos in the next few years to check the possibility that atmospheric neutrinos undergo detectable flavor oscillations

  6. Physics prospects of future neutrino oscillation experiments in Asia

    OpenAIRE

    Hagiwara, Kaoru

    2004-01-01

    The three neutrino model has 9 physical parameters, 3 neutrino masses, 3 mixing angles and 3 CP violating phases. Among them, neutrino oscillation experiments can probe 6 parameters: 2 mass squared differences, 3 mixing angles, and 1 CP phase. The experiments performed so far determined the magnitudes of the two mass squared differences, the sign of the smaller mass squared difference, the magnitudes of two of the three mixing angles, and the upper bound on the third mixing angle. The sign of...

  7. Implications of Fermionic Dark Matter on recent neutrino oscillation data

    OpenAIRE

    Singirala, Shivaramakrishna

    2016-01-01

    We investigate flavor phenomenology and dark matter in the context of scotogenic model. In this model, the neutrino masses are generated through radiative corrections at one-loop level. Considering the neutrino mixing matrix to be of tri-bimaximal form with additional perturbations to accommodate the recently observed non-zero value of reactor mixing angle $\\theta_{13}$, we obtain the relation between various neutrino oscillation parameters and the model parameters. Working in degenerate heav...

  8. Neutrino Oscillation in Magnetized Gamma-Ray Burst Fireball

    OpenAIRE

    Sahu, Sarira; Fraija, Nissim; Keum, Yong-Yeon

    2009-01-01

    Neutrinos of energy about 5-20 MeV are produced due to the stellar collapse or merger events that trigger the Gamma-Ray Burst. Also low energy MeV neutrinos are produced within the fireball due to electron positron annihilation and nucleonic bremsstrahlung. Many of these neutrinos will propagate through the dense and relativistic magnetized plasma of the fireball. We have studied the possibility of resonant oscillation of $\

  9. Measurement of atmospheric neutrino oscillations and matter effects with PINGU

    International Nuclear Information System (INIS)

    With IceCube's low-energy extension DeepCore the first significant effects of atmospheric neutrino oscillations have been observed. The planned ''Precision Icecube Next Generation Upgrade'' (PINGU) inside DeepCore will lower the energy threshold to a few GeV, where matter effects of neutrino oscillations have to be taken into account. The Mikheyev-Smirnov-Wolfenstein (MSW) effect modifies the mixing between flavor and mass eigenstates of the neutrinos, resulting in stronger oscillations. Furthermore, neutrinos when passing through the Earth core experience parametric enhancement due to multiple discontinuities in the electron density. In this talk the effects of matter oscillations and the capabilities to measure these effects with PINGU are investigated.

  10. Compact Perturbative Expressions For Neutrino Oscillations in Matter

    CERN Document Server

    Denton, Peter B; Parke, Stephen J

    2016-01-01

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

  11. Generalized cosmological constraints on neutrino oscillations - Relaxed or strengthened

    International Nuclear Information System (INIS)

    I discuss cosmological constraints, based on BBN production of He-4, on electron-sterile neutrino oscillations proceeding after electron neutrino freeze-out. The general case of sterile neutrino state partially filled at the onset of oscillations is discussed 0 s s ≠ 0 has a two- fold effect on He-4: (a) it enhances the energy density, increasing the production of He-4 and strengthening BBN constraints on oscillations and (b) it suppresses the kinetic effects of oscillations on BBN, particularly neutrino spectrum distortion, thus decreasing He-4 overproduction and relaxing BBN constraints. The cosmological constraints depend on the interplay between the two effects: when the effect (a) dominates, the constraints are strengthened, while when the effect (b) dominates, the constraints are relaxed. (author)

  12. Tau neutrinos underground: Signals of νμ→ντ oscillations with extragalactic neutrinos

    International Nuclear Information System (INIS)

    The appearance of high energy tau neutrinos due to νμ→ντ oscillations of extragalactic neutrinos can be observed by measuring the neutrino induced upward hadronic and electromagnetic showers and upward muons. We evaluate quantitatively the tau neutrino regeneration in the Earth for a variety of extragalactic neutrino fluxes. Charged-current interactions of the upward tau neutrinos below and in the detector, and the subsequent tau decay, create muons or hadronic and electromagnetic showers. The background for these events are muon neutrino and electron neutrino charged-current and neutral-current interactions, where in addition to extragalactic neutrinos, we consider atmospheric neutrinos. We find significant signal to background ratios for the hadronic combined with electromagnetic showers with energies above 10--100 TeV initiated by the extragalactic neutrinos. We show that the tau neutrinos from point sources also have the potential for discovery above a 1 TeV threshold. A kilometer-size neutrino telescope has a very good chance of detecting the appearance of tau neutrinos when both muon and hadronic combined with electromagnetic showers are detected

  13. Particle production with left-right neutrino oscillations

    Science.gov (United States)

    Enomoto, Seishi; Matsuda, Tomohiro

    2016-03-01

    When the Higgs field starts oscillation after Higgs inflation, gauge bosons are produced nonperturbatively near the enhanced symmetry point (ESP). Just after the particle production, when the Higgs field is going away from the ESP, these gauge bosons gain mass and decay or annihilate into Standard Model (SM) fermions. Left-handed neutrinos can be generated in that way. If one assumes the seesaw mechanism, the mass matrix of a pair of left- and right-handed neutrinos is nondiagonal. Although their mixing in the mass eigenstates is negligible in the true vacuum, it could be significant near the edge of the Higgs oscillation, where the off-diagonal component is large. Therefore, the left-handed neutrinos generated from the gauge bosons can start neutrino oscillation between the right-handed neutrinos. We study the particle production when such left-right (L-R) neutrino oscillation is significant. For a working example, the nonthermal leptogenesis scenario after Higgs inflation is examined, which cannot be realized without the L-R neutrino oscillation. The same mechanism could be applied to other singlet particles whose abundance has been neglected.

  14. Future Neutrino Oscillation Sensitivities for LBNE

    CERN Document Server

    Bass, Matthew; Wilson, Robert J

    2013-01-01

    The primary goal of the Long-Baseline Neutrino Experiment (LBNE) is to measure the neutrino mixing matrix parameters. The design, optimized to search for CP violation and to determine the neutrino mass hierarchy, includes a large $\\mathcal{O}(10$ kt) Liquid Argon Time Projection Chamber (LAr TPC) at 1300 km downstream of a wide-band neutrino beam. A brief introduction to the neutrino mixing parameters will be followed by a discussion of sensitivity study analysis methods and a summary of the results for LBNE. The studies include comparisons with the Tokai-to-Kamioka (T2K) and NuMI Off-axis electron-neutrino Appearance (NO$\

  15. A Review of Long-baseline Neutrino Oscillation Experiments

    OpenAIRE

    Feldman, G J; Hartnell, J.; T. Kobayashi

    2012-01-01

    A review of accelerator long-baseline neutrino oscillation experiments is provided, including all experiments performed to date and the projected sensitivity of those currently in progress. Accelerator experiments have played a crucial role in the confirmation of the neutrino oscillation phenomenon and in precision measurements of the parameters. With a fixed baseline and detectors providing good energy resolution, precise measurements of the ratio of distance/energy (L/E) on the scale of ind...

  16. Flavor-Universal Form of Neutrino Oscillation Probabilities in Matter

    CERN Document Server

    Minakata, Hisakazu

    2015-01-01

    We construct a new perturbative framework to describe neutrino oscillation in matter with the unique expansion parameter \\epsilon, which is defined as \\Delta m^2_{21} / \\Delta m^2_{ren} with the renormalized atmospheric \\Delta m^2_{ren} \\equiv \\Delta m^2_{31} - s^2_{12} \\Delta m^2_{21}. It allows us to derive the maximally compact expressions of the oscillation probabilities in matter to order \\epsilon in the form akin to those in vacuum. This feature allows immediate physical interpretation of the formulas, and facilitates understanding of physics of neutrino oscillations in matter. Moreover, quite recently, we have shown that our three-flavor oscillation probabilities P(\

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

    Science.gov (United States)

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

    2016-08-01

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

  18. Neutrino oscillation in Magnetized Gamma-Ray Burst Fireball

    International Nuclear Information System (INIS)

    Energy MeV neutrinos are produced within the fireball due to electron positron annihilation and nucleonic bremsstrahlung. Many of these neutrinos will propagate through the dense and relativistic magnetized plasma of the fireball. We have studied the possibility of resonant oscillation of νe ↔ νμ,τ by taking into account the neutrino oscillation parameters from SuperKamiokande (SK). Using the resonance condition we have calculated the resonance length, lepton asymmetry and the baryon load for a fireball radius of 100 Km.

  19. Short Wavelength Oscillations with Right-Handed Neutrinos

    CERN Document Server

    Paschos, Emmanuel A

    2016-01-01

    The standard model is extended with three right-handed, singlet neutrinos with general couplings permitted by the $SU(2)_{L}\\times U(1)$ symmetry. The traditional oscillations are accounted for, as usually, by three left-handed neutrinos. The article investigates new structures that develop when the masses of the right-handed states are in the eV range. The new states interfere and oscillate with the standard light neutrinos. New structures appear when the detectors average over short wavelengths. I use these results to present and classify properties of the observed anomalies in the MiniBooNe, reactor and Gallium-detector experiments.

  20. Constraints on New Physics from Long Baseline Neutrino Oscillation Experiments

    OpenAIRE

    Honda, Minako; Kao, Yee; Okamura, Naotoshi; Pronin, Alexey; Takeuchi, Tatsu

    2007-01-01

    New physics beyond the Standard Model can lead to extra matter effects on neutrino oscillation if the new interactions distinguish among the three flavors of neutrino. In a previous paper, we argued that a long-baseline neutrino oscillation experiment in which the Fermilab-NUMI beam in its high-energy mode is aimed at the planned Hyper-Kamiokande detector would be capable of constraining the size of those extra effects, provided the vacuum value of \\sin^2 2\\theta_{23} is not too close to one....

  1. A New Type of Accessible Environmental Influences on Neutrino Oscillation

    Institute of Scientific and Technical Information of China (English)

    CHANG Chao-Hsi; DONG Hui-Shi; FENG Tai-Fu; FENG Xi-Chen; LI Xue-Qian; MA Feng-Cai; TAO Zhi-Jian

    2001-01-01

    Considering a new type of environment influences,we use a two-energy-level (v1-v2) quantum system to investigate neutrino oscillations in medium.Besides the matter effects derived by Wolfenstein,there may exist extra terms due to a unitary evolution of the system between pure and mixed states,so the evolution equation is modified obviously.We show that the extra terms may play some role and induce observable effects in solar neutrino problem, especially,in the long baseline neutrino oscillation experiments which are under serious consideration recently,if the parameters fall into a suitable region.

  2. Coherence of neutrino oscillations in the wave packet approach

    CERN Document Server

    Giunti, C

    1998-01-01

    The temporal and spatial coherence widths of the microscopic process by which a neutrino is detected are incorporated in the quantum mechanical wave packet treatment of neutrino oscillations, confirming the observation of Kiers, Nussinov and Weiss that an accurate measurement of the energies of the particles participating in the detection process can increase the coherence length. However, the wave packet treatment presented here shows that the coherence length has an upper bound, determined by the neutrino energy and the mass-squared difference, beyond which the coherence of the oscillation process is lost.

  3. Recent neutrino oscillation results from T2K

    Indian Academy of Sciences (India)

    H A Tanaka; on behalf of the T2K Collaboration

    2012-11-01

    The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations in a ∼ 600 MeV muon neutrino beam sent at 295 km from the Japan Proton Accelerator Complex (J-PARC) to the Super Kamiokande (SK) detector in Kamioka. The primary goals of T2K are to search for the appearance of electron neutrinos at SK resulting from 13 > 0 and to precisely measure 23 and $ m_{32}^{2}$ via disappearance. We report on T2K results obtained from neutrino data taken in 2010 and 2011.

  4. Neutrino Oscillation Physics Potential of the T2K Experiment

    CERN Document Server

    Abe, K; Aihara, H; Akiri, T; Andreopoulos, C; Aoki, S; Ariga, A; Assylbekov, S; Autiero, D; Barbi, M; Barker, G J; Barr, G; Bass, M; Batkiewicz, M; Bay, F; Berardi, V; Berger, B E; Berkman, S; 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; Rodr'iguez, J Caravaca; 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; Dewhurst, D; Di Lodovico, F; Di Luise, S; Drapier, O; Duboyski, T; Duffy, K; Dumarchez, J; Dytman, S; Dziewiecki, M; Emery-Schrenk, S; Ereditato, A; Escudero, L; Finch, A J; Friend, M; Fujii, Y; Fukuda, Y; Furmanski, A P; Galymov, V; Giffin, S; Giganti, C; Gilje, K; Goeldi, D; Golan, T; Gonin, M; Grant, N; Gudin, D; Hadley, D R; Haesler, A; Haigh, M D; Hamilton, P; Hansen, D; Hara, T; Hartz, M; Hasegawa, T; Hastings, N C; Hayato, Y; Hearty, C; Helmer, R L; Hierholzer, M; Hignight, J; Hillairet, A; Himmel, A; Hiraki, T; Hirota, S; Holeczek, J; Horikawa, S; Huang, K; Ichikawa, A K; Ieki, K; Ieva, M; Ikeda, M; Imber, J; Insler, J; Irvine, T J; Ishida, T; Ishii, T; Iwai, E; Iwamoto, K; Iyogi, K; Izmaylov, A; Jacob, A; Jamieson, B; Johnson, R A; Johnson, S; Jo, J H; Jonsson, P; Jung, C K; Kabirnezhad, M; Kaboth, A C; Kajita, T; Kakuno, H; Kameda, J; Kanazawa, Y; Karlen, D; Karpikov, I; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kikawa, T; Kilinski, A; Kim, J; King, S; Kisiel, J; Kitching, P; Kobayashi, T; Koch, L; Kolaceke, A; Konaka, A; Kormos, L L; Korzenev, A; Koseki, K; Koshio, Y; Kropp, W; Kubo, H; Kudenko, Y; Kurjata, R; Kutter, T; Lagoda, J; Laihem, K; Lamont, I; Larkin, E; Laveder, M; Lawe, M; Lazos, M; Lindner, T; Lister, C; Litchfield, R P; Longhin, A; Ludovici, L; Magaletti, L; Mahn, K; Malek, M; Manly, S; Marino, A D; Marteau, J; Martin, J F; Martynenko, S; Maruyama, T; Matveev, V; Mavrokoridis, K; Mazzucato, E; McCarthy, M; McCauley, N; McFarland, K S; McGrew, C; Mefodiev, A; Metelko, C; Mezzetto, M; Mijakowski, P; Miller, C A; Minamino, A; Mineev, O; Missert, A; Miura, M; Moriyama, S; Mueller, Th A; Murakami, A; Murdoch, M; Murphy, S; Myslik, J; Nakadaira, T; Nakahata, M; Nakamura, K; Nakayama, S; Nakaya, T; Nakayoshi, K; Nielsen, C; Nirkko, M; Nishikawa, K; Nishimura, Y; O'Keeffe, H M; Ohta, R; Okumura, K; Okusawa, T; Oryszczak, W; Oser, S M; Ovsyannikova, T; Owen, R A; Oyama, Y; Palladino, V; Palomino, J L; Paolone, V; Payne, D; Perevozchikov, O; Perkin, J D; Petrov, Y; Pickard, L; Guerra, E S Pinzon; Pistillo, C; Plonski, P; Poplawska, E; Popov, B; Posiadala-Zezula, M; Poutissou, J -M; Poutissou, R; Przewlocki, P; Quilain, B; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M A M; Redij, A; Reeves, M; Reinherz-Aronis, E; Riccio, C; Rodrigues, P A; Rojas, P; Rondio, E; Roth, S; Rubbia, A; Ruterbories, D; Sacco, R; Sakashita, K; S'anchez, F; Sato, F; Scantamburlo, E; Scholberg, K; Schoppmann, S; Schwehr, J; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Sgalaberna, D; Shaker, F; Shiozawa, M; Short, S; Shustrov, Y; Sinclair, P; Smith, B; Smy, M; Sobczyk, J T; Sobel, H; Sorel, M; Southwell, L; Stamoulis, P; Steinmann, J; Still, B; Suda, Y; Suzuki, A; Suzuki, K; Suzuki, S Y; Suzuki, Y; Tacik, R; Tada, M; Takahashi, S; Takeda, A; Takeuchi, Y; Tanaka, H K; Tanaka, H A; Tanaka, M M; Terhorst, D; Terri, R; Thompson, L F; Thorley, A; Tobayama, S; Toki, W; Tomura, T; Totsuka, Y; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vacheret, A; Vagins, M; Vasseur, G; Wachala, T; 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; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Yuan, T; Yu, M; Zalewska, A; Zalipska, J; Zambelli, L; Zaremba, K; Ziembicki, M; Zimmerman, E D; Zito, M; Zmuda, J

    2014-01-01

    The observation of the recent electron neutrino appearance in a muon neutrino beam and the high-precision measurement of the mixing angle $\\theta_{13}$ have led to a re-evaluation of the physics potential of the T2K long-baseline neutrino oscillation experiment. Sensitivities are explored for CP violation in neutrinos, non-maximal $\\sin^22\\theta_{23}$, the octant of $\\theta_{23}$, and the mass hierarchy, in addition to the measurements of $\\delta_{CP}$, $\\sin^2\\theta_{23}$, and $\\Delta m^2_{32}$, for various combinations of $\

  5. Measurement of Atmospheric Neutrino Oscillations with Very Large Volume Neutrino Telescopes

    Directory of Open Access Journals (Sweden)

    J. P. Yáñez

    2015-01-01

    Full Text Available Neutrino oscillations have been probed during the last few decades using multiple neutrino sources and experimental set-ups. In the recent years, very large volume neutrino telescopes have started contributing to the field. First ANTARES and then IceCube have relied on large and sparsely instrumented volumes to observe atmospheric neutrinos for combinations of baselines and energies inaccessible to other experiments. Using this advantage, the latest result from IceCube starts approaching the precision of other established technologies and is paving the way for future detectors, such as ORCA and PINGU. These new projects seek to provide better measurements of neutrino oscillation parameters and eventually determine the neutrino mass ordering. The results from running experiments and the potential from proposed projects are discussed in this review, emphasizing the experimental challenges involved in the measurements.

  6. Geometric gravitational origin of neutrino oscillations and mass-energy

    CERN Document Server

    Gonzalez-Martin, Gustavo R

    2012-01-01

    A mass-energy scale for neutrinos was calculated from the null cone curvature using geometric concepts. The scale is variable depending on the gravitational potential and the trajectory inclination with respect to the field direction. The mass-energy at the Earth surface varies from a horizontal value 0.402 eV to a vertical value 0.569 eV. Earth spinor waves with winding numbers n show squared energy differences within ranges from 2.05 x 10*(-3) to 4.10 x 10*(-3) eV*2 for n=0,1 neutrinos and from 6.14 x 10*(-5) to 12.3 x 10*(-5) eV*2 for n=1,2 neutrinos. These waves interfere and the different phase velocities produce neutrino-like oscillations. The experimental results for atmospheric and solar neutrino oscillation mass parameters respectivelly fall within these theoretical ranges. Neutrinos in outer space, where interactions may be neglected, appear as particles travelling with zero mass on null geodesics. These gravitational curvature energies are consistent with neutrino oscillations, zero neutrino rest m...

  7. Physics prospects of future neutrino oscillation experiments in Asia

    CERN Document Server

    Hagiwara, K

    2004-01-01

    The three neutrino model has 9 physical parameters, 3 neutrino masses, 3 mixing angles and 3 CP violating phases. Among them, neutrino oscillation experiments can probe 6 parameters: 2 mass squared differences, 3 mixing angles, and 1 CP phase. The experiments performed so far determined the magnitudes of the two mass squared differences, the sign of the smaller mass squared difference, the magnitudes of two of the three mixing angles, and the upper bound on the third mixing angle. The sign of the larger mass squared difference (the neutrino mass hierarchy pattern), the magnitude of the third mixing angle and the CP violating phase, and a two-fold ambiguity in the mixing angle that dictates the atmospheric neutrino oscillation should be determined by future oscillation experiments. In this talk, I introduce a few ideas of future long baseline neutrino oscillation experiments which make use of the super neutrino beams from J-PARC (Japan Proton Accelerator Research Complex) in Tokai village. We examine the poten...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bass, Matthew [Colorado State Univ., Fort Collins, CO (United States)

    2014-01-01

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

  9. Neutrino oscillations make their first appearance in OPERA

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    1400 metres underground in the INFN Gran Sasso Laboratory, the Opera experiment has just observed its first candidate for neutrino oscillation – the phenomenon that confirms that neutrinos have mass. It is the first time that an experiment has observed the direct appearance of the new type of neutrinos produced in the oscillation. Opera uses a dedicated beam produced at CERN’s Super Proton Synchrotron (SPS).   Tracks of first candidate event observed by the OPERA experiment. Neutrinos, abundant in cosmic rays, are involved in several of the nuclear reactions that take place in the Sun, and also in radioactive decays. Numerous as they are, they continue to hold many secrets for scientists. One is the fact that the three types of neutrinos—electron, muon and tau neutrinos—can change into each another. This physical phenomenon, known as neutrino ‘oscillations’, was originally described in an article by Bruno Pontecorvo and Vla...

  10. Basic oscillation measurables in the neutrino pair beam

    Science.gov (United States)

    Asaka, T.; Tanaka, M.; Yoshimura, M.

    2016-09-01

    It was recently shown that the neutrino-pair emission may occur with large rates, their energy being extended to GeV region, if appropriate heavy ions are circulated in a quantum state of mixture. In the present work it is further demonstrated that the vector current contribution of neutrino interaction with electrons in ion, not necessarily suppressed in high atomic number ions, gives rise to the oscillating component, even when a single neutrino is detected alone. On the other hand, the single neutrino detection in Z-boson decay does not show the oscillating component, as known for some time. CP violation measurements in the neutrino pair beam may become a possibility, along with determination of mass hierarchical patterns.

  11. Constant matter neutrino oscillations in a parametrization-free formulation

    CERN Document Server

    Flores, L J

    2015-01-01

    Neutrino oscillations are now a well stablished and deeply studied phenomena. Its mixing parameters, except for the CP-phase, are measured with good accuracy. Three neutrino oscillation picture in matter is currently of great interest due to the different long baseline neutrino experiments that are already running or under construction. In this work we re-analyze the exact expression for the neutrino probabilities (in a constant density medium) and introduce an approximate formula. Our results are showed in a formulation that is independent of the parametrization and could be useful for unitary tests of the leptonic mixing matrix. We illustrate how the approximation, besides being simple, can reproduce the neutrino probabilities with good accuracy.

  12. Constant matter neutrino oscillations in a parametrization-free formulation

    Science.gov (United States)

    Flores, L. J.; Miranda, O. G.

    2016-02-01

    Neutrino oscillations are now a well-established and deeply studied phenomena. Their mixing parameters, except for the C P phase, are measured with good accuracy. The three-neutrino oscillation picture in matter is currently of great interest due to the different long-baseline neutrino experiments that are already running or under construction. In this work, we reanalyze the exact expression for the neutrino probabilities (in a constant density medium) and introduce an approximate formula. Our results are shown in a formulation that is independent of the parametrization and could be useful for unitary tests of the leptonic mixing matrix. We illustrate how the approximation, besides being simple, can reproduce the neutrino probabilities with good accuracy.

  13. Expectation values of flavor-neutrino numbers with respect to neutrino-source hadron states: Neutrino oscillations and decay probabilities

    International Nuclear Information System (INIS)

    On the basis of quantum field theory, we consider a unified description of various processes accompanied by neutrinos, namely, weak decays and oscillation processes. The structures of the expectation values of flavor-neutrino numbers with respect to the neutrino-source hadron state are investigated. Due to the smallness of neutrino masses, we naturally obtain the old (i.e., pre-mixing) formulas of decay probabilities. In addition, it is shown that the oscillation formulas, similar to the usual ones, are derived irrespectively of the details of neutrino-producing processes. The derived oscillation formulas are regarded as being the same in form as the usually adopted ones, except for some simple distinctions

  14. Supernova Neutrinos: Production, Oscillations and Detection

    CERN Document Server

    Mirizzi, Alessandro; Janka, Hans-Thomas; Saviano, Ninetta; Scholberg, Kate; Bollig, Robert; Hudepohl, Lorenz; Chakraborty, Sovan

    2015-01-01

    Neutrinos play a crucial role in the collapse and explosion of massive stars, governing the infall dynamics of the stellar core, triggering and fueling the explosion and driving the cooling and deleptonization of the newly formed neutron star. Due to their role neutrinos carry information from the heart of the explosion and, due to their weakly interacting nature, offer the only direct probe of the dynamics and thermodynamics at the center of a supernova. In this paper, we review the present status of modelling the neutrino physics and signal formation in collapsing and exploding stars. We assess the capability of current and planned large underground neutrino detectors to yield faithful information of the time and flavor dependent neutrino signal from a future Galactic supernova. We show how the observable neutrino burst would provide a benchmark for fundamental supernova physics with unprecedented richness of detail. Exploiting the treasure of the measured neutrino events requires a careful discrimination o...

  15. Lower bound on neutrino mass and possible CP violation in neutrino oscillations

    CERN Document Server

    Verma, Rohit

    2013-01-01

    The phenomenology of the most general lepton mass matrices obtained through weak basis transformations has been discussed. Using a hierarchical parametrization of these mass matrices, the exact relations for lepton mixing angles have been obtained assuming normal neutrino mass hierarchy and natural structures of lepton mass matrices. The recent three neutrino oscillation data together with the condition of naturalness on Dirac lepton mass matrices provide a lower bound on the lightest neutrino mass of m{\

  16. Neutrino oscillations and uncertainty in the solar model

    Science.gov (United States)

    Dearborn, D. S.; Fuller, G. M.

    1989-06-01

    The Mikheyev-Smirnov-Wolfenstein (MSW) resonant neutrino oscillation mechanism is investigated for the Sun using a detailed numerical solar model and a modified version of the Parke-Walker technique for following the neutrino phases through the oscillation resonance. We present overall solar-neutrino spectra and the associated expected neutrino count rates for the 37Cl, 71Ga, and Kamiokande detectors for ranges of masses and vacuum mixing angles for two neutrino species. We also investigate the effects of uncertainties in the solar model. In particular, we examine the effect of opacity changes on the expected solar-neutrino spectrum and resulting parameter space for the MSW mechanism. We find that plausible uncertainties in the standard solar model, and in particular the opacity, translate into significant expansion in the constraints on neutrino masses and vacuum mixing angles from neutrino experiments. It is shown, however, that forthcoming results from the Kamiokande solar-neutrino experiment could put stringent constraints on even the expanded MSW parameter space.

  17. Neutrino oscillation effects in Soudan 2 upward-stopping muons

    International Nuclear Information System (INIS)

    Upward-going stopping muons initiated by atmospheric νμ and νμ interactions in the rock below the Soudan 2 detector have been isolated, together with a companion sample of neutrino-induced single muons, created within the detector, which travel downwards and exit. The downward-going sample is consistent with the atmospheric-neutrino flux prediction, but the upward-going sample exhibits a sizable depletion. Both are consistent with previously reported Soudan 2 neutrino-oscillation results. Inclusion of the two samples in an all-event likelihood analysis, using recent 3D-atmospheric-neutrino-flux calculations, reduces both the allowed oscillation parameter region and the probability of the no-oscillation hypothesis

  18. Neutrino Oscillation Effects on Supernova Light Element Synthesis

    CERN Document Server

    Yoshida, T; Yokomakura, H; Kimura, K; Takamura, A; Hartmann, D H

    2006-01-01

    Neutrino oscillations affect light element synthesis through the neutrino-process in supernova explosions. The 7Li and 11B yields produced in a supernova explosion of a 16.2 solar-mass star model increase by factors of 1.9 and 1.3 in the case of large mixing angle solution with normal mass hierarchy and sin^{2}2theta_{13} > 0.002 compared with those without the oscillations. In the case of inverted mass hierarchy or nonadiabatic 13-mixing resonance, the increment of their yields is much smaller. Neutrino oscillations raise the reaction rates of charged-current neutrino-process reactions in the region outside oxygen-rich layers. The number ratio of 7Li/11B could be a tracer of normal mass hierarchy and relatively large theta_{13}, still satisfying sin^{2}2theta_{13} < 0.1, through future precise observations in stars having strong supernova component.

  19. A new approach to anti-neutrino running in long baseline neutrino oscillation experiments

    CERN Document Server

    Agarwalla, Sanjib K; Link, Jonathan M; Mohapatra, Debabrata

    2010-01-01

    We study the possibility to replace the anti-neutrino run of a long baseline neutrino oscillation experiment, with anti-neutrinos from muon decay at rest. The low energy of these neutrinos allows the use of inverse beta decay for detection in a Gadolinium-doped water Cerenkov detector. We show that this approach yields a factor of five times larger anti-neutrino event sample. The resulting discovery reaches in theta_13, the mass hierarchy and leptonic CP violation are compared with those from a conventional superbeam experiment with combined neutrino and anti-neutrino running. We find that this approach yields a greatly improved reach for CP violation and theta_13 while leaving the ability to measure the mass hierarchy intact.

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

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Stephen James [College of William and Mary, Williamsburg, VA (United States)

    2011-05-01

    Experimental evidence has established that neutrino flavor states evolve over time. A neutrino of a particular flavor that travels some distance can be detected in a different neutrino flavor state. The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline experiment that is designed to study this phenomenon, called neutrino oscillations. MINOS is based at Fermilab near Chicago, IL, and consists of two detectors: the Near Detector located at Fermilab, and the Far Detector, which is located in an old iron mine in Soudan, MN. Both detectors are exposed to a beam of muon neutrinos from the NuMI beamline, and MINOS measures the fraction of muon neutrinos that disappear after traveling the 734 km between the two detectors. One can measure the atmospheric neutrino mass splitting and mixing angle by observing the energy-dependence of this muon neutrino disappearance. MINOS has made several prior measurements of these parameters. Here I describe recently-developed techniques used to enhance our sensitivity to the oscillation parameters, and I present the results obtained when they are applied to a dataset that is twice as large as has been previously analyzed. We measure the mass splitting Δm232 = (2.32-0.08+0.12) x 10-3 eV2/c4 and the mixing angle sin2(2θ32) > 0.90 at 90% C.L. These results comprise the world's best measurement of the atmospheric neutrino mass splitting. Alternative disappearance models are also tested. The neutrino decay hypothesis is disfavored at 7.2σ and the neutrino quantum decoherence hypothesis is disfavored at 9.0σ.

  1. Neutrino oscillations on the way to long-baseline experiments

    CERN Document Server

    Ryabov, V A

    2003-01-01

    The motivations and physical objectives of experiments in the search for nu /sub mu / to nu /sub e/, nu /sub tau / oscillations in long- baseline accelerator neutrino beams are reviewed. Neutrino beams, detectors, and methods for detecting oscillations (detection of the disappearance of nu /sub mu /, and the appearance of nu /sub e/ and nu /sub tau /) in the current K2K (KEK to Super Kamiokande) experiment and in the MINOS (FNAL to Soudan) and OPERA (CERN to Gran Sasso) near-future experiments are discussed. Possibilities of measuring the oscillation parameters in these experiments are considered in connection with new data obtained in CHOOZ and Palo Verde reactor experiments, the solar neutrino deficit and nu /sub mu // nu /sub e/ anomaly of atmospheric neutrinos, which are observed in large-scale underground detectors, and the excess of nu /sub e/ events in the LSND experiment. Neutrino-oscillation scenarios used in models with three and four (including sterile) types of neutrino, as well as the possibility...

  2. Particle production with L-R neutrino oscillation

    CERN Document Server

    Enomoto, Seishi

    2016-01-01

    When the Higgs field starts oscillation after Higgs inflation, gauge bosons are produced non-perturbatively near the Enhanced Symmetry Point (ESP). Just after the particle production, when the Higgs field is going away from the ESP, these gauge bosons gain mass and decay or annihilate into Standard Model (SM) fermions. Left-handed neutrinos can be generated in that way. If one assumes the see-saw mechanism, the mass matrix of a pair of left and right-handed neutrinos is non-diagonal. Although their mixing in the mass eigenstates is negligible in the true vacuum, it could be significant near the edge of the Higgs oscillation, where the off-diagonal component is large. Therefore, the left-handed neutrinos generated from the gauge bosons can start neutrino oscillation between the right-handed neutrinos. We study the particle production when such L-R neutrino oscillation is significant. For a working example, the non-thermal leptogenesis scenario after Higgs inflation is examined, which cannot be realized without...

  3. Variables for probing neutrino oscillation at super-Kamiokande and the Sudbury Neutrino Observatory

    Indian Academy of Sciences (India)

    Debasish Majumdar

    2000-01-01

    We propose several new variables, insensitive to the absolute flux of the incident solar or supernova neutrino beam, which probe the shape of the observed spectrum at super-Kamiokande and Sudbury Neutrino Observatory experiments and can sensitively signal neutrino oscillations. One class of such variables involve moments of the distributions recorded at the two facilities while another variable, specific to SNO, utilises the integrated charged and neutral current signals. The utility of these variables in the context of supernova neutrinos both from the collapse epoch and the post-bounce era is also discussed.

