Mixing of fourth-generation neutrinos

International Nuclear Information System (INIS)

Nussinov, S.

1987-01-01

This paper reviews some of the constraints on the mixing of massive decaying neutrinos. Some of the possible implications for neutrino physics of the recent supernova, and in particular the apparent overabundance of neutrino energy, are discussed

Features of neutrino mixing

Science.gov (United States)

Chiu, S. H.; Kuo, T. K.

2018-03-01

The elements (squared) of the neutrino mixing matrix are found to satisfy, as functions of the induced mass, a set of differential equations. They show clearly the dominance of pole terms when the neutrino masses "cross." Using the known vacuum mixing parameters as initial conditions, it is found that these equations have very good approximate solutions, for all values of the induced mass. The results are applicable to long baseline experiments.

Noncommutative spectral geometry, Bogoliubov transformations and neutrino oscillations

International Nuclear Information System (INIS)

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

2015-01-01

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. (paper)

Symmetric mixed states of n qubits: Local unitary stabilizers and entanglement classes

Energy Technology Data Exchange (ETDEWEB)

Lyons, David W.; Walck, Scott N. [Lebanon Valley College, Annville, Pennsylvania 17003 (United States)

2011-10-15

We classify, up to local unitary equivalence, local unitary stabilizer Lie algebras for symmetric mixed states of n qubits into six classes. These include the stabilizer types of the Werner states, the Greenberger-Horne-Zeilinger state and its generalizations, and Dicke states. For all but the zero algebra, we classify entanglement types (local unitary equivalence classes) of symmetric mixed states that have those stabilizers. We make use of the identification of symmetric density matrices with polynomials in three variables with real coefficients and apply the representation theory of SO(3) on this space of polynomials.

Nonzero θ13 and neutrino masses from the modified tri-bi-maximal neutrino mixing matrix

International Nuclear Information System (INIS)

Damanik, A.

2014-01-01

There are 3 types of neutrino mixing matrices: tri-bi-maximal, bi-maximal and democratic. These 3 types of neutrino mixing matrices predict that the mixing angle θ 13 should be null. Motivated by the recent experimental evidence of nonzero and relatively large θ 13 , we modified the tribimaximal mixing matrix by introducing a simple perturbation matrix into tribimaximal neutrino mixing matrix. In this scenario, we obtained nonzero mixing angle θ 13 =7.9 degrees which is in agreement with the present experimental results. By imposing 2 zeros texture into the obtained neutrino mass matrix from modified tribimaximal mixing matrix, we then have the neutrino mass spectrum in normal hierarchy. Some phenomenological implications are also discussed. It appears that if we use the solar neutrino squared-mass difference to determine the values of neutrino masses, then we cannot have the correct value for the atmospheric squared-mass difference. Conversely, if we use the experimental value of the squared-mass difference to determine the neutrino masses, then we cannot have the correct value for the solar neutrino squared-mass difference

Neutrino mixing and lepton CP-phase in neutrino oscillations

International Nuclear Information System (INIS)

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

2001-01-01

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 [ru

Neutrino bi-large mixings and family

International Nuclear Information System (INIS)

Bando, Masako; Obara, Midori

2004-01-01

After a brief review of quark-lepton relations in grand unified theories (GUT), we show that the Pati-Salam relation with only one type of Higgs field configuration with ''four zero symmetric texture'' can reproduce two large neutrino mixings as well as observed mass differences. This is quite in contrast to the case of SU(5) where bi-large mixings essentially come from the charged lepton sector with non-symmetric charged lepton mass matrix. (author)

Lepton mixing and the 'solar neutrino puzzle'

International Nuclear Information System (INIS)

Bilenky, S.M.; Pontecorvo, B.

1977-01-01

The results of the well-known solar neutrino experiments in which the Cl-Ar method was employed are discussed; the results of this experiment gave a too-small neutrino signal and were referred to as the 'solar neutrino puzzle'. A number of explanations have been offered to account for the results, but it is stated that the explanation in terms of lepton mixing and neutrino sterility is attractive in terms of present day elementary particle physics and much more natural than the other explanations offered. Headings are as follows: neutrino oscillations and lepton charge, oscillations and solar neutrino experiments, lepton mixing according to old and present ideas, neutrino oscillations and the 'solar neutrino puzzle'. (U.K.)

Neutrino masses and mixings: Big Bang and Supernova nucleosynthesis and neutrino dark matter

International Nuclear Information System (INIS)

Fuller, George M.

1999-01-01

The existence of small mixings between light active and sterile neutrino species could have implications for Big Bang and Supernova Heavy Element Nucleosynthesis. As well, such mixing would force us to abandon cherished constraints on light neutrino Dark Matter. Two proposed 4-neutrino mass and mixing schemes, for example, can both accomodate existing experimental results and lead to elegant solutions to the neutron-deficit problem for r-Process nucleosynthesis from neutrino-heated supernova ejecta. Each of these solutions is based on matter-enhanced (MSW) active-sterile neutrino transformation. In plausible extensions of these schemes to the early universe, Shi and Fuller have shown that relatively light mass (∼200 eV to ∼10 keV) sterile neutrinos produced via active-sterile MSW conversion can have a ''cold'' energy spectrum. Neutrinos produced in this way circumvent the principal problem of light neutrino dark matter and would be, essentially, Cold Dark Matter

Neutrino mass and mixing with discrete symmetry

International Nuclear Information System (INIS)

King, Stephen F; Luhn, Christoph

2013-01-01

This is a review paper about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of see-saw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mechanisms for flavon vacuum alignment and different model building strategies that have been proposed to generate the reactor angle. We then briefly review grand unified theories (GUTs) and how they may be combined with discrete family symmetry to describe all quark and lepton masses and mixing. Finally, we discuss three model examples which combine an SU(5) GUT with the discrete family symmetries A 4 , S 4 and Δ(96). (review article)

Neutrino mixing in a grand unified theory

International Nuclear Information System (INIS)

Milton, K.; Tanaka, K.

1980-01-01

Neutrino mixing in a grand unified theory in which the neutrino mass matrix is determined by the Gell-Mann-Ramond-Slansky mechanism was investigated. With an arbitrary real right-handed Majorana mass matrix which incorporates three neutrino mass scales, the effects of the up-quark mass matrix are found to be dominant and as a result no significant mixing of ν/sub e/ occurs, while ν/sub μ/ - ν/sub γ/ mixing can be substantial

Three neutrino flavors: Oscillations, mixing, and the solar-neutrino problem

International Nuclear Information System (INIS)

Pantaleone, J.

1991-01-01

An analytical, quantitative description of solar-neutrino propagation is presented which includes three flavors, matter dependence, and long-wavelength effects. Using the derived expression for the electron-neutrino survival probability, it is demonstrated that mixing is possible between the two-flavor Mikheyev-Smirnov-Wolfenstein and two-flavor long-wavelength solutions to the solar-neutrino problem. However, adiabatic conversion of a neutrino mass eigenstate tends to suppress all subsequent long-wavelength effects such as ''seasonal'' variations in the solar-neutrino flux

Parametrization of Seesaw Models and Light Sterile Neutrinos

CERN Document Server

Blennow, Mattias

2011-01-01

The recent recomputation of the neutrino fluxes from nuclear reactors relaxes the tension between the LSND and MiniBooNE anomalies and disappearance data when interpreted in terms of sterile neutrino oscillations. The simplest extension of the Standard Model with such fermion singlets is the addition of right-handed sterile neutrinos with small Majorana masses. Even when introducing three right-handed neutrinos, this scenario has less free parameters than the 3+2 scenarios studied in the literature. This begs the question whether the best fit regions obtained can be reproduced by this simplest extension of the Standard Model. In order to address this question, we devise an exact parametrization of Standard Model extensions with right-handed neutrinos. Apart from the usual 3x3 neutrino mixing matrix and the 3 masses of the lightest neutrinos, the extra degrees of freedom are encoded in another 3x3 unitary matrix and 3 additional mixing angles. The parametrization includes all the correlations among masses and ...

Equivalence of quantum states under local unitary transformations

International Nuclear Information System (INIS)

Fei Shaoming; Jing Naihuan

2005-01-01

In terms of the analysis of fixed point subgroup and tensor decomposability of certain matrices, we study the equivalence of quantum bipartite mixed states under local unitary transformations. For non-degenerate case an operational criterion for the equivalence of two such mixed bipartite states under local unitary transformations is presented

Non-unitary probabilistic quantum computing

Science.gov (United States)

Gingrich, Robert M.; Williams, Colin P.

2004-01-01

We present a method for designing quantum circuits that perform non-unitary quantum computations on n-qubit states probabilistically, and give analytic expressions for the success probability and fidelity.

Curtailing the dark side in non-standard neutrino interactions

Energy Technology Data Exchange (ETDEWEB)

Coloma, Pilar [Theoretical Physics Department, Fermi National Accelerator Laboratory,P.O. Box 500, Batavia, IL 60510 (United States); Denton, Peter B. [Theoretical Physics Department, Fermi National Accelerator Laboratory,P.O. Box 500, Batavia, IL 60510 (United States); Niels Bohr International Academy, University of Copenhagen, The Niels Bohr Institute,Blegdamsvej 17, DK-2100, Copenhagen (Denmark); Gonzalez-Garcia, M.C. [Departament de Fisíca Quàntica i Astrofísica and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA),Pg. Lluis Companys 23, 08010 Barcelona (Spain); C.N. Yang Institute for Theoretical Physics, Stony Brook University,Stony Brook, NY 11794-3840 (United States); Maltoni, Michele [Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid,Calle de Nicolás Cabrera 13-15, Cantoblanco, E-28049 Madrid (Spain); Schwetz, Thomas [Institut für Kernphysik, Karlsruher Institut für Technologie (KIT), D-76021 Karlsruhe (Germany)

2017-04-20

In presence of non-standard neutrino interactions the neutrino flavor evolution equation is affected by a degeneracy which leads to the so-called LMA-Dark solution. It requires a solar mixing angle in the second octant and implies an ambiguity in the neutrino mass ordering. Non-oscillation experiments are required to break this degeneracy. We perform a combined analysis of data from oscillation experiments with the neutrino scattering experiments CHARM and NuTeV. We find that the degeneracy can be lifted if the non-standard neutrino interactions take place with down quarks, but it remains for up quarks. However, CHARM and NuTeV constraints apply only if the new interactions take place through mediators not much lighter than the electroweak scale. For light mediators we consider the possibility to resolve the degeneracy by using data from future coherent neutrino-nucleus scattering experiments. We find that, for an experiment using a stopped-pion neutrino source, the LMA-Dark degeneracy will either be resolved, or the presence of new interactions in the neutrino sector will be established with high significance.

Non-standard interaction effects at reactor neutrino experiments

International Nuclear Information System (INIS)

Ohlsson, Tommy; Zhang, He

2009-01-01

We study non-standard interactions (NSIs) at reactor neutrino experiments, and in particular, the mimicking effects on θ 13 . We present generic formulas for oscillation probabilities including NSIs from sources and detectors. Instructive mappings between the fundamental leptonic mixing parameters and the effective leptonic mixing parameters are established. In addition, NSI corrections to the mixing angles θ 13 and θ 12 are discussed in detailed. Finally, we show that, even for a vanishing θ 13 , an oscillation phenomenon may still be observed in future short baseline reactor neutrino experiments, such as Double Chooz and Daya Bay, due to the existences of NSIs

Neutrino Masses and Mixings and Astrophysics

Science.gov (United States)

Fuller, George M.

1998-10-01

Here we discuss the implications of light neutrino masses and neutrino flavor/type mixing for dark matter, big bang nucleosynthesis, and models of heavy element nucleosynthesis in super novae. We will also argue the other way and discuss possible constraints on neutrino physics from these astrophysical considerations.

Neutrino mixing, flavor states and dark energy

International Nuclear Information System (INIS)

Blasone, M.; Capolupo, A.; Capozziello, S.; Vitiello, G.

2008-01-01

We shortly summarize the quantum field theory formalism for the neutrino mixing and report on recent results showing that the vacuum condensate induced by neutrino mixing can be interpreted as a dark energy component of the Universe

A framework for testing leptonic unitarity by neutrino oscillation experiments

Energy Technology Data Exchange (ETDEWEB)

Fong, Chee Sheng [Instituto de Física, Universidade de São Paulo,C.P. 66.318, 05315-970 São Paulo (Brazil); Minakata, Hisakazu [Department of Physics, Yachay Tech,San Miguel de Urcuquí, 100119 (Ecuador); Nunokawa, Hiroshi [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro,C.P. 38097, 22451-900, Rio de Janeiro (Brazil)

2017-02-22

If leptonic unitarity is violated by new physics at an energy scale much lower than the electroweak scale, which we call low-scale unitarity violation, it has different characteristic features from those expected in unitarity violation at high-energy scales. They include maintaining flavor universality and absence of zero-distance flavor transition. We present a framework for testing such unitarity violation at low energies by neutrino oscillation experiments. Starting from the unitary 3 active plus N (arbitrary positive integer) sterile neutrino model we show that by restricting the active-sterile and sterile-sterile neutrino mass squared differences to ≳ 0.1 eV{sup 2} the oscillation probability in the (3+N) model becomes insensitive to details of the sterile sector, providing a nearly model-independent framework for testing low-scale unitarity violation. Yet, the presence of the sterile sector leaves trace as a constant probability leaking term, which distinguishes low-scale unitarity violation from the high-scale one. The non-unitary mixing matrix in the active neutrino subspace is common for the both cases. We analyze how severely the unitarity violation can be constrained in ν{sub e}-row by taking a JUNO-like setting to simulate medium baseline reactor experiments. Possible modification of the features of the (3+N) model due to matter effect is discussed to first order in the matter potential.

Neutrino Mass Models: impact of non-zero reactor angle

International Nuclear Information System (INIS)

King, Stephen F.

2011-01-01

In this talk neutrino mass models are reviewed and the impact of a non-zero reactor angle and other deviations from tri-bi maximal mixing are discussed. We propose some benchmark models, where the only way to discriminate between them is by high precision neutrino oscillation experiments.

Neutrino masses and mixing

International Nuclear Information System (INIS)

Fogli, G.

1998-01-01

The paper presents an analysis of the solar neutrino problem in terms of both Mikheyev-Smirnov-Wolfenstein (MSW) and vacuum neutrino oscillations, with the inclusion of the data collected by the SuperKamiokande experiment during 306.3 days of operation. In particular, the observed energy spectrum of the recoil electrons from 8 B neutrino scattering is discussed in detail and used to constrain the mass-mixing parameter space. Going to the atmospheric neutrino anomaly, the paper performs both a two- and three-flavor analysis of the most recent SuperKamiokande atmospheric neutrino data. The variations of the zenith distributions of ν events in the presence of flavor oscillations are investigated. It is seen that fits to the SK data, with and without the addition of the CHOOZ constrains, strongly limit the parameter space. Detailed bounds in triangle graphs are reported

Neutrino masses and mixing: evidence and implications

International Nuclear Information System (INIS)

Gonzalez-Garcia, M.C.; Nir, Yosef

2003-01-01

Measurements of various features of the fluxes of atmospheric and solar neutrinos have provided evidence for neutrino oscillations and therefore for neutrino masses and mixing. The authors review the phenomenology of neutrino oscillations in vacuum and in matter. They present the existing evidence from solar and atmospheric neutrinos as well as the results from laboratory searches, including the final status of the Liquid Scintillator Neutrino Detector (LSND) experiment. The theoretical inputs that are used to interpret the experimental results are described in terms of neutrino oscillations. The allowed ranges for the mass and mixing parameters are derived in two frameworks: First, each set of observations is analyzed separately in a two-neutrino framework; Second, the data from solar and atmospheric neutrinos are analyzed in a three-active-neutrino framework. The theoretical implications of these results are then discussed, including the existence of new physics, the estimate of the scale of this new physics, and the lessons for grand unified theories, for models of extra dimensions and singlet fermions in the bulk, and for flavor models

Neutrino mass and mixing, and non-accelerator experiments

International Nuclear Information System (INIS)

Robertson, R.G.H.

1992-01-01

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

Neutrino mass and mixing in the seesaw playground

International Nuclear Information System (INIS)

King, Stephen F.

2016-01-01

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

Two Light Sterile Neutrinos that Mix Maximally with Each Other and Moderately with Three Active Neutrinos

International Nuclear Information System (INIS)

Krolikowski, W.

2004-01-01

Since the 3+1 neutrino models with one light sterile neutrino turn out to be not very effective, at least two light sterile neutrinos may be needed to reconcile the solar and atmospheric neutrino experiments with the LSND result, if this is confirmed by the ongoing MiniBooNE experiment (and when the CPT invariance is assumed to hold for neutrino oscillations). We present an attractive 3+2 neutrino model, where two light sterile neutrinos mix maximally with each other, in analogy to the observed maximal mixing of muon and tauon active neutrinos. But, while the mixing of ν e and (ν μ - ν τ )/√2 is observed as large (though not maximal), the mixing of ν e with the corresponding combination of two light sterile neutrinos is expected to be only moderate because of the reported smallness of LSND oscillation amplitude. The presented model turns out, however, not to be more effective in explaining the hypothetic LSND result than the simplest 3+1 neutrino model. On the other hand, in the considered 3+2 model, the deviations from conventional oscillations of three active neutrinos appear to be minimal within a larger class of 3+2 models. (author)

Hierarchical Neutrino Masses and Mixing in Flipped-SU(5)

CERN Document Server

Rizos, J

2010-01-01

We consider the problem of neutrino masses and mixing in the framework of flipped SU(5). The right-handed neutrino mass, generated through the operation of a seesaw mechanism by a sector of gauge singlets, leads naturally, at a subsequent level, to the standard seesaw mechanism resulting into three light neutrino states with masses of the desired phenomenological order of magnitude. In this framework we study simple Ansatze for the singlet couplings for which hierarchical neutrino masses emerge naturally, parametrized in terms of the Cabbibo parameter. The resulting neutrino mixing matrices are characterized by a hierarchical structure, in which theta-(13) is always predicted to be the smallest. Finally, we discuss a possible factorized parametrization of the neutrino mass that, in addition to Cabbibo mixing, encodes also mixing due to the singlet sector.

Unitary evolution between pure and mixed states

International Nuclear Information System (INIS)

Reznik, B.

1996-01-01

We propose an extended quantum mechanical formalism that is based on a wave operator d, which is related to the ordinary density matrix via ρ=dd degree . This formalism allows a (generalized) unitary evolution between pure and mixed states. It also preserves much of the connection between symmetries and conservation laws. The new formalism is illustrated for the case of a two-level system. copyright 1996 The American Physical Society

Neutrino oscillations in non-inertial frames and the violation of the equivalence principle neutrino mixing induced by the equivalence principle violation

International Nuclear Information System (INIS)

Lambiase, G.

2001-01-01

Neutrino oscillations are analyzed in an accelerating and rotating reference frame, assuming that the gravitational coupling of neutrinos is flavor dependent, which implies a violation of the equivalence principle. Unlike the usual studies in which a constant gravitational field is considered, such frames could represent a more suitable framework for testing if a breakdown of the equivalence principle occurs, due to the possibility to modulate the (simulated) gravitational field. The violation of the equivalence principle implies, for the case of a maximal gravitational mixing angle, the presence of an off-diagonal term in the mass matrix. The consequences on the evolution of flavor (mass) eigenstates of such a term are analyzed for solar (oscillations in the vacuum) and atmospheric neutrinos. We calculate the flavor oscillation probability in the non-inertial frame, which does depend on its angular velocity and linear acceleration, as well as on the energy of neutrinos, the mass-squared difference between two mass eigenstates, and on the measure of the degree of violation of the equivalence principle (Δγ). In particular, we find that the energy dependence disappears for vanishing mass-squared difference, unlike the result obtained by Gasperini, Halprin, Leung, and other physical mechanisms proposed as a viable explanation of neutrino oscillations. Estimations on the upper values of Δγ are inferred for a rotating observer (with vanishing linear acceleration) comoving with the earth, hence ω∝7.10 -5 rad/sec, and all other alternative mechanisms generating the oscillation phenomena have been neglected. In this case we find that the constraints on Δγ are given by Δγ≤10 2 for solar neutrinos and Δγ≤10 6 for atmospheric neutrinos. (orig.)

Maximal neutrino mixing from a minimal flavor symmetry

International Nuclear Information System (INIS)

Aranda, Alfredo; Carone, Christopher D.; Lebed, Richard F.

2000-01-01

We study a number of models, based on a non-Abelian discrete group, that successfully reproduce the simple and predictive Yukawa textures usually associated with U(2) theories of flavor. These models allow for solutions to the solar and atmospheric neutrino problems that do not require altering successful predictions for the charged fermions or introducing sterile neutrinos. Although Yukawa matrices are hierarchical in the models we consider, the mixing between second- and third-generation neutrinos is naturally large. We first present a quantitative analysis of a minimal model proposed in earlier work, consisting of a global fit to fermion masses and mixing angles, including the most important renormalization group effects. We then propose two new variant models: The first reproduces all important features of the SU(5)xU(2) unified theory with neither SU(5) nor U(2). The second demonstrates that discrete subgroups of SU(2) can be used in constructing viable supersymmetric theories of flavor without scalar universality even though SU(2) by itself cannot. (c) 2000 The American Physical Society

Hierarchical neutrino masses and mixing in flipped-SU(5)

Energy Technology Data Exchange (ETDEWEB)

Rizos, J. [Physics Department, University of Ioannina, 45110 Ioannina (Greece); Tamvakis, K., E-mail: tamvakis@uoi.g [Physics Department, University of Ioannina, 45110 Ioannina (Greece); Physics Department, CERN, CH-1211, Geneva 23 (Switzerland)

2010-02-22

We consider the problem of neutrino masses and mixing in the framework of flipped SU(5). The right-handed neutrino mass, generated through the operation of a seesaw mechanism by a sector of gauge singlets, leads naturally, at a subsequent level, to the standard seesaw mechanism resulting into three light neutrino states with masses of the desired phenomenological order of magnitude. In this framework we study simple Ansaetze for the singlet couplings for which hierarchical neutrino masses emerge naturally as lambda{sup n}:lambda:1 or lambda{sup n}:lambda{sup 2}:1, parametrized in terms of the Cabbibo parameter. The resulting neutrino mixing matrices are characterized by a hierarchical structure, in which theta{sub 13} is always predicted to be the smallest. Finally, we discuss a possible factorized parametrization of the neutrino mass that, in addition to Cabbibo mixing, encodes also mixing due to the singlet sector.

Neutrino oscillations: The rise of the PMNS paradigm

Science.gov (United States)

Giganti, C.; Lavignac, S.; Zito, M.

2018-01-01

Since the discovery of neutrino oscillations, the experimental progress in the last two decades has been very fast, with the precision measurements of the neutrino squared-mass differences and of the mixing angles, including the last unknown mixing angle θ13. Today a very large set of oscillation results obtained with a variety of experimental configurations and techniques can be interpreted in the framework of three active massive neutrinos, whose mass and flavour eigenstates are related by a 3 × 3 unitary mixing matrix, the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix, parametrized by three mixing angles θ12, θ23, θ13 and a CP-violating phase δCP. The additional parameters governing neutrino oscillations are the squared-mass differences Δ mji2 = mj2 - mi2, where mi is the mass of the ith neutrino mass eigenstate. This review covers the rise of the PMNS three-neutrino mixing paradigm and the current status of the experimental determination of its parameters. The next years will continue to see a rich program of experimental endeavour coming to fruition and addressing the three missing pieces of the puzzle, namely the determination of the octant and precise value of the mixing angle θ23, the unveiling of the neutrino mass ordering (whether m1

Discrete symmetries and solar neutrino mixing

Energy Technology Data Exchange (ETDEWEB)

Kapetanakis, D.; Mayr, P.; Nilles, H.P. (Physik Dept., Technische Univ. Muenchen, Garching (Germany) Max-Planck-Inst. fuer Physik, Werner-Heisenberg-Inst., Muenchen (Germany))

1992-05-21

We study the question of resonant solar neutrino mixing in the framework of the supersymmetric extension of the standard model. Discrete symmetries that are consistent with solar neutrino mixing and proton stability are classified. In the minimal model they are shown to lead to two distinct patterns of allowed dimension-four operators. Imposing anomaly freedom, only three different discrete Z{sub N}-symmetries (with N=2, 3, 6) are found to be phenomenologically acceptable. (orig.).

Discrete symmetries and solar neutrino mixing

International Nuclear Information System (INIS)

Kapetanakis, D.; Mayr, P.; Nilles, H.P.

1992-01-01

We study the question of resonant solar neutrino mixing in the framework of the supersymmetric extension of the standard model. Discrete symmetries that are consistent with solar neutrino mixing and proton stability are classified. In the minimal model they are shown to lead to two distinct patterns of allowed dimension-four operators. Imposing anomaly freedom, only three different discrete Z N -symmetries (with N=2, 3, 6) are found to be phenomenologically acceptable. (orig.)

On flavor violation for massive and mixed neutrinos

International Nuclear Information System (INIS)

Blasone, M.; Capolupo, A.; Ji, C.R.; Vitiello, G.

2009-01-01

We discuss flavor charges and states for interacting mixed neutrinos in QFT. We show that the Pontecorvo states are not eigenstates of the flavor charges. This implies that their use in describing the flavor neutrinos produces a violation of lepton charge conservation in the production/detection vertices. The flavor states defined as eigenstates of the flavor charges give the correct representation of mixed neutrinos in charged current weak interaction processes.

Neutrino mixing in SO(10)

International Nuclear Information System (INIS)

Milton, K.; Hama, S.; Nandi, S.; Tanaka, K.

1980-01-01

Neutrino mixing angles were computed in terms of upquark mass ratios in a grand unified field theory based on the gauge group SO(10) supplemented by a discrete symmetry. Only large ν/sub μ/ - ν/sub tau/ mixing were found

Knitting neutrino mass textures with or without Tri-Bi maximal mixing

Energy Technology Data Exchange (ETDEWEB)

Leontaris, G.K., E-mail: leonta@uoi.gr [Theoretical Physics Division, Ioannina University, GR-45110 Ioannina (Greece); Vlachos, N.D. [Theoretical Physics Division, Aristotle University, GR-54124 Thessaloniki (Greece)

2011-08-03

The solar and baseline neutrino oscillation data suggest bimaximal neutrino mixing among the first two generations, and trimaximal mixing between all three neutrino flavors. It has been conjectured that this indicates the existence of an underlying symmetry for the leptonic fermion mass textures. The experimentally measured quantities, however, are associated to the latter indirectly and in a rather complicated way through the mixing matrices of the charged leptons and neutrinos. Motivated by these facts, we derive exact analytical expressions which directly link the charged lepton and neutrino mass and mixing parameters to measured quantities and obtain constraints on the parameter space. We discuss deviations from Tri-Bi mixing matrices and present minimal extensions of the Harrison, Perkins and Scott matrices capable of interpreting all neutrino data.

Particle Physics Seminar: Towards 3+1 Neutrino Mixing

CERN Multimedia

Geneva University

2011-01-01

GENEVA UNIVERSITY Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Wednesday  12 October  2011 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium “Towards 3+1 Neutrino Mixing” Par Prof. Carlo Giunti, INFN Torino I will review the recent experimental indications in favor of  short-baseline neutrino oscillations. I will discuss their interpretation in the framework of neutrino mixing schemes with one or more sterile neutrinos which have masses around the eV scale. Taking into account also cosmological constraints, I will present arguments in favor of 3+1 neutrino mixing with one sterile neutrino at the eV scale. Information : http://dpnc.unige.ch/seminaire/annonce.html Organizer : G. Pasztor

Masses, flavor mix and CP violation

International Nuclear Information System (INIS)

Chaussard, L.

2004-06-01

The author describes the relationships between masses, mixing of flavors and CP violation. This document is divided into 4 chapters: 1) fermions' masses, 2) mixing of flavors and CP violation, 3) beauty physics and 4) neutrino physics. In chapter 1 an attempt is made to explain what is behind the concepts of lepton mass and quark mass. As for neutrinos, the only neutral fermion, Dirac's and Majorana's views are exposed as well as their consequences. Fermion flavors are mixed in the process of mass generation and this mix is responsible for the breaking of CP and T symmetries. In chapter 2 the author shows how the analysis of particle oscillations from neutral mesons (K 0 , D 0 , B d 0 and B s 0 ) and from neutrinos can shed light on CP violation. Chapter 3 is dedicated to the contribution of beauty physics to the determination of the unitary triangle, through the oscillations of beauty mesons. In chapter 4 the author reviews the experimental results obtained recently concerning neutrino mass and neutrino oscillations and draws some perspectives on future neutrino experiments. (A.C.)

Softly Broken Lepton Numbers: an Approach to Maximal Neutrino Mixing

International Nuclear Information System (INIS)

Grimus, W.; Lavoura, L.

2001-01-01

We discuss models where the U(1) symmetries of lepton numbers are responsible for maximal neutrino mixing. We pay particular attention to an extension of the Standard Model (SM) with three right-handed neutrino singlets in which we require that the three lepton numbers L e , L μ , and L τ be separately conserved in the Yukawa couplings, but assume that they are softly broken by the Majorana mass matrix M R of the neutrino singlets. In this framework, where lepton-number breaking occurs at a scale much higher than the electroweak scale, deviations from family lepton number conservation are calculable, i.e., finite, and lepton mixing stems exclusively from M R . We show that in this framework either maximal atmospheric neutrino mixing or maximal solar neutrino mixing or both can be imposed by invoking symmetries. In this way those maximal mixings are stable against radiative corrections. The model which achieves maximal (or nearly maximal) solar neutrino mixing assumes that there are two different scales in M R and that the lepton number (dash)L=L e -L μ -L τ 1 is conserved in between them. We work out the difference between this model and the conventional scenario where (approximate) (dash)L invariance is imposed directly on the mass matrix of the light neutrinos. (author)

Flavor democracy and type-II seesaw realization of bilarge neutrino mixing

International Nuclear Information System (INIS)

Rodejohann, Werner; Xing Zhizhong

2004-01-01

We generalize the democratic neutrino mixing ansatz by incorporating the type-II seesaw mechanism with S(3) flavor symmetry. For only the triplet mass term or only the conventional seesaw term large neutrino mixing can be achieved only by assuming an unnatural suppression of the flavor democracy contribution. We show that bilarge neutrino mixing can naturally appear if the flavor democracy term is strongly suppressed due to significant cancellation between the conventional seesaw and triplet mass terms. Explicit S(3) symmetry breaking yields successful neutrino phenomenology and various testable correlations between the neutrino mass and mixing parameters. Among the results are a normal neutrino mass ordering, 0.005= e3 vertical bar = 2 2θ 23 >=0.005, positive J CP and moderate cancellation in the effective mass of the neutrinoless double beta decay

Leptogenesis from oscillations of heavy neutrinos with large mixing angles

Energy Technology Data Exchange (ETDEWEB)

Drewes, Marco; Garbrecht, Björn [Physik-Department T70, Technische Universität München,James-Franck-Straße, 85748 Garching (Germany); Gueter, Dario [Physik-Department T70, Technische Universität München,James-Franck-Straße, 85748 Garching (Germany); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, 80805 München (Germany); Excellence Cluster Universe, Technische Universität München,Boltzmannstraße 2, 85748 Garching (Germany); Klarić, Juraj [Physik-Department T70, Technische Universität München,James-Franck-Straße, 85748 Garching (Germany)

2016-12-29

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 the LHC, BELLE II, NA62, 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, the generation of the baryon asymmetry can be calculated analytically up to corrections of order one.

Lepton mixing and the ''solar neutrino puzzle''

International Nuclear Information System (INIS)

Bilenky, S.M.; Pontecorvo, B.

1977-01-01

The results of the well known solar neutrino experiment of Davis et al. are discussed, in which the Cl-Ar method is used. The result of the experiment, a too small neutrino signal (the so-called ''solar neutrino puzzle'), has been tentatively accounted for in a number of quite exotic explanations. It appears that the explanation in terms of lepton mixing and neutrino sterility is quite attractive from the point of view of present day elementary particle physics and is much more natural than the other explanations of the ''puzzle''

Bilarge neutrino mixing and mass of the lightest neutrino from third generation dominance in a democratic approach

International Nuclear Information System (INIS)

Dermisek, Radovan

2004-01-01

We show that both small mixing in the quark sector and large mixing in the lepton sector can be obtained from a simple assumption of universality of Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading order. We discuss conditions under which bilarge mixing in the lepton sector is achieved with a minimal amount of fine-tuning requirements for possible models. From knowledge of the solar and atmospheric mixing angles we determine the allowed values of sin θ 13 . If embedded into grand unified theories, the third generation Yukawa coupling unification is a generic feature while masses of the first two generations of charged fermions depend on small perturbations. In the neutrino sector, the heavier two neutrinos are model dependent, while the mass of the lightest neutrino in this approach does not depend on perturbations in the leading order. The right-handed neutrino mass scale can be identified with the GUT scale in which case the mass of the lightest neutrino is given as (m top 2 /M GUT )sin 2 θ 23 sin 2 θ 12 in the limit sin θ 13 ≅0. Discussing symmetries we make a connection with hierarchical models and show that the basis independent characteristic of this scenario is a strong dominance of the third generation right-handed neutrino, M 1 ,M 2 -4 M 3 , M 3 =M GUT

Search for the sterile neutrino mixing with the ICAL detector at INO

Energy Technology Data Exchange (ETDEWEB)

Behera, S.P. [Bhabha Atomic Research Centre, Nuclear Physics Division, Mumbai (India); Homi Bhabha National Institute, Mumbai (India); Ghosh, Anushree [Universidad Tecnica Federico Santa Maria, Departamento de Fisica, Valparaiso (Chile); Choubey, Sandhya [Harish-Chandra Research Institute, Allahabad (India); Datar, V.M. [INO Cell, Tata Institute of Fundamental Research, Mumbai (India); Mishra, D.K. [Bhabha Atomic Research Centre, Nuclear Physics Division, Mumbai (India); Mohanty, A.K. [Bhabha Atomic Research Centre, Nuclear Physics Division, Mumbai (India); Homi Bhabha National Institute, Mumbai (India); Saha Institute of Nuclear Physics, Kolkata (India)

2017-05-15

The study has been carried out on the prospects of probing the sterile neutrino mixing with the magnetized iron calorimeter (ICAL) at the India-based Neutrino Observatory (INO), using atmospheric neutrinos as a source. The so-called 3 + 1 scenario is considered for active-sterile neutrino mixing and lead to projected exclusion curves in the sterile neutrino mass and mixing angle plane. The analysis is performed using the neutrino event generator NUANCE, modified for ICAL, and folded with the detector resolutions obtained by the INO collaboration from a full GEANT4-based detector simulation. A comparison has been made between the results obtained from the analysis considering only the energy and zenith angle of the muon and combined with the hadron energy due to the neutrino induced event. A small improvement has been observed with the addition of the hadron information to the muon. In the analysis we consider neutrinos coming from all zenith angles and the Earth matter effects are also included. The inclusion of events from all zenith angles improves the sensitivity to sterile neutrino mixing by about 35% over the result obtained using only down-going events. The improvement mainly stems from the impact of Earth matter effects on active-sterile mixing. The expected precision of ICAL on the active-sterile mixing is explored and the allowed confidence level (C.L.) contours presented. At the assumed true value of 10 {sup circle} for the sterile mixing angles and marginalization over Δm{sup 2}{sub 41} and the sterile mixing angles, the upper bound at 90% C.L. (from two-parameter plots) is around 20 {sup circle} for θ{sub 14} and θ{sub 34}, and about 12 {sup circle} for θ{sub 24}. (orig.)

Non-cyclic phases for neutrino oscillations in quantum field theory

International Nuclear Information System (INIS)

Blasone, Massimo; Capolupo, Antonio; Celeghini, Enrico; Vitiello, Giuseppe

2009-01-01

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.

Non-unitary probabilistic quantum computing circuit and method

Science.gov (United States)

Williams, Colin P. (Inventor); Gingrich, Robert M. (Inventor)

2009-01-01

A quantum circuit performing quantum computation in a quantum computer. A chosen transformation of an initial n-qubit state is probabilistically obtained. The circuit comprises a unitary quantum operator obtained from a non-unitary quantum operator, operating on an n-qubit state and an ancilla state. When operation on the ancilla state provides a success condition, computation is stopped. When operation on the ancilla state provides a failure condition, computation is performed again on the ancilla state and the n-qubit state obtained in the previous computation, until a success condition is obtained.

Neutrino mass models and the implications of a non-zero reactor angle

International Nuclear Information System (INIS)

King, S.F.

2009-01-01

In this talk we survey some of the recent promising developments in the search for the theory behind neutrino mass and mixing, and indeed all fermion masses and mixing. The talk is organized in terms of a neutrino mass models decision tree according to which the answers to experimental questions provide sign posts to guide through the maze of theoretical models eventually towards a complete theory of flavour and unification. It is also discussed the theoretical implications of the measurement of non-zero reactor angle, as hinted at by recent experimental measurements.

Tri-maximal vs. bi-maximal neutrino mixing

International Nuclear Information System (INIS)

Scott, W.G

2000-01-01

It is argued that data from atmospheric and solar neutrino experiments point strongly to tri-maximal or bi-maximal lepton mixing. While ('optimised') bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal mixing is an a priori hypothesis, which is not excluded, taking account of terrestrial matter effects

SL(2, 7) representations and their relevance to neutrino physics

Energy Technology Data Exchange (ETDEWEB)

Aliferis, G.; Vlachos, N.D. [University of Thessaloniki, Department of Nuclear and Particle Physics, Thessaloniki (Greece); Leontaris, G.K. [University of Ioannina, Physics Department, Ioannina (Greece); CERN, Department of Physics, Geneva 23 (Switzerland)

2017-06-15

The investigation of the role of finite groups in flavor physics and, particularly, in the interpretation of the neutrino data has been the subject of intensive research. Motivated by this fact, in this work we derive the three-dimensional unitary representations of the projective linear group PSL{sub 2}(7). Based on the observation that the generators of the group exhibit a Latin square pattern, we use available computational packages on discrete algebra to determine the generic properties of the group elements. We present analytical expressions and discuss several examples which reproduce the neutrino mixing angles in accordance with the experimental data. (orig.)

Monochromatic neutrino beams

International Nuclear Information System (INIS)

Bernabeu, Jose; Burguet-Castell, Jordi; Espinoza, Catalina; Lindroos, Mats

2005-01-01

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

Introduction to the physics of massive and mixed neutrinos

CERN Document Server

Bilenky, Samoil

2018-01-01

Small neutrino masses are the first signs of new physics beyond the Standard Model of particle physics. Since the first edition of this textbook appeared in 2010, the Nobel Prize has been awarded "for the discovery of neutrino oscillations, which shows that neutrinos have mass". The measurement of the small neutrino mixing angle $\\theta_{13}$ in 2012, launched the precision stage of the investigation of neutrino oscillations. This measurement now allows such fundamental problems as the three-neutrino mass spectrum - is it normal or inverted? – and the $CP$ violation in the lepton sector to be tackled. In order to understand the origin of small neutrino masses, it remains crucial to reveal the nature of neutrinos with definite masses: are they Dirac neutrinos possessing a conserved lepton number, which distinguishes neutrinos and antineutrinos, or are they Majorana neutrinos with identical neutrinos and antineutrinos? Experiments searching for the neutrinoless double beta decay are presently under way to ans...

Bounds on neutrino mixing with exotic singlet neutrinos E

Indian Academy of Sciences (India)

1Department of Physics, Government College, Sawai Madhopur 322 001, India. 2Department of Physics ... ZZ (where a = e,µ or τ) with the inclusion of neutrino mixing. The threshold of the process Ôs ..... JKS thanks University Grants Commission and NKS thanks DST for financial assistance. References. [1] P Langacker ...

