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Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Neutrino Mass and Mixing with Discrete Symmetry  

E-Print Network (OSTI)

This is a review article 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 A4, S4 and Delta(96).

Stephen F. King; Christoph Luhn

2013-01-07T23:59:59.000Z

2

Neutrino Mass and Mixing with Discrete Symmetry  

E-Print Network (OSTI)

This is a review article 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 seesaw 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 mec...

King, Stephen F

2013-01-01T23:59:59.000Z

3

Neutrino masses and mixings with non-zero $?_{13}$ in Type I+II Seesaw Models  

E-Print Network (OSTI)

We study the survivability of neutrino mass models with normal as well as inverted hierarchical mass patterns in the presence of both type I and type II seesaw contributions to neutrino mass within the framework of generic left-right symmetric models. At leading order, the Dirac neutrino mass matrix is assumed to be diagonal with either charged lepton (CL) type or up quark (UQ) type structure which gets corrected by non-leading effects giving rise to deviations from tri-bi-maximal (TBM) mixing and hence non-zero value of $\\theta_{13}$. Using the standard form of neutrino mass matrix which incorporates such non-leading effects, we parametrize the neutrino mass matrix incorporating both oscillation as well as cosmology data. Also considering extremal values of Majorana CP phases such that the neutrino mass eigenvalues have the structure $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$, we then calculate the predictions for neutrino parameters in the presence of both type I and type II seesaw contributions, taking one of them dominant and the other sub-dominant. We show that these mass models can survive in our framework with certain exceptions.

Debasish Borah; Mrinal Kumar Das

2012-10-18T23:59:59.000Z

4

Generation of Neutrino Masses and Mixings in Gauge Theories  

E-Print Network (OSTI)

I review models which present large flavor mixings of the lepton sector based on the gauge theory. (Invited talk at WIN99) 1

Morimitsu Tanimoto

1999-01-01T23:59:59.000Z

5

Majorana ghosts: From topological superconductor to the origin of neutrino masses, three generations and their mass mixing  

E-Print Network (OSTI)

A cutting-edge step towards understanding the nature of neutrino has been taken by the experimental discovery of neutrino mass mixing during the past decade, which indicates neutrino has a small but non-vanishing mass. A natural way to explain the origin of this small mass is the so-called seesaw mechanism, which requires the neutrino to be a Majorana fermion. Recently, Majorana's spirit returns in modern condensed matter physics -- in the context of Majorana zero modes in certain classes of topological superconductors(TSCs). In this paper, we assume a relativistic Majorana fermion is made up of four Majorana zero modes. We begin with an exactly solvable 1D DIII class TSC and show that the pair of Majorana zero modes on each end will realize a T^4=-1 representation of the time reversal symmetry and carry 1/4 spin. We find that a pair of Majorana zero modes can realize a P^4=-1 parity symmetry and even a \\bar C^4=-1 nontrivial charge conjugation symmetry. We then point out that the nontrivial charge conjugatio...

Gu, Zheng-Cheng

2013-01-01T23:59:59.000Z

6

Almost Degenerate Neutrinos with Maximal Mixing  

E-Print Network (OSTI)

If the upper limit on the effective (Majorana) neutrino mass from neutrinoless double beta decay experiments is confirmed to be much less than an electron-volt, then one way to reconcile it with the degenerate neutrino mass pattern suggested recently to explain the observed deficit of solar and atmospheric neutrinos as well as neutrinos as HDM is to postulate that there be maximal mixing among the three light (or two) neutrinos. This suggestion is advanced in this paper and is analysed.

R. N. Mohapatra; S. Nussinov

1994-11-11T23:59:59.000Z

7

neutrino_mixing_s805.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

NEUTRINO NEUTRINO PHYSICS AS EXPLORED BY FLAVOR CHANGE Written May 2002 by B. Kayser (Fermilab). I. The physics of flavor change: The rather convincing evidence that atmospheric neutrinos change from one flavor to another has now been joined by new, very strong evidence that the solar neutrinos do this as well. Neutrino flavor change implies that neutrinos have nonzero masses. That is, there is a spectrum of three or more neutrino mass eigenstates, ν 1 , ν 2 , ν 3 , . . ., that are the analogues of the charged-lepton mass eigenstates, e, µ, and τ . Neutrino flavor change also implies leptonic mixing. That is, the weak interaction coupling the W boson to a charged lepton and a neutrino can couple any charged-lepton mass eigenstate α to any neutrino mass eigenstate ν i . Here, α = e, µ, or τ , and e is the electron, etc. Leptonic W + decay can yield a particular + α in association with any ν i . The amplitude

8

Solar neutrinos with three flavor mixings  

SciTech Connect

The recent{sup 71}Ga solar neutrino observation is combined with the {sup 37}Cl and Kamiokande-II observations in an analysis for neutrino masses and mixings. The allowed parameter region is found for matter enhanced mixings among all three neutrino flavors. Distortions of the solar neutrino spectrum unique to three flavors are possible and may be observed in continuing and next generation experiments.

Harley, D.; Pantaleone, J. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory; Kuo, T.K. [Purdue Univ., Lafayette, IN (United States). Dept. of Physics

1992-12-31T23:59:59.000Z

9

Solar neutrinos with three flavor mixings  

SciTech Connect

The recent[sup 71]Ga solar neutrino observation is combined with the [sup 37]Cl and Kamiokande-II observations in an analysis for neutrino masses and mixings. The allowed parameter region is found for matter enhanced mixings among all three neutrino flavors. Distortions of the solar neutrino spectrum unique to three flavors are possible and may be observed in continuing and next generation experiments.

Harley, D.; Pantaleone, J. (Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory); Kuo, T.K. (Purdue Univ., Lafayette, IN (United States). Dept. of Physics)

1992-01-01T23:59:59.000Z

10

Minimal Neutrino Texture with Neutrino Mass Ratio and Cabibbo Angle  

E-Print Network (OSTI)

We present neutrino mass matrix textures in a minimal framework of the type-I seesaw mechanism where two right-handed Majorana neutrinos are introduced in order to reproduce experimental results of neutrino oscillations. The textures can lead to experimentally favored leptonic mixing angles described by the tri-bimaximal mixing with one additional rotation. We present minimal and next to minimal textures for the normal mass hierarchy case in a context of the texture zero. A minimal texture in the inverted hierarchy case is also constructed, which does not have any vanishing entries in a Dirac neutrino mass matrix. We also discuss some cases that model parameters in the textures are supposed to be a neutrino mass ratio and/or the Cabibbo angle. Predicted regions of mixing angles, a leptonic CP-violation parameter, and an effective mass for the neutrino-less double beta decay are presented in all textures.

Yusuke Shimizu; Ryo Takahashi; Morimitsu Tanimoto

2012-12-24T23:59:59.000Z

11

AN OVERVIEW OF NEUTRINO MASSES AND MIXING IN SO(10) MODELS.  

SciTech Connect

We review in this talk various SUSY SO(10) models. Specifically, we discuss how small neutrino masses are generated in and generic predictions of different SO(10) models. A comparison of the predictions of these models for sin{sup 2} {theta}{sub 13}is given.

CHEN,M.C.MAHANTHAPPA,K.T.

2003-06-05T23:59:59.000Z

12

Neutrino Mass and Grand Unification  

E-Print Network (OSTI)

Seesaw mechanism appears to be the simplest and most appealing way to understand small neutrino masses observed in recent experiments. It introduces three right handed neutrinos with heavy masses to the standard model, with at least one mass required by data to be close to the scale of conventional grand unified theories. This may be a hint that the new physics scale implied by neutrino masses and grand unification of forces are one and the same. Taking this point of view seriously, I explore different ways to resolve the puzzle of large neutrino mixings in grand unified theories such as SO(10) and models based on its subgroup $SU(2)_L\\times SU(2)_R\\times SU(4)_c$.

R. N. Mohapatra

2004-12-03T23:59:59.000Z

13

Neutrino mass, a status report  

SciTech Connect

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

Robertson, R.G.H.

1993-08-01T23:59:59.000Z

14

Majorana Neutrino Masses from Flavor Symmetries  

E-Print Network (OSTI)

In this talk we discuss the implications of the Minimal Supersymmetric Standard Model augmented by a single U(1) anomalous family symmetry for neutrino masses and mixing angles. The left-handed neutrino states are provided with Majorana masses through a dimension-five operator in the absence of right handed neutrino components. Assuming symmetric lepton mass matrices, the model predicts inverse hierarchical neutrino mass spectrum, theta_13=0 and large mixing while at the same time it provides acceptable mass matrices for the charged fermions.

A. Psallidas

2005-05-11T23:59:59.000Z

15

Neutrino Mass and Flavour Models  

E-Print Network (OSTI)

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.

King, Stephen F

2009-01-01T23:59:59.000Z

16

Neutrino Mass and Flavour Models  

E-Print Network (OSTI)

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.

Stephen F King

2009-09-16T23:59:59.000Z

17

Unified Graphical Summary of Neutrino Mixing Parameters  

E-Print Network (OSTI)

The neutrino mixing parameters are presented in a number of different ways by the various experiments, e.g. SuperKamiokande, K2K, SNO, KamLAND and Chooz and also by the Particle Data Group. In this paper, we argue that presenting the data in terms of $\\sin^2 \\theta$, where $\\theta$ is the mixing angle appropriate for a given experiment has a direct physical interpretation. For current atmospheric, solar and reactor neutrino experiments, the $\\sin^2 \\theta$'s are effectively the probability of finding a given flavor in a particular neutrino mass eigenstate. The given flavor and particular mass eigenstate varies from experiment to experiment, however, the use of $\\sin^2 \\theta$ provides a unified picture of all the data. Using this unified picture we present a graphical way to represent these neutrino mixing parameters which includes the uncertainties. All of this is performed in the context of the present experimental status of three neutrino oscillations.

Olga Mena; Stephen Parke

2003-12-10T23:59:59.000Z

18

Neutrino Masses and Oscillations: Triumphs and Challenges  

E-Print Network (OSTI)

The recent progress in establishing the existence of finite neutrino masses and mixing between generations of neutrinos has been remarkable, if not astounding. The combined results from studies of atmospheric neutrinos, solar neutrinos, and reactor antineutrinos paint an intriguing picture for theorists and provide clear motivation for future experimental studies. In this review, we summarize the status of experimental and theoretical work in this field and explore the future opportunities that emerge in light of recent discoveries.

R. D. McKeown; P. Vogel

2004-02-03T23:59:59.000Z

19

Determining the neutrino mass hierarchy  

Science Conference Proceedings (OSTI)

In this proceedings I review the physics that future experiments will use to determine the neutrino mass hierarchy.

Parke, Stephen J.; /Fermilab

2006-07-01T23:59:59.000Z

20

Mass Hierarchy via Mossbauer and Reactor Neutrinos  

E-Print Network (OSTI)

We show how one could determine the neutrino mass hierarchy with Mossbauer neutrinos and also revisit the question of whether the hierarchy can be determined with reactor neutrinos.

Stephen Parke; Hisakazu Minakata; Hiroshi Nunokawa; Renata Zukanovich Funchal

2008-12-10T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Neutrino mixing, flavor states and dark energy  

E-Print Network (OSTI)

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.

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

2007-11-06T23:59:59.000Z

22

Dark energy induced by neutrino mixing  

E-Print Network (OSTI)

The energy content of the vacuum condensate induced by the neutrino mixing is interpreted as dynamically evolving dark energy.

Antonio Capolupo; Salvatore Capozziello; Giuseppe Vitiello

2006-12-05T23:59:59.000Z

23

Neutrino Mass Models: Impact of non-zero reactor angle  

E-Print Network (OSTI)

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

Stephen F. King

2011-06-21T23:59:59.000Z

24

Common Radiative Origin of Active and Sterile Neutrino Masses  

E-Print Network (OSTI)

Sterile neutrinos with sub-electron volt (eV) masses have recently received serious attention due to the tantalizing hints from reactor neutrino experiments as well as cosmology. While the nine year old Wilkinson Mass Anisotropy Probe experiment suggests the effective number of relativistic degrees of freedom to be $N_{\\text{eff}} = 3.84 \\pm 0.40$, recently reported Planck collaboration results show more preference towards the standard three light neutrino scenario $ N_{\\text{eff}} = 3.30^{+0.54}_{-0.51}$. Keeping in mind that the issue of existence or non-existence of sub-eV scale sterile neutrinos is not yet settled, here we outline a mechanism to generate sub-eV scale masses for three active and one sterile neutrinos simultaneously. The model is based on an abelian extension of standard model where the fermion and scalar fields are charged under the additional U(1) gauge group in such an anomaly free way that it allows one eV scale neutrino and three massless neutrinos at tree level. However, at one loop level, this model naturally allows three active and one sterile neutrino with mass at the sub-eV scale. The model also allows for mixing between active and sterile neutrinos at one loop level which can have interesting signatures in reactor neutrino experiments.

Debasish Borah; Rathin Adhikari

2013-10-21T23:59:59.000Z

25

Solar mass-varying neutrino oscillations  

E-Print Network (OSTI)

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

V. Barger; Patrick Huber; Danny Marfatia

2005-02-21T23:59:59.000Z

26

Graphene, neutrino mass and oscillation  

E-Print Network (OSTI)

A resolution of the Abraham-Minkowski dilemma is presented that other constant velocities can play the role of c in the theory of relativity. For example, in 2005 electrons of graphene were discovered to behave as if the coefficient is a Fermi velocity. Then we propose a conjecture for neutrinos to avoid the contradiction among two-component theory, negative rest mass-square and oscillation.

Z. Y. Wang

2009-09-10T23:59:59.000Z

27

On entanglement in neutrino mixing and oscillations  

E-Print Network (OSTI)

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.

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

2010-03-29T23:59:59.000Z

28

On entanglement in neutrino mixing and oscillations  

E-Print Network (OSTI)

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.

Blasone, M; De Siena, S; Illuminati, F

2010-01-01T23:59:59.000Z

29

The SNO Solar Neutrino Data, Neutrinoless Double Beta-Decay and Neutrino Mass Spectrum  

E-Print Network (OSTI)

Assuming 3 neutrino mixing and massive Majorana neutrinos, we analyze the implications of the results of the solar neutrino experiments, including the latest SNO data, which favor the LMA MSW solution of the solar neutrino problem with \\tan^2 \\theta_sol | in neutrinoless double beta decay. For \\cos (2 \\theta_sol) \\geq 0.26, which follows from the analysis of the new solar neutrino data, we find significant lower limits on || in the cases of quasi-degenerate and inverted hierarchy neutrino mass spectrum, || \\geq 0.035 eV and || \\geq 8.5 10^-3 eV, respectively. If the spectrum is hierarchical the upper limit holds || \\leq 8.2 10^-3 eV. Correspondingly, not only a measured value of || \

S. Pascoli; S. T. Petcov

2002-05-02T23:59:59.000Z

30

QLC relation and neutrino mass hierarchy  

E-Print Network (OSTI)

neutrino mass matrix is generated at high energies, s 12 = cneutrino mass matrix is generated at low energy scales. Ontrino mass matrix is generated at some high energy scale. We

Ferrandis, Javier

2009-01-01T23:59:59.000Z

31

Discrete symmetries and neutrino masses  

SciTech Connect

We constructed a model of neutrino masses using Froggatt-Nielsen mechanism with U(1)xZ{sub 3}xZ{sub 2} flavor symmetry. The model predicts that (2/3)m{sub 2}/m{sub 3}{approx}{radical}(2)sin{theta}{sub 13} at lepton number violating scale M{sub 1}. It is shown that the small values for m{sub 2}/m{sub 3} and sin{theta}{sub 13} are consequences of breaking discrete symmetries.

Siyeon, Kim [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

2005-02-01T23:59:59.000Z

32

Probing the Absolute Mass Scale of Neutrinos  

SciTech Connect

The experimental efforts of the Neutrino Physics Group at MIT center primarily around the exploration of neutrino mass and its significance within the context of nuclear physics, particle physics, and cosmology. The group has played a prominent role in the Sudbury Neutrino Observatory, a neutrino experiment dedicated to measure neutrino oscillations from 8B neutrinos created in the sun. The group is now focusing its efforts in the measurement of the neutrino mass directly via the use of tritium beta decay. The MIT group has primary responsibilities in the Karlsruhe Tritium Neutrino mass experiment, expected to begin data taking by 2013. Specifically, the MIT group is responsible for the design and development of the global Monte Carlo framework to be used by the KATRIN collaboration, as well as responsibilities directly associated with the construction of the focal plane detector. In addition, the MIT group is sponsoring a new research endeavor for neutrino mass measurements, known as Project 8, to push beyond the limitations of current neutrino mass experiments.

Prof. Joseph A. Formaggio

2011-10-12T23:59:59.000Z

33

Neutrino mass hierarchy extraction using atmospheric neutrinos in ice  

E-Print Network (OSTI)

We show that the measurements of 10 GeV atmospheric neutrinos by an upcoming array of densely packed phototubes buried deep inside the IceCube detector at the South Pole can be used to determine the neutrino mass hierarchy for values of sin^2(2theta13) close to the present bound, if the hierarchy is normal. These results are obtained for an exposure of 100 Mton years and systematic uncertainties up to 10%.

Olga Mena; Irina Mocioiu; Soebur Razzaque

2008-03-20T23:59:59.000Z

34

Radiative inverse seesaw neutrino mass and dark matter  

SciTech Connect

Seesaw mechanism provides a natural explanation of light neutrino masses through suppression of heavy seesaw scale. In inverse seesaw models the seesaw scale can be much lower than that in the usual seesaw models. If terms inducing seesaw masses are further induced by loop corrections, the seesaw scale can be lowered to be in the range probed by experiments at the LHC without fine tuning. This talk, presented by X-G He, discuss models constructed in a recent preprint by us (arxiv:201207.6308) in which neutrino masses are generated at two loop level through inverse seesaw mechanism. These models also naturally have dark matter candidates. Although the recent data from Xenon100 put stringent constraint on the models, they can be consistent with data on neutrino masses, mixing, dark matter relic density and direct detection.

Guo Gang [INPAC, Department of Physics and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University, Shanghai (China); He Xiaogang [INPAC, Department of Physics and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University, Shanghai (China) and Department of Physics, National Tsing Hua University, and NCTS, Hsinchu, Taiwan (China); Li Guannan [INPAC, Department of Physics and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University, Shanghai, Taiwan (China)

2013-05-23T23:59:59.000Z

35

Gravity Effects on Neutrino Masses in Split Supersymmetry  

E-Print Network (OSTI)

The mass differences and mixing angles of neutrinos can neither be explained by R-Parity violating split supersymmetry nor by flavor blind quantum gravity alone. It is shown that combining both effects leads, within the allowed parameter range, to good agreement with the experimental results. The atmospheric mass is generated by supersymmetry through mixing between neutrinos and neutralinos, while the solar mass is generated by gravity through flavor blind dimension five operators. Maximal atmospheric mixing forces the tangent squared of the solar angle to be equal to 1/2. The scale of the quantum gravity operator is predicted within a 5% error, implying that the reduced Planck scale should lie around the GUT scale. In this way, the model is very predictive and can be tested at future experiments.

Marco Aurelio Diaz; Benjamin Koch; Boris Panes

2009-02-10T23:59:59.000Z

36

Dirac Neutrino Masses from Generalized Supersymmetry Breaking  

SciTech Connect

We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the standard model with a generalized supersymmetry breaking sector. If the superpotential neutrino Yukawa terms are forbidden by the gauge symmetry [such as a U(1){sup '}], sub-eV scale effective Dirac mass terms can arise at tree level from hard supersymmetry breaking Yukawa couplings, or at one loop due to nonanalytic soft supersymmetry breaking trilinear scalar couplings. The radiative neutrino magnetic and electric dipole moments vanish at one-loop order.

Demir, Durmus A.; Everett, Lisa L.; Langacker, Paul [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir (Turkey); Deutsches Elektronen-Synchrotron, DESY, D-22603 Hamburg (Germany); Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); School of Natural Sciences, Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540 (United States)

2008-03-07T23:59:59.000Z

37

The Frobenius group T13 and the canonical see-saw mechanism applied to neutrino mixing  

E-Print Network (OSTI)

The compatibility of the Frobenius group T13 with the canonical see-saw mechanism of neutrino mixing is examined. The Standard Model is extended in a minimalist way, by introducing a family symmetry and three right-handed neutrinos. To fit experiments and place constraints on the possibilities, tribimaximal mixing is used as a guideline. The application of both a family symmetry group and the canonical see-saw mechanism naturally generates small neutrino masses. The various possibilities from combining these two models are listed. Enough constraints are produced to narrow down the parameters of the neutrino mass matrix to two. This is therefore a predictive model where neutrino mass eigenvalues and allowed regions for neutrinoless double beta decay are suggested.

Christine Hartmann

2011-09-23T23:59:59.000Z

38

Addendum: The SNO Solar Neutrino Data, Neutrinoless Double Beta-Decay and Neutrino Mass Spectrum  

E-Print Network (OSTI)

We update our earlier study in [1], which was inspired by the 2002 SNO data, on the implications of the results of the solar neutrino experiments for the predictions of the effective Majorana mass in neutrinoless double beta-decay, ||. We obtain predictions for || using the values of the neutrino oscillation parameters, obtained in the analyzes of the presently available solar neutrino data, including the just published data from the salt phase of the SNO experiment, the atmospheric neutrino and CHOOZ data and the first data from the KamLAND experiment. The main conclusion reached in ref. [1] of the existence of significant lower bounds on || in the cases of neutrino mass spectrum of inverted hierarchical (IH) and quasi-degenerate (QD) type is strongly reinforced by fact that combined solar neutrino data i) exclude the possibility of cos(2 \\theta_\\odot)=0 at more than 5 s.d., ii) determine as a best fit value cos(2 \\theta_\\odot)=0.40, and ii) imply at 95% C.L. that cos(2 \\theta_\\odot) \\geq 0.22, \\theta_\\odot being the solar neutrino mixing angle. For the IH and QD spectra we get using, e.g., the 90% C.L. allowed ranges of values of the oscillation parameters, || \\geq 0.010 eV and || \\geq 0.043 eV, respectively. We also comment on the possibility to get information on the neutrino mass spectrum and on the CP-violation in the lepton sector due to Majorana CP-violating phases.

S. Pascoli; S. T. Petcov

2003-09-30T23:59:59.000Z

39

Neutrino Oscillations  

E-Print Network (OSTI)

This review summarizes recent experimental and theoretical progress in determining neutrino mixing angles and masses through neutrino oscillations. We describe the basic physics of oscillation phenomena in vacuum and matter, as well as the status of solar, reactor, atmospheric, and accelerator neutrino experiments that probe these phenomena. The results from current global analyses of neutrino parameters are given. Future efforts that may improve the precision with which these parameters are known or probe new aspects of the neutrino mixing matrix are described.

A. B. Balantekin; W. C. Haxton

2013-03-09T23:59:59.000Z

40

Neutrinoless double beta decay and neutrino masses  

SciTech Connect

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

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

2012-07-27T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Neutrino telescopes as a probe of active and sterile neutrino mixings  

E-Print Network (OSTI)

If the ultrahigh-energy (UHE) neutrino fluxes produced from a distant astrophysical source can be measured at a km^3-size neutrino telescope, they will provide a promising way to help determine the flavor mixing pattern of three active neutrinos. Considering the conventional UHE neutrino source with the flavor ratio \\phi_e : \\phi_\\mu : \\phi_\\tau = 1 : 2 : 0, I show that \\phi^D_e : \\phi^D_\\mu : \\phi^D_\\tau = (1 -2 \\Delta) : (1 +\\Delta) : (1 +\\Delta) holds at the detector of a neutrino telescope, where \\Delta characterizes the effect of \\mu-\\tau symmetry breaking (i.e., \\theta_13 \

Xing, Zhi-zhong

2007-01-01T23:59:59.000Z

42

Neutrino telescopes as a probe of active and sterile neutrino mixings  

E-Print Network (OSTI)

If the ultrahigh-energy (UHE) neutrino fluxes produced from a distant astrophysical source can be measured at a km^3-size neutrino telescope, they will provide a promising way to help determine the flavor mixing pattern of three active neutrinos. Considering the conventional UHE neutrino source with the flavor ratio \\phi_e : \\phi_\\mu : \\phi_\\tau = 1 : 2 : 0, I show that \\phi^D_e : \\phi^D_\\mu : \\phi^D_\\tau = (1 -2 \\Delta) : (1 +\\Delta) : (1 +\\Delta) holds at the detector of a neutrino telescope, where \\Delta characterizes the effect of \\mu-\\tau symmetry breaking (i.e., \\theta_13 \

Zhi-zhong Xing

2007-11-27T23:59:59.000Z

43

Confronting mass-varying neutrinos with MiniBooNE  

E-Print Network (OSTI)

We study the proposal that mass-varying neutrinos could provide an explanation for the LSND signal for \\bar\

V. Barger; D. Marfatia; K. Whisnant

2005-09-16T23:59:59.000Z

44

Searching for the Neutrino Mixing Angle Theta-13 at Reactors  

E-Print Network (OSTI)

Two neutrino mixing angles have been measured, and much of the neutrino community is turning its attention to the unmeasured mixing angle, $\\quq$, whose best limit comes from the reactor neutrino experiment CHOOZ.\\cite{bib:chooz} New two detector reactor neutrino experiments are being planned, along with more ambitious accelerator experiments, to measure or further limit $\\quq$. Here I will overview how to measure $\\quq$ using reactor neutrinos, mention some experiments that were considered and are not going forward, and review the current status of four projects: Double Chooz in France, Daya Bay in China, RENO in South Korea and Angra in Brazil. Finally I will mention how the neutrino observer can gauge progress in these projects two years from now as we approach the times corresponding to early estimates for new results.

Goodman, Maury

2007-01-01T23:59:59.000Z

45

Determining the heavy seesaw neutrino mass matrix from low-energy parameters  

E-Print Network (OSTI)

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with inter-family or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.

He, Xiao-Gang; Volkas, Raymond R

2008-01-01T23:59:59.000Z

46

Determining the heavy seesaw neutrino mass matrix from low-energy parameters  

E-Print Network (OSTI)

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with inter-family or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.

Xiao-Gang He; Sandy S. C. Law; Raymond R. Volkas

2008-10-07T23:59:59.000Z

47

Determining the heavy seesaw neutrino mass matrix from low-energy parameters  

Science Conference Proceedings (OSTI)

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intrafamily symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with interfamily or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.

He Xiaogang [Department of Physics, Center for Theoretical Sciences and LeCosPA Center, National Taiwan University, Taipei 10617, Taiwan (China); Law, Sandy S. C.; Volkas, Raymond R. [School of Physics, University of Melbourne, Victoria 3010 (Australia)

2008-12-01T23:59:59.000Z

48

Experimental Requirements to Determine the Neutrino Mass Hierarchy Using Reactor Neutrinos  

E-Print Network (OSTI)

This paper presents experimental requirements to determine the neutrino mass hierarchy using reactor neutrinos. The detector shall be located at a baseline around 58 km from the reactor(s) to measure the energy spectrum of electron antineutrinos ($\\bar{\

Liang Zhan; Yifang Wang; Jun Cao; Liangjian Wen

2009-01-20T23:59:59.000Z

49

Testing Mass Varying Neutrino With Short Gamma Ray Burst  

E-Print Network (OSTI)

In this paper we study the possibility of probing for the absolute neutrino mass and its variation with short Gamma Ray Burst (GRB). We have calculated the flight time difference between a massive neutrino and a photon in two different approaches to mass varying neutrinos. Firstly we parametrize the neutrino mass as a function of redshift in a model independent way, then we consider two specific models where the neutrino mass varies during the evolution of the Quintessence fields. Our calculations show in general the value of the time delay is changed substantially relative to a constant neutrino mass. Furthermore our numerical results show that the flight time delay in these models is expected to be larger than the duration time of the short GRB, which opens a possibility of testing the scenario of mass varying neutrino with the short GRB.

Hong Li; Zigao Dai; Xinmin Zhang

2004-11-17T23:59:59.000Z

50

Experimental Neutrino Physics: Final Report  

Science Conference Proceedings (OSTI)

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

Lane, Charles E.; Maricic, Jelena

2012-09-05T23:59:59.000Z

51

Testing mass-varying neutrinos with reactor experiments  

E-Print Network (OSTI)

We propose that reactor experiments could be used to constrain the environment dependence of neutrino mass and mixing parameters, which could be induced due to an acceleron coupling to matter fields. There are several short-baseline reactor experiment projects with different fractions of air and earth matter along the neutrino path. Moreover, the short baselines, in principle, allow the physical change of the material between source and detector. Hence, such experiments offer the possibility for a direct comparison of oscillations in air and matter. We demonstrate that for sin 2 (2?13) ? 0.04, two reactor experiments (one air, one matter) with baselines of at least 1.5 km can constrain any oscillation effect which is different in air and matter at the level of a few per cent. Furthermore, we find that using the same experiment while physically moving the material between source and detector improves systematics. PACS: 14.60.Pq

unknown authors

2005-01-01T23:59:59.000Z

52

Majorana neutrino mass matrices with three texture zeros and the sterile neutrino  

E-Print Network (OSTI)

As a consequence of the LSND anomaly and other hints of an eV scale sterile neutrino from particle physics and cosmology, the neutrino sector of the standard model of particle physics has to be extended and the smallest extension is the (3+1) model, i.e. three active neutrinos plus one sterile one. In this work we study the neutrino mass matrix $M_\

Yongchao Zhang

2013-01-30T23:59:59.000Z

53

Neutrino Mass Models and the Implications of a Non-Zero Reactor Angle  

E-Print Network (OSTI)

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 us through the maze of theoretical models eventually towards a complete theory of flavour and unification. We also discuss the theoretical implications of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

S. F. King

2009-04-21T23:59:59.000Z

54

Neutrino Mass Models and the Implications of a Non-Zero Reactor Angle  

E-Print Network (OSTI)

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 us through the maze of theoretical models eventually towards a complete theory of flavour and unification. We also discuss the theoretical implications of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

King, S F

2009-01-01T23:59:59.000Z

55

Geometric gravitational origin of neutrino oscillations and mass-energy  

E-Print Network (OSTI)

A mass-energy scale for neutrinos was calculated from the null cone curvature using geometric concepts. The scale is variable depending on the gravitational potential and the trajectory inclination with respect to the field direction. The proposed neutrino covariant equation provides the adequate curvature. The mass-energy at the Earth surface varies from a horizontal value 0.402 eV to a vertical value 0.569 eV. Earth spinor waves with winding numbers n show squared energy differences within ranges from 2.05 x 10*(-3) to 4.10 x 10*(-3) eV*2 for n=0,1 neutrinos and from 3.89 x 10*(-5) to 7.79 x 10*(-5) eV*2 for n=1,2 neutrinos. These waves interfere and the different phase velocities produce neutrino-like oscillations. The experimental results for atmospheric and solar neutrino oscillation mass parameters respectivelly fall within these theoretical ranges. Neutrinos in outer space, where interactions may be neglected, appear as particles travelling with zero mass on null geodesics. These gravitational curvature energies are consistent with neutrino oscillations, zero neutrino rest masses and Einstein's General Relativity and energy mass equivalence principle. When analyzing or averaging experimental neutrino mass-energy results of different experiments on the Earth it is of interest to consider the possible influence of the trajectory inclination angle.

Gustavo R. Gonzalez-Martin

2012-12-10T23:59:59.000Z

56

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

E-Print Network (OSTI)

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

J. F. Beacom; P. Vogel

1999-07-16T23:59:59.000Z

57

White Paper: Measuring the Neutrino Mass Hierarchy  

E-Print Network (OSTI)

This white paper is a condensation of a report by a committee appointed jointly by the Nuclear Science and Physics Divisions at Lawrence Berkeley National Laboratory (LBNL). The goal of this study was to identify the most promising technique(s) for resolving the neutrino mass hierarchy. For the most part, we have relied on calculations and simulations presented by the proponents of the various experiments. We have included evaluations of the opportunities and challenges for these experiments based on what is available already in the literature.

Cahn, R N; Freedman, S J; Haxton, W C; Kadel, R W; Kolomensky, Yu G; Luk, K B; McDonald, P; Gann, G D Orebi; Poon, A W P

2013-01-01T23:59:59.000Z

58

White Paper: Measuring the Neutrino Mass Hierarchy  

E-Print Network (OSTI)

This white paper is a condensation of a report by a committee appointed jointly by the Nuclear Science and Physics Divisions at Lawrence Berkeley National Laboratory (LBNL). The goal of this study was to identify the most promising technique(s) for resolving the neutrino mass hierarchy. For the most part, we have relied on calculations and simulations presented by the proponents of the various experiments. We have included evaluations of the opportunities and challenges for these experiments based on what is available already in the literature.

R. N. Cahn; D. A. Dwyer; S. J. Freedman; W. C. Haxton; R. W. Kadel; Yu. G. Kolomensky; K. B. Luk; P. McDonald; G. D. Orebi Gann; A. W. P. Poon

2013-07-21T23:59:59.000Z

59

Geometric gravitational origin of neutrino oscillations and mass-energy  

E-Print Network (OSTI)

A mass-energy scale for neutrinos was calculated from the null cone curvature using geometric concepts. The scale is variable depending on the gravitational potential and the trajectory inclination with respect to the field direction. The mass-energy at the Earth surface varies from a horizontal value 0.402 eV to a vertical value 0.569 eV. Earth spinor waves with winding numbers n show squared energy differences within ranges from 2.05 x 10*(-3) to 4.10 x 10*(-3) eV*2 for n=0,1 neutrinos and from 3.89 x 10*(-5) to 7.79 x 10*(-5) eV*2 for n=1,2 neutrinos. These waves interfere and the different phase velocities produce neutrino-like oscillations. The experimental results for atmospheric and solar neutrino oscillation mass parameters respectivelly fall within these theoretical ranges. Neutrinos in outer space, where interactions may be neglected, appear as particles travelling with zero mass on null geodesics. These gravitational curvature energies are consistent with neutrino oscillations, zero neutrino rest masses and Einstein's General Relativity and energy mass equivalence principle. When analyzing or averaging experimental neutrino mass-energy results of different experiments on the Earth it is of interest to consider the possible influence of the trajectory inclination angle.

Gustavo R. Gonzalez-Martin

2012-12-10T23:59:59.000Z

60

Impact of active-sterile neutrino mixing on supernova explosion and nucleosynthesis  

E-Print Network (OSTI)

We show that for the active-sterile flavor mixing parameters suggested by the reactor neutrino anomaly, substantial \\\

Meng-Ru Wu; Tobias Fischer; Lutz Huther; Gabriel Martnez-Pinedo; Yong-Zhong Qian

2013-05-10T23:59:59.000Z

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61

Neutrino Physics: Fundamentals of Neutrino Oscillations  

E-Print Network (OSTI)

In this lecture we review some of the basic properties of neutrinos, in particular their mass and the oscillation behavior. First we discuss how to describe the neutrino mass. Then, under the assumption that neutrinos are massive and mixed, the fundamentals of the neutrino oscillations are discussed with emphasis on subtle aspects which have been overlooked in the past. We then review the terrestrial neutrino oscillation experiments in the framework of three generations of neutrinos with the standard mass hierarchy. Finally, a brief summary of the current status of the solar and atmospheric neutrino problems will be given.

C. W. Kim

1996-07-22T23:59:59.000Z

62

Deviations from Tri-Bimaximal Neutrino Mixing Using Type II Seesaw  

E-Print Network (OSTI)

We study the possibility of generating deviations from tri-bimaximal (TBM) neutrino mixing to explain the non-zero reactor mixing angle within the framework of both type I and type II seesaw mechanisms. The type I seesaw term gives rise to the $\\mu-\\tau$ symmetric TBM pattern of neutrino mass matrix as predicted by generic flavor symmetry models like $A_4$ whereas the type II seesaw term gives rise to the required deviations from TBM pattern to explain the non-zero $\\theta_{13}$. Considering extremal values of Majorana CP phases such that the neutrino mass eigenvalues have the structure $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$, we numerically fit the type I seesaw term by taking oscillation as well as cosmology data and then compute the predictions for neutrino parameters after the type II seesaw term is introduced. We consider a minimal structure of the type II seesaw term and check whether the predictions for neutrino parameters lie in the $3\\sigma$ range. We also outline two possible flavor symmetry models to justify the minimal structure of the type II seesaw term considered in the analysis.

Debasish Borah

2013-07-09T23:59:59.000Z

63

Type II Leptogenesis and the Neutrino Mass Scale  

E-Print Network (OSTI)

We discuss the effect of the neutrino mass scale on baryogenesis via the out-of-equilibrium decay of the lightest right-handed (s)neutrinos in type II see-saw models. We calculate the type II contributions to the decay asymmetries for minimal scenarios based on the Standard Model and on the Minimal Supersymmetric Standard Model, where the additional direct mass term for the neutrinos arises from a Higgs triplet vacuum expectation value. The result in the supersymmetric case is new and we correct the previous result in the scenario based on the Standard Model. We confirm and generalize our results by calculating the decay asymmetries in an effective approach, which is independent of the realization of the type II contribution. We derive a general upper bound on the decay asymmetry in type II see-saw models and find that it increases with the neutrino mass scale, in sharp contrast to the type I case which leads to an upper bound of about 0.1 eV on the neutrino mass scale. We find a lower bound on the mass of the lightest right-handed neutrino, significantly below the corresponding type I bound for partially degenerate neutrinos. This lower bound decreases with increasing neutrino mass scale, making leptogenesis more consistent with the gravitino constraints in supersymmetric models.

Stefan Antusch; Steve F. King

2004-05-11T23:59:59.000Z

64

Flavor identification of astronomical high energy neutrinos and the accuracy of mixing angles  

SciTech Connect

Typical initial neutrino fluxes from pion decays may be different depending on energy, since the muon decays can be excluded due to the electromagnetic energy loss. However, the specification of the initial flux ratio is limited by the accuracy of neutrino mixing parameters. We will discuss the expected measurement of relative flavors at future neutrino telescopes, focusing on the ambiguity in current neutrino parameters.

Hwang, Ggyoung-Riun; Siyeon, Kim [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

2008-11-23T23:59:59.000Z

65

Cosmological mass limits on neutrinos, axions, and other light particles  

E-Print Network (OSTI)

The small-scale power spectrum of the cosmological matter distribution together with other cosmological data provides a sensitive measure of the hot dark matter fraction, leading to restrictive neutrino mass limits. We extend this argument to generic cases of low-mass thermal relics. We vary the cosmic epoch of thermal decoupling, the radiation content of the universe, and the new particle's spin degrees of freedom. Our treatment covers various scenarios of active plus sterile neutrinos or axion-like particles. For three degenerate massive neutrinos, we reproduce the well-known limit of m_nu solar eV-mass axions to be discovered by the CAST experiment.

Steen Hannestad; Georg Raffelt

2003-12-11T23:59:59.000Z

66

Guesswork for Dirac and Majorana neutrino mass matrices  

E-Print Network (OSTI)

In the framework of seesaw mechanism with three neutrino flavors, we propose tentatively an efficient parametrization for the spectra of Dirac and righthanded Majorana neutrino mass matrices in terms of three free parameters. Two of them are related to (and determined by) the corresponding parameters introduced previously for the mass spectra of charged leptons and up and down quarks. The third is determined from the experimental estimate of solar $\\Delta m^2_{21}$. Then, the atmospheric $\\Delta m^2_{32}$ is {\\it predicted} close to its experimental estimation. With the use of these three parameters all light active-neutrino masses $ m_1 thermal leptogenesis might work.

