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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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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.


1

Neutrino Masses and Flavor Mixing  

E-Print Network [OSTI]

We discuss the neutrino oscillations, using texture zero mass matrices for the leptons. The reactor mixing angle $\\theta^{}_{l}$ is calculated. The ratio of the masses of two neutrinos is determined by the solar mixing angle. We can calculate the masses of the three neutrinos: $m_1$ $\\approx$ 0.003 eV - $m_2$ $\\approx$ 0.012 eV - $m_3$ $\\approx$ 0.048 eV.

Fritzsch, Harald

2015-01-01T23:59:59.000Z

2

Neutrino Masses and Flavor Mixing  

E-Print Network [OSTI]

We discuss the neutrino oscillations, using texture zero mass matrices for the leptons. The reactor mixing angle $\\theta^{}_{l}$ is calculated. The ratio of the masses of two neutrinos is determined by the solar mixing angle. We can calculate the masses of the three neutrinos: $m_1$ $\\approx$ 0.003 eV - $m_2$ $\\approx$ 0.012 eV - $m_3$ $\\approx$ 0.048 eV.

Harald Fritzsch

2015-03-06T23:59:59.000Z

3

Neutrino Mixing  

E-Print Network [OSTI]

In this review we present the main features of the current status of neutrino physics. After a review of the theory of neutrino mixing and oscillations, we discuss the current status of solar and atmospheric neutrino oscillation experiments. We show that the current data can be nicely accommodated in the framework of three-neutrino mixing. We discuss also the problem of the determination of the absolute neutrino mass scale through Tritium beta-decay experiments and astrophysical observations, and the exploration of the Majorana nature of massive neutrinos through neutrinoless double-beta decay experiments. Finally, future prospects are briefly discussed.

Carlo Giunti; Marco Laveder

2004-10-01T23:59:59.000Z

4

Results on neutrino mass and mixing from Super Kamiokande  

E-Print Network [OSTI]

the mass 2 dierene above 1 eV , sale than disussed in thisallowing to probe mass sales smaller than 1 eV is neutrino

Kielczewska, Danuta; Super Kamiokande Collaboration, .; K2K Collaboration, .

2002-01-01T23:59:59.000Z

5

Neutrino Mass and Mixing: from Theory to Experiment  

E-Print Network [OSTI]

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

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

2014-02-18T23:59:59.000Z

6

Neutrino masses and mixing: a flavour symmetry roadmap  

E-Print Network [OSTI]

Over the last ten years tri-bimaximal mixing has played an important role in modeling the flavour problem. We give a short review of the status of flavour symmetry models of neutrino mixing. We concentrate on non-Abelian discrete symmetries, which provide a simple way to account for the TBM pattern. We discuss phenomenological implications such as neutrinoless double beta decay, lepton flavour violation as well as theoretical aspects such as the possibility to explain quarks and leptons within a common framework, such as grand unified models.

Morisi, S

2012-01-01T23:59:59.000Z

7

Neutrino masses and mixing: a flavour symmetry roadmap  

E-Print Network [OSTI]

Over the last ten years tri-bimaximal mixing has played an important role in modeling the flavour problem. We give a short review of the status of flavour symmetry models of neutrino mixing. We concentrate on non-Abelian discrete symmetries, which provide a simple way to account for the TBM pattern. We discuss phenomenological implications such as neutrinoless double beta decay, lepton flavour violation as well as theoretical aspects such as the possibility to explain quarks and leptons within a common framework, such as grand unified models.

S. Morisi; J. W. F. Valle

2012-06-28T23:59:59.000Z

8

Double Beta Decay Constraints on Neutrino Masses and Mixing; Reanalysis with KamLAND Data  

E-Print Network [OSTI]

In the light of KamLAND data just released, we reanalyze and update the constraints on neutrino masses and mixing parameters, the most general ones that can be derived in three-flavor mixing scheme of neutrinos with use of the bounds imposed by neutrinoless double beta decay search and reactor experiments. We point out that with KamLAND data and assuming Majorana neutrinos one can derive, for the first time, an upper bound on neutrino contribution to the cosmological \\Omega parameter, \\Omega_{\

Hisakazu Minakata; Hiroaki Sugiyama

2003-03-04T23:59:59.000Z

9

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

E-Print Network [OSTI]

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

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

2006-12-05T23:59:59.000Z

10

Riddle of the Neutrino Mass  

E-Print Network [OSTI]

We discuss some known approaches and results as well as few new ideas concerning origins and nature of neutrino mass. The key issues include (i) connections of neutrino and charged fermions masses, relation between masses and mixing, energy scale of new physics behind neutrino mass where possibilities spread from the Planck and GUT masses down to a sub-eV scale. The data hint two different new physics involved in generation of neutrino mass. Determination of the CP phase as well as mass hierarchy can play important role in identification of new physics. It may happen that sterile neutrinos provide the key to resolve the riddle.

Smirnov, A Yu

2015-01-01T23:59:59.000Z

11

Neutrino as topological Majorana zero modes: the origin of three generations of neutrinos and their mass mixing  

E-Print Network [OSTI]

Recently, Majorana's spirit returns to modern condensed matter physics -- in the context of topological Majorana zero mode that represents a local half degree of freedom carrying non-Abelian statistics.In this paper, we investigate the topological nature of a Majorana fermion by assuming that it is made up of four Majorana zero modes at cutoff energy scale. First, we show that a pair of Majorana zero modes can realize a $T^4=-1$ time reversal symmetry, a $P^4=-1$ parity symmetry and even a nontrivial $\\overline C^4=-1$ charge conjugation symmetry. Next, we propose a $\\overline CPT$ super algebra for the Majorana fermion made up of four Majorana zero modes. Furthermore, the origin of three generations of neutrinos(assuming they are Majorana fermions) can be naturally explained as three distinguishable ways to form a pair of (local) complex fermions out of four Majorana zero modes. Finally, we compute the neutrino mass mixing matrix and mass ratios of the three mass eigenstates from a first principle at leading order(in the absence of $CP$ violation and charged lepton corrections). We obtain $\\theta_{12} =31.7^\\circ$, $\\theta_{23}=45^\\circ$, $\\theta_{13}=0^\\circ$ and $m_1/m_3=m_2/m_3=3/\\sqrt{5}$. We predict the effective mass in neutrinoless double beta decay to be $m_{\\beta\\beta}=m_1/\\sqrt{5}$.

Zheng-Cheng Gu

2014-03-07T23:59:59.000Z

12

Implications of the KamLAND Measurement on the Lepton Flavor Mixing Matrix and the Neutrino Mass Matrix  

E-Print Network [OSTI]

We explore some important implications of the KamLAND measurment on the lepton flavor mixing matrix $V$ and the neutrino mass matrix $M$. The model-independent constraints on nine matrix elements of $V$ are obtained to a reasonable degree of accuracy. We find that nine two-zero textures of $M$ are compatible with current experimental data, but two of them are only marginally allowed. Instructive predictions are given for the absolute neutrino masses, Majorana phases of CP violation, effective masses of the tritium beta decay and neutrinoless double beta decay.

Wan-lei Guo; Zhi-zhong Xing

2002-12-10T23:59:59.000Z

13

Observables in Neutrino Mass Spectroscopy Using Atoms  

E-Print Network [OSTI]

The process of collective de-excitation of atoms in a metastable level into emission mode of a single photon plus a neutrino pair, called radiative emission of neutrino pair (RENP), is sensitive to the absolute neutrino mass scale, to the neutrino mass hierarchy and to the nature (Dirac or Majorana) of massive neutrinos. We investigate how the indicated neutrino mass and mixing observables can be determined from the measurement of the corresponding continuous photon spectrum taking the example of a transition between specific levels of the Yb atom. The possibility of determining the nature of massive neutrinos and, if neutrinos are Majorana fermions, of obtaining information about the Majorana phases in the neutrino mixing matrix, is analyzed in the cases of normal hierarchical, inverted hierarchical and quasi-degenerate types of neutrino mass spectrum. We find, in particular, that the sensitivity to the nature of massive neutrinos depends critically on the atomic level energy difference relevant in the RENP.

D. N. Dinh; S. T. Petcov; N. Sasao; M. Tanaka; M. Yoshimura

2012-09-21T23:59:59.000Z

14

Neutrino Oscillations With Recently Measured Sterile-Active Neutrino Mixing Angle  

E-Print Network [OSTI]

This brief report is an extension of a prediction of neutrino oscillation with a sterile neutrino using parameters of the sterile neutrino mass and mixing angle recently extracted from experiment.

Leonard S. Kisslinger

2014-10-10T23:59:59.000Z

15

Dark energy, cosmological constant and neutrino mixing  

E-Print Network [OSTI]

The today estimated value of dark energy can be achieved by the vacuum condensate induced by neutrino mixing phenomenon. Such a tiny value is recovered for a cut-off of the order of Planck scale and it is linked to the sub eV neutrino mass scale. Contributions to dark energy from auxiliary fields or mechanisms are not necessary in this approach.

A. Capolupo; S. Capozziello; G. Vitiello

2007-05-02T23:59:59.000Z

16

Double Beta Decay and the Absolute Neutrino Mass Scale  

E-Print Network [OSTI]

After a short review of the current status of three-neutrino mixing, the implications for the values of neutrino masses are discussed. The bounds on the absolute scale of neutrino masses from Tritium beta-decay and cosmological data are reviewed. Finally, we discuss the implications of three-neutrino mixing for neutrinoless double-beta decay.

Carlo Giunti

2003-08-20T23:59:59.000Z

17

Minimal Schemes for Large Neutrino Mixings with Inverted Hierarchy  

E-Print Network [OSTI]

Existing oscillation data point to nonzero neutrino masses with large mixings. We analyze the generic features of the neutrino Majorana mass matrix with inverted hierarchy and construct realistic {\\it minimal schemes} for the neutrino mass matrix that can explain the large (but not maximal) \

Duane A. Dicus; Hong-Jian He; John N. Ng

2002-05-17T23:59:59.000Z

18

Absolute neutrino mass measurements  

SciTech Connect (OSTI)

The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

Wolf, Joachim [Karlsruhe Institute of Technology (KIT), IEKP, Postfach 3640, 76021 Karlsruhe (Germany)

2011-10-06T23:59:59.000Z

19

Effective Mass Matrix for Light Neutrinos Consistent with Solar and Atmospheric Neutrino Experiments  

E-Print Network [OSTI]

We propose an effective mass matrix for light neutrinos which is consistent with the mixing pattern indicated by solar and atmospheric neutrino experiments. Two scenarios for the mass eigenvalues are discussed and the connection with double beta decay is noted.

S. P. Rosen; Waikwok Kwong

1995-01-20T23:59:59.000Z

20

Can Neutrinos be Degenerate in Mass?  

E-Print Network [OSTI]

We reconsider the possibility that the masses of the three light neutrinos of the Standard Model might be almost degenerate and close to the present upper limits from Tritium beta decay and cosmology. In such a scenario, the cancellations required by the latest upper limit on neutrinoless double-beta decay enforce near-maximal mixing that may be compatible only with the vacuum-oscillation scenario for solar neutrinos. We argue that the mixing angles yielded by degenerate neutrino mass-matrix textures are not in general stable under small perturbations. We evaluate within the MSSM the generation-dependent one-loop renormalization of neutrino mass-matrix textures that yielded degenerate masses and large mixing at the tree level. We find that m_{nu_e} > m_{nu_mu} > m_{nu_tau} after renormalization, excluding MSW effects on solar neutrinos. We verify that bimaximal mixing is not stable, and show that the renormalized masses and mixing angles are not compatible with all the experimental constraints, even for tanbeta as low as unity. These results hold whether the neutrino masses are generated by a see-saw mechanism with heavy neutrinos weighing approx. 10^{13} GeV or by non-renormalizable interactions at a scale approx. 10^5 GeV. We also comment on the corresponding renormalization effects in the minimal Standard Model, in which m_{nu_e} < m_{nu_mu} < m_{nu_tau}. Although a solar MSW effect is now possible, the perturbed neutrino masses and mixings are still not compatible with atmospheric- and solar-neutrino data.

John Ellis; Smaragda Lola

1999-04-13T23:59:59.000Z

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

WMAPping out Neutrino Masses  

E-Print Network [OSTI]

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

Aaron Pierce; Hitoshi Murayama

2003-10-28T23:59:59.000Z

22

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

23

Flavor Mixing and CP Violation of Massive Neutrinos  

E-Print Network [OSTI]

We present an overview of recent progress in the phenomenological study of neutrino masses, lepton flavor mixing and CP violation. We concentrate on the model-independent properties of massive neutrinos, both in vacuum and in matter. Current experimental constraints on the neutrino mass spectrum and the lepton flavor mixing parameters are summarized. The Dirac- and Majorana-like phases of CP violation, which are associated respectively with the long-baseline neutrino oscillations and the neutrinoless double beta decay, are discussed in detail. The seesaw mechanism, the leptogenesis scenario and the strategies to construct lepton mass matrices are briefly described. The features of flavor mixing between one sterile neutrino and three active neutrinos are also explored.

Zhi-zhong Xing

2004-11-26T23:59:59.000Z

24

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

2006-12-11T23:59:59.000Z

25

Supernova Bounds on keV-mass Sterile Neutrinos  

E-Print Network [OSTI]

Sterile neutrinos of keV masses are one of the most promising candidates for the warm dark matter, which could solve the small-scale problems encountered in the scenario of cold dark matter. We present a detailed study of the production of such sterile neutrinos in a supernova core, and derive stringent bounds on the active-sterile neutrino mixing angles and sterile neutrino masses based on the standard energy-loss argument.

Zhou, Shun

2015-01-01T23:59:59.000Z

26

Phenomenology of Absolute Neutrino Masses  

E-Print Network [OSTI]

The phenomenology of absolute neutrino masses is reviewed, focusing on tritium beta decay, cosmological measurements and neutrinoless double-beta decay.

Carlo Giunti

2004-12-11T23:59:59.000Z

27

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...

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

2005-11-18T23:59:59.000Z

28

Corrections to Scaling Neutrino Mixing: Non-zero $?_{13}, ?_{CP}$ and Baryon Asymmetry  

E-Print Network [OSTI]

We study a very specific type of neutrino mass and mixing structure based on the idea of Strong Scaling Ansatz (SSA) where the ratios of neutrino mass matrix elements belonging to two different columns are equal. There are three such possibilities, all of which are disfavored by the latest neutrino oscillation data. We focus on the specific scenario which predicts vanishing reactor mixing angle $\\theta_{13}$ and inverted hierarchy with vanishing lightest neutrino mass. Motivated by several recent attempts to explain non-zero $\\theta_{13}$ by incorporating corrections to a leading order neutrino mass or mixing matrix giving $\\theta_{13}=0$, here we study the origin of non-zero $\\theta_{13}$ as well as leptonic Dirac CP phase $\\delta_{CP}$ by incorporating two different corrections to scaling neutrino mass and mixing: one where type II seesaw acts as a correction to scaling neutrino mass matrix and the other with charged lepton correction to scaling neutrino mixing. Although scaling neutrino mass matrix originating from type I seesaw predicts inverted hierarchy, the total neutrino mass matrix after type II seesaw correction can give rise to either normal or inverted hierarchy. However, charged lepton corrections do not disturb the inverted hierarchy prediction of scaling neutrino mass matrix. We further discriminate between neutrino hierarchies, different choices of lightest neutrino mass and Dirac CP phase by calculating baryon asymmetry and comparing with the observations made by the Planck experiment.

Rupam Kalita; Debasish Borah; Mrinal Kumar Das

2015-03-11T23:59:59.000Z

29

Simple neutrino mass matrix with only two free parameters  

E-Print Network [OSTI]

A simple form of neutrino mass matrix which has only two free parameters is proposed from a phenomenological point of view. Using this mass matrix, we succeed to reproduce all the observed values for the MNS lepton mixing angles and the neutrino mass squared difference ratio. Our model also predicts $\\delta_{\

Hiroyuki Nishiura; Takeshi Fukuyama

2014-05-10T23:59:59.000Z

30

Simple neutrino mass matrix with only two free parameters  

E-Print Network [OSTI]

A simple form of neutrino mass matrix which has only two free parameters is proposed from a phenomenological point of view. Using this mass matrix, we succeed to reproduce all the observed values for the MNS lepton mixing angles and the neutrino mass squared difference ratio. Our model also predicts $\\delta_{\

Nishiura, Hiroyuki

2014-01-01T23:59:59.000Z

31

Constraints on the Sum of Neutrino Masses from Cosmology and their impact on world neutrino data  

E-Print Network [OSTI]

We derive upper limits on the sum of neutrino masses from an updated combination of data from Cosmic Microwave Background experiments and Galaxy Redshifts Surveys. The results are discussed in the context of three-flavor neutrino mixing and compared with neutrino oscillation data, with upper limits on the effective neutrino mass in Tritium beta decay from the Mainz and Troitsk experiments and with the claimed lower bound on the effective Majorana neutrino mass in neutrinoless double beta decay from the Heidelberg-Moscow experiment.

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

2005-01-25T23:59:59.000Z

32

Absolute Values of Neutrino Masses: Status and Prospects  

E-Print Network [OSTI]

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

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

2003-03-27T23:59:59.000Z

33

Majorana neutrino masses in the three-flavor Pauli model  

SciTech Connect (OSTI)

A special Majorana model for three neutrino flavors is developed on the basis of the Pauli transformation group. In this model, the neutrinos possess a partially conserved generalized lepton (Pauli) charge that makes it possible to discriminate between neutrinos of different type. It is shown that, within the model in question, a transition from the basic 'mass' representation, where the average value of this charge is zero, to the representation associated with physical neutrinos characterized by specific Pauli 'flavor' charges establishes a relation between the neutrino mixing angles {theta}{sub mix,12}, {theta}{sub mix,23}, and {theta}{sub mix,13} and an additional relation between the Majorana neutrino masses. The Lagrangian mass part, which includes a term invariant under Pauli transformations and a representation-dependent term, concurrently assumes a 'quasi-Dirac' form. With allowance for these relations, the existing set of experimental data on the features of neutrino oscillations makes it possible to obtain quantitative estimates for the absolute values of the neutrino masses and the 2{beta}-decay mass parameter m{sub {beta}{beta}} and a number of additional constraints on the neutrino mixing angles.

Gaponov, Yu. V. [Russian Research Centre Kurchatov Institute (Russian Federation)

2011-02-15T23:59:59.000Z

34

Neutrino Masses in Flipped SU(5)  

E-Print Network [OSTI]

We analyse the fermion masses and mixings in the flipped SU(5) model. The fermion mass matrices are evolved from the GUT scale down to $m_W$ by solving the renormalization group equations for the Yukawa couplings. The constraints imposed by the charged fermion data are then utilised to make predictions about the neutrino properties . It is found that the {\\it generalized } see-saw mechanism which occurs naturally in this model can provide {\\it i})a solution to the solar neutrino problem via the MSW mechanism and {\\it ii})a sufficiently large $\

Leontaris, George K

1993-01-01T23:59:59.000Z

35

Neutrino mixing and oscillations in astrophysical environments  

SciTech Connect (OSTI)

A brief review of the current status of neutrino mixing and oscillations in astrophysical environments, with particular emphasis on the Sun and core-collapse supernovae, is given. Implications of the existence of sterile states which mix with the active neutrinos are discussed.

Balantekin, A. B. [Physics Department, University of Wisconsin, Madison WI 53706 (United States)

2014-05-02T23:59:59.000Z

36

What we (would like to) know about the neutrino mass  

E-Print Network [OSTI]

We present updated values for the mass-mixing parameters relevant to neutrino oscillations, with particular attention to emerging hints in favor of theta_13>0. We also discuss the status of absolute neutrino mass observables, and a possible approach to constrain theoretical uncertainties in neutrinoless double beta decay. Desiderata for all these issues are also briefly mentioned.

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

2008-09-17T23:59:59.000Z

37

Current Direct Neutrino Mass Experiments  

E-Print Network [OSTI]

In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

Drexlin, G; Mertens, S; Weinheimer, C

2013-01-01T23:59:59.000Z

38

Cosmo MSW effect for mass varying neutrinos  

E-Print Network [OSTI]

We consider neutrinos with varying masses which arise in scenarios relating neutrino masses to the dark energy density in the universe. We point out that the neutrino mass variation can lead to level crossing and thus a cosmo MSW effect, having dramatic consequences for the flavor ratio of astrophysical neutrinos.

Pham Quang Hung; Heinrich Päs

2005-02-24T23:59:59.000Z

39

Absolute Values of Neutrino Masses implied by the Seesaw Mechanism  

E-Print Network [OSTI]

It is found that the seesaw mechanism not only explain the smallness of neutrino masses but also account for the large mixing angles simultaneously, once the unification of the neutrino Dirac mass matrix with that of up-quark sector is realized. We show that provided the Majorana masses have hierarchical structure as is seen in the up-quark sector, we can reduce the information about the absolute values of neutrino masses through the data set of neutrino experiments. The results for the light neutrino masses are $m_1:m_2:m_3\\approx 1:3:17$ $(m_1\\simeq m_2:m_3\\approx 1.2:1)$ in the case of normal mass spectrum (inverted mass spectrum), and the heaviest Majorana mass turns out to be $m_3^R=1\\times 10^{15}$ GeV which just corresponds to the GUT scale.

Tsujimoto, H

2005-01-01T23:59:59.000Z

40

Mixed MSW and Vacuum Solutions of Solar Neutrino Problem  

E-Print Network [OSTI]

Assuming three flavour neutrino mixing takes place in vacuum, we investigate the possibility that the solar $\

Qiu-Yu Liu

1997-08-11T23:59:59.000Z

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

Small entries of neutrino mass matrices  

E-Print Network [OSTI]

We consider phenomenologically allowed structures of the neutrino mass matrix in the case of three light neutrino species. Constraints from the solar, atmospheric and reactor neutrino experiments as well as those from the neutrinoless double beta decay are taken into account. Both hierarchical and quasi-degenerate neutrino mass cases are studied. Assuming maximal $\

E. Kh. Akhmedov

1999-09-15T23:59:59.000Z

42

Introduction to direct neutrino mass measurements and KATRIN  

E-Print Network [OSTI]

The properties of neutrinos and especially their rest mass play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double beta decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. On the other hand experiments such as MARE, KATRIN and the recently proposed Project 8 will investigate the spectral shape of beta-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Here, because of neutrino flavour mixing, the neutrino mass appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. It combines an ultra-luminous molecular windowless gaseous tritium source with an integrating high-resolution spectrometer of MAC-E filter type. It will investigate the neutrino rest mass with 0.2 eV/c (90% C.L.) sensitivity and allow beta spectroscopy close to the tritium endpoint at 18.6 keV with unprecedented precision.

Thomas Thümmler; for the KATRIN Collaboration

2010-12-10T23:59:59.000Z

43

Neutrino mass limit from tritium beta decay  

E-Print Network [OSTI]

The paper reviews recent experiments on tritium beta spectroscopy searching for the absolute value of the electron neutrino mass $m(\

E. W. Otten; C. Weinheimer

2009-09-11T23:59:59.000Z

44

Neutrino masses and Neutrinoless Double Beta Decay: Status and expectations  

E-Print Network [OSTI]

Two most outstanding questions are puzzling the world of neutrino Physics: the possible Majorana nature of neutrinos and their absolute mass scale. Direct neutrino mass measurements and neutrinoless double beta decay (0nuDBD) are the present strategy to solve the puzzle. Neutrinoless double beta decay violates lepton number by two units and can occurr only if neutrinos are massive Majorana particles. A positive observation would therefore necessarily imply a new regime of physics beyond the standard model, providing fundamental information on the nature of the neutrinos and on their absolute mass scale. After the observation of neutrino oscillations and given the present knowledge of neutrino masses and mixing parameters, a possibility to observe 0nuDBDD at a neutrino mass scale in the range 10-50 meV could actually exist. This is a real challenge faced by a number of new proposed projects. Present status and future perpectives of neutrinoless double-beta decay experimental searches is reviewed. The most important parameters contributing to the experimental sensitivity are outlined. A short discussion on nuclear matrix element calculations is also given. Complementary measurements to assess the absolute neutrino mass scale (cosmology and single beta decays) are also discussed.

Oliviero Cremonesi

2010-02-07T23:59:59.000Z

45

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

E-Print Network [OSTI]

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

Y. F. Li; Si-shuo Liu

2011-11-28T23:59:59.000Z

46

Small scales structures and neutrino masses  

E-Print Network [OSTI]

We review the impact of massive neutrinos on cosmological observables at the linear order. By means of N-body simulations we investigate the signatures left by neutrinos on the fully non-linear regime. We present the effects induced by massive neutrinos on the matter power spectrum, the halo mass function and on the halo-matter bias in massive neutrino cosmologies. We also investigate the clustering of cosmic neutrinos within galaxy clusters.

Villaescusa-Navarro, Francisco

2015-01-01T23:59:59.000Z

47

Absolute Values of Neutrino Masses implied by the Seesaw Mechanism  

E-Print Network [OSTI]

It is found that the seesaw mechanism not only explain the smallness of neutrino masses but also account for the large mixing angles simultaneously, even if the unification of the neutrino Dirac mass matrix with that of up-type quark sector is realized. We show that provided the Majorana masses have hierarchical structure as is seen in the up-type quark sector and all mass matrices are real, we can reduce the information about the absolute values of neutrino masses through the data set of neutrino experiments. Especially for $\\theta_{13}=0$, we found that the neutrino masses are decided as $m_1:m_2:m_3\\approx 1:3:17$ or $1:50:250$ ($m_1\\simeq m_2:m_3\\approx 3:1$ or $12:1$) in the case of normal mass spectrum (inverted mass spectrum), and the greatest Majorana mass turns out to be $m_3^R=1\\times 10^{15}$ GeV which just corresponds to the GUT scale. Including the decoupling effects caused by three singlet neutrinos, we also perform a renormalization group analysis to fix the neutrino Yukawa coupling matrix at low energy.

H. Tsujimoto

2005-12-12T23:59:59.000Z

48

Neutrino Mass Matrix in Triplet Higgs Models with A-bar 4 Symmetry  

SciTech Connect (OSTI)

The tribimaximal form of the neutrino mixing matrix can be naturally obtained with A-bar 4 flavor symmetry. We consider triplet Higgs model with A-bar 4 symmetry to generate the neutrino masses. With neutrino oscillation data we show that the mass matrix can be (almost) reconstructed, which allows us to predict the absolute neutrino mass scale including the neutrinoless double beta decay, the decay rates of the doubly charged Higgs boson to lepton pairs.

Baek, Seungwon [Institute of Basic Science and Department of Physics, Korea University, Seoul (Korea, Republic of); Chu Oh, Myoung [Department of Physics, University of Seoul, Seoul (Korea, Republic of)

2009-04-19T23:59:59.000Z

49

Large Mixing Angle MSW and Atmospheric Neutrinos from Single Right-Handed Neutrino Dominance and U(1) Family Symmetry  

E-Print Network [OSTI]

Single right-handed neutrino dominance (SRHND) in the 23 sector of the light effective neutrino mass matrix has been proposed as a natural explanation for the concurrent large 23 mixing angle and large 23 mass hierarchy. In this paper we show how large 12 mixing angles, suitable for the large mixing angle (LMA) MSW solution to the solar neutrino problem, may arise from SRHND. In order to understand the conditions for SRHND and LMA MSW we first consider the case of one and two right-handed neutrinos, and obtain simple analytic conditions which are then extended to the case of three right-handed neutrinos. We then introduce a single U(1) family symmetry and show how these analytic conditions may be translated into U(1) charge assignments and perform a systematic search for the simplest examples.

S. F. King

2000-03-27T23:59:59.000Z

50

Oscillation dynamics of active-unsterile neutrino mixing in a 2+1-tilde mixing scheme  

SciTech Connect (OSTI)

We consider the possibility that sterile neutrinos exist and admit a description as unparticles; we call these unsterile neutrinos. We then examine the nature of neutrino oscillations in a model where an unsterile can mix with two active flavors with a very simple mass matrix of the seesaw type. Despite these simplifications, we find a number of remarkable features, all of which will occur generically when more realistic cases are considered. These include momentum dependent mixing angles, invisible decay widths for the unsterile-like mode, as well as the inheritance of a nonvanishing spectral density for the massive activelike modes. We also obtain the disappearance and appearance probabilities for the activelike neutrinos and find remarkable interference effects between the active and unsterile neutrinos as a consequence of threshold effects, yielding new oscillatory contributions with different oscillation lengths. These effects are only measurable on short baseline experiments because there both probabilities are suppressed as compared to mixing with a canonical sterile neutrino, thereby providing a diagnostics tool to discriminate unsterile from canonical sterile neutrinos. We conclude with a discussion of whether these new phenomena could aid in the reconciliation of the LSND and MiniBooNE results.

Boyanovsky, D. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Holman, R.; Hutasoit, Jimmy A. [Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

2010-02-01T23:59:59.000Z

51

Almost Maximal Lepton Mixing with Large T Violation in Neutrino Oscillations and Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

We point out two simple but instructive possibilities to construct the charged lepton and neutrino mass matrices, from which the nearly bi-maximal neutrino mixing with large T violation can naturally emerge. The two lepton mixing scenarios are compatible very well with current experimental data on solar and atmospheric neutrino oscillations, and one of them may lead to an observable T-violating asymmetry between \

Zhi-zhong Xing

2001-07-02T23:59:59.000Z

52

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

2011-03-28T23:59:59.000Z

53

Majorana Neutrinos, Neutrino Mass Spectrum and the || ~ 0.001 eV Frontier in Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

If future neutrino oscillation experiments show that the neutrino mass spectrum is with normal ordering, m1 | > 0.01 eV give negative results, the next frontier in the quest for neutrinoless double beta-decay will correspond to || ~ 0.001 eV. Assuming that massive neutrinos are Majorana particles and their exchange is the dominant mechanism generating neutrinoless double beta-decay, we analise the conditions under which ||, in the case of three neutrino mixing and neutrino mass spectrum with normal ordering, would satisfy || > 0.001 eV. We consider the specific cases of i) normal hierarchical neutrino mass spectrum, ii) of relatively small value of the CHOOZ angle theta13 as well as iii) the general case of spectrum with normal ordering, partial hierarchy and a value of theta13 close to the existing upper limit. We study the ranges of the lightest neutrino mass m1 and/or of sin^2 theta13, for which ||> 0.001 eV and discuss the phenomenological implications of such scenarios. We provide also an estimate of || when the three neutrino masses and the neutrino mixing originate from neutrino mass term of Majorana type for the (left-handed) flavour neutrinos and m1 Ue1^2 + m2 U_e2^2 + m3 Ue3^2 =0, but there does not exist a symmetry which forbids the neutrinoless double beta-decay.

S. Pascoli; S. T. Petcov

2007-11-30T23:59:59.000Z

54

CP-phase effects on the effective neutrino mass m{sub ee} in the case of quasidegenerate neutrinos  

SciTech Connect (OSTI)

We study the possibility that the three mass states of the ordinary active neutrinos actually split into pairs of quasidegenerate states, with {Delta}m{sub kk}{sup '2{approx}}10{sup -12} eV{sup 2} or less, as a result of mixing of active neutrinos with sterile neutrinos. While in laboratory experiments these quasidegenerate pairs will look identical to single active states, the CP phase factors associated with active-sterile mixing might cause cancellations in the effective electron neutrino mass m{sub ee} measured in the neutrinoless double beta decay experiments thereby revealing the split nature of states.

Maalampi, J. [Department of Physics, P.O. Box 35, FIN-40014 University of Jyvaeskylae (Finland); Helsinki Institute of Physics, P.O. Box 64, FIN-00014 University of Helsinki (Finland); Riittinen, J. [Department of Physics, P.O. Box 35, FIN-40014 University of Jyvaeskylae (Finland)

2010-02-01T23:59:59.000Z

55

Non-Oscillation Probes of Neutrino Masses  

SciTech Connect (OSTI)

The absolute scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing statements on the neutrino mass from cosmological observations, two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double beta decay and the direct neutrino mass search. For both methods currently experiments with a sensitivity of O(100) meV are being set up or commissioned.

Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster Institut fuer Kernphysik, Wilhelm-Klemm-Str. 9, D-48149 Muenster (Germany)

2010-03-30T23:59:59.000Z

56

Non-oscillation probes of neutrino masses  

E-Print Network [OSTI]

The absolute scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing statements on the neutrino mass from cosmological observations two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double beta decay and the direct neutrino mass search. For both methods currently experiments with a sensitivity of order 100 meV are being set up or commissioned.

C. Weinheimer

2009-12-23T23:59:59.000Z

57

Neutrino Majorana Mass from Black Hole  

E-Print Network [OSTI]

We propose a new mechanism to generate the neutrino Majorana mass in TeV-scale gravity models. The black hole violates all non-gauged symmetries and can become the origin of lepton number violating processes. The fluctuation of higher-dimensional spacetime can result in the production of a black hole, which emits 2 neutrinos. If neutrinos are Majorana particles, this process is equivalent to the free propagation of a neutrino with the insertion of the black hole. From this fact, we derive the neutrino Majorana mass. The result is completely consistent with the recently observed evidence of neutrinoless double beta decay. And the obtained neutrino Majorana mass satisfies the constraint from the density of the neutrino dark matter, which affects the cosmic structure formation. Furthermore, we can explain the ultrahigh energy cosmic rays by the Z-burst scenario with it.

Yosuke Uehara

2002-05-25T23:59:59.000Z

58

Constraining Mass Spectra with Sterile Neutrinos from Neutrinoless Double Beta Decay, Tritium Beta Decay and Cosmology  

E-Print Network [OSTI]

We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that some of the allowed mass patterns are severely restricted by the current constraints, in particular by the cosmological constraints on the total sum of neutrino masses and by the non-maximality of the solar neutrino mixing angle. Furthermore, we estimate the form of the four neutrino mass matrices and also comment on the situation in scenarios with two additional sterile neutrinos.

Srubabati Goswami; Werner Rodejohann

2006-05-18T23:59:59.000Z

59

Constraining mass spectra with sterile neutrinos from neutrinoless double beta decay, tritium beta decay, and cosmology  

SciTech Connect (OSTI)

We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that some of the allowed mass patterns are severely restricted by the current constraints, in particular, by the cosmological constraints on the total sum of neutrino masses and by the nonmaximality of the solar neutrino mixing angle. Furthermore, we estimate the form of the four neutrino mass matrices and also comment on the situation in scenarios with two additional sterile neutrinos.

Goswami, Srubabati [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

2006-06-01T23:59:59.000Z

60

Neutrino mixing and CP violation phases in Zee-Babu model  

E-Print Network [OSTI]

We show that the neutrino mass matrix of the Zee-Babu model is able to fit the most recent data on neutrino masses and mixing with large $\\theta_{13}$ and provides %the values of the Dirac and Majorana CP violation phases. For the normal hierarchy, the Majorana phases ($\\al_{2 1}, \\al_{3 1}$) are equal to zero, while for the inverted pattern, one phase ($\\al_{3 1}$) takes the value $2 \\pi$. The Dirac phase ($\\de$) is predicted to either $0$ or $\\pi$. The effective mass governing neutrinoless double beta decay and the sum of neutrino masses are consistent with the recent analysis. The model gives some regions of the parameters of neutrino mixing angles in both normal and inverted neutrino mass hierarchy.

Van Vien, Vo; Thu, Pham Ngoc

2014-01-01T23:59:59.000Z

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61

Flavor $\\S_{4}$ [circle times operator] $\\Z_{2}$ symmetry and neutrino mixing  

E-Print Network [OSTI]

We present a model of the lepton masses and flavor mixing based on the discrete group $S^{}_4\\otimes Z^{}_2$. In this model, all the charged leptons and neutrinos are assigned to the ${\\bf \\underline{3}}_\\alpha$ representation of $S^{}_4$ in the Yamanouchi bases. The charged lepton and neutrino masses are mainly determined by the vacuum expectation value structures of the Higgs fields. Our model predicts a nearly tri-bimaximal lepton flavor mixing pattern, which is fully in agreement with the current experimental results. The neutrino mass spectrum takes the nearly degenerate pattern, which may be well tested in the future precise experiments.

Zhang, H

2007-01-01T23:59:59.000Z

62

Neutrino Mixing and CP Phase Correlations  

E-Print Network [OSTI]

A special form of the $3 \\times 3$ Majorana neutrino mass matrix derivable from $\\mu - \\tau$ interchange symmetry accompanied by a generalized $CP$ transformation was obtained many years ago. It predicts $\\theta_{23} = \\pi/4$ as well as $\\delta_{CP} = \\pm \\pi/2$, with $\\theta_{13} \

Ma, Ernest; Popov, Oleg

2015-01-01T23:59:59.000Z

63

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

2009-06-26T23:59:59.000Z

64

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

2008-10-21T23:59:59.000Z

65

On-shell renormalization of the mixing matrices in Majorana neutrino theories  

E-Print Network [OSTI]

We generalize a recently proposed on-shell approach to renormalize the Cabibbo-Kobayashi-Maskawa quark-mixing matrix to the case of an extended leptonic sector that includes Dirac and Majorana neutrinos in the framework of the seesaw mechanism. An important property of this formulation is the gauge independence of both the renormalized and bare lepton mixing matrices. Also, the texture zero in the neutrino mass matrix is preserved.