New limits on neutrino magnetic moment through nonvanishing 13-mixing

Science.gov (United States)

Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.

2018-05-01

The relatively large value of the neutrino mixing angle θ13 set by recent measurements allows us to use solar neutrinos to set a limit on the neutrino magnetic moment involving the second and third flavor families, μ23. The existence of a random magnetic field in the solar convective zone can produce a significant antineutrino flux when a nonvanishing neutrino magnetic moment is assumed. Even if we consider a vanishing neutrino magnetic moment involving the first family, electron antineutrinos are indirectly produced through the mixing between the first and third families and μ23≠0 . Using KamLAND limits on the solar flux of electron antineutrino, we set the limit μ23behavior of solar magnetic fields. This is the first time that a limit on μ23 has been established in the literature directly from neutrino interactions with magnetic fields, and, interestingly enough, is comparable with the limits on the neutrino magnetic moment involving the first family and with the ones coming from modifications to the electroweak cross section.

Leptonic unitary triangles and boomerangs

International Nuclear Information System (INIS)

Dueck, Alexander; Rodejohann, Werner; Petcov, Serguey T.

2010-01-01

We review the idea of leptonic unitary triangles and extend the concept of the recently proposed unitary boomerangs to the lepton sector. Using a convenient parametrization of the lepton mixing, we provide approximate expressions for the side lengths and the angles of the six different triangles and give examples of leptonic unitary boomerangs. Possible applications of the leptonic unitary boomerangs are also briefly discussed.

Non-unitary boson mapping and its application to nuclear collective motions

International Nuclear Information System (INIS)

Takada, Kenjiro

2001-01-01

First, the general theory of boson mapping for even-number many-fermion systems is surveyed. In order to overcome the confusion concerning the so-called unphysical or spurious states in the boson mapping, the correct concept of the unphysical states is precisely given in a clear-cut way. Next, a method to apply the boson mapping to a truncated many-fermion Hilbert space consisting of collective phonons is proposed, by putting special emphasis on the Dyson-type non-unitary boson mapping. On the basis of this method, it becomes possible for the first time to apply the Dyson-type boson mapping to analyses of collective motions in realistic nuclei. This method is also extended to be applicable to odd-number-fermion systems. As known well, the Dyson-type boson mapping is a non-unitary transformation and it gives a non-Hermitian boson Hamiltonian. It is not easy (but not impossible) to solve the eigenstates of the non-Hermitian Hamiltonian. A Hermitian treatment of this non-Hermitian eigenvalue problem is discussed and it is shown that this treatment is a very good approximation. using this Hermitian treatment, we can obtain the normal-ordered Holstein-Primakoff-type boson expansion in the multi-collective-phonon subspace. Thereby the convergence of the boson expansion can be tested. Some examples of application of the Dyson-type non-unitary boson mapping to simplified models and realistic nuclei are also shown, and we can see that it is quite useful for analysis of the collective motions in realistic nuclei. In contrast to the above-mentioned ordinary type of boson mapping, which may be called a a 'static' boson mapping, the Dyson-type non-unitary self-consistent-collective-coordinate method is discussed. The latter is, so to speak, a 'dynamical' boson mapping, which is a dynamical extension of the ordinary boson mapping to be capable to include the coupling effects from the non-collective degrees of freedom self-consistently.Thus all of the Dyson-type non-unitary boson

Neutrino oscillations and the seesaw origin of neutrino mass

Energy Technology Data Exchange (ETDEWEB)

Miranda, O.G., E-mail: omr@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000 Mexico, Distrito Federal (Mexico); Valle, J.W.F. [AHEP Group, Institut de Física Corpuscular – C.S.I.C./Universitat de València, Parc Cientific de Paterna, C/Catedratico José Beltrán, 2, E-46980 Paterna (València) (Spain)

2016-07-15

The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.

On entanglement in neutrino mixing and oscillations

International Nuclear Information System (INIS)

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

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.

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.

Neutrino oscillations from discrete non-Abelian family symmetries

International Nuclear Information System (INIS)

Schmaltz, M.

1995-01-01

I disuss a SUSY GUT model with a non-Abelian discrete family symmetry that explains the observed hierarchical pattern of quark and lepton masses. This SO(10)xΔ(75) model predicts modified quadratic seesaw neutrino masses and mixing angles which are interesting for three reasons: (i) they offer a solution to the solar neutrino problem, (ii) the τ neutrino has the right mass for a cosmologically interesting hot dark matter candidate, and (iii) they suggest a positive result for the ν μ →ν τ oscillation searches by the CHORUS and NOMAD Collaborations. However, the model shares some problems with many other predictive GUT models of quark and lepton masses. The predictions from well-known mass and angle relations, such as the relation λ b GUT =λ τ GUT , fail in many cases. Attempts to correct these relations seem to lead to rather contrived models

Pattern of neutrino mixing in grand unified theories

International Nuclear Information System (INIS)

Milton, K.; Tanaka, K.

1981-01-01

It was found previously in SO(10) grand unified theories that if the neutrinos have a Dirac mass and a right-handed Majorana mass (approx. 10 15 GeV) but no left-handed Majorana mass, there is small ν/sub e/ mixing but ν/sub μ/ - ν/sub tau/ mixing can be substantial. This problem is reexamined on the basis of a formalism that assumes that the up, down, lepton, and neutrino mass matrices arise from a single complex 10 and a single 126 Higgs boson. This formalism determines the Majorana mass matrix in terms of quark mass matrices. Adopting three different sets of quark mass matrices that produce acceptable fermion mass ratios and Cabbibo mixing produces results consistent with the above; however, in the optimum case, ν/sub e/ - ν/sub μ/ mixing can be of the order of the Cabbibo angle

Origins of tiny neutrino mass and large flavor mixings

International Nuclear Information System (INIS)

Haba, Naoyuki

2015-01-01

Active neutrino masses are extremely smaller than those of other quarks and leptons, and there are large flavor mixings in the lepton sector, contrary to the quark sector. They are great mysteries in the standard model, but also excellent hints of new physics beyond the standard model. Thus, questions 'What is an origin of tiny neutrino mass?' and 'What is an origin of large lepton flavor mixings?' are very important. In this paper, we overview various attempts to solve these big questions. (author)

Large neutrino mixings in MSSM and SUSY GUTs: Democratic approach

International Nuclear Information System (INIS)

Shafi, Qaisar; Tavartkiladze, Zurab

2003-01-01

We show how, with aid from a U (1) flavor symmetry, 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. 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). We then proceed to an example based on 5D SUSY SU(5) GUT in which the neutrino democracy idea can be realized. A crucial role is played by bulk states, the so-called 'copies', which are split by compactifying the fifth dimension on an S(1)/Z2 x Z'2 orbifold

Models of neutrino mass and mixing

International Nuclear Information System (INIS)

Ma, Ernest

2000-01-01

There are two basic theoretical approaches to obtaining neutrino mass and mixing. In the minimalist approach, one adds just enough new stuff to the Minimal Standard Model to get m ν ≠0 and U αi ≠1. In the holistic approach, one uses a general framework or principle to enlarge the Minimal Standard Model such that, among other things, m ν ≠0 and U αi ≠1. In both cases, there are important side effects besides neutrino oscillations. I discuss a number of examples, including the possibility of leptogenesis from R parity nonconservation in supersymmetry

Neutrino oscillations from discrete non-Abelian family symmetries

International Nuclear Information System (INIS)

Schmaltz, M.

1994-11-01

The author discusses a SUSY-GUT model with a non-Abelian discrete family symmetry that explains the observed hierarchical pattern of quark and lepton masses. This SO(10) x Δ(75) model predicts modified quadratic seesaw neutrino masses and mixing angles which are interesting for three reasons: (1) they offer a solution to the solar neutrino problem, (2) the tau neutrino has the right mass for a cosmologically interesting hot dark matter candidate, and (3) they suggest a positive result for the ν μ → ν τ oscillation searches by the CHORUS and NOMAD collaborations. However, the model shares some problems with many other predictive GUT models of quark and lepton masses. Well-known and once successful mass and angle relations, such as the SU(5) relation λ b GUT = λ t GUT , are found to be in conflict with the current experimental status. Attempts to correct these relations seem to lead to rather contrived models

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

Directory of Open Access Journals (Sweden)

Yu-Feng Li

2014-11-01

Full Text Available 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.

Flavor S4xZ2 symmetry and neutrino mixing

International Nuclear Information System (INIS)

Zhang He

2007-01-01

We present a model of the lepton masses and flavor mixing based on the discrete group S 4 xZ 2 . In this model, all the charged leptons and neutrinos are assigned to the 3 - b arα representation of S 4 in the Yamanouchi bases. The charged lepton and neutrino masses are mainly determined by the vacuum expectation value structures of the Higgs fields. A nearly tri-bimaximal lepton flavor mixing pattern, which is in agreement with the current experimental results, can be accommodated in our model. The neutrino mass spectrum takes the nearly degenerate pattern, and thus can be well tested in the future precise experiments

Prospects for experiments on neutrino masses and mixing via neutrino oscillations at future accelerators

International Nuclear Information System (INIS)

Lanou, R.E. Jr.

1982-01-01

A study is made of the requirements necessary for improvement in our knowledge of limits in mass and mixing parameters for neutrinos via oscillation phenomena at accelerators. It is concluded that increased neutrino event rate (flux x energy) at modest energy machines (e.g., AGS and LAMPF) is the single most important requirement. This will permit smaller E/L ratios and refinement of systematics

Role of neutrino mixing in accelerated proton decay

Science.gov (United States)

Blasone, M.; Lambiase, G.; Luciano, G. G.; Petruzziello, L.

2018-05-01

The decay of accelerated protons has been analyzed both in the laboratory frame (where the proton is accelerated) and in the comoving frame (where the proton is at rest and interacts with the Fulling-Davies-Unruh thermal bath of electrons and neutrinos). The equality between the two rates has been exhibited as an evidence of the necessity of Fulling-Davies-Unruh effect for the consistency of quantum field theory formalism. Recently, it has been argued that neutrino mixing can spoil such a result, potentially opening new scenarios in neutrino physics. In the present paper, we analyze in detail this problem, and we find that, assuming flavor neutrinos to be fundamental and working within a certain approximation, the agreement can be restored.

Unifying leptogenesis, dark matter and high-energy neutrinos with right-handed neutrino mixing via Higgs portal

Energy Technology Data Exchange (ETDEWEB)

Bari, Pasquale Di; Ludl, Patrick Otto [Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Palomares-Ruiz, Sergio [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València,Apartado de Correos 22085, E-46071 Valencia (Spain)

2016-11-21

We revisit a model in which neutrino masses and mixing are described by a two right-handed (RH) neutrino seesaw scenario, implying a strictly hierarchical light neutrino spectrum. A third decoupled RH neutrino, N{sub DM} with mass M{sub DM}, plays the role of cold dark matter (DM) and is produced by the mixing with a source RH neutrino, N{sub S} with mass M{sub S}, induced by Higgs portal interactions. The same interactions are also responsible for N{sub DM} decays. We discuss in detail the constraints coming from DM abundance and stability conditions showing that in the hierarchical case, for M{sub DM}≫M{sub S}, there is an allowed window on M{sub DM} values necessarily implying a contribution, from DM decays, to the high-energy neutrino flux recently detected by IceCube. We also show how the model can explain the matter-antimatter asymmetry of the Universe via leptogenesis in the quasi-degenerate limit. In this case, the DM mass should be within the range 300 GeV ≲M{sub S}neutrino flux and show the predicted event spectrum for two exemplary cases. Although DM decays, with a relatively hard spectrum, cannot account for all the IceCube high-energy data, we illustrate how this extra source of high-energy neutrinos could reasonably explain some potential features in the observed spectrum. In this way, this represents a unified scenario for leptogenesis and DM that could be tested during the next years with more high-energy neutrino events.

Searches for New Physics at MiniBooNE: Sterile Neutrinos and Mixing Freedom

Energy Technology Data Exchange (ETDEWEB)

Karagiorgi, Georgia S. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2010-09-01

data, with and without constraints from other oscillation experiments with similar sensitivities to those models. A general search for new physics scenarios which would lead to effective non-unitarity of the standard 3 x 3 neutrino mixing matrix, or mixing freedom, is also performed using neutrino and antineutrino data available from MiniBooNE.

A model of radiative neutrino masses. Mixing and a possible fourth generation

International Nuclear Information System (INIS)

Babu, K.S.; Ma, E.; Pantaleone, J.

1989-01-01

We consider the phenomenological consequences of a recently proposed model with four lepton generations such that the three known neutrinos have radiatively induced Majorana masses. Mixing among generations in the presence of a heavy fourth neutrino necessitates a reevaluation of the usual experimental tests of the standard model. One interesting possibility is to have a τ lifetime longer than predicted by the standard three-generation model. Another is to have neutrino masses and mixing angles in the range needed for a natural explanation of the solar-neutrino puzzle in terms of the Mikheyev-Smirnov-Wolfenstein effect. (orig.)

Implications of neutrino masses and mixing for weak processes

International Nuclear Information System (INIS)

Shrock, R.E.

1981-01-01

A general theory is presented of weak processes involving neutrinos which consistently incorporates the possibility of nonzero neutrino masses and associated lepton mixing. The theory leads to new tests for and bounds on such masses and mixing. These tests make use of (π,K)/sub l2/ decay, nuclear β decay, and μ and tau decays, among others. New experiments at SIN and KEK to apply the tests are mentioned. Further, some implications are discussed for (1) the analysis of the spectral parameters in leptonic decays to determine the Lorentz structure of the weak leptonic couplings; (2) fundamental weak interaction constants such as G/sub μ/, G/sub V/', f/sub π/, f/sub K/, V/sub uq/, q = d or s, m/sub W/, and m/sub Z/; and (3) neutrino propagation

LSND versus MiniBooNE: Sterile neutrinos with energy dependent masses and mixing?

CERN Document Server

Schwetz, Thomas

2008-01-01

Standard active-sterile neutrino oscillations do not provide a satisfactory description of the LSND evidence for neutrino oscillations together with the constraints from MiniBooNE and other null-result short-baseline oscillation experiments. However, if the mass or the mixing of the sterile neutrino depends in an exotic way on its energy all data become consistent. I explore the phenomenological consequences of the assumption that either the mass or the mixing scales with the neutrino energy as $1/E_\

Large and almost maximal neutrino mixing within the type II see-saw mechanism

International Nuclear Information System (INIS)

Lindner, Manfred; Rodejohann, Werner

2007-01-01

Within the type II see-saw mechanism the light neutrino mass matrix is given by a sum of a direct (or triplet) mass term and the conventional (type I) see-saw term. Both versions of the see-saw mechanism explain naturally small neutrino masses, but the type II scenario offers interesting additional possibilities to explain large or almost maximal or vanishing mixings which are discussed in this paper. We first introduce 'type II enhancement' of neutrino mixing, where moderate cancellations between the two terms can lead to large neutrino mixing even if all individual mass matrices and terms generate small mixing. However, nearly maximal or vanishing mixings are not naturally explained in this way, unless there is a certain initial structure (symmetry) which enforces certain elements of the matrices to be identical or related in a special way. We therefore assume that the leading structure of the neutrino mass matrix is the triplet term and corresponds to zero U e3 and maximal θ 23 . Small but necessary corrections are generated by the conventional see-saw term. Then we assume that one of the two terms corresponds to an extreme mixing scenario, such as bimaximal or tri-bimaximal mixing. Deviations from this scheme are introduced by the second term. One can mimic Quark-Lepton Complementarity in this way. Finally, we note that the neutrino mass matrix for tri-bimaximal mixing can be-depending on the mass hierarchy-written as a sum of two terms with simple structure. Their origin could be the two terms of type II see-saw

Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters

International Nuclear Information System (INIS)

Ahmad, Q.R.; Bullard, T.V.; Cox, G.A.; Duba, C.A.; Formaggio, J.A.; Germani, J.V.; Hamian, A.A.; Hazama, R.; Heeger, K.M.; Howe, M.; Kazkaz, K.; Manor, J.; Meijer Drees, R.; Orrell, J.L.; Schaffer, K.K.; Smith, M.W.E.; Steiger, T.D.; Stonehill, L.C.; Allen, R.C.; Buehler, G.

2002-01-01

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8 B spectrum, the night minus day rate is 14.0%±6.3% +1.5 -1.4 % of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the ν e asymmetry is found to be 7.0%±4.9% +1.3 -1.2 % . A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution

A neutrino mass-mixing sum rule from SO(10) and neutrinoless double beta decay

Energy Technology Data Exchange (ETDEWEB)

Buccella, F. [INFN, Sezione di Napoli,Complesso University Monte S. Angelo, I-80126 Napoli (Italy); Chianese, M. [INFN, Sezione di Napoli,Complesso University Monte S. Angelo, I-80126 Napoli (Italy); Dipartimento di Fisica Ettore Pancini, Università di Napoli Federico II,Complesso University Monte S. Angelo, I-80126 Napoli (Italy); Mangano, G. [INFN, Sezione di Napoli,Complesso University Monte S. Angelo, I-80126 Napoli (Italy); Miele, G.; Morisi, S.; Santorelli, P. [INFN, Sezione di Napoli,Complesso University Monte S. Angelo, I-80126 Napoli (Italy); Dipartimento di Fisica Ettore Pancini, Università di Napoli Federico II,Complesso University Monte S. Angelo, I-80126 Napoli (Italy)

2017-04-03

Minimal SO(10) grand unified models provide phenomenological predictions for neutrino mass patterns and mixing. These are the outcome of the interplay of several features, namely: i) the seesaw mechanism; ii) the presence of an intermediate scale where B-L gauge symmetry is broken and the right-handed neutrinos acquire a Majorana mass; iii) a symmetric Dirac neutrino mass matrix whose pattern is close to the up-type quark one. In this framework two natural characteristics emerge. Normal neutrino mass hierarchy is the only allowed, and there is an approximate relation involving both light-neutrino masses and mixing parameters. This differs from what occurring when horizontal flavour symmetries are invoked. In this case, in fact, neutrino mixing or mass relations have been separately obtained in literature. In this paper we discuss an example of such comprehensive mixing-mass relation in a specific realization of SO(10) and, in particular, analyse its impact on the expected neutrinoless double beta decay effective mass parameter 〈m{sub ee}〉, and on the neutrino mass scale. Remarkably a lower limit for the lightest neutrino mass is obtained (m{sub lightest}≳7.5×10{sup −4} eV, at 3 σ level).

Geometric phase of neutrinos: Differences between Dirac and Majorana neutrinos

Science.gov (United States)

Capolupo, A.; Giampaolo, S. M.; Hiesmayr, B. C.; Vitiello, G.

2018-05-01

We analyze the non-cyclic geometric phase for neutrinos. We find that the geometric phase and the total phase associated to the mixing phenomenon provide a theoretical tool to distinguish between Dirac and Majorana neutrinos. Our results hold for neutrinos propagating in vacuum and through the matter. We feed the values of the experimental parameters in our formulas in order to make contact with experiments. Although it remains an open question how the geometric phase of neutrinos could be detected, our theoretical results may open new scenarios in the investigation of the neutrino nature.

Entanglement entropy of non-unitary integrable quantum field theory

Directory of Open Access Journals (Sweden)

Davide Bianchini

2015-07-01

Full Text Available In this paper we study the simplest massive 1+1 dimensional integrable quantum field theory which can be described as a perturbation of a non-unitary minimal conformal field theory: the Lee–Yang model. We are particularly interested in the features of the bi-partite entanglement entropy for this model and on building blocks thereof, namely twist field form factors. Non-unitarity selects out a new type of twist field as the operator whose two-point function (appropriately normalized yields the entanglement entropy. We compute this two-point function both from a form factor expansion and by means of perturbed conformal field theory. We find good agreement with CFT predictions put forward in a recent work involving the present authors. In particular, our results are consistent with a scaling of the entanglement entropy given by ceff3log⁡ℓ where ceff is the effective central charge of the theory (a positive number related to the central charge and ℓ is the size of the region. Furthermore the form factor expansion of twist fields allows us to explore the large region limit of the entanglement entropy and find the next-to-leading order correction to saturation. We find that this correction is very different from its counterpart in unitary models. Whereas in the latter case, it had a form depending only on few parameters of the model (the particle spectrum, it appears to be much more model-dependent for non-unitary models.

Theoretical Models of Neutrino Mixing Recent Developments

CERN Document Server

Altarelli, Guido

2009-01-01

The data on neutrino mixing are at present compatible with Tri-Bimaximal (TB) mixing. If one takes this indication seriously then the models that lead to TB mixing in first approximation are particularly interesting and A4 models are prominent in this list. However, the agreement of TB mixing with the data could still be an accident. We discuss a recent model based on S4 where Bimaximal mixing is instead valid at leading order and the large corrections needed to reproduce the data arise from the diagonalization of charged leptons. The value of $\\theta_{13}$ could distinguish between the two alternatives.

Neutrino Mixing and Masses from a Minimum Principle

CERN Document Server

Alonso, R; Isidori, G; Maiani, L

2013-01-01

We analyze the structure of quark and lepton mass matrices under the hypothesis that they are determined from a minimum principle applied to a generic potential invariant under the $\\left[SU(3)\\right]^5\\otimes \\mathcal O(3)$ flavor symmetry, acting on Standard Model fermions and right-handed neutrinos. Unlike the quark case, we show that hierarchical masses for charged leptons are naturally accompanied by degenerate Majorana neutrinos with one mixing angle close to maximal, a second potentially large, a third one necessarily small, and one maximal relative Majorana phase. Adding small perturbations the predicted structure for the neutrino mass matrix is in excellent agreement with present observations and could be tested in the near future via neutrino-less double beta decay and cosmological measurements. The generalization of these results to arbitrary sew-saw models is also discussed.

On the algebra of local unitary invariants of pure and mixed quantum states

International Nuclear Information System (INIS)

Vrana, Peter

2011-01-01

We study the structure of the inverse limit of the graded algebras of local unitary invariant polynomials using its Hilbert series. For k subsystems, we show that the inverse limit is a free algebra and the number of algebraically independent generators with homogenous degree 2m equals the number of conjugacy classes of index m subgroups in a free group on k - 1 generators. Similarly, we show that the inverse limit in the case of k-partite mixed state invariants is free and the number of algebraically independent generators with homogenous degree m equals the number of conjugacy classes of index m subgroups in a free group on k generators. The two statements are shown to be equivalent. To illustrate the equivalence, using the representation theory of the unitary groups, we obtain all invariants in the m = 2 graded parts and express them in a simple form both in the case of mixed and pure states. The transformation between the two forms is also derived. Analogous invariants of higher degree are also introduced.

Large mixing of light and heavy neutrinos in seesaw models and the LHC

International Nuclear Information System (INIS)

He Xiaogang; Oh, Sechul; Tandean, Jusak; Wen, C.-C.

2009-01-01

In the type-I seesaw model the size of mixing between light and heavy neutrinos, ν and N, respectively, is of order the square root of their mass ratio, (m ν /m N ) 1/2 , with only one generation of the neutrinos. Since the light-neutrino mass must be less than an eV or so, the mixing would be very small, even for a heavy-neutrino mass of order a few hundred GeV. This would make it unlikely to test the model directly at the LHC, as the amplitude for producing the heavy neutrino is proportional to the mixing size. However, it has been realized for some time that, with more than one generation of light and heavy neutrinos, the mixing can be significantly larger in certain situations. In this paper we explore this possibility further and consider specific examples in detail in the context of type-I seesaw. We study its implications for the single production of the heavy neutrinos at the LHC via the main channel qq ' →W*→lN involving an ordinary charged lepton l. We then extend the discussion to the type-III seesaw model, which has richer phenomenology due to presence of the charged partners of the heavy neutrinos, and examine the implications for the single production of these heavy leptons at the LHC. In the latter model the new kinds of solutions that we find also make it possible to have sizable flavor-changing neutral-current effects in processes involving ordinary charged leptons.

Neutrino mixing: from the broken μ-τ symmetry to the broken Friedberg–Lee symmetry

International Nuclear Information System (INIS)

Xing, Zhizhong

2007-01-01

I argue that the observed flavor structures of leptons and quarks might imply the existence of certain flavor symmetries. The latter should be a good starting point to build realistic models towards deeper understanding of the fermion mass spectra and flavor mixing patterns. The μ-τ permutation symmetry serves for such an example to interpret the almost maximal atmospheric neutrino mixing angle (θ 23 ~ 45°) and the strongly suppressed CHOOZ neutrino mixing angle (θ 13 < 10°). In this talk I like to highlight a new kind of flavor symmetry, the Friedberg–Lee symmetry, for the effective Majorana neutrino mass operator. Luo and I have shown that this symmetry can be broken in an oblique way, such that the lightest neutrino remains massless but an experimentally-favored neutrino mixing pattern is achievable. We get a novel prediction for θ 13 in the CP-conserving case: sinθ 13 = tanθ 12 |(1 - tanθ 23 )/(1 + tanθ 23 )|. Our scenario can simply be generalized to accommodate CP violation and be combined with the seesaw mechanism. Finally I stress the importance of probing possible effects of μ-τ symmetry breaking either in terrestrial neutrino oscillation experiments or with ultrahigh-energy cosmic neutrino telescopes. (author)

Remarks on ''Neutrino masses and mixing angles in a predictive theory of fermion masses''

International Nuclear Information System (INIS)

Lavoura, L.; Silva, J.P.

1994-01-01

In the extension of the Dimopoulos-Hall-Raby model of the fermion mass matrices to the neutrino sector, there is an entry in the up-quark and neutrino Dirac mass matrices which can be assumed to arise from the Yukawa coupling of a 120, instead of a 10 or a 126, of SO(10). Although this assumption leads to an extra undetermined complex parameter in the model, the resulting lepton mixing matrix exhibits the remarkable feature that the ν τ does not mix with the other two neutrinos. Making a reasonable assumption about the extra parameter, we are able to fit the large-mixing-angle MSW solution of the solar-neutrino problem, and we obtain m ντ ∼10 eV, the right mass range to close the Universe. Other possibilities for explaining the solar-neutrino deficit are also discussed

Investigation of alternative mechanisms to neutrino oscillations in the MINOS experiment; Investigacao de Mecanismos Alternativos a Oscilacao de Neutrinos no Experimentos MINOS

Energy Technology Data Exchange (ETDEWEB)

de Abreu Barbosa Coelho, Joao [Campinas State Univ., Sao Paulo (Brazil)

2012-01-01

The neutrino oscillation model is very successful in explaining a large variety of experiments. The model is based on the premise that the neutrinos that interact through the weak force via charged current are not mass eigenstates, but a superposition of them. In general, a quantum superposition is subject to loss of coherence, so that pure states tend toward mixed states. This type of evolution is not possible within the context of isolated quantum systems because the evolution is unitary and, therefore, is invariant under time reversal. By breaking unitarity, an arrow of time is introduced and the characteristic effect for neutrinos is a damping of oscillations. In this thesis, some phenomenological decoherence and decay models are investigated, which could be observed by MINOS, a neutrino oscillation experiment that consists of measuring the neutrino flux produced in a particle accelerator 735 km away. We analyse the disappearance of muon neutrinos in MINOS. Information from other experiments is used to constrain the number of parameters, leaving only one extra parameter in each model. We assume a power law energy dependence of the decoherence parameter. The official MINOS software and simulation are used to obtain the experiment's sensitivities to the effects of unitarity breaking considered.

Polynomial approximation of non-Gaussian unitaries by counting one photon at a time

Science.gov (United States)

Arzani, Francesco; Treps, Nicolas; Ferrini, Giulia

2017-05-01

In quantum computation with continuous-variable systems, quantum advantage can only be achieved if some non-Gaussian resource is available. Yet, non-Gaussian unitary evolutions and measurements suited for computation are challenging to realize in the laboratory. We propose and analyze two methods to apply a polynomial approximation of any unitary operator diagonal in the amplitude quadrature representation, including non-Gaussian operators, to an unknown input state. Our protocols use as a primary non-Gaussian resource a single-photon counter. We use the fidelity of the transformation with the target one on Fock and coherent states to assess the quality of the approximate gate.

Neutrinos

CERN Multimedia

CERN. Geneva

2004-01-01

The Standard Model predicts that the neutrinos are massless and do not mix. Generic extensions of the Standard Model predict that neutrinos are massive (but, very likely, much lighter than the charged fermions). Therefore, the search for neutrino masses and mixing tests the Standard Model and probes new phasics. Measurements of various features of the fluxes of atmospheric, solar and, more recently, reactor neutrinos have provided evidence for neutrino oscillations and therefore for neutrino masses and mixing. These results have significant theoretical implications: new physics exists, and its scale can be estimated. There are interesting lessons for grand unified theories and for models of extra dimensions. The measured neutrino flavor parameters pose a challenge to flavor models.

Addendum to 'Update on neutrino mixing in the early universe'

International Nuclear Information System (INIS)

Di Bari, P.

2003-01-01

In the light of the recent WMAP results we update the constraints on a class of nonstandard big bang nucleosynthesis (BBN) models with a simultaneous combination of nonstandard neutrino distributions and an extra effective number of neutrinos in the expansion rate. These models can be described in terms of the two parameters ΔN ν tot , constrained by the primordial helium abundance Y p measurement, and ΔN ν ρ , constrained by a combination of cosmic microwave background and primordial deuterium data. Small deviations from standard big bang nucleosynthesis are suggested. Different nonstandard scenarios can be distinguished by a measurement of the difference ΔN ν f ν =ΔN ν tot -ΔN ν ρ . From the current data we estimate ΔN ν f ν ≅-1.4 -1.4 +0.9 , mildly disfavoring solutions with a low expansion rate, characterized by ΔN ν f ν =0 and negative ΔN ν ρ . Active-sterile neutrino mixing could be a viable explanation only for high values of Y p > or approx. 0.24. The existence of large positive neutrino chemical potentials ξ i ∼0.05, implying ΔN ν ρ ≅0, would be a possible explanation of the data within the analyzed class of nonstandard BBN models. Interestingly, it would also provide a way to evade the cosmological bounds for ''class A 3+1'' four neutrino mixing models. A scenario with a decaying sterile neutrino is also considered

The MSW Effect and Matter Effects in Neutrino Oscillations

Science.gov (United States)

Smirnov, A. Yu.

2006-03-01

The MSW (Mikheyev-Smirnov-Wolfenstein) effect is the adiabatic or partially adiabatic neutrino flavor conversion in media with varying density. The main notions related to the effect, its dynamics and physical picture are reviewed. The large mixing MSW effect is realized inside the Sun providing a solution of the solar neutrino problem. The small mixing MSW effect driven by the 1-3 mixing can be realized for the supernova (SN) neutrinos. Inside collapsing stars new elements of the MSW dynamics may show up: non-oscillatory transition, non-adiabatic conversion, time dependent adiabaticity violation induced by shock waves. Effects of the resonance enhancement and the parametric enhancement of oscillations can be realized for atmospheric and accelerator neutrinos in the Earth. Precise results for neutrino oscillations in low density media with arbitrary density profile are presented and the attenuation effect is described. The area of applications is the solar and SN neutrinos inside the Earth, and the results are crucial for the neutrino oscillation tomography.

Measuring the deviation of the 2-3 lepton mixing from maximal with atmospheric neutrinos

CERN Document Server

González-Garciá, M C; Smirnov, A Yu

2004-01-01

The measurement of the deviation of the 2-3 leptonic mixing from maximal, D_23 = 1/2 - sin^2(theta_23), is one of the key issues for understanding the origin of the neutrino masses and mixing. In the three-neutrino context we study the dependence of various observables in the atmospheric neutrinos on D_23. We perform a global three-neutrino analysis of the atmospheric and reactor neutrino data taking into account the effects of both the oscillations driven by the "solar" parameters (Delta_m_21^2 and theta_12) and the 1-3 mixing. The departure from the one-dominant mass scale approximation results into the shift of the 2-3 mixing from maximal by Delta_sin^2(theta_23) ~ 0.04, so that D_23 ~ 0.04 +- 0.07 (1 sigma). Though value of the shift is not statistically significant, the tendency is robust. The shift is induced by the excess of the e-like events in the sub-GeV sample. We show that future large scale water Cherenkov detectors can determine D_23 with accuracy of a few percent, comparable with the sensitivit...

Renormalization-group equations of neutrino masses and flavor mixing parameters in matter

Science.gov (United States)

Xing, Zhi-zhong; Zhou, Shun; Zhou, Ye-Ling

2018-05-01

We borrow the general idea of renormalization-group equations (RGEs) to understand how neutrino masses and flavor mixing parameters evolve when neutrinos propagate in a medium, highlighting a meaningful possibility that the genuine flavor quantities in vacuum can be extrapolated from their matter-corrected counterparts to be measured in some realistic neutrino oscillation experiments. Taking the matter parameter a≡ 2√{2}{G}F{N}_eE to be an arbitrary scale-like variable with N e being the net electron number density and E being the neutrino beam energy, we derive a complete set of differential equations for the effective neutrino mixing matrix V and the effective neutrino masses {\\tilde{m}}_i (for i = 1 , 2 , 3). Given the standard parametrization of V , the RGEs for {{\\tilde{θ}}_{12}, {\\tilde{θ}}_{13}, {\\tilde{θ}}_{23}, \\tilde{δ}} in matter are formulated for the first time. We demonstrate some useful differential invariants which retain the same form from vacuum to matter, including the well-known Naumov and Toshev relations. The RGEs of the partial μ- τ asymmetries, the off-diagonal asymmetries and the sides of unitarity triangles of V are also obtained as a by-product.

A multi-signature approach to low-scale sterile neutrino phenomenology

CERN Document Server

Ross-Lonergan, Mark

2017-01-01

Since the discovery of non-zero neutrino masses, through the observation of neutrino flavour oscillations, we had a plethora of successful experiments which have made increasingly precise measurements of the mixing angles and mass-differences that drive the phenomena. In this thesis we highlight the fact that there is still significant room for new physics, however, when one removes the assumption of unitarity of the 3x3 neutrino mixing matrix, an assumption inherent in the 3ν paradigm. We refit all global data to show just how much non-unitarity is currently allowed. The canonical way that such a non-unitarity is introduced to the 3x3 neutrino mixing matrix is by the addition of additional neutral fermions, singlets under the Standard Model gauge group. These “Sterile Neutrinos” have a wide range of the- oretical and phenomenological implications. Alongside the sensitivity non-unitarity measurements have to sterile neutrinos, in this thesis we will study in detail two additional signatures of low-scale ...

Neutrino masses and mixings

International Nuclear Information System (INIS)

Wolfenstein, L.

1991-01-01

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

GUT and flavor models for neutrino masses and mixing

Science.gov (United States)

Meloni, Davide

2017-10-01

In the recent years experiments have established the existence of neutrino oscillations and most of the oscillation parameters have been measured with a good accuracy. However, in spite of many interesting ideas, no real illumination was sparked on the problem of flavor in the lepton sector. In this review, we discuss the state of the art of models for neutrino masses and mixings formulated in the context of flavor symmetries, with particular emphasis on the role played by grand unified gauge groups.

On Bimaximal Neutrino Mixing and GUT's

CERN Document Server

Altarelli, Guido; Meloni, Davide

2015-04-21

We briefly discuss the present status of models of neutrino mixing. Among the existing viable options we review the virtues of Bimaximal Mixing (that could be implemented by an $S_4$ discrete symmetry), corrected by terms arising from the charged lepton mass diagonalization. In particular in a GUT formulation the property of quark lepton "weak" complementarity can be naturally realized. We discuss in some detail two new versions of particular GUT models, one based on $SU(5)$ and one on $SO(10)$ and the associated phenomenology. We compare these approaches based on symmetry to models based on chance, like Anarchy or $U(1)_{FN}$.

Large neutrino mixing from renormalization group evolution

International Nuclear Information System (INIS)

Balaji, K.R.S.; Mohapatra, R.N.; Parida, M.K.; Paschos, E.A.

2000-10-01

The renormalization group evolution equation for two neutrino mixing is known to exhibit nontrivial fixed point structure corresponding to maximal mixing at the weak scale. The presence of the fixed point provides a natural explanation of the observed maximal mixing of ν μ - ν τ , if the ν μ and ν τ are assumed to be quasi-degenerate at the seesaw scale without constraining the mixing angles at that scale. In particular, it allows them to be similar to the quark mixings as in generic grand unified theories. We discuss implementation of this program in the case of MSSM and find that the predicted mixing remains stable and close to its maximal value, for all energies below the O(TeV) SUSY scale. We also discuss how a particular realization of this idea can be tested in neutrinoless double beta decay experiments. (author)

Efficient Nonlocal M-Control and N-Target Controlled Unitary Gate Using Non-symmetric GHZ States

Science.gov (United States)

Chen, Li-Bing; Lu, Hong

2018-03-01

Efficient local implementation of a nonlocal M-control and N-target controlled unitary gate is considered. We first show that with the assistance of two non-symmetric qubit(1)-qutrit(N) Greenberger-Horne-Zeilinger (GHZ) states, a nonlocal 2-control and N-target controlled unitary gate can be constructed from 2 local two-qubit CNOT gates, 2 N local two-qutrit conditional SWAP gates, N local qutrit-qubit controlled unitary gates, and 2 N single-qutrit gates. At each target node, the two third levels of the two GHZ target qutrits are used to expose one and only one initial computational state to the local qutrit-qubit controlled unitary gate, instead of being used to hide certain states from the conditional dynamics. This scheme can be generalized straightforwardly to implement a higher-order nonlocal M-control and N-target controlled unitary gate by using M non-symmetric qubit(1)-qutrit(N) GHZ states as quantum channels. Neither the number of the additional levels of each GHZ target particle nor that of single-qutrit gates needs to increase with M. For certain realistic physical systems, the total gate time may be reduced compared with that required in previous schemes.

Theory of Neutrino Masses and Mixing

CERN Document Server

González-Garciá, M Concepción

2003-01-01

In this talk I will review our present knowledge on neutrino masses and mixing trying to emphasize what has been definitively proved and what is in the process of being probed. I will also discuss the most important theoretical implications of these results: the existence of new physics, the estimate of the scale of this new physics as well as some other possible consequences such as leptogenesis origin of the baryon asymmetry.

Doubly perturbed S3 neutrinos and the s13 mixing parameter

International Nuclear Information System (INIS)

Jora, Renata; Schechter, Joseph; Shahid, M. Naeem

2010-01-01

We further study a predictive model for the masses and mixing matrix of three Majorana neutrinos. At zeroth order the model yielded degenerate neutrinos and a generalized tribimaximal mixing matrix. At first order the mass splitting was incorporated and the tribimaximal mixing matrix emerged with very small corrections but with a zero value for the parameter s 13 . In the present paper a different, assumed weaker, perturbation is included which gives a nonzero value for s 13 and further corrections to other quantities. These corrections are worked out and their consequences discussed under the simplifying assumption that the conventional CP violation phase vanishes. It is shown that the existing measurements of the parameter s 23 provide strong bounds on s 13 in this model.

Limits on heavy neutrino mixing from the beta decay of 38mK confined in a magneto-optical trap

International Nuclear Information System (INIS)

Trinczek, M.C.

