Note: This page contains sample records for the topic majorana neutrinos neutrino from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

The search for Majorana neutrinos  

NASA Astrophysics Data System (ADS)

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

Atre, Anupama

2

Can neutrino-electron scattering tell us whether neutrinos are Dirac or Majorana particles  

SciTech Connect

There has recently been interest in the possibility that neutrino-electron scattering experiments could determine whether neutrinos are Dirac or Majorana particles by providing information on their electromagnetic structure. We try to explain why studies of neutrino electromagnetic structure actually cannot distinguish between Dirac and Majorana neutrinos. 9 refs.

Kayser, B.

1988-04-01

3

Physical range of majorana neutrino mixing parameters  

Microsoft Academic Search

If neutrinos are Majorana fermions, the lepton mixing parameter space consists of six mixing parameters: three mixing angles and three CP-odd phases. A related issue concerns the physical range of the mixing parameters. What values should these take so that all physically distinguishable mixing scenarios are realized? We present a detailed discussion of the lepton mixing parameter space in the

André de Gouvêa; James Jenkins

2008-01-01

4

Higher dimensional models of light Majorana neutrinos confronted by data  

SciTech Connect

We discuss experimental and observational constraints on certain models of higher dimensional light Majorana neutrinos. Models with flavor blind brane-bulk couplings plus three or four flavor diagonal light Majorana neutrinos on the brane, with subsequent mixing induced solely by the Kaluza-Klein tower of states, are found to be excluded by data on the oscillations of solar, atmospheric and reactor neutrinos, taken together with the cosmological upper bound on the sum of neutrino masses. Extra dimensions, if relevant to neutrino mixing, need to discriminate between neutrino flavors.

Hewett, JoAnne L. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States); Roy, Probir [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai - 400 005 (India); Roy, Sourov [Helsinki Institute of Physics, P.O. Box 64, FIN-00014 University of Helsinki, Helsinki (Finland)

2004-09-01

5

Higher Dimensional Models of Light Majorana Neutrinos Confronted by Data  

SciTech Connect

We discuss experimental and observational constraints on certain models of higher Dimensional light Majorana neutrinos. Models with flavor blind brane-bulk couplings plus three or four flavor diagonal light Majorana neutrinos on the brane, with subsequent mixing induced solely by the Kaluza-Klein tower of states, are found to be excluded by data on the oscillations of solar, atmospheric and reactor neutrinos, taken together with the WMAP upper bound on the sum of neutrino masses. Extra dimensions, if relevant to neutrino mixing, need to discriminate between neutrino flavors.

Hewett, J

2004-05-03

6

Toward Neutrino Texture Dominated by Majorana Lefthanded Mass Matrix  

NASA Astrophysics Data System (ADS)

A form of mixing matrix for three active and three sterile, conventional Majorana neutrinos is proposed. Its Majorana lefthanded part arises from the popular bimaximal mixing matrix for three active neutrinos that works satisfactorily in solar and atmospheric experiments if the LSND effect is ignored. One of three sterile neutrinos, effective in the Majorana righthanded and Dirac parts of the proposed mixing matrix, is responsible perturbatively for the possible LSND effect by inducing one of three extra neutrino mass states to exist actively. The corresponding form of neutrino mass matrix is derived. If all three extra neutrino mass states get vanishing masses, the neutrino mass matrix is dominated by its specific Majorana lefthanded part. Then, the observed qualitative difference between mixings of neutrinos and down quarks may be connected with this Majorana lefthanded dominance realized for neutrinos. If m21 ? m22 for two of three basic neutrino mass states, the sum rule sin 2 2? sol + sin 2 2 ? Chooz/2 + sin2 2? LSND = 1 holds in the two-flavor approximation (for each of three cases). Thus, the solar neutrino oscillation amplitude, not fully maximal, leaves some room for the LSND effect, depending on the magnitude of Chooz effect (not observed so far).

Krolikowski, Wojciech

2001-07-01

7

Model Independent Explorations of Majorana Neutrino Mass Origins  

Microsoft Academic Search

The scale of neutrino mass generation may be too large to explore directly, but useful information may still be extracted from independent experimental channels. Here I survey various model independent probes of Majorana neutrino mass origins. An introduction to the concepts relevant to the analysis is followed by a discussion of the physical ranges of neutrino parameters within the context

James Jenkins

2008-01-01

8

Majorana neutrinos and low-energy tests of electroweak models  

SciTech Connect

Tests based on neutrinoless double-..beta.. decay and rare muon processes are proposed for the detection of a heavy Majorana neutrino with a mass of approx.100 GeV. Existence of such a neutrino would distinguish between the standard and left-right-symmetric electroweak gauge models with U(1) in the latter identified with (B-L). The sensitivity of these processes to the mass of the heavy Majorana neutrino is discussed.

Riazuddin, %.R.; Marshak, R.E.; Mohapatra, R.N.

1981-09-01

9

Parametrizing Majorana neutrino couplings in the Higgs sector  

NASA Astrophysics Data System (ADS)

Nonzero masses for the active neutrinos—regardless of their nature or origin—arise only after electroweak symmetry breaking. We discuss the parameterization of neutrino couplings to a Higgs sector consisting of one SU(2)L scalar doublet and one SU(2)L scalar triplet, and allow for right-handed neutrinos whose Majorana mass parameters arise from the vacuum expectation value of a standard model scalar singlet. If the neutrinos are Majorana fermions, all Yukawa couplings can be expressed as functions of the neutrino mass eigenvalues and a subset of the elements of the neutrino mixing matrix. In the mass basis, the Yukawa couplings are, in general, not diagonal. This is to be contrasted to the case of charged fermions or Dirac neutrinos, where couplings to the Higgs-boson are diagonal in the mass basis and proportional only to the fermion masses. Nonetheless, all physically distinguishable parameters can be reached if all neutrino masses are constrained to be positive, all mixing angles constrained to lie in the first quadrant (??[0,?/2]), and all Majorana phases to lie in the first two quadrants (??[0,?}), as long as all Dirac phases vary within the entire unit circle (??[0,2?}). We discuss several concrete examples and comment on the Casas-Ibarra parameterization for the neutrino Yukawa couplings in the case of the type I seesaw Lagrangian. We also comment on the case where SU(2)L fermion triplets replace the right-handed neutrinos.

de Gouvêa, André; Huang, Wei-Chih; Shalgar, Shashank

2011-08-01

10

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

NASA Astrophysics Data System (ADS)

The intent of this paper is to convey a new primary physical idea of a Dirac-Majorana neutrino duality in relation to the topical problem of neutrino oscillations. In view of the new atmospheric, solar and the LSND neutrino oscillation data, the Pontecorvo ? - K0 oscillation analogy is generalized to the notion of neutrino duality with substantially different physical meaning ascribed to the long-baseline and the short-baseline neutrino oscillations. At the level of CP-invariance, the suggestion of dual neutrino properties defines the symmetric two-mixing-angle form of the widely discussed four-neutrino (2 +2)-mixing scheme, as a result of the lepton charge conservation selection rule and a minimum of two Dirac neutrino fields. With neutrino duality, the two-doublet structure of the Majorana neutrino mass spectrum is a vestige of the two-Dirac-neutrino origin. The fine neutrino mass doublet structure is natural because it is produced by a lepton charge symmetry violating perturbation on a zero-approximation system of two twofold mass-degenerate Dirac neutrino-antineutrino pairs. A set of inferences related to the neutrino oscillation phenomenology in vacuum is considered.

Lipmanov, E. M.

11

Massive Majorana neutrinos in pre-bounce supernovae.  

National Technical Information Service (NTIS)

The currently accepted models of supernova collapse rely on the standard electroweak theory and massless left-handed neutrinos. We consider the effect of massive right-handed Majorana neutrinos on this scenario. In order that they do not upset the agreeme...