W. Krolikowski

2004-01-14T23:59:59.000Z

67

Effects of Environment Dependence of Neutrino Mass versus Solar and Reactor Neutrino Data  

E-Print Network (OSTI)

In this work we study the phenomenological consequences of the environment dependence of neutrino mass on solar and reactor neutrino phenomenology. Such dependence can be induced, for example, by Yukawa interactions with a light scalar particle which couples to neutrinos and matter and it is expected, among others, in mass varying neutrino scenarios. Under the assumption of one mass scale dominance, we perform a global analysis of solar and KamLAND neutrino data which depends on 4 parameters: the two standard oscillation parameters, Delta m^2 and tan^2(theta), and two new coefficients, which parameterize the environment dependence of the neutrino mass. We find that, generically, the inclusion of the environment dependent terms does not lead to a very statistically significant improvement on the description of the data in the most favoured MSW LMA (or LMA-I) region. It does, however, substantially improve the fit in the high-Delta m^2 LMA (or LMA-II) region which can be allowed at 98.9% CL. Conversely the analysis allow us to place stringent constraints on the size of the environment dependence terms, which can be translated on a bound on the product of the effective neutrino-scalar (lambda^\

M. C. Gonzalez-Garcia; P. C. de Holanda; R. Zukanovich Funchal

2005-11-08T23:59:59.000Z

68

Perturbative generation of theta_{13} from tribimaximal neutrino mixing  

E-Print Network (OSTI)

Solar and atmospheric neutrino oscillations are consistent with a tribimaximal form of the mixing matrix U of the lepton sector. Exact tribimaximal mixing leads to theta_{13}=0. Recent results from the Daya Bay and RENO reactor experiments have established a non-zero value of theta_{13}. Keeping the leading behaviour of U as tribimaximal we perform a model-independent perturbative calculation for the purpose of incorporating a small but non-vanishing theta_{13}. We calculate up to first order in perturbation theory and include corrections proportional to \\sin \\theta_{13}. We identify the nature of the perturbation matrix and consider the possibility of the solar neutrino splitting to also arise perturbatively. Finally we briefly discuss a gauge model where such a correction term arises through one loop effects.

Brahmachari, Biswajoy

2012-01-01T23:59:59.000Z

69

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

E-Print Network (OSTI)

Medium-baseline reactor neutrino oscillation experiments (MBRO) have been proposed to determine the neutrino mass hierarchy (MH) and to make precise measurements of the neutrino oscillation parameters. With sufficient statistics, better than ~3%/\\sqrt{E} energy resolution and well understood energy non-linearity, MH can be determined by analyzing oscillation signals driven by the atmospheric mass-squared difference in the survival spectrum of reactor antineutrinos. With such high performance MBRO detectors, oscillation parameters, such as \\sin^22\\theta_{12}, \\Delta m^2_{21}, and \\Delta m^2_{32}, can be measured to sub-percent level, which enables a future test of the PMNS matrix unitarity to ~1% level and helps the forthcoming neutrinoless double beta decay experiments to constrain the allowed values. Combined with results from the next generation long-baseline beam neutrino and atmospheric neutrino oscillation experiments, the MH determination sensitivity can reach higher levels. In addition to the neutrino oscillation physics, MBRO detectors can also be utilized to study geoneutrinos, astrophysical neutrinos and proton decay. We propose to start a U.S. R&D program to identify, quantify and fulfill the key challenges essential for the success of MBRO experiments.

A. B. Balantekin; H. Band; R. Betts; J. J. Cherwinka; J. A. Detwiler; S. Dye; K. M. Heeger; R. Johnson; S. H. Kettell; K. Lau; J. G. Learned; C. J. Lin; J. J. Ling; B. Littlejohn; D. W. Liu; K. B. Luk; J. Maricic; K. McDonald; R. D. McKeown; J. Napolitano; J. C. Peng; X. Qian; N. Tolich; W. Wang; C. White; M. Yeh; C. Zhang; T. Zhao

2013-07-28T23:59:59.000Z

70

Neutrino mixings and grand unification: SU(5) GUT with anomaly free U(1){sub F}  

Science Conference Proceedings (OSTI)

The model of supersymmetric SU(5) GUT augmented with anomaly free U(1){sub F} flavor symmetry is presented. The field content and the U(1){sub F} charge assignment is obtained by specific embedding of SU(5) Multiplication-Sign U(1){sub F} in larger non-Abelian group. We focus on a particular case which gives very economical field content with the U(1){sub F} charges fixed in such a way that for quarks and leptons appealing texture zero Yukawa couplings are generated. The model gives realistic fermion masses and mixings and predict inverted hierarchical neutrino mass scenario with interesting implications.

Tavartkiladze, Zurab [Center for Elementary Particle Physics, ITP, Ilia State University, 0162 Tbilisi (Georgia)

2013-05-23T23:59:59.000Z

71

Search for the ?_{13} Neutrino Mixing Angle Using Reactor Anti-Neutrinos  

E-Print Network (OSTI)

The measurement of the last undetermined neutrino mixing angle \\theta_{13} is the main goal of the future experimental research on neutrino oscillations. At present, \\theta_{13} is only known to be much smaller than the two other mixing angles, \\theta_{12} and \\theta_{23}. The present bound, which is dominated by the result of the CHOOZ reactor experiment, is \\sin^{2}2\\theta_{13}reactor anti-neutrino disappearance experiments has not been fully exploited yet. A rich experimental program is underway, which aims at exploring in the near future up to \\sin^{2}2\\theta_{13}\\lesssim0.01. The targeted sensitivity requires a clear-cut strategy to reduce significantly both statistical and systematical errors with respect to past reactor experiments. A key feature for the success of all projects is the installation of one or more near identical detectors. The experimental concept and the status of the upcoming or proposed reactor experiments, and as well the prospects of the reactor-based search for \\theta_{13} are reviewed.

Dario Motta

2007-02-01T23:59:59.000Z

72

The Neutrino Mass Hierarchy from Nuclear Reactor Experiments  

E-Print Network (OSTI)

10 years from now reactor neutrino experiments will attempt to determine which neutrino mass eigenstate is the most massive. In this letter we present the results of more than seven million detailed simulations of such experiments, studying the dependence of the probability of successfully determining the mass hierarchy upon the analysis method, the neutrino mass matrix parameters, reactor flux models, geoneutrinos and, in particular, combinations of baselines. We show that a recently reported spurious dependence of the data analysis upon the high energy tail of the reactor spectrum can be removed by using a weighted Fourier transform. We determine the optimal baselines and corresponding detector locations. For most values of the CP-violating, leptonic Dirac phase delta, a degeneracy prevents NOvA and T2K from determining either delta or the hierarchy. We determine the confidence with which a reactor experiment can determine the hierarchy, breaking the degeneracy.

Emilio Ciuffoli; Jarah Evslin; Xinmin Zhang

2013-02-04T23:59:59.000Z

73

Measuring the mass of a sterile neutrino with a very short baseline reactor experiment  

E-Print Network (OSTI)

An analysis of the world's neutrino oscillation data, including sterile neutrinos, (M. Sorel, C. M. Conrad, and M. H. Shaevitz, Phys. Rev. D 70, 073004) found a peak in the allowed region at a mass-squared difference $\\Delta m^2 \\cong 0.9$ eV$^2$. We trace its origin to harmonic oscillations in the electron survival probability $P_{ee}$ as a function of L/E, the ratio of baseline to neutrino energy, as measured in the near detector of the Bugey experiment. We find a second occurrence for $\\Delta m^2 \\cong 1.9$ eV$^2$. We point out that the phenomenon of harmonic oscillations of $P_{ee}$ as a function of L/E, as seen in the Bugey experiment, can be used to measure the mass-squared difference associated with a sterile neutrino in the range from a fraction of an eV$^2$ to several eV$^2$ (compatible with that indicated by the LSND experiment), as well as measure the amount of electron-sterile neutrino mixing. We observe that the experiment is independent, to lowest order, of the size of the reactor and suggest the possibility of a small reactor with a detector sitting at a very short baseline.

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

2007-01-04T23:59:59.000Z

74

Solar neutrino oscillations  

Science Conference Proceedings (OSTI)

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

Haxton, W.C.

1993-12-31T23:59:59.000Z

75

Probing the Neutrino Mass Hierarchy via Atmospheric $?_?+ \\bar ?_?$ Survival Rates in Megaton Water Cerenkov Detectors  

E-Print Network (OSTI)

The neutrino mass hierarchy, presently unknown, is a powerful discriminator among various classes of unification theories. We show that the $\

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

2005-06-15T23:59:59.000Z

76

Counting muons to probe the neutrino mass spectrum  

E-Print Network (OSTI)

The experimental evidence that \\theta_{13} is large opens new opportunities to identify the neutrino mass spectrum. We outline a possibility to investigate this issue by means of conventional technology. The ideal setup turns out to be long baseline experiment: the muon neutrino beam, with 10^{20} protons on target, has an average energy of 6 (8) GeV; the neutrinos, after propagating 6000 (8000) km, are observed by a muon detector of 1 Mton and with a muon energy threshold of 2 GeV. The expected number of muon events is about 1000, and the difference between the two neutrino spectra is sizeable, about 30%. This allows the identification of the mass spectrum just counting muon tracks. The signal events are well characterized experimentally by their time and direction of arrival, and 2/3 of them are in a region with little atmospheric neutrino background, namely, between 4 GeV and 10 GeV. The distances from CERN to Baikal Lake and from Fermilab to KM3NET, or ANTARES, fit in the ideal range.

Carolina Lujan-Peschard; Giulia Pagliaroli; Francesco Vissani

2013-01-19T23:59:59.000Z

77

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

Science Conference Proceedings (OSTI)

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

KETTELL, S.; ET AL.

2006-10-16T23:59:59.000Z

78

Conflict between the identification of a cosmic neutrino source and the sensitivity to mixing angles in a neutrino telescope  

SciTech Connect

Neutrino fluxes at telescopes depend on both initial fluxes out of astronomical bursts and flavor mixing during their travel to the Earth. However, since the information on the initial composition requires better precision in mixing angles and vice versa, neutrino detection at telescopes cannot provide solutions to both problems by itself. Thus, a probability to be measured at long-baseline oscillation is considered as a complement to the telescope, and problems like source identification and parameter degeneracy are examined under a few assumptions.

Hwang, Ggyoung-Riun; Siyeon, Kim [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

2008-11-01T23:59:59.000Z

79

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

E-Print Network (OSTI)

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

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

2007-09-07T23:59:59.000Z

80

Neutrino Magnetic Moments, Flavor Mixing, and the Super-Kamiokande Solar Data  

Science Conference Proceedings (OSTI)

We find that magnetic neutrino-electron scattering is unaffected by oscillations for vacuum mixing of Dirac neutrinos with only diagonal moments and for Majorana neutrinos with two flavors. For Mikheyev-Smirnov-Wolfenstein mixing, these cases are again obtained, though the effective moments can depend on the neutrino energy. Thus, e.g., the magnetic moments measured with {nu}(bar sign){sub e} from a reactor and {nu}{sub e} from the Sun could be different. With minimal assumptions, we find a new limit on {mu}{sub {nu}} using the 825-d Super-Kamiokande solar neutrino data: |{mu}{sub {nu}}|{<=}1.5x10{sup -} {sup 10}{mu}{sub B} at 90% CL, comparable to the existing reactor limit. (c) 1999 The American Physical Society.

Beacom, J. F.; Vogel, P.

1999-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
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81

Neutrinos: Windows to New Physics  

E-Print Network (OSTI)

After briefly reviewing how the symmetries of the Standard Model (SM) are affected by neutrino masses and mixings, I discuss how these parameters may arise from GUTs and how patterns in the neutrino sector may reflect some underlying family symmetry. Leptogenesis provides a nice example of how different physical phenomena may be connected to the same neutrino window of physics beyond the SM. I end with some comments on the LSND signal and briefly discuss the idea that neutrinos have environment dependent masses.

R. D. Peccei

2006-09-20T23:59:59.000Z

82

Neutrino oscillations in nuclear media  

E-Print Network (OSTI)

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

Iman Motie; She-Sheng Xue

2011-04-14T23:59:59.000Z

83

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

DOE R&D Accomplishments (OSTI)

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

Cooper, N. G. [ed.

1997-00-00T23:59:59.000Z

84

Improving the neutrino mass hierarchy identification with inelasticity measurement in PINGU and ORCA  

E-Print Network (OSTI)

Multi-megaton scale under ice and underwater detectors of atmospheric neutrinos with few GeV's energy threshold (PINGU, ORCA) open up new possibilities in the determination of neutrino properties, and in particular the neutrino mass hierarchy. With a dense array of optical modules it will be possible to determine the inelasticity, $y$, of the charged current $\

Mathieu Ribordy; Alexei Yu Smirnov

2013-03-04T23:59:59.000Z

85

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

SciTech Connect

The MiniBooNE experiment was designed to perform a search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations in a region of {Delta}m{sup 2} and sin{sup 2} 2{theta} very different from that allowed by standard, three-neutrino oscillations, as determined by solar and atmospheric neutrino experiments. This search was motivated by the LSND experimental observation of an excess of {bar {nu}}{sub e} events in a {bar {nu}}{sub {mu}} beam which was found compatible with two-neutrino oscillations at {Delta}m{sup 2} {approx} 1 eV{sup 2} and sin{sup 2} 2{theta} < 1%. If confirmed, such oscillation signature could be attributed to the existence of a light, mostly-sterile neutrino, containing small admixtures of weak neutrino eigenstates. In addition to a search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, MiniBooNE has also performed a search for {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations, which provides a test of the LSND two-neutrino oscillation interpretation that is independent of CP or CPT violation assumptions. This dissertation presents the MiniBooNE {nu}{sub {mu}} {yields} {nu}{sub e} and {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} analyses and results, with emphasis on the latter. While the neutrino search excludes the two-neutrino oscillation interpretation of LSND at 98% C.L., the antineutrino search shows an excess of events which is in agreement with the two-neutrino {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillation interpretation of LSND, and excludes the no oscillations hypothesis at 96% C.L. Even though the neutrino and antineutrino oscillation results from MiniBooNE disagree under the single sterile neutrino oscillation hypothesis, a simple extension to the model to include additional sterile neutrino states and the possibility of CP violation allows for differences between neutrino and antineutrino oscillation signatures. In view of that, the viability of oscillation models with one or two sterile neutrinos is investigated in global fits to MiniBooNE and LSND 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.

Karagiorgi, Georgia S.; /MIT

2010-07-01T23:59:59.000Z

86

Form invariance and symmetry in the neutrino mass matrix  

SciTech Connect

We present the general form of the unitary matrices keeping invariant the Majorana neutrino mass matrix of specific texture suitable for explaining oscillation data. In the case of the tri-bimaximal pattern with two degenerate masses, we give a specific realization of the underlying U(1) symmetry which can be uplifted to a symmetry in a complete theory including charged leptons. For this, we present a model with three light SM-like Higgs doublets and one heavy Higgs triplet and find that one can accommodate the hierarchy of the charged-lepton masses. The lepton mass spectrum can also be achieved in another model extending the SM with three SM-singlet scalars transforming nontrivially under the flavor symmetry. We discuss how such a model has room for generating enough baryon asymmetry through leptogenesis in the framework of type-I and -II seesaw mechanisms.

Lashin, E. I. [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh (Saudi Arabia); Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Nasri, S.; Malkawi, E. [Department of Physics, UAE University, P.O. Box 17551, Al-Ain (United Arab Emirates); Chamoun, N. [Physics Department, HIAST, P.O. Box 31983, Damascus (Syrian Arab Republic)

2011-01-01T23:59:59.000Z

87

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

E-Print Network (OSTI)

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

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

2013-06-10T23:59:59.000Z

88

Signals of CPT Violation and Non-Locality in Future Neutrino Oscillation Experiments  

E-Print Network (OSTI)

We investigate the sensitivities of future neutrino oscillation experiments for measuring the neutrino mass squared differences and leptonic mixing angles independently with neutrinos and anti-neutrinos. We update the expected sensitivities of Neutrino Factories to the ``atmospheric'' (anti-)neutrino parameters using an optimized setup. A dedicated beta-Beam facility, in combination with a SPMIN reactor experiment, could give excellent sensitivities also to the ``solar'' parameters, for neutrinos and anti-neutrinos respectively. A signal of a different mass matrix for neutrinos and anti-neutrinos would imply CPT violation and non-locality of the underlying particle theory.

Antusch, S

2008-01-01T23:59:59.000Z

89

Signals of CPT Violation and Non-Locality in Future Neutrino Oscillation Experiments  

E-Print Network (OSTI)

We investigate the sensitivities of future neutrino oscillation experiments for measuring the neutrino mass squared differences and leptonic mixing angles independently with neutrinos and anti-neutrinos. We update the expected sensitivities of Neutrino Factories to the "atmospheric" (anti-)neutrino parameters using an optimized setup. A dedicated beta-Beam facility, in combination with a SPMIN reactor experiment, could give excellent sensitivities also to the "solar" parameters, for neutrinos and anti-neutrinos respectively. A signal of a different mass matrix for neutrinos and anti-neutrinos would imply CPT violation and non-locality of the underlying particle theory.

S. Antusch; E. Fernandez-Martinez

2008-04-17T23:59:59.000Z

90

Double Chooz, A Search for the Neutrino Mixing Angle theta-13  

E-Print Network (OSTI)

The Double Chooz Reactor Neutrino Experiment in France plans to quickly measure the neutrino mixing angle theta-13, or limit it to sin^2 2-theta_13 less than 0.025. The physics reach, experimental site, detector structures, scintillator, photodetection, electronics, calibration and simulations are described. The possibility of using Double Chooz to explore the possible use of a antineutrino detector for non-proliferation goals is also presented.

Lasserre, T

2006-01-01T23:59:59.000Z

91

Determination of the mass hierarchy with medium-baseline reactor-neutrino experiments  

E-Print Network (OSTI)

I discuss the sensitivity of future medium baseline reactor antineutrino experiments on the neutrino mass hierarchy. By using the standard chi^2 analysis, we find that the sensitivity depends strongly on the baseline length L and the energy resolution (delta E/E)^2 = (a/ E/MeV)^2 + b^2, where a and b parameterize the statistical and systematic uncertainties, respectively. The optimal length is found to be L ~ 40-55 km, the larger resolution the shorter optimal L. For a 5 kton detector (with 12% weight fraction of free proton) placed at L ~ 50 km away from a 20 GW_th reactor, an experiment would determine the mass hierarchy with (Delta chi^2)_min ~ 9 on average after 5 (15) or more years of running with the (a, b) = (2, 0.5)% ((3, 0.5)%) energy resolution. This type of experiment can also measure the relevant mixing parameters with the accuracy of ~ 0.5%.

Yoshitaro Takaesu

2013-04-19T23:59:59.000Z

92

Original neutrino fluxes and hidden mass in the universe  

Science Conference Proceedings (OSTI)

The status of neutrino experiments in connection with the fundamental problem of searches for a signal from dark matter is discussed. Limits on the magnitude of the effect of dark-matter-particle annihilation in the Sun that were obtained with neutrino telescopes are presented. In particular, the first results from the NT-200 Baikal Deep Underwater Neutrino Telescope are described.

Suvorova, O. V., E-mail: suvorova@cpc.inr.ac.ru [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

2011-01-15T23:59:59.000Z

93

Statistical Evaluation of Experimental Determinations of Neutrino Mass Hierarchy  

SciTech Connect

Statistical methods of presenting experimental results in constraining the neutrino mass hierarchy (MH) are discussed. Two problems are considered and are related to each other: how to report the findings for observed experimental data, and how to evaluate the ability of a future experiment to determine the neutrino mass hierarchy, namely, sensitivity of the experiment. For the first problem where experimental data have already been observed, the classical statistical analysis involves constructing confidence intervals for the parameter {Delta}m{sup 2}{sub 32}. These intervals are deduced from the parent distribution of the estimation of {Delta}m{sup 2}{sub 32} based on experimental data. Due to existing experimental constraints on |{Delta}m{sup 2}{sub 32}|, the estimation of {Delta}m{sup 2}{sub 32} is better approximated by a Bernoulli distribution (a Binomial distribution with 1 trial) rather than a Gaussian distribution. Therefore, the Feldman-Cousins approach needs to be used instead of the Gaussian approximation in constructing confidence intervals. Furthermore, as a result of the definition of confidence intervals, even if it is correctly constructed, its confidence level does not directly reflect how much one hypothesis of the MH is supported by the data rather than the other hypothesis. We thus describe a Bayesian approach that quantifies the evidence provided by the observed experimental data through the (posterior) probability that either one hypothesis of MH is true. This Bayesian presentation of observed experimental results is then used to develop several metrics to assess the sensitivity of future experiments. Illustrations are made using a simple example with a confined parameter space, which approximates the MH determination problem with experimental constraints on the |{Delta}m{sup 2}{sub 32}|.

X. Qian, A. Tan, W. Wang, J. J. Ling, R. D. McKeown, C. Zhang

2012-12-01T23:59:59.000Z

94

Hierarchical Neutrino Masses and Leptogenesis in Type I+II Seesaw Models  

E-Print Network (OSTI)

The baryon to photon ratio in the present Universe is very accurately measured to be $6.19 \\times 10^{-10}$. We study the possible origin of this baryon asymmetry in the neutrino sector through the generic mechanism of baryogenesis through leptogenesis. We consider both type I and type II seesaw origin of neutrino masses within the framework of left right symmetric models (LRSM). Using the latest best fit global neutrino oscillation data and assuming the Dirac neutrino mass matrix to be either charged lepton (CL) or up quark (UQ) type, we compute the predictions for baryon to photon ratio keeping the lightest active neutrino mass eigenstate a free parameter for both normal and inverted hierarchical cases. We show that in inverted hierarchical scenario with type I seesaw, observed baryon asymmetry can not be generated for both CL and UQ type Dirac neutrino mass matrices. We also study the predictions for baryon asymmetry when the neutrino masses arise from a combination of both type I and type II seesaw (with one of them dominant at a time) as well as different combinations of Majorana neutrino phases and show that the observed baryon asymmetry can be generated within these models upto certain exceptions.

Debasish Borah; Mrinal Kumar Das

2013-03-07T23:59:59.000Z

95

Neutrino-2008: Where are we? Where are we going?  

E-Print Network (OSTI)

Our present knowledge of neutrinos can be summarized in terms of the "standard neutrino scenario". Phenomenology of this scenario as well as attempts to uncover physics behind neutrino mass and mixing are described. Goals of future studies include complete reconstruction of the neutrino mass and flavor spectrum, further test of the standard scenario and search for new physics beyond it. Developments of new experimental techniques may lead to construction of new neutrino detectors from table-top to multi-Megaton scales which will open new horizons in the field. With detection of neutrino bursts from the Galactic supernova and high energy cosmic neutrinos neutrino astrophysics will enter qualitatively new phase. Neutrinos and LHC (and future colliders), neutrino astronomy, neutrino structure of the Universe, and probably, neutrino technologies will be among leading topics of research.

Alexei Yu. Smirnov

2008-10-15T23:59:59.000Z

96

Neutrino-2008: Where are we? Where are we going?  

E-Print Network (OSTI)

Our present knowledge of neutrinos can be summarized in terms of the "standard neutrino scenario". Phenomenology of this scenario as well as attempts to uncover physics behind neutrino mass and mixing are described. Goals of future studies include complete reconstruction of the neutrino mass and flavor spectrum, further test of the standard scenario and search for new physics beyond it. Developments of new experimental techniques may lead to construction of new neutrino detectors from table-top to multi-Megaton scales which will open new horizons in the field. With detection of neutrino bursts from the Galactic supernova and high energy cosmic neutrinos neutrino astrophysics will enter qualitatively new phase. Neutrinos and LHC (and future colliders), neutrino astronomy, neutrino structure of the Universe, and probably, neutrino technologies will be among leading topics of research.

Smirnov, Alexei Yu

2008-01-01T23:59:59.000Z

97

Neutrino masses and heavy triplet leptons at the LHC: Testability of the type III seesaw mechanism  

Science Conference Proceedings (OSTI)

We study LHC signatures of the type III seesaw mechanism in which SU(2){sub L} triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model particles which depend on how light and heavy leptons mix with each other. We concentrate on the usual solutions with small light and heavy lepton mixing of the order of the square root of the ratio of light and heavy masses, (m{sub {nu}}/M{sub {nu}}{sub {sub R}}){sup 1/2}. This class of solutions can lead to a visible displaced vertex detectable at the LHC which can be used to distinguish small mixing and large mixing between light and heavy leptons. We show that, in this case, the couplings of light and heavy triplet leptons to gauge and Higgs bosons, which determine the decay widths and branching ratios, can be expressed in terms of light neutrino masses and their mixing. Using these relations, we study heavy triplet lepton decay patterns and production cross section at the LHC. If these heavy triplet leptons are below a TeV or so, they can be easily produced at the LHC due to their gauge interactions from being nontrivial representations of SU(2){sub L}. We consider two ideal production channels, (1) E{sup +}E{sup -}{yields}l{sup +}l{sup +}l{sup -}l{sup -}jj (l=e, {mu}, {tau}) and (2) E{sup {+-}}N{yields}l{sup {+-}}l{sup {+-}}jjjj in detail. For case 1, we find that with one or two of the light leptons being {tau} it can also be effectively studied. With judicious cuts at the LHC, the discovery of the heavy triplet leptons as high as a TeV can be achieved with 100 fb{sup -1} integrated luminosity.

Li Tong [Center for High Energy Physics, Peking University, Beijing, 100871 (China); He Xiaogang [Center for High Energy Physics, Peking University, Beijing, 100871 (China); Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China)

2009-11-01T23:59:59.000Z

98

Neutrino Oscillation Physics  

Science Conference Proceedings (OSTI)

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

Kayser, Boris

2012-06-01T23:59:59.000Z

99

New Neutrino Mass Bounds from Sloan Digital Sky Survey III Data Release 8 Photometric Luminous Galaxies  

E-Print Network (OSTI)

We present neutrino mass bounds using 900,000 luminous galaxies with photometric redshifts measured from Sloan Digital Sky Survey III Data Release Eight (SDSS DR8). The galaxies have photometric redshifts between $z = 0.45$ and $z = 0.65$, and cover 10,000 square degrees and thus probe a volume of 3$h^{-3}$Gpc$^3$, enabling tight constraints to be derived on the amount of dark matter in the form of massive neutrinos. A new bound on the sum of neutrino masses $\\sum m_\

de Putter, Roland; Giusarma, Elena; Ho, Shirley; Cuesta, Antonio; Seo, Hee-Jong; Ross, Ashley; White, Martin; Bizyaev, Dmitry; Brewington, Howard; Kirkby, David; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Percival, Will J; Ross, Nicholas P; Schneider, Donald P; Shelden, Alaina; Simmons, Audrey; Snedden, Stephanie

2012-01-01T23:59:59.000Z

100

Exotic Solutions to the Solar Neutrino Problem and Some Implications for Low Energy Solar Neutrino Experiments  

E-Print Network (OSTI)

In this talk, I review, from the phenomenological point of view, solutions to the solar neutrino problem, which are not provided by the conventional neutrino oscillation induced by mass and flavor mixing, and show that they can provide a good fit to the observed data. I also consider some simple implications for low energy solar neutrino experiments.

H. Nunokawa

2001-05-03T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Cluster mass function in mixed models  

E-Print Network (OSTI)

We study the cluster mass function in mixed dark matter (MDM) models, using two COBE normalized simulations with Omega_h = 0.26 and n=1.2, and Omega_h = 0.14 and n = 1.05, both with 2 massive nu's (MDM1 and MDM2, respectively). For the sake of comparison, we also simulate a CDM model with spectral index n=0.8 (TCDM), also COBE normalized. We argue that, in our non--hydro simulations, where CDM particles describe both actual CDM and baryons, the galaxy distribution traces CDM particles. Therefore, we use them to define clusters and their velocities to work out cluster masses. As CDM particles are more clustered than HDM and therefore have, in average, greater velocities, this leads to significant differences from PS predictions. Such predictions agree with simulations if both HDM and CDM are used to define clusters. Clusters defined through CDM in MDM models, instead, are less numerous than PS estimates, by a factor ~0.3, at the low mass end; the factor becomes \\~0.6-0.8, depending on the mix, on intermediate mass scales (~4-5, h^-1 10^14 Msun) and almost vanishes on the high mass end. Therefore: (i) MDM models expected to overproduce clusters over intermediate scales are viable; (ii) the greater reduction factor at small scales agrees with the observational data dependence on the cluster mass M (which, however, may be partially due to sample incompleteness); (iii) the higher spectral normalization is felt at large scales, where MDM models produce more objects (hence, large clusters) than CDM. MDM1 even exceeds Donahue et al. (1998) findings, while MDM2 is consistent with them. (abridged)

A. Gardini; S. A. Bonometto; G. Murante

1999-05-21T23:59:59.000Z

102

Neutrino Mixings and Leptonic CP Violation from CKM Matrix and Majorana Phases  

E-Print Network (OSTI)

The high scale mixing unification hypothesis recently proposed by three of us (R. N. M., M. K. P. and G. R.) states that if at the seesaw scale, the quark and lepton mixing matrices are equal then for quasi-degenerate neutrinos, radiative corrections can lead to large solar and atmospheric mixings and small reactor angle at the weak scale in agreement with data. Evidence for quasi-degenerate neutrinos could, within this framework, be interpreted as a sign of quark-lepton unification at high scale. In the current work, we extend this model to show that the hypothesis works quite successfully in the presence of CP violating phases (which were set to zero in the first paper). In the case where the PMNS matrix is identical to the CKM matrix at the seesaw scale, with a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to be ($\\simeq 0.3^{\\circ}$) and leptonic CP-violation parameter $J_{CP} \\simeq (4 - 8)\\times 10^{-5}$ and $\\theta_{13} = 3.5^{\\circ}$. If on the other hand, the PMNS matrix is assumed to also have Majorana phases initially, the resulting theory damps radiative magnification phenomenon for a large range of parameters but nevertheless has enough parameter space to give the two necessary large neutrino mixing angles. In this case, one has $\\theta_{13} = 3.5^{\\circ} - 10^{\\circ}$ and $|J_{CP}|$ as large as $0.02-0.04$ which are accessible to long baseline neutrino oscillation experiments.

S. K. Agarwalla; M. K. Parida; R. N. Mohapatra; G. Rajasekaran

2006-11-16T23:59:59.000Z

103

Evidence for neutrino mass: A decade of discovery  

E-Print Network (OSTI)

and emission from the Sun or solar neu- trinos undergo a ?generation. Solar models trace the evolution of the Sun overway from the Sun to Earth, and the electron solar neutrino ?

Heeger, Karsten M.

2004-01-01T23:59:59.000Z

104

Neutrino Phenomenology  

E-Print Network (OSTI)

A general overview of neutrino physics 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 the indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos and their confirmation with artificial neutrino sources.

Esteban Roulet

2004-12-27T23:59:59.000Z

105

Octahedral Symmetry with Geometrical Breaking: New Prediction for Neutrino Mixing Angle theta_{13} and CP Violation  

E-Print Network (OSTI)

We propose octahedral group O_h as the family symmetry of neutrino-lepton sector. We find that O_h contains subgroups Z_2(mu-tau) x Z_2(solar) and Z_4^l for realizing the bimaximal (BM) mixings, theta_{23} = theta_{12} = 45^o and theta_{13}=0^o, where Z_2(mu-tau) x Z_2(solar) and Z_4^l serve as the residual symmetries of neutrinos and charged leptons, respectively. We present geometric interpretations of BM mixing in the octahedron, and construct natural geometrical breaking of Z_4^l, leading to nontrivial deviations from the BM mixings. Our theory makes truly simple predictions of a relatively large reactor angle, theta_{13} = 45^o - theta_{12} = 7.5^o - 13.7^o (3 sigma), the nearly maximal atmospheric angle and the approximate maximal Dirac CP violation. These agree well with the current neutrino data, and will be further probed by the on-going and upcoming oscillation experiments.

Hong-Jian He; Xun-Jie Xu

2012-03-13T23:59:59.000Z

106

Solar models and solar neutrino oscillations John N Bahcall and Carlos Pea-Garay  

E-Print Network (OSTI)

Solar models and solar neutrino oscillations John N Bahcall and Carlos Peña-Garay Institute and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for performing new solar neutrino experiments and what we

Bahcall, John

107

Solar models and solar neutrino oscillations John N Bahcall and Carlos PeaGaray  

E-Print Network (OSTI)

Solar models and solar neutrino oscillations John N Bahcall and Carlos Peña­Garay Institute and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for performing new solar neutrino experiments and what we

Bahcall, John

108

Cosmology Favoring Extra Radiation and Sub-eV Mass Sterile Neutrinos as an Option  

SciTech Connect

Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{sub s} and effective number N{sub s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{sub s} is in the sub-eV range.

Hamann, Jan; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C (Denmark); Raffelt, Georg G. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany); Tamborra, Irene [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany); Dipartimento Interateneo di Fisica 'Michelangelo Merlin', Via Amendola 173, 70126 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Wong, Yvonne Y. Y. [Institut fuer Theoretische Teilchenphysik und Kosmologie, RWTH Aachen, 52056 Aachen (Germany)

2010-10-29T23:59:59.000Z

109

A4xSU(5) SUSY GUT of Flavour with Trimaximal Neutrino Mixing  

E-Print Network (OSTI)

Recent T2K, MINOS and Double CHOOZ results, together with global fits of mixing parameters, indicate a sizeable reactor angle theta13 ~ 8 deg which, if confirmed, would rule out tri-bimaximal (TB) lepton mixing. Recently two of us studied the vacuum alignment of the Altarelli-Feruglio A4 family symmetry model including additional flavons in the 1' and 1" representations, leading to so-called "trimaximal" neutrino mixing and allowing a potentially large reactor angle. Here we show how such a model may arise from a Supersymmetric (SUSY) Grand Unified Theory (GUT) based on SU(5), leading to sum rule bounds |s| reactor angle deviations from their TB mixing values, delta is the CP violating oscillation phase, and thetaC is the Cabibbo angle.

Iain K. Cooper; Stephen F. King; Christoph Luhn

2012-03-06T23:59:59.000Z

110

A4xSU(5) SUSY GUT of Flavour with Trimaximal Neutrino Mixing  

E-Print Network (OSTI)

Recent T2K, MINOS and Double CHOOZ results, together with global fits of mixing parameters, indicate a sizeable reactor angle theta13 ~ 8 deg which, if confirmed, would rule out tri-bimaximal (TB) lepton mixing. Recently two of us studied the vacuum alignment of the Altarelli-Feruglio A4 family symmetry model including additional flavons in the 1' and 1" representations, leading to so-called "trimaximal" neutrino mixing and allowing a potentially large reactor angle. Here we show how such a model may arise from a Supersymmetric (SUSY) Grand Unified Theory (GUT) based on SU(5), leading to sum rule bounds |s| reactor angle deviations from their TB mixing values, delta is the CP violating oscillation phase, and thetaC is the Cabibbo angle.

Cooper, Iain K; Luhn, Christoph

2012-01-01T23:59:59.000Z

111

Neutrino Mass and Dark Matter in light of recent AMS-02 results  

E-Print Network (OSTI)

We study a simple extension of the Standard Model supplemented by an electroweak triplet scalar field to accommodate small neutrino masses by the type-II seesaw mechanism, while an additional singlet scalar field can play the role of cold dark matter (DM) in our Universe. This DM candidate is naturally leptophilic, and for DM masses above the seesaw scale, the lepton flux due to its annihilation carries information about the neutrino mass hierarchy. Using the recently released high precision data on positron fraction and flux from AMS-02 experiment, and assuming a DM interpretation of the observed positron excess, we show that a good fit to the AMS-02 data can be obtained in our model for a normal hierarchy of neutrino masses, while the inverted hierarchy case is strongly disfavored. The model predictions for excess photon and neutrino fluxes, while simultaneously satisfying the AMS-02 positron excess, are consistent with the current limits on the inclusive photon flux from Fermi-LAT and on the neutrino flux from IceCube respectively. Moreover, the absence of an excess anti-proton flux as suggested by PAMELA data sets an indirect upper limit on the DM-nucleon spin-independent elastic scattering cross section which is stronger than the existing DM direct detection bound from LUX in the AMS-02 preferred DM mass range.

P. S. Bhupal Dev; Dilip Kumar Ghosh; Nobuchika Okada; Ipsita Saha

2013-07-23T23:59:59.000Z

112

A Precision Measurement of the Neutrino Mixing Angle theta_13 using Reactor Antineutrinos at Daya Bay  

E-Print Network (OSTI)

A reactor-neutrino experiment, Daya Bay, has been proposed to determine the least-known neutrino mixing angle theta_13 using electron antineutrinos produced at the Daya Bay nuclear power complex in China. Daya Bay is an international collaboration with institutions from China, the United States, the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use eight identical detectors deployed at three different locations optimized for monitoring the antineutrino rates from the six reactors and for detecting any rate deficit and spectral distortion near the first oscillation maximum. The overburden of the under ground experimental halls, connected with tunnels, ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic background is small compared to the number of observed antineutrino events. Civil construction of tunnels and experimental facilities is planned to start in 2007, with detector construction beginning in 2008. The experiment will begin collecting data in 2010. By compa...

Guo, Xinheng

2007-01-01T23:59:59.000Z

113

neutrino-properties-web.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

THE THE NEUTRINO PROPERTIES LISTINGS Revised August 2013 by P. Vogel (Caltech) and A. Piepke (University of Alabama). The following Listings concern measurements of various properties of neutrinos. Nearly all of the measurements, all of which so far are limits, actually concern superpositions of the mass eigenstates ν i , which are in turn related to the weak eigenstates ν ℓ , via the neutrino mixing matrix |ν ℓ = i U ℓi |ν i . In the analogous case of quark mixing via the CKM matrix, the smallness of the off-diagonal terms (small mixing angles) permits a "dominant eigenstate" approximation. However, the results of neutrino oscillation searches show that the mixing matrix contains two large mixing angles and a third angle that is not exceedingly small. We cannot, therefore, associate any particular state |ν i with any particular lepton label e, µ or τ . Nevertheless,

114

A Class of Inert N-tuplet Models with Radiative Neutrino Mass and Dark Matter  

E-Print Network (OSTI)

We present a class of models with radiative neutrino mass and stable dark-matter candidates. Neutrino mass is generated by a one-loop diagram with the same topography as Ma's 2006 proposal (which used an inert scalar-doublet and singlet fermion). We generalize this approach and determine all variants with new fields no larger than the adjoint representation. When the neutrino mass diagram contains a Majorana mass insertion there are two possibilities, both of which are known. If the mass insertion is of the Dirac type there are seven additional models, two of which are excluded by direct-detection experiments. The other five models are also constrained, such that only scalar dark-matter is viable. There are cases with an inert singlet, an inert doublet, and an inert triplet, providing a natural setting for inert N-tuplet models of dark matter, with the additional feature of achieving radiative neutrino mass. We show that some of the models admit a simple explanation for the (requisite) discrete symmetry, and ...

Law, Sandy S C

2013-01-01T23:59:59.000Z

115

A Class of Inert N-tuplet Models with Radiative Neutrino Mass and Dark Matter  

E-Print Network (OSTI)

We present a class of models with radiative neutrino mass and stable dark-matter candidates. Neutrino mass is generated by a one-loop diagram with the same topography as Ma's 2006 proposal (which used an inert scalar-doublet and singlet fermion). We generalize this approach and determine all variants with new fields no larger than the adjoint representation. When the neutrino mass diagram contains a Majorana mass insertion there are two possibilities, both of which are known. If the mass insertion is of the Dirac type there are seven additional models, two of which are excluded by direct-detection experiments. The other five models are also constrained, such that only scalar dark-matter is viable. There are cases with an inert singlet, an inert doublet, and an inert triplet, providing a natural setting for inert N-tuplet models of dark matter, with the additional feature of achieving radiative neutrino mass. We show that some of the models admit a simple explanation for the (requisite) discrete symmetry, and briefly discuss cases with representations larger than the adjoint, which can admit a connection to the astrophysical gamma-ray signal.