Andrea A. Almasy; Bernd A. Kniehl; Alberto Sirlin

2009-04-20T23:59:59.000Z

66

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

E-Print Network [OSTI]

In the context of three-flavor neutrino mixing, we present a thorough study of the phenomenological constraints applicable to three observables sensitive to absolute neutrino masses: The effective neutrino mass in Tritium beta decay (m_beta); the effective Majorana neutrino mass in neutrinoless double beta decay (m_2beta); and the sum of neutrino masses in cosmology (Sigma). We discuss the correlations among these variables which arise from the combination of all the available neutrino oscillation data, in both normal and inverse neutrino mass hierarchy. We set upper limits on m_beta by combining updated results from the Mainz and Troitsk experiments. We also consider the latest results on m_2beta from the Heidelberg-Moscow experiment, both with and without the lower bound claimed by such experiment. We derive upper limits on Sigma from an updated combination of data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite and the 2 degrees Fields (2dF) Galaxy Redshifts Survey, with and without Lyman-alpha forest data from the Sloan Digital Sky Survey (SDSS), in models with a non-zero running of the spectral index of primordial inflationary perturbations. The results are discussed in terms of two-dimensional projections of the globally allowed region in the (m_beta,m_2beta,Sigma) parameter space, which neatly show the relative impact of each data set. In particular, the (in)compatibility between Sigma and m_2beta constraints is highlighted for various combinations of data. We also briefly discuss how future neutrino data (both oscillatory and non-oscillatory) can further probe the currently allowed regions.

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

2004-11-17T23:59:59.000Z

67

PINGU and the neutrino mass hierarchy: Statistical and systematic aspects  

E-Print Network [OSTI]

The proposed PINGU project (Precision IceCube Next Generation Upgrade) is expected to collect O(10^5) atmospheric muon and electron neutrino in a few years of exposure, and to probe the neutrino mass hierarchy through its imprint on the event spectra in energy and direction. In the presence of nonnegligible and partly unknown shape systematics, the analysis of high-statistics spectral variations will face subtle challenges that are largely unprecedented in neutrino physics. We discuss these issues both on general grounds and in the currently envisaged PINGU configuration, where we find that possible shape uncertainties at the (few) percent level can noticeably affect the sensitivity to the hierarchy. We also discuss the interplay between the mixing angle theta_23 and the PINGU sensitivity to the hierarchy. Our results suggest that more refined estimates of spectral uncertainties are needed in next-generation, large-volume atmospheric neutrino experiments.

Capozzi, F; Marrone, A

2015-01-01T23:59:59.000Z

68

Mass Varying Neutrinos in the Sun  

E-Print Network [OSTI]

In this work we study the phenomenological consequences of the dependence of mass varying neutrinos on the neutrino density in the Sun, which we precisely compute in each point along the neutrino trajectory. We find that a generic characteristic of these scenarios is that they establish a connection between the effective Delta m^2 in the Sun and the absolute neutrino mass scale. This does not lead to any new allowed region in the oscillation parameter space. On the contrary, due to this effect, the description of solar neutrino data worsens for large absolute mass. As a consequence a lower bound on the level of degeneracy can be derived from the combined analysis of the solar and KamLAND data. In particular this implies that the analysis favours normal over inverted mass orderings. These results, in combination with a positive independent determination of the absolute neutrino mass, can be used as a test of these scenarios together with a precise determination of the energy dependence of the survival probability of solar neutrinos, in particular for low energies.

Marco Cirelli; M. C. Gonzalez-Garcia; Carlos Pena-Garay

2005-07-08T23:59:59.000Z

69

Neutrino masses, leptogenesis, and sterile neutrino dark matter  

E-Print Network [OSTI]

We analyze a scenario in which the lightest heavy neutrino $N_1$ is a dark matter candidate and the second- heaviest neutrino $N_2$ decays producing a lepton number. If $N_1$ were in thermal equilibrium, its energy density today would be much larger than that of the observed dark matter, so we consider energy injection by the decay of $N_2$. In this paper, we show the parameters of this scenario that give the correct abundances of dark matter and baryonic matter and also induce the observed neutrino masses. This model can explain a possible sterile neutrino dark matter signal of $M_1$=7 keV in the x-ray observation of x-ray multi-mirror mission.

Takanao Tsuyuki

2014-07-20T23:59:59.000Z

70

Determination of neutrino masses, present and future  

E-Print Network [OSTI]

Oscillation experiments show that neutrinos have masses. They however only determine the neutrinop mass differences. Information on the absolute masses can be obtained by studying the kinematics in weak decays, or by searching for neutrinoless double beta decay. Recent results are reviewed, as well as future projects.

Jean-Luc Vuilleumier

2003-06-04T23:59:59.000Z

71

Neutrinoless double-beta decay with three or four neutrino mixing  

E-Print Network [OSTI]

Considering the scheme with mixing of three neutrinos and a mass hierarchy that can accommodate the results of solar and atmospheric neutrino experiments, it is shown that the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses. Considering the four-neutrino schemes that can accommodate also the results of the LSND experiment, it is shown that only one of them is compatible with the results of neutrinoless double-beta decay experiments and with the measurement of the abundances of primordial elements produced in Big-Bang Nucleosynthesis. It is shown that in this scheme, under the assumptions that massive neutrinos are Majorana particles and there are no cancellations among the contributions of the different neutrino masses, the results of the LSND experiment imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay.

C. Giunti

1999-08-27T23:59:59.000Z

72

Arbitrary mass Majorana neutrinos in neutrinoless double beta decay  

E-Print Network [OSTI]

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

Amand Faessler; Marcela Gonzalez; Sergey Kovalenko; Fedor Simkovic

2014-08-26T23:59:59.000Z

73

Neutrino mass matrix solutions and neutrinoless double beta decay  

E-Print Network [OSTI]

We present a determination of the neutrino mass matrix which holds for values of the neutrinoless double beta decay effective mass m_{ee} larger than the neutrino mass differences. We find eight possible solutions and discuss for each one the corresponding neutrino mass eigenvalues and zero texture. A minimal structure of the perturbations to add to these zero textures to recover the full mass matrix is also determined. Implications for neutrino hot dark matter are discussed for each solution.

Thomas Hambye

2002-01-31T23:59:59.000Z

74

Neutrino mixing schemes and neutrinoless double beta decay  

E-Print Network [OSTI]

We study the possible structure of the neutrino mass matrix taking into consideration the solar and atmospheric neutrinos and the neutrinoless double beta decay. We emphasize on mass matrices with vanishing elements. There are only a very few possibilities remaining at present. We concentrate on three generation scenarios and find that with three parameters there are few possibilities with and without any vanishing elements. For completeness we also present a five parameter four neutrino (with one sterile neutrino) mass matrix which can explain all these experiments and the LSND result.

H. V. Klapdor-Kleingrothaus; U. Sarkar

2002-02-22T23:59:59.000Z

75

Neutrinoless Double Beta Decay and Neutrino Masses  

E-Print Network [OSTI]

Neutrinoless double beta decay is a promising test for lepton number violating physics beyond the standard model 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 neutrinoless double beta decay 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 neutrinoless double beta decay from unknown nuclear background using only one isotope, i.e., within one experiment.

Michael Duerr

2012-06-04T23:59:59.000Z

76

Neutrinoless double beta decay and neutrino masses  

SciTech Connect (OSTI)

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

77

Double Beta Decay, Majorana Neutrinos, and Neutrino Mass  

E-Print Network [OSTI]

The theoretical and experimental issues relevant to neutrinoless double-beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the non-observation of neutrinoless double-beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.

Frank T. Avignone III; Steven R. Elliott; Jonathan Engel

2007-11-26T23:59:59.000Z

78

Double beta decay, Majorana neutrinos, and neutrino mass  

SciTech Connect (OSTI)

The theoretical and experimental issues relevant to neutrinoless double beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics, and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the nonobservation of neutrinoless double beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.

Avignone, Frank T. III; Elliott, Steven R.; Engel, Jonathan [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599-3255 (United States)

2008-04-15T23:59:59.000Z

79

Double beta decay and neutrino mass models  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

80

Experiments for the absolute neutrino mass measurement  

E-Print Network [OSTI]

Experimental results and perspectives of different methods to measure the absolute mass scale of neutrinos are briefly reviewed. The mass sensitivities from cosmological observations, double beta decay searches and single beta decay spectroscopy differ in sensitivity and model dependance. Next generation experiments in the three fields reach the sensitivity for the lightest mass eigenstate of $m_1<0.2eV$, which will finally answer the question if neutrino mass eigenstates are degenerate. This sensitivity is also reached by the only model-independent approach of single beta decay (KATRIN experiment). For higher sensitivities on cost of model-dependance the neutrinoless double beta decay search and cosmological observation have to be applied. Here, in the next decade sensitivities are approached with the potential to test inverted hierarchy models.

Markus Steidl

2009-06-02T23:59:59.000Z

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.


81

CPT and lepton number violation in neutrino sector: Modified mass matrix and oscillation due to gravity  

E-Print Network [OSTI]

We study the consequences of CPT and lepton number violation in neutrino sector. For CPT violation we take gravity with which neutrino and antineutrino couple differently. Gravity mixes neutrino and antineutrino in an unequal ratio to give two mass eigenstates. Lepton number violation interaction together with CPT violation gives rise to neutrino-antineutrino oscillation. Subsequently, we study the neutrino flavor mixing and oscillation under the influence of gravity. It is found that gravity changes flavor oscillation significantly which influences the relative abundance of different flavors in present universe. We show that the neutrinoless double beta decay rate is modified due to presence of gravity- the origin of CPT violation, as the mass of the flavor state is modified.

Monika Sinha; Banibrata Mukhopadhyay

2007-11-21T23:59:59.000Z

82

Unsterile-active neutrino mixing: Consequences on radiative decay and bounds from the x-ray background  

SciTech Connect (OSTI)

We consider a sterile neutrino to be an unparticle, namely, an unsterile neutrino, with anomalous dimension {eta} and study its mixing with a canonical active neutrino via a seesaw mass matrix. We show that there is no unitary transformation that diagonalizes the mixed propagator and a field redefinition is required. The propagating or 'mass' states correspond to an unsterilelike and activelike mode. The unsterile mode features a complex pole or resonance for 0{<=}{eta}<1/3 with an 'invisible width' which is the result of the decay of the unsterile mode into the active mode and the massless particles of the hidden conformal sector. For {eta}{>=}1/3, the complex pole disappears, merging with the unparticle threshold. The active mode is described by a stable pole, but 'inherits' a nonvanishing spectral density above the unparticle threshold as a consequence of the mixing. We find that the radiative decay width of the unsterile neutrino into the active neutrino (and a photon) via charged current loops, is suppressed by a factor {approx}[2sin{sup 2}({theta}{sub 0})(M{sup 2}/{lambda}{sup 2})]{sup {eta}}{sup /(1-{eta})}, where {theta}{sub 0} is the mixing angle for {eta}=0, M is approximately the mass of the unsterile neutrino, and {lambda}>>M is the unparticle scale. The suppression of the radiative (visible) decay width of the sterile neutrino weakens the bound on the mass and mixing angle from the x-ray or soft gamma-ray background.

Boyanovsky, D. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Holman, R.; Hutasoit, Jimmy A. [Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

2009-07-15T23:59:59.000Z

83

Quark and lepton masses and mixing in the landscape  

E-Print Network [OSTI]

Even if quark and lepton masses are not uniquely predicted by the fundamental theory, as may be the case in the string theory landscape, nevertheless their pattern may reveal features of the underlying theory. We use statistical techniques to show that the observed masses appear to be representative of a scale invariant distribution, rho(m) ~ 1/m. If we extend this distribution to include all the Yukawa couplings, we show that the resulting CKM matrix elements typically show a hierarchical pattern similar to observations. The Jarlskog invariant measuring the amount of CP violation is also well reproduced in magnitude. We also apply this framework to neutrinos using the seesaw mechanism. The neutrino results are ambiguous, with the observed pattern being statistically allowed even though the framework does not provide a natural explanation for the observed two large mixing angles. Our framework highly favors a normal hierarchy of neutrino masses. We also are able to make statistical predictions in the neutrino sector when we specialize to situations consistent with the known mass differences and two large mixing angles. Within our framework, we show that with 95% confidence the presently unmeasured MNS mixing angle sin theta_{13} is larger than 0.04 and typically of order 0.1. The leptonic Jarlskog invariant is found to be typically of order 10^{-2} and the magnitude of the effective Majorana mass m_{ee} is typically of order 0.001 eV.

John F. Donoghue; Koushik Dutta; Andreas Ross

2006-01-27T23:59:59.000Z

84

Neutrinoless double beta decay, solar neutrinos and mass scales  

E-Print Network [OSTI]

We obtain bounds for the neutrino masses by combining atmospheric and solar neutrino data with the phenomenology of neutrinoless double beta decay where hypothetical values of || are envisaged from future 0\

Per Osland; Geir Vigdel

2001-09-13T23:59:59.000Z

85

Improving constraints on the neutrino mass using sufficient statistics  

E-Print Network [OSTI]

We use the "Dark Energy and Massive Neutrino Universe" (DEMNUni) simulations to compare the constraining power of "sufficient statistics" with the standard matter power spectrum on the sum of neutrino masses, $M_\

Wolk, M; Bel, J; Carbone, C; Carron, J

2015-01-01T23:59:59.000Z

86

Measurable neutrino mass scale in A{sub 4}xSU(5)  

SciTech Connect (OSTI)

We propose a supersymmetric A{sub 4}xSU(5) model of quasidegenerate neutrinos which predicts the effective neutrino mass m{sub ee} relevant for neutrinoless double beta decay to be proportional to the neutrino mass scale, thereby allowing its determination approximately independently of unknown Majorana phases. Such a natural quasidegeneracy is achieved by using A{sub 4} family symmetry (as an example of a non-Abelian family symmetry with real triplet representations) to enforce a contribution to the neutrino mass matrix proportional to the identity. Tribimaximal neutrino mixing as well as quark CP violation with {alpha}{approx_equal}90 deg. d a leptonic CP phase {delta}{sub MNS{approx_equal}}90 deg. arise from the breaking of the A{sub 4} family symmetry by the vacuum expectation values of four 'flavon' fields pointing in specific postulated directions in flavor space.

Antusch, S.; Spinrath, M. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, D-80805 Muenchen (Germany); King, Stephen F. [School of Physics and Astronomy, University of Southampton, SO17 1BJ Southampton (United Kingdom)

2011-01-01T23:59:59.000Z

87

Neutrinoless double beta decay and direct searches for neutrino mass  

E-Print Network [OSTI]

Study of the neutrinoless double beta decay and searches for the manifestation of the neutrino mass in ordinary beta decay are the main sources of information about the absolute neutrino mass scale, and the only practical source of information about the charge conjugation properties of the neutrinos. Thus, these studies have a unique role in the plans for better understanding of the whole fast expanding field of neutrino physics.

Craig Aalseth; Henning Back; Loretta Dauwe; David Dean; Guido Drexlin; Yuri Efremenko; Hiro Ejiri; Steven Elliott; Jon Engel; Brian Fujikawa; Reyco Henning; G. W. Hoffmann; Karol Lang; Kevin Lesko; Tadafumi Kishimoto; Harry Miley; Rick Norman; Silvia Pascoli; Serguey Petcov; Andreas Piepke; Werner Rodejohann; David Saltzberg; Sean Sutton; Petr Vogel; Ray Warner; John Wilkerson; Lincoln Wolfenstein

2004-12-21T23:59:59.000Z

88

Experimental Neutrino Physics: Final Report  

SciTech Connect (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

89

Colliding neutrino beams  

E-Print Network [OSTI]

From several neutrino oscillation experiments, we understand now that neutrinos have mass. However, we really don't know what mechanism is responsible for producing this neutrino mass. Current or planned neutrino experiments utilize neutrino beams and long-baseline detectors to explore flavor mixing but do not address the question of the origin of neutrino mass. In order to answer that question, neutrino interactions need to be explored at much higher energies. This paper outlines a program to explore neutrinos and their interactions with various particles through a series of experiments involving colliding neutrino beams.

Reinhard Schwienhorst

2007-11-08T23:59:59.000Z

90

LSP Squark Decays at the LHC and the Neutrino Mass Hierarchy  

E-Print Network [OSTI]

The existence of R-parity in supersymmetric models can be naturally explained as being a discrete subgroup of gauged baryon minus lepton number (B-L). The most minimal supersymmetric B-L model triggers spontaneous R-parity violation, while remaining consistent with proton stability. This model is well-motivated by string theory and makes several interesting, testable predictions. Furthermore, R-parity violation contributes to neutrino masses, thereby connecting the neutrino sector to the decay of the lightest supersymmetric particle (LSP). This paper analyzes the decays of third generation squark LSPs into a quark and a lepton. In certain cases, the branching ratios into charged leptons reveal information about the neutrino mass hierarchy, a current goal of experimental neutrino physics, as well as the $\\theta_{23}$ neutrino mixing angle. Furthermore, optimization of leptoquark searches for this scenario is discussed. Using currently available data, the lower bounds on the third generation squarks are computed.

Zachary Marshall; Burt A. Ovrut; Austin Purves; Sogee Spinner

2014-08-05T23:59:59.000Z

91

Neutrinoless Double Beta Decay with Negligible Neutrino Mass  

E-Print Network [OSTI]

If the electron neutrino has an effective nonzero Majorana mass, then neutrinoless double beta decay will occur. However, the latter is possible also with a negligible neutrino mass. We show how this may happen in a simple model of scalar diquarks and dileptons. This possibility allows neutrino masses to be small and hierarchical, without conflicting with the possible experimental evidence of neutrinoless double beta decay.

Biswajoy Brahmachari; Ernest Ma

2002-02-27T23:59:59.000Z

92

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

2014-05-21T23:59:59.000Z

93

absolute neutrino mass: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

obtained in tritium beta decay experiments, cosmological observations and neutrinoless double-beta decay experiments. Carlo Giunti 2005-11-10 3 Absolute neutrino mass from...

94

absolute neutrino masses: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

obtained in tritium beta decay experiments, cosmological observations and neutrinoless double-beta decay experiments. Carlo Giunti 2005-11-10 3 Absolute neutrino mass from...

95

Sterile neutrinos produced near the EW scale I: mixing angles, MSW resonances and production rates  

E-Print Network [OSTI]

We study the production of sterile neutrinos in the region $T\\sim M_W$ in an extension beyond the standard model with the see-saw mass matrix originating in Yukawa couplings to Higgs-like scalars with masses and vev's of the order of the electroweak scale. Sterile neutrinos are produced by the decay of scalars and standard model vector bosons. We obtain the index of refraction, dispersion relations, mixing angles in the medium and production rates including those for right-handed sterile neutrinos, from the standard model and beyond the standard model self-energies. For $1 \\lesssim M_W/T \\lesssim 3$ we find narrow MSW resonances with $k \\lesssim T$ for both left and right handed neutrinos even in absence of a lepton asymmetry in the (active) neutrino sector, as well as very low energy ($k/T \\ll |\\xi|$) narrow MSW resonances in the presence of a lepton asymmetry consistent with the bounds from WMAP and BBN. For small vacuum mixing angle, consistent with observational bounds, the absorptive part of the self-ene...

Wu, Jun; Boyanovsky, Daniel

2009-01-01T23:59:59.000Z

96

Strong thermal leptogenesis and the absolute neutrino mass scale  

E-Print Network [OSTI]

We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass $m_1 \\gtrsim 10\\,{\\rm meV}$ for normal ordering (NO) and $m_1 \\gtrsim 3\\,{\\rm meV}$ for inverted ordering (IO) for models with orthogonal matrix entries respecting $|\\Omega_{ij}^2| \\lesssim 2$. . We show analytically why lower values of $m_1$ require a high level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and can be tighten by a future determination of the Dirac phase. Our analysis also allows to place more stringent constraint for a specific model or class of models, such as $SO(10)$-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of $m_1$. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing $m_1$. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.

Pasquale Di Bari; Sophie E. King; Michele Re Fiorentin

2014-03-24T23:59:59.000Z

97

Three-Neutrino MSW Effect and the LNW Mass Matrix  

E-Print Network [OSTI]

We review recent work on analytical solutions to the MSW equations for three neutrino flavours, for exponential and linear potentials. An application to a particular mass matrix is also discussed. The three neutrino masses are determined, respectively, to be 0.001--0.004, and roughly 0.01 and 0.05 eV.

Per Osland; Tai Tsun Wu

2001-03-27T23:59:59.000Z

98

Direct determination of Neutrino Mass from Tritium Beta Spectrum  

E-Print Network [OSTI]

The investigation of the endpoint region of the tritium beta decay spectrum is still the most sensitive direct method to determine the neutrino mass scale. In the nineties and the beginning of this century the tritium beta decay experiments at Mainz and Troitsk have reached a sensitivity on the neutrino mass of 2 eV/c^2 . They were using a new type of high-resolution spectrometer with large sensitivity, the MAC-E-Filter, and were studying the systematics in detail. Currently, the KATRIN experiment is being set up at Forschungszentrum Karlsruhe, Germany. KATRIN will improve the neutrino mass sensitivity by one order of magnitude down to 0.2 eV/c^2, sufficient to cover the degenerate neutrino mass scenarios and the cosmologically relevant neutrino mass range.

C. Weinheimer

2009-12-08T23:59:59.000Z

99

Texture Zero Mass Matrices and Flavor Mixing of Quarks and Leptons  

E-Print Network [OSTI]

We discuss mass matrices with four texture zeros for the quarks and leptons. The three mixing angles for the quarks and leptons are functions of the fermion masses. The results agree with the experimental data. The ratio of the masses of the first two neutrinos is given by the solar mixing angle. The neutrino masses are calculated: $m_1$ $\\approx$ 0.003 eV , $m_2$ $\\approx$ 0.012 eV , $m_3$ $\\approx$ 0.048 eV.

Fritzsch, Harald

2015-01-01T23:59:59.000Z

100

How to Describe Neutrino Mixing and CP Violation  

E-Print Network [OSTI]

We present a classification of possible parametrizations of the 3x3 lepton flavor mixing matrix in terms of the rotation and phase angles. A particular parametrization, which is most convenient to describe the observables of neutrino oscillations and that of the neutrinoless double beta decay, is studied in detail. The possibility to determine the Dirac- and Majorana-type CP-violating phases are also discussed.

Harald Fritzsch; Zhi-zhong Xing

2001-07-29T23:59:59.000Z

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

Acquiring information about neutrino parameters by detecting supernova neutrinos  

SciTech Connect (OSTI)

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle {theta}{sub 13}, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about {theta}{sub 13} and neutrino masses by detecting supernova neutrinos. We apply these methods to some current neutrino experiments.

Huang, Ming-Yang; Guo, Xin-Heng [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Young, Bing-Lin [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 5001 (United States); Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2010-08-01T23:59:59.000Z

102

Constraining four neutrino mass patterns from neutrinoless double beta decay  

E-Print Network [OSTI]

All existing data on neutrino oscillations (including those from the LSND experiment) imply a four neutrino scheme with six different allowed mass patterns. Some of the latter are shown to be disfavored by using a conservative upper bound on the $\\beta beta 0 \

Sandip Pakvasa; Probir Roy

2002-04-19T23:59:59.000Z

103

MiniBooNE Results and Neutrino Schemes with 2 sterile Neutrinos: Possible Mass Orderings and Observables related to Neutrino Masses  

E-Print Network [OSTI]

The MiniBooNE and LSND experiments are compatible with each other when two sterile neutrinos are added to the three active ones. In this case there are eight possible mass orderings. In two of them both sterile neutrinos are heavier than the three active ones. In the next two scenarios both sterile neutrinos are lighter than the three active ones. The remaining four scenarios have one sterile neutrino heavier and another lighter than the three active ones. We analyze all scenarios with respect to their predictions for mass-related observables. These are the sum of neutrino masses as constrained by cosmological observations, the kinematic mass parameter as measurable in the KATRIN experiment, and the effective mass governing neutrinoless double beta decay. It is investigated how these non-oscillation probes can distinguish between the eight scenarios. Six of the eight possible mass orderings predict positive signals in the KATRIN and future neutrinoless double beta decay experiments. We also remark on scenarios with three sterile neutrinos. In addition we make some comments on the possibility of using decays of high energy astrophysical neutrinos to discriminate between the mass orderings in presence of two sterile neutrinos.

Srubabati Goswami; Werner Rodejohann

2007-10-08T23:59:59.000Z

104

Renormalization of a two-loop neutrino mass model  

SciTech Connect (OSTI)

We analyze the renormalization group structure of a radiative neutrino mass model consisting of a singly charged and a doubly charged scalar fields. Small Majorana neutrino masses are generated by the exchange of these scalars via two-loop diagrams. We derive boundedness conditions for the Higgs potential and show how they can be satisfied to energies up to the Planck scale. Combining boundedness and perturbativity constraints with neutrino oscillation phenomenology, new limits on the masses and couplings of the charged scalars are derived. These in turn lead to lower limits on the branching ratios for certain lepton flavor violating (LFV) processes such as ??e?, ??3e and ? ? e conversion in nuclei. Improved LFV measurements could test the model, especially in the case of inverted neutrino mass hierarchy where these are more prominent.

Babu, K. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States); Julio, J. [Fisika LIPI, Kompleks Puspiptek Serpong, Tangerang 15310, Indonesia and Jožef Stefan Institute, Jamova Cesta 39, 1001 Ljubljana (Slovenia)

2014-06-24T23:59:59.000Z

105

Three-Neutrino MSW Effect and the Lehmann Mass Matrix  

E-Print Network [OSTI]

Recent work on analytical solutions to the MSW equations for three neutrino flavours is reviewed, with emphasis on the exponential density. Application to a particular mass matrix, proposed by Lehmann, Newton and Wu, is also discussed. Within this model, the experimental data allow a determination of the three neutrino masses. They are found to be 0.002-0.004, 0.01 and 0.05 eV.

Per Osland

2002-10-22T23:59:59.000Z

106

Neutrino mass spectrum and neutrinoless double beta decay  

E-Print Network [OSTI]

The relations between the effective Majorana mass of the electron neutrino, $m_{ee}$, responsible for neutrinoless double beta decay, and the neutrino oscillation parameters are considered. We show that for any specific oscillation pattern $m_{ee}$ can take any value (from zero to the existing upper bound) for normal mass hierarchy and it can have a minimum for inverse hierarchy. This means that oscillation experiments cannot fix in general $m_{ee}$. Mass ranges for $m_{ee}$ can be predicted in terms of oscillation parameters with additional assumptions about the level of degeneracy and the type of hierarchy of the neutrino mass spectrum. These predictions for $m_{ee}$ are systematically studied in the specific schemes of neutrino mass and flavor which explain the solar and atmospheric neutrino data. The contributions from individual mass eigenstates in terms of oscillation parameters have been quantified. We study the dependence of $m_{ee}$ on the non-oscillation parameters: the overall scale of the neutrino mass and the relative mass phases. We analyze how forthcoming oscillation experiments will improve the predictions for $m_{ee}$. On the basis of these studies we evaluate the discovery potential of future \\znbb decay searches. The role \\znbb decay searches will play in the reconstruction of the neutrino mass spectrum is clarified. The key scales of $m_{ee}$, which will lead to the discrimination among various schemes are: $m_{ee} \\sim 0.1$ eV and $m_{ee} \\sim 0.005$ eV.

H. V. Klapdor-Kleingrothaus; H. Päs; A. Y. Smirnov

2000-10-08T23:59:59.000Z

107

Particle physics implications of the WMAP neutrino mass bound  

E-Print Network [OSTI]

The recently published cosmological bound on the absolute neutrino masses obtained from the Wilkinson Microwave Anisotropy Probe (WMAP) data has important consequences for neutrino experiments and models. Taken at face value, the new bound excludes the determination of the absolute neutrino mass in the KATRIN experiment and disfavors a neutrino oscillation interpretation of the LSND experiment. Combined with the KamLAND and Super-K data, the WMAP bound defines an accessible range for the neutrinoless double beta decay amplitude. The bound also impacts the Z-burst annihilation mechanism for resonant generation of extreme-energy cosmic rays on the cosmic neutrino background in two ways: it constrains the local overdensity of neutrino dark matter which is not helpful, but it also limits the resonant energy to a favorable range. In R-parity violating SUSY models neutrino masses are generated by trilinear and bilinear lepton number violating couplings. The WMAP result improves the constraints on these couplings over their existing values by an order of magnitude.

G. Bhattacharyya; H. Päs; L. Song; T. J. Weiler

2003-04-25T23:59:59.000Z

108

Neutrinoless double beta decay and neutrino physics  

E-Print Network [OSTI]

The connection of neutrino physics with neutrinoless double beta decay is reviewed. After presenting the current status of the PMNS matrix and the theoretical background of neutrino mass and lepton mixing, we will summarize the various implications of neutrino physics for double beta decay. The influence of light sterile neutrinos and other exotic modifications of the three neutrino picture is also discussed.

Werner Rodejohann

2012-08-20T23:59:59.000Z

109

Neutrino mass matrices with M{sub ee}=0  

SciTech Connect (OSTI)

Motivated by the possibility that the amplitude for neutrinoless double beta decay may be much smaller than the planned sensitivity of future experiments, we study Ansaetze for the neutrino mass matrix with M{sub ee}=0. For the case in which CP is conserved, we consider two classes of real-valued mass matrices: ''Class I'' defined by |M{sub e{mu}|}=|M{sub e{tau}|}, and ''Class II'' defined by |M{sub {mu}{mu}|}=|M{sub {tau}{tau}|}. The important phenomenological distinction between the two is that Class I permits only small values of V{sub e3} up to {approx}0.03, while Class II admits large values of V{sub e3} up to its empirical upper limit of 0.22. Then we introduce CP-violating complex phases into the mass matrix. We show that it is possible to have tribimaximal mixing with M{sub ee}=0 and |M{sub {mu}{tau}|}=|M{sub {mu}{mu}|}=|M{sub {tau}{tau}|} if the Majorana phase angles are {+-}{pi}/4. Alternatively, for smaller values of |M{sub {mu}{tau}|}=|M{sub {mu}{mu}|}=|M{sub {tau}{tau}|} it is possible to obtain |V{sub e3}|{approx}0.2 and generate relatively large CP-violating amplitudes. To eliminate phase redundancy, we emphasize rephasing any mass matrix with M{sub ee}=0 into a standard form with two complex phases. The discussion alternates between analytical and numerical but remains purely phenomenological, without any attempt to derive mass matrices from a fundamental theory.

BenTov, Yoni [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Zee, A. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)

2011-10-01T23:59:59.000Z

110

Effects of Mass Varying Neutrinos on Cosmological Parameters as determined from the Cosmic Microwave Background  

E-Print Network [OSTI]

In models with a light scalar field (the `acceleron') coupled to neutrinos, neutrino masses depend on neutrino density. The resulting coupled system of mass varying neutrinos (MaVaNs) and the acceleron can act as a negative pressure fluid and is a candidate for dark energy \\cite{Fardon:2003eh} . MaVaNs also allow for higher $\\Sigma$m$_\

Akshay Ghalsasi; Ann E. Nelson

2014-05-04T23:59:59.000Z

111

Neutrino Oscillation Studies with Reactors  

E-Print Network [OSTI]

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

Petr Vogel; Liangjian Wen; Chao Zhang

2015-03-03T23:59:59.000Z

112

Neutrino Oscillation Studies with Reactors  

E-Print Network [OSTI]

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

Vogel, Petr; Zhang, Chao

2015-01-01T23:59:59.000Z

113

Decay Oscillations in Electron Capture and the Neutrino Mass Difference  

E-Print Network [OSTI]

Quantum mechanical theory disallows the model that has been used to infer the neutrino mass difference from the reported "GSI oscillations" in the rates of decay of hydrogen-like ions by electron capture. It has not been proved that the existence of mass-difference-dependent oscillations conflicts with quantum mechanics but no consistent quantum mechanical model has been shown to predict them.

Murray Peshkin

2014-03-17T23:59:59.000Z

114

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

2013-08-14T23:59:59.000Z

115

Neutrinoless double {beta}-decay and neutrino mass hierarchies  

SciTech Connect (OSTI)

In the framework of the seesaw mechanism the normal hierarchy is favorable for the neutrino mass spectrum. For this spectrum we present a detailed calculation of the half-lives of neutrinoless double {beta}-decay for several nuclei of experimental interest. The half-lives are evaluated by considering the most comprehensive nuclear matrix elements, which were obtained within the renormalized quasiparticle random phase approximation by the Bratislava-Caltech-Tuebingen group. The dependence of the half-lives on sin{sup 2}{theta}{sub 13} and the lightest neutrino mass is studied. We present also the results of the calculations of the half-lives of neutrinoless double {beta}-decay in the case of the inverted hierarchy of neutrino masses.

Bilenky, S. M. [Scuola Internazionale Superiore di Studi Avanzati, I-34014 Trieste (Italy); Faessler, Amand; Gutsche, Thomas; Simkovic, Fedor [Institute fuer Theoretische Physik der Universitaet Tuebingen, D-72076 Tuebingen (Germany)

2005-09-01T23:59:59.000Z

116

Neutrino masses and the number of neutrino species from WMAP and 2dFGRS  

E-Print Network [OSTI]

We have performed a thorough analysis of the constraints which can be put on neutrino parameters from cosmological observations, most notably those from the WMAP satellite and the 2dF galaxy survey. For this data we find an upper limit on the sum of active neutrino mass eigenstates of \\sum m_nu neutrinoless double beta decay reported by the Heidelberg-Moscow experiment. In terms of the relativistic energy density in neutrinos or other weakly interacting species we find, in units of the equivalent number of neutrino species, N_nu, that N_nu = 4.0+3.0-2.1 (95% conf.). When BBN constraints are added, the bound on N_\

Steen Hannestad

2003-03-04T23:59:59.000Z

117

Tribimaximal neutrino mixing and neutrinoless double beta decay  

SciTech Connect (OSTI)

We present a tribimaximal lepton mixing scheme where the neutrinoless double beta decay rate has a lower bound which correlates with the ratio {alpha}{identical_to}{delta}m{sub sol}{sup 2}/{delta}m{sub atm}{sup 2} well determined by current data, as well as with the unknown Majorana CP phase {phi}{sub 12} characterizing the solar neutrino subsystem. For the special value {phi}{sub 12}=({pi}/2) (opposite CP-sign neutrinos) the {beta}{beta}{sub 0{nu}} rate vanishes at tree level when {delta}m{sub sol}{sup 2}/{delta}m{sub atm}{sup 2}=3/80, only allowed at 3{sigma}. For all other cases the rate is nonzero, and lies within current and projected experimental sensitivities close to {phi}{sub 12}=0. We suggest two model realizations of this scheme in terms of A{sub 4}xZ{sub 2} and A{sub 4}xZ{sub 4} flavor symmetries.

Hirsch, M.; Morisi, S.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular-- C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

2008-11-01T23:59:59.000Z

118

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

SciTech Connect (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

119

Spontaneous R-Parity Breaking, Stop LSP Decays and the Neutrino Mass Hierarchy  

E-Print Network [OSTI]

The MSSM with right-handed neutrino supermultiplets, gauged B-L symmetry and a non-vanishing sneutrino expectation value is the minimal theory that spontaneously breaks R-parity and is consistent with the bounds on proton stability and lepton number violation. This minimal B-L MSSM can have a colored/charged LSP, of which a stop LSP is the most amenable to observation at the LHC. We study the R-parity violating decays of a stop LSP into a bottom quark and charged leptons--the dominant modes for a generic "admixture" stop. A numerical analysis of the relative branching ratios of these decay channels is given using a wide scan over the parameter space. The fact that R-parity is violated in this theory by a vacuum expectation value of a sneutrino links these branching ratios directly to the neutrino mass hierarchy. It is shown how a discovery of bottom-charged lepton events at the LHC can potentially determine whether the neutrino masses are in a normal or inverted hierarchy, as well as determining the theta_23 neutrino mixing angle. Finally, present LHC bounds on these leptoquark signatures are used to put lower bounds on the stop mass.

Zachary Marshall; Burt A. Ovrut; Austin Purves; Sogee Spinner

2014-06-03T23:59:59.000Z

120

Nonzero {theta}{sub 13} for neutrino mixing in a supersymmetric B-L gauge model with T{sub 7} lepton flavor symmetry  

SciTech Connect (OSTI)

We discuss how {theta}{sub 13}{ne}0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T{sub 7} in the context of a supersymmetric extension of the standard model with gauged U(1){sub B-L}. We predict a correlation between {theta}{sub 13} and {theta}{sub 23}, as well as the effective neutrino mass m{sub ee} in neutrinoless double beta decay.

Cao Qinghong [Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, U.S.A (United States); Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Khalil, Shaaban [Centre for Theoretical Physics, The British University in Egypt, El Sherouk City, Postal No. 11837, P.O. Box 43 (Egypt); Department of Mathematics, Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Ma, Ernest [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Okada, Hiroshi [School of Physics, KIAS, Seoul 130-722 (Korea, Republic of)

2011-10-01T23:59:59.000Z

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
to obtain the most current and comprehensive results.


121

Testing Radiative Neutrino Mass Models at the LHC  

E-Print Network [OSTI]

The Large Hadron Collider provides us new opportunities to search for the origin of neutrino mass. Beyond the minimal see-saw models a plethora of models exist which realise neutrino mass at tree- or loop-level, and it is important to be sure that these possibilities are satisfactorily covered by searches. The purpose of this paper is to advance a systematic approach to this problem. Majorana neutrino mass models can be organised by SM-gauge-invariant operators which violate lepton number by two units. In this paper we write down the minimal ultraviolet completions for all of the mass-dimension 7 operators. We predict vector-like quarks, vector-like leptons, scalar leptoquarks, a charged scalar, and a scalar doublet, whose properties are constrained by neutrino oscillation data. A detailed collider study is presented for $O_3=LLQ\\bar dH$ and $O_8 = L\\bar d\\bar e^\\dagger \\bar u^\\dagger H$ completions with a vector-like quark $\\chi\\sim(3, 2, -\\frac{5}{6})$ and a leptoquark $\\phi\\sim(\\bar 3,1,\\frac{1}{3})$. The existing LHC limits extracted from searches for vector-like fermions and sbottoms/stops are $m_\\chi \\gtrsim 620$ GeV and $m_\\phi\\gtrsim 600$ GeV.