  4. Effect of resonant neutrino oscillation on TeV neutrino flavor ratio from choked GRBs

    Institute of Scientific and Technical Information of China (English)

    Sarira Sahu; Bing Zhang

    2010-01-01

    In the collapsar scenario of the long duration Gamma-Ray Bursts (GRBs), multi-TeV neutrino emission is predicted as the jet makes its way through the stellar envelope. Such a neutrino signal is also expected for more general "failed" GRBs in which a putative jet is "choked" by a heavy envelope. If the Ve→ Vμneutrino oscillation parameters are in the atmospheric neutrino oscillation range, we show that the resonant oscillation of Ve ←→Vμ,t can take place within the inner high density region of the choked jet progenitor with a heavy envelope, altering the V flavor ratio on its surface to φsve:φsvμ:φsvt =5:11:2. Considering vacuum oscillations of these neutrinos on their way to Earth, the final flavor ratio detected on Earth is further modified to either 1:1.095:1.095 for the large mixing angle solution to the solar neutrino data, or 1:1.3:1.3 for maximal mixing among the muon and tau neutrinos in the vacuum.

  5. Physics prospects of future neutrino oscillation experiments in Asia

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Kaoru [Theory Division, KEK, Tsukuba 305-0801 (Japan)

    2004-12-15

    The three neutrino model has 9 physical parameters, 3 neutrino masses, 3 mixing angles and 3 CP violating phases. Among them, neutrino oscillation experiments can probe 6 neutrino parameters: 2 mass squared differences, 3 mixing angles, and 1 CP phase. The experiments performed so far determined the magnitudes of the two mass squared differences, the sign of the smaller mass squared difference, the magnitudes of two of the three mixing angles, and the upper bound on the third mixing angle. The sign of the larger mass squared difference (the neutrino mass hierarchy pattern), the magnitude of the third mixing angle and the CP violating phase, and a two-fold ambiguity in the mixing angle that dictates the atmospheric neutrino oscillation should be determined by future oscillation experiments. In this talk, I introduce a few ideas of future long baseline neutrino oscillation experiments which make use of the super neutrino beams from J-PARC (Japan Proton Accelerator Research Complex) in Tokai village. We examine the potential of HyperKamiokande (HK), the proposed 1 Mega-ton water Cerenkov detector, and then study the fate and possible detection of the off-axis beam from J-PARC in Korea, which is available free throughout the period of the T2K (Tokai-to-SuperKamiokande) and the possible T-to-HK projects. Although the CP violating phase can be measured accurately by studying {nu}{sub {mu}}->{nu}{sub e} and {nu}-bar {sub {mu}}->{nu}-bar {sub e} oscillations at HK, there appear multiple solution ambiguities which can be solved only by determining the neutrino mass hierarchy and the twofold ambiguity in the mixing angle. We show that very long baseline experiments with higher energy beams from J-PARC and a possible huge Water Cerenkov Calorimeter detector proposed in Beijing can resolve the neutrino mass hierarchy. If such a detector can be built in China, future experiments with a muon storage ring neutrino factory at J-PARC will be able to lift all the degeneracies in the

  6. Physics prospects of future neutrino oscillation experiments in Asia

    International Nuclear Information System (INIS)

    The three neutrino model has 9 physical parameters, 3 neutrino masses, 3 mixing angles and 3 CP violating phases. Among them, neutrino oscillation experiments can probe 6 neutrino parameters: 2 mass squared differences, 3 mixing angles, and 1 CP phase. The experiments performed so far determined the magnitudes of the two mass squared differences, the sign of the smaller mass squared difference, the magnitudes of two of the three mixing angles, and the upper bound on the third mixing angle. The sign of the larger mass squared difference (the neutrino mass hierarchy pattern), the magnitude of the third mixing angle and the CP violating phase, and a two-fold ambiguity in the mixing angle that dictates the atmospheric neutrino oscillation should be determined by future oscillation experiments. In this talk, I introduce a few ideas of future long baseline neutrino oscillation experiments which make use of the super neutrino beams from J-PARC (Japan Proton Accelerator Research Complex) in Tokai village. We examine the potential of HyperKamiokande (HK), the proposed 1 Mega-ton water Cerenkov detector, and then study the fate and possible detection of the off-axis beam from J-PARC in Korea, which is available free throughout the period of the T2K (Tokai-to-SuperKamiokande) and the possible T-to-HK projects. Although the CP violating phase can be measured accurately by studying νμ->νe and ν-bar μ->ν-bar e oscillations at HK, there appear multiple solution ambiguities which can be solved only by determining the neutrino mass hierarchy and the twofold ambiguity in the mixing angle. We show that very long baseline experiments with higher energy beams from J-PARC and a possible huge Water Cerenkov Calorimeter detector proposed in Beijing can resolve the neutrino mass hierarchy. If such a detector can be built in China, future experiments with a muon storage ring neutrino factory at J-PARC will be able to lift all the degeneracies in the three neutrino model parameters

  7. Physics prospects of future neutrino oscillation experiments in Asia

    Science.gov (United States)

    Hagiwara, Kaoru

    2004-12-01

    The three neutrino model has 9 physical parameters, 3 neutrino masses, 3 mixing angles and 3 CP violating phases. Among them, neutrino oscillation experiments can probe 6 neutrino parameters: 2 mass squared differences, 3 mixing angles, and 1 CP phase. The experiments performed so far determined the magnitudes of the two mass squared differences, the sign of the smaller mass squared difference, the magnitudes of two of the three mixing angles, and the upper bound on the third mixing angle. The sign of the larger mass squared difference (the neutrino mass hierarchy pattern), the magnitude of the third mixing angle and the CP violating phase, and a two-fold ambiguity in the mixing angle that dictates the atmospheric neutrino oscillation should be determined by future oscillation experiments. In this talk, I introduce a few ideas of future long baseline neutrino oscillation experiments which make use of the super neutrino beams from J-PARC (Japan Proton Accelerator Research Complex) in Tokai village. We examine the potential of HyperKamiokande (HK), the proposed 1 Mega-ton water Čerenkov detector, and then study the fate and possible detection of the off-axis beam from J-PARC in Korea, which is available free throughout the period of the T2K (Tokai-to-SuperKamiokande) and the possible T-to-HK projects. Although the CP violating phase can be measured accurately by studying ν→ν and ν→ν oscillations at HK, there appear multiple solution ambiguities which can be solved only by determining the neutrino mass hierarchy and the twofold ambiguity in the mixing angle. We show that very long baseline experiments with higher energy beams from J-PARC and a possible huge Water Čerenkov Calorimeter detector proposed in Beijing can resolve the neutrino mass hierarchy. If such a detector can be built in China, future experiments with a muon storage ring neutrino factory at J-PARC will be able to lift all the degeneracies in the three neutrino model parameters.

  8. Flavor distribution of UHE cosmic neutrino oscillations at neutrino telescopes

    Science.gov (United States)

    Xing, Zhi-Zhong

    2009-04-01

    If the ultrahigh-energy (UHE) cosmic neutrinos produced from a distant astrophysical source can be measured at a km-size neutrino telescope such as the IceCube or KM3NeT, they will open a new window to understand the nature of flavor mixing and to probe possible new physics. Considering the conventional UHE cosmic neutrino source with the flavor ratio φe:φμ:φτ=1:2:0, I point out two sets of conditions for the flavor democracy φeT:φμT:φτT=1:1:1 to show up at neutrino telescopes: either θ13=0 and θ23=π/4 (CP invariance) or δ=±π/2 and θ23=π/4 (CP violation) in the standard parametrization of the 3×3 neutrino mixing matrix V. Allowing for slight μ-τ symmetry breaking effects characterized by Δ∈[-0.1,+0.1], I find φeT:φμT:φτT=(1-2Δ):(1+Δ):(1+Δ) as a good approximation. Another possibility to constrain Δ is to detect the ν flux of E≈6.3PeV via the Glashow resonance channel νe→W→anything. I also give some brief comments on (1) possible non-unitarity of V in the seesaw framework and its effects on the flavor distribution at neutrino telescopes and (2) a generic description and determination of the cosmic neutrino flavor composition at distant astrophysical sources.

  9. Neutrino oscillations in the field of a rotating deformed mass

    CERN Document Server

    Geralico, Andrea

    2012-01-01

    The neutrino oscillations in the field of a rotating deformed mass is investigated. The phase shift is evaluated in the case of weak field limit, slow rotation and small deformation. To this aim the Hartle-Thorne metric is used, which is an approximate solution of the vacuum Einstein equations accurate to second order in the rotation parameter $a/M$ and to first order in the mass quadrupole moment $q$. Implications on atmospheric, solar and astrophysical neutrinos are discussed.

  10. Neutrino Oscillations as a Lepton-Flavor-Violating Interaction

    CERN Document Server

    Hwang, W -Y Pauchy

    2012-01-01

    To describe neutrino oscillations in the quantum mechanics sense, we propose to use an off-diagonal neutrino-Higgs (mass) interaction, as discussed recently in a family gauge theory. This extra orthogonal SU_f(3) family gauge theory may help us to resolve a few outstanding puzzles - the question of why there are only three generations, the question of why the masses of neutrinos are so tiny, and the question of why the darkmatter world is so huge (25%) as compared to the visible ordinary-matter world (5%).

  11. Neutrino oscillations, seesaw mechanism and the quest for new physics

    CERN Document Server

    Miranda, O G

    2016-01-01

    The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, have brought neutrino physics to the precision era. Apart from dedicated leptonic CP violation studies, upcoming experiments should probe the unitarity of the lepton mixing matrix. These will shed light on the scale of new physics, such as the seesaw scale, and thereby guide us towards what could be the next step in particle physics. Moreover these efforts may also bring the key to elucidate some of the current cosmological puzzles.

  12. Particle quantum states with indefinite mass and neutrino oscillations

    CERN Document Server

    Lobanov, A E

    2015-01-01

    Spaces of particle states are constructed in such a way that charged leptons, neutrinos, as well as down- and up-type quarks are combined in multiplets with their components being considered as different quantum states of a single particle. In the theory based on the Lagrangian of fermion sector of the Standard Model modified with this approach the phenomenon of neutrino oscillations appears. By example of pion decay it is shown that the states of the neutrino, arising in the process of decay may be described by a superposition of states with identical momenta with very high accuracy.

  13. The effect of spontaneous collapses on neutrino oscillations

    CERN Document Server

    Donadi, S; Curceanu, C; Ferialdi, L

    2012-01-01

    We compute the effect of collapse models on neutrino oscillations. The effect of the collapse is to modify the evolution of the `spatial' part of the wave function, which indirectly amounts to a change on the flavor components. In many respects, this phenomenon is similar to neutrino propagation through matter. For the analysis we use the mass proportional CSL model, and perform the calculation to second order perturbation theory. As we will show, the CSL prediction is very small - mainly due to the very small mass of neutrinos - and practically undetectable.

  14. Neutrino oscillation effect on the indirect signal of neutralino dark matter from the Earth core

    CERN Document Server

    Fornengo, N

    1999-01-01

    We investigate the effect induced by neutrino oscillation on the dark matter indirect detection signal which consists in a muon neutrino flux produced by neutralino annihilation in the Earth core. We consider the neutrino oscillation parameters relevant to the atmosferic neutrino deficit, both in the nu_mu -> nu_tau and nu_mu -> nu_s cases.

  15. Millicharged neutrino with anomalous magnetic moment in rotating magnetized matter

    CERN Document Server

    Studenikin, Alexander

    2014-01-01

    We consider a millicharged neutrino with nonzero magnetic moment in the presence of rotating and magnetized background matter. The exact solution of the corresponding modified Dirac equation for the neutrino wave function is found. The neutrino energy spectrum is obtained and the effect of neutrino energy quantization is discussed in details. We introduce a new kind of spin operator which is a superposition of longitudinal and transverse polarizations operators for description of the neutrino spin properties in the considered background environment. Within the quasi-classical approach to the problem, radius of the neutrino orbits is derived and the effective "matter induced Lorentz force" is introduced. It is shown that in the considered environment, and also in matter with nonzero gradient of density, neutrino moves with acceleration. In this case a new type of the electromagnetic neutrino radiation (termed "light of millicharged neutrino") can be produced. The considered problem is of interest for astrophys...

  16. Supernova neutrino oscillations: what do we understand?

    OpenAIRE

    Dighe, Amol

    2009-01-01

    We summarize our current understanding of the neutrino flavor conversions inside a core collapse supernova, clarifying the important role played by the "collective effects" in determining flavor conversion probabilities. The potentially observable $\

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

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Tian [Iowa State U.

    2016-01-01

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

  18. A search for oscillations of muon-neutrinos to electron-neutrinos

    CERN Document Server

    Procario, Michael

    1986-01-01

    The author has searched in the heavy liquid bubble chamber BEBC for electron neutrino charge current events which could arise from oscillation of the muon neutrinos (average energy ∼1.5 GeV) obtained with a low energy proton beam at the CERN PS targeted 825 m upstream from BEBC. The appearance of electron neutrino CC interactions provides a sensitive indication of nu/sub μ/ → nu/sub e/ oscillation. The author observed 460 muon neutrino CC events and 4 electron neutrino CC events with an estimated background of 3.5 electron neutrino CC events. Using the likelihood ratio method to test the oscillation hypothesis, the author finds no evidence for nu/sub μ/ → nu/sub e/ oscillation and set the limits δm2 ≤ 0.13 eV2 (maximal mixing) and sin22theta ≤ 0.018 for δm2 = 3 eV2 at 90% confidence level

  19. MeV scale leptonic force for cosmic neutrino spectrum and muon anomalous magnetic moment

    CERN Document Server

    Araki, Takeshi; Ota, Toshihiko; Sato, Joe; Shimomura, Takashi

    2015-01-01

    Characteristic patterns of cosmic neutrino spectrum reported by the IceCube collaboration and long-standing inconsistency between theory and experiment in muon anomalous magnetic moment are simultaneously explained by an extra leptonic force mediated by a gauge field with a mass of the MeV scale. With different assumptions for redshift distribution of cosmic neutrino sources, diffuse neutrino flux is calculated with the scattering between cosmic neutrino and cosmic neutrino background through the new leptonic force. Our analysis sheds light on a relation among lepton physics at the three different scales, PeV, MeV, and eV, and provides possible clues to the distribution of sources of cosmic neutrino and also to neutrino mass spectrum.

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

    Science.gov (United States)

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

    2013-11-22

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

  1. Measuring $\\theta_{13}$ via Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Toner, Ruth B. [Univ. of Cambridge (United Kingdom). Pembroke College

    2011-01-01

    One of the primary goals in neutrino physics at the present moment is to make a measurement of the neutrino oscillation parameter $\\theta_{13}$. This parameter, in addition to being unknown, could potentially allow for the introduction of CP violation into the lepton sector. The MINOS long-baseline neutrino oscillation experiment has the ability to make a measurement of this parameter, by looking for the oscillation of muon neutrinos to electron neutrinos between a Near and Far Detector over a distance of 735 km. This thesis discusses the development of an analysis framework to search for this oscillation mode. Two major improvements to pre-existing analysis techniques have been implemented by the author. First, a novel particle ID technique based on strip topology, known as the Library Event Matching (LEM) method, is optimized for use in MINOS. Second, a multiple bin likelihood method is developed to fit the data. These two improvements, when combined, increase MINOS' sensitivity to $\\sin^2(2\\theta_{13})$ by 27\\% over previous analyses. This thesis sees a small excess over background in the Far Detector. A Frequentist interpretation of the data rules out $\\theta_{13}=0$ at 91\\%. A Bayesian interpretation of the data is also presented, placing the most stringent upper boundary on the oscillation parameter to date, at $\\sin^2(2\\theta_{13})<0.09(0.015)$ for the Normal (Inverted) Hierarchy and $\\delta_{CP}=0$.

  2. Neutrinospheres, resonant neutrino oscillations, and pulsar kicks

    CERN Document Server

    Barkovich, M; Montemayor, R

    2005-01-01

    Pulsars are rapidly rotating neutron stars and are the outcome of the collapse of the core of a massive star with a mass of the order of or larger than eight solar masses. This process releases a huge gravitational energy of about 10^{53} erg, mainly in the form of neutrinos. During the collapse the density increases, and so does the magnetic field due to the trapping of the flux lines of the progenitor star by the high conductivity plasma. When the density reaches a value of around 10^{12} g cm^{-3} neutrinos become trapped within the protoneutron star and a neutrinosphere, characterized inside by a diffusive transport of neutrinos and outside by a free streaming of neutrinos, is formed and lasts for a few seconds. Here we focus on the structure of the neutrinosphere, the resonant flavor conversion that can happen in its interior, and the neutrino flux anisotropies induced by this phenomena in the presence of a strong magnetic field. We present a detailed discussion in the context of the spherical Eddington ...

  3. Fourier Analysis of the Parametric Resonance in Neutrino Oscillations

    OpenAIRE

    Koike, Masafumi; Ota, Toshihiko; Saito, Masako; Sato, Joe

    2009-01-01

    Parametric enhancement of the appearance probability of the neutrino oscillation under the inhomogeneous matter is studied. Fourier expansion of the matter density profile leads to a simple resonance condition and manifests that each Fourier mode modifies the energy spectrum of oscillation probability at around the corresponding energy; below the MSW resonance energy, a large-scale variation modifies the spectrum in high energies while a small-scale one does in low energies. In contrast to th...

  4. First Indication of Terrestrial Matter Effects on Solar Neutrino Oscillation

    CERN Document Server

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

    2013-01-01

    We report an indication that the elastic scattering rate of solar $^8$B neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through the Earth during nighttime. We determine the day/night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be $(-3.2\\pm1.1(\\text{stat})\\pm0.5(\\text{syst}))\\%$, which deviates from zero by 2.7 $\\sigma$. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a non-zero day/night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day/night asymmetry is consistent with neutrino oscillations for $3\\times10^{-5}$eV$^2\\leq\\Delta m^2_{21}\\leq9\\times10^{-5}$eV$^2$ and large mixing values of $\\theta_{12}$, at the $68\\%$ C.L.

  5. First neutrino oscillation measurements in NOvA

    Science.gov (United States)

    Messier, M. D.

    2016-07-01

    The NOvA experiment uses the Fermilab NuMI neutrino beam and a newly constructed 14 kt detector to address several open questions in neutrino oscillations including the neutrino mass hierarchy, the precise value of the angle θ23, and the CP-violating phase δCP. The experiment has been running since 2014 and has recently released its first results from an equivalent exposure of 2.74 ×1020 protons-on-target equal to 8% of the eventual data set. Measurements of νμ →νμ oscillations find Δ m322 = (2.52-0.18+0.20) ×10-3 eV2 and 0.38 neutrino mass hierarchy. The experiment has observed νμ →νe oscillations at 3.3 σ C.L. in this early data and disfavors the inverted neutrino mass hierarchy in the range 0.1 π <δCP < 0.5 π at the 90% C.L.

  6. Precision measurement of neutrino oscillation parameters at INO-ICAL detector

    Indian Academy of Sciences (India)

    Daljeet Kaur; Md Naimuddin; Sanjeev Kumar Verma

    2016-02-01

    A magnetized Iron CALorimeter (ICAL) detector at the India-based neutrino observatory (INO) is used to study neutrino oscillation sensitivity using atmospheric muon neutrino source. The ICAL detector will be able to detect muon tracks and hadron showers produced by neutrino interactions with the iron target. We have performed precision measurement analysis for the atmospheric neutrino oscillation parameters with the muon neutrino events, generated by Monte Carlo NUANCE event generator. A marginalized 2 analysis based on reconstructed neutrino energy and muon zenith angle binning scheme has been performed to determine the sensitivity for the atmospheric neutrino mixing parameters, ${\\rm sin}^{2} \\theta_{23}$ and $|\\Delta m^{2}_{23}|$.

  7. History of "Anomalous" Atmospheric Neutrino Events: A First Person Account

    CERN Document Server

    LoSecco, John M

    2016-01-01

    The modern picture of the neutrino as a multiple mass highly mixed neutral particle has emerged over 40 years of study. Best known of the issues leading to this picture was the apparent loss of neutrinos coming from the sun. This article describes another piece of evidence that supports the picture; the substantial reduction of high energy muon type neutrinos observed in nature. For much of the 40 year period, before the modern picture emerged this observation was known as the "atmospheric neutrino anomaly", since as will be seen, these neutrinos originate in the Earth's atmosphere. This paper describes the discovery of the atmospheric neutrino anomaly. We explore the scientific context and motivations in the late 1970's from which this work emerged. The gradual awareness that the observations of atmospheric neutrinos were not as expected took place in the 1983-1986 period.

  8. Observation of oscillations of atmospheric neutrinos with the IceCube Neutrino Observatory

    International Nuclear Information System (INIS)

    Neutrino oscillations have become one of the most important research topics in particle physics since their discovery 15 years ago. In the past, the study of neutrino oscillations has been largely the domain of dedicated experiments, but in the last year also the large-volume neutrino telescopes ANTARES and IceCube reported their results on the oscillations of atmospheric muon neutrinos and thus joined the community of experiments studying neutrino oscillations. The precision of their results is not yet competitive, but their sheer size and the consequently enormous statistics give rise to the expectation of a competitive measurement in the future. This thesis describes an analysis that was done on IceCube data taken with the nearly complete detector in the years 2010/2011. IceCube is the world's largest neutrino detector, located at the geographic South Pole, where it uses the Antarctic ice sheet as its detection medium. It detects neutrinos interacting within or close to the instrumented volume by observing the Cherenkov light which is emitted by secondary particles produced in these interactions. An array of optical sensors deployed within a cubic kilometer of ice detects the Cherenkov light and makes it possible to reconstruct the energy and direction of the initial neutrino. Unfortunately, IceCube detects not only neutrinos: the desired neutrino signal is buried in a huge background of atmospheric muons, produced in air showers induced by cosmic rays. This background has to be rejected first. The analysis presented here employs an event selection that is based on the idea of using the outer layers of IceCube as an active veto against the background of atmospheric muons and achieves the necessary background rejection of more than 6 orders of magnitude while keeping a high-statistics sample of several thousands of muon neutrinos. In contrast to the earlier IceCube analysis, which used only the zenith angle, it then performs a 2-dimensional likelihood fit on

  9. Matter Effect on Neutrino Oscillations from the violation of Universality in Neutrino Neutral Current Interactions

    OpenAIRE

    Honda, Minako; Okamura, Naotoshi; Takeuchi, Tatsu

    2006-01-01

    The violation of lepton-flavor-universality in the neutrino-Z interactions can lead to extra matter effects on neutrino oscillations at high energies, beyond that due to the usual charged-current interaction of the electron-neutrino. We show that the dominant effect of the violation is a shift in the effective value of \\theta_{23}. This is in contrast to the dominant effect of the charged-current interaction which shifts \\theta_{12} and \\theta_{13}. The shift in \\theta_{23} will be difficult ...

  10. KamLAND, terrestrial heat sources and neutrino oscillations

    CERN Document Server

    Fiorentini, G; Lissia, M; Ricci, B; Schönert, S

    2003-01-01

    We comment on the first indication of geo-neutrino events from KamLAND and on the prospects for understanding Earth energetics. Practically all models of terrestrial heat production are consistent with data within the presently limited statistics, the fully radiogenic model being closer to the observed value ($\\approx 9$ geo-events). In a few years KamLAND should collect sufficient data for a clear evidence of geo-neutrinos, however discrimination among models requires a detector with the class and size of KamLAND far away from nuclear reactors. We also remark that the event ratio from Thorium and Uranium decay chains is well fixed $N(Th)/N(U) \\simeq 0.25$, a constraint that can be useful for determining neutrino oscillation parameters. We show that a full spectral analysis, including this constraint, further reduces the oscillation parameter space compared to an analysis with an energy threshold $E_{vis}>2.6 MeV$.

  11. Optimization of Neutrino Oscillation Parameters Using Differential Evolution

    Institute of Scientific and Technical Information of China (English)

    Ghulam Mustafa; Faisal Akram; Bilal Masud

    2013-01-01

    We show how the traditional grid based method for finding neutrino oscillation parameters △m2 and tan2θ can be combined with an optimization technique,Differential Evolution (DE),to get a significant decrease in computer processing time required to obtain minimal chi-square (x2) in four different regions of the parameter space.We demonstrate efficiency for the two-neutrinos case.For this,the x2 function for neutrino oscillations is evaluated for grids with different density of points in standard allowed regions of the parameter space of △m2 and tan2 θ using experimental and theoretical total event rates of chlorine (Homestake),Gallex+GNO,SAGE,Superkamiokande,and SNO detectors.We find that using DE in combination with the grid based method with small density of points can produce the results comparable with the one obtained using high density grid,in much lesser computation time.

  12. Status of the Daya Bay Reactor Neutrino Oscillation Experiment

    International Nuclear Information System (INIS)

    The last unknown neutrino mixing angle θ13 is one of the fundamental parameters of nature; it is also a crucial parameter for determining the sensitivity of future long-baseline experiments aimed to study CP violation in the neutrino sector. Daya Bay is a reactor neutrino oscillation experiment designed to achieve a sensitivity on the value of sin2(2*θ13) to better than 0.01 at 90% CL. The experiment consists of multiple identical detectors placed underground at different baselines to minimize systematic errors and suppress cosmogenic backgrounds. With the baseline design, the expected anti-neutrino signal at the far site is about 360 events per day and at each of the near sites is about 1500 events per day. An overview and current status of the experiment will be presented.

  13. Atmospheric neutrino oscillations in IceCube-79

    International Nuclear Information System (INIS)

    We present the results of an analysis of data collected by IceCube/DeepCore in 2010-2011 when operating in the 79 string configuration. This analysis results in the first significant detection of neutrino oscillations in a high-energy neutrino telescope. A low-energy muon neutrino sample (20-100 GeV) containing the oscillation signal was extracted from data collected by DeepCore. A high-energy muon neutrino sample (100 GeV-10 TeV) was extracted from IceCube data in order to constrain the systematic uncertainties. The non-oscillation hypothesis was rejected with more than 5σ. We fitted the oscillation parameters Δ m223 and sin22 θ23 to these data samples. In a 2-flavor formalism we find Δ m223 = (2.5±0.6). 10-3 eV2 and sin22 θ23 > 0.92 while maximum mixing is favored. These results are in good agreement with the world average values.

  14. Masses, mélange et oscillations de neutrinos

    CERN Document Server

    Wilquet, Gaston

    The experimental situation concerning the measurements of neutrinos masses, mixing and oscillation is reviewed, as well as of the underlying phenomenology. A particular attention is given to the CERN experimental program to which I took or take part, CHARM-II, CHORUS and OPERA. In the last chapter, I try to put into perspective the medium and long term experimental programme.

  15. Experimental study of neutrino oscillations at a fission reactor

    International Nuclear Information System (INIS)

    The energy spectrum of neutrinos from a fission reactor was studied with the aim of gaining information on neutrino oscillations. The well shielded detector was set up at a fixed position of 8.76 m from the point-like core of the Laue-Langevin reactor in an antineutrino flux of 9.8 x 1011cm-2s-1. The target protons in the reaction antiνsub(e)p → e+n were provided by liquid scintillation counters (total volume of 377l) which also served as positron detectors. The product neutrons moderated in the scintillator were detected by 3He wire chambers. A coincidence signature was required between the prompt positron and the delayed neutron events. The positron energy resolution was 18% FWHM at 0.91 MeV. The signal-to-background ratio was better than one to one between 2 MeV and 6 MeV positron energy. At a counting rate of 1.58 counts per hour, 4890+-180 neutrino induced events were detected. The shape of the measured positron spectrum was analyzed in terms of the parameters Δ2 and sin2 2theta for two-neutrino oscillations. The experimental data are consistent with no oscillations. An upper limit of 0.15 eV2 (90% c.l.) for the mass-squared differences Δ2 of the neutrinos was obtained, assuming maximum mixing of the two neutrino states. The ratio of the measured to the expected integral yield of positrons assuming no oscillations was determined to be ∫Ysub(exp)/∫Ysub(th) = 0.955+-0.035 (statistical)+-0.110 (systematic)

  16. Measurement of Neutrino Oscillation Parameters from Muon Neutrino Disappearance with an Off-axis Beam

    CERN Document Server

    Abe, K; 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; Boyd, S B; Brailsford, D; Bravar, A; Bronner, C; Buchanan, N; Calland, R G; Rodriguez, J Caravaca; 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; 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; 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; 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; Guerra, E S Pinzon; 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; Sanchez, 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 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

    2013-01-01

    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 $3.01 \\times 10^{20}$ protons on target. In the absence of neutrino oscillations, $205 \\pm 17$ (syst.) events are expected to be detected and only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum assuming three neutrino flavors, normal mass hierarchy and $\\theta_{23}\\leq \\pi/4$ yields a best-fit mixing angle $\\sin^2(2\\theta_{23})=1.000$ and mass splitting $|\\Delta m^2_{32}| =2.44 \\times 10^{-3}$ eV$^2$/c$^4$. If $\\theta_{23}\\geq \\pi/4$ is assumed, the best-fit mixing angle changes to $\\sin^2(2\\theta_{23})=0.999$ and the mass splitting remains unchanged.

  17. Mixing transformations in quantum field theory and neutrino oscillations

    CERN Document Server

    Blasone, M; Vitiello, G

    1996-01-01

    Field mixing transformations are studied in quantum field theory and the generator of the transformations is found to induce an SU(2) coherent structure in the vacuum state, both for bosons and for fermions. The Fock space for mixed fields is unitarily inequivalent to the Fock space of the unmixed fields in the infinite volume limit. We study neutrino mixing and oscillations and find that the oscillation amplitude is depressed by a factor which is momentum and mass dependent. The usual formula is recovered in the relativistic limit. Phenomenological features of the modified oscillation formula are discussed. Finally, preliminary results of the Green's function formalism are presented.

  18. J-PARC Press Release: Electron neutrino oscillation detected at T2K

    CERN Multimedia

    T2K Press Office

    2011-01-01

    Tsukuba, Japan, June 15, 2011. The T2K experiment, whose primary purpose is to study neutrino interactions at a large distance from their source, has detected 6 electron neutrino candidate events based on the data collected before March 11, 2011. For the first time, it was possible to observe an indication that muon neutrinos are able to transform into electron neutrinos over a distance of 295 km through the quantum mechanical phenomena of neutrino flavor oscillations.   The Super-Kamiokande detector, in Japan. © 2011, High Energy Accelerator Research Organization, KEK. The T2K experiment is searching for the neutrino oscillation phenomena, where particular types of neutrinos transform into other types of neutrinos. These observations help determine neutrino masses, as well elucidating the uncharted nature of neutrinos, such as the relationship among three neutrino generations (types). T2K aims at the world’s best sensitivity by detecting neutrinos with the Super-Kamiokande d...

  19. Unity of CP and T Violation in Neutrino Oscillations

    CERN Document Server

    Blom, Martin; Blom, Martin; Minakata, Hisakazu

    2004-01-01

    In a previous work a simultaneous P- CP[P] and P- T[P] bi-probability plot was proposed as a useful tool for unified graphical description of CP and T violation in neutrino oscillation. The ``baseball diamond'' structure of the plot is understood as a consequence of the approximate CP-CP and the T-CP relations obeyed by the oscillation probabilities. In this paper, we make a step forward toward deeper understanding of the unified graphical representation by showing that these two relations are identical in its content, suggesting a truly unifying view of CP and T violation in neutrino oscillations. We suspect that the unity reflects the underlying CPT theorem. We also present calculation of corrections to the CP-CP and the T-CP relations to leading order in Delta m^2_{21} / Delta m^2_{31} and s^2_{13}.

  20. Anomalous aharonov-bohm gap oscillations in carbon nanotubes.

    Science.gov (United States)

    Sangalli, Davide; Marini, Andrea

    2011-10-12

    The gap oscillations caused by a magnetic flux penetrating a carbon nanotube represent one of the most spectacular observations of the Aharonov-Bohm effect at the nanoscale. Our understanding of this effect is, however, based on the assumption that the electrons are strictly confined on the tube surface, on trajectories that are not modified by curvature effects. Using an ab initio approach based on density functional theory, we show that this assumption fails at the nanoscale inducing important corrections to the physics of the Aharonov-Bohm effect. Curvature effects and electronic density that is spilled out of the nanotube surface are shown to break the periodicity of the gap oscillations. We predict the key phenomenological features of this anomalous Aharonov-Bohm effect in semiconductive and metallic tubes and the existence of a large metallic phase in the low flux regime of multiwalled nanotubes, also suggesting possible experiments to validate our results. PMID:21805987

  1. Neutrino oscillation experiment at J-PARC

    CERN Document Server

    Nishikawa, K

    2004-01-01

    A plan of the next-generation long-baseline neutrino experiment is described. The experiment will use the high intensity neutrino beam from the JPARC (Japan Proton Accelerator Research Complex) 50 GeV proton synchrotron and Super-Kamiokande. A sensitive search for nu /sub mu / to nu /sub e/ and a precision measurement of theta /sub 23/ will be the main objectives of the first stage of the experiment. An order-of-magnitude improvement through the experiments, which will start in a few years, is expected. With success in observing nu /sub mu / to nu /sub e/ in the first stage, CP violation in the lepton sector can be investigated with a 1 Mt water Cherenkov detector (Hyper-Kamiokande) and upgraded PS in the second stage of the experiment.

  2. Short baseline neutrino oscillations: when entanglement suppresses coherence

    CERN Document Server

    Boyanovsky, Daniel

    2011-01-01

    For neutrino oscillations to take place the entangled quantum state of a neutrino and a charged lepton produced via charged current interactions must be disentangled. Implementing a non-perturbative Wigner-Weisskopf method we obtain the correct \\emph{entangled} quantum state of neutrinos and charged leptons from the (two-body) decay of a parent particle. The source lifetime and disentanglement length scale lead to a suppression of the oscillation probabilities in short-baseline experiments. The suppression is determined by $\\pi\\, L_d/L_{osc}$ where $L_d$ is the \\emph{smallest} of the decay length of the parent particle or the disentanglement length scale. For $L_d \\geq L_{osc}$ coherence and oscillations are suppressed. These effects are more prominent in \\emph{short base line experiments} and at low neutrino energy. We obtain the corrections to the appearance and disappearance probabilities modified by both the lifetime of the source and the disentanglement scale and discuss their implications for accelerato...