2001-01-01

This thesis details the search for mixing between electron neutrinos and possible heavy neutrinos using the positron decay of 38m K produced at ISAC, TRIUMF's new radioactive beam facility. Using the novel technique of laser atom trapping to confine 38m K, direct limits on such mixing in β-decay are determined for the mass range of 0.7 MeV/c 2 to 3.8 MeV/c 2 . The results, for part of this mass range, provide the best direct limits for the mixing of heavy neutrinos with the electron neutrino in the literature to date. The Standard Model of electroweak physics has been able to describe a wide range of experimental results, but an unresolved question arises in accounting for lepton masses. The charged leptons (electrons, muons and taus) have masses which vary enormously from one to another (m e = 0.511 MeV/c 2 , m μ = 106 MeV/c 2 , m τ = 1777 MeV/c 2 ), while their accompanying neutrinos appear to have no (or very little) mass. If neutrinos have finite mass, then mixing could occur among the different neutrino species. Thus, evidence of mixing would indicate the existence of non-zero neutrino mass and of the need to modify or extend the Standard Model. Consequently, this is a highly active field of physics. Evidence of possible neutrino mass and oscillation has been recently observed by the detection of energetic neutrinos from the atmosphere. The TRINAT collaboration at TRIUMF has searched for evidence of physics beyond the Standard Model using a radioactive source of 38m K atoms held in a neutral atom trap. The trap provides a source of several thousand atoms confined to a volume of less than a cubic millimeter, suspended in a vacuum vessel, in which the 38m K undergoes radioactive decay with the emission of a positron and a neutrino. This results in the creation of a daughter nucleus, 38 Ar , with momentum equal to the vector sum of the momenta of the positron and the neutrino. The unperturbed nucleus then recoils from the trap and is detected in coincidence

Neutrino masses and oscillations

Energy Technology Data Exchange (ETDEWEB)

Smirnov, A Yu

1996-11-01

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.

Radiative seesaw-type mechanism of fermion masses and non-trivial quark mixing

Energy Technology Data Exchange (ETDEWEB)

Arbelaez, Carolina; Hernandez, A.E.C.; Kovalenko, Sergey; Schmidt, Ivan [Universidad Tecnica Federico Santa Maria, Centro Cientifico-Tecnologico de Valparaiso-CCTVal, Valparaiso (Chile)

2017-06-15

We propose a predictive inert two-Higgs doublet model, where the standard model (SM) symmetry is extended by S{sub 3} x Z{sub 2} x Z{sub 12} and the field content is enlarged by extra scalar fields, charged exotic fermions and two heavy right-handed Majorana neutrinos. The charged exotic fermions generate a non-trivial quark mixing and provide one-loop-level masses for the first- and second-generation charged fermions. The masses of the light active neutrinos are generated from a one-loop-level radiative seesaw mechanism. Our model successfully explains the observed SM fermion mass and mixing pattern. (orig.)

Neutrino emissivity in the quark-hadron mixed phase of neutron stars

Energy Technology Data Exchange (ETDEWEB)

Spinella, William M. [Computational Science Research Center San Diego State University, San Diego, CA (United States); San Diego State University, Department of Physics, San Diego, CA (United States); Weber, Fridolin [San Diego State University, Department of Physics, San Diego, CA (United States); University of California San Diego, Center for Astrophysics and Space Sciences, La Jolla, CA (United States); Contrera, Gustavo A. [CONICET, Buenos Aires (Argentina); CONICET - Dept. de Fisica, UNLP, IFLP, La Plata (Argentina); Universidad Nacional de La Plata, Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina); Orsaria, Milva G. [CONICET, Buenos Aires (Argentina); Universidad Nacional de La Plata, Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina)

2016-03-15

Numerous theoretical studies using various equation of state models have shown that quark matter may exist at the extreme densities in the cores of high-mass neutron stars. It has also been shown that a phase transition from hadronic matter to quark matter would result in an extended mixed phase region that would segregate phases by net charge to minimize the total energy of the phase, leading to the formation of a crystalline lattice. The existence of quark matter in the core of a neutron star may have significant consequences for its thermal evolution, which for thousands of years is facilitated primarily by neutrino emission. In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the core. To this end we calculate the equation of state using the relativistic mean-field approximation to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures (

Search for sterile neutrinos at a new short-baseline CERN neutrino beam

International Nuclear Information System (INIS)

Mauri, N.

2014-01-01

In the last few years the experimental results on neutrino/anti-neutrino oscillations at Short-Baseline (SBL) showed a tension with several phenomenological models. The recent and carefully recomputed anti-neutrino fluxes from nuclear reactors have further increased this tension drawing a picture not fully compatible with the 3 neutrino oscillation scenario. A sterile neutrino is a neutral lepton which does not couple with W/Z bosons. it is not an exotic particle, its existence being a natural consequence of neutrinos having a non-zero mass. Sterile neutrinos can mix with the active ones through additional mass eigenstates, with no necessary mass scale. We will present an experimental search for sterile neutrinos with a new CERN-SPS neutrino beam using muon spectrometers and large LAr detectors. To definitely clarify the physics issue, the proposed experiment will study oscillations in a muon neutrino / antineutrino beam both in appearance and disappearance modes, exploring the Δm 2 ∼ 1 eV 2 range

Neutrino mixing and oscillation in a grand unified field theory SO(10)

International Nuclear Information System (INIS)

Tanaka, K.

1980-01-01

The investigation shows that it is very difficult to achieve neutrino mixing of other than the V/sub μ/-ν/sub tau/ type in any minimal SO(10) model in which neutrino masses are generated by the Gell-Mann-Ramond-Slansky mechanism, because of the severe constraints placed on the mass matrix by quark phenomenology

Neutrino mass and mixing: from theory to experiment

International Nuclear Information System (INIS)

King, Stephen F; Merle, Alexander; Morisi, Stefano; Shimizu, Yusuke; Tanimoto, Morimitsu

2014-01-01

The origin of fermion mass hierarchies and mixings is one of the unresolved and most difficult problems in high-energy physics. One possibility to address the flavour problems is by extending the standard model to include a family symmetry. In the recent years it has become very popular to use non-Abelian discrete flavour symmetries because of their power in the prediction of the large leptonic mixing angles relevant for neutrino oscillation experiments. Here we give an introduction to the flavour problem and to discrete groups that have been used to attempt a solution for it. We review the current status of models in light of the recent measurement of the reactor angle, and we consider different model-building directions taken. The use of the flavons or multi-Higgs scalars in model building is discussed as well as the direct versus indirect approaches. We also focus on the possibility of experimentally distinguishing flavour symmetry models by means of mixing sum rules and mass sum rules. In fact, we illustrate in this review the complete path from mathematics, via model building, to experiments, so that any reader interested in starting work in the field could use this text as a starting point in order to obtain a broad overview of the different subject areas

A note on the mixings of heavy neutrinos and muon decays

International Nuclear Information System (INIS)

Kalyniak, P.; Ng, J.N.

1982-11-01

The authors set limits on the mixing of heavy neutrinos into the muon family /U sub(μi)/sup(2) for neutrino masses in the range of 30 to 70 MeV/c 2 . Both the Michel parameter and the e + spectrum are used. This complements limits from leptonic decays of pseudoscalar mesons. They also give indications of how current experiments can be used to improve these limits

Search for active-sterile neutrino mixing using neutral-current interactions in NOvA

Science.gov (United States)

Adamson, P.; Aliaga, L.; Ambrose, D.; Anfimov, N.; Antoshkin, A.; Arrieta-Diaz, E.; Augsten, K.; Aurisano, A.; Backhouse, C.; Baird, M.; Bambah, B. A.; Bays, K.; Behera, B.; Bending, S.; Bernstein, R.; Bhatnagar, V.; Bhuyan, B.; Bian, J.; Blackburn, T.; Bolshakova, A.; Bromberg, C.; Brown, J.; Brunetti, G.; Buchanan, N.; Butkevich, A.; Bychkov, V.; Campbell, M.; Catano-Mur, E.; Childress, S.; Choudhary, B. C.; Chowdhury, B.; Coan, T. E.; Coelho, J. A. B.; Colo, M.; Cooper, J.; Corwin, L.; Cremonesi, L.; Cronin-Hennessy, D.; Davies, G. S.; Davies, J. P.; Derwent, P. F.; Dharmapalan, R.; Ding, P.; Djurcic, Z.; Dukes, E. C.; Duyang, H.; Edayath, S.; Ehrlich, R.; Feldman, G. J.; Frank, M. J.; Gabrielyan, M.; Gallagher, H. R.; Germani, S.; Ghosh, T.; Giri, A.; Gomes, R. A.; Goodman, M. C.; Grichine, V.; Groh, M.; Group, R.; Grover, D.; Guo, B.; Habig, A.; Hartnell, J.; Hatcher, R.; Hatzikoutelis, A.; Heller, K.; Himmel, A.; Holin, A.; Howard, B.; Hylen, J.; Jediny, F.; Judah, M.; Kafka, G. K.; Kalra, D.; Kasahara, S. M. S.; Kasetti, S.; Keloth, R.; Kolupaeva, L.; Kotelnikov, S.; Kourbanis, I.; Kreymer, A.; Kumar, A.; Kurbanov, S.; Lackey, T.; Lang, K.; Lee, W. M.; Lin, S.; Lokajicek, M.; Lozier, J.; Luchuk, S.; Maan, K.; Magill, S.; Mann, W. A.; Marshak, M. L.; Matera, K.; Matveev, V.; Méndez, D. P.; Messier, M. D.; Meyer, H.; Miao, T.; Miller, W. H.; Mishra, S. R.; Mohanta, R.; Moren, A.; Mualem, L.; Muether, M.; Mufson, S.; Murphy, R.; Musser, J.; Nelson, J. K.; Nichol, R.; Niner, E.; Norman, A.; Nosek, T.; Oksuzian, Y.; Olshevskiy, A.; Olson, T.; Paley, J.; Patterson, R. B.; Pawloski, G.; Pershey, D.; Petrova, O.; Petti, R.; Phan-Budd, S.; Plunkett, R. K.; Poling, R.; Potukuchi, B.; Principato, C.; Psihas, F.; Radovic, A.; Rameika, R. A.; Rebel, B.; Reed, B.; Rocco, D.; Rojas, P.; Ryabov, V.; Sachdev, K.; Sail, P.; Samoylov, O.; Sanchez, M. C.; Schroeter, R.; Sepulveda-Quiroz, J.; Shanahan, P.; Sheshukov, A.; Singh, J.; Singh, J.; Singh, P.; Singh, V.; Smolik, J.; Solomey, N.; Song, E.; Sousa, A.; Soustruznik, K.; Strait, M.; Suter, L.; Talaga, R. L.; Tas, P.; Thayyullathil, R. B.; Thomas, J.; Tian, X.; Tognini, S. C.; Tripathi, J.; Tsaris, A.; Urheim, J.; Vahle, P.; Vasel, J.; Vinton, L.; Vold, A.; Vrba, T.; Wang, B.; Wetstein, M.; Whittington, D.; Wojcicki, S. G.; Wolcott, J.; Yadav, N.; Yang, S.; Zalesak, J.; Zamorano, B.; Zwaska, R.; NOvA Collaboration

2017-10-01

We report results from the first search for sterile neutrinos mixing with active neutrinos through a reduction in the rate of neutral-current interactions over a baseline of 810 km between the NOvA detectors. Analyzing a 14-kton detector equivalent exposure of 6.05 ×1020 protons-on-target in the NuMI beam at Fermilab, we observe 95 neutral-current candidates at the Far Detector compared with 83.5 ±9.7 (stat ) ±9.4 (syst ) events predicted assuming mixing only occurs between active neutrino species. No evidence for νμ→νs transitions is found. Interpreting these results within a 3 +1 model, we place constraints on the mixing angles θ24<20.8 ° and θ34<31.2 ° at the 90% C.L. for 0.05 eV2≤Δ m412≤0.5 eV2 , the range of mass splittings that produce no significant oscillations over the Near Detector baseline.

Gravitational instabilities of the cosmic neutrino background with non-zero lepton number

Directory of Open Access Journals (Sweden)

Neil D. Barrie

2017-09-01

Full Text Available We argue that a cosmic neutrino background that carries non-zero lepton charge develops gravitational instabilities. Fundamentally, these instabilities are related to the mixed gravity-lepton number anomaly. We have explicitly computed the gravitational Chern–Simons term which is generated quantum-mechanically in the effective action in the presence of a lepton number asymmetric neutrino background. The induced Chern–Simons term has a twofold effect: (i gravitational waves propagating in such a neutrino background exhibit birefringent behaviour leading to an enhancement/suppression of the gravitational wave amplitudes depending on the polarisation, where the magnitude of this effect is related to the size of the lepton asymmetry; (ii Negative energy graviton modes are induced in the high frequency regime, which leads to very fast vacuum decay producing, e.g., positive energy photons and negative energy gravitons. From the constraint on the present radiation energy density, we obtain an interesting bound on the lepton asymmetry of the universe.

Seesaw neutrino masses with large mixings from dimensional deconstruction

International Nuclear Information System (INIS)

Balaji, K.R.S.; Lindner, Manfred; Seidl, Gerhart

2003-01-01

We demonstrate a dynamical origin for the dimension-five seesaw operator in dimensional deconstruction models. Light neutrino masses arise from the seesaw scale which corresponds to the inverse lattice spacing. It is shown that the deconstructing limit naturally prefers maximal leptonic mixing. Higher-order corrections which are allowed by gauge invariance can transform the bimaximal into a bilarge mixing. These terms may appear to be nonrenormalizable at scales smaller than the deconstruction scale

A brief status of non-standard neutrino interactions

International Nuclear Information System (INIS)

Ohlsson, Tommy

2013-01-01

In this plenary talk, we review the status of non-standard neutrino interactions (NSIs). First, we give a brief introduction to neutrino flavor transitions with NSIs based on the standard paradigm of neutrino oscillations. Then, we discuss alternative scenarios for neutrino flavor transitions such as neutrino decoherence, neutrino decay, and NSIs. Second, we investigate NSIs with three neutrino flavors. In general, we introduce production and detection NSIs, including the so-called zero-distance effect, and matter NSIs. In addition, we study mappings and approximate formulas for NSIs. Third, we present a brief account of theoretical models for NSIs. Fourth and most important, we investigate in detail the phenomenology of NSIs based on different types of data from neutrino experiments. Fifth, we give some phenomenological bounds on both matter and production/detection NSIs as well as we present sensitivity and discovery reach of NSIs at future experiments. Finally, we present a summary and state our conclusions

CP violation and neutrino masses and mixings from quark mass hierarchies

International Nuclear Information System (INIS)

Buchmueller, W.; Covi, L.; Emmanuel-Costa, D.; Wiesenfeldt, S.

2007-10-01

We study the connection between quark and lepton mass matrices in a supersymmetric SO(10) GUT model in six dimensions, compactified on an orbifold. The physical quarks and leptons are mixtures of brane and bulk states. This leads to a characteristic pattern of mass matrices and high-energy CP violating phases. The hierarchy of up and down quark masses determines the CKM matrix and most charged lepton and neutrino masses and mixings. The small hierarchy of neutrino masses is a consequence of the mismatch of the up and down quark mass hierarchies. The effective CP violating phases in the quark sector, neutrino oscillations and leptogenesis are unrelated. In the neutrino sector we can accomodate naturally sin θ 23 ∝1, sin θ 13 1 2 ∝√(Δm 2 sol ) 3 ∝√(Δm 2 atm ). (orig.)

CP violation and neutrino masses and mixings from quark mass hierarchies

International Nuclear Information System (INIS)

Buchmueller, Wilfried; Covi, Laura; Emmanuel-Costa, David; Wiesenfeldt, Soeren

2007-01-01

We study the connection between quark and lepton mass matrices in a supersymmetric SO(10) GUT model in six dimensions, compactified on an orbifold. The physical quarks and leptons are mixtures of brane and bulk states. This leads to a characteristic pattern of mass matrices and high-energy CP violating phases. The hierarchy of up and down quark masses determines the CKM matrix and most charged lepton and neutrino masses and mixings. The small hierarchy of neutrino masses is a consequence of the mismatch of the up and down quark mass hierarchies. The effective CP violating phases in the quark sector, neutrino oscillations and leptogenesis are unrelated. In the neutrino sector we can accomodate naturally sin θ 23 ∼ 1, sin θ 13 ∼ 1 ∼ 2 ∼ (Δm 2 sol ) 1/2 3 ∼ (Δm 2 atm ) 1/2

Non-standard neutrino interactions in the mu–tau sector

Directory of Open Access Journals (Sweden)

Irina Mocioiu

2015-04-01

Full Text Available We discuss neutrino mass hierarchy implications arising from the effects of non-standard neutrino interactions on muon rates in high statistics atmospheric neutrino oscillation experiments like IceCube DeepCore. We concentrate on the mu–tau sector, which is presently the least constrained. It is shown that the magnitude of the effects depends strongly on the sign of the ϵμτ parameter describing this non-standard interaction. A simple analytic model is used to understand the parameter space where differences between the two signs are maximized. We discuss how this effect is partially degenerate with changing the neutrino mass hierarchy, as well as how this degeneracy could be lifted.

Simpson's neutrino and the singular see-saw

International Nuclear Information System (INIS)

Allen, T.J.; Johnson, R.; Ranfone, S.; Schechter, J.; Walle, J.W.F.

1991-01-01

The authors of this paper derive explicit forms for the neutrino and lepton mixing-matrices which describe the generic singular see-saw model. The dependence on the hierarchy parameter is contrasted with the non-singular case. Application is made to Simpson's 17 keV neutrino

Hiding an elephant: heavy sterile neutrino with large mixing angle does not contradict cosmology

Energy Technology Data Exchange (ETDEWEB)

Bezrukov, F. [The University of Manchester, School of Physics and Astronomy, Oxford Road, Manchester M13 9PL (United Kingdom); Chudaykin, A.; Gorbunov, D., E-mail: Fedor.Bezrukov@manchester.ac.uk, E-mail: chudy@ms2.inr.ac.ru, E-mail: gorby@ms2.inr.ac.ru [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation)

2017-06-01

We study a model of a keV-scale sterile neutrino with a relatively large mixing with the Standard Model sector. Usual considerations predict active generation of such particles in the early Universe, which leads to constraints from the total Dark Matter density and absence of X-ray signal from sterile neutrino decay. These bounds together may deem any attempt of creation of the keV scale sterile neutrino in the laboratory unfeasible. We argue that for models with a hidden sector coupled to the sterile neutrino these bounds can be evaded, opening new perspectives for the direct studies at neutrino experiments such as Troitsk ν-mass and KATRIN. We estimate the generation of sterile neutrinos in scenarios with the hidden sector dynamics keeping the sterile neutrinos either massless or superheavy in the early Universe. In both cases the generation by oscillations from active neutrinos in plasma is suppressed.

Experimental search for muon-neutrino oscillations and analysis of the simultaneous mixing of three neutrino flavors

International Nuclear Information System (INIS)

Bluemer, J.

1985-01-01

In the present thesis the experiment of the CDHS collaboration on the search for inclusive muon-neutrino oscillations is described. The event rates of ν μ reactions via charged currents was simultaneously measured in two detectors which were 130 m and 885 m away from the beam origin. The data contain no hints for oscillation effects. At maximal mixing mass differences of the contributing eigenstates are excluded in a range 0.26 ≤ Δm 2 ≤ 90 eV 2 with 90% confidence. The best sensitivity was reached for Δm 2 =2.5 eV 2 and allows there a maximal mixing parameter sin 2 2 ≤ 0.053. From the CDHS data the hitherto best limits on oscillation parameters resulted. From a common analysis of different oscillation experiments the allowed parameters for the case of simultaneous transitions between electron, muon, and tau neutrinos could be obtained. Regarding systematic uncertainties also here no evidence for oscillations exists. (orig./HSI) [de

Majorana mass term, Dirac neutrinos and selective neutrino oscillations

International Nuclear Information System (INIS)

Leung, C.N.

1987-01-01

In a theory of neutrino mixing via a Majorana mass term involving only the left-handed neutrinos there exist selection rules for neutrino oscillations if true Dirac and/or exactly zero mass eigenstates are present. In the case of three neutrino flavours no oscillation is allowed if the mass spectrum contains one Dirac and one nondegenerate Majorana massive neutrino. The origin of these selection rules and their implications are discussed and the number of possible CP-violating phases in the lepton mixing matrix when Dirac and Majorana mass eigenstates coexist is given. (orig.)

Identifying the neutrino mass hierarchy with supernova neutrinos

International Nuclear Information System (INIS)

Tomas, Ricard

2006-01-01

We review how a high-statistics observation of the neutrino signal from a future galactic core-collapse supernova (SN) may be used to discriminate between different neutrino mixing scenarios. We discuss two complementary methods that allow for the positive identification of the mass hierarchy without knowledge of the emitted neutrino fluxes, provided that the 13-mixing angle is large, sin 2 θ 13 -5 . These two approaches are the observation of modulations in the neutrino spectra by Earth matter effects or by the passage of shock waves through the SN envelope. If the value of the 13-mixing angle is unknown, using additionally the information encoded in the prompt neutronization ν e burst-a robust feature found in all modern SN simulations-can be sufficient to fix both the neutrino hierarchy and to decide whether θ 13 is 'small' or 'large'

Testing non-standard CP violation in neutrino propagation

International Nuclear Information System (INIS)

Winter, Walter

2009-01-01

Non-standard physics which can be described by effective four fermion interactions may be an additional source of CP violation in the neutrino propagation. We discuss the detectability of such a CP violation at a neutrino factory. We assume the current baseline setup of the international design study of a neutrino factory (IDS-NF) for the simulation. We find that the CP violation from certain non-standard interactions is, in principle, detectable significantly below their current bounds - even if there is no CP violation in the standard oscillation framework. Therefore, a new physics effect might be mis-interpreted as the canonical Dirac CP violation, and a possibly even more exciting effect might be missed

On Analytic Solution of resonant Mixing for Solar Neutrino Oscillations

OpenAIRE

Masatoshi, ITO; Takao, KANEKO; Masami, NAKAGAWA; Department of Physics, Meijo University; Department of Physics, Meijo University; Department of Physics, Meijo University

1988-01-01

Behavior of resonant mixing in matter-enhancing region for solar neutrino oscillation, the Mikheyev-Smirnov-Wolfenstein mechanism, is reanalyzed by means of an analytic treatment recently proposed. We give solutions in terms of confluent hypergeometric functions, which agree with "exact" solutions of coupled differential equations.

Neutrino mass and the solar neutrino problem

International Nuclear Information System (INIS)

Wolfenstein, L.

1987-01-01

Theoretical ideas about neutrino mass based on grand-unified theories are reviewed. These give the see-saw formula in which neutrino mass is inversely proportional to a large mass scale M. For M between 10/sup 11/ and 10/sup 15/ Gev the study of solar neutrinos appears to be the best probe of neutrino masses and mixings

Measurement of theta13 with reactor neutrinos

International Nuclear Information System (INIS)

Heeger, Karsten M.; Freedman, Stuart J.; Kadel, Richard W.; Luk, Kam-Biu

2004-01-01

Recent experimental results have provided unambiguous evidence that neutrinos have a small but finite mass and mix from one type into another. The phenomenon of neutrino mixing is characterized by the coupling between the neutrino flavor (nu e,mu,tau ) and mass eigenstates (nu 1,2,3 ) and the associated mixing angles. Previous neutrino oscillation experiments have determined two of the three mixing angles in the neutrino mixing matrix, U MNSP . Using multiple neutrino detectors placed at different distances from a nuclear power plant, a future reactor neutrino experiment has the potential to discover and measure the coupling of the electron neutrino flavor to the third mass eigenstate, U e3 , the last undetermined element of the neutrino mixing matrix

Detecting supernova neutrinos in Daya Bay Neutrino Laboratory

International Nuclear Information System (INIS)

Huang Mingyang; Guo Xinheng; Yang Binglin

2011-01-01

While detecting supernova neutrinos in the Daya Bay neutrino laboratory, several supernova neutrino effects need to be considered, including the supernova shock effects, the neutrino collective effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, and the Earth matter effects. The phenomena of neutrino oscillation is affected by the above effects. Using some ratios of the event numbers of different supernova neutrinos, we propose some possible methods to identify the mass hierarchy and acquire information about the neutrino mixing angle θ13 and neutrino masses. (authors)

Physics Reach with a Monochromatic Neutrino Beam from Electron Capture

CERN Document Server

Bernabeu, J.; Espinoza, C.; Lindroos, M.

2005-01-01

Neutrino oscillation experiments from different sources have demonstrated non-vanishing neutrino masses and flavour mixings. The next experiments have to address the determination of the connecting mixing U(e3) and the existence of the CP violating phase. Whereas U(e3) measures the strength of the oscillation probability in appearance experiments, the CP phase acts as a phase-shift in the interference pattern. Here we propose to separate these two parameters by energy dependence, using the novel idea of a monochromatic neutrino beam facility based on the acceleration of ions that decay fast through electron capture. Fine tuning of the boosted neutrino energy allows precision measurements able to open a window for the discovery of CP violation, even for a mixing as small as 1 degree

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...

Nonunitary Lagrangians and Unitary Non-Lagrangian Conformal Field Theories

Science.gov (United States)

Buican, Matthew; Laczko, Zoltan

2018-02-01

In various dimensions, we can sometimes compute observables of interacting conformal field theories (CFTs) that are connected to free theories via the renormalization group (RG) flow by computing protected quantities in the free theories. On the other hand, in two dimensions, it is often possible to algebraically construct observables of interacting CFTs using free fields without the need to explicitly construct an underlying RG flow. In this Letter, we begin to extend this idea to higher dimensions by showing that one can compute certain observables of an infinite set of unitary strongly interacting four-dimensional N =2 superconformal field theories (SCFTs) by performing simple calculations involving sets of nonunitary free four-dimensional hypermultiplets. These free fields are distant cousins of the Majorana fermion underlying the two-dimensional Ising model and are not obviously connected to our interacting theories via an RG flow. Rather surprisingly, this construction gives us Lagrangians for particular observables in certain subsectors of many "non-Lagrangian" SCFTs by sacrificing unitarity while preserving the full N =2 superconformal algebra. As a by-product, we find relations between characters in unitary and nonunitary affine Kac-Moody algebras. We conclude by commenting on possible generalizations of our construction.

Nonunitary Lagrangians and Unitary Non-Lagrangian Conformal Field Theories.

Science.gov (United States)

Buican, Matthew; Laczko, Zoltan

2018-02-23

In various dimensions, we can sometimes compute observables of interacting conformal field theories (CFTs) that are connected to free theories via the renormalization group (RG) flow by computing protected quantities in the free theories. On the other hand, in two dimensions, it is often possible to algebraically construct observables of interacting CFTs using free fields without the need to explicitly construct an underlying RG flow. In this Letter, we begin to extend this idea to higher dimensions by showing that one can compute certain observables of an infinite set of unitary strongly interacting four-dimensional N=2 superconformal field theories (SCFTs) by performing simple calculations involving sets of nonunitary free four-dimensional hypermultiplets. These free fields are distant cousins of the Majorana fermion underlying the two-dimensional Ising model and are not obviously connected to our interacting theories via an RG flow. Rather surprisingly, this construction gives us Lagrangians for particular observables in certain subsectors of many "non-Lagrangian" SCFTs by sacrificing unitarity while preserving the full N=2 superconformal algebra. As a by-product, we find relations between characters in unitary and nonunitary affine Kac-Moody algebras. We conclude by commenting on possible generalizations of our construction.

Reconstructing Neutrino Mass Spectrum

OpenAIRE

Smirnov, A. Yu.

1999-01-01

Reconstruction of the neutrino mass spectrum and lepton mixing is one of the fundamental problems of particle physics. In this connection we consider two central topics: (i) the origin of large lepton mixing, (ii) possible existence of new (sterile) neutrino states. We discuss also possible relation between large mixing and existence of sterile neutrinos.

Physical region for three-neutrino mixing angles

Science.gov (United States)

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

2005-01-01

We derive a set of symmetry relations for the three-neutrino mixing angles, including the Mikheyev-Smirnov-Wolfenstein (MSW) matter effect. Though interesting in their own right, these relations are used to choose the physical region of the mixing angles such that oscillations are parametrized completely and uniquely. We propose that the preferred way of setting the bounds on the mixing angles should be θ12∈[0,π/2], θ13∈[-π/2,π/2], θ23∈[0,π/2], and δ∈[0,π). No CP violation then results simply from setting δ=0. In the presence of the MSW effect, this choice of bounds is a new result. Since the size of the asymmetry about θ13=0 is dependent on the details of the data analysis and is a part of the results of the analysis, we argue that the negative values of θ13 should not be ignored.

The virial equation of state for unitary fermion thermodynamics with non-Gaussian correlations

International Nuclear Information System (INIS)

Chen Jisheng; Li Jiarong; Wang Yanping; Xia Xiangjun

2008-01-01

We study the roles of the dynamical high order perturbation and statistically non-linear infrared fluctuation/correlation in the virial equation of state for the Fermi gas in the unitary limit. Incorporating the quantum level crossing rearrangement effects, the spontaneously generated entropy departing from the mean-field theory formalism leads to concise thermodynamical expressions. The dimensionless virial coefficients with complex non-local correlations are calculated up to the fourth order for the first time. The virial coefficients of unitary Fermi gas are found to be proportional to those of the ideal quantum gas with integer ratios through a general term formula. Counterintuitively, contrary to those of the ideal bosons (a (0) 2 =-(1/4√2)) or fermions (a (0) 2 =(1/4√2)), the second virial coefficient a 2 of Fermi gas at unitarity is found to be equal to zero. With the vanishing leading order quantum correction, the BCS–BEC crossover thermodynamics manifests the famous pure classical Boyle's law in the Boltzmann regime. The non-Gaussian correlation phenomena can be validated by studying the Joule–Thomson effect

Higgs mass from neutrino-messenger mixing

International Nuclear Information System (INIS)

Byakti, Pritibhajan; Khosa, Charanjit K.; Mummidi, V.S.; Vempati, Sudhir K.

2017-01-01

The discovery of the Higgs particle at 125 GeV has put strong constraints on minimal messenger models of gauge mediation, pushing the stop masses into the multi-TeV regime. Extensions of these models with matter-messenger mixing terms have been proposed to generate a large trilinear parameter, A t , relaxing these constraints. The detailed survey of these models (DOI: 10.1007/JHEP05(2013)055; 10.1007/JHEP08(2013)093 ) so far considered messenger mixings with only MSSM superfields. In the present work, we extend the survey to MSSM with inverse-seesaw mechanism. The neutrino-sneutrino corrections to the Higgs mass in the inverse seesaw model are not significant in the minimal gauge mediation model, unless one considers messenger-matter interaction terms. We classify all possible models with messenger-matter interactions and perform thorough numerical analysis to find out the promising models. We found that out of the 17 possible models 9 of them can lead to Higgs mass within the observed value without raising the sfermion masses significantly. The successful models have stop masses ∼1.5 TeV with small or negligible mixing and yet a light CP even Higgs at 125 GeV.

Acquiring information about neutrino parameters by detecting supernova neutrinos

Science.gov (United States)

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

2010-08-01

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle θ13, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about θ13 and neutrino masses by detecting supernova neutrinos. We apply these methods to some current neutrino experiments.

Solar neutrino spectrum, sterile neutrinos and additional radiation in the Universe

International Nuclear Information System (INIS)

Holanda, Pedro Cunha de

2011-01-01

Full text: Recent results from the SNO, Super-Kamiokande and Borexino experiments do not show the expected upturn of the energy spectrum of events (the ratio R ≡ N obs /N SSM ) at low energies. At the same time, cosmological observations testify for possible existence of additional relativistic degrees of freedom in the early Universe: ΔN eff = 1 - 2. These facts strengthen the case of very light sterile neutrino, ν s , with Δm 0 1 2 ∼ (0.7 - 2) . 10 -5 e V 2 , which mixes weakly with the active neutrinos. The ν s mixing in the mass eigenstate ν 1 characterized by sin 2 2∝ ∼ 10 -3 can explain an absence of the upturn. The mixing of ν s in the eigenstate ν 3 with sin 2 β ∼ 0.1 leads to production of ν s via oscillations in the Universe and to additional contribution Δ N eff ∼ 0.7 -1 before the big bang nucleosynthesis and later. Such a mixing can be tested in forthcoming experiments with the atmospheric neutrinos as well as in future accelerator long baseline experiments. It has substantial impact on conversion of the supernova neutrinos. We perform a qualitative and quantitative analysis of solar neutrino data including a fourth neutrino with different mixings with the active neutrino sector.(author)

Reactor anti-neutrinos: measurement of the θ13 leptonic mixing angle and search for potential sterile neutrinos

International Nuclear Information System (INIS)

Collin, A.

2014-01-01

The Double Chooz experiment aims to measure the θ 13 mixing angle through the disappearance -induced by the oscillation phenomenon - of anti-neutrinos produced by the Chooz nuclear reactors. In order to reduce systematic uncertainties, the experiment relies on the relative comparison of detected signals in two identical liquid scintillator detectors. The near one, giving the normalization of the emitted flux, is currently being built and will be delivered in spring 2014. The far detector, sensitive to θ 13 , is located at about one kilometer and is taking data since 2011. In this first phase of the experiment, the far detector data are compared to a prediction of the emitted neutrino flux to estimate θ 13 . In this thesis, the Double Chooz experiment and its analysis are presented, especially the background studies and the rejection of parasitic signals due to light emitted by photo-multipliers. Neutron fluxes between the different detector volumes impact the definition of the fiducial volume of neutrino interactions and the efficiency of detection. Detailed studies of these effects are presented. As part of the Double Chooz experiment, studies were performed to improve the prediction of neutrino flux emitted by reactors. This work revealed a deficit of observed neutrino rates in the short baseline experiments of last decades. This deficit could be explained by an oscillation to a sterile state. The Stereo project aims to observe a typical signature of oscillations: the distortion of neutrino spectra both in energy and baseline. This thesis presents the detector concept and simulations as well as sensitivity studies. Background sources and the foreseen shielding are also discussed. (author) [fr

Solar neutrino

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, D [Tokyo Univ. (Japan). Coll. of General Education

1975-01-01

The measurement of solar neutrino was performed by using the reaction /sup 37/cl+..nu..sub(e)..-->../sup 37/Ar+e/sup -/ by Davis et al. The argon gas produced through the above mentioned reaction in a tank containing 610 ton of C/sub 2/Cl/sub 4/ was collected and measured. The rate of production of /sup 37/Ar was 0.13+-0.20/day, and the net production rate by the solar neutrino was 0.06+-0.20/day, being corrected for background. This value corresponds to 0.5+-1.0 SNU. Theoretical calculation with the model of spherically symmetric solar development gave an expected value of 5.6 SNU, which is in contradiction with the experimental value. Reason of this discrepancy was considered. The possibility of decay of neutrino to the other particles with weak interaction is very slight. Various models of the sun were investigated, but the results were still inconsistent with the experiment. The mixing of matters in the sun may cause the reduction of neutrino. If He gas comes to the center of the sun by mixing, the reaction, /sup 3/He+/sup 3/He, progresses excessively at the center, and it produces the expansion of the core of the sun. Then, the temperature drops and the neutrino is reduced. Various models which can explain the neutrino of less than ISNU have been presented. However, other theory says that the reduction of neutrino is not expected even if the mixing is considered. A problem concerning the mixing is whether the thermal instability which causes the mixing exists. (Kato, T.).

Direct and semi-direct approaches to lepton mixing with a massless neutrino

International Nuclear Information System (INIS)

King, Stephen F.; Ludl, Patrick Otto

2016-01-01

We discuss the possibility of enforcing a massless Majorana neutrino in the direct and semi-direct approaches to lepton mixing, in which the PMNS matrix is partly predicted by subgroups of a discrete family symmetry, extending previous group searches up to order 1535. We find a phenomenologically viable scheme for the semi-direct approach based on Q(648) which contains Δ(27) and the quaternion group as subgroups. This leads to novel predictions for the first column of the PMNS matrix corresponding to a normal neutrino mass hierarchy with m_1=0, and sum rules for the mixing angles and phase which are characterised by the solar angle being on the low side θ_1_2∼31"∘ and the Dirac (oscillation) CP phase δ being either about ±45"∘ or ±π.

Acquire information about neutrino parameters by detecting supernova neutrinos

OpenAIRE

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

2010-01-01

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle $\\theta_{13}$, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about $\\theta_{13}$ and neutrino masses ...

Neutrino mass matrix

International Nuclear Information System (INIS)

Strobel, E.L.

1985-01-01

Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed

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

International Nuclear Information System (INIS)

Acero-Ortega, Mario Andres

2009-01-01

data showed a very low compatibility, so we did not use the I.L.L. data for additional analyses. Our fit of the S.R.S. experiment gave very small values of the goodness-of-fit, indicating that the data are incompatible with the oscillations hypothesis, as well as with the no oscillations hypothesis. We do not have any explanation for this result. From the analysis of the Gosgen experiment, we obtained upper limits for the mixing parameters, excluding the region with sin 2 2θ ≥ 0.3 and Δm ≥ 0.05 eV 2 at 3σ C.L.. With the combination of these data with those of Gallium, Bugey and Chooz, we found that the hint of neutrino oscillations persists with 0.03 ≤ sin 2 2θ ≤ 0.07 and Δm 2 ≅ 1.93 eV 2 , with a good compatibility of the data. However, the no oscillations hypothesis cannot be excluded. Motivated by these results, in the second part of this work we studied cosmological constrains on a light non-thermal sterile neutrino. We fitted up-to-date cosmological data with an extended LCDM model, including light relics with a mass in the range 0.1-10 eV. We obtained constrains on the current density and velocity dispersion of those relics, as well as constrains on their mass, assuming that they consist either of early decoupled thermal relics, or of non-resonantly produced sterile neutrinos. Our results are useful to constrain particle-motivated models with three active neutrinos and one extra light species. We got, for instance, that at the 3σ confidence level, a sterile neutrino with mass m s = 2 eV can be accommodated with the data provided that it is thermally distributed with T s /T id ν ≤ 0.8 (with T id ν the temperature of neutrinos in the instantaneous decoupling limit), or is non-resonantly produced with ΔN eff ≤ 0.5. The bounds become dramatically tighter when the mass increases. For m s ≤ 0.9 eV and at the same confidence level, the data is still compatible with a standard thermalized neutrino. (author)

JUNO. Determination of the neutrino mass hierarchy using reactor neutrinos

Energy Technology Data Exchange (ETDEWEB)

Wonsak, Bjoern [Hamburg University, Inst. Exp. Phys., Hamburg (Germany)

2015-07-01

The Jiangmen Underground Neutrino Observatory (JUNO) is a medium-baseline reactor neutrino experiment located in China. Its aim is to determine the neutrino mass hierarchy at more than 3 sigma significance after six years of data taking by using a 20kt liquid scintillator detector. To achieve this goal, an energy resolution of less than 3%/√(E) is necessary, creating strict requirements on the detector design and the liquid scintillator. Moreover, JUNO will be the only experiment in the near future able to measure the solar mixing parameters with a precision of better than 1%. This is at the same level as our current knowledge on flavour mixing in the quark sector, marking an important milestone of neutrino physics. In addition, supernova neutrinos, geo-neutrinos, sterile neutrinos as well as solar and atmospheric neutrinos can be studied. JUNO was approved in 2013 and the construction of the underground facility started early this year. In this talk the status of the experiment and its prospects is discussed.

Neutrino mass models and CP violation

International Nuclear Information System (INIS)

Joshipura, Anjan S.

2011-01-01

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

Self-induced neutrino flavor conversion without flavor mixing

International Nuclear Information System (INIS)

Chakraborty, S.; Izaguirre, I.; Raffelt, G.G.; Hansen, R. S.