S. Goswami K. Kar A. Raychaudhuri

1992-01-01

12

Parametrizing Majorana neutrino couplings in the Higgs sector  

Microsoft Academic Search

Nonzero masses for the active neutrinos---regardless of their nature or origin---arise only after electroweak symmetry breaking. We discuss the parameterization of neutrino couplings to a Higgs sector consisting of one SU(2)L scalar doublet and one SU(2)L scalar triplet, and allow for right-handed neutrinos whose Majorana mass parameters arise from the vacuum expectation value of a standard model scalar singlet. If

André de Gouvêa; Wei-Chih Huang; Shashank Shalgar

2011-01-01

13

Parameterizing Majorana Neutrino Couplings in the Higgs Sector  

Microsoft Academic Search

Nonzero masses for the active neutrinos - regardless of their nature or\\u000aorigin - arise only after electroweak symmetry breaking. We discuss the\\u000aparameterization of neutrino couplings to a Higgs sector consisting of one\\u000aSU(2)_L scalar doublet and one SU(2)_L scalar triplet, and allow for\\u000aright-handed neutrinos whose Majorana mass parameters arise from the vacuum\\u000aexpectation value of a Standard

Andre de Gouvea; Wei-Chih Huang; Shashank Shalgar

2010-01-01

14

Multilepton collider signatures of heavy Dirac and Majorana neutrinos  

NASA Astrophysics Data System (ADS)

We discuss the possibility of observing multi-lepton signals at the Large Hadron Collider (LHC) from the production and decay of heavy standard model (SM) singlet neutrinos added in extensions of SM to explain the observed light neutrino masses by seesaw mechanism. In particular, we analyze two “smoking gun” signals depending on the Dirac or Majorana nature of the heavy neutrino: (i) for Majorana case, the same-sign di-lepton signal which can be used as a probe of lepton-number violation, and (ii) for Dirac case, the tri-lepton signal which conserves lepton number but may violate lepton flavor. Within a minimal Left-Right symmetric framework in which these additional neutrino states arise naturally, we find that in both cases, the signals can be identified with virtually no background beyond a TeV, and the heavy gauge boson WR can be discovered in this process. This analysis also provides a direct way to probe the nature of seesaw physics involving the SM singlets at TeV-scale, and in particular, to distinguish type-I seesaw with purely Majorana heavy neutrinos from inverse seesaw with pseudo-Dirac counterparts.

Chen, Chien-Yi; Dev, P. S. Bhupal

2012-05-01

15

Distinguishing between Dirac and Majorana neutrinos withtwo-particle interferometry  

SciTech Connect

Two-particle interferometry, a second-order interferenceeffect, is explored as another possible tool to distinguish betweenmassive Dirac and Majorana neutrinos. A simple theoretical framework isdiscussed in the context of several gedanken experiments. The method canin principle provide both the mass scale and the quantum nature of theneutrino for a certain class of incoherent left-handed sourcecurrents.

Gutierrez, Thomas D.

2006-03-02

16

Probing Majorana neutrino CP phases and masses in neutrino-antineutrino conversion  

Microsoft Academic Search

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± 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± decays as a distinctive signature of nu-nu¯ oscillations. We show

David Delepine; Vannia González Macías; Shaaban Khalil; Gabriel López Castro

2010-01-01

17

Probing Majorana neutrino CP phases and masses in neutrino–antineutrino conversion  

Microsoft Academic Search

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 ?± decays. Within the generic framework of quantum field theory, we compute the non-factorizable probability for producing a pair of same-charged muons in ?± decays as a distinctive signature of ?????¯ oscillations. We show

David Delepine; Vannia González Macías; Shaaban Khalil; Gabriel López Castro

2010-01-01

18

Probing the Majorana neutrino CP phases and masses in neutrino-antineutrino conversion  

Microsoft Academic Search

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± 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± decays as a distinctive signature of numu - bar numu

D. Delepine; V. González Macías; S. Khalil; G. López Castro

2011-01-01

19

Model independent explorations of Majorana neutrino mass origins  

NASA Astrophysics Data System (ADS)

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

Jenkins, James Phearl, Jr.

20

Neutrinos.  

PubMed

Neutrinos represent a new "window" to the Universe, spanning a large range of energy. We discuss the science of neutrino astrophysics and focus on two energy regimes. At "lower" energies ( approximately 1 MeV), studies of neutrinos born inside the sun, or produced in interactions of cosmic rays with the atmosphere, have allowed the first incontrovertible evidence that neutrinos have mass. At energies typically one thousand to one million times higher, sources further than the sun (both within the Milky Way and beyond) are expected to produce a flux of particles that can be detected only through neutrinos. PMID:10588680

Besson, D; Cowen, D; Selen, M; Wiebusch, C

1999-12-01

21

Geometry of Majorana neutrino and new symmetries  

Microsoft Academic Search

Experimental observation of Majorana fermion matter gives a new impetus to the understanding of the Lorentz symmetry and its extension, the geometrical properties of the ambient space-time structure, matter--antimatter symmetry and some new ways to understand the baryo-genesis problem in cosmology. Based on the primordial Majorana fermion matter assumption, we discuss a possibility to solve the baryo-genesis problem through the

G. G. Volkov

2006-01-01

22

Connection between the neutrino seesaw mechanism and properties of the Majorana neutrino mass matrix  

SciTech Connect

If it can be ascertained experimentally that the 3x3 Majorana neutrino mass matrix M{sub {nu}} has vanishing determinants for one or more of its 2x2 submatrices, it may be interpreted as supporting evidence for the theoretically well-known canonical seesaw mechanism. I show how these two things are connected and offer a realistic M{sub {nu}} with two zero subdeterminants as an example.

Ma, Ernest [Physics Department, University of California, Riverside, California 92521 (United States)

2005-06-01

23

Masses, mixing angles and phases of general Majorana neutrino mass matrix  

NASA Astrophysics Data System (ADS)

General Majorana neutrino mass matrix is complex symmetric and for three generations of neutrinos it contains 12 real parameters. We diagonalize this general neutrino mass matrix and express the three neutrino masses, three mixing angles, one Dirac CP phase and two Majorana phases (removing three unphysical phases) in terms of the neutrino mass matrix elements. We apply the results in the context of a neutrino mass matrix derived from a broken cyclic symmetry invoking type-I seesaw mechanism. Phenomenological study of the above mass matrix allows enough parameter space to satisfy the neutrino oscillation data with only 10% breaking of this symmetry. In this model only normal mass hierarchy is allowed. In addition, the Dirac CP phase and the Majorana phases are numerically estimated. ? m i and | m ?ee | are also calculated.

Adhikary, Biswajit; Chakraborty, Mainak; Ghosal, Ambar

2013-10-01

24

Majorana neutrinos and photinos from kaon decay  

Microsoft Academic Search

We discuss the suggestion by Deshpande and Eilam of putting bounds on the ..nu..\\/sub tau\\/ mass from the decay K\\/sup +\\/..--> pi..\\/sup +\\/..nu..nu-bar. We show that the Dirac or Majorana nature of the ..nu..\\/sub tau\\/ can make a significant difference in the pion energy spectrum. We also discuss the relative importance of the K\\/sup +\\/..--> pi..\\/sup +\\/lambda\\/sub ..gamma..\\/lambda\\/sub ..gamma..\\/ mode,

José Nieves; Palash Pal

1985-01-01

25

Majorana neutrinos and photinos from kaon decay  

SciTech Connect

We discuss the suggestion by Deshpande and Eilam of putting bounds on the ..nu../sub tau/ mass from the decay K/sup +/..--> pi../sup +/..nu..nu-bar. We show that the Dirac or Majorana nature of the ..nu../sub tau/ can make a significant difference in the pion energy spectrum. We also discuss the relative importance of the K/sup +/..--> pi../sup +/lambda/sub ..gamma../lambda/sub ..gamma../ mode, lambda/sub ..gamma../ being the photino.

Nieves, J.F.; Pal, P.B.