Yi Cai; Jackson D. Clarke; Michael A. Schmidt; Raymond R. Volkas

2014-10-22T23:59:59.000Z

122

Testing Radiative Neutrino Mass Models at the LHC  

E-Print Network [OSTI]

The Large Hadron Collider provides us new opportunities to search for the origin of neutrino mass. Beyond the minimal see-saw models a plethora of models exist which realise neutrino mass at tree- or loop-level, and it is important to be sure that these possibilities are satisfactorily covered by searches. The purpose of this paper is to advance a systematic approach to this problem. Majorana neutrino mass models can be organised by SM-gauge-invariant operators which violate lepton number by two units. In this paper we write down the minimal ultraviolet completions for all of the mass-dimension 7 operators. We predict vector-like quarks, vector-like leptons, scalar leptoquarks, a charged scalar, and a scalar doublet, whose properties are constrained by neutrino oscillation data. A detailed collider study is presented for $O_3=LLQ\\bar dH$ and $O_8 = L\\bar d\\bar e^\\dagger \\bar u^\\dagger H$ completions with a vector-like quark $\\chi\\sim(3, 2, -\\frac{5}{6})$ and a leptoquark $\\phi\\sim(\\bar 3,1,\\frac{1}{3})$. The existing LHC limits extracted from searches for vector-like fermions and sbottoms/stops are $m_\\chi \\gtrsim 620$ GeV and $m_\\phi\\gtrsim 600$ GeV.

Yi Cai; Jackson D. Clarke; Michael A. Schmidt; Raymond R. Volkas

2015-02-07T23:59:59.000Z

123

Improved measurements of the neutrino mixing angle ?[subscript 13] with the Double Chooz detector  

E-Print Network [OSTI]

The Double Chooz experiment presents improved measurements of the neutrino mixing angle ?[subscript 13] using the data collected in 467.90 live days from a detector positioned at an average distance of 1050 m from two ...

Conrad, Janet

124

E-Print Network 3.0 - active-sterile neutrino mixing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Collection: Physics 4 arXiv:hep-ph0608147v113Aug2006 NUHEP-TH06-06 Neutrino Phenomenology of Very Low-Energy Seesaws Summary: , related via the standard lepton mixing...

125

Study of Two-Loop Neutrino Mass Generation Models  

E-Print Network [OSTI]

We study the models with the Majorana neutrino masses generated radiatively by two-loop diagrams due to the Yukawa $\\rho \\bar \\ell_R^c \\ell_R$ and effective $\\rho^{\\pm\\pm} W^\\mp W^\\mp$ couplings along with a scalar triplet $\\Delta$, where $\\rho$ is a doubly charged singlet scalar, $\\ell_R$ the charged lepton and $W$ the charged gauge boson. A generic feature in these types of models is that the neutrino mass spectrum has to be a normal hierarchy. Furthermore, by using the neutrino oscillation data and comparing with the global fitting result in the literature, we find a unique neutrino mass matrix and predict the Dirac and two Majorana CP phases to be $1.40\\pi$, $1.11\\pi$ and $1.47\\pi$, respectively. We also discuss the model parameters constrained by the lepton flavor violating processes and electroweak oblique parameters. In addition, we show that the rate of the neutrinoless double beta decay $(0\

Geng, Chao-Qiang

2015-01-01T23:59:59.000Z

126

Forbidden unique beta-decays and neutrino mass  

SciTech Connect (OSTI)

The measurement of the electron spectrum in beta-decays provides a robust direct determination of the values of neutrino masses. The planned rhenium beta-decay experiment, called the “Microcalorimeter Arrays for a Rhenium Experiment” (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which is expected to collect data in a near future. In this contribution we discuss the spectrum of emitted electrons close to the end point in the case of the first unique forbidden beta-decay of {sup 79}Se, {sup 107}Pd and {sup 187}Re. It is found that the p{sub 3/2}-wave emission dominates over the s{sub 1/2}-wave. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed beta-decay of {sup 3}H.

Dvornický, Rastislav [Bogoliubov Laboratory of Theoretical Physics, JINR Dubna, 141980 Dubna, Moscow region, Russian Federation and Department of Nuclear Physics and Biophysics, Comenius University, Mlynská dolina F1, SK-84215 Bratislava (Slovakia); Šimkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynská dolina F1, SK-84215 Bratislava, Slovakia and IEAP, Czech Technical University, CZ-128 00 Prague (Czech Republic)

2013-12-30T23:59:59.000Z

127

Measuring the neutrino mass from future wide galaxy cluster catalogues  

SciTech Connect (OSTI)

We present forecast errors on a wide range of cosmological parameters obtained from a photometric cluster catalogue of a future wide-field Euclid-like survey. We focus in particular on the total neutrino mass as constrained by a combination of the galaxy cluster number counts and correlation function. For the latter we consider only the shape information and the Baryon Acoustic Oscillations (BAO), while marginalising over the spectral amplitude and the redshift space distortions. In addition to the cosmological parameters of the standard ?CDM+? model we also consider a non-vanishing curvature, and two parameters describing a redshift evolution for the dark energy equation of state. For completeness, we also marginalise over a set of ''nuisance'' parameters, representing the uncertainties on the cluster mass determination. We find that combining cluster counts with power spectrum information greatly improves the constraining power of each probe taken individually, with errors on cosmological parameters being reduced by up to an order of magnitude. In particular, the best improvements are for the parameters defining the dynamical evolution of dark energy, where cluster counts break degeneracies. Moreover, the resulting error on neutrino mass is at the level of ?(M{sub ?}) ? 0.9 eV, comparable with that derived from present Ly? forest measurements and Cosmic Microwave background (CMB) data in the framework of a non-flat Universe. Further adopting Planck priors and reducing the number of free parameters to a ?CDM+? cosmology allows to place constraints on the total neutrino mass of ?(M{sub ?}) ? 0.08 eV, close to the lower bound enforced by neutrino oscillation experiments. Finally, in the optimistic case where uncertainties in the calibration of the mass-observable relation were so small to be neglected, the combination of Planck priors with cluster counts and power spectrum would constrain the total neutrino mass down to ?(M{sub ?}) ? 0.034 eV, i.e. the minimum neutrino mass predicted by oscillation experiments would be detected in a ?CDM framework. We thus show that galaxy clusters from future wide galaxy surveys will be an excellent tool for studying cosmology and fundamental physics.

Carbone, Carmelita; Moscardini, Lauro; Cimatti, Andrea [Dipartimento di Astronomia, Alma Mater Studiorum-Università di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Fedeli, Cosimo, E-mail: carmelita.carbone@unibo.it, E-mail: cosimo.fedeli@astro.ufl.edu, E-mail: lauro.moscardini@unibo.it, E-mail: a.cimatti@unibo.it [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States)

2012-03-01T23:59:59.000Z

128

Ultra-low Q values for neutrino mass measurements  

SciTech Connect (OSTI)

We investigate weak nuclear decays with extremely small kinetic energy release (Q value) and thus extremely good sensitivity to the absolute neutrino mass scale. In particular, we consider decays into excited daughter states, and we show that partial ionization of the parent atom can help to tune Q values to << 1 keV. We discuss several candidate isotopes undergoing {beta}{sup {+-}}, bound state {beta}, or electron capture decay, and come to the conclusion that a neutrino mass measurement using low-Q decays might only be feasible if no ionization is required, and if future improvements in isotope production technology, nuclear mass spectroscopy, and atomic structure calculations are possible. Experiments using ions, however, are extremely challenging due to the large number of ions that must be stored. New precision data on nuclear excitation levels could help to identify further isotopes with low-Q decay modes and possibly less challenging requirements.

Kopp, Joachim; /Heidelberg, Max Planck Inst. /Fermilab; Merle, Alexander; /Heidelberg, Max Planck Inst.

2009-11-01T23:59:59.000Z

129

Democratic Neutrino Theory  

E-Print Network [OSTI]

New theory of neutrino masses and mixing is introduced. This theory is based on a simple S_3 symmetric democratic neutrino mass matrix, and predicts the neutrino mass spectrum of normal ordering. Taking into account the matter effect and proper averaging of the oscillations, this theory agrees with the variety of atmospheric, solar and accelerator neutrino data. Moreover, the absolute scale of the neutrino masses m of 0.03 eV is determined in this theory, using the atmospheric neutrino oscillation data. In case of tiny perturbations in the democratic mass matrix only one this scale parameter m allows to explain the mentioned above neutrino results, and the theory has huge predictive power.

Dmitry Zhuridov

2014-05-21T23:59:59.000Z

130

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

SciTech Connect (OSTI)

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

131

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

SciTech Connect (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.] [ed.

1997-12-31T23:59:59.000Z

132

Majorana neutrino masses and the neutrinoless double-beta decay  

SciTech Connect (OSTI)

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

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

2006-12-15T23:59:59.000Z

133

Model-independent Constraint on the Neutrino Mass Spectrum from the Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

We present a concise formula to relate the effective mass term of the neutrinoless double beta decay to a single neutrino mass, two Majorana CP-violating phases and four observables of neutrino oscillations for a generic neutrino mass spectrum. If the alleged evidence for the neutrinoless double beta decay is taken into account, one may obtain a rough but model-independent constraint on the absolute scale of neutrino masses -- it is most likely to be in the range between 0.1 eV and 1 eV.

Zhi-zhong Xing

2002-02-22T23:59:59.000Z

134

Assessment of molecular effects on neutrino mass measurements from tritium beta decay  

E-Print Network [OSTI]

The beta decay of molecular tritium currently provides the highest sensitivity in laboratory-based neutrino mass measurements. The upcoming Karlsruhe Tritium Neutrino (KATRIN) experiment will improve the sensitivity to 0.2 eV, making a percent-level quantitative understanding of molecular effects essential. The modern theoretical calculations available for neutrino-mass experiments agree with spectroscopic data. Moreover, when neutrino-mass experiments performed in the 1980s with gaseous tritium are re-evaluated using these modern calculations, the extracted neutrino mass-squared values are consistent with zero instead of being significantly negative. On the other hand, the calculated molecular final-state branching ratios are in tension with dissociation experiments performed in the 1950s. We re-examine the theory of the final-state spectrum of molecular tritium decay and its effect on the determination of the neutrino mass, with an emphasis on the role of the vibrational- and rotational-state distribution i...

Bodine, L I; Robertson, R G H

2015-01-01T23:59:59.000Z

135

Majorana Neutrino Masses from Neutrinoless Double Beta Decay and Cosmology  

E-Print Network [OSTI]

When three Majorana neutrinos describe the solar and atmospheric neutrino data via oscillations, a nonzero measurement of neutrinoless double beta ($0\

V. Barger; K. Whisnant

1999-04-08T23:59:59.000Z

136

Phenomenology Of Sterile Neutrinos At Different Mass Scales: Neutrinoless Double Beta Decay And Neutrino Oscillations.  

E-Print Network [OSTI]

??The existence of neutrino oscillation is the first evidence of physics beyond the Standard Model. It proves that neutrinos are massive and motivates the study… (more)

WONG, CHAN,FAI

2012-01-01T23:59:59.000Z

137

Neutrino mass, bulk majoron and neutrinoless double beta decay  

E-Print Network [OSTI]

A new economical model for neutrino masses is proposed in the context of brane bulk scenarios for particle physics, where global B-L symmetry of the standard model is broken spontaneously by a gauge singlet Higgs field in the bulk. This leads to a bulk majoron whose KK excitations may make it visible if neutrinoless double beta decay if the string scale is close to a TeV. It also leads to neutron-anti-neutron oscillation process with transition times which can be in the range accessible to proposed experiments.

R. N. Mohapatra; A. Perez-Lorenzana; C. A. de S. Pires

2000-08-15T23:59:59.000Z

138

Baryon Asymmetry in Neutrino Mass Models with and without ?_13  

E-Print Network [OSTI]

We investigate the comparative studies of cosmological baryon asymmetry in different neutrino mass models with and without {\\theta}_13 by considering the three diagonal form of Dirac neutrino mass matrices, down-quark (4,2), up-quark (8,4) and charged lepton (6,2). The predictions of any models with {\\theta}_13 are consistent in all the three stages of leptogenesis calculations and the results are better than the predictions of any models without {\\theta}_13 which are consistent in a piecemeal manner with the observational data. For the best model, the normal hierarchy Type-IA for charged lepton (6,2) without {\\theta}_13, the predicted inflaton mass required to produce the observed baryon asymmetry is found to be 3.6x10 to the power 10 GeV corresponding to reheating temperature TR 4.5x10 to the power 6 GeV, while for the same model with {\\theta}_13, the inflaton mass is 2.24x10 to the power 11 GeV, TR 4.865x10 to the power 6 GeV and weak scale gravitino mass m(2 divided by 3) 100 GeV without causing the gravitino problem. These values apply to the recent discovery of Higgs boson of mass 125 GeV. The relic abundance of gravitino is proportional to the reheating temperature of the thermal bath. One can have the right order of relic dark matter abundance only if the reheating temperature is bounded to below 10 to the power 7 GeV.

Ng. K. Francis

2014-03-26T23:59:59.000Z

139

Neutrino fluxes from nonuniversal Higgs mass LSP annihilations in the Sun  

SciTech Connect (OSTI)

We extend our previous studies of the neutrino fluxes expected from neutralino LSP annihilations inside the Sun to include variants of the minimal supersymmetric extension of the Standard Model (MSSM) with squark, slepton and gaugino masses constrained to be universal at the GUT scale, but allowing one or two nonuniversal supersymmetry breaking parameters contributing to the Higgs masses (NUHM1,2). As in the constrained MSSM (CMSSM) with universal Higgs masses, there are large regions of the NUHM parameter space where the LSP density inside the Sun is not in equilibrium, so that the annihilation rate may be far below the capture rate, and there are also large regions where the capture rate is not dominated by spin-dependent LSP-proton scattering. The spectra possible in the NUHM are qualitatively similar to those in the CMSSM. We calculate neutrino-induced muon fluxes above a threshold energy of 10 GeV, appropriate for the IceCube/DeepCore detector, for points where the NUHM yields the correct cosmological relic density for representative choices of the NUHM parameters. We find that the IceCube/DeepCore detector can probe regions of the NUHM parameter space in addition to analogues of the focus point strip and the tip of the coannihilation strip familiar from the CMSSM. These include regions with enhanced Higgsino-gaugino mixing in the LSP composition, that occurs where neutralino mass eigenstates cross over. On the other hand, rapid-annihilation funnel regions in general yield neutrino fluxes that are unobservably small.

Ellis, John [TH Division, Physics Department, CERN, 1211 Geneva 23, Switzerland and Theoretical Physics and Cosmology Group, Department of Physics, King's College London, London WC2R 2LS (United Kingdom); Olive, Keith A. [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States) and Department of Physics and SLAC, Stanford University, Palo Alto, California 94305 (United States); Savage, Christopher [Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE-10691 Stockholm (Sweden); Spanos, Vassilis C. [Institute of Nuclear Physics, NCSR 'Demokritos', GR-15310 Athens (Greece)

2011-04-15T23:59:59.000Z

140

Scotogenic $Z_2$ or $U(1)_D$ Model of Neutrino Mass with $\\Delta(27)$ Symmetry  

E-Print Network [OSTI]

The scotogenic model of radiative neutrino mass with $Z_2$ or $U(1)_D$ dark matter is shown to accommodate $\\Delta(27)$ symmetry naturally. The resulting neutrino mass matrix is identical to either of two forms, one proposed in 2006, the other in 2008. These two structures are studied in the context of present neutrino data, with predictions of $CP$ violation and neutrinoless double beta decay.

Ma, Ernest

2014-01-01T23:59:59.000Z

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.


141

Light neutrino mass spectrum with one or two right-handed singlet fermions added  

E-Print Network [OSTI]

We analyse two cases of the minimal extension of the Standard Model when one or two right-handed fields are added to the three left-handed fields. A second Higgs doublet (two Higgs doublet model - 2HDM) is included in our model. We calculate one-loop radiative corrections to the mass parameters which produce mass terms for the neutral leptons. In both cases we numerically analyse light neutrino masses as functions of the heavy neutrino masses. Parameters of the model are varied to find light neutrino masses that are compatible with experimental data of solar and atmospheric neutrino mass differences for normal hierarchy. We choose values for the parameters of the tree-level by numerical scans, where we look for the best agreement between computed and experimental neutrino oscillation angles.

Darius Jurciukonis; Thomas Gajdosik; Andrius Juodagalvis

2014-10-16T23:59:59.000Z

142

Vacuum and MSW interpretations of solar neutrino data with the LNW mass matrix  

E-Print Network [OSTI]

The Lehmann-Newton-Wu mass matrix, which was recently applied to neutrinos, is further investigated. The analytic results presented earlier are confirmed numerically for the solar density profile of the Standard Solar Model. The combined analysis of atmospheric and solar neutrino data favors the MSW solution over the vacuum-oscillation solution. The total rates from the solar neutrino detectors and spectrum distortion reported by the Super-Kamiokande collaboration for solar neutrinos favors one heavy (m3\\sim 0.05 eV) and two light (m1, m2\\lsim 0.003 eV) neutrinos.

Per Osland; Geir Vigdel

2000-07-14T23:59:59.000Z

143

Testing large mixing MSW solutions of the solar neutrino problem through Earth regeneration effects  

E-Print Network [OSTI]

Large mixing MSW solutions to the solar neutrino problem appear to be currently favored by the data. We discuss the possibility of discriminating them by means of present and future experiments. In particular, we show that the study of energy and time dependence of the Earth regeneration effect can be useful in this respect.

Antonio Palazzo

2001-03-02T23:59:59.000Z

144

Neutrinoless double beta decay in four-neutrino models  

E-Print Network [OSTI]

The most stringent constraint on the so-called effective electron neutrino mass from the present neutrinoless double beta decay experiments is |M_{ee}| < 0.2 eV, while the planned next generation experiment GENIUS is anticipated to reach a considerably more stringent limit |M_{ee}|< 0.001 eV. We investigate the constraints these bounds set on the neutrino masses and mixings of neutrinos in four-neutrino models where there exists a sterile neutrino along with the three ordinary neutrinos. We find that the GENIUS experiment would be sensitive to the electron neutrino masses down to the limit m_{\

Anna Kalliomaki; Jukka Maalampi

2000-03-29T23:59:59.000Z

145

Neutrinos and Collider Physics  

E-Print Network [OSTI]

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

Deppisch, Frank F; Pilaftsis, Apostolos

2015-01-01T23:59:59.000Z

146

Is a large mixing angle MSW effect the solution of the solar neutrino problems? J. N. Bahcall  

E-Print Network [OSTI]

Is a large mixing angle MSW effect the solution of the solar neutrino problems? J. N. Bahcall results on solar neutrinos provide hints that the LMA MSW solution could be correct. We perform accurate/or low probability LOW Mikheyev- Smirnou-Wolfenstein MSW solutions and vacuum oscilla- tions; cf. Ref. 12

Bahcall, John

147

Is a large mixing angle MSW effect the solution of the solar neutrino problems? J. N. Bahcall  

E-Print Network [OSTI]

Is a large mixing angle MSW effect the solution of the solar neutrino problems? J. N. Bahcall 1999# Recent results on solar neutrinos provide hints that the LMA MSW solution could be correct. We­ Smirnou­Wolfenstein #MSW# solutions and vacuum oscilla­ tions; cf. Ref. #12# for a recent discussion

Bahcall, John

148

Left-right models with light neutrino mass prediction and dominant neutrinoless double beta decay rate  

E-Print Network [OSTI]

In TeV scale left-right symmetric models, new dominant predictions to neutrinoless double beta decay and light neutrino masses are in mutual contradiction because of large contribution to the latter through popular seesaw mechanisms. We show that in a class of left-right models with high-scale parity restoration, these results coexist without any contravention with neutrino oscillation data and the relevant formula for light neutrino masses is obtained via gauged inverse seesaw mechanism. The most dominant contribution to the double beta decay is shown to be via $W^-_L- W^-_R$ mediation involving both light and heavy neutrino exchanges, and the model predictions are found to discriminate whether the Dirac neutrino mass is of quark-lepton symmetric origin or without it. We also discuss associated lepton flavor violating decays.

M. K. Parida; Sudhanwa Patra

2013-01-14T23:59:59.000Z

149

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

150

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

151

Limits on the Majorana neutrino mass in the 0.1 eV range  

E-Print Network [OSTI]

The Heidelberg-Moscow experiment gives the most stringent limit on the Majorana neutrino mass. After 24 kg yr of data with pulse shape measurements, we set a lower limit on the half-life of the neutrinoless double beta decay in 76Ge of T_1/2 > 5.7 * 10^{25} yr at 90% C.L., thus excluding an effective Majorana neutrino mass greater than 0.2 eV. This allows to set strong constraints on degenerate neutrino mass models.

L. Baudis; A. Dietz; G. Heusser; H. V. Klapdor-Kleingrothaus; I. V. Krivosheina; St. Kolb; B. Majorovits; V. F. Melnikov; H. Paes; F. Schwamm; H. Strecker; V. Alexeev; A. Balysh; A. Bakalyarov; S. T. Belyaev; V. I. Lebedev; S. Zhukov

1999-02-10T23:59:59.000Z

152

Constraining Sterile Neutrinos Using Reactor Neutrino Experiments  

E-Print Network [OSTI]

Models of neutrino mixing involving one or more sterile neutrinos have resurrected their importance in the light of recent cosmological data. In this case, reactor antineutrino experiments offer an ideal place to look for signatures of sterile neutrinos due to their impact on neutrino flavor transitions. In this work, we show that the high-precision data of the Daya Bay experi\\-ment constrain the 3+1 neutrino scenario imposing upper bounds on the relevant active-sterile mixing angle $\\sin^2 2 \\theta_{14} \\lesssim 0.06$ at 3$\\sigma$ confidence level for the mass-squared difference $\\Delta m^2_{41}$ in the range $(10^{-3},10^{-1}) \\, {\\rm eV^2}$. The latter bound can be improved by six years of running of the JUNO experiment, $\\sin^22\\theta_{14} \\lesssim 0.016$, although in the smaller mass range $ \\Delta m^2_{41} \\in (10^{-4} ,10^{-3}) \\, {\\rm eV}^2$. We have also investigated the impact of sterile neutrinos on precision measurements of the standard neutrino oscillation parameters $\\theta_{13}$ and $\\Delta m^2_{31}$ (at Daya Bay and JUNO), $\\theta_{12}$ and $\\Delta m^2_{21}$ (at JUNO), and most importantly, the neutrino mass hierarchy (at JUNO). We find that, except for the obvious situation where $\\Delta m^2_{41}\\sim \\Delta m^2_{31}$, sterile states do not affect these measurements substantially.

Ivan Girardi; Davide Meloni; Tommy Ohlsson; He Zhang; Shun Zhou

2014-08-21T23:59:59.000Z

153

Diffuse supernova neutrinos: oscillation effects, stellar cooling and progenitor mass dependence  

SciTech Connect (OSTI)

We estimate the diffuse supernova neutrino background (DSNB) using the recent progenitor-dependent, long-term supernova simulations from the Basel group and including neutrino oscillations at several post-bounce times. Assuming multi-angle matter suppression of collective effects during the accretion phase, we find that oscillation effects are dominated by the matter-driven MSW resonances, while neutrino-neutrino collective effects contribute at the 5–10% level. The impact of the neutrino mass hierarchy, of the time-dependent neutrino spectra and of the diverse progenitor star population is 10% or less, small compared to the uncertainty of at least 25% of the normalization of the supernova rate. Therefore, assuming that the sign of the neutrino mass hierarchy will be determined within the next decade, the future detection of the DSNB will deliver approximate information on the MSW-oscillated neutrino spectra. With a reliable model for neutrino emission, its detection will be a powerful instrument to provide complementary information on the star formation rate and for learning about stellar physics.

Lunardini, Cecilia [Arizona State University, Tempe, AZ, 85287-1504 (United States); Tamborra, Irene, E-mail: Cecilia.Lunardini@asu.edu, E-mail: tamborra@mpp.mpg.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) Föhringer Ring 6, 80805 München (Germany)

2012-07-01T23:59:59.000Z

154

Improved measurements of the neutrino mixing angle $?_{13}$ with the Double Chooz detector  

E-Print Network [OSTI]

The Double Chooz experiment presents improved measurements of the neutrino mixing angle $\\theta_{13}$ using the data collected in 467.90 live days from a detector positioned at an average distance of 1050 m from two reactor cores at the Chooz nuclear power plant. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties with respect to previous publications, whereas the efficiency of the $\\bar\

Y. Abe; J. C. dos Anjos; J. C. Barriere; E. Baussan; I. Bekman; M. Bergevin; T. J. C. Bezerra; L. Bezrukov; E. Blucher; C. Buck; J. Busenitz; A. Cabrera; E. Caden; L. Camilleri; R. Carr; M. Cerrada; P. -J. Chang; E. Chauveau; P. Chimenti; A. P. Collin; E. Conover; J. M. Conrad; J. I. Crespo-Anadón; K. Crum; A. S. Cucoanes; E. Damon; J. V. Dawson; J. Dhooghe; D. Dietrich; Z. Djurcic; M. Dracos; M. Elnimr; A. Etenko; M. Fallot; F. von Feilitzsch; J. Felde; S. M. Fernandes; V. Fischer; D. Franco; M. Franke; H. Furuta; I. Gil-Botella; L. Giot; M. Göger-Neff; L. F. G. Gonzalez; L. Goodenough; M. C. Goodman; C. Grant; N. Haag; T. Hara; J. Haser; M. Hofmann; G. A. Horton-Smith; A. Hourlier; M. Ishitsuka; J. Jochum; C. Jollet; F. Kaether; L. N. Kalousis; Y. Kamyshkov; D. M. Kaplan; T. Kawasaki; E. Kemp; H. de Kerret; D. Kryn; M. Kuze; T. Lachenmaier; C. E. Lane; T. Lasserre; A. Letourneau; D. Lhuillier; H. P. Lima Jr; M. Lindner; J. M. López-Castaño; J. M. LoSecco; B. Lubsandorzhiev; S. Lucht; J. Maeda; C. Mariani; J. Maricic; J. Martino; T. Matsubara; G. Mention; A. Meregaglia; T. Miletic; R. Milincic; A. Minotti; Y. Nagasaka; Y. Nikitenko; P. Novella; L. Oberauer; M. Obolensky; A. Onillon; A. Osborn; C. Palomares; I. M. Pepe; S. Perasso; P. Pfahler; A. Porta; G. Pronost; J. Reichenbacher; B. Reinhold; M. Röhling; R. Roncin; S. Roth; B. Rybolt; Y. Sakamoto; R. Santorelli; A. C. Schilithz; S. Schönert; S. Schoppmann; M. H. Shaevitz; R. Sharankova; S. Shimojima; D. Shrestha; V. Sibille; V. Sinev; M. Skorokhvatov; E. Smith; J. Spitz; A. Stahl; I. Stancu; L. F. F. Stokes; M. Strait; A. Stüken; F. Suekane; S. Sukhotin; T. Sumiyoshi; Y. Sun; R. Svoboda; K. Terao; A. Tonazzo; H. H. Trinh Thi; G. Valdiviesso; N. Vassilopoulos; C. Veyssiere; M. Vivier; S. Wagner; N. Walsh; H. Watanabe; C. Wiebusch; L. Winslow; M. Wurm; G. Yang; F. Yermia; V. Zimmer

2015-01-21T23:59:59.000Z

155

Charge dependent relation between the masses of different generations and Neutrino masses  

E-Print Network [OSTI]

Despite the enormous achievements, the Standard model of Particle physics can not be consider as complete theory of fundamental interactions. Among other things, it can not describe the gravitational interaction and it depends on 19 parameters. The Standard model includes 12 fermions (matter elementary particles with spin $\\frac{1}{2}$) which are divided in three generations, groups with same interactions but different masses. Each generation can be classified into two leptons (with electric charges $Q=-1$, electron-like and $Q=0$, neutrino) and two quarks (with electric charges $Q=-\\frac{1}{3}$, down-type and $Q=\\frac{2}{3}$, up-type). However, the understanding of the relationship between generations and ratio of masses of different generations are unknown. Here we show that there exists the simple relation between masses of different generations which depend only on the electric charges for $Q=-1,\\, \\, Q=-\\frac{1}{3}$ and $Q=\\frac{2}{3}$. It is in pretty good agreement with experimental data. Assuming that the same relation valid for $Q=0$, we are able to calculate neutrino masses. Therefore, our results could pave the way for further investigations beyond Standard model.

Branislav Sazdovic

2015-01-29T23:59:59.000Z

156

Neutrino Physics: A Selective Overview  

E-Print Network [OSTI]

Neutrinos in the Standard Model of particle physics are massless, neutral fermions that seemingly do little more than conserve 4-momentum, angular momentum, lepton number, and lepton flavour in weak interactions. In the last decade conclusive evidence has demonstrated that the Standard Model's description of neutrinos does not match reality. We now know that neutrinos undergo flavour oscillations, violating lepton flavour conservation and implying that neutrinos have non-zero mass. A rich oscillation phenomenology then becomes possible, including matter-enhanced oscillation and possibly CP violation in the neutrino sector. Extending the Standard Model to include neutrino masses requires the addition of new fields and mass terms, and possibly new methods of mass generation. In this review article I will discuss the evidence that has established the existence of neutrino oscillation, and then highlight unresolved issues in neutrino physics, such as the nature of three-generational mixing (including CP-violating effects), the origins of neutrino mass, the possible existence of light sterile neutrinos, and the difficult question of measuring the absolute mass scale of neutrinos.

Scott M. Oser

2006-04-11T23:59:59.000Z

157

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

158

The Power of Neutrino Mass Sum Rules for Neutrinoless Double Beta Decay Experiments  

E-Print Network [OSTI]

Neutrino mass sum rules relate the three neutrino masses within generic classes of flavour models, leading to restrictions on the effective mass parameter measured in experiments on neutrinoless double beta decay as a function of the lightest neutrino mass. We perform a comprehensive study of the implications of such neutrino mass sum rules, which provide a link between model building, phenomenology, and experiments. After a careful explanation of how to derive predictions from sum rules, we discuss a large number of examples both numerically, using all three global fits available for the neutrino oscillation data, and analytically wherever possible. In some cases, our results disagree with some of those in the literature for reasons that we explain. Finally we discuss the experimental prospects for many current and near-future experiments, with a particular focus on the uncertainties induced by the unknown nuclear physics involved. We find that, in many cases, the power of the neutrino mass sum rules is so strong as to allow certain classes of models to be tested by the next generation of neutrinoless double beta decay experiments. Our study can serve as both a guideline and a theoretical motivation for future experimental studies.

Stephen F. King; Alexander Merle; Alexander J. Stuart

2013-07-31T23:59:59.000Z

159

Neutrinoless double beta decay and pseudo-Dirac neutrino mass predictions through inverse seesaw mechanism  

E-Print Network [OSTI]

In the inverse seesaw extension of the standard model, supersymmetric or non-supersymmetric, while the light left-handed neutrinos are Majorana, the heavy right-handed neutrinos are pseudo-Dirac fermions. We show how one of these latter category of particles can contribute quite significantly to neutrinoless double beta decay. The neutrino virtuality momentum is found to play a crucial role in the non-standard contributions leading to the prediction of the pseudo-Dirac fermion mass in the range of $120\\, {MeV}-500\\, {MeV}$. When the Dirac neutrino mass matrix in the inverse seesaw formula is similar to the up-quark mass matrix, characteristic of high scale quark-lepton symmetric origin, the predicted branching ratios for lepton flavor violating decays are also found to be closer to the accessible range of ongoing experiments.

Ram Lal Awasthi; M. K. Parida; Sudhanwa Patra

2013-01-21T23:59:59.000Z

160

The LMA MSW Solution of the Solar Neutrino Problem, Inverted Neutrino Mass Hierarchy and Reactor Neutrino Experiments  

E-Print Network [OSTI]

In the context of three-neutrino oscillations, we study the possibility of using antineutrinos from nuclear reactors to explore the 10^{-4} {\\rm eV^2} MSW solution of the solar neutrino problem and measure $\\ms$ with high precision. The KamLAND experiment is not expected to determine $\\ms$ if the latter happens to lie in the indicated region. By analysing both the total event rate suppression and the energy spectrum distortion caused by \\bar{\

S. T. Petcov; M. Piai

2002-03-18T23:59:59.000Z

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

Assessment of molecular effects on neutrino mass measurements from tritium beta decay  

E-Print Network [OSTI]

The beta decay of molecular tritium currently provides the highest sensitivity in laboratory-based neutrino mass measurements. The upcoming Karlsruhe Tritium Neutrino (KATRIN) experiment will improve the sensitivity to 0.2 eV, making a percent-level quantitative understanding of molecular effects essential. The modern theoretical calculations available for neutrino-mass experiments agree with spectroscopic data. Moreover, when neutrino-mass experiments performed in the 1980s with gaseous tritium are re-evaluated using these modern calculations, the extracted neutrino mass-squared values are consistent with zero instead of being significantly negative. On the other hand, the calculated molecular final-state branching ratios are in tension with dissociation experiments performed in the 1950s. We re-examine the theory of the final-state spectrum of molecular tritium decay and its effect on the determination of the neutrino mass, with an emphasis on the role of the vibrational- and rotational-state distribution in the ground electronic state. General features can be reproduced quantitatively from considerations of kinematics and zero-point motion. We summarize the status of validation efforts and suggest means for resolving the apparent discrepancy in dissociation rates.

L. I. Bodine; D. S. Parno; R. G. H. Robertson

2015-02-12T23:59:59.000Z

162

Observables sensitive to absolute neutrino masses: A reappraisal after WMAP-3y and first MINOS results  

E-Print Network [OSTI]

In the light of recent neutrino oscillation and non-oscillation data, we revisit the phenomenological constraints applicable to three observables sensitive to absolute neutrino masses: The effective neutrino mass in single beta decay (m_beta); the effective Majorana neutrino mass in neutrinoless double beta decay (m_2beta); and the sum of neutrino masses in cosmology (Sigma). In particular, we include the constraints coming from the first Main Injector Neutrino Oscillation Search (MINOS) data and from the Wilkinson Microwave Anisotropy Probe (WMAP) three-year (3y) data, as well as other relevant cosmological data and priors. We find that the largest neutrino squared mass difference is determined with a 15% accuracy (at 2-sigma) after adding MINOS to world data. We also find upper bounds on the sum of neutrino masses Sigma ranging from ~2 eV (WMAP-3y data only) to ~0.2 eV (all cosmological data) at 2-sigma, in agreement with previous studies. In addition, we discuss the connection of such bounds with those placed on the matter power spectrum normalization parameter sigma_8. We show how the partial degeneracy between Sigma and sigma_8 in WMAP-3y data is broken by adding further cosmological data, and how the overall preference of such data for relatively high values of sigma_8 pushes the upper bound of Sigma in the sub-eV range. Finally, for various combination of data sets, we revisit the (in)compatibility between current Sigma and m_2beta constraints (and claims), and derive quantitative predictions for future single and double beta decay experiments.

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

2006-08-04T23:59:59.000Z

163

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

164

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

165

Neutrino mass, lepton number, and the origin of matter  

E-Print Network [OSTI]

antiparticles? And many other things% Do neutrinos violate CP? #12;Neutrinoless Double Beta Decay W. Rodejohann? #12;Neutrinoless Double Beta Decay 1 sigma W. Rodejohann, 1206.2560 #12;14 F. Iachello #12;15 Regions

166

Improved limit on {theta}{sub 13} and implications for neutrino masses in neutrinoless double beta decay and cosmology  

SciTech Connect (OSTI)

We analyze the impact of a measurement, or of an improved bound, on {theta}{sub 13} for the determination of the effective neutrino mass in neutrinoless double beta decay and cosmology. In particular, we discuss how an improved limit on (or a specific value of) {theta}{sub 13} can influence the determination of the neutrino mass spectrum via neutrinoless double beta decay. We also discuss the interplay with improved cosmological neutrino mass searches.

Lindner, Manfred; Merle, Alexander; Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

2006-03-01T23:59:59.000Z

167

EFFECTS OF THE NEUTRINO MASS SPLITTING ON THE NONLINEAR MATTER POWER SPECTRUM  

SciTech Connect (OSTI)

We have performed cosmological N-body simulations which include the effect of the masses of the individual neutrino species. The simulations were aimed at studying the effect of different neutrino hierarchies on the matter power spectrum. Compared to the linear theory predictions, we find that nonlinearities enhance the effect of hierarchy on the matter power spectrum at mildly nonlinear scales. The maximum difference between the different hierarchies is about 0.5% for a sum of neutrino masses of 0.1 eV. Albeit this is a small effect, it is potentially measurable from upcoming surveys. In combination with neutrinoless double-{beta} decay experiments, this opens up the possibility of using the sky to determine if neutrinos are Majorana or Dirac fermions.

Wagner, Christian; Verde, Licia; Jimenez, Raul [Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E08028 Barcelona (Spain)

2012-06-20T23:59:59.000Z

168

Neutrino masses in SU(4){sub L}?U(1){sub X} gauge models  

SciTech Connect (OSTI)

Neutrino masses are obtained within SU(4){sub L}?U(1){sub X} electroweak gauge models with spontaneous symmetry breaking by simply exploiting the tree level realization of certain dimension-five effective operators. The scalar sector needs not to be enlarged, since these operators are constructed as direct products among scalar multiplets already existing in the model. There is a unique generic matrix for Yukawa couplings in the neutrino sector, while the charged leptons are already in their diagonal basis. The experimentally observed phenomenology in the neutrino sector is obtained as a natural consequence of this particular approach.