  3. Studying neutrino oscillations using quasi-elastic events in MINOS

    Energy Technology Data Exchange (ETDEWEB)

    Kumaratunga, Sujeewa Terasita [Univ. of Minnesota, Minneapolis, MN (United States)

    2008-02-01

    MINOS (Main Injector Neutrino Oscillation Search), is a long baseline neutrino experiment designed to search for neutrino oscillations using two detectors at Fermi National Accelerator Laboratory, IL (Near Detector) and Soudan, MN (Far Detector). It will study vμ → vτ oscillations and make a measurement on the oscillation parameters, Δm$2\\atop{23}$ and sin223, via a vμ beam made at Fermilab. Charge current neutrino interactions in the MINOS detectors are of three types: quasi-elastic scattering (QEL), resonance scattering (RES) and deep inelastic scattering (DIS). Of these, quasi-elastic scattering leaves the cleanest signal with just one μ and one proton in the final state, thus rendering the reconstruction of the neutrino energy more accurate. This thesis will outline a method to separate QEL events from the others in the two detectors and perform a calculation of Δm$2\\atop{23}$ and sin223 using those events. The period under consideration was May 2005 to February 2006. The number of observed quasi-elastic events with energies below 10 GeV was 29, where the expected number was 60 ± 3. A fit to the energy distribution of these events gives Δm$2\\atop{23}$ = 2.91$+0.49\\atop{-0.53}$(stat)$+0.08\\atop{-0.09}$(sys) x 10-3 eV2 and sin223 = 0.990-0.180(stat)-0.030(sys).

  4. Entanglement in a QFT Model of Neutrino Oscillations

    International Nuclear Information System (INIS)

    Tools of quantum information theory can be exploited to provide a convenient description of the phenomena of particle mixing and flavor oscillations in terms of entanglement, a fundamental quantum resource. We extend such a picture to the domain of quantum field theory where, due to the nontrivial nature of flavor neutrino states, the presence of antiparticles provides additional contributions to flavor entanglement. We use a suitable entanglement measure, the concurrence, that allows extracting the two-mode (flavor) entanglement from the full multimode, multiparticle flavor neutrino states

  5. Precise Measurement of Solar Neutrino Oscillation Parameters from Recent Experiments

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; LIU Qiu-Yu

    2009-01-01

    We analyse the available data of solar neutrino experiments up to the date May 2008,including SK-I,SK-II,SNO phase-I,SNO phase-II and first-generation Ga and C1 experiments.They show great improvement in constraints on solar neutrino oscillation parameters.Together with the new results from long base line reactor experiment KamLAND,the parameters are precisely determined,with la allowed region in △m212 = 7 586+0.212-0.203×10-5 eV2,tan2 θ12=0.457+0.076-0.067

  6. Fourier analysis of the parametric resonance in neutrino oscillations

    International Nuclear Information System (INIS)

    Parametric enhancement of the appearance probability of the neutrino oscillation under the inhomogeneous matter is studied. Fourier expansion of the matter density profile leads to a simple resonance condition and manifests that each Fourier mode modifies the energy spectrum of oscillation probability at around the corresponding energy; below the MSW resonance energy, a large-scale variation modifies the spectrum in high energies while a small-scale one does in low energies. In contrast to the simple parametric resonance, the enhancement of the oscillation probability is itself an slow oscillation as demonstrated by a numerical analysis with a single Fourier mode of the matter density. We derive an analytic solution to the evolution equation on the resonance energy, including the expression of frequency of the slow oscillation.

  7. A study of muon neutrino to electron neutrino oscillations in the MINOS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tingjun; /Stanford U., Phys. Dept.

    2009-03-01

    The observation of neutrino oscillations (neutrino changing from one flavor to another) has provided compelling evidence that the neutrinos have non-zero masses and that leptons mix, which is not part of the original Standard Model of particle physics. The theoretical framework that describes neutrino oscillation involves two mass scales ({Delta}m{sub atm}{sup 2} and {Delta}m{sub sol}{sup 2}), three mixing angles ({theta}{sub 12}, {theta}{sub 23}, and {theta}{sub 13}) and one CP violating phase ({delta}{sub CP}). Both mass scales and two of the mixing angles ({theta}{sub 12} and {theta}{sub 23}) have been measured by many neutrino experiments. The mixing angle {theta}{sub 13}, which is believed to be very small, remains unknown. The current best limit on {theta}13 comes from the CHOOZ experiment: {theta}{sub 13} < 11{sup o} at 90% C.L. at the atmospheric mass scale. {delta}{sub CP} is also unknown today. MINOS, the Main Injector Neutrino Oscillation Search, is a long baseline neutrino experiment based at Fermi National Accelerator Laboratory. The experiment uses a muon neutrino beam, which is measured 1 km downstream from its origin in the Near Detector at Fermilab and then 735 km later in the Far Detector at the Soudan mine. By comparing these two measurements, MINOS can obtain parameters in the atmospheric sector of neutrino oscillations. MINOS has published results on the precise measurement of {Delta}m{sub atm}{sup 2} and {theta}{sub 23} through the disappearance of muon neutrinos in the Far Detector and on a search for sterile neutrinos by looking for a deficit in the number of neutral current interactions seen in the Far Detector. MINOS also has the potential to improve the limit on the neutrino mixing angle {theta}{sub 13} or make the first measurement of its value by searching for an electron neutrino appearance signal in the Far Detector. This is the focus of the study presented in this thesis. We developed a neural network based algorithm to distinguish

  8. A study of muon neutrino to electron neutrino oscillations in the MINOS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tingjun [Stanford Univ., CA (United States)

    2009-03-01

    The observation of neutrino oscillations (neutrino changing from one flavor to another) has provided compelling evidence that the neutrinos have non-zero masses and that leptons mix, which is not part of the original Standard Model of particle physics. The theoretical framework that describes neutrino oscillation involves two mass scales (Δmatm2 and Δmsol2), three mixing angles (θ12, θ23, and θ13) and one CP violating phase (δCP). Both mass scales and two of the mixing angles (θ12 and θ23) have been measured by many neutrino experiments. The mixing angle θ13, which is believed to be very small, remains unknown. The current best limit on θ13 comes from the CHOOZ experiment: θ13 < 11° at 90% C.L. at the atmospheric mass scale. δCP is also unknown today. MINOS, the Main Injector Neutrino Oscillation Search, is a long baseline neutrino experiment based at Fermi National Accelerator Laboratory. The experiment uses a muon neutrino beam, which is measured 1 km downstream from its origin in the Near Detector at Fermilab and then 735 km later in the Far Detector at the Soudan mine. By comparing these two measurements, MINOS can obtain parameters in the atmospheric sector of neutrino oscillations. MINOS has published results on the precise measurement of Δmatm2 and θ23 through the disappearance of muon neutrinos in the Far Detector and on a search for sterile neutrinos by looking for a deficit in the number of neutral current interactions seen in the Far Detector. MINOS also has the potential to improve the limit on the neutrino mixing angle θ13 or make the first measurement of its value by searching for an electron neutrino appearance signal in the Far Detector. This is the focus of the study presented in this thesis. We developed a neural network based algorithm to

  9. Active-active and active-sterile neutrino oscillation solutions to the atmospheric neutrino anomaly

    CERN Document Server

    González-Garciá, M Concepción; Peres, O L G; Valle, José W F

    1999-01-01

    We perform a fit to the full data set corresponding to 25.5 kt-yr of data of the Super-Kamiokande experiment as well as to all other experiments in order to compare the two most likely solutions to the atmospheric neutrino anomaly in terms of oscillations in the $\

  10. Implications on neutrino oscillation plus decay from recent solar neutrino data

    CERN Document Server

    Indumathi, D

    2002-01-01

    Recently the Sudbury Neutrino Observatory (SNO) has measured both the rates as well as the day-night asymmetries in the flux of neutrinos from the Sun in the charged-current (CC), neutral-current (NC) and elastic scattering (ES) channels. Motivated by the small but negative day-night asymmetry in the NC channel at SNO (1.2 standard deviations away from zero), we consider whether such a non-zero asymmetry can be generated in a framework where active neutrinos can both oscillate and decay, since the NC day-night asymmetry is zero in a frame-work that includes pure oscillations of active flavours. We find that the neutral current day-night asymmetry is strictly zero when we include both oscillations and decay. The result holds for arbitrary number of active neutrino species, with some reasonable assumptions on the decay parameters. Hence, a non-zero asymmetry in the neutral current sector, if it survives, can only come from oscillations/decay into sterile flavours. We also examine the allowed region of parameter...

  11. Panofsky Prize Lecture: Evidence for Oscillation of Atmospheric Neutrinos

    Science.gov (United States)

    Totsuka, Yoji

    2002-04-01

    Atmospheric neutrinos are decay products of pions and kaons (and of their decay products muons) produced by nuclear interactions of cosmic rays with air nuclei. Though their flux is not known well, only within 20 %, physics quantities that are independent of the flux uncertainty exist. The ratio of the number of muon neutrinos to the number of electron neutrinos is estimated to be accurate within 5 %. The other quantity is the shape of the zenith-angle distribution. Kamiokande and Super-Kamiokande are water Cherenkov detectors with 3,000 ton and 50,000 ton pure water, respectively. Kamiokande was operational in 1983 - 1996, and Super-K in 1996 - 2001 and 2003 - in future. We had already noted in 1988 that the observed μ/e ratio, which represented ν_mu/ν_e, was smaller by about 40 %. Later in 1994 we noted that the zenith angle distribution of muon neutrinos was strongly distorted, namely much fewer muons observed in the upward direction, while downward-going muons were what we expected. Electrons were quite normal. In 1996 Super-Kamiokande was ready. Its fiducial volume is 22.5 kton, much larger than Kamiokande's 1.04 kton. In 1998 based on 25.5 kton years of data we presented convincing results on the small μ/e ratio which was caused by fewer number of muons in the upward direction. The essential feature of the observed anomaly was that the disappearance of muon neutrinos depended strongly on their path length and on their energies. Electrons showed no anomaly within the experimental limit. These results were quantitatively and almost uniquely explained by oscillation of muon neutrinos to tau neutrinos, thus evidence for the finite but tiny mass of neutrinos.

  12. Neutrino oscillations in magnetized media and implications for the pulsar velocity puzzle

    CERN Document Server

    Grasso, D

    1998-01-01

    After a brief presentation of the general techniques used to determine neutrino potentials in a magnetized medium I will discuss MSW resonant oscillations of active and sterile neutrinos in such environment. Using my results I will reconsider the viability of a solution of the pulsar velocity puzzle based on such a kind of neutrino oscillations.

  13. Neutrinospheres, resonant neutrino oscillations, and pulsar kicks

    OpenAIRE

    Barkovich, M.; D'Olivo, J.C.; Montemayor, R.

    2005-01-01

    Pulsars are rapidly rotating neutron stars and are the outcome of the collapse of the core of a massive star with a mass of the order of or larger than eight solar masses. This process releases a huge gravitational energy of about 10^{53} erg, mainly in the form of neutrinos. During the collapse the density increases, and so does the magnetic field due to the trapping of the flux lines of the progenitor star by the high conductivity plasma. When the density reaches a value of around 10^{12} g...

  14. Wave-packet treatment of reactor neutrino oscillation experiments and its implications on determining the neutrino mass hierarchy

    Science.gov (United States)

    Chan, Yat-Long; Chu, M.-C.; Tsui, Ka Ming; Wong, Chan Fai; Xu, Jianyi

    2016-06-01

    We derive the neutrino flavor transition probabilities with the neutrino treated as a wave packet. The decoherence and dispersion effects from the wave-packet treatment show up as damping and phase-shifting of the plane-wave neutrino oscillation patterns. If the energy uncertainty in the initial neutrino wave packet is larger than around 0.01 of the neutrino energy, the decoherence and dispersion effects would degrade the sensitivity of reactor neutrino experiments to mass hierarchy measurement to lower than 3 σ confidence level.

  15. A combined muon-neutrino and electron-neutrino oscillation search at MiniBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Monroe, Jocelyn R.; /Columbia U.

    2006-07-01

    MiniBooNE seeks to corroborate or refute the unconfirmed oscillation result from the LSND experiment. If correct, the result implies that a new kind of massive neutrino, with no weak interactions, participates in neutrino oscillations. MiniBooNE searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations with the Fermi National Accelerator Laboratory 8 GeV beam line, which produces a {nu}{sub {mu}} beam with an average energy of {approx} 0.8 GeV and an intrinsic {nu}{sub e} content of 0.4%. The neutrino detector is a 6.1 m radius sphere filled with CH{sub 2}, viewed by 1540 photo-multiplier tubes, and located 541 m downstream from the source. This work focuses on the estimation of systematic errors associated with the neutrino flux and neutrino interaction cross section predictions, and in particular, on constraining these uncertainties using in-situ MiniBooNE {nu}{sub {mu}} charged current quasielastic (CCQE) scattering data. A data set with {approx} 100,000 events is identified, with 91% CCQE purity. This data set is used to measure several parameters of the CCQE cross section: the axial mass, the Fermi momentum, the binding energy, and the functional dependence of the axial form factor on four-momentum transfer squared. Constraints on the {nu}{sub {mu}} and {nu}{sub e} fluxes are derived using the {nu}{sub {mu}} CCQE data set. A Monte Carlo study of a combined {nu}{sub {mu}} disappearance and {nu}{sub e} appearance oscillation fit is presented, which improves the {nu}{sub {mu}} {yields} {nu}{sub e} oscillation sensitivity of MiniBooNE with respect to a {nu}{sub e} appearance-only fit by 1.2-1.5{sigma}, depending on the value of {Delta}m{sup 2}.

  16. Effects of new physics in neutrino oscillations in matter

    International Nuclear Information System (INIS)

    A new flavour-changing electron neutrino interaction with matter would always dominate the νe oscillation probability at sufficiently high neutrino energies. Being suppressed by θ13, the energy scale at which the new effect starts to be relevant may be within the reach of realistic experiments, where the peculiar dependence of the signal with energy could give rise to a clear signature in the νe → ντ channel. The latter could be observed by means of a coarse large magnetized detector exploiting τ → μ decays. We discuss the possibility of identifying or constraining such effects with a high energy neutrino factory. We also comment on the model-independent limits on them

  17. Limits on neutrino oscillations in the CNGS neutrino beam and event classification with the OPERA detector

    International Nuclear Information System (INIS)

    OPERA, the oscillation project with emulsion-tracking apparatus, is a long-baseline neutrino oscillation experiment. It combines an almost pure, high-energy νμ beam produced at the SPS accelerator at CERN, Switzerland, with the OPERA neutrino detector located at a distance of about 730 km in the LNGS underground laboratory in Italy. By using a lead/photo emulsion target, ντ charged current (CC) interactions of ντ from νμ → ντ oscillations can be observed on an event-by-event basis with very low background rates. Within this thesis, a νμ→νμ disappearance search is described that uses a flux normalization. independent measurement of the CC event fraction as a function of the hadronic energy as measured by the electronic detectors of OPERA. This allows to derive limits on νμ→νμ oscillations, complementary to the main ντ appearance analysis. For maximal mixing, vertical stroke Δm223 vertical stroke >4.4 x 10-3 eV2 is excluded at 90% C.L. by the disappearance analysis. This thesis represents the first application of this method, including systematic uncertainties, in a long-baseline neutrino oscillation experiment.

  18. Limits on neutrino oscillations in the CNGS neutrino beam and event classification with the OPERA detector

    Energy Technology Data Exchange (ETDEWEB)

    Ferber, Torben

    2012-09-15

    OPERA, the oscillation project with emulsion-tracking apparatus, is a long-baseline neutrino oscillation experiment. It combines an almost pure, high-energy {nu}{sub {mu}} beam produced at the SPS accelerator at CERN, Switzerland, with the OPERA neutrino detector located at a distance of about 730 km in the LNGS underground laboratory in Italy. By using a lead/photo emulsion target, {nu}{sub {tau}} charged current (CC) interactions of {nu}{sub {tau}} from {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillations can be observed on an event-by-event basis with very low background rates. Within this thesis, a {nu}{sub {mu}}{yields}{nu}{sub {mu}} disappearance search is described that uses a flux normalization. independent measurement of the CC event fraction as a function of the hadronic energy as measured by the electronic detectors of OPERA. This allows to derive limits on {nu}{sub {mu}}{yields}{nu}{sub {mu}} oscillations, complementary to the main {nu}{sub {tau}} appearance analysis. For maximal mixing, vertical stroke {Delta}m{sup 2}{sub 23} vertical stroke >4.4 x 10{sup -3} eV{sup 2} is excluded at 90% C.L. by the disappearance analysis. This thesis represents the first application of this method, including systematic uncertainties, in a long-baseline neutrino oscillation experiment.

  19. Violation of the Leggett-Garg Inequality in Neutrino Oscillations

    CERN Document Server

    Formaggio, J A; Murskyj, M M; Weiss, T E

    2016-01-01

    The Leggett-Garg inequality, an analogue of Bell's inequality involving correlations of measurements on a system at different times, stands as one of the hallmark tests of quantum mechanics against classical predictions. Neutrinos, and in particular the phenomenon of neutrino oscillations, should adhere to quantum-mechanical predictions and provide an observable violation of the Leggett-Garg inequality. We demonstrate how oscillation phenomena can be used to test for violations of the classical bound. A study of the MINOS experiment's data shows a greater than 6{\\sigma} violation over a distance of 735 km, representing the longest distance over which either the Leggett-Garg inequality or Bell's inequality has been tested. By exploiting stationarity and the prepared-ensemble condition, rather than weak measurements, our results provide strong evidence against "hidden-variable theories," which are deterministic alternatives to quantum mechanics. Several alternative tests of the Leggett-Garg inequality with neut...

  20. Present and future neutrino oscillation experiments in Japan

    International Nuclear Information System (INIS)

    Present status of the long base-line neutrino oscillation experiment(KEKPS-E362) and future plan are described. With 1020 protons on target from 12 GeV KEK-PS, the experiment can observe neutrino oscillation with more than 3σ effect for Δm2 ≥2 x 10-3 eV2 and sin2 2Θ ≥ 0.4 in the νμ disappearance channel, and Δm2 ≥3 x 10-3 eV2, sin2 Θ ≥ 0.1 in the νμ → νe appearance channel. The next step of the program will be the identification of ντ. A preliminary study indicates it is possible to identify τ production in water Cherenkov detector. (orig.)

  1. How to Measure CP Violation in Neutrino Oscillation Experiments?

    CERN Document Server

    Minakata, H; Minakata, Hisakazu; Nunokawa, Hiroshi

    1997-01-01

    We propose a new method for measuring CP violation in neutrino oscillation experiments. The idea is to isolate the term due to the CP-violating phase out of the oscillation probability by taking difference between yields of two (or three) detectors at path-lengths $L = 250 (\\frac{E}{1.35 {GeV}}) (\\frac{\\Delta m^2}{10^{-2}{eV}^2})^{-1} {km}$ and at $L/3$ (and also at $2L/3$ in the case of three detectors). We use possible hierarchies in neutrino masses suggested by the astrophysical and the cosmological observations to motivate the idea and to examine how the method works.

  2. Simple and compact expressions for neutrino oscillation probabilities in matter

    Energy Technology Data Exchange (ETDEWEB)

    Minakata, Hisakazu [Univ. de Sao Paulo, Sao Paulo (Brazil); Parke, Stephen J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-05-07

    We reformulate perturbation theory for neutrino oscillations in matter with an expansion parameter related to the ratio of the solar to the atmospheric Δm2 scales. Unlike previous works, use a renormalized basis in which certain first-order effects are taken into account in the zeroth-order Hamiltonian. Using this perturbation theory we derive extremely compact expressions for the neutrino oscillations probabilities in matter. We find, for example, that the νe disappearance probability at this order is of a simple two flavor form with an appropriately identified mixing angle and Δm2. Furthermore, despite exceptional simplicity in their forms they accommodate all order effects θ13 and the matter potential.

  3. Accelerator-based Short-baseline Neutrino Oscillation Experiments

    CERN Document Server

    Gollapinni, Sowjanya

    2015-01-01

    Over the last two decades, several experiments have reported anomalous results that could be hinting at the exciting possibility of sterile neutrino states in the $eV^{2}$ mass scale. Liquid Argon Time Projection Chambers (LArTPCs) are a particularly promising technology to explore this physics due to their fine-grained tracking and exceptional calorimetric capabilities. The MicroBooNE experiment, a 170 ton LArTPC scheduled to start taking data very soon with Fermilab's Booster Neutrino Beam (BNB), will combine LArTPC development with the main physics goal of understanding the low-energy electromagnetic anomaly seen by the MiniBooNE experiment. Looking towards the future, MicroBooNE will become a part of the \\textit{short-baseline neutrino} program which expands the physics capabilities of the BNB in many important ways by adding additional LArTPC detectors to search for light sterile neutrinos and bring a definitive resolution to the set of existing experimental anomalies. This paper will give an overview of...

  4. CP asymmetry in Neutrino Oscillations and New Physics1

    International Nuclear Information System (INIS)

    The CP asymmetry in neutrino oscillations, assuming new physics at production and/or detection processes, is analyzed. We compute this CP asymmetry using the standard quantum field theory within a general new physics scenario that may generate new sources of CP and flavor violation. Well known results for the CP asymmetry are reproduced in the case of V-A operators, and additional contributions from new physics operators are derived.

  5. Entanglement in a QFT Model of Neutrino Oscillations

    OpenAIRE

    Blasone, M.; Dell’Anno, F.; De Siena, S.; Illuminati, F.

    2014-01-01

    Tools of quantum information theory can be exploited to provide a convenient description of the phenomena of particle mixing and flavor oscillations in terms of entanglement, a fundamental quantum resource. We extend such a picture to the domain of quantum field theory where, due to the nontrivial nature of flavor neutrino states, the presence of antiparticles provides additional contributions to flavor entanglement. We use a suitable entanglement measure, the concurrence, that allows e...

  6. The Physics Potential of Future Long Baseline Neutrino Oscillation Experiments

    OpenAIRE

    Lindner, M.

    2002-01-01

    We discuss in detail different future long baseline neutrino oscillation setups and we show the remarkable potential for very precise measurements of mass splittings and mixing angles. Furthermore it will be possible to make precise tests of coherent forward scattering and MSW effects, which allow to determine the sign of $\\Delta m^2$. Finally strong limits or measurements of leptonic CP violation will be possible, which is very interesting since it is most likely connected to the baryon asym...

  7. Neutrino mixing and oscillations in quantum field theory

    CERN Document Server

    Alfinito, E; Iorio, A; Vitiello, G

    1996-01-01

    We show that the generator of field mixing transformations in Quantum Field Theory induces a non trivial structure in the vacuum which turns out to be a coherent state, both for bosons and for fermions, although with a different condensate structure. The Fock space for mixed fields is unitarily inequivalent to the Fock space of the massive (free) fields in the infinite volume limit. As a practical application we study neutrino mixing and oscillations. A new oscillation formula is found where the oscillation amplitude is depressed, with respect to the usual one, by a factor which is momentum and mass dependent. In the relativistic limit, the usual formula is recovered. We finally discuss in some detail phenomenological features of the modified oscillation formula.

  8. Entropy, Entanglement, and Transition Probabilities in Neutrino Oscillations

    CERN Document Server

    Blasone, Massimo; De Siena, Silvio; Illuminati, Fabrizio

    2007-01-01

    We show that the phenomenon of flavor oscillations can be described in terms of entangled flavor states belonging to the classes of Bell and W states. We analyze bipartite and multipartite flavor entanglements as measured by the reduced linear entropies of all possible bipartitions. Such entanglement monotones are found to be essentially equivalent to the flavor transition probabilities, that are experimentally accessible quantities. Therefore entanglement acquires a novel, operational physical characterization in the arena of elementary particle physics. We discuss in detail the fundamental cases of two- and three-flavor neutrino oscillations.

  9. Unity of CP and T Violation in Neutrino Oscillations

    OpenAIRE

    Blom, Martin; Minakata, Hisakazu

    2004-01-01

    In a previous work a simultaneous P- CP[P] and P- T[P] bi-probability plot was proposed as a useful tool for unified graphical description of CP and T violation in neutrino oscillation. The ``baseball diamond'' structure of the plot is understood as a consequence of the approximate CP-CP and the T-CP relations obeyed by the oscillation probabilities. In this paper, we make a step forward toward deeper understanding of the unified graphical representation by showing that these two relations ar...

  10. Probing Neutrino Oscillation Parameters using High Power Superbeam from ESS

    CERN Document Server

    Agarwalla, Sanjib Kumar; Prakash, Suprabh

    2014-01-01

    A high-power neutrino superbeam experiment at the ESS facility has been proposed such that the source-detector distance falls at the second oscillation maximum, giving very good sensitivity to the measurement of CP violation. In this work, we explore the comparative physics reach of the experiment in terms of leptonic CP-violation, precision on atmospheric parameters, non-maximal theta23, and its octant for a variety of choices for the baselines. We also vary the neutrino vs. the anti-neutrino running time for the beam, and study its impact on the physics goals of the experiment. We find that for the determination of CP violation, 540 km baseline with 7 years of neutrino and 3 years of anti-neutrino (7nu+3nubar) run-plan performs the best and one expects a 4sigma sensitivity to CP violation for 59% of true values of deltaCP. The projected reach for the 200 km baseline with 7nu+3nubar run-plan is somewhat worse with 4sigma sensitivity for 51% of true values of deltaCP. On the other hand, for the discovery of a...

  11. Kinetic equations for baryogenesis via sterile neutrino oscillation

    International Nuclear Information System (INIS)

    We investigate baryogenesis in the νMSM (neutrino Minimal Standard Model), which is the SM extended by three right-handed neutrinos with masses below the electroweak scale. The baryon asymmetry of the universe can be generated by the mechanism via flavor oscillation of right-handed (sterile) neutrinos which are responsible to masses of active neutrinos confirmed by various experiments. We present the kinetic equations for the matrix of densities of leptons which describe the generation of asymmetries. Especially, the momentum dependence of the matrix of densities is taken into account. By solving these equations numerically, it is found that the momentum distribution is significantly distorted from the equilibrium one, since the production for the modes with lower momenta k << T (T is the temperature of the universe) is enhanced, while suppressed for higher modes. As a result, the most important mode for the yields of sterile neutrinos as well as the baryon asymmetry is k ≅ 2T, which is smaller than (k) inferred from the thermal average. The comparison with the previous works is also discussed

  12. Opera neutrino oscillation experiment: On the way to ντ observation

    International Nuclear Information System (INIS)

    The hypothesis of neutrino flavour changing in weak interaction representation via oscillations is confirmed by several experiments, all based on the observation of the disappearance of a given neutrino flavour. The direct appearance of a flavour different from the initial one, was never observed so far. OPERA is the first long baseline neutrino oscillation experiment employing nuclear emulsions for the direct observation of tau neutrinos in the CERN to Gran Sasso muon neutrino beam. At present the experiment is in the data taking phase. The number of detected neutrino interactions have exceeded one thousand. Experiment status and a summary of results from 2007 and 2008 runs is presented in this paper.

  13. Connecting Leptonic Unitarity Triangle to Neutrino Oscillation with CP Violation in Vacuum and in Matter

    CERN Document Server

    He, Hong-Jian

    2016-01-01

    Leptonic unitarity triangle (LUT) provides fundamental means to geometrically describe CP violation in neutrino oscillation. In this work, we use LUT to present a new geometrical interpretation of the vacuum oscillation probability, and derive a compact new oscillation formula in terms of only 3 independent parameters of the corresponding LUT. Then, we systematically study matter effects for the geometrical formulation of neutrino oscillation with CP violation. Including matter effects, we derive a very compact new oscillation formula by using the LUT formulation. We further demonstrate that this geometrical formula holds well for practical applications to neutrino oscillations in matter, including T2K, MINOS, and NOvA experiments.

  14. Neutrino oscillations in Gallium and reactor experiments and cosmological effects of a light sterile neutrino

    International Nuclear Information System (INIS)

    Neutrino oscillations is a very well studied phenomenon and the observations from Solar, very-long-baseline Reactor, Atmospheric and Accelerator neutrino oscillation experiments give very robust evidence of three-neutrino mixing. On the other hand, some experimental data have shown anomalies that could be interpreted as indication of exotic neutrino physics beyond three-neutrino mixing. Furthermore, from a cosmological point of view, the possibility of extra light species contributing as a subdominant hot (or warm) component of the Universe is still interesting. In the first part of this Thesis, we focused on the anomaly observed in the Gallium radioactive source experiments. These experiments were done to test the Gallium solar neutrino detectors GALLEX and SAGE, by measuring the electron neutrino flux produced by intense artificial radioactive sources placed inside the detectors. The measured number of events was smaller than the expected one. We interpreted this anomaly as a possible indication of the disappearance of electron neutrinos and, in the effective framework of two-neutrino mixing, we obtained sin22θ ≥ 0.03 and Δm2 ≥ 0.1 eV2. We also studied the compatibility of this result with the data of the Bugey and Chooz reactor antineutrino disappearance experiments. We found that the Bugey data present a hint of neutrino oscillations with 0.02 ≤ sin22θ ≤ 0.07 and Δm2 ≅ 1.95 eV2, which is compatible with the Gallium allowed region of the mixing parameters. Then, combining the data of Bugey and Chooz, the data of Gallium and Bugey, and the data of Gallium, Bugey and Chooz, we found that this hint persists, with an acceptable compatibility of the experimental data. Furthermore, we analyzed the experimental data of the I.L.L., S.R.S, and Gosgen nuclear Reactor experiments. We obtained a good fit of the I.L.L. data, showing 1 and 2σ allowed regions in the oscillation parameters space. However, the combination of I.L.L. data with the Bugey data showed

  15. Analysis of the atmospheric neutrino data in terms of 3-neutrino oscillations

    CERN Document Server

    Maltoni, M

    2001-01-01

    A global analysis of atmospheric and reactor neutrino data is presented in terms of three-neutrino oscillations. We consider in our analysis both contained events and upward-going neutrino-induced muon events, including the previous data samples of Frejus, IMB, Nusex, and Kamioka experiments as well as the full 71 kton-yr (1144 days) Super-Kamiokande data set, the recent 5.1 kton-yr contained events of Soudan-2 and the results on upgoing muons from the MACRO detector. After presenting the results for the analysis of atmospheric data alone, we add to our data sample the reactor bound of the CHOOZ experiment, showing and important complementarity between the atmospheric and reactor limits which results in a stronger constraint on the allowed value of theta_13.

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

    Science.gov (United States)

    Fujikawa, Kazuo; Tureanu, Anca

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

  17. Studies of mu-neutrino going to e-neutrino oscillation appearance in the MINOS experiment

    Science.gov (United States)

    Sousa, Alexandre Bruno Pereira E.

    The MINOS experiment uses a long baseline neutrino beam, measured 1 km downstream from its origin in the Near Detector at Fermilab, and 734 km later in the large underground Far Detector in the Soudan mine. By comparing these two measurements, MINOS can probe the atmospheric domain of the neutrino oscillation phenomenology with unprecedented precision. Besides the ability to perform a world leading determination of the Dm223 and theta23 parameters, via numu flux disappearance, MINOS has the potential to make a leading measurement of nu mu → nue oscillations in the atmospheric sector by looking for nue appearance at the Far Detector. The observation of nue appearance, tantamount to establishing a non-zero value of the theta13 mixing angle, opens the way to studies of CP violation in the leptonic sector, the neutrino spectral mass pattern ordering and neutrino oscillations in matter, the driving motivations of the next generation of neutrino experiments. In this thesis, we study the MINOS potential for measuring theta13 in the context of the MINOS Mock Data Challenge using a multivariate discriminant analysis method. We show the method's validity in the application to nue event classification and background identification, as well as in its ability to identify a nue signal in a Mock Data sample generated with undisclosed parameters. An independent shower reconstruction method based on three-dimensional hit matching and clustering was developed, providing several useful discriminator variables used in the multivariate analysis method. We also demonstrate that within 2 years of running, MINOS has the potential to improve the current best limit on theta 13, from the CHOOZ experiment, by a factor of 2.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa Ricoux, Juan Pedro [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2009-01-01

    We perform a search for vμ → ve oscillations, a process which would manifest a nonzero value of the θ13 mixing angle, in the MINOS long-baseline neutrino oscillation experiment. The analysis consists of searching for an excess of ve charged-current candidate events over the predicted backgrounds, made mostly of neutral-current events with high electromagnetic content. A novel technique to select electron neutrino events is developed, which achieves an improved separation between the signal and the backgrounds, and which consequently yields a better reach in θ13. The backgrounds are predicted in the Far Detector from Near Detector measurements. An excess is observed in the Far Detector data over the predicted backgrounds, which is consistent with the background-only hypothesis at 1.2 standard deviations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa Ricoux, Juan Pedro; /Caltech

    2009-10-01

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

  20. Complementarity Between Hyperkamiokande and DUNE in Determining Neutrino Oscillation Parameters

    CERN Document Server

    Fukasawa, Shinya; Yasuda, Osamu

    2016-01-01

    In this work we investigate the sensitivity to the neutrino mass hierarchy, the octant of the mixing angle $\\theta_{23}$ and the CP phase $\\delta_{CP}$ in the future long baseline experiments T2HK and DUNE as well as in the atmospheric neutrino observation at Hyperkamiokande (HK). These three experiments have the excellent facility to discover the above mentioned neutrino oscillation parameters in terms of both statistics and matter effect. In our analysis we find that the sensitivity is enhanced greatly if we combine these three experiments. Our results show that the hierarchy sensitivity of both T2HK and HK are limited due to the presence of parameter degeneracy. But this degeneracy is removed when T2HK and HK are added together. With T2HK+HK (DUNE), the neutrino mass hierarchy can be determined at least at $ 5 \\sigma$ (8\\,$\\sigma$) C.L. for any value of true $\\delta_{CP}$. With T2HK+HK+DUNE the significance of the mass hierarchy increases to almost 15 $\\sigma$ for the unfavorable value of $\\delta_{CP}$. Fo...