1985-10-01

26

Low-energy neutrino Majorana phases and charged-lepton electric dipole moments  

SciTech Connect

If the neutrinos are Majorana fermions, there are at least three new, potentially observable CP-odd phases that parametrize CP-invariance violating phenomena. We currently have no information regarding any of them and know that two out of the three, the so-called Majorana phases, are very hard to access experimentally. Here, we discuss the effect of Majorana phases on charged-lepton electric dipole moments (EDM), and explicitly show that neutrino Majorana phases induce EDMs even in the absence of other sources of CP-invariance violation. We also argue that while the Majorana neutrino contribution to EDMs is tiny, there is one generic ultraviolet completion to the standard model plus massive Majorana neutrinos - the standard model plus a triplet Higgs boson - that leads to significantly enhanced contributions which are still proportional to the low-energy neutrino Majorana phases. If this particular scenario is realized in nature, it seems possible, at least in principle, to measure the Majorana phases by precisely measuring charged-lepton EDMs.

Gouvea, Andre de; Gopalakrishna, Shrihari [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

2005-11-01

27

Bulk Majorana mass terms and Dirac neutrinos in the Randall-Sundrum model  

NASA Astrophysics Data System (ADS)

We present a novel scheme where Dirac neutrinos are realized even if lepton number violating Majorana mass terms are present. The setup is the Randall-Sundrum framework with bulk right-handed neutrinos. Bulk mass terms of both Majorana and Dirac type are considered. It is shown that massless zero mode solutions exist when the bulk Dirac mass term is set to zero. In this limit, it is found that the effective 4D small neutrino mass is primarily of Dirac nature, with the Majorana-type contributions being negligible. Interestingly, this scenario is very similar to the one known with flat extra dimensions. Neutrino phenomenology is discussed by fitting both charged lepton masses and neutrino masses simultaneously. A single Higgs localized on the IR brane is highly constrained, as unnaturally large Yukawa couplings are required to fit charged lepton masses. A simple extension with two Higgs doublets is presented, which facilitates a proper fit for the lepton masses.

Iyer, Abhishek M.; Vempati, Sudhir K.

2013-10-01

28

Instanton Induced Neutrino Majorana Masses in CFT Orientifolds with MSSM-like spectra  

Microsoft Academic Search

Recently it has been shown that string instanton effects may give rise to neutrino Majorana masses in certain classes of semi-realistic string compactifications. In this paper we make a systematic search for supersymmetric MSSM-like Type II Gepner orientifold constructions admitting boundary states associated with instantons giving rise to neutrino Majorana masses and other L- and\\/or B-violating operators. We analyze the

L. E. Ibanez; Bert Schellekens; Angel M. Uranga

2007-01-01

29

The search for Majorana neutrinos with neutrinoless double beta decays: From CUORICINO to LUCIFER experiment  

NASA Astrophysics Data System (ADS)

The study of neutrino properties is one of the fundamental challenges in particle physics nowadays. Fifty years of investigations established that neutrinos are massive but the absolute mass scale has not yet been measured. Moreover its true nature is still unknown. Is the neutrino its own antiparticle (thus violating the lepton number) as proposed by Majorana in 1937? The only way to probe the neutrino nature is through the observation of Neutrinoless Double Beta Decay (0???), a very rare spontaneous nuclear transition which emits two electrons and no neutrinos. In this paper, after a brief introduction to the theoretical framework of Majorana's neutrino, a presentation of experimental challenges posed by 0??? search will be given as well as an overview of present status and future perpectives of experiments.

Bellini, F.

2012-11-01

30

Low-energy neutrino Majorana phases and charged-lepton electric dipole moments  

Microsoft Academic Search

If the neutrinos are Majorana fermions, there are at least three new, potentially observable CP-odd phases that parametrize CP-invariance violating phenomena. We currently have no information regarding any of them and know that two out of the three, the so-called Majorana phases, are very hard to access experimentally. Here, we discuss the effect of Majorana phases on charged-lepton electric dipole

André de Gouvêa; Shrihari Gopalakrishna

2005-01-01

31

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

NASA Astrophysics Data System (ADS)

Corrections to the neutrino magnetic dipole moment from the singly charged Higgs bosons h (±) and tilde ? ^{( ± )} were calculated within the left-right symmetric model involving Majorana neutrinos. It is shown that, if the h (±) and tilde ? ^{( ± )} bosons lie at the electroweak scale, the contributions from Higgs sector are commensurate with the contribution of charged gauge bosons or may even exceed it. The behavior of the neutrino flux inmatter and in amagnetic field was studied. It was found that resonance transitions between light and heavy neutrinos are forbidden.

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

2013-04-01

32

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

Microsoft Academic Search

We propose a new strategy for detecting the CP-violating phases and the\\u000aeffective mass of muon Majorana neutrinos by measuring observables associated\\u000awith neutrino-antineutrino oscillations in $\\\\pi^{\\\\pm}$ decays. Within the\\u000ageneric framework of quantum field theory, we compute the non-factorizable\\u000aprobability for producing a pair of same-charged muons in $\\\\pi^{\\\\pm}$ decays as\\u000aa distinctive signature of $\\\

David Delepine; Vannia Gonzalez Macias; Shaaban Khalil; Gabriel Lopez Castro

2009-01-01

33

A new strategy for probing the Majorana neutrino CP violating phases and masses1  

Microsoft Academic Search

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+\\/- 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+\\/- decays as a distinctive signature of numu-numu oscillations. Using the

David Delepine; Vannia González Macias; Shaaban Khalil; Gabriel López Castro

2011-01-01

34

Production of right-handed gauge bosons and heavy Majorana neutrinos at the Superconducting Super Collider  

Microsoft Academic Search

The processes p+p-->2l+\\/-+X, p+p-->WR-->N+l+X, and p+p-->ZR-->2N+l+X (where N is a heavy Majorana neutrino) are discussed and estimated at the energy scale of the Superconducting Super Collider (SSC). These reactions may serve as the indications of right-handed gauge bosons and heavy Majorana neutrinos that propagate in the intermediate state or are produced directly. The observation of same-sign charged-lepton pairs in final

Ho Tso-Hsiu; Ching Cheng-Rui; Tao Zhi-Jian

1990-01-01

35

GeV Majorana neutrinos in top-quark decay at the LHC  

SciTech Connect

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

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

2009-01-01

36

Bounding resonant Majorana neutrinos from four-body B and D decays  

NASA Astrophysics Data System (ADS)

Searches of lepton-number violation in different processes are very useful to constrain the parameter space of Majorana neutrinos. Here we use available upper bounds on the branching fractions of B-?D0?+?-?- and D0?(?-?-/K-?-)?-?- decays to derive constraints on the mass and mixings of Majorana neutrinos by assuming they are produced resonantly in these four-body decays. While the excluded region obtained from B- decays are competitive with existing limits from three-body D- and B- decays, it is shown that experimental improvements on D0 decays offer a good potential to provide similar results.

López Castro, G.; Quintero, N.

2013-04-01

37

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

SciTech Connect

The goal of the Majorana Experiment is to determine the effective Majorana masss of the eletron neutrino. Detection of the neutrino mass implied by oscillation results in within our grasp. This exciting physics goal is best pursued using double-beta decay of germanium because of the historical and emerging advances in eliminating competing signals from radioactive backgrounds. The Majorana Experiment will consist of a large mass of 76Ge in the form of high-resolution detectors deep underground, searching for a sharp peak at the BB endpoint. We present here an overview of the entire project in order to help put in perspective the scope, the level and technial risk, and the readiness of the Collaboration to begin the undertaking.

Gaitskell, R.; Barabash, A.; Konovalov, S.; Stekhanov, V.; Umatov,, V.; Brudanin, V.; Egorov, S.; Webb, J.; Miley, Harry S.; Aalseth, Craig E.; Anderson, Dale N.; Bowyer, Ted W.; Brodzinski, Ronald L.; Jordan, David B.; Kouzes, Richard T.; Smith, Leon E.; Thompson, Robert C.; Warner, Ray A.; Tornow, W.; Young, A.; Collar, J. I.; Avignone, Frank T.; Palms, John M.; Doe, P. J.; Elliott, Steven R.; Kazkaz, K.; Robertson, Hamish; Wilkerson, John

2002-03-07

38

Probing Majorana neutrinos in the regime of the normal mass hierarchy  

NASA Astrophysics Data System (ADS)

An approach to developing a feasible neutrinoless double beta decay experiment capable of probing Majorana masses in the regime of the nondegenerate normal neutrino mass hierarchy is proposed. For such an experiment, this study suggests that Te130 is likely the best choice of candidate isotope and that metal-loaded liquid scintillator likely represents the best choice of detector technology. An evaluation of the required loading, scintillator properties and detector configuration is presented. While further development of Te-loaded liquid scintillator is required, recent progress in this area suggests that this task may not be insurmountable. This could open the door for a future experiment of unparalleled sensitivity that might be accommodated in a volume of the order of 10-20 kilotons. To the best of our knowledge, this is the first time that a potentially practical experimental approach to exploring Majorana neutrino masses in the nondegenerate normal hierarchy has been suggested.