2016-01-01

Neutrino-neutrino refraction in dense media can cause self-induced flavor conversion triggered by collective run-away modes of the interacting flavor oscillators. The growth rates were usually found to be of order a typical vacuum oscillation frequency Δ m 2 /2E. However, even in the simple case of a ν e beam interacting with an opposite-moving ν-bar e beam, and allowing for spatial inhomogeneities, the growth rate of the fastest-growing Fourier mode is of order μ=√2 G F  n ν , a typical ν–ν interaction energy. This growth rate is much larger than the vacuum oscillation frequency and gives rise to flavor conversion on a much shorter time scale. This phenomenon of 'fast flavor conversion' occurs even for vanishing Δ m 2 /2E and thus does not depend on energy, but only on the angle distributions. Moreover, it does not require neutrinos to mix or to have masses, except perhaps for providing seed disturbances. We also construct a simple homogeneous example consisting of intersecting beams and study a schematic supernova model proposed by Ray Sawyer, where ν e and ν-bar e emerge with different zenith-angle distributions, the key ingredient for fast flavor conversion. What happens in realistic astrophysical scenarios remains to be understood

Soft A4 → Z3 symmetry breaking and cobimaximal neutrino mixing

Science.gov (United States)

Ma, Ernest

2016-04-01

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

The neutrino mass hierarchy measurement with a neutrino telescope in the Mediterranean Sea: A feasibility study

Energy Technology Data Exchange (ETDEWEB)

Tsirigotis, A. G. [Physics Laboratory, Hellenic Open University (Greece); Collaboration: KM3NeT Collaboration

2014-11-18

With the measurement of a non zero value of the θ{sub 13} neutrino mixing parameter, interest in neutrinos as source of the baryon asymmetry of the universe has increased. Among the measurements of a rich and varied program in near future neutrino physics is the determination of the mass hierarchy. We present the status of a study of the feasibility of using a densely instrumented undersea neutrino detector to determine the mass hierarchy, utilizing the Mikheyev-Smirnov-Wolfenstein (MSW) effect on atmospheric neutrino oscillations. The detector will use technology developed for KM3NeT. We present the systematic studies of the optimization of a detector in the required 5–10 GeV energy regime. These studies include new tracking and interaction identification algorithms as well as geometrical optimizations of the detector.

Higgs mass from neutrino-messenger mixing

Energy Technology Data Exchange (ETDEWEB)

Byakti, Pritibhajan [Center for High Energy Physics, Indian Institute of Science,C.V. Raman Ave, Bangalore 560012 (India); Department of Theoretical Physics, Indian Association for the Cultivation of Science,2A & 2B Raja S.C. Mullick Road, Kolkata 700 032 (India); Khosa, Charanjit K. [Center for High Energy Physics, Indian Institute of Science,C.V. Raman Ave, Bangalore 560012 (India); Mummidi, V.S. [Harish-Chandra Research Institute,Chhatnag Road, Jhusi, Allahabad 211019 (India); Vempati, Sudhir K. [Center for High Energy Physics, Indian Institute of Science,C.V. Raman Ave, Bangalore 560012 (India)

2017-03-06

The discovery of the Higgs particle at 125 GeV has put strong constraints on minimal messenger models of gauge mediation, pushing the stop masses into the multi-TeV regime. Extensions of these models with matter-messenger mixing terms have been proposed to generate a large trilinear parameter, A{sub t}, relaxing these constraints. The detailed survey of these models (DOI: 10.1007/JHEP05(2013)055; 10.1007/JHEP08(2013)093 ) so far considered messenger mixings with only MSSM superfields. In the present work, we extend the survey to MSSM with inverse-seesaw mechanism. The neutrino-sneutrino corrections to the Higgs mass in the inverse seesaw model are not significant in the minimal gauge mediation model, unless one considers messenger-matter interaction terms. We classify all possible models with messenger-matter interactions and perform thorough numerical analysis to find out the promising models. We found that out of the 17 possible models 9 of them can lead to Higgs mass within the observed value without raising the sfermion masses significantly. The successful models have stop masses ∼1.5 TeV with small or negligible mixing and yet a light CP even Higgs at 125 GeV.

Solar neutrino masses and mixing from bilinear R-parity broken supersymmetry: Analytical versus numerical results

Science.gov (United States)

Díaz, M.; Hirsch, M.; Porod, W.; Romão, J.; Valle, J.

2003-07-01

We give an analytical calculation of solar neutrino masses and mixing at one-loop order within bilinear R-parity breaking supersymmetry, and compare our results to the exact numerical calculation. Our method is based on a systematic perturbative expansion of R-parity violating vertices to leading order. We find in general quite good agreement between the approximate and full numerical calculations, but the approximate expressions are much simpler to implement. Our formalism works especially well for the case of the large mixing angle Mikheyev-Smirnov-Wolfenstein solution, now strongly favored by the recent KamLAND reactor neutrino data.

The experimental status of neutrino masses and mixings

International Nuclear Information System (INIS)

Robertson, R.G.H.

1992-01-01

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

Homestake result, sterile neutrinos, and low energy solar neutrino experiments

Science.gov (United States)

de Holanda, P. C.; Smirnov, A. Yu.

2004-06-01

The Homestake result is about ˜2σ lower than the Ar-production rate, QAr, predicted by the large mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R≡Nobs/NSSM) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, Δm201˜(0.2 2)×10-5 eV2, sterile neutrino exists which mixes very weakly with active neutrinos: sin2 2α˜(10-5 10-3). We perform both the analytical and numerical study of the conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E=(0.5 5) MeV thus suppressing the Be, or/and pep, CNO, as well as B electron neutrino fluxes. Apart from diminishing QAr it leads to decrease of the Ge-production rate and may lead to the decrease of the BOREXINO signal as well as the CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO, and KamLAND as well as by the new low energy experiments will allow us to check this possibility.

Neutrino mass?

International Nuclear Information System (INIS)

Kayser, B.

1992-01-01

After arguing that we should be looking for evidence of neutrino mass, we illustrate the possible consequences of neutrino mass and mixing. We then turn to the question of whether neutrinos are their own antiparticles, and to the process which may answer this question: neutrinoless double beta decay. Next, we review the proposed Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem, and discuss models which can generate neutrino electromagnetic moments large enough to play a role in the sun. Finally, we consider how the possible 17 keV neutrino, if real, would fit in with everything we know about neutrinos. (orig.)

Understanding neutrino masses and mixings

Indian Academy of Sciences (India)

various possible oscillation solutions to the solar neutrino puzzle. It seems .... A first hint of this new ingredient came from the observation of Weinberg that if ..... Using the discussion of the above paragraph, the Dirac mass of the neutrino as .... that contributes to charged fermion masses, one can write the quark and lepton.

Updated fit to three neutrino mixing: exploring the accelerator-reactor complementarity

International Nuclear Information System (INIS)

Esteban, Ivan; Gonzalez-Garcia, M.C.; Maltoni, Michele; Martinez-Soler, Ivan; Schwetz, Thomas

2017-01-01

We perform a combined fit to global neutrino oscillation data available as of fall 2016 in the scenario of three-neutrino oscillations and present updated allowed ranges of the six oscillation parameters. We discuss the differences arising between the consistent combination of the data samples from accelerator and reactor experiments compared to partial combinations. We quantify the confidence in the determination of the less precisely known parameters θ 23 , δ CP , and the neutrino mass ordering by performing a Monte Carlo study of the long baseline accelerator and reactor data. We find that the sensitivity to the mass ordering and the θ 23 octant is below 1σ. Maximal θ 23 mixing is allowed at slightly more than 90% CL. The best fit for the CP violating phase is around 270 ∘ , CP conservation is allowed at slightly above 1σ, and values of δ CP ≃90 ∘ are disfavored at around 99% CL for normal ordering and higher CL for inverted ordering.

On random unitary channels

International Nuclear Information System (INIS)

Audenaert, Koenraad M R; Scheel, Stefan

2008-01-01

In this paper, we provide necessary and sufficient conditions for a completely positive trace-preserving (CPT) map to be decomposable into a convex combination of unitary maps. Additionally, we set out to define a proper distance measure between a given CPT map and the set of random unitary maps, and methods for calculating it. In this way one could determine whether non-classical error mechanisms such as spontaneous decay or photon loss dominate over classical uncertainties, for example, in a phase parameter. The present paper is a step towards achieving this goal

Global Analysis of Neutrino Data

CERN Document Server

González-Garciá, M C

2005-01-01

In this talk I review the present status of neutrino masses and mixing and some of their implications for particle physics phenomenology. I first discuss the minimum extension of the Standard Model of particle physics required to accommodate neutrino masses and introduce the new parameters present in the model and in particular the possibility of leptonic mixing. I then describe the phenomenology of neutrino masses and mixing leading to flavour oscillations and present the existing evidence from solar, reactor, atmospheric and long-baseline neutrinos as well as the results from laboratory searches at short distances. I derive the allowed ranges for the mass and mixing parameters when the bulk of data is consistently analyzed in the framework of mixing between the three active neutrinos and obtain as a result the most up-to-date determination of the leptonic mixing matrix. Then I briefly summarize the status of some proposed phenomenological explanations to accommodate the LSND results: the role of sterile neu...

Collective neutrino oscillations and neutrino wave packets

Energy Technology Data Exchange (ETDEWEB)

Akhmedov, Evgeny; Lindner, Manfred [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Kopp, Joachim, E-mail: akhmedov@mpi-hd.mpg.de, E-mail: jkopp@uni-mainz.de, E-mail: lindner@mpi-hd.mpg.de [PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Johannes Gutenberg University, 55099 Mainz (Germany)

2017-09-01

Effects of decoherence by wave packet separation on collective neutrino oscillations in dense neutrino gases are considered. We estimate the length of the wave packets of neutrinos produced in core collapse supernovae and the expected neutrino coherence length, and then proceed to consider the decoherence effects within the density matrix formalism of neutrino flavour transitions. First, we demonstrate that for neutrino oscillations in vacuum the decoherence effects are described by a damping term in the equation of motion of the density matrix of a neutrino as a whole (as contrasted to that of the fixed-momentum components of the neutrino density matrix). Next, we consider neutrino oscillations in ordinary matter and dense neutrino backgrounds, both in the adiabatic and non-adiabatic regimes. In the latter case we study two specific models of adiabaticity violation—one with short-term and another with extended non-adiabaticity. It is demonstrated that, while in the adiabatic case a damping term is present in the equation of motion of the neutrino density matrix (just like in the vacuum oscillation case), no such term in general appears in the non-adiabatic regime.

Neutrino spectrum of Einstein universes

International Nuclear Information System (INIS)

Holm, C.

1988-01-01

The study of higher-dimensional Kaluza--Klein universes constructed from the unitary groups U/sub N/ is continued. They form Bergmann manifolds of dimension N 2 with Finslerian geometry induced by their hyperspin structure. In this paper Lagrangians for relativistic wave equations, which are generalizations of the Klein--Gordan, Dirac, and Weyl neutrino equations, are formulated. The wave equations are in general of differential order N. The hyperneutrino equation is examined in detail as the simplest example and its discrete symmetries are discussed. It is found that for N = 3 and N>4 TCP and all its constituent symmetries are violated. The boson calculus is used to solve the linear neutrino equation exactly on U/sub N/ and the energy spectra of the neutrino and antineutrino are presented. It is found that the density ratio of negative to positive energy states is unity only for N = 2, producing asymmetry for all higher-dimensional U/sub N/. The neutrino acquires a negligible rest mass of O(10 -31 eV) due to the global curvature of our manifold

Neutrino mass spectrum with υμ → υs oscillations of atmospheric neutrinos

International Nuclear Information System (INIS)

Liu, Q.Y.; Smirnov, A.Yu.

1998-02-01

We consider the ''standard'' spectrum of the active neutrinos (characterized by strong mass hierarchy and small mixing) with additional sterile, υ s . The sterile neutrino mixes strongly with the muon neutrino, so that υ μ ↔ υ s oscillations solve the atmospheric neutrino problem. We show that the parametric enhancement of the υ μ ↔ υ s 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 υ μ and υ s . The heaviest neutrino (approx. υ τ ) 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)

The effect of random matter density perturbations on the large mixing angle solution to the solar neutrino problem

Science.gov (United States)

Guzzo, M. M.; Holanda, P. C.; Reggiani, N.

2003-08-01

The neutrino energy spectrum observed in KamLAND is compatible with the predictions based on the Large Mixing Angle realization of the MSW (Mikheyev-Smirnov-Wolfenstein) mechanism, which provides the best solution to the solar neutrino anomaly. From the agreement between solar neutrino data and KamLAND observations, we can obtain the best fit values of the mixing angle and square difference mass. When doing the fitting of the MSW predictions to the solar neutrino data, it is assumed the solar matter do not have any kind of perturbations, that is, it is assumed the the matter density monothonically decays from the center to the surface of the Sun. There are reasons to believe, nevertheless, that the solar matter density fluctuates around the equilibrium profile. In this work, we analysed the effect on the Large Mixing Angle parameters when the density matter randomically fluctuates around the equilibrium profile, solving the evolution equation in this case. We find that, in the presence of these density perturbations, the best fit values of the mixing angle and the square difference mass assume smaller values, compared with the values obtained for the standard Large Mixing Angle Solution without noise. Considering this effect of the random perturbations, the lowest island of allowed region for KamLAND spectral data in the parameter space must be considered and we call it very-low region.

Anti-neutrino imprint in solar neutrino flare

Science.gov (United States)

Fargion, D.

2006-10-01

A future neutrino detector at megaton mass might enlarge the neutrino telescope thresholds revealing cosmic supernova background and largest solar flares (SFs) neutrinos. Indeed the solar energetic (Ep>100 MeV) flare particles (protons, α), while scattering among themselves on solar corona atmosphere must produce prompt charged pions, whose chain decays are source of a solar (electron muon) neutrino 'flare' (at tens or hundreds MeV energy). These brief (minutes) neutrino 'bursts' at largest flare peak may overcome by three to five orders of magnitude the steady atmospheric neutrino noise on the Earth, possibly leading to their detection above detection thresholds (in a full mixed three flavour state). Moreover the birth of anti-neutrinos at a few tens of MeV very clearly flares above a null thermal 'hep' anti-neutrino solar background and also above a tiny supernova relic and atmospheric noise. The largest prompt solar anti-neutrino 'burst' may be well detected in future Super Kamikande (gadolinium implemented) anti-neutrino \\bar\

Neutrino physics present and future

CERN Multimedia

CERN. Geneva

2006-01-01

Our understanding of neutrinos has been revolutionized by the discovery that they have nonzero masses and very large mixing. We will explain the phenomenology of massive neutrinos, including neutrino oscillation in vacuum and in matter, and the physics of neutrinos that are their own antiparticles. We will review the evidence for neutrino masses and mixing, and summarize what has been learned about the neutrinos so far. Identifying the very interesting open questions raised by the discovery of neutrino mass, we will discuss how these questions may be answered through future experiments. Finally, we will consider the possibility that CP violation by neutrinos is the key to understanding the matter-antimatter asymmetry of the universe, and discuss the see-saw theory of why neutrino masses are so tiny.

Neutrino magnetic moments and the solar neutrino problem

Energy Technology Data Exchange (ETDEWEB)

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

1994-08-01

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

Neutrino magnetic moments and the solar neutrino problem

International Nuclear Information System (INIS)

Akhmedov, E.Kh.; Valencia Univ.

1994-01-01

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

Results from neutrino experiments

International Nuclear Information System (INIS)

Smirnov, A.Yu.

1993-11-01

Recent (first or/and the best) results from the neutrino experiments are reviewed and their implications for the theory are discussed. The sense of the experiments is the searching for neutrino masses, mixing and interactions beyond the standard model. Present laboratory experiments give upper bounds on the masses and the mixing which are at the level of predictions of the ''electroweak see-saw''. Positive indications of nonzero lepton mixing follow from studies of the solar and atmospheric neutrinos. (author). 95 refs, 11 figs

Neutrino physics

CERN Document Server

Hernandez, P.

2016-01-01

This is the writeup of the lectures on neutrino physics delivered at various schools: TASI and Trieste in 2013 and the CERN-Latin American School in 2015. The topics discussed in this lecture include: general properties of neutrinos in the SM, the theory of neutrino masses and mixings (Dirac and Majorana), neutrino oscillations both in vacuum and in matter, as well as an overview of the experimental evidence for neutrino masses and of the prospects in neutrino oscillation physics. We also briefly review the relevance of neutri- nos in leptogenesis and in beyond-the-Standard-Model physics.

Heavy neutrino mixing in the T2HK, the T2HKK and an extension of the T2HK with a detector at Oki Islands

International Nuclear Information System (INIS)

Abe, Yugo; Asano, Yusuke; Haba, Naoyuki; Yamada, Toshifumi

2017-01-01

We study the discovery potential for the mixing of heavy isospin-singlet neutrinos in extensions of the Tokai-to-Kamioka (T2K) experiment, the Tokai-to-Hyper-Kamiokande (T2HK), the Tokai-to-Hyper-Kamiokande-to-Korea (T2HKK) with a Korea detector with ≅ 1000 km baseline length and 1 circle off-axis angle, and a plan of adding a small detector at Oki Islands to the T2HK. We further pursue the possibility of measuring the neutrino mass hierarchy and the standard CP-violating phase δ CP in the presence of heavy neutrino mixing by fitting data with the standard oscillation parameters only. We show that the sensitivity to heavy neutrino mixing is highly dependent on δ CP and new CP-violating phases in the heavy neutrino mixing matrix, and deteriorates considerably when these phases conspire to suppress interference between the standard oscillation amplitude and an amplitude arising from heavy neutrino mixing, at the first oscillation peak. Although this suppression is avoided by the use of a beam with smaller off-axis angle, the T2HKK and the T2HK+small Oki detector do not show improvement over the T2HK. As for the mass hierarchy measurement, the wrong mass hierarchy is possibly favored in the T2HK because heavy neutrino mixing can mimic matter effects. In contrast, the T2HKK and the T2HK+small Oki detector are capable of correctly measuring the mass hierarchy despite heavy neutrino mixing, as measurements with different baselines resolve degeneracy between heavy neutrino mixing and matter effects. Notably, adding a small detector at Oki to the T2HK drastically ameliorates the sensitivity, which is the central appeal of this paper. As for the δ CP measurement, there can be a sizable discrepancy between the true δ CP and the value obtained by fitting data with the standard oscillation parameters only, which can be comparable to 1σ resolution of the δ CP measurement. Hence, if a hint of heavy neutrino mixing is discovered, it is necessary to incorporate the effects

Heavy neutrino mixing in the T2HK, the T2HKK and an extension of the T2HK with a detector at Oki Islands

Energy Technology Data Exchange (ETDEWEB)

Abe, Yugo [Shimane University, Graduate School of Science and Engineering, Matsue (Japan); Miyakonojo College, National Institute of Technology, Miyakonojo-shi Miyazaki (Japan); Asano, Yusuke; Haba, Naoyuki; Yamada, Toshifumi [Shimane University, Graduate School of Science and Engineering, Matsue (Japan)

2017-12-15

We study the discovery potential for the mixing of heavy isospin-singlet neutrinos in extensions of the Tokai-to-Kamioka (T2K) experiment, the Tokai-to-Hyper-Kamiokande (T2HK), the Tokai-to-Hyper-Kamiokande-to-Korea (T2HKK) with a Korea detector with ≅ 1000 km baseline length and 1 {sup circle} off-axis angle, and a plan of adding a small detector at Oki Islands to the T2HK. We further pursue the possibility of measuring the neutrino mass hierarchy and the standard CP-violating phase δ{sub CP} in the presence of heavy neutrino mixing by fitting data with the standard oscillation parameters only. We show that the sensitivity to heavy neutrino mixing is highly dependent on δ{sub CP} and new CP-violating phases in the heavy neutrino mixing matrix, and deteriorates considerably when these phases conspire to suppress interference between the standard oscillation amplitude and an amplitude arising from heavy neutrino mixing, at the first oscillation peak. Although this suppression is avoided by the use of a beam with smaller off-axis angle, the T2HKK and the T2HK+small Oki detector do not show improvement over the T2HK. As for the mass hierarchy measurement, the wrong mass hierarchy is possibly favored in the T2HK because heavy neutrino mixing can mimic matter effects. In contrast, the T2HKK and the T2HK+small Oki detector are capable of correctly measuring the mass hierarchy despite heavy neutrino mixing, as measurements with different baselines resolve degeneracy between heavy neutrino mixing and matter effects. Notably, adding a small detector at Oki to the T2HK drastically ameliorates the sensitivity, which is the central appeal of this paper. As for the δ{sub CP} measurement, there can be a sizable discrepancy between the true δ{sub CP} and the value obtained by fitting data with the standard oscillation parameters only, which can be comparable to 1σ resolution of the δ{sub CP} measurement. Hence, if a hint of heavy neutrino mixing is discovered, it is

E sub 6 leptoquarks and the solar neutrino problem

Science.gov (United States)

Roulet, Esteban

1991-01-01

The possibility that non-conventional neutrino oscillations take place in the superstring inspired E sub 6 models is considered. In this context, the influence of leptoquark mediated interactions of the neutrinos with nucleons in the resonant flavor conversion is discussed. It is shown that this effect can be significant for v sub e - v sub tau oscillations if these neutrinos have masses required in the ordinary Mikheyev-Smirnov-Wolfenstein (MSW) effect, and may lead to a solution of the solar neutrino problem even in the absence of vacuum mixings. On the other hand, this model cannot lead to a resonant behavior in the sun if the neutrinos are massless.

Updated determination of the solar neutrino fluxes from solar neutrino data

Energy Technology Data Exchange (ETDEWEB)

Bergström, Johannes [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Gonzalez-Garcia, M. C. [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA) (Spain); C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States); Maltoni, Michele [Instituto de Física Teórica UAM/CSIC,Calle de Nicolás Cabrera 13-15, Universidad Autónoma de Madrid,Cantoblanco, E-28049 Madrid (Spain); Peña-Garay, Carlos [Instituto de Física Corpuscular (IFIC), CSIC and Universitat de Valencia,Calle Catedrático José Beltrán, 2, E-46090 Paterna, Valencia (Spain); Serenelli, Aldo M. [Institut de Ciencies de l’Espai (ICE-CSIC/IEEC),Campus UAB, Carrer de Can Magrans s/n, 08193 Cerdanyola del Valls (Spain); Song, Ningqiang [C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States)

2016-03-18

We present an update of the determination of the solar neutrino fluxes from a global analysis of the solar and terrestrial neutrino data in the framework of three-neutrino mixing. Using a Bayesian analysis we reconstruct the posterior probability distribution function for the eight normalization parameters of the solar neutrino fluxes plus the relevant masses and mixing, with and without imposing the luminosity constraint. We then use these results to compare the description provided by different Standard Solar Models. Our results show that, at present, both models with low and high metallicity can describe the data with equivalent statistical agreement. We also argue that even with the present experimental precision the solar neutrino data have the potential to improve the accuracy of the solar model predictions.

Neutrino-oscillation search with cosmic-ray neutrinos

International Nuclear Information System (INIS)

Ayres, D.S.; Cortez, B.; Gaisser, T.K.; Mann, A.K.; Shrock, R.E.; Sulak, L.R.

1984-01-01

A sensitive search for neutrino oscillations involving ν/sub e/, ν/sub μ/, and ν/sub tau/ may be provided by measurements of the ratio of the total interaction rates of upward- and downward-going cosmic-ray neutrinos within a massive (approx.10 kton) detector. Assuming mixing between all pairs of ν/sub e/, ν/sub μ/, and ν/sub tau/, the experiment is capable of observing time-averaged probabilities /sub t/ and /sub t/ of magnitude set by mixing strengths corresponding to, e.g., the d- to s-quark mixing strength, and of reaching the limit Δm/sub i/j 2 equivalentVertical Barm/sub i/ 2 -m/sub j/ 2 Vertical Barroughly-equal10 -4 eV 2 , where m/sub i/, and m/sub j/ are neutrino mass eigenstates, and P/sub e/tau and P/sub mutau/ are the probabilities for ν/sub e/ and ν/sub μ/, respectively, to oscillate into ν/sub tau/ after traversing a distance Lroughly-equal diameter of the Earth. Possible ambiguities may be resolved through comparison of the ratios N/sub e//N/sub μ/ for the upward- and downward-going neutrinos

Optimal unitary dilation for bosonic Gaussian channels

International Nuclear Information System (INIS)

Caruso, Filippo; Eisert, Jens; Giovannetti, Vittorio; Holevo, Alexander S.

2011-01-01

A general quantum channel can be represented in terms of a unitary interaction between the information-carrying system and a noisy environment. In this paper the minimal number of quantum Gaussian environmental modes required to provide a unitary dilation of a multimode bosonic Gaussian channel is analyzed for both pure and mixed environments. We compute this quantity in the case of pure environment corresponding to the Stinespring representation and give an improved estimate in the case of mixed environment. The computations rely, on one hand, on the properties of the generalized Choi-Jamiolkowski state and, on the other hand, on an explicit construction of the minimal dilation for arbitrary bosonic Gaussian channel. These results introduce a new quantity reflecting ''noisiness'' of bosonic Gaussian channels and can be applied to address some issues concerning transmission of information in continuous variables systems.

Sterile neutrino

International Nuclear Information System (INIS)

Anon.

2007-01-01

Paper deals with the information on the occurrence of the fields of the sterile neutrinos (the righthanded ones) mixed with the normal neutrinos (the lefthanded ones). Both the Max Plank Radioastronomy Institute and the Los Angeles University assumes that the occurrence of the keV mass sterile neutrinos may explain the dark matter nature, the fast rotation of the observed pulsars and the reionization processes. The issues associated with the possibility to record the sterile neutrinos were analyzed in the course of the Sterile Neutrinos in Astrophysics and Cosmology Workshop (Crans Montana, March 2006 [ru

Testing the principle of equivalence by solar neutrinos

International Nuclear Information System (INIS)

Minakata, Hisakazu; Washington Univ., Seattle, WA; Nunokawa, Hiroshi; Washington Univ., Seattle, WA

1994-04-01

We discuss the possibility of testing the principle of equivalence with solar neutrinos. If there exists a violation of the equivalence principle quarks and leptons with different flavors may not universally couple with gravity. The method we discuss employs a quantum mechanical phenomenon of neutrino oscillation to probe into the non-university of the gravitational couplings of neutrinos. We develop an appropriate formalism to deal with neutrino propagation under the weak gravitational fields of the sun in the presence of the flavor mixing. We point out that solar neutrino observation by the next generation water Cherenkov detectors can improve the existing bound on violation of the equivalence principle by 3-4 orders of magnitude if the nonadiabatic Mikheyev-Smirnov-Wolfenstein mechanism is the solution to the solar neutrino problem

The KASKA project - a Japanese medium-baseline reactor-neutrino oscillation experiment to measure the mixing angle $\\theta_{13}$ -

OpenAIRE

Kuze, Masahiro; Collaboration, for the KASKA

2005-01-01

A new reactor-neutrino oscillation experiment, KASKA, is proposed to measure the unknown neutrino-mixing angle $\\theta_{13}$ using the world's most powerful Kashiwazaki-Kariwa nuclear power station. It will measure a very small deficit of reactor-neutrino flux using three identical detectors, two placed just close to the sources and one at a distance of about 1.8km. Its conceptual design and physics reach are discussed.

The Neutrino: A Better Understanding Through Astrophysics: Final Report

Energy Technology Data Exchange (ETDEWEB)

Kneller, James P. [North Carolina State Univ., Raleigh, NC (United States)

2016-10-12

The final report for the award "The Neutrino: A Better Understanding Through Astrophysics" is given. The goals of the work were the following: to construct new theoretical approaches to the problem of neutrino propagation in media including where neutrino-neutrino interactions are important; to pioneer the use of new approaches, including super-scattering operators, for the evolution of neutrino thermal and statistical ensembles; to implement these new approaches in computer codes to study neutrino evolution in supernovae and other hot, dense environments; to increase the realism of simulated signals of a Galactic supernovae neutrino burst in current and future neutrino detectors; to study the simulated signals to determine the ability to extract information on the missing neutrino mixing parameters and the dynamics of the supernova explosion; and to study sterile neutrinos and non-standard interactions of neutrinos in supernovae and their effect upon the signal. Accomplishments made in these areas are described.

The Neutrino: A Better Understanding Through Astrophysics: Final Report

International Nuclear Information System (INIS)

Kneller, James P.

2016-01-01

The final report for the award 'The Neutrino: A Better Understanding Through Astrophysics' is given. The goals of the work were the following: to construct new theoretical approaches to the problem of neutrino propagation in media including where neutrino-neutrino interactions are important; to pioneer the use of new approaches, including super-scattering operators, for the evolution of neutrino thermal and statistical ensembles; to implement these new approaches in computer codes to study neutrino evolution in supernovae and other hot, dense environments; to increase the realism of simulated signals of a Galactic supernovae neutrino burst in current and future neutrino detectors; to study the simulated signals to determine the ability to extract information on the missing neutrino mixing parameters and the dynamics of the supernova explosion; and to study sterile neutrinos and non-standard interactions of neutrinos in supernovae and their effect upon the signal. Accomplishments made in these areas are described.

Updated fit to three neutrino mixing: exploring the accelerator-reactor complementarity

Energy Technology Data Exchange (ETDEWEB)

Esteban, Ivan [Departament de Fisíca Quàntica i Astrofísica and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Gonzalez-Garcia, M.C. [Departament de Fisíca Quàntica i Astrofísica and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA),Pg. Lluis Companys 23, 08010 Barcelona (Spain); C.N. Yang Institute for Theoretical Physics, State University of New York at Stony Brook,Stony Brook, NY 11794-3840 (United States); Maltoni, Michele; Martinez-Soler, Ivan [Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid,Calle de Nicolás Cabrera 13-15, Cantoblanco, E-28049 Madrid (Spain); Schwetz, Thomas [Institut für Kernphysik, Karlsruher Institut für Technologie (KIT),D-76021 Karlsruhe (Germany)

2017-01-20

We perform a combined fit to global neutrino oscillation data available as of fall 2016 in the scenario of three-neutrino oscillations and present updated allowed ranges of the six oscillation parameters. We discuss the differences arising between the consistent combination of the data samples from accelerator and reactor experiments compared to partial combinations. We quantify the confidence in the determination of the less precisely known parameters θ{sub 23}, δ{sub CP}, and the neutrino mass ordering by performing a Monte Carlo study of the long baseline accelerator and reactor data. We find that the sensitivity to the mass ordering and the θ{sub 23} octant is below 1σ. Maximal θ{sub 23} mixing is allowed at slightly more than 90% CL. The best fit for the CP violating phase is around 270{sup ∘}, CP conservation is allowed at slightly above 1σ, and values of δ{sub CP}≃90{sup ∘} are disfavored at around 99% CL for normal ordering and higher CL for inverted ordering.

C{sub T} for non-unitary CFTs in higher dimensions

Energy Technology Data Exchange (ETDEWEB)

Osborn, Hugh [Department of Applied Mathematics and Theoretical Physics, Wilberforce Road,Cambridge CB3 0WA, England (United Kingdom); Stergiou, Andreas [Department of Physics, Yale University,New Haven, CT 06520 (United States)

2016-06-13

The coefficient C{sub T} of the conformal energy-momentum tensor two-point function is determined for the non-unitary scalar CFTs with four- and six-derivative kinetic terms. The results match those expected from large-N calculations for the CFTs arising from the O(N) non-linear sigma and Gross-Neveu models in specific even dimensions. C{sub T} is also calculated for the CFT arising from (n−1)-form gauge fields with derivatives in 2n+2 dimensions. Results for (n−1)-form theory extended to general dimensions as a non-gauge-invariant CFT are also obtained; the resulting C{sub T} differs from that for the gauge-invariant theory. The construction of conformal primaries by subtracting descendants of lower-dimension primaries is also discussed. For free theories this also leads to an alternative construction of the energy-momentum tensor, which can be quite involved for higher-derivative theories.

The neutrino factory beam and experiments

CERN Document Server

Blondel, A; Campanelli, M; Cervera-Villanueva, Anselmo; Cline, David B; Collot, J; De Jong, M; Donini, Andrea; Dydak, Friedrich; Edgecock, R; Gavela-Legazpi, Maria Belen; Gómez-Cadenas, J J; González-Garciá, M Concepción; Gruber, P M; Harris, D A; Hernández, Pilar; Kuno, Y; Litchfield, P J; McFarland, K; Mena, O; Migliozzi, P; Palladino, Vittorio; Panman, J; Papadopoulos, I M; Para, A; Peña-Garay, C; Pérez, P; Rigolin, Stefano; Romanino, Andrea; Rubbia, André; Strolin, P; Wojcicki, S G

2000-01-01

The discovery of neutrino oscillations marks a major milestone in the history of neutrino physics, and opens a new window to the still mysterious origin of masses and flavour-mixing. Many current and forthcoming experiments will answer open questions; however, a major step forward, up to and possibly including CP violation in the neutrino-mixing matrix, requires the neutrino beams from a \

Neutrino mixing and masses in SO(10) GUTs with hidden sector and flavor symmetries

Energy Technology Data Exchange (ETDEWEB)

Chu, Xiaoyong [International Centre for Theoretical Physics,Strada Costiera 11, I-34100 Trieste (Italy); Smirnov, Alexei Yu. [Max-Planck-Institute for Nuclear Physics,Saupfercheckweg 1, D-69117 Heidelberg (Germany); International Centre for Theoretical Physics,Strada Costiera 11, I-34100 Trieste (Italy)

2016-05-23

We consider the neutrino masses and mixing in the framework of SO(10) GUTs with hidden sector consisting of fermionic and bosonic SO(10) singlets and flavor symmetries. The framework allows to disentangle the CKM physics responsible for the CKM mixing and different mass hierarchies of quarks and leptons and the neutrino new physics which produces smallness of neutrino masses and large lepton mixing. The framework leads naturally to the relation U{sub PMNS}∼V{sub CKM}{sup †}U{sub 0}, where structure of U{sub 0} is determined by the flavor symmetry. The key feature of the framework is that apart from the Dirac mass matrices m{sub D}, the portal mass matrix M{sub D} and the mass matrix of singlets M{sub S} are also involved in generation of the lepton mixing. This opens up new possibilities to realize the flavor symmetries and explain the data. Using A{sub 4}×Z{sub 4} as the flavor group, we systematically explore the flavor structures which can be obtained in this framework depending on field content and symmetry assignments. We formulate additional conditions which lead to U{sub 0}∼U{sub TBM} or U{sub BM}. They include (i) equality (in general, proportionality) of the singlet flavons couplings, (ii) equality of their VEVs; (iii) correlation between VEVs of singlets and triplet, (iv) certain VEV alignment of flavon triplet(s). These features can follow from additional symmetries or be remnants of further unification. Phenomenologically viable schemes with minimal flavon content and minimal number of couplings are constructed.

Neutrino Oscillations Physics

Science.gov (United States)

Fogli, Gianluigi

2005-06-01

We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

Neutrino bilarge mixing and flavor physics in the flipped SU(5) model

Energy Technology Data Exchange (ETDEWEB)

Huang Chaoshang; Li Tianjun; Liao Wei E-mail: liaow@ictp.trieste.it

2003-11-24

We have constructed a specific supersymmetric flipped SU(5) GUT model in which bilarge neutrino mixing is incorporated. Because the up-type and down-type quarks in the model are flipped in the representations ten and five with respect to the usual SU(5), the radiatively generated flavor mixing in squark mass matrices due to the large neutrino mixing has a pattern different from those in the conventional SU(5) and SO(10) supersymmetric GUTs. This leads to phenomenological consequences quite different from SU(5) or SO(10) supersymmetric GUT models. That is, it has almost no impact on B physics. On the contrary, the model has effects in top and charm physics as well as lepton physics. In particular, it gives promising prediction on the mass difference, {delta}M{sub D}, of the D-D-bar mixing which for some ranges of the parameter space with large tan{beta} can be at the order of 10{sup 9} {Dirac_h} s{sup -1}, one order of magnitude smaller than the experimental upper bound. In some regions of the parameter space {delta}M{sub D} can saturate the present bound. For these ranges of parameter space, t{yields}u,c+h{sup 0} can reach 10{sup -5}-10{sup -6} which would be observed at the LHC and future {gamma}-{gamma} colliders.

New effects of non-standard self-interactions of neutrinos in a supernova

Energy Technology Data Exchange (ETDEWEB)

Das, Anirban; Dighe, Amol; Sen, Manibrata, E-mail: anirbandas@theory.tifr.res.in, E-mail: amol@theory.tifr.res.in, E-mail: manibrata@theory.tifr.res.in [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005 (India)

2017-05-01

Neutrino self-interactions are known to lead to non-linear collective flavor oscillations in a core-collapse supernova. We point out new possible effects of non-standard self-interactions (NSSI) of neutrinos on flavor conversions in a two-flavor framework. We show that, for a single-energy neutrino-antineutrino ensemble, a flavor instability is generated even in normal hierarchy for large enough NSSI. Using a toy model for the neutrino spectra, we show that flavor-preserving NSSI lead to pinching of spectral swaps, while flavor-violating NSSI cause swaps to develop away from a spectral crossing or even in the absence of a spectral crossing. Consequently, NSSI could give rise to collective oscillations and spectral splits even during neutronization burst, for both hierarchies.

Evenly distributed unitaries: On the structure of unitary designs

International Nuclear Information System (INIS)

Gross, D.; Audenaert, K.; Eisert, J.

2007-01-01

We clarify the mathematical structure underlying unitary t-designs. These are sets of unitary matrices, evenly distributed in the sense that the average of any tth order polynomial over the design equals the average over the entire unitary group. We present a simple necessary and sufficient criterion for deciding if a set of matrices constitutes a design. Lower bounds for the number of elements of 2-designs are derived. We show how to turn mutually unbiased bases into approximate 2-designs whose cardinality is optimal in leading order. Designs of higher order are discussed and an example of a unitary 5-design is presented. We comment on the relation between unitary and spherical designs and outline methods for finding designs numerically or by searching character tables of finite groups. Further, we sketch connections to problems in linear optics and questions regarding typical entanglement

Neutrino factories

International Nuclear Information System (INIS)

Dydak, F.

2002-01-01

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

Renormalization group evolution of Dirac neutrino masses

International Nuclear Information System (INIS)

Lindner, Manfred; Ratz, Michael; Schmidt, Michael Andreas

2005-01-01

There are good reasons why neutrinos could be Majorana particles, but there exist also a number of very good reasons why neutrinos could have Dirac masses. The latter option deserves more attention and we derive therefore analytic expressions describing the renormalization group evolution of mixing angles and of the CP phase for Dirac neutrinos. Radiative corrections to leptonic mixings are in this case enhanced compared to the quark mixings because the hierarchy of neutrino masses is milder and because the mixing angles are larger. The renormalization group effects are compared to the precision of current and future neutrino experiments. We find that, in the MSSM framework, radiative corrections of the mixing angles are for large tan β comparable to the precision of future experiments

Neutrino nonstandard interactions in the supernova

International Nuclear Information System (INIS)

Das, C. R.; Pulido, Joao

2011-01-01

Neutrino nonstandard interactions (NSI) were investigated earlier in the solar case and were shown to reduce the tensions between the data and the large mixing angle solution predictions. We extend the previous framework to the supernova and evaluate the appearance probabilities for neutrinos and antineutrinos as a function of their energy after leaving the collapsing star with and without NSI. For normal hierarchy the probability for electron neutrinos and antineutrinos at low energy (E < or approx. 0.8-0.9 MeV) is substantially increased with respect to the non-NSI case and joins its value for inverse hierarchy which is constant with energy. Also for inverse hierarchy the NSI and non-NSI probabilities are the same for each neutrino and antineutrino species. Although detection in such a low energy range remains at present an experimental challenge, it will become a visible trace of NSI with normal hierarchy if they exist. On the other hand, the neutrino decay probability into an antineutrino and a majoron, an effect previously shown to be induced by dense matter, is, as in the case of the sun, too small to be observed as a direct consequence of NSI.