Sandy S. C. Law; Kristian L. McDonald

2013-05-28T23:59:59.000Z

116

Octahedral Symmetry with Geometrical Breaking: New Prediction for Neutrino Mixing Angle theta_{13} and CP Violation  

E-Print Network (OSTI)

We propose octahedral group O_h as the family symmetry of neutrino-lepton sector, with subgroups Z_2(mu-tau) x Z_2(solar) and Z_4^l as the residual symmetries of neutrinos and charged leptons, respectively. We find that O_h is a minimal group which contains the subgroups Z_2(mu-tau) x Z_2(solar) and Z_4^l for realizing the bimaximal mixings theta_{23} = theta_{12} = 45^o. We present geometric interpretations of O_h and its residual symmetries, and further construct a natural geometrical breaking of Z_4^l. Our theory makes truly simple new predictions of a relatively large reactor angle, theta_{13} = 45^o - theta_{12} = 7.9^o - 14.0^o (3 sigma), the maximal atmospheric angle theta_{23} = 45^o, and the maximal Dirac CP violation delta_D = +-90^o. These agree well with the current neutrino data, and will be further probed by the on-going and upcoming oscillation experiments.

He, Hong-Jian

2012-01-01T23:59:59.000Z

117

Light Sterile Neutrinos and Short Baseline Neutrino Oscillation Anomalies  

E-Print Network (OSTI)

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

JiJi Fan; Paul Langacker

2012-01-31T23:59:59.000Z

118

Neutrino Unification  

E-Print Network (OSTI)

Present neutrino data are consistent with neutrino masses arising from a common seed at some ``neutrino unification'' scale $M_X$. Such a simple theoretical ansatz naturally leads to quasi-degenerate neutrinos that could lie in the electron-volt range with neutrino mass splittings induced by renormalization effects associated with supersymmetric thresholds. In such a scheme the leptonic analogue of the Cabibbo angle $\\theta_{\\odot}$ describing solar neutrino oscillations is nearly maximal. Its exact value is correlated with the smallness of $\\theta_{reactor}$. These features agree both with latest data on the solar neutrino spectra and with the reactor neutrino data. The two leading mass-eigenstate neutrinos present in \

P. H. Chankowski; A. Ioannisian; S. Pokorski; J. W. F Valle

2000-11-10T23:59:59.000Z

119

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

SciTech Connect

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

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

2011-02-15T23:59:59.000Z

120

Searching for sterile neutrinos in ice  

E-Print Network (OSTI)

Oscillation interpretation of the results from the LSND, MiniBooNE and some other experiments requires existence of sterile neutrino with mass $\\sim 1$ eV and mixing with the active neutrinos $|U_{\\mu 0}|^2 \\sim (0.02 - 0.04)$. It has been realized some time ago that existence of such a neutrino affects significantly the fluxes of atmospheric neutrinos in the TeV range which can be tested by the IceCube Neutrino Observatory. In view of the first IceCube data release we have revisited the oscillations of high energy atmospheric neutrinos in the presence of one sterile neutrino. Properties of the oscillation probabilities are studied in details for various mixing schemes both analytically and numerically. The energy spectra and angular distributions of the $\

Soebur Razzaque; A. Yu. Smirnov

2011-04-07T23:59:59.000Z

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121

The role of the Higgs meson in the cosmological constraint on the mass of very heavy neutrinos  

Science Conference Proceedings (OSTI)

According to LEP experiments of the measurement of the width and height of a Z-boson peak, there are three neutrino species. However, this constraint applies only to light neutrinos with mass m 44 GeV. Because the experimental search for neutrinos on accelerators at very high energies ({ge}M{sub Z}) is a difficult problem, the investigation of indirect astrophysical effects becomes an important source of information on the properties of new particles. According to the Big Bang theory, the background of relic neutrinos also containing new species of very heavy neutrinos (if they exist) should exist in the Universe, and their annihilation in the halo of the Galaxy could lead to peculiarities in the spectrum of cosmic rays. The astrophysical constraints on the mass of heavy neutrinos were obtained by analyzing the spectra of cosmic electrons and photons and by using the idea about neutrino condensation in the time-dependent gravitational field of collapsing matter. In this paper, the authors take into account a finite mass of a Higgs meson and show how neutrino annihilation into a Higgs meson, which decays to a W pair modifies the restriction on heavy neutrino mass.

Konoplich, R.V.; Sorokina, E.V.; Khlopov, M.Yu. [Moscow Institute of Engineering Physics (Russian Federation)

1994-07-01T23:59:59.000Z

122

The Simplest Models of Radiative Neutrino Mass: Excluding Simplified Zee Models and Beyond  

E-Print Network (OSTI)

The complexity of radiative neutrino-mass models can be judged by: (i) whether they require the imposition of ad hoc symmetries, (ii) the number of new multiplets they introduce, and (iii) the number of arbitrary parameters that appear. Adopting the view that the imposition of arbitrary new symmetries is the least appealing approach, the simplest models have two new multiplets and a minimal number of new parameters. With this in mind, we search for the simplest models of radiative neutrino mass. We are lead to two new models, containing a real scalar triplet and a charged scalar doublet (respectively), in addition to the charged singlet scalar considered by Zee [h^+\\sim(1,1,2)]. The new models are essentially simplified versions of the Zee model and appear to be \\emph{the simplest} models of radiative neutrino mass. However, these models are only of pedagogical interest; despite successfully generating nonzero masses, present-day data is sufficient to rule them out. The lessons learned from these models also enable one to exclude a more general class of radiative models. Moving beyond the minimal cases, we find a new model of two-loop masses that employs the charged doublet \\Phi\\sim(1,2,3) and the doubly-charged scalar k^{++}\\sim(1,1,4).

Sandy S. C. Law; Kristian L. McDonald

2013-03-26T23:59:59.000Z

123

The Simplest Models of Radiative Neutrino Mass: Excluding Simplified Zee Models and Beyond  

E-Print Network (OSTI)

The complexity of radiative neutrino-mass models can be judged by: (i) whether they require the imposition of ad hoc symmetries, (ii) the number of new multiplets they introduce, and (iii) the number of arbitrary parameters that appear. Adopting the view that the imposition of arbitrary new symmetries is the least appealing approach, the simplest models have two new multiplets and a minimal number of new parameters. With this in mind, we search for the simplest models of radiative neutrino mass. We are lead to two new models, containing a real scalar triplet and a charged scalar doublet (respectively), in addition to the charged singlet scalar considered by Zee [h^+\\sim(1,1,2)]. The new models are essentially simplified versions of the Zee model and appear to be \\emph{the simplest} models of radiative neutrino mass. However, these models are only of pedagogical interest; despite successfully generating nonzero masses, present-day data is sufficient to rule them out. The lessons learned from these models also ...

Law, Sandy S C

2013-01-01T23:59:59.000Z

124

CP-violating Phases in Active-Sterile Solar Neutrino Oscillations  

E-Print Network (OSTI)

Effects of CP-violating phases in active-sterile solar neutrino oscillations are discussed in a general scheme of 3+N_{s} mixing, without any constraint on the mixing between the three active and the N_{s} sterile neutrinos, assuming only a realistic hierarchy of neutrino mass-squared differences. A generalized Parke formula describing the neutrino oscillation probabilities inside the Sun is calculated. The validity of the analytical calculation and the probability variation due to the unknown CP-violating phases are illustrated with a numerical calculation of the evolution equation in the case of 3+1 neutrino mixing.

H. W. Long; Y. F. Li; C. Giunti

2013-04-08T23:59:59.000Z

125

NEW NEUTRINO MASS BOUNDS FROM SDSS-III DATA RELEASE 8 PHOTOMETRIC LUMINOUS GALAXIES  

SciTech Connect

We present neutrino mass bounds using 900,000 luminous galaxies with photometric redshifts measured from Sloan Digital Sky Survey III Data Release 8. The galaxies have photometric redshifts between z = 0.45 and z = 0.65 and cover 10,000 deg{sup 2}, thus probing a volume of 3 h {sup -3} Gpc{sup 3} and enabling tight constraints to be derived on the amount of dark matter in the form of massive neutrinos. A new bound on the sum of neutrino masses {Sigma}m{sub {nu}} < 0.27 eV, at the 95% confidence level (CL), is obtained after combining our sample of galaxies, which we call ''CMASS'', with Wilkinson Microwave Anisotropy Probe (WMAP) seven-year cosmic microwave background data and the most recent measurement of the Hubble parameter from the Hubble Space Telescope (HST). This constraint is obtained with a conservative multipole range of 30 < l < 200 in order to minimize nonlinearities, and a free bias parameter in each of the four redshift bins. We study the impact of assuming this linear galaxy bias model using mock catalogs and find that this model causes a small ({approx}1{sigma}-1.5{sigma}) bias in {Omega}{sub DM} h {sup 2}. For this reason, we also quote neutrino bounds based on a conservative galaxy bias model containing additional, shot-noise-like free parameters. In this conservative case, the bounds are significantly weakened, e.g., {Sigma}m{sub {nu}} < 0.38 eV (95% CL) for WMAP+HST+CMASS (l{sub max} = 200). We also study the dependence of the neutrino bound on the multipole range (l{sub max} = 150 versus l{sub max} = 200) and on which combination of data sets is included as a prior. The addition of supernova and/or baryon acoustic oscillation data does not significantly improve the neutrino mass bound once the HST prior is included. A companion paper describes the construction of the angular power spectra in detail and derives constraints on a general cosmological model, including the dark energy equation of state w and the spatial curvature {Omega}{sub K}, while a second companion paper presents a measurement of the scale of baryon acoustic oscillations from the same data set. All three works are based on the catalog by Ross et al.

De Putter, Roland [ICC, University of Barcelona (IEEC-UB), Marti i Franques 1, E-08028 Barcelona (Spain); Mena, Olga; Giusarma, Elena [Instituto de Fisica Corpuscular, University of Valencia-CSIC (Spain); Ho, Shirley; Seo, Hee-Jong; White, Martin; Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Cuesta, Antonio [Yale University, New Haven, CT (United States); Ross, Ashley J.; Percival, Will J. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom); Bizyaev, Dmitry; Brewington, Howard; Malanushenko, Elena; Malanushenko, Viktor; Oravetz, Daniel; Pan, Kaike; Shelden, Alaina; Simmons, Audrey [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059 (United States); Kirkby, David [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); and others

2012-12-10T23:59:59.000Z

126

Cosmological bounds on neutrino degeneracy improved by flavor oscillations  

E-Print Network (OSTI)

We study three-flavor neutrino oscillations in the early universe in the presence of neutrino chemical potentials. We take into account all effects from the background medium, i.e. collisional damping, the refractive effects from charged leptons, and in particular neutrino self-interactions that synchronize the neutrino oscillations. We find that effective flavor equilibrium between all active neutrino species is established well before the big-bang nucleosynthesis (BBN) epoch if the neutrino oscillation parameters are in the range indicated by the atmospheric neutrino data and by the large mixing angle (LMA) MSW solution of the solar neutrino problem. For the other solutions of the solar neutrino problem, partial flavor equilibrium may be achieved if the angle theta_13 is close to the experimental limit tan^2(theta_13)radiation contribution from degenerate neutrinos is limited to such low values that it is neither observable in the large-scale structure of the universe nor in the anisotropies of the cosmic microwave background radiation. Existing limits and possible future measurements, for example in KATRIN, of the absolute neutrino mass scale will provide unambiguous information on the cosmic neutrino mass density, essentially free of the uncertainty of the neutrino chemical. potentials.

A. D. Dolgov; S. H. Hansen; S. Pastor; S. T. Petcov; G. G. Raffelt; D. V. Semikoz

2002-01-30T23:59:59.000Z

127

Mass production test of Hamamatsu MPPC for T2K neutrino oscillation experiment  

E-Print Network (OSTI)

In the T2K near neutrino detectors, about 60 000 Hamamatsu Multi-Pixel Photon Counters (MPPCs) will be used. The mass production of MPPC has started in February 2008.In order to perform quality assurance and to characterize each device, we have developed an MPPC test system. For each MPPC, gain, breakdown voltage, noise rate, photo detection efficiency, and cross-talk and after-pulse rate are measured as functions of the bias voltage and temperature. The design of the test system and the measurement procedure are described.

M. Yokoyama; T. Nakaya; S. Gomi; A. Minamino; N. Nagai; K. Nitta; D. Orme; M. Otani; T. Murakami; T. Nakadaira; M. Tanaka

2008-07-20T23:59:59.000Z

128

Solar Neutrinos Before and After Neutrino 2004  

E-Print Network (OSTI)

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

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

2004-06-28T23:59:59.000Z

129

Long Baseline Neutrino Beams and Large Detectors  

SciTech Connect

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

Samios,N.P.

2008-10-27T23:59:59.000Z

130

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

Science Conference Proceedings (OSTI)

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

Coleman, Stephen James; /William-Mary Coll.

2011-01-01T23:59:59.000Z

131

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

Science Conference Proceedings (OSTI)

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

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

2011-12-16T23:59:59.000Z

132

FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.  

SciTech Connect

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

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

2001-06-30T23:59:59.000Z

133

Analysis of the SN1987A two-stage explosion hypothesis with account for the MSW neutrino flavour conversion  

E-Print Network (OSTI)

Detection of 5 events by the Liquid Scintillation Detector (LSD) on February, 23, 1987 was interpreted in the literature as the detection of neutrinos from the first stage of the two-stage supernova collapse. We pose rigid constraints on the properties of the first stage of the collapse, taking into account neutrino flavour conversion due to the MSW-effect and general properties of supernova neutrino emission. The constraints depend on the unknown neutrino mass hierarchy and mixing angle \\theta_{13}.

Oleg Lychkovskiy

2007-07-17T23:59:59.000Z

134

Can the Super-Kamiokande Atmospheric Data Predict the Solar Neutrino Deficit?  

E-Print Network (OSTI)

In this Letter we show that the evidence for neutrino oscillations from the Super-Kamiokande atmospheric neutrino data fully determines the 3x3 neutrino-oscillations mixing matrix and predicts an energy independent solar neutrino deficit at the level of 45%. This corresponds to a ratio of measured to predicted neutrino flux of R_e^{Solar} = 0.55, in good agreement with the experimental results. We achieve this result within the framework of a minimal, three-generations neutrino mixing, with mass squared differences of dM^2 = 0.45 eV^2 and dm^2 = O(10^-3) eV^2. The mixing matrix derived here is characterized by the mixing angles theta = 35.1, beta = 5.5, and psi = 23.3, and a vanishing CP-violating phase, delta = 0.

Stancu, I

1999-01-01T23:59:59.000Z

135

Hidden from View: Neutrino Masses, Dark Matter and TeV-Scale Leptogenesis in a Neutrinophilic 2HDM  

E-Print Network (OSTI)

We consider a simple extension of the Standard Model providing dark matter and a TeV-scale seesaw mechanism that also allows for viable leptogenesis. In addition to the Standard Model degrees of freedom, the model contains a neutrinophilic Higgs doublet, a scalar singlet, and six singlet fermions (including three right-handed Majorana neutrinos) that are charged under a local $U(1)^\\prime$ gauge symmetry. We show how the $U(1)^\\prime$ charge assignments and the choice of scalar potential can lead to a TeV-scale seesaw mechanism and $\\mathcal{O}(1)$ neutrino Yukawa couplings in a straightforward way. While this scenario has all the ingredients one would expect for significant experimental signatures, including several new TeV scale degrees of freedom, we find that most distinctive features associated with neutrino mass generation, leptogenesis and the dark sector are likely to remain inaccessible in the absence of additional lepton flavor symmetries.

Wei Chao; Michael J. Ramsey-Musolf

2012-12-22T23:59:59.000Z

136

Neutrino mass sensitivity by MAC-E-Filter based time-of-flight spectroscopy with the example of KATRIN  

E-Print Network (OSTI)

The KArlsruhe TRItium Neutrino (KATRIN) experiment aims at a measurement of the neutrino mass with a 90 % confidence limit (C.L.) sensitivity of 0.2 eV/c$^2$ by measuring the endpoint region of the tritium $\\beta$ decay spectrum from a windowless gaseous molecular tritium source using an integrating spectrometer of the MAC-E-Filter type. We discuss the idea of using the MAC-E-Filter in a time-of-flight mode (MAC-E-TOF) in which the neutrino mass is determined by a measurement of the electron time-of-flight (TOF) spectrum that depends on the neutrino mass. MAC-E-TOF spectroscopy here is a very sensitive method since the $\\beta$-electrons are slowed down to distinguishable velocities by the MAC-E-Filter. Their velocity depends strongly on their surplus energy above the electric retarding potential. Using MAC-E-TOF, a statistical sensitivity gain is expected. Because a small number of retarding-potential settings is sufficient for a complete measurement, in contrast to about 40 different retarding potentials used in the standard MAC-E-Filter mode, there is a gain in measurement time and hence statistical power. The improvement of the statistical uncertainty of the squared neutrino mass has been determined by Monte Carlo simulation to be a factor 5 for an ideal case neglecting background and timing uncertainty. Additionally, two scenarios to determine the time-of-flight of the $\\beta$-electrons are discussed, which use the KATRIN detector for creating the stop signal and different methods for obtaining a start signal. These comprise the hypothetical case of an `electron tagger' which detects passing electrons with minimal interference and the more realistic case of `gated filtering', where the electron flux is periodically cut off by pulsing the pre-spectrometer potential.

Nicholas Steinbrink; Volker Hannen; Eric L. Martin; R. G. Hamish Robertson; Michael Zacher; Christian Weinheimer

2013-08-02T23:59:59.000Z

137

Pseudo-Dirac neutrinos in the new standard model  

Science Conference Proceedings (OSTI)

The addition of gauge-singlet fermions to the standard model Lagrangian renders the neutrinos massive and allows one to explain all that is experimentally known about neutrino masses and lepton mixing by varying the values of the Majorana mass parameters M for the gauge singlets and the neutrino Yukawa couplings {lambda}. Here we explore the region of parameter space where M values are much smaller than the neutrino Dirac masses {lambda}v. In this region, neutrinos are pseudo-Dirac fermions. We find that current solar data constrain M values to be less than at least 10{sup -9} eV, and discuss the sensitivity of future experiments to tiny gauge-singlet fermion masses. We also discuss a useful basis for analyzing pseudo-Dirac neutrino mixing effects. In particular, we identify a simple relationship between elements of M and the induced enlarged mixing matrix and new mass-squared differences. These allow one to directly relate bounds on the new mass-squared differences to bounds on the singlet fermion Majorana masses.

Gouvea, Andre de; Huang, W.-C.; Jenkins, James [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States); Elementary Particles and Field Theory Group, MS B285, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

2009-10-01T23:59:59.000Z

138

Scientific Opportunities with the Long-Baseline Neutrino Experiment  

E-Print Network (OSTI)

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. This document is submitted as a white paper to the 2013 DPF Community Summer Study program.

C. Adams; T. Akiri; M. Andrews; I. Anghel; E. Arrieta-Diaz; M. Artuso; J. Asaadi; X. Bai; M. Baird; B. Balantekin; B. Baller; B. Baptista; D. Barker; W. Barletta; G. Barr; A. Bashyal; M. Bass; V. Bellini; B. E. Berger; M. Bergevin; E. Berman; H. Berns; A. Bernstein; R. Bernstein; V. Bhatnagar; B. Bhuyan; M. Bishai; A. Blake; E. Blaufuss; B. Bleakley; E. Blucher; S. Blusk; V. Bocean; T. Bolton; R. Breedon; A. Brandt; C. Bromberg; R. Brown; N. Buchanan; B. Bugg; L. Camilleri; R. Carr; G. Carminati; F. Cavanna; A. Chen; H. Chen; K. Chen; D. Cherdack; C. Chi; S. Childress; B. Choudhary; C. Christofferson; E. Church; D. Cline; T. Coan; J. Coelho; S. Coleman; J. Conrad; M. Convery; R. Corey; L. Corwin; G. S. Davies; S. Dazeley; A. de Gouvea; J. K. de Jong; C. Escobar; K. De; D. Demuth; M. Diwan; Z. Djurcic; J. Dolph; G. Drake; H. Duyang; S. Dye; D. Edmunds; S. Elliott; S. Eno; S. Enomoto; A. Farbin; L. Falk; J. Felde; F. Feyzi; L. Fields; B. Fleming; J. Fowler; W. Fox; A. Friedland; B. Fujikawa; H. Gallagher; R. Gandhi; G. Garvey; V. M. Gehman; G. Geronimo; R. Gill; M. C. Goodman; J. Goon; M. Graham; R. Gran; C. Grant; H. Greenlee; L. Greenler; V. Guarino; E. Guardincerri; R. Guenette; S. Habib; A. Habig; R. W. Hackenburg; A. Hahn; T. Haines; T. Handler; S. Hans; J. Hartnell; J. Harton; R. Hatcher; A. Hatzikoutelis; S. Hays; E. Hazen; M. Headley; A. Heavey; K. Heeger; J. Heise; R. Hellauer; A. Himmel; M. Hogan; A. Holin; G. Horton-Smith; J. Howell; P. Hurh; J. Huston; J. Hylen; R. Imlay; J. Insler; Z. Isvan; C. Jackson; D. Jaffe; C. James; M. Johnson; R. Johnson; S. Johnson; W. Johnston; J. Johnstone; B. Jones; H. Jostlein; T. Junk; R. Kadel; G. Karagiorgi; J. Kaspar; T. Katori; B. Kayser; E. Kearns; P. Keener; S. H. Kettell; M. Kirby; J. Klein; G. Koizumi; S. Kopp; W. Kropp; V. A. Kudryavtsev; A. Kumar; J. Kumar; T. Kutter; K. Lande; C. Lane; K. Lang; F. Lanni; R. Lanza; T. Latorre; F. La Zia; J. Learned; D. Lee; K. Lee; S. Li; Y. Li; Z. Li; J. Libo; S. Linden; J. Ling; J. Link; L. Littenberg; H. Liu; Q. Liu; T. Liu; J. Losecco; W. Louis; B. Lundberg; T. Lundin; C. Maesano; S. Magill; G. Mahler; S. Malys; F. Mammoliti; S. Mandal; A. Mann; A. Mann; P. Mantsch; A. Marchionni; W. Marciano; C. Mariani; J. Maricic; A. Marino; M. Marshak; J. Marshall; S. Matsuno; C. Mauger; N. Mayer; E. McCluskey; K. McDonald; K. McFarland; D. McKee; R. McKeown; R. McTaggart; R. Mehdiyev; D. Mei; Y. Meng; B. Mercurio; M. D. Messier; W. Metcalf; R. Meyhandan; R. Milincic; W. Miller; G. Mills; S. Mishra; S. Moed Sher; N. Mokhov; D. Montanari; C. D. Moore; J. Morfin; W. Morse; S. Mufson; D. Muller; J. Musser; D. Naples; J. Napolitano; M. Newcomer; E. Niner; B. Norris; T. Olson; B. Page; S. Pakvasa; J. Paley; O. Palamara; V. Paolone; V. Papadimitriou; S. Park; Z. Parsa; B. Paulos; K. Partyka; Z. Pavlovic; A. Perch; J. D. Perkin; S. Peeters; R. Petti; R. Plunkett; C. Polly; S. Pordes; R. Potenza; A. Prakash; O. Prokofiev; G. Perdue; X. Qian; J. L. Raaf; V. Radeka; R. Rajendran; I. Rakhno; R. Rameika; J. Ramsey; B. Rebel; S. Rescia; D. Reitzner; M. Richardson; K. Riesselman; M. Robinson; M. Ronquest; M. Rosen; C. Rosenfeld; R. Rucinski; S. Sahijpal; H. Sahoo; N. Samios; M. C. Sanchez; H. Schellman; R. Schmitt; D. Schmitz; J. Schneps; K. Scholberg; S. Seibert; M. Shaevitz; P. Shanahan; R. Sharma; T. Shaw; N. Simos; V. Singh; G. Sinnis; W. Sippach; T. Skwarnicki; M. Smy; H. Sobel; M. Soderberg; J. Sondericker; W. Sondheim; N. J. C. Spooner; M. Stancari; I. Stancu; A. Stefanik; J. Stewart; S. Stone; J. Strait; M. Strait; S. Striganov; G. Sullivan; L. Suter; R. Svoboda; B. Szczerbinska; M. Szydagis; A. Szelc; R. Talaga; M. Tamsett; S. Tariq; R. Tayloe; C. Taylor; D. Taylor; D. Taylor; A. Teymourian; H. Themann; M. Thiesse; J. Thomas; L. F. Thompson; M. Thomson; C. Thorn; X. Tian; D. Tiedt; W. Toki; N. Tolich; M. Tripathi; I. Tropin; M. Tzanov; J. Urheim; S. Usman; M. Vagins; R. Van Berg; R. Van de Water; G. Varner; K. Vaziri; G. Velev; B. Viren; T. Wachala; D. Wahl; A. Waldron; C. W. Walter; H. Wang; W. Wang; D. Warner; R. Wasserman; B. Watson; A. Weber; W. Wei; R. Wendell; M. Wetstein; A. White; H. White; L. Whitehead; D. Whittington; J. Willhite; W. Willis; R. J. Wilson; L. Winslow; E. Worcester; T. Wyman; T. Xin; K. Yarritu; J. Ye; J. Yu; M. Yeh; B. Yu; G. Zeller; C. Zhang; C. Zhang; E. D. Zimmerman; R. Zwaska

2013-07-28T23:59:59.000Z

139

A search for an additional neutrino mass eigenstate in 2 to 100 eV region from "Troitsk nu-mass" data - detailed analysis  

E-Print Network (OSTI)

In this paper we present the details of our previously published results for a search for an additional neutrino mass state in $\\beta$-electron spectrum from the Troitsk nu-mass experiment. Here we present steps of the analysis, show a set of likelihood functions obtained for each additional heavy mass value. We demonstrate how systematic errors were estimated. We also compare our results with those published recently for a similar analysis for Mainz data and try to explain why there is a factor of 2-3 difference in the sensitivity for an additional heavy mass.

A. I. Belesev; A. I. Berlev; E. V. Geraskin; A. A. Golubev; N. A. Likhovid; A. A. Nozik; V. S. Pantuev; V. I. Parfenov; A. K. Skasyrskaya

2013-07-22T23:59:59.000Z

140

Neutrino Oscillation Experiments at Nuclear Reactors  

E-Print Network (OSTI)

In this paper I give an overview of the status of neutrino oscillation experiments performed using nuclear reactors as sources of neutrinos. I review the present generation of experiments (Chooz and Palo Verde) with baselines of about 1 km as well as the next generation that will search for oscillations with a baseline of about 100 km. While the present detectors provide essential input towards the understanding of the atmospheric neutrino anomaly, in the future, the KamLAND reactor experiment represents our best opportunity to study very small mass neutrino mixing in laboratory conditions. In addition KamLAND with its very large fiducial mass and low energy threshold, will also be sensitive to a broad range of different physics.

Giorgio Gratta

1999-05-06T23:59:59.000Z

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141

Light Sterile Neutrinos and Short Baseline Neutrino Oscillation Anomalies  

E-Print Network (OSTI)

We study two possible explanations for short baseline neutrino oscillation anomalies, such as the LSND and MiniBooNE anti-neutrino data, and for the reactor anomaly. The first scenario is the mini-seesaw mechanism with two eV-scale sterile neutrinos. We present both analytic formulas and numerical results showing that this scenario could account for the short baseline and reactor anomalies and is consistent with the observed masses and mixings of the three active neutrinos. We also show that this scenario could arise naturally from an effective theory containing a TeV-scale VEV, which could be related to other TeV-scale physics. The minimal version of the mini-seesaw relates the active-sterile mixings to five real parameters and favors an inverted hierarchy. It has the interesting property that the effective Majorana mass for neutrinoless double beta decay vanishes, while the effective masses relevant to tritium beta decay and to cosmology are respectively around 0.2 and 2.4 eV. The second scenario contains o...

Fan, JiJi

2012-01-01T23:59:59.000Z

142

A unified analysis of the reactor neutrino program towards the measurement of the theta_13 mixing angle  

E-Print Network (OSTI)

We present in this article a detailed quantitative discussion of the measurement of the leptonic mixing angle theta_13 through currently scheduled reactor neutrino oscillation experiments. We thus focus on Double Chooz (Phase I & II), Daya Bay (Phase I & II) and RENO experiments. We perform a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematic error and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. After reviewing the experiments, we present a new analysis of their sensitivities to sin^2(2 theta_13) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup.

Guillaume Mention; Thierry Lasserre; Dario Motta

2007-04-04T23:59:59.000Z

143

Neutrino mass sensitivity by MAC-E-Filter based time-of-flight spectroscopy with the example of KATRIN  

E-Print Network (OSTI)

The KATRIN experiment aims at a measurement of the neutrino mass with a 90 % C.L. sensitivity of 0.2 eV/c$^2$ by measuring the endpoint region of the tritium $\\beta$ decay spectrum from a windowless gaseous molecular tritium source using an integrating spectrometer of the MAC-E-Filter type. We discuss the idea of using the MAC-E-Filter in a time-of-flight mode (MAC-E-TOF) in which the neutrino mass is determined by a measurement of the electron time-of-flight (TOF) spectrum that depends on the neutrino mass. MAC-E-TOF spectroscopy here is a very sensitive method since the $\\beta$-electrons are slowed down to distinguishable velocities by the MAC-E-Filter. Their velocity depends strongly on their surplus energy above the electric retarding potential. Using MAC-E-TOF, a statistical sensitivity gain is expected. Because a small number of retarding-potential settings is sufficient for a complete measurement, in contrast to about 40 different retarding potentials used in the standard MAC-E-Filter mode, there is a gain in measurement time and hence statistical power. The improvement of the statistical uncertainty of the squared neutrino mass has been determined by Monte Carlo simulation to be a factor 5 for an ideal case neglecting background and timing uncertainty. Additionally, two scenarios to determine the time-of-flight of the $\\beta$-electrons are discussed, which use the KATRIN detector for creating the stop signal and different methods for obtaining a start signal. These comprise the hypothetical case of an `electron tagger' which detects passing electrons with minimal interference and the more realistic case of `gated filtering', where the electron flux is periodically cut off by pulsing the pre-spectrometer potential.

Nicholas Steinbrink; Volker Hannen; Eric L. Martin; R. G. Hamish Robertson; Michael Zacher; Christian Weinheimer

2013-08-02T23:59:59.000Z

144

Constraints on electromagnetic properties of sterile neutrinos from MiniBooNE results  

E-Print Network (OSTI)

Among the class of models with small mixing angles between sterile and active neutrinos, we place constraints on the effective muon-to-sterile neutrino magnetic and electric dipole transition moments from the combined MiniBooNE results for the sterile neutrino mass range of $10\\;\\mathrm{MeV}distribution as a function of polar angle. However, good agreement with the anomalous event distribution in reconstructed energy can be achieved for some values of magnetic and electric moments.

Alexander Radionov

2013-03-19T23:59:59.000Z

145

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

We show that the detection of neutrinos from a typical gamma ray burst requires a kilometer-scale detector. We argue that large bursts should be visible with the neutrino telescopes under construction. We emphasize the 3 techniques by which neutrino telescopes can perform this search: by triggering on i) bursts of muons from muon neutrinos, ii) muons from air cascades initiated by high energy gamma rays and iii) showers made by relatively low energy ($\\simeq 100\\,\\mev$) electron neutrinos. Timing of neutrino-photon coincidences may yield a measurement of the neutrino mass to order $10^{-5}$~eV, an interesting range in light of the solar neutrino anomaly.

F. Halzen; G. Jaczko

1996-02-07T23:59:59.000Z

146

Nucleosynthesis and Neutrinos  

SciTech Connect

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

Kajino, Toshitaka [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan)

2011-05-06T23:59:59.000Z

147

Light and Superlight Sterile Neutrinos in the Minimal Radiative Inverse Seesaw Model  

E-Print Network (OSTI)

We explore the possibility of light and superlight sterile neutrinos in the recently proposed Minimal Radiative Inverse Seesaw extension of the Standard Model for neutrino masses, in which all existing neutrino data can be explained. In particular, we discuss two benchmark scenarios with one of the three sterile neutrino states in the keV-range, having very small mixing with the active neutrinos to account for the Dark Matter in the Universe, while (i) the other two light sterile neutrino states could be in the eV-range, possessing a nonzero mixing with the active states as required to explain the LSND+MiniBooNE+reactor neutrino data, or (ii) one of the light sterile states is in the eV-range, whereas the second one could be superlight and almost mass-degenerate with the solar neutrinos. Such superlight sterile neutrinos could give rise to potentially observable effects in future neutrino oscillation experiments and may also offer a possible explanation for the extra radiation observed in the Universe.

P. S. Bhupal Dev; Apostolos Pilaftsis

2012-12-16T23:59:59.000Z

148

Subpanel on accelerator-based neutrino oscillation experiments  

SciTech Connect

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

NONE

1995-09-01T23:59:59.000Z

149

A phenomenological outlook on three-flavor atmospheric neutrino oscillations  

E-Print Network (OSTI)

The recent observations of atmospheric nu events from the Super-Kamiokande experiment are compatible with three-flavor neutrino oscillations, occurring dominantly in the nu_munu_tau channel and subdominantly in the nu_munu_e channel. We present an updated analysis of the three-flavor mass-mixing parameters consistent with the present phenomenology, including the latest 45 kTy data sample from Super-Kamiokande. A comparison with our previous results, based on 33 kTy data, shows that the oscillation evidence is strengthened, and that the neutrino mass-mixing parameters are constrained in smaller ranges.

G. L. Fogli; E. Lisi; A. Marrone; G. Scioscia

1999-04-27T23:59:59.000Z

150

Sterile Neutrino Fits to Short-Baseline Neutrino Oscillation Measurements  

E-Print Network (OSTI)

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

Conrad, J. M.

2013-01-01T23:59:59.000Z

151

Solar Neutrino Matter Effects Redux  

E-Print Network (OSTI)

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

A. B. Balantekin; A. Malkus

2011-09-24T23:59:59.000Z

152

On Geometric Symmetry and New Rich Physics in Particle Mixing  

E-Print Network (OSTI)

As known from general relativity, particle mass and energy create the geometry of macroscopic space. Since the concept of particle mass matrix is a generalization of mass concept in physics with extra flavor generation, the particle mixing angles may be related to the geometry of space. In this paper geometric symmetry of neutrino mixing angles is identified with the outer macroscopic space symmetry. Though it is not a common idea, together with color symmetry it predicts two large and one relatively small theta_13 neutrino mixing angles in agreement with data, equal numbers of space dimensions and particle flavors and colors, and leads naturally to united bimaximal neutrino and zero quark mixing patterns at benchmark point. A formal analogy of neutrino and quark benchmark mixing patterns with two kinds of inertial motion in Newton's classical mechanics is observed. It conforms to the fact of two very different types of particle mixing patterns - neutrino mixing conforms to point particle inertial motion, while white color quark mixing conforms to inertial solid body rotation with the strong QCD bond of quark colors being analogous to the strong bond of point particles in solid body. The discussed semi-empirical flavor mixing phenomenology indicates inert stable dark matter candidate as complete copy of the visible matter with hypothetical advanced observable dark matter civilization.

E. M. Lipmanov

2012-12-05T23:59:59.000Z

153

Solar Neutrinos  

NLE Websites -- All DOE Office Websites (Extended Search)

Solar Neutrinos at the Conclusion of the Sudbury Neutrino Observatory Noah Oblath April 22, 2008 The study of solar neutrinos began with the idea that one could use the neutrinos...

154

Mixing and Water-Mass Formation in the Australian Subantarctic  

Science Conference Proceedings (OSTI)

A cruise south of eastern Australia confirmed the formation of a Subantarctic Mode Water type in late winter on the equatorward side of the Subantarctic Front. This water type, mixed with the winter surface waters farther north, would form the T-...

Rory O. R. Y. Thompson; R. J. Edwards

1981-10-01T23:59:59.000Z

155

Theory of Neutrinos: A White Paper  

E-Print Network (OSTI)

During 2004, four divisions of the American Physical Society commissioned a study of neutrino physics to take stock of where the field is at the moment and where it is going in the near and far future. Several working groups looked at various aspects of this vast field. The summary was published as a main report entitled ``The Neutrino Matrix'' accompanied by short 50 page versions of the report of each working group. Theoretical research in this field has been quite extensive and touches many areas and the short 50 page report provided only a brief summary and overview of few of the important points. The theory discussion group felt that it may be of value to the community to publish the entire study as a white paper and the result is the current article. After a brief overview of the present knowledge of neutrino masses and mixing and some popular ways to probe the new physics implied by recent data, the white paper summarizes what can be learned about physics beyond the Standard Model from the various proposed neutrino experiments. It also comments on the impact of the experiments on our understanding of the origin of the matter-antimatter asymmetry of the Universe and the basic nature of neutrino interactions as well as the existence of possible additional neutrinos. Extensive references to original literature are provided.

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

2005-10-17T23:59:59.000Z

156

Cosmic coincidences and relic neutrinos  

E-Print Network (OSTI)

A simple phenomenological description for the energy transfer between a variable cosmological constant (CC) and a gas of relic neutrinos in an expanding universe can account for a near coincidence between the neutrino and dark-energy densities to hold over a significant portion of the history of the universe. Although such a cosmological setup may promote neutrinos to mass-varying particles, both with slow and quick neutrino mass changing with the expansion of the universe naturally implemented in the model, it also works equally well for static neutrino masses. We also stress what sort of models for variable CC can potentially underpin the above scenario.

R. Horvat

2006-12-04T23:59:59.000Z

157

New Results on Solar Neutrinos  

E-Print Network (OSTI)

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

Alain Bellerive

2010-12-11T23:59:59.000Z

158

New Results on Solar Neutrinos  

E-Print Network (OSTI)

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

Bellerive, Alain

2010-01-01T23:59:59.000Z

159

Quasi-energy-independent solar neutrino transitions  

E-Print Network (OSTI)

Current solar, atmospheric, and reactor neutrino data still allow oscillation scenarios where the squared mass differences are all close to 10^-3 eV^2, rather than being hierarchically separated. For solar neutrinos, this situation (realized in the upper part of the so-called large-mixing angle solution) implies adiabatic transitions which depend weakly on the neutrino energy and on the matter density, as well as on the ``atmospheric'' squared mass difference. In such a regime of ``quasi-energy-independent'' (QEI) transitions, intermediate between the more familiar ``Mikheyev-Smirnov-Wolfenstein'' (MSW) and energy-independent (EI) regimes, we first perform analytical calculations of the solar nu_e survival probability at first order in the matter density, beyond the usual hierarchical approximations. We then provide accurate, generalized expressions for the solar neutrino mixing angles in matter, which reduce to those valid in the MSW, QEI and EI regimes in appropriate limits. Finally, a representative QEI scenario is discussed in some detail.

G. L. Fogli; E. Lisi; A. Palazzo

2001-05-09T23:59:59.000Z

160

The Solar Neutrino Day/Night Effect in Super-Kamiokande  

E-Print Network (OSTI)

The time variation of the elastic scattering rate of solar neutrinos with electrons in Super-Kamiokande-I was fit to the day/night variations expected from active two-neutrino oscillations in the Large Mixing Angle region. Combining Super-Kamiokande measurements with other solar and reactor neutrino data, the mixing angle is determined as sin^2theta=0.276+0.033-0.026 and the mass squared difference between the two neutrino mass eigenstates as Delta m^2=7.1+0.6-0.5x10^-5eV^2. For the best fit parameters, a day/night asymmetry of -1.7+-1.6(stat)+1.3-1.2(syst)% was determined from the Super-Kamiokande data, which has improved statistical precision over previous measurements and is in excellent agreement with the expected value of -1.6%.

Michael Burghard Smy; for the Super-Kamiokande Collaboration

2003-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Leptogenesis with Dirac Neutrinos  

E-Print Network (OSTI)

We describe a "neutrinogenesis" mechanism whereby, in the presence of right-handed neutrinos with sufficiently small pure Dirac masses, (B+L)-violating sphaleron processes create the baryon asymmetry of the Universe, even when B=L=0 initially. It is shown that the resulting neutrino mass constraints are easily fulfilled by the neutrino masses suggested by current experiments. We present a simple toy model which uses this mechanism to produce the observed baryon asymmetry of the Universe. (PostScript Errors corrected in latest Version).