Biller, Steven D.

2013-04-01

39

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

SciTech Connect

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

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

2005-06-01

40

Are neutrinos their own antiparticles?  

NASA Astrophysics Data System (ADS)

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

2009-06-01

41

Astrophysical neutrinos  

Microsoft Academic Search

Three main aspects of neutrino astrophysics are surveyed: the use of neutrinos as a stellar probe; the exploration of neutrino properties by astrophysical observations; and the possibility and significance of cosmic neutrino fluxes.The anticipated early detection of solar neutrinos should accurately specify conditions at the centre of the sun. Details of the solar neutrino flux and detection are summarized together

M A Ruderman

1965-01-01

42

Neutrino sector with Majorana mass terms and Friedberg-Lee symmetry  

SciTech Connect

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

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

2008-04-01

43

Search for heavy Majorana neutrinos in ?±?±+jets and e±e±+jets events in pp collisions at s=7 TeV  

NASA Astrophysics Data System (ADS)

A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two same-sign charged leptons of the same flavour and two jets. The data correspond to an integrated luminosity of 4.98 fb of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events is observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing parameter, |, for ?=e,?, as a function of heavy Majorana-neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for mN>90 GeV.

CMS Collaboration Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Reis, T.; Thomas, L.; Vander Marcken, G.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins Junior, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Khalil, S.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Anagnostou, G.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.

2012-10-01

44

Neutrino astronomy and neutrino properties  

NASA Astrophysics Data System (ADS)

The natural sources of neutrinos and the energy of neutrinos derived from these sources are described. The present knowledge of the neutrino properties which most affect the astrophysics of neutrinos (such as the number of families and the neutrino mass, magnetic moment, and lifetime) is reviewed. The present neutrino telescopes and the telescopes planned for the 1990s are described, together with their threshold, mass, area, and angular resolution properties. Special attention is given to the supernova neutrino detectors.

Cline, David B.

1989-12-01

45

Neutrino Magnetic Moments and Electromagnetic Leptogenesis  

SciTech Connect

We analyze the connection between neutrino magnetic moments and neutrino masses. Electroweak radiative corrections to the neutrino mass are used to derive naturalness upper bounds on neutrino magnetic moments, generated by physics above the electroweak scale. For Dirac (Majorana) neutrinos the bound is several orders of magnitude stronger (weaker) than present experimental limits. The discovery of a neutrino magnetic moment near the present experimental sensitivity would thus suggest that neutrinos are Majorana particles. We also outline a new baryogenesis-via-leptogenesis scenario where the lepton asymmetry is generated by CP violating decays of heavy right handed neutrinos via electromagnetic dipole moment couplings.

Bell, Nicole F. [School of Physics, University of Melbourne, Victoria 3010 (Australia)

2009-12-17

46

Neutrino masses from new generations  

Microsoft Academic Search

We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence\\u000a of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed\\u000a light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present\\u000a data can

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

2011-01-01

47

THE SEARCH FOR MASSIVE NEUTRINOS - Short Contribution  

NASA Astrophysics Data System (ADS)

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

Kirsten, T.

48

Neutrino oscillations, neutrino masses and supersymmetry  

NASA Astrophysics Data System (ADS)

The neutrino mass matrix is constraint considering in a three-generation scenario, which includes or excludes LSND and considers the atmospheric neutrinos of Super-Kamiokande and the solar neutrino experiments. In this way one is able to construct the neutrino mass matrix, up to a mass scale and up to the Majorana neutrino CP eigenvalues. By using the expectation value of the electron neutrino mass obtained in the neutrinoless double beta decay, one can derive an upper limit of 2.53 [eV] for the sum of the masses of the three neutrinos. In a second part we use the R violating minimal supersymmetric model (R-MSSM) to construct the neutrino mass matrix. The contributions on the tree level yield by mixing with the neutralinos (photino, zino, higgsino 1 and higgsino 2) a separable 3 . 3 mass matrix, which has two mass eigenvalues, which are zero and a third eigenvalue different from zero. This yields a hierachichal structure of two neutrinos with small masses and a third neutrino with a larger mass. If one includes the loop diagrams of quarks and SUSY quarks and of leptons and SUSY leptons one obtains for the three neutrinos a sum of tree separable matrices. Such a separable mass matrix of rank 3 has 9 independent parameters. One can fit five parameters from the neutrino oscillations: the three mixing angles of the matrix transforming the neutrinos from the mass eigenstates to the weak eigenstates and the two differences of the squared masses. One therefore has to reduce the nine free parameters of the mass matrix in the R-MSSM from nine to five. This is possible imposing a constraint on the cubic couplings employing an additional U(1) flavour symmetry. This approach has been very successful in studying the Yukawa couplings to fix the masses of the quarks and the non-neutrino leptons. In this way it is possible to reduce the R-parity violating coupling constants of the the R-MSSM from six to one. This reduces the free parameters of the neutrino mass matrix obtained in the SUSY model to four. We find in a three-family mixing scheme an averaged Majorana neutrino mass, which in principle can be obtained from the neutrinoless double beta decay, of < m > = 0.009 to 0.045[eV]. These predictions can perhaps be tested by the next generation of neutrinoless double beta decay experiments.

Faessler, A.

2002-07-01

49

No-neutrino double beta decay: more than one neutrino  

SciTech Connect

Interference effects between light and heavy Majorana neutrinos in the amplitude for no-neutrino double beta decay are discussed. The effects include an upper bound on the heavy neutrino mass, and an A dependence for the effective mass extracted from double beta decay. Thus the search for the no-neutrino decay mode should be pursued in several nuclei, and particularly in Ca/sup 48/, where the effective mass may be quite large.

Rosen, S.P.

1983-01-01

50

Neutrino physics  

SciTech Connect

The field of neutrino physics has expanded greatly in recent years with the discovery that neutrinos change flavor and therefore have mass. Although there are many neutrino physics results since the last DIS workshop, these proceedings concentrate on recent neutrino physics results that either add to or depend on the understanding of Deep Inelastic Scattering. They also describe the short and longer term future of neutrino DIS experiments.

Harris, Deborah A.; /Fermilab

2008-09-01

51

Neutrino tomography  

NASA Astrophysics Data System (ADS)

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

Millhouse, Margaret A.; Latimer, David C.

2013-09-01

52

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

SciTech Connect

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

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

2004-08-01

53

Direct neutrino mass measurements  

NASA Astrophysics Data System (ADS)

The determination of the neutrino rest mass plays an important role at the intersections of cosmology, particle physics and astroparticle physics. This topic is currently being addressed by two complementary approaches in laboratory experiments. Neutrinoless double beta decay experiments probe whether neutrinos are Majorana particles and determine an effective neutrino mass value. Single beta decay experiments such as KATRIN and MARE investigate the spectral shape of ?-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Owing to neutrino flavour mixing, the neutrino mass parameter 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. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows ?-spectroscopy close to the T 2 end-point with unprecedented precision and will reach a sensitivity of 200 meV/ c 2 (90% C.L.) on the neutrino rest mass.

Thümmler, T.

2011-07-01

54

Neutrino physics  

SciTech Connect

Thanks to compelling evidence that neutrinos can change flavor, we now know that they have nonzero masses, and that leptons mix. In these lectures, we explain the physics of neutrino flavor change, both in vacuum and in matter. Then, we describe what the flavor-change data have taught us about neutrinos. Finally, we consider some of the questions raised by the discovery of neutrino mass, explaining why these questions are so interesting, and how they might be answered experimentally.