Extracting limits for the difuse non-electron neutrino flux from SNO data

Energy Technology Data Exchange (ETDEWEB)

Miguez, B.S.R.; Kemp, E.; Peres, O.L.G. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin

2009-07-01

Full text. There is a prediction of a diffuse neutrino flux yield from the time integration of all supernova already exploded in the past governed by stellar formation and supernovae occurrence rates. The spectral characteristics of these neutrinos differ from those from recent supernovae mainly in two features: the reduction in their fluxes and their energy 'redshift' due the expansion of the universe. Thus, despite the fact that one single supernova is a transient state, their cumulative effect produces a steady flux of diffuse neutrinos everywhere in universe. These neutrinos have never been observed before. Only upper limits on their fluxes have been reported by the collaborations operating neutrino telescopes. Recently the SNO experiment have made an analysis where the total flux of diffuse electron neutrinos has an upper limit of phi{sub e} <= 61-93 cm{sup -2} s{sup -1}, depending on a specific supernova model. At the present, the best limit for the diffuse flux of non-electron neutrinos is phi{sub x} <= 10{sub 4} cm{sup -2} s{sup -1}, resulted from an analysis of the Super-Kamiokande data. In this work we have extended the SNO analysis including the elastic scattering on electrons via neutral current interactions to extract information on diffuse flux of the non-electron neutrino flavours (i.e. muon and tauon neutrinos). We make a comparison among our results and others from different experiments (LVD, SK, LSD). (author)

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 (Δm_atm² and Δm_sol²), three mixing angles (θ₁₂, θ₂₃, and θ₁₃) and one CP violating phase (δ_CP). 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. δ_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 Δm_atm² 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

Flavor composition of the IceCube neutrinos: A quest for sterile neutrinos?

International Nuclear Information System (INIS)

Biondi, R.

2016-01-01

The identification of flavor content in the cosmic high-energy neutrinos recently observed by the IceCube collaboration could spread the light on the origin of these neutrinos. We study the expected fraction of muon tracks for different cases of the neutrino flavor composition at the sources taking into account uncertainties in the neutrino mixing angles and CP-phase. We show that in the frame of the three known neutrinos it is hard to explain the ν_μ fraction observed at IceCube. However if the cosmic component is produced in some hidden sector, in the form of sterile neutrinos which then oscillate into ordinary ones, a better agreement can be obtained. Especially, in a scenario when heavy dark matter with mass of few PeV decay into sterile neutrinos which then oscillate in ordinary neutrinos due to tiny mixing with the latter, it is possible to explain the low fraction of muon tracks in the events observed by IceCube in the energy region from 60TeV to 2PeV

Effects of neutrino oscillations on the supernova signal in LVD

International Nuclear Information System (INIS)

Aglietta, M.; Antonioli, P.; Bari, G.; Castagnoli, C.; Fulgione, W.; Galeotti, P.; Ghia, P.L.; Giusti, P.; Kemp, E.; Malguin, A.S.; Nurzia, G.; Pesci, A.; Picchi, P.; Pless, I.A.; Ryasny, V.G.; Ryazhskaya, O.G.; Sartorelli, G.; Selvi, M.; Vigorito, C.; Vissani, F.; Votano, L.; Yakushev, V.F.; Zatsepin, G.T.; Zichichi, A.

2002-01-01

We study the impact of neutrino oscillations on the supernova neutrino signal in the Large Volume Detector (LVD). The number of expected events for a galactic supernova (D = 10 kpc) is calculated, assuming neutrino masses and mixing that explain solar and atmospheric neutrino results. The possibility to detect neutrinos in different channels makes LVD sensitive to different scenarios for ν properties, such as normal or inverted ν mass hierarchy, and/or adiabatic or non adiabatic MSW resonances associated to U e3 . Of particular importance are the charged current (c.c.) reactions on 12 C: oscillations increase by almost one order of magnitude the number of events expected from this channel

Neutrino 2012: Outlook – theory

Energy Technology Data Exchange (ETDEWEB)

Smirnov, A.Yu. [International Center for Theoretical Physics, Trieste (Italy)

2013-02-15

Ongoing developments in theory and phenomenology are related to the measured large value of 1–3 mixing and indications of significant deviation of the 2–3 mixing from maximal one. “Race” for the mass hierarchy has started and there is good chance that multi-megaton scale atmospheric neutrino detectors with low threshold (e.g. PINGU) will establish the type of hierarchy. Two IceCube candidates of the PeV cosmic neutrinos if confirmed, is the beginning of new era of high energy neutrino astronomy. Accumulation of data on solar neutrinos (energy spectrum, D-N asymmetry, value of Δm{sub 21}{sup 2}) may uncover some new physics. The Tri-bimaximal mixing is disfavored and the existing discrete symmetry paradigm may change. The confirmed QLC prediction, θ{sub 13}≈θ{sub C}/√(2), testifies for GUT, seesaw and some symmetry at very high scales. However, the same value of 1–3 mixing can be obtained in various ways which have different implications. The situation in lepton sector changes from special (with specific neutrino symmetries, etc.) to normal, closer to that in the quark sector. Sterile neutrinos are challenge for neutrino physics but also opportunity with many interesting phenomenological consequences. Further studies of possible connections between neutrinos and the dark sector of the Universe may lead to breakthrough both in particle physics and cosmology.

Neutrino mixing and R{sub K} anomaly in U(1){sub X} models: a bottom-up approach

Energy Technology Data Exchange (ETDEWEB)

Bhatia, Disha; Chakraborty, Sabyasachi; Dighe, Amol [Tata Institute of Fundamental Research,Mumbai 400005 (India)

2017-03-22

We identify a class of U(1){sub X} models which can explain the R{sub K} anomaly and the neutrino mixing pattern, by using a bottom-up approach. The different X-charges of lepton generations account for the lepton universality violation required to explain R{sub K}. In addition to the three right-handed neutrinos needed for the Type-I seesaw mechanism, these minimal models only introduce an additional doublet Higgs and a singlet scalar. While the former helps in reproducing the quark mixing structure, the latter gives masses to neutrinos and the new gauge boson Z{sup ′}. Our bottom-up approach determines the X-charges of all particles using theoretical consistency and experimental constraints. We find the parameter space allowed by the constraints from neutral meson mixing, rare b→s decays and direct collider searches for Z{sup ′}. Such a Z{sup ′} may be observable at the ongoing run of the Large Hadron Collider with a few hundred fb{sup −1} of integrated luminosity.

Neutrino Factory Targets and the MICE Beam

International Nuclear Information System (INIS)

Walaron, Kenneth A.

2007-01-01

The future of particle physics in the next 20 years must include detailed study of neutrinos. The first proof of physics beyond the Standard Model of particle physics is evident in results from recent neutrino experiements which imply that neutrinos have mass and flavour mixing. The Neutrino Factory is the leading contender to measure precisely the neutrino mixing parameters to probe beyond the Standard Model physics.

Projection quantum mechanics and neutrino mixing

Energy Technology Data Exchange (ETDEWEB)

Góźdź, A., E-mail: andrzej.gozdz@umcs.lublin.pl; Góźdź, M., E-mail: mgozdz@kft.umcs.lublin.pl [University of Maria Curie–Skłodowska, Faculty of Mathematics, Physics and Computer Science (Poland)

2017-03-15

The theory of neutrino oscillations rests on the assumption, that the interaction basis and the physical (mass) basis of neutrino states are different. Therefore neutrino is produced in a certain welldefined superposition of three mass eigenstates, which propagate separately and may be detected as a different superposition. This is called flavor oscillations. It is, however, not clear why neutrinos behave this way, i.e., what is the underlying mechanism which leads to the production of a superposition of physical states in a single reaction. In this paper we argue, that one of the reasons may be connected with the temporal structure of the process. In order to discuss the role of time in processes on the quantum level, we use a special formulation of the quantum mechanics, which is based on the projection time evolution. We arrive at the conclusion, that for short reaction times the formation of a superposition of states of similar masses is natural.

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

International Nuclear Information System (INIS)

Blennow, Mattias

2008-01-01

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

Beam and experiments summary [neutrino studies

CERN Document Server

Blondel, A; Campanelli, M; Cervera-Villanueva, Anselmo; Cline, David B; Collot, J; De Jong, M; Donini, Andrea; Dydak, Friedrich; Edgecock, R; Gavela-Legazpi, Maria Belen; Gómez-Cadenas, J J; González-Garciá, M Concepción; Gruber, P; Harris, D A; Hernández, Pilar; Kuno, Y; Litchfield, P J; McFarland, K; Mena, O; Migliozzi, P; Palladino, Vittorio; Panman, J; Papadopoulos, I M; Para, A; Peña-Garay, C; Pérez, P; Rigolin, Stefano; Romanino, Andrea; Rubbia, André; Strolin, P; Wojcicki, S G

2000-01-01

The discovery of neutrino oscillations marks a major milestone in the history of neutrino physics, and opens a new window to the still mysterious origin of masses and flavour mixing. Many current and forthcoming experiments will. Answer open questions; however, a major step forward, up to and possibly including CP violation in the neutrino-mixing matrix, requires the neutrino beams from a neutrino factory. The neutrino factory is a new concept for producing neutrino beams of unprecedented quality in terms of intensity, flavour composition, and precision of the beam parameters. Most importantly, the neutrino factory is the only known way to generate a high- intensity beam of electron neutrinos of high energy. The neutrino beam from a neutrino factory, in particular the electron-neutrino beam, enables the exploration of otherwise inaccessible domains in neutrino oscillation physics by exploiting baselines of planetary dimensions. Suitable detectors pose formidable challenges but seem within reach with only mode...

Neutrino oscillations in a predictive SUSY GUT

International Nuclear Information System (INIS)

Blazek, T.; Raby, S.; Tobe, K.

1999-01-01

In this paper we present a predictive SO(10) supersymmetric grand unified theory with the family symmetry U(2)xU(1) which has several nice features. We are able to fit fermion masses and mixing angles, including recent neutrino data, with nine parameters in the charged fermion sector and four in the neutrino sector. The family symmetry plays a preeminent role. (i) The model is ''natural''--we include all terms allowed by the symmetry. It restricts the number of arbitrary parameters and enforces many zeros in the effective mass matrices. (ii) Family symmetry breaking from U(2)xU(1)→U(1)→ nothing generates the family hierarchy. It also constrains squark and slepton mass matrices, thus ameliorating flavor violation resulting from squark and slepton loop contributions. (iii) It naturally gives large angle ν μ -ν τ mixing describing atmospheric neutrino oscillation data and small angle ν e -ν s mixing, consistent with the small mixing angle Mikheyev-Smirnov-Wolfenstein (MSW) solution to solar neutrino data. (iv) Finally, in this paper we assume minimal family symmetry-breaking vacuum expectation values (VEV's). As a result we cannot obtain a three neutrino solution to both atmospheric and solar neutrino oscillations. In addition, the solution discussed here cannot fit liquid scintillation neutrino detector (LSND) data even though this solution requires a sterile neutrino ν s . It is important to note, however, that with nonminimal family symmetry-breaking VEV's, a three neutrino solution is possible with the small mixing angle MSW solution to solar neutrino data and large angle ν μ -ν τ mixing describing atmospheric neutrino oscillation data. In the four neutrino case, nonminimal family VEV's may also permit a solution for LSND. The results with nonminimal family breaking are still under investigation and will be reported in a future paper. (c) 1999 The American Physical Society

Phenomenology of neutrino oscillations at the neutrino factory

International Nuclear Information System (INIS)

Tang, Jian

2011-01-01

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 μ + → ν e → ν μ → μ - and the right-charge muons coming from the chain μ + → anti ν μ → anti ν μ → μ - (similar to μ - chains), where ν e → ν μ and anti ν μ → anti ν μ 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 τ decays, generated by appearance channels ν μ → ν τ and ν e → ν τ , on the discovery reaches of the mass orderings, the leptonic CP violation, and the non-zero θ 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 effects of one additional massive sterile neutrino are discussed in the context of a combined short and long baseline setup. It is found that near detectors can provide the required sensitivity at the

Neutrino masses and flavor mixing in the extended double Seesaw model with two texture zeros

International Nuclear Information System (INIS)

Hu, Li-Jun; Dulat, Sayipjamal; Ablat, Abduleziz

2011-01-01

We study the light neutrino mass matrix in the extended double Seesaw model (EDSM), and as a result we get its general form. Also we demonstrate that conventional type-I and double seesaw mechanisms can be regarded as two special cases. We analyze the structure of the 9 x 9 neutrino mass matrix in this scenario, and surprisingly we find that EDSM will degenerate to a conventional type-I seesaw mechanism when M R = M S M μ -1 M S T holds exactly. Considering two simple ansaetze in two texture zeros for its 3 x 3 submatrices, we calculate the neutrino masses and flavor mixing angles, in which the θ 13 is a nonzero large angle. (orig.)

Mikheyev-Smirnov-Wolfenstein effect on neutrino decay

International Nuclear Information System (INIS)

Chou Chihkang; Chou Marty; National Central Univ., Chung-li

2001-01-01

It has early been pointed out by R. S. Raghavan et al. that in solar matter, conversion of the electron neutrino to a ''heaver'' flavor by the MSW effect can catalyze neutrino decay in the small mixing angle MSW solution. Since recent results on solar neutrinos provide hints that the large mixing angle MSW solution could be correct, we present a detailed study of the MSW effect with neutrino decay for both small and large mixing angles. The lower limit for the lifetime of 10 MeV neutrinos is estimated to be τ(10 MeV) >or∼ 10 3 s. (orig.)

Searches for heavy neutrinos from Z decays

International Nuclear Information System (INIS)

Abreu, P.; Adam, W.; Adami, F.

1992-01-01

We have searched for possible fourth family heavy neutrinos, pair produced in Z 0 decays, in a sample of about 112 000 hadronic Z 0 final states collected with the DELPHI detector. For all mixing matrix elements we exclude a new Dirac neutrino light than 44.5 GeV at a 95% confidence level, if the neutrino couples to the electron or muon family, and lighter than 44.0 GeV, if the neutrino couples to the tau family. Depending on the values of the mixing element and to which lepton family the neutrino couples, we obtain mass limits up to 46.2 GeV. For all mixing matrix elements we exclude a new Majorana neutrino lighter than 39.0 GeV, if it couples to the electron or the muon family, and lighter than 38.2 GeV, if it couples to the tau family. Depending on the values of the mixing matrix element and to which lepton family the neutrino couples, we obtain mass limits up to 44.7 GeV. We also exclude stable new Dirac neutrinos lighter than 45.0 GeV and new Majorana neutrinos lighter than 39.5 GeV. (orig.)

New neutrino oscillation results from NOVA

CERN Multimedia

CERN. Geneva

2018-01-01

Neutrinos oscillate among flavors as they travel because a neutrino of a particular flavor is also a superposition of multiple neutrinos with slightly different masses.  The interferometric nature of oscillations allows these tiny mass differences to be measured, along with the parameters of the PMNS matrix which governs the mixing. However, since neutrinos only interact weakly, a powerful neutrino source and massive detectors are required to measure them. In this talk I will show recently updated results from NOvA, a long-baseline neutrino oscillation experiment at Fermilab with two functionally identical scintillator detectors. I will present measurements of muon neutrino disappearance and electron neutrino appearance, and what constraints those measurements put on the remaining open questions in neutrino oscillations: Is the neutrino mass hierarchy "normal" or "inverted?" Do neutrino oscillations violate CP symmetry? Is the mixing in the atmospheric sector maximal? The recent update includes 50%...

Non-standard interactions with high-energy atmospheric neutrinos at IceCube

Energy Technology Data Exchange (ETDEWEB)

Salvado, Jordi; Mena, Olga; Palomares-Ruiz, Sergio; Rius, Nuria [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València,Apartado de Correos 22085, E-46071 Valencia (Spain)

2017-01-31

Non-standard interactions in the propagation of neutrinos in matter can lead to significant deviations from expectations within the standard neutrino oscillation framework and atmospheric neutrino detectors have been considered to set constraints. However, most previous works have focused on relatively low-energy atmospheric neutrino data. Here, we consider the one-year high-energy through-going muon data in IceCube, which has been already used to search for light sterile neutrinos, to constrain new interactions in the μτ-sector. In our analysis we include several systematic uncertainties on both, the atmospheric neutrino flux and on the detector properties, which are accounted for via nuisance parameters. After considering different primary cosmic-ray spectra and hadronic interaction models, we improve over previous analysis by using the latest data and showing that systematics currently affect very little the bound on the off-diagonal ε{sub μτ}, with the 90% credible interval given by −6.0×10{sup −3}<ε{sub μτ}<5.4×10{sup −3}, comparable to previous results. In addition, we also estimate the expected sensitivity after 10 years of collected data in IceCube and study the precision at which non-standard parameters could be determined for the case of ε{sub μτ} near its current bound.

Experimental Neutrino Physics: Final Report

Energy Technology Data Exchange (ETDEWEB)

Lane, Charles E.; Maricic, Jelena

2012-09-05

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

Hardron production and neutrino beams

Science.gov (United States)

Guglielmi, A.

2006-11-01

The precise measurements of the neutrino mixing parameters in the oscillation experiments at accelerators require new high-intensity and high-purity neutrino beams. Ancillary hadron-production measurements are then needed as inputs to precise calculation of neutrino beams and of atmospheric neutrino fluxes.

Quasi-Dirac neutrino oscillations

Science.gov (United States)

Anamiati, Gaetana; Fonseca, Renato M.; Hirsch, Martin

2018-05-01

Dirac neutrino masses require two distinct neutral Weyl spinors per generation, with a special arrangement of masses and interactions with charged leptons. Once this arrangement is perturbed, lepton number is no longer conserved and neutrinos become Majorana particles. If these lepton number violating perturbations are small compared to the Dirac mass terms, neutrinos are quasi-Dirac particles. Alternatively, this scenario can be characterized by the existence of pairs of neutrinos with almost degenerate masses, and a lepton mixing matrix which has 12 angles and 12 phases. In this work we discuss the phenomenology of quasi-Dirac neutrino oscillations and derive limits on the relevant parameter space from various experiments. In one parameter perturbations of the Dirac limit, very stringent bounds can be derived on the mass splittings between the almost degenerate pairs of neutrinos. However, we also demonstrate that with suitable changes to the lepton mixing matrix, limits on such mass splittings are much weaker, or even completely absent. Finally, we consider the possibility that the mass splittings are too small to be measured and discuss bounds on the new, nonstandard lepton mixing angles from current experiments for this case.

Sudbury Neutrino Observatory

International Nuclear Information System (INIS)

Beier, E.W.

1992-03-01

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

Sterile neutrino search with the Double Chooz experiment

Energy Technology Data Exchange (ETDEWEB)

Hellwig, Denise; Bekman, Ilja; Kampmann, Philipp; Schoppmann, Stefan; Soiron, Michael; Stahl, Achim; Wiebusch, Christopher [III. Physikalisches Institut B, RWTH Aachen (Germany)

2016-07-01

The Double Chooz experiment is a reactor neutrino disappearance experiment located at the Chooz nuclear power plant, France. It measures the electron-antineutrino flux of the two nuclear reactors with two detectors of identical design. A far detector at a distance of about 1 km is operating since 2011; a near detector at a distance of about 400 m is operating since the end of 2014. The combination of the two detectors offers sensitivity to sterile neutrino mixing parameters. Sterile neutrinos are neutrino mass states not taking part in weak interactions, but may mix with known neutrino states. This induces additional mixing angles and mass differences. This talk describes the search for sterile neutrinos and the sensitivity of Double Chooz to the mixing angle θ{sub 14}.

Neutrino oscillation measurements with reactors

Energy Technology Data Exchange (ETDEWEB)

McKeown, R.D. [W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

2010-11-01

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 currently under development. These recent studies and potential future developments will be discussed.

C2GT intercepting CERN neutrinos to Gran Sasso in the Gulf of Taranto to measure $\\theta_13$

CERN Document Server

Ball, A E; Camilleri, L L; Catinaccio, A; Chelkov, G A; Dydak, F; Elagin, A; Frandsen, Poul Kjaer; Gostkin, M I; Grant, A; Guskov, A; Joram, C; Krumshtein, Z; Müller, H; Postema, H; Price, M; Rovelli, T; Schinzel, D; Séguinot, Jacques; Valenti, G; Voss, R; Wotschack, J; Zhemchugov, A S

2007-01-01

Today's greatest challenge in accelerator-based neutrino physics is to measure the mixing angle \\thonethree\\ which is known to be much smaller than the solar mixing angle \\thonetwo\\ and the atmospheric mixing angle \\thtwothree . A non-zero value of the angle \\thonethree\\ is a prerequisite for observing CP violation in neutrino mixing. In this paper, we discuss a deep-sea neutrino experiment with 1.5~Mt fiducial target mass in the Gulf of Taranto with the prime objective of measuring \\thonethree. The detector is exposed to the CERN neutrino beam to Gran Sasso in off-axis geometry. Monochromatic muon-neutrinos of $\\approx 800$~MeV energy are the dominant beam component. Neutrinos are detected through quasi-elastic, charged-current reactions in sea water; electrons and muons are detected in a large-surface, ring-imaging Cherenkov detector. The profile of the seabed in the Gulf of Taranto allows for a moveable experiment at variable distances from CERN, starting at 1100 km. From the oscillatory pattern of the dis...

Impact of hierarchy upon the values of neutrino mixing parameters

International Nuclear Information System (INIS)

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

2010-01-01

A neutrino-oscillation analysis is performed of the more finely binned Super-Kamiokande (Super-K) atmospheric, MINOS, and CHOOZ data to examine the effect of neutrino hierarchy in this data set on the value of θ 13 and the deviation of θ 23 from maximal mixing. Exact oscillation probabilities are used, thus incorporating all powers of θ 13 and ε:=θ 23 -π/4. The extracted oscillation parameters are found to be dependent on the hierarchy, particularly for θ 13 . We find, at a 90% confidence level, that these parameters are Δ 32 =2.44 -0.20 +0.26 and 2.48 -0.22 +0.25 x10 -3 eV 2 , ε=θ 23 -π/4=0.06 -0.16 +0.06 and 0.06 -0.17 +0.08 , and θ 13 =-0.07 -0.11 +0.18 and -0.13 -0.16 +0.23 , for the normal and inverted hierarchies, respectively. The inverted hierarchy is preferred at a statistically insignificant level of 0.3σ.

Perturbative estimates of lepton mixing angles in unified models

International Nuclear Information System (INIS)

Antusch, Stefan; King, Stephen F.; Malinsky, Michal

2009-01-01

Many unified models predict two large neutrino mixing angles, with the charged lepton mixing angles being small and quark-like, and the neutrino masses being hierarchical. Assuming this, we present simple approximate analytic formulae giving the lepton mixing angles in terms of the underlying high energy neutrino mixing angles together with small perturbations due to both charged lepton corrections and renormalisation group (RG) effects, including also the effects of third family canonical normalization (CN). We apply the perturbative formulae to the ubiquitous case of tri-bimaximal neutrino mixing at the unification scale, in order to predict the theoretical corrections to mixing angle predictions and sum rule relations, and give a general discussion of all limiting cases. We also discuss the implications for the sum rule relations of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

Neutrino Mass and Flavour Models

International Nuclear Information System (INIS)

King, Stephen F.

2010-01-01

We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and unification, and show how such models can also solve the SUSY flavour and CP problems. We also discuss the theoretical implications of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

Investigation of matter enhanced neutrino oscillations relevant to the solar neutrino problem

International Nuclear Information System (INIS)

Losecco, J.M.; Bionta, R.M.; Casper, D.; Claus, R.; Errede, S.; Foster, G.; Park, H.S.; Seidel, S.; Shumard, E.; Sinclair, D.; Stone, J.L.; Sulak, L.; Van der Velde, J.C.; Blewitt, G.; Cortez, B.; Lehmann, E.; Bratton, C.B.; Gajewski, W.; Ganezer, K.S.; Haines, T.J.; Kropp, W.R.; Reines, F.; Schultz, J.; Sobel, H.W.; Wuest, C.; Goldhaber, M.; Jones, T.W.; Kielczewska, D.; Learned, J.G.; Svoboda, R.

1987-01-01

We study the effect of matter enhanced neutrino oscillations on atmospheric neutrinos. A recently proposed solution to the solar neutrino problem with Δm 2 =1.1x10 -4 eV 2 suggests enhanced effects in the range 200 MeV-500 MeV. We find no evidence of this effect for ν μ ??ν e mixing. Limits are set on the magnitude of the mixing angle. Our limit is sin θ V <0.14 at 90% confidence level. The limit is dominated by statistical errors and may be improved. (orig.)

Testing CPT invariance with neutrinos

International Nuclear Information System (INIS)

Ohlsson, Tommy

2003-01-01

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

Neutrino masses in the SU(5) x (lower case x) SU(5)' mirror symmetric model

International Nuclear Information System (INIS)

Collie, M.; Foot, R.

1998-02-01

Motivated by the atmospheric and solar neutrino anomalies, we study neutrino masses in a parity invariant SU(5) x SU(5)' grand unified model. Two distinct ways of incorporating neutrino masses into this model are envisaged. One way involves adding a gauge singlet fermion to each generation. The other way, is to extend the scalar sector. This possibility suggests that photon - mirror photon kinetic mixing is non-zero since is generated radiatively. It is argued that the kinetic mixing is such models may well be close to the experimental limit

Tribimaximal neutrino mixing from A4 replication

International Nuclear Information System (INIS)

Carone, Christopher D.; Lebed, Richard F.

2011-01-01

Motivated by dimensional deconstruction, we propose a model of tribimaximal neutrino mixing based on A 4 xA 4 symmetry. In this model, the two triplet symmetry-breaking fields of conventional A 4 models are taken to transform under different A 4 group factors, but are not distinguished by any other quantum numbers. An additional bi-triplet flavor field breaks A 4 xA 4 to its diagonal subgroup. If the bi-triplet transforms under an additional Z 3 symmetry, we show that one can construct a general, renormalizable superpotential that yields the desired pattern of symmetry breaking. We identify the features that this model has in common with a deconstructed 5D theory in which A 4 is a subgroup of a continuous gauged flavor symmetry in the bulk.

Sterile neutrinos in lepton number and lepton flavor violating decays

International Nuclear Information System (INIS)

Helo, Juan Carlos; Kovalenko, Sergey; Schmidt, Ivan

2011-01-01

We study the contribution of massive dominantly sterile neutrinos, N, to the lepton number and lepton flavor violating semileptonic decays of τ and B, D, K-mesons. We focus on special domains of sterile neutrino masses m N where it is close to its mass-shell. This leads to an enormous resonant enhancement of the decay rates of these processes. This allows us to derive stringent limits on the sterile neutrino mass m N and its mixing U αN with active flavors. We apply a joint analysis of the existing experimental bounds on the decay rates of the studied processes. In contrast to other approaches in the literature our limits are free from ad hoc assumptions on the relative size of the sterile neutrino mixing parameters. We analyze the impact of this sort of assumptions on the extraction of the limits on m N and U αN , and discuss the effect of finite detector size. Special attention was paid to the limits on meson decays with e ± e ± in final state, derived from non-observation of 0νββ-decay. We point out that observation of these decays may, in particular, shed light on the Majorana phases of the neutrino mixing matrix.

Concluding talk: fundamental lessons and challenges from neutrinos

CERN Document Server

Altarelli, G

2014-01-01

We present a concise review of the experimental developments on neutrino mixing and their theoretical implications as presented and discussed at this Conference. The recent data disfavour many models but the surviving ones still span a wide range going from Anarchy (no structure, no symmetry in the neutrino sector) to a maximum of symmetry, as for the models based on discrete non-abelian flavour groups which can be improved following the indications from the recent data.

Quench of non-Markovian coherence in the deep sub-Ohmic spin–boson model: A unitary equilibration scheme

International Nuclear Information System (INIS)

Yao, Yao

2015-01-01

The deep sub-Ohmic spin–boson model shows a longstanding non-Markovian coherence at low temperature. Motivating to quench this robust coherence, the thermal effect is unitarily incorporated into the time evolution of the model, which is calculated by the adaptive time-dependent density matrix renormalization group algorithm combined with the orthogonal polynomials theory. Via introducing a unitary heating operator to the bosonic bath, the bath is heated up so that a majority portion of the bosonic excited states is occupied. It is found in this situation the coherence of the spin is quickly quenched even in the coherent regime, in which the non-Markovian feature dominates. With this finding we come up with a novel way to implement the unitary equilibration, the essential term of the eigenstate-thermalization hypothesis, through a short-time evolution of the model

Neutrinos today

International Nuclear Information System (INIS)

Pontecorvo, B.; Bilen'kij, S.

1987-01-01

After the famous 1983 discovery of intermediate W, Z 0 bosons it may be stated with certainty that W, Z 0 are entirely responsible for the production of neutrinos and for their interactions. Neutrino physics notions are presented from this point of view in the first four introductory, quite elementary, paragraphs of the paper. The following seven paragraphs are more sophisticated. They are devoted to the neutrino mass and neutrino mixing question, which is the most actual problem in today neutrino physics. Vacuum neutrino oscillations, matter neutrino oscillations and netrinoless double-decay are considered. Solar neutrino physics is discussed in some detail from the point of view of vacuum and matter neutrino oscillations. The role played by neutrinos in the Universe is briefly considered. In the last paragraph there discussed the probable observation by different groups of neutrinos connected with the Supernova 1987 A: the first observation of gravitational star collapse (at least the general rehearsal of such observation) opens up a new era in astronomy of today exerimental physics and astrophysics is presented at the end of the paper in the form of a Table

Neutrino mass and physics beyond the Standard Model; Masse des Neutrinos et Physique au-dela du Modele Standard

Energy Technology Data Exchange (ETDEWEB)

Hosteins, P

2007-09-15

The purpose of this thesis is to study, in the neutrino sector, the flavour structures at high energy. The work is divided into two main parts. The first part is dedicated to the well known mechanism to produce small neutrino masses: the seesaw mechanism, which implies the existence of massive particles whose decays violate lepton number. Therefore this mechanism can also be used to generate a net baryon number in the early universe and explain the cosmological observation of the asymmetry between matter and antimatter. However, it is often non-trivial to fulfill the constraints coming at the same time from neutrino oscillations and cosmological experiments, at least in frameworks where the couplings can be somehow constrained, like some Grand Unification models. Therefore we devoted the first part to the study of a certain class of seesaw mechanism which can be found in the context of SO(10) theories for example. We introduce a method to extract the mass matrix of the heavy right-handed neutrinos and explore the phenomenological consequences of this quantity, mainly concerning the production of a sufficient baryon asymmetry. When trying to identify the underlying symmetry governing the mixings between the different generations, we see that there is a puzzling difference between the quark and the lepton sectors. However, the quark and lepton parameters have to be compared at the scale of the flavour symmetry breaking, therefore we have to make them run to the appropriate scale. Thus, it is worthwhile investigating models where quantum corrections allow an approximate unification of quark and lepton mixings. This is why the other part of the thesis investigates the running of the effective neutrino mass operator in models with an extra compact dimension, where quantum corrections to the neutrino masses and mixings can be potentially large due to the multiplicity of states.

NEUTRINO MASS

OpenAIRE

Kayser, Boris

1988-01-01

This is a review article about the most recent developments on the field of neutrino mass. The first part of the review introduces the idea of neutrino masses and mixing angles, summarizes the most recent experimental data then discusses the experimental prospects and challenges in this area. The second part of the review discusses the implications of these results for particle physics and cosmology, including the origin of neutrino mass, the see-saw mechanism and sequential dominance, and la...

The universal sound velocity formula for the strongly interacting unitary Fermi gas

International Nuclear Information System (INIS)

Liu Ke; Chen Ji-Sheng

2011-01-01

Due to the scale invariance, the thermodynamic laws of strongly interacting limit unitary Fermi gas can be similar to those of non-interacting ideal gas. For example, the virial theorem between pressure and energy density of the ideal gas P = 2E/3V is still satisfied by the unitary Fermi gas. This paper analyses the sound velocity of unitary Fermi gases with the quasi-linear approximation. For comparison, the sound velocities for the ideal Boltzmann, Bose and Fermi gas are also given. Quite interestingly, the sound velocity formula for the ideal non-interacting gas is found to be satisfied by the unitary Fermi gas in different temperature regions. (general)

Neutrino mass sum-rule

Science.gov (United States)

Damanik, Asan

2018-03-01

Neutrino mass sum-rele is a very important research subject from theoretical side because neutrino oscillation experiment only gave us two squared-mass differences and three mixing angles. We review neutrino mass sum-rule in literature that have been reported by many authors and discuss its phenomenological implications.

Texture zeros in neutrino mass matrix

Energy Technology Data Exchange (ETDEWEB)

Dziewit, B., E-mail: bartosz.dziewit@us.edu.pl; Holeczek, J., E-mail: jacek.holeczek@us.edu.pl; Richter, M., E-mail: monikarichter18@gmail.com [University of Silesia, Institute of Physics (Poland); Zajac, S., E-mail: s.zajac@uksw.edu.pl [Cardinal Stefan Wyszyński University in Warsaw, Faculty of Mathematics and Natural Studies (Poland); Zralek, M., E-mail: marek.zralek@us.edu.pl [University of Silesia, Institute of Physics (Poland)

2017-03-15

The Standard Model does not explain the hierarchy problem. Before the discovery of nonzero lepton mixing angle θ{sub 13} high hopes in explanation of the shape of the lepton mixing matrix were combined with non-Abelian symmetries. Nowadays, assuming one Higgs doublet, it is unlikely that this is still valid. Texture zeroes, that are combined with abelian symmetries, are intensively studied. The neutrino mass matrix is a natural way to study such symmetries.

Workshop on low energy neutrino physics

International Nuclear Information System (INIS)

2009-01-01

The main topics of the workshop are: the determination of the neutrino mixing angle theta-13, the experiments concerning the monitoring of reactors based on the measurement of neutrino spectra, solar neutrinos, supernovae neutrinos, geo-neutrinos, neutrino properties, neutrinoless double beta decay and future low energy neutrino detectors. This document gathers together the program of the workshop, the slides of the presentations, some abstracts and some posters

A see-saw mechanism with light sterile neutrinos

International Nuclear Information System (INIS)

McKellar, B.H.J.; Garbutt, M.; Stephenson, G.J.; Goldman, T.

2001-01-01

The usual see-saw mechanism for the generation of light neutrino masses is based on the assumption that all of the flavours of right-handed (more properly, sterile) neutrinos are heavy. If the sterile Majorana mass matrix is singular, one or more of the sterile neutrinos will have zero mass before mixing with the active (left-handed) neutrinos and be light after that mixing is introduced In particular, a rank 1 sterile mass matrix leads naturally to two pseudo-Dirac pairs, one very light active Majorana neutrino and one heavy sterile Majorana neutrino. For any pattern of Dirac masses, there exists a region of parameter space in which the two pseudo-Dirac pairs are nearly degenerate in mass. This, in turn, leads to large amplitude mixing of active states as well as mixing into sterile states

Visible neutrino decay at DUNE

Energy Technology Data Exchange (ETDEWEB)

Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

2017-05-09

If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

Unitary field theories

International Nuclear Information System (INIS)

Bergmann, P.G.

1980-01-01

A problem of construction of the unitary field theory is discussed. The preconditions of the theory are briefly described. The main attention is paid to the geometrical interpretation of physical fields. The meaning of the conceptions of diversity and exfoliation is elucidated. Two unitary field theories are described: the Weyl conformic geometry and Calitzy five-dimensioned theory. It is proposed to consider supersymmetrical theories as a new approach to the problem of a unitary field theory. It is noted that the supergravitational theories are really unitary theories, since the fields figuring there do not assume invariant expansion

Astrophysical neutrinos flavored with beyond the Standard Model physics

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, Rasmus W.; Ackermann, Markus; Winter, Walter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Lechner, Lukas [Vienna Univ. of Technology (Austria). Dept. of Physics; Kowalski, Marek [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik

2017-07-15

We systematically study the allowed parameter space for the flavor composition of astrophysical neutrinos measured at Earth, including beyond the Standard Model theories at production, during propagation, and at detection. One motivation is to illustrate the discrimination power of the next-generation neutrino telescopes such as IceCube-Gen2. We identify several examples that lead to potential deviations from the standard neutrino mixing expectation such as significant sterile neutrino production at the source, effective operators modifying the neutrino propagation at high energies, dark matter interactions in neutrino propagation, or non-standard interactions in Earth matter. IceCube-Gen2 can exclude about 90% of the allowed parameter space in these cases, and hence will allow to efficiently test and discriminate models. More detailed information can be obtained from additional observables such as the energy-dependence of the effect, fraction of electron antineutrinos at the Glashow resonance, or number of tau neutrino events.

Astrophysical neutrinos flavored with beyond the Standard Model physics

International Nuclear Information System (INIS)

Rasmussen, Rasmus W.; Ackermann, Markus; Winter, Walter; Lechner, Lukas; Kowalski, Marek; Humboldt-Universitaet, Berlin

2017-07-01

We systematically study the allowed parameter space for the flavor composition of astrophysical neutrinos measured at Earth, including beyond the Standard Model theories at production, during propagation, and at detection. One motivation is to illustrate the discrimination power of the next-generation neutrino telescopes such as IceCube-Gen2. We identify several examples that lead to potential deviations from the standard neutrino mixing expectation such as significant sterile neutrino production at the source, effective operators modifying the neutrino propagation at high energies, dark matter interactions in neutrino propagation, or non-standard interactions in Earth matter. IceCube-Gen2 can exclude about 90% of the allowed parameter space in these cases, and hence will allow to efficiently test and discriminate models. More detailed information can be obtained from additional observables such as the energy-dependence of the effect, fraction of electron antineutrinos at the Glashow resonance, or number of tau neutrino events.

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

Sterile Neutrinos in Cold Climates

International Nuclear Information System (INIS)

Jones, Benjamin J.P.

2015-01-01

Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system; test-stand measurements of liquid argon optical properties with dissolved impurities; optimization of wavelength-shifting coatings for liquid argon scintillation light detection; testing and deployment of high-voltage surge arrestors to protect TPC field cages; and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin 2 2θ 24 ≤ 0.02 at m 2 ~ 0.3 eV 2 , and the LSND and MiniBooNE allowed regions are excluded at

Universality of Planck's constant and a constraint from the absence of ℏ-induced neutrino mixing

Science.gov (United States)

Llanes-Estrada, Felipe J.

2014-03-01

You have probably often set ℏ = 1 but for what particle? I revisit here the possibility of a non-universal Planck-constant. Anomaly cancellation suggests that all particles in the same family perceive the same ℏ at fixed charges e, gw, gs; the difference between the muon's and the electron's (and thus the first and second families) can be tightly constrained by the muon's anomalous magnetic moment, but constraints are weaker for the third family. Neutrino mixing could have proceeded a priori not only by the Lagrangian neutrino mass-term, but also by the kinetic term if Planck's constant was not equal for all three species. An experimental constraint follows as such contributions, characterized by oscillations proportional to the energy, as opposed to the inverse energy, have been generically analyzed in the past. This provides at the same time support for gauge invariance. On the other hand if ℏ differs among particles while fixing the fine structure constants αem, αs, etc. instead of the charges, it affects the muonic atom puzzle without much constrain from g - 2 . Based on arXiv:1312.3566. Supported by spanish grants FPA2011-27853-C02-01 and CPAN.