  1. Physics potential of the CERN-MEMPHYS neutrino oscillation project

    International Nuclear Information System (INIS)

    We consider the physics potential of CERN based neutrino oscillation experiments consisting of a Beta Beam (βB) and a Super Beam (SPL) sending neutrinos to MEMPHYS, a 440 kt water Cerenkov detector at Frejus, at a distance of 130 km from CERN. The θ13 discovery reach and the sensitivity to CP violation are investigated, including a detailed discussion of parameter degeneracies and systematical errors. For βB and SPL sensitivities similar to the ones of the phase II of the T2K experiment (T2HK) are obtained, where the results for the CERN-MEMPHYS experiments are less affected by systematical uncertainties. We point out that by a combination of data from βB and SPL a measurement with antineutrinos is not necessary and hence the same physics results can be obtained within about half of the measurement time compared to one single experiment. Furthermore, it is shown how including data from atmospheric neutrinos in the MEMPHYS detector allows to resolve parameter degeneracies and, in particular, provides sensitivity to the neutrino mass hierarchy and the octant of θ23. (author)

  2. Results on θ13 neutrino oscillations from reactor experiments

    International Nuclear Information System (INIS)

    Definitive measurements of the smallest neutrino mixing angle θ13 were made by Daya Bay, Double Chooz and RENO in 2012, based on the disappearance of electron antineutrinos emitted from reactors. Averaging the results of the 3 reactor experiments with the standard Particle Data Group method, one obtains sin2(2*θ13) = 0.098 ± 0.013. The new generation reactor experiments have significantly improved sensitivity for θ13 using 2 identical detectors of 10 - 40 tons at near (300 - 400 m) and far (1 - 2 km) locations. The surprisingly large value of θ13 will strongly promote the next round of neutrino experiments to find CP violation effects and determine the neutrino mass hierarchy. More precise measurements of θ13 by the 3 reactor experiments will provide the first glimpse of the CP phase angle if accelerator beam results are combined. Based on a total of 5 years of data, the reactor experiment is expected to obtain a measured sin2(θ13) value with a precision of 7% at RENO, 4% at Daya Bay, and 10% at Double Chooz. It will also make a direct measurement of Δm312 from the energy dependent oscillation effects, and measure a precise neutrino spectrum

  3. Constraint on Neutrino Decay with Medium-Baseline Reactor Neutrino Oscillation Experiments

    CERN Document Server

    Abrahao, Thamys; Nunokawa, Hiroshi; Quiroga, Alexander A

    2015-01-01

    The experimental bound on lifetime of nu_3, the neutrino mass eigenstate with the smallest nu_e component, is much weaker than those of nu_1 and nu_2 by many orders of magnitude to which the astrophysical constraints apply. We argue that the future reactor neutrino oscillation experiments with medium-baseline (~ 50 km), such as JUNO or RENO-50, has the best chance of placing the most stringent constraint on nu_3 lifetime among all neutrino experiments which utilize the artificial source neutrinos. Assuming decay into invisible states, we show by a detailed chi^2 analysis that the nu_3 lifetime divided by its mass, tau_3/ m_3, can be constrained to be tau_3/m_3 > 7.5 (5.5) x 10^{-11} s/eV at 95% (99%) C.L. by 100 kt.years exposure by JUNO. It may be further improved to the level comparable to the atmospheric neutrino bound by its longer run.

  4. Constraint on neutrino decay with medium-baseline reactor neutrino oscillation experiments

    Science.gov (United States)

    Abrahão, Thamys; Minakata, Hisakazu; Nunokawa, Hiroshi; Quiroga, Alexander A.

    2015-11-01

    The experimental bound on lifetime of ν 3, the neutrino mass eigenstate with the smallest ν e component, is much weaker than those of ν 1 and ν 2 by many orders of magnitude to which the astrophysical constraints apply. We argue that the future reactor neutrino oscillation experiments with medium-baseline (˜50 km), such as JUNO or RENO-50, has the best chance of placing the most stringent constraint on ν3 lifetime among all neutrino experiments which utilize the artificial source neutrinos. Assuming decay into invisible states, we show by a detailed χ 2 analysis that the ν 3 lifetime divided by its mass, τ 3 /m 3, can be constrained to be τ 3 /m 3 > 7 .5 (5 .5) × 10-11 s/eV at 95% (99%) C.L. by 100 kt·years exposure by JUNO. It may be further improved to the level comparable to the atmospheric neutrino bound by its longer run. We also discuss to what extent ν 3 decay affects mass-ordering determination and precision measurements of the mixing parameters.

  5. Study on the Neutrino Oscillation with a Next Generation Medium-Baseline Reactor Experiment

    International Nuclear Information System (INIS)

    For over fifty years, reactor experiments have played an important role in neutrino physics, in both discoveries and precision measurements. One of the methods to verify the existence of neutrino is the observation of neutrino oscillation phenomena. Electron antineutrinos emitted from a reactor provide the measurement of the small mixing angle θ13, providing rich programs of neutrino properties, detector development, nuclear monitoring, and application. Using reactor neutrinos, future reactor neutrino experiments, more precise measurements of θ12,Δm122, and mass hierarchy will be explored. The precise measurement of θ13 would be crucial for measuring the CP violation parameters at accelerators. Therefore, reactor neutrino physics will assist in the complete understanding of the fundamental nature and implications of neutrino masses and mixing. In this paper, we investigated several characteristics of RENO-50, which is a future medium-baseline reactor neutrino oscillation experiment, by using the GloBES simulation package

  6. Reproducing sterile neutrinos and the behavior of flavor oscillations with superconducting-magnetic proximity effects

    Science.gov (United States)

    Baker, Thomas E.

    2016-03-01

    The physics of a superconductor subjected to a magnetic field is known to be equivalent to neutrino oscillations. Examining the properties of singlet-triplet oscillations in the magnetic field, a sterile neutrino is suggested to be represented by singlet Cooper pairs and moderates flavor oscillations between three flavor neutrinos (triplet Cooper pairs). A superconductor-exchange spring system's rotating magnetization profile is used to simulate the mass-flavor oscillations in the neutrino case and the physics of neutrino oscillations are discussed. Connecting the condensed matter system and the particle physics system with this analogy may allow for the properties of the condensed matter system to inform neutrino experiments. Support is graciously acknowledged from the Pat Beckman Memorial Scholarship from the Orange County Chapter of the Achievement Rewards for College Scientists Foundation.

  7. Neutrino spin oscillations in matter under the influence of gravitational and electromagnetic fields

    International Nuclear Information System (INIS)

    We derive the new quasi-classical equation for the description of the spin evolution of a neutrino propagating in a curved space-time and interacting with a background matter and an external electromagnetic field. This equation is used to analyze neutrino spin oscillations in these external backgrounds. We obtain the effective Hamiltonian and the transition probability for oscillations of neutrinos when they move in the vicinity of a rotating black hole, surrounded by an accretion disk, and interact with an external magnetic field. The appearance of new resonances in neutrino spin oscillations in this system is considered. The approximate treatment of spin oscillations of radially propagating ultra high energy neutrinos is developed. We also discuss the applications of our results to the description of neutrino spin oscillations in realistic astrophysical media

  8. Neutrino oscillation and expected event rate of supernova neutrinos in the adiabatic explosion model

    International Nuclear Information System (INIS)

    We study how the influence of the shock wave appears in neutrino oscillations and the neutrino spectrum by using the density profile of the adiabatic explosion model of a core-collapse supernova, which is calculated in an implicit Lagrangian code for general relativistic spherical hydrodynamics. We calculate expected event rates of neutrino detection at Super-Kamiokande (SK) and Sudbury Neutrino Observatory (SNO) for various θ13 values and both normal and inverted hierarchies. The predicted event rates of νe and νe depend on the mixing angle θ13 for the inverted and normal mass hierarchies, respectively, and the influence of the shock wave appears for about 2-8 s when sin22θ13 is larger than 10-3. These neutrino signals for the shock-wave propagation is decreased by e in inverted hierarchy (SK) or by e in normal hierarchy (SNO) compared with the case without shock. The obtained ratio of the total event for high-energy neutrinos (20 MeVIEEνIE60 MeV) to low-energy neutrinos (5 MeV νIE20 MeV) is consistent with the previous studies in schematic semianalytic or other hydrodynamic models of the shock propagation. The time dependence of the calculated ratio of the event rates of high-energy neutrinos to the event rates of low-energy neutrinos is a very useful observable which is sensitive to θ13 and mass hierarchies. Namely, the time-dependent ratio shows a clearer signal of the shock-wave propagation that exhibits a remarkable decrease by at most a factor of ∼2 for νe in inverted hierarchy (SK), whereas it exhibits a smaller change by ∼10% for νe in normal hierarchy (SNO). Observing the time-dependent high-energy to low-energy ratio of the neutrino events thus would provide a piece of very useful information to constrain θ13 and mass hierarchy and eventually help understand how the shock wave propagates inside the star.

  9. Short-baseline neutrino oscillations, Planck, and IceCube

    CERN Document Server

    Cherry, John F; Shoemaker, Ian M

    2016-01-01

    We examine a framework with light new physics, which couples to the Standard Model only via neutrino mixing. Taking the hints from the short-baseline anomalies seriously and combining them with modern cosmological data and recent IceCube measurements, we obtain surprisingly effective constraints on the hidden force: keV $\\lesssim M \\lesssim0.3$ GeV for the mediator mass and $g_{h}>10^{-6}-10^{-3}$ for the coupling constant. Flavor equilibration between the hidden and active neutrinos can be delayed until temperatures of $\\sim 1$ MeV, but not below $\\sim 100$ keV. This scenario can be tested with next-generation Cosmic Microwave Background, IceCube, and oscillation experiments.

  10. How neutrino oscillations can induce an effective neutrino number of less than three during big bang nucleosynthesis

    International Nuclear Information System (INIS)

    Ordinary-sterile neutrino oscillations can generate significant neutrino asymmetry in the early Universe. In this paper we extend this work by computing the evolution of neutrino asymmetries and light element abundances during the big bang nucleosynthesis (BBN) epoch. We show that a significant electron-neutrino asymmetry can be generated in a way that is approximately independent of the oscillation parameters δm2 and sin22θ for a range of parameters in an interesting class of models. The numerical value of the asymmetry leads to the prediction that the effective number of neutrino flavors during BBN is either about 2.5 or 3.4, depending on the sign of the asymmetry. Interestingly, one class of primordial deuterium abundance data favors an effective number of neutrino flavors during the epoch of BBN of less than 3. copyright 1997 The American Physical Society

  11. Emulsion chamber with big radiation length for detecting neutrino oscillations

    International Nuclear Information System (INIS)

    A conceptual scheme of a hybrid-emulsion spectrometer for investigating various channels of neutrino oscillations is proposed. The design emphasizes detection of τ leptons by detached vertices, reliable identification of electrons, and good spectrometry for all charged particles and photons. A distributed target is formed by layers of low-Z material, emulsion-plastic-emulsion sheets, and air gaps in which τ decays are detected. The tracks of charged secondaries, including electrons, are momentum-analyzed by curvature in magnetic field using hits in successive thin layers of emulsion. The τ leptons are efficiently detected in all major decay channels, including τ-→e-νν-bar. The performance of a model spectrometer, that contains 3 t of nuclear emulsion and 20 t of passive material, is estimated for different experimental environments. When irradiated by the νμ beam of a proton accelerator over a medium baseline of ν>∼1 km/GeV, the spectrometer will efficiently detect either the νμ→ντ or the νμ→νe transitions in the mass-difference region of Δm2∼1 eV2, as suggested by the results of LSND. When exposed to the neutrino beam of a muon storage ring over a long baseline of ν>∼10-20 km/GeV, the model detector will efficiently probe the entire pattern of neutrino oscillations in the region Δm2∼10-2-10-3 eV2, as suggested by the data on atmospheric neutrinos

  12. Emulsion chamber with big radiation length for detecting neutrino oscillations

    Science.gov (United States)

    Asratyan, A. E.; Davidenko, G. V.; Dolgolenko, A. G.; Kaftanov, V. S.; Kubantsev, M. A.; Verebryusov, V. S.

    2000-08-01

    A conceptual scheme of a hybrid-emulsion spectrometer for investigating various channels of neutrino oscillations is proposed. The design emphasizes detection of τ leptons by detached vertices, reliable identification of electrons, and good spectrometry for all charged particles and photons. A distributed target is formed by layers of low- Z material, emulsion-plastic-emulsion sheets, and air gaps in which τ decays are detected. The tracks of charged secondaries, including electrons, are momentum-analyzed by curvature in magnetic field using hits in successive thin layers of emulsion. The τ leptons are efficiently detected in all major decay channels, including τ-→ e-νν¯. The performance of a model spectrometer, that contains 3 t of nuclear emulsion and 20 t of passive material, is estimated for different experimental environments. When irradiated by the ν μ beam of a proton accelerator over a medium baseline of ˜1 km/ GeV, the spectrometer will efficiently detect either the ν μ→ν τ or the ν μ→ν e transitions in the mass-difference region of Δm 2˜1 eV2, as suggested by the results of LSND. When exposed to the neutrino beam of a muon storage ring over a long baseline of ˜10- 20 km/ GeV, the model detector will efficiently probe the entire pattern of neutrino oscillations in the region Δ m2˜10 -2- 10 -3 eV2, as suggested by the data on atmospheric neutrinos.

  13. Precision Measurement of Neutrino Oscillation Parameters with KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    O' Donnell, Thomas [Univ. of California, Berkeley, CA (United States)

    2011-12-01

    This dissertation describes a measurement of the neutrino oscillation parameters m2 21, θ12 and constraints on θ13 based on a study of reactor antineutrinos at a baseline of ~ 180 km with the KamLAND detector. The data presented here was collected between April 2002 and November 2009, and amounts to a total exposure of 2.64 ± 0.07 × 1032 proton-years. For this exposure we expect 2140 ± 74(syst) antineutrino candidates from reactors, assuming standard model neutrino behavior, and 350±88(syst) candidates from background. The number observed is 1614. The ratio of background-subtracted candidates observed to expected is (NObs - NBkg)/ (NExp) = 0.59 ± 0.02(stat) ± 0.045(syst) which confirms reactor neutrino disappearance at greater than 5σ significance. Interpreting this deficit as being due to neutrino oscillation, the best-fit oscillation parameters from a three-flavor analysis are m2 21= 7.60+0.20 -0.19×10-5eV2, θ12 = 32.5 ± 2.9 degrees and sin2 θ13 = 0.025+0.035 -0.035, the 95% confidence-level upper limit on sin2 θ13 is sin2 θ13 < 0.083. Assuming CPT invariance, a combined analysis of KamLAND and solar neutrino data yields best-fit values: m2 21 = 7.60+0.20 -0.20 × 10-5eV2, θ12 = 33.5+1.0 -1.1 degrees, and sin2 θ13 = 0.013 ± 0.028 or sin2 θ13 < 0.06 at the 95% confidence level.

  14. Status of the mechanism of resonance enhancement of neutrino oscillations in matter

    International Nuclear Information System (INIS)

    The present status of the mechanism of resonance enhancement of neutrino oscillations in matter has been considered by using the existent experimental data and it is concluded that this effect has no clear experimental confirmation. To prove that this mechanism is realized it is necessary to fulfil precision experiments with solar neutrinos and neutrinos which have passed through the Earth matter

  15. The Effect of Spontaneous Collapses on Neutrino Oscillations

    Science.gov (United States)

    Donadi, Sandro; Bassi, Angelo; Ferialdi, Luca; Curceanu, Catalina

    2013-09-01

    We compute the effect of collapse models on neutrino oscillations. The effect of the collapse is to modify the evolution of the spatial part of the wave function and we will show that this indirectly amounts to a change on the flavor components. For the analysis we use the mass proportional CSL model, and perform the calculation to second order perturbation theory. As we will show, the CSL effect is very small—mainly due to the very small mass of neutrinos—and practically undetectable.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-02

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

  17. Beta Beams: an accelerator based facility to explore Neutrino oscillation physics

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Payet, J; Chance, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, VL; Gramegna, F; Marchi, T; Collazuol, G; De Rosa, G; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A

    2011-01-01

    The discovery that the neutrino changes flavor as it travels through space has implications for the Standard Model of particle physics (SM)[1]. To know the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. This will require a high intensity beam-based neutrino oscillation facility. The EURONu Design Study will review three currently accepted methods of realizing this facility (the so-called Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make a decision on the layout and construction of the future European neutrino oscillation facility. ”Beta Beams” produce collimated pure electron neutrino and antineutrino beams by accelerating beta active ions to high energies and letting them decay in a race-track shaped storage ring. EURONu Beta Beams are based on CERNs infrastructure and the fact that some of the already ...

  18. Search for Matter-Dependent Atmospheric Neutrino Oscillations in Super-Kamiokande

    CERN Document Server

    Abe, K; Iida, T; Ikeda, M; Kameda, J; Koshio, Y; Minamino, A; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Ogawa, H; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Watanabe, H; Yamada, S; Higuchi, I; Ishihara, C; Kajita, T; Kaneyuki, K; Mitsuka, G; Nishino, H; Okumura, K; Saji, C; Takenaga, Y; Clark, S; Desai, S; Dufour, F; Kearns, E; Likhoded, S; Litos, M; Raaf, Jennifer L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Cravens, J P; Dunmore, J; Kropp, W R; Liu, D W; Mine, S; Regis, C; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Hartfield, B; Hill, J; Keig, W E; Jang, J S; Jeong, I S; Kim, J Y; Lim, I T; Scholberg, K; Fechner, M; Tanimoto, N; Walter, C W; Wendell, R; Tasaka, S; Guillian, G; Learned, J G; Matsuno, S; Messier, M D; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Oyama, Y; Totsuka, Y; Suzuki, A T; Nakaya, T; Tanaka, H; Yokoyama, M; Haines, T J; Dazeley, S; Svoboda, R; Habig, A; Fukuda, Y; Sato, T; Itow, Y; Koike, T; Tanaka, T; Jung, C K; Kato, T; Kobayashi, K; McGrew, C; Sarrat, A; Terri, R; Yanagisawa, C; Tamura, N; Idehara, Y; Sakuda, M; Sugihara, M; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Ishizuka, T; Okazawa, H; Choi, Y; Seo, H K; Gando, Y; Inoue, K; Furuse, Y; Ishii, H; Nishijima, K; Watanabe, Y; Koshiba, M; Chen, S; Deng, Z; Liu, Y; Kielczewska, D; Berns, H; Shiraishi, K K; Thrane, E; Wilkes, R J

    2008-01-01

    We consider muon neutrino to tau neutrino oscillations in the context of the Mass Varying Neutrino (MaVaN) model, where the neutrino mass can vary depending on the electron density along the flight path of the neutrino. Our analysis assumes a mechanism with dependence only upon the electron density, hence ordinary matter density, of the medium through which the neutrino travels. Fully-contained, partially-contained and upward-going muon atmospheric neutrino data from the Super--Kamiokande detector, taken from the entire SK--I period of 1489 live days, are compared to MaVaN model predictions. We find that, for the case of 2-flavor oscillations, and for the specific models tested, oscillation independent of electron density is favored over density dependence. Assuming maximal mixing, the best-fit case and the density-independent case do not differ significantly.

  19. Global three-parameter model for neutrino oscillations using Lorentz violation

    CERN Document Server

    Katori, T; Tayloe, R; Katori, Teppei; Kostelecky, Alan; Tayloe, Rex

    2006-01-01

    A model of neutrino oscillations is presented that has only three degrees of freedom and is consistent with existing data. The model is a subset of the renormalizable sector of the Standard-Model Extension (SME), and it offers an alternative to the standard three-neutrino massive model. All classes of neutrino data are described, including solar, reactor, atmospheric, and LSND oscillations. The disappearance of solar neutrinos is obtained without matter-enhanced oscillations. Quantitative predictions are offered for the ongoing MiniBooNE experiment and for the future experiments OscSNS, NOvA, and T2K.

  20. A torsional completion of gravity for Dirac matter fields and its applications to neutrino oscillations

    CERN Document Server

    Fabbri, Luca

    2016-01-01

    In this paper, we consider the torsional completion of gravitation for an underlying background filled with Dirac fields, applying it to the problem of neutrino oscillations: we discuss how in this context neutrinos even when massless and left-handed may nevertheless display oscillations.

  1. Updated Global Analysis of the Atmospheric Neutrino Data in terms of neutrino oscillations

    CERN Document Server

    Fornengo, N; Valle, José W F

    2000-01-01

    A global analysis of all the available atmospheric neutrino data is presentedin terms of neutrino oscillations in the nu_mu -> nu_tau and nu_mu -> nu_schannels, where nu_s denotes a sterile neutrino. We perform our analysis of thecontained events data as well as the upward-going neutrino-induced muon fluxes.In addition to the previous data samples of Frejus, Nusex, IMB and Kamiokaexperiments, we include the full data set of the 52 kton-yr ofSuper-Kamiokande, the recent 4.6 kton-yr contained events of Soudan2 and theresults on upgoing muons from the MACRO and Baksan detectors. From thestatistical analysis it emerges that the nu_mu -> nu_tau channel provides thebest agreement with the combined data, with a best fit point of sin^2(2 theta)= 0.99 and Delta m^2 = 3.0 * 10^{-3} eV^2. Although somehow disfavoured, thenu_mu -> nu_s channels cannot be ruled out on the basis of the global fit tothe full set of observables.

  2. Unified understanding of neutrino oscillation and negative mass-square of neutrino

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The author indicates that even a conclusive confirmation of neutrino oscillation does not necessarily imply the existence of massive neutrinos. The negative value of neutrino mass-square may be an alternative key with realistic physical meaning. Reexamining special relativity (SR) we find that there actually exists a formal phase velocity of "de Broglie's wave" in tenporal Lorentz transformation attributed to the intrinsical essence of Minkowski's space. The properties of spacelike interval between two events have already included constrains to describe superluminal motion and SR is compatible with the faster-than-light motion originally in algebraic domain. Pay attention to that the operator representation, p←→ -ih , has just verified for subluminal particles, not for superluminal particles, adhering to de Broglie's coexistence idea between waves and particles, it is possible to deduce a formal two-component Weyl equation to describe any species of free neutrinos with imaginary rest mass, which is equivalent to making use of the Dirac equation for a free spin-1/2 particle with zero rest mass in form.

  3. GPS survey in long baseline neutrino-oscillation measurement

    CERN Document Server

    Noumi, H; Inagaki, T; Hasegawa, T; Katoh, Y; Kohama, M; Kurodai, M; Kusano, E; Maruyama, T; Minakawa, M; Nakamura, K; Nishikawa, K; Sakuda, M; Suzuki, Y; Takasaki, M; Tanaka, K H; Yamanoi, Y; 10.1109/TNS.2004.836042

    2004-01-01

    We made a series of surveys to obtain neutrino beam line direction toward SuperKamiokande (SK) at a distance of 250 km for the long- baseline neutrino oscillation experiment at KEK. We found that the beam line is directed to SK within 0.03 mr and 0.09 mr (in sigma) in the horizontal and vertical directions, respectively. During beam operation, we monitored the muon distribution from secondary pions produced at the target and collected by a magnetic horn system. We found that the horn system functions like a lens of a point-to- parallel optics with magnification of approximately -100 and the focal length of 2.3 m. Namely, a small displacement of the primary beam position at the target is magnified about a factor -100 at the muon centroid, while the centroid position is almost stable against a change of the incident angle of the primary beam. Therefore, the muon centroid can be a useful monitor of the neutrino beam direction. We could determine the muon centroid within 6 mm and 12 mm in horizontal and vertical ...

  4. Physics potential of the CERN-MEMPHYS neutrino oscillation project

    CERN Document Server

    Campagne, J E; Mezzetto, Mauro; Schwetz, T

    2007-01-01

    We consider the physics potential of CERN based neutrino oscillation experiments consisting of a Beta Beam (BB) and a Super Beam (SPL) sending neutrinos to MEMPHYS, a 440 kt water Cerenkov detector at Frejus, at a distance of 130 km from CERN. The $\\theta_{13}$ discovery reach and the sensitivity to CP violation are investigated, including a detailed discussion of parameter degeneracies and systematical errors. For BB and SPL sensitivities similar to the ones of the phase II of the T2K experiment (T2HK) are obtained, where the results for the CERN-MEMPHYS experiments are less affected by systematical uncertainties. We point out that by a combination of data from BB and SPL a measurement with antineutrinos is not necessary and hence the same physics results can be obtained within about half of the measurement time compared to one single experiment. Furthermore, it is shown how including data from atmospheric neutrinos in the MEMPHYS detector allows to resolve parameter degeneracies and, in particular, provides...

  5. Neutrino oscillations with a polarized laser beam: an analogical demonstration experiment

    OpenAIRE

    Weinheimer, C.

    2010-01-01

    The underlying physics of neutrino oscillation in vacuum can be demonstrated by an optical analogical experiment. Two different neutrino flavors are represented by two polarization states of a laser beam, whereas the different phase propagation in vacuum is mimicked by the propagation difference of an ordinary and an extraordinary beam in a birefringent crystal. This allows us to demonstrate neutrino oscillation by optical methods in a fully microscopic way at the particle level. The descript...

  6. Can a non-unitary effect be prominent In neutrino oscillation measurements?

    Institute of Scientific and Technical Information of China (English)

    L(U) Lei; WANG Wen-Yu; XIONG zhao-Hua

    2010-01-01

    Subject to neutrino experiments, the mixing matrix of ordinary neutrinos can still have small vi-olation from unitarity. We introduce a quasi-unitary matrix to interpret this violation and propose a natural scheme to parameterize it. A quasi-unitary factor △QF is defined to be measured in neutrino oscillation exper-iments and the numerical results show that the improvement in experimental precision may help us figure out the secret of neutrino mixing.

  7. On the Sensitivity of L/E Analysis of Super-Kamiokande Atmospheric Neutrino Data to Neutrino Oscillation Part~1

    CERN Document Server

    Konishi, E; Galkin, V I; Ishiwata, M; Nakamura, I; Takahashi, N; Kato, M; Misaki, A

    2010-01-01

    It is said that the finding of the maximum oscillation in neutrino oscillation by Super-Kamiokande is one of the major achievements of the SK. In present paper, we examine the assumption made by Super-Kamiokande Collaboration that the direction of the incident neutrino is approximately the same as that of the produced lepton, which is the cornerstone in their L/E analysis and we find this approximation does not hold even approximately. In the Part 2 of the subsequent paper, we apply the results from Figures 12, 13 and 14 to L/E analysis and conclude that one cannot obtain the maximum oscillation in L/E analysis which shows strongly the oscillation pattern from the neutrino oscillation.

  8. Types of Particle Oscillations and Their Realizations in Neutral K Meson and Neutrino Oscillations

    CERN Document Server

    Beshtoev, K M

    2000-01-01

    Two particle vacuum transitions (oscillations) are studied in the general case. We found that: 1) a nondiagonal mass term characterising oscillations is the width of two particle transitions into each other (this width can be computed by the standard method); 2) two types of oscillations take place: real and virtual. Solution of the problem of origin of mixing angle in the theory of vacuum oscillations is given. It is shown that neutral K meson and neutrino oscillations must proceed via two stages. First, neutral K^{o}, antineutral K-eigenstates of strong interaction (or nu(e), nu(mu), nu(tau) eigenstates of weak interactions) are created. Then, owing to the presence of the strangeness violating weak interaction (or the lepton number violating interactions), these meson states (or neutrino states) are converted into superpositions of neutral K(1) and neutral K(2)-eigenstates of the weak interaction violating strangeness (or nu(1), nu(2), nu(3)-eigenstates of the interaction-violating lepton numbers). Further,...

  9. Search for neutrino oscillations at a fission reactor

    International Nuclear Information System (INIS)

    In the Gosgen oscillation experiment flux and energy spectrum of these electron antineutrinos were monitored at two distances from the reactor core (37.9 m, 45.9 m). The detector system, well shielded against cosmic radiation, is based on the detection reaction upsilonsub(e)sup(c) + p->n + esup(*) and an alternating array of liquid scintillators and He wire chambers serves as positron and neutron detectors. As signature for a good event a time and position correlation of the detected neutron and positron is required. In addition the measured position energy spectrum directly reflects the incident neutrino energies. To analyze the data in terms of oscillations, either the spectra measured in each position are compared to theoretical predictions for different oscillation parameters or a relative comparison of both measurements is performed. Allowing in the analysis a variation of 2 standard deviations for the systematic uncertainties the following limits on the oscillation parameters are obtained in a combination of the data from both measuring positions: mixing angle: [large mass param.] sin2 20 2 2 (90% c.l.). (orig./HSI)

  10. Neutrino masses, anomalous U(1) gauge symmetry and doublet-triplet splitting

    International Nuclear Information System (INIS)

    We propose an attractive scenario of grand unified theories in which doublet-triplet splitting is naturally realized in SO(10) unification using the Dimopoulos-Wilczek mechanism. The anomalous U(1)A gauge symmetry plays an essential role in the double-triplet splitting mechanism. It is interesting that the anomalous U(1)A charges determine the unification scale and mass spectrum of additional particles, as well as the order of the Yukawa couplings of quarks and leptons. For the neutrino sector, bi-maximal mixing angles are naturally obtained, and proton decay via dimension 5 operators is suppressed. It is suggestive that the anomalous U(1)A gauge symmetry motivated by superstring theory effectively solves the two biggest problems in grand unified theories, the fermion mass hierarchy problem and doublet-triplet splitting problem. (author)

  11. NEUTRINO MASS AND NEUTRINO OSCILLATION EXPERIMENTS%中微子质量和中微子振荡实验

    Institute of Scientific and Technical Information of China (English)

    何景棠

    2001-01-01

    The history and status of neutrino mass measurements are summarized in this paper. Several experimental results on solar neutrino missing and on atmospheric muon neutrino missing are described. These results imply that there are neutrino oscillations, this means that neutrino has mass. This is the signal of beyond the standard model. Several important experiments to study neutrino oscillation in the beginning of the 21st century, such as long-base-line neurino oscillation, the idea to build a muon storage ring for producing a high energy electron neutrino beam to carry out neutrino oscillation experiment and to measure the CP violation in neutrino oscillation, are also introduced.%本文介绍中微子质量测量的历史和现状。介绍太阳中微子丢失实验的结果和大气μ中微子丢失实验结果。这些结果表明存在中微子振荡,即中微子具有质量。它是超出标准模型的信号。本文还介绍了21世纪初研究中微子振荡的若干重要实验,例如长基线中微子振荡实验以及建造μ子贮存环来产生高能电子中微子束进行中微子振荡的实验以及测量中微子振荡时的CP破坏的设想。

  12. Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam

    Science.gov (United States)

    Agafonova, N.; Aleksandrov, A.; Anokhina, A.; Aoki, S.; Ariga, A.; Ariga, T.; Bender, D.; Bertolin, A.; Bodnarchuk, I.; Bozza, C.; Brugnera, R.; Buonaura, A.; Buontempo, S.; Büttner, B.; Chernyavsky, M.; Chukanov, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; De Serio, M.; Del Amo Sanchez, P.; Di Crescenzo, A.; Di Ferdinando, D.; Di Marco, N.; Dmitrievski, S.; Dracos, M.; Duchesneau, D.; Dusini, S.; Dzhatdoev, T.; Ebert, J.; Ereditato, A.; Fini, R. A.; Fukuda, T.; Galati, G.; Garfagnini, A.; Goldberg, J.; Gornushkin, Y.; Grella, G.; Guler, A. M.; Gustavino, C.; Hagner, C.; Hara, T.; Hollnagel, A.; Hosseini, B.; Ishiguro, K.; Jakovcic, K.; Jollet, C.; Kamiscioglu, C.; Kamiscioglu, M.; Kim, J. H.; Kim, S. H.; Kitagawa, N.; Klicek, B.; Kodama, K.; Komatsu, M.; Kose, U.; Kreslo, I.; Lauria, A.; Ljubicic, A.; Longhin, A.; Malgin, A.; Malenica, M.; Mandrioli, G.; Matsuo, T.; Matveev, V.; Mauri, N.; Medinaceli, E.; Meregaglia, A.; Mikado, S.; Monacelli, P.; Montesi, M. C.; Morishima, K.; Muciaccia, M. T.; Naganawa, N.; Naka, T.; Nakamura, M.; Nakano, T.; Nakatsuka, Y.; Niwa, K.; Ogawa, S.; Omura, T.; Ozaki, K.; Paoloni, A.; Paparella, L.; Park, B. D.; Park, I. G.; Pasqualini, L.; Pastore, A.; Patrizii, L.; Pessard, H.; Podgrudkov, D.; Polukhina, N.; Pozzato, M.; Pupilli, F.; Roda, M.; Roganova, T.; Rokujo, H.; Rosa, G.; Ryazhskaya, O.; Sato, O.; Schembri, A.; Shakirianova, I.; Shchedrina, T.; Sheshukov, A.; Shibuya, H.; Shiraishi, T.; Shoziyoev, G.; Simone, S.; Sioli, M.; Sirignano, C.; Sirri, G.; Spinetti, M.; Stanco, L.; Starkov, N.; Stellacci, S. M.; Stipcevic, M.; Strolin, P.; Takahashi, S.; Tenti, M.; Terranova, F.; Tioukov, V.; Tufanli, S.; Vilain, P.; Vladymyrov, M.; Votano, L.; Vuilleumier, J. L.; Wilquet, G.; Wonsak, B.; Yoon, C. S.; Zemskova, S.