Kayser, Boris; /Fermilab

2005-06-01

55

Neutrino Detectors  

NASA Astrophysics Data System (ADS)

The neutrino was postulated by Wolfgang Pauli in the early 1930s, but could only be detected for the first time in the 1950s. Ever since scientists all around the world have worked on the detection and understanding of this particle which so scarcely interacts with matter. Depending on the origin and nature of the neutrino, various types of experiments have been developed and operated. In this entry, we will review neutrino detectors in terms of neutrino energy and associated detection technique as well as the scientific outcome of some selected examples. After a brief historical introduction, the detection of low-energy neutrinos originating from nuclear reactors or from the Earth is used to illustrate the principles and difficulties which are encountered in detecting neutrinos. In the context of solar neutrino spectroscopy, where the neutrino is used as a probe for astrophysics, three different types of neutrino detectors are presented - water ?erenkov, radiochemical, and liquid-scintillator detectors. Moving to higher neutrino energies, we discuss neutrinos produced by astrophysical sources and from accelerators. The entry concludes with an overview of a selection of future neutrino experiments and their scientific goals.

von Feilitzsch, Franz; Lanfranchi, Jean-Côme; Wurm, Michael

56

Probing late neutrino mass properties with supernova neutrinos  

NASA Astrophysics Data System (ADS)

Models of late-time neutrino mass generation contain new interactions of the cosmic background neutrinos with supernova relic neutrinos (SRNs). Exchange of an on-shell light scalar may lead to significant modification of the differential SRN flux observed at earth. We consider an Abelian U(1) model for generating neutrino masses at low scales, and show that there are cases for which the changes induced in the flux allow one to distinguish the Majorana or Dirac nature of neutrinos, as well as the type of neutrino mass hierarchy (normal or inverted or quasidegenerate). In some region of parameter space the determination of the absolute values of the neutrino masses is also conceivable. Measurements of the presence of these effects may be possible at the next-generation water Cerenkov detectors enriched with Gadolinium, or a 100 kton liquid argon detector.

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

2007-09-01

57

Probing Late Neutrino Mass Properties With SupernovaNeutrinos  

SciTech Connect

Models of late-time neutrino mass generation contain new interactions of the cosmic background neutrinos with supernova relic neutrinos (SRNs). Exchange of an on-shell light scalar may lead to significant modification of the differential SRN flux observed at earth. We consider an Abelian U(1) model for generating neutrino masses at low scales, and show that there are cases for which the changes induced in the flux allow one to distinguish the Majorana or Dirac nature of neutrinos, as well as the type of neutrino mass hierarchy (normal or inverted or quasi-degenerate). In some region of parameter space the determination of the absolute values of the neutrino masses is also conceivable. Measurements of the presence of these effects may be possible at the next-generation water Cerenkov detectors enriched with Gadolinium, or a 100 kton liquid argon detector.

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

2007-08-08

58

Neutrino oscillometry  

NASA Astrophysics Data System (ADS)

Neutrino oscillations are studied employing sources of low energy monoenergetic neutrinos following electron capture by the nucleus and measuring electron recoils. Since the neutrino energy is very low the oscillation length L23 appearing in this electronic neutrino disappearance experiment can be so small that the full oscillation can take place inside the detector so that one may determine very accurately the neutrino oscillation parameters. In particular, since the oscillation probability is proportional to sin22?13, one can measure or set a better limit on the unknown parameter ?13. One, however, has to pay the price that the expected counting rates are very small. Thus one needs a very intensive neutrino source and a large detector with as low as possible energy threshold and high energy and position resolution. Both spherical gaseous and cylindrical liquid detectors are studied. Different source candidates are considered.

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

2012-08-01

59

Massive neutrinos in particle physics and astrophysics  

SciTech Connect

The concepts of Majorana and Dirac neutrinos are reviewed from an operational point of view and survey the experimental search for neutrino mass. Also reviewed are the work of Mikheyev and Smirnov on the enhancement of neutrino oscillations via the mechanism of Wolfenstein matter oscillations. Results of an extensive computation of MSW effects in the sun are described. 41 refs., 6 figs.

Rosen, S.P.

1986-01-01

60

Neutrino mass  

SciTech Connect

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

Bowles, T.J.

1994-04-01

61

Neutrino Oscillations and Neutrino Masses.  

NASA Astrophysics Data System (ADS)

A few aspects of neutrino physics have been examined in three parts. As an introduction, we reviewed the Standard Model as well as the Solar and atmospheric neutrinos. Chapter 4 deals with a rigorous treatment of neutrino oscillations using the formalism of the quantum field theory without resorting to the concept of neutrino weak eigenstates. In Chapters 5, 6, and 7, we review and apply the finite temperature field theory to the calculation of the fermion effective masses at the temperature of 250 GeV and above. In Chapter 8, we present the maximal mixing among three generations of neutrinos as a unified solution to the Solar and atmospheric neutrino problems. Finally we conclude the thesis in Chapter 9.

Lee, Jaeyoung

1995-01-01

62

Solar Neutrinos Before and After Neutrino 2004  

Microsoft Academic Search

We compare, using a three neutrino analysis, the allowed neutrino oscillation parameters and solar neutrino fluxes determined by the experimental data available Before and After Neutrino 2004. New data available after Neutrino 2004 include refined KamLAND and gallium measurements. We use six different approaches to analyzing the KamLAND data. We present detailed results using all the available neutrino and anti-neutrino

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

2004-01-01

63

Neutrino mass  

SciTech Connect

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

Bowles, T.J.

1993-04-01

64

Neutrino mass  

SciTech Connect

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

Bowles, T.J.

1993-01-01

65

Neutrino astronomy  

SciTech Connect

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

Schramm, D.N.

1980-01-01

66

Neutrino Telescopes  

SciTech Connect

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

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

2005-02-21

67

Neutrino Astrophysics.  

National Technical Information Service (NTIS)

Neutrino or antineutrino emission from collapsing or bouncing stars is considered. Up to 10 exp 15 GM CCM exp -3 , a hot neutron fluid behaves like an ideal gas and the neutron--proton ratio is generally less than that of a cold neutron star. The neutrino...

S. A. Bludman

1975-01-01

68

Stellar neutrinos  

SciTech Connect

Neutrino provide an important diagnostic of behavior deep inside the solar core. They also play a major role in the evolution of red giants. Horizontal branch stars, and core-collapse supernovae. I discuss some of the interesting neutrino physics issues that have arisen in studies of stellar evolution.

Haxton, W.C.

1992-09-01

69

Tripartite neutrino mass matrix  

NASA Astrophysics Data System (ADS)

The 3×3 Majorana neutrino mass matrix is written as a sum of 3 terms, i.e., M?=MA+MB+MC, where MA is proportional to the identity matrix and MB,C are invariant under different Z3 transformations. This M? is very suitable for understanding atmospheric and solar neutrino oscillations, with sin22?atm and tan2?sol fixed at 1 and 0.5 respectively, in excellent agreement with present data. It has in fact been proposed before, but only as an ansatz. This Letter uncovers its underlying symmetry, thus allowing a complete theory of leptons and quarks to be constructed.

Ma, Ernest

2004-03-01

70

Gauge Trimming of Neutrino Masses  

SciTech Connect

We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ''right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This ''Leptocratic'' Model predicts the existence of light quasi-sterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.

Chen, Mu-Chun; /Fermilab /UC, Irvine; de Gouvea, Andre; /Northwestern U. /Fermilab; Dobrescu, Bogdan A.; /Fermilab

2006-12-01

71

Gauge trimming of neutrino masses  

NASA Astrophysics Data System (ADS)

We show that under a new U(1) gauge symmetry, which is nonanomalous in the presence of one “right-handed neutrino” per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This “leptocratic” model predicts the existence of light quasisterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.

Chen, Mu-Chun; de Gouvêa, André; Dobrescu, Bogdan A.

2007-03-01

72

Gauge trimming of neutrino masses  

SciTech Connect

We show that under a new U(1) gauge symmetry, which is nonanomalous in the presence of one 'right-handed neutrino' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This 'leptocratic' model predicts the existence of light quasisterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.