Karin Dick; Manfred Lindner; Michael Ratz; David Wright

1999-07-30T23:59:59.000Z

162

Using open clusters to study mixing in low- and intermediate-mass stars  

E-Print Network (OSTI)

In many evolutionary stages, low- and intermediate-mass stars show signs of mixing of the surface material with material from the interior. To account for all the details revealed by the observations it is necessary to include non-standard physical processes in the models (e.g. atomic diffusion and rotation-induced mixing). The study of mixing in stars of different masses, ages, and chemical composition helps to identify and constrain these processes. In this sense, stars in open clusters are the ideal targets. All stars in one given cluster have the same age and chemical composition, and their masses can be well estimated. By studying many clusters, one can separate and trace the effects of these different parameters.

Smiljanic, Rodolfo

2011-01-01T23:59:59.000Z

163

Determining Reactor Neutrino Flux  

E-Print Network (OSTI)

Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understanding of the correlation of uncertainties is required for $\\theta_{13}$ experiments. Precise determination of reactor neutrino flux will also improve the sensitivity of the non-proliferation monitoring and future reactor experiments. We will discuss the flux calculation and recent progresses.

Cao, Jun

2011-01-01T23:59:59.000Z

164

Determining Reactor Neutrino Flux  

E-Print Network (OSTI)

Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understanding of the correlation of uncertainties is required for $\\theta_{13}$ experiments. Precise determination of reactor neutrino flux will also improve the sensitivity of the non-proliferation monitoring and future reactor experiments. We will discuss the flux calculation and recent progresses.

Jun Cao

2011-01-12T23:59:59.000Z

165

Neutrino Oscillations with Reactor Neutrinos  

E-Print Network (OSTI)

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

Anatael Cabrera

2007-01-11T23:59:59.000Z

166

Three-neutrino model analysis of the world's oscillation data  

E-Print Network (OSTI)

A model of neutrino oscillation experiments is constructed. The experiments incorporated are: solar neutrinos (Chlorine, Gallium, Super-K, and SNO), reactor neutrinos (Bugey and CHOOZ), beam stop neutrinos (LSND decay at rest and decay in flight), and atmospheric neutrinos. Utilizing this model and the standard three-neutrino mixing extension of the standard model, the data are analyzed. Solutions for the mixing angles and mass-squared differences are found to occur in pairs corresponding to the interchange $\\Delta m^2_{12} \\leftrightarrow \\Delta m^2_{23}$. Two pairs of solutions are found that reasonably reproduce the data, including the LSND data. These solutions are $\\theta_{12}\\approx 0.5$, $\\theta_{13}\\approx 0.1$, $\\theta_{23}\\approx 0.7$, $\\Delta m^2_{12} \\approx 5\\times 10^{-5}$ eV$^2$ and $\\Delta m^2_{23} \\approx 0.2$ eV$^2$ or 2.4 eV$^2$. Other statistically significant solutions are also found which produce negligible oscillations for the LSND experiments.

Latimer, D C

2003-01-01T23:59:59.000Z

167

Three-neutrino model analysis of the world's oscillation data  

E-Print Network (OSTI)

A model of neutrino oscillation experiments is constructed. The experiments incorporated are: solar neutrinos (Chlorine, Gallium, Super-K, and SNO), reactor neutrinos (Bugey and CHOOZ), beam stop neutrinos (LSND decay at rest and decay in flight), and atmospheric neutrinos. Utilizing this model and the standard three-neutrino mixing extension of the standard model, the data are analyzed. Solutions for the mixing angles and mass-squared differences are found to occur in pairs corresponding to the interchange $\\Delta m^2_{12} \\leftrightarrow \\Delta m^2_{23}$. Two pairs of solutions are found that reasonably reproduce the data, including the LSND data. These solutions are $\\theta_{12}\\approx 0.5$, $\\theta_{13}\\approx 0.1$, $\\theta_{23}\\approx 0.7$, $\\Delta m^2_{12} \\approx 5\\times 10^{-5}$ eV$^2$ and $\\Delta m^2_{23} \\approx 0.2$ eV$^2$ or 2.4 eV$^2$. Other statistically significant solutions are also found which produce negligible oscillations for the LSND experiments.

D. C. Latimer; D. J. Ernst

2003-10-30T23:59:59.000Z

168

Day-night asymmetry of high and low energy solar neutrino events in Super-Kamiokande and in the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

In the context of solar neutrino oscillations among active states, we briefly discuss the current likelihood of Mikheyev-Smirnov-Wolfenstein (MSW) solutions to the solar neutrino problem, which appear to be currently favored at large mixing, where small Earth regeneration effects might still be observable in Super-Kamiokande (SK) and in the Sudbury Neutrino Observatory (SNO). We point out that, since such effects are larger at high (low) solar neutrino energies for high (low) values of the mass square difference \\delta m^2, it may be useful to split the night-day rate asymmetry in two separate energy ranges. We show that the difference \\Delta of the night-day asymmetry at high and low energy may help to discriminate the two large-mixing solutions at low and high \\delta m^2 through a sign test, both in SK and in SNO, provided that the sensitivity to \\Delta can reach the (sub)percent level.

G. L. Fogli; E. Lisi; D. Montanino; A. Palazzo

2000-08-01T23:59:59.000Z

169

The use of a high intensity neutrino beam from the ESS proton linac for measurement of neutrino CP violation and mass hierarchy  

E-Print Network (OSTI)

It is proposed to complement the ESS proton linac with equipment that would enable the production, concurrently with the production of the planned ESS beam used for neutron production, of a 5 MW beam of 10$^{23}$ 2.5 GeV protons per year in microsecond short pulses to produce a neutrino Super Beam, and to install a megaton underground water Cherenkov detector in a mine to detect $\

E. Baussan; M. Dracos; T. Ekelof; E. Fernandez Martinez; H. Ohman; N. Vassilopoulos

2012-12-20T23:59:59.000Z

170

Fission Cycling in Supernova Nucleosynthesis: Active-Sterile Neutrino Oscillations  

E-Print Network (OSTI)

We investigate nucleosynthesis in the supernovae post-core bounce neutrino-driven wind environment in the presence of active-sterile neutrino transformation. We consider active-sterile neutrino oscillations for a range of mixing parameters: vacuum mass-squared differences of 0.1 eV^2 10^-4. We find a consistent r-process pattern for a large range of mixing parameters that is in rough agreement with the halo star CS 22892-052 abundances and the pattern shape is determined by fission cycling. We find that the allowed region for the formation of the r-process peaks overlaps the LSND and NSBL (3+1) allowed region.

J. Beun; G. C. McLaughlin; R. Surman; W. R. Hix

2006-02-01T23:59:59.000Z

171

Solar Neutrino Measurements  

E-Print Network (OSTI)

A review of solar neutrino experiments is provided, including experimental measurements to date and proposed future measurements. Experiments to date have provided a clear determination that solar neutrinos are undergoing flavor transformation and that the dominant mechanism for this transformation is oscillation. The mixing parameters are well defined and limits are placed on sub-dominant modes. The measurements also provide strong confirmation of solar model calculations. New experiments under development will study neutrino oscillation parameters and sub-dominant modes with greater precision and will investigate solar fluxes further, concentrating primarily on the low energy pp, $^7$Be, pep and CNO reactions.

A. B. McDonald

2004-06-10T23:59:59.000Z

172

Limit on electron neutrino mass from observation of the beta decay of molecular tritium  

Science Conference Proceedings (OSTI)

We report the most sensitive upper limit set on the mass of the electron antineutrino. The upper limit of 9.4 eV (95% confidence level) was obtained from a study of the shape of the beta decay spectrum of free molecular tritium. Achieving such a level of sensitivity required precise determinations of all processes that modify the shape of the observed spectrum. This result is in clear disagreement with a reported value for the mass of 26(5) eV. 30 refs., 3 figs., 2 tabs.

Wilkerson, J.F.; Bowles, T.J.; Friar, J.L.; Robertson, R.G.H.; Stephenson, G.J. Jr.; Wark, D.L. (Los Alamos National Lab., NM (USA)); Knapp, D.A. (Lawrence Livermore National Lab., CA (USA))

1990-01-01T23:59:59.000Z

173

Neutrino Physics  

DOE R&D Accomplishments (OSTI)

The prediction and verification of the neutrino are reviewed, together with the V A theory for its interactions (particularly the difficulties with the apparent existence of two neutrinos and the high energy cross section). The Brookhaven experiment confirming the existence of two neutrinos and the cross section increase with momentum is then described, and future neutrino experiments are considered. (D.C.W.)

Lederman, L. M.

1963-01-09T23:59:59.000Z

174

Review of Solar and Reactor Neutrinos  

E-Print Network (OSTI)

Over the last several years, experiments have conclusively demonstrated that neutrinos are massive and that they mix. There is now direct evidence for $\

A. W. P. Poon

2005-09-19T23:59:59.000Z

175

Off-shell OPERA neutrinos  

E-Print Network (OSTI)

In the OPERA experiment, superluminal propagation of neutrinos can occur if one of the neutrino masses is extremely small. However the effect only has appreciable amplitude at energies of order this mass and thus has negligible overlap with the multi-GeV scale of the experiment.

Tim R. Morris

2011-10-14T23:59:59.000Z

176

Hanohano: A Deep Ocean Anti-Neutrino Detector for Unique Neutrino Physics and Geophysics Studies  

E-Print Network (OSTI)

The science potential of a 10 kiloton deep-ocean liquid scintillation detector for ~1 MeV energy scale electron anti-neutrinos has been studied. Such an instrument, designed to be portable and function in the deep ocean (3-5 km) can make unique measurements of the anti-neutrinos from radioactive decays in the Earth'.s mantle. Ths information speaks to some of the most fundamental questions in geology about the origin of the Earth, plat e tectonics, the geomagnetic field and even somewhat indirectly to global warming. Measurements in multiple locations will strengthen the potential insights. On the particle physics side, we have identified a unique role in the study of anti-neutrinos from a nuclear power complex, at a range of 55-60 km off shore. Not only can precision measurements be made of most neutrino mixing parameters, including $\\theta_{13}$ (depending on magnitude), but the neutrino mass hierarchy can be determined in a method not heretofore discussed, and one which does not rely upon matter effects. This detector is under active study on paper, in the laboratory, and at sea. An interdisciplinary and international collaboration is in formation, and plans are in motion for a major proposal, to be followed by construction over several years.

John G. Learned; Stephen T. Dye; Sandip Pakvasa

2008-10-28T23:59:59.000Z

177

Solar Neutrino Measurements  

E-Print Network (OSTI)

Abstract. A review of solar neutrino experiments is provided, including experimental measurements to date and proposed future measurements. Experiments to date have provided a clear determination that solar neutrinos are undergoing flavor transformation and that the dominant mechanism for this transformation is oscillation. The mixing parameters are well defined and limits are placed on subdominant modes. The measurements also provide strong confirmation of solar model calculations. New experiments under development will study neutrino oscillation parameters and sub-dominant modes with greater precision and will investigate solar fluxes further, concentrating primarily on the low energy pp, 7Be, pep and CNO reactions. PACS numbers: 26.65+t, 95.55.Vj, 95.85.Ry, 96.60.Vg, 14.60.PqSolar Neutrino Measurements 2 1.

A. B. Mcdonald

2004-01-01T23:59:59.000Z

178

Investigation of Neutrino Properties in Experiments at Nuclear Reactors: Present Status and Prospects  

E-Print Network (OSTI)

This paper was submitted in Russian edition of Journal Physics of Atomic Nuclei in 2001. The present status of experiments that are being performed at nuclear reactors in order to seek the neutrino masses, mixing, and magnetic moments, whose discovery would be a signal of the existence of physics beyond the Standard Model, is considered, along with their future prospects.

L. A. Mikaelyan

2002-10-03T23:59:59.000Z

179

Review of Solar Neutrino Experiments  

E-Print Network (OSTI)

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

Alain Bellerive

2003-12-16T23:59:59.000Z

180

Entanglement in neutrino oscillations  

E-Print Network (OSTI)

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

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

2007-07-30T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Glossary Item - Neutrino  

NLE Websites -- All DOE Office Websites (Extended Search)

that rarely interact with matter. Scientists know of three types of neutrinos: electron-neutrinos, muon-neutrinos and tau-neutrinos. Wolfgang Pauli first proposed the...

182

Neutrino Factories  

SciTech Connect

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

Geer, Steve; /Fermilab

2010-01-01T23:59:59.000Z

183

Neutrinos and Lepton Flavour Violation in the Left-Right Twin Higgs Model  

E-Print Network (OSTI)

We analyse the lepton sector of the Left-Right Twin Higgs Model. This model offers an alternative way to solve the "little hierarchy" problem of the Standard Model. We show that one can achieve an effective see-saw to explain the origin of neutrino masses and that this model can accommodate the observed neutrino masses and mixings. We have also studied the lepton flavour violation process l_1 -> l_2 \\gamma and discussed how the experimental bound from these branching ratios constrains the scale of symmetry breaking of this Twin Higgs model.

Asmaa Abada; Irene Hidalgo

2007-11-08T23:59:59.000Z

184

Evidence for Neutrino Oscillations I: Solar and Reactor Neutrinos  

E-Print Network (OSTI)

This paper discusses evidence for neutrino oscillations obtained from measurements with solar neutrinos and reactor neutrinos.

A. B. McDonald

2004-12-06T23:59:59.000Z

185

Sterile Neutrinos for Warm Dark Matter and the Reactor Anomaly in Flavor Symmetry Models  

E-Print Network (OSTI)

We construct a flavor symmetry model based on the tetrahedral group A_4 in which the right-handed neutrinos from the seesaw mechanism can be both keV warm dark matter particles and eV-scale sterile neutrinos. This is achieved by giving the right-handed neutrinos appropriate charges under the same Froggatt-Nielsen symmetry responsible for the hierarchy of the charged lepton masses. We discuss the effect of next-to-leading order corrections to deviate the zeroth order tri-bimaximal mixing. These corrections have two sources: (i) higher order seesaw terms, which are important when the seesaw particles are eV-scale, and (ii) higher-dimensional effective operators suppressed by additional powers of the cut-off scale of the theory. Whereas the mixing angles of the active neutrinos typically receive corrections of the same order, the mixing of the sterile neutrinos with the active ones is rather stable as it is connected with a hierarchy of mass scales. We also modify an effective A_4 model to incorporate keV-scale ...

Barry, James; Zhang, He

2011-01-01T23:59:59.000Z

186

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

E-Print Network (OSTI)

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...

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; Mller, H; Postema, H; Price, M; Rovelli, T; Schinzel, D; Sguinot, Jacques; Valenti, G; Voss, R; Wotschack, J; Zhemchugov, A S

2007-01-01T23:59:59.000Z

187

Water mass transformation due to mixed layer entrainment and mesoscale stirring: In series or parallel?  

E-Print Network (OSTI)

The convergence of advective and di#usive buoyancy flux must match the air-sea buoyancy flux between two outcropping isopycnals. This leads to a diagnostic framework for water mass transformation in which a myriad of di#erent processes can be incorporated under a unifying balance. We review how the diapycnal advection due to ubiquitous mixed layer entrainment can be included in this framework, and we estimate its contribution to the large scale transformation. We also consider how decomposing the flow and buoyancy field into mean, eddy and turbulent parts leads to clarifying the interaction of mixed layer and mesoscale (or sub-mesoscale) eddies in the overall large scale balance. 1.

A. Tandon

2001-01-01T23:59:59.000Z

188

Neutrino Superbeams  

NLE Websites -- All DOE Office Websites (Extended Search)

Upgraded conventional neutrino beams: Neutrino superbeams Upgraded conventional neutrino beams: Neutrino superbeams The capabilities of greatly upgraded conventional neutrino beams and the comparison with neutrino factories is under study. This page collects together some useful working information-- and at the bottom you can find links to studies that have already been done! GROUP REPORT: Oscillation Measurements with Upgraded Conventional Neutrino Beams V. Barger et al., hep-ex/0103052 (FERMILAB-FN-703), Addendum to Report FN-692 to the Fermilab Directorate, March 5, 2001. MI upgrade limitations Conf-97-199, W. Chou NUMI low energy beam with L = 732 km uoscillation signals for point IA1 (LMA scenario) but with sin**2 2theta(13) = 0.01, from Steve Geer. NUMI medium energy beam with L = 2800 km oscillation signals for

189

Neutrino oscillations in an SO(10) supersymmetric grand unified theory with U(2)xU(1){sup n} family symmetry  

Science Conference Proceedings (OSTI)

In a previous paper we analyzed fermion masses (focusing on neutrino masses and mixing angles) in an SO(10) SUSY GUT with U(2)xU(1){sup n} family symmetry. The model is ''natural'' containing all operators in the Lagrangian consistent with the states and their charges. With minimal family symmetry breaking vacuum expectation values (VEVs) the model is also predictive giving a unique solution to atmospheric (with maximal {nu}{sub {mu}}{yields}{nu}{sub {tau}} mixing) and solar (with SMA MSW {nu}{sub e}{yields}{nu}{sub s} mixing) neutrino oscillations. In this paper we analyze the case of general family breaking VEVs. We now find several new solutions for three, four, and five neutrinos. For three neutrinos we now obtain SMA MSW, LMA MSW, or vacuum oscillation solutions for solar neutrinos. In all three cases the atmospheric data are described by maximal {nu}{sub {mu}}{yields}{nu}{sub {tau}} mixing. In the four and five neutrino cases, in addition to fitting atmospheric and solar data as before, we are now able to fit LSND data. All this is obtained with the additional parameters coming from the family symmetry breaking VEVs, providing only minor changes in the charged fermion fits. (c) 2000 The American Physical Society.

Blazek, T. [Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States); Raby, S. [Department of Physics, The Ohio State University, 174 W. 18th Ave., Columbus, Ohio 43210 (United States); Tobe, K. [Department of Physics, The Ohio State University, 174 W. 18th Ave., Columbus, Ohio 43210 (United States)

2000-09-01T23:59:59.000Z

190

Collective Neutrino Flavor Transformation In Supernovae  

E-Print Network (OSTI)

We examine coherent active-active channel neutrino flavor evolution in environments where neutrino-neutrino forward scattering can engender large-scale collective flavor transformation. We point out a key quantity, the "total effective energy", which is conserved in several important regimes. Using this concept, we analyze collective neutrino and antineutrino flavor oscillation in the "synchronized" mode and what we term the "bi-polar" mode. We thereby are able to explain why large collective flavor mixing can develop on short timescales even when vacuum mixing angles are small in, e.g., a dense gas of initially pure $\

Huaiyu Duan; George M. Fuller; Yong-Zhong Qian

2005-11-09T23:59:59.000Z

191

STATUS OF THE US LONG BASELINE NEUTRINO EXPERIMENT STUDY.  

SciTech Connect

The US Long Baseline Neutrino Experiment Study was commissioned jointly by Brookhaven National Laboratory and Fermi National Accelerator Laboratory to investigate the potential for future U.S. based long baseline neutrino oscillation experiments beyond the currently planned program. The Study focused on MW class convention at neutrino beams that can be produced at Fermilab or BNL. The experimental baselines are based on two possible detector locations: (1) off-axis to the existing Fermilab NuMI beamline at baselines of 700 to 810 km and (2) NSF's proposed future Deep Underground Science and Engineering Laboratory (DUSEL) at baselines greater than 1000 km. Two detector technologies are considered: a megaton class Water Cherenkov detector deployed deep underground at a DUSEL site, or a 100kT Liquid Argon Time-Projection Chamber (TPC) deployed on the surface at any of the proposed sites. The physics sensitivities of the proposed experiments are summarized. We find that conventional horn focused wide-band neutrino beam options from Fermilab or BNL aimed at a massive detector with a baseline of > 1000 km have the best sensitivity to CP violation and the neutrino mass hierarchy for values of the mixing angle {theta}{sub 13} down to 2.2{sup o}.

BISHAI,M.

2006-09-21T23:59:59.000Z

192

Neutrino Oscillometry  

E-Print Network (OSTI)

Neutrino oscillations are studied employing sources of low energy monoenergetic neutrinos following electron capture by the nucleus and measuring electron recoils. Since the neutrino energy is very low the oscillation length appearing in this electronic neutrino disappearance experiment can be so small that the full oscillation can take place inside the detector. Thus one may determine very accurately all the neutrino oscillation parameters. In particular one can measure or set a better limit on the unknown parameter theta13. 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 energy and position resolution. Both spherical gaseous and cylindrical liquid detectors are studied. Different source candidates are considered

Vergados, J D; Novikov, Yu N

2010-01-01T23:59:59.000Z

193

Neutrino Oscillometry  

E-Print Network (OSTI)

Neutrino oscillations are studied employing sources of low energy monoenergetic neutrinos following electron capture by the nucleus and measuring electron recoils. Since the neutrino energy is very low the oscillation length appearing in this electronic neutrino disappearance experiment can be so small that the full oscillation can take place inside the detector. Thus one may determine very accurately all the neutrino oscillation parameters. In particular one can measure or set a better limit on the unknown parameter theta13. 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 energy and position resolution. Both spherical gaseous and cylindrical liquid detectors are studied. Different source candidates are considered

J. D. Vergados; Y. Giomataris; Yu. N. Novikov

2010-10-21T23:59:59.000Z

194

Solar Neutrinos  

DOE R&D Accomplishments (OSTI)

The prospect of studying the solar energy generation process directly by observing the solar neutrino radiation has been discussed for many years. The main difficulty with this approach is that the sun emits predominantly low energy neutrinos, and detectors for observing low fluxes of low energy neutrinos have not been developed. However, experimental techniques have been developed for observing neutrinos, and one can foresee that in the near future these techniques will be improved sufficiently in sensitivity to observe solar neutrinos. At the present several experiments are being designed and hopefully will be operating in the next year or so. We will discuss an experiment based upon a neutrino capture reaction that is the inverse of the electron-capture radioactive decay of argon-37. The method depends upon exposing a large volume of a chlorine compound, removing the radioactive argon-37 and observing the characteristic decay in a small low-level counter.

Davis, R. Jr.; Harmer, D. S.

1964-12-00T23:59:59.000Z

195

Strong Upper Limits on Sterile Neutrino Warm Dark Matter  

Science Conference Proceedings (OSTI)

Sterile neutrinos are attractive dark matter candidates. Their parameter space of mass and mixing angle has not yet been fully tested despite intensive efforts that exploit their gravitational clustering properties and radiative decays. We use the limits on gamma-ray line emission from the Galactic center region obtained with the SPI spectrometer on the INTEGRAL satellite to set new constraints, which improve on the earlier bounds on mixing by more than 2 orders of magnitude, and thus strongly restrict a wide and interesting range of models.

Yueksel, Hasan [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Beacom, John F. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Watson, Casey R. [Department of Physics and Astronomy, Millikin University, Decatur, Illinois 62522 (United States)

2008-09-19T23:59:59.000Z

196

Progress in the physics of massive neutrinos  

E-Print Network (OSTI)

The current status of the physics of massive neutrinos is reviewed with a forward-looking emphasis. The article begins with the general phenomenology of neutrino oscillations in vacuum and matter and documents the experimental evidence for oscillations of solar, reactor, atmospheric and accelerator neutrinos. Both active and sterile oscillation possibilities are considered. The impact of cosmology (BBN, CMB, leptogenesis) and astrophysics (supernovae, highest energy cosmic rays) on neutrino observables and vice versa, is evaluated. The predictions of grand unified, radiative and other models of neutrino mass are discussed. Ways of determining the unknown parameters of three-neutrino oscillations are assessed, taking into account eight-fold degeneracies in parameters that yield the same oscillation probabilities, as well as ways to determine the absolute neutrino mass scale (from beta-decay, neutrinoless double-beta decay, large scale structure and Z-bursts). Critical unknowns at present are the amplitude of \

V. Barger; D. Marfatia; K. Whisnant

2003-08-12T23:59:59.000Z

197

Background Study on nu_e Appearance from a nu_mu Beam in Very Long Baseline Neutrino Oscillation Experiments with a Large Water Cherenkov Detector  

E-Print Network (OSTI)

There is a growing interest in very long baseline neutrino oscillation experimentation using accelerator produced neutrino beam as a machinery to probe the last three unmeasured neutrino oscillation parameters: the mixing angle theta_13, the possible CP violating phase delta_CP and the mass hierarchy, namely, the sign of delta-m^2_32. Water Cherenkov detectors such as IMB, Kamiokande and Super-Kamiokande have shown to be very successful at detecting neutrino interactions. Scaling up this technology may continue to provide the required performance for the next generation of experiments. This report presents the latest effort to demonstrate that a next generation (> 100 kton) water Cherenkov detector can be used effectively for the rather difficult task of detecting nu_e events from the neutrino oscillation nu_mu -> nu_e despite the large expected potential background resulting from pi^0 events produced via neutral current interactions.

Chiaki Yanagisawa; Chang Kee Jung; Trung Le; Brett Viren

2010-08-05T23:59:59.000Z

198

Background Study on nu_e Appearance from a nu_mu Beam in Very Long Baseline Neutrino Oscillation Experiments with a Large Water Cherenkov Detector  

E-Print Network (OSTI)

There is a growing interest in very long baseline neutrino oscillation experimentation using accelerator produced neutrino beam as a machinery to probe the last three unmeasured neutrino oscillation parameters: the mixing angle theta_13, the possible CP violating phase delta_CP and the mass hierarchy, namely, the sign of delta-m^2_32. Water Cherenkov detectors such as IMB, Kamiokande and Super-Kamiokande have shown to be very successful at detecting neutrino interactions. Scaling up this technology may continue to provide the required performance for the next generation of experiments. This report presents the latest effort to demonstrate that a next generation (> 100 kton) water Cherenkov detector can be used effectively for the rather difficult task of detecting nu_e events from the neutrino oscillation nu_mu -> nu_e despite the large expected potential background resulting from pi^0 events produced via neutral current interactions.

Yanagisawa, Chiaki; Le, Trung; Viren, Brett

2010-01-01T23:59:59.000Z

199

Neutrino Physics at the Turn of the Millenium  

E-Print Network (OSTI)

Recent solar & atmospheric nu-data strongly indicate need for physics beyond the Standard Model. I review the ways of reconciling them in terms of 3-nu oscillations. Though not implied by data, bi-maximal nu-mixing models emerge as a possibility. SUSY with broken R-parity provides an attractive way to incorporate it, opening the possibility of testing nu-anomalies at high- energy colliders such as the LHC or at the upcoming long-baseline or nu- factory experiments. Reconciling, in addition, the LSND hint requires a fourth, light sterile neutrino, nus. The simplest are the most symmetric scenarios, in which 2 of the 4 neutrinos are maximally-mixed and lie at the LSND scale, while the others are at the solar scale. The lightness of nus, the nearly maximal atmospheric mixing, and the solar/atmospheric splittings all follow naturally from the assumed lepton-number symmetry and its breaking. These basic schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments such as SNO. However underground experiments have not yet proven neutrino masses, as there are many alternatives. For example flavour changing interactions can play an important role in the explanation of solar and contained atmospheric data and could be tested e.g through \\mu \\to e + \\gamma, \\mu-e conversion in nuclei, unaccompanied by neutrino-less double beta decay. Conversely, a short-lived numu might play a role in the explanation of the atmospheric data. Finally, in the presence of a nus, a long-lived heavy nutau could delay the time at which the matter and radiation contributions to the energy density of the Universe become equal, reducing density fluctuations on smaller scales, thus saving the standard CDM scenario, while the light nue, numu and nus would explain the solar & atmospheric data.

J. W. F. Valle

1999-11-03T23:59:59.000Z

200

Experimental limits on massive neutrinos from e/sup +/e/sup /minus// annihilations at 29 GeV  

SciTech Connect

A search was made in 29 GeV e/sup +/e/sup /minus// annihilations for massive neutrinos decaying to e/sup +-/X/sup /minus plus//(..nu..) where X is a muon or meson. A 300 pb/sup /minus/1/ data sample yielded just one candidate event with a mass m/sub ex/ > 1.8 GeV. Significant limits are found for new neutrinos with masses from 1.8 to 6.7 GeV and with mixing parameters in the range 10/sup /minus/6/ < chemically bondUchemically bond/sup 2/ < 1. 12 refs., 4 figs.

Akerlof, C.; Chapman, J.; Errede, D.; Ken, M.T.; Meyer, D.I.; Neal, H.; Nitz, D.; Thun, R.; Tschirhart, R.; Derrick, M.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Triangular mass matrices for quarks and leptons  

E-Print Network (OSTI)

We assume that all quark and lepton $3 \\times 3$ mass matrices which appear in the standard model lagrangian (after spontaneous symmetry breaking) with neutrinos treated as Dirac patricles have the triangular form. Such matrices have not only less non-zero elements (three of them are equal to zero) but also lead to very asymmetrical decomposition into one diagonal and two unitary matrices for quarks and leptons. We also assume that unitary matrices which transform flavor into definite mass states for right handed components (weakly non-interacting) in the same weak isodoublet are equal. Using all available experimental data on quark and lepton masses and mixing angles, treating in the universal way quarks and leptons, we determine the triangular mass matrices for up and down type quarks, neutrinos and charged leptons and as a consequence mixing matrices for left-handed and right handed components. As the result of the fit we get predictions for the neutrino masses including smallest neutrino mass. The calculations without CP violation and with inclusion of this effect in quark sector are also presented.

S. Tatur; J. Bartelski

2006-05-24T23:59:59.000Z

202

A Lithium Experiment in the Program of Solar Neutrino Research  

E-Print Network (OSTI)

The experiments sensitive to pp-neutrinos from the Sun are very perspective for the precise measurement of a mixing angle $\\theta_{12}$. A $\

A. Kopylov; I. Orekhov; V. Petukhov; A. Solomatin

2006-01-12T23:59:59.000Z

203

Proton hexality from an anomalous flavor U(1) and neutrino masses--Linking to the string scale  

E-Print Network (OSTI)

Masses Linking to the String Scale* Herbi K. Dreiner 1 ,Masses Linking to the String Scale arXiv:0708.0989v2 [hep-allows the calculation of g string , g X and G SM s Ka? -

Dreiner, Herbi K.

2008-01-01T23:59:59.000Z

204

Multipartite entangled states in particle mixing  

Science Conference Proceedings (OSTI)

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

Blasone, M. [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (Italy); Dell'Anno, F.; De Siena, S. [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (Italy); CNR-INFM Coherentia, Napoli (Italy); Di Mauro, M. [INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (Italy); Illuminati, F. [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno, Baronissi (Italy); CNR-INFM Coherentia, Napoli (Italy); ISI Foundation for Scientific Interchange, Viale Settimio Severo 65, 00173 Torino (Italy)

2008-05-01T23:59:59.000Z

205

Multipartite entangled states in particle mixing  

E-Print Network (OSTI)

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

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

2007-11-14T23:59:59.000Z

206

Solar Neutrinos: Status and Prospects  

E-Print Network (OSTI)

We describe the current status of solar neutrino measurements and of the theory -- both neutrino physics and solar astrophysics -- employed in interpreting measurements. Important recent developments include Super-Kamiokande's determination of the neutrino-electron elastic scattering rate for 8B neutrinos to 3%; the latest SNO global analysis in which the inclusion of low-energy data from SNO I and II significantly narrowed the range of allowed values for the neutrino mixing angle theta12; Borexino results for both the 7Be and pep neutrino fluxes, the first direct measurements constraining the rate of ppI and ppII burning in the Sun; global reanalyses of solar neutrino data that take into account new reactor results on theta13; a new decadal evaluation of the nuclear physics of the pp chain and CNO cycle defining best values and uncertainties in the nuclear microphysics input to solar models; recognition of an emerging discrepancy between two tests of solar metallicity, helioseismological mappings of the soun...

Robertson, W C Haxton R G Hamish

2012-01-01T23:59:59.000Z

207

Water Mass Transformations in the Southern Ocean Diagnosed from Observations: Contrasting Effects of AirSea Fluxes and Diapycnal Mixing  

Science Conference Proceedings (OSTI)

Transformation and formation rates of water masses in the Southern Ocean are estimated in a neutral-surface framework using airsea fluxes of heat and freshwater together with in situ estimates of diapycnal mixing. The airsea fluxes are taken ...

Gualtiero Badin; Richard G. Williams; Zhao Jing; Lixin Wu

2013-07-01T23:59:59.000Z

208

Daya Bay Reactor Neutrino Project at NERSC  

NLE Websites -- All DOE Office Websites (Extended Search)

Daya Bay Reactor Neutrino Daya Bay Reactor Neutrino Experiment Daya Bay Reactor Neutrino Experiment Daya Bay is an international neutrino-oscillation experiment designed to determine the last unknown neutrino mixing angle θ13 using anti-neutrinos produced by the Daya Bay and Ling Ao Nuclear Power Plant reactors. The experiment is being built by blasting three kilometers of tunnel through the granite rock under the mountains where the power plants are located. Data collection is now scheduled to start in in 2011. On the PDSF cluster at NERSC, Daya Bay performs simulations of the detectors, reactors, and surrounding mountains to help design and anticipate detector properties and behavior. Once real data are available, Daya Bay will be using NERSC to analyze data and NERSC HPSS will be the central U.S. repository for all raw

209

Dynamical Collective Calculation of Supernova Neutrino Signals  

SciTech Connect

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

Gava, Jerome; Kneller, James; Volpe, Cristina; McLaughlin, G. C. [Institut de Physique Nucleaire, F-91406 Orsay cedex, CNRS/IN2P3 and University of Paris-XI (France); Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States)

2009-08-14T23:59:59.000Z

210

Resonant Spin-Flavor Precession Solution to the Solar Neutrino Problem and electron antineutrinos from the Sun  

E-Print Network (OSTI)

We have found allowed squared mass difference, magnetic field, mixing angle - regions for the Resonant Spin-Flavor Precession Solution to the Solar Neutrino Problem fitted with the data of all acting solar neutrino experiments. The typical mass difference region varying in dependence on the mixing angle is allowed for some discrete magnetic field regions in a wide range for the fixed neutrino transition magnetic moment. Except of the first allowed range with the lowest field strength the magnetic field amplitude within other discrete allowed regions depend essentially on the shape of a regular magnetic field profile in the convective zone of the Sun. For the non-zero neutrino mixing one can find at 99.9% C.L. an upper limit on the mixing, originated by the non-observation of electron antineutrinos in the SuperKamiokande detector. This limit occurs also sensitive to the magnetic field profile. While at 67% C.L. there is another more stringent upper limit coming from inconsistency of the gallium experiments with others. A new allowed region appears in the case of an additional assumption that the Homestake data are 1.3 times less than the experimental event rate.

A. A. Bykov; V. Yu. Popov; T. I. Rashba; V. B. Semikoz

2000-02-16T23:59:59.000Z

211

Pion condensation in a dense neutrino gas  

E-Print Network (OSTI)

We argue that using an equilibrated gas of neutrinos it is possible to probe the phase diagram of QCD for finite isospin and small baryon chemical potentials. We discuss this region of the phase diagram in detail and demonstrate that for large enough neutrino densities a Bose-Einstein condensate of positively charged pions arises. Moreover, we show that for nonzero neutrino density the degeneracy in the lifetimes and masses of the charged pions is lifted.

Hiroaki Abuki; Tomas Brauner; Harmen J. Warringa

2009-01-16T23:59:59.000Z

212

Measuring Neutrino Oscillations with Nuclear Reactors  

SciTech Connect

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

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

2007-10-26T23:59:59.000Z

213

Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing  

E-Print Network (OSTI)

June 25, 2010 Higgs Mass Constraints on a Fourth Family:and experimental limits on the Higgs boson mass restrict CKMGeV lower limit on the Higgs boson mass that is especially

Chanowitz, Michael S.

2010-01-01T23:59:59.000Z

214

Using MiniBooNE neutral current elastic cross section results to constrain 3+1 sterile neutrino models  

E-Print Network (OSTI)

The MiniBooNE Neutral Current Elastic (NCEL) cross section results are used to extract limits in the $\\Delta m^{2}-\\sin^{2}\\vartheta_{\\mu s}$ plane for a 3+1 sterile neutrino model with a mass splitting $0.1 \\leq \\Delta m^{2} \\leq 10.0$ eV$^{2}$. GENIE is used with a cross section model close to the one employed by MiniBooNE to make event rate predictions using simulations on the MiniBooNE target material CH$_{2}$. The axial mass is a free parameter in all fits. Sterile modifications to the flux and changes to the cross section in the simulation relate the two and allow limits to be set on sterile neutrino mixing using cross section results. The large axial mass problem makes it necessary for experiments to perform their own axial mass fits, but a prior fit to the same dataset could mask a sterile oscillation signal. Results are given with and without a penalty term on the axial mass from a prior fit. We find that a simultaneous fit to the axial mass and the sterile neutrino parameters favours very high axial mass values. The general problems that the current uncertainty on charged-current quasi-elastic (CCQE) cross sections at MiniBooNE energies pose for sterile neutrino measurements are discussed.

Callum Wilkinson; Susan Cartwright; Lee Thompson

2013-09-04T23:59:59.000Z

215

Future neutrino oscillation facilities: physics priorities and open issues  

E-Print Network (OSTI)

The recent discovery that neutrinos have mass opens a wide new field of experimentation. Accelerator-made neutrinos are essential. Ideas for future facilities include superbeams beta-beams and neutrino factories, each associated with one or several options for detector systems. A summary of the perceived virtues and shortcomings of these options, and a number of open questions, are presented.

Alain Blondel

2006-01-19T23:59:59.000Z

216

Extremely High Energy Neutrinos, Neutrino Hot Dark Matter, and the Highest Energy Cosmic Rays  

E-Print Network (OSTI)

Extremely high energy (up to 10**(22) eV) cosmic neutrino beams initiate high energy particle cascades in the background of relic neutrinos from the Big Bang. We perform numerical calculations to show that such cascades could contribute more than 10% to the observed cosmic ray flux above 10**(19) eV if neutrinos have masses in the electron volt range. The required intensity of primary neutrinos could be consistent with astrophysical models for their production if the maximum neutrino energy reaches to 10**(22) eV and the massive neutrino dark matter is locally clustered. Future observations of ultra high energy cosmic rays will lead to an indirect but practical search for neutrino dark matter.

Shigeru Yoshida; Guenter Sigl; Sangjin Lee

1998-08-14T23:59:59.000Z

217

Why Are Neutrinos Light? -- An Alternative  

SciTech Connect

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

Hall, Lawrence J.; Oliver, Steven J.

2004-09-23T23:59:59.000Z

218

Solar Neutrinos  

E-Print Network (OSTI)

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

R. G. H. Robertson

2006-02-05T23:59:59.000Z

219

Solar Neutrinos: Status and Prospects  

E-Print Network (OSTI)

We describe the current status of solar neutrino measurements and of the theory -- both neutrino physics and solar astrophysics -- employed in interpreting measurements. Important recent developments include Super-Kamiokande's determination of the neutrino-electron elastic scattering rate for 8B neutrinos to 3%; the latest SNO global analysis in which the inclusion of low-energy data from SNO I and II significantly narrowed the range of allowed values for the neutrino mixing angle theta12; Borexino results for both the 7Be and pep neutrino fluxes, the first direct measurements constraining the rate of ppI and ppII burning in the Sun; global reanalyses of solar neutrino data that take into account new reactor results on theta13; a new decadal evaluation of the nuclear physics of the pp chain and CNO cycle defining best values and uncertainties in the nuclear microphysics input to solar models; recognition of an emerging discrepancy between two tests of solar metallicity, helioseismological mappings of the sound speed in the solar interior, and analyses of the metal photoabsorption lines based on our best current description of the Sun's photosphere; a new round of standard solar model calculations optimized to agree either with helioseismology or with the new photospheric analysis; and, motivated by the solar abundance problem, the development of nonstandard, accreting solar models, in order to investigate possible consequences of the metal segregation that occurred in the proto-solar disk. We review this progress and describe how new experiments such as SNO+ could help us further exploit neutrinos as a unique probe of stellar interiors.

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

2012-08-28T23:59:59.000Z

220

Flavor oscillations of low energy neutrinos in the rotating neutron star  

E-Print Network (OSTI)

We study flavor oscillations of low energy neutrinos propagating in dense matter of a rotating neutron star. On the basis of the exact solutions of the wave equations for neutrinos mass eigenstates we derive the transition probability for neutrinos having big initial angular momentum. It is found that flavor oscillations of neutrinos with energies of several electron-Volts can be resonancely enhanced.