Palcu, Adrian [Faculty of Exact Sciences - Aurel Vlaicu University Arad, Str. Elena Dr?goi 2, Arad - 310330 (Romania)

2013-11-13T23:59:59.000Z

169

Cold Dark Matter, Radiative Neutrino Mass, mu to e gamma, and Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

Two of the most important and pressing questions in cosmology and particle physics are: (1) What is the nature of cold dark matter? and (2) Will near-future experiments on neutrinoless double beta decay be able to ascertain that the neutrino is a Majorana particle, i.e. its own antiparticle? We show that these two seemingly unrelated issues are intimately connected if neutrinos acquire mass only because of their interactions with dark matter.

Jisuke Kubo; Ernest Ma; Daijiro Suematsu

2006-08-24T23:59:59.000Z

170

A new strategy for probing the Majorana neutrino CP violating phases and masses  

E-Print Network [OSTI]

We propose a new strategy for detecting the CP-violating phases and the effective mass of muon Majorana neutrinos by measuring observables associated with neutrino-antineutrino oscillations in $\\pi^{\\pm}$ decays. Within the generic framework of quantum field theory, we compute the non-factorizable probability for producing a pair of same-charged muons in $\\pi^{\\pm}$ decays as a distinctive signature of $\

Delepine, David; Castro, Gabriel Lopez

2009-01-01T23:59:59.000Z

171

Neutrino Physics  

E-Print Network [OSTI]

The fundamental properties of neutrinos are reviewed in these lectures. The first part is focused on the basic characteristics of neutrinos in the Standard Model and how neutrinos are detected. Neutrino masses and oscillations are introduced and a summary of the most important experimental results on neutrino oscillations to date is provided. Then, present and future experimental proposals are discussed, including new precision reactor and accelerator experiments. Finally, different approaches for measuring the neutrino mass and the nature (Majorana or Dirac) of neutrinos are reviewed. The detection of neutrinos from supernovae explosions and the information that this measurement can provide are also summarized at the end.

Gil-Botella, I

2013-01-01T23:59:59.000Z

172

Nuclear structure aspects of neutrinoless {beta}{beta} decay: limits on the electron neutrino mass  

SciTech Connect (OSTI)

We discuss some features of the nuclear structure elements participant in the calculation of the mass sector of the half-life of the neutrinoless double beta decay, and the consequences upon the adopted limits of the electron-neutrino mass.

Civitarese, O. [Department of Physics. University of La Plata, 1900 La Plata (Argentina); Suhonen, J. [Department of Physics. University of Jyvaeskyla, (Finland)

2007-02-12T23:59:59.000Z

173

The Neutrinoless Double Beta Decay, Physics beyond the Standard Model and the Neutrino Mass  

E-Print Network [OSTI]

The Neutrinoless double beta Decay allows to determine the effectice Majorana electron neutrino mass. For this the following conditions have to be satisfied: (i) The neutrino must be a Majorana particle, i. e. identical to the antiparticle. (ii) The half life has to be measured. (iii)The transition matrix element must be reliably calculated. (iv) The leading mechanism must be the light Majorana neutrino exchange. The present contribution studies the accuracy with which one can calculate by different methods: (1) Quasi-Particle Random Phase Approach (QRPA), (2) the Shell Model (SM), (3) the (before the variation) angular momentum projected Hartree-Fock-Bogoliubov method (PHFB)and the (4) Interacting Boson Approach (IBA). In the second part we investigate how to determine experimentally the leading mechanism for the Neutrinoless Double Beta Decay. Is it (a) the light Majorana neutrino exchange as one assumes to determine the effective Majorana neutrino mass, ist it the heavy left (b) or right handed (c) Majorana neutrino exchange allowed by left-right symmetric Grand Unified Theories (GUT's). Is it a mechanism due to Supersymmetry e.g. with gluino exchange and R-parity and lepton number violating terms. At the end we assume, that Klapdor et al. have indeed measured the Neutrinoless Double Beta Decay(, although contested,)and that the light Majorana neutrino exchange is the leading mechanism. With our matrix elements we obtain then an effective Majorana neutrino mass of: = 0.24 [eV], exp (pm) 0.02; theor. (pm) 0.01 [eV

Amand Faessler

2012-03-16T23:59:59.000Z

174

STATUS OF THE MILANO NEUTRINO MASS EXPERIMENT WITH THERMAL DETECTORS  

E-Print Network [OSTI]

Science, University of California, Berkeley CA 94720, USA In this paper we present our recent developments eV. The recent hints on atmospheric, solar and reactor neutrino oscillations 1 increase the interest=C and therefore any material with a low heat capacity C

175

Prospects for detecting Dark Matter with neutrino telescopes in Intermediate Mass Black Holes scenarios  

E-Print Network [OSTI]

Current strategies of indirect Dark Matter detection with neutrino telescopes are based on the search for high-energy neutrinos from the Solar core or from the center of the Earth. Here, we propose a new strategy based on the detection of neutrinos from Dark Matter annihilations in 'mini-spikes' around Intermediate Mass Black Holes. Neutrino fluxes, in this case, depend on the annihilation cross-section of Dark Matter particles, whereas solar and terrestrial fluxes are sensitive to the scattering cross-section off nucleons, a circumstance that makes the proposed search complementary to the existing ones. We discuss the prospects for detection with upcoming under-water and under-ice experiments such as ANTARES and IceCube, and show that several, up to many, sources could be detected with both experiments. A kilometer scale telescope in the Mediterranean appears to be ideally suited for the proposed search.

Bertone, Gianfranco

2006-01-01T23:59:59.000Z

176

Prospects for detecting Dark Matter with neutrino telescopes in Intermediate Mass Black Holes scenarios  

E-Print Network [OSTI]

Current strategies of indirect Dark Matter detection with neutrino telescopes are based on the search for high-energy neutrinos from the Solar core or from the center of the Earth. Here, we propose a new strategy based on the detection of neutrinos from Dark Matter annihilations in 'mini-spikes' around Intermediate Mass Black Holes. Neutrino fluxes, in this case, depend on the annihilation cross-section of Dark Matter particles, whereas solar and terrestrial fluxes are sensitive to the scattering cross-section off nucleons, a circumstance that makes the proposed search complementary to the existing ones. We discuss the prospects for detection with upcoming under-water and under-ice experiments such as ANTARES and IceCube, and show that several, up to many, sources could be detected with both experiments. A kilometer scale telescope in the Mediterranean appears to be ideally suited for the proposed search.

Gianfranco Bertone

2006-05-26T23:59:59.000Z

177

Charge dependent relation between the masses of different generations and Neutrino masses  

E-Print Network [OSTI]

Despite the enormous achievements, the Standard model of Particle physics can not be consider as complete theory of fundamental interactions. Among other things, it can not describe the gravitational interaction and it depends on 19 parameters. The Standard model includes 12 fermions (matter elementary particles with spin $\\frac{1}{2}$) which are divided in three generations, groups with same interactions but different masses. Each generation can be classified into two leptons (with electric charges $Q=-1$, electron-like and $Q=0$, neutrino) and two quarks (with electric charges $Q=-\\frac{1}{3}$, down-type and $Q=\\frac{2}{3}$, up-type). However, the understanding of the relationship between generations and ratio of masses of different generations are unknown. Here we show that there exists the simple relation between masses of different generations which depend only on the electric charges for $Q=-1,\\, \\, Q=-\\frac{1}{3}$ and $Q=\\frac{2}{3}$. It is in pretty good agreement with experimental data. Assuming that...

Sazdovic, Branislav

2015-01-01T23:59:59.000Z

178

Pseudo-Dirac Neutrinos, a Challenge for Neutrino Telescopes  

E-Print Network [OSTI]

Neutrinos may be pseudo-Dirac states, such that each generation is actually composed of two maximally-mixed Majorana neutrinos separated by a tiny mass difference. The usual active neutrino oscillation phenomenology would be unaltered if the pseudo-Dirac splittings are $\\delta m^2 \\alt 10^{-12}$ eV$^2$; in addition, neutrinoless double beta decay would be highly suppressed. However, it may be possible to distinguish pseudo-Dirac from Dirac neutrinos using high-energy astrophysical neutrinos. By measuring flavor ratios as a function of $L/E$, mass-squared differences down to $\\delta m^2 \\sim 10^{-18}$ eV$^2$ can be reached. We comment on the possibility of probing cosmological parameters with neutrinos.

John F. Beacom; Nicole F. Bell; Dan Hooper; John G. Learned; Sandip Pakvasa; Thomas J. Weiler

2004-01-05T23:59:59.000Z

179

E-Print Network 3.0 - active-unsterile neutrino mixing Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

University, Atomic Physics Collection: Fission and Nuclear Technologies ; Physics 7 Phenomenology of FourthPhenomenology of Fourth Generation NeutrinosGeneration Neutrinos Summary:...

180

ADDENDUM on the mass neutrino oscillation in a gravitational field  

E-Print Network [OSTI]

In the article {\\it Gen. Rel. Grav.} {\\bf 32}, 1633 (2000), by J. G. Pereira and C. M. Zhang, the special relativity energy-momentum tensor was used to discuss the neutrino phase-splitting in a weak gravitational field. However, it would be more appropriate to use the general relativity energy-momentum tensor. When we do that, as we are going to see, some results change, but the basic conclusion remains the same.

J. G. Pereira; C. M. Zhang

2002-05-08T23:59:59.000Z

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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181

KATRIN: an experiment to determine the neutrino mass from the beta decay of tritium  

E-Print Network [OSTI]

KATRIN is a very large scale tritium-beta-decay experiment to determine the mass of the neutrino. It is presently under construction at the Karlsruhe Institute of Technology north campus, and makes use of the Karlsruhe Tritium Laboratory built as a prototype for the ITER project. The combination of a large retarding-potential electrostatic-magnetic spectrometer and an intense gaseous molecular tritium source makes possible a sensitivity to neutrino mass of 0.2 eV, about an order of magnitude below present laboratory limits. The measurement is kinematic and independent of whether the neutrino is Dirac or Majorana. The status of the project is summarized briefly in this report.

,

2013-01-01T23:59:59.000Z

182

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

2011-07-04T23:59:59.000Z

183

Top-Quark Mass Data and the Sum of Quasi-Degenerate Neutrino Masses (One small electroweak-bound e-parameter organizes elementary particle 3-flavor phenomenology)  

E-Print Network [OSTI]

The absolute neutrino masses and type of neutrino mass hierarchy are among the main problems in neutrino physics. Top-quark mass is another topical problem in particle physics. These problems extend the old puzzle of electron-muon mass ratio close to the fine structure constant, which is still not solved by known theory. Here I continue the search for a general flavor pattern that may incorporate these problems. Relations between neutrino/electron and electron/top-quark pole mass ratios are obtained from supposition that realistic elementary particle dimensionless bare flavor quantities are small deviated (measured by universal parameter e) from the values of a stated flavor pattern (at e=0) and experimental data hints. With the world average t-quark mass data the sum of QD-neutrino masses is estimated (0.50 +- 0.003)eV in agreement with cosmological constraints and known QD-neutrino mass estimations from experimental data on neutrino oscillation mass-squared differences.

E. M. Lipmanov

2008-10-01T23:59:59.000Z

184

MADPH071500 IZTECHP07/05 DESY07213 Dirac Neutrino Masses from Generalized Supersymmetry Breaking  

E-Print Network [OSTI]

#ective Dirac mass terms involving the ``wrong Higgs'' field can arise either at tree level due to hard. The neutrino magnetic and electric dipole moments resulting from the radiative mechanism also vanish at one the ultraviolet behavior of the SM beyond Fermi ener­ gies. Low­energy softly­broken supersymmetry thus pro­ vides

185

On the minimum dark matter mass testable by neutrinos from the Sun  

SciTech Connect (OSTI)

We discuss a limitation on extracting bounds on the scattering cross section of dark matter with nucleons, using neutrinos from the Sun. If the dark matter particle is sufficiently light (less than about 4 GeV), the effect of evaporation is not negligible and the capture process goes in equilibrium with the evaporation. In this regime, the flux of solar neutrinos of dark matter origin becomes independent of the scattering cross section and therefore no constraint can be placed on it. We find the minimum values of dark matter masses for which the scattering cross section on nucleons can be probed using neutrinos from the Sun. We also provide simple and accurate fitting functions for all the relevant processes of GeV-scale dark matter in the Sun.

Busoni, Giorgio; Simone, Andrea De; Huang, Wei-Chih, E-mail: giorgio.busoni@sissa.it, E-mail: andrea.desimone@sissa.it, E-mail: wei-chih.huang@sissa.it [SISSA and INFN, Sezione di Trieste, via Bonomea 265, I-34136 Trieste (Italy)

2013-07-01T23:59:59.000Z

186

Optimizing the Determination of the Neutrino Mixing Angle $?_{13}$ from Reactor Data  

E-Print Network [OSTI]

The technical breakthroughs of multiple detectors developed by Daya Bay and RENO collaborations have gotten great attention. Yet the optimal determination of neutrino mixing parameters from reactor data depends on the statistical method and demands equal attention. We find that a straightforward method using a minimal parameters will generally outperform a multi-parameter method by delivering more reliable values with sharper resolution. We review standard confidence levels and statistical penalties for models using extra parameters, and apply those rules to our analysis. We find that the methods used in recent work of the Daya Bay and RENO collaborations have several undesirable properties. The existing work also uses non-standard measures of significance which we are unable to explain. A central element of the current methods consists of variationally fitting many more parameters than data points. As a result the experimental resolution of $\\sin ^{2}(2\\theta _{13})$ is degraded. The results also become extremely sensitive to certain model parameters that can be adjusted arbitrarily. The number of parameters to include in evaluating significance is an important issue that has generally been overlooked. The measures of significance applied previously would be consistent if and only if all parameters but one were considered to have no physical relevance for the experiment's hypothesis test. Simpler, more transparent methods can improve the determination of the mixing angle $\\theta _{13}$ from reactor data, and exploit the advantages from superb hardware technique of the experiments. We anticipate that future experimental analysis will fully exploit those advantages.

Amir N. Khan; Douglas W. McKay; John P. Ralston

2014-01-17T23:59:59.000Z

187

Heavy Sterile Neutrinos and Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

We investigate the possibility of producing neutrinoless double beta decay without having an electron neutrino with a mass in the vicinity of 1 eV. We do so by having a much lighter electron neutrino mix with a much heavier (m > 1 GeV) sterile neutrino. We study the constraints on the masses and mixings of such heavy sterile neutrinos from existing laboratory, astrophysical and cosmological information, and discuss the properties it would require in order to produce a detectable signal in current searches for neutrinoless double beta decay.

P. Bamert; C. P. Burgess; R. N. Mohapatra

1994-10-12T23:59:59.000Z

188

Systematic errors in the measurement of neutrino masses due to baryonic feedback processes: Prospects for stage IV lensing surveys  

E-Print Network [OSTI]

We examine the importance of baryonic feedback effects on the matter power spectrum on small scales, and the implications for the precise measurement of neutrino masses through gravitational weak lensing. Planned large galaxy surveys such as the Large Synoptic Sky Telescope (LSST) and Euclid are expected to measure the sum of neutrino masses to extremely high precision, sufficient to detect non-zero neutrino masses even in the minimal mass normal hierarchy. We show that weak lensing of galaxies while being a very good probe of neutrino masses, is extremely sensitive to baryonic feedback processes. We use publicly available results from the Overwhelmingly Large Simulations (OWLS) project to investigate the effects of active galactic nuclei feedback, the nature of the stellar initial mass function, and gas cooling rates, on the measured weak lensing shear power spectrum. Using the Fisher matrix formalism and priors from CMB+BAO data, we show that when one does not account for feedback, the measured neutrino mass may be substantially larger or smaller than the true mass, depending on the dominant feedback mechanism, with the mass error |\\Delta m_nu| often exceeding the mass m_nu itself. We also consider gravitational lensing of the cosmic microwave background (CMB) and show that it is not sensitive to baryonic feedback on scales l < 2000, although CMB experiments that aim for sensitivities sigma(m_nu) < 0.02 eV will need to include baryonic effects in modeling the CMB lensing potential. A combination of CMB lensing and galaxy lensing can help break the degeneracy between neutrino masses and baryonic feedback processes. We conclude that future large galaxy lensing surveys such as LSST and Euclid can only measure neutrino masses accurately if the matter power spectrum can be measured to similar accuracy.

Aravind Natarajan; Andrew R. Zentner; Nicholas Battaglia; Hy Trac

2014-09-04T23:59:59.000Z

189

Large or Small Angle MSW from Single Right-Handed Neutrino Dominance  

E-Print Network [OSTI]

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

S. F. King

1999-08-26T23:59:59.000Z

190

Neutrino  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of1, 2007Transmission toBeam ExcitationNeutrino

191

Neutrinoless Double Beta Decay and Heavy Sterile Neutrinos  

E-Print Network [OSTI]

The experimental rate of neutrinoless double beta decay can be saturated by the exchange of virtual sterile neutrinos, that mix with the ordinary neutrinos and are heavier than 200 MeV. Interestingly, this hypothesis is subject only to marginal experimental constraints, because of the new nuclear matrix elements. This possibility is analyzed in the context of the Type I seesaw model, performing also exploratory investigations of the implications for heavy neutrino mass spectra, rare decays of mesons as well as neutrino-decay search, LHC, and lepton flavor violation. The heavy sterile neutrinos can saturate the rate only when their masses are below some 10 TeV, but in this case, the suppression of the light-neutrino masses has to be more than the ratio of the electroweak scale and the heavy-neutrino scale; i.e., more suppressed than the naive seesaw expectation. We classify the cases when this condition holds true in the minimal version of the seesaw model, showing its compatibility (1) with neutrinoless double beta rate being dominated by heavy neutrinos and (2) with any light neutrino mass spectra. The absence of excessive fine-tunings and the radiative stability of light neutrino mass matrices, together with a saturating sterile neutrino contribution, imply an upper bound on the heavy neutrino masses of about 10 GeV. We extend our analysis to the Extended seesaw scenario, where the light and the heavy sterile neutrino contributions are completely decoupled, allowing the sterile neutrinos to saturate the present experimental bound on neutrinoless double beta decay. In the models analyzed, the rate of this process is not strictly connected with the values of the light neutrino masses, and a fast transition rate is compatible with neutrinos lighter than 100 meV.

Manimala Mitra; Goran Senjanovic; Francesco Vissani

2011-12-21T23:59:59.000Z

192

New mechanism for neutrino mass generation and triply charged Higgs bosons at the LHC  

SciTech Connect (OSTI)

We propose a new mechanism for generating small neutrino masses which predicts the relation m{sub {nu}}{approx}v{sup 4}/M{sup 3}, where v is the electroweak scale, rather than the conventional seesaw formula m{sub {nu}}{approx}v{sup 2}/M. Such a mass relation is obtained via effective dimension seven operators LLHH(H{sup {dagger}}H)/M{sup 3}, which arise when an isospin 3/2 Higgs multiplet {phi} is introduced along with isotriplet leptons. The masses of these particles are naturally in the TeV scale. The triply charged Higgs boson contained in {phi} can be pair produced at the LHC and the Tevatron, with {phi}{sup +++} decaying into W{sup +}l{sup +}l{sup +} or W{sup +}W{sup +}W{sup +}, possibly with displaced vertices. The leptonic decays of {phi}{sup +++} will help discriminate between normal and inverted hierarchies of neutrino masses. This scenario also allows for raising the standard Higgs boson mass to values in excess of 500 GeV.

Babu, K. S.; Nandi, S.; Tavartkiladze, Zurab [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2009-10-01T23:59:59.000Z

193

ILC phenomenology in a TeV scale radiative seesaw model for neutrino mass, dark matter and baryon asymmetry  

E-Print Network [OSTI]

We discuss phenomenology in a new TeV scale model which would explain neutrino oscillation, dark matter, and baryon asymmetry of the Universe simultaneously by the dynamics of the extended Higgs sector and TeV-scale right-handed neutrinos. Tiny neutrino masses are generated at the three-loop level due to the exact $Z_2$ symmetry, by which the stability of the dark matter candidate is guaranteed. The model provides various discriminative predictions in Higgs phenomenology, which can be tested at the Large Hadron Collider and the International Linear Collider.

Mayumi Aoki; Shinya Kanemura; Osamu Seto

2010-08-14T23:59:59.000Z

194

Transport and mixing of chemical air masses in idealized baroclinic life cycles  

E-Print Network [OSTI]

with stratospheric air is larger for LC2, owing to the presence of the deep cyclonic vortices that entrain and mixTransport and mixing of chemical air masses in idealized baroclinic life cycles L. M. Polvani1 December 2007. [1] The transport, mixing, and three-dimensional evolution of chemically distinct air masses

Esler, Gavin

195

E-Print Network 3.0 - active neutrino masses Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Nazionale di Fisica Nucleare, Milano Weak Interactions Group Collection: Physics 6 Phenomenology of FourthPhenomenology of Fourth Generation NeutrinosGeneration Neutrinos Summary:...

196

$N_{\\rm eff}$ in low-scale seesaw models versus the lightest neutrino mass  

E-Print Network [OSTI]

We evaluate the contribution to $N_{\\rm eff}$ of the extra sterile states in low-scale Type I seesaw models (with three extra sterile states). We explore the full parameter space and find that at least two of the heavy states always reach thermalisation in the Early Universe, while the third one might not thermalise provided the lightest neutrino mass is below ${\\mathcal O}(10^{-3}$eV). Constraints from cosmology therefore severely restrict the spectra of heavy states in the range 1eV- 100 MeV. The implications for neutrinoless double beta decay are also discussed.

Hernandez, P; Lopez-Pavon, J

2014-01-01T23:59:59.000Z

197

Radiative decay of keV-mass sterile neutrinos in a strongly magnetized plasma  

E-Print Network [OSTI]

The radiative decay of sterile neutrinos with typical masses of 10 keV is investigated in the presence of a strong magnetic field and degenerate plasma. Full account is taken of the strongly modified photon dispersion relation relative to vacuum. The limiting cases of relativistic and non-relativistic plasma are analyzed. The decay rate in a strongly magnetized plasma as a function of the electron number density is compared with the un-magnetized case. We find that a strong magnetic field suppresses the catalyzing influence of the plasma on the decay rate.

Alexandra A. Dobrynina; Nicolay V. Mikheev; Georg G. Raffelt

2015-01-07T23:59:59.000Z

198

Delayed pulsar kicks from the emission of sterile neutrinos  

SciTech Connect (OSTI)

The observed velocities of pulsars suggest the possibility that sterile neutrinos with mass of several keV are emitted from a cooling neutron star. The same sterile neutrinos could constitute all or part of cosmological dark matter. The neutrino-driven kicks can exhibit delays depending on the mass and the mixing angle, which can be compared with the pulsar data. We discuss the allowed ranges of sterile neutrino parameters, consistent with the latest cosmological and x-ray bounds, which can explain the pulsar kicks for different delay times.

Kusenko, Alexander; Mandal, Bhabani Prasad; Mukherjee, Alok [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Department of Physics, Banaras Hindu University, Varanasi-221005 (India)

2008-06-15T23:59:59.000Z

199

Conversion of experimental half-life to effective electron neutrino mass in 0nubetabeta decay  

SciTech Connect (OSTI)

The Germanium Detector Array (GERDA) collaboration will be searching for neutrinoless double beta decay of {sup 76}Ge. As a result it will measure the half-life T{sub 1/2} of this rare process; or at least a new value for the lower limit for T{sub 1/2} will be derived. The sensitivity of the GERDA experiment on the effective electron neutrino mass depends on the theoretical value for the nuclear matrix element M and the kinematical phase space factor G.In this Brief Report we focus on existing difficulties in applying the dimensionless values of M calculated by various theoretical groups, which use different methods and parametrizations. The implicit radius dependencies in M and G are discussed. Resulting values of the neutrino mass are tabulated for various representative half-lives T{sub 1/2} representing the sensitivity of the various phases of the GERDA experiment.

Smolnikov, Anatoly; Grabmayr, Peter [Joint Institute for Nuclear Research, Dubna, Russia, and Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Kepler Center for Astro and Particle Physics, Eberhard Karls Universitaet Tuebingen (Germany)

2010-02-15T23:59:59.000Z

200

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

SciTech Connect (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

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

Solar Neutrinos and the Decaying Neutrino Hypothesis  

E-Print Network [OSTI]

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

Jeffrey M. Berryman; Andre de Gouvea; Daniel Hernandez

2014-11-02T23:59:59.000Z

202

Neutrinos: Theory and Phenomenology  

SciTech Connect (OSTI)

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

Parke, Stephen

2013-10-22T23:59:59.000Z

203

Neutrino Properties Before and After KamLAND  

E-Print Network [OSTI]

We review neutrino oscillation physics, including the determination of mass splittings and mixings from current solar, atmospheric, reactor and accelerator neutrino data. A brief discussion is given of cosmological and astrophysical implications. Non-oscillation phenomena such as neutrinoless double beta decay would, if discovered, probe the absolute scale of neutrino mass and also reveal their Majorana nature. Non-oscillation descriptions in terms of spin-flavor precession (SFP) and non-standard neutrino interactions (NSI) currently provide an excellent fit of the solar data. However they are at odds with the first results from the KamLAND experiment which imply that, despite their theoretical interest, non-standard mechanisms can only play a sub-leading role in the solar neutrino anomaly. Accepting the LMA-MSW solution, one can use the current solar neutrino data to place important restrictions on non-standard neutrino properties, such as neutrino magnetic moments. Both solar and atmospheric neutrino data can also be used to place constraints on neutrino instability as well as the more exotic possibility of $CPT$ and Lorentz Violation. Weillustrate the potential of future data from experiments such as KamLAND, Borexino and the upcoming neutrino factories in constraining non-standard neutrino properties.

S. Pakvasa; J. W. F. Valle

2003-02-05T23:59:59.000Z

204

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

SciTech Connect (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

205

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}.

Lychkovskiy, Oleg

2007-01-01T23:59:59.000Z

206

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

2007-12-20T23:59:59.000Z

207

A new upper limit on the total neutrino mass from the 2dF Galaxy Redshift Survey  

E-Print Network [OSTI]

We constrain f_nu = Omega_nu / Omega_m, the fractional contribution of neutrinos to the total mass density in the Universe, by comparing the power spectrum of fluctuations derived from the 2dF Galaxy Redshift Survey with power spectra for models with four components: baryons, cold dark matter, massive neutrinos and a cosmological constant. Adding constraints from independent cosmological probes we find f_nu < 0.13 (at 95% confidence) for a prior of 0.1< Omega_m <0.5, and assuming the scalar spectral index n=1. This translates to an upper limit on the total neutrino mass and m_nu,tot < 1.8 eV for "concordance" values of Omega_m and the Hubble constant. Very similar results are obtained with a prior on Omega_m from Type Ia supernovae surveys, and with marginalization over n.

O. Elgaroy; O. Lahav; W. J. Percival; J. A. Peacock; D. S. Madgwick; S. L. Bridle; C. M. Baugh; I. K. Baldry; J. Bland-Hawthorn; T. Bridges; R. Cannon; S. Cole; M. Colless; C. Collins; W. Couch; G. Dalton; R. De Propris; S. P. Driver; G. P. Efstathiou; R. S. Ellis; C. S. Frenk; K. Glazebrook; C. Jackson; I. Lewis; S. Lumsden; S. Maddox; P. Norberg; B. A. Peterson; W. Sutherland; K. Taylor

2002-06-14T23:59:59.000Z

208

Neutrinos in Nuclear Physics  

E-Print Network [OSTI]

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

R. D. McKeown

2014-12-03T23:59:59.000Z

209

Neutrinos in Nuclear Physics  

E-Print Network [OSTI]

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

McKeown, R D

2014-01-01T23:59:59.000Z

210

Energy Loss of Neutrinos in 20M{center_dot} Star  

SciTech Connect (OSTI)

Current ideas on neutrino oscillation plus confirmation from neutrino experiments make possible the changing of neutrino flavor due to interactions with the electrons in medium. When neutrinos pass through a medium and interact with the electrons, an effective potential energy is produced due to coherent forward scattering that occurred in the medium. This potential engenders significant changes in the neutrino masses and their mixing in the medium. Thus electron neutrinos would oscillate into different mass eigenstate and this is dependent on the energy of the neutrinos. Some of the energy will be lost in the coherent scattering with the electrons by the charged current interaction. We have calculated the energy loss of the neutrinos by using a stopping power equation for a 20M{center_dot} star.

Ahmad, Nor Sofiah; Yusof, Norhasliza; Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603, Kuala Lumpur (Malaysia)

2010-08-12T23:59:59.000Z

211

Updated fit to three neutrino mixing: status of leptonic CP violation  

E-Print Network [OSTI]

We present a global analysis of solar, atmospheric, reactor and accelerator neutrino data in the framework of three-neutrino oscillations based on data available in summer 2014. We provide the allowed ranges of the six oscillation parameters and show that their determination is stable with respect to uncertainties related to reactor neutrino and solar neutrino flux predictions. We find that the maximal possible value of the Jarlskog invariant in the lepton sector is $0.0329 \\pm 0.0009$ ($\\pm 0.0027$) at the $1\\sigma$ ($3\\sigma$) level and we use leptonic unitarity triangles to illustrate the ability of global oscillation data to obtain information on CP violation. We discuss "tendencies and tensions" of the global fit related to the octant of $\\theta_{23}$ as well as the CP violating phase $\\delta_\\mathrm{CP}$. The favored values of $\\delta_\\mathrm{CP}$ are around $3\\pi/2$ while values around $\\pi/2$ are disfavored at about $\\Delta\\chi^2 \\simeq 6$. We comment on the non-trivial task to assign a confidence level to this $\\Delta\\chi^2$ value by performing a Monte Carlo study of T2K data.

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

2014-12-16T23:59:59.000Z

212

FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.  

SciTech Connect (OSTI)

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

213

Heavy Sterile Neutrinos and Neutrinoless Double Beta Decay  

E-Print Network [OSTI]

Sterile neutrinos of mass up to a few tens of TeV can saturate the present experimental bound of neutrinoless double beta decay process. Due to the updated nuclear matrix elements, the bound on mass and mixing angle is now improved by one order of magnitude. We have performed a detailed analysis of neutrinoless double beta decay for the minimal Type I seesaw scenario. We have shown that in spite of the naive expectation that the light neutrinos give the dominant contribution, sterile neutrinos can saturate the present experimental bound of neutrinoless double beta decay process. However, in order to be consistent with radiative stability of light neutrino masses, the mass scale of sterile neutrinos should be less than 10 GeV.

Manimala Mitra; Goran Senjanovic; Francesco Vissani

2012-05-17T23:59:59.000Z

214

The Intermediate Neutrino Program  

E-Print Network [OSTI]

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

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

2015-04-01T23:59:59.000Z

215

The Intermediate Neutrino Program  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

216

LMA MSW Solution from the Inverted Hierarchical Model of Neutrinos  

E-Print Network [OSTI]

We examine whether the inverted hierarchical model of neutrinos is compatible with the explanation of the large mixing angles (LMA)MSW solution of the solar neutrino problem. The left-handed Majorana neutrino mass matrix for the inverted hierarchical model, is generated through the seesaw mechanism using the diagonal form of the Dirac neutrino mass matrix and the non-diagonal texture of the right-handed Majorana mass matrix. In a model independent way, we construct a specific form of the charged lepton mass matrix having a special structure in 1-2 block, which contribution to the leptonic mixing (MNS) matrix leads to the predictions $\\sin^{2}2\\theta_{12}=0.8517$, $\\sin^{2}2\\theta_{23}=0.9494$, and $|V_{e3}|=0.159$ at the unification scale. These predictions are found to be consistent with the LMA MSW solution of the solar neutrino problem. The inverted hierarchical model is also found to be stable against the quantum radiative corrections in the MSSM. A numerical analysis of the renormalisation group equations (RGEs) in the MSSM shows a mild decrease of the mixing angles with the decrease of energy scale and the corresponding values of the neutrino mixings at the top-quark mass scale are found as $\\sin^{2}2\\theta_{12}=0.8472$, $\\sin^{2}2\\theta_{23}=0.9399$, $|V_{e3}|=0.1509$ respectively.

Mahadev Patgiri; N. Nimai Singh

2001-12-08T23:59:59.000Z

217

Neutrino-antineutrino correlations in dense anisotropic media  

E-Print Network [OSTI]

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

Julien Serreau; Cristina Volpe

2015-01-08T23:59:59.000Z

218

Independent measurement of the neutrino mixing angle theta(13) via neutron capture on hydrogen at Daya Bay  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

A new measurement of the ?13 mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of the ?13 measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GWth reactors, the rate deficit observed at the far hall is interpreted as sin22?13=0.083±0.018 in the three-flavor oscillation model. When combined with the gadolinium-capture result from Daya Bay, we obtain sin22?13=0.089±0.008 as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.

Jaffe D. E.; Jaffe, D.E., et al. Daya Bay Collaboration

2014-10-01T23:59:59.000Z

219

Model of Large Mixing Angle MSW Solution  

E-Print Network [OSTI]

We have obtained the neutrino mass matrix with the large mixing angle (LMA) MSW solution, $\\sin^2 2\\th_\\odot=0.65\\sim 0.97$ and $\\Delta m_{\\odot}^2= 10^{-5}\\sim 10^{-4}\\eV^2$, in the $S_{3L}\\times S_{3R}$ flavor symmetry. The structure of our neutrino mass matrix is found to be stable against radiative corrections.

Morimitsu Tanimoto

2000-02-15T23:59:59.000Z

220

HOLMES - The Electron Capture Decay of 163Ho to Measure the Electron Neutrino Mass with sub-eV sensitivity  

E-Print Network [OSTI]

The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform a calorimetric measurement of the energy released in the decay of 163Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. This measurement was proposed in 1982 by A. De Rujula and M. Lusignoli, but only recently the detector technological progress allowed to design a sensitive experiment. HOLMES will deploy a large array of low temperature microcalorimeters with implanted 163Ho nuclei. The resulting mass sensitivity will be as low as 0.4 eV. HOLMES will be an important step forward in the direct neutrino mass measurement with a calorimetric approach as an alternative to spectrometry. It will also establish the potential of this approach to extend the sensitivity down to 0.1 eV. We outline here the project with its technical challenges and perspectives.

B. Alpert; M. Balata; D. Bennett; M. Biasotti; C. Boragno; C. Brofferio; V. Ceriale; D. Corsini; M. De Gerone; R. Dressler; M. Faverzani; E. Ferri; J. Fowler; F. Gatti; A. Giachero; J. Hays-Wehle; S. Heinitz; G. Hilton; U. Koester; M. Lusignoli; M. Maino; J. Mates; S. Nisi; R. Nizzolo; A. Nucciotti; G. Pessina; G. Pizzigoni; A. Puiu; S. Ragazzi; C. Reintsema; M. Ribeiro Gomes; D. Schmidt; D. Schumann; M. Sisti; D. Swetz; F. Terranova; J. Ullom

2015-02-10T23:59:59.000Z

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221

HOLMES - The Electron Capture Decay of 163Ho to Measure the Electron Neutrino Mass with sub-eV sensitivity  

E-Print Network [OSTI]

The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform a calorimetric measurement of the energy released in the decay of 163Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. This measurement was proposed in 1982 by A. De Rujula and M. Lusignoli, but only recently the detector technological progress allowed to design a sensitive experiment. HOLMES will deploy a large array of low temperature microcalorimeters with implanted 163Ho nuclei. The resulting mass sensitivity will be as low as 0.4 eV. HOLMES will be an important step forward in the direct neutrino mass measurement with a calorimetric approach as an alternative to spectrometry. It will also establish the potential of this approach to extend the sensitivity down to 0.1 eV. We outline here the project with its technical challenges and perspectives.

B. Alpert; M. Balata; D. Bennett; M. Biasotti; C. Boragno; C. Brofferio; V. Ceriale; D. Corsini; P. K. Day; M. De Gerone; R. Dressler; M. Faverzani; E. Ferri; J. Fowler; F. Gatti; A. Giachero; J. Hays-Wehle; S. Heinitz; G. Hilton; U. Koester; M. Lusignoli; M. Maino; J. Mates; S. Nisi; R. Nizzolo; A. Nucciotti; G. Pessina; G. Pizzigoni; A. Puiu; S. Ragazzi; C. Reintsema; M. Ribeiro Gomes; D. Schmidt; D. Schumann; M. Sisti; D. Swetz; F. Terranova; J. Ullom

2015-03-17T23:59:59.000Z

222

HOLMES - The Electron Capture Decay of 163Ho to Measure the Electron Neutrino Mass with sub-eV sensitivity  

E-Print Network [OSTI]

The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform a calorimetric measurement of the energy released in the decay of 163Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. This measurement was proposed in 1982 by A. De Rujula and M. Lusignoli, but only recently the detector technological progress allowed to design a sensitive experiment. HOLMES will deploy a large array of low temperature microcalorimeters with implanted 163Ho nuclei. The resulting mass sensitivity will be as low as 0.4 eV. HOLMES will be an important step forward in the direct neutrino mass measurement with a calorimetric approach as an alternative to spectrometry. It will also establish the potential of this approach to extend the sensitivity down to 0.1 eV. We outline here the project with its technical challenges and perspectives.

B. Alpert; M. Balata; D. Bennett; M. Biasotti; C. Boragno; C. Brofferio; V. Ceriale; D. Corsini; M. De Gerone; R. Dressler; M. Faverzani; E. Ferri; J. Fowler; F. Gatti; A. Giachero; J. Hays-Wehle; S. Heinitz; G. Hilton; U. Koester; M. Lusignoli; M. Maino; J. Mates; S. Nisi; R. Nizzolo; A. Nucciotti; G. Pessina; G. Pizzigoni; A. Puiu; S. Ragazzi; C. Reintsema; M. Ribeiro Gomes; D. Schmidt; D. Schumann; M. Sisti; D. Swetz; F. Terranova; J. Ullom

2014-12-16T23:59:59.000Z

223

Scientific Opportunities with the Long-Baseline Neutrino Experiment  

SciTech Connect (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.