    2015-06-01

    The OPERA experiment, exposed to the CERN to Gran Sasso ν μ beam, collected data from 2008 to 2012. Four oscillated ν τ Charged Current interaction candidates have been detected in appearance mode, which are consistent with ν μ → ν τ oscillations at the atmospheric Δ m 2 within the "standard" three-neutrino framework. In this paper, the OPERA ν τ appearance results are used to derive limits on the mixing parameters of a massive sterile neutrino.

  13. A Search For Matter Enhanced Neutrino Oscillations Through Measurements Of Day And Night Solar Neutrino Fluxes At The Sudbury Neutrino Observatory

    CERN Document Server

    Miknaitis, K K

    2005-01-01

    The Sudbury Neutrino Observatory (SNO) is a heavy-water Cherenkov detector designed to study 8B neutrinos from the sun. Through the charged-current (CC) and neutral-current (NC) reactions of neutrinos on deuterium, SNO separately determines the flux of electron neutrinos and the flux of all active flavors of solar 8B neutrinos. SNO is also sensitive to the elastic scattering (ES) of neutrinos on electrons in the heavy water. Measurements of the CC and NC rates in SNO have conclusively demonstrated solar neutrino flavor change. This flavor change is believed to be caused by matter-enhanced oscillations in the sun, through the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Matter effects could also change the flavor composition of neutrinos that traverse the earth. A comparison of the day and night measured CC flux at SNO directly tests for the MSW effect and contributes to constraints on neutrino oscillation parameters in the MSW model. We perform measurements of the day and night neutrino fluxes using data from t...

  14. Tests of Lorentz and CPT violation with MiniBooNE neutrino oscillation excesses

    CERN Document Server

    Katori, Teppei

    2012-01-01

    Violation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck-scale physics. Various types of data are analyzed to search for Lorentz violation under the Standard-Model Extension (SME) framework, including neutrino oscillation data. MiniBooNE is a short-baseline neutrino oscillation experiment at Fermilab. The measured excesses from MiniBooNE cannot be reconciled within the neutrino Standard Model; thus it might be a signal of new physics, such as Lorentz violation. We have analyzed the sidereal time dependence of MiniBooNE data for signals of the possible breakdown of Lorentz invariance in neutrinos. In this brief review, we introduce Lorentz violation, the neutrino sector of the SME, and the analysis of short-baseline neutrino oscillation experiments. We then present the results of the search for Lorentz violation in MiniBooNE data. This review is based on the published result (ArXiv:1109.3480).

  15. Neutrino oscillations at DUNE with improved energy reconstruction

    CERN Document Server

    De Romeri, Valentina; Sorel, Michel

    2016-01-01

    We study the physics reach of the long-baseline oscillation analysis of the DUNE experiment when realistic simulations are used to estimate its neutrino energy reconstruction capabilities. Our studies indicate that significant improvements in energy resolution compared to what is customarily assumed are plausible. This improved energy resolution can increase the sensitivity to leptonic CP violation in two ways. On the one hand, the CP-violating term in the oscillation probability has a characteristic energy dependence that can be better reproduced. On the other hand, the second oscillation maximum, especially sensitive to $\\delta_{CP}$, is better reconstructed. These effects lead to a significant improvement in the fraction of values of $\\delta_{CP}$ for which a $5 \\sigma$ discovery of leptonic CP-violation would be possible. The precision of the $\\delta_{CP}$ measurement could also be greatly enhanced, with a reduction of the maximum uncertainties from $26^\\circ$ to $18^\\circ$ for a 300~MW$\\cdot$kt$\\cdot$yr ...

  16. Neutrino-antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis

    CERN Document Server

    Fujikawa, Kazuo

    2015-01-01

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

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

    CERN Document Server

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

    2014-01-01

    We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10\\,GeV and 100\\,GeV, where a strong disappearance signal is expected. The detector volume surrounding DeepCore is used as a veto region to suppress the atmospheric muon background. Neutrino events are selected where the detected Cherenkov photons of the secondary particles minimally scatter, and the neutrino energy and arrival direction are reconstructed. Both variables are used to obtain the neutrino oscillation parameters from the data, with the best fit given by $\\Delta m^2_{32}=2.72^{+0.19}_{-0.20}\\times 10^{-3}\\,\\mathrm{eV}^2$ and $\\sin^2\\theta_{23} = 0.53^{+0.09}_{-0.12}$ (normal mass hierarchy assumed). The results are compatible and comparable in precision to those of dedicated oscillation experiments.

  18. Recent Results from the K2K - Neutrino Oscillation Experiment

    Science.gov (United States)

    Hill, James E.

    2002-12-01

    The K2K Long-Baseline neutrino oscillation experiment has been aquiring data since mid-1999 and has analysed those up to July of 2001. Fifty-six fully contained events are observed in the fiducial volume of the far detector where 80.6-8.0+7.3 are expected based partly on measurements near the beam production point. There is virtually no background for the contained event search. The methods established in this experiment are crucial for operation of future similar experiments to probe the nature of mixing in the neutral lepton sector, a necessary step in understanding the nature of family structure and of mass itself. A brief history and a few notes about the future and direction of the field precede the description of the experiment and its results.

  19. Emulsion Chamber with Big Radiation Length for Detecting Neutrino Oscillations

    CERN Document Server

    Asratyan, A E; Dolgolenko, A G; Kaftanov, V S; Kubantsev, M A; Verebryusov, V S

    2000-01-01

    A conceptual scheme of a hybrid-emulsion spectrometer for investigatingvarious channels of neutrino oscillations is proposed. The design emphasizesdetection of $\\tau$ leptons by detached vertices, reliable identification ofelectrons, and good spectrometry for all charged particles and photons. Adistributed target is formed by layers of low-Z material,emulsion-plastic-emulsion sheets, and air gaps in which $\\tau$ decays aredetected. The tracks of charged secondaries, including electrons, aremomentum-analyzed by curvature in magnetic field using hits in successive thinlayers of emulsion. The $\\tau$ leptons are efficiently detected in all majordecay channels, including \\xedec. Performance of a model spectrometer, thatcontains 3 tons of nuclear emulsion and 20 tons of passive material, isestimated for different experimental environments. When irradiated by the$\

  20. Matter Effects on Neutrino Oscillations in Different Supernova Models

    Science.gov (United States)

    Xu, Jing; Hu, Li-Jun; Li, Rui-Cheng; Guo, Xin-Heng; Young, Bing-Lin

    2016-04-01

    In recent years, with the development of simulations about supernova explosion, we have a better understanding about the density profiles and the shock waves in supernovae than before. There might be a reverse shock wave, another sudden change of density except the forward shock wave, or even no shock wave, emerging in the supernova. Instead of using the expression of the crossing probability at the high resonance, PH, we have studied the matter effects on neutrino oscillations in different supernova models. In detail, we have calculated the survival probability of ve (Ps) and the conversion probability of vx (Pc) in the Schrödinger equation within a simplified two-flavor framework for a certain case, in which the neutrino transfers through the supernova matter from an initial flavor eigenstate located at the core of the supernova. Our calculations was based on the data of density in three different supernova models obtained from simulations. In our work, we do not steepen the density gradient around the border of the shock wave, which differs to what was done in most of the other simulations. It is found that the mass and the density distribution of the supernova do make a difference on the behavior of Ps and Pc. With the results of Ps and Pc, we can estimate the number of ve (and vx) remained in the beam after they go through the matter in the supernova. Supported by National Science Foundation of China under Grant Nos. 11175020 and 11275025

  1. Neutrino oscillations: An essay in honor of Felix Boehm

    International Nuclear Information System (INIS)

    We briefly review the theory of neutrino oscillations and the MSW effect and report on new calculations by Rosen and Gelb for solar neutrino-electron scattering. The aim of these calculations is to try to use the scattering process as a means of choosing between the three types of MSW solutions for the 37Cl experiment. Both the efficiency and the resolution of the Kamiokande II detector are taken into account and the ratio R of the MSW prediction to the standard solar model prediction is calculated for different cuts on the minimum electron energy. We find that the adiabatic solution requires R to be less than 1/3, the large angle one requires it to be less than 2/3, and the nonadiabatic one restricts it to a value close to 1/2. The central value of the published KII data is close to 1/2, but the errors are too large to exclude the other solutions. 20 refs., 1 fig

  2. Calculation of oscillation probabilities of atmospheric neutrinos using nuCraft

    CERN Document Server

    Wallraff, Marius

    2014-01-01

    NuCraft (nucraft.hepforge.org) is an open-source Python project that calculates neutrino oscillation probabilities for neutrinos from cosmic-ray interactions in the atmosphere for their propagation through Earth. The solution is obtained by numerically solving the Schr\\"odinger equation. The code supports arbitrary numbers of neutrino flavors including additional sterile neutrinos, CP violation, arbitrary mass hierarchies, matter effects with a configurable Earth model, and takes into account the production height distribution of neutrinos in the Earth's atmosphere.

  3. Measurement of Neutrino Oscillations with the MINOS Detectors in the NuMI Beam

    CERN Document Server

    Adamson, P; Arms, K E; Armstrong, R; Auty, D J; Ayres, D S; Baller, B; Barnes, P D; Barr, G; Barrett, W L; Becker, B R; Belias, A; Bernstein, R H; Bhattacharya, D; Bishai, M; Blake, A; Bock, G J; Böhm, J; Böhnlein, D J; Bogert, D; Bower, C; Buckley-Geer, E; Cavanaugh, S; Chapman, J D; Cherdack, D; Childress, S; Choudhary, B C; Cobb, J H; Coleman, S J; Culling, A J; De Jong, J K; Dierckxsens, M; Diwan, M V; Dorman, M; Dytman, S A; Escobar, C O; Evans, J J; Falk-Harris, E; Feldman, G J; Frohne, M V; Gallagher, H R; Godley, A; Goodman, M C; Gouffon, P; Gran, R; Grashorn, E W; Grossman, N; Grzelak, K; Habig, A; Harris, D; Harris, P G; Hartnell, J; Hatcher, R; Heller, K; Himmel, A; Holin, A; Hylen, J; Irwin, G M; Ishitsuka, M; Jaffe, D E; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Kim, J J; Kim, M S; Koizumi, G; Kopp, S; Kordosky, M; Koskinen, D J; Kotelnikov, S K; Kreymer, A; Kumaratunga, S; Lang, K; Ling, J; Litchfield, P J; Litchfield, R P; Loiacono, L; Lucas, P; Ma, J; Mann, W A; Marchionni, A; Marshak, M L; Marshall, J S; Mayer, N; McGowan, A M; Meier, J R; Merzon, G I; Messier, M D; Metelko, C J; Michael, D G; Miller, J L; Miller, W H; Mishra, S R; Moore, C D; Morfn, J; Mualem, L; Mufson, S; Murgia, S; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nicholls, T C; Ochoa-Ricoux, J P; Oliver, W P; Ospanov, R; Paley, J; Paolone, V; Para, A; Patzak, T; Pavlovi, Z; Pawloski, G; Pearce, G F; Peck, C W; Peterson, E A; Petyt, D A; Pittam, R; Plunkett, R K; Rahaman, A; Rameika, R A; Raufer, T M; Rebel, B; Reichenbacher, J; Rodrigues, P A; Rosenfeld, C; Rubin, H A; Ruddick, K; Ryabov, V A; Sanchez, M C; Saoulidou, N; Schneps, J; Schreiner, P; Seun, S M; Shanahan, P; Smart, W; Smith, C; Sousa, A; Speakman, B; Stamoulis, P; Strait, M; Symes, P; Tagg, N; Talaga, R L; Tavera, M A; Thomas, J; Thompson, J; Thomson, M A; Thron, J L; Tinti, G; Trostin, I; Tsarev, V A; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Ward, C P; Ward, D R; Watabe, M; Weber, A; Webb, R C; Wehmann, A; West, N; White, C; Wojcicki, S G; Wright, D M; Yang, T; Zois, M; Zhang, K; Zwaska, R

    2008-01-01

    This letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum mechanical oscillations of neutrino flavor with mass splitting $|\\Delta m^2|=(2.43\\pm 0.13)\\times10^{-3}$ eV$^2$ (68% confidence level) and mixing angle $\\sin^2(2\\theta)>0.90$ (90% confidence level). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight, namely neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard deviation levels, respectively.

  4. Spectral function in electro-weak interactions and its impact on neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jen, C.-M. [Center for Neutrino Physics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2015-10-15

    Neutrino oscillation experiments have entered the high-precision era in the last few years. The oscillation parameters, as a measure of the neutrino properties, are extracted from the energy-dependent oscillation probability function. Different types of nuclear dynamics deeply influence the determination of neutrino energies in neutrino oscillation experiments. As a consequence, a comprehensive understanding of various nuclear dynamics interprets the scenario behind the neutrino interaction with nucleus and nuclei. The initial ground-state structure of the target nucleus is categorized in one typical nuclear dynamics, and its realistic description is generally referred as the spectral function (SF). Implementing the SF for each target nucleus into the GENIE neutrino event generator is the preliminary step necessary to obtain a reliable determination of the kinematics of all detectable final-products from neutrino interactions. At the intermedium-range of neutrino energies (∼ 1 GeV), the kinematic energy reconstruction is the vastly used approach and consists in identifying final-products as coming from the charged-current quasi-elastic-like (CCQE-like) neutrino interactions.

  5. Spectral function in electro-weak interactions and its impact on neutrino oscillation experiments

    International Nuclear Information System (INIS)

    Neutrino oscillation experiments have entered the high-precision era in the last few years. The oscillation parameters, as a measure of the neutrino properties, are extracted from the energy-dependent oscillation probability function. Different types of nuclear dynamics deeply influence the determination of neutrino energies in neutrino oscillation experiments. As a consequence, a comprehensive understanding of various nuclear dynamics interprets the scenario behind the neutrino interaction with nucleus and nuclei. The initial ground-state structure of the target nucleus is categorized in one typical nuclear dynamics, and its realistic description is generally referred as the spectral function (SF). Implementing the SF for each target nucleus into the GENIE neutrino event generator is the preliminary step necessary to obtain a reliable determination of the kinematics of all detectable final-products from neutrino interactions. At the intermedium-range of neutrino energies (∼ 1 GeV), the kinematic energy reconstruction is the vastly used approach and consists in identifying final-products as coming from the charged-current quasi-elastic-like (CCQE-like) neutrino interactions

  6. Sterile-active neutrino oscillations and shortcuts in the extra dimension

    OpenAIRE

    Päs, Heinrich; Pakvasa, Sandip; Weiler, Thomas J.

    2005-01-01

    We discuss a possible new resonance in active-sterile neutrino oscillations arising in theories with large extra dimensions. Fluctuations in the brane effectively increase the path-length of active neutrinos relative to the path-length of sterile neutrinos through the extra-dimensional bulk. Well below the resonance, the standard oscillation formulas apply. Well above the resonance, active-sterile oscillations are suppressed. We show that a resonance energy in the range of 30-400 MeV allows a...

  7. The numerical computer experiment for the neutrino events with the SK neutrino oscillation parameters occurring outside the Superkamiokande detector

    OpenAIRE

    Takahashi, N; Konishi, E; Misaki, A.

    2008-01-01

    Adopting neutrino oscillation parameters obtained by Super-Kamiokande, a numerical computer experiment for neutrino events occurring outside the detector, is carried out in the same SK live days, 1645.9 live days, constructing the virtual Super-Kamiokande detector in the computer. The numerical results by the computer experiment could be directly compared with the real SK experimental data. The comparison shows that it is difficult to obtain convincing conclusion on the existence of the neutr...

  8. On the sign of the neutrino asymmetry induced by active-sterile neutrino oscillations in the early Universe

    International Nuclear Information System (INIS)

    We deal with the problem of the final sign of the neutrino asymmetry generated by active-sterile neutrino oscillations in the Early Universe solving the full momentum dependent quantum kinetic equations. We study the parameter region 10-2 2|/eV2 ≤ 103. For a large range of sin2 2θ0 values the sign of the neutrino asymmetry is fixed and does not oscillate. For values of mixing parameters in the region 10-6 2 2θ0 -4 (eV2/|δm2|), the neutrino asymmetry appears to undergo rapid oscillations during the period where the exponential growth occurs. Our numerical results indicate that the oscillations are able to change the neutrino asymmetry sign. The sensitivity of the solutions and in particular of the final sign of lepton number to small changes in the initial conditions depends whether the number of oscillations is high enough. It is however not possible to conclude whether this effect is induced by the presence of a numerical error or is an intrinsic feature. As the amplitude of the statistical fluctuations is much lower than the numerical error, our numerical analysis cannot demonstrate the possibility of a chaotical generation of lepton domains. In any case this possibility is confined to a special region in the space of mixing parameters and it cannot spoil the compatibility of the νμ ↔ νs solution to the neutrino atmospheric data obtained assuming a small mixing of the νs with an eV - τ neutrino

  9. Neutrino flavor oscillations in the IceCube DeepCore Array

    Science.gov (United States)

    Giordano, Gerardo

    A large number of experiments of different types have provided strong evidence for neutrino oscillations and thus for physics beyond the Standard Model of Particle Physics. New experiments are being built and designed to further investigate neutrino oscillations, to obtain precision measurements of dominant oscillation parameters and discover sub-dominant effects. On the other hand, neutrino telescopes, like IceCube and the IceCube DeepCore Array, are using neutrinos as a means of learning about astrophysical sources, discovering dark matter and other high energy phenomena. Atmospheric neutrinos constitute a background for these searches. This dissertation shows that the large number of atmospheric neutrinos that the IceCube DeepCore detector will accumulate can be used in order to extract useful information about neutrino oscillations. Atmospheric neutrino interactions within the IceCube DeepCore array are examined in the context of neutrino flavor oscillations. The detection of an appearance of a tau-flavored neutrino flux, not present in the original atmospheric neutrino flux is calculated and quantified using the statistical interpretation of the neutrino-induced electromagnetic and hadronic cascades within the detector. The "track signal" of Cherenkov light created by muons created from either charged current interactions of muon-type neutrinos with detector volume nuclei or the decay of tau leptons within the detector's instrumented volume are also examined. Using a chi-squared analysis, new precision bounds are determined for the main atmospheric neutrino oscillation parameters and shown to drastically reduce the current parameter space. The implications of these new precision measurements are discussed in the context of currently open questions in the area of neutrino flavor oscillation studies. Future work and the impact of future measurements on this analysis are also discussed. Full three-flavor neutrino oscillation transition probabilities with matter

  10. Sensitivity to oscillation with a sterile fourth generation neutrino from ultra-low threshold neutrino-nucleus coherent scattering

    CERN Document Server

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

    2015-01-01

    We discuss prospects for probing short-range sterile neutrino oscillation using neutrino-nucleus coherent scattering with ultra-low energy ($\\sim 10$ eV - 100 eV) recoil threshold cryogenic Si and Ge detectors. The analysis is performed in the context of a specific and contemporary reactor-based experimental proposal, developed in cooperation with the Nuclear Science Center at Texas A&M University, and references available technology based upon economical and scalable detector arrays. The baseline of the experiment is substantially shorter than existing measurements, as near as 1 meter from the reactor core, and is moreover variable, extending continuously up to a range of about 20~meters. This proximity and variety combine to provide extraordinary sensitivity to a wide spectrum of oscillation scales, while facilitating the tidy cancellation of leading systematic uncertainties in the reactor source. For expected exposures, we demonstrate sensitivity to first/fourth neutrino oscillation with a mass gap $\\D...

  11. Latest results on atmospheric neutrino oscillations from IceCube/DeepCore

    Science.gov (United States)

    de André, J. P. A. M.; IceCube Collaboration

    2016-05-01

    The IceCube Neutrino Observatory, located at the South Pole, is the world’s largest neutrino detector. DeepCore, the low energy extension for IceCube, with a threshold of about ten GeV is well suited to study neutrino oscillations using neutrinos produced in the Earth’s atmosphere and traveling distances as large as the Earth’s diameter before being detected. Using these neutrinos DeepCore makes measurements of the neutrino oscillation parameters θ23 and |Δm 2 32| with precisions approaching that of dedicated experiments, and based on preliminary studies these results can still be further improved. These new studies as well as the current results obtained in DeepCore are discussed here.

  12. Neutrino oscillation from the beam with Gaussian-like energy distribution

    CERN Document Server

    Han, Rong-Sheng; Wang, Ke-Lin

    2015-01-01

    A recent neutrino experiment at Daya Bay gives superior data of the distribution of the prompt energy. In this paper, the energy distribution presented in the experiment is simulated by applying a Gaussian-like packet to the neutrino wave function received by the detector. We find that the wave packet of neutrinos is expanded during the propagation. As a result, the mixing angle $\\theta_{13}$ is more difficult to be measured than $\\theta_{12}$ and $\\theta_{23}$ in long baseline experiments. Some other propagation properties, such as the time evaluation of the survival probability, the neutrino oscillation and the $CP$ violation, are also studied with the employment of the coherent state method. When the Gaussian packet width increases, the amplitude of the neutrino oscillation decreases, whereas the oscillation period increases gradually.

  13. Neutrino spin-flavor oscillations in electromagnetic fields of various configurations

    CERN Document Server

    Dvornikov, Maxim

    2007-01-01

    We study spin-flavor oscillations of Dirac neutrinos with mixing and having non-zero matrix of magnetic moments in magnetic fields of various configurations. We discuss constant transversal and twisting magnetic fields. To describe the dynamics of Dirac neutrinos we use relativistic quantum mechanics approach based on the exact solutions to the Dirac-Pauli equation in an external electromagnetic field. We derive transition probabilities for different neutrino magnetic moments matrices.

  14. A Measurement of Atmospheric Neutrino Oscillation Parameters by Super-Kamiokande I

    CERN Document Server

    Ashie, Y; Ishihara, K; Itow, Y; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Namba, T; Nambu, R; Obayashi, Y; Shiozawa, M; Suzuki, Y; Takeuchi, Y; Taki, K; Yamada, S; Ishitsuka, M; Kajita, T; Kaneyuki, K; Nakayama, S; Okada, A; Okumura, K; Saji, C; Takenaga, Y; Clark, S T; Desai, S; Kearns, E; Likhoded, S; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Cravens, J P; Gajewski, W; Kropp, W R; Liu, D W; Mine, S; Smy, M B; Sobel, H W; Sterner, C W; Vagins, M R; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Scholberg, K; Walter, C W; Ellsworth, R W; Tasaka, S; Guillian, G; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D; Messier, M D; Hayato, Y; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Maruyama, T; Nakamura, K; Nitta, K; Oyama, Y; Sakuda, M; Totsuka, Y; Suzuki, A T; Hasegawa, M; Hayashi, K; Kato, I; Maesaka, H; Morita, T; Nakaya, T; Nishikawa, K; Sasaki, T; Ueda, S; Yamamoto, S; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Blaufuss, E; Goodman, J A; Sullivan, G W; Turcan, D; Habig, A; Fukuda, Y; Jung, C K; Kato, T; Kobayashi, K; Malek, M; Mauger, C; McGrew, C; Sarrat, A; Sharkey, E; Yanagisawa, C; Toshito, T; Miyano, K; Tamura, N; Ishii, J; Kuno, Y; Yoshida, M; Kim, S B; Yoo, J; Okazawa, H; Ishizuka, T; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Shirai, J; Suzuki, A; Koshiba, M; Nakajima, Y; Nishijima, K; Harada, T; Ishino, H; Watanabe, Y; Kielczewska, D; Zalipska, J; Berns, H G; Gran, R; Shiraishi, K K; Stachyra, A; Washburn, K; Wilkes, R J

    2005-01-01

    We present a combined analysis of fully-contained, partially-contained and upward-going muon atmospheric neutrino data from a 1489 day exposure of the Super--Kamiokande detector. The data samples span roughly five decades in neutrino energy, from 100 MeV to 10 TeV. A detailed Monte Carlo comparison is described and presented. The data is fit to the Monte Carlo expectation, and is found to be consistent with neutrino oscillations of $\

  15. Neutrino oscillation provides clues to dark matter and signals from the chilled universe

    CERN Multimedia

    2006-01-01

    The new verification that oscillations exists and neutrinos have mass though not detectible easy provides the first clue to extra dimensions, dark matter, hyperspace and chilled universe acting as a platform below it. (1/2 page)

  16. How neutrinos get mass and what other things may happen besides oscillations?

    Indian Academy of Sciences (India)

    M A Ernest

    2000-07-01

    In this talk I address the theoretical issue of why new physics is required to obtain a nonzero neutrino mass. I then discuss what other things may happen besides neutrino oscillations. In particular I consider a possible new scenario of leptogenesis in -parity nonconserving supersymmetry.

  17. A test of the equivalence principle by long-baseline neutrino-oscillation experiments

    CERN Document Server

    Iida, K; Yasuda, O; Iida, Kazuhito; Minakata, Hisakazu; Yasuda, Osamu

    1993-01-01

    We show that a breakdown of the universality of the gravitational couplings to different neutrino flavors can be tested in long-baseline neutrino-oscillation experiments. In particular we have analyzed in detail a proposed experiment at SOUDAN 2 with $\

  18. OscSNS: A Precision Neutrino Oscillation Experiment at the SNS

    CERN Document Server

    ,

    2013-01-01

    The growing evidence for short-baseline neutrino oscillations and the possible existence of sterile neutrinos necessitates the development of a cost-effective experiment that can resolve these mysteries. The OscSNS \\cite{1} experiment, located at the Spallation Neutron Source (SNS), Oak Ridge Laboratory, is ideal for this purpose.

  19. On the chaoticity of active-sterile neutrino oscillations in the early universe

    DEFF Research Database (Denmark)

    Braad, Poul-Erik; Hannestad, Steen

    2000-01-01

    We have investigated the evolution of the neutrino asymmetry in active-sterile neutrino oscillations in the early universe. We find that there are large regions of parameter space where the asymmetry is extremely sensitive to variations in the initial asymmetry as well as the external parameters...

  20. CP-Violation in Neutrino Oscillations from EC/{beta}{sup +} decaying ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Catalina [Centre for Theoretical Particle Physics, IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2012-08-15

    We discuss the separation of unknown neutrino properties by means of the energy dependence of the oscillation probability and we consider an hybrid setup which combines the electron capture and the {beta}{sup +} decay from the same radioactive proton-rich ion with the same boost. We conclude that the combination of the two decay channels, with different neutrino energies, achieves remarkable results.

  1. The Discovery reach of $CP$ violation in neutrino oscillation with non-standard interaction effects

    CERN Document Server

    Rahman, Zini; Adhikari, Rathin

    2015-01-01

    We have studied the $CP$ violation discovery reach in neutrino oscillation experiment with superbeam, neutrino factory and monoenergetic neutrino beam. For NSI satisfying model-dependent bound for shorter baselines (like CERN-Fr\\'ejus set-up ) there is insignificant effect of NSI on the the discovery reach of $CP$ violation due to $\\delta$. Particularly, for superbeam and neutrino factory we have also considered relatively longer baselines for which there could be significant NSI effects on $CP$ violation discovery reach for higher allowed values of NSI. For monoenergetic beam only shorter baselines are considered to study $CP$ violation with different nuclei as neutrino sources. Interestingly for non-standard interactions - $\\varepsilon_{e\\mu}$ and $\\varepsilon_{e\\tau}$ of neutrinos with matter during propagation in longer baselines in superbeam, there is possibility of better discovery reach of $CP$ violation than that with only Standard Model interactions of neutrinos with matter. For complex NSI we have s...

  2. Global analysis of the post-SNO solar neutrino data for standard and nonstandard oscillation mechanisms

    International Nuclear Information System (INIS)

    What can we learn from solar neutrino observations? Is there any solution to the solar neutrino anomaly which is favored by the present experimental panorama? After SNO results, is it possible to affirm that neutrinos have mass? In order to answer such questions we analyze the current available data from the solar neutrino experiments, including the recent SNO result, in view of many acceptable solutions to the solar neutrino problem based on different conversion mechanisms, for the first time using the same statistical procedure. This allows us to do a direct comparison of the goodness of the fit among different solutions, from which we can discuss and conclude on the current status of each proposed dynamical mechanism. These solutions are based on different assumptions: (a) neutrino mass and mixing (b) a nonvanishing neutrino magnetic moment, (c) the existence of nonstandard flavor-changing and nonuniversal neutrino interactions, and (d) a tiny violation of the equivalence principle. We investigate the quality of the fit provided by each one of these solutions not only to the total rate measured by all the solar neutrino experiments but also to the recoil electron energy spectrum measured at different zenith angles by the Super-Kamiokande Collaboration. We conclude that several nonstandard neutrino flavor conversion mechanisms provide a very good fit to the experimental data which is comparable with (or even slightly better than) the most famous solution to the solar neutrino anomaly based on the neutrino oscillation induced by mass

  3. Neutrinos Oscillations with Long-Base-Line Beams (Past, Present and very near Future)

    CERN Document Server

    Stanco, Luca

    2010-01-01

    We overview the status of the studies on neutrino oscillations with accelerators at the present running experiments. Past and present results enlighten the path towards the observation of massive neutrinos and the settling of their oscillations. The very near future may still have addiction from the outcome of the on-going experiments. OPERA is chosen as a relevant example justified by the very recent results released.

  4. Lepton masses and neutrino oscillations in three-generation Calabi-Yau string theory

    International Nuclear Information System (INIS)

    Properties of leptons in the framework of the E8xE'8 heterotic string compacified on three-generation Calabi-Yau manifolds are investigated. It is shown that the experimental smallness of neutrino masses, mνe/mτ [i.e. me/mτ=O (10-3)]. Neutrino oscillations are calculated with νe,μ↔ντ being the dominant predicted oscillation. (orig.)

  5. First Anti-neutrino Oscillation Results from the T2K Experiment

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Neutrinos are some of the most abundant but yet most elusive particles in the universe. They have almost no mass, only interact weakly and relatively little is known about their properties. Furthermore it has been firmly established over the last decade that neutrinos can undergo flavour transitions as mass and flavor eigenstates are not identical. These neutrino oscillations have been studied using natural sources as well as nuclear reactors or with neutrinos produced at accelerators. T2K is a long baseline neutrino oscillation beam that uses a beam of muon (anti-)neutrinos that is directed form J-PARC at the east cost of Japan over a distance of almost 300 km to the SuperKamiokande water Cherenkov detector in the west. The facility is complemented by a near detector complex 280 m downstream of the neutrino production target to characterise the beam and the neutrino interaction dynamics. T2K has taken data with a muon neutrino beam since early 2010 and is studying the disappearance of muon neutrinos as well...

  6. Oscillations, Neutrino Masses and Scales of New Physics

    OpenAIRE

    Barenboim Szuchman, Gabriela Alejandra; Scheck, Florian

    1999-01-01

    We show that all the available experimental information involving neutrinos can be accounted for within the framework of already existing models where neutrinos have zero mass at tree level, but obtain a small Dirac mass by radiative corrections.

  7. A First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background

    CERN Document Server

    Follin, Brent; Millea, Marius; Pan, Zhen

    2015-01-01

    The freestreaming of cosmological neutrinos prior to recombination of the baryon-photon plasma alters gravitational potentials and therefore the details of the time-dependent gravitational driving of acoustic oscillations. We report here a first detection of the resulting shifts in the temporal phase of the oscillations, which we infer from their signature in the Cosmic Microwave Background (CMB) temperature power spectrum. The magnitude of the shift is proportional to the fraction of the total radiation density in neutrinos. Parameterizing the shift via an effective number of neutrino species we find $1.9 < N_\

  8. MONOLITH a massive magnetized tracking calorimeter for the study of atmospheric neutrino oscillations

    CERN Document Server

    Terranova, F

    2001-01-01

    MONOLITH is a proposed massive (34 kton) magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of high energy atmospheric muon neutrinos. The main goal is to establish (or reject) the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The Delta m/sup 2/ sensitivity range for this measurement comfortably covers the complete Super-Kamiokande allowed region. Other measurements include studies of matter effects and the up/down ratio of NC events, the study of cosmic ray muons in the multi-TeV range, and auxiliary measurements from the CERN to Gran Sasso neutrino beam. (2 refs).

  9. The effect of Topcolor Assisted Technicolor, and other models, on Neutrino Oscillation

    OpenAIRE

    Honda, Minako; Kao, Yee; Okamura, Naotoshi; Pronin, Alexey; Takeuchi, Tatsu

    2007-01-01

    New physics beyond the Standard Model can lead to extra matter effects on neutrino oscillation if the new interactions distinguish among the three flavors of neutrino. In Ref.1, we argued that a long-baseline neutrino oscillation experiment in which the Fermilab-NUMI beam in its high-energy mode is aimed at the planned Hyper-Kamiokande detector would be capable of constraining the size of those extra matter effects, provided the vacuum value of \\sin^2 2\\theta_{23} is not too close to one. In ...