Maxim Dvornikov

2010-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

Science Conference Proceedings (OSTI)

Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillation - a channel that may yield insight into the vanishingly small mixing parameter {theta}{sub 13}, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single {pi}{sup 0} (NC 1{pi}{sup 0}) production. Unfortunately, the available data concerning NC 1{pi}{sup 0} production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1{pi}{sup 0} production yield substantially differing predictions in the critical E{sub {nu}} {approx} 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data ({approx} 10{sup 6} neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns the measurement of both neutrino and antineutrino NC 1{pi}{sup 0} production cross sections at MiniBooNE. The size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the first measurements of the absolute NC 1{pi}{sup 0} cross section as well as the first differential cross sections in both neutrino and antineutrino mode. Specifically, we measure single differential cross sections with respect to pion momentum and pion angle. We find the flux-averaged, total cross sections for NC 1{pi}{sup 0} production on CH{sub 2} to be (4.76 {+-} 0.05{sub stat} {+-} 0.76{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at = 808 MeV for neutrino induced production and (1.48 {+-} 0.05{sub stat} {+-} 0.23{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at = 664 MeV for antineutrino induced production.

Anderson, Colin; /Yale U.

2010-12-01T23:59:59.000Z

222

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

SciTech Connect

Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillation - a channel that may yield insight into the vanishingly small mixing parameter {theta}{sub 13}, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single {pi}{sup 0} (NC 1{pi}{sup 0}) production. Unfortunately, the available data concerning NC 1{pi}{sup 0} production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1{pi}{sup 0} production yield substantially differing predictions in the critical E{sub {nu}} {approx} 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data ({approx} 10{sup 6} neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns the measurement of both neutrino and antineutrino NC 1{pi}{sup 0} production cross sections at MiniBooNE. The size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the first measurements of the absolute NC 1{pi}{sup 0} cross section as well as the first differential cross sections in both neutrino and antineutrino mode. Specifically, we measure single differential cross sections with respect to pion momentum and pion angle. We find the flux-averaged, total cross sections for NC 1{pi}{sup 0} production on CH{sub 2} to be (4.76 {+-} 0.05{sub stat} {+-} 0.76{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at = 808 MeV for neutrino induced production and (1.48 {+-} 0.05{sub stat} {+-} 0.23{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at = 664 MeV for antineutrino induced production.

Anderson, Colin; /Yale U.

2010-12-01T23:59:59.000Z

223

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

DOE Data Explorer (OSTI)

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

SAGE Collaboration

224

Masatoshi Koshiba and Cosmic Neutrinos  

Office of Scientific and Technical Information (OSTI)

Masatoshi Koshiba and Cosmic Neutrinos Masatoshi Koshiba and Cosmic Neutrinos Resources with Additional Information Masatoshi Koshiba Courtesy of Sebastian Brandt 'The 2002 Nobel Prize in Physics has been awarded to ... Masatoshi Koshiba of the International Center for Elementary Particle Physics at the University of Tokyo in Japan, ... "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos." ... Neutrinos are important in astrophysics since they might have played a considerable role in shaping early galaxies; they are the form of energy coming directly from the solar core; and they account for the largest share of energy released during supernova explosions....'1 ...Koshiba, professor emeritus at the University of Tokyo, received his doctorate from the University of Rochester in [1955]. This year [2000], he is the co-recipient of the Wolf Prize in Physics, considered second only to the Nobel Prize in prestige, for his discovery that neutrinos have mass. Neutrinos are tiny particles smaller than atoms, and Koshiba's discovery is being hailed for its ramifications in the study of astronomical objects and the fundamental properties of matter, helping scientists to understand the birth of the universe. Koshiba started his career as a research associate at the University of Rochester, then went on to teach at the University of Tokyo." 2

225

Sterile neutrinos in the 3+s scenario and solar data  

E-Print Network (OSTI)

The flatness of the SuperKamiokande neutrino electron scattering spectrum and the apparent downturn of the charged current spectrum in the SNO data which the Large Mixing Angle solution (LMA) to the solar neutrino problem fails to predict are analysed in the context of an extension to the standard electroweak model with light sterile neutrinos. It is found that a sterile neutrino which is quasi degenerate with the active ones with $\\Delta m^2_{41}=10^{-5}eV^2$ and mixing $sin\\theta_{14}=0.04$ provides a suitable improvement to the LMA data fits.

Pulido, Joao

2013-01-01T23:59:59.000Z

226

Sterile neutrinos in the 3+s scenario and solar data  

E-Print Network (OSTI)

The flatness of the SuperKamiokande neutrino electron scattering spectrum and the apparent downturn of the charged current spectrum in the SNO data which the Large Mixing Angle solution (LMA) to the solar neutrino problem fails to predict are analysed in the context of an extension to the standard electroweak model with light sterile neutrinos. It is found that a sterile neutrino which is quasi degenerate with the active ones with $\\Delta m^2_{41}=10^{-5}eV^2$ and mixing $sin\\theta_{14}=0.04$ provides a suitable improvement to the LMA data fits.

Joao Pulido; C. R. Das

2013-10-01T23:59:59.000Z

227

Noncommutative Theory in Light of Neutrino Oscillation  

E-Print Network (OSTI)

Solar neutrino problem and atmospheric neutrino anomaly which are both long-standing issues studied intensively by physicists in the past several decades, are reckoned to be able to be solved simultaneously in the framework of the assumption of the neutrino oscillation. For the presence of the Lorentz invariance in the Standard Model, the massless neutrino can't have flavor mixing and oscillation. However, we exploit the q-deformed noncommutative theory to derive a general modified dispersion relation, which implies some violation of the Lorentz invariance. Then it is found that the application of the q-deformed dispersion relation to the neutrino oscillation can provide a sound explanation for the current data from the reactor and long baseline experiments.

Shao-Xia Chen; Zhao-Yu Yang

2003-12-07T23:59:59.000Z

228

Propagation of Neutrinos through Magnetized Gamma-Ray Burst Fireball  

E-Print Network (OSTI)

The neutrino self-energy is calculated in a weakly magnetized plasma consists of electrons, protons, neutrons and their anti-particles and using this we have calculated the neutrino effective potential up to order $M^{-4}_W$. In the absence of magnetic field it reduces to the known result. We have also calculated explicitly the effective potentials for different backgrounds which may be helpful in different environments. By considering the mixing of three active neutrinos in the medium with the magnetic field we have derived the survival and conversion probabilities of neutrinos from one flavor to another and also the resonance condition is derived. As an application of the above, we considered the dense and relativistic plasma of the Gamma-Ray Bursts fireball through which neutrinos of 5-30 MeV can propagate and depending on the fireball parameters they may oscillate resonantly or non-resonantly from one flavor to another. These MeV neutrinos are produced due to stellar collapse or merger events which trigger the Gamma-Ray Burst. The fireball itself also produces MeV neutrinos due to electron positron annihilation, inverse beta decay and nucleonic bremsstrahlung. Using the three neutrino mixing and considering the best fit values of the neutrino parameters, we found that electron neutrinos are hard to oscillate to another flavors. On the other hand, the muon neutrinos and the tau neutrinos oscillate with equal probability to one another, which depends on the neutrino energy, temperature and size of the fireball. Comparison of oscillation probabilities with and without magnetic field shows that, they depend on the neutrino energy and also on the size of the fireball. By using the resonance condition, we have also estimated the resonance length of the propagating neutrinos as well as the baryon content of the fireball.

Sarira Sahu; Nissim Fraija; Yong-Yeon Keum

2009-09-16T23:59:59.000Z

229

Multipartite entangled states in particle mixing  

E-Print Network (OSTI)

In the physics of flavor mixing, the flavor states are expressed as superpositions of mass eigenstates. By using the occupation number to define a multiqubit space, the flavor states can be interpreted as multipartite mode-entangled states. By exploiting a suitable global measure of entanglement, based on the entropies related to all possible bipartitions of the system, we analyze the correlation properties of such states in the instances of three- and four-flavor mixing. Depending on the mixing parameters, and, in particular, on the values taken by the free phases, responsible for the CP-violation, entanglement concentrates in certain bipartitions. We quantify in detail the amount and the distribution of entanglement in the physically relevant cases of flavor mixing in quark and neutrino systems.

Blasone, M; De Siena, S; Di Mauro, M; Illuminati, F

2007-01-01T23:59:59.000Z

230

Measuring Active-Sterile Neutrino Oscillations with a Stopped Pion Neutrino Source  

E-Print Network (OSTI)

The question of the existence of light sterile neutrinos is of great interest in many areas of particle physics, astrophysics, and cosmology. Furthermore, should the MiniBooNE experiment at Fermilab confirm the LSND oscillation signal, then new measurements are required to identify the mechanism responsible for these oscillations. Possibilities include sterile neutrinos, CP or CPT violation, variable mass neutrinos, Lorentz violation, and extra dimensions. In this paper, we consider an experiment at a stopped pion neutrino source to determine if active-sterile neutrino oscillations with delta-m greater than 0.1 eV2 can account for the signal. By exploiting stopped pi+ decay to produce a monoenergetic nu_mu source, and measuring the rate of the neutral current reaction nu_x + 12C -> nu_x +12C* as a function of distance from the source, we show that a convincing test for active-sterile neutrino oscillations can be performed.

G. T. Garvey; A. Green; C. Green; W. C. Louis; G. B. Mills; G. McGregor; H. Ray; R. Schirato; R. G. Van de Water; D. H. White

2005-01-03T23:59:59.000Z

231

Neutrino and Electron-positron Pair Emission from Phase-induced Collapse of Neutron Stars to Quark Stars  

E-Print Network (OSTI)

We study the energy released from phase-transition induced collapse of neutron stars, which results in large amplitude stellar oscillations. To model this process we use a Newtonian hydrodynamic code, with a high resolution shock-capturing scheme. The physical process considered is a sudden phase transition from normal nuclear matter to a mixed phase of quark and nuclear matter. We show that both the temperature and the density at the neutrinosphere oscillate with time. However, they are nearly 180 degree out of phase. Consequently, extremely intense, pulsating neutrino/antineutrino and leptonic pair fluxes will be emitted. During this stage several mass ejecta can be ejected from the stellar surface by the neutrinos and antineutrinos. These ejecta can be further accelerated to relativistic speeds by the electron/positron pairs, created by the neutrino and antineutrino annihilation outside the stellar surface. We suggest that this process may be a possible mechanism for short Gamma-Ray Bursts.

Cheng, K S

2010-01-01T23:59:59.000Z

232

Countintg Extra Dimensions: Magnetic Cherenkov Radiation from High Energy Neutrinos  

E-Print Network (OSTI)

In theories which require a space of dimension d>4, there is a natural mechanism of suppressing neutrino masses: while Standard Model fields are confined to a 3-brane, right handed neutrinos live in the bulk. Due to Kaluza-Klein excitations, the effective magnetic moments of neutrinos are enhanced. The effective magnetic moment is a monotonically growing function of the energy of the neutrino: consequently, high energy neutrinos can emit observable amounts of magnetic Cherenkov radiation. By observing the energy dependence of the magnetic Cherenkov radiation, one may be able to determine the number of compactified dimensions.

G. Domokos; Andrea Erdas; S. Kovesi-Domokos

2002-12-30T23:59:59.000Z

233

Evolution of the Vertical Mass Flux and Diagnosed Net Lateral Mixing in Isolated Convective Clouds  

Science Conference Proceedings (OSTI)

The evolution of the vertical mass flux in isolated cumulus and cumulus congestus clouds is documented using two King Airs during the Convection and Precipitation/Electrification Experiment (CaPE,), conducted in east-central Florida during the ...

Gary M. Barnes; James C. Fankhauser; Wesley D. Browning

1996-12-01T23:59:59.000Z

234

Solar Neutrinos in 2011  

E-Print Network (OSTI)

I give an overview of the recent developments in the solar neutrino field. I focus on the Borexino detector, which has uncovered the solar neutrino spectrum below 5 MeV, providing new tests and confirmation for solar neutrino oscillations. I report on the updated measurements of the 8B solar neutrino flux by water Cherenkov and organic scintillator detectors. I review the precision measurement of the 7Be solar neutrino flux by Borexino and the search for its day-night asymmetry. I present Borexino's latest result on the study of pep and CNO neutrinos. Finally, I discuss the outstanding questions in the field and future solar neutrino experiments.

Chavarria, Alvaro

2012-01-01T23:59:59.000Z

235

Quantifying the Role of Mixed Layer Entrainment for Water Mass Transformation in the North Atlantic  

Science Conference Proceedings (OSTI)

Forcing by wind stress and airsea buoyancy flux climatologies between ?t = 23.5 and 26.5 results in differing water mass transformations in the North Atlantic, reflecting the opposing tendencies of wind stress and airsea fluxes. This difference ...

Amit Tandon; Konstantin Zahariev

2001-04-01T23:59:59.000Z

236

Neutrino Spectroscopy with Atoms and Molecules  

E-Print Network (OSTI)

We give a comprehensive account of our proposed experimental method of using atoms or molecules in order to measure parameters of neutrinos still undetermined; the absolute mass scale, the mass hierarchy pattern (normal or inverted), the neutrino mass type (Majorana or Dirac), and the CP violating phases including Majorana phases. There are advantages of atomic targets, due to the closeness of available atomic energies to anticipated neutrino masses, over nuclear target experiments. Disadvantage of using atomic targets, the smallness of rates, is overcome by the macro-coherent amplification mechanism. The atomic or molecular process we use is a cooperative deexcitation of a collective body of atoms in a metastable level |e> emitting a neutrino pair and a photon; |e> -> |g> + gamma + nu_i nu_j where nu_i's are neutrino mass eigenstates. The macro-coherence is developed by trigger laser irradiation. We discuss aspects of the macro-coherence development by setting up the master equation for the target quantum state and propagating electric field. With a choice of heavy target atom or molecule such as Xe or I_2 that has a large M1 x E1 matrix element between |e> and |g>, we show that one can determine three neutrino masses along with the mass hierarchy pattern by measuring the photon spectral shape. If one uses a target of available energy of a fraction of 1 eV, Majorana CP phases may be determined. Our master equation, when applied to E1 x E1 transition such as pH_2 vibrational transition Xv=1 -> 0, can describe explosive PSR events in which most of the energy stored in |e> is released within a few nanoseconds. The present paper is intended to be self-contained explaining some details related theoretical works in the past, and further reports new simulations and our ongoing experimental efforts of the project to realize the neutrino mass spectroscopy using atoms/molecules.

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

2012-11-21T23:59:59.000Z

237

Cosmological lepton asymmetry with a nonzero mixing angle $\\theta_{13}$  

E-Print Network (OSTI)

While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of the latest cosmological data, taking into account the effect of flavor oscillations. We present our results for two different values of the neutrino mixing angle \\theta_{13}, and show that for large \\theta_{13} the limits on the total neutrino asymmetry become more stringent, diluting even large initial flavor asymmetries. In particular, we find that the present bounds are still dominated by the limits coming from Big Bang Nucleosynthesis, while the limits on the total neutrino mass from cosmological data are essentially independent of \\theta_{13}. Finally, we perform a forecast for COrE, taken as an example of a future CMB experiment, and find that it could improve the limits on the total lepton asymmetry approximately by up to a factor 5.

Castorina, Emanuele; Lattanzi, Massimiliano; Lesgourgues, Julien; Mangano, Gianpiero; Melchiorri, Alessandro; Pastor, Sergio

2012-01-01T23:59:59.000Z

238

EFFECTS OF ALTERNATE ANTIFOAM AGENTS, NOBLE METALS, MIXING SYSTEMS AND MASS TRANSFER ON GAS HOLDUP AND RELEASE FROM NONNEWTONIAN SLURRIES  

Science Conference Proceedings (OSTI)

Gas holdup tests performed in a small-scale mechanically-agitated mixing system at the Savannah River National Laboratory (SRNL) were reported in 2006. The tests were for a simulant of waste from the Hanford Tank 241-AZ-101 and featured additions of DOW Corning Q2-3183A Antifoam agent. Results indicated that this antifoam agent (AFA) increased gas holdup in the waste simulant by about a factor of four and, counter intuitively, that the holdup increased as the simulant shear strength decreased (apparent viscosity decreased). These results raised questions about how the AFA might affect gas holdup in Hanford Waste Treatment and Immobilization Plant (WTP) vessels mixed by air sparging and pulse-jet mixers (PJMs). And whether the WTP air supply system being designed would have the capacity to handle a demand for increased airflow to operate the sparger-PJM mixing systems should the AFA increase retention of the radiochemically generated flammable gases in the waste by making the gas bubbles smaller and less mobile, or decrease the size of sparger bubbles making them mix less effectively for a given airflow rate. A new testing program was developed to assess the potential effects of adding the DOW Corning Q2-3183A AFA to WTP waste streams by first confirming the results of the work reported in 2006 by Stewart et al. and then determining if the AFA in fact causes such increased gas holdup in a prototypic sparger-PJM mixing system, or if the increased holdup is just a feature of the small-scale agitation system. Other elements of the new program include evaluating effects other variables could have on gas holdup in systems with AFA additions such as catalysis from trace noble metals in the waste, determining mass transfer coefficients for the AZ-101 waste simulant, and determining whether other AFA compositions such as Dow Corning 1520-US could also increase gas holdup in Hanford waste. This new testing program was split into two investigations, prototypic sparger-PJM tests and modeling being conducted at the Pacific Northwest National Laboratory (PNNL), and small-scale agitation tests and evaluations of effects waste and AFA ingredients have on gas retention and mass transfer being conducted at SRNL. Only work conducted at SRNL is reported here. Key results are: (1) The unexpected gas holdup behavior reported in 2006 for a small-scale agitation system is confirmed. The gas holdup data from small-scale and bench-scale impeller-type mixing systems reported herein show very different trends than the behavior exhibited by the prototypic sparger-PJM mixing system tested in the PNNL APEL facility. Results obtained from testing this 1/4-scale prototypic mixing system will be reported by PNNL. The reason for this difference in holdup behavior between the two different mixing systems is not known at this time. Consequently, data from the small mechanical agitation systems should not be extrapolated to prototypic plant conditions. (2) Bench-scale and small-scale tests conducted with Dow Corning 1520-US AFA show it to be a viable replacement to Dow Corning Q2-3183A AFA. This alternative AFA will, however, require significantly higher dosage (concentration) to perform the same antifoam function. (3) Addition of noble metals to the AZ-101 waste simulant does not produce a catalytic gas retention effect with the AFA. The Gas holdup is similar whether or not noble metals are present in the AZ-101 simulant. (4) Mass transfer tests were performed in a large (0.76 m diameter) bubble column filled to 1.3, 3.4, and 7.4 m elevations with water and the AZ-101 waste simulant. Mass transfer coefficients for air bubbles emanating from a prototypic 0.051 m diameter sparger were obtained from the transient decay of dissolved oxygen concentration in the initially saturated fluids. Adding AFA to water reduces the mass transfer coefficient slightly. AFA addition reduces the mass transfer coefficient for AZ-101 simulant more than it does for water because the shear strength of the simulant allows for larger bubble sizes, and larger bubbles have smaller surf

Guerrero, H; Mark Fowley, M; Charles Crawford, C; Michael Restivo, M; Robert Leishear, R

2007-12-24T23:59:59.000Z

239

Solar neutrino oscillations and indications of matter effects in the Sun  

E-Print Network (OSTI)

Assuming the current best-fit solutions to the solar neutrino problem at large mixing angle, we briefly illustrate how prospective data from the Sudbury Neutrino Observatory (SNO) and from the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) can increase our confidence in the occurrence of standard matter effects on active neutrino flavor oscillations in the Sun, which are starting to emerge from current data.

G. L. Fogli; E. Lisi; A. Palazzo; A. M. Rotunno

2002-11-26T23:59:59.000Z

240

Longevity Problem of Sterile Neutrino Dark Matter  

E-Print Network (OSTI)

Sterile neutrino dark matter of mass O(1-10) keV decays into an active neutrino and an X-ray photon, and the non-observation of the corresponding X-ray line requires the sterile neutrino to be more long-lived than estimated based on the seesaw formula : the longevity problem. We show that, if one or more of the B-L Higgs fields are charged under a flavor symmetry (or discrete R symmetry), the split mass spectrum for the right-handed neutrinos as well as the required longevity is naturally realized. We provide several examples in which the predicted the X-ray flux is just below the current bound.

Hiroyuki Ishida; Kwang Sik Jeong; Fuminobu Takahashi

2013-09-12T23:59:59.000Z

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241

Quantization in relativistic classical mechanics: the Stueckelberg equation, neutrino oscillation and large-scale structure of the Universe  

E-Print Network (OSTI)

Based on the Chetaev theorem on stable dynamical trajectories in the presence of dissipative forces, we obtain the generalized condition for stability of relativistic classical Hamiltonian systems (with an invariant evolution parameter) in the form of the Stueckelberg equation. As is known, this equation is the basis of a competing paradigm known as parametrized relativistic quantum mechanics (pRQM). It is shown that the energy of dissipative forces, which generate the Chetaev generalized condition of stability, coincides exactly with Bohmian relativistic quantum potential. We show that the squared amplitude of a wave function in the Stueckelberg equation is equivalent to the probability density function for the number of particle trajectories, relative to which the velocity and the position of the particle are not hidden parameters. The conditions for reasonableness of trajectory interpretation of pRQM are discussed. On basis of analysis of a general formalism for vacuum-flavor mixing of neutrino within the context of the standard and pRQM models we show that the corresponding expressions for the probability of transition from one neutrino flavor to another differ appreciably, but they are experimentally testable: the estimations of absolute value for neutrino mass based on modern experimental data for solar and atmospheric neutrinos show that the pRQM results have a preference. It is noted that the selection criterion of mass solutions relies on proximity between the average size of condensed neutrino clouds, which is described by the Muraki formula (29th ICRC, 2005) and depends on the neutrino mass, and the average size of typical observed void structure (dark matter + hydrogen gas), which plays the role of characteristic dimension of large-scale structure of the Universe.

V. D. Rusov; D. S. Vlasenko

2012-02-07T23:59:59.000Z

242

Precision spectroscopy with reactor anti-neutrinos  

E-Print Network (OSTI)

In this work we present an accurate parameterization of the anti-neutrino flux produced by the isotopes 235U, 239Pu and 241Pu in nuclear reactors. We determine the coefficients of this parameterization, as well as their covariance matrix, by performing a fit to spectra inferred from experimentally measured beta spectra. Subsequently we show that flux shape uncertainties play only a minor role in the KamLAND experiment, however, we find that future reactor neutrino experiments to measure the mixing angle $\\theta_{13}$ are sensitive to the fine details of the reactor neutrino spectra. Finally, we investigate the possibility to determine the isotopic composition in nuclear reactors through an anti-neutrino measurement. We find that with a 3 month exposure of a one ton detector the isotope fractions and the thermal reactor power can be determined at a few percent accuracy, which may open the possibility of an application for safeguard or non-proliferation objectives.

Huber, P; Huber, Patrick; Schwetz, Thomas

2004-01-01T23:59:59.000Z

243

STANDARD SOLAR NEUTRINOS  

E-Print Network (OSTI)

The predictions of an improved standard solar model are compared with the observations of the four solar neutrino experiments. The improved model includes premain sequence evolution, element diffusion, partial ionization effects, and all the possible nuclear reactions between the main elements. It uses updated values for the initial solar element abundances, the solar age, the solar luminosity, the nuclear reaction rates and the radiative opacities. Neither nuclear equilibrium, nor complete ionization are assumed. The calculated 8 B solar neutrino flux is consistent, within the theoretical and experimental uncertainties, with the solar neutrino flux measured by Kamiokande. The results from the 37 Cl and 71 Ga radiochemical experiments seem to suggest that the terrestrial 7 Be solar neutrino flux is much smaller than that predicted. However, the present terrestrial defecit of 7 Be solar neutrinos may be due to the use of inaccurate theoretical neutrino absorption cross sections near threshold for extracting solar neutrino fluxes from production rates. Conclusive evidence for a real deficit of 7 Be solar neutrinos will require experiments such as BOREXINO or HELLAZ. A real defecit of 7 Be solar neutrinos can be due to either astrophysical reasons or neutrino properties beyond the standard electroweak model. Only future neutrino experiments, such as SNO, Superkamiokande, BOREXINO and HELLAZ, will be able to provide conclusive evidence that the solar neutrino problem is a consequence of neutrino properties beyond the standard electroweak model. Earlier indications may be provided by long baseline neutrino oscillation experiments. 1

Arnon Dar

2008-01-01T23:59:59.000Z

244

Reactor Neutrino Experiments with a Large Liquid Scintillator Detector  

E-Print Network (OSTI)

We discuss several new ideas for reactor neutrino oscillation experiments with a Large Liquid Scintillator Detector. We consider two different scenarios for a measurement of the small mixing angle $\\theta_{13}$ with a mobile $\\bar{\

Joachim Kopp; Manfred Lindner; Alexander Merle; Mark Rolinec

2006-06-13T23:59:59.000Z

245

The particle world - neutrinos | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

What are neutrinos telling us? What are neutrinos telling us? NuMI/MINOS NuMI is a facility at Fermilab that produces an intense beam of neutrinos for MINOS, an experiment that promises to unlock the many secrets of this most mysterious particle. (Credit: Fermilab) Tools for a scientific revolution The discovery that neutrinos have mass opens a window on physics beyond the Standard Model. The Standard Model cannot accommodate neutrino masses without the introduction of new particles, which themselves raise new questions. In fact, the size of the neutrino masses is consistent with expectations from unified theories that require the new particles for the unification itself. The most pressing question about neutrinos involves how many different kinds there are. Results from the Liquid Scintillator Neutrino Detector

246

HIggs Boson Mass in the Minimal Unified Subquark Model  

E-Print Network (OSTI)

In the original paper entitled, "Masses of Fundamental Particles", not only the masses of fundamental particles including the weak bosons, Higgs scalar, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite model of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

Hidezumi Terazawa

2011-09-17T23:59:59.000Z

247

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

SciTech Connect

Massive stars end their lives in explosions with kinetic energies on the order of 10{sup 51} erg. Immediately after the explosion has been launched, a region of low density and high entropy forms behind the ejecta, which is continuously subject to neutrino heating. The neutrinos emitted from the remnant at the center, the protoneutron star (PNS), heat the material above the PNS surface. This heat is partly converted into kinetic energy, and the material accelerates to an outflow that is known as the neutrino-driven wind. For the first time we simulate the collapse, bounce, explosion, and the neutrino-driven wind phases consistently over more than 20 s. Our numerical model is based on spherically symmetric general relativistic radiation hydrodynamics using spectral three-flavor Boltzmann neutrino transport. In simulations where no explosions are obtained naturally, we model neutrino-driven explosions for low- and intermediate-mass Fe-core progenitor stars by enhancing the charged current reaction rates. In the case of a special progenitor star, the 8.8 M{circle_dot} O-Ne-Mg-core, the explosion in spherical symmetry was obtained without enhanced opacities. The post-explosion evolution is in qualitative agreement with static steady-state and parametrized dynamic models of the neutrino-driven wind. On the other hand, we generally find lower neutrino luminosities and mean neutrino energies, as well as a different evolutionary behavior of the neutrino luminosities and mean neutrino energies. The neutrino-driven wind is proton-rich for more than 10 s and the contraction of the PNS differs from the assumptions made for the conditions at the inner boundary in previous neutrino-driven wind studies. Despite the moderately high entropies of about 100 k{sub B}/baryon and the fast expansion timescales, the conditions found in our models are unlikely to favor r-process nucleosynthesis. The simulations are carried out until the neutrino-driven wind settles down to a quasi-stationary state. About 5 s after the bounce, the peak temperature inside the PNS already starts to decrease because of the continued deleptonization. This moment determines the beginning of a cooling phase dominated by the emission of neutrinos. We discuss the physical conditions of the quasi-static PNS evolution and take the effects of deleptonization and mass accretion from early fallback into account.

Fischer, T. [University of Basel; Mezzacappa, Anthony [ORNL; Thielemann, F.-K. [University of Basel; Liebendoerfer, M. [University of Basel; Whitehouse, S. [University of Basel

2010-01-01T23:59:59.000Z

248

Neutrino Nucleosynthesis in Supernovae  

Science Conference Proceedings (OSTI)

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

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

2009-05-04T23:59:59.000Z

249

Detecting Tau Neutrino Oscillations at PeV Energies  

E-Print Network (OSTI)

It is suggested that a large deep underocean (or ice) neutrino detector, given the presence of significant numbers of neutrinos in the PeV energy range as predicted by various models of Active Galactic Nuclei, can make unique measurements of the properties of neutrinos. It will be possible to observe the existence of the tau neutrino, measure its mixing with other flavors, in fact test the mixing pattern for all three flavors based upon the mixing parameters suggested by the atmospheric and solar neutrino data, and measure the tau neutrino cross section. The key signature is the charged current tau neutrino interaction, which produces a double cascade, one at either end of a lightly radiating track. At a few PeV these cascades would be separated by roughly 100 m, and thus be easily resolvable in next generation DUMAND-like detectors. First examples might be found in detectors presently under construction. Future applications are precise neutrino astronomy and earth tomography. This paper is an expanded version of hep-ph/9405296, for publication.

John G. Learned; Sandip Pakvasa

1994-08-16T23:59:59.000Z

250

Report of the Solar and Atmospheric Neutrino Working Group  

SciTech Connect

The highest priority of the Solar and Atmospheric Neutrino Experiment Working Group is the development of a real-time, precision experiment that measures the pp solar neutrino flux. A measurement of the pp solar neutrino flux, in comparison with the existing precision measurements of the high energy {sup 8}B neutrino flux, will demonstrate the transition between vacuum and matter-dominated oscillations, thereby quantitatively testing a fundamental prediction of the standard scenario of neutrino flavor transformation. The initial solar neutrino beam is pure {nu}{sub e}, which also permits sensitive tests for sterile neutrinos. The pp experiment will also permit a significantly improved determination of {theta}{sub 12} and, together with other solar neutrino measurements, either a measurement of {theta}{sub 13} or a constraint a factor of two lower than existing bounds. In combination with the essential pre-requisite experiments that will measure the {sup 7}Be solar neutrino flux with a precision of 5%, a measurement of the pp solar neutrino flux will constitute a sensitive test for non-standard energy generation mechanisms within the Sun. The Standard Solar Model predicts that the pp and {sup 7}Be neutrinos together constitute more than 98% of the solar neutrino flux. The comparison of the solar luminosity measured via neutrinos to that measured via photons will test for any unknown energy generation mechanisms within the nearest star. A precise measurement of the pp neutrino flux (predicted to be 92% of the total flux) will also test stringently the theory of stellar evolution since the Standard Solar Model predicts the pp flux with a theoretical uncertainty of 1%. We also find that an atmospheric neutrino experiment capable of resolving the mass hierarchy is a high priority. Atmospheric neutrino experiments may be the only alternative to very long baseline accelerator experiments as a way of resolving this fundamental question. Such an experiment could be a very large scale water Cerenkov detector, or a magnetized detector with flavor and antiflavor sensitivity. Additional priorities are nuclear physics measurements which will reduce the uncertainties in the predictions of the Standard Solar Model, and similar supporting measurements for atmospheric neutrinos (cosmic ray fluxes, magnetic fields, etc.). We note as well that the detectors for both solar and atmospheric neutrino measurements can serve as multipurpose detectors, with capabilities of discovering dark matter, relic supernova neutrinos, proton decay, or as targets for long baseline accelerator neutrino experiments.

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

2004-10-22T23:59:59.000Z

251

Effect of Collective Neutrino Oscillations on the Neutrino Mechanism of Core-Collapse Supernovae  

E-Print Network (OSTI)

In the seconds after collapse of a massive star, the newborn proto-neutron star (PNS) radiates neutrinos of all flavors. The absorption of electron-type neutrinos below the radius of the stalled shockwave may drive explosions (the "neutrino mechanism"). Because the heating rate is proportional to the square of neutrino energy, flavor conversion of mu and tau neutrinos to electron-type neutrinos via collective neutrino oscillations (CnuO) may in principle increase the heating rate and drive explosions. In order to assess the potential importance of CnuO for the shock revival, we solve the steady-state boundary value problem of spherically-symmetric accretion between the PNS surface (r_nu) and the shock (r_S), including a scheme for flavor conversion via CnuO. For a given r_nu, PNS mass (M), accretion rate (Mdot), and assumed values of the neutrino energies from the PNS, we calculate the critical neutrino luminosity above which accretion is impossible and explosion results. We show that CnuO can decrease the critical luminosity by a factor of at most ~1.5, but only if the flavor conversion is fully completed inside r_S and if there is no matter suppression. The magnitude of the effect depends on the model parameters (M, Mdot, and r_nu) through the shock radius and the physical scale for flavor conversion. We quantify these dependencies and find that CnuO could lower the critical luminosity only for small M and Mdot, and large r_nu. However, for these parameter values CnuO are suppressed due to matter effects. By quantifying the importance of CnuO and matter suppression at the critical neutrino luminosity for explosion, we show in agreement with previous studies that CnuO are unlikely to affect the neutrino mechanism of core-collapse supernovae significantly.

Ondrej Pejcha; Basudeb Dasgupta; Todd A. Thompson

2011-06-28T23:59:59.000Z

252

BNL | Neutrino Research History  

NLE Websites -- All DOE Office Websites (Extended Search)

Brookhaven Neutrino Research Brookhaven Neutrino Research image of neutrinos Tens of billions of neutrinos are passing through every square centimeter of the Earth's surface right now. A Ghost-Particle Retrospective Neutrinos, ghostlike particles that flooded the universe just moments after the Big Bang, are born in the hearts of stars and other nuclear reactions. Untouched by electromagnetism and nearly as fast as light, neutrinos pass practically unhindered through everything from planets to people, only rarely responding to the weak nuclear force and the even weaker gravity. In fact, at any given moment, tens of billions of neutrinos are passing through every square centimeter of the Earth's surface. Neutrino Research News photomultiplier tubes New Results from Daya Bay: Tracking the Disappearance of Ghostlike

253

Outlook on Neutrino Physics  

E-Print Network (OSTI)

Some of the hot topics in neutrino physics are discussed, with particular emphasis on neutrino oscillations. After proposing credibility criteria for assessing various claimed effects, particular stress is laid on the solar neutrino deficit, which seems unlikely to have an astrophysical explanation. Comments are also made on the possibility of atmospheric neutrino oscillations and on the LSND experiment, as well as cosmological aspects of neutrinos and neutralinos. Several of the central issues in neutrino physics may be resolved by the new generation of experiments now underway, such as CHORUS, NOMAD and Superkamiokande, and in preparation, such as SNO and a new round of accelerator- and reactor-based neutrino-oscillation experiments. At the end, there is a brief review of ways in which present and future CERN experiments may be able to contribute to answering outstanding questions in neutrino physics.

John Ellis

1996-11-29T23:59:59.000Z

254

Introduction to Neutrino Physics  

SciTech Connect

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

Linares, Edgar Casimiro [Division de Ciencias e Ingenierias Campus Leon, Loma del Bosque 103 Col. Lomas del Campestre, C.P. 37150 Leon (Mexico) and Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Av. Complutense, 22, C.P. 28040, Madrid (Spain)

2009-04-30T23:59:59.000Z

255

Fundamental neutrino experiments  

E-Print Network (OSTI)

We review fundamental open problems in neutrino physics and propose two basic experiments for their possible resolution.

Ruggero Maria Santilli

2006-11-06T23:59:59.000Z

256

Neutrino observations from the Sudbury Neutrino Observatory  

SciTech Connect

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

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

2001-09-24T23:59:59.000Z

257

The Effect of Massive Neutrinos on Matter Power Spectrum  

E-Print Network (OSTI)

We investigate the impact of massive neutrinos on the distribution of matter in the semi-nonlinear regime (0.1eV-1.9 eV respectively. We also discuss the precision levels that future cosmological datasets would have to achieve in order to resolve between the normal and inverted neutrino mass hierarchies.

Agarwal, Shankar

2010-01-01T23:59:59.000Z

258

Opportunities in Neutrino Theory -- a Snowmass White Paper  

E-Print Network (OSTI)

Neutrino masses are clear evidence for physics beyond the standard model and much more remains to be understood about the neutrino sector. We highlight some of the outstanding questions and research opportunities in neutrino theory. We show that most of these questions are directly connected to the very rich experimental program currently being pursued (or at least under serious consideration) in the United States and worldwide. Finally, we also comment on the state of the theoretical neutrino physics community in the U.S.

Andre de Gouvea; Alexander Friedland; Patrick Huber; Irina Mocioiu

2013-09-27T23:59:59.000Z

259

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

E-Print Network (OSTI)

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 energy and position resolution. Both spherical gaseous and cylindrical liquid detectors are studied. Different source candidates are considered.

J. D. Vergados; Yu. N. Novikov

2010-06-19T23:59:59.000Z

260

Reactor Searches for Neutrino Magnetic Moment as a Probe of Extra Dimensions  

E-Print Network (OSTI)

We present calculations of the magnetic moment contribution to neutrino electron scattering in large extra dimension brane-bulk models (LED) with three bulk neutrinos. We discuss the cases with two and three large extra dimensions of sizes $R$. The calculations are done using reactor flux from Uranium, $^{235}U$ as the neutrino source. We find that if the electron neutrino mass is chosen to be in the range of one eV, the differential cross section for $\\bar{\

Mohapatra, Rabindra N; Yu, Haibo; Ng, Siew-Phang; Yu, Haibo

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


261

Reactor Searches for Neutrino Magnetic Moment as a Probe of Extra Dimensions  

E-Print Network (OSTI)

We present calculations of the magnetic moment contribution to neutrino electron scattering in large extra dimension brane-bulk models (LED) with three bulk neutrinos. We discuss the cases with two and three large extra dimensions of sizes $R$. The calculations are done using reactor flux from Uranium, $^{235}U$ as the neutrino source. We find that if the electron neutrino mass is chosen to be in the range of one eV, the differential cross section for $\\bar{\

R. N. Mohapatra; Siew-Phang Ng; Haibo Yu

2004-04-29T23:59:59.000Z

262

Tau Neutrino Appearance with a 1000 Megaparsec Baseline  

E-Print Network (OSTI)

A high-energy neutrino telescope, such as the operating AMANDA detector, may detect neutrinos produced in sources, possibly active galactic nuclei or gamma-ray bursts, distant by a thousand megaparsecs. These sources produce mostly nu_e or nu_mu neutrinos. Above 1 PeV, nu_e and nu_mu are absorbed by charged-current interactions in the Earth before reaching the opposite surface. However, the Earth never becomes opaque to nu_tau since the tau^- produced in a charged-current nu_tau interaction decays back into nu_tau before losing significant energy. This preferential penetration of tau neutrinos through the Earth above 10^14 eV provides an experimental signature for neutrino oscillations. The appearance of a nu_tau component would be evident as a flat zenith angle dependence of a source intensity at the highest neutrino energies. Such an angular dependence would indicate nu_tau mixing with a sensitivity to delta-m^2 as low as 10^-17 eV^2, for the farthest sources. In addition, the presence of tau neutrino mixing would provide the opportunity for neutrino astronomy well beyond the PeV cutoff, possibly out to the energies matching those of the highest energy protons observed above 10^20 eV.

Francis Halzen; David Saltzberg

1998-04-21T23:59:59.000Z

263

New insights into single-particle mixing state using aircraft aerosol time-of-flight mass spectrometry  

E-Print Network (OSTI)

of contact nucleation in ice phase initiation in clouds, J.of cloud sampling. The ice phase CVI sample was collectedthe liquid, mixed, and ice phase sampling, externally mixed

Pratt, Kerri Anne

2009-01-01T23:59:59.000Z

264

Anomaly-free constraints in neutrino seesaw models  

SciTech Connect

The implementation of seesaw mechanisms to give mass to neutrinos in the presence of an anomaly-free U(1){sub X} gauge symmetry is discussed in the context of minimal extensions of the standard model. It is shown that type-I and type-III seesaw mechanisms cannot be simultaneously implemented with an anomaly-free local U(1){sub X}, unless the symmetry is a replica of the well-known hypercharge. For combined type-I/II or type-III/II seesaw models it is always possible to find nontrivial anomaly-free charge assignments, which are however tightly constrained, if the new neutral gauge boson is kinematically accessible at LHC. The discovery of the latter and the measurement of its decays into third-generation quarks, as well as its mixing with the standard Z boson, would allow one to discriminate among different seesaw realizations.