Adams, C.; et al.,

2013-07-28T23:59:59.000Z

224

CUORE and beyond: bolometric techniques to explore inverted neutrino mass hierarchy  

E-Print Network [OSTI]

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of $^{130}$Te. With 741 kg of TeO$_2$ crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is $1.6\\times 10^{26}$ y at $1\\sigma$ ($9.5\\times10^{25}$ y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40--100 meV (50--130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with $^{130}$Te and possibly other double beta decay candidate nuclei.

D. R. Artusa; F. T. Avignone III; O. Azzolini; M. Balata; T. I. Banks; G. Bari; J. Beeman; F. Bellini; A. Bersani; M. Biassoni; C. Brofferio; C. Bucci; X. Z. Cai; A. Camacho; L. Canonica; X. G. Cao; S. Capelli; L. Carbone; L. Cardani; M. Carrettoni; N. Casali; D. Chiesa; N. Chott; M. Clemenza; S. Copello; C. Cosmelli; O. Cremonesi; R. J. Creswick; I. Dafinei; A. Dally; V. Datskov; A. De Biasi; M. M. Deninno; S. Di Domizio; M. L. di Vacri; L. Ejzak; D. Q. Fang; H. A. Farach; M. Faverzani; G. Fernandes; E. Ferri; F. Ferroni; E. Fiorini; M. A. Franceschi; S. J. Freedman; B. K. Fujikawa; A. Giachero; L. Gironi; A. Giuliani; J. Goett; P. Gorla; C. Gotti; T. D. Gutierrez; E. E. Haller; K. Han; K. M. Heeger; R. Hennings-Yeomans; H. Z. Huang; R. Kadel; K. Kazkaz; G. Keppel; Yu. G. Kolomensky; Y. L. Li; C. Ligi; X. Liu; Y. G. Ma; C. Maiano; M. Maino; M. Martinez; R. H. Maruyama; Y. Mei; N. Moggi; S. Morganti; T. Napolitano; S. Nisi; C. Nones; E. B. Norman; A. Nucciotti; T. O'Donnell; F. Orio; D. Orlandi; J. L. Ouellet; M. Pallavicini; V. Palmieri; L. Pattavina; M. Pavan; M. Pedretti; G. Pessina; V. Pettinacci; G. Piperno; C. Pira; S. Pirro; E. Previtali; V. Rampazzo; C. Rosenfeld; C. Rusconi; E. Sala; S. Sangiorgio; N. D. Scielzo; M. Sisti; A. R. Smith; L. Taffarello; M. Tenconi; F. Terranova; W. D. Tian; C. Tomei; S. Trentalange; G. Ventura; M. Vignati; B. S. Wang; H. W. Wang; L. Wielgus; J. Wilson; L. A. Winslow; T. Wise; A. Woodcraft; L. Zanotti; C. Zarra; B. X. Zhu; S. Zucchelli

2014-07-04T23:59:59.000Z

225

CUORE and beyond: bolometric techniques to explore inverted neutrino mass hierarchy  

E-Print Network [OSTI]

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of $^{130}$Te. With 741 kg of TeO$_2$ crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is $1.6\\times 10^{26}$ y at $1\\sigma$ ($9.5\\times10^{25}$ y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40--100 meV (50--130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with $^{130}$Te and possibly other double beta decay candidate nuclei.

Artusa, D R; Azzolini, O; Balata, M; Banks, T I; Bari, G; Beeman, J; Bellini, F; Bersani, A; Biassoni, M; Brofferio, C; Bucci, C; Cai, X Z; Camacho, A; Canonica, L; Cao, X G; Capelli, S; Carbone, L; Cardani, L; Carrettoni, M; Casali, N; Chiesa, D; Chott, N; Clemenza, M; Copello, S; Cosmelli, C; Cremonesi, O; Creswick, R J; Dafinei, I; Dally, A; Datskov, V; De Biasi, A; Deninno, M M; Di Domizio, S; di Vacri, M L; Ejzak, L; Fang, D Q; Farach, H A; Faverzani, M; Fernandes, G; Ferri, E; Ferroni, F; Fiorini, E; Franceschi, M A; Freedman, S J; Fujikawa, B K; Giachero, A; Gironi, L; Giuliani, A; Goett, J; Gorla, P; Gotti, C; Gutierrez, T D; Haller, E E; Han, K; Heeger, K M; Hennings-Yeomans, R; Huang, H Z; Kadel, R; Kazkaz, K; Keppel, G; Kolomensky, Yu G; Li, Y L; Ligi, C; Liu, X; Ma, Y G; Maiano, C; Maino, M; Martinez, M; Maruyama, R H; Mei, Y; Moggi, N; Morganti, S; Napolitano, T; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; O'Donnell, T; Orio, F; Orlandi, D; Ouellet, J L; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Pettinacci, V; Piperno, G; Pira, C; Pirro, S; Previtali, E; Rampazzo, V; Rosenfeld, C; Rusconi, C; Sala, E; Sangiorgio, S; Scielzo, N D; Sisti, M; Smith, A R; Taffarello, L; Tenconi, M; Terranova, F; Tian, W D; Tomei, C; Trentalange, S; Ventura, G; Vignati, M; Wang, B S; Wang, H W; Wielgus, L; Wilson, J; Winslow, L A; Wise, T; Woodcraft, A; Zanotti, L; Zarra, C; Zhu, B X; Zucchelli, S

2014-01-01T23:59:59.000Z

226

Does the LMA MSW solar solution imply the Dirac nature of neutrinos?  

E-Print Network [OSTI]

Operating with the bilarge neutrino mixing, we show that in the option of Dirac neutrinos the fermion universality -- expressed by the proportionality of neutrino masses to charged-lepton masses -- predicts $\\Delta m_{21}^2$ of the order $10^{-5} {\\rm eV}^2$, consistently with the LMA MSW solar solution. In contrast, in the option of Majorana neutrinos the fermion universality -- introduced as the seesaw proportionality of neutrino masses to charged-lepton masses squared -- predicts $\\Delta m_{21}^2$ of the order $10^{-8} {\\rm eV}^2$, what is consistent rather with the LOW MSW solar solution. Thus, the favored LMA MSW estimation of $\\Delta m_{21}^2$ might be a signal from the Dirac nature of neutrinos.

Wojciech Krolikowski

2002-10-30T23:59:59.000Z

227

Neutrino Theory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

operators in the Lagrangian (Majorana mass terms), or both. The ongoing neutrinoless double-beta decay searches may be able to shine light on the matter. But the neutrino sector...

228

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

229

Neutrino-driven supernova of a low-mass iron-core progenitor boosted by three-dimensional turbulent convection  

E-Print Network [OSTI]

We present the first successful simulation of a neutrino-driven supernova explosion in three dimensions (3D), using the Prometheus-Vertex code with an axis-free Yin-Yang grid and a sophisticated treatment of three-flavor, energy-dependent neutrino transport. The progenitor is a non-rotating, zero-metallicity 9.6 Msun star with an iron core. While in spherical symmetry outward shock acceleration sets in later than 300 ms after bounce, a successful explosion starts at ~130 ms post-bounce in two dimensions (2D). The 3D model explodes at about the same time but with faster shock expansion than in 2D and a more quickly increasing and roughly 10 percent higher explosion energy. The more favorable explosion conditions in 3D are explained by lower temperatures and thus reduced neutrino emission in the cooling layer below the gain radius. This moves the gain radius inward and leads to a bigger mass in the gain layer, whose larger recombination energy boosts the explosion energy in 3D. These differences are caused by less coherent, less massive, and less rapid convective downdrafts associated with post-shock convection in 3D. The less violent impact of these accretion downflows in the cooling layer produces less dissipative heating and therefore diminishes energy losses by neutrino emission. We thus have, for the first time, identified a reduced mass accretion rate, lower infall velocities, and a smaller surface filling factor of convective downdrafts as consequences of 3D postshock turbulence that facilitate neutrino-driven explosions and strengthen them compared to the 2D case.

Tobias Melson; Hans-Thomas Janka; Andreas Marek

2015-01-08T23:59:59.000Z

230

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

SciTech Connect (OSTI)

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

Babi?, Andrej [Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, 842 48 Bratislava (Slovakia); Šimkovic, Fedor [Bogoliubov Laboratory of Theoretical Physics, JINR, Joliot-Curie 6, 141980 Dubna, Moscow region, Russia and Institute of Experimental and Applied Physics, Czech Technical University, CZ-128 00 Prague (Czech Republic)

2013-12-30T23:59:59.000Z

231

Atmospheric and Solar neutrinos in the light of the SuperKamiokande results  

E-Print Network [OSTI]

The hierarchy $\\Delta m^2_{atm} \\gg \\Delta m^2_\\odot$ and the large $\\theta_{23}$ mixing angle, as suggested by neutrino oscillation experiments, can be accounted for by a variety of lepton flavour models. A dichotomy emerges: i) Models were all neutrino masses are bounded by $m_{atm}\\equiv (\\Delta m^2_{atm})^{1/2}\\approx 0.03 eV$; ii) Models of quasi-degenerate neutrinos. It is shown how these different patterns of neutrino masses may arise from different lepton flavour symmetries. Physical implications are discussed in the various cases.

Riccardo Barbieri

1999-01-07T23:59:59.000Z

232

New upper limits on the tau-neutrino mass from primordial helium considerations  

SciTech Connect (OSTI)

In this paper we reconsider recently derived bounds on MeV tau neutrinos, taking into account previously unaccounted for effects. We find that, assuming that the neutrino lifetime is longer than [similar to]100 sec, the constraint [ital N][sub eff][lt]3.6 rules out [nu][sub [tau

Dolgov, A.D.; Rothstein, I.Z. (The Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States))

1993-07-26T23:59:59.000Z

233

Neutrino interaction with background matter in a noninertial frame  

E-Print Network [OSTI]

We study Dirac neutrinos propagating in rotating background matter. First we derive the Dirac equation for a single massive neutrino in the noninertial frame, where matter is at rest. This equation is written in the effective curved space-time corresponding to the corotating frame. We find the exact solution of the Dirac equation. The neutrino energy levels for ultrarelativistic particles are obtained. Then we discuss several neutrino mass eigenstates, with a nonzero mixing between them, interacting with rotating background matter. We derive the effective Schr\\"{o}dinger equation governing neutrino flavor oscillations in rotating matter. The new resonance condition for neutrino oscillations is obtained. We also examine the correction to the resonance condition caused by the matter rotation.

Dvornikov, Maxim

2015-01-01T23:59:59.000Z

234

Search for neutrinos from annihilation of captured low-mass dark matter particles in the Sun by Super-Kamiokande  

E-Print Network [OSTI]

Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV/$c^2$ $\\sim$ 200-GeV/$c^2$) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent (SD) WIMP-proton cross section for WIMP masses below 200 GeV/$c^2$ (at 10 GeV/$c^2$, 1.49$\\times 10^{-39}$ cm$^2$ for $\\chi\\c...

:,; Abe, K; Haga, Y; Hayato, Y; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakano, Y; Nakayama, S; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Tomura, T; Wendell, R A; Irvine, T; Kajita, 2 T; Kametani, I; Kaneyuki, 2 K; Lee, K P; Nishimura, Y; Okumura, 2 K; McLachlan, T; Labarga, 2 L; Kearns, E; Raaf, J L; Stone, 4 J L; Sulak, L R; Berkman, 4 S; Tanaka, 5 H A; Tobayama, 5 S; Goldhaber, M; Carminati, G; Kropp, W R; Mine, S; Renshaw, A; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Bronner, C; Hirota, S; Huang, K; Ieki, K; Ikeda, M; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Itow, Y; Mitsuka, G; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Yanagisawa, C; Ishino, H; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Yano, T; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Yokoyama, M; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J

2015-01-01T23:59:59.000Z

235

Muon neutrino disappearance at MINOS  

SciTech Connect (OSTI)

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

Armstrong, R.; /Indiana U.

2009-08-01T23:59:59.000Z

236

Low-mass helium star models for type Ib supernovae - Light curves, mixing, and nucleosynthesis  

SciTech Connect (OSTI)

The applicability of theoretical models of He-star explosions to type Ib SN explosions is explored. Particular attention is given to light curves and mixing, Rayleigh-Taylor instabilities and mixing, and nucleosynthesis and the mass of Ni-56. Typical numerical results are presented in graphs, and it is concluded that the explosions of SN 1983N and SN 1983I can be accurately represented in terms of explosions of He stars with M(alpha) of 3-4 solar mass. A strong M(alpha) dependence of light-curve shape, photospheric velocity, and Ni-56 mass is found. 44 refs.

Shigeyama, Toshikazu; Nomoto, Kenichi; Tsujimoto, Takuji; Hashimoto, Masaki (Tokyo Univ. (Japan) Kyushu Univ., Fukuoka (Japan))

1990-09-01T23:59:59.000Z

237

Solar neutrinos - Eclipse effect  

E-Print Network [OSTI]

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

Mohan Narayan; G. Rajasekaran; Rahul Sinha

1997-03-12T23:59:59.000Z

238

Predictions From High Scale Mixing Unification Hypothesis  

E-Print Network [OSTI]

Starting with 'High Scale Mixing Unification' hypothesis, we investigate the renormalization group evolution of mixing parameters and masses for both Dirac and Majorana type neutrinos. Following this hypothesis, the PMNS mixing parameters are taken to be identical to the CKM ones at a unifying high scale. Then, they are evolved to a low scale using MSSM renormalization-group equations. For both type of neutrinos, the renormalization group evolution 'naturally' results in a non-zero and small value of leptonic mixing angle $\\theta_{13}$. One of the important predictions of this analysis is that, in both cases, the mixing angle $\\theta_{23}$ turns out to be non-maximal for most of the parameter range. We also elaborate on the important differences between Dirac and Majorana neutrinos within our framework and how to experimentally distinguish between the two scenarios. Furthermore, for both cases, we also derive constraints on the allowed parameter range for the SUSY breaking and unification scales, for which th...

Srivastava, Rahul

2015-01-01T23:59:59.000Z

239

airborne particle mass: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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...

240

Neutrinoless Double Beta Decay and Future Neutrino Oscillation Precision Experiments  

E-Print Network [OSTI]

We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the Delta m^2 corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter theta_{12} will govern large part of the uncertainty. We focus in particular on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses which allow to distinguish the normal from the inverted hierarchy. All aspects are discussed as a function of the uncertainty stemming from the involved nuclear matrix elements. The implications of a vanishing, or extremely small, effective mass are also investigated. By giving a large list of possible neutrino mass matrices and their predictions for the observables, we finally explore how a measurement of (or an improved limit on) neutrinoless double beta decay can help to identify the neutrino mass matrix if more precise values of the relevant parameters are known.

S. Choubey; W. Rodejohann

2005-07-25T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
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241

Neutrinoless double beta decay and future neutrino oscillation precision experiments  

SciTech Connect (OSTI)

We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the {delta}m{sup 2} corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter {theta}{sub 12} will govern a large part of the uncertainty. We focus, in particular, on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses which allow to distinguish the normal from the inverted hierarchy. All aspects are discussed as a function of the uncertainty stemming from the involved nuclear matrix elements. The implications of a vanishing, or extremely small, effective mass are also investigated. By giving a large list of possible neutrino mass matrices and their predictions for the observables, we finally explore how a measurement of (or an improved limit on) neutrinoless double beta decay can help to identify the neutrino mass matrix if more precise values of the relevant parameters are known.

Choubey, Sandhya [Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

2005-08-01T23:59:59.000Z

242

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

SciTech Connect (OSTI)

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

Patterson, Ryan Benton; /Princeton U.

2007-11-01T23:59:59.000Z

243

A Dynamical Framework for KeV Dirac Neutrino Warm Dark Matter  

E-Print Network [OSTI]

If the source of the reported $3.5$ keV x-ray line is a sterile neutrino, comprising an $\\mathcal{O}(1)$ fraction of the dark matter (DM), then it exhibits the property that its mass times mixing angle is $\\sim \\mbox{few} \\times 10^{-2}$ eV, a plausible mass scale for the active neutrinos. This property is a common feature of Dirac neutrino mixing. We present a framework that dynamically produces light active and keV sterile Dirac neutrinos, with appropriate mixing angles to be the x-ray line source. The central idea is that the right-handed active neutrino is a composite state, while elementary sterile neutrinos gain keV masses similarly to the quarks in extended Technicolor. The entire framework is fixed by just two dynamical scales and may automatically exhibit a warm dark matter (WDM) production mechanism -- dilution of thermal relics from late decays of a heavy composite neutrino -- such that the keV neutrinos may comprise an $\\mathcal{O}(1)$ fraction of the DM. In this framework, the WDM is typically quite cool and within structure formation bounds, with temperature $\\sim \\mbox{few}\\times 10^{-2}~T_\

Dean J. Robinson; Yuhsin Tsai

2014-08-06T23:59:59.000Z

244

Neutrino-driven supernova of a low-mass iron-core progenitor boosted by three-dimensional turbulent convection  

E-Print Network [OSTI]

We present the first successful simulation of a neutrino-driven supernova explosion in three dimensions (3D), using the Prometheus-Vertex code with an axis-free Yin-Yang grid and a sophisticated treatment of three-flavor, energy-dependent neutrino transport. The progenitor is a non-rotating, zero-metallicity 9.6 Msun star with an iron core. While in spherical symmetry outward shock acceleration sets in later than 300 ms after bounce, a successful explosion starts at ~130 ms post-bounce in two dimensions (2D). The 3D model explodes at about the same time but with faster shock expansion than in 2D and a more quickly increasing and roughly 10 percent higher explosion energy. The more favorable explosion conditions in 3D are explained by lower temperatures and thus reduced neutrino emission in the cooling layer below the gain radius. This moves the gain radius inward and leads to a bigger mass in the gain layer, whose larger recombination energy boosts the explosion energy in 3D. These differences are caused by l...

Melson, Tobias; Marek, Andreas

2015-01-01T23:59:59.000Z

245

Neutrino Physics at Fermilab  

ScienceCinema (OSTI)

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

Niki Saoulidou

2010-01-08T23:59:59.000Z

246

Role of Sterile Neutrino Warm Dark Matter in Rhenium and Tritium Beta Decays  

E-Print Network [OSTI]

Sterile neutrinos with mass in the range of one to a few keV are important as extensions of the Standard Model of particle physics and are serious dark matter (DM) candidates. This DM mass scale (warm DM) is in agreement with both cosmological and galactic observations. We study the role of a keV sterile neutrino through its mixing with a light active neutrino in Rhenium 187 and Tritium beta decays. We pinpoint the energy spectrum of the beta particle, 0 Tritium beta spectra and estimate the size of this perturbation by means of the dimensionless ratio R of the sterile neutrino to the active neutrino contributions. We comment on the possibility of searching for sterile neutrino signatures in two experiments which are currently running at present, MARE and KATRIN, focused on the Rhenium 187 and Tritium beta decays respectively.

H. J. de Vega; O. Moreno; E. Moya de Guerra; M. Ramon Medrano; N. Sanchez

2012-09-24T23:59:59.000Z

247

Radiative Generation of Quark Masses and Mixing Angles in the Two Higgs Doublet Model  

E-Print Network [OSTI]

We present a framework to generate the quark mass hierarchies and mixing angles by extending the Standard Model with one extra Higgs doublet. The charm and strange quark masses are generated by small quantum effects, thus explaining the hierarchy between the second and third generation quark masses. All the mixing angles are also generated by small quantum effects: the Cabibbo angle is generated at zero-th order in perturbation theory, while the remaining off-diagonal entries of the Cabibbo-Kobayashi-Maskawa matrix are generated at first order, hence explaining the observed hierarchy $|V_{ub}|,|V_{cb}|\\ll |V_{us}|$. The values of the radiatively generated parameters depend only logarithmically on the heavy Higgs mass, therefore this framework can be reconciled with the stringent limits on flavor violation by postulating a sufficiently large new physics scale.

Alejandro Ibarra; Ana Solaguren-Beascoa

2014-07-04T23:59:59.000Z

248

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

249

Is the tribimaximal mixing accidental?  

SciTech Connect (OSTI)

The tribimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on the structure of the neutrino mass matrix and on the underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM-mass relations. As a result, the mass matrix may have an 'anarchical' structure with random values of elements or it may have some symmetry that differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain 'flavor alignment' as well as hierarchical matrices with a two-component structure, where the dominant and subdominant contributions have different symmetries. This opens up new approaches to understanding the lepton mixing.

Abbas, Mohammed [Ain Shams University, Faculty of Sciences, Abbassiyah 11566, Cairo (Egypt); Center for Theoretical Physics (CTP), British University in Egypt, BUE, El-Sherouk City, Cairo (Egypt); Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34014 Trieste (Italy); Smirnov, A. Yu. [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34014 Trieste (Italy); Institute for Nuclear Research, Russian Academy of Sciences, Moscow (Russian Federation)

2010-07-01T23:59:59.000Z

250

Testing the Bimodal/Schizophrenic Neutrino Hypothesis in Neutrinoless Double Beta Decay and Neutrino Telescopes  

E-Print Network [OSTI]

The standard assumption is that all three neutrino mass states are either Dirac or Majorana. However, it was recently suggested by Allaverdi, Dutta and one of the authors (R.N.M.) that mixed, or bimodal, flavor neutrino scenarios are conceivable and are consistent with all known observations (these were called "schizophrenic" in the ADM paper). In that case each individual mass eigenstate can be either Dirac or Majorana, so that the flavor eigenstates are "large" admixtures of both. An example of this "bimodal" situation is to consider one mass state as a Dirac particle (with a sterile partner), while the other two are of Majorana type. Since only Majorana particles contribute to neutrinoless double beta decay, the usual dependence of this observable on the neutrino mass is modified within this scenario. We study this in detail and, in particular, generalize the idea for all possible bimodal combinations. Inevitably, radiative corrections will induce a pseudo-Dirac nature to the Dirac states at the one-loop level, and the effects of the pseudo-Dirac mass splitting will show up in the flavor ratios of neutrinos from distant cosmological sources. Comparison of the effective mass in neutrinoless double beta decay as well as flavor ratios at neutrino telescopes, for different pseudo-Dirac cases and with their usual phenomenology, can distinguish the different bimodal possibilities.

James Barry; Rabindra N. Mohapatra; Werner Rodejohann

2011-06-27T23:59:59.000Z

251

Solar Neutrino Results from Super-Kamiokande  

E-Print Network [OSTI]

Super-Kamiokande-IV (SK-IV) data taking began in September of 2008, after upgrading the electronics and data acquisition system. Due to these upgrades and improvements to water system dynamics, calibration and analysis techniques, a solar neutrino signal could be extracted at recoil electron kinetic energies as low as 3.5 MeV. When the SK-IV data is combined with the previous three SK phases, the SK extracted solar neutrino flux is found to be $[2.37\\pm0.015\\mbox{(stat.)}\\pm0.04\\mbox{(syst.)}]\\times10^6$/(cm$^{2}$sec). The combination of the SK recoil electron energy spectra slightly favors distortions due to a changing electron flavor content. Such distortions are predicted when assuming standard solar neutrino oscillation solutions. An extended maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the neutrino-electron elastic scattering rate results in a day-night asymmetry of $[-3.2\\pm1.1$(stat.)$\\pm0.5$(syst.)]$\\%$. A solar neutrino global oscillation analysis including all current solar neutrino data, as well as KamLAND reactor antineutrino data, measures the solar mixing angle as $\\sin^2\\theta_{12}=0.305\\pm0.013$, the solar neutrino mass squared splitting as $\\Delta m^2_{21}=7.49^{+0.19}_{-0.17}\\times10^{-5}$eV$^2$ and $\\sin^2\\theta_{13}=0.026^{+0.017}_{-0.012}$.

Andrew Renshaw

2014-03-18T23:59:59.000Z

252

Massive neutrinos and cosmology  

E-Print Network [OSTI]

The present experimental results on neutrino flavour oscillations provide evidence for non-zero neutrino masses, but give no hint on their absolute mass scale, which is the target of beta decay and neutrinoless double-beta decay experiments. Crucial complementary information on neutrino masses can be obtained from the analysis of data on cosmological observables, such as the anisotropies of the cosmic microwave background or the distribution of large-scale structure. In this review we describe in detail how free-streaming massive neutrinos affect the evolution of cosmological perturbations. We summarize the current bounds on the sum of neutrino masses that can be derived from various combinations of cosmological data, including the most recent analysis by the WMAP team. We also discuss how future cosmological experiments are expected to be sensitive to neutrino masses well into the sub-eV range.

Julien Lesgourgues; Sergio Pastor

2006-05-29T23:59:59.000Z

253

Radiatively broken symmetries of nonhierarchical neutrinos  

E-Print Network [OSTI]

Symmetry-based ideas, such as the quark-lepton complementarity (QLC) principle and the tri-bimaximal mixing (TBM) scheme, have been proposed to explain the observed mixing pattern of neutrinos. We argue that such symmetry relations need to be imposed at a high scale $\\Lambda \\sim 10^{12}$ GeV characterizing the large masses of right-handed neutrinos required to implement the seesaw mechanism. For nonhierarchical neutrinos, renormalisation group evolution down to a laboratory energy scale $\\lambda \\sim 10^3$ GeV tends to radiatively break these symmetries at a significant level and spoil the mixing pattern predicted by them. However, for Majorana neutrinos, suitable constraints on the extra phases $\\alpha_{2,3}$ enable the retention of those high scale mixing patterns at laboratory energies. We examine this issue within the Minimal Supersymmetric Standard Model (MSSM) and demonstrate the fact posited above for two versions of QLC and two versions of TBM. The appropriate constraints are worked out for all these...

Dighe, Amol; Roy, Probir

2007-01-01T23:59:59.000Z

254

BLACK HOLE-NEUTRON STAR MERGERS WITH A HOT NUCLEAR EQUATION OF STATE: OUTFLOW AND NEUTRINO-COOLED DISK FOR A LOW-MASS, HIGH-SPIN CASE  

SciTech Connect (OSTI)

Neutrino emission significantly affects the evolution of the accretion tori formed in black hole-neutron star mergers. It removes energy from the disk, alters its composition, and provides a potential power source for a gamma-ray burst. To study these effects, simulations in general relativity with a hot microphysical equation of state (EOS) and neutrino feedback are needed. We present the first such simulation, using a neutrino leakage scheme for cooling to capture the most essential effects and considering a moderate mass (1.4 M{sub ?} neutron star, 5.6 M{sub ?} black hole), high-spin (black hole J/M {sup 2} = 0.9) system with the K{sub 0} = 220 MeV Lattimer-Swesty EOS. We find that about 0.08 M{sub ?} of nuclear matter is ejected from the system, while another 0.3 M{sub ?} forms a hot, compact accretion disk. The primary effects of the escaping neutrinos are (1) to make the disk much denser and more compact, (2) to cause the average electron fraction Y{sub e} of the disk to rise to about 0.2 and then gradually decrease again, and (3) to gradually cool the disk. The disk is initially hot (T ? 6 MeV) and luminous in neutrinos (L{sub ?} ? 10{sup 54} erg s{sup –1}), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution.

Deaton, M. Brett; Duez, Matthew D. [Department of Physics and Astronomy, Washington State University, Pullman, WA 99164 (United States); Foucart, Francois; O'Connor, Evan [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, Ontario M5S 3H8 (Canada); Ott, Christian D.; Scheel, Mark A.; Szilagyi, Bela [TAPIR, MC 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Kidder, Lawrence E.; Muhlberger, Curran D., E-mail: mbdeaton@wsu.edu, E-mail: m.duez@wsu.edu [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States)

2013-10-10T23:59:59.000Z

255

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

2011-12-19T23:59:59.000Z

256

Neutrino effects in two-body electron-capture measurements at GSI  

E-Print Network [OSTI]

Oscillatory behavior of electron capture rates in the two-body decay of hydrogen-like ions into recoil ions plus undetected neutrinos, with a period of approximately 7 s, was reported in storage ring single-ion experiments at the GSI Laboratory, Darmstadt. Ivanov and Kienle [PRL 103, 062502 (2009)] have relegated this period to neutrino masses through neutrino mixing in the final state. New arguments are given here against this interpretation, while suggesting that these `GSI Oscillations' may be related to neutrino spin precession in the static magnetic field of the storage ring. This scenario requires a Dirac neutrino magnetic moment six times smaller than the Borexino solar neutrino upper limit 0.54 x 10E(-10) of the Bohr magneton [PRL 101, 091302 (2008)], and its consequences are explored.

Avraham Gal

2010-05-30T23:59:59.000Z

257

Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters  

E-Print Network [OSTI]

We present the results of a global neutrino oscillation data analysis within the three-flavour framework. We include latest results from the MINOS long-baseline experiment (including electron neutrino appearance as well as anti-neutrino data), updating all relevant solar (SK II+III), atmospheric (SK I+II+III) and reactor (KamLAND) data. Furthermore, we include a recent re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These results have important consequences for the analysis of reactor experiments and in particular for the status of the mixing angle $\\theta_{13}$. In our recommended default analysis we find from the global fit that the hint for non-zero $\\theta_{13}$ remains weak, at 1.8$\\sigma$ for both neutrino mass hierarchy schemes. However, we discuss in detail the dependence of these results on assumptions concerning the reactor neutrino analysis.

Thomas Schwetz; Mariam Tórtola; J. W. F. Valle

2011-03-28T23:59:59.000Z

258

Realistic Earth matter effects and a method to acquire information about small ?_{13} in the detection of supernova neutrinos  

E-Print Network [OSTI]

In this paper, we first calculate the realistic Earth matter effects in the detection of type II supernova neutrinos at the Daya Bay reactor neutrino experiment which is currently under construction. It is found that the Earth matter effects depend on the neutrino incident angle $\\theta$, the neutrino mass hierarchy $\\Delta m_{31}^{2}$, the crossing probability at the high resonance region inside the supernova, $P_{H}$, the neutrino temperature, $T_{\\alpha}$, and the pinching parameter in the neutrino spectrum, $\\eta_{\\alpha}$. We also take into account the collective effects due to neutrino-neutrino interactions inside the supernova. With the expression for the dependence of $P_H$ on the neutrino mixing angle $\\theta_{13}$, we obtain the relations between $\\theta_{13}$ and the event numbers for various reaction channels of supernova neutrinos. Using these relations, we propose a possible method to acquire information about $\\theta_{13}$ smaller than $1.5^\\circ$. Such a sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment which has a sensitivity of the order of $\\theta_{13}\\sim 3^\\circ$. Furthermore, we apply this method to other neutrino experiments, i.e. Super-K, SNO, KamLAND, LVD, MinBooNE, Borexino, and Double-Chooz. We also study the energy spectra of the differential event numbers, ${\\rm d}N/{\\rm d}E$.

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

2009-04-14T23:59:59.000Z

259

Solar Neutrinos and the Eclipse Effect  

E-Print Network [OSTI]

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

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

1999-09-01T23:59:59.000Z

260

Are neutrinos their own antiparticles?  

SciTech Connect (OSTI)

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

Kayser, Boris; /Fermilab

2009-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrino mass mixing" from the National Library of EnergyBeta (NLEBeta).
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261

Electromagnetic properties of massive neutrinos  

SciTech Connect (OSTI)

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

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

2013-10-15T23:59:59.000Z

262

Theory of Neutrinos: a White Paper  

SciTech Connect (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 [1] 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.

Mohapatra, R.N.; Antusch, S.; Babu, K.S.; Barenboim, G.; Chen, Mu-Chun; Davidson, S.; de Gouvea, A.; de Holanda, P.; Dutta, Bhaskar; Grossman, Y.; Joshipura, A.; Kayser,; Kersten, J.; Keum, Y.Y.; King, S.F.; Langacker, P.; Lindner, M.; Loinaz, W.; Masina, I.; Mocioiu, I.; Mohanty, S.; /Maryland U. /Madrid, Autonoma U. /Southampton U. /Oklahoma

2006-01-11T23:59:59.000Z

263

Theory of neutrinos: A White paper  

SciTech Connect (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 [1] 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.

Mohapatra, R.N.; Antusch, S.; Babu, K.S.; Barenboim, G.; Chen, Mu-Chun; Davidson, S.; de Gouvea, A.; de Holanda, P.; Dutta, Bhaskar; Grossman, Y.; Joshipura, A.; Kayser,; Kersten, J.; Keum, Y.Y.; King, S.F.; Langacker, P.; Lindner, M.; Loinaz, W.; Masina, I.; Mocioiu, I.; Mohanty, S.; /Maryland U. /Madrid, Autonoma U. /Southampton U. /Oklahoma

2005-10-01T23:59:59.000Z

264

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

2005-12-02T23:59:59.000Z

265

Seismic diagnostics of mixing beyond the convective core in intermediate mass main-sequence stars  

E-Print Network [OSTI]

We study prospects for seismic sounding the layer of a partial mixing above the convective core in main-sequence stars with masses in the 1.2 -- 1.9 solar mass range. There is an initial tendency to an increase of convective core mass in such stars and this leads to ambiguities in modeling. Solar-like oscillations are expected to be excited in such objects. Frequencies of such oscillations provide diagnostics, which are sensitive to the structure of the innermost part of the star and they are known as the small separations. We construct evolutionary models of stars in this mass range assuming various scenarios for element mixing, which includes formation of element abundance jumps, as well as semiconvective and overshooting layers. We find that the three point small separations employing frequencies of radial and dipole modes provide the best probe of the element distribution above the convective core. With expected accuracy of frequency measurement from the space experiments, a discrimination between various scenarios should be possible.

B. L. Popielski; W. A. Dziembowski

2005-05-25T23:59:59.000Z

266

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

E-Print Network [OSTI]

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

Yu-Feng Li; Ye-Ling Zhou

2014-10-01T23:59:59.000Z

267

High Precision Atomic Mass Spectrometry with Applications to Neutrino Physics, Fundamental Constants and Physical Chemistry.  

E-Print Network [OSTI]

?? The Florida State University single-ion cryogenic Penning trap mass spectrometer has been used to precisely measure the masses of the doublets 76Ge/76Se and 74Ge/74Se… (more)

Mount, Brianna Jane

2010-01-01T23:59:59.000Z

268

Shifted focus point of the Higgs mass parameter from the minimal mixed mediation of SUSY breaking  

E-Print Network [OSTI]

We employ both the minimal gravity- and the minimal gauge mediations of supersymmetry breaking at the grand unified theory scale (GUT) in a single supergravity framework. In such a "minimal mixed mediation model," a "focus point" of the Higgs mass parameter, m_{h_u}^2 emerges at 3-4 TeV energy scale, which is exactly the stop mass scale needed for explaining the 126 GeV Higgs boson mass without the "A-term" at the three loop level. As a result, m_{h_u}^2 can be quite insensitive to various trial stop masses at low energy, reducing the fine-tuning measures to be much smaller than 100 even for 3-4 TeV low energy stop mass and -0.5 < A_t / m_0 < 0 at the GUT scale. In this model the gluino mass is predicted to be about 2.3 TeV, which could readily be tested at LHC run 2.

Kyae, Bumseok

2015-01-01T23:59:59.000Z

269

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

2002-02-06T23:59:59.000Z

270

arXiv:0706.1732v2[hep-ph]11Jul2007 NUHEP-TH/07-06 GeV Seesaw, Accidentally Small Neutrino Masses, and Higgs Decays to Neutrinos  

E-Print Network [OSTI]

mixing and will provide important input for interpretation of next-generation neutrinoless double beta decay experiments. Measurement of the mass hierarchy is important input to the search for leptonic CP

271

The Gell-Mann -- Okubo mass relation among baryons from fully-dynamical mixed-action lattice QCD  

E-Print Network [OSTI]

We explore the Gell-Mann--Okubo mass relation among the octet baryons using fully-dynamical, mixed-action (domain-wall on rooted-staggered) lattice QCD calculations at a lattice spacing of b ~ 0.125 fm and pion masses of m_pi ~ 290 MeV, 350 MeV, 490 MeV and 590 MeV. Deviations from the Gell-Mann--Okubo mass relation are found to be small at each quark mass.

Silas R. Beane; Kostas Orginos; Martin J. Savage

2006-04-16T23:59:59.000Z

272

Beams for European Neutrino Experiments (BENE) Midterm scientific report  

E-Print Network [OSTI]

The activities of BENE during 2004 and 2005 are reviewed. Neutrino oscillation experiments at accelerators offer the richest possibilities of precision studies of neutrino mixing and mass differences, with the potential of important discoveries including leptonic CP or T violation. Two main options for a major initiative have been studied: 1) a high-energy Neutrino Factory coupled to a large dense magnetized detector; 2) a lower energy betabeam and conventional superbeam, coupled to a very large low-density, non-magnetic, detector. Both offer signi cant scienti c breakthroughs over other planned facilities. Much remains to be done to optimize and establish the cost, performance, and feasibility of either solution so as to allow comparison and decision. The proposal of a FP7 Design Study of a Neutrino Facility to be completed by the end of the decade is being prepared. Its success will require strong support and engagement at CERN and other European laboratories and funding agencies. International contributors...