  10. Search for Differences in Oscillation Parameters for Atmospheric Neutrinos and Antineutrinos at Super-Kamiokande

    CERN Document Server

    Abe, K; Iida, T; Ikeda, M; Iyogi, K; Kameda, J; Koshio, Y; Kozuma, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Takeuchi, Y; Ueno, K; Ueshima, K; Watanabe, H; Yamada, S; Yokozawa, T; Ishihara, C; Kaji, H; Lee, K P; Kajita, T; Kaneyuki, K; McLachlan, T; Okumura, K; Shimizu, Y; Tanimoto, N; Martens, K; Vagins, M R; Labarga, L; Magro, L M; Dufour, F; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Goldhaber, M; Bays, K; Kropp, W R; Mine, S; Regis, C; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Albert, J B; Scholberg, K; Walter, C W; Wendell, R; Wongjirad, T M; Tasaka, S; Learned, J G; Matsuno, S; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Nishino, H; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Minamino, A; Nakaya, T; Fukuda, Y; Itow, Y; Mitsuka, G; Tanaka, T; Jung, C K; Taylor, I; Yanagisawa, C; Ishino, H; Kibayashi, A; Mino, S; Mori, T; Sakuda, M; Toyota, H; Kuno, Y; Kim, S B; Yang, B S; Ishizuka, T; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Yokoyama, M; Totsuka, Y; Chen, S; Heng, Y; Yang, Z; Zhang, H; Kielczewska, D; Mijakowski, P; Connolly, K; Dziomba, M; Wilkes, R J

    2011-01-01

    We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande -I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best fit antineutrino mixing is found to be at (dm2bar, sin2 2 thetabar) = (2.0x10^-3 eV^2, 1.0) and is consistent with the overall Super-K measurement.

  11. Day-Night Asymmetries in Active-Sterile Solar Neutrino Oscillations

    CERN Document Server

    Long, H W; Giunti, C

    2013-01-01

    Day-night asymmetries in active-sterile solar neutrino oscillations are discussed in the general $3+N_{s}$ mixing framework with three active and N_s sterile neutrinos. Analytical expressions of the probability of neutrino flavor transitions in the Earth in the perturbative approximation and in the slab approximation are presented and the effects of active-sterile mixing and of the CP-violating phases are discussed. The accuracy of the analytical approximations and the properties of the day-night asymmetries are illustrated numerically in the 3+1 neutrino mixing framework.

  12. Vacuum oscillations and the distorted solar neutrino spectrum observed by Superkamiokande

    OpenAIRE

    Berezinsky, V.; Fiorentini, G.; Lissia, M.

    1998-01-01

    The excess of solar-neutrino events above 13 MeV that has been recently observed by Superkamiokande can be explained by vacuum oscillations (VO). If the boron neutrino flux is 20% smaller than the standard solar model (SSM) prediction and the chlorine signal is assumed 30% (or 3.5 sigmas) higher than the measured one, there exists a VO solution that reproduces both the observed boron neutrino spectrum, including the high energy distortion, and the other measured neutrino rates. This solution ...

  13. Prospects for Reconstruction of Leptonic Unitarity Quadrangle and Neutrino Oscillation Experiments

    CERN Document Server

    Verma, Surender

    2016-01-01

    After the observation of non-zero $\\theta_{13}$ the goal has shifted to observe $CP$ violation in the leptonic sector. Neutrino oscillation experiments can, directly, probe the Dirac $CP$ phases. Alternatively, one can measure $CP$ violation in the leptonic sector using Leptonic Unitarity Quadrangle(LUQ). The existence of Standard Model (SM) gauge singlets - sterile neutrinos - will provide additional sources of $CP$ violation. We investigate the connection between neutrino survival probability and rephasing invariants of the $4\\times4$ neutrino mixing matrix. In general, LUQ contain eight geometrical parameters out of which five are independent. We obtain $CP$ asymmetry($P_{\

  14. GeV - PeV Neutrino Production and Oscillation in hidden jets from GRBs

    CERN Document Server

    Fraija, Nissim

    2013-01-01

    Long gamma-ray bursts have been widely associated with collapsing massive stars in the framework of collapsar model. High-energy neutrinos and photons can be produced in the internal shocks of middle relativistic jets from core-collapse supernova. Although photons can hardly escape, high-energy neutrinos could be the only signature when the jets are hidden. We show that using suitable parameters, high-energy neutrinos in GeV - PeV range can be produced in the hidden jet inside the collapsar, thus demonstrating that these objects are candidates to produce neutrinos with energies between 1 - 10 PeV which were observed with IceCube. On the other hand, due to matter effects, high-energy neutrinos may oscillate resonantly from one flavor to another before leaving the star. Using two (solar, atmospheric and accelerator parameters) and three neutrino mixing, we study the possibility of resonant oscillation for these neutrinos created in internal shocks. Also we compute the probabilities of neutrino oscillations in t...

  15. Experimental Results on Neutrino Oscillations Using Atmospheric, Solar and Accelerator Beams

    International Nuclear Information System (INIS)

    The innermost secrets of the mysterious neutrino are being revealed in underground detectors. Recent data on atmospheric neutrinos, primarily from the Super-Kamiokande experiment, confirm the neutrino flavor mixing and non-zero masses. The high precision measurement of angular distribution allows to determine the value of Δm2 between 0.0013 eV2 and 0.0054 eV2 at 90% c.l. Studies of up-down asymmetries in different event samples indicate that νμ↔ντ oscillations are more likely explanation of the data than νμ↔νs. The deficit of the observed solar neutrino flux compared to the predictions of the standard solar model, often interpreted by neutrino oscillations, is further studied in the SuperKamiokande detector. The energy spectrum is measured above 5.5 MeV for the Sun's positions above and below the horizon. A day-night effect is observed at a statistical significance of 2 σ. The K2K (KEK to Kamioka) is the first long-baseline neutrino-oscillation experiment. During runs in 1999 the first 3 events were observed in the SuperKamiokande detector caused by neutrinos produced at the KEK accelerator at a distance of 250 km. The predicted number of events without any oscillations is 12.3+1.7-1.9. (author)

  16. Special Issue on "Neutrino Oscillations: Celebrating the Nobel Prize in Physics 2015" in Nuclear Physics B

    Science.gov (United States)

    Ohlsson, Tommy

    2016-07-01

    In 2015, the Nobel Prize in Physics was awarded jointly to Takaaki Kajita from the Super-Kamiokande Collaboration and Arthur B. McDonald from the SNO Collaboration "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Furthermore, the Daya Bay, K2K and T2K, KamLAND, SNO, and Super-Kamiokande Collaborations shared the Fundamental Physics Breakthrough Prize the same year. In order to celebrate this successful and fruitful year for neutrino oscillations, the editors and the publisher of Nuclear Physics B decided to publish a Special Issue on neutrino oscillations. We invited prominent scientists in the area of neutrino physics that relates to neutrino oscillations to write contributions for this Special Issue, which was open to both original research articles as well as review articles. The authors of this Special Issue consist of e.g. the two Nobel Laureates, International Participants of the Nobel Symposium 129 on Neutrino Physics at Haga Slott in Enköping, Sweden (August 19-24, 2004), selected active researchers, and members from large experimental collaborations with major results in the last ten years. In total, this Special Issue consists of 28 contributions. Please note that the cover of this Special Issue contains a figure from each of the 26 contributions that have figures included.

  17. Shifts of neutrino oscillation parameters in reactor antineutrino experiments with non-standard interactions

    CERN Document Server

    Li, Yu-Feng

    2014-01-01

    We discuss reactor antineutrino oscillations with non-standard interactions (NSIs) at the neutrino production and detection processes. The neutrino oscillation probability is calculated with a parametrization of the NSI parameters by splitting them into the averages and differences of the production and detection processes respectively. The average parts induce constant shifts of the neutrino mixing angles from their true values, and the difference parts can generate the energy (and baseline) dependent corrections to the initial mass-squared differences. We stress that only the shifts of mass-squared differences are measurable in reactor antineutrino experiments. Taking Jiangmen Underground Neutrino Observatory (JUNO) as an example, we analyze how NSIs influence the standard neutrino measurements and to what extent we can constrain the NSI parameters.

  18. Shifts of neutrino oscillation parameters in reactor antineutrino experiments with non-standard interactions

    International Nuclear Information System (INIS)

    We discuss reactor antineutrino oscillations with non-standard interactions (NSIs) at the neutrino production and detection processes. The neutrino oscillation probability is calculated with a parametrization of the NSI parameters by splitting them into the averages and differences of the production and detection processes respectively. The average parts induce constant shifts of the neutrino mixing angles from their true values, and the difference parts can generate the energy (and baseline) dependent corrections to the initial mass-squared differences. We stress that only the shifts of mass-squared differences are measurable in reactor antineutrino experiments. Taking Jiangmen Underground Neutrino Observatory (JUNO) as an example, we analyze how NSIs influence the standard neutrino measurements and to what extent we can constrain the NSI parameters

  19. Nuclear Effects in Neutrino Interactions and their Impact on the Determination of Oscillation Parameters

    CERN Document Server

    Benhar, Omar

    2013-01-01

    The quantitative description of the effects of nuclear dynamics on the measured neutrino-nucleus cross sections -- needed to reduce the systematic uncertainty of long baseline neutrino oscillation experiments -- involves severe difficulties. Owing to the uncertainty on the incoming neutrino energy, different reaction mechanisms contribute to the cross section measured at fixed energy and scattering angle of the outgoing lepton, and must therefore be consistently taken into account within a unified model. We review the theoretical approach based on the impulse approximation and the use of realistic nucleon spectral functions, allowing one to describe a variety of reaction mechanisms active in the broad kinematical range covered by neutrino experiments. The extension of this scheme to include more complex mechanisms involving the two-nucleon current, which are believed to be important, is also outlined. The impact of nuclear effects on the determination of neutrino oscillation parameters is illustrated by analy...

  20. A search for muon neutrino to electron neutrino oscillations at Δm2 > 0.1 eV2

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Ryan Benton [Princeton Univ., NJ (United States)

    2007-11-01

    The evidence is compelling that neutrinos undergo flavor change as they propagate. In recent years, experiments have observed this phenomenon of neutrino oscillations using disparate neutrino sources: the sun, fission reactors, accelerators, and secondary cosmic rays. The standard model of particle physics needs only simple extensions - neutrino masses and mixing - to accommodate all neutrino oscillation results to date, save one. The 3.8σ-significant $\\bar{v}$e excess reported by the LSND collaboration is consistent with $\\bar{v}$μ →$\\bar{v}$e oscillations with a mass-squared splitting of Δm2 ~ 1 eV2. This signal, which has not been independently verified, is inconsistent with other oscillation evidence unless more daring standard model extensions (e.g. sterile neutrinos) are considered.

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

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Ryan Benton; /Princeton U.

    2007-11-01

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

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

    CERN Document Server

    Lipmanov, E M

    1999-01-01

    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 in these eigenstates. A neutrino flavor hierarchy condition is suggested: a direct link between the neutrino flavor and the flavor of the charged leptons which interconnects the two mixing angles, theta and phi, via the charged lepton mass ratios, with the net result tg^2 phi = (tg^2 theta)^gamma, gamma ~ 2.06. It leads to distinct inferences testable at SNO and Super-K.

  3. Density Fluctuation Effects on Collective Neutrino Oscillations in O-Ne-Mg Core-Collapse Supernovae

    CERN Document Server

    Cherry, John F; Carlson, Joe; Duan, Huaiyu; Fuller, George M; Qian, Yong-Zhong

    2011-01-01

    We investigate the effect of matter density fluctuations on supernova collective neutrino flavor oscillations. In particular, we use full multi-angle, 3-flavor, self-consistent simulations of the evolution of the neutrino flavor field in the envelope of an O-Ne-Mg core collapse supernova at shock break-out (neutrino neutronization burst) to study the effect of the matter density "bump" left by the He-burning shell. We find a seemingly counterintuitive increase in the overall electron neutrino survival probability created by this matter density feature. We discuss this behavior in terms of the interplay between the matter density profile and neutrino collective effects. While our results give new insights into this interplay, they also suggest an immediate consequence for supernova neutrino burst detection: it will be difficult to use a burst signal to extract information on fossil burning shells or other fluctuations of this scale in the matter density profile. Consistent with previous studies, our results al...

  4. Oscillating Decay Rate in Electron Capture and the Neutrino Mass Difference

    CERN Document Server

    Peshkin, Murray

    2014-01-01

    Reported oscillations in the rate of decay of certain ions by K-electron capture have raised questions about whether and how such oscillations can arise in quantum mechanical theory and whether they can measure the neutrino mass difference. Here I show that simple principles of quantum mechanics answer some questions and clarify what must be done theoretically or experimentally to answer some others.

  5. Conformal neutrinos: An alternative to the see-saw mechanism

    International Nuclear Information System (INIS)

    We analyze a scenario where the right-handed neutrinos make part of a strongly coupled conformal field theory and acquire an anomalous dimension γ1/2 giving rise to an inverse see-saw mechanism. In this case light sterile neutrinos do appear and neutrino oscillation experiments are able to probe our model.

  6. Searches for Sterile Neutrinos with the IceCube Detector

    CERN Document Server

    ,

    2016-01-01

    The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy in the approximate 320 GeV to 20 TeV range, to search for the oscillation signatures of light sterile neutrinos. No evidence for anomalous $\

  7. The Standard Model of Particle Physics. Neutrino Oscillations

    OpenAIRE

    Giacomelli, Giorgio

    2009-01-01

    The Standard Model (SM) of Particle Physics was tested to great precision by experiments at the highest energy colliders (LEP, Hera, Tevatron, SLAC). The only missing particle is the Higgs boson, which will be the first particle to be searched for at the new Large Hadron Collider (LHC) at CERN. The SM anticipated that there are 3 types of left handed neutrinos. Experiments on atmospheric and solar neutrinos (made in Japan, Italy, Canada, Russia and the US) have shown the existence of neutrino...

  8. Magnus expansion and three-neutrino oscillations in matter

    Energy Technology Data Exchange (ETDEWEB)

    Cabral-Rosetti, L G [Departamento de Posgrado, Centro Interdisciplinario de Investigacion y Docencia en Educacion Tecnica (CIIDET), Av. Universidad 282 Pte., Col. Centro, A. Postal 752, C.P. 76000, Santiago de Queretaro, Qro. (Mexico); Aguilar-Arevalo, A A [Instituto de Ciencias Nucleares, Departameto de Fisica de Altas EnergIas, Universidad Nacional Autonoma de Mexico (ICN-UNAM). Apartado Postal 70-543, 04510 Mexico, D. F. (Mexico); D' Olivo, J C [Instituto de Ciencias Nucleares, Departameto de Fisica de Altas EnergIas, Universidad Nacional Autonoma de Mexico (ICN-UNAM). Apartado Postal 70-543, 04510 Mexico, D. F. (Mexico)

    2006-05-15

    We present a semi-analytical derivation of the survival probability of solar neutrinos in the three generation scheme, based on the Magnus approximation of the evolution operator of a three level system, and assuming a mass hierarchy among neutrino mass eigenstates. We have used an exponential profile for the solar electron density in our approximation. The different interesting density regions that appear throughout the propagation are analyzed. Finally, some comments on the allowed regions in the solar neutrino parameter space are addressed.

  9. Magnus expansion and three-neutrino oscillations in matter

    International Nuclear Information System (INIS)

    We present a semi-analytical derivation of the survival probability of solar neutrinos in the three generation scheme, based on the Magnus approximation of the evolution operator of a three level system, and assuming a mass hierarchy among neutrino mass eigenstates. We have used an exponential profile for the solar electron density in our approximation. The different interesting density regions that appear throughout the propagation are analyzed. Finally, some comments on the allowed regions in the solar neutrino parameter space are addressed

  10. Democratic Approach To Atmospheric And Solar Neutrino Oscillations

    CERN Document Server

    Shafi, Qaisar; Shafi, Qaisar; Tavartkiladze, Zurab

    2002-01-01

    Working with a U(1) flavor symmetry, we show how the hierarchical structure in the charged fermion sector and a democratic approach for neutrinos that yields large solar and atmospheric neutrino mixings can be simultaneously realized in the MSSM framework. However, in SU(5) due to the unified multiplets we encounter difficulties. Namely, democracy for the neutrinos leads to a wrong hierarchical pattern for charged fermion masses and mixings. We discuss how this is overcome in flipped SU(5).

  11. Three-generation neutrino oscillations in curved spacetime

    CERN Document Server

    Zhang, Yu-Hao

    2016-01-01

    Three-generation MSW effect in curved spacetime is studied and a brief discussion on the gravitational correction to the neutrino self-energy is given. The modified mixing parameters and corresponding conversion probabilities of neutrinos after traveling through celestial objects of constant densities are obtained. The method to distinguish between the normal hierarchy and inverted hierarchy is discussed in this framework. Due to the gravitational redshift of energy, in some extreme situations, the resonance energy of neutrinos might be shifted noticeably and the gravitational effect on the self-energy of neutrino becomes significant at the vicinities of spacetime singularities.

  12. Neutrino Oscillations, the Higgs Boson, and the Private Higgs Model

    Science.gov (United States)

    BenTov, Jonathan

    "CESR, PEP, PETRA, ISABELLE, p-bar p colliders, LEP, the tevatron, and ep machines are at various levels of design or construction. They will study the properties of b-matter, see weak intermediaries, and perhaps find the t-quark and the Higgs boson. Never before was there such a bestiary waiting to be discovered; and what surprises will be found!" - S. L. Glashow ("The Future of Elementary Particle Physics," Quarks and Leptons, NATO Advanced Study Institutes Series Volume 61, 1980, pp 687-713) The situation in 1980 was clearly different from the present situation in 2013, in which we face the very real possibilty that no new degrees of freedom will ever again be within reach of a collider. In an intriguing twist of fate, this very fact results in a sharp paradox for fundamental physics: the Higgs mass should be MP/m h ˜ 1017 times larger than it actually is, and the vacuum energy density of the universe should be (M P/A)4 ˜ (1031)4 times larger than it actually is, and apparently nature refuses to give us any more clues as to why. These together are what I would call the main problem of 21st century physics: despite all of the predictive success of particle physics so far, we must find a way to suitably modify the rules of quantum field theory, lest we accept the unproductive defeatist attitude that our universe is simply fine-tuned. In the meantime, there is much interesting work to be done in more "traditional" particle physics: we have learned that neutrinos actually have tiny but nonzero masses, which is clear and unambiguous evidence for physics beyond the Standard Model. I will allocate the first third of this document to phenomena related to neutrino oscillations. In particular, I would like to argue that some of the apparent differences between neutrino mixing and quark mixing are to an extent illusory, and actually many aspects of the two sectors can be understood in a coherent framework for extending the Standard Model. The remaining two-thirds of this

  13. Long baseline neutrino oscillation experiment at the AGS. Physics design report

    International Nuclear Information System (INIS)

    The authors present a design for a multi-detector long baseline neutrino oscillation experiment at the BNL AGS. It has been approved by the BNL-HENP-PAC as AGS Experiment 889. The experiment will search for oscillations in the νμ, disappearance channel and the νμ ↔ νe appearance channel by means of four identical neutrino detectors located 1, 3, 24, and 68km from the AGS neutrino source. Observed depletion of the νμ flux (via quasi-elastic muon neutrino events, νμn → μ-p) in the far detectors not attended by an observed proportional increase of the νe flux (via quasi-elastic electron neutrino events, νen → e-p) in those detectors will be prima facie evidence for the oscillation channel νμ ↔ ντ. The experiment is directed toward exploration of the region of the neutrino oscillation parameters Δm2 and sin22θ, suggested by the Kamiokande and IMB deep underground detectors but it will also explore a region more than two orders of magnitude larger than that of previous accelerator experiments. The experiment will run in a mode new to BNL. It will receive the fast extracted proton beam on the neutrino target approximately 20 hours per day when the AGS is not filling RHIC. A key aspect of the experimental design involves placing the detectors 1.5 degrees off the center line of the neutrino beam, which has the important advantage that the central value of the neutrino energy (∼ 1 GeV) and the beam spectral shape are, to a good approximation, the same in all four detectors. The proposed detectors are massive, imaging, water Cherenkov detectors similar in large part to the Kamiokande and IMB detectors. The design has profited from their decade-long experience, and from the detector designs of the forthcoming SNO and SuperKamiokande detectors

  14. A Proposal for a Three Detector Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam

    CERN Document Server

    Antonello, M; Bellini, V.; Benetti, P.; Bertolucci, S.; Bilokon, H.; Boffelli, F.; Bonesini, M.; Bremer, J.; Calligarich, E.; Centro, S.; Cocco, A.G.; Dermenev, A.; Falcone, A.; Farnese, C.; Fava, A.; Ferrari, A.; Gibin, D.; Gninenko, S.; Golubev, N.; Guglielmi, A.; Ivashkin, A.; Kirsanov, M.; Kisiel, J.; Kose, U.; Mammoliti, F.; Mannocchi, G.; Menegolli, A.; Meng, G.; Mladenov, D.; Montanari, C.; Nessi, M.; Nicoletto, M.; Noto, F.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Potenza, R.; Rappoldi, A.; Raselli, G.L.; Rossella, M.; Rubbia, C.; Sala, P.; Scaramelli, A.; Sobczyk, J.; Spanu, M.; Stefan, D.; Sulej, R.; Sutera, C.M.; Torti, M.; Tortorici, F.; Varanini, F.; Ventura, S.; Vignoli, C.; Wachala, T.; Zani, A.; Adams, C.; Andreopoulos, C.; Ankowski, A.M.; Asaadi, J.; Bagby, L.; Baller, B.; Barros, N.; Bass, M.; Bishai, M.; Bitadze, A.; Bugel, L.; Camilleri, L.; Cavanna, F.; Chen, H.; Chi, C.; Church, E.; Cianci, D.; Collin, G.H.; Conrad, J.M.; De Geronimo, G.; Dharmapalan, R.; Djurcic, Z.; Ereditato, A.; Esquivel, J.; Evans, J.; Fleming, B.T.; Foreman, W.M.; Freestone, J.; Gamble, T.; Garvey, G.; Genty, V.; Goldi, D.; Gramellini, E.; Greenlee, H.; Guenette, R.; Hackenburg, A.; Hanni, R.; Ho, J.; Howell, J.; James, C.; Jen, C.M.; Jones, B.J.P.; Kalousis, L.N.; Karagiorgi, G.; Ketchum, W.; Klein, J.; Klinger, J.; Kreslo, I.; Kudryavtsev, V.A.; Lissauer, D.; Livesly, P.; Louis, W.C.; Luthi, M.; Mariani, C.; Mavrokoridis, K.; McCauley, N.; McConkey, N.; Mercer, I.; Miao, T.; Mills, G.B.; Montanari, D.; Moon, J.; Moss, Z.; Mufson, S.; Norris, B.; Nowak, J.; Pal, S.; Palamara, O.; Pater, J.; Pavlovic, Z.; Perkin, J.; Pulliam, G.; Qian, X.; Qiuguang, L.; Radeka, V.; Rameika, R.; Ratoff, P.N.; Richardson, M.; von Rohr, C.Rudolf; Russell, B.; Schmitz, D.W.; Shaevitz, M.H.; Sippach, B.; Soderberg, M.; Soldner-Rembold, S.; Spitz, J.; Spooner, N.; Strauss, T.; Szelc, A.M.; Taylor, C.E.; Terao, K.; Thiesse, M.; Thompson, L.; Thomson, M.; Thorn, C.; Toups, M.; Touramanis, C.; Van de Water, R.G.; Weber, M.; Whittington, D.; Wongjirad, T.; Yu, B.; Zeller, G.P.; Zennamo, J.; Acciarri, R.; An, R.; Barr, G.; Blake, A.; Bolton, T.; Bromberg, C.; Caratelli, D.; Carls, B.; Convery, M.; Dytmam, S.; Eberly, B.; Gollapinni, S.; Graham, M.; Grosso, R.; Hen, O.; Hewes, J.; Horton-Smith, G.; Johnson, R.A.; Joshi, J.; Jostlein, H.; Kaleko, D.; Kirby, B.; Kirby, M.; Kobilarcik, T.; Li, Y.; Littlejohn, B.; Lockwitz, S.; Lundberg, B.; Marchionni, A.; Marshall, J.; McDonald, K.; Meddage, V.; Miceli, T.; Mooney, M.; Moulai, M.H.; Murrells, R.; Naples, D.; Nienaber, P.; Paolone, V.; Papavassiliou, V.; Pate, S.; Pordes, S.; Raaf, J.L.; Rebel, B.; Rochester, L.; Schukraft, A.; Seligman, W.; St. John, J.; Tagg, N.; Tsai, Y.; Usher, T.; Van de Water, R.; Wolbers, S.; Woodruff, K.; Xu, M.; Yang, T.; Zhang, C.; Badgett, W.; Biery, K.; Brice, S.J.; Dixon, S.; Geynisman, M.; Moore, C.; Snider, E.; Wilson, P.

    2015-01-01

    A Short-Baseline Neutrino (SBN) physics program of three LAr-TPC detectors located along the Booster Neutrino Beam (BNB) at Fermilab is presented. This new SBN Program will deliver a rich and compelling physics opportunity, including the ability to resolve a class of experimental anomalies in neutrino physics and to perform the most sensitive search to date for sterile neutrinos at the eV mass-scale through both appearance and disappearance oscillation channels. Using data sets of 6.6e20 protons on target (P.O.T.) in the LAr1-ND and ICARUS T600 detectors plus 13.2e20 P.O.T. in the MicroBooNE detector, we estimate that a search for muon neutrino to electron neutrino appearance can be performed with ~5 sigma sensitivity for the LSND allowed (99% C.L.) parameter region. In this proposal for the SBN Program, we describe the physics analysis, the conceptual design of the LAr1-ND detector, the design and refurbishment of the T600 detector, the necessary infrastructure required to execute the program, and a possible...

  15. Neutrino Luminosity and Matter-Induced Modification of Collective Neutrino Flavor Oscillations in Supernovae

    CERN Document Server

    Cherry, John F; Carlson, Joe; Duan, Huaiyu; Fuller, George M; Qian, Yong-Zhong

    2011-01-01

    We show that the bump in the electron number density profile at the base of the hydrogen envelope in O-Ne-Mg core-collapse supernovae causes an interesting interplay between neutrino-electron and neutrino-neutrino forward scattering effects in the flavor evolution of low-energy nu_e in the neutronization burst. The bump allows a significant fraction of the low-energy nu_e to survive by rendering their flavor evolution nonadiabatic. Increasing the luminosity of the neutronization burst shifts the bump-affected nu_e to lower energy with reduced survival probability. Similarly, lowering the luminosity shifts the bump-affected neutrinos to higher energies. While these low energy neutrinos lie near the edge of detectability, the population of bump-affected neutrinos has direct influence on the spectral swap formation in the neutrino signal at higher energies.

  16. Direct detection of Earth matter effects (MSW) in flavor oscillations at neutrino beams from stored muon decays

    CERN Document Server

    Bueno, A G; Rubbia, André

    2000-01-01

    We explore the possibility of a neutrino oscillation experiment with a very long baseline in the range of $6500\\ \\rm km$ and a neutrino beam produced by the decays of muons circulating in a storage ring. The recent developments in view of muon colliders allow us to envisage neutrino sources of a sufficiently high intensity. We first consider $\

  17. Results of a neutrino oscillation experiment performed at a meson factory beam-stop

    International Nuclear Information System (INIS)

    This document describes a neutrino oscillation experiment performed at the Los Alamos Meson Physics Facility. The oscillation mode searched for is /bar /nu///sub μ/ → /bar /nu///sub e/. The first chapter is a review of the known properties of the neutrino and a description of the phenomenon of neutrino oscillation. Previous experimental limits on this unobserved phenomenon are also given. The second chapter describes the experimental apparatus used by the E645 experiment to detect neutrinos produced in the LAMPF beam stop. The salient features of the detector are its large mass (20 tons of CH2), its fine segmentation (to allow good particle tracking), good energy resolution, its recording of the history both before and after tracks appear in the detector, an active cosmic-ray anticoincidence shield, and 2000 gm/cm2 of passive cosmic-ray shielding. It is located 26.8 m from the neutrino source, which has a mean neutrino energy of 40 MeV. The third chapter details the reduction of the 1.3 million event data sample to a 49 event sample of neutrino candidates. Principle backgrounds are Michel electrons from stopping cosmic-ray muons and protons from np elastic scattering by cosmic-ray neutrons. The fourth chapter explains how background levels from neutrino-nuclear scattering are predicted. The result of a maximum-likelihood analysis reveals no evidence for oscillation. 90% confidence levels are set at δm2 = .10 eV2 for large mixing and sin2(2θ) = .014 for large δm2. 82 refs., 18 figs., 55 tabs

  18. Parametric resonance in neutrino oscillation: A guide to control the effects of inhomogeneous matter density

    Science.gov (United States)

    Koike, Masafumi; Ota, Toshihiko; Saito, Masako; Sato, Joe

    2016-08-01

    Effects of the inhomogeneous matter density on the three-generation neutrino oscillation probability are analyzed. Realistic profile of the matter density is expanded into a Fourier series. Taking in the Fourier modes one by one, we demonstrate that each mode has its corresponding target energy. The high Fourier mode selectively modifies the oscillation probability of the low-energy region. This rule is well described by the parametric resonance between the neutrino oscillation and the matter effect. The Fourier analysis gives a simple guideline to systematically control the uncertainty of the oscillation probability caused by the uncertain density of matter. Precise analysis of the oscillation probability down to the low-energy region requires accurate evaluation of the Fourier coefficients of the matter density up to the corresponding high modes.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hannestad, Steen [Department of Physics and Astronomy,Aarhus University, 8000 Aarhus C (Denmark); Aarhus Institute of Advanced Studies,Aarhus University, 8000 Aarhus C (Denmark); Hansen, Rasmus Sloth [Department of Physics and Astronomy,Aarhus University, 8000 Aarhus C (Denmark); School of Physics, The University of New South Wales,Sydney NSW 2052 (Australia); Tram, Thomas [Institute of Cosmology and Gravitation, University of Portsmouth,Portsmouth PO1 3FX (United Kingdom); Wong, Yvonne Y.Y. [School of Physics, The University of New South Wales,Sydney NSW 2052 (Australia)

    2015-08-11

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

  20. Four-neutrino analysis of 1.5km-baseline reactor antineutrino oscillations

    CERN Document Server

    Kang, Sin Kyu; Ko, Young-Ju; Siyeon, Kim

    2014-01-01

    The masses of sterile neutrinos are not yet known, and depending on the orders of magnitudes, their existence may explain reactor anomalies or the spectral shape of reactor neutrino events at 1.5km-baseline detector. Here, we present four-neutrino analysis of the results announced by RENO and Daya Bay, which performed the definitive measurements of $\\theta_{13}$ based on the disappearance of reactor antineutrinos at km-order baselines. Our results using 3+1 scheme include the exclusion curve of $\\Delta m^2_{41}$ vs. $\\theta_{14}$ and the adjustment of $\\theta_{13}$ due to correlation with $\\theta_{14}$. The value of $\\theta_{13}$ obtained by RENO and Daya Bay with a three-neutrino oscillation analysis is included in the $1\\sigma$ interval of $\\theta_{13}$ allowed by our four-neutrino analysis.

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

    CERN Document Server

    Hannestad, Steen; Tram, Thomas; Wong, Yvonne Y Y

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-08-01

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

  3. Inner conductor of the magnetic double-horn for the neutrino oscillation experiment with BEBC

    CERN Multimedia

    1982-01-01

    In 1980 renewed interest arose in probing for neutrino non-zero masses and associated neutrino oscillations. Low-energy muon-neutrino beams (produced with a proton beam from the PS) were directed towards the SPS neutrino detectors, BEBC, WA1 and WA18 (Annual Report 1982, p.43, Fig.13). Experiments PS169 (WA1) and PS181 (WA18) were "disappearence" experiments and used a "bare" production target, whereas experiment PS180 (BEBC), looked for electron-neutrino "appearence" and used a horn-focused beam. The manufacture of the inner conductor of the double-horn (a particular breed of current-sheet lens) required exceedingly delicate machining. For further pictures see 8304055 and Annual Report 1982, p.137; and p.43 for a description of the experiments.

  4. CP Violation vs. Matter Effect in Long-Baseline Neutrino Oscillation Experiments

    CERN Document Server

    Minakata, H; Minakata, Hisakazu; Nunokawa, Hiroshi

    1997-01-01

    We investigate, within the framework of three generations of neutrinos, the effects of CP violation in long-baseline neutrino oscillation experiments. We aim at illuminating the global feature of the interplay between genuine effect due to the CP violating phase and a fake one due to the earth matter effect. To this goal, we develop a formalism based on the adiabatic approximation and perturbative treatment of the matter effect which allows us to obtain approximate analytic expressions of the oscillation probabilities. We present an order-of-magnitude estimation and a detailed numerical computation of the absolute and the relative magnitudes of the CP violations under the mass hierarchy suggested by the atmospheric neutrino anomaly and the cosmological dark matter. We find that the genuine CP violating effect is at most $\\sim$ 1%, and the matter effect dominates over the intrinsic CP violation only in a region of parameters where the oscillation probability of $\

  5. Matter Effects of Thin Layers Detecting Oil by Oscillations of Solar Neutrinos

    CERN Document Server

    Ioannisian, A N; Ioannisian, Ara N.; Smirnov, Alexei Yu.

    2002-01-01

    We consider a possibility to use the solar neutrinos for studies of small scale structures of the Earth and for geological research. Effects of thin layers of matter with density contrast on oscillations of Beryllium neutrinos inside the Earth are studied. We find that change of the $^7Be$ neutrino flux can reach 0.25 % for layers with density of oil and size $(10 - 100)$ km. Problems of detection are discussed. Hypothetical method would consist of measuring the $^7Be -$ flux by e.g. large deep underwater detector-submarine which could change its location.