Emmanuel-Costa, D. [Departamento de Fisica and Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Franco, Edison T. [Instituto de Fisica Teorica, Universidade Estadual Paulista, Rua Doutor Bento Teobaldo Ferraz 271 - Bloco II, 01140-070 - Sao Paulo, SP (Brazil); Departamento de Fisica and Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Felipe, R. Gonzalez [Area Cientifica de Fisica, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro 1, 1959-007 Lisboa (Portugal); Departamento de Fisica and Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal)

2009-06-01T23:59:59.000Z

265

Anomaly-free constraints in neutrino seesaw models  

E-Print Network (OSTI)

The implementation of seesaw mechanisms to give mass to neutrinos in the presence of an anomaly-free U(1)_X gauge symmetry is discussed in the context of minimal extensions of the standard model. It is shown that type-I and type-III seesaw mechanisms cannot be simultaneously implemented with an anomaly-free local U(1)_X, unless the symmetry is a replica of the well-known hypercharge. For combined type-I/II or type-III/II seesaw models it is always possible to find nontrivial anomaly-free charge assignments, which are however tightly constrained, if the new neutral gauge boson is kinematically accessible at LHC. The discovery of the latter and the measurement of its decays into third-generation quarks, as well as its mixing with the standard Z boson, would allow one to discriminate among different seesaw realizations.

D. Emmanuel-Costa; Edison T. Franco; R. Gonzalez Felipe

2009-02-10T23:59:59.000Z

266

MINOS Sterile Neutrino Search  

SciTech Connect

The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the {nu}{sub {mu}} {yields} V{sub {tau}} transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling {approx}2.5 x 10{sup 20} protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.

Koskinen, David Jason; /University Coll. London

2009-09-01T23:59:59.000Z

267

Atmospheric neutrino oscillations and tau neutrinos in ice  

E-Print Network (OSTI)

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

Gerardo Giordano; Olga Mena; Irina Mocioiu

2010-04-20T23:59:59.000Z

269

Discovering New Light States at Neutrino Experiments  

SciTech Connect

Experiments designed to measure neutrino oscillations also provide major opportunities for discovering very weakly coupled states. In order to produce neutrinos, experiments such as LSND collide thousands of Coulombs of protons into fixed targets, while MINOS and MiniBooNE also focus and then dump beams of muons. The neutrino detectors beyond these beam dumps are therefore an excellent arena in which to look for long-lived pseudoscalars or for vector bosons that kinetically mix with the photon. We show that these experiments have significant sensitivity beyond previous beam dumps, and are able to partially close the gap between laboratory experiments and supernovae constraints on pseudoscalars. Future upgrades to the NuMI beamline and Project X will lead to even greater opportunities for discovery. We also discuss thin target experiments with muon beams, such as those available in COMPASS, and show that they constitute a powerful probe for leptophilic PNGBs.

Essig, Rouven; /SLAC; Harnik, Roni; /Fermilab; Kaplan, Jared; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.

2011-08-11T23:59:59.000Z

270

Solar neutrino detection  

SciTech Connect

More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.

Miramonti, Lino [Physics department of Milano University and INFN (Italy)

2009-04-30T23:59:59.000Z

271

Solar neutrino detection  

E-Print Network (OSTI)

More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.

Lino Miramonti

2009-01-22T23:59:59.000Z

272

Spectroscopy of Solar Neutrinos  

E-Print Network (OSTI)

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

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

2010-04-06T23:59:59.000Z

273

Coral Radiocarbon Records of Indian Ocean Water Mass Mixing and Wind-Induced Upwelling Along the Coast of Sumatra, Indonesia  

SciTech Connect

Radiocarbon ({sup 14}C) in the skeletal aragonite of annually banded corals track radiocarbon concentrations in dissolved inorganic carbon (DIC) in surface seawater. As a result of nuclear weapons testing in the 1950s, oceanic uptake of excess {sup 14}C in the atmosphere has increased the contrast between surface and deep ocean {sup 14}C concentrations. We present accelerator mass spectrometric (AMS) measurements of radiocarbon isotope ({Delta}{sup 14}C) in Porites corals from the Mentawai Islands, Sumatra (0 S, 98 E) and Watamu, Kenya (3 S, 39 E) to document the temporal and spatial evolution of the {sup 14}C gradient in the tropical Indian Ocean. The rise in {Delta}{sup 14}C in the Sumatra coral, in response to the maximum in nuclear weapons testing, is delayed by 2-3 years relative to the rise in coral {Delta}{sup 14}C from the coast of Kenya. Kenya coral {Delta}{sup 14}C values rise quickly because surface waters are in prolonged contact with the atmosphere. In contrast, wind-induced upwelling and rapid mixing along the coast of Sumatra entrains {sup 14}C-depleted water from the subsurface, which dilutes the effect of the uptake of bomb-laden {sup 14}C by the surface-ocean. Bimonthly AMS {Delta}{sup 14}C measurements on the Mentawai coral reveal mainly interannual variability with minor seasonal variability. The interannual signal may be a response to changes in the Walker circulation, the development of easterly wind anomalies, shoaling of the eastern thermocline, and upwelling of {sup 14}C-depleted water along the coast of Sumatra. Singular spectrum analysis of the Sumatra coral {Delta}{sup 14}C record reveals a significant 3-year periodicity. The results lend support to the concept that ocean atmosphere interactions between the Pacific and Indian Oceans operate in concert with the El Ni{tilde n}o-Southern Oscillation (ENSO).

Guilderson, T P; Grumet, N S; Abram, N J; Beck, J W; Dunbar, R B; Gagan, M K; Hantoro, W S; Suwargadi, B W

2004-02-06T23:59:59.000Z

274

Particle mixing, flavor condensate and dark energy  

E-Print Network (OSTI)

The mixing of neutrinos and quarks generate a vacuum condensate that, at the present epoch, behaves as a cosmological constant. The value of the dark energy is constrained today by the very small breaking of the Lorentz invariance.

Massimo Blasone; Antonio Capolupo; Giuseppe Vitiello

2009-12-08T23:59:59.000Z

275

NEUTRINOS, OLD AND NEW  

SciTech Connect

Results are reported from a series of experiments that led to the conclusion that neutrinos exist in 4 states. (C.H.)

Reines, F.

1963-08-30T23:59:59.000Z

276

Neutrino-nucleus interactions  

SciTech Connect

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

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

2011-01-01T23:59:59.000Z

277

Neutrino Factory Feasibility Study  

NLE Websites -- All DOE Office Websites (Extended Search)

Witherell's Letter (Postscript) Final Version of the Neutrino Source Study Report (PDF) Organization Chart (Postscript) Two Day Meeting at Fermilab on February 15-16, 2000...

278

Phenomenology of neutrino oscillations  

Science Conference Proceedings (OSTI)

see that the statistical uncertainty is the least for the super-Kamioka (SK) water Cerenkov detector, which is thus presaging the era of precision neutrino physics.

279

Solar neutrino Research  

NLE Websites -- All DOE Office Websites (Extended Search)

the neutrino detector. The pioneering experiments conducted in the Homestake Mine, Lead, South Dakota, led to the awarding of the 2002 Nobel Prize in Physics to Raymond Davis,...

280

Double Chooz: Searching for theta13 with reactor neutrinos  

E-Print Network (OSTI)

The Double Chooz experiment is meant to search for the neutrino mixing angle theta13 taking advantage of the neutrinos generated at the nuclear power plant of Chooz. Double Chooz relies on neutrino flux measurements at two different locations, the so-called far and near detectors, although the first phase runs only with the far detector. The commissioning of the far detector started in January 2011 and first results improving the current limit on theta13 are expected by the summer 2011. The status of the Double Chooz experiment is presented.

Novella, P

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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281

Double Chooz: Searching for theta13 with reactor neutrinos  

E-Print Network (OSTI)

The Double Chooz experiment is meant to search for the neutrino mixing angle theta13 taking advantage of the neutrinos generated at the nuclear power plant of Chooz. Double Chooz relies on neutrino flux measurements at two different locations, the so-called far and near detectors, although the first phase runs only with the far detector. The commissioning of the far detector started in January 2011 and first results improving the current limit on theta13 are expected by the summer 2011. The status of the Double Chooz experiment is presented.

P. Novella; for the Double Chooz collaboration

2011-05-30T23:59:59.000Z

282

Implications of texture 4 zero lepton mass matrices for U_{e3}  

E-Print Network (OSTI)

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \\Delta m_{12}^2 constrained by SNP and s_{23} and \\Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\

Randhawa, M; Sen-Gupta, M; Randhawa, Monika; Ahuja, Gulsheen; Gupta, Manmohan

2002-01-01T23:59:59.000Z

283

Implications of texture 4 zero lepton mass matrices for U_{e3}  

E-Print Network (OSTI)

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \\Delta m_{12}^2 constrained by SNP and s_{23} and \\Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\

Monika Randhawa; Gulsheen Ahuja; Manmohan Gupta

2002-03-12T23:59:59.000Z

284

Muon and Tau Neutrinos Spectra from Solar Flares  

E-Print Network (OSTI)

Solar neutrino flares and mixing are considered. Most power-full solar flare as the ones occurred on 23th February 1956, September 29th 1989, 28th October and on 2nd-4th November 2003 are sources of cosmic rays, X, gamma and neutrino bursts. These flares took place both on front or in the edge and in the hidden solar disk. The observed and estimated total flare energy should be a source of a prompt secondary neutrino burst originated, by proton-proton-pion production on the sun itself; a more delayed and spread neutrino flux signal arise by the solar charged flare particles reaching the terrestrial atmosphere. Our first estimates of neutrino signals in largest underground detectors hint for few events in correlation with, gamma,radio onser. Our approximated spectra for muons and taus from these rare solar eruption are shown over the most common background. The muon and tau signature is very peculiar and characteristic over electron and anti-electron neutrino fluxes. The rise of muon neutrinos will be detectable above the minimal muon threshold of 113 MeV. The rarest tau appearence will be possible only for hardest solar neutrino energies above 3.471 GeV

D. Fargion; F. Moscato

2004-05-03T23:59:59.000Z

285

STANDARD PHYSICS SOLUTION TO THE SOLAR NEUTRINO PROBLEM?  

E-Print Network (OSTI)

The 8 B solar neutrino flux predicted by the standard solar model (SSM) is consistent within the theoretical and experimental uncertainties with that observed at Kamiokande. The Gallium and Chlorine solar neutrino experiments, however, seem to imply that the 7 Be solar neutrino flux is strongly suppressed compared with that predicted by the SSM. If the 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 3 He in the solar core, and dense plasma effects which may strongly enhance p-capture by 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. 1 1

Arnon Dar

2008-01-01T23:59:59.000Z

286

Absorption of solar radiation by solar neutrinos  

E-Print Network (OSTI)

We calculate the absorption probability of photons radiated from the surface of the Sun by a left-handed neutrino with definite mass and a typical momentum for which we choose |p_1|=0.2 MeV, producing a heavier right-handed antineutrino. Considering two transitions the \

G. Duplancic; P. Minkowski; J. Trampetic

2003-04-16T23:59:59.000Z

287

Energy-Scale Dependence of the Lepton-Flavor-Mixing Matrix hep-ph/9904292  

E-Print Network (OSTI)

We study an energy-scale dependence of the lepton-flavor-mixing matrix in the minimal supersymmetric standard model with the effective dimension-five operators which give the masses of neutrinos. We analyze the renormalization group equations of ?ijs which are coefficients of these effective operators under the approximation to neglect the corrections of O(?2). As a consequence, we find that all phases in ? do not depend on the energy-scale, and that only ng ? 1 (ng: generation number) real independent parameters in the lepton-flavor-mixing matrix depend on the energyscale.

N. Haba; Y. Matsui; N. Okamura; M. Sugiura

1999-01-01T23:59:59.000Z

288

$^3$He Transport in the Sun and the Solar Neutrino Problem  

E-Print Network (OSTI)

Recent solar neutrino experiments have shown that both $\\phi(^8$B) and the neutrino flux ratio $\\phi(^7$Be)/$\\phi(^8$B) are substantially below their standard solar model values, leading some to discount the possibility of an astrophysical solution to the solar neutrino puzzle. We test this conclusion phenomenologically and find that the discrepancies can be significantly reduced by a distinctive pattern of core mixing on timescales characteristic of $^3$He equilibration.

Andrew Cumming; W. C. Haxton

1996-08-20T23:59:59.000Z

289

Neutrino absortion cross sections in supernova environment  

E-Print Network (OSTI)

We study charged-current neutrino cross sections on neutronrich nuclei in the mass $A\\sim60$ region. Special attention is paid to environmental effects, i.e. finite temperature and density, on the cross sections. As these effects are largest for small neutrino energies, it is sufficient to study only the Gamow-Teller (GT) contributions to the cross sections. The relevant GT strength distributions are derived from large-scale shell model calculations. We find that the low-energy cross sections are enhanced at finite temperatures. However, for $(\

J. M. Sampaio; K. Langanke; G. Martinez-Pinedo

2001-04-04T23:59:59.000Z

290

Solar neutrino physics: Sensitivity to light dark matter particles  

E-Print Network (OSTI)

Neutrinos are produced in several neutrino nuclear reactions of the proton-proton chain and carbon-nitrogen-oxygen cycle that take place at different radius of the Sun's core. Hence, measurements of solar neutrino fluxes provide a precise determination of the local temperature. The accumulation of non-annihilating light dark matter particles (with masses between 5 GeV and 16 GeV in the Sun produces a change in the local solar structure, namely, a decrease in the central temperature of a few percent. This variation depends on the properties of the dark matter particles, such as the mass of the particle and its spin-independent scattering cross-section on baryon-nuclei, specifically, the scattering with helium, oxygen, and nitrogen among other heavy elements. This temperature effect can be measured in almost all solar neutrino fluxes. In particular, by comparing the neutrino fluxes generated by stellar models with current observations, namely 8B neutrino fluxes, we find that non-annihilating dark matter particles with a mass smaller than 10 GeV and a spin-independent scattering cross-section with heavy baryon-nuclei larger than 3 x 10^{-37} cm^-2 produce a variation in the 8B neutrino fluxes that would be in conflict with current measurements.

Ilidio Lopes; Joseph Silk

2013-09-29T23:59:59.000Z

291

Very Long Baseline Neutrino Oscillation Experiment for Precise Determination of Oscillation Parameters and Search for nu_mu -> nu_e Appearance and CP Violation  

E-Print Network (OSTI)

The possibility of making a low cost, very intense (1MW) high energy proton source at the Brookhaven Alternating Gradient Synchrotron (BNL-AGS) along with the forthcoming new large underground detectors (approaching 1 MT in mass) at the National Underground Science and Engineering Laboratory (NUSEL) in Homestake, South Dakota or at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, allows us to propose a program of experiments that will address fundamental aspects of neutrino oscillations and CP-invariance violation. This program is unique because of the very long baseline of more than 2500 km from BNL to the underground laboratory in the West. We used the running scenario of a low energy, wide band neutrino beam with 1 MW AGS, 500 kT of fiducial mass water Cherenkov detector, and 5x10^7 seconds of running time. In this report we show that with these conditions we precisely measure dm^2_32 and sin^2(2theta_23) and have excellent sensitivity to sin^2(2theta_13) with a distinctive signal spectrum. If sin^2(2theta_13) > 0.01 the experiment is sensitive to the CP-violating phase in the mixing matrix with only neutrino running. By running in the anti-neutrino mode we distinguish between the cases dm^2_31 > 0 versus dm^2_31 nu_e appearance channel.

BNL Neutrino Working Group; M. Diwan

2002-10-31T23:59:59.000Z

292

Neutrino Counter Nuclear Weapon  

E-Print Network (OSTI)

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

Alfred Tang

2008-05-26T23:59:59.000Z

293

Monte Carlo Neutrino Oscillations  

E-Print Network (OSTI)

We demonstrate that the effects of matter upon neutrino propagation may be recast as the scattering of the initial neutrino wavefunction. Exchanging the differential, Schrodinger equation for an integral equation for the scattering matrix S permits a Monte Carlo method for the computation of S that removes many of the numerical difficulties associated with direct integration techniques.

James P. Kneller; Gail C. McLaughlin

2005-09-29T23:59:59.000Z

294

Scalar neutrinos at the LHC  

Science Conference Proceedings (OSTI)

We study a softly broken supersymmetric model whose gauge symmetry is that of the standard model gauge group times an extra Abelian symmetry U(1){sup '}. We call this gauge-extended model the U(1){sup '} model, and we study a U(1){sup '} model with a secluded sector such that neutrinos acquire Dirac masses via higher-dimensional terms allowed by the U(1){sup '} invariance. In this model the {mu} term of the minimal supersymmetric model (MSSM) is dynamically induced by the vacuum expectation value of a singlet scalar. In addition, the model contains exotic particles necessary for anomaly cancellation, and extra singlet bosons for achieving correct Z{sup '}/Z mass hierarchy. The neutrinos are charged under U(1){sup '}, and thus, their production and decay channels differ from those in the MSSM in strength and topology. We implement the model into standard packages and perform a detailed analysis of sneutrino production and decay at the Large Hadron Collider, for various mass scenarios, concentrating on three types of signals: (1) 0l+MET, (2) 2l+MET, and (3) 4l+MET. We compare the results with those of the MSSM whenever possible, and analyze the standard model background for each signal. The sneutrino production and decays provide clear signatures enabling distinction of the U(1){sup '} model from the MSSM at the LHC.

Demir, Durmus A. [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir, Turkey, (Turkey); Frank, Mariana [Department of Physics, Concordia University, 7141 Sherbrooke St. West, Montreal, Quebec, Canada H4B 1R6, (Canada); Selbuz, Levent [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir, Turkey, (Turkey); Department of Engineering Physics, Ankara University, TR06100 Ankara (Turkey); Turan, Ismail [Ottawa-Carleton Institute of Physics, Carleton University, 1125 Colonel By Drive Ottawa, Ontario, K1S 5B6 (Canada)

2011-05-01T23:59:59.000Z

295

Solar Neutrino Physics  

SciTech Connect

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

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

1999-07-15T23:59:59.000Z

296

A large liquid argon time projection chamber for long-baseline, off-axis neutrino oscillation physics with the NuMI beam  

Science Conference Proceedings (OSTI)

Results from neutrino oscillation experiments in the last ten years have revolutionized the field of neutrino physics. While the overall oscillation picture for three neutrinos is now well established and precision measurements of the oscillation parameters are underway, crucial issues remain. In particular, the hierarchy of the neutrino masses, the structure of the neutrino mixing matrix, and, above all, CP violation in the neutrino sector are the primary experimental challenges in upcoming years. A program that utilizes the newly commissioned NuMI neutrino beamline, and its planned upgrades, together with a high-performance, large-mass detector will be in an excellent position to provide decisive answers to these key neutrino physics questions. A Liquid Argon time projection chamber (LArTPC) [2], which combines fine-grained tracking, total absorption calorimetry, and scalability, is well matched for this physics program. The few-millimeter-scale spatial granularity of a LArTPC combined with dE/dx measurements make it a powerful detector for neutrino oscillation physics. Scans of simulated event samples, both directed and blind, have shown that electron identification in {nu}{sub e} charged current interactions can be maintained at an efficiency of 80%. Backgrounds for {nu}{sub e} appearance searches from neutral current events with a {pi}{sup 0} are reduced well below the {approx} 0.5-1.0% {nu}{sub e} contamination of the {nu}{sub {mu}} beam [3]. While the ICARUS collaboration has pioneered this technology and shown its feasibility with successful operation of the T600 (600-ton) LArTPC [4], a detector for off-axis, long-baseline neutrino physics must be many times more massive to compensate for the low event rates. We have a baseline concept [5] based on the ICARUS wire plane structure and commercial methods of argon purification and housed in an industrial liquefied-natural-gas tank. Fifteen to fifty kton liquid argon capacity tanks have been considered. A very preliminary cost estimate for a 50-kton detector is $100M (unloaded) [6]. Continuing R&D will emphasize those issues pertaining to implementation of this very large scale liquid argon detector concept. Key hardware issues are achievement and maintenance of argon purity in the environment of an industrial tank, the assembly of very large electrode planes, and the signal quality obtained from readout electrodes with very long wires. Key data processing issues include an initial focus on rejection of cosmic rays for a surface experiment. Efforts are underway at Fermilab and a small number of universities in the US and Canada to address these issues with the goal of embarking on the construction of industrial-scale prototypes within one year. One such prototype could be deployed in the MiniBooNE beamline or in the NuMI surface building where neutrino interactions could be observed. These efforts are complementary to efforts around the world that include US participation, such as the construction of a LArTPC for the 2-km detector location at T2K [7]. The 2005 APS neutrino study [1] recommendations recognize that ''The development of new technologies will be essential for further advances in neutrino physics''. In a recent talk to EPP2010, Fermilab director P. Oddone, discussing the Fermilab program, states on his slides: ''We want to start a long term R&D program towards massive totally active liquid Argon detectors for extensions of NOvA''. [8]. As such, we are poised to enlarge our R&D efforts to realize the promise of a large liquid argon detector for neutrino physics.

Finley, D.; Jensen, D.; Jostlein, H.; Marchionni, A.; Pordes, S.; Rapidis, P.A.; /Fermilab; Bromberg, C.; /Michigan State U.; Lu, C.; McDonald, T.; /Princeton U.; Gallagher, H.; Mann, A.; Schneps, J.; /Tufts U.; Cline, D.; Sergiampietri, F.; Wang, H.; /UCLA; Curioni, A.; Fleming, B.T.; /Yale U.; Menary, S.; /York U., Canada

2005-09-01T23:59:59.000Z

297

Solar neutrinos: Probing the sun or neutrinos  

SciTech Connect

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

Wilkerson, J.F.

1991-01-01T23:59:59.000Z

298

The Standard Model of Particle Physics. Neutrino Oscillations  

E-Print Network (OSTI)

The Standard Model (SM) of Particle Physics was tested to great precision by experiments at the highest energy colliders (LEP, Hera, Tevatron, SLAC). The only missing particle is the Higgs boson, which will be the first particle to be searched for at the new Large Hadron Collider (LHC) at CERN. The SM anticipated that there are 3 types of left handed neutrinos. Experiments on atmospheric and solar neutrinos (made in Japan, Italy, Canada, Russia and the US) have shown the existence of neutrino oscillations, which imply that neutrinos have very small mass differences and violate the conservation of individual leptonic numbers. Neutrino oscillations were verified in long baseline neutrino experiments (in Japan and in the USA); and cosmology has given reasonably precise indications on the sum of the neutrino masses. In this general lecture will be summarized some of the main properties of the SM and some of the main results obtained in the field and the experiments in preparation. Some of the main open questions will be briefly discussed.

Giorgio Giacomelli

2009-01-16T23:59:59.000Z

299

Neutrinos and Nucleosynthesis in Gamma-Ray Burst Accretion Disks  

E-Print Network (OSTI)

We calculate the nuclear composition of matter in accretion disks surrounding stellar mass black holes as are thought to accompany gamma-ray bursts (GRBs). We follow a mass element in the accretion disk starting at the point of nuclear dissociation and calculate the evolution of the electron fraction due to electron, positron, electron neutrino and electron antineutrino captures. We find that the neutronization of the disk material by electron capture can be reversed by neutrino interactions in the inner regions of disks with accretion rates of 1 M_solar/s and higher. For these cases the inner disk regions are optically thick to neutrinos, and so to estimate the emitted neutrino fluxes we find the surface of last scattering for the neutrinos (the equivalent of the proto-neutron star neutrinosphere) for each optically thick disk model. We also estimate the influence of neutrino interactions on the neutron-to-proton ratio in outflows from GRB accretion disks, and find it can be significant even when the disk is optically thin to neutrinos.

R. Surman; G. C. McLaughlin

2003-07-31T23:59:59.000Z

300

Lifting Slepton Masses with a Non-universal, Non-anomalous U(1)'_{NAF} in Anomaly Mediated SUSY breaking  

E-Print Network (OSTI)

We extend the Minimum Supersymmetry Standard Model by a non-anomalous family (NAF) U(1)'_{NAF} gauge symmetry. All gauge anomalies are cancelled with no additional exotics other than the three right-handed neutrinos. The FI D-terms associated with the U(1)'_{NAF} symmetry lead to additional positive contributions to slepton squared masses. In a RG invariant way, this thus solves the tachyonic slepton mass problem in Anomaly Mediated Supersymmetry Breaking. In addition, the U (1)'_{NAF} symmetry naturally gives rise to the fermion mass hierarchy and mixing angles, and determines the mass spectrum of the sparticles.

Mu-Chun Chen; Jinrui Huang

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Global Analysis of Solar Neutrino Oscillations Including SNO CC Measurement  

E-Print Network (OSTI)

For active and sterile neutrinos, we present the globally allowed solutions for two neutrino oscillations. We include the SNO CC measurement and all other relevant solar neutrino and reactor data. Five active neutrino oscillation solutions (LMA, LOW, SMA, VAC, and Just So2) are currently allowed at 3 sigma; three sterile neutrino solutions (Just So2, SMA, and VAC) are allowed at 3 sigma. The goodness of fit is satisfactory for all eight solutions. We also investigate the robustness of the allowed solutions by carrying out global analyses with and without: 1) imposing solar model constraints on the 8B neutrino flux, 2) including the Super-Kamiokande spectral energy distribution and day-night data, 3) including a continuous mixture of active and sterile neutrinos, 4) using an enhanced CC cross section for deuterium (due to radiative corrections), and 5) a optimistic, hypothetical reduction by a factor of three of the error of the SNO CC rate. For every analysis strategy used in this paper, the most favored solutions all involve large mixing angles: LMA, LOW, or VAC. The favored solutions are robust, but the presence at 3 sigma of individual sterile solutions and the active Just So2 solution is sensitive to the analysis assumptions.

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

2001-06-25T23:59:59.000Z

302

Imprint of Sterile Neutrinos in the Cosmic Microwave Background Radiation  

E-Print Network (OSTI)

The existence of low-mass sterile neutrinos is suggested by the current status of solar and atmospheric neutrinos together with the LSND experiment. In typical four-flavor scenarios, neutrinos would contribute to a cosmic hot dark matter component and to an increased radiation content at the epoch of matter-radiation equality. These effects leave their imprint in sky maps of the cosmic microwave background radiation (CMBR) and may thus be detectable with the precision measurements of the upcoming MAP and PLANCK missions.

Steen Hannestad; Georg Raffelt

1998-05-17T23:59:59.000Z

303

Meter-baseline tests of sterile neutrinos at Daya Bay  

E-Print Network (OSTI)

We explore the sensitivity of an experiment at the Daya Bay site, with a point radioactive source and a few meter baseline, to neutrino oscillations involving one or more eV mass sterile neutrinos. We find that within a year, the entire 3+2 and 1+3+1 parameter space preferred by global fits can be excluded at the 3\\sigma level, and if an oscillation signal is found, the 3+1 and 3+2 scenarios can be distinguished from each other at more than the 3\\sigma level provided one of the sterile neutrinos is lighter than 0.5 eV.

Y. Gao; D. Marfatia

2013-02-22T23:59:59.000Z

304

Reactor Neutrino Experiments  

E-Print Network (OSTI)

Precisely measuring $\\theta_{13}$ is one of the highest priority in neutrino oscillation study. Reactor experiments can cleanly determine $\\theta_{13}$. Past reactor neutrino experiments are reviewed and status of next precision $\\theta_{13}$ experiments are presented. Daya Bay is designed to measure $\\sin^22\\theta_{13}$ to better than 0.01 and Double Chooz and RENO are designed to measure it to 0.02-0.03. All are heading to full operation in 2010. Recent improvements in neutrino moment measurement are also briefed.

Jun Cao

2007-12-06T23:59:59.000Z

305

Low Energy Neutrino Measurements  

E-Print Network (OSTI)

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

Davide D'Angelo

2012-11-22T23:59:59.000Z

306

Review of Recent Neutrino Physics Research  

E-Print Network (OSTI)

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

Leonard S. Kisslinger

2013-06-17T23:59:59.000Z

307

The recent results of solar neutrino measuerments in Super-Kamiokande  

E-Print Network (OSTI)

The results of solar neutrino data from the first phase of Super-Kamiokande are presented. Super-Kamiokande can measure not only the solar neutrino flux but also its energy spectrum and its time variations such as day vs. night and seasonal differences. This information can severely restrict parameters of solar neutrino oscillation. From the combination of several experiments results with those of Super-K, the Large Mixing Angle solution is uniquely allowed at the 98.1 % confidence level; this global solar neutrino oscillation analysis is presented. The current status of the second phase of Super-Kamiokande is presented.

Yusuke Koshio

2003-01-01T23:59:59.000Z

308

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

SciTech Connect

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

Stoica, Sabin [Horia Hulubei Foundation, P.O. Box MG-12, 077125 Magurele-Bucharest (Romania) and Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, Magurele-Bucharest 077125 (Romania)

2012-11-20T23:59:59.000Z

309

Superluminal group velocity through near-maximal neutrino oscillations  

E-Print Network (OSTI)

Recently it was suggested that the observation of superluminal neutrinos by the OPERA collaboration may be due to group velocity effects resulting from close-to-maximal oscillation between neutrino mass eigenstates, in analogy to known effects in optics. We show that superluminal propagation does occur through this effect for a series of very narrow energy ranges, but this phenomenum cannot explain the OPERA measurement.

Tim R. Morris

2011-10-11T23:59:59.000Z

310

Probing Late Neutrino Mass Properties With Supernova Neutrinos  

E-Print Network (OSTI)

detector, are nuclear reactor electron antineutrinos, butwhich is not near nuclear reactors would have a bettera large background from nuclear reactor antineutrinos [13,

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

2007-01-01T23:59:59.000Z

311

neutrino.html  

NLE Websites -- All DOE Office Websites (Extended Search)

Fall 2000 Fall 2000 Tau Neutrino Evidence Announced at Fermilab This summer scientists at Fermi National Accelerator Laboratory announced the first direct evidence for the subatomic particle, the tau neutrino. The tau is an almost massless particle that carries no electric charge and barely interacts with surrounding matter. Previous experiments showed indirect evidence for its existence, but it had not been observed directly as yet. The tau is the third neutrino of the Standard Model of elementary particles, a theoretical description that groups all particles into three generations. The first electron neutrino was discovered in 1956, the muon in 1962. The Fermilab experiment responsible for the announcement is the Direct Observation of the Nu Tau (DONUT) experiment. DONUT is a collaboration of

312

Fast Light, Fast Neutrinos?  

E-Print Network (OSTI)

Light has been observed with group velocities both faster and slower than the speed of light. The recent report from OPERA of superluminal 17 GeV neutrinos may describe a similar phenomenon.

Cahill, Kevin

2011-01-01T23:59:59.000Z

313

SOLAR NEUTRINOS. II. EXPERIMENTAL  

SciTech Connect

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

Davis, R. Jr.

1964-03-16T23:59:59.000Z

314

Radiochemical solar neutrino experiments  

E-Print Network (OSTI)

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

V. N. Gavrin; B. T. Cleveland

2007-03-06T23:59:59.000Z

315

NERSC Global Filesystem Played a Key Role in Discovery of the Last Neutrino  

NLE Websites -- All DOE Office Websites (Extended Search)

NGFS Played a Key NGFS Played a Key Role in Neutrino Finding NERSC Global Filesystem Played a Key Role in Discovery of the Last Neutrino Mixing Angle February 7, 2013 | Tags: High Energy Physics (HEP), NERSC Global Filesystems (NGF), Science Gateways John Hules, JAHules@lbl.gov, +1 510 486 6008 XBD201107-00790-183.jpg Daya Bay Neutrino Facility in China. Photo by Roy Kaltschmidt, Lawrence Berkeley National Laboratory. Discovery of the last neutrino mixing angle - one of Science magazine's top ten breakthroughs of the year 2012 - was announced in March 2012, just a few months after the Daya Bay Neutrino Experiment's first detectors went online in southeast China. Collaborating scientists from China, the United States, the Czech Republic, and Russia were thrilled that their experiment was producing more data than expected, and that a positive

316

Dark energy and particle mixing  

E-Print Network (OSTI)

We show that the vacuum condensate due to particle mixing is responsible of a dynamically evolving dark energy. In particular, we show that values of the adiabatic index close to -1 for vacuum condensates of neutrinos and quarks imply, at the present epoch, contributions to the vacuum energy compatible with the estimated upper bound on the dark energy.

A. Capolupo; S. Capozziello; G. Vitiello

2008-08-30T23:59:59.000Z

317

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

E-Print Network (OSTI)

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

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

2011-09-08T23:59:59.000Z

318

Mass Transport Properties of LiD-U Mixtures from Orbital Free Molecular Dynamics Simulations and a Pressure-Matching Mixing Rule  

SciTech Connect

Mass transport properties for LiD-U mixtures were calculated using a pressure matching mixture rule for the mixing of LiD and of U properties simulated with Orbital Free Molecular Dynamics (OFMD). The mixing rule was checked against benchmark OFMD simulations for the fully interacting three-component (Li, D, U) system. To obtain transport coefficients for LiD-U mixtures of different (LiD){sub x}U{sub (1-x)} compositions as functions of temperature and mixture density is a tedious task. Quantum molecular dynamics (MD) simulations can be employed, as in the case LiD or U. However, due to the presence of the heavy constituent U, such simulations proceed so slowly that only a limited number of numerical data points in the (x, {rho}, T) phase space can be obtained. To finesse this difficulty, transport coefficients for a mixture can be obtained using a pressure-matching mixing rule discussed. For both LiD and U, the corresponding transport coefficients were obtained earlier from quantum molecular dynamics simulations. In these simulations, the quantum behavior of the electrons was represented using an orbital free (OF) version of density functional theory, and ions were advanced in time using classical molecular dynamics. The total pressure of the system, P = nk{sub B}T/V + P{sub e}, is the sum of the ideal gas pressure of the ions plus the electron pressure. The mass self-diffusion coefficient for species {alpha}, D{sub {alpha}}, the mutual diffusion coefficient for species {alpha} and {beta}, D{alpha}{beta}, and the shear viscosity, {eta}, are computed from the appropriate autocorrelation function. The details of similar QMD calculations on LiH are described in Ref. [1] for 0.5 eV < T < 3 eV, and in Ref. [2] for 2 eV < T < 6 eV.

Burakovsky, Leonid [Los Alamos National Laboratory; Kress, Joel D. [Los Alamos National Laboratory; Collins, Lee A. [Los Alamos National Laboratory

2012-05-31T23:59:59.000Z

319

The Sun's Interior Metallicity Constrained by Neutrinos  

E-Print Network (OSTI)

Observed solar neutrino fluxes are employed to constrain the interior composition of the Sun. Including the effects of neutrino flavor mixing, the results from Homestake, Sudbury, and Gallium experiments constrain the Mg, Si, and Fe abundances in the solar interior to be within a factor 0.89 to 1.34 of the surface values with 68% confidence. If the O and/or Ne abundances are increased in the interior to resolve helioseismic discrepancies with recent standard solar models, then the nominal interior Mg, Si, and Fe abundances are constrained to a range of 0.83 to 1.24 relative to the surface. Additional research is needed to determine whether the Sun's interior is metal poor relative to its surface.

Guillermo Gonzalez

2006-05-25T23:59:59.000Z

320

SNO: solving the mystery of the missing neutrinos  

DOE Green Energy (OSTI)

The end of an era came on 28 November 2006 when the Sudbury Neutrino Observatory (SNO) finally stopped data-taking after eight exciting years of discoveries. During this time the Observatory saw evidence that neutrinos, produced in the fusion of hydrogen in the solar core, change flavour while passing through the Sun on their way to the Earth. This observation explained the longstanding puzzle as to why previous experiments had seen fewer solar neutrinos than predicted and confirmed that these elusive particles have mass. Solar neutrinos were first detected in Ray Davis's radiochemical experiment in 1967, for which discovery he shared the 2002 Nobel Prize in Physics. Surprisingly he found only about a third of the number predicted from models of the Sun's output. This deficit, the so-called Solar Neutrino Problem, was confirmed by Kamiokande-II while other experiments saw related deficits of solar neutrinos. A possible explanation for this deficit, suggested by Gribov and Pontecorvo in 1969, was that some of the electron-type neutrinos, which are produced in the Sun, had ''oscillated'' into neutrinos that could not be detected in the Davis detector. The oscillation mechanism requires that neutrinos have non-zero mass. The unique advantage, which was pointed out by the late Herb Chen in 1985, of using heavy water (D{sub 2}O) to detect the neutrinos from {sup 8}B decays in the solar fusion process is that it enables both the number of electron-type and of all types of neutrinos to be measured. A comparison of the flux of electron-type neutrinos to that of all flavours could then reveal whether flavour transformation is the cause of the solar neutrino deficit. In heavy water neutrinos of all types can break a deuteron apart into its constituent proton and neutron (neutral-current reaction), while only electron-type neutrinos can change the deuteron into two protons and release an electron (charged-current reaction). SNO was designed by scientists from Canada, the USA and the UK to attain a detection rate of about 10 solar neutrinos per day using 1000 tonnes of heavy water. Neutrino interactions were detected by 9,456 photomultiplier tubes surrounding the heavy water, which was contained in a 12-m diameter acrylic sphere. This sphere was surrounded by 7000 tonnes of ultra-pure water to shield against radioactivity. Figure 1 shows the layout of the SNO detector, which is located about 2 km underground in Inco's Creighton nickel mine near Sudbury in Canada, to all but eliminate cosmic rays from reaching the detector. The pattern of hit photomultiplier tubes following the creation of an electron by an electron-type neutrino is shown in Figure 2.

Jelley, Nick; Poon, Alan

2007-03-30T23:59:59.000Z

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321

The neutrino self-energy in a magnetized medium  

E-Print Network (OSTI)

In this work we calculate the neutrino self-energy in presence of a magnetized medium. The magnetized medium consists of electrons, positrons, neutrinos and a uniform classical magnetic field. The calculation is done assuming the background magnetic field is weak compared to the $W$-Boson mass squared, as a consequence of which only linear order corrections in the field are included in the $W$ boson propagator. The electron propagator consists all order corrections in the background field. Although the neutrino self-energy in a magnetized medium in various limiting cases has been calculated previously in this article we produce the most general expression of the self-energy in absence of the Landau quantization of the charged gauge fields. We calculate the effect of the Landau quantization of the charged leptons on the neutrino self-energy in the general case. Our calculation is specifically suited for situations where the background plasma may be CP symmetric.

Alberto Bravo Garcia; Kaushik Bhattacharya; Sarira Sahu

2007-06-27T23:59:59.000Z

322

Solar Neutrinos Before and After KamLAND  

E-Print Network (OSTI)

We use the recently reported KamLAND measurements on oscillations of reactor anti-neutrinos, together with the data of previously reported solar neutrino experiments, to show that: (1) the total 8B neutrino flux emitted by the Sun is 1.00(1.0 \\pm 0.06) of the standard solar model (BP00) predicted flux, (2) the KamLAND measurements reduce the area of the globally allowed oscillation regions that must be explored in model fitting by six orders of magnitude in the Delta m^2-tan^2 theta plane, (3) LMA is now the unique oscillation solution to a CL of 4.7sigma, (4) maximal mixing is disfavored at 3.1 sigma, (5) active-sterile admixtures are constrained to sin^2 eta<0.13 at 1 sigma, (6) the observed ^8B flux that is in the form of sterile neutrinos is 0.00^{+0.09}_{-0.00} (1 sigma), of the standard solar model (BP00) predicted flux, and (7) non-standard solar models that were invented to completely avoid solar neutrino oscillations are excluded by KamLAND plus solar at 7.9 sigma . We also refine quantitative predictions for future 7Be and p-p solar neutrino experiments.