Chen, M.-C.; Gouvea, Andre de; Dobrescu, Bogdan A. [Theoretical Physics Department, Fermilab, Batavia, Illinois 60510 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States); Theoretical Physics Department, Fermilab, Batavia, Illinois 60510 (United States); Theoretical Physics Department, Fermilab, Batavia, Illinois 60510 (United States)

2007-03-01

73

GeV Seesaw, Accidentally Small Neutrino Masses, and Higgs Decays to Neutrinos  

Microsoft Academic Search

If the Standard Model particle content is extended by gauge singlet fermions (right-handed neutrinos), active neutrinos generically acquire (Majorana) masses, in agreement with our current understanding of the lepton sector. If the right-handed neutrino masses are of the same order as the electroweak symmetry breaking scale, it is usually expected that these will not mediate any experimentally observable effects. Here,

Andre de Gouvea

2007-01-01

74

Baryogenesis via Sterile neutrino oscillation and neutrino parameters  

NASA Astrophysics Data System (ADS)

We investigate baryogenesis in the ?MSM which is the Minimal Standard Model (MSM) extended by three right-handed neutrinos with Majorana masses being smaller than the weak scale. In this model three sterile neutrinos, which are almost right-handed states, play important roles in cosmology. The baryon asymmetry of the universe (BAU) is generated via mechanism through flavor oscillation between two sterile neutrinos N2 and N3 which are degenerate in masses. We consider the case when BAU is solely originated from the CP violating phases in the mixing matrix of active neutrinos, i.e., the Dirac phase ? and the Majorana phase ?, and study how BAU depends on these CP violating phases.

Asaka, Takehiko; Ishida, Hiroyuki

2010-04-01

75

Neutrino oscillations  

SciTech Connect

The interest in neutrino oscillations is such that there are several experiments approved or planned for the near future. There are experiments already complete which have searched for oscillations particularly between nu/sub ..mu../ ..-->.. nu/sub e/. We shall concentrate here on accelerator experiments and try to show the principal limitations on the experimental sensitivity to changes in neutrino flavor. We shall give a critical review of the methodology that has been used or proposed for accelerator experiments.

White, D.H.

1982-01-01

76

Minimal neutrino texture with neutrino mass ratio and Cabibbo angle  

NASA Astrophysics Data System (ADS)

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

Shimizu, Yusuke; Takahashi, Ryo; Tanimoto, Morimitsu

2013-06-01

77

Textures for neutrino mass matrices  

SciTech Connect

We give a classification of heavy Majorana neutrino mass matrices with up to three texture zeros, assuming the Dirac masses of the neutrinos to be of the same form as the ones of the up quarks in the five texture zero solutions for the quark matrices. This is the case for many unified and partially unified models. We find that it is possible to have solutions which account for the solar and atmospheric neutrino problems as well as the COBE observations simultaneously, and we motivate the existence of such solutions from symmetries. {copyright} {ital 1996 The American Physical Society.}

Leontaris, G.K.; Lola, S.; Scheich, C.; Vergados, J.D. [Theoretical Physics Division, Ioannina University, GR-45110 Ioannina (Greece)]|[Institut fuer Theoretische Physik, Univerisitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)]|[Departamento de Fisica Teorica, Universidad Autonoma de Madrid, 28049, Madrid (Spain)]|[Department of Natural Sciences, University of Cyprus, Nicosia (Cyprus)

1996-06-01

78

GUT implications from neutrino mass  

NASA Astrophysics Data System (ADS)

An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO(10) SUSY GUT model formulated by Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super-beam and a neutrino factory for determining the small Ue3 mixing matrix element.

Albright, Carl H.

2003-05-01

79

Cosmic microwave background, matter–antimatter asymmetry and neutrino masses  

Microsoft Academic Search

We study the implications of thermal leptogenesis for neutrino parameters. Assuming that decays of N1, the lightest of the heavy Majorana neutrinos, initiate baryogenesis, we show that the final baryon asymmetry is determined by only four parameters: the CP asymmetry ?1, the heavy neutrino mass M1, the effective light neutrino mass m1, and the quadratic mean m of the light neutrino masses.

W. Buchmüller; P. Di Bari; M. Plümacher

2002-01-01

80

Large neutrino asymmetries from neutrino oscillations  

SciTech Connect

We reexamine neutrino oscillations in the early universe. Contrary to previous studies, we show that large neutrino asymmetries can arise due to oscillations between ordinary neutrinos and sterile neutrinos. This means that the big bang nucleosynthesis (BBN) bounds on the mass and mixing of ordinary neutrinos with sterile neutrinos can be evaded. Also, it is possible that the neutrino asymmetries can be large enough ({approx_gt}10{percent}) to have a significant effect on BBN through nuclear reaction rates. {copyright} {ital 1996 The American Physical Society.}

Foot, R.; Thomson, M.J.; Volkas, R.R. [Research Centre for High Energy Physics, School of Physics, University of Melbourne, Parkville, 3052 (Australia)

1996-05-01

81

Neutrino physics at accelerators  

Microsoft Academic Search

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. Neutrinos are particles that interact only weakly and this gives them a somewhat special

Enrique Fernandez

82

The solar neutrino problem.  

NASA Astrophysics Data System (ADS)

The solar neutrino problem (SNP) is reviewed on the bases of neutrino physics, solar neutrino detection and standard solar model. It is interesting that the detected neutrino flux values of different solar neutrino detectors are lower than the values calculated by SMM in different degree. The studies on SNP in particle physics and in astrophysics are also discussed respectively.

Xu, Renxin; Luo, Xianhan

1995-12-01

83

Neutrino Masses from the Top Down  

NASA Astrophysics Data System (ADS)

General classes of mechanisms for generating small neutrino masses are surveyed from a top-down (superstring) perspective. In particular, string constructions have motivated various possibilities involving higher-dimensional operators, string instantons, and wave-function overlaps in large or warped extra dimensions. These constructions may yield small Dirac masses, Majorana masses via the Weinberg operator, or Majorana masses from a seesaw mechanism, although the last typically differ in detail from the more conventional Grand Unified Theory models. Possibilities for mixing between light, active neutrinos and sterile neutrinos are surveyed.

Langacker, Paul

2012-11-01

84

NEUTRINO FACTORIES - PHYSICS POTENTIALS.  

SciTech Connect

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

PARSA,Z.

2001-02-16

85

Pseudo-Dirac neutrinos in the new standard model  

Microsoft Academic Search

The addition of gauge-singlet fermions to the standard model Lagrangian renders the neutrinos massive and allows one to explain all that is experimentally known about neutrino masses and lepton mixing by varying the values of the Majorana mass parameters M for the gauge singlets and the neutrino Yukawa couplings lambda. Here we explore the region of parameter space where M

André de Gouvêa; Wei-Chih Huang; James Jenkins

2009-01-01

86

Pseudo-Dirac neutrinos in the new standard model  

Microsoft Academic Search

The addition of gauge-singlet fermions to the standard model Lagrangian renders the neutrinos massive and allows one to explain all that is experimentally known about neutrino masses and lepton mixing by varying the values of the Majorana mass parameters M for the gauge singlets and the neutrino Yukawa couplings . Here we explore the region of parameter space where M

Andre de Gouvea; W.-C. Huang; James Jenkins

2009-01-01

87

Solar neutrinos.  

NASA Astrophysics Data System (ADS)

The main purpose of this paper is to review the progress made in the field of solar-neutrino physics with the results of the last-generation experiments together with the new perspectives suggested by the future projects. An elementary introduction to energy production mechanisms and stellar models is given. Neutrino properties and oscillations are discussed with particular interest in matter effects. Present experiments and future projects are reviewed. Particular attention is devoted to the compelling background and low-statistics problems. Finally, presently available results from running experiments are discussed, in the framework of the SNP. Some conclusions on the possibilities of the new proposed projects to actually slove the problem are also given.

Cremonesi, O.