  6. Neutrino Oscillations Experiments using Off-axis NuMI Beam

    CERN Document Server

    Para, A

    2001-01-01

    NuMI neutrino beam is constructed to aim at the MINOS detector in Soudan mine. Neutrinos emitted at angles $10-20 mrad$ with respect to the beam axis create an intense beam with a well defined energy, dependent on the angle. Additional surface detectors positioned at the transverse distance of several kilometers from the mine offer an opportunity for very precise mesurements of the neutrino oscillation parameters. The mixing matrix element $|U_{e3}|^{2}$ can be measured down to a value of 0.0025 with the exposure of the order of $20 kton\\times years$.

  7. Solar Neutrino Oscillation Parameters after SNO Phase-III and SAGE Part-III

    International Nuclear Information System (INIS)

    We analyse the recently published results from solar neutrino experiments SNO Phase-III and SAGE Part-III and show their constraints on solar neutrino oscillation parameters, especially for the mixing angle θ12. Through a global analysis using all existing data from SK, SNO, Ga and Cl radiochemical experiments and long base line reactor experiment KamLAND, we obtain the parameters shown. We also find that the discrepancy between the KamLAND and solar neutrino results can be reduced by choosing a small non-zero value for the mixing angle θ13. (the physics of elementary particles and fields)

  8. Neutrino mass and oscillation angle phenomena within the asymmetric left-right models

    International Nuclear Information System (INIS)

    The light and heavy Majorana neutrinos which appear naturally in SU(2)L x SU(2)R x U(1)B-L model are investigated. The exact solutions are presented for the system of two neutrinos with multipole moments propagating through magnetic and matter fields. The cross section of the reaction e-e-→ W-kW-n calculated and its dependence on the mass of the right-handed neutrino and the oscillation angle is investigated. The process e+e- → W+kW-n is also included in our analysis. (author). 26 refs, 9 figs

  9. The solar LMA neutrino oscillation solution in the Zee model

    CERN Document Server

    Balaji, K R S; Schwetz, T

    2001-01-01

    We examine the neutrino mass matrix in the version of Zee model where both Higgs doublets couple to the leptons. We show that in this case one can accommodate the large mixing angle (LMA) MSW solution of the solar neutrino problem, while avoiding maximal solar mixing and conflicts with constraints on lepton family number-violating interactions. In the simplified scenario we consider, we have the neutrino mass spectrum characterized by $m_1 \\simeq m_2 \\simeq \\sqrt{\\Delta m^2_\\mathrm{atm}}/\\sin 2\\theta$ and $m_3/m_1 \\simeq \\cos 2\\theta$, where $\\theta$ is the solar mixing angle.

  10. A short history of neutrinos, what we have learned about them, what we have learned using them, up to neutrino oscillations.”

    CERN Document Server

    CERN. Geneva

    2012-01-01

    This, the opening talk of the Kyoto conference, Neutrino 2012, attempts a brief review of the history of the neutrinos, up to neutrino oscillations, beginning with the discovery of the continuous β spectrum in 1914, to the demonstration of the tau neutrino in 2001, the contributions of the study of neutrino interactions to the evolution of the electroweak and the QCD theories, in particular the discovery of neutral currents, the demonstrations that the partons of nuclear structure are quarks, and the first quantitative confirmation of QCD in the scaling violations of deep inelastic scattering, and the structure functions of the nucleon.

  11. Running of Neutrino Oscillation Parameters in Matter with Flavor-Diagonal Non-Standard Interactions of the Neutrino

    CERN Document Server

    Agarwalla, Sanjib Kumar; Saha, Debashis; Takeuchi, Tatsu

    2015-01-01

    In this article we unravel the role of matter effect in neutrino oscillation in the presence of lepton-flavor-conserving, non-universal non-standard interactions (NSI's) of the neutrino. Employing the Jacobi method, we derive approximate analytical expressions for the effective mass-squared differences and mixing angles in matter. It is shown that, within the effective mixing matrix, the Standard Model (SM) W-exchange interaction only affects $\\theta_{12}$ and $\\theta_{13}$, while the flavor-diagonal NSI's only affect $\\theta_{23}$. The CP-violating phase $\\delta$ remains unaffected. Using our simple and compact analytical approximation, we study the impact of the flavor-diagonal NSI's on the neutrino oscillation probabilities for various appearance and disappearance channels. At higher energies and longer baselines, it is found that the impact of the NSI's can be significant in the numu to numu channel, which can probed in future atmospheric neutrino experiments, if the NSI's are of the order of their curren...

  12. A Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande

    OpenAIRE

    Group, Hyper-Kamiokande Working; :; Abe, K; Aihara, H.; Andreopoulos, C.; Anghel, I.; Ariga, A.; Ariga, T.(Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, 3012 , Bern, Switzerland); Asfandiyarov, R; Askins, M.; Back, J. J.; P. Ballett; Barbi, M.; Barker, G J; Barr, G.

    2014-01-01

    Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of $CP$ asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this document, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from ...

  13. Measurement of neutrino oscillation with KamLAND: Evidence of spectral distortion

    OpenAIRE

    Araki, T; Horton-Smith, G. A.; Mauger, C.; McKeown, R. D.; Vogel, P.

    2005-01-01

    We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 v_e candidate events with energies above 3.4 MeV compared to 365.2±23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8±7.3 expected background events, the statistical significance for reactor v_e over bar (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of ...

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

    Science.gov (United States)

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

    2016-05-01

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

  15. Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

    OpenAIRE

    Bay, Daya; Collaborations, MINOS+; :; Adamson, P.; An, F. P.; Anghel, I.(University of Illinois at Chicago (UIC), Chicago, U.S.A); Aurisano, A.; Balantekin, A. B.; Band, H R.; Barr, G.; Bishai, M.; Blake, A.; Bock, S. Blyth G. J.; Bogert, D.; Cao, D.

    2016-01-01

    Searches for a light sterile neutrino have been independently performed by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to pro...

  16. A measurement of hadron production cross sections for the simulation of accelerator neutrino beams and a search for muon-neutrino to electron-neutrino oscillations in the delta m**2 about equals 1-eV**2 region

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, David W.; /Columbia U.

    2008-01-01

    A measurement of hadron production cross-sections for the simulation of accelerator neutrino beams and a search for muon neutrino to electron neutrino oscillations in the {Delta}m{sup 2} {approx} 1 eV{sup 2} region. This dissertation presents measurements from two different high energy physics experiments with a very strong connection: the Hadron Production (HARP) experiment located at CERN in Geneva, Switzerland, and the Mini Booster Neutrino Experiment (Mini-BooNE) located at Fermilab in Batavia, Illinois.

  17. νΛMDM: A model for sterile neutrino and dark matter reconciles cosmological and neutrino oscillation data after BICEP2

    International Nuclear Information System (INIS)

    We propose an ultraviolet complete theory for cold dark matter (CDM) and sterile neutrinos that can accommodate both cosmological data and neutrino oscillation experiments within 1σ level. We assume a new U(1)X dark gauge symmetry which is broken at ∼O(MeV) scale resulting light dark photon. Such a light mediator for DM's self-scattering and scattering-off sterile neutrinos can resolve three controversies for cold DM on small cosmological scales: cusp vs. core, too-big-to-fail and missing satellites. We can also accommodate ∼O(1) eV scale sterile neutrinos as the hot dark matter (HDM) and can fit some neutrino anomalies from neutrino oscillation experiments within 1σ. Finally, the right amount of HDM can make a sizable contribution to dark radiation, and also helps to reconcile the tension between the data on the tensor-to-scalar ratio reported by Planck and BICEP2 Collaborations

  18. RENO: An Experiment for Neutrino Oscillation Parameter theta_13 Using Reactor Neutrinos at Yonggwang

    OpenAIRE

    RENO Collaboration; Ahn, J. K.

    2010-01-01

    The RENO experiment is a short baseline neutrino experiment in Korea aiming to measure the neutrino mixing angle theta_13 or set limit to sin^2(2 theta_13) less than 0.02. This document describes physics goals, experimental site, detector design, scintillator, electronics, calibration, simulation, and physics reach.

  19. On the degeneracies of the mass-squared differences for three-neutrino oscillations

    OpenAIRE

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

    2004-01-01

    Using an algebraic formulation, we explore two well-known degeneracies involving the mass-squared differences for three-neutrino oscillations assuming CP symmetry is conserved. For vacuum oscillation, we derive the expression for the mixing angles that permit invariance under the interchange of two mass-squared differences. This symmetry is most easily expressed in terms of an ascending mass order. This can be used to reduce the parameter space by one half in the absence of the MSW effect. Fo...

  20. First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background.

    Science.gov (United States)

    Follin, Brent; Knox, Lloyd; Millea, Marius; Pan, Zhen

    2015-08-28

    The unimpeded relativistic propagation of cosmological neutrinos prior to recombination of the baryon-photon plasma alters gravitational potentials and therefore the details of the time-dependent gravitational driving of acoustic oscillations. We report here a first detection of the resulting shifts in the temporal phase of the oscillations, which we infer from their signature in the cosmic microwave background temperature power spectrum. PMID:26371637

  1. Status and neutrino oscillation physics potential of the Hyper-Kamiokande Project in Japan

    Science.gov (United States)

    De Rosa, Gianfranca; Hyper-Kamiokande Protocollaboration

    2016-05-01

    Hyper-Kamiokande (Hyper-K), a proposed one-megaton water Cherenkov detector to be built in Japan, is the logical continuation of the highly successful program of neutrino (astro) physics and proton decay using the water Cherenkov technique. In its baseline design, the Hyper-K detector consists of two cylindrical tanks lying side-by-side, the outer dimensions of each tank being 48m × 54m × 250m. The inner detector region will be instrumented with 99,000 20-inch photo-sensors. An international proto-collaboration has been intensively working on the R&D of key components such as optimization of cavern, tank construction, development of high performance photo-sensors, design of new near detectors and improvements to the J-PARC neutrino beam. Hyper-K will study the CP asymmetry in neutrino oscillations using the neutrino and anti-neutrino beams produced at J-PARC. With an exposure of 7.5 MW × 107 seconds, CP violating parameter delta can be measured to better than 19 degrees at all values of delta, and CP violation can be detected with more than 3 sigma significance for 76% of the values. An overview of the status of project and the studies of the sensitivity of this detector to physics quantities governing neutrino oscillation is presented.

  2. Highlights from e-EPS: Neutrino Oscillation / DPG President / Outreach Database

    CERN Multimedia

    2012-01-01

    e-EPS News is a monthly addition to the CERN Bulletin line-up, showcasing articles from e-EPS – the European Physical Society newsletter – as part of a collaboration between the two publications.   Asian experiments unlock neutrino oscillation mystery Two reactor experiments, China’s Daya Bay and Korea’s RENO, have made the best measurement of the neutrino mixing angle, θ13, an essential property for neutrino research. The discovery of a non-zero θ13 at approximately 9˚ – which was published in March and April this year – completes our picture of neutrino mixing. This quite large value for the mixing angle will make it easier to conduct future long baseline neutrino experiments. This, in turn, may lead to a better understanding of the matter-antimatter asymmetry seen in the Universe. Neutrino oscillations – the change in flavour&a...

  3. Noncommutative spectral geometry, Bogoliubov transformations and neutrino oscillations

    CERN Document Server

    Gargiulo, Maria Vittoria; Vitiello, Giuseppe

    2015-01-01

    In this report we show that neutrino mixing is intrinsically contained in Connes' noncommutative spectral geometry construction, thanks to the introduction of the doubling of algebra, which is connected to the Bogoliubov transformation. It is known indeed that these transformations are responsible for the mixing, turning the mass vacuum state into the flavor vacuum state, in such a way that mass and flavor vacuum states are not unitary equivalent. There is thus a red thread that binds the doubling of algebra of Connes' model to the neutrino mixing.

  4. Noncommutative spectral geometry, Bogoliubov transformations and neutrino oscillations

    Science.gov (United States)

    Vittoria Gargiulo, Maria; Sakellariadou, Mairi; Vitiello, Giuseppe

    2015-07-01

    In this report we show that neutrino mixing is intrinsically contained in Connes’ noncommutatives pectral geometry construction, thanks to the introduction of the doubling of algebra, which is connected to the Bogoliubov transformation. It is known indeed that these transformations are responsible for the mixing, turning the mass vacuum state into the flavor vacuum state, in such a way that mass and flavor vacuum states are not unitary equivalent. There is thus a red thread that binds the doubling of algebra of Connes’ model to the neutrino mixing.

  5. Geometric gravitational origin of neutrino oscillations and mass-energy

    OpenAIRE

    Gonzalez-Martin, Gustavo R.

    2012-01-01

    A mass-energy scale for neutrinos was calculated from the null cone curvature using geometric concepts. The scale is variable depending on the gravitational potential and the trajectory inclination with respect to the field direction. The proposed neutrino covariant equation provides the adequate curvature. The mass-energy at the Earth surface varies from a horizontal value 0.402 eV to a vertical value 0.569 eV. Earth spinor waves with winding numbers n show squared energy differences within ...

  6. First Indication of Terrestrial Matter Effects on Solar Neutrino Oscillation

    OpenAIRE

    Renshaw, A.; Abe, K.; Hayato, Y.; Iyogi, K.; Kameda, J.; Kishimoto, Y.; Miura, M.; Moriyama, S.; Nakahata, M.(University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan); Nakano, Y.; Nakayama, S.; Sekiya, H.; Shiozawa, M; Suzuki, Y; TAKEDA, A

    2013-01-01

    We report an indication that the elastic scattering rate of solar $^8$B neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through the Earth during nighttime. We determine the day/night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be $(-3.2\\pm1.1(\\text{stat})\\pm0.5(\\text{syst}))\\%$, which deviates from zero by 2.7 $\\sigma$. Since the elastic scattering process is mostl...

  7. Constraints on Sterile Neutrino Oscillations using DUNE Near Detector

    CERN Document Server

    Choubey, Sandhya

    2016-01-01

    DUNE (Deep Underground Neutrino Experiment) is a proposed long-baseline neutrino experiment in the US with a baseline of 1300 km from Fermi National Accelerator Laboratory (Fermilab) to Sanford Underground Research Facility, which will house a 40 kt Liquid Argon Time Projection Chamber (LArTPC) as the far detector. The experiment will also have a fine grained near detector for accurately measuring the initial fluxes. We show that the energy range of the fluxes and baseline of the DUNE near detector is conducive for observing $\

  8. Some remarks on the Wolfenstein equation of neutrino oscillations in matter

    International Nuclear Information System (INIS)

    The Wolfenstein equation for neutrinos passing through matter is considered. Although from this equation one can obtain enhancement of neutrino oscillations in matter. In deriving the equation some physical requirements were not taken into account: 1. The Wolfenstein equation is left-right-side symmetric but not the equation with a left-side (the standard weak) interaction. 2. In this equation we must put only the terms which appear at the same distances, namely M2, W (i.e. their contributions must be combined). Taking into account these physical requirements results in this equation including a hypothetical interaction but not the weak one. Besides, this equation does not result in enhancement of neutrino oscillations in matter

  9. Vacuum oscillations and variations of solar neutrino rates in SuperKamiokande and Borexino

    CERN Document Server

    Faid, B; Lisi, E; Montanino, D

    1999-01-01

    The vacuum oscillation solution to the solar neutrino problem predicts characteristics variations of the observable neutrinos rates, as a result of the L/E_nu dependence of the nu_e survival probability (L and E_nu being the neutrino pathlength and energy, respectively). The E_nu-dependence can be studied through distortions of the recoil electron spectrum in the SuperKamiokande experiment. The L-dependence can be investigated through a Fourier analysis of the signal in the SuperKamiokande and Borexino experiments. We discuss in detail the interplay among such observable variations of the signal, and show how they can help to test and constrain the vacuum oscillation solution(s). The analysis includes the 374-day SuperKamiokande data.

  10. New initiatives on lepton flavor violation and neutrino oscillation with high intense muon and neutrino sources

    CERN Document Server

    Kuno, Yoshitaka; Pakvasa, Sandip

    2002-01-01

    The area of physics involving muons and neutrinos has become exciting in particle physics. Using their high intensity sources, physicists undertake, in various ways, extensive searches for new physics beyond the Standard Model, such as tests of supersymmetric grand unification (SUSY-GUT) and precision measurements of the muon and neutrino properties, which will in future extend to ambitious studies such as determination of the three-generation neutrino mixing matrix elements and CP violation in the lepton sector. The physics of this field is advancing, with potential improvements of the source

  11. Solar neutrino physics oscillations: Sensitivity to the electronic density in the Sun's core

    CERN Document Server

    Lopes, Ilídio; 10.1088/0004-637X/765/1/14

    2013-01-01

    Solar neutrinos coming from different nuclear reactions are now detected with a high statistics. Consequently, an accurate spectroscopic analysis of the neutrino fluxes arriving on the Earth's detectors become available, in the context of neutrino oscillations. In this work, we explore the possibility of using this information to infer the radial profile of the electronic density in the solar core. So, we discuss the constraints on the Sun's density and chemical composition that can be determined from solar neutrino observations. This approach constitutes an independent and alternative diagnostic to the helioseismic investigations already done. The direct inversion method, that we propose to get the radial solar electronic density profile, is almost independent of the solar model.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Sterile neutrinos are thermalised in the early Universe via oscillations with the active neutrinos for certain mixing parameters. The most detailed calculation of this thermalisation process involves the solution of the momentum-dependent quantum kinetic equations, which track the evolution of the...... neutrino phase space distributions. Until now the collision terms in the quantum kinetic equations have always been approximated using equilibrium distributions, but this approximation has never been checked numerically. In this work we revisit the sterile neutrino thermalisation calculation using the full...... via scattering and the importance of redistributing momentum through scattering, as well as details of Pauli blocking. Finally, we devise a new approximation scheme, which improves upon some of the shortcomings of previous schemes....

  13. The neutrino oscillation experiment in the reactor of Angra dos Reis

    International Nuclear Information System (INIS)

    The ANGRA project plans and status is presented, a new neutrino oscillation experiment in reactors, proposed to be assembled in Angra dos Reis nuclear complex. This experiment is intended to measure the angle θ13, the last of the three mixing angles in the neutrino sector even without a positive measure. This project proposes a multi-experiment with high sensitivity, able to achieve a sensitivity to detect anti-neutrinos disappearance of sin2 2θ13 = 0.006 in three years of operation, combining a high-brightness, low noise in cosmic rays and a careful control of systematic errors. It is planned to also explore the possibility of using the detection of neutrinos for the purpose of safeguards and non-proliferation of nuclear weapons.(author)

  14. Comparison of the CERN-MEMPHYS and T2HK neutrino oscillation experiments

    OpenAIRE

    Schwetz, Thomas

    2006-01-01

    In this talk I compare the physics potential of possible future neutrino oscillation experiments from CERN to a Mt scale water Cerenkov detector at Frejus (MEMPHYS) and of the T2HK proposal in Japan, where for the CERN experiments an SPL Superbeam and a $\\gamma=100$ Beta Beam are considered.

  15. Connecting Radiative Neutrino Mass, Neutron-Antineutron Oscillation, Proton Decay, and Leptogenesis through Dark Matter

    OpenAIRE

    Gu, Pei-Hong; Ma, Ernest; Sarkar, Utpal

    2016-01-01

    The scotogenic mechanism for radiative neutrino mass is generalized to include neutron-antineutron oscillation as well as proton decay. Dark matter is stabilized by extending the notion of lepton parity to matter parity. Leptogenesis is also a possible byproduct. This framework unifies the description of all these important, but seemingly unrelated, topics in physics beyond the standard model of particle interactions.

  16. Non-cyclic phases for neutrino oscillations in quantum field theory

    International Nuclear Information System (INIS)

    We show the presence of non-cyclic phases for oscillating neutrinos in the context of quantum field theory. Such phases carry information about the non-perturbative vacuum structure associated with the field mixing. By subtracting the condensate contribution of the flavor vacuum, the previously studied quantum mechanics geometric phase is recovered.

  17. Consequences of an Abelian $Z'$ for neutrino oscillations and dark matter

    CERN Document Server

    Plestid, Ryan

    2016-01-01

    The Standard Model's accidental and anomaly-free currents: $B-L$, $L_e-L_\\mu$, $L_e-L_\\tau$, and $L_\\mu-L_\\tau$, could be indicative of a hidden gauge structure beyond the Standard Model. Additionally, neutrino masses can be generated by a dimension-5 operator that generically breaks all of these symmetries. It is therefore important to investigate the compatibility of a gauged $U'(1)$ and neutrino phenomenology. We consider gauging each of the symmetries above with a minimal extended matter content. This includes the $Z'$, an order parameter to break the $U'(1)$, and three right-handed neutrinos. We find all but $B-L$ require additional matter content to explain the measured neutrino oscillation parameters. We also discuss the compatibility of the measured neutrino textures with a non-thermal dark matter production mechanism involving the decay of the $Z'$. Finally, we present a parametric relation that implies that a sterile neutrino dark matter candidate should not be expected to contribute to neutrino mas...

  18. Consequences of an Abelian Z' for neutrino oscillations and dark matter

    Science.gov (United States)

    Plestid, Ryan

    2016-02-01

    The Standard Model's accidental and anomaly-free currents, B -L , Le-Lμ, Le-Lτ, and Lμ-Lτ, could be indicative of a hidden gauge structure beyond the Standard Model. Additionally, neutrino masses can be generated by a dimension-5 operator that generically breaks all of these symmetries. It is therefore important to investigate the compatibility of a gauged U'(1 ) and neutrino phenomenology. We consider gauging each of the symmetries above with a minimal extended matter content. This includes the Z', an order parameter to break the U'(1 ), and three right-handed neutrinos. We find all but B -L require additional matter content to explain the measured neutrino oscillation parameters. We also discuss the compatibility of the measured neutrino textures with a nonthermal dark matter production mechanism involving the decay of the Z'. Finally, we present a parametric relation that implies that any sterile neutrino dark matter candidate should not be expected to contribute to neutrino masses beyond ten parts per million.

  19. Neutrino oscillation studies with laser-driven beam dump facilities

    CERN Document Server

    Bulanov, S V; Migliozzi, P; Pegoraro, F; Tajima, T; Terranova, F

    2004-01-01

    A new mechanism is suggested for efficient proton acceleration in the GeV energy range; applications to non-conventional high intensity proton drivers and, hence, to low-energy (10-200 MeV) neutrino sources are discussed. In particular we investigate possible uses to explore subdominant $\\bar{\

  20. Mass neutrino oscillations in Reissner-Nordstrom space-time

    Institute of Scientific and Technical Information of China (English)

    Huang Xiu-Ju; Wang Yong-Jiu

    2004-01-01

    Along the geodesic we calculate the interference phase of the mass neutrinos propagating in the radial direction in the Reissner-Nordstrom field. From the calculation we find that, though there exists electric charge in the gravitational source, the phase increases very little compared with that in the Schwarzschild field.

  1. A Long Baseline Neutrino Oscillation Experiment Using J-PARC Neutrino Beam and Hyper-Kamiokande

    CERN Document Server

    :,; Aihara, H; Andreopoulos, C; Anghel, I; Ariga, A; Ariga, T; Asfandiyarov, R; Askins, M; Back, J J; Ballett, P; Barbi, M; Barker, G J; Barr, G; Bay, F; Beltrame, P; Berardi, V; Bergevin, M; Berkman, S; Berry, T; Bhadra, S; Blaszczyk, F d M; Blondel, A; Bolognesi, S; Boyd, S B; Bravar, A; Bronner, C; Cafagna, F S; Carminati, G; Cartwright, S L; Catanesi, M G; Choi, K; Choi, J H; Collazuol, G; Cowan, G; Cremonesi, L; Davies, G; De Rosa, G; Densham, C; Detwiler, J; Dewhurst, D; Di Lodovico, F; Di Luise, S; Drapier, O; Emery, S; Ereditato, A; Fernandez, P; Feusels, T; Finch, A; Fitton, M; Friend, M; Fujii, Y; Fukuda, Y; Fukuda, D; Galymov, V; Ganezer, K; Gonin, M; Gumplinger, P; Hadley, D R; Haegel, L; Haesler, A; Haga, Y; Hartfiel, B; Hartz, M; Hayato, Y; Hierholzer, M; Hill, J; Himmel, A; Hirota, S; Horiuchi, S; Huang, K; Ichikawa, A K; Iijima, T; Ikeda, M; Imber, J; Inoue, K; Insler, J; Intonti, R A; Irvine, T; Ishida, T; Ishino, H; Ishitsuka, M; Itow, Y; Izmaylov, A; Jamieson, B; Jang, H I; Jiang, M; Joo, K K; Jung, C K; Kaboth, A; Kajita, T; Kameda, J; Karadhzov, Y; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kim, J Y; Kim, S B; Kishimoto, Y; Kobayashi, T; Koga, M; Konaka, A; Kormos, L L; Korzenev, A; Koshio, Y; Kropp, W R; Kudenko, Y; Kutter, T; Kuze, M; Labarga, L; Lagoda, J; Laveder, M; Lawe, M; Learned, J G; Lim, I T; Lindner, T; Longhin, A; Ludovici, L; Ma, W; Magaletti, L; Mahn, K; Malek, M; Mariani, C; Marti, L; Martin, J F; Martin, C; Martins, P P J; Mazzucato, E; McCauley, N; McFarland, K S; McGrew, C; Mezzetto, M; Minakata, H; Minamino, A; Mine, S; Mineev, O; Miura, M; Monroe, J; Mori, T; Moriyama, S; Mueller, T; Muheim, F; Nakahata, M; Nakamura, K; Nakaya, T; Nakayama, S; Needham, M; Nicholls, T; Nirkko, M; Nishimura, Y; Noah, E; Nowak, J; Nunokawa, H; O'Keeffe, H M; Okajima, Y; Okumura, K; Oser, S M; O'Sullivan, E; Owen, R A; Oyama, Y; Perez, J; Pac, M Y; Palladino, V; Palomino, J L; Paolone, V; Payne, D; Perevozchikov, O; Perkin, J D; Pistillo, C; Playfer, S; Posiadala-Zezula, M; Poutissou, J -M; Quilain, B; Quinto, M; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M; Redij, A; Retiere, F; Riccio, C; Richard, E; Rondio, E; Rose, H J; Ross-Lonergan, M; Rott, C; Rountree, S D; Rubbia, A; Sacco, R; Sakuda, M; Sanchez, M C; Scantamburlo, E; Scholberg, K; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Shaikhiev, A; Shimizu, I; Shiozawa, M; Short, S; Sinnis, G; Smy, M B; Sobczyk, J; Sobel, H W; Stewart, T; Stone, J L; Suda, Y; Suzuki, Y; Suzuki, A T; Svoboda, R; Tacik, R; Takeda, A; Taketa, A; Takeuchi, Y; Tanaka, H A; Tanaka, H K M; Tanaka, H; Terri, R; Thompson, L F; Thorpe, M; Tobayama, S; Tolich, N; Tomura, T; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vagins, M R; Vasseur, G; Vogelaar, R B; Walter, C W; Wark, D; Wascko, M O; Weber, A; Wendell, R; Wilkes, R J; Wilking, M J; Wilson, J R; Xin, T; Yamamoto, K; Yanagisawa, C; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Zito, M

    2014-01-01

    Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of $CP$ asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this document, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis has been updated from the previous Letter of Intent [K. Abe et al., arXiv:1109.3262 [hep-ex

  2. First results with the experimental set-up at a Bugey reactor: neutrino oscillations, search of axions

    International Nuclear Information System (INIS)

    This work presents an experimental set-up at the Bugey PWR reactor to put into evidence neutrino oscillations. The first part describes a neutrino detector specially designed for the investigation of neutrino oscillations at two distances (13.50 m and 19 m) under the core of the reactor. Preliminary analysis are presented. The second part reports a search for axions, using the neutrino detector well-shielded volume. Created in competition with electro magnetic transitions, axion should be produced in abondance in the reactor core. This experiment excludes the existence of the axion of the standard model

  3. Sterile neutrino oscillations in MINOS and hadron production in pC collisions

    Energy Technology Data Exchange (ETDEWEB)

    Tinti, Gemma Maria; /Oxford U.

    2010-07-01

    MINOS is a long baseline neutrino oscillation experiment, starting with a muon-neutrino beam, for the precise measurement of the atmospheric neutrino oscillation parameters |{Delta}m{sup 2}| and {theta}{sub 23}. The Near Detector measures the neutrino flux and spectra before oscillations. The beam propagates for 735 km to the Far Detector, which measures the depleted spectrum after oscillations. The depletion can be interpreted as {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillations. Subdominant {nu}{sub {mu}} {yields} {nu}{sub e} oscillations may be allowed if the mixing angle {theta}{sub 13} {ne} 0. The two detectors are functionally identical in order to cancel systematic errors when using the Near Detector data to constrain the Far Detector prediction. A crucial part of the analysis is the relative calibration between the two detectors, which is known at the 2% level. A calibration procedure to remove the time and temperature dependence of the detector response using through-going cosmic muons is presented here. Although the two-detector approach reduces the systematic uncertainties related to the neutrino flux, a cross check on the neutrino parent meson ratios is performed in this thesis. The cross sections of mesons produced in proton-carbon interactions from the NA49 experiment have been measured and the results have been compared to the MINOS expectations. A neutrino oscillation analysis allowing mixing to a sterile neutrino is performed, under the assumption that the additional mass splitting is {Omicron}(1 eV{sup 2}). The analysis uses the energy spectrum of the neutral current interaction products, as neutral current interactions are sensitive to sterile neutrino mixing but not to the active flavour neutrino mixing. The neutrino oscillation parameters have been found to be: |{Delta}m{sup 2}| = 2.43{sub -0.18}{sup +0.21} x 10{sup -3} eV{sup 2}, {theta}{sub 23} = 40.27{sup o}{sub -5.17}{sup +14.64}, {theta}{sub 24} = 0.00{sup o}{sup +5.99} and {theta

  4. Long baseline neutrino oscillation experiment at the AGS. Physics design report

    Energy Technology Data Exchange (ETDEWEB)

    Beavis, D.; Carroll, A.; Chiang, I. [Brookhaven National Lab., Long Island, NY (United States); E889 Collaboration

    1995-04-01

    The authors present a design for a multi-detector long baseline neutrino oscillation experiment at the BNL AGS. It has been approved by the BNL-HENP-PAC as AGS Experiment 889. The experiment will search for oscillations in the {nu}{sub {mu}}, disappearance channel and the {nu}{sub {mu}} {leftrightarrow} {nu}{sub e} appearance channel by means of four identical neutrino detectors located 1, 3, 24, and 68km from the AGS neutrino source. Observed depletion of the {nu}{sub {mu}} flux (via quasi-elastic muon neutrino events, {nu}{sub {mu}}n {yields} {mu}{sup {minus}}p) in the far detectors not attended by an observed proportional increase of the {nu}{sub e} flux (via quasi-elastic electron neutrino events, {nu}{sub e}n {yields} e{sup {minus}}p) in those detectors will be prima facie evidence for the oscillation channel {nu}{sub {mu}} {leftrightarrow} {nu}{sub {tau}}. The experiment is directed toward exploration of the region of the neutrino oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}, suggested by the Kamiokande and IMB deep underground detectors but it will also explore a region more than two orders of magnitude larger than that of previous accelerator experiments. The experiment will run in a mode new to BNL. It will receive the fast extracted proton beam on the neutrino target approximately 20 hours per day when the AGS is not filling RHIC. A key aspect of the experimental design involves placing the detectors 1.5 degrees off the center line of the neutrino beam, which has the important advantage that the central value of the neutrino energy ({approx} 1 GeV) and the beam spectral shape are, to a good approximation, the same in all four detectors. The proposed detectors are massive, imaging, water Cherenkov detectors similar in large part to the Kamiokande and IMB detectors. The design has profited from their decade-long experience, and from the detector designs of the forthcoming SNO and SuperKamiokande detectors.

  5. PeP-neutrino Detection by Lithium Detector as a Direct Way to Search for Oscillation of Solar Neutrinos

    CERN Document Server

    Kopylov, A V

    2000-01-01

    The high sensitivity of lithium detector to pep- and Be7-neutrinos makes a lithium radiochemical detector a powerful tool for the search of the oscillations of solar neutrinos. The first phase of lithium experiment on the installation with 10 tons of metallic lithium will enable to collect data within 1 year of measurements to provide very definite information about SMA MSW solution. the second phase with 10 modules 10 tons each will measure the semiannual variations of the signal, thus the contributions of pep- and Be7-lines will be weighted, what will give a "smoking-gun" evidence about "just-so" solution for large mixing angles and delta-m2 about 10-10 - 10-9 eV2. If both regions are not confirmed the results of lithium detector can be interpreted in favor of LMA MSW solution.

  6. A quantum-information theoretic analysis of three-flavor neutrino oscillations. Quantum entanglement, nonlocal and nonclassical features of neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Subhashish; Alok, Ashutosh Kumar [Indian Institute of Technology Jodhpur, Jodhpur (India); Srikanth, R. [Poornaprajna Institute of Scientific Research, Banglore (India); Hiesmayr, Beatrix C. [University of Vienna, Vienna (Austria)

    2015-10-15

    Correlations exhibited by neutrino oscillations are studied via quantum-information theoretic quantities. We show that the strongest type of entanglement, genuine multipartite entanglement, is persistent in the flavor changing states. We prove the existence of Bell-type nonlocal features, in both its absolute and genuine avatars. Finally, we show that a measure of nonclassicality, dissension, which is a generalization of quantum discord to the tripartite case, is nonzero for almost the entire range of time in the evolution of an initial electron-neutrino. Via these quantum-information theoretic quantities, capturing different aspects of quantum correlations, we elucidate the differences between the flavor types, shedding light on the quantum-information theoretic aspects of the weak force. (orig.)