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

2002-12-11T23:59:59.000Z

323

Atmospheric neutrino oscillation analysis with sub-leading effects in Super-Kamiokande I, II, and III  

E-Print Network (OSTI)

We present a search for non-zero theta_{13} and deviations of sin^2 theta_{23} from 0.5 in the oscillations of atmospheric neutrino data from Super-Kamiokande -I, -II, and -III. No distortions of the neutrino flux consistent with non-zero theta_{13} are found and both neutrino mass hierarchy hypotheses are in agreement with the data. The data are best fit at Delta m^2 = 2.1 x 10^-3 eV^2, sin^2 theta_{13} = 0.0, and sin^2 theta_{23} =0.5. In the normal (inverted) hierarchy theta_{13} and Delta m^2 are constrained at the one-dimensional 90% C.L. to sin^2 theta_{13} < 0.04 (0.09) and 1.9 (1.7) x 10^-3 < Delta m^2 < 2.6 (2.7) x 10^-3 eV^2. The atmospheric mixing angle is within 0.407 <= sin^2 theta_{23} <= 0.583 at 90% C.L.

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

2010-02-18T23:59:59.000Z

324

Light Sterile Neutrino from extra dimensions and Four-Neutrino Solutions to Neutrino Anomalies  

E-Print Network (OSTI)

We propose a four-neutrino model which can reconcile the existing data coming from underground experiments in terms of neutrino oscillations, together with the hint from the LSND experiment and a possible neutrino contribution to the hot dark matter of the Universe. It applies the idea that extra compact dimensions, probed only by gravity and possibly gauge-singlet fields, can lower the fundamental scales such as the Planck, string or unification scales. Our fourth light neutrino $\

A. Ioannisian; J. W. F. Valle

1999-11-14T23:59:59.000Z

325

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

DOE R&D Accomplishments (OSTI)

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

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

1963-06-00T23:59:59.000Z

326

Neutrino Oscillations and Blazars  

E-Print Network (OSTI)

Three independent predictions follow from postulating the existence of protons co-accelerated with electrons in extragalactic jets (i) multi-TeV gamma ray emission from nearby blazars, (ii) extragalactic cosmic ray protons up to 10^20 eV, and (iii) extragalactic neutrinos up to 5 10^18 eV. Recent gamma ray observations of Mrk 421 and Mrk 501 employing the air-Cerenkov technique are consistent with the predicted gamma ray spectrum, if one corrects for pair attenuation on the infrared background. Prediction (ii) is consistent with cosmic ray data, if one requires that jets are responsible for at least a sizable fraction of the extragalactic gamma ray background. With kubic kilometer neutrino telescopes, it will be possible to test (iii), although the muon event rates are rather low. Neutrino oscillations can increase the event rate by inducing tau-cascades removing the Earth shadowing effect.

Karl Mannheim

1998-12-22T23:59:59.000Z

327

Neutrino Oscillations and Blazars  

E-Print Network (OSTI)

Three independent predictions follow from postulating the existence of protons co-accelerated with electrons in extragalactic jets (i) multi-TeV gamma ray emission from nearby blazars, (ii) extragalactic cosmic ray protons up to ? 10 20 eV, and (iii) extragalactic neutrinos up to ? 5 10 18 eV. Recent gamma ray observations of Mrk 421 and Mrk 501 employing the air-Cerenkov technique are consistent with the predicted gamma ray spectrum, if one corrects for pair attenuation on the infrared background. Prediction (ii) is consistent with cosmic ray data, if one requires that jets are responsible for a at least a sizable fraction of the extragalactic gamma ray background. With kubic kilometer neutrino telescopes, it will be possible to test (iii), although the muon event rates are rather low. Neutrino oscillations can increase the event rate by inducing tau-cascades removing the so-called Earth shadowing effect. 1

Karl Mannheim

1999-01-01T23:59:59.000Z

328

The Daya Bay Antineutrino Detector Filling System and Liquid Mass Measurement  

E-Print Network (OSTI)

The Daya Bay Reactor Neutrino Experiment has measured the neutrino mixing angle \\theta_{13} to world-leading precision. The experiment uses eight antineutrino detectors filled with 20-tons of gadolinium-doped liquid scintillator to detect antineutrinos emitted from the Daya Bay nuclear power plant through the inverse beta decay reaction. The precision measurement of sin^{2}2\\theta_{13} relies on the relative antineutrino interaction rates between detectors at near (400 m) and far (roughly 1.8 km) distances from the nuclear reactors. The measured interaction rate in each detector is directly proportional to the number of protons in the liquid scintillator target. A precision detector filling system was developed to simultaneously fill the three liquid zones of the antineutrino detectors and measure the relative target mass between detectors to <0.02%. This paper describes the design, operation, and performance of the system and the resulting precision measurement of the detectors' target liquid masses.

H. R. Band; J. J. Cherwinka; E. Draeger; K. M. Heeger; P. Hinrichs; C. A. Lewis; H. Mattison; M. C. McFarlane; D. M. Webber; D. Wenman; W. Wang; T. Wise; Q. Xiao

2013-07-03T23:59:59.000Z

329

The Neutrino Signal from Protoneutron Star Accretion and Black Hole Formation  

SciTech Connect

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

Fischer, T. [University of Basel; Whitehouse, S. [University of Basel; Mezzacappa, Anthony [ORNL; Thielemann, F.-K. [University of Basel; Liebendoerfer, M. [University of Basel

2009-01-01T23:59:59.000Z

330

Thermal masses in leptogenesis  

E-Print Network (OSTI)

We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles.

Kiessig, Clemens P

2009-01-01T23:59:59.000Z

331

Frederick Reines and the Neutrino  

Office of Scientific and Technical Information (OSTI)

Frederick Reines and the Detection of the Neutrino Frederick Reines and the Detection of the Neutrino Resources with Additional Information '[Frederick] Reines - known among scientists as the "father of neutrino physics" - won the Nobel Prize for physics in 1995 ["for the detection of the neutrino"], nearly 40 years after his neutrino experiments changed the world of physics and set in motion a new way of looking at the universe. ... Frederick Reines Courtesy University of California Irvine Until Reines's discovery, physicists had only theorized the existence of the neutrino - and physicists believed the tiny particles would never be detected. Reines's research laid the groundwork for new avenues of physics inquiry and hundreds of physics experiments that have tested central theories about the structure of our cosmos. The neutrino is one of the tiny spinning particles that are the building blocks of nature. ...

332

HIggs Boson Mass in the Minimal Unified Subquark Model  

E-Print Network (OSTI)

In the original paper entitled, "Masses of Fundamental Particles"(arXiv:1109.3705v5, 10 Feb 2012), not only the masses of fundamental particles including the weak bosons, Higgs boson, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite models of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

Hidezumi Terazawa

2011-09-17T23:59:59.000Z

333

Implications of Neutrino Balls as the Source of Gamma-Ray Bursts  

E-Print Network (OSTI)

(To appear in the Astrophysical Journal) Holdom and Malaney (1994) have suggested a mechanism for gamma-ray bursts which requires that stars be captured by a neutrino ball. Neutrino balls would be, for the most part, denser than main sequence stars, but their density would decrease as their mass increased. We show that small neutrino balls would subject stars to tidal forces sufficient to disrupt them. We thus argue that if neutrino balls existed at the centres of galaxies, only the largest would be able to act as a source of gamma-ray bursts. Such neutrino balls would have a mass of order $10^7\\Msun$. Tidal capture of stars by a neutrino ball would not be important, but dynamical friction against the neutrinos or star-disc interactions could both be important capture mechanisms. We find that a gamma-ray burst would occur in a galaxy containing such a neutrino ball roughly every $10^2\\y$, and the fraction of all galaxies contributing to the gamma-ray burst flux would be $\\sim 10^{-4}$, assuming that this was the mechanism of all gamma-ray bursts. These numbers have implications for neutrino ball models of active galaxies, assuming that all gamma-ray bursts and all AGN come from neutrino balls. Either a small fraction $\\sim 10^{-2}$ of the lifetime of such an object could be spent as an AGN, or that the probability of a neutrino ball becoming an AGN would be $10^{-2}$. It is not possible to rule out the possibility that neutrino balls might exist at the centres of galaxies through direct ground-based observation of stellar kinematics.

D. Syer; Cita

1994-06-10T23:59:59.000Z

334

Three flavor neutrino oscillations, LSND, SNP and ANP  

E-Print Network (OSTI)

The recently reanalysed LSND data is investigated in the context of three flavor oscillations, with an emphasis on mass hierarchies and $s_{13}$. The resultant mass hierarchies and oscillation angles are tested with regard to "key" features of solar neutrinos and atmospheric neutrinos, e.g., "average" survival probability in the case of solar neutrinos, and zenith angle dependence and up-down asymmetry in the case of high energy atmospheric neutrinos. We find there are three distinct mass hierarchies, e.g., $\\Delta m ANP and CHOOZ, therefore, strongly supporting the neutrino oscillations observed at LSND. Further, the solutions of $s_{13}$ found in the third case correspond to the value of $s_{13}$ found by Akhmedov {\\it et al.} in the case of "SMA" and "LOW" solutions. A rough estimate of the possibility of the existence of CP violation in the leptonic sector is also carried out for different possible ranges of $s_{13}$, indicating that the CP asymmetries may be measureable even in the case of LSND.

Gulsheen Ahuja; Monika Randhawa; Manmohan Gupta

2001-04-19T23:59:59.000Z

335

Signals, backgrounds and calibrations in the Sudbury Neutrino Observatory  

Science Conference Proceedings (OSTI)

The Sudbury Neutrino Observatory is a large underground neutrino detector which is presently under construction

Bhaskar Sur; The SNO Collaboration

1995-01-01T23:59:59.000Z

336

New Neutrinos Algal Biofuels  

E-Print Network (OSTI)

New Neutrinos Algal Biofuels Charged-Particle Vision Primordial Soup LOS ALAMOS SCIENCE biofuels to run our cars, but if it costs $10 per gallon and requires petroleum products for production seven billion people, the nation seeks a competitive alternative to crude oil. Biofuel is a popular

337

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

Office of Scientific and Technical Information (OSTI)

Raymond Davis, Jr., Solar Neutrinos, Raymond Davis, Jr., Solar Neutrinos, and the Solar Neutrino Problem Resources with Additional Information Raymond Davis, Jr. Photo Courtesy of Brookhaven National Laboratory (BNL) Raymond Davis, Jr., who conducted research in the Chemistry Department at Brookhaven National Laboratory (BNL) from 1948 through 1984, was awarded the 2002 Nobel Prize in Physics "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos." Dr. Davis is also a recipient of the 2003 Fermi Award. He was the first scientist to detect solar neutrinos, ghostlike particles produced in the nuclear reactions that power the sun. "Neutrinos are fascinating particles, so tiny and fast that they can pass straight through everything, even the earth itself, without even slowing down," said Davis. "When I began my work, I was intrigued by the idea of learning something new. The interesting thing about doing new experiments is that you never know what the answer is going to be!"

338

Precision Solar Neutrino Measurements with the Sudbury Neutrino Observatory  

Science Conference Proceedings (OSTI)

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

Oblath, Noah [Center for Experimental Nuclear Physics and Astrophysics University of Washington, Seattle, WA (United States)

2007-10-26T23:59:59.000Z

339

A High Precision Reactor Neutrino Detector for the Double Chooz Experiment  

E-Print Network (OSTI)

Double Chooz is a reactor neutrino experiment which investigates the last neutrino mixing angle; theta-13. It is necessary to measure reactor neutrino disappearance with precision 1% or better to detect finite value of theta-13. This requirement is the most strict compared to other reactor neutrino experiments performed so far. The Double Chooz experiment makes use of a number of techniques to reduce the possible errors to achieve the sensitivity. The detector is now under construction and it is expected to take first neutrino data in 2009 and to measure sin^22theta-13 with a sensitivity of 0.03 (90%C.L.) In this proceedings, the technical concepts of Double Chooz detector are explained stressing on how it copes with the systematic errors.

Fumihiko Suekane; for the Double Chooz Collaboration

2009-06-09T23:59:59.000Z

340

Magnetic Field and Flavor Effects on the Gamma-Ray Burst Neutrino Flux  

E-Print Network (OSTI)

We reanalyze the prompt muon neutrino flux from gamma-ray bursts (GRBs), at the example of the often used reference Waxman-Bahcall GRB flux, in terms of the particle physics involved. We first reproduce this reference flux treating synchrotron energy losses of the secondary pions explicitly. Then we include additional neutrino production modes, the neutrinos from muon decays, the magnetic field effects on all secondary species, and flavor mixing with the current parameter uncertainties. We demonstrate that the combination of these effects modifies the shape of the original Waxman-Bahcall GRB flux significantly, and changes the normalization by a factor of three to four. As a consequence, the gamma-ray burst search strategy of neutrino telescopes may be based on the wrong flux shape, and the constraints derived for the GRB neutrino flux, such as the baryonic loading, may in fact be already much stronger than anticipated.

Philipp Baerwald; Svenja Hmmer; Walter Winter

2010-09-21T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Search for the Cosmic Neutrino Background and KATRIN  

E-Print Network (OSTI)

The Cosmic Microwave Background (CMB) has been detected in 1964 by Penzias and Wilson. It shows today a remarkable constant temperature of T ~ 2.7 K independent of the direction. Present density is about 370 photons per cubic-cm. The size of the hot spots, which deviates only in the fifth decimal of the temperature from the average value, tells us, that the universe is flat. About 300 000 years after the Big Bang at a temperature of T = 3000 K already in the matter dominated era the electrons combine with the protons and 4He and the photons move freely in the neutral universe. So the temperature and distribution of the photons give us information of the universe 300 000 years after the Big Bang. Information about earlier times can, in principle, be derived from the Cosmic Neutrino Background. The neutrinos decouple already 1 second after the Big Bang at a temperature of about 10^{10} K. Today their temperature is ~ 1.95 K and the average density is 56 electron-neutrinos per cubic-cm. Registration of these neutrinos is an extremely challenging experimental problem which can hardly be solved with the present technologies. On the other hand it represents a tempting opportunity to check one of the key element of the Big Bang cosmology and to probe the early stages of the universe evolution. The search for the cosmic relic neutrinos with the induced beta decay Electron-neutrino + 3H --> 3He + e- is the topic of this contribution. The signal would show up by a peak in the electron spectrum with an energy of the neutrino mass above the Q value. We discuss the prospects of this approach and argue that it is able to set limits on the relic neutrino density in our vicinity.

Amand Faessler; Rastislav Hodak; Sergey Kovalenko; Fedor Simkovic

2013-04-20T23:59:59.000Z

342

Neutrino signature of supernova hydrodynamical instabilities in three dimensions  

E-Print Network (OSTI)

The first full-scale three-dimensional (3D) core-collapse supernova (SN) simulations with sophisticated neutrino transport show pronounced effects of the standing accretion shock instability (SASI) for two high-mass progenitors (20 and 27 M_sun). In a low-mass progenitor (11.2 M_sun), large-scale convection is the dominant nonradial hydrodynamic instability in the postshock accretion layer. The SASI-associated modulation of the neutrino signal (80 Hz in our two examples) will be clearly detectable in IceCube or the future Hyper-Kamiokande detector, depending on progenitor properties, distance, and observer location relative to the main SASI sloshing direction. The neutrino signal from the next galactic SN can therefore diagnose the nature of the hydrodynamic instability.

Irene Tamborra; Florian Hanke; Bernhard Mueller; Hans-Thomas Janka; Georg Raffelt

2013-07-30T23:59:59.000Z

343

On the Detection of the Free Neutrino  

DOE R&D Accomplishments (OSTI)

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

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

1953-08-06T23:59:59.000Z

344

Coupling active and sterile neutrinos in the cosmon plus seesaw framework  

E-Print Network (OSTI)

The cosmological evolution of neutrino energy densities driven by cosmon-type field equations is introduced assuming that active and sterile neutrinos are intrinsically connected by cosmon fields through the {\\em seesaw} mechanism. Interpreting sterile neutrinos as dark matter adiabatically coupled with dark energy results in a natural decoupling of (active) mass varying neutrino (MaVaN) equations. Identifying the dimensionless scale of the {\\em seesaw} mechanism, $m/M$, with a power of the cosmological scale factor, $a$, allows for embedding the resulting masses into the generalized Chaplygin gas (GCG) scenario for the dark sector. Without additional assumptions, our findings establish a precise connection among three distinct frameworks: the cosmon field dynamics for MaVaN's, the {\\em seesaw} mechanism for dynamical mass generation and the GCG scenario. Our results also corroborate with previous assertions that mass varying particles can be the right responsible for the stability issue and for the cosmic ac...

Bernardini, Alex E

2009-01-01T23:59:59.000Z

345

Coupling active and sterile neutrinos in the cosmon plus seesaw framework  

E-Print Network (OSTI)

The cosmological evolution of neutrino energy densities driven by cosmon-type field equations is introduced assuming that active and sterile neutrinos are intrinsically connected by cosmon fields through the {\\em seesaw} mechanism. Interpreting sterile neutrinos as dark matter adiabatically coupled with dark energy results in a natural decoupling of (active) mass varying neutrino (MaVaN) equations. Identifying the dimensionless scale of the {\\em seesaw} mechanism, $m/M$, with a power of the cosmological scale factor, $a$, allows for embedding the resulting masses into the generalized Chaplygin gas (GCG) scenario for the dark sector. Without additional assumptions, our findings establish a precise connection among three distinct frameworks: the cosmon field dynamics for MaVaN's, the {\\em seesaw} mechanism for dynamical mass generation and the GCG scenario. Our results also corroborate with previous assertions that mass varying particles can be the right responsible for the stability issue and for the cosmic acceleration of the universe.

Alex E. Bernardini

2009-11-02T23:59:59.000Z

346

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

SciTech Connect

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

Ochoa Ricoux, Juan Pedro; /Caltech

2009-10-01T23:59:59.000Z

347

Solar Neutrino Observations at the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

The Sudbury Neutrino Observatory (SNO) is a 1000-tonne heavy water Cherenkov detector. Its usage of \\dto as target allows the simultaneous measurements of the $\

Poon, A W P

2002-01-01T23:59:59.000Z

348

Solar Neutrino Observations at the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

The Sudbury Neutrino Observatory (SNO) is a 1000-tonne heavy water Cherenkov detector. Its usage of \\dto as target allows the simultaneous measurements of the $\

A. W. P. Poon

2002-11-06T23:59:59.000Z

349

Solar neutrino experiments: An update  

Science Conference Proceedings (OSTI)

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

Hahn, R.L.

1993-12-31T23:59:59.000Z

350

Low-energy solar anti-neutrinos  

E-Print Network (OSTI)

If neutrino conversions within the Sun result in partial polarization of initial solar neutrino fluxes, then a new opportunity arises to observe the anti-\

V. B. Semikoz; S. Pastor; J. W. F. Valle

1998-08-13T23:59:59.000Z

351

Light Sterile Neutrinos: A White Paper  

E-Print Network (OSTI)

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.

K. N. Abazajian; M. A. Acero; S. K. Agarwalla; A. A. Aguilar-Arevalo; C. H. Albright; S. Antusch; C. A. Arguelles; A. B. Balantekin; G. Barenboim; V. Barger; P. Bernardini; F. Bezrukov; O. E. Bjaelde; S. A. Bogacz; N. S. Bowden; A. Boyarsky; A. Bravar; D. Bravo Berguno; S. J. Brice; A. D. Bross; B. Caccianiga; F. Cavanna; E. J. Chun; B. T. Cleveland; A. P. Collin; P. Coloma; J. M. Conrad; M. Cribier; A. S. Cucoanes; J. C. D'Olivo; S. Das; A. de Gouvea; A. V. Derbin; R. Dharmapalan; J. S. Diaz; X. J. Ding; Z. Djurcic; A. Donini; D. Duchesneau; H. Ejiri; S. R. Elliott; D. J. Ernst; A. Esmaili; J. J. Evans; E. Fernandez-Martinez; E. Figueroa-Feliciano; B. T. Fleming; J. A. Formaggio; D. Franco; J. Gaffiot; R. Gandhi; Y. Gao; G. T. Garvey; V. N. Gavrin; P. Ghoshal; D. Gibin; C. Giunti; S. N. Gninenko; V. V. Gorbachev; D. S. Gorbunov; R. Guenette; A. Guglielmi; F. Halzen; J. Hamann; S. Hannestad; W. Haxton; K. M. Heeger; R. Henning; P. Hernandez; P. Huber; W. Huelsnitz; A. Ianni; T. V. Ibragimova; Y. Karadzhov; G. Karagiorgi; G. Keefer; Y. D. Kim; J. Kopp; V. N. Kornoukhov; A. Kusenko; P. Kyberd; P. Langacker; Th. Lasserre; M. Laveder; A. Letourneau; D. Lhuillier; Y. F. Li; M. Lindner; J. M. Link; B. L. Littlejohn; P. Lombardi; K. Long; J. Lopez-Pavon; W. C. Louis; L. Ludhova; J. D. Lykken; P. A. N. Machado; M. Maltoni; W. A. Mann; D. Marfatia; C. Mariani; V. A. Matveev; N. E. Mavromatos; A. Melchiorri; D. Meloni; O. Mena; G. Mention; A. Merle; E. Meroni; M. Mezzetto; G. B. Mills; D. Minic; L. Miramonti; D. Mohapatra; R. N. Mohapatra; C. Montanari; Y. Mori; Th. A. Mueller; H. P. Mumm; V. Muratova; A. E. Nelson; J. S. Nico; E. Noah; J. Nowak; O. Yu. Smirnov; M. Obolensky; S. Pakvasa; O. Palamara; M. Pallavicini; S. Pascoli; L. Patrizii; Z. Pavlovic; O. L. G. Peres; H. Pessard; F. Pietropaolo; M. L. Pitt; M. Popovic; J. Pradler; G. Ranucci; H. Ray; S. Razzaque; B. Rebel; R. G. H. Robertson; W. Rodejohann; S. D. Rountree; C. Rubbia; O. Ruchayskiy; P. R. Sala; K. Scholberg; T. Schwetz; M. H. Shaevitz; M. Shaposhnikov; R. Shrock; S. Simone; M. Skorokhvatov; M. Sorel; A. Sousa; D. N. Spergel; J. Spitz; L. Stanco; I. Stancu; A. Suzuki; T. Takeuchi; I. Tamborra; J. Tang; G. Testera; X. C. Tian; A. Tonazzo; C. D. Tunnell; R. G. Van de Water; L. Verde; E. P. Veretenkin; C. Vignoli; M. Vivier; R. B. Vogelaar; M. O. Wascko; J. F. Wilkerson; W. Winter; Y. Y. Y. Wong; T. T. Yanagida; O. Yasuda; M. Yeh; F. Yermia; Z. W. Yokley; G. P. Zeller; L. Zhan; H. Zhang

2012-04-18T23:59:59.000Z

352

Neutrino Opacities in Nuclear Matter  

E-Print Network (OSTI)

Neutrino-matter cross sections and interaction rates are central to the core-collapse supernova phenomenon and, very likely, to the viability of the explosion mechanism itself. In this paper, we describe the major neutrino scattering, absorption, and production processes that together influence the outcome of core collapse and the cooling of protoneutron stars. One focus is on energy redistribution and many-body physics, but our major goal is to provide a useful resource for those interested in supernova neutrino microphysics.

Adam Burrows; Sanjay Reddy; Todd A. Thompson

2004-04-21T23:59:59.000Z

353

Limits on Neutrino-Neutrino Scattering in the Early Universe  

E-Print Network (OSTI)

In the standard model neutrinos are assumed to have streamed across the Universe since they last scattered at the weak decoupling epoch when the temperature of the standard-model plasma was ~MeV. The shear stress of free-streaming neutrinos imprints itself gravitationally on the Cosmic Microwave Background (CMB) and makes the CMB a sensitive probe of neutrino scattering. Yet, the presence of nonstandard physics in the neutrino sector may alter this standard chronology and delay neutrino free-streaming until a much later epoch. We use observations of the CMB to constrain the strength of neutrino self-interactions G_eff and put limits on new physics in the neutrino sector from the early Universe. Recent measurements of the CMB at large multipoles made by the Planck satellite and high-l experiments are critical for probing this physics. Within the context of conventional LambdaCDM parameters cosmological data are compatible with G_eff cooled to as low as ~25 eV. Intriguingly, we also find an alternative cosmology compatible with cosmological data in which neutrinos scatter off each other until z~10^4 with a preferred interaction strength in a narrow region around G_eff = 1/(10 MeV)^2. This distinct self-interacting neutrino cosmology is characterized by somewhat lower values of both the scalar spectral index and the amplitude of primordial fluctuations. While we phrase our discussion here in terms of a specific scenario in which a late onset of neutrino free-streaming could occur, our constraints on the neutrino visibility function are very general.

Francis-Yan Cyr-Racine; Kris Sigurdson

2013-06-06T23:59:59.000Z

354

Neutrino Factory Feasibility Study  

NLE Websites -- All DOE Office Websites (Extended Search)

6-1 - 6-1 - April 15 th , 2000 6. Cooling 6.1 Introduction The goal of this six-month study is an integrated design for a neutrino source, subject to realistic engineering constraints. As will become evident, the coupling between the cooling-channel design and the design of the upstream components is critical to achieving the best performance. Nevertheless, to make sufficiently rapid progress it has been necessary to design the various components semi-independently, then optimize and iterate to converge towards an integrated design. While we have not yet arrived at a fully optimized design, we have studied sufficiently the cooling channels described below to determine that their performance is limited primarily by the performance of the current phase-rotation and buncher designs. While the designs presented here suffice for an entry-level neutrino factory (10

355

Neutrino Oscillations and Blazars  

E-Print Network (OSTI)

Three independent predictions follow from postulating the existence of protons co-accelerated with electrons in extragalactic jets (i) multi-TeV gamma ray emission from nearby blazars, (ii) extragalactic cosmic ray protons up to ray observations of Mrk 421 and Mrk 501 employing the air-Cerenkov technique are consistent with the predicted gamma ray spectrum, if one corrects for pair attenuation on the infrared background. Prediction (ii) is consistent with cosmic ray data, if one requires that jets are responsible for the extragalactic gamma ray background above 100 MeV. With kubic kilometer neutrino telescopes, it will be possible to test (iii), although the muon event rates are rather low. Neutrino oscillations can increase the event rate by inducing tau-cascades removing the Earth shadowing effect.

Mannheim, K

1999-01-01T23:59:59.000Z

356

Neutrino Clustering in the Galaxy with a Global Monopole  

E-Print Network (OSTI)

In spherically symmetric, static spacetime, we show that only j=1/2 fermions can satisfy both Einstein's field equation and Dirac's equation. It is also shown that neutrinos are able to have effective masses and cluster in the galactic halo when they are coupled to a global monopole situated at the galactic core. Astronomical implications of the results are discussed.

T. H. Lee; B. H. J. McKellar

2002-12-03T23:59:59.000Z

357

Integrated Nucleosynthesis in Neutrino Driven Winds  

E-Print Network (OSTI)

Although they are but a small fraction of the mass ejected in core-collapse supernovae, neutrino-driven winds (NDWs) from nascent proto-neutron stars (PNSs) have the potential to contribute significantly to supernova nucleosynthesis. In previous works, the NDW has been implicated as a possible source of r-process and light p-process isotopes. In this paper we present time-dependent hydrodynamic calculations of nucleosynthesis in the NDW which include accurate weak interaction physics coupled to a full nuclear reaction network. Using two published models of PNS neutrino luminosities, we predict the contribution of the NDW to the integrated nucleosynthetic yield of the entire supernova. For the neutrino luminosity histories considered, no true r-process occurs in the most basic scenario. The wind driven from an older $1.4 M_\\odot$ model for a PNS is moderately neutron-rich at late times however, and produces $^{87}$Rb, $^{88}$Sr, $^{89}$Y, and $^{90}$Zr in near solar proportions relative to oxygen. The wind fro...

Roberts, L F; Hoffman, R D

2010-01-01T23:59:59.000Z

358

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

SciTech Connect

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

Monroe, Jocelyn R.; /Columbia U.

2006-07-01T23:59:59.000Z

359

Research Program towards Observation of Neutrino-Nucleus Coherent Scattering  

E-Print Network (OSTI)

The article describes the research program pursued by the TEXONO Collaboration towards an experiment to observe coherent scattering between neutrinos and the nucleus at the power reactor. The motivations of studying this process are surveyed. In particular, a threshold of 100-200 eV has been achieved with an ultra-low-energy germanium detector prototype. This detection capability at low energy can also be adapted to conduct searches of Cold Dark Matter in the low-mass region as well as to enhance the sensitivities in the study of neutrino magnetic moments.

Henry T. Wong

2005-11-01T23:59:59.000Z

360

On the Dynamics of Non-Relativistic Flavor-Mixed Particles  

E-Print Network (OSTI)

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

Mikhail V. Medvedev

2013-05-06T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Observation of Geo-Neutrinos  

E-Print Network (OSTI)

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

Borexino Collaboration

2010-03-01T23:59:59.000Z

362

Geomagnetic Effects on Atmospheric Neutrinos  

E-Print Network (OSTI)

Geomagnetic effects distort the zenith angle distribution of sub--GeV and few--GeV atmospheric neutrinos, breaking the up--down symmetry that would be present in the absence of neutrino oscillations and without a geomagnetic field. The geomagnetic effects also produce a characteristic azimuthal dependence of the $\

Paolo Lipari; T. K. Gaisser; Todor Stanev

1998-03-09T23:59:59.000Z

363

Solar Hydrogen Burning and Neutrinos  

E-Print Network (OSTI)

We summarize the current status of laboratory measurements of nuclear cross sections of the pp chain and CN cycle. We discuss the connections between such measurements, predictions of solar neutrino fluxes, and the conclusion that solar neutrinos oscillate before reaching earth.

W. C. Haxton; P. D. Parker; C. E. Rolfs

2005-01-10T23:59:59.000Z

364

Is there evidence for sterile neutrinos in IceCube data?  

E-Print Network (OSTI)

Data from the LSND and MiniBooNE experiments, and revised expectations of the antineutrino flux from nuclear reactors suggest the existence of eV-mass sterile neutrinos. 3+2 and 1+3+1 scenarios accommodate all relevant short-baseline neutrino data except for the low-energy MiniBooNE anomaly. We analyze the angular distribution of upward going atmospheric neutrino events in the IceCube-40 dataset for evidence of sterile neutrinos within these scenarios. Depending on how systematic uncertainties are handled, we find strong evidence for, or weak evidence against sterile neutrinos. We show that future IceCube data will definitively settle the issue.

V. Barger; Y. Gao; D. Marfatia

2011-09-27T23:59:59.000Z

365

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

SciTech Connect

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

Shima, T.; /Osaka U., Res. Ctr. Nucl. Phys.; Doe, P.J.; /Washington U., Seattle; Ejiri, H.; /Osaka U., Res. Ctr. Nucl. Phys. /NIRS, Chiba /Prague, Tech. U.; Elliot, S.R.; /Washington U., Seattle /Los Alamos; Engel, J.; /North Carolina U.; Finger, M.; /Charles U.; Finger, M.; /Charles U.; Fushimi, K.; /Tokushima U.; Gehman, V.M.; /Washington U., Seattle /Los Alamos; Greenfield, M.B.; /Tokyo, Intl. Christian U.; Hazama, R.; /Hiroshima U. /NIRS, Chiba

2008-01-01T23:59:59.000Z

366

Split Two-Higgs-Doublet Model and Neutrino Condensation  

E-Print Network (OSTI)

We split the two-Higgs-doublet model by assuming very different vevs for the two doublets: the vev is at weak scale (174 GeV) for the doublet \\Phi_1 and at neutrino-mass scale (10^{-2} \\sim 10^{-3} eV) for the doublet \\Phi_2. \\Phi_1 is responsible for giving masses to all fermions except neutrinos; while \\Phi_2 is responsible for giving neutrino masses through its tiny vev without introducing see-saw mechanism. Among the predicted five physical scalars H, h, A^0 and H^{\\pm}, the CP-even scalar h is as light as 10^{-2} \\sim 10^{-3}eV while others are at weak scale. We identify h as the cosmic dark energy field and the other CP-even scalar H as the Standard Model Higgs boson; while the CP-odd A^0 and the charged H^{\\pm} are the exotic scalars to be discovered at future colliders. Also we demonstrate a possible dynamical origin for the doublet \\Phi_2 from neutrino condensation caused by some unknown dynamics.

Fei Wang; Wenyu Wang; Jin Min Yang

2006-01-03T23:59:59.000Z

367

Measurement of muon neutrino quasi-elastic scattering on carbon  

SciTech Connect

Low energy (200 < E{sub v} < 2000 MeV) neutrino oscillation experiments, including MiniBooNE, require a model of charged current quasi-elastic (CCQE) neutrino interactions to predict signal samples. Using a high-statistics sample of muon neutrino CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events observed in a carbon-based detector. The extracted parameters include an effective axial mass, M{sub A} = 1.23 {+-} 0.20 GeV, used to describe the four-momentum dependence of the axial-vector form factor of the nucleon; and a Pauli-suppression parameter, {kappa} = 1.019 {+-} 0.011.

Aguilar-Arevalo, A.A.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; Djurcic, Z.; /Alabama U. /Bucknell

2007-06-01T23:59:59.000Z

368

The Daya Bay Reactor Neutrino Experiment Sees Evidence that Electron...  

Office of Science (SC) Website

Neutrino Experiment Sees Evidence that Electron Neutrinos Turn into Muon Neutrinos Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP...

369

Diffuse supernova neutrino background is detectable in Super-Kamiokande  

Science Conference Proceedings (OSTI)

The diffuse supernova neutrino background (DSNB) provides an immediate opportunity to study the emission of MeV thermal neutrinos from core-collapse supernovae. The DSNB is a powerful probe of stellar and neutrino physics, provided that the core-collapse rate is large enough and that its uncertainty is small enough. To assess the important physics enabled by the DSNB, we start with the cosmic star formation history of Hopkins and Beacom (2006) and confirm its normalization and evolution by cross-checks with the supernova rate, extragalactic background light, and stellar mass density. We find a sufficient core-collapse rate with small uncertainties that translate into a variation of {+-}40% in the DSNB event spectrum. Considering thermal neutrino spectra with effective temperatures between 4-6 MeV, the predicted DSNB is within a factor 4-2 below the upper limit obtained by Super-Kamiokande in 2003. Furthermore, detection prospects would be dramatically improved with a gadolinium-enhanced Super-Kamiokande: the backgrounds would be significantly reduced, the fluxes and uncertainties converge at the lower threshold energy, and the predicted event rate is 1.2-5.6 events yr{sup -1} in the energy range 10-26 MeV. These results demonstrate the imminent detection of the DSNB by Super-Kamiokande and its exciting prospects for studying stellar and neutrino physics.

Horiuchi, Shunsaku [Department of Physics, School of Science, University of Tokyo, Tokyo 113-0033 (Japan); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Beacom, John F. [Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Dwek, Eli [Observational Cosmology Lab, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2009-04-15T23:59:59.000Z

370

High energy neutrino emission from the earliest gamma-ray bursts  

SciTech Connect

We discuss the high energy neutrino emission from gamma-ray bursts resulting from the earliest generation (''population III'') stars forming in the Universe, whose core collapses into a black hole. These gamma-ray bursts are expected to produce a highly relativistic, magnetically dominated jet, where protons can be accelerated to ultrahigh energies. These interact with the photons produced by the jet, leading to ultrahigh energy photomeson neutrinos as well as secondary leptons and photons. The photon luminosity and the shock properties, and thus the neutrino spectrum, depend on the mass of the black holes as well as on the density of the surrounding external gas. We calculate the individual source neutrino spectral fluxes and the expected diffuse neutrino flux for various source parameters and evolution scenarios. Both the individual and diffuse signals appear detectable in the 1-300 PeV range with current and planned neutrino detectors such as IceCube and ARIANNA, provided the black hole mass is in excess of 30-100 solar masses. This provides a possible test for the debated mass of the progenitor stellar objects, as well as a probe for the early cosmological environment and the formation rate of the earliest structures.

Gao Shan; Toma, Kenji; Meszaros, Peter [Department of Physics, Department of Astronomy and Astrophysics, Center for Particle Astrophysics, Pennsylvania State University, University Park, 16802 (United States)

2011-05-15T23:59:59.000Z

371

High-energy atmospheric neutrinos  

E-Print Network (OSTI)

High-energy neutrinos, arising from decays of mesons that were produced through the cosmic rays collisions with air nuclei, form unavoidable background noise in the astrophysical neutrino detection problem. The atmospheric neutrino flux above 1 PeV should be supposedly dominated by the contribution of charmed particle decays. These (prompt) neutrinos originated from decays of massive and shortlived particles, $D^\\pm$, $D^0$, $\\bar{D}{}^0$, $D_s^\\pm$, $\\Lambda^+_c$, form the most uncertain fraction of the high-energy atmospheric neutrino flux because of poor explored processes of the charm production. Besides, an ambiguity in high-energy behavior of pion and especially kaon production cross sections for nucleon-nucleus collisions may affect essentially the calculated neutrino flux. There is the energy region where above flux uncertainties superimpose. A new calculation presented here reveals sizable differences, up to the factor of 1.8 above 1 TeV, in muon neutrino flux predictions obtained with usage of known...

Sinegovsky, S I; Sinegovskaya, T S

2010-01-01T23:59:59.000Z

372

High-energy atmospheric neutrinos  

E-Print Network (OSTI)

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

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

2010-10-12T23:59:59.000Z

373

Physics potential of T2KK: An extension of the T2K neutrino oscillation experiment with a far detector in Korea  

E-Print Network (OSTI)

We study physics potential of placing a far detector in the east coast of Korea, where the off-axis beam from J-PARC at Tokai village for the T2K project has significant intensity at a few GeV range. In particular we examine the capability of determining the mass hierarchy pattern and the CP phase of the lepton-flavor-mixing matrix when a 100 kt water Cerenkov detector is placed at various locations in Korea for the off-axis beam (OAB) of 2.5 deg. and 3 deg. at the Super-Kamiokande site. The best results are found for a combination of 3 deg. OAB at SK (L = 295 km) and 0.5 deg. OAB at L = 1000km, where the mass hierarchy pattern can be determined at 3-\\sigma level for sin^2 2\\theta_{RCT} \\simgt 0.05 (0.06) when the hierarchy is normal (inverted), after 5 years of running (5 \\times 10^{21}POT). We also find that the leptonic CP phase, \\delta_{MNS}, can be constrained uniquely, without invoking anti-neutrino beams, as long as the mass hierarchy pattern is determined. Those results are obtained by assuming that the charged current quasi-elastic events can be separated from the other backgrounds with high efficiency, the neutrino energy can be reconstructed with a hundred MeV uncertainty, and the earth matter density along the baseline can be determined with 3% accuracy.

Kaoru Hagiwara; Naotoshi Okamura; Ken-ichi Senda

2006-07-23T23:59:59.000Z

374

Update of the solar neutrino oscillation analysis with the 766 Ty KamLAND spectrum  

E-Print Network (OSTI)

We investigate the impact of the 766.3 Ty KamLAND spectrum data on the determination of the solar neutrino oscillation parameters. We show that the observed spectrum distortion in the KamLAND experiment firmly establishes $\\Delta m^2_{21}$ to lie in the low-LMA solution region. The high-LMA solution is excluded at more than 4$\\sigma$ by the global solar neutrino and KamLAND spectrum data. The maximal solar neutrino mixing is ruled out at $6\\sigma$ level. The $3\\sigma$ allowed region in the $\\Delta m^2_{21}-\\sin^2\\theta_{12}$ plane is found to be remarkably stable with respect to leaving out the data from one of the solar neutrino experiments from the global analysis. We perform a three flavor neutrino oscillation analysis of the global solar neutrino and KamLAND spectrum data as well. The $3\\sigma$ upper limit on $\\sin^2\\theta_{13}$ is found to be $ \\sin^2\\theta_{13} solar neutrino oscillation parameters are also discussed.