Baldini, A; Blondel, A; Campagne, J E; Cavata, C; Donini, A; Dracos, M; Dumarchez, J; Edgecock, R; Efthymiopoulos, I; Garoby, R; Huber, P; Long, K; Lindroos, M; Méot, F; Mezzetto, Mauro; Palladino, V; Rees, G; Sievers, P; Strolin, P; Volpe, C

2006-01-01T23:59:59.000Z

273

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

2000-09-19T23:59:59.000Z

274

Earth Matter Effect on Democratic Neutrinos  

E-Print Network [OSTI]

The neutrino propagation through the Earth is investigated in the framework of the democratic neutrino theory. In this theory the neutrino mixing angle theta-1-3 is approximately determined, which allows one to make a well defined neutrino oscillogram driven by the 1-3 mixing in the matter of the Earth. Significant differences in this oscillogram from the case of models with relatively small theta-1-3 are discussed.

Dmitry Zhuridov

2014-08-30T23:59:59.000Z

275

Three-flavor MSW solutions of the solar neutrino problem  

E-Print Network [OSTI]

We perform an updated phenomenological analysis of the Mikheyev-Smirnov-Wolfenstein (MSW) solutions of the solar neutrino problem, assuming oscillations between two and three neutrino families. The analysis includes the total rates of the Homestake, SAGE, GALLEX, Kamiokande and Super-Kamiokande experiments, as well as the day-night asymmetry and the 18-bin energy spectrum of Super-Kamiokande. Solutions are found at several values of the theta_{13} mixing angle. Among the most interesting features, we find that solar neutrino data alone put the constraint theta_{13} MSW solutions extends at and beyond maximal (nu_1,nu_2) mixing (theta_{12} > pi/4), especially if the neutrino square mass splitting is in its lower range (m^2_2-m^2_1 ~ 10^{-7} eV^2) and if theta_{13} is nonzero. In particular, bimaximal (or nearly bimaximal) mixing is possible for atmospheric and MSW solar neutrino oscillations within the stringent reactor bounds on theta_{13}.

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

1999-12-03T23:59:59.000Z

276

Improved Description of One- and Two-Hole States after Electron Capture in 163 Holmium and the Determination of the Neutrino Mass  

E-Print Network [OSTI]

The atomic pair 163 Holmium and 163 Dysprosium$ seems due to the small Q value of about 2.3 to 2.8 keV the best case to determine the neutrino mass by electron capture. The bolometer spectrum measures the full deexcitation energy of Dysprosium by X rays, by Auger electrons and by the recoil of Holmium. The spectrum has an upper energy limit given by the Q value minus the neutrino mass. Till now this spectrum has been calculated allowing in Dysprosium excitations with 3s1/2, 3p1/2, 4s1/2, 4p1/2, 5s1/2, 5p1/2 holes only. Robertson calculated recently also the spectrum with two electron hole excitations in Dy. He took the probability for the excitation for the second electron hole from work of Carlson and Nestor for Z=54 Xenon. He claims, that the bolometer spectrum with two holes is "not well enough understood to permit a sensitive determination of the neutrino mass in this way." The purpose of the present work is to determine the theoretical bolometer spectrum with two hole excitations more reliably. In additi...

Faessler, Amand

2015-01-01T23:59:59.000Z

277

Lepton textures and neutrino oscillations  

E-Print Network [OSTI]

Systematic analyses of the textures arising in lepton mass matrices have been carried out using unitary transformations and condition of naturalness for the Dirac and Majorana neutrino possibilities. It is observed that the recent three neutrino oscillation data together with the effective mass in neutrinoless double beta decay provide vital clues in predicting the general structures of these lepton mass matrices.

Verma, Rohit

2014-01-01T23:59:59.000Z

278

The use the 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 $\

Baussan, E; Ekelof, T; Martinez, E Fernandez; Ohman, H; Vassilopoulos, N

2012-01-01T23:59:59.000Z

279

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

2013-02-09T23:59:59.000Z

280

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

2012-03-08T23:59:59.000Z

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.


281

Wavelet Approach to Search for Sterile Neutrinos in Tritium $?$-Decay Spectra  

E-Print Network [OSTI]

Sterile neutrinos in the mass range of a few keV are candidates for both cold and warm dark matter. An ad-mixture of a heavy neutrino mass eigenstate to the electron neutrino would result in a minuscule distortion - a 'kink' - in a $\\beta$-decay spectrum. In this paper we show that a wavelet transform is a very powerful shape analysis method to detect this signature. For a tritium source strength, similar to what is expected from the KATRIN experiment, a statistical sensitivity to active-to-sterile neutrino mixing down to $\\sin^2 \\theta= 10^{-6}$ ($90\\%$ CL) can be obtained after 3 years of measurement time. It is demonstrated that the wavelet approach is largely insensitive to systematic effects that result in smooth spectral modifications. To make full use of this analysis technique a high resolution measurement (FWHM of $\\sim100$~eV) of the tritium $\\beta$-decay spectrum is required.

S. Mertens; K. Dolde; M. Korzeczek; F. Glueck; S. Groh; R. D. Martin; A. W. P. Poon; M. Steidl

2015-01-08T23:59:59.000Z

282

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

2002-10-07T23:59:59.000Z

283

Imprints of CP violation induced by sterile neutrinos in T2K  

E-Print Network [OSTI]

We investigate the impact of light ($\\sim$ eV) sterile neutrinos in the long-baseline experiment T2K. We show that, within the 3+1 scheme, for mass-mixing parameters suggested by the short-baseline anomalies, the interference among the sterile and the atmospheric oscillation frequencies induces a new term in the $\

N. Klop; A. Palazzo

2015-02-10T23:59:59.000Z

284

Probing neutrino physics at LHC through R-parity breaking supersymmetry  

E-Print Network [OSTI]

R-parity conservation is an ad-hoc assumption in the most popular versions of supersymmetric scenarios. Hence R-parity violation (RPV) not only is allowed but, if induced by bilinear terms (bRPV), it also provides an explanation for the observed neutrino masses and mixing. Here bRPV models are discussed, giving emphasis on the $\\mu$-from-$\

Vasiliki A. Mitsou

2014-01-20T23:59:59.000Z

285

Energy Loss of Neutrinos in 20 M{sub {center_dot}} and 40 M{sub {center_dot}} Massive Stars  

SciTech Connect (OSTI)

The progress from the theoretical and experimental aspects in neutrino physics shines light into neutrino physics as well as in astrophysics. It is known that when neutrinos pass through a medium, the neutrinos interact with electrons before emerging from the stars with an effective potential energy produced due to coherent forward scatterings that occurred in the medium. This potential engenders significant changes in the neutrino masses and their mixing in the medium. Thus electron neutrinos would oscillate into different mass eigenstate and this is dependent on the energy of the neutrinos. Some of the energy will be lost in the coherent scattering with the electrons by the charged current interaction. We have calculated the energy loss of the neutrinos by using a stopping power equation for both rotating and non-rotating 20 M{sub {center_dot}} and 40 M{sub {center_dot}} stars. The total energy loss of neutrinos depends on the electron density in the stars and on the survival probability of the electron neutrino. For high electron density profile and the survival probability, the energy loss will be significant.

Sofiah Ahmad, Nor; Yusof, Norhasliza; Abu Kassim, Hasan [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

286

Neutral Current Coherent Cross Sections- Implications on Gaseous Spherical TPC's for detecting SN and Earth neutrinos  

E-Print Network [OSTI]

The detection of galactic supernova (SN) neutrinos represents one of the future frontiers of low-energy neutrino physics and astrophysics. The neutron coherence of neutral currents (NC) allows quite large cross sections in the case of neutron rich targets, which can be exploited in detecting earth and sky neutrinos by measuring nuclear recoils. A core-collapse supernova represents one of the most powerful source of (anti)neutrinos in the Universe. These (NC) cross sections are not dependent on flavor conversions and, thus, their measurement will provide useful information about the neutrino source. In particular the case of SN they will yield information about the primary neutrino fluxes, i.e. before flavor conversions in neutrino sphere. The advantages of large gaseous low threshold and high resolution time projection counters (TPC) detectors TPC detectors will be discussed. These are especially promising since they are expected to be relatively cheap and easy to maintain. The information thus obtained can also be useful to other flavor sensitive detectors, e.g. the large liquid scintillation detectors like LENA. All together such detectors will provide invaluable information on the astrophysics of core-collapse explosion and on the neutrino mixing parameters. In particular, neutrino flavor transitions in SN envelope might be sensitive to the value of theta-{13} and to the unknown neutrino mass hierarchy. Till a real SN explosion is detected, one can use available earth neutrino sources with similar energy spectra to test the behavior of these detectors. Among them, the ORNL Neutron Spallation source (SNS) and boosted radioactive neutrino beams are good candidates.

J. D. Vergados

2011-11-27T23:59:59.000Z

287

Sterile Neutrinos in Neutrinoless Double Beta Decay: An Update  

E-Print Network [OSTI]

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

Faessler, Amand; Kovalenko, Sergey; Simkovic, Fedor

2014-01-01T23:59:59.000Z

288

Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster  

E-Print Network [OSTI]

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle $\\theta_{13}$ in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small $L/E$, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current $\

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

2014-04-09T23:59:59.000Z

289

Atmospheric Neutrinos  

E-Print Network [OSTI]

This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

Thomas K. Gaisser

2006-12-11T23:59:59.000Z

290

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

2011-12-11T23:59:59.000Z

291

Fourth generation neutrinos and neutrino induced hadron production in the resonance region.  

E-Print Network [OSTI]

??We investigate two aspects in neutrino physics. First, we consider the extension of the standard model by a fourth fermion generation. Allowing finite mixing of… (more)

Schalla, Dario

2013-01-01T23:59:59.000Z

293

A combined beta-beam and electron capture neutrino experiment  

E-Print Network [OSTI]

The next generation of long baseline neutrino experiments will aim at determining the value of the unknown mixing angle, theta_{13}, the type of neutrino mass hierarchy and the presence of CP-violation in the lepton sector. Beta-beams and electron capture experiments have been studied as viable candidates for long baseline experiments. They use a very clean electron neutrino beam from the beta-decays or electron capture decays of boosted ions. In the present article we consider an hybrid setup which combines a beta-beam with an electron capture beam by using boosted Ytterbium ions. We study the sensitivity to the CP-violating phase delta and the theta_{13} angle, the CP-discovery potential and the reach to determine the type of neutrino mass hierarchy for this type of long baseline experiment. The analysis is performed for different neutrino beam energies and baselines. Finally, we also discuss how the results would change if a better knowledge of some of the assumed parameters was achieved by the time this experiment could take place.

J. Bernabeu; C. Espinoza; C. Orme; S. Palomares-Ruiz; S. Pascoli

2009-02-27T23:59:59.000Z

294

Neutrinos: in and out of the standard model  

SciTech Connect (OSTI)

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

Parke, Stephen; /Fermilab

2006-07-01T23:59:59.000Z

295

Neutrinos: Nature's Identity Thieves?  

ScienceCinema (OSTI)

The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.

Dr. Don Lincoln

2013-07-22T23:59:59.000Z

296

Neutrinos: Nature's Identity Thieves?  

ScienceCinema (OSTI)

The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.

Lincoln, Don

2014-08-07T23:59:59.000Z

297

arXiv:hep-ph/0412300v121Dec2004 Neutrinoless double beta decay and direct searches for neutrino mass  

E-Print Network [OSTI]

arXiv:hep-ph/0412300v121Dec2004 Neutrinoless double beta decay and direct searches for neutrino (Dated: December 22, 2004) Study of the neutrinoless double beta decay and searches for the manifestation and recommendations on them. · Observation of the neutrinoless double-beta decay (0) would prove that the total lepton

Piepke, Andreas G.

298

Statistical Understanding of Quark and Lepton Masses in Gaussian Landscapes  

E-Print Network [OSTI]

The fundamental theory of nature may allow a large landscape of vacua. Even if the theory contains a unified gauge symmetry, the 22 flavor parameters of the Standard Model, including neutrino masses, may be largely determined by the statistics of this landscape, and not by any symmetry. Then the measured values of the flavor parameters do not lead to any fundamental symmetries, but are statistical accidents; their precise values do not provide any insights into the fundamental theory, rather the overall pattern of flavor reflects the underlying landscape. We investigate whether random selection from the statistics of a simple landscape can explain the broad patterns of quark, charged lepton, and neutrino masses and mixings. We propose Gaussian landscapes as simplified models of landscapes where Yukawa couplings result from overlap integrals of zero-mode wavefunctions in higher-dimensional supersymmetric gauge theories. In terms of just five free parameters, such landscapes can account for all gross features of flavor, including: the hierarchy of quark and charged lepton masses; small quark mixing angles, with 13 mixing less than 12 and 23 mixing; very light Majorana neutrino masses, with the solar to atmospheric neutrino mass ratio consistent with data; distributions for leptonic 12 and 23 mixings that are peaked at large values, while the distribution for 13 mixing is peaked at low values; and order unity CP violating phases in both the quark and lepton sectors. While the statistical distributions for flavor parameters are broad, the distributions are robust to changes in the geometry of the extra dimensions. Constraining the distributions by loose cuts about observed values leads to narrower distributions for neutrino measurements of 13 mixing, CP violation, and neutrinoless double beta decay.

Lawrence J. Hall; Michael P. Salem; Taizan Watari

2007-08-10T23:59:59.000Z

299

Neutrino Astronomy and Cosmic Rays Spectroscopy at Horizons  

E-Print Network [OSTI]

A new air-showering physics may rise in next years at horizon, offering at different angles and altitudes a fine tuned filtered Cosmic Rays astrophysics and an upward Neutrino induced air-showering astronomy. Most of this opportunity arises because of neutrino masses, their mixing and the consequent replenishment of rarest tau flavor during its flight in Space. Horizontal air atmosphere act as a filter for High energy Cosmic Rays (CR) and as a beam dump for Ultra High Energy (UHE) neutrinos and a powerfull amplifier for its tau decay in air by its wide showering areas. Earth sharp shadows plays the role of a huge detector volume for UHE neutrino and a noise-free screen for upcoming EeVs tau air-showers (as well PeVs anti-neutrino electron air interactions). Projects for Tau Airshowers are growing at the top of a mountains or at the edge of a cliff. ASHRA in Hawaii and CRNTN in Utah are tracking fluorescence lights, while other novel projects on Crown array detectors on mountains, on balloons and satellites are elaborated for Cherenkov lights. AUGER, facing the Ande edges, ARGO located within a deep valley are testing inclined showers; MILAGRO (and MILAGRITO) may be triggered by horizontal up-going muon bundles from the Earth edges; HIRES and AUGER UHECR detectors, linking twin array telescopes along their axis may test horizontal Cerenkov blazing photons. MAGIC (Hess, Veritas) and Shalon Telescopes may act already like a detector for few PeVs and Glashow resonance neutrino events; MAGIC pointing downward to terrestrial ground acts as a massive tens of km^3 detector, making it the most sensitive dedicated neutrino telescope. MAGIC facing the sea edges must reveal mirrored downward UHECR Air-showers Cherenkov flashes. Magic-crown systems may lead to tens km^3, neutrino detectors.

D. Fargion

2006-04-20T23:59:59.000Z

300

Neutrinos in the Electron  

E-Print Network [OSTI]

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

E. L. Koschmieder

2006-09-26T23:59:59.000Z

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

Strong Upper Limits on Sterile Neutrino Warm Dark Matter  

SciTech Connect (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

302

Neutrino oscillation experiments and limits on lepton-number and lepton-flavor violating processes  

E-Print Network [OSTI]

Using a three neutrino framework we investigate bounds for the effective Majorana neutrino mass matrix. The mass measured in neutrinoless double beta decay is its (11) element. Lepton-number and -flavor violating processes sensitive to each element are considered and limits on branching ratios or cross sections are given. Those processes include $\\mu^- e^+$ conversion, $K^+ \\to \\pi^- \\mu^+ \\mu^+$ or recently proposed high-energy scattering processes at HERA. Including all possible mass schemes, the three solar solutions and other allowed possibilities, there is a total of 80 mass matrices. The obtained indirect limits are up to 14 orders of magnitude more stringent than direct ones. It is investigated how neutrinoless double beta decay may judge between different mass and mixing schemes as well as solar solutions. Prospects for detecting processes depending on elements of the mass matrix are also discussed.

W. Rodejohann

2000-06-19T23:59:59.000Z

303

Exploring the Earth matter effect with atmospheric neutrinos in ice  

E-Print Network [OSTI]

We study the possibility to perform neutrino oscillation tomography and to determine the neutrino mass hierarchy in kilometer-scale ice Cerenkov detectors by means of the theta13-driven matter effects which occur during the propagation of atmospheric neutrinos deep through the Earth. We consider the ongoing IceCube/DeepCore neutrino observatory and future planned extensions, such as the PINGU detector, which has a lower energy threshold. Our simulations include the impact of marginalization over the neutrino oscillation parameters and a fully correlated systematic uncertainty on the total number of events. For the current best-fit value of the mixing angle theta13, the DeepCore detector, due to its relatively high-energy threshold, could only be sensitive to fluctuations on the normalization of the Earth's density of \\Delta\\rho \\simeq \\pm 10% at ~ 1.6 sigma CL after 10 years in the case of a true normal hierarchy. For the two PINGU configurations we consider, overall density fluctuations of \\Delta\\rho \\simeq \\pm 3% (\\pm 2%) could be measured at the 2 sigma CL after 10 years, also in the case of a normal mass hierarchy. We also compare the prospects to determine the neutrino mass hierarchy in these three configurations and find that this could be achieved at the 5 sigma CL, for both hierarchies, after 5 years in DeepCore and about 1 year in PINGU. This clearly shows the importance of lowering the energy threshold below 10 GeV so that detectors are fully sensitive to the resonant matter effects.

Sanjib Kumar Agarwalla; Tracey Li; Olga Mena; Sergio Palomares-Ruiz

2012-12-10T23:59:59.000Z

304

E-Print Network 3.0 - argon-37 artificial neutrino Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the neutrino, like any fermion, cannot... of neutrino mass deduced from neutrinoless double beta decay cannot be used as constraints ... Source: Ecole Polytechnique, Centre de...

305

E-Print Network 3.0 - atmospheric neutrino anomaly Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Physics Group Collection: Physics 15 Vol. 30 (1999) ACTA PHYSICA POLONICA B No 11 PHENOMENOLOGY OF NEUTRINO MASSES Summary: ; Atmospheric neutrino anomaly: Interpreted as...

306

Detectors for Neutrino Physics at the First Muon Collider  

E-Print Network [OSTI]

We consider possible detector designs for short-baseline neutrino experiments using neutrino beams produced at the First Muon Collider complex. The high fluxes available at the muon collider make possible high statistics deep-inelastic scattering neutrino experiments with a low-mass target. A design of a low-energy neutrino oscillation experiment on the ``tabletop'' scale is also discussed.

Deborah A. Harris; Kevin S. McFarland

1998-04-20T23:59:59.000Z

307

Supernova neutrinos and explosive nucleosynthesis  

SciTech Connect (OSTI)

Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and ?{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on ?{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

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

2014-05-09T23:59:59.000Z

308

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

309

Neutrino condensates at center of galaxies as background for the MSW mechanism  

E-Print Network [OSTI]

The possibility is explored that neutrino condensates, possible candidates for the explanation of very massive objects in galactic centers, could act as background for the Mikheyev-Smirnov-Wolfeinstein mechanism responsible of neutrino oscillations. Assuming a simple neutrino star model with constant density, the lower limit of the mass squared difference of neutrino oscillations is inferred. Consequences on neutrino asymmetry are discussed.

S. Capozziello; G. Iovane; G. Lambiase

2003-04-01T23:59:59.000Z

310

Discovering Long Wavelength Neutrino Oscillations in the Distorted Neutrino Spectrum of Galactic Supernova Remnants  

E-Print Network [OSTI]

We investigate the muon neutrino event rate in km$^3$ neutrino telescopes due to a number of galactic supernova remnants expected on the basis of these objects' known $\\gamma$-ray signals. We evaluate the potential of these neutrino signals to exhibit evidence of the sub-dominant neutrino oscillations expected in various neutrino mixing schemes including pseudo-Dirac scenarios and the Exact Parity Model. With ten years' data, neutrino signals from Sgr A East should either discover or exclude neutrino oscillations governed by a $\\delta m^2$ parameter in the range $10^{-12}$ to $10^{-15}$ eV$^2$. Such a capability is not available to terrestrial or solar system neutrino experiments.

Roland M. Crocker; Fulvio Melia; Raymond R. Volkas

2001-06-06T23:59:59.000Z

311

Neutrino Physics with Thermal Detectors  

SciTech Connect (OSTI)

The investigation of fundamental neutrino properties like its mass and its nature calls for the design of a new generation of experiments. High sensitivity, high energy resolution, and versatility together with the possibility of a simple multiplexing scheme are the key features of future detectors for these experiments. Thermal detectors can combine all these features. This paper reviews the status and the perspectives for what concerns the application of this type of detectors to neutrino physics, focusing on direct neutrino mass measurements and neutrinoless double beta decay searches.

Nucciotti, A. [Dipartimento di Fisica, Universita di Milano Bicocca and INFN Sezione di Milano-Bicocca Piazza della Scienza, 3, 20126 Milano (Italy)

2009-11-09T23:59:59.000Z

312

Cosmological and supernova neutrinos  

SciTech Connect (OSTI)

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

Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GSÜ, Department of Physics, ?i?li, ?stanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

2014-06-24T23:59:59.000Z

313

Probing Neutrino Hierarchy and Chirality via Wakes  

E-Print Network [OSTI]

The relic neutrinos are expected to acquire a bulk relative velocity with respect to the dark matter at low redshifts, and downstream of dark matter halos neutrino wakes are expected to develop. We propose a method of measuring the neutrino mass based on this mechanism. The neutrino wake will cause a dipole distortion of the galaxy-galaxy lensing pattern. This effect could be detected by combining upcoming lensing surveys, e.g. the LSST and Euclid surveys with a low redshift galaxy survey or a 21cm intensity mapping survey which can map the neutrino flow field. The data obtained with LSST and Euclid should enable us to make positive detection if the three neutrino masses are Quasi-Degenerate, and a future high precision 21cm lensing survey would allow the normal hierarchy and inverted hierarchy cases to be distinguished, and even the right handed Dirac neutrinos may be detectable.

Hong-Ming Zhu; Ue-Li Pen; Xuelei Chen; Derek Inman

2014-12-04T23:59:59.000Z

314

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

2003-09-16T23:59:59.000Z

315

The MSW effect and Solar Neutrinos  

E-Print Network [OSTI]

The MSW (Mikheyev-Smirnov-Wolfenstein) effect is the effect of transformation of one neutrino species (flavor) into another one in a medium with varying density. Three basic elements of the effect include: the refraction of neutrinos in matter, the resonance (level crossing) and the adiabaticity. The key notion is {\\it the neutrino eigenstates} in matter. Physical picture of the effect is described in terms of the flavors and the relative phases of eigenstates and the transitions between eigenstates. Features of the large mixing realization of the MSW effect are discussed. The large mixing MSW effect (LMA) provides the solution of the solar neutrino problem. We show in details how this mechanism works. Physics beyond the LMA solution is discussed. The lower $Ar$-production rate (in comparison with the LMA prediction) and absence of significant "turn up" of the spectrum at low energies can be due to an additional effect of the light sterile neutrino with very small mixing.

A. Yu. Smirnov

2003-05-09T23:59:59.000Z

316

On the Electric Charge of the Neutrino  

E-Print Network [OSTI]

Exact expression is obtained for the differential cross section of elastic electroweak scattering of longitudinal polarized massive Dirac neutrinos with the electric charge and anomalous magnetic moment on a spinless nucleus. This formula contains all necessary information about the nature of the neutrino mass, charge and magnetic moment. Some of them state that between the mass of the neutrino its electric charge there exists an interconnection.

Rasulkhozha S. Sarafiddinov

2010-12-09T23:59:59.000Z

317

Last CPT-Invariant Hope for LSND Neutrino Oscillations  

E-Print Network [OSTI]

It is shown that the 99% confidence limits from the analyses of the data of cosmological and neutrino experiments imply a small marginally allowed region in the space of the neutrino oscillation parameters of 3+1 four-neutrino mixing schemes. This region can be confirmed or falsified by experiments in the near future.

C. Giunti

2003-02-21T23:59:59.000Z

318

A New Lorentz-Violating Model of Neutrino Oscillations  

E-Print Network [OSTI]

A new model for neutrino oscillations is introduced, in which mass-like behavior is seen at high energies, but various behavior can be predicted at low energies. The model employs no neutrino masses, but instead relies on the Lorentz-violating parameters a and c. Oscillations into antineutrinos and sterile neutrinos are also considered.

Kevin Labe

2010-07-31T23:59:59.000Z

319

La Thuile 2014: Theoretical premises to neutrino round table  

E-Print Network [OSTI]

This talk, dedicated to the memory of G. Giacomelli, introduced the round table on neutrinos held in February 2014. The topics selected for the discussion are: 1) the neutrinoless double beta decay rate (interpretation in terms of light neutrinos, nuclear uncertainties); 2) the physics in the gigantic water Cherenkov detectors (proton decay, atmospheric neutrinos); 3) the study of neutrino oscillations (mass hierarchy and CP violation; other neutrino states); 4) the neutrino astronomy at low and high energies (solar, supernova, cosmic neutrinos). The importance of an active interplay between theory and experiment is highlighted.

Francesco Vissani

2014-05-25T23:59:59.000Z

320

La Thuile 2014: Theoretical premises to neutrino round table  

E-Print Network [OSTI]

This talk, dedicated to the memory of G. Giacomelli, introduced the round table on neutrinos held in February 2014. The topics selected for the discussion are: 1) the neutrinoless double beta decay rate (interpretation in terms of light neutrinos, nuclear uncertainties); 2) the physics in the gigantic water Cherenkov detectors (proton decay, atmospheric neutrinos); 3) the study of neutrino oscillations (mass hierarchy and CP violation; other neutrino states); 4) the neutrino astronomy at low and high energies (solar, supernova, cosmic neutrinos). The importance of an active interplay between theory and experiment is highlighted.

Vissani, Francesco

2014-01-01T23:59:59.000Z

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.


321

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

SciTech Connect (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

322

KeV Warm Dark Matter and Composite Neutrinos  

E-Print Network [OSTI]

Elementary keV sterile Dirac neutrinos can be a natural ingredient of the composite neutrino scenario. For a certain class of composite neutrino theories, these sterile neutrinos naturally have the appropriate mixing angles to be resonantly produced warm dark matter (WDM). Alternatively, we show these sterile neutrinos can be WDM produced by an entropy-diluted thermal freeze-out, with the necessary entropy production arising not from an out-of-equilibrium decay, but rather from the confinement of the composite neutrino sector, provided there is sufficient supercooling.

Dean J Robinson; Yuhsin Tsai

2012-09-25T23:59:59.000Z

323

Masses of Fundamental Particles  

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

2014-06-11T23:59:59.000Z

324

Combining CPT-conjugate Neutrino channels at Fermilab  

E-Print Network [OSTI]

We explore an alternative strategy to determine the neutrino mass hierarchy by making use of possible future neutrino facilities at Fermilab. Here, we use CPT-conjugate neutrino channels, exploiting a nu_mu beam from the NuMI beamline and a barnu_e beam from a betabeam experimental setup. Both experiments are performed at approximately the same E/L. We present different possible accelerator scenarios for the betabeam neutrino setup and fluxes. This CPT-conjugate neutrino channel scenario can extract the neutrino mass hierarchy down to sin^2 (2 theta_13) \\approx 0.02.

Andreas Jansson; Olga Mena; Stephen Parke; Niki Saoulidou

2007-11-07T23:59:59.000Z

325

MSW effect with flavor changing interactions and the atmospheric neutrino problem  

E-Print Network [OSTI]

We consider flavor changing effective neutrino interactions in the context of massive neutrinos in the issue of atmospheric neutrinos. Assuming as usual that this is an indication of the oscillation of muon neutrinos into tau neutrinos we show that there is a set of parameters which is consistent with the MSW resonance condition for the typical Earth density and atmospheric neutrino energies. In particular we show that even if the vacuum mixing angle vanishes it is still possible to have a resonance which is compatible with the atmospheric neutrino data. We also briefly consider the case of the solar neutrino problem.

J. C. Montero; V. Pleitez

2000-05-08T23:59:59.000Z

326

Light Dark Matter Detection Prospects at Neutrino Experiments  

E-Print Network [OSTI]

We consider the prospects for the detection of relatively light dark matter through direct annihilation to neutrinos. We specifically focus on the detection possibilities of water Cherenkov and liquid scintillator neutrino detection devices. We find in particular that liquid scintillator detectors may potentially provide excellent detection prospects for dark matter in the 4-10 GeV mass range. These experiments can provide excellent corroborative checks of the DAMA/LIBRA annual modulation signal, but may yield results for low mass dark matter in any case. We identify important tests of the ratio of electron to muon neutrino events (and neutrino versus anti-neutrino events), which discriminate against background atmospheric neutrinos. In addition, the fraction of events which arise from muon neutrinos or anti-neutrinos ($R_{\\mu}$ and $R_{\\bar \\mu}$) can potentially yield information about the branching fractions of hypothetical dark matter annihilations into different neutrino flavors. These results apply to n...

Kumar, Jason; Smith, Stefanie

2009-01-01T23:59:59.000Z

327

An infrared origin of leptonic mixing and its test at DeepCore  

E-Print Network [OSTI]

Fermion mixing is generally believed to be a low-energy manifestation of an underlying theory whose energy scale is much larger than the electroweak scale. In this paper we investigate the possibility that the parameters describing lepton mixing actually arise from the low-energy behavior of the neutrino interacting fields. In particular, we conjecture that the measured value of the mixing angles for a given process depends on the number of unobservable flavor states at the energy of the process. We provide a covariant implementation of such conjecture, draw its consequences in a two neutrino family approximation and compare these findings with current experimental data. Finally we show that this infrared origin of mixing will be manifest at the Ice Cube DeepCore array, which measures atmospheric oscillations at energies much larger than the tau lepton mass; it will hence be experimentally tested in a short time scale.

F. Terranova

2011-10-10T23:59:59.000Z

328

Lepton number violating processes mediated by Majorana neutrinos at hadron colliders  

SciTech Connect (OSTI)

We study the lepton number violating like-sign dilepton processes h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}jjX and h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}W{sup {+-}}X, mediated by heavy GeV scale Majorana neutrinos. We focus on the resonantly enhanced contributions with a nearly on-mass-shell Majorana neutrino in the s channel. We study the constraints on like-sign dilepton production at the Tevatron and the LHC on the basis of the existing experimental limits on the masses of heavy neutrinos and their mixings U{sub {alpha}}{sub N} with {alpha}={nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}. Special attention is paid to the constraints from neutrinoless double beta decay. We note that searches for like-sign e{sup {+-}}e{sup {+-}} events at Tevatron and LHC may provide evidence of CP violation in the neutrino sector. We also discuss the conditions under which it is possible to extract individual constraints on the mixing matrix elements in a model independent way.

Kovalenko, Sergey; Lu Zhun; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico, Santa Maria, Casilla 110-V, Valparaiso (Chile) and Center of Subatomic Physics, Valparaiso (Chile)

2009-10-01T23:59:59.000Z

329

UHE Cosmic Rays and Neutrinos Showering on Planet Edges  

E-Print Network [OSTI]

Ultra High Energy (UHE) Cosmic Rays, UHECR, may graze high altitude atmosphere leading to horizontal upward air-showers. Also PeVs electron antineutrino hitting electron in atmosphere may air-shower at W boson resonant mass. On the other side ultra high energy muon and electron neutrinos may also lead, by UHE neutrinos mass state mixing, to the rise of a corresponding UHE Tau neutrino flavor; the consequent UHE tau neutrinos, via charge current interactions in matter, may create UHE taus at horizons (Earth skimming neutrinos or Hor-taus) whose escape in atmosphere and whose consequent decay in flight, may be later amplified by upward showering on terrestrial, planetary atmospheres. Indeed because of the finite terrestrial radius, its thin atmosphere size its dense crust, the UHE tau cannot extend much more than 360 kilometers in air, corresponding to an energy of about 7.2 EeV, near but below GZK cut-off ones; on the contrary Jupiter (or even Saturn) may offer a wider, less dense and thicker gaseous layer at the horizons where Tau may loose little energy, travel longer before decay and rise and shower at 4-6 10^{19} eV or ZeV extreme energy. Titan atmosphere may open a rare window of opportunity for Up-ward Taus at PeVs. Also solar atmosphere may play a role, but unfortunately tau-showers secondaries maybe are too noisy to be disentangled, while Jupiter atmosphere, or better, Saturn one, may offer a clearer imprint for GZK (and higher Z-Burst) Tau showering, well below the horizons edges.

D. Fargion; P. Oliva; O. Lanciano

2006-10-24T23:59:59.000Z

330

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

2009-08-26T23:59:59.000Z

331

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background  

E-Print Network [OSTI]

We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range, with couplings to ordinary active neutrinos large enough to guarantee thermal and chemical equilibrium at epochs in the early universe with temperatures T > 1 GeV, but in a range to give decay lifetimes from seconds to minutes. Such neutrinos would decouple early, with relic densities comparable to those of photons, but decay out of equilibrium, with consequent prodigious entropy generation prior to, or during, Big Bang Nucleosynthesis (BBN). Most of the ranges of sterile neutrino rest mass and lifetime considered are at odds with Cosmic Microwave Background (CMB) limits on the relativistic particle contribution to energy density (e.g., as parameterized by N_eff). However, some sterile neutrino parameters can lead to an acceptable N_eff. These parameter ranges are accompanied by considerable dilution of the ordinary background relic neutrinos, possibly an adverse effect on BBN, but sometimes fall in a range which can explain measured neutrino masses in some particle physics models. A robust signature of these sterile neutrinos would be a measured N_eff not equal to 3 coupled with no cosmological signal for neutrino rest mass when the detection thresholds for these probes are below laboratory-established neutrino mass values, either as established by the atmospheric neutrino oscillation scale or direct measurements with, e.g., KATRIN or neutrino-less double beta decay experiments.

George M. Fuller; Chad T. Kishimoto; Alexander Kusenko

2011-10-28T23:59:59.000Z

332

E-Print Network 3.0 - artificial neutrino source Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chiba University Collection: Physics 48 arXiv:hep-ph0412300v121Dec2004 Neutrinoless double beta decay and direct searches for neutrino mass Summary: of the neutrino mass in...

333

Constrains on Dark Matter sterile neutrino resonant production in the light of Planck  

E-Print Network [OSTI]

Few independent detections of a weak X-ray emission line at an energy of ~3.5 keV seen toward a number of astrophysical sites have been reported. If this signal will be confirmed to be the signature of decaying DM sterile neutrino with a mass of ~7.1 keV, then the cosmological observables should be consistent with its properties. We compute the radiation and matter perturbations including the full resonance sweep solution for active - sterile neutrino flavor conversion and place constraints on the cosmological parameters and sterile neutrino properties by using most of the present cosmological measurements. We find the sterile neutrino upper limits for mass and mixing angle of 7.86 keV (equivalent to 2.54 keV thermal mass) and 9.41 x 10^{-9} (at 95% CL) respectively, for a lepton number per flavor of 0.0042, that is significantly higher than that inferred in Abazajian (2014) from the linear large scale structure constraints. This reflects the sensitivity of the high precision CMB anisotropies to the helium ab...

Popa, L A; Tonoiu, D

2015-01-01T23:59:59.000Z

334

Analytical Theory of Neutrino Oscillations in Matter with CP violation  

E-Print Network [OSTI]

We develop an exact analytical formulation of neutrino oscillations in matter within the framework of the Standard Neutrino Model assuming 3 Dirac Neutrinos. Our Hamiltonian formulation, which includes CP violation, leads to expressions for the partial oscillation probabilities that are linear combinations of spherical Bessel functions in the eigenvalue differences. The coefficients of these Bessel functions are polynomials in the neutrino CKM matrix elements, the neutrino mass differences squared, the strength of the neutrino interaction with matter, and the neutrino mass eigenvalues in matter. We give exact closed-form expressions for all partial oscillation probabilities in terms of these basic quantities. Adopting the Standard Neutrino Model, we then examine how the exact expressions for the partial oscillation probabilities might simplify by expanding in one of the small parameters {\\alpha} and sin{\\theta}13 of this model. We show explicitly that for small {\\alpha} and sin{\\theta}13 there are branch poin...

Johnson, Mikkel B; Kisslinger, Leonard S

2015-01-01T23:59:59.000Z

335

Neutrinos at high energy accelerators  

E-Print Network [OSTI]

PREAMBLE, BRIEF HISTORY AND PRELIMINARIES, QUICK REVIEW OF BASIC NEUTRINO PROPERTIES, CHARGED CURRENT NEUTRINO PROCESSES, NEUTRAL CURRENT NEUTRINO PROCESSES, VERY HEAVY NEUTRINOS, CONCLUDING SUMMARY

Probir Roy

1993-08-02T23:59:59.000Z

336

Neutrino oscillations and neutrinoless double beta decay  

E-Print Network [OSTI]

The relation between neutrino oscillation parameters and neutrinoless double beta decay is studied, assuming normal and inverse hierarchies for Majorana neutrino masses. For normal hierarchy the crucial dependence on U_{e3} is explored. The link with tritium beta decay is also briefly discussed.

D. Falcone; F. Tramontano

2001-03-16T23:59:59.000Z

337

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

SciTech Connect (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

338

Inverse neutrinoless double beta decay revisited: Neutrinos, Higgs triplets, and a muon collider  

SciTech Connect (OSTI)

We revisit the process of inverse neutrinoless double beta decay (e{sup -}e{sup -{yields}}W{sup -}W{sup -}) at future linear colliders. The cases of Majorana neutrino and Higgs triplet exchange are considered. We also discuss the processes e{sup -{mu}-{yields}}W{sup -}W{sup -} and {mu}{sup -{mu}-{yields}}W{sup -}W{sup -}, which are motivated by the possibility of muon colliders. For heavy neutrino exchange, we show that masses up to 10{sup 6} (10{sup 5}) GeV could be probed for ee and e{mu} machines, respectively. The stringent limits for mixing of heavy neutrinos with muons render {mu}{sup -{mu}-{yields}}W{sup -}W{sup -} less promising, even though this process is not constrained by limits from neutrinoless double beta decay. If Higgs triplets are responsible for inverse neutrinoless double beta decay, observable signals are only possible if a very narrow resonance is met. We also consider unitarity aspects of the process in case both Higgs triplets and neutrinos are exchanged. An exact seesaw relation connecting low energy data with heavy neutrino and triplet parameters is found.