Lepton charges and lepton mixing

International Nuclear Information System (INIS)

Pontecorvo, B.

1978-01-01

A review is given of theoretical and experimental investigations of lepton charges and lepton mixing known to the author at the time of the Budapest Conference, July 1970. The review is more biased towards experiment than theory. The recent and relevant expermental limits on possible lepton charge non-conservation are summarized, which were obtained by measuring probabilities of various processes. The status of the lepton mixing theory in the case when the only neutral leptons are neutrinos is reviewed, the main points being the μ→eγ decay and neutrino oscillations. The ''solar neutrino puzzle'' is discussed. A model of the μ→eγ and μ→3e decays is given as an example of drastic effects of heavy lepton mixing, and the relation between processes like μ→eγ, etc., and neutrino oscillations is considered. Recent papers on lepton nonconservation effects are then classified in groups, the related literature being presented extensively, if not fully

Flipped Heavy Neutrinos from the Solar Neutrino Problem to Baryogenesis

CERN Document Server

Ellis, Jonathan Richard; Olive, Keith A

1993-01-01

We discuss baryogenesis using the flipped $SU(5)$ model for lepton mass matrices. We show that the generalized see-saw mechanism in this model can not only provide MSW neutrino mixing suitable for solving the solar neutrino problem, and supply a hot dark matter candidate ($\

Solar neutrino oscillation parameters after SNO Phase-III and SAGE Part-III

International Nuclear Information System (INIS)

Yang Ping; Liu Qiuyu

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 θ 12 . 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 Δm 12 2 =7.684 -0.208 +0.212 x 10 -5 eV 2 , tan 2 θ 12 =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 θ 13 . (authors)

Neutrino oscillations in the early universe

International Nuclear Information System (INIS)

Enqvist, K.

1990-01-01

The oscillations of electron neutrinos into inert neutrinos may have resonant behaviour in the heat bath of the early Universe. It is shown that any initial neutrino asymmetry will be washed away by the oscillations. Neutrino oscillations would affect also primordial helium production, which implies stringent limits on the neutrino mixing parameters. (orig.)

Neutrino masses, mixings, and FCNC’s in an S3 flavor symmetric extension of the standard model

International Nuclear Information System (INIS)

Mondragón, A.; Mondragón, M.; Peinado, E.

2011-01-01

By introducing threeHiggs fields that are SU(2) doublets and a flavor permutational symmetry, S 3 , in the theory, we extend the concepts of flavor and generations to the Higgs sector and formulate a Minimal S 3 -Invariant Extension of the Standard Model. The mass matrices of the neutrinos and charged leptons are re-parameterized in terms of their eigenvalues, then the neutrino mixing matrix, V PMNS , is computed and exact, explicit analytical expressions for the neutrino mixing angles as functions of the masses of neutrinos and charged leptons are obtained in excellent agreement with the latest experimental data. We also compute the branching ratios of some selected flavor-changing neutral current (FCNC) processes, as well as the contribution of the exchange of neutral flavor-changing scalars to the anomaly of the magnetic moment of the muon, as functions of the masses of charged leptons and the neutral Higgs bosons. We find that the S 3 × Z 2 flavor symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector, well below the present experimental bounds by many orders of magnitude. The contribution of FCNC’s to the anomaly of the muon’s magnetic moment is small, but not negligible.

Neutrino masses and large mixings as a indirect signature of grand unified theory

International Nuclear Information System (INIS)

Maekawa, Nobuhiro

2015-01-01

Grand unified theory (GUT) unifies not only three forces (electromagnetic force, strong force and weak force) but also quarks and leptons. As an experimental support for the unification of forces, it is well-known that three gauge couplings meet at a scale (the GUT scale). However, it is not so well-known that there is an experimental support even for the unification of matters (quarks and leptons). We explain the indirect support in this document and show that the important key is what the neutrino experiments have revealed for 20 years. Concretely, for the unification of matters in SU(5) GUT, various observed hierarchies of quark and lepton masses and mixings can be understood only from one assumption that '10 dimensional fields of SU(5) induce stronger hierarchy for the Yukawa couplings than 5-bar fields'. For this explanation, the knowledges on neutrino masses and mixings are critical. In the end, we comment E 6 unification in which the above assumption in the SU(5) GUT can be induced. (author)

Active-sterile neutrino conversion: consequences for the r-process and supernova neutrino detection

Science.gov (United States)

Fetter, J.; McLaughlin, G. C.; Balantekin, A. B.; Fuller, G. M.

2003-02-01

We examine active-sterile neutrino conversion in the late time post-core-bounce supernova environment. By including the effect of feedback on the Mikheyev-Smirnov-Wolfenstein (MSW) conversion potential, we obtain a large range of neutrino mixing parameters which produce a favorable environment for the r-process. We look at the signature of this effect in the current generation of neutrino detectors now coming on line. We also investigate the impact of the neutrino-neutrino forward-scattering-induced potential on the MSW conversion.

Neutrino mass textures with maximal CP violation

International Nuclear Information System (INIS)

Aizawa, Ichiro; Kitabayashi, Teruyuki; Yasue, Masaki

2005-01-01

We show three types of neutrino mass textures, which give maximal CP violation as well as maximal atmospheric neutrino mixing. These textures are described by six real mass parameters: one specified by two complex flavor neutrino masses and two constrained ones and the others specified by three complex flavor neutrino masses. In each texture, we calculate mixing angles and masses, which are consistent with observed data, as well as Majorana CP phases

Neutrino Oscillations at Reactors: What Next?

OpenAIRE

Mikaelyan, L. A.; Sinev, V. V.

1999-01-01

We shortly review past and future experiments at reactors aimed at searches for neutrino masses and mixing. We also consider new idea to search at Krasnoyarsk for small mixing angle oscillations in the atmosheric neutrino mass parameter region.

Highlights on experimental neutrino physics

International Nuclear Information System (INIS)

Kemp, Ernesto

2013-01-01

Full text: In the last years a remarkable progress was achieved in a deeper understanding of neutrino sector. Nowadays we know all mixing angles and mass splits which govern the neutrino oscillation phenomena. The parameters of neutrino mixing were measured by combining results of different experimental approaches including accelerator beams, nuclear reactors, radiative decays and astrophysical neutrinos. Nevertheless, there are open questions which can be viewed as key points to consolidate our knowledge on the intrinsic properties of neutrinos such as mass hierarchy and the existence of a CP violation in leptonic sector. To answer these questions and also to improve the precision of the already known mixing parameters, a series of huge experimental efforts are being set up, even in a world-wide scale in some cases. In this presentation I will review the current knowledge of the fundamental properties of neutrinos and the experimental scenario in which we expect, in a time frame of a decade, to find missing pieces in the leptonic sector. The findings can strengthen the foundations of the Standard Model as well as open very interesting paths for new physics. (author)

The Daya Bay and T2K results on sin2⁡2θ13 and non-standard neutrino interactions

Directory of Open Access Journals (Sweden)

I. Girardi

2014-09-01

Full Text Available We show that the relatively large best fit value of sin2⁡2θ13=0.14(0.17 measured in the T2K experiment for fixed values of i the Dirac CP violation phase δ=0, and ii the atmospheric neutrino mixing parameters θ23=π/4, |Δm322|=2.4×10−3 eV2, can be reconciled with the Daya Bay result sin2⁡2θ13=0.090±0.009 if the effects of non-standard neutrino interactions (NSI in the relevant ν¯e→ν¯e and νμ→νe oscillation probabilities are taken into account.

The Intermediate Neutrino Program

CERN Document Server

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

2015-01-01

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

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

International Nuclear Information System (INIS)

Kersten, Joern; Smirnov, Alexei Yu.

2007-01-01

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

Oscillation Physics with a Neutrino Factory

CERN Document Server

Apollonio, M.; Broncano, A.; Bonesini, M.; Bouchez, J.; Bueno, A.; Burguet-Castell, J.; Casper, D.; Catanesi, G.; Cervera, A.; Cooper, S.; Donega, M.; Donini, A.; de Gouvea, A.; de Min, A.; Edgecock, R.; Ellis, J.; Fechner, M.; Fernandez, E.; Ferri, F.; Gavela, B.; Giannini, G.; Gibin, D.; Gilardoni, S.; Gomez-Cadenas, J.J.; Gruber, P.; Guglielmi, A.; Hernandez, P.; Huber, P.; Laveder, M.; Lindner, M.; Meloni, D.; Mena, O.; Menghetti, H.; Mezzetto, M.; Migliozzi, P.; Navas-Concha, S.; Palladino, V.; Papadopoulos, I.; Peach, K.; Radicioni, E.; Ragazzi, S.; Rigolin, S.; Romanino, A.; Rico, J.; Rubbia, A.; Santin, G.; Sartorelli, G.; Selvi, M.; Spiro, M.; Tabarelli, T.; Tonazzo, A.; Velasco, M.; Volkov, G.; Winter, W.; Zucchelli, P.

2004-01-01

A generation of neutrino experiments have established that neutrinos mix and probably have mass. The mixing phenomenon points to processes beyond those of the Standard Model, possibly at the Grand Unification energy scale. A extensive sequence of of experiments will be required to measure precisely all the parameters of the neutrino mixing matrix, culminating with the discovery and study of leptonic CP violation. As a first step, extensions of conventional pion/kaon decay beams, such as off-axis beams or low-energy super-beams, have been considered. These could yield first observations of $\

Can OPERA help in constraining neutrino non-standard interactions?

Energy Technology Data Exchange (ETDEWEB)

Esteban-Pretel, A.; Valle, J.W.F. [AHEP Group, Institut de Fisica Corpuscular, C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain); Huber, P. [Theory Division, Department of Physics, CERN, CH-1211 Geneva 23 (Switzerland); Institute for Particle, Nuclear and Astronomical Sciences, Physics Department, Virgina Tech, Blacksburg, VA 24062 (United States)], E-mail: pahuber@vt.edu

2008-10-09

We study how much the unique ability of the OPERA experiment to directly detect {nu}{sub {tau}} can help in probing new, non-standard contact interactions of the third family of neutrinos. We perform a combined analysis of future, high-statistics MINOS and OPERA data. For the case of non-standard interactions in {nu}{sub {mu}} to {nu}{sub e} transitions we also include the impact of possible Double Chooz data. In all cases we find that the {nu}{sub {tau}} sample of OPERA is too small to be statistically significant, even if one doubles the nominal exposure of OPERA to 9x10{sup 19} pot. OPERA's real benefit for this measurement lies in its very high neutrino energy and hence very different L/E compared to MINOS.

Renormalisation group analysis of single right-handed neutrino dominance

International Nuclear Information System (INIS)

King, S.F.; Nimai Singh, N.

2000-01-01

We perform a renormalisation group (RG) analysis of neutrino masses and mixing angles in the see-saw mechanism in the minimal supersymmetric standard model with three right-handed neutrinos, including the effects of the heavy neutrino thresholds. We focus on the case that one of the right-handed neutrinos provides the dominant contribution to the 23 block of the light Majorana matrix, causing its determinant to approximately vanish and giving an automatic neutrino mass hierarchy, so-called single right-handed neutrino dominance which may arise from a U(1) family symmetry. In these models radiative corrections can increase atmospheric and solar neutrino mixing by up to about 10% and 5%, respectively, and may help to achieve bi-maximal mixing. Significantly we find that the radiative corrections over the heavy neutrino threshold region are at least as important as those usually considered from the lightest right-handed neutrino down to low energies

Unitary Root Music and Unitary Music with Real-Valued Rank Revealing Triangular Factorization

Science.gov (United States)

2010-06-01

AFRL-RY-WP-TP-2010-1213 UNITARY ROOT MUSIC AND UNITARY MUSIC WITH REAL-VALUED RANK REVEALING TRIANGULAR FACTORIZATION (Postprint) Nizar...DATES COVERED (From - To) June 2010 Journal Article Postprint 08 September 2006 – 31 August 2009 4. TITLE AND SUBTITLE UNITARY ROOT MUSIC AND...UNITARY MUSIC WITH REAL-VALUED RANK REVEALING TRIANGULAR FACTORIZATION (Postprint) 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8650-05-D-1912-0007 5c

Neutrino masses in the minimal gauged (B -L ) supersymmetry

Science.gov (United States)

Yan, Yu-Li; Feng, Tai-Fu; Yang, Jin-Lei; Zhang, Hai-Bin; Zhao, Shu-Min; Zhu, Rong-Fei

2018-03-01

We present the radiative corrections to neutrino masses in a minimal supersymmetric extension of the standard model with local U (1 )B -L symmetry. At tree level, three tiny active neutrinos and two nearly massless sterile neutrinos can be obtained through the seesaw mechanism. Considering the one-loop corrections to the neutrino masses, the numerical results indicate that two sterile neutrinos obtain KeV masses and the small active-sterile neutrino mixing angles. The lighter sterile neutrino is a very interesting dark matter candidate in cosmology. Meanwhile, the active neutrinos mixing angles and mass squared differences agree with present experimental data.

Measurement of the neutrino mixing angle θ13 with the Double Chooz experiment

Science.gov (United States)

Ostrovskiy, Igor

2009-10-01

The neutrino mixing angle θ13 is last one which value is still unknown. Measuring the θ13 is important for completing our understanding of three flavor neutrino oscillations. Moreover, leptonic CP violation could only be measured in case the value of θ13 is not zero. The current best limit (^2(2θ13)Ardennes. Described in this talk, is another experiment, Double Chooz, that is being prepared at the same site. The Double Chooz experiment offers several fundamental improvements and is aiming to surpass the current limit by an order of magnitude (^2(2θ13) < 0.03). Details of the detector design, overview of systematic errors and expected sensitivity, as well as current status of the experiment are presented.

Neutrino burst from SN1987A and the solar-neutrino puzzle

International Nuclear Information System (INIS)

Arafune, J.; Fukugita, M.; Yanagida, T.; Yoshimura, M.

1987-01-01

The prompt ν/sub e/ signal from the supernova explosion in the Large Magellanic Cloud presumably detected by Kamiokande II does not necessarily mean that the Mikheyev-Smirnov-Wolfenstein effect on the solar-neutrino flux is not operative. The electron neutrino, once rotated to a different-flavor neutrino in the progenitor star, can come back via the matter-oscillation effect in the Earth, or a residual ν/sub e/ flux from the progenitor can directly hit the detector, saving the Mikheyev-Smirnov-Wolfenstein explanation of the solar-neutrino problem for a range of mixing parameters

Supersymmetric interpretations of the neutrino anomalies

CERN Document Server

Valle, José W F

2002-01-01

Solar and atmospheric neutrino data strongly indicate the need for physics beyond the standard model. The neutrino oscillation interpretation of the atmospheric data is rather unambiguous, with more options still open for the solar data. After a brief summary of the latest global fits of neutrino data, I discuss theoretical neutrino mass models. This is done first from a top-bottom approach inspired by unification ideas involving a see-saw mechanism or high dimension operators. Then I consider bottom-up approaches, with especial emphasis on the idea that the origin of neutrino mass and mixing is intrinsically supersymmetric. Models involve effective bilinear breaking of R-parity. This allows for the possibility of probing the neutrino mixing also in the context of high-energy collider experiments such as the LHC. (41 refs).

Neutrino physics with JUNO

Science.gov (United States)

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

2016-03-01

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

The Intermediate Neutrino Program

Energy Technology Data Exchange (ETDEWEB)

Adams, C.; et al.

2015-03-23

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

The Intermediate Neutrino Program

Energy Technology Data Exchange (ETDEWEB)

Adams, C. [Yale Univ., New Haven, CT (United States); Alonso, J. R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ankowski, A. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Asaadi, J. A. [Syracuse Univ., NY (United States); Ashenfelter, J. [Yale Univ., New Haven, CT (United States); Axani, S. N. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Babu, K [Oklahoma State Univ., Stillwater, OK (United States); Backhouse, C. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Band, H. R. [Yale Univ., New Haven, CT (United States); Barbeau, P. S. [Duke Univ., Durham, NC (United States); Barros, N. [Univ. of Pennsylvania, Philadelphia, PA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Betancourt, M. [Illinois Inst. of Technology, Chicago, IL (United States); Bishai, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blucher, E. [Univ. of Chicago, IL (United States); Bouffard, J. [State Univ. of New York (SUNY), Albany, NY (United States); Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brice, S. [Illinois Inst. of Technology, Chicago, IL (United States); Bryan, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Camilleri, L. [Columbia Univ., New York, NY (United States); Cao, J. [Inst. of High Energy Physics, Beijing (China); Carlson, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carr, R. E. [Columbia Univ., New York, NY (United States); Chatterjee, A. [Univ. of Texas, Arlington, TX (United States); Chen, M. [Univ. of California, Irvine, CA (United States); Chen, S. [Tsinghua Univ., Beijing (China); Chiu, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Church, E. D. [Illinois Inst. of Technology, Chicago, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Collar, J. I. [Univ. of Chicago, IL (United States); Collin, G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Conrad, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Convery, M. R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Cooper, R. L. [Indiana Univ., Bloomington, IN (United States); Cowen, D. [Pennsylvania State Univ., University Park, PA (United States); Davoudiasl, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gouvea, A. D. [Northwestern Univ., Evanston, IL (United States); Dean, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deichert, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Descamps, F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); DeYoung, T. [Michigan State Univ., East Lansing, MI (United States); Diwan, M. V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Djurcic, Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Dolinski, M. J. [Drexel Univ., Philadelphia, PA (United States); Dolph, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Donnelly, B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dwyer, D. A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dytman, S. [Univ. of Pittsburgh, PA (United States); Efremenko, Y. [Univ. of Tennessee, Knoxville, TN (United States); Everett, L. L. [Univ. of Wisconsin, Madison, WI (United States); Fava, A. [University of Padua, Padova (Italy); Figueroa-Feliciano, E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Fleming, B. [Yale Univ., New Haven, CT (United States); Friedland, A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fujikawa, B. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gaisser, T. K. [Univ. of Delaware, Newark, DE (United States); Galeazzi, M. [Univ. of Miami, FL (United States); Galehouse, DC [Univ. of Akron, OH (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garvey, G. T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gautam, S. [Tribhuvan Univ., Kirtipur (Nepal); Gilje, K. E. [Illinois Inst. of Technology, Chicago, IL (United States); Gonzalez-Garcia, M. [Stony Brook Univ., NY (United States); Goodman, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Gordon, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gramellini, E. [Yale Univ., New Haven, CT (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guglielmi, A. [University of Padua, Padova (Italy); Hackenburg, R. W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hackenburg, A. [Yale Univ., New Haven, CT (United States); Halzen, F. [Univ. of Wisconsin, Madison, WI (United States); Han, K. [Yale Univ., New Haven, CT (United States); Hans, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harris, D. [Illinois Inst. of Technology, Chicago, IL (United States); Heeger, K. M. [Yale Univ., New Haven, CT (United States); Herman, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, R. [Univ. of Chicago, IL (United States); Holin, A. [Univ. College London, Bloomsbury (United Kingdom); Huber, P. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Jaffe, D. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Johnson, R. A. [Univ. of Cincinnati, OH (United States); Joshi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Karagiorgi, G. [Univ. of Manchester (United Kingdom); Kaufman, L. J. [Indiana Univ., Bloomington, IN (United States); Kayser, B. [Illinois Inst. of Technology, Chicago, IL (United States); Kettell, S. H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kirby, B. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Klein, J. R. [Univ. of Texas, Arlington, TX (United States); Kolomensky, Y. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Kriske, R. M. [Univ. of Minnesota, Minneapolis, MN (United States); Lane, C. E. [Drexel Univ., Philadelphia, PA (United States); Langford, T. J. [Yale Univ., New Haven, CT (United States); Lankford, A. [Univ. of California, Irvine, CA (United States); Lau, K. [Univ. of Houston, TX (United States); Learned, J. G. [Univ. of Hawaii, Honolulu, HI (United States); Ling, J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Link, J. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Lissauer, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littenberg, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littlejohn, B. R. [Illinois Inst. of Technology, Chicago, IL (United States); Lockwitz, S. [Illinois Inst. of Technology, Chicago, IL (United States); Lokajicek, M. [Inst. of Physics of the Academy of Sciences of Czech Republic, Prague (Czech Republic); Louis, W. C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Luk, K. [Univ. of California, Berkeley, CA (United States); Lykken, J. [Illinois Inst. of Technology, Chicago, IL (United States); Marciano, W. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Maricic, J. [Univ. of Hawaii, Honolulu, HI (United States); Markoff, D. M. [North Carolina Central Univ., Durham, NC (United States); Caicedo, D. A. M. [Illinois Inst. of Technology, Chicago, IL (United States); Mauger, C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mavrokoridis, K. [Univ. of Liverpool (United Kingdom); McCluskey, E. [Illinois Inst. of Technology, Chicago, IL (United States); McKeen, D. [Univ. of Washington, Seattle, WA (United States); McKeown, R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mills, G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mocioiu, I. [Pennsylvania State Univ., University Park, PA (United States); Monreal, B. [Univ. of California, Santa Barbara, CA (United States); Mooney, M. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morfin, J. G. [Illinois Inst. of Technology, Chicago, IL (United States); Mumm, P. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Napolitano, J. [Temple Univ., Philadelphia, PA (United States); Neilson, R. [Drexel Univ., Philadelphia, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nessi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Norcini, D. [Yale Univ., New Haven, CT (United States); Nova, F. [Univ. of Texas, Austin, TX (United States); Nygren, D. R. [Univ. of Texas, Arlington, TX (United States); Gann, GDO [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Palamara, O. [Illinois Inst. of Technology, Chicago, IL (United States); Parsa, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States); Patterson, R. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paul, P. [Stony Brook Univ., NY (United States); Pocar, A. [Univ. of Massachusetts, Amherst, MA (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Raaf, J. L. [Illinois Inst. of Technology, Chicago, IL (United States); Rameika, R. [Illinois Inst. of Technology, Chicago, IL (United States); Ranucci, G. [National Inst. of Nuclear Physics, Milano (Italy); Ray, H. [Univ. of Florida, Gainesville, FL (United States); Reyna, D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rich, G. C. [Triangle Universities Nuclear Lab., Durham, NC (United States); Rodrigues, P. [Univ. of Rochester, NY (United States); Romero, E. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Rosero, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rountree, S. D. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Rybolt, B. [Univ. of Tennessee, Knoxville, TN (United States); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Santucci, G. [Stony Brook Univ., NY (United States); Schmitz, D. [Univ. of Chicago, IL (United States); Scholberg, K. [Duke Univ., Durham, NC (United States); Seckel, D. [Univ. of Delaware, Newark, DE (United States); Shaevitz, M. [Columbia Univ., New York, NY (United States); Shrock, R. [Stony Brook Univ., NY (United States); Smy, M. B. [Univ. of California, Irvine, CA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Sonzogni, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sousa, A. B. [Univ. of Cincinnati, OH (United States); Spitz, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); John, J. M. S. [Univ. of Cincinnati, OH (United States); Stewart, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Strait, J. B. [Illinois Inst. of Technology, Chicago, IL (United States); Sullivan, G. [Univ. of Maryland, College Park, MD (United States); Svoboda, R. [Univ. of California, Davis, CA (United States); Szelc, A. M. [Yale Univ., New Haven, CT (United States); Tayloe, R. [Indiana Univ., Bloomington, IN (United States); Thomson, M. A. [Univ. of Cambridge (United Kingdom); Toups, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vacheret, A. [Univ. of Oxford (United Kingdom); Vagins, M. [Univ. of California, Irvine, CA (United States); Water, R. G. V. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogelaar, R. B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Weber, M. [Bern (Switzerland); Weng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wetstein, M. [Univ. of Chicago, IL (United States); White, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); White, B. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitehead, L. [Univ. of Houston, TX (United States); Whittington, D. W. [Indiana Univ., Bloomington, IN (United States); Wilking, M. J. [Stony Brook Univ., NY (United States); Wilson, R. J. [Colorado State Univ., Fort Collins, CO (United States); Wilson, P. [Illinois Inst. of Technology, Chicago, IL (United States); Winklehner, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Winn, D. R. [Fairfield Univ., CT (United States); Worcester, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Yeh, M [Brookhaven National Lab. (BNL), Upton, NY (United States); Yokley, Z. W. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yoo, J. [Illinois Inst. of Technology, Chicago, IL (United States); Yu, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, J. [Univ. of Texas, Arlington, TX (United States); Zhang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-04-03

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

Neutrino Oscillations:. a Phenomenological Approach

Science.gov (United States)

Fogli, G. L.; Lisi, E.; Marrone, A.; Palazzo, A.; Rotunno, A. M.; Montanino, D.

We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

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.

Random unitary operations and quantum Darwinism

International Nuclear Information System (INIS)

Balaneskovic, Nenad

2016-01-01

We study the behavior of Quantum Darwinism (Zurek, Nature Physics 5, 181-188 (2009)) within the iterative, random unitary operations qubit-model of pure decoherence (Novotn'y et al, New Jour. Phys. 13, 053052 (2011)). We conclude that Quantum Darwinism, which describes the quantum mechanical evolution of an open system from the point of view of its environment, is not a generic phenomenon, but depends on the specific form of initial states and on the type of system-environment interactions. Furthermore, we show that within the random unitary model the concept of Quantum Darwinism enables one to explicitly construct and specify artificial initial states of environment that allow to store information about an open system of interest and its pointer-basis with maximal efficiency. Furthermore, we investigate the behavior of Quantum Darwinism after introducing dissipation into the iterative random unitary qubit model with pure decoherence in accord with V. Scarani et al (Phys. Rev. Lett. 88, 097905 (2002)) and reconstruct the corresponding dissipative attractor space. We conclude that in Zurek's qubit model Quantum Darwinism depends on the order in which pure decoherence and dissipation act upon an initial state of the entire system. We show explicitly that introducing dissipation into the random unitary evolution model in general suppresses Quantum Darwinism (regardless of the order in which decoherence and dissipation are applied) for all positive non-zero values of the dissipation strength parameter, even for those initial state configurations which, in Zurek's qubit model and in the random unitary model with pure decoherence, would lead to Quantum Darwinism. Finally, we discuss what happens with Quantum Darwinism after introducing into the iterative random unitary qubit model with pure decoherence (asymmetric) dissipation and dephasing, again in accord with V. Scarani et al (Phys. Rev. Lett. 88, 097905 (2002)), and reconstruct the corresponding

Invariant box-parameterization of neutrino oscillations

International Nuclear Information System (INIS)

Weiler, Thomas J.; Wagner, DJ

1998-01-01

The model-independent 'box' parameterization of neutrino oscillations is examined. The invariant boxes are the classical amplitudes of the individual oscillating terms. Being observables, the boxes are independent of the choice of parameterization of the mixing matrix. Emphasis is placed on the relations among the box parameters due to mixing-matrix unitarity, and on the reduction of the number of boxes to the minimum basis set. Using the box algebra, we show that CP-violation may be inferred from measurements of neutrino flavor mixing even when the oscillatory factors have averaged. General analyses of neutrino oscillations among n≥3 flavors can readily determine the boxes, which can then be manipulated to yield magnitudes of mixing matrix elements

Study of experimentally undetermined neutrino parameters in the light of baryogenesis considering type I and type II Seesaw models

International Nuclear Information System (INIS)

Kalita, Rupam

2017-01-01

We study to connect all the experimentally undetermined neutrino parameters namely lightest neutrino mass, neutrino CP phases and baryon asymmetry of the Universe within the framework of a model where both type I and type II seesaw mechanisms can contribute to tiny neutrino masses. In this work we study the effects of Dirac and Majorana neutrino phases in the origin of matter-antimatter asymmetry through the mechanism of leptogenesis. Type I seesaw mass matrix considered to a tri-bimaximal (TBM) type neutrino mixing which always gives non zero reactor mixing angle. The type II seesaw mass matrix is then considered in such a way that the necessary deviation from TBM mixing and the best fit values of neutrino parameters can be obtained when both type I and type II seesaw contributions are taken into account. We consider different contribution from type I and type II seesaw mechanism to study the effects of neutrino CP phases in the baryon asymmetry of the universe. We further study to connect all these experimentally undetermined neutrino parameters by considering various contribution of type I and type II seesaw. (author)

About the unitary discretizations of Heisenberg equations of motion

International Nuclear Information System (INIS)

Vazquez, L.

1986-01-01

In a recent paper Bender et al. (1985) have used a unitary discretization of Heisenberg equations for a one-dimensional quantum system in order to obtain information about the spectrum of the underlying continuum theory. The method consists in comparing the matrix elements between adjacent Fock states of the operators and at two steps. At the same time a very simple variational approach must be made. The purpose of this paper is to show that with unitary schemes, accurate either to order τ or τ 2 , we obtain the same spectrum results in the framework of the above method. On the other hand the same eigenvalues are obtained with a non-unitary scheme (Section II). In Section III we discuss the construction of the Hamiltonian associated to the unitary discretizations. (orig.)

Identifying the neutrino mass spectrum from a supernova neutrino burst

International Nuclear Information System (INIS)

Dighe, A.S.; Smirnov, A.Yu.

1999-12-01

We study the role that the future detection of the neutrino burst from a galactic supernova can play in the reconstruction of the neutrino mass spectrum. We consider all possible 3ν mass and flavor spectra which describe the solar and atmospheric neutrino data. For each of these spectra we find the observable effects of the supernova neutrino conversions both in the matter of the star and the earth. We show that studies of the electron neutrino and antineutrino spectra as well as observations of the neutral current effects from supernova will allow us (i) to identify the solar neutrino solution, (ii) to determine the type of mass hierarchy (normal or inverted) and (iii) to probe the mixing vertical bar U e3 vertical bar 2 to values as low as 10 -4 - 10 -3 . (author)

Measurement of the Neutrino Mixing Angle θ23 in NOvA

Science.gov (United States)

Adamson, P.; Aliaga, L.; Ambrose, D.; Anfimov, N.; Antoshkin, A.; Arrieta-Diaz, E.; Augsten, K.; Aurisano, A.; Backhouse, C.; Baird, M.; Bambah, B. A.; Bays, K.; Behera, B.; Bending, S.; Bernstein, R.; Bhatnagar, V.; Bhuyan, B.; Bian, J.; Blackburn, T.; Bolshakova, A.; Bromberg, C.; Brown, J.; Brunetti, G.; Buchanan, N.; Butkevich, A.; Bychkov, V.; Campbell, M.; Catano-Mur, E.; Childress, S.; Choudhary, B. C.; Chowdhury, B.; Coan, T. E.; Coelho, J. A. B.; Colo, M.; Cooper, J.; Corwin, L.; Cremonesi, L.; Cronin-Hennessy, D.; Davies, G. S.; Davies, J. P.; Derwent, P. F.; Desai, S.; Dharmapalan, R.; Ding, P.; Djurcic, Z.; Dukes, E. C.; Duyang, H.; Edayath, S.; Ehrlich, R.; Feldman, G. J.; Frank, M. J.; Gabrielyan, M.; Gallagher, H. R.; Germani, S.; Ghosh, T.; Giri, A.; Gomes, R. A.; Goodman, M. C.; Grichine, V.; Group, R.; Grover, D.; Guo, B.; Habig, A.; Hartnell, J.; Hatcher, R.; Hatzikoutelis, A.; Heller, K.; Himmel, A.; Holin, A.; Hylen, J.; Jediny, F.; Judah, M.; Kafka, G. K.; Kalra, D.; Kasahara, S. M. S.; Kasetti, S.; Keloth, R.; Kolupaeva, L.; Kotelnikov, S.; Kourbanis, I.; Kreymer, A.; Kumar, A.; Kurbanov, S.; Lang, K.; Lee, W. M.; Lin, S.; Liu, J.; Lokajicek, M.; Lozier, J.; Luchuk, S.; Maan, K.; Magill, S.; Mann, W. A.; Marshak, M. L.; Matera, K.; Matveev, V.; Méndez, D. P.; Messier, M. D.; Meyer, H.; Miao, T.; Miller, W. H.; Mishra, S. R.; Mohanta, R.; Moren, A.; Mualem, L.; Muether, M.; Mufson, S.; Murphy, R.; Musser, J.; Nelson, J. K.; Nichol, R.; Niner, E.; Norman, A.; Nosek, T.; Oksuzian, Y.; Olshevskiy, A.; Olson, T.; Paley, J.; Pandey, P.; Patterson, R. B.; Pawloski, G.; Pershey, D.; Petrova, O.; Petti, R.; Phan-Budd, S.; Plunkett, R. K.; Poling, R.; Potukuchi, B.; Principato, C.; Psihas, F.; Radovic, A.; Rameika, R. A.; Rebel, B.; Reed, B.; Rocco, D.; Rojas, P.; Ryabov, V.; Sachdev, K.; Sail, P.; Samoylov, O.; Sanchez, M. C.; Schroeter, R.; Sepulveda-Quiroz, J.; Shanahan, P.; Sheshukov, A.; Singh, J.; Singh, J.; Singh, P.; Singh, V.; Smolik, J.; Solomey, N.; Song, E.; Sousa, A.; Soustruznik, K.; Strait, M.; Suter, L.; Talaga, R. L.; Tamsett, M. C.; Tas, P.; Thayyullathil, R. B.; Thomas, J.; Tian, X.; Tognini, S. C.; Tripathi, J.; Tsaris, A.; Urheim, J.; Vahle, P.; Vasel, J.; Vinton, L.; Vold, A.; Vrba, T.; Wang, B.; Wetstein, M.; Whittington, D.; Wojcicki, S. G.; Wolcott, J.; Yadav, N.; Yang, S.; Zalesak, J.; Zamorano, B.; Zwaska, R.; NOvA Collaboration

2017-04-01

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05 ×1 020 protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ23 mixing (θ23=π /4 ). Assuming the normal mass hierarchy, we find Δ m322 =(2.67 ±0.11 )×10-3 eV2 and sin2θ23 at the two statistically degenerate values 0.40 4-0.022+0.030 and 0.62 4-0.030+0.022, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6 σ significance.

Joule-Thomson Coefficient for Strongly Interacting Unitary Fermi Gas

International Nuclear Information System (INIS)

Liao Kai; Chen Jisheng; Li Chao

2010-01-01

The Joule-Thomson effect reflects the interaction among constituent particles of macroscopic system. For classical ideal gas, the corresponding Joule-Thomson coefficient is vanishing while it is non-zero for ideal quantum gas due to the quantum degeneracy. In recent years, much attention is paid to the unitary Fermi gas with infinite two-body scattering length. According to universal analysis, the thermodynamical law of unitary Fermi gas is similar to that of non-interacting ideal gas, which can be explored by the virial theorem P = 2E/3V. Based on previous works, we further study the unitary Fermi gas properties. The effective chemical potential is introduced to characterize the nonlinear levels crossing effects in a strongly interacting medium. The changing behavior of the rescaled Joule-Thomson coefficient according to temperature manifests a quite different behavior from that for ideal Fermi gas. (general)

Neutrino mass and physics beyond the Standard Model

International Nuclear Information System (INIS)

Hosteins, P.

2007-09-01

The purpose of this thesis is to study, in the neutrino sector, the flavour structures at high energy. The work is divided into two main parts. The first part is dedicated to the well known mechanism to produce small neutrino masses: the seesaw mechanism, which implies the existence of massive particles whose decays violate lepton number. Therefore this mechanism can also be used to generate a net baryon number in the early universe and explain the cosmological observation of the asymmetry between matter and antimatter. However, it is often non-trivial to fulfill the constraints coming at the same time from neutrino oscillations and cosmological experiments, at least in frameworks where the couplings can be somehow constrained, like some Grand Unification models. Therefore we devoted the first part to the study of a certain class of seesaw mechanism which can be found in the context of SO(10) theories for example. We introduce a method to extract the mass matrix of the heavy right-handed neutrinos and explore the phenomenological consequences of this quantity, mainly concerning the production of a sufficient baryon asymmetry. When trying to identify the underlying symmetry governing the mixings between the different generations, we see that there is a puzzling difference between the quark and the lepton sectors. However, the quark and lepton parameters have to be compared at the scale of the flavour symmetry breaking, therefore we have to make them run to the appropriate scale. Thus, it is worthwhile investigating models where quantum corrections allow an approximate unification of quark and lepton mixings. This is why the other part of the thesis investigates the running of the effective neutrino mass operator in models with an extra compact dimension, where quantum corrections to the neutrino masses and mixings can be potentially large due to the multiplicity of states

Electron electric dipole moment in mirror fermion model with electroweak scale non-sterile right-handed neutrinos

Directory of Open Access Journals (Sweden)

Chia-Feng Chang

2018-03-01

Full Text Available The electric dipole moment of the electron is studied in detail in an extended mirror fermion model with the following unique features of (a right-handed neutrinos are non-sterile and have masses at the electroweak scale, and (b a horizontal symmetry of the tetrahedral group is used in the lepton and scalar sectors. We study the constraint on the parameter space of the model imposed by the latest ACME experimental limit on electron electric dipole moment. Other low energy experimental observables such as the anomalous magnetic dipole moment of the muon, charged lepton flavor violating processes like muon decays into electron plus photon and muon-to-electron conversion in titanium, gold and lead are also considered in our analysis for comparison. In addition to the well-known CP violating Dirac and Majorana phases in the neutrino mixing matrix, the dependence of additional phases of the new Yukawa couplings in the model is studied in detail for all these low energy observables.

Electron electric dipole moment in mirror fermion model with electroweak scale non-sterile right-handed neutrinos

Science.gov (United States)

Chang, Chia-Feng; Hung, P. Q.; Nugroho, Chrisna Setyo; Tran, Van Que; Yuan, Tzu-Chiang

2018-03-01

The electric dipole moment of the electron is studied in detail in an extended mirror fermion model with the following unique features of (a) right-handed neutrinos are non-sterile and have masses at the electroweak scale, and (b) a horizontal symmetry of the tetrahedral group is used in the lepton and scalar sectors. We study the constraint on the parameter space of the model imposed by the latest ACME experimental limit on electron electric dipole moment. Other low energy experimental observables such as the anomalous magnetic dipole moment of the muon, charged lepton flavor violating processes like muon decays into electron plus photon and muon-to-electron conversion in titanium, gold and lead are also considered in our analysis for comparison. In addition to the well-known CP violating Dirac and Majorana phases in the neutrino mixing matrix, the dependence of additional phases of the new Yukawa couplings in the model is studied in detail for all these low energy observables.

Revisiting cosmological bounds on sterile neutrinos

Energy Technology Data Exchange (ETDEWEB)

Vincent, Aaron C. [Institute for Particle Physics Phenomenology (IPPP), Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Martínez, Enrique Fernández [Departamento and Instituto de Física Teórica (IFT), UAM/CSIC, Universidad Autonoma de Madrid, C/ Nicolás Cabrera 13-15, E-28049 Cantoblanco, Madrid (Spain); Hernández, Pilar; Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Lattanzi, Massimiliano, E-mail: aaron.vincent@durham.ac.uk, E-mail: enrique.fernandez-martinez@uam.es, E-mail: m.pilar.hernandez@uv.es, E-mail: omena@ific.uv.es, E-mail: lattanzi@fe.infn.it [Dipartimento di Fisica e Science della Terra, Università di Ferrara and INFN, sezione di Ferrara, Polo Scientifico e Tecnologico, Edificio C Via Saragat, 1, I-44122 Ferrara (Italy)

2015-04-01

We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R{sub CMB} and the sound horizon r{sub s} from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin{sup 2}θ ∼< 0.026 (m{sub s}/eV){sup −2}.

Establishing atmospheric neutrino oscillations with Super-Kamiokande

International Nuclear Information System (INIS)

Kajita, T.; Kearns, E.; Shiozawa, M.