  7. Neutrino Spin Oscillations in a Black Hole Background in Noncommutative Spaces

    CERN Document Server

    Alavi, S A

    2013-01-01

    We study neutrino spin oscillations in a black hole background in noncommutative spaces. In the case of a charged black hole, the maximum frequency of oscillation is a monotonically increasing function of the noncommutativity parameter. For a neutral black hole the maximum frequency decreases with increasing the noncommutativity parameter. In both cases, the frequency of spin oscillations decreases as the distance from the black hole grows. It is shown that the lower bound of the square root of the noncommutativity parameter is 0.5 l_{p}. We present an astrophysical application of our results.

  8. Search for neutrino oscillations in the MINOS experiment by using quasi-elastic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Piteira, Rodolphe; /Paris U., VI-VII

    2005-09-01

    The enthusiasm of the scientific community for studying oscillations of neutrinos is equaled only by the mass of their detectors. The MINOS experiment determines and compares the near spectrum of muonic neutrinos from the NUMI beam to the far one, in order to measure two oscillation parameters: {Delta}m{sub 23}{sup 2} and sin{sup 2} (2{theta}{sub 23}). The spectra are obtained by analyzing the charged current interactions which difficulty lies in identifying the interactions products (e.g. muons). An alternative method identifying the traces of muons, bent by the magnetic field of the detectors, and determining their energies is presented in this manuscript. The sensitivity of the detectors is optimal for the quasi-elastic interactions, for which a selection method is proposed, to study their oscillation. Even though it reduces the statistics, such a study introduces fewer systematic errors, constituting the ideal method on the long range.

  9. Analytical Approximation of the Neutrino Oscillation Probabilities at large \\theta_{13}

    CERN Document Server

    Agarwalla, Sanjib Kumar; Takeuchi, Tatsu

    2014-01-01

    We present a simple analytical approximation to the neutrino oscillation probabilities in matter. The moderately large value of \\theta_{13}, recently discovered by the reactor experiments Daya Bay and RENO, limits the ranges of applicability of previous analytical approximations which relied on expanding in \\sin\\theta_{13}. In contrast, our approximation, which is applicable to all oscillations channels at all energies and baselines, works well for large \\theta_{13}. We demonstrate the accuracy of our approximation by comparing it to the exact numerical result, as well as the approximations of Cervera et al. and Asano and Minakata. We also discuss the utility of our approach in figuring out the required baseline lengths and neutrino energies for the oscillation probabilities to exhibit certain desirable features.

  10. Simulations study of neutrino oscillation parameters with the Iron Calorimeter Detector (ICAL): an improved analysis

    CERN Document Server

    Mohan, Lakshmi S

    2016-01-01

    We present an updated and improved simulations analysis of precision measurements of neutrino oscillation parameters from the study of charged-current interactions of atmospheric neutrinos in the Iron Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO). The present analysis is done in the extended muon energy range of 0.5--25 GeV, as compared to the previous analyses which were limited to the range 1--11 GeV of muon energy. A substantial improvement in the precision measurement of the oscillation parameters in the 2--3 sector, including the magnitude and sign of the 2--3 mass-squared difference $\\Delta{m^2_{32}}$ and especially $\\theta_{23}$ is observed. The sensitivities are further improved by the inclusion of additional systematics which constrains the ratio of neutrino to anti-neutrino fluxes. The best $1\\sigma$ precision on $\\sin^2 \\theta_{23}$ and $|\\Delta{m^2_{32}}|$ achievable with the new analysis for 500 kTon yr exposure of ICAL are $\\sim9\\%$ and $\\sim2.5\\%$ respective...

  11. The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines

    CERN Document Server

    :,; Agostino, L; Aittola, M; Alekou, A; Andrieu, B; Antoniou, F; Asfandiyarov, R; Autiero, D; Bésida, O; Balik, A; Ballett, P; Bandac, I; Banerjee, D; Bartmann, W; Bay, F; Biskup, B; Blebea-Apostu, A M; Blondel, A; Bogomilov, M; Bolognesi, S; Borriello, E; Brancus, I; Bravar, A; Buizza-Avanzini, M; Caiulo, D; Calin, M; Calviani, M; Campanelli, M; Cantini, C; Cata-Danil, G; Chakraborty, S; Charitonidis, N; Chaussard, L; Chesneanu, D; Chipesiu, F; Crivelli, P; Dawson, J; De Bonis, I; Declais, Y; Sanchez, P Del Amo; Delbart, A; Di Luise, S; Duchesneau, D; Dumarchez, J; Efthymiopoulos, I; Eliseev, A; Emery, S; Enqvist, T; Enqvist, K; Epprecht, L; Erykalov, A N; Esanu, T; Franco, D; Friend, M; Galymov, V; Gavrilov, G; Gendotti, A; Giganti, C; Gilardoni, S; Goddard, B; Gomoiu, C M; Gornushkin, Y A; Gorodetzky, P; Haesler, A; Hasegawa, T; Horikawa, S; Huitu, K; Izmaylov, A; Jipa, A; Kainulainen, K; Karadzhov, Y; Khabibullin, M; Khotjantsev, A; Kopylov, A N; Korzenev, A; Kosyanenko, S; Kryn, D; Kudenko, Y; Kuusiniemi, P; Lazanu, I; Lazaridis, C; Levy, J -M; Loo, K; Maalampi, J; Margineanu, R M; Marteau, J; Martin-Mari, C; Matveev, V; Mazzucato, E; Mefodiev, A; Mineev, O; Mirizzi, A; Mitrica, B; Murphy, S; Nakadaira, T; Narita, S; Nesterenko, D A; Nguyen, K; Nikolics, K; Noah, E; Novikov, Yu; Oprima, A; Osborne, J; Ovsyannikova, T; Papaphilippou, Y; Pascoli, S; Patzak, T; Pectu, M; Pennacchio, E; Periale, L; Pessard, H; Popov, B; Ravonel, M; Rayner, M; Resnati, F; Ristea, O; Robert, A; Rubbia, A; Rummukainen, K; Saftoiu, A; Sakashita, K; Sanchez-Galan, F; Sarkamo, J; Saviano, N; Scantamburlo, E; Sergiampietri, F; Sgalaberna, D; Shaposhnikova, E; Slupecki, M; Smargianaki, D; Stanca, D; Steerenberg, R; Sterian, A R; Sterian, P; Stoica, S; Strabel, C; Suhonen, J; Suvorov, V; Toma, G; Tonazzo, A; Trzaska, W H; Tsenov, R; Tuominen, K; Valram, M; Vankova-Kirilova, G; Vannucci, F; Vasseur, G; Velotti, F; Velten, P; Venturi, V; Viant, T; Vihonen, S; Vincke, H; Vorobyev, A; Weber, A; Wu, S; Yershov, N; Zambelli, L; Zito, M

    2014-01-01

    The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of $\\sim 20$ kton liquid double phase TPC complemented by a magnetised iron calorimeter, to be installed at the Pyh\\"asalmi mine, at a distance of 2300 km from CERN. The conventional neutrino beam is produced by 400 GeV protons accelerated at the SPS accelerator delivering 700 kW of power. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the $L/E$ behaviour, and distinguishing effects arising from $\\delta_{CP}$ and matter. In this paper we show how this comprehensive physics case can be further enhanced and complemented if a neutrino beam produced at the Protvino IHEP accelerator complex, at a distance of 1160 km, and with modest power of 450 kW is aimed towards the same far detectors. We show that the coupling of two independent sub-MW conventional neutrino and antineutrino beams at different baselines from CERN and Protvino will allow to measure ...

  12. Implications of Neutrino Oscillations on the Dark-Matter World

    International Nuclear Information System (INIS)

    According to my own belief that “The God wouldn't create a world that is so boring that a particle knows only the very feeble weak interaction.”, maybe we underestimate the roles of neutrinos. We note that right-handed neutrinos play no roles, or don't exist, in the minimal Standard Model. We discuss the language to write down an extended Standard Model - using renormalizable quantum field theory as the language; to start with a certain set of basic units under a certain gauge group; in fact, to use the three right-handed neutrinos to initiate the family gauge group SUf(3). Specifically we use the left-handed and right-handed spinors to form the basic units together with SUc(3)×SUL(2)×U(1)×SUf(3) as the gauge group. The dark-matter SUf(3) world couples with the lepton world, but not with the quark world. Amazingly enough, the space of the Standard-Model Higgs Φ(1,2), the family Higgs triplet Φ(3, 1), and the neutral part of the mixed family Higgs Φ0(3,2) undergoes the spontaneous symmetry breaking, i.e. the Standard-Model Higgs mechanism and the “project-out” family Higgs mechanism, to give rise to the weak bosons W± and Z0, one Standard-Model Higgs, the eight massive family gauge bosons, and the remaining four massive neutral family Higgs particles, and nothing more. Thus, the roles of neutrinos in this extended Standard Model are extremely interesting in connection with the dark-matter world

  13. Proposed TRV Measurement via L-nL Neutrino Oscillations

    CERN Document Server

    Kisslinger, Leonard S; Johnson, Mikkel B

    2011-01-01

    This is an extension of the L-2L experiment for measurement of time reversal violation (TRV) proposed in a recent publication. The main new aspects are taking into account the curvature of the earth's surface for long baseline neutrino beams, and recognizing that the matter effects disappear when the baseline is extended. A slight modification of the MINOS project, with a new detector at 2L, is proposed.

  14. Implications of Neutrino Oscillations on the Dark-Matter World

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, W-Y. Pauchy, E-mail: wyhwang@phys.ntu.edu.tw

    2014-01-15

    According to my own belief that “The God wouldn't create a world that is so boring that a particle knows only the very feeble weak interaction.”, maybe we underestimate the roles of neutrinos. We note that right-handed neutrinos play no roles, or don't exist, in the minimal Standard Model. We discuss the language to write down an extended Standard Model - using renormalizable quantum field theory as the language; to start with a certain set of basic units under a certain gauge group; in fact, to use the three right-handed neutrinos to initiate the family gauge group SU{sub f}(3). Specifically we use the left-handed and right-handed spinors to form the basic units together with SU{sub c}(3)×SU{sub L}(2)×U(1)×SU{sub f}(3) as the gauge group. The dark-matter SU{sub f}(3) world couples with the lepton world, but not with the quark world. Amazingly enough, the space of the Standard-Model Higgs Φ(1,2), the family Higgs triplet Φ(3, 1), and the neutral part of the mixed family Higgs Φ{sup 0}(3,2) undergoes the spontaneous symmetry breaking, i.e. the Standard-Model Higgs mechanism and the “project-out” family Higgs mechanism, to give rise to the weak bosons W{sup ±} and Z{sup 0}, one Standard-Model Higgs, the eight massive family gauge bosons, and the remaining four massive neutral family Higgs particles, and nothing more. Thus, the roles of neutrinos in this extended Standard Model are extremely interesting in connection with the dark-matter world.

  15. Implications of Neutrino Oscillations on the Dark-Matter World

    Science.gov (United States)

    Hwang, W.-Y. Pauchy

    2014-01-01

    According to my own belief that "The God wouldn't create a world that is so boring that a particle knows only the very feeble weak interaction.", maybe we underestimate the roles of neutrinos. We note that right-handed neutrinos play no roles, or don't exist, in the minimal Standard Model. We discuss the language to write down an extended Standard Model - using renormalizable quantum field theory as the language; to start with a certain set of basic units under a certain gauge group; in fact, to use the three right-handed neutrinos to initiate the family gauge group SUf (3). Specifically we use the left-handed and right-handed spinors to form the basic units together with SUc (3) × SUL (2) × U (1) × SUf (3) as the gauge group. The dark-matter SUf (3) world couples with the lepton world, but not with the quark world. Amazingly enough, the space of the Standard-Model Higgs Φ (1 , 2), the family Higgs triplet Φ(3, 1), and the neutral part of the mixed family Higgs Φ0 (3 , 2) undergoes the spontaneous symmetry breaking, i.e. the Standard-Model Higgs mechanism and the "project-out" family Higgs mechanism, to give rise to the weak bosons W± and Z0, one Standard-Model Higgs, the eight massive family gauge bosons, and the remaining four massive neutral family Higgs particles, and nothing more. Thus, the roles of neutrinos in this extended Standard Model are extremely interesting in connection with the dark-matter world.

  16. Slow control systems of the Reactor Experiment for Neutrino Oscillation

    Science.gov (United States)

    Choi, J. H.; Jang, H. I.; Choi, W. Q.; Choi, Y.; Jang, J. S.; Jeon, E. J.; Joo, K. K.; Kim, B. R.; Kim, H. S.; Kim, J. Y.; Kim, S. B.; Kim, S. Y.; Kim, W.; Kim, Y. D.; Ko, Y. J.; Lee, J. K.; Lim, I. T.; Pac, M. Y.; Park, I. G.; Park, J. S.; Park, R. G.; Seo, H. K.; Seo, S. H.; Shin, C. D.; Siyeon, K.; Yeo, I. S.; Yu, I.

    2016-02-01

    The RENO experiment has been in operation since August 2011 to measure reactor antineutrino disappearance using identical near and far detectors. For accurate measurements of neutrino mixing parameters and efficient data taking, it is crucial to monitor and control the detector in real time. Environmental conditions also need to be monitored for stable operation of detectors as well as for safety reasons. In this paper, we report the design, hardware, operation, and performance of the slow control system.

  17. Mass neutrino oscillations in Robertson-Walker space-time

    Institute of Scientific and Technical Information of China (English)

    Huang Xiu-Ju; Li Ze-Jun; Wang Yong-Jiu

    2006-01-01

    Along the geodesic we calculate the interference phase of the mass neutrinos propagating in the radial direction in Robertson-Walker space-time. Since our universe is expanding, the phase factor Φ is increasing under the condition of the same proper physical distance l. Different values of curvature parameter k in Robertson-Walker metric represent different cosmological models, correspondingly, we obtain the different interference phases.

  18. High-power Kerr-lens mode-locked thin-disk oscillator in the anomalous and normal dispersion regimes

    Science.gov (United States)

    Pronin, Oleg; Brons, Jonathan; Seidel, Marcus; Lücking, Fabian; Grasse, Christian; Boehm, Gerhard; Amann, Marcus C.; Pervak, Vladimir; Apolonski, Alexander; Kalashnikov, Vladimir L.; Krausz, Ferenc

    2013-03-01

    A femtosecond thin-disk Yb:YAG oscillator in both the anomalous and the normal dispersion regime is demonstrated. Both regimes are realized with practically the same resonator configuration. The power scaling potential of the anomalous and normal dispersion regimes is analyzed both theoretically and experimentally. The recipe to obtain Kerr-lens mode-locking (KLM) in the thin-disk configuration is presented here and oscillator characteristics as well as start-up difficulties are described. The oscillator stability in terms of output power, beam pointing and sensitivity to back reflections is measured and corresponds to the level of commercial systems.

  19. Matter neutrino oscillations, an approximation in a parametrization-free framework

    CERN Document Server

    Flores, L J

    2016-01-01

    Neutrino oscillations are one of the most studied and successful phenomena since the establishment of the solar neutrino problem in late 1960's. In this work we discuss the exact expressions for the probability P_{\\alpha\\beta} in a constant density medium, in terms of the standard vacuum parameters and the medium density. Besides of being compact, these expressions are independent of any particular parametrization, which could be helpful in the application of unitary tests of the mixing matrix. In addition, we introduce a new approximation on P_{\\alpha\\beta} and compare it with the most commonly used, discussing their main differences.

  20. Top squark and neutralino decays in a -parity violating model constrained by neutrino oscillation data

    Indian Academy of Sciences (India)

    Sujoy Poddar

    2007-11-01

    In a -parity violating (RPV) model of neutrino mass with three bilinear couplings and three trilinear couplings ′33, where is the lepton index, we find six generic scenarios each with a distinctive pattern of the trilinear couplings consistent with the neutrino oscillation data. These patterns may be reflected in direct RPV decays of the lighter top squark or in the RPV decays of the lightest superparticle, assumed to be the lightest neutralino. Typical signal sizes at the Tevatron RUN II and the LHC have been estimated and the results turn out to be encouraging.

  1. Neutrino Scattering Uncertainties and their Role in Long Baseline Oscillation Experiments

    International Nuclear Information System (INIS)

    The field of oscillation physics is about to make an enormous leap forward in statistical precision: first through the MINOS experiment in the coming year, and later through the NOvA and T2K experiments. Because of the relatively poor understanding of neutrino interactions in the energy ranges of these experiments, there are systematics that can arise in interpreting far detector data that can be as large as or even larger than the expected statistical uncertainties. We describe how these systematic errors arise, and how specific measurements in a dedicated neutrino scattering experiment like MINERvA can reduce the cross section systematic errors to well below the statistical errors

  2. Theoretical constraints on the vacuum oscillation solution to the solar neutrino problem

    OpenAIRE

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

    1999-01-01

    The vacuum oscillation (VO) solution to the solar anomaly requires an extremely small neutrino mass splitting, Delta m^2_{sol}\\leq 10^{-10} eV^2. We study under which circumstances this small splitting (whatever its origin) is or is not spoiled by radiative corrections. The results depend dramatically on the type of neutrino spectrum. If m_1^2 \\sim m_2^2 \\geq m_3^2, radiative corrections always induce too large mass splittings. Moreover, if m_1 and m_2 have equal signs, the solar mixing angle...

  3. Neutrino Scattering Uncertainties and their Role in Long Baseline Oscillation Experiments

    Energy Technology Data Exchange (ETDEWEB)

    D.A. Harris; G. Blazey; Arie Bodek; D. Boehnlein; S. Boyd; William Brooks; Antje Bruell; Howard S. Budd; R. Burnstein; D. Casper; A. Chakravorty; Michael Christy; Jesse Chvojka; M.A.C. Cummings; P. deBarbaro; D. Drakoulakos; J. Dunmore; Rolf Ent; Hugh Gallagher; David Gaskell; Ronald Gilman; Charles Glashausser; Wendy Hinton; Xiaodong Jiang; T. Kafka; O. Kamaev; Cynthia Keppel; M. Kostin; Sergey Kulagin; Gerfried Kumbartzki; Steven Manly; W.A. Mann; Kevin Mcfarland-porter; Wolodymyr Melnitchouk; Jorge Morfin; D. Naples; John Nelson; Gabriel Niculescu; Maria-ioana Niculescu; W. Oliver; Michael Paolone; Emmanuel Paschos; A. Pla-Dalmau; Ronald Ransome; C. Regis; P. Rubinov; V. Rykalin; Willis Sakumoto; P. Shanahan; N. Solomey; P. Spentzouris; P. Stamoulis; G. Tzanakos; Stephen Wood; F.X. Yumiceva; B. Ziemer; M. Zois

    2004-10-01

    The field of oscillation physics is about to make an enormous leap forward in statistical precision: first through the MINOS experiment in the coming year, and later through the NOvA and T2K experiments. Because of the relatively poor understanding of neutrino interactions in the energy ranges of these experiments, there are systematics that can arise in interpreting far detector data that can be as large as or even larger than the expected statistical uncertainties. We describe how these systematic errors arise, and how specific measurements in a dedicated neutrino scattering experiment like MINERvA can reduce the cross section systematic errors to well below the statistical errors.

  4. Preparation of the experiment (antiνsub(e)d) at Bugey: research of neutrino oscillations

    International Nuclear Information System (INIS)

    The electronic anti-neutrino on deuterons reaction is a possible way to observe neutrino oscillations, and an indication for their existence has been obtained by a group of the Irvine University with a nuclear reactor. A new experimental project at Bugey PWR reactor, using the (antiνsub(e)d) reaction, is presented in this report. The architecture of the shielding and the constitution of the detector have been settled with transport neutronic codes. To obtain accurate estimations on the measurable quantities and the sensitiveness of this experiment, we have made detailed calculations of the (antiνsub(e)d) reaction cross-sections (neutral current, charged current)

  5. Recent results from the K2.neutrino oscillation experiment

    CERN Document Server

    Sakuda, M

    2001-01-01

    We report the latest results of the oscillation search in the nu /sub mu / disappearance mode from data taken from June, 1999, to June, 2000, with the K2K experiment. We observed 27 fully-contained events in the 22.5 kton fiducial volume of Super-Kamiokande (SK), while the corresponding expected number of events is estimated to be 40.3/sub -4.6//sup +4.7/ in the case of no oscillations.

  6. Acceleration and propagation of cosmic radiation. Production, oscillation and detection of neutrinos

    International Nuclear Information System (INIS)

    In recent years, the old problem of cosmic-ray acceleration and propagation has become alive again, with the discovery of the diffusive shock acceleration mechanism, and with the first measurements of the cosmic-ray antiproton flux, which appears to be higher than expected. I have shown that the new acceleration mechanism was slow and I have calculated the maximum energy that can be reached by particles accelerated in various astrophysical sites. I have also studied in detail a cosmic-ray propagation model which takes into account the antiproton measurements. Neutrino astronomy is a field much more recent and in rapid expansion, thanks to a convergence of interests between astrophysicists and elementary particle physicists. Several large neutrino detectors already exist; really huge ones are in project. I have studied the possible impact of the high energy (> 1 TeV) neutrino astronomy on models of cosmic-ray sources such as Cygnus X3. Comparing the low energy (∼ 10 MeV) cosmic-ray antineutrinos with other sources of neutrinos and antineutrinos (sun, supernova, earth...), I have pointed out that the antineutrino background resulting from all the nuclear power-stations of the planet was sizeable. This background is a nuisance for some astrophysical applications but could be useful for studies on vacuum or matter neutrino oscillations (MSW effect). I have also examined the MSW effect in another context: the travel through the earth of neutrinos from the supernova explosion SN1987a

  7. Reconciling Super-Kamiokande, LSND and Homestake neutrino-oscillation data

    CERN Document Server

    Ahluwalia, D V

    1998-01-01

    The L/E-flatness of the e-like events observed in the recent atmospheric-neutrino data from Super-Kamiokande (SuperK) is interpreted to reflect a new symmetry of the neutrino-oscillation mixing matrix. From that we obtain an analytical set of constraints yielding a class of mixing matrices of the property to simultaneously fit both the SuperK and the LSND data. The resulting mass squared difference relevant for the LSND experiment is found as 0.3 eV^2. These considerations are purely data dictated. A different framework is then applied to the solar neutrino problem. The considerations on solar neutrino deficit reflect on the one hand the emerging experimental situation, and on the other our reluctance, to invoke a flavor-neutral (i.e. sterile) neutrino, or to discard one of the experiments . A scenario is considered, which, if realized, will force upon us a violation of the CPT symmetry. It will in addition favor the electron neutrino-antineutrino system to belong to the `self'-`anti-self' charge conjugate co...

  8. Very long baseline neutrino oscillation experiments for precise measurments of oscillation parameters and search for n Mu yields n epsilon.

    CERN Document Server

    Diwan, M; Brennan, M; Chen, M C; Fernow, R; Marciano, W; Weng, W

    2002-01-01

    Brookhaven National Laboratory and collaborators started a neutrino working group to identify new opportunities in the field of neutrino oscillations and explore how our laboratory facilities can be used to explore this field of research. The memo to the working group and the charge are included in Appendix I. This report is the result of the deliberations of the working group. Previously, we wrote a letter of intent to build a new high intensity neutrino beam at BNL. A new intense proton beam will be used to produce a conventional horn focused neutrino beam directed at a detector located in either the Homestake mine in Lead, South Dakota at 2540 km or the Waste Isolation Pilot Plant (WIPP) in Carlsbad, NM at 2880 km. As a continuation of the study that produced the letter of intent, this report examines several items in more detail. We mainly concentrate on the use of water Cherenltov detectors because of their size, resolution, and background rejection capability, and cost. We examine the prospects of build...

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

    Energy Technology Data Exchange (ETDEWEB)

    Pawloski, Gregory [Univ. of Minnesota, Minneapolis, MN (United States)

    2014-06-30

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

  10. The History of "Anomalous" Atmospheric Neutrino Events: A First Person Account

    Science.gov (United States)

    LoSecco, John M.

    2016-07-01

    The modern picture of the neutrino as a multiple-mass, highly mixed neutral particle has emerged over forty years of study. Best known of the issues leading to this picture was the apparent loss of neutrinos coming from the sun. This article describes another piece of evidence that supports the picture; the substantial reduction of high-energy muon-type neutrinos observed in nature. For much of the forty-year period before the modern picture emerged, this observation was known as the "atmospheric neutrino anomaly," since these neutrinos originate in the Earth's atmosphere. This paper describes the discovery of the atmospheric neutrino anomaly. I explore the scientific context and motivations in the late 1970s, from which this work emerged. The gradual awareness that the observations of atmospheric neutrinos were not as expected took place in the 1983-1986 period.

  11. Missing energy and the measurement of the CP-violating phase in neutrino oscillations

    CERN Document Server

    Ankowski, Artur M; Huber, Patrick; Mariani, Camillo; Vagnoni, Erica

    2015-01-01

    In the next generation of long-baseline neutrino oscillation experiments, aiming to determine the charge-parity violating phase $\\delta_{CP}$ in the appearance channel, fine-grained time-projection chambers are expected to play an important role. In this Letter, we analyze an influence of realistic detector capabilities on the $\\delta_{CP}$ sensitivity for a setup similar to that of the Deep Underground Neutrino Experiment. We find that the effect of the missing energy, carried out by undetected particles, is sizable. Although the reconstructed neutrino energy can be corrected for the missing energy, the accuracy of such procedure has to exceed 20\\%, to avoid a sizable bias in the extracted $\\delta_{CP}$ value.

  12. Solar neutrino oscillation parameters after SNO Phase-III and SAGE Part-III

    International Nuclear Information System (INIS)

    We analyse the recently published results from solar neutrino experiments SNO Phase-III and SAGE Part-III and show their constraints on solar neutrino oscillation parameters, especially for the mixing angle θ12. Through a global analysis using all existing data from SK, SNO, Ga and Cl radiochemical experiments and long base line reactor experiment KamLAND , we obtain the parameters Δm122=7.684-0.208+0.212 x 10-5 eV2, tan2θ12=0.440-0.057+0.059. We also find that the discrepancy between the KamLAND and solar neutrino results can be reduced by choosing a small non-zero value for the mixing angle θ13. (authors)

  13. Precision positioning of SuperKamiokande with GPS for a long-baseline neutrino oscillation experiment

    International Nuclear Information System (INIS)

    A positioning of the neutrino detector superkamiokande (SK) was made for a long-baseline neutrino oscillation experiment planned at KEK. For positioning, global positioning system (GPS) was employed. It has been demonstrated that GPS is of practical use for measuring the positions of SK and KEK, being 250 km distance from each other, to a better resolution. The geodetic coordinates at the SK center were obtained to be Lat. 36 25'32.5862'' N., Long. 137 18'37.1241'' E., H. 371.839 m in the global ellipsoidal coordinate system, WGS-84. The obtained coordinates are based on the coordinates given at a triangulation point at the KEK site. The present work will be fed back for constructing the neutrino beam line. (orig.)

  14. From DeepCore to PINGU: Measuring atmospheric neutrino oscillations at the South Pole

    CERN Document Server

    ,

    2016-01-01

    Very large volume neutrino telescopes (VLVNTs) observe atmospheric neutrinos over a wide energy range (GeV to TeV), after they travel distances as large as the Earth's diameter. DeepCore, the low energy extension of IceCube, has started making meaningful measurements of the neutrino oscillation parameters $\\theta_{23}$ and $|\\Delta m^2_{32}|$ by analyzing the atmospheric flux at energies above 10 GeV. PINGU, a proposed project to lower DeepCore's energy threshold, aims to use the same flux to further increase the precision with which these parameters are known, and eventually determine the sign of $\\Delta m^2_{32}$. The latest results from DeepCore, and the planned transition to PINGU, are discussed here.

  15. Solar Neutrino Oscillation Parameters after SNO Phase-Ⅲ and SAGE Part-Ⅲ

    Institute of Scientific and Technical Information of China (English)

    YANG Ping; LIU Qiu-Yu

    2009-01-01

    We analyse the recently published results from solar neutrino experiments SNO Phase-Ⅲ and SAGE Part-Ⅲ and show their constraints on solar neutrino oscillation parameters,especially for the mixing angle θ12.Through a global analysis using all existing data from SK,SNO,Ga&C1 radiochemical experiments and long base line reactor experiment KamLAND,we obtain the parameters Δm212=7.684+0.212-0.208×10-5 eV2,tan2 θ12-0.440+0.059-0.057.We also find that the discrepancy between the KamLAND and solar neutrino results can be reduced by choosing a small non-zero value for the mixing angle θ13.

  16. Systematic uncertainties in long-baseline neutrino oscillations for large θ₁₃

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar; Huber, Patrick; Kopp, Joachim; Winter, Walter

    2013-02-01

    We study the physics potential of future long-baseline neutrino oscillation experiments at large θ₁₃, focusing especially on systematic uncertainties. We discuss superbeams, \\bbeams, and neutrino factories, and for the first time compare these experiments on an equal footing with respect to systematic errors. We explicitly simulate near detectors for all experiments, we use the same implementation of systematic uncertainties for all experiments, and we fully correlate the uncertainties among detectors, oscillation channels, and beam polarizations as appropriate. As our primary performance indicator, we use the achievable precision in the measurement of the CP violating phase $\\deltacp$. We find that a neutrino factory is the only instrument that can measure $\\deltacp$ with a precision similar to that of its quark sector counterpart. All neutrino beams operating at peak energies ≳2 GeV are quite robust with respect to systematic uncertainties, whereas especially \\bbeams and \\thk suffer from large cross section uncertainties in the quasi-elastic regime, combined with their inability to measure the appearance signal cross sections at the near detector. A noteworthy exception is the combination of a γ =100 \\bbeam with an \\spl-based superbeam, in which all relevant cross sections can be measured in a self-consistent way. This provides a performance, second only to the neutrino factory. For other superbeam experiments such as \\lbno and the setups studied in the context of the \\lbne reconfiguration effort, statistics turns out to be the bottleneck. In almost all cases, the near detector is not critical to control systematics since the combined fit of appearance and disappearance data already constrains the impact of systematics to be small provided that the three active flavor oscillation framework is valid.

  17. Results from the KARMEN nu-bar submu -> nu-bar sub e neutrino oscillation search

    CERN Document Server

    Eitel, K

    1999-01-01

    The neutrino experiment KARMEN is situated at the beam stop neutrino source ISIS. It provides nu submu's, nu sub e 's and nu-bar's in equal intensities from the pi sup + -mu sup + -decay at rest (DAR). The oscillation channel nu-bar submu -> nu-bar sub e is investigated in the appearance mode with a 56 t liquid scintillation calorimeter at a mean distance of 17.7 m from the nu-source looking for p (nu-bar sub e , e sup +) n reactions. In the data collected through 1997 and 1998 no potential oscillation event was observed. Using a unified approach to small signals as recommended by the PDG, this leads to an upper limit for the mixing angle of sin sup 2 (2 THETA) nu-bar sub e evidence.

  18. Search for Neutrino Oscillations in Appearance Mode with the Opera Experiment

    Science.gov (United States)

    Dzhatdoev, T. A.; Troshina, V. L.

    2014-03-01

    The present paper highlights the data analysis status of the OPERA experiment. The experiment was designed to perform the neutrino interactions analysis on event-by-event basis, and optimized to search for νμ → ντ oscillation in appearance mode, also allowing to perform a νe appearance search. We review the data simulation and the analysis chains implemented to search for ντ interactions. The main kinematical parameters sensitive to the neutrino flavor are discussed, the uncertainties of the event parameter estimation are reviewed, and the main sources of background for the νμ → ντ oscillation search are examined. The topologies of the two first ντ candidate events are presented. Finally, we review the status of the νe appearance search and present the constraints set by the OPERA experiment on the mixing angle θ13 and on the LSND/MiniBooNE anomaly.

  19. Measurement of atmospheric neutrino oscillations with IceCube/DeepCore

    International Nuclear Information System (INIS)

    IceCube's low-energy optimization DeepCore became operational in May 2010 and is taking data since then. It lowers the energy threshold of IceCube by roughly an order of magnitude. The huge statistics of about 150000 triggered atmospheric muon neutrinos per year and the low energy threshold of about 10 GeV permit to study oscillations. The disappearance probability depends on the neutrino energy and the traveled distance and thus on the zenith angle observed by IceCube. Maximum disappearance is expected at energies of about 25 GeV for vertically upward going neutrinos. For shorter oscillation lengths this flux minimum shifts towards 1 GeV close to the horizon. This study aims for a likelihood analysis of the two experimental observables (zenith and neutrino energy) for a high statistics measurement of the mixing angle θ23 and the mass difference Δm223. This talk presents the analysis method and first results from the data taken by IceCube in its 79-string configuration.

  20. Earth matter effect on atmospheric neutrino oscillation in (3+3) model

    CERN Document Server

    Rahman, Mushfiqur

    2015-01-01

    In a recent combined analysis of short baseline neutrino oscillation data by Conrad et al it is shown that (3+3) neutrino model, defined by three active and three sterile neutrinos, results in an overall goodness of $67\\%$ and a compatibility of $90\\%$ among all data sets - to be compared to the compatibility of $0.043\\% $ and $13\\% $ for a (3+1) and a (3+2) model, respectively. Aside from the fact that (3+3) model still finds inconsistencies with MiniBooNE appearance data sets, its high quality overall compatibility and goodness of fit led us to study the atmospheric neutrinos in this model which travel distances of thousands of kilometers through earth. We show that in this mixing scheme matter resonance effect inside earth enhances the small vacuum oscillations into near-maximal transitions and at high energies these maximal transitions occur in the TeV range, whereas at low energies those can occur in the few GeV region. We also calculate the zenith angle distributions of $\