Rodejohann, Werner [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany)

2010-06-01T23:59:59.000Z

339

accuracy neutrino oscillation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay. G. Rajasekaran 2000-04-17 22 Neutrino Mass and Oscillation HEP -...

340

Anomalous magnetic and electric moments of $?$ and lepton flavor mixing matrix in effective lagrangian approach  

E-Print Network [OSTI]

In an effective lagrangian approach [EM97] to new physics, the authors in ref. [HL99] pushed tau anomalous magnetic and electric dipole moments (AMDM and EDM) down to $10^{-11}$ and $10^{-25} e cm$ by using a Fritzsch-Xing lepton mass matrix ansatz. In this note, we find that, in this approach, there exists the connection between $\\tau$ AMDM and EDM and the lepton flavor mixing matrix. By using the current neutrino oscillation experimental results, we investigate the parameter space of lepton mixing angles to $\\tau$ AMDM and EDM. We can obtain the same or smaller bounds of $\\delta a_\\tau$ and $d_\\tau$ acquired in ref. [HL99] and constrain $\\theta_l$ (the mixing angle obtained by long-baseline neutrino oscillation experiments) from $\\tau$ AMDM and EDM.

J. Q. Zhang; X. C. Song; W. J. Huo; T. F. Feng

2002-06-17T23:59:59.000Z

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

Theory of Interactions of Non-Relativistic Flavor-Mixed Particles and its possible Implications to the Physics of Dark Matter and the Cosmic Neutrino Background  

E-Print Network [OSTI]

from [2]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.2 The distribution of dark matter in a region of size 5h?1 Mpc. The classical ?CDMmodel is on the left and the two-component flavor-mixed ?CDMmodel....3 The distribution of dark matter in a region of size 50h?1 Mpc. The classical ?CDMmodel is on the left and the two-component flavor-mixed ?CDMmodel is on the right. One can see that the large structure match quite well. Figure (2.2) is a zoomed in region located...

Ford, Alexander L.

2012-12-31T23:59:59.000Z

342

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

DOE Data Explorer [Office of Scientific and Technical Information (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

343

Sensitivity of Next-Generation Tritium Beta-Decay Experiments for keV-Scale Sterile Neutrinos  

E-Print Network [OSTI]

We investigate the sensitivity of tritium $\\beta$-decay experiments for keV-scale sterile neutrinos. Relic sterile neutrinos in the keV mass range can contribute both to the cold and warm dark matter content of the universe. This work shows that a large-scale tritium beta-decay experiment, similar to the KATRIN experiment that is under construction, can reach a statistical sensitivity of the active-sterile neutrino mixing of $\\sin^2\\theta \\sim 10^{-8}$. The effect of uncertainties in the known theoretical corrections to the tritium $\\beta$-decay spectrum were investigated, and found not to affect the sensitivity significantly. It is demonstrated that controlling uncorrelated systematic effects will be one of the main challenges in such an experiment.

S. Mertens; T. Lasserre; S. Groh; F. Glueck; A. Huber; A. W. P. Poon; M. Steidl; N. Steinbrink; C. Weinheimer

2014-12-14T23:59:59.000Z

344

Scrutinizing the eta-eta' mixing, masses and pseudoscalar decay constants in the framework of U(3) chiral effective field theory  

E-Print Network [OSTI]

We study the $\\eta$-$\\eta'$ mixing up to next-to-next-to-leading-order in $U(3)$ chiral perturbation theory in the light of recent lattice simulations and phenomenological inputs. A general treatment for the $\\eta$-$\\eta'$ mixing at higher orders, with the higher-derivative, kinematic and mass mixing terms, is addressed. The connections between the four mixing parameters in the two-mixing-angle scheme and the low energy constants in the $U(3)$ chiral effective theory are provided both for the singlet-octet and the quark-flavor bases. The axial-vector decay constants of pion and kaon are studied in the same order and confronted with the lattice simulation data as well. The quark-mass dependences of $m_\\eta$, $m_{\\eta'}$ and $m_K$ are found to be well described at next-to-leading order. Nonetheless, in order to simultaneously describe the lattice data and phenomenological determinations for the properties of light pseudoscalars $\\pi, K, \\eta$ and $\\eta'$, the next-to-next-to-leading order study is essential. Fu...

Guo, Xu-Kun; Oller, Jose Antonio; Sanz-Cillero, Juan Jose

2015-01-01T23:59:59.000Z

345

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

2009-11-10T23:59:59.000Z

346

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

347

Deviations from tribimaximal mixing due to the vacuum expectation value misalignment in A{sub 4} models  

SciTech Connect (OSTI)

The addition of an A{sub 4} family symmetry and extended Higgs sector to the standard model can generate the tribimaximal mixing pattern for leptons, assuming the correct vacuum expectation value alignment of the Higgs scalars. Deviating this alignment affects the predictions for the neutrino oscillation and neutrino mass observables. An attempt is made to classify the plethora of models in the literature, with respect to the chosen A{sub 4} particle assignments. Of these models, two particularly popular examples have been analyzed for deviations from tribimaximal mixing by perturbing the vacuum expectation value alignments. The effect of perturbations on the mixing angle observables is studied. However, it is only investigation of the mass-related observables (the effective mass for neutrinoless double beta decay and the sum of masses from cosmology) that can lead to the exclusion of particular models by constraints from future data, which indicates the importance of neutrino mass in disentangling models. The models have also been tested for fine-tuning of the parameters. Furthermore, a well-known seesaw model is generalized to include additional scalars, which transform as representations of A{sub 4} not included in the original model.

Barry, James; Rodejohann, Werner

2010-05-01T23:59:59.000Z

348

The accretion of solar material onto white dwarfs: No mixing with core material implies that the mass of the white dwarf is increasing  

SciTech Connect (OSTI)

Cataclysmic Variables (CVs) are close binary star systems with one component a white dwarf (WD) and the other a larger cooler star that fills its Roche Lobe. The cooler star is losing mass through the inner Lagrangian point of the binary and some unknown fraction of this material is accreted by the WD. One consequence of the WDs accreting material, is the possibility that they are growing in mass and will eventually reach the Chandrasekhar Limit. This evolution could result in a Supernova Ia (SN Ia) explosion and is designated the Single Degenerate Progenitor (SD) scenario. This paper is concerned with the SD scenario for SN Ia progenitors. One problem with the single degenerate scenario is that it is generally assumed that the accreting material mixes with WD core material at some time during the accretion phase of evolution and, since the typical WD has a carbon-oxygen CO core, the mixing results in large amounts of carbon and oxygen being brought up into the accreted layers. The presence of enriched carbon causes enhanced nuclear fusion and a Classical Nova explosion. Both observations and theoretical studies of these explosions imply that more mass is ejected than is accreted. Thus, the WD in a Classical Nova system is losing mass and cannot be a SN Ia progenitor. However, the composition in the nuclear burning region is important and, in new calculations reported here, the consequences to the WD of no mixing of accreted material with core material have been investigated so that the material involved in the explosion has only a Solar composition. WDs with a large range in initial masses and mass accretion rates have been evolved. I find that once sufficient material has been accreted, nuclear burning occurs in all evolutionary sequences and continues until a thermonuclear runaway (TNR) occurs and the WD either ejects a small amount of material or its radius grows to about 10{sup 12} cm and the evolution is ended. In all cases where mass ejection occurs, the mass of the ejecta is far less than the mass of the accreted material. Therefore, all the WDs are growing in mass. It is also found that the accretion time to explosion can be sufficiently short for a 1.0M{sub ?} WD that recurrent novae can occur on a low mass WD. This mass is lower than typically assumed for the WDs in recurrent nova systems. Finally, the predicted surface temperatures when the WD is near the peak of the explosion imply that only the most massive WDs will be significant X-ray emitters at this time.

Starrfield, Sumner, E-mail: starrfield@asu.edu [School of Earth and Space Exploration, Arizona State University, P. O. Box 871404, Tempe, AZ 85287-1404 (United States)] [School of Earth and Space Exploration, Arizona State University, P. O. Box 871404, Tempe, AZ 85287-1404 (United States)

2014-04-15T23:59:59.000Z

349

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

SciTech Connect (OSTI)

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

350

Neutrino oscillation constraints on neutrinoless double beta decay  

E-Print Network [OSTI]

We have studied the constraints imposed by the results of neutrino oscillation experiments on the effective Majorana mass || that characterizes the contribution of Majorana neutrino masses to the matrix element of neutrinoless double-beta decay. We have shown that in a general scheme with three Majorana neutrinos and a hierarchy of neutrino masses (which can be explained by the see-saw mechanism), the results of neutrino oscillation experiments imply rather strong constraints on the parameter ||. From the results of the first reactor long-baseline experiment CHOOZ and the Bugey experiment it follows that || | > 10^{-1} eV would be a signal for a non-hierarchical neutrino mass spectrum and/or non-standard mechanisms of lepton number violation.

S. M. Bilenky; C. Giunti; C. W. Kim; M. Monteno

1997-11-20T23:59:59.000Z

351

Neutrino Fluxes from NUHM LSP Annihilations in the Sun  

SciTech Connect (OSTI)

We extend our previous studies of the neutrino fluxes expected from neutralino LSP annihilations inside the Sun to include variants of the minimal supersymmetric extension of the Standard Model (MSSM) with squark, slepton and gaugino masses constrained to be universal at the GUT scale, but allowing one or two non-universal supersymmetry-breaking parameters contributing to the Higgs masses (NUHM1,2). As in the constrained MSSM (CMSSM) with universal Higgs masses, there are large regions of the NUHM parameter space where the LSP density inside the Sun is not in equilibrium, so that the annihilation rate may be far below the capture rate, and there are also large regions where the capture rate is not dominated by spin-dependent LSP-proton scattering. The spectra possible in the NUHM are qualitatively similar to those in the CMSSM. We calculate neutrino-induced muon fluxes above a threshold energy of 10 GeV, appropriate for the IceCube/DeepCore detector, for points where the NUHM yields the correct cosmological relic density for representative choices of the NUHM parameters. We find that the IceCube/DeepCore detector can probe regions of the NUHM parameter space in addition to analogues of the focus-point strip and the tip of the coannihilation strip familiar from the CMSSM. These include regions with enhanced Higgsino-gaugino mixing in the LSP composition, that occurs where neutralino mass eigenstates cross over. On the other hand, rapid-annihilation funnel regions in general yield neutrino fluxes that are unobservably small.

Ellis, John; /CERN /King's Coll. London; Olive, Keith A.; /Minnesota U. /SLAC; Savage, Christopher; /Stockholm U., OKC; Spanos, Vassilis C.; /Democritos Nucl. Res. Ctr.

2011-08-12T23:59:59.000Z

352

Short-baseline electron neutrino disappearance, tritium beta decay, and neutrinoless double-beta decay  

SciTech Connect (OSTI)

We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of 3+1 four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}. The combined fit gives {Delta}m{sup 2}(greater-or-similar sign)0.1 eV{sup 2} and 0.11(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.48 at 2{sigma}. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in {beta} decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of sin{sup 2}2{theta} below 0.10 at 2{sigma}. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives {Delta}m{sup 2}{approx_equal}2 eV and 0.01(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.13 at 2{sigma}. Assuming a hierarchy of masses m{sub 1}, m{sub 2}, m{sub 3}<neutrino masses in {beta} decay and neutrinoless double-{beta} decay are, respectively, between about 0.06 and 0.49 and between about 0.003 and 0.07 eV at 2{sigma}. We also consider the possibility of reconciling the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data with different mixings in the neutrino and antineutrino sectors. We find a 2.6{sigma} indication of a mixing angle asymmetry.

Giunti, Carlo; Laveder, Marco [INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Dipartimento di Fisica G. Galilei, Universita di Padova, and INFN, Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy)

2010-09-01T23:59:59.000Z

353

Electromagnetic properties of neutrinos  

E-Print Network [OSTI]

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

Carlo Giunti; Alexander Studenikin

2010-06-08T23:59:59.000Z

354

Status of three-neutrino oscillation parameters, circa 2013  

E-Print Network [OSTI]

The standard three-neutrino (3nu) oscillation framework is being increasingly refined by results coming from different sets of experiments, using neutrinos from solar, atmospheric, accelerator and reactor sources. At present, each of the known oscillation parameters [the two squared mass gaps (delta m^2, Delta m^2) and the three mixing angles (theta_12}, theta_13, theta_23)] is dominantly determined by a single class of experiments. Conversely, the unknown parameters [the mass hierarchy, the theta_23 octant and the CP-violating phase delta] can be currently constrained only through a combined analysis of various (eventually all) classes of experiments. In the light of recent new results coming from reactor and accelerator experiments, and of their interplay with solar and atmospheric data, we update the estimated N-sigma ranges of the known 3nu parameters, and revisit the status of the unknown ones. Concerning the hierarchy, no significant difference emerges between normal and inverted mass ordering. A slight overall preference is found for theta_23 in the first octant and for nonzero CP violation with sin delta < 0; however, for both parameters, such preference exceeds 1 sigma only for normal hierarchy. We also discuss the correlations and stability of the oscillation parameters within different combinations of data sets.

F. Capozzi; G. L. Fogli; E. Lisi; A. Marrone; D. Montanino; A. Palazzo

2014-05-05T23:59:59.000Z

355

A Toroidal Magnetised Iron Neutrino Detector (MIND) for a Neutrino Factory  

E-Print Network [OSTI]

A neutrino factory has unparalleled physics reach for the discovery and measurement of CP violation in the neutrino sector. A far detector for a neutrino factory must have good charge identification with excellent background rejection and a large mass. An elegant solution is to construct a magnetized iron neutrino detector (MIND) along the lines of MINOS, where iron plates provide a toroidal magnetic field and scintillator planes provide 3D space points. In this report, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of large $\\theta_{13}$. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent $\\delta_{CP}$ reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of $\\delta_{CP}$.

A. Bross; R. Wands; R. Bayes; A. Laing; F. J. P. Soler; A. Cervera Villanueva; T. Ghosh; J. J. Gómez Cadenas; P. Hernández; J. Martín-Albo; J. Burguet-Castell

2013-08-06T23:59:59.000Z

356

Earth Matter Effects in Detection of Supernova Neutrinos  

E-Print Network [OSTI]

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability P_H inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on the direction of the incoming supernova neutrinos, and reaches the biggest value when the incident angle of neutrinos is around 93^\\circ. In the reaction channel \\bar{\

X. -H. Guo; Bing-Lin Young

2006-05-11T23:59:59.000Z

357

Recent Results from Long-Baseline Neutrino Experiments  

E-Print Network [OSTI]

We are moving into an era of precision measurements of neutrino mixing, and it is increasingly necessary to use a 3-flavor framework to describe the results. This paper will focus on recent results from long-baseline neutrino experiments, especially accelerator-based beams. Using $\

Alysia D. Marino

2014-11-12T23:59:59.000Z

358

Neutrino Factory Downstream Systems  

E-Print Network [OSTI]

Neutrino Factory Downstream Systems Michael S. Zisman*Factory accelerator systems downstream from the target andthe Neutrino Factory systems downstream of the target and

Zisman, Michael S.

2010-01-01T23:59:59.000Z

359

On Symmetric Lepton Mixing Matrices  

E-Print Network [OSTI]

Contrary to the quark mixing matrix, the lepton mixing matrix could be symmetric. We study the phenomenological consequences of this possibility. In particular, we find that symmetry would imply that |U_{e3}| is larger than 0.16, i.e., above its current 2 sigma limit. The other mixing angles are also constrained and CP violating effects in neutrino oscillations are suppressed, even though |U_{e3}| is sizable. Maximal atmospheric mixing is only allowed if the other observables are outside their current 3 sigma ranges, and sin^2 theta_{23} lies typically below 0.5. The Majorana phases are not affected, but the implied values of the solar neutrino mixing angle have some effect on the predictions for neutrinoless double beta decay. We further discuss some formal properties of a symmetric mixing matrix.

Hochmuth, K A; Hochmuth, Kathrin A.; Rodejohann, Werner

2007-01-01T23:59:59.000Z

360

Is Cosmology Compatible with Sterile Neutrinos?  

SciTech Connect (OSTI)

By combining data from cosmic microwave background experiments (including the recent WMAP third year results), large scale structure, and Lyman-{alpha} forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless+1 massive neutrino case, we bound the mass of the sterile neutrino to m{sub s}<0.26 eV (0.44 eV) at 95% (99.9%) C.L., which excludes at high significance the sterile neutrino hypothesis as an explanation of the LSND anomaly. We generalize the analysis to account for active neutrino masses and the possibility that the sterile abundance is not thermal. In the latter case, the contraints in the (mass,density) plane are nontrivial. For a mass of >1 or <0.05 eV, the cosmological energy density in sterile neutrinos is always constrained to be {omega}{sub {nu}}<0.003 at 95% C.L., but for a mass of {approx}0.25 eV, {omega}{sub {nu}} can be as large as 0.01.

Dodelson, Scott; Melchiorri, Alessandro; Slosar, Anze [Particle Astrophysics Center, FERMILAB, Batavia, Illinois 60510-0500 (United States); Physics Department and Sezione INFN, University of Rome 'La Sapienza', Ple Aldo Moro 2, 00185 Rome (Italy); Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana (Slovenia)

2006-07-28T23:59:59.000Z

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

Symmetrical parametrizations of the lepton mixing matrix  

SciTech Connect (OSTI)

Advantages of the original symmetrical form of the parametrization of the lepton mixing matrix are discussed. It provides a conceptually more transparent description of neutrino oscillations and lepton number violating processes like neutrinoless double beta decay, clarifying the significance of Dirac and Majorana phases. It is also ideal for parametrizing scenarios with light sterile neutrinos.

Rodejohann, W. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, 69029 Heidelberg (Germany); Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

2011-10-01T23:59:59.000Z

362

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

2003-02-05T23:59:59.000Z

363

Phenomenology of Maximal and Near-Maximal Lepton Mixing  

E-Print Network [OSTI]

We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other ($x$=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter $\\epsilon\\equiv1-2\\sin^2\\theta_{ex}$ and quantify the present experimental status for $|\\epsilon|neutrinoless double beta decay.

M. C. Gonzalez-Garcia; C. Peña-Garay; Y. Nir; A. Yu. Smirnov

2000-09-18T23:59:59.000Z

364

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

365

Global neutrino parameter estimation using Markov Chain Monte Carlo  

E-Print Network [OSTI]

We present a Markov Chain Monte Carlo global analysis of neutrino parameters using both cosmological and experimental data. Results are presented for the combination of all presently available data from oscillation experiments, cosmology, and neutrinoless double beta decay. In addition we explicitly study the interplay between cosmological, tritium decay and neutrinoless double beta decay data in determining the neutrino mass parameters. We furthermore discuss how the inference of non-neutrino cosmological parameters can benefit from future neutrino mass experiments such as the KATRIN tritium decay experiment or neutrinoless double beta decay experiments.

Steen Hannestad

2007-10-10T23:59:59.000Z

366

Renormalization Group Evolution of Neutrino Parameters in Presence of Seesaw Threshold Effects and Majorana Phases  

E-Print Network [OSTI]

We examine the renormalization group evolution (RGE) for different mixing scenarios in the presence of seesaw threshold effects from high energy scale (GUT) to the low electroweak (EW) scale in the Standard Model (SM) and the Minimal Supersymmetric Standard Model (MSSM). We consider four mixing scenarios namely Tri-Bimaximal Mixing, Bimaximal Mixing, Hexagonal Mixing and Golden Ratio Mixing which come from different flavor symmetries at the GUT scale. All these mixing scenarios give vanishing reactor angle ($\\theta_{13}$) and maximal atmospheric mixing angle. The solar mixing angle has different value for all four cases. In the light of non zero value of $\\theta_{13}$ it becomes interesting to study the present status of these symmetries, i.e. whether they can generate the current neutrino oscillation data at low energy scale or not. We find that the Majorana phases play an important role in the RGE running of these mixing patterns along with the seesaw threshold corrections. We present a comparative study of the RGE of all these mixing scenarios both with and without Majorana CP phases when seesaw threshold corrections are taken into consideration. We find that in the absence of these Majorana phases both the RGE running and seesaw effects may lead to $\\theta_{13}energies both in the SM and the MSSM. However, if the Majorana phases are incorporated to the mixing matrix the running can be enhanced both in the SM and the MSSM. Even by incorporating non zero Majorana CP phases in the SM, we do not get $\\theta_{13}$ in its present 3$\\sigma$ range. The current values of the two mass squared differences and mixing angles including $\\theta_{13}$ can be produced in the MSSM case with tan$\\beta$ = 10 and non zero Majorana CP phases at low energy.

Shivani Gupta; Sin Kyu Kang; C. S. Kim

2014-06-29T23:59:59.000Z

367

Neutrino physics at accelerators  

E-Print Network [OSTI]

Present and future neutrino experiments at accelerators are mainly concerned with understanding the neutrino oscillation phenomenon and its implications. Here a brief account of neutrino oscillations is given together with a description of the supporting data. Some current and planned accelerator neutrino experiments are also explained.

Enrique Fernandez

2006-07-16T23:59:59.000Z

368

Muons and Neutrinos 2007  

E-Print Network [OSTI]

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

Thomas K. Gaisser

2008-01-29T23:59:59.000Z

369

Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor  

E-Print Network [OSTI]

Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions the neutrino floor can still be surpassed using timing information, though certain velocity streams may prove problematic.

Jonathan H. Davis

2014-12-03T23:59:59.000Z

370

Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor  

E-Print Network [OSTI]

Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions the neutrino floor can still be surpassed using timing information, though certain velocity streams may prove problematic.

Jonathan H. Davis

2015-03-09T23:59:59.000Z

371

Heavy neutrinos and the $pp\\to lljj$ CMS data  

E-Print Network [OSTI]

We show that the excess in the $pp \\to ee jj$ CMS data can be naturally interpreted within the Minimal Left Right Symmetric model (MLRSM), keeping $g_L = g_R$, if CP phases and non-degenerate masses of heavy neutrinos are taken into account. As an additional benefit, a natural interpretation of the reported ratio (14:1) of the opposite-sign (OS) $pp\\to l^\\pm l^\\mp jj$ to the same-sign (SS) $pp\\to l^\\pm l^\\pm jj$ lepton signals is possible. Finally, a suppression of muon pairs with respect to electron pairs in the $pp \\to lljj$ data is obtained, in accordance with experimental data. If the excess in the CMS data survives in the future, it would be a first clear hint towards presence of heavy neutrinos in right-handed charged currents with specific CP phases, mixing angles and masses, which will have far reaching consequences for particle physics directions.

Gluza, J

2015-01-01T23:59:59.000Z

372

Non-linear evolution of the cosmic neutrino background  

SciTech Connect (OSTI)

We investigate the non-linear evolution of the relic cosmic neutrino background by running large box-size, high resolution N-body simulations which incorporate cold dark matter (CDM) and neutrinos as independent particle species. Our set of simulations explore the properties of neutrinos in a reference ?CDM model with total neutrino masses between 0.05-0.60 eV in cold dark matter haloes of mass 10{sup 11}?10{sup 15} h{sup ?1}M{sub s}un, over a redshift range z = 0?2. We compute the halo mass function and show that it is reasonably well fitted by the Sheth-Tormen formula, once the neutrino contribution to the total matter is removed. More importantly, we focus on the CDM and neutrino properties of the density and peculiar velocity fields in the cosmological volume, inside and in the outskirts of virialized haloes. The dynamical state of the neutrino particles depends strongly on their momentum: whereas neutrinos in the low velocity tail behave similarly to CDM particles, neutrinos in the high velocity tail are not affected by the clustering of the underlying CDM component. We find that the neutrino (linear) unperturbed momentum distribution is modified and mass and redshift dependent deviations from the expected Fermi-Dirac distribution are in place both in the cosmological volume and inside haloes. The neutrino density profiles around virialized haloes have been carefully investigated and a simple fitting formula is provided. The neutrino profile, unlike the cold dark matter one, is found to be cored with core size and central density that depend on the neutrino mass, redshift and mass of the halo, for halos of masses larger than ? 10{sup 13.5}h{sup ?1}M{sub s}un. For lower masses the neutrino profile is best fitted by a simple power-law relation in the range probed by the simulations. The results we obtain are numerically converged in terms of neutrino profiles at the 10% level for scales above ? 200 h{sup ?1}kpc at z = 0, and are stable with respect to box-size and starting redshift of the simulation. Our findings are particularly important in view of upcoming large-scale structure surveys, like Euclid, that are expected to probe the non-linear regime at the percent level with lensing and clustering observations.

Villaescusa-Navarro, Francisco; Viel, Matteo [INAF/Osservatorio Astronomico di Trieste, Via Tiepolo 11, 34143, Trieste (Italy); Bird, Simeon [Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ, 08540 (United States); Peña-Garay, Carlos, E-mail: villaescusa@oats.inaf.it, E-mail: spb@ias.edu, E-mail: penya@ific.uv.es, E-mail: viel@oats.inaf.it [Instituto de Física Corpuscular, CSIC-UVEG, E-46071, Paterna, Valencia (Spain)

2013-03-01T23:59:59.000Z

373

Light Dark Matter Detection Prospects at Neutrino Experiments  

E-Print Network [OSTI]

We consider the prospects for the detection of relatively light dark matter through direct annihilation to neutrinos. We specifically focus on the detection possibilities of water Cherenkov and liquid scintillator neutrino detection devices. We find in particular that liquid scintillator detectors may potentially provide excellent detection prospects for dark matter in the 4-10 GeV mass range. These experiments can provide excellent corroborative checks of the DAMA/LIBRA annual modulation signal, but may yield results for low mass dark matter in any case. We identify important tests of the ratio of electron to muon neutrino events (and neutrino versus anti-neutrino events), which discriminate against background atmospheric neutrinos. In addition, the fraction of events which arise from muon neutrinos or anti-neutrinos ($R_{\\mu}$ and $R_{\\bar \\mu}$) can potentially yield information about the branching fractions of hypothetical dark matter annihilations into different neutrino flavors. These results apply to neutrinos from secondary and tertiary decays as well, but will suffer from decreased detectability.

Jason Kumar; John G. Learned; Stefanie Smith

2010-04-13T23:59:59.000Z

374

Photomultiplier Tubes: Calibration and Neutrino Physics  

SciTech Connect (OSTI)

Photomultiplier Tubes are devices designed to amplify very small light signals, on the order of single photons, to levels that are detectable by conventional electronics. Such a high level of amplification, however, comes with a quite a few potential problems, as the relationship between a light signal in and the current out- the response of the system- can be difficult to determine, meaning that photomultiplier tubes' use in scientific research requires a great deal of sensitive calibration. Once calibrated, the photomultiplier tube is a tool that can be used on a number of interesting problems, including the field of neutrino physics. This work deals with the use of photomultiplier tubes' use in the upcoming Double Chooz experiment to determine the mixing angle theta{sub 13}, between different neutrino mass eigenstates. Calibration of the tubes requires measurement of the charge characteristics, most notably, the gain, pedestal, and the dark rate of a tube. Moreover, for all modern tubes, there is an additional feature which can be used to calibrate the system, the single photo electron peak, which describes the response of the tube to a single photon. Some theories predict higher order effects, in addition to the single photoelectron peak, including things like incomplete multiplication of a single photon electron, features which are theoretically able to be determined by a detailed examination of the single photoelectron peak. This paper goes through the methods of calibrating a phototubes both with and without a single photoelectron peak, and is unable to determine conclusively whether or not partial multiplication is able to explain certain features of photomultiplier tubes with a single photoelectron peak.

Damon, Edward; Maricic, Jelena [Drexel University, Philadelphia, PA 19104 (United States)

2010-03-30T23:59:59.000Z

375

The Accretion of Solar Material onto White Dwarfs: No Mixing with Core Material Implies that the Mass of the White Dwarf is Increasing  

E-Print Network [OSTI]

Cataclysmic Variables (CVs) are close binary star systems with one component an accreting white dwarf (WD) and the other a larger cooler star that fills its Roche Lobe. One consequence of the WDs accreting material, is the possibility that they are growing in mass and will eventually reach the Chandrasekhar Limit. This evolution could result in a Supernova Ia (SN Ia) explosion and is designated the Single Degenerate Progenitor (SD) scenario. One problem with the single degenerate scenario is that it is generally assumed that the accreting material mixes with WD core material at some time during the accretion phase of evolution and, since the typical WD has a carbon-oxygen (CO) core, the mixing results in large amounts of carbon and oxygen being brought up into the accreted layers. The presence of enriched carbon causes enhanced nuclear fusion and a Classical Nova (CN)explosion. Thus, the WD in a Classical Nova system is decreasing in mass and cannot be a SN Ia progenitor. In new calculations reported here, th...

Starrfield, Sumner

2015-01-01T23:59:59.000Z

376

Report of the Solar and Atmospheric Neutrino Working Group  

SciTech Connect (OSTI)

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

377

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

E-Print Network [OSTI]

We study the physics potential of the detection of the Cosmic Neutrino Background via neutrino capture on tritium, taking the proposed PTOLEMY experiment as a case study. With the projected energy resolution of $\\Delta \\sim$ 0.15 eV, the experiment will be sensitive to neutrino masses with degenerate spectrum, $m_1 \\simeq m_2 \\simeq m_3 = m_\

Andrew J. Long; Cecilia Lunardini; Eray Sabancilar

2014-11-12T23:59:59.000Z

378

Search for heavy Majorana neutrinos in $\\mu^\\pm \\mu^\\pm$+jets events in proton-proton collisions at $\\sqrt{s}$ = 8 TeV  

E-Print Network [OSTI]

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

CMS Collaboration

2015-01-01T23:59:59.000Z

379

Precision reconstruction of the dark matter-neutrino relative velocity from N-body simulations  

E-Print Network [OSTI]

Discovering the mass of neutrinos is a principle goal in high energy physics and cosmology. In addition to cosmological measurements based on two-point statistics, the neutrino mass can also be estimated by observations of neutrino wakes resulting from the relative motion between dark matter and neutrinos. Such a detection relies on an accurate reconstruction of the dark matter-neutrino relative velocity which is affected by non-linear structure growth and galaxy bias. We investigate our ability to reconstruct this relative velocity using large N-body simulations where we evolve neutrinos as distinct particles alongside the dark matter. We find that the dark matter velocity power spectrum is overpredicted by linear theory whereas the neutrino velocity power spectrum is underpredicted. The magnitude of the relative velocity observed in the simulations is found to be lower than what is predicted in linear theory. Since neither the dark matter nor the neutrino velocity fields are directly observable from galaxy ...

Inman, Derek; Pen, Ue-Li; Farchi, Alban; Yu, Hao-Ran; Harnois-Deraps, Joachim

2015-01-01T23:59:59.000Z

380

PILOT_PROTEIN: Identification of Unmodified and Modified Proteins via High-Resolution Mass Spectrometry and Mixed-Integer Linear  

E-Print Network [OSTI]

accuracy with a lower false positive rate. All materials are freely available to the scientific community and protein identification and can help reduce the number of false positive resulPILOT_PROTEIN: Identification of Unmodified and Modified Proteins via High-Resolution Mass

Shorter, James

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.


381

The MSW effect and Matter Effects in Neutrino Oscillations  

E-Print Network [OSTI]

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

A. Yu. Smirnov

2004-12-27T23:59:59.000Z

382

Significant neutrinoless double beta decay with quasi-Dirac neutrinos  

E-Print Network [OSTI]

A significant signal of neutrinoless double beta decay can be consistent with the existence of light quasi-Dirac neutrinos. To demonstrate this possibility, we consider a realistic model where the neutrino masses and the neutrinoless double beta decay can be simultaneously generated after a Peccei-Quinn symmetry breaking.

Pei-Hong Gu

2012-09-13T23:59:59.000Z

383

Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs  

E-Print Network [OSTI]

We show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and cosmic microwave background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, and scenarios for light and heavy sterile neutrinos.

Grohs, E; Kishimoto, C T; Paris, M W

2015-01-01T23:59:59.000Z

384

Radiative emission of neutrino pair free of quantum electrodynamic backgrounds  

E-Print Network [OSTI]

A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties so far not accessible. The important point for the background rejection is the fact that the dispersion relation between wave vector along propagating direction in wave guide (and in a photonic-crystal type fiber) and frequency is modified by a discretized non-vanishing effective mass. This effective mass acts as a cutoff of allowed frequencies, and one may select the RENP photon energy region free of all macro-coherently amplified QED processes by choosing the cutoff larger than the mass of neutrinos.

M. Yoshimura; N. Sasao; M. Tanaka

2015-01-23T23:59:59.000Z

385

Radiative emission of neutrino pair free of quantum electrodynamic backgrounds  

E-Print Network [OSTI]

A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties so far not accessible. The important point for the background rejection is the fact that the dispersion relation between wave vector along propagating direction in wave guide (and in a photonic-crystal type fiber) and frequency is modified by a discretized non-vanishing effective mass. This effective mass acts as a cutoff of allowed frequencies, and one may select the RENP photon energy region free of all macro-coherently amplified QED processes by choosing the cutoff larger than the mass of neutrinos.

Yoshimura, M; Tanaka, M

2015-01-01T23:59:59.000Z

386

Optimizing Medium Baseline Reactor Neutrino Experiments  

E-Print Network [OSTI]

10 years from now medium baseline reactor neutrino experiments will attempt to determine the neutrino mass hierarchy from the observed antineutrino spectra. In this letter we present the results of more than four million detailed simulations of such experiments, studying the dependence of the probability of successfully determining the hierarchy upon the analysis method, the neutrino mass matrix parameters, reactor flux models and, in particular, combinations of baselines. We show that the strong dependence of the hierarchy determination upon mass differences and flux models found by Qian et al. results from a spurious dependence of the Fourier analysis upon the high energy tail of the reactor spectrum which can be removed by using a weighted Fourier transform. Such experiments necessarily use flux from multiple reactors at distinct baselines, smearing the oscillation signal and thus impeding the determination of the hierarchy. Using the results of our simulations, we determine the optimal baselines and corre...

Ciuffoli, Emilio; Zhang, Xinmin

2013-01-01T23:59:59.000Z

387

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

388

The effect of massive neutrinos on the SZ and X-ray observables of galaxy clusters  

E-Print Network [OSTI]

Massive neutrinos are expected to influence the formation of the large-scale structure of the Universe, depending on the value of their total mass, $\\Sigma m_\

Roncarelli, M; Moscardini, L

2014-01-01T23:59:59.000Z

389

Neutrino Astronomy Scott Wilbur  

E-Print Network [OSTI]

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

Golwala, Sunil

390

Vanishing Effective Mass of the Neutrinoless Double Beta Decay?  

E-Print Network [OSTI]

We stress that massive neutrinos may be Majorana particles even if the effective mass of the neutrinoless double beta decay m_ee vanishes. We show that current neutrino oscillation data do allow m_ee = 0 to hold, if the Majorana CP-violating phases lie in two specific regions. Strong constraints on three neutrino masses can then be obtained. We find that the neutrino mass spectrum performs a normal hierarchy: m_1 < m_2 < m_3. A possible texture of the neutrino mass matrix is also illustrated under the m_ee = 0 condition.

Zhi-zhong Xing

2003-07-18T23:59:59.000Z

391

Neutrino Oscillation Appearance Experiment using Nuclear Emulsion and Magnetized Iron  

E-Print Network [OSTI]

This report describes an apparatus that could be used to measure both the identity and charge of an outgoing lepton in a charged current neutrino interaction. This capability in a massive detector would allow the most comprehensive set of neutrino oscillation physics measurements. By measuring the six observable transitions between initial and final state neutrinos, one would be able to measure all elements of the neutrino mixing matrix, as well as search for CP violation, and matter effects. If the measured matrix is not unitary, then one would also have an unambiguous determination of sterile neutrinos. Emulsion is considered as the tracking medium, and different techniques are discussed for the application of a magnetic field.

D. A. Harris; A. Para

2000-01-13T23:59:59.000Z

392

E-Print Network 3.0 - absolute mass measurements Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

mass of neutrinos and determining their Majorana... -free measurement of neutrinoless double-beta decay (0) in 120 kg of 76 Ge with the goal of determining the neutrino... mass....

393

LSND neutrino oscillation results  

SciTech Connect (OSTI)

In the past several years, a number of experiments have searched for neutrino oscillations, where a neutrino of one type (say {bar {nu}}{sub {mu}}) spontaneously transforms into a neutrino of another type (say {bar {nu}}{sub e}). For this phenomenon to occur, neutrinos must be massive and the apparent conservation law of lepton families must be violated. In 1995 the LSND experiment published data showing candidate events that are consistent with {bar {nu}}{sub {mu}} oscillations. Additional data are reported here which provide stronger evidence for neutrino oscillations.

Louis, W.C.