1993-12-01

88

Sterile neutrinos as dark matter  

SciTech Connect

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

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

1993-03-01

89

GeV Seesaw, Accidentally Small Neutrino Masses, and Higgs Decays to Neutrinos  

Microsoft Academic Search

If the Standard Model particle content is extended by gauge singlet fermions\\u000a(right-handed neutrinos), active neutrinos generically acquire (Majorana)\\u000amasses, in agreement with our current understanding of the lepton sector. If\\u000athe right-handed neutrino masses are of the same order as the electroweak\\u000asymmetry breaking scale, it is usually expected that these will not mediate any\\u000aexperimentally observable effects. Here,

Andre de Gouvea

2007-01-01

90

Minimalistic neutrino mass model  

Microsoft Academic Search

We consider the simplest model which solves the solar and atmospheric neutrino puzzles, in the sense that it contains the smallest amount of beyond the Standard Model ingredients. The solar neutrino data is accounted for by Planck-mass effects while the atmospheric neutrino anomaly is due to the existence of a single right-handed neutrino at an intermediate mass scale between 109

André de Gouvêa; José W. F. Valle

2001-01-01

91

Future Neutrino Experiments  

SciTech Connect

There are a number of future neutrino experiments addressing fundamental questions about the neutrino and about what the neutrino can tell us about the universe. A class of these experiments are long baseline neutrino oscillation v{sub e} appearance searches which can measure the final unknowns of the 3x3 neutrino mixing matrix and look for CP violation in the neutrino sector. The massive detectors needed for these experiments can also search for proton decay and measure extra-terrestrial neutrino sources. There are a number of efforts worldwide to launch these experiments. These efforts, with a focus on US plans, are described.

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

2009-12-17

92

Renormalisation group analysis of single right-handed neutrino dominance  

Microsoft Academic Search

We perform a renormalisation group (RG) analysis of neutrino masses and mixing angles in the see-saw mechanism in the minimal supersymmetric standard model with three right-handed neutrinos, including the effects of the heavy neutrino thresholds. We focus on the case that one of the right-handed neutrinos provides the dominant contribution to the 23 block of the light Majorana matrix, causing

S. F. King; N. Nimai Singh

2000-01-01

93

Cosmic Microwave Background, Matter-Antimatter Asymmetry and Neutrino Masses  

Microsoft Academic Search

We study the implications of thermal leptogenesis for neutrino parameters.\\u000aAssuming that decays of N_1, the lightest of the heavy Majorana neutrinos,\\u000ainitiate baryogenesis, we show that the final baryon asymmetry is determined by\\u000aonly four parameters: the CP asymmetry epsilon_1, the heavy neutrino mass M_1,\\u000athe effective light neutrino mass \\\\tilde{m}_1, and the quadratic mean \\\\bar{m}\\u000aof the light

W. Buchmuller; P. Di Bari

2002-01-01

94

Supernova neutrino detection  

NASA Astrophysics Data System (ADS)

When a massive star collapses at the end of its life, nearly all of the gravitational binding energy of the resulting remnant is released in the form of neutrinos. The burst of neutrinos from a Galactic core collapse supernova will be detected in neutrino detectors worldwide. This talk will cover supernova neutrino detection techniques in general, current supernova neutrino detectors, and prospects for specific future experiments.

Scholberg, Kate

2012-07-01

95

Tachyonic neutrinos and the neutrino masses  

NASA Astrophysics Data System (ADS)

With a recent claim of superluminal neutrinos shown to be in error, 2012 may not be a propitious time to consider the evidence that one or more neutrinos may indeed be tachyons. Nevertheless, there are a growing number of observations that continue to suggest this possibility - albeit with an m?2<0 having a much smaller magnitude than was implied by the original OPERA claim. One recently published non-standard analysis of SN 1987A neutrinos supports a tachyonic mass eigenstate, and here we show how it leads to 3 + 3 mirror neutrino model having an unconventional mass hierarchy. The model incorporates one superluminal active-sterile neutrino pair, and it is testable in numerous ways, including making a surprising prediction about an unpublished aspect of the SN 1987A neutrinos. Additional supporting evidence involving earlier analyses of cosmic rays is summarized to add credence to the tachyonic neutrino hypothesis.

Ehrlich, Robert

2013-01-01

96

Relic Neutrino Absorption Spectroscopy  

SciTech Connect

Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmological parameters determining the expansion rate of the universe, and by the large redshift history of the cosmic neutrino sources. We investigate the possibility of determining the existence of the cosmic neutrino background within the next decade from a measurement of these absorption dips in the neutrino flux. As a by-product, we study the prospects to infer the absolute neutrino mass scale. We find that, with the presently planned neutrino detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant energy regime above 10{sup 21} eV, relic neutrino absorption spectroscopy becomes a realistic possibility. It requires, however, the existence of extremely powerful neutrino sources, which should be opaque to nucleons and high-energy photons to evade present constraints. Furthermore, the neutrino mass spectrum must be quasi-degenerate to optimize the dip, which implies m{sub {nu}} 0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.

Eberle, b

2004-01-28

97

Neutrino masses and a TeV scale seesaw mechanism  

SciTech Connect

A simple extension of the standard model providing a TeV-scale seesaw mechanism is presented. Beside the standard model particles and right-handed Majorana neutrinos, the model contains a singly charged scalar, an extra Higgs doublet, and three vectorlike singly charged fermions. In our model, Dirac neutrino mass matrix raises only at the loop level. Small but nonzero Majorana neutrino masses come from integrating out heavy Majorana neutrinos, which can be at the TeV-scale. The phenomenologies of the model are investigated, including scalar mass spectrum, neutrino masses and mixings, lepton flavor violations, heavy neutrino magnetic moments as well as possible collider signatures of the model at the LHC.

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

2010-07-01

98

Neutrino Masses with Dynamical Electroweak Symmetry Breaking  

NASA Astrophysics Data System (ADS)

In this talk I discuss the problem of accounting for light neutrino masses in theories with dynamical electroweak symmetry breaking. I will first describe this problem generally in a class of extended technicolor (ETC) models, describing the full set of Dirac and Majorana masses that arise in such theories. I will then present an explicit model exhibiting a combination of suppressed Dirac masses and a seesaw involving dynamically generated condensates of standard-model singlet, ETC-nonsinglet fermions. Because of the suppression of the Dirac neutrino mass terms, a seesaw yielding realistic neutrino masses does not require superheavy Majorana masses; indeed, the Majorana masses are typically much smaller than the largest ETC scale.

Appelquist, Thomas

2003-08-01

99

Neutrino Physics at Fermilab  

SciTech Connect

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.

Saoulidou, Niki

2008-04-09

100

Neutrino properties and puzzles  

SciTech Connect

Sixty years after the existence of the neutrino was first postulated, we are still lacking in information on the fundamental properties of neutrinos. Measurements have consistently pushed the limits on the mass, magnetic moment, and possible mixing down. Solar neutrino experiments are now shedding more light on the solar neutrino problem'' and are starting to give a hint that perhaps these quantities are nonzero. The present status of our knowledge of neutrino properties, the newest experimental data on the solar neutrino problem,'' and future plans will be presented. 27 refs.

Bowles, T.J.

1990-01-01

101

PREFACE: Nobel Symposium 129 on Neutrino Physics  

NASA Astrophysics Data System (ADS)

Nobel Symposium 129 on Neutrino Physics was held at Haga Slott in Enköping, Sweden during August 19 24, 2004. Invited to the symposium were around 40 globally leading researchers in the field of neutrino physics, both experimental and theoretical. In addition to these participants, some 30 local researchers and graduate students participated in the symposium. The dominant theme of the lectures was neutrino oscillations, which after several years were recently verified by results from the Super-Kamiokande detector in Kamioka, Japan and the SNO detector in Sudbury, Canada. Discussion focused especially on effects of neutrino oscillations derived from the presence of matter and the fact that three different neutrinos exist. Since neutrino oscillations imply that neutrinos have mass, this is the first experimental observation that fundamentally deviates from the standard model of particle physics. This is a challenge to both theoretical and experimental physics. The various oscillation parameters will be determined with increased precision in new, specially designed experiments. Theoretical physics is working intensively to insert the knowledge that neutrinos have mass into the theoretical models that describe particle physics. It will probably turn out that the discovery of neutrino oscillations signifies a breakthrough in the description of the very smallest constituents of matter. The lectures provided a very good description of the intensive situation in the field right now. The topics discussed also included mass models for neutrinos, neutrinos in extra dimensions as well as the `seesaw mechanism', which provides a good description of why neutrino masses are so small. Also discussed, besides neutrino oscillations, was the new field of neutrino astronomy. Among the questions that neutrino astronomy hopes to answer are what the dark matter in the Universe consists of and where cosmic radiation at extremely high energies comes from. For this purpose, large neutrino telescopes are built deep in the Antarctic ice, in the Baikal Lake, and in the Mediterranean Sea. Among prominent unanswered questions, highlighted as one of the most important, was whether neutrinos are Dirac or Majorana particles. By studying neutrino double beta decay, researchers hope to answer this question, but it will put very large demands on detectors. The programme also included ample time for lively and valuable discussions, which cannot normally be held at ordinary conferences. The symposium concluded with a round-table discussion, where participants discussed the future of neutrino physics.Without a doubt, neutrino physics today is moving toward a very exciting and interesting period. An important contribution to the success of the symposium was the wonderful setting that the Haga Slott manor house hotel and conference center offered to the participants.