Abhijit Bandyopadhyay; Sandhya Choubey; Srubabati Goswami; S. T. Petcov; D. P. Roy

2004-06-29T23:59:59.000Z

375

Neutrinos in Cosmology and Astrophysics  

E-Print Network (OSTI)

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

A. B. Balantekin; G. M. Fuller

2013-03-15T23:59:59.000Z

376

The neutrino process and neutrino r-process  

SciTech Connect

Almost all of the 3 {center dot} 10{sup 53} ergs released in a core-collapse supernova is carried off by the neutrinos emitted from the cooling neutron star. These neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions, leading to the spallation of nucleonsa and {alpha}-particles and the production of new daughter nuclei, I will describe rather detailed network calculations that suggest this neutrino process'' is an important nucleosynthesis mechanisms that may be responsible for the galactic abundances of {sup 7}Li, {sup 11}B, {sup 19}F, {sup 138}La, {sup 180}Ta, and a number of other nuclei. I also discuss the possibility of an r-process in the He zone of a low-Z progenitor that could be driven, in part, by neutrinos.

Haxton, W.C.

1991-01-01T23:59:59.000Z

377

The neutrino process and neutrino r-process  

SciTech Connect

Almost all of the 3 {center_dot} 10{sup 53} ergs released in a core-collapse supernova is carried off by the neutrinos emitted from the cooling neutron star. These neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions, leading to the spallation of nucleonsa and {alpha}-particles and the production of new daughter nuclei, I will describe rather detailed network calculations that suggest this ``neutrino process`` is an important nucleosynthesis mechanisms that may be responsible for the galactic abundances of {sup 7}Li, {sup 11}B, {sup 19}F, {sup 138}La, {sup 180}Ta, and a number of other nuclei. I also discuss the possibility of an r-process in the He zone of a low-Z progenitor that could be driven, in part, by neutrinos.

Haxton, W.C.

1991-12-31T23:59:59.000Z

378

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

ux in the Standard Solar Model of the Sun. The long-standingwithin the solar core (inner ?20% of the Suns radius). Thesolar neutrino ?ux probe the nuclear fusion reactions fueling the Sun.

Marino, Alysia Diane

2004-01-01T23:59:59.000Z

379

Constraining neutrino magnetic moment with solar and reactor neutrino data  

E-Print Network (OSTI)

We use solar neutrino data to derive stringent bounds on Majorana neutrino transition moments (TMs). Such moments, if present, would contribute to the neutrino-electron scattering cross section and hence alter the signal observed in Super-Kamiokande. Using the latest solar neutrino data, combined with the results of the reactor experiment KamLAND, we perform a simultaneous fit of the oscillation parameters and TMs. Furthermore, we include data from the reactor experiments Rovno, TEXONO and MUNU in our analysis, improving significantly the current constraints on TMs. A comparison with previous works shows that our bounds are the strongest and most general results presented up to now. Finally, we perform a simulation of the future Borexino experiment and show that it will improve the bounds from today's data by order of magnitude.

M. A. Tortola

2004-01-19T23:59:59.000Z

380

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

the neutrinos from a nuclear reactor by the Cl 37 ( , e ? )the Savannah River nuclear reactor in 1956 [9]. Here Reinessources include nuclear reactors and the decays of cosmic-

Marino, Alysia Diane

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
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381

The Double Chooz reactor neutrino experiment  

E-Print Network (OSTI)

The Double Chooz reactor neutrino experiment will be the next detector to search for a non vanishing theta13 mixing angle with unprecedented sensitivity, which might open the way to unveiling CP violation in the leptonic sector. The measurement of this angle will be based in a precise comparison of the antineutrino spectrum at two identical detectors located at different distances from the Chooz nuclear reactor cores in France. Double Chooz is particularly attractive because of its capability to measure sin2(2theta13) to 3 sigmas if sin2(2theta13) > 0.05 or to exclude sin2(2theta13) down to 0.03 at 90% C.L. for Dm2 = 2.5 x 10-3 eV2 in three years of data taking with both detectors. The construction of the far detector starts in 2008 and the first neutrino results are expected in 2009. The current status of the experiment, its physics potential and design and expected performance of the detector are reviewed.

I. Gil-Botella

2007-10-23T23:59:59.000Z

382

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

E-Print Network (OSTI)

The objective of the Majorana Experiment is to study neutrinoless double beta decay (0nbb) with an effective Majorana-neutrino mass sensitivity below 50 meV in order to characterize the Majorana nature of the neutrino, the Majorana mass spectrum, and the absolute mass scale. An experimental study of the neutrino mass scale implied by neutrino oscillation results is now technically within our grasp. This exciting physics goal is best pursued using the well-established technique of searching for 0nbb of 76Ge, augmented with recent advances in signal processing and detector design. The Majorana Experiment will consist of a large mass of 76Ge in the form of high-resolution intrinsic germanium detectors located deep underground within a low-background shielding environment. Observation of a sharp peak at the bb endpoint will quantify the 0nbb half-life and thus the effective Majorana mass of the electron neutrino. In addition to the modest R&D program, we present here an overview of the entire project in order to help put in perspective the scope, the low level of technical risk, and the readiness of the Collaboration to immediately begin the undertaking.

The Majorana collaboration

2003-11-13T23:59:59.000Z

383

Neutrino Emission from Gamma-Ray Burst Fireballs, Revised  

E-Print Network (OSTI)

We review the neutrino flux from gamma-ray bursts, which is estimated from gamma-ray observations and used for the interpretation of recent IceCube data, from a particle physics perspective. We numerically calculate the neutrino flux for the same astrophysical assumptions as the analytical fireball neutrino model, including the dominant pion and kaon production modes, flavor mixing, and magnetic field effects on the secondary muons, pions, and kaons. We demonstrate that taking into account the full energy dependencies of all spectra, the normalization of the expected neutrino flux reduces by about one order of magnitude and the spectrum shifts to higher energies, where we can pin down the exact origin of the discrepancies by the re-computation of the analytical models. We also reproduce the IceCube-40 analysis for exactly the same bursts and same assumptions and illustrate the impact of uncertainties. We conclude that the baryonic loading of the fireballs, which is an important control parameter for the emission of cosmic rays, can be constrained significantly with the full-scale experiment after about ten years.

Svenja Hmmer; Philipp Baerwald; Walter Winter

2011-12-05T23:59:59.000Z

384

Non-Standard Models, Solar Neutrinos, and Large ?_{13}  

E-Print Network (OSTI)

Solar neutrino experiments have yet to see directly the transition region between matter-enhanced and vacuum oscillations. The transition region is particularly sensitive to models of non-standard neutrino interactions and propagation. We examine several such non-standard models, which predict a lower-energy transition region and a flatter survival probability for the ^{8}B solar neutrinos than the standard large-mixing angle (LMA) model. We find that while some of the non-standard models provide a better fit to the solar neutrino data set, the large measured value of \\theta_{13} and the size of the experimental uncertainties lead to a low statistical significance for these fits. We have also examined whether simple changes to the solar density profile can lead to a flatter ^{8}B survival probability than the LMA prediction, but find that this is not the case for reasonable changes. We conclude that the data in this critical region is still too poor to determine whether any of these models, or LMA, is the best description of the data.

R. Bonventre; A. LaTorre; J. R. Klein; G. D. Orebi Gann; S. Seibert; O. Wasalski

2013-05-24T23:59:59.000Z

385

Neutrinos interacting with Polarizable Media  

E-Print Network (OSTI)

We study Cherenkov and transition radiation of neutral spin 1/2 particles which carry magnetic moments or electric dipole moments. In particular, we estimate the radiation caused by the solar neutrino flux in dielectric media.

W. Grimus; H. Neufeld

1994-10-20T23:59:59.000Z

386

Neutrino capital of the world  

E-Print Network (OSTI)

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

Johnson, Carolyn Y., 1980-

2004-01-01T23:59:59.000Z

387

The Fermilab neutrino beam program  

Science Conference Proceedings (OSTI)

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

Rameika, Regina A.; /Fermilab

2007-01-01T23:59:59.000Z

388

Fermion Masses and Coupling Unification in E6. Life in the Desert  

E-Print Network (OSTI)

We present an $E_6$ Grand Unified model with a realistic pattern of fermion masses. All standard model fermions are unified in three fundamental 27-plets (i.e. supersymmetry is not invoked), which involve in addition right handed neutrinos and three families of vector like heavy quarks and leptons. The lightest of those can lie in the low TeV range, being accessible to future collider experiments. Due to the high symmetry, the masses and mixings of all fermions are closely related. The new heavy fermions play a crucial role for the quark and lepton mass matrices and the bilarge neutrino oscillations. In all channels generation mixing and ${\\cal CP}$ violation arise from a single antisymmetric matrix. The $E_6$ breaking proceeds via an intermediate energy region with $SU(3)_L\\tm SU(3)_R\\tm SU(3)_C$ gauge symmetry and a discrete left-right symmetry. This breaking pattern leads in a straightforward way to the unification of the three gauge coupling constants at high scales, providing for a long proton lifetime. The model also provides for the unification of the top, bottom and tau Yukawa couplings and for new interesting relations in flavor and generation space.

Berthold Stech; Zurab Tavartkiladze

2003-11-12T23:59:59.000Z

389

Self-induced conversion in dense neutrino gases: Pendulum in flavour space  

E-Print Network (OSTI)

Neutrino-neutrino interactions can lead to collective flavour conversion effects in supernovae and in the early universe. We demonstrate that the case of "bipolar" oscillations, where a dense gas of neutrinos and antineutrinos in equal numbers completely converts from one flavour to another even if the mixing angle is small, is equivalent to a pendulum in flavour space. Bipolar flavour conversion corresponds to the swinging of the pendulum, which begins in an unstable upright position (the initial flavour), and passes through momentarily the vertically downward position (the other flavour) in the course of its motion. The time scale to complete one cycle of oscillation depends logarithmically on the vacuum mixing angle. Likewise, the presence of an ordinary medium can be shown analytically to contribute to a logarithmic increase in the bipolar conversion period. We further find that a more complex (and realistic) system of unequal numbers of neutrinos and antineutrinos is analogous to a spinning top subject to a torque. This analogy easily explains how such a system can oscillate in both the bipolar and the synchronised mode, depending on the neutrino density and the size of the neutrino-antineutrino asymmetry. Our simple model applies strictly only to isotropic neutrino gasses. In more general cases, and especially for neutrinos streaming from a supernova core, different modes couple to each other with unequal strength, an effect that can lead to kinematical decoherence in flavour space rather than collective oscillations. The exact circumstances under which collective oscillations occur in non-isotropic media remain to be understood.

S. Hannestad; G. G. Raffelt; G. Sigl; Y. Y. Y. Wong

2006-08-31T23:59:59.000Z

390

Probing Radiative Solar Neutrinos Decays  

E-Print Network (OSTI)

Motivated by a pilot experiment conducted by F.Vannucci et al. during a solar eclipse, we work out the geometry governing the radiative decays of solar neutrinos. Surprisingly, although a smaller proportion of the photons can be detected, the case of strongly non-degenerate neutrinos brings better limits in terms of the fundamental couplings. We advocate satellite-based experiments to improve the sensitivity.

Frre, J M

1998-01-01T23:59:59.000Z

391

Neutrino oscillations, global analysis and theta(13)  

E-Print Network (OSTI)

At the previous Venice meeting NO-VE 2008, we discussed possible hints in favor of a nonzero value for the unknown neutrino mixing angle theta(13), emerging from the combination of solar and long-baseline reactor data, as well as from the combination of atmospheric, CHOOZ and long-baseline accelerator nu_mu->nu_mu data. Recent MINOS 2009 results in the nu_mu->nu_e appearance channel also seem to support such hints. A combination of all current oscillation data provides, as preferred range, sin^2 theta(13) = 0.02 +- 0.01 (1\\sigma). We review several issues raised by such hints in the last year, and comment on their possible near-future improvements and tests.

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

2009-05-21T23:59:59.000Z

392

Atmospheric Neutrinos in the MINOS Far Detector  

Science Conference Proceedings (OSTI)

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

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

2004-12-01T23:59:59.000Z

393

Neutrino factories: realization and physics potential  

SciTech Connect

Neutrino Factories offer an exciting option for the long-term neutrino physics program. This new type of neutrino facility will provide beams with unique properties. Low systematic uncertainties at a Neutrino Factory, together with a unique and precisely known neutrino flavor content, will enable neutrino oscillation measurements to be made with unprecedented sensitivity and precision. Over recent years, the resulting neutrino factory physics potential has been discussed extensively in the literature. In addition, over the last six years the R&D necessary to realize a Neutrino Factory has been progressing, and has developed into a significant international activity. It is expected that, within about five more years, the initial phase of this R&D program will be complete and, if the community chooses to build this new type of neutrino source within the following decade, neutrino factory technology will be ready for the final R&D phase prior to construction. In this paper (1) an overview is given of the technical ingredients needed for a Neutrino Factory, (2) beam properties are described, (3) the resulting neutrino oscillation physics potential is summarized, (4) a more detailed description is given for one representative Neutrino Factory design, and (5) the ongoing R&D program is summarized, and future plans briefly described.

Geer, S.; /Fermilab; Zisman, M.S.; /LBL, Berkeley

2006-12-01T23:59:59.000Z

394

Solar Neutrino Oscillation Parameters in Experiments with Reactor Anti-Neutrinos  

E-Print Network (OSTI)

We review the current status of the solar neutrino oscillation parameters. We discuss the conditions under which measurements from future solar neutrino experiments would determine the oscillation parameters precisely. Finally we expound the potential of long baseline reactor anti-neutrino experiments in measuring the solar neutrino oscillation parameters.

Sandhya Choubey

2004-02-27T23:59:59.000Z

395

Measurement of theta13 with reactor neutrinos  

E-Print Network (OSTI)

? detectors ~1 km nuclear reactor Figure 2. Concept of a 2-Measurement of ? 13 with Reactor Neutrinos K.M. Heeger a ,power plant, a future reactor neutrino experiment has the

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

2004-01-01T23:59:59.000Z

396

Solar Neutrinos: Models, Observations, and New Opportunities  

E-Print Network (OSTI)

I discuss the development and resolution of the solar neutrino problem, as well as opportunities now open to us to extend our knowledge of main-sequence stellar evolution and neutrino astrophysics.

W. C. Haxton

2007-10-11T23:59:59.000Z

397

Manual Calibration System for Daya Bay Reactor Neutrino Experiment  

E-Print Network (OSTI)

The Daya Bay Reactor Neutrino Experiment has measured the last unknown neutrino mixing angle, {\\theta}13, to be non-zero at the 7.7{\\sigma} level. This is the most precise measurement to {\\theta}13 to date. To further enhance the understanding of the response of the antineutrino detectors (ADs), a detailed calibration of an AD with the Manual Calibration System (MCS) was undertaken during the summer 2012 shutdown. The MCS is capable of placing a radioactive source with a positional accuracy of 25 mm in R direction, 20 mm in Z axis and 0.5{\\deg} in {\\Phi} direction. A detailed description of the MCS is presented followed by a summary of its performance in the AD calibration run.

Hanxiong Huang; Xichao Ruan; Jie Ren; Chengjun Fan; Yannan Chen; Yinglong Lv; Zhaohui Wang; Zuying Zhou; Long Hou; Biao Xin; Chaoju Yu; Jiawen Zhang; Yinghong Zhang; Jingzhi Bai; Honglin Zhuang; Wei He; Jianglai Liu; Elizabeth Worcester; Harry Themann; Jeff Cherwinka; David M. Webber

2013-05-10T23:59:59.000Z

398

Atmospheric neutrino flux at INO site  

Science Conference Proceedings (OSTI)

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

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

2011-11-23T23:59:59.000Z

399

Neutrino magnetic moment in a magnetized plasma  

E-Print Network (OSTI)

The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.

N. V. Mikheev; E. N. Narynskaya

2010-11-08T23:59:59.000Z

400

The Lake Baikal neutrino experiment: selected results  

E-Print Network (OSTI)

We review the present status of the lake Baikal Neutrino Experiment and present selected physical results gained with the consequetive stages of the stepwise increasing detector: from NT-36 to NT-96. Results cover atmospheric muons, neutrino events, very high energy neutrinos, search for neutrino events from WIMP annihilation, search for magnetic monopoles and environmental studies. We also describe an air Cherenkov array developed for the study of angular resolution of NT-200.

BAIKAL Collaboration; V. Balkanov

2000-01-10T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

On Ultrahigh-energy Neutrino Scattering  

E-Print Network (OSTI)

We predict the neutrino-nucleon cross section at ultrahigh energies relevant in connection with the search for high-energy cosmic neutrinos. Our investigation, employing the color-dipole picture, among other things allows us to quantitatively determine which fraction of the ultrahigh-energy neutrino-nucleon cross section stems from the saturation versus the color transparency region. We disagree with various results in the literature that predict a strong suppression of the neutrino-nucleon cross section at ultrahigh energies.

Kuroda, Masaaki

2013-01-01T23:59:59.000Z

402

Solar Neutrinos with Super-Kamiokande  

E-Print Network (OSTI)

The discrepancy of the measured solar neutrino flux compared to the predictions of the standard solar model may be explained by the neutrino flavor oscillation hypothesis. A more direct and less model-dependent test of this hypothesis is a measurement of the distortion of the shape of the solar neutrino energy spectrum. Super-Kamiokande studies the energy spectrum of recoil electrons from solar neutrino scattering in water above 5.5 MeV.

Smy, M B

1999-01-01T23:59:59.000Z

403

A Very Intense Neutrino Super Beam Experiment for Leptonic CP Violation Discovery based on the European Spallation Source Linac: A Snowmass 2013 White Paper  

E-Print Network (OSTI)

Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European Spallation Source currently under construction in Lund, Sweden to deliver, in parallel with the spallation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spallation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few $\\mu$s with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300-600 km from Lund will make it possible to discover leptonic CP violation at 5 $\\sigma$ significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 $\\sigma$ if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented.

E. Baussan; M. Blennow; M. Bogomilov; E. Bouquerel; J. Cederkall; P. Christiansen; P. Coloma; P. Cupial; H. Danared; C. Densham; M. Dracos; T. Ekelof; M. Eshraqi; E. Fernandez Martinez; G. Gaudiot; R. Hall-Wilton; J. -P. Koutchouk; M. Lindroos; R. Matev; D. McGinnis; M. Mezzetto; R. Miyamoto; L. Mosca; T. Ohlsson; H. Ohman; F. Osswald; S. Peggs; P. Poussot; R. Ruber; J. Y. Tang; R. Tsenov; G. Vankova-Kirilova; N. Vassilopoulos; E. Wildner; J. Wurtz

2013-09-26T23:59:59.000Z

404

Neutrino properties from reactor and accelerator experiments  

E-Print Network (OSTI)

In this talk, I discuss the general theory of neutrino oscillation experiments, putting special emphasis on the momentum distribution of the incoming neutrino beam. Then I discuss recent neutrino oscillation experiments, viz., LSND, KARMEN and CHOOZ. Experiments foreseeable in the near future have also been discussed at the end.

Pal, P B

1998-01-01T23:59:59.000Z

405

Neutrinos and Non-proliferation in Europe  

E-Print Network (OSTI)

Triggered by the demand of the IAEA, neutrino physicists in Europe involved with the Double Chooz experiment are studying the potential of neutrino detection to monitor nuclear reactors. In particular a new set of experiments at the ILL is planned to improve the knowledge of the neutrino spectrum emitted in the fission of 235U and 239Pu.

Cribier, Michel

2006-01-01T23:59:59.000Z

406

SOLAR NEUTRINOS: WHERE WE ARE JOHN BAHCALL  

E-Print Network (OSTI)

SOLAR NEUTRINOS: WHERE WE ARE JOHN BAHCALL Institute for Advanced Study, Princeton, NJ 08540 This talk compares standard model predictions for solar neutrino experiments with the results of actual a standard solar model. I emphasize the importance of recent analyses in which the neutrino fluxes

Bahcall, John

407

Neutrino oscillations present status and outlook  

E-Print Network (OSTI)

I summarize the status of three-flavour neutrino oscillations with date of Oct. 2007, and provide an outlook for the developments to be expected in the near future. Furthermore, I discuss the status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results, and comment on implications for the future neutrino oscillation program.

Schwetz, Thomas

2008-01-01T23:59:59.000Z

408

Neutrino oscillations: present status and outlook  

E-Print Network (OSTI)

I summarize the status of three-flavour neutrino oscillations with date of Oct. 2007, and provide an outlook for the developments to be expected in the near future. Furthermore, I discuss the status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results, and comment on implications for the future neutrino oscillation program.

Thomas Schwetz

2007-10-26T23:59:59.000Z

409

Neutrino oscillations: present status and outlook  

Science Conference Proceedings (OSTI)

I summarize the status of three-flavour neutrino oscillations with date of Oct. 2007, and provide an outlook for the developments to be expected in the near future. Furthermore, I discuss the status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results, and comment on implications for the future neutrino oscillation program.

Schwetz, Thomas [Physics Department, Theory Division, CERN, CH-1211 Geneva 23 (Switzerland)

2008-02-21T23:59:59.000Z

410

Reactor-based Neutrino Oscillation Experiments  

E-Print Network (OSTI)

The status of neutrino oscillation searches employing nuclear reactors as sources is reviewed. This technique, a direct continuation of the experiments that proved the existence of neutrinos, is today an essential tool in investigating the indications of oscillations found in studying neutrinos produced in the sun and in the earth's atmosphere. The low-energy of the reactor \

Carlo Bemporad; Giorgio Gratta; Petr Vogel

2001-07-26T23:59:59.000Z

411

The Role of Collective Neutrino Flavor Oscillations in Core-Collapse Supernova Shock Revival  

E-Print Network (OSTI)

We explore the effects of collective neutrino flavor oscillations due to neutrino-neutrino interactions on the neutrino heating behind a stalled core-collapse supernova shock. We carry out axisymmetric (2D) radiation-hydrodynamic core-collapse supernova simulations, tracking the first 400 ms of the post-core-bounce evolution in 11.2 solar mass and 15 solar mass progenitor stars. Using inputs from these 2D simulations, we perform neutrino flavor oscillation calculations in multi-energy single-angle and multi-angle single-energy approximations. Our results show that flavor conversions do not set in until close to or outside the stalled shock, enhancing heating by not more than a few percent in the most optimistic case. Consequently, we conclude that the postbounce pre-explosion dynamics of standard core-collapse supernovae remains unaffected by neutrino oscillations. Multi-angle effects in regions of high electron density can further inhibit collective oscillations, strengthening our conclusion.

Basudeb Dasgupta; Evan P. O'Connor; Christian D. Ott

2011-06-06T23:59:59.000Z

412

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs), following Mannheim, Protheroe, and Rachen (2000). It is shown that if GRBs produce the ultrahigh-energy cosmic rays, they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV, contrary to their observed energy flux which is only a minute fraction of this flux, and (b) a cumulative neutrino flux a factor of 20 below the AMANDA (Neutrino 2000) limit on isotropic neutrinos. This could have two implications, either GRBs do not produce the ultrahigh energy cosmic rays or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV implausibly increasing the energy requirements, but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO, HEGRA-AIROBICC, and the Tibet-Array. All crucial measurements to test the models will be available in the next few years. These are measurements of (i) high-energy neutrinos with AMANDA-ICECUBE or an enlarged ANTARES/NESTOR ocean detector, (ii) GRB redshifts from HETE-2 follow-up studies, and (iii) GRB spectra above 10 GeV with low-threshold imaging air Cherenkov telescopes such as MAGIC and the space telescopes AGILE and GLAST.

Karl Mannheim

2000-10-18T23:59:59.000Z

413

Probing the Sun's inner core using solar neutrinos: a new diagnostic method  

E-Print Network (OSTI)

The electronic density in the Sun's inner core is inferred from the 8B, 7Be and pep neutrino flux measurements of the Super-Kamiokande, SNO and Borexino experiments. We have developed a new method in which we use the KamLAND detector determinations of the neutrino fundamental oscillation parameters: the mass difference and the vacuum oscillation angle. Our results suggest that the solar electronic density in the Sun's inner core (for a radius smaller than 10% of the solar radius) is well above the current prediction of the standard solar model, and by as much as 25%. A potential confirmation of these preliminary findings can be achieved when neutrino detectors are able to reduce the error of the electron-neutrino survival probability by a factor of 15.

Ildio Lopes

2013-08-15T23:59:59.000Z

414

Probing the Sun's inner core using solar neutrinos: a new diagnostic method  

E-Print Network (OSTI)

The electronic density in the Sun's inner core is inferred from the 8B, 7Be and pep neutrino flux measurements of the Super-Kamiokande, SNO and Borexino experiments. We have developed a new method in which we use the KamLAND detector determinations of the neutrino fundamental oscillation parameters: the mass difference and the vacuum oscillation angle. Our results suggest that the solar electronic density in the Sun's inner core (for a radius smaller than 10% of the solar radius) is well above the current prediction of the standard solar model, and by as much as 25%. A potential confirmation of these preliminary findings can be achieved when neutrino detectors are able to reduce the error of the electron-neutrino survival probability by a factor of 15.

Lopes, Ildio

2013-01-01T23:59:59.000Z

415

Liquid helium and liquid neon-sensitive, low background scintillation media for the detection of low energy neutrinos  

SciTech Connect

The use of liquid helium and neon as scintillators for neutrino detection is investigated. Several unique properties of these cryogens make them promising candidates for real-time solar neutrino spectroscopy: large ultraviolet scintillation yields from ionizing radiation, transparency to their own scintillation light, and low levels of radioactive impurities. When neutrinos scatter from electrons in liquid helium or neon, ultraviolet light is emitted. The ultraviolet scintillation light can be efficiently converted to the visible with wavelength shifting films. In this way the neutrino-electron scattering events can be detected by photomultiplier tubes at room temperature. The authors conclude that the solar neutrino flux from the p + p {yields} e{sup +} + d + {nu}{sub e} reaction could be characterized and monitored versus time using a 10 ton mass of liquid helium or neon as a scintillation target.

McKinsey, D.N.; Doyle, J.M.

2000-02-01T23:59:59.000Z

416

Supernova neutrinos and nucleosynthesis  

E-Print Network (OSTI)

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

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

2013-09-21T23:59:59.000Z

417

The liquid Argon TPC: a powerful detector for future neutrino experiments and proton decay searches  

E-Print Network (OSTI)

We discuss the possibility of new generation neutrino and astroparticle physics experiments exploiting the liquid Argon Time Projection Chamber (LAr TPC) technique, following a graded strategy that envisions applications with increasing detector masses (from 100 ton to 100 kton). The ICARUS R&D program has already demonstrated that the technology is mature with the test of the T600 detector at surface. Since 2003 we have been working with the conceptual design of a very large LAr TPC with a mass of 50-100 kton to be built by employing a monolithic technology based on the use of industrial, large volume, cryogenic tankers developed by the petro-chemical industry. Such a detector, if realized, would be an ideal match for a Super Beam, Beta Beam or Neutrino Factory, covering a broad physics program that includes the detection of atmospheric, solar and supernova neutrinos, and searches for proton decay, in addition to the rich accelerator neutrino physics program. A "test module" with a mass of the order of 10 kton operated underground or at shallow depth would represent a necessary milestone towards the realization of the 100 kton detector, with an interesting physics program on its own. In parallel, physics is calling for a shorter scale application of the LAr TPC technique at the level of 100 ton mass, for low energy neutrino physics and for use as a near station setup in future long baseline neutrino facilities. We outline here the main physics objectives and the design of such a detector for operation in the upcoming T2K neutrino beam. We finally present the result of a series of R&D studies conducted with the aim of validating the design of the proposed detectors.

A. Ereditato; A. Rubbia

2005-09-02T23:59:59.000Z

418

Do hep neutrinos affect the solar neutrino energy spectrum?  

E-Print Network (OSTI)

If the low energy cross section for 3He + p goes to 4He + e + nu_e, the `hep' reaction, is > 20 times larger than the best (but uncertain) theoretical estimates, then this reaction could significantly influence the electron energy spectrum produced by solar neutrino interactions and measured in the SuperKamiokande, SNO, and ICARUS experiments. We compare predicted energy spectra for different assumed hep fluxes and different neutrino oscillation scenarios with the observed SuperKamiokande spectrum. The spectra with enhanced hep contributions provide better fits to the SuperKamiokande data.

John Bahcall; Plamen Krastev

1998-07-29T23:59:59.000Z

419

Neutrino oscillations in noisy media  

SciTech Connect

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

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

1994-05-27T23:59:59.000Z

420

Neutrino-cooled accretion and GRB variability  

E-Print Network (OSTI)

For accretion rates Mdot~0.1 Msun/s to a few solar mass black hole the inner part of the disk is expected to make a transition from advection dominance to neutrino cooling. This transition is characterized by sharp changes of the disk properties. I argue here that during this transition, a modest increase of the accretion rate leads to powerful enhancement of the Poynting luminosity of the GRB flow and decrease of its baryon loading. These changes of the characteristics of the GRB flow translate into changing gamma-ray spectra from the photosphere of the flow. The photospheric interpretation of the GRB emission explains the observed narrowing of GRB pulses with increasing photon energy and the luminosity-spectral peak relation within and among bursts.

Dimitrios Giannios

2007-04-12T23:59:59.000Z

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421

On solar neutrino fluxes in radiochemical experiments  

E-Print Network (OSTI)

We analyze fluctuations of the solar neutrino flux using data from the Homestake, GALLEX, GNO, SAGE and Super Kamiokande experiments. Spectral analysis and direct quantitative estimations show that the most stable variation of the solar neutrino flux is a quasi-five-year periodicity. The revised values of the mean solar neutrino flux are presented in Table 4. They were used to estimate the observed pp-flux of the solar electron neutrinos near the Earth. We consider two alternative explanations for the origin of a variable component of the solar neutrino deficit.

R. N. Ikhsanov; Yu. N. Gnedin; E. V. Miletsky

2005-12-08T23:59:59.000Z

422

Measuring Neutrinos with the ANTARES Telescope  

Science Conference Proceedings (OSTI)

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

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

2009-12-17T23:59:59.000Z

423

Solar neutrinos and the sun  

E-Print Network (OSTI)

We present updated standard solar models (SSMs) that incorporate the latest results for nuclear fusion rates, recently published. We show helioseismic results for high and low metallicity compositions and also for an alternative set of solar abundance, derived from 3D model atmospheres, which give intermediate results. For the high and low metallicity models, we show that current solar neutrino data can not differentiate between models and that a measurement of the CNO fluxes is necessary to achieve that goal. A few additional implications of a hypothetical measurement of CNO neutrinos, both in terms of solar and stellar physics, are discussed.

Aldo Serenelli

2011-09-12T23:59:59.000Z

424

Solar neutrinos and the sun  

E-Print Network (OSTI)

We present updated standard solar models (SSMs) that incorporate the latest results for nuclear fusion rates, recently published. We show helioseismic results for high and low metallicity compositions and also for an alternative set of solar abundance, derived from 3D model atmospheres, which give intermediate results. For the high and low metallicity models, we show that current solar neutrino data can not differentiate between models and that a measurement of the CNO fluxes is necessary to achieve that goal. A few additional implications of a hypothetical measurement of CNO neutrinos, both in terms of solar and stellar physics, are discussed.

Serenelli, Aldo

2011-01-01T23:59:59.000Z

425

Stimulated Neutrino Transformation Through Turbulence  

E-Print Network (OSTI)

We derive an analytical solution for the flavor evolution of a neutrino through a turbulent density profile which is found to accurately predict the amplitude and transition wavelength of numerical solutions on a case-by-case basis. The evolution is seen to strongly depend upon those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues and, unexpectedly, we also find a dependence upon the long wavelength modes when the ratio of their amplitude and the wavenumber is of order, or greater than, the first root of the Bessel function $J_0$.

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

2013-10-21T23:59:59.000Z

426

Electron Neutrino Appearance in the MINOS Experiment  

SciTech Connect

The MINOS experiment is a long-baseline neutrino oscillation experiment which sends a high intensity muon neutrino beam through two functionally identical detectors, a Near detector at the Fermi National Accelerator Laboratory in Illinois, 1km from the beam source, and a Far detector, 734km away, in the Soudan Mine in Minnesota. MINOS may be able to measure the neutrino mixing angle parameter sin{sup 2} 2{theta}{sub 13} for the first time. Detector granularity, however, makes it very hard to distinguish any {nu}{sub e} appearance signal events characteristic of a non-zero value of {theta}{sub 13} from background neutral current (NC) and short-track {nu}{sub {mu}} charged current (CC) events. Also, uncertainties in the hadronic shower modeling in the kinematic region characteristic of this analysis are relatively large. A new data-driven background decomposition method designed to address those issues is developed and its results presented. By removing the long muon tracks from {nu}{sub {mu}}-CC events, the Muon Removed Charge Current (MRCC) method creates independent pseudo-NC samples that can be used to correct the MINOS Monte Carlo to agree with the high-statistics Near detector data and to decompose the latter into components so as to predict the expected Far detector background. The MRCC method also provides an important cross-check in the Far detector to test the background in the signal selected region. MINOS finds a 1.0-1.5 {sigma} {nu}{sub e}-CC excess above background in the Far detector data, depending on method used, for a total exposure of 3.14 x 10{sup 20} protons-on-target. Interpreting this excess as signal, MINOS can set limits on sin{sup 2} 2{theta}{sub 13}. Using the MRCC method, MINOS sets a limit of sin{sup 2} 2{theta}{sub 13} < 0.265 at the 90% confidence limit for a CP-violating phase {delta} = 0.

Holin, Anna Maria; /University Coll. London

2010-06-01T23:59:59.000Z

427

The Neutrino Eye: A Megaton Low Energy Neutrino  

E-Print Network (OSTI)

, despite the evident truth of that statement, the history of the water Cherenkov detectors demonstrates requirements. After all, there are million ton oil tankers, and there are oil platforms of much larger.4.4 Supernovae Out to 2Mpc The entire history of extra­solar neutrino astronomy consists of the the few second

Learned, John

428

Invisible Higgs Boson Decay into Massive Neutrinos of 4th Generation  

E-Print Network (OSTI)

Results from several recent experiments provide inderect evidences in the favor of existence of a 4th generation neutrino. Such a neutrino of mass about 50 GeV is compatible with current physical and astrophysical constraints and well motivated in the framework of superstring phenomenology. If sufficiently stable the existence of such a neutrino leads to the drastic change of Higgs boson physics: for a wide range of Higgs boson masses the dominant mode of Higgs boson decay is invisible and the branching ratios for the most promising modes of Higgs boson search are significantly reduced. The proper strategy of Higgs boson searches in such a framework is discussed. It is shown that in the same framework the absence of a signal in the search for invisible Higgs boson decay at LEP means either that the mass of Higgs is greater than 113.5 GeV or that the mass difference between the Higgs mass and doubled neutrino mass is small.

K. Belotsky; D. Fargion; M. Khlopov; R. Konoplich; K. Shibaev

2002-10-09T23:59:59.000Z

429

Solar Neutrinos: Solved and Unsolved Problems John N. Bahcall  

E-Print Network (OSTI)

Chapter 10 Solar Neutrinos: Solved and Unsolved Problems John N. Bahcall Institute for Advanced study solar neutrinos? What does the combined standard model (solar plus electroweak) predict for solar neutrinos? Why are the calculations of neutrino fluxes robust? What are the three solar neutrino problems

Bahcall, John

430

WHY DO SOLAR NEUTRINO EXPERIMENTS BELOW J. N. BAHCALL  

E-Print Network (OSTI)

V. The rare 8 B neutrino ux is the only solar neutrino source for which measurements of the energy have been quantities for low energy solar neutrinos is impor- tant and can be used to constrain models of the neutrino that can do everything. I think we should be happy if a low energy solar neutrino experiment can measure

Bahcall, John

431

WHY DO SOLAR NEUTRINO EXPERIMENTS BELOW J. N. BAHCALL  

E-Print Network (OSTI)

V. The rare 8 B neutrino flux is the only solar neutrino source for which measurements of the energy have been quantities for low energy solar neutrinos is impor- tant and can be used to constrain models of the neutrino that can do everything. I think we should be happy if a low energy solar neutrino experiment can measure

Bahcall, John

432

RELATIVISTIC GLOBAL SOLUTIONS OF NEUTRINO-DOMINATED ACCRETION FLOWS  

SciTech Connect

Neutrino-dominated accretion flows (NDAFs) around rotating stellar-mass black holes are plausible candidates for the central engines of gamma-ray bursts (GRBs). We investigate one-dimensional global solutions of NDAFs, taking into account general relativity in the Kerr metric, neutrino physics, and nucleosynthesis more precisely than previous works. We calculate 16 solutions with different characterized accretion rates and black hole spins to exhibit the radial distributions of various physical properties in NDAFs. We confirm that the electron degeneracy has important effects in NDAFs and we find that the electron fraction is about 0.46 in the outer region for all 16 solutions. From the perspective of the mass fraction, free nucleons, {sup 4}He, and {sup 5}6Fe dominate in the inner, middle, and outer regions, respectively. The influence of neutrino trapping on the annihilation is of importance for the superhigh accretion ( M-dot =10 M{sub sun} s{sup -1}) and most of the 16 solutions have an adequate annihilation luminosity for GRBs.

Xue Li; Liu Tong; Gu Weimin; Lu Jufu, E-mail: tongliu@xmu.edu.cn [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China)

2013-08-15T23:59:59.000Z

433

Luminescent Bolometer and Neutrino Physics  

E-Print Network (OSTI)

The luminescent bolometer, proposed in 1988, is now seriously considered for several applications in nuclear and particle physics: dark matter searches, double beta decays, low energy neutrino physics, heavy ion physics... It is also a very promising device for basic condensed-matter physics and chemistry experiments, and may lead to astrophysical applications. The luminescent bolometer is based on the simultaneous detection of light and phonons, allowing for particle identification and for a detailed study of the detector response. Digitized analysis of the signals produced in several sensors installed on the same crystal is then a very powerful tool. Superconducting sensors allow to detect the scintillation light pulse followed by the delayed front of phonons, and can be extremely sensitive leading to single photon counting in the visible range. They also provide information on the position of the event inside the absorber, and can be fast enough for all proposed applications. The luminescent bolometer, with superconducting sensors, appears extremely promising for real time $solar$ neutrino experiments based on new indium single crystal scintillators. We focus on this particular application, discussing the status of the art as well as open problems and presenting an updated description of a full scale real time solar neutrino experiment sensitive to the low energy sector. Other applications of the luminescent bolometer (e.g. spectroscopy or neutrino detection at reactors), involving indium compounds and other single crystal scintillators, are equally considered and discussed in detail.

Luis Gonzalez-Mestres

1997-11-25T23:59:59.000Z

434

SISSA 47/2004/EP hep-ph/0406328 Update of the Solar Neutrino Oscillation Analysis with  

E-Print Network (OSTI)

We investigate the impact of the 766.3 Ty KamLAND spectrum data on the determination of the solar neutrino oscillation parameters. We show that the observed spectrum distortion in the KamLAND experiment firmly establishes ?m2 21 to lie in the low-LMA solution region. The high-LMA solution is excluded at more than 4? by the global solar neutrino and KamLAND spectrum data. The maximal solar neutrino mixing is ruled out at 6? level. The 3? allowed region in the ?m2 21 ? sin2 ?12 plane is found to be remarkably stable with respect to leaving out the data from one of the solar neutrino experiments from the global analysis. We perform a three flavor neutrino oscillation analysis of the global solar neutrino and KamLAND spectrum data as well. The 3? upper limit on sin2 ?13 is found to be sin2 ?13 solar neutrino oscillation parameters are also discussed. 1 1

The Ty Kamland Spectrum; Abhijit B; Hya Choubey; Srubabati Goswami; S. T. Petcov; D. P. Roy

2004-01-01T23:59:59.000Z

435

Aspects of Neutrino Production in Supernovae  

E-Print Network (OSTI)

I discuss neutrino production in supernovae (SNe) and the detection of both Galactic core collapse events and the diffuse extra-galactic MeV neutrino background expected from the integrated history of star formation. In particular, I consider what processes might affect our expectations for both. I focus on ``rapid'' rotation, defined as leading to millisecond initial neutron star spin periods. Rotation affects the neutrino luminosity, the average neutrino energy, the duration of the Kelvin-Helmholtz cooling epoch, and the ratios of luminosities and average energies between