2016-01-01

In this article we review the discovery of atmospheric neutrino oscillation by the Super-Kamiokande experiment. This review outlines the sequence of observations and their associated publications that solved the atmospheric neutrino anomaly and established the existence of neutrino oscillations with nearly maximal mixing of muon neutrinos and tau neutrinos. We also discuss subsequent and ongoing studies that use atmospheric neutrinos to continue to reveal the nature of the neutrino.

A contribution to the study of fermions and of their mixing angles in Quantum Field Theory

International Nuclear Information System (INIS)

Duret, Q.

2008-09-01

This thesis is divided into two parts. The first one is devoted to the study of the fermion mixing angles in Quantum Field Theory (QFT). We show that, due to the non-ortho-normality of its mass eigenstates, the mixing matrix of a non-degenerate system of coupled fermions cannot be considered a priori to be unitary; then, in the standard model framework, that all mixing angles of quarks and leptons are consistent with a precise structure of neutral currents, in which universality and absence of flavour changing currents are equally violated. This scheme yields the quark-lepton complementarity relation between the Cabibbo angle and the second mixing angle of neutrinos. We also recover perturbatively the non unitarity of the mixing matrix by canceling nondiagonal one-loop transitions between mass eigenstates, and show how the gauge symmetry nevertheless guarantees the unitarity of the Cabibbo matrix which occurs in renormalized gauge currents. We finally study the flavour transformations that are relevant in this procedure, and outline a link between the neutral currents and the mass matrix usually considered for coupled systems. The second part presents the first results of a general study of the constraints cast in QFT by the discrete symmetries (parity P, charge conjugation C and time reversal T) on the fermionic Lagrangian and propagator. We show for one generation that the latter, being written in the most general way compatible with Lorentz invariance, are naturally PCT-invariant, and that the eigenstates of a C-invariant propagator are Majorana fermions. (author)

Mikheyev-Smirnov-Wolfenstein effect with flavor-changing neutrino interactions

International Nuclear Information System (INIS)

Roulet, E.

1991-01-01

We consider the effect that flavor-nondiagonal neutrino interactions with matter have on the resonant ν oscillations. It is shown that, even in the absence of ν mixing in a vacuum, an efficient conversion of the electron neutrinos from the Sun to another ν flavor can result if the strength of this interaction is ∼10 -2 G F . We show how this can be implemented in the minimal supersymmetric standard model with R-parity breaking. Here, the L-violating couplings induce neutrino masses, mixings, and the flavor-nondiagonal neutrino interactions that can provide a Mikheyev-Smirnov-Wolfenstein-like solution to the solar-neutrino problem even for negligible vacuum mixings

Sterile Neutrinos in Cold Climates

Energy Technology Data Exchange (ETDEWEB)

Jones, Benjamin J.P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2015-09-01

Measurements of neutrino oscillations at short baselines contain an intriguing set of experimental anomalies that may be suggestive of new physics such as the existence of sterile neutrinos. This three-part thesis presents research directed towards understanding these anomalies and searching for sterile neutrino oscillations. Part I contains a theoretical discussion of neutrino coherence properties. The open-quantum-system picture of neutrino beams, which allows a rigorous prediction of coherence distances for accelerator neutrinos, is presented. Validity of the standard treatment of active and sterile neutrino oscillations at short baselines is verified, and non-standard coherence loss effects at longer baselines are predicted. Part II concerns liquid argon detector development for the MicroBooNE experiment, which will search for short-baseline oscillations in the Booster Neutrino Beam at Fermilab. Topics include characterization and installation of the MicroBooNE optical system; test-stand measurements of liquid argon optical properties with dissolved impurities; optimization of wavelength-shifting coatings for liquid argon scintillation light detection; testing and deployment of high-voltage surge arrestors to protect TPC field cages; and software development for optical and TPC simulation and reconstruction. Part III presents a search for sterile neutrinos using the IceCube neutrino telescope, which has collected a large sample of atmospheric-neutrino-induced events in the 1-10 TeV energy range. Sterile neutrinos would modify the detected neutrino flux shape via MSW-resonant oscillations. Following a careful treatment of systematic uncertainties in the sample, no evidence for MSW-resonant oscillations is observed, and exclusion limits on 3+1 model parameter space are derived. Under the mixing assumptions made, the 90% confidence level exclusion limit extends to sin²2θ₂₄ ≤ 0.02 at m² ~ 0.3 eV², and the LSND and Mini

Effective hamiltonian within the microscopic unitary nuclear model

International Nuclear Information System (INIS)

Avramenko, V.I.; Blokhin, A.L.

1989-01-01

Within the microscopic version of the unitary collective model with the horizontal mixing the effective Hamiltonian for 18 O and 18 Ne nuclei is constructed. The algebraic structure of the Hamiltonian is compared to the familiar phenomenological ones with the SU(3)-mixing terms which describe the coupled rotational and vibrational spectra. The Hamiltonian, including central nuclear and Coulomb interaction, is diagonalized on the basis of three SU(3) irreducible representations with two orbital symmetries. 32 refs.; 2 figs.; 4 tabs

Expections for future neutrino searches at accelerators

International Nuclear Information System (INIS)

Reay, N.W.

1995-01-01

Anomalies in the flux of solar and atmosphere neutrinos have motivated a renaissance in the study of neutrino oscillations. Among many new experiments proposed, approved or commencing to run are several which rely on neutrino beams created at accelerators. These latter can be divided into short-baseline efforts searching at ultra-small mixing for neutrino masses in the cosmologically interesting mass range, and long-baseline efforts searching at larger mixing for oscillations in the mass range suggested by the atmosphere anomaly. A brief summary of these searches will be presented

Invariant box parameterization of neutrino oscillations

International Nuclear Information System (INIS)

Weiler, T.J.; Wagner, D.

1998-01-01

The model-independent 'box' parameterization of neutrino oscillations is examined. The invariant boxes are the classical amplitudes of the individual oscillating terms. Being observables, the boxes are independent of the choice of parameterization of the mixing matrix. Emphasis is placed on the relations among the box parameters due to mixing matrix unitarity, and on the reduction of the number of boxes to the minimum basis set. Using the box algebra, we show that CP-violation may be inferred from measurements of neutrino flavor mixing even when the oscillatory factors have averaged. General analyses of neutrino oscillations among n≥3 flavors can readily determine the boxes, which can then be manipulated to yield magnitudes of mixing matrix elements. copyright 1998 American Institute of Physics

Search for sterile neutrinos with IceCube DeepCore

Energy Technology Data Exchange (ETDEWEB)

Terliuk, Andrii [DESY, Platanenallee 6, 15738 Zeuthen (Germany); Collaboration: IceCube-Collaboration

2016-07-01

The DeepCore detector is a sub-array of the IceCube Neutrino Observatory that lowers the energy threshold for neutrino detection down to approximately 10 GeV. DeepCore is used for a variety of studies including atmospheric neutrino oscillations. The standard three-neutrino oscillation paradigm is tested using the DeepCore detector by searching for an additional light, sterile neutrino with a mass on the order of 1 eV. Sterile neutrinos do not interact with the ordinary matter, however they can be mixed with the three active neutrino states. Such mixture changes the picture of standard neutrino oscillations for atmospheric neutrinos with energies below 100 GeV. The capabilities of DeepCore detector to measure such sterile neutrino mixing will be presented in this talk.

Standard physics solution to the solar neutrino problem?

Energy Technology Data Exchange (ETDEWEB)

Dar, A [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Physics

1996-11-01

The {sup 8}B solar neutrino flux predicted by the standard solar model (SSM) is consistent within the theoretical and experimental uncertainties with that at Kamiokande. The Gallium and Chlorine solar neutrino experiments, however, seem to imply that the {sup 7}Be solar neutrino flux is strongly suppressed compared with that predicted by the SSM. If the {sup 7}Be solar neutrino flux is suppressed, still it can be due to astrophysical effects not included in the simplistic SSM. Such effects include short term fluctuations or periodic variation of the temperature in the solar core, rotational mixing of {sup 3}He in the solar core, and dense plasma effects which may strongly enhance p-capture by {sup 7}Be relative to e-capture. The new generation of solar observations which already look non stop deep into the sun, like Superkamiokande through neutrinos, and SOHO and GONG through acoustic waves, may point at the correct solution. Only Superkamiokande and/or future solar neutrino experiments, such as SNO, BOREXINO and HELLAZ, will be able to find out whether the solar neutrino problem is caused by neutrino properties beyond the minimal standard electroweak model or whether it is just a problem of the too simplistic standard solar model. (author) 1 fig., 3 tabs., refs.

Decoherence effect in neutrinos produced in microquasar jets

Science.gov (United States)

Mosquera, M. E.; Civitarese, O.

2018-04-01

We study the effect of decoherence upon the neutrino spectra produced in microquasar jets. In order to analyse the precession of the polarization vector of neutrinos we have calculated its time evolution by solving the corresponding equations of motion, and by assuming two different scenarios, namely: (i) the mixing between two active neutrinos, and (ii) the mixing between one active and one sterile neutrino. The results of the calculations corresponding to these scenarios show that the onset of decoherence does not depends on the activation of neutrino-neutrino interactions when realistic values of the coupling are used in the calculations. We discuss also the case of neutrinos produced in windy microquasars and compare the results which those obtained with more conventional models of microquasars.

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

International Nuclear Information System (INIS)

Blennow, Mattias; Ohlsson, Tommy; Edsjö, Joakim

2008-01-01

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

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)

Entanglement in neutrino oscillations

International Nuclear Information System (INIS)

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

2009-01-01

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)

An Experimentalist's Overview of Solar Neutrinos

Science.gov (United States)

Oser, Scott M.

2012-02-01

Four decades of solar neutrino research have demonstrated that solar models do a remarkable job of predicting the neutrino fluxes from the Sun, to the extent that solar neutrinos can now serve as a calibrated neutrino source for experiments to understand neutrino oscillations and mixing. In this review article I will highlight the most significant experimental results, with emphasis on the latest model-independent measurements from the Sudbury Neutrino Observatory. The solar neutrino fluxes are seen to be generally well-determined experimentally, with no indications of time variability, while future experiments will elucidate the lower energy part of the neutrino spectrum, especially pep and CNO neutrinos.

An Experimentalist's Overview of Solar Neutrinos

International Nuclear Information System (INIS)

Oser, Scott M

2012-01-01

Four decades of solar neutrino research have demonstrated that solar models do a remarkable job of predicting the neutrino fluxes from the Sun, to the extent that solar neutrinos can now serve as a calibrated neutrino source for experiments to understand neutrino oscillations and mixing. In this review article I will highlight the most significant experimental results, with emphasis on the latest model-independent measurements from the Sudbury Neutrino Observatory. The solar neutrino fluxes are seen to be generally well-determined experimentally, with no indications of time variability, while future experiments will elucidate the lower energy part of the neutrino spectrum, especially pep and CNO neutrinos.

Non-thermal production of minimal dark matter via right-handed neutrino decay

International Nuclear Information System (INIS)

Aoki, Mayumi; Toma, Takashi; Vicente, Avelino

2015-01-01

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2) L quintuplet and a scalar SU(2) L septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations

Daya bay reactor neutrino experiment

International Nuclear Information System (INIS)

Cao Jun

2010-01-01

Daya Bay Reactor Neutrino Experiment is a large international collaboration experiment under construction. The experiment aims to precisely determine the neutrino mixing angle θ 13 by detecting the neutrinos produced by the Daya Bay Nuclear Power Plant. θ 13 is one of two unknown fundamental parameters in neutrino mixing. Its magnitude is a roadmap of the future neutrino physics, and very likely related to the puzzle of missing antimatter in our universe. The precise measurement has very important physics significance. The detectors of Daya Bay is under construction now. The full operation is expected in 2011. Three years' data taking will reach the designed the precision, to determine sin 2 2θ 13 to better than 0.01. Daya Bay neutrino detector is an underground large nuclear detector of low background, low energy, and high precision. In this paper, the layout of the experiment, the design and fabrication progress of the detectors, and some highlighted nuclear detecting techniques developed in the detector R and D are introduced. (author)

Improved determination of sterile neutrino dark matter spectrum

International Nuclear Information System (INIS)

Ghiglieri, J.; Laine, M.

2015-01-01

The putative recent indication of an unidentified 3.55 keV X-ray line in certain astrophysical sources is taken as a motivation for an improved theoretical computation of the cosmological abundance of 7.1 keV sterile neutrinos. If the line is interpreted as resulting from the decay of Warm Dark Matter, the mass and mixing angle of the sterile neutrino are known. Our computation then permits for a determination of the lepton asymmetry that is needed for producing the correct abundance via the Shi-Fuller mechanism, as well as for an estimate of the non-equilibrium spectrum of the sterile neutrinos. The latter plays a role in structure formation simulations. Results are presented for different flavour structures of the neutrino Yukawa couplings and for different types of pre-existing lepton asymmetries, accounting properly for the charge neutrality of the plasma and incorporating approximately hadronic contributions.

Are OPERA neutrinos faster than light because of non-inertial reference frames?

Science.gov (United States)

Germanà, C.

2012-02-01

Context. Recent results from the OPERA experiment reported a neutrino beam traveling faster than light. The challenging experiment measured the neutrino time of flight (TOF) over a baseline from the CERN to the Gran Sasso site, concluding that the neutrino beam arrives ~60 ns earlier than a light ray would do. Because the result, if confirmed, has an enormous impact on science, it might be worth double-checking the time definitions with respect to the non-inertial system in which the neutrino travel time was measured. An observer with a clock measuring the proper time τ free of non-inertial effects is the one located at the solar system barycenter (SSB). Aims: Potential problems in the OPERA data analysis connected with the definition of the reference frame and time synchronization are emphasized. We aim to investigate the synchronization of non-inertial clocks on Earth by relating this time to the proper time of an inertial observer at SSB. Methods: The Tempo2 software was used to time-stamp events observed on the geoid with respect to the SSB inertial observer time. Results: Neutrino results from OPERA might carry the fingerprint of non-inertial effects because they are timed by terrestrial clocks. The CERN-Gran Sasso clock synchronization is accomplished by applying corrections that depend on special and general relativistic time dilation effects at the clocks, depending on the position of the clocks in the solar system gravitational well. As a consequence, TOF distributions are centered on values shorter by tens of nanoseconds than expected, integrating over a period from April to December, longer if otherwise. It is worth remarking that the OPERA runs have always been carried out from April/May to November. Conclusions: If the analysis by Tempo2 holds for the OPERA experiment, the excellent measurement by the OPERA collaboration will turn into a proof of the general relativity theory in a weak field approximation. The analysis presented here is falsifiable

Evidence for leptonic CP phase from NOνA, T2K and ICAL

Indian Academy of Sciences (India)

2016-01-13

Jan 13, 2016 ... The phenomenon of neutrino oscillation is now well understood from the solar, atmospheric, reactor and accelerator neutrino experiments. This oscillation is characterized by a unitary PMNS matrix which is parametrized by three mixing angles (12, 23 and 13) and one phase (CP) known as the ...

Neutrino astrophysics

International Nuclear Information System (INIS)

Roulet, E.

2001-01-01

A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos. The major role that neutrinos play in astrophysics and cosmology is illustrated. (author)

Looking for Cosmic Neutrino Background

Directory of Open Access Journals (Sweden)

Chiaki eYanagisawa

2014-06-01

Full Text Available Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for 1 measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s, and the sign of mass splitting between the mass eigenstates m3 and m1, and 2 better measurements to determine whether the mixing angle theta23 is less than pi/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles is also in progress with continuous improvement. On the other hand, although the ideas of detecting cosmic neutrino background have been discussed since 1960s, there has not been a serious concerted effort to achieve this goal. One of the reasons is that it is extremely difficult to detect such low energy neutrinos from the Big Bang. While there has been tremendous accumulation of information on Cosmic Microwave Background since its discovery in 1965, there is no direct evidence for Cosmic Neutrino Background. The importance of detecting Cosmic Neutrino Background is that, although detailed studies of Big Bang Nucleosynthesis and Cosmic Microwave Background give information of the early Universe at ~a few minutes old and ~300 k years old, respectively, observation of Cosmic Neutrino Background allows us to study the early Universe at $sim$ 1 sec old. This article reviews progress made in the past 50 years on detection methods of Cosmic Neutrino Background.

Neutrino-Flavoured Sneutrino Dark Matter

CERN Document Server

March-Russell, John; McCullough, Matthew

2010-01-01

A simple theory of supersymmetric dark matter (DM) naturally linked to neutrino flavour physics is studied. The DM sector comprises a spectrum of mixed lhd-rhd sneutrino states where both the sneutrino flavour structure and mass splittings are determined by the associated neutrino masses and mixings. Prospects for indirect detection from solar capture are good due to a large sneutrino-nucleon cross-section afforded by the inelastic splitting (solar capture limits exclude an explanation of DAMA/LIBRA). We find parameter regions where all heavier states will have decayed, leaving only one flavour mixture of sneutrino as the candidate DM. Such regions have a unique `smoking gun' signature--sneutrino annihilation in the Sun produces a pair of neutrino mass eigenstates free from vacuum oscillations, with the potential for detection at neutrino telescopes through the observation of a hard spectrum of nu_mu and nu_tau (for a normal neutrino hierarchy). Next generation direct detection experiments can explore much of...

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

Tests of CPT invariance at neutrino factories

International Nuclear Information System (INIS)

Bilenky, Samoil M.; Freund, Martin; Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

2002-01-01

We investigate possible tests of CPT invariance on the level of event rates at neutrino factories. We do not assume any specific model but phenomenological differences in the neutrino-antineutrino masses and mixing angles in a Lorentz invariance preserving context, such as could be induced by physics beyond the standard model. We especially focus on the muon neutrino and antineutrino disappearance channels in order to obtain constraints on the neutrino-antineutrino mass and mixing angle differences; we found, for example, that the sensitivity |m 3 -m(bar sign) 3 |(less-or-similar sign)1.9x10 -4 eV could be achieved

Measurement of the Neutrino Mixing Angle θ.sub.23./sub. in NOvA

Czech Academy of Sciences Publication Activity Database

Adamson, P.; Aliaga, L.; Ambrose, D.; Lokajíček, Miloš; Zálešák, Jaroslav

2017-01-01

Roč. 118, č. 15 (2017), s. 1-7, č. článku 151802. ISSN 0031-9007 R&D Projects: GA MŠk LM2015068; GA MŠk(CZ) LG15047 Institutional support: RVO:68378271 Keywords : muon tau * symmetry * mass * hierarchy * neutrino * mixing * NOvA * experimental results Sub ject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 8.462, year: 2016

Eighty years of neutrino physics

International Nuclear Information System (INIS)

Roy, D.P.

2009-01-01

This is a pedagogical overview of neutrino physics from the invention of neutrino by Pauli in 1930 to the precise measurement of neutrino mass and mixing parameters via neutrino oscillation experiments in recent years. I have tried to pitch it at the level of undergraduate students, occasionally cutting corners to avoid the use of advanced mathematical tools. I hope it will be useful in introducing this exciting field to a broad group of young physicists. (author)

Texture one zero Dirac neutrino mass matrix with vanishing determinant or trace condition

Science.gov (United States)

Singh, Madan

2018-06-01

In the light of non-zero and relatively large value of rector mixing angle (θ13), we have performed a detailed analysis of texture one zero neutrino mass matrix Mν in the scenario of vanishing determinant/trace conditions, assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of Mν, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at 3σ confidence level. Numerical and some approximate analytical results are presented.

Implication of the solar neutrino experiments

International Nuclear Information System (INIS)

Dar, A.; Nussinov, S.

1992-01-01

The recent results from the KAMIOKANDE II and BAKSAN solar neutrino experiments, if correct, imply that lepton flavour is not conserved. The Mikheyev-Smirnov-Wolfenstein (MSW) solution to the solar neutrino problem, which was first exposed by the HOMESTAKE Cl experiment, fully explains also these results if the electron neutrino is mixed with the muon neutrino or the tau neutrino with mixing parameters Δm 2 ≅ 10 -6 eV 2 2 and sin 2 Θ ≅ 4 x 10 -2 . This MSW solution can be tested with the new generation of solar neutrino experiments which will be able to detect both the predicted distortion of the spectrum of 8 B solar νe's and the 'missing' ν e 's that appear as ν μ 's or ν τ 's. Further evidence may be obtained from the day-night effect and from the flavour content of the neutronization burst from the birth of a neutron star in a nearby supernova. Moreover, the MSW solution combined with the seesaw mechanism for generating neutrino masses further suggests m νe ≅ 10 -8 eV, m νμ ≅ 10 -3 cV, m ντ ≅ 10eV, and sin 2 2Θ ≅ 4x10 -2 for ν μ ν τ mixing. These predictions can be tested by previously proposed neutrino oscillation experiments at accelerators and by detecting neutrinos from a nearby supernova explosion. A tau neutrino with m ντ ≅ 10 eV can account for most of the dark matter in the Universe and is a viable candidate for the hot dark matter scenario of the formation of large scale structure in the Universe. (orig.)

The possibility to observe the non-standard interaction by the Hyperkamiokande atmospheric neutrino experiment

Energy Technology Data Exchange (ETDEWEB)

Fukasawa, Shinya; Yasuda, Osamu, E-mail: yasuda@phys.se.tmu.ac.jp

2017-01-15

It was suggested that a tension between the mass-squared differences obtained from the solar neutrino and KamLAND experiments can be solved by introducing the non-standard flavor-dependent interaction in neutrino propagation. In this paper we discuss the possibility to test such a hypothesis by atmospheric neutrino observations at the future Hyper-Kamiokande experiment. Assuming that the mass hierarchy is known, we find that the best-fit value from the solar neutrino and KamLAND data can be tested at more than 8σ, while the one from the global analysis can be examined at 5.0σ (1.4σ) for the normal (inverted) mass hierarchy.

Trimaximal TM1 neutrino mixing in S4 with spontaneous CP violation

International Nuclear Information System (INIS)

Luhn, Christoph

2013-01-01

The measurement of the reactor angle by the Daya Bay and RENO experiments in 2012 has ruled out the tri-bimaximal paradigm. Adopting an S 4 family symmetry, we propose direct models of the trimaximal type TM 1 in which the tri-bimaximal Klein symmetry of the neutrino sector is broken to a residual Z 2 symmetry. In such a scenario, the solar mixing angle is decreased compared to its tri-bimaximal value by about 1°, thus bringing it in excellent agreement with experimental observation. The atmospheric mixing angle, on the other hand, depends on the CP violating Dirac phase δ. Imposing CP conservation in the family symmetry limit, we show how to break the CP symmetry via flavon VEVs with well-defined complex phases, so that sizable deviations of the atmospheric angle from maximal mixing, consistent with the latest global fits, are produced

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

Energy Technology Data Exchange (ETDEWEB)

Long, Andrew J.; Lunardini, Cecilia; Sabancilar, Eray, E-mail: andrewjlong@asu.edu, E-mail: Cecilia.Lunardini@asu.edu, E-mail: Eray.Sabancilar@asu.edu [Physics Department, Arizona State University, Tempe, Arizona 85287 (United States)

2014-08-01

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

Physics of the neutrino mass

International Nuclear Information System (INIS)

Mohapatra, R N

2004-01-01

Recent neutrino oscillation experiments have yielded valuable information on the nature of neutrino masses and mixings and qualify as the first evidence for physics beyond the standard model. Even though we are far from a complete understanding of the new physics implied by them, there are many useful hints. As the next precision era in neutrino physics is about to be launched, we review the physics of neutrino mass: what we have learned and what we are going to learn

Magnus approximation in neutrino oscillations

International Nuclear Information System (INIS)

Acero, Mario A; Aguilar-Arevalo, Alexis A; D'Olivo, J C

2011-01-01

Oscillations between active and sterile neutrinos remain as an open possibility to explain some anomalous experimental observations. In a four-neutrino (three active plus one sterile) mixing scheme, we use the Magnus expansion of the evolution operator to study the evolution of neutrino flavor amplitudes within the Earth. We apply this formalism to calculate the transition probabilities from active to sterile neutrinos with energies of the order of a few GeV, taking into account the matter effect for a varying terrestrial density.

Non-thermal production of minimal dark matter via right-handed neutrino decay

Energy Technology Data Exchange (ETDEWEB)

Aoki, Mayumi [Institute for Theoretical Physics, Kanazawa University,Kanazawa 920-1192 (Japan); Toma, Takashi [Laboratoire de Physique Théorique, CNRS - UMR 8627, Université de Paris-Sud 11,F-91405 Orsay Cedex (France); Vicente, Avelino [IFPA, Dep. AGO, Université de Liège,Bat B5, Sart-Tilman B-4000 Liège 1 (Belgium); Instituto de Física Corpuscular, CSIC-Universitat de València,Apdo. 22085, E-46071 Valencia (Spain)

2015-09-29

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.

Non-thermal production of minimal dark matter via right-handed neutrino decay

Energy Technology Data Exchange (ETDEWEB)

Aoki, Mayumi [Institute for Theoretical Physics, Kanazawa University, Kanazawa 920-1192 (Japan); Toma, Takashi [Laboratoire de Physique Théorique, CNRS - UMR 8627, Université de Paris-Sud 11, F-91405 Orsay Cedex (France); Vicente, Avelino, E-mail: mayumi@hep.s.kanazawa-u.ac.jp, E-mail: takashi.toma@th.u-psud.fr, E-mail: Avelino.Vicente@ulg.ac.be [IFPA, Dep. AGO, Université de Liège, Bat B5, Sart-Tilman B-4000 Liège 1 (Belgium)

2015-09-01

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.

GENIUS Project, Neutrino Oscillations and Cosmology: Neutrinos Reveal Their Nature ?

International Nuclear Information System (INIS)

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

2000-01-01

The neutrinoless double beta decay as well as any other laboratory experiment has not been able to answer the question of the neutrino's nature. Hints on the answer are available when neutrino oscillations and (ββ) 0ν are considered simultaneously. In this case phenomenologically interesting neutrino mass schemes can lead to non-vanishing and large values of (m ν ). As a consequence, some schemes with Majorana neutrinos can be ruled out even now. If we assume that in addition neutrinos contribute to Hot Dark Matter then the window for Majorana neutrinos is even more restricted, e.g. GENIUS experiment will be sensitive to scenarios with three Majorana neutrinos. (author)

Lepton mixing and CP violation phase in the 3-3-1 model with neutral leptons based on T{sub 13} flavor symmetry

Energy Technology Data Exchange (ETDEWEB)

Vien, Vo Van, E-mail: wvienk16@gmail.com [Department of Physics, Tay Nguyen University, Le Duan, Buon Ma Thuot, DakLak (Viet Nam)

2015-08-15

We study a 3-3-1 model based on non-Abelian discrete symmetry group T{sub 13} which accommodates lepton mixing with non-zero θ{sub 13} and CP violation phase. The neutrinos get small masses and mixing with CP violation phase from S U(3) L antisextets which are all in triplets under T{sub 13}. If both breakings T{sub 13} → Z{sub 3} and Z{sub 3} → {Identity} are taken place in neutrino sector, and T{sub 13} is broken into Z{sub 3} in lepton sector, the realistic neutrino mixing form is obtained as a natural consequence of P{sub l} and T{sub 13} symmetries. The model predicts the lepton mixing with non-zero θ{sub 13}, and also gives a remarkable prediction of Dirac CP violation δ{sub CP} = 292.5∘ in the normal spectrum, and δ {sub CP} = 303.161∘ in the inverted spectrum which is still missing in the neutrino mixing matrix. There exist some regions of model parameters that can fit the experimental data in 2014 on neutrino masses and mixing without perturbation. (author)

Search for active-sterile neutrino mixing using neutral-current interactions in NOvA

Czech Academy of Sciences Publication Activity Database

Adamson, P.; Aliaga, L.; Ambrose, D.; Lokajíček, Miloš; Zálešák, Jaroslav

2017-01-01

Roč. 96, č. 7 (2017), s. 1-9, č. článku 072006. ISSN 2470-0010 R&D Projects: GA MŠk LM2015068; GA MŠk(CZ) LG15047 Institutional support: RVO:68378271 Keywords : NOvA * Fermilab * mass difference * near detector * far detector * mixing angle * neutrino * oscillation * experimental results Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 4.568, year: 2016

Total cross section measurement of muon neutrinos on isoscalar target. Exact determination of the electroweak mixing parameter

International Nuclear Information System (INIS)

Pain, R.

1987-09-01

The work presented in this thesis is concerned with high energy muon-neutrino nucleon interactions. The experiment was performed at CERN in 1984 using the CHARM marble target-calorimeter exposed to the 160 GeV narrow band beam. The experimental analysis is based on an event-by-event classification of neutral currents (NC) and charged currents (CC) interactions and on precise measurements of neutrinos and antineutrinos fluxes. This leads to precise measurements of CC total cross-sections of neutrinos and antineutrinos between 10 and 160 GeV and of NC to CC ratios of total cross-sections of events with hadron energy greater than 4 GeV: R n eutrino and R a ntineutrino. From the measurements of R n eutrino and of the ratio of CC total cross-sections of antineutrinos and neutrinos, we obtain a high precision value of the electroweak mixing angle. Comparison of this result with those obtained in proton-antiproton collisions make it possible to derive a measurement of electroweak radiative corrections and a precise determination of ρ [fr

On the unitary transformation between non-quasifree and quasifree state spaces and its application to quantum field theory on curved spacetimes

International Nuclear Information System (INIS)

Gottschalk, Hanno; Hack, Thomas-Paul

2009-12-01

Using *-calculus on the dual of the Borchers-Uhlmann algebra endowed with a combinatorial co-product, we develop a method to calculate a unitary transformation relating the GNS representations of a non-quasifree and a quasifree state of the free hermitian scalar field. The motivation for such an analysis and a further result is the fact that a unitary transformation of this kind arises naturally in scattering theory on non-stationary backgrounds. Indeed, employing the perturbation theory of the Yang-Feldman equations with a free CCR field in a quasifree state as an initial condition and making use of extended Feynman graphs, we are able to calculate the Wightman functions of the interacting and outgoing fields in a φ p -theory on arbitrary curved spacetimes. A further examination then reveals two major features of the aforementioned theory: firstly, the interacting Wightman functions fulfil the basic axioms of hermiticity, invariance, spectrality (on stationary spacetimes), perturbative positivity, and locality. Secondly, the outgoing field is free and fulfils the CCR, but is in general not in a quasifree state in the case of a non-stationary spacetime. In order to obtain a sensible particle picture for the outgoing field and, hence, a description of the scattering process in terms of particles (in asymptotically flat spacetimes), it is thus necessary to compute a unitary transformation of the abovementioned type. (orig.)

On the unitary transformation between non-quasifree and quasifree state spaces and its application to quantum field theory on curved spacetimes

Energy Technology Data Exchange (ETDEWEB)

Gottschalk, Hanno [Bonn Univ. (Germany). Inst. fuer Angewandte Mathematik; Hack, Thomas-Paul [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2009-12-15

Using *-calculus on the dual of the Borchers-Uhlmann algebra endowed with a combinatorial co-product, we develop a method to calculate a unitary transformation relating the GNS representations of a non-quasifree and a quasifree state of the free hermitian scalar field. The motivation for such an analysis and a further result is the fact that a unitary transformation of this kind arises naturally in scattering theory on non-stationary backgrounds. Indeed, employing the perturbation theory of the Yang-Feldman equations with a free CCR field in a quasifree state as an initial condition and making use of extended Feynman graphs, we are able to calculate the Wightman functions of the interacting and outgoing fields in a {phi}{sup p}-theory on arbitrary curved spacetimes. A further examination then reveals two major features of the aforementioned theory: firstly, the interacting Wightman functions fulfil the basic axioms of hermiticity, invariance, spectrality (on stationary spacetimes), perturbative positivity, and locality. Secondly, the outgoing field is free and fulfils the CCR, but is in general not in a quasifree state in the case of a non-stationary spacetime. In order to obtain a sensible particle picture for the outgoing field and, hence, a description of the scattering process in terms of particles (in asymptotically flat spacetimes), it is thus necessary to compute a unitary transformation of the abovementioned type. (orig.)

Neutrino oscillations. Theory and experiment

International Nuclear Information System (INIS)

Beshtoev, Kh.M.

2001-01-01

Theoretical schemes on neutrino oscillations are considered. The experimental data on neutrino oscillations obtained in the Super-Kamiokande (Japan) and SNO (Canada) experiments are given. Comparison of these data with the predictions obtained in the theoretical schemes is done. Conclusion is made that the experimental data confirm only the scheme with transitions (oscillations) between aromatic ν e -, ν μ -, ν τ - neutrinos with maximal angle mixings. (author)

Classification of delocalization power of global unitary operations in terms of LOCC one-piece relocalization

Directory of Open Access Journals (Sweden)

Akihito Soeda

2010-06-01

Full Text Available We study how two pieces of localized quantum information can be delocalized across a composite Hilbert space when a global unitary operation is applied. We classify the delocalization power of global unitary operations on quantum information by investigating the possibility of relocalizing one piece of the quantum information without using any global quantum resource. We show that one-piece relocalization is possible if and only if the global unitary operation is local unitary equivalent of a controlled-unitary operation. The delocalization power turns out to reveal different aspect of the non-local properties of global unitary operations characterized by their entangling power.

Quark-lepton universality and large leptonic mixing

International Nuclear Information System (INIS)

Joshipura, Anjan S.; Smirnov, A.Yu.

2006-01-01

A unified description of fermionic mixing is proposed which assumes that in certain basis (i) a single complex unitary matrix V diagonalizes mass matrices of all fermions to the leading order (ii) the SU(5) relation M d =M l T exists between the mass matrices of the down quarks and the charged leptons, and (iii) M d - bar =M d . These assumptions automatically lead to different mixing patterns for quarks and leptons: Quarks remain unmixed to leading order (i.e. V CKM =1) while leptons have non-trivial mixing given by a symmetric unitary matrix V PMNS 0 =V T V. V depends on two physical mixing angles and for values of these angles ∼20 o -25 o it reproduces the observed mixing patterns rather well. We identify conditions under which the universal mixing V follows from the universal mass matrices of fermions. Relatively small perturbations to the leading order structure lead to the CKM mixing and corrections to V PMNS 0 . We find that if the correction matrix equals the CKM matrix, the resulting lepton mixing agrees well with data and predicts (V PMNS ) e3 >0.08

Pulsar kicks from a dark-matter sterile neutrino

International Nuclear Information System (INIS)

Fuller, George M.; Kusenko, Alexander; Mocioiu, Irina; Pascoli, Silvia

2003-01-01

We show that a sterile neutrino with a mass in the 1-20 keV range and a small mixing with the electron neutrino can simultaneously explain the origin of the pulsar motions and the dark matter in the Universe. An asymmetric neutrino emission from a hot nascent neutron star can be the explanation of the observed pulsar velocities. In addition to the pulsar kick mechanism based on resonant neutrino transitions, we point out a new possibility: an asymmetric off-resonant emission of sterile neutrinos. The two cases correspond to different values of the masses and mixing angles. In both cases we identify the ranges of parameters consistent with the pulsar kick, as well as cosmological constraints

Reactor Neutrino Detection for Non Proliferation with the NUCIFER Experiment

Energy Technology Data Exchange (ETDEWEB)

Bouvet, L. [CEA, Centre de Saclay, IRFU, Gif-sur-Yvette, (France); Bouvier, S.; Bui, V. M. [Laboratoire Subatech, Ecole des Mines, Nantes Cedex 3 (France); others, and

2012-06-15

Neutrinos are the most abundant matter particles in the Universe. Thoroughly investigated in basic science, the neutrino field is now delivering first applications to the monitoring of nuclear reactors. The neutrinos are emitted in the decay chain of the fission products; therefore measuring their flux provides real-time information, directly related to the fission process occurring in the reactor core. Because of the very weak interaction of neutrinos with matter a neutrino detector can stand outside the core containment vessel and provide a non-intrusive and inherently tamper resistant measurement. After a brief review of the existing data and worldwide projects, we present the NUCIFER experiment. The active part of the detector is a tank filled up with one ton of Gadolinium-doped liquid scintillator. Sixteen photomultiplier tubes, isolated from the liquid by an acrylic buffer, read out the light produced by the interaction of a neutrino with the protons of the liquid. The tank is surrounded by plastic scintillator plates to veto the cosmic rays. Then polyethylene and lead shielding suppress the background coming from external neutrons and gamma rays respectively. The NUCIFER detector has been designed for an optimal compromise between the detection performances and the specifications of operation in a safeguards regime. Its global footprint is 2.8 m x 2.8 m and it can monitor remotely the nuclear power plant thermal power and Plutonium content with very little maintenance on years scale. The experiment is currently installed near the OSIRIS research reactor (70 MWth) at CEA, in Saclay, France. First data are expected by May 2012. This work is done in contact with the IAEA/SGTN division that is currently investigating the potentiality of neutrinos as a novel safeguards tool. A dedicated working group has been created in 2010 to coordinate the simulation effort of various reactor types as well as the development of dedicated detectors and define and eventually

Unitary or Non-Unitary Nature of Working Memory? Evidence from Its Relation to General Fluid and Crystallized Intelligence

Science.gov (United States)

Dang, Cai-Ping; Braeken, Johan; Ferrer, Emilio; Liu, Chang

2012-01-01

This study explored the controversy surrounding working memory: whether it is a unitary system providing general purpose resources or a more differentiated system with domain-specific sub-components. A total of 348 participants completed a set of 6 working memory tasks that systematically varied in storage target contents and type of information…

Addendum to "Compact Perturbative Expressions for Neutrino Oscillations in Matter"

Energy Technology Data Exchange (ETDEWEB)

Denton, Peter B. [Bohr Inst.; Minakata, Hisakazu [CSIC, Madrid; Parke, Stephen J. [Fermilab

2018-01-19

In this paper we rewrite the neutrino mixing angles and mass squared differences in matter given, in our original paper, in a notation that is more conventional for the reader. Replacing the usual neutrino mixing angles and mass squared differences in the expressions for the vacuum oscillation probabilities with these matter mixing angles and mass squared differences gives an excellent approximation to the oscillation probabilities in matter. Comparisons for T2K, NOvA, T2HKK and DUNE are also given for neutrinos and anti-neutrinos, disappearance and appearance channels, normal ordering and inverted ordering.

Improving LMA predictions with non-standard interactions: neutrino decay in solar matter?

CERN Document Server

Das, C R

2010-01-01

It has been known for some time that the well established LMA solution to the observed solar neutrino deficit fails to predict a flat energy spectrum for SuperKamiokande as opposed to what the data indicates. It also leads to a Chlorine rate which appears to be too high as compared to the data. We investigate the possible solution to these inconsistencies with non standard neutrino interactions, assuming that they come as extra contributions to the $\

Minimalistic Neutrino Mass Model

CERN Document Server

De Gouvêa, A; Gouvea, Andre de

2001-01-01

We consider the simplest model which solves the solar and atmospheric neutrino puzzles, in the sense that it contains the smallest amount of beyond the Standard Model ingredients. The solar neutrino data is accounted for by Planck-mass effects while the atmospheric neutrino anomaly is due to the existence of a single right-handed neutrino at an intermediate mass scale between 10^9 GeV and 10^14 GeV. Even though the neutrino mixing angles are not exactly predicted, they can be naturally large, which agrees well with the current experimental situation. Furthermore, the amount of lepton asymmetry produced in the early universe by the decay of the right-handed neutrino is very predictive and may be enough to explain the current baryon-to-photon ratio if the right-handed neutrinos are produced out of thermal equilibrium. One definitive test for the model is the search for anomalous seasonal effects at Borexino.