1996-06-01T23:59:59.000Z

394

Impact of neutrino flavor oscillations on the neutrino-driven wind nucleosynthesis of an electron-capture supernova  

E-Print Network [OSTI]

Neutrino oscillations, especially to light sterile states, can affect the nucleosynthesis yields because of their possible feedback effect on the electron fraction (Ye). For the first time, we perform nucleosynthesis calculations for neutrino-driven wind trajectories from the neutrino-cooling phase of an 8.8 Msun electron-capture supernova, whose hydrodynamic evolution was computed in spherical symmetry with sophisticated neutrino transport and whose Ye evolution was post-processed by including neutrino oscillations both between active and active-sterile flavors. We also take into account the alpha-effect as well as weak magnetism and recoil corrections in the neutrino absorption and emission processes. We observe effects on the Ye evolution which depend in a subtle way on the relative radial positions of the sterile MSW resonances, of collective flavor transformations, and on the formation of alpha-particles. For the adopted supernova progenitor, we find that neutrino oscillations, also to a sterile state with eV-mass, do not significantly affect the element formation and in particular cannot make the post-explosion wind outflow neutron rich enough to activate a strong r-process. Our conclusions become even more robust when, in order to mimic equation-of-state dependent corrections due to nucleon potential effects in the dense-medium neutrino opacities, four cases with reduced Ye in the wind are considered. In these cases, despite the conversion of neutrinos to sterile neutrinos, Ye increases compared to the values obtained without oscillations and active flavor transformations. This is a consequence of a complicated interplay between sterile-neutrino production, neutrino-neutrino interactions, alpha-effect.

Else Pllumbi; Irene Tamborra; Shinya Wanajo; H. -Thomas Janka; Lorenz Huedepohl

2014-06-11T23:59:59.000Z

395

Collective neutrino oscillations in supernovae  

SciTech Connect (OSTI)

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

Duan, Huaiyu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)

2014-06-24T23:59:59.000Z

396

Neutrino halos in clusters of galaxies and their weak lensing signature  

SciTech Connect (OSTI)

We study whether non-linear gravitational effects of relic neutrinos on the development of clustering and large-scale structure may be observable by weak gravitational lensing. We compute the density profile of relic massive neutrinos in a spherical model of a cluster of galaxies, for several neutrino mass schemes and cluster masses. Relic neutrinos add a small perturbation to the mass profile, making it more extended in the outer parts. In principle, this non-linear neutrino perturbation is detectable in an all-sky weak lensing survey such as EUCLID by averaging the shear profile of a large fraction of the visible massive clusters in the universe, or from its signature in the general weak lensing power spectrum or its cross-spectrum with galaxies. However, correctly modeling the distribution of mass in baryons and cold dark matter and suppressing any systematic errors to the accuracy required for detecting this neutrino perturbation is severely challenging.

Villaescusa-Navarro, Francisco; Peña-Garay, Carlos [IFIC, Universidad de Valencia-CSIC, E-46071, Valencia (Spain); Miralda-Escudé, Jordi [Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys, 23, 08010-Barcelona (Spain); Quilis, Vicent, E-mail: villa@ific.uv.es, E-mail: miralda@icc.ub.es, E-mail: penya@ific.uv.es, E-mail: vicent.quilis@uv.es [Departamento de Astronomia y Astrofísica, Universidad de Valencia, C/ Dr. Moliner, 50, E-46100, Burjassot, Valencia (Spain)

2011-06-01T23:59:59.000Z

397

Constraints on the Mass and Mixing of the 4th Generation Quark From Direct CP Violation$?^{\\prime}/?$ and Rare K Decays  

E-Print Network [OSTI]

We investigate the $\\epsilon^{\\prime} /\\epsilon$ for $K\\to \\pi\\pi$ in a sequential fourth generation model. By giving the basic formulae for $\\epsilon^{\\prime}/\\epsilon$ in this model, we analyze the numerical results which are dependent of $m_{t^{\\prime}}$ and imaginary part of the fourth CKM factor, ${Im}V^{*}_{t^{'}s}V_{t^{'}d}$ (or $V^{*}_{t^{'}s}V_{t^{'}d}$ and the fourth generation CKM matrix phase $\\theta$). We find that, unlike the SM, when taking the central values of all parameters for $\\epsilon^{\\prime}/\\epsilon$, the values of $\\epsilon^{\\prime}/ \\epsilon$ can easily fit to the current experimental data for all values of hadronic matrix elements estimated from various approaches. Also, we show that the experimental values of $\\epsilon^{\\prime}/\\epsilon$ and rare K decays can provide a strong constraint on both mass and mixing of the fourth generation quark. When taking the values of hadronic matrix elements from the lattice or 1/N expansion calculations, a large region of the up-type quark mass $m_{t^{\\prime}}$ is excluded.

Chao-Shang Huang; Wu-Jun Huo; Yue-Liang Wu

2000-08-04T23:59:59.000Z

398

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

SciTech Connect (OSTI)

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

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

2014-05-02T23:59:59.000Z

399

Equivalent Neutrinos, Light WIMPs, and the Chimera of Dark Radiation  

E-Print Network [OSTI]

According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing that a measurement of Neff>3 can be consistent with DeltaNnu=0 (dark radiation without dark radiation). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (DeltaNnu>0). In particular, if there is a light WIMP that annihilates to photons after the SM neutrinos have decoupled, the photons are heated beyond their usual heating from e+- annihilation, reducing the late time ratio of neutrino and photon temperatures (and number densities), leading to Neff3 even in the absence of equivalent neutrinos or dark radiation. A measurement of Neff>3 is thus no guarantee of the presence of equivalent neutrinos or dark radiation. In the presence of light WIMPs and/or equivalent neutrinos there are degeneracies among the light WIMP mass and its nature (fermion or boson, as well as its couplings to neutrinos or photons), the number and nature (fermion or boson) of the equivalent neutrinos, and their decoupling temperature (the strength of their interactions with the SM particles). There's more to a measurement of Neff than meets the eye.

Gary Steigman

2013-03-18T23:59:59.000Z

400

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background  

E-Print Network [OSTI]

We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range, with couplings to ordinary active neutrinos large enough to guarantee thermal and chemical equilibrium at epochs in the early universe with temperatures T > 1 GeV, but in a range to give decay lifetimes from seconds to minutes. Such neutrinos would decouple early, with relic densities comparable to those of photons, but decay out of equilibrium, with consequent prodigious entropy generation prior to, or during, Big Bang Nucleosynthesis (BBN). Most of the ranges of sterile neutrino rest mass and lifetime considered are at odds with Cosmic Microwave Background (CMB) limits on the relativistic particle contribution to energy density (e.g., as parameterized by N_eff). However, some sterile neutrino parameters can lead to an acceptable N_eff. These parameter ranges are accompanie...

Fuller, George M; Kusenko, Alexander

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,
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

Dark Matter vs. Neutrinos: The effect of astrophysical uncertainties and timing information on the neutrino floor  

E-Print Network [OSTI]

Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments will run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder ...

Davis, Jonathan H

2014-01-01T23:59:59.000Z

402

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

403

Reducing cosmological small scale structure via a large dark matter-neutrino interaction: constraints and consequences  

E-Print Network [OSTI]

Cold dark matter explains a wide range of data on cosmological scales. However, there has been a steady accumulation of evidence for discrepancies between simulations and observations at scales smaller than galaxy clusters. Solutions to these small scale structure problems may indicate that simulations need to improve how they include feedback from baryonic matter, or may imply that dark matter properties differ from the standard cold, noninteracting scenario. One promising way to affect structure formation on small scales is a relatively strong coupling of dark matter to neutrinos. We construct an experimentally viable, simple, renormalizable, model with new interactions between neutrinos and dark matter. We show that addressing the small scale structure problems requires dark matter with a mass that is tens of MeV, and a present-day density determined by an initial particle-antiparticle asymmetry in the dark sector. Generating a sufficiently large dark matter-neutrino coupling requires a new heavy neutrino with a mass around 100 MeV. The heavy neutrino is mostly sterile but has a substantial $\\tau$ neutrino component, while the three nearly massless neutrinos are partly sterile. We provide the first discussion of how such dark matter-neutrino interactions affect neutrino (especially $\\tau$ neutrino) phenomenology. This model can be tested by future astrophysical, particle physics, and neutrino oscillation data. A feature in the neutrino energy spectrum and flavor content from a future nearby supernova would provide strong evidence of neutrino-dark matter interactions. Promising signatures include anomalous matter effects in neutrino oscillations due to nonstandard interactions and a component of the $\\tau$ neutrino with mass around 100 MeV.

Bridget Bertoni; Seyda Ipek; David McKeen; Ann E. Nelson

2014-12-09T23:59:59.000Z

404

MINOS Sterile Neutrino Search  

SciTech Connect (OSTI)

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

405

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

E-Print Network [OSTI]

Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of $CP$ asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this document, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis has been updated from the previous Letter of Intent [K. Abe et al., arXiv:1109.3262 [hep-ex

Hyper-Kamiokande Working Group; :; K. Abe; H. Aihara; C. Andreopoulos; I. Anghel; A. Ariga; T. Ariga; R. Asfandiyarov; M. Askins; J. J. Back; P. Ballett; M. Barbi; G. J. Barker; G. Barr; F. Bay; P. Beltrame; V. Berardi; M. Bergevin; S. Berkman; T. Berry; S. Bhadra; F. d. M. Blaszczyk; A. Blondel; S. Bolognesi; S. B. Boyd; A. Bravar; C. Bronner; F. S. Cafagna; G. Carminati; S. L. Cartwright; M. G. Catanesi; K. Choi; J. H. Choi; G. Collazuol; G. Cowan; L. Cremonesi; G. Davies; G. De Rosa; C. Densham; J. Detwiler; D. Dewhurst; F. Di Lodovico; S. Di Luise; O. Drapier; S. Emery; A. Ereditato; P. Fernandez; T. Feusels; A. Finch; M. Fitton; M. Friend; Y. Fujii; Y. Fukuda; D. Fukuda; V. Galymov; K. Ganezer; M. Gonin; P. Gumplinger; D. R. Hadley; L. Haegel; A. Haesler; Y. Haga; B. Hartfiel; M. Hartz; Y. Hayato; M. Hierholzer; J. Hill; A. Himmel; S. Hirota; S. Horiuchi; K. Huang; A. K. Ichikawa; T. Iijima; M. Ikeda; J. Imber; K. Inoue; J. Insler; R. A. Intonti; T. Irvine; T. Ishida; H. Ishino; M. Ishitsuka; Y. Itow; A. Izmaylov; B. Jamieson; H. I. Jang; M. Jiang; K. K. Joo; C. K. Jung; A. Kaboth; T. Kajita; J. Kameda; Y. Karadhzov; T. Katori; E. Kearns; M. Khabibullin; A. Khotjantsev; J. Y. Kim; S. B. Kim; Y. Kishimoto; T. Kobayashi; M. Koga; A. Konaka; L. L. Kormos; A. Korzenev; Y. Koshio; W. R. Kropp; Y. Kudenko; T. Kutter; M. Kuze; L. Labarga; J. Lagoda; M. Laveder; M. Lawe; J. G. Learned; I. T. Lim; T. Lindner; A. Longhin; L. Ludovici; W. Ma; L. Magaletti; K. Mahn; M. Malek; C. Mariani; L. Marti; J. F. Martin; C. Martin; P. P. J. Martins; E. Mazzucato; N. McCauley; K. S. McFarland; C. McGrew; M. Mezzetto; H. Minakata; A. Minamino; S. Mine; O. Mineev; M. Miura; J. Monroe; T. Mori; S. Moriyama; T. Mueller; F. Muheim; M. Nakahata; K. Nakamura; T. Nakaya; S. Nakayama; M. Needham; T. Nicholls; M. Nirkko; Y. Nishimura; E. Noah; J. Nowak; H. Nunokawa; H. M. O'Keeffe; Y. Okajima; K. Okumura; S. M. Oser; E. O'Sullivan; R. A. Owen; Y. Oyama; J. Perez; M. Y. Pac; V. Palladino; J. L. Palomino; V. Paolone; D. Payne; O. Perevozchikov; J. D. Perkin; C. Pistillo; S. Playfer; M. Posiadala-Zezula; J. -M. Poutissou; B. Quilain; M. Quinto; E. Radicioni; P. N. Ratoff; M. Ravonel; M. Rayner; A. Redij; F. Retiere; C. Riccio; E. Richard; E. Rondio; H. J. Rose; M. Ross-Lonergan; C. Rott; S. D. Rountree; A. Rubbia; R. Sacco; M. Sakuda; M. C. Sanchez; E. Scantamburlo; K. Scholberg; M. Scott; Y. Seiya; T. Sekiguchi; H. Sekiya; A. Shaikhiev; I. Shimizu; M. Shiozawa; S. Short; G. Sinnis; M. B. Smy; J. Sobczyk; H. W. Sobel; T. Stewart; J. L. Stone; Y. Suda; Y. Suzuki; A. T. Suzuki; R. Svoboda; R. Tacik; A. Takeda; A. Taketa; Y. Takeuchi; H. A. Tanaka; H. K. M. Tanaka; H. Tanaka; R. Terri; L. F. Thompson; M. Thorpe; S. Tobayama; N. Tolich; T. Tomura; C. Touramanis; T. Tsukamoto; M. Tzanov; Y. Uchida; M. R. Vagins; G. Vasseur; R. B. Vogelaar; C. W. Walter; D. Wark; M. O. Wascko; A. Weber; R. Wendell; R. J. Wilkes; M. J. Wilking; J. R. Wilson; T. Xin; K. Yamamoto; C. Yanagisawa; T. Yano; S. Yen; N. Yershov; M. Yokoyama; M. Zito

2015-01-18T23:59:59.000Z

406

Analytical Theory of Neutrino Oscillations in Matter with CP violation  

E-Print Network [OSTI]

We develop an exact analytical formulation of neutrino oscillations in matter within the framework of the Standard Neutrino Model assuming 3 Dirac Neutrinos. Our Hamiltonian formulation, which includes CP violation, leads to expressions for the partial oscillation probabilities that are linear combinations of spherical Bessel functions in the eigenvalue differences. The coefficients of these Bessel functions are polynomials in the neutrino CKM matrix elements, the neutrino mass differences squared, the strength of the neutrino interaction with matter, and the neutrino mass eigenvalues in matter. We give exact closed-form expressions for all partial oscillation probabilities in terms of these basic quantities. Adopting the Standard Neutrino Model, we then examine how the exact expressions for the partial oscillation probabilities might simplify by expanding in one of the small parameters {\\alpha} and sin{\\theta}13 of this model. We show explicitly that for small {\\alpha} and sin{\\theta}13 there are branch points in the analytic structure of the eigenvalues that lead to singular behavior of expansions near the solar and atmospheric resonances. We present numerical calculations that indicate how to use the small-parameter expansions in practice.

Mikkel B. Johnson; Ernest M. Henley; Leonard S. Kisslinger

2015-01-16T23:59:59.000Z

407

NOvA: Exploring Neutrino Mysteries  

ScienceCinema (OSTI)

Neutrinos are a mystery to physicists. They exist in three different flavors and mass states and may be able to give hints about the origins of the matter-dominated universe. A new long-baseline experiment led by Fermilab called NOvA may provide some answers.

Vahle, Tricia; Messier, Mark

2014-08-12T23:59:59.000Z

408

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

2004-03-22T23:59:59.000Z

409

Particle mixing as possible explanation of the dark energy conundrum  

E-Print Network [OSTI]

The vacuum condensate due to neutrino and quark mixing behaves as a perfect fluid and, at the present epoch, as a cosmological constant. The very small breaking of the Lorentz invariance constrains today the value of the dark energy.

Antonio Capolupo; Giuseppe Vitiello

2009-01-28T23:59:59.000Z

410

Measurement of the top quark mass at CDF using the "neutrino phi weighting" template method on a lepton plus isolated track sample  

E-Print Network [OSTI]

We present a measurement of the top quark mass with tt? dilepton events produced in pp? collisions at the Fermilab Tevatron (?s=1.96??TeV) and collected by the CDF II detector. A sample of 328 events with a charged ...

Choudalakis, Georgios

411

The MSW conversion of solar neutrinos and random matter density perturbations  

E-Print Network [OSTI]

We present a generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile. The study is focused on the effect of such matter perturbations upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active $\

H. Nunokawa; A. Rossi; V. B. Semikoz; J. W. F. Valle

1996-10-29T23:59:59.000Z

412

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

413

Physics of Massive Neutrinos  

E-Print Network [OSTI]

I summarize the present status of global analyses of neutrino oscillations, including the most recent KamLAND and K2K data, as well as the latest solar and atmospheric neutrino fluxes. I give the allowed ranges of the three--flavour oscillation parameters from the current worlds' global neutrino data sample, their best fit values and discuss the small parameters DeltaM_solar/DeltaM_atm and sin^2 theta_13, which characterize the strength of CP violation in neutrino oscillations. I briefly discuss neutrinoless double beta decay and the LSND neutrino oscillation hint, as well as the robustness of the neutrino oscillation results in the presence of non-standard physics.

J. W. F. Valle

2004-10-07T23:59:59.000Z

414

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

415

Neutrinos: Nature's Ghosts?  

ScienceCinema (OSTI)

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

Lincoln, Don

2014-08-12T23:59:59.000Z

416

Neutrino Oscillation Physics  

E-Print Network [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.

Boris Kayser

2013-12-25T23:59:59.000Z

417

Composite Dirac Neutrinos  

E-Print Network [OSTI]

We present a mechanism that naturally produces light Dirac neutrinos. The basic idea is that the right-handed neutrinos are composite. Any realistic composite model must involve `hidden flavor' chiral symmetries. In general some of these symmetries may survive confinement, and in particular, one of them manifests itself at low energy as an exact $B-L$ symmetry. Dirac neutrinos are therefore produced. The neutrinos are naturally light due to compositeness. In general, sterile states are present in the model, some of them can naturally be warm dark matter candidates.

Yuval Grossman; Dean J Robinson

2011-01-25T23:59:59.000Z

418

Atmospheric Neutrino Fluxes  

E-Print Network [OSTI]

Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

Thomas K. Gaisser

2005-02-18T23:59:59.000Z

419

Probing the Majorana nature of the neutrino with neutrinoless double beta decay  

E-Print Network [OSTI]

Neutrinoless double beta decay (NDBD) is the only experiment that could probe the Majorana nature of the neutrino. Here we study the theoretical implications of NDBD for models yielding tri-bimaximal lepton mixing like A4 and S4.

S. Morisi

2009-10-14T23:59:59.000Z

420

Neutrinos from Stellar Collapse: Comparison of signatures in water and heavy water detectors  

E-Print Network [OSTI]

Signatures of neutrino and antineutrino signals from stellar collapse in heavy water detectors are contrasted with those in water detectors. The effects of mixing, especially due to the highly dense matter in the supernova core, are studied. The mixing parameters used are those sets allowed by current understanding of available neutrino data: from solar, atmospheric and laboratory neutrino experiments. Signals at a heavy water detector, especially the dominant charged current reactions on deuteron, are very sensitive to some of these sets of allowed mixing parameters. Theoretical uncertainties on supernova neutrino spectra notwithstanding, a combination of supernova measurements with water and heavy water detectors may be able to distinguish many of these mixing possibilities and thus help in ruling out many of them.

Gautam Dutta; D. Indumathi; M. V. N. Murthy; G. Rajasekaran

2001-06-29T23:59:59.000Z

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.


421

Measurement of Muon Neutrino Quasi-Elastic Scattering on Carbon  

E-Print Network [OSTI]

The observation of neutrino oscillations is clear evidence for physics beyond the standard model. To make precise measurements of this phenomenon, neutrino oscillation experiments, including MiniBooNE, require an accurate description of neutrino charged current quasi-elastic (CCQE) cross sections 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_A^eff = 1.23+/-0.20 GeV, that describes the four-momentum dependence of the axial-vector form factor of the nucleon; and a Pauli-suppression parameter, kappa = 1.019+/-0.011. Such a modified Fermi gas model may also be used by future accelerator-based experiments measuring neutrino oscillations on nuclear targets.

MiniBooNE collaboration

2007-06-07T23:59:59.000Z

422

Measurement of the Top Quark Mass using Dilepton Events and a Neutrino Weighting Algorithm with the D0 Experiment at the Tevatron (Run II)  

SciTech Connect (OSTI)

Elementary particle physics raises questions that are several thousand years old. What are the fundamental components of matter and how do they interact? These questions are linked to the question of what happened in the very first moments after the creation of the universe. Modern physics systematically tests nature to find answers to these and other fundamental questions. Precise theories are developed that describe various phenomena and at the same time are reduced to a few basic principals of nature. Simplification and reduction have always been guiding concepts of physics. The interplay between experimental data and theoretical descriptions led to the Standard Model of elementary particle physics. It summarizes the laws of nature and is one of most precise descriptions of nature achieved by mankind. Despite the great success of the Standard Model it is not the ultimate theory of everything. Models beyond the Standard Model try to unify all interactions in one grand unified theory. The number of free parameters is attempted to be reduced. Gravity is attempted to be incorporated. Extensions to the Standard Model like supersymmetry address the so-called hierarchy problem. Precision measurements are the key for searches of new particles and new physics. A powerful tool of experimental particle physics are particle accelerators. They provide tests of the Standard Model at smallest scales. New particles are produced and their properties are investigated. In 1995 the heaviest known elementary particle, called top quark, has been discovered at Fermilab. It differs from all other lighter quarks due to the high mass and very short lifetime. This makes the top quark special and an interesting object to be studied. A rich program of top physics at Fermilab investigates whether the top quark is really the particle as described by the Standard Model. The top quark mass is a free parameter of the theory that has been measured precisely. This thesis presents a precise measurement of the top quark mass by the D0 experiment at Fermilab in the dilepton final states. The comparison of the measured top quark masses in different final states allows an important consistency check of the Standard Model. Inconsistent results would be a clear hint of a misinterpretation of the analyzed data set. With the exception of the Higgs boson, all particles predicted by the Standard Model have been found. The search for the Higgs boson is one of the main focuses in high energy physics. The theory section will discuss the close relationship between the physics of the Higgs boson and the top quark.

Meyer, Joerg; /Bonn U.

2007-01-01T23:59:59.000Z

423

Solar Neutrino Experiments Neutrinos are ghostlike particles that  

E-Print Network [OSTI]

experiments by sci- entists around the world, all working to con- firm the solar neutrino deficit. First came#12;Solar Neutrino Experiments Neutrinos are ghostlike particles that were postulated by Wolfgang to Davis's major triumph, which came in the early 1970s, when he successfully de- tected solar neutrinos

424

Diffractive-Like (or Parametric-Resonance-Like?) Enhancement of the Earth (Day-Night) Effect for Solar Neutrinos Crossing the Earth Core  

E-Print Network [OSTI]

It is shown that the strong enhancement of the Earth (day-night) effect for solar neutrinos crossing the Earth core in the case of the small mixing angle MSW electron neutrino to muon (tau) neutrino transition solution of the solar neutrino problem is due to a new resonance effect in the solar neutrino transitions in the Earth and not just to the MSW effect in the core. The effect is in many respects similar to the electron paramagnetic resonance. The conditions for existence of this new resonance effect are discussed. They include specific constraints on the neutrino oscillation lengths in the Earth mantle and in the Earth core, thus the resonance is a ``neutrino oscillation length resonance''. The effect exhibits strong dependence on the neutrino energy. Analytic expression for the probability accounting for the solar neutrino transitions in the Earth, which provides a high precision description of the transitions, including the new resonance effect, is derived. The implications of our results for the searches of the day-night asymmetry in the solar neutrino experiments are briefly discussed. The new resonance effect is operative also in the muon neutrino to electron neutrino (electron neutrino to muon neutrino) transitions of atmospheric neutrinos crossing the Earth core.

S. T. Petcov

2005-04-18T23:59:59.000Z

425

New Sensitivity to Solar WIMP Annihilation using Low-Energy Neutrinos  

E-Print Network [OSTI]

Dark matter particles captured by the Sun through scattering may annihilate and produce neutrinos, which escape. Current searches are for the few high-energy neutrinos produced in the prompt decays of some final states. We show that interactions in the solar medium lead to a large number of pions for nearly all final states. Positive pions and muons decay at rest, producing low-energy neutrinos with known spectra, including nuebar through neutrino mixing. We demonstrate that Super-Kamiokande can thereby provide a new probe of the spin-dependent WIMP-proton cross section. Compared to other methods, the sensitivity is competitive and the uncertainties are complementary.

Carsten Rott; Jennifer Siegal-Gaskins; John F. Beacom

2013-09-05T23:59:59.000Z

426

Common Origin of 3.55 keV X-Ray Line and Galactic Center Gamma Ray Excess in a Radiative Neutrino Mass Model  

E-Print Network [OSTI]

We attempt to simultaneously explain the recently observed 3.55 keV X-ray line in the analysis of XMM-Newton telescope data and the galactic center gamma ray excess observed by the Fermi gamma ray space telescope within an abelian gauge extension of standard model. We consider a two component dark matter scenario with a mass difference 3.55 keV such that the heavier one can decay into the lighter one and a photon with energy 3.55 keV. The lighter dark matter candidate is protected from decaying into the standard model particles by a remnant $Z_2$ symmetry into which the abelian gauge symmetry gets spontaneously broken. If the mass of the dark matter particle is chosen to be within $31-40$ GeV, then this model can also explain the galactic center gamma ray excess if the dark matter annihilation into $b\\bar{b}$ pairs has a cross section of $\\langle \\sigma v \\rangle \\simeq (1.4-2.0) \\times 10^{-26} \\; \\text{cm}^3/\\text{s}$. We constrain the model from the requirement of producing correct dark matter relic densit...

Borah, Debasish; Adhikari, Rathin

2015-01-01T23:59:59.000Z

427

The quest for neutrinoless double beta decay: Pseudo-Dirac, Majorana and sterile neutrinos  

E-Print Network [OSTI]

In this paper we analyze the neutrinoless double beta decay predictions in some scenarios with admixture of pseudo-Dirac and Majorana neutrinos in the 3 and 3+1 neutrino frameworks. We found that some of the cases can be falsifiable in near-term and future generations of neutrinoless double beta decay experiments even for the normal neutrino mass hierarchy. In the 3+1 framework we consider the sterile neutrino with a mass of the order of 1 eV. The complementarity between cosmological constraints and the future sensitivity for the next generations of the neutrinoless double beta decay searches is exploited.

A. Meroni; E. Peinado

2014-11-09T23:59:59.000Z

428

The quest for neutrinoless double beta decay: Pseudo-Dirac, Majorana and sterile neutrinos  

E-Print Network [OSTI]

In this paper we analyze the neutrinoless double beta decay predictions in some scenarios with admixture of pseudo-Dirac and Majorana neutrinos in the 3 and 3+1 neutrino frameworks. We found that some of the cases can be falsifiable in near-term and future generations of neutrinoless double beta decay experiments even for the normal neutrino mass hierarchy. In the 3+1 framework we consider the sterile neutrino with a mass of the order of 1 eV. The complementarity between cosmological constraints and the future sensitivity for the next generations of the neutrinoless double beta decay searches is exploited.

Meroni, A

2014-01-01T23:59:59.000Z

429

The Sudbury Neutrino Observatory  

SciTech Connect (OSTI)

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

Hime, A.

1996-09-01T23:59:59.000Z

430

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 $S$-matrix elements can be arbitrarily large even when the elastic scattering $S$-matrix elements vanish. 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 inside the potential 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

2014-05-28T23:59:59.000Z

431

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

2003-11-24T23:59:59.000Z

432

7Be Solar Neutrino Measurement with KamLAND  

E-Print Network [OSTI]

We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kton-day exposure of KamLAND. The observed rate is 582 +/- 90 (kton-day)^-1, which corresponds to a 862 keV 7Be solar neutrino flux of (3.26 +/- 0.50) x 10^9 cm^-2s^-1, assuming a pure electron flavor flux. Comparing this flux with the standard solar model prediction and further assuming three flavor mixing, a nu_e survival probability of 0.66 +/- 0.14 is determined from the KamLAND data. Utilizing a global three flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82 +/- 0.98) x 10^9 cm^-2s^-1, which is consistent with the standard solar model predictions.

A. Gando; Y. Gando; H. Hanakago; H. Ikeda; K. Inoue; K. Ishidoshiro; H. Ishikawa; Y. Kishimoto; M. Koga; R. Matsuda; S. Matsuda; T. Mitsui; D. Motoki; K. Nakajima; K. Nakamura; A. Obata; A. Oki; Y. Oki; M. Otani; I. Shimizu; J. Shirai; A. Suzuki; K. Tamae; K. Ueshima; H. Watanabe; B. D. Xu; S. Yamada; Y. Yamauchi; H. Yoshida; A. Kozlov; Y. Takemoto; S. Yoshida; C. Grant; G. Keefer; D. W. McKee; A. Piepke; T. I. Banks; T. Bloxham; S. J. Freedman; B. K. Fujikawa; K. Han; L. Hsu; K. Ichimura; H. Murayama; T. O'Donnell; H. M. Steiner; L. A. Winslow; D. Dwyer; C. Mauger; R. D. McKeown; C. Zhang; B. E. Berger; C. E. Lane; J. Maricic; T. Miletic; J. G. Learned; M. Sakai; G. A. Horton-Smith; A. Tang; K. E. Downum; K. Tolich; Y. Efremenko; Y. Kamyshkov; O. Perevozchikov; H. J. Karwowski; D. M. Markoff; W. Tornow; J. A. Detwiler; S. Enomoto; K. Heeger; M. P. Decowski

2014-05-23T23:59:59.000Z

433

Right-handed Neutrinos as Superheavy Dark Matter  

E-Print Network [OSTI]

We propose that right-handed neutrinos are very long-lived dark matter. The long lifetime is realized by the separation of the wavefunction of right-handed neutrinos and that of other fermions in an extra dimension. Such long-lived and superheavy dark matter can naturally explain observed ultra high energy cosmic rays above the GZK cutoff (5 * 10^{19} eV) and huge amounts of cold dark matter simultaneously. Furthermore, the exponentially suppressed Yukawa couplings of right-handed neutrinos leads to the high predictablilty on the mass parameter of the neutrinoless double beta decay, as all the models which predict very small neutrino mass of one generation.

Yosuke Uehara

2002-01-04T23:59:59.000Z

434

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

2013-05-07T23:59:59.000Z

435

High energy cosmic rays, gamma rays and neutrinos from AGN  

E-Print Network [OSTI]

The author reviews a model for the emission of high energy cosmic rays, gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed since 1985. Further discussion of the knee energy phenomenon of the cosmic ray energy spectrum requires the existence of a heavy particle with mass in the knee energy range. A possible method of detecting such a particle in the Pierre Auger Project is suggested. Also presented is a relation between the spectra of neutrinos and gamma-rays emitted from AGN. This relation can be tested by high energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and possibly by the Pierre Auger Project.

Yukio Tomozawa

2008-02-03T23:59:59.000Z

436

Is the solar neutrino deficit energy-dependent?  

E-Print Network [OSTI]

All existing measurements of the solar neutrino flux are compared with the predictions of the most recent solar model by Bahcall and Pinsonneault, modified by introducing the hypothesis of neutrino oscillations with mass differences large enough to render energy-independent any quantity observable on earth. It is concluded that the data are consistent with this hypothesis and that, at least for the time being, any energy-dependence of the solar neutrino deficit must be regarded as just an attractive theoretical possibility, but not as a compelling reality.

G. Conforto; A. Marchionni; F. Martelli; F. Vetrano

1997-08-11T23:59:59.000Z

437

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

SciTech Connect (OSTI)

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

438

Neutrino and anti-neutrino energy loss rates due to iron isotopes suitable for core-collapse simulations  

E-Print Network [OSTI]

Accurate estimate of neutrino energy loss rates are needed for the study of the late stages of the stellar evolution, in particular for cooling of neutron stars and white dwarfs. The energy spectra of neutrinos and antineutrinos arriving at the Earth can also provide useful information on the primary neutrino fluxes as well as neutrino mixing scenario (it is to be noted that these supernova neutrinos are emitted after the supernova explosion which is a much later stage of stellar evolution than that considered in this paper). Recently an improved microscopic calculation of weak-interaction mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory. Here I present for the first time the fine-grid calculation of the neutrino and anti-neutrino energy loss rates due to $^{54,55,56}$Fe in stellar matter. In the core of massive stars isotopes of iron, $^{54,55,56}$Fe, are considered to be key players in decreasing the electron-to-baryon ratio ($Y_{e}$) mainly via electron capture on these nuclide. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes. The calculated cooling rates are also compared with previous calculations.

Jameel-Un Nabi

2014-08-19T23:59:59.000Z

439

Hybrid MSW + VO Solution of the Solar Neutrino Problem in String-Motivated Unified Theories  

E-Print Network [OSTI]

It is shown that the hybrid MSW + VO solution of the solar neutrino problem, according to which the solar nu_e undergo matter-enhanced transitions into nu_mu, nu_tau in the Sun followed by long wave length (about 1.5 10^8 km) nu_e -> nu_mu, nu_tau oscillations in vacuum between the Sun and the Earth, can occur naturally in string-motivated grand unified theories. We consider the supersymmetric version of a string-type SU(4)xSU(2)_LxSU(2)_R theory with U(1)_X family symmetry, which was shown to successfully describe the charged fermion masses and the quark mixing, and extend the earlier fermion mass analysis to the neutrino sector. We show that the four oscillation parameters Delta m_31^2, Delta m_21^2 and sin^2 2 theta_12, sin^2 2 theta_13, characterising the combined matter-enhanced transitions and vacuum oscillations of the solar nu_e, naturally get values in the ranges of the hybrid MSW + VO solutions found recently.

B. C. Allanach; G. K. Leontaris; S. T. Petcov

1997-12-19T23:59:59.000Z

440

Relic keV sterile neutrinos and reionization  

E-Print Network [OSTI]

A sterile neutrino with mass of several keV can account for cosmological dark matter, as well as explain the observed velocities of pulsars. We show that X-rays produced by the decays of these relic sterile neutrinos can boost the production of molecular hydrogen, which can speed up the cooling of gas and the early star formation, which can, in turn, lead to a reionization of the universe at a high enough redshift to be consistent with the WMAP results.

Peter L. Biermann; Alexander Kusenko

2005-12-31T23:59:59.000Z

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441

Cosmology with self-interacting sterile neutrinos and dark matter - A pseudoscalar model  

E-Print Network [OSTI]

Short baseline neutrino oscillation experiments have shown hints of the existence of additional sterile neutrinos in the eV mass range. Such sterile neutrinos are incompatible with cosmology because they suppress structure formation unless they can be prevented from thermalising in the early Universe. Here we present a novel scenario in which both sterile neutrinos and dark matter are coupled to a new, light pseudoscalar. This can prevent thermalisation of sterile neutrinos and make dark matter sufficiently self-interacting to have an impact on galactic dynamics and possibly resolve some of the known problems with the standard cold dark matter scenario. Our model singles out a dimensionless coupling strength for both sterile neutrinos and dark matter in the range $g_s \\sim g_d \\sim 10^{-5}$ and predicts a dark matter particle mass in the MeV range.

Maria Archidiacono; Steen Hannestad; Rasmus Sloth Hansen; Thomas Tram

2014-04-23T23:59:59.000Z

442

MSW effect for large mixing angles  

E-Print Network [OSTI]

The traditional physical description of neutrino flavor conversion in the Sun focuses on the notion of resonance. However, the resonance picture is valid only in the limit of small mixing angles theta. For large values of theta, the resonance picture leads to seemingly paradoxical results. This observation is important for understanding the physics of neutrino flavor conversion in the Sun, since the latest solar neutrino data seems to prefer large mixing angles. Here we review the basic arguments and in particular show that the resonance does not in general coincide with either the point of maximal violation of adiabaticity in the nonadiabatic case or the point of maximal flavor conversion in the adiabatic case. We also discuss a modified adiabaticity criterion.

Alexander Friedland

2001-06-04T23:59:59.000Z

443

Search for Lepton Number Violating Charged Current Processes with Neutrino Beams  

E-Print Network [OSTI]

We propose a new idea to test a class of loop-induced neutrino mass mechanisms by searching for lepton number violating charged current processes with incident of a neutrino beam. The expected rates of these processes are estimated based on some theoretical assumptions. They turn out to be sizable so that detection of such processes could be possible at near detectors in future highly intense neutrino-beam facilities.

Shinya Kanemura; Yoshitaka Kuno; Toshihiko Ota

2012-05-25T23:59:59.000Z

444

Improved limits on sterile neutrino dark matter from full-sky observations by the Fermi-GBM  

E-Print Network [OSTI]

For the first time, we use the Gamma-ray Burst Monitor (GBM) on-board the Fermi satellite to search for sterile neutrino decay lines in the energy range 10-25 keV corresponding to sterile neutrino mass range 20-50 keV. This energy range has been out of reach of traditional X-ray satellites such as Chandra, Suzaku, XMM-Newton, and gamma-ray satellites such as INTEGRAL. Furthermore, the extremely wide field of view of the GBM opens a large fraction of the Milky Way dark matter halo to be probed. We start with 1601 days worth of GBM data, implement stringent data cuts, and perform two simple line search analyses on the reduced data: in the first, the line flux is limited without background modeling, and in the second, the background is modeled as a power-law. We find no significant excess lines in both our searches. We set new limits on sterile neutrino mixing angles, improving on previous limits by approximately an order of magnitude. Better understanding of detector and astrophysical backgrounds, as well as de...

Horiuchi, Shunsaku; Gaskins, Jennifer M; Smith, Miles; Preece, Robert

2015-01-01T23:59:59.000Z

445

Cyclotrons as Drivers for Precision Neutrino Measurements  

E-Print Network [OSTI]

As we enter the age of precision measurement in neutrino physics, improved flux sources are required. These must have a well-defined flavor content with energies in ranges where backgrounds are low and cross section knowledge is high. Very few sources of neutrinos can meet these requirements. However, pion/muon and isotope decay-at-rest sources qualify. The ideal drivers for decay-at-rest sources are cyclotron accelerators, which are compact and relatively inexpensive. This paper describes a scheme to produce decay-at-rest sources d