Solar Neutrino Day-Night Effect

International Nuclear Information System (INIS)

Blennow, Mattias; Ohlsson, Tommy; Snellman, Hakan

2005-01-01

We summarize the results of Ref. [M. Blennow, T. Ohlsson and H. Snellman, Phys. Rev. D 69 (2004) 073006, hep-ph/0311098] in which we determine the effects of three flavor mixing on the day-night asymmetry in the flux of solar neutrinos. Analytic methods are used to determine the difference in the day and night solar electron neutrino survival probabilities and numerical methods are used to determine the effect of three flavor mixing at detectors

Renormalization of fermion mixing

International Nuclear Information System (INIS)

Schiopu, R.

2007-01-01

hermiticity. After analysing the complete renormalized Lagrangian in a general theory including vector and scalar bosons with arbitrary renormalizable interactions, we consider two specific models: quark mixing in the electroweak Standard Model and mixing of Majorana neutrinos in the seesaw mechanism. A counter term for fermion mixing matrices can not be fixed by only taking into account self-energy corrections or fermion field renormalization constants. The presence of unstable particles in the theory can lead to a non-unitary renormalized mixing matrix or to a gauge parameter dependence in its counter term. Therefore, we propose to determine the mixing matrix counter term by fixing the complete correction terms for a physical process to experimental measurements. As an example, we calculate the decay rate of a top quark and of a heavy neutrino. We provide in each of the chosen models sample calculations that can be easily extended to other theories. (orig.)

Renormalization of fermion mixing

Energy Technology Data Exchange (ETDEWEB)

Schiopu, R.

2007-05-11

hermiticity. After analysing the complete renormalized Lagrangian in a general theory including vector and scalar bosons with arbitrary renormalizable interactions, we consider two specific models: quark mixing in the electroweak Standard Model and mixing of Majorana neutrinos in the seesaw mechanism. A counter term for fermion mixing matrices can not be fixed by only taking into account self-energy corrections or fermion field renormalization constants. The presence of unstable particles in the theory can lead to a non-unitary renormalized mixing matrix or to a gauge parameter dependence in its counter term. Therefore, we propose to determine the mixing matrix counter term by fixing the complete correction terms for a physical process to experimental measurements. As an example, we calculate the decay rate of a top quark and of a heavy neutrino. We provide in each of the chosen models sample calculations that can be easily extended to other theories. (orig.)

Question of neutrino mass

International Nuclear Information System (INIS)

Branco, G.C.; Senjanovic, G.

1978-01-01

We investigate the question of neutrino mass in theories in which neutrinos are four-component Dirac particles. Our analysis is done in the framework of left-right--symmetric theories. The requirement of calculability and natural smallness of neutrino mass leads to the following constraints: (i) left and right charged weak currents must be ''orthogonal'' to each other, and (ii) there should be no W/sub L/-W/sub R/ mixing at the three level. Finally, we exhibit a model in which, due to the existence of an unbroken symmetry of the total Lagrangian, the electron and muon neutrinos remain massless to all orders in perturbation theory

Neutrino charge in the non-linear R sub(xi) gauge

International Nuclear Information System (INIS)

Monyonko, N.M.; Reid, J.H.

1982-12-01

We show that the electromagnetic Ward identity for the charged W boson is satisfied in the non-linear R sub(xi) gauge. Consequently the one-loop contributions to the neutrino charge give zero, which they do not in the conventional R sub(xi) gauge

Search for sterile neutrinos in MINOS and MINOS+ using a two-detector fit

Energy Technology Data Exchange (ETDEWEB)

Adamson, P.; et al.

2017-10-17

A search for mixing between active neutrinos and light sterile neutrinos has been performed by looking for muon neutrino disappearance in two detectors at baselines of 1.04 km and 735 km, using a combined MINOS and MINOS+ exposure of $16.36\\times10^{20}$ protons-on-target. A simultaneous fit to the charged-current muon neutrino and neutral-current neutrino energy spectra in the two detectors yields no evidence for sterile neutrino mixing using a 3+1 model. The most stringent limit to date is set on the mixing parameter $\\sin^2\\theta_{24}$ for most values of the sterile neutrino mass-splitting $\\Delta m^2_{41} > 10^{-4}$ eV$^2$.

Nearly degenerate neutrinos, supersymmetry and radiative corrections

International Nuclear Information System (INIS)

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

2000-01-01

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

Majorana neutrinos in a warped 5D standard model

International Nuclear Information System (INIS)

Huber, S.J.; Shafi, Q.

2002-05-01

We consider neutrino oscillations and neutrinoless double beta decay in a five dimensional standard model with warped geometry. Although the see-saw mechanism in its simplest form cannot be implemented because of the warped geometry, the bulk standard model neutrinos can acquire the desired (Majorana) masses from dimension five interactions. We discuss how large mixings can arise, why the large mixing angle MSW solution for solar neutrinos is favored, and provide estimates for the mixing angle U e3 . Implications for neutrinoless double beta decay are also discussed. (orig.)

Constraints on three flavor neutrino mixing

Indian Academy of Sciences (India)

expression for electron neutrino survival probability, integrated over the time of .... the numerator and the theoretical uncertainty in the denominator, added in quadrature. .... There are detailed Monte Carlo predictions for these fluxes, and they.

Exploring new features of neutrino oscillations with very low energy monoenergetic neutrinos

CERN Document Server

Vergados, J D

2010-01-01

In the present work we propose to study neutrino oscillations employing sources of monoenergetic neutrinos following electron capture by the nucleus. Since the neutrino energy is very low the smaller of the two oscillation lengths, L23, appearing in this electronic neutrino disappearance experiment can be so small that the full oscillation can take place inside the detector and one may determine very accurately the neutrino oscillation parameters. Since in this case the oscillation probability is proportional to theta13, one can measure or set a better limit on the unknown parameter theta13. This is quite important, since, if this mixing angle vanishes, there is not going to be CP violation in the leptonic sector. The best way to detect it is by measuring electron recoils in neutrino-electron scattering. One, however, has to pay the price that the expected counting rates are very small. Thus one needs a very intensive neutrino source and a large detector with as low as possible energy threshold and high energ...

A three-parameter neutrino mass matrix with maximal CP violation

International Nuclear Information System (INIS)

Grimus, W.; Lavoura, L.

2009-01-01

Using the seesaw mechanism, we construct a model for the light-neutrino Majorana mass matrix which yields trimaximal lepton mixing together with maximal CP violation and maximal atmospheric-neutrino mixing. We demonstrate that, in our model, the light-neutrino mass matrix retains its form under the one-loop renormalization-group evolution. With our neutrino mass matrix, the absolute neutrino mass scale is a function of |U e3 | and of the atmospheric mass-squared difference. We study the effective mass in neutrinoless ββ decay as a function of |U e3 |, showing that it contains a fourfold ambiguity

Probing neutrino dark energy with extremely high-energy cosmic neutrinos

International Nuclear Information System (INIS)

Ringwald, A.; Schrempp, L.

2006-06-01

Recently, a new non-Standard Model neutrino interaction mediated by a light scalar field was proposed, which renders the big-bang relic neutrinos of the cosmic neutrino background a natural dark energy candidate, the so-called Neutrino Dark Energy. As a further consequence of this interaction, the neutrino masses become functions of the neutrino energy densities and are thus promoted to dynamical, time/redshift dependent quantities. Such a possible neutrino mass variation introduces a redshift dependence into the resonance energies associated with the annihilation of extremely high-energy cosmic neutrinos on relic anti-neutrinos and vice versa into Z-bosons. In general, this annihilation process is expected to lead to sizeable absorption dips in the spectra to be observed on earth by neutrino observatories operating in the relevant energy region above 10 13 GeV. In our analysis, we contrast the characteristic absorption features produced by constant and varying neutrino masses, including all thermal background effects caused by the relic neutrino motion. We firstly consider neutrinos from astrophysical sources and secondly neutrinos originating from the decomposition of topological defects using the appropriate fragmentation functions. On the one hand, independent of the nature of neutrino masses, our results illustrate the discovery potential for the cosmic neutrino background by means of relic neutrino absorption spectroscopy. On the other hand, they allow to estimate the prospects for testing its possible interpretation as source of Neutrino Dark Energy within the next decade by the neutrino observatories ANITA and LOFAR. (Orig.)

Zooming in on neutrino oscillations with DUNE

Science.gov (United States)

Srivastava, Rahul; Ternes, Christoph A.; Tórtola, Mariam; Valle, José W. F.

2018-05-01

We examine the capabilities of the DUNE experiment as a probe of the neutrino mixing paradigm. Taking the current status of neutrino oscillations and the design specifications of DUNE, we determine the experiment's potential to probe the structure of neutrino mixing and C P violation. We focus on the poorly determined parameters θ23 and δC P and consider both two and seven years of run. We take various benchmarks as our true values, such as the current preferred values of θ23 and δC P, as well as several theory-motivated choices. We determine quantitatively DUNE's potential to perform a precision measurement of θ23, as well as to test the C P violation hypothesis in a model-independent way. We find that, after running for seven years, DUNE will make a substantial step in the precise determination of these parameters, bringing to quantitative test the predictions of various theories of neutrino mixing.

Present status and future prospects of the atmospheric neutrino experiments

International Nuclear Information System (INIS)

Kajita, Takaaki

2003-01-01

During the last several years, the understanding of the neutrino masses and mixings has been improved significantly. In this paper, we discuss neutrino oscillation studies in atmospheric neutrino experiments. Prospects of future atmospheric neutrino experiments are also discussed

Sterile neutrinos and indirect dark matter searches in IceCube

Science.gov (United States)

Argüelles, Carlos A.; Kopp, Joachim

2012-07-01

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

Neutrino Oscillation Results from NOvA

CERN Multimedia

CERN. Geneva

2016-01-01

NOvA is an accelerator long-baseline neutrino oscillation experiment optimised to measure electron neutrino appearance in a high-purity beam of muon neutrinos from Fermilab. The exciting discovery of the theta13 neutrino mixing angle in 2012 has opened a door to making multiple new measurements of neutrinos. These include leptonic CP violation, the neutrino mass ordering and the octant of theta23. NOvA with its 810km baseline and higher energy beam has about triple the matter effect of T2K which opens a new window on the neutrino mass ordering. With about 20% of our design beam exposure and significant analysis improvements we have recently released updated results. I will present both our disappearance and appearance measurements.

Tri-Bimaximal Neutrino Mixing from Discrete Symmetry in Extra Dimensions

CERN Document Server

Altarelli, Guido; Altarelli, Guido; Feruglio, Ferruccio

2005-01-01

We discuss a particularly symmetric model of neutrino mixings where, with good accuracy, the atmospheric mixing angle theta_{23} is maximal, theta_{13}=0 and the solar angle satisfies sin^2(theta_{12})=1/3 (Harrison-Perkins-Scott (HRS) matrix). The discrete symmetry A_4 is a suitable symmetry group for the realization of this type of model. We construct a model where the HRS matrix is exactly obtained in a first approximation without imposing ad hoc relations among parameters. The crucial issue of the required VEV alignment in the scalar sector is discussed and we present a natural solution of this problem based on a formulation with extra dimensions. We study the corrections from higher dimensionality operators allowed by the symmetries of the model and discuss the conditions on the cut-off scales and the VEVs in order for these corrections to be completely under control. Finally, the observed hierarchy of charged lepton masses is obtained by assuming a larger flavour symmetry. We also show that, under gener...

Simulating nonlinear neutrino flavor evolution

Energy Technology Data Exchange (ETDEWEB)

Duan, H [Institute for Nuclear Theory, University of Washington, Seattle, WA 98195 (United States); Fuller, G M [Department of Physics, University of California, San Diego, La Jolla, CA 92093 (United States); Carlson, J [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: hduan@phys.washington.edu, E-mail: gfuller@ucsd.edu, E-mail: carlson@lanl.gov

2008-10-01

We discuss a new kind of astrophysical transport problem: the coherent evolution of neutrino flavor in core collapse supernovae. Solution of this problem requires a numerical approach which can simulate accurately the quantum mechanical coupling of intersecting neutrino trajectories and the associated nonlinearity which characterizes neutrino flavor conversion. We describe here the two codes developed to attack this problem. We also describe the surprising phenomena revealed by these numerical calculations. Chief among these is that the nonlinearities in the problem can engineer neutrino flavor transformation which is dramatically different to that in standard Mikheyev-Smirnov-Wolfenstein treatments. This happens even though the neutrino mass-squared differences are measured to be small, and even when neutrino self-coupling is sub-dominant. Our numerical work has revealed potential signatures which, if detected in the neutrino burst from a Galactic core collapse event, could reveal heretofore unmeasurable properties of the neutrinos, such as the mass hierarchy and vacuum mixing angle {theta}{sub 13}.

Simulating nonlinear neutrino flavor evolution

Science.gov (United States)

Duan, H.; Fuller, G. M.; Carlson, J.

2008-10-01

We discuss a new kind of astrophysical transport problem: the coherent evolution of neutrino flavor in core collapse supernovae. Solution of this problem requires a numerical approach which can simulate accurately the quantum mechanical coupling of intersecting neutrino trajectories and the associated nonlinearity which characterizes neutrino flavor conversion. We describe here the two codes developed to attack this problem. We also describe the surprising phenomena revealed by these numerical calculations. Chief among these is that the nonlinearities in the problem can engineer neutrino flavor transformation which is dramatically different to that in standard Mikheyev Smirnov Wolfenstein treatments. This happens even though the neutrino mass-squared differences are measured to be small, and even when neutrino self-coupling is sub-dominant. Our numerical work has revealed potential signatures which, if detected in the neutrino burst from a Galactic core collapse event, could reveal heretofore unmeasurable properties of the neutrinos, such as the mass hierarchy and vacuum mixing angle θ13.

Neutrino oscillations at proton accelerators

International Nuclear Information System (INIS)

Michael, Douglas

2002-01-01

Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino oscillations. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex oscillation phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino oscillations could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of oscillation phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino oscillation experiments

Neutrino Oscillations at Proton Accelerators

Science.gov (United States)

Michael, Douglas

2002-12-01

Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino oscillations. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex oscillation phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino oscillations could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of oscillation phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino oscillation experiments.

Muon neutrino disappearance at MINOS

International Nuclear Information System (INIS)

Armstrong, R.

2009-01-01

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

Neutrino mass hierarchy and three-flavor spectral splits of supernova neutrinos

International Nuclear Information System (INIS)

Dasgupta, Basudeb; Mirizzi, Alessandro; Tomas, Ricard; Tamborra, Irene

2010-01-01

It was recently realized that three-flavor effects could peculiarly modify the development of spectral splits induced by collective oscillations, for supernova neutrinos emitted during the cooling phase of a protoneutron star. We systematically explore this case, explaining how the impact of these three-flavor effects depends on the ordering of the neutrino masses. In inverted mass hierarchy, the solar mass splitting gives rise to instabilities in regions of the (anti)neutrino energy spectra that were otherwise stable under the leading two-flavor evolution governed by the atmospheric mass splitting and by the 1-3 mixing angle. As a consequence, the high-energy spectral splits found in the electron (anti)neutrino spectra disappear, and are transferred to other flavors. Imperfect adiabaticity leads to smearing of spectral swap features. In normal mass hierarchy, the three-flavor and the two-flavor instabilities act in the same region of the neutrino energy spectrum, leading to only minor departures from the two-flavor treatment.

Sterile neutrinos beyond LSND at the neutrino factory

International Nuclear Information System (INIS)

Meloni, Davide; Tang Jian; Winter, Walter

2010-01-01

We discuss the effects of one additional sterile neutrino at the Neutrino Factory. Compared to earlier analyses, which have been motivated by Liquid Scintillator Neutrino Detector (LSND) results, we do not impose any constraint on the additional mass squared splitting. This means that the additional mass eigenstate could, with small mixings, be located among the known ones, as it is suggested by the recent analysis of cosmological data. We use a self-consistent framework at the Neutrino Factory without any constraints on the new parameters. We demonstrate for a combined short and long baseline setup that near detectors can provide the expected sensitivity at the LSND-motivated Δm 41 2 -range, while some sensitivity can also be obtained in the region of the atmospheric mass splitting from the long baselines. We point out that limits on such very light sterile neutrinos may also be obtained from a reanalysis of atmospheric and solar neutrino oscillation data, as well as from supernova neutrino observations. In the second part of the analysis, we compare our sensitivity with the existing literature using additional assumptions, such as |Δm 41 2 |>>|Δm 31 2 |, leading to averaging of the fast oscillations in the far detectors. We demonstrate that while the Neutrino Factory has excellent sensitivity compared to existing studies using similar assumptions, one has to be very careful interpreting these results for a combined short and long baseline setup where oscillations could occur in the near detectors. We also test the impact of additional ν τ detectors at the short and long baselines, and we do not find a substantial improvement of the sensitivities.

Reconstructing neutrino properties from collider experiments in a Higgs triplet neutrino mass model

International Nuclear Information System (INIS)

Aristizabal Sierra, D.; Hirsch, M.; Valle, J. W. F.; Villanova del Moral, A.

2003-01-01

We extend the minimal supersymmetric standard model with bilinear R-parity violation to include a pair of Higgs triplet superfields. The neutral components of the Higgs triplets develop small vacuum expectation values (VEVs) quadratic in the bilinear R-parity breaking parameters. In this scheme the atmospheric neutrino mass scale arises from bilinear R-parity breaking while for reasonable values of parameters the solar neutrino mass scale is generated from the small Higgs triplet VEVs. We calculate neutrino masses and mixing angles in this model and show how the model can be tested at future colliders. The branching ratios of the doubly charged triplet decays are related to the solar neutrino angle via a simple formula

A unified approach to the minimal unitary realizations of noncompact groups and supergroups

International Nuclear Information System (INIS)

Guenaydin, Murat; Pavlyk, Oleksandr

2006-01-01

We study the minimal unitary representations of non-compact groups and supergroups obtained by quantization of their geometric realizations as quasi-conformal groups and supergroups. The quasi-conformal groups G leave generalized light-cones defined by a quartic norm invariant and have maximal rank subgroups of the form H x SL(2, R) such that G/H x SL(2, R) are para-quaternionic symmetric spaces. We give a unified formulation of the minimal unitary representations of simple non-compact groups of type A 2 , G 2 , D 4 , F 4 , E 6 , E 7 , E 8 and Sp(2n, R). The minimal unitary representations of Sp(2n, R) are simply the singleton representations and correspond to a degenerate limit of the unified construction. The minimal unitary representations of the other noncompact groups SU(m, n), SO(m, n), SO*(2n) and SL(m, R) are also given explicitly. We extend our formalism to define and construct the corresponding minimal representations of non-compact supergroups G whose even subgroups are of the form H x SL(2, R). If H is noncompact then the supergroup G does not admit any unitary representations, in general. The unified construction with H simple or Abelian leads to the minimal representations of G(3), F(4) and O Sp(n|2, R) (in the degenerate limit). The minimal unitary representations of O Sp(n|2, R) with even subgroups SO(n) x SL(2, R) are the singleton representations. We also give the minimal realization of the one parameter family of Lie superalgebras D(2, 1; σ)

Is the search for transitions between neutrino types converging?

International Nuclear Information System (INIS)

Mann, A.K.

1994-01-01

In recent years, questions concerning the masses of the known neutrinos and the degree to which they mix have received increasing attention. New astrophysical data and new theoretical conjectures appear to be capable of answering these questions. This paper provides an overview of the subject for the non-expert while not inducing deep sleep in the knowledgeable

Unitary Transformation in Quantum Teleportation

International Nuclear Information System (INIS)

Wang Zhengchuan

2006-01-01

In the well-known treatment of quantum teleportation, the receiver should convert the state of his EPR particle into the replica of the unknown quantum state by one of four possible unitary transformations. However, the importance of these unitary transformations must be emphasized. We will show in this paper that the receiver cannot transform the state of his particle into an exact replica of the unknown state which the sender wants to transfer if he has not a proper implementation of these unitary transformations. In the procedure of converting state, the inevitable coupling between EPR particle and environment which is needed by the implementation of unitary transformations will reduce the accuracy of the replica.

Neutrino mass hierarchy determination via atmospheric neutrinos with future detectors

International Nuclear Information System (INIS)

Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Mehta, Poonam; Sankar, S Uma; Shalgar, Shashank

2008-01-01

The issue of determining the neutrino mass hierarchy is one of the outstanding questions in neutrino physics. We consider the potential of hierarchy determination using atmospheric neutrinos as the source in three different proposed future detectors: A large Iron Calorimeter detector, a megaton Water Cerenkov detector and a large-mass Liquid Argon detector. If the mixing angle θ 13 is about 10 deg. (close to CHOOZ upper bound), the hierarchy sensitivity is essentially determined by resonant matter effects. To maximize the potential of these effects in atmospheric neutrinos, charge discrimination capability in the detector is desirable. Hence, detectors with this capability have an advantage in hierarchy determination. We compare and contrast the performance of the above three detectors in this respect. We perform a realistic analysis of the above future detectors for atmospheric neutrinos and show that it is possible to achieve a significant hierarchy sensitivity if the detector characteristics are favourable. Note: The abstract has been modified from its original form to incorporate suggestions received during the conference. The poster is being submitted in its original form.

Experimental Neutrino Physics

Energy Technology Data Exchange (ETDEWEB)

Wilkes, Richard Jeffrey [Univ. of Washington, Seattle, WA (United States)

2017-11-15

The University of Washington (UW) HEP neutrino group performed experimental research on the physics of neutrinos, using the capabilities offered by the T2K Experiment and the Super-Kamiokande Neutrino Observatory. The UW group included senior investigator R. J. Wilkes, two PhD students, four MS degree students, and a research engineer, all of whom are members of the international scientific collaborations for T2K and Super-Kamiokande. During the period of support, within T2K we pursued new precision studies sensitive to new physics, going beyond the limits of current measurements of the fundamental neutrino oscillation parameters (mass differences and mixing angles). We began efforts to measure (or significantly determine the absence of) 1 the CP-violating phase parameter δCP and determine the neutrino mass hierarchy. Using the Super-Kamiokande (SK) detector we pursued newly increased precision in measurement of neutrino oscillation parameters with atmospheric neutrinos, and extended the current reach in searches for proton decay, in addition to running the most sensitive supernova watch instrument [Scholberg 2012], performing other astrophysical neutrino studies, and analyzing beam-induced events from T2K. Overall, the research addressed central questions in the field of particle physics. It included the training of graduate students (both PhD and professional MS degree students), and postdoctoral researchers. Undergraduate students also participated as laboratory assistants.

Mirror model for sterile neutrinos

International Nuclear Information System (INIS)

Berezinsky, Veniamin; Narayan, Mohan; Vissani, Francesco

2003-01-01

Sterile neutrinos are studied as subdominant contribution to solar neutrino physics. The mirror-matter neutrinos are considered as sterile neutrinos. We use the symmetric mirror model with gravitational communication between mirror and visible sectors. This communication term provides mixing between visible and mirror neutrinos with the basic scale μ=v EW 2 /M Pl =2.5x10 -6 eV, where v EW =174 GeV is the vacuum expectation value of the standard electroweak group and M Pl is the Planckian mass. It is demonstrated that each mass eigenstate of active neutrinos splits into two states separated by small Δm 2 . Unsuppressed oscillations between active and sterile neutrinos (ν a ↔ν s ) occur only in transitions between each of these close pairs ('windows'). These oscillations are characterized by very small Δm 2 and can suppress the flux and distort spectrum of pp-neutrinos in detectable way. The other observable effect is anomalous seasonal variation of neutrino flux, which appears in LMA solution. The considered subdominant neutrino oscillations ν a ↔ν s can reveal itself as big effects in observations of supernova neutrinos and high-energy (HE) neutrinos. In the case of HE neutrinos they can provide a very large diffuse flux of active neutrinos unconstrained by the e-m cascade upper limit

Radiative stability of neutrino-mass textures

Indian Academy of Sciences (India)

physics pp. 647-650. Radiative stability of neutrino-mass textures. M K PARIDA ... A major challenge to particle physics at present is the theoretical understanding of ... A possible origin of two large neutrino mixings for /e -/μ and /μ -/г but small.

First measurement of muon-neutrino disappearance in NOvA

Czech Academy of Sciences Publication Activity Database

Adamson, P.; Ader, C.; Andrews, M.; Lokajíček, Miloš; Zálešák, Jaroslav

2016-01-01

Roč. 93, č. 5 (2016), 1-8, č. článku 051104. ISSN 2470-0010 R&D Projects: GA MŠk(CZ) LG15047; GA MŠk LM2015068 Institutional support: RVO:68378271 Keywords : neutrino: oscillation * neutrino/mu: beam * neutrino * mixing angle * neutrino: mass difference * neutrino * mass: hierarchy * NOvA Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.568, year: 2016

Simulation of coherent nonlinear neutrino flavor transformation in the supernova environment: Correlated neutrino trajectories

Science.gov (United States)

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

2006-11-01

We present results of large-scale numerical simulations of the evolution of neutrino and antineutrino flavors in the region above the late-time post-supernova-explosion proto-neutron star. Our calculations are the first to allow explicit flavor evolution histories on different neutrino trajectories and to self-consistently couple flavor development on these trajectories through forward scattering-induced quantum coupling. Employing the atmospheric-scale neutrino mass-squared difference (|δm2|≃3×10-3eV2) and values of θ13 allowed by current bounds, we find transformation of neutrino and antineutrino flavors over broad ranges of energy and luminosity in roughly the “bi-polar” collective mode. We find that this large-scale flavor conversion, largely driven by the flavor off-diagonal neutrino-neutrino forward scattering potential, sets in much closer to the proto-neutron star than simple estimates based on flavor-diagonal potentials and Mikheyev-Smirnov-Wolfenstein evolution would indicate. In turn, this suggests that models of r-process nucleosynthesis sited in the neutrino-driven wind could be affected substantially by active-active neutrino flavor mixing, even with the small measured neutrino mass-squared differences.

The NESSiE Concept for Sterile Neutrinos

CERN Document Server

Stanco, L; Bagulya, A; Benettoni, M; Bernardini, P; Bertolin, A; Brugnera, R; Calabrese, M; Cecchetti, A; Cecchini, S; Chernyavskiy, M; Collazuol, G; Creti, P; Corso, F Dal; Dalkarov, O; Del Prete, A; De Mitri, I; De Robertis, G; De Serio, M; Esposti, L Degli; Di Ferdinando, D; Dore, U; Dusini, S; Dzhatdoev, T; Fanin, C; Fini, R A; Fiore, G; Galati, G; Garfagnini, A; Giacomelli, G; Giacomelli, R; Golovanov, S; Guandalin, C; Guerzoni, M; Klicek, B; Kose, U; Jakovcic, K; Laurenti, G; Laveder, M; Lippi, I; Loddo, F; Longhin, A; Loverre, P; Malenica, M; Mancarella, G; Mandrioli, G; Margiotta, A; Marsella, G; Mauri, N; Medinaceli, E; Mengucci, A; Mezzetto, M; Michinelli, R; Mingazheva, R; Morgunova, O; Muciaccia, M T; Orecchini, D; Paoloni, A; Papadia, G; Paparella, L; Pastore, A; Patrizii, L; Polukhina, N; Pozzato, M; Roda, M; Roganova, T; Rosa, G; Sahnoun, Z; Simone, S; Sioli, M; Sirignano, C; Sirri, G; Spurio, M; Starkov, N; Stipcevic, M; Surdo, A; Tenti, M; Togo, V; Ventura, M; Vladymyrov, M; Zago, M

2013-01-01

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the third mixing angle theta13 in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, several puzzling measurements exist, which deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake a definitive experiment to clarify the muon disappearance measurements at small L/E, which will be able to put severe constraints to any model with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. Within the context of the current CERN project, aimed to revitalize the neutrino field in Europe, we will illustrate the achievements that can be obtained by a double muon-spectrometer system, with emphasis on the search ...

The Deep Underground Neutrino Experiment: The precision era of neutrino physics

Energy Technology Data Exchange (ETDEWEB)

Kemp, E. [Gleb Wataghin Institute of Physics, Universidade de Campinas - UNICAMP, Campinas Brazil

2017-12-01

The last decade was remarkable for neutrino physics. In particular, the phenomenon of neutrino flavor oscillations has been firmly established by a series of independent measurements. All parameters of the neutrino mixing are now known, and we have the elements to plan a judicious exploration of new scenarios that are opened by these recent advances. With precise measurements, we can test the three-neutrino paradigm, neutrino mass hierarchy, and charge conjugation parity (CP) asymmetry in the lepton sector. The future long-baseline experiments are considered to be a fundamental tool to deepen our knowledge of electroweak interactions. The Deep Underground Neutrino Experiment (DUNE) will detect a broadband neutrino beam from Fermilab in an underground massive liquid argon time-projection chamber at an L/E of about 103 km GeV-1 to reach good sensitivity for CP-phase measurements and the determination of the mass hierarchy. The dimensions and the depth of the far detector also create an excellent opportunity to look for rare signals like proton decay to study violation of the baryonic number, as well as supernova neutrino bursts, broadening the scope of the experiment to astrophysics and associated impacts in cosmology. In this paper, we discuss the physics motivations and the main experimental features of the DUNE project required to reach its scientific goals.

Neutrino masses and beyond from supersymmetry

International Nuclear Information System (INIS)

Kong, O.C.W.

2004-01-01

A generic form of the supersymmetric SM naturally gives rise to the lepton number violating neutrino masses and mixings, without the need for extra superfields beyond the minimal spectrum. Hence, SUSY can be considered the origin of beyond SM properties of neutrinos. We have developed a formulation under which one can efficiently analyze the model. Various sources of neutrino masses are discussed. Such mass contributions come from lepton number and flavor violating couplings that also give rise to a rich phenomenology of the neutrinos and other leptons, also to be discussed. (author)

A liquid scintillator detector for the solar neutrino

Energy Technology Data Exchange (ETDEWEB)

Ranucci, G [Lab. Nazionali del Gran Sasso, Assergi (Italy) Massachusetts Inst. of Technology, Cambridge, MA (United States) Joint Inst. for Nuclear Research, Dubna (USSR) Technical Univ. of Munich, Garching (Germany) Physics Dept., Univ. Genova (Italy) INFN, Genova (Italy) Univ. Hawaii, Honolulu, HI (United States) CCR Euratom, Ispra (Italy) Physics Dept., Univ. Milano (Italy) INFN, Milano (Italy) AT and T Bell Lab., Murray Hill, NJ (United States) Physics Dept., Univ. Pavia (Italy) INFN, Pavia (Italy) Physics Dept., Univ. Perugia (Italy) INFN, Perugia (Italy) Drexel Univ., Philadelphia, PA (United States) Charles Univ., Prague (Czechoslovakia) Czech Technical Univ., Prague (Czechoslovakia); Borex Collaboration

1992-05-01

Results of the three solar neutrino experiments presently running strongly suggest new neutrino physics scenarios to explain the discrepancy between the expected and measured neutrino flux. New experiments are needed to decide among the several theoretical explanations for this that has become known as the solar neutrino problem. This paper describes the unique features of the proposed low energy solar neutrino detector Borexino, that fully exploiting the powerful handless of liquid scintillation spectroscopy on large scale, will probe emerging suggestions on scenarios invoking neutrino mass mixing and magnetic moment. (orig.).

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

Energy Technology Data Exchange (ETDEWEB)

Cooper, N.G. [ed.

1997-12-31

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

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

International Nuclear Information System (INIS)

Cooper, N.G.

1997-01-01

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

Teleportation of M-Qubit Unitary Operations

Institute of Scientific and Technical Information of China (English)

郑亦庄; 顾永建; 郭光灿

2002-01-01

We discuss teleportation of unitary operations on a two-qubit in detail, then generalize the bidirectional state teleportation scheme from one-qubit to M-qubit unitary operations. The resources required for the optimal implementation of teleportation of an M-qubit unitary operation using a bidirectional state teleportation scheme are given.

Scientific Opportunities with the Long-Baseline Neutrino Experiment

Energy Technology Data Exchange (ETDEWEB)

Adams, C.; et al.

2013-07-28

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

Family number non-conservation induced by the supersymmetric mixing of scalar leptons

International Nuclear Information System (INIS)

Levine, M.J.S.

1987-08-01

The most egregious aspect of (N = 1) supersymmetric theories is that each particle state is accompanied by a 'super-partner', a state with identical quantum numbers save that it differs in spin by one half unit. For the leptons these are scalars and are called ''sleptons'', or scalar leptons. These consist of the charged sleptons (selectron, smuon, stau) and the scalar neutrinos ('sneutrinos'). We examine a model of supersymmetry with soft breaking terms in the electroweak sector. Explicit mixing among the scalar leptons results in a number of effects, principally non-conservation of lepton family number. Comparison with experiment permits us to place constraints upon the model. 49 refs., 12 figs

Large or small angle MSW from single right-handed neutrino dominance

International Nuclear Information System (INIS)

King, S.F

2000-01-01

In this talk we discuss a natural explanation of both neutrino mass hierarchies and large neutrino mixing angles, as required by the atmospheric neutrino data, in terms of a single right-handed neutrino giving the dominant contribution to the 23 block of the light effective neutrino matrix, and illustrate this mechanism in the framework of models with U(1) family symmetries. Sub-dominant contributions from other right-handed neutrinos are required to give small mass splittings appropriate to the MSW solution to the solar neutrino problem. We present three explicit examples for achieving the small angle MSW solution in the framework of U(1) family symmetry models containing three right-handed neutrinos, which can naturally describe all quark and lepton masses and mixing angles. In this talk we also extend the analysis to the large angle MSW solution

Fermion masses and mixings in the 3-3-1 model with right-handed neutrinos based on the S{sub 3} flavor symmetry

Energy Technology Data Exchange (ETDEWEB)

Hernandez, A.E.C. [Universidad Tecnica Federico Santa Maria, Valparaiso (Chile); Martinez, R.; Ochoa, F. [Universidad Nacional de Colombia, Departamento de Fisica, Bogota (Colombia)

2016-11-15

We propose a 3-3-1 model where the SU(3){sub C} x SU(3){sub L} x U(1){sub X} symmetry is extended by S{sub 3} x Z{sub 3} x Z{sub 3}{sup '} x Z{sub 8} x Z{sub 16} and the scalar spectrum is enlarged by extra SU(3){sub L} singlet scalar fields. The model successfully describes the observed SM fermion mass and mixing pattern. In this framework, the light active neutrino masses arise via an inverse seesaw mechanism and the observed charged fermion mass and quark mixing hierarchy is a consequence of the Z{sub 3} x Z{sub 3}{sup '} x Z{sub 8} x Z{sub 16} symmetry breaking at very high energy. The obtained physical observables for both quark and lepton sectors are compatible with their experimental values. The model predicts the effective Majorana neutrino mass parameter of neutrinoless double beta decay to be m{sub ββ} = 4 and 48 meV for the normal and the inverted neutrino spectra, respectively. Furthermore, we found a leptonic Dirac CP-violating phase close to (π)/(2) and a Jarlskog invariant close to about 3 x 10{sup -2} for both normal and inverted neutrino mass hierarchy. (orig.)

Absolute values of neutrino masses: status and prospects

International Nuclear Information System (INIS)

Bilenky, S.M.; Giunti, C.; Grifols, J.A.; Masso, E.

2003-01-01

Compelling evidences in favor of neutrino masses and mixing obtained in the last years in Super-Kamiokande, SNO, KamLAND and other neutrino experiments made the physics of massive and mixed neutrinos a frontier field of research in particle physics and astrophysics. There are many open problems in this new field. In this review we consider the problem of the absolute values of neutrino masses, which apparently is the most difficult one from the experimental point of view. We discuss the present limits and the future prospects of β-decay neutrino mass measurements and neutrinoless double-β decay. We consider the important problem of the calculation of nuclear matrix elements of neutrinoless double-β decay and discuss the possibility to check the results of different model calculations of the nuclear matrix elements through their comparison with the experimental data. We discuss the upper bound of the total mass of neutrinos that was obtained recently from the data of the 2dF Galaxy Redshift Survey and other cosmological data and we discuss future prospects of the cosmological measurements of the total mass of neutrinos. We discuss also the possibility to obtain information on neutrino masses from the observation of the ultra high-energy cosmic rays (beyond the GZK cutoff). Finally, we review the main aspects of the physics of core-collapse supernovae, the limits on the absolute values of neutrino masses from the observation of SN1987A neutrinos and the future prospects of supernova neutrino detection

New phenomena in neutrino physics

International Nuclear Information System (INIS)

Kopp, Joachim

2009-01-01

In this thesis, we discuss two new concepts in neutrino physics: The neutrino Moessbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Moessbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Moessbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration. (orig.)

New phenomena in neutrino physics

Energy Technology Data Exchange (ETDEWEB)

Kopp, Joachim

2009-04-15

In this thesis, we discuss two new concepts in neutrino physics: The neutrino Moessbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Moessbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Moessbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration. (orig.)

Neutrino oscillations in strong magnetic fields

International Nuclear Information System (INIS)

Likhachev, G.G.; Studenikin, A.I.

1994-07-01

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 B cr as a function of characteristics of neutrinos in vacuum (Δm 2 ν , mixing angle θ), effective particle density of matter n eff , 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 ≥ B cr 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

New unitary affine-Virasoro constructions

International Nuclear Information System (INIS)

Halpern, M.B.; Kiritsis, E.; Obers, N.A.; Poratti, M.; Yamron, J.P.

1990-01-01

This paper reports on a quasi-systematic investigation of the Virasoro master equation. The space of all affine-Virasoro constructions is organized by K-conjugation into affine-Virasoro nests, and an estimate of the dimension of the space shows that most solutions await discovery. With consistent ansatze for the master equation, large classes of new unitary nests are constructed, including quadratic deformation nests with continuous conformal weights, and unitary irrational central charge nests, which may dominate unitary rational central charge on compact g

Neutrino mass hierarchy and matter effects

OpenAIRE

Smirnov, Alexei Yu.

2013-01-01

Matter effects modify the mixing and the effective masses of neutrinos in a way which depends on the neutrino mass hierarchy. Consequently, for normal and inverted hierarchies the oscillations and flavor conversion results are different. Sensitivity to the mass hierarchy appears whenever the matter effects on the 1-3 mixing and mass splitting become substantial. This happens in supernovae in wide energy range and in the matter of the Earth. The Earth density profile is a multi-layer medium wh...

Unitary transformations in solid state physics

International Nuclear Information System (INIS)

Wagner, M.

1986-01-01

The main emphasis of this book is on the practical application of unitary transformations to problems in solid state physics. This is a method used in the field of nonadiabatic electron-phonon phenomena where the Born-Oppenheimer approximation is no longer applicable. The book is intended as a tool for those who want to apply unitary transformations quickly and on a more elementary level and also for those who want to use this method for more involved problems. The book is divided into 6 chapters. The first three chapters are concerned with presenting quick applications of unitary transformations and chapter 4 presents a more systematic procedure. The last two chapters contain the major known examples of the utilization of unitary transformations in solid state physics, including such highlights as the Froehlich and the Fulton-Gouterman transformations. The book is supplemented by extended tables of unitary transformations, whose properties and peculiarities are also listed. This tabulated material is unique and will be of great practical use to those applying the method of unitary transformations in their work. (Auth.)

Atmospheric neutrino-induced muons in the MACRO detector

CERN Document Server

Ronga, F

1999-01-01

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.

Entanglement-continuous unitary transformations

Energy Technology Data Exchange (ETDEWEB)

Sahin, Serkan; Orus, Roman [Institute of Physics, Johannes Gutenberg University, 55099 Mainz (Germany)

2016-07-01