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

2005-01-01

102

Neutrino physics in the seesaw model  

Microsoft Academic Search

The seesaw model of heavy and light Majorana neutrinos and its low-energy effective theory are studied, when the number of heavy neutrinos is equal to or less than the number of light lepton generations. We establish a general relationship between the high-energy parameters and the low-energy observables involving only the light fields. It is shown how low-energy measurements of the

A. Broncano; M. B. Gavela; E. Jenkins

2003-01-01

103

Flavor Mixing, Neutrino Masses and Neutrino Oscillations  

SciTech Connect

We study a model for the mass matrices of the leptons. We are able to relate the mass eigenvalues of the charged leptons and of the neutrinos to the mixing angles and can predict the masses of the neutrinos. We find a normal hierarchy--the masses are 0.004 eV, 0.01 eV and 0.05 eV. The atmospheric mixing angle is given by the mass ratios of the charged leptons and the neutrinos. We find 38 degrees, consistent with the experiments. The mixing element, connecting the first neutrino with the electron, is found to be 0.05.

Fritzsch, H. [University of Munich, Physics Department, Munich (Germany)

2009-05-14

104

Test of neutrino oscillations using atmospheric neutrinos  

SciTech Connect

We study the distributions of 135 atmospheric neutrino events collected in 420 days of running in a large, deep underground detector. These events come from neutrinos with path lengths ranging from a few kilometers to over 10/sup 4/ kimometers. The average neutrino energy is 920 MeV. No evidence for neutrino oscillations is observed. Flux-independent limits for ..delta..m/sub ..nu..//sup 2/ in the range of 2.2 x 10/sup -5/ to 11.2 x 10/sup -5/ eV/sup 2/ are set for maximum mixing.

LoSecco, J.M.; Bionta, R.M.; Biewitt, G.; Bratton, C.B.; Casper, D.; Chrysicopoulou, P.; Claus, R.; Cortez, B.G.; Errede, S.; Foster, G.W.

1985-05-27

105

Oscillations of neutrino velocity  

NASA Astrophysics Data System (ADS)

In this paper, we consider the problem of quantum measurement of neutrino velocity. We show, that the well known neutrino flavor oscillations are always accompanied by the oscillations of neutrino velocity. In particular, the velocity of a freely moving neutrino is demonstrated to periodically exceed the speed of light. Unfortunately, the superluminal effect turns out to be too small to be experimentally detected. It is also shown that neutrino velocity significantly depends on the energy, size and shape of the neutrino wave packet. Owing to the big experimental error of the recent experiments, these dependences remained unnoticeable. Finally, we have shown that the recent claims that superluminal neutrinos should lose energy during their flight is not true. Instead, our formula suggests the approximate conservation of energy along neutrino trajectory. All these results have been obtained without violation of special theory of relativity.

Sazdovi?, Branislav; Vasili?, Milovan

2013-03-01

106

Geo-neutrino Observation  

NASA Astrophysics Data System (ADS)

Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; McDonough, W. F.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.

2009-12-01

107

Minimalistic Neutrino Mass Model  

Microsoft Academic Search

We consider the simplest model which solves the solar and atmospheric neutrino puzzles, in the sense that it contains the smallest amount of beyond the Standard Model ingredients. The solar neutrino data is accounted for by Planck-mass effects while the atmospheric neutrino anomaly is due to the existence of a single right-handed neutrino at an intermediate mass scale between 10^9

A De Gouvêa; Jose W. F. Valle

2000-01-01

108

Topics in neutrino astrophysics  

Microsoft Academic Search

In this thesis, we investigate observable consequences of active and sterile neutrinos, in galactic, cluster, and cosmological scales. We assume that sterile neutrinos with masses of order 10's eV, 10's keV, and MeV were formed by oscillation of active neutrinos in the early universe. If sterile neutrinos with mass ~ 30 eV exist, they affect the structure of galaxies and

Man Ho Chan

2009-01-01

109

Neutrinos in the early universe  

NASA Astrophysics Data System (ADS)

The neutrinos from the Big Bang or the Cosmic Neutrino Background (CNB) carry precious information from the early epoch when our universe was only 1 s old. Although not yet directly detected, CNB may be revealed indirectly through cosmological observations due to neutrino important cosmological influence.We review the cosmological role of neutrinos and the cosmological constraints on neutrino characteristics. Namely, we discuss the impact of neutrinos in the early universe: the cosmic expansion, neutrino decoupling, the role of neutrinos in the primordial production of light elements, leptogenesis, etc. We briefly discuss the role of neutrino at later stages of the universe.Due to the considerable cosmological influence of neutrinos, cosmological bounds on neutrino properties from observational data exist. We review the cosmological constraints on the effective number of neutrino species, neutrino mass and mixing parameters, lepton number of the universe, presence of sterile neutrino, etc.

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

2012-12-01

110

Supernova Neutrino Detection  

Microsoft Academic Search

The neutrino burst from a core collapse supernova can provide information about the explosion mechanism and the mechanisms of proto neutron star cooling but also about the intrinsic properties of the neutrino such as flavor oscillations. One important question is to understand to which extend can the supernova and the neutrino physics be decoupled in the observation of a single

Inés Gil-Botella

2011-01-01

111

Neutrino Physics with Opera  

NASA Astrophysics Data System (ADS)

Neutrino physics with the OPERA experiment will be discussed in this paper. First the OPERA physic goal will be presented. A description of the neutrino beam and of the detector will follow. The analysis of the beam induced neutrino interactions will then be presented.

Bertolin, Alessandro

2011-10-01

112

Relic Neutrino Absorption Spectroscopy.  

National Technical Information Service (NTIS)

Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, v...

B. Eberle A. Ringwald

2004-01-01

113

Exploring the Neutrino Questions  

Microsoft Academic Search

Neutrinos are the most elusive of the fundamental constituents of matter and are responsible for the biggest particle physics discovery of the past decade: contrary to theoretical expectations, it is now established that neutrinos have mass. I'll review what we have learned about neutrino properties, and describe a list of known unknowns that can only be addressed by several distinct

Andre de Gouvea

2008-01-01

114

Atmospheric neutrino fluxes  

Microsoft Academic Search

A detailed Monte Carlo simulation of neutrino fluxes of atmospheric origin is made taking into account the muon polarization effect on neutrinos from muon decay. There still remains a significant discrepancy between the calculated (ve+ve)\\/(vmu+vmu) ratio and that observed by the Kamiokande group, which can be explained by three neutrino oscillations. However, the ratio evaluated at the Frejus site and

M. Honda; K. Kasahara; K. Hidaka; S. Midorikawa

1990-01-01

115

Solar neutrino oscillations  

SciTech Connect

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

Haxton, W.C.

1993-12-31

116

Status of Sterile Neutrinos  

NASA Astrophysics Data System (ADS)

The analysis of ?e and ? disappearance experiments in terms of neutrino oscillations in the framework of 3+1 neutrino mixing is reviewed taking into account the Gallium anomaly, the reactor anomaly, solar neutrino data and ?eC scattering data.

Giunti, C.

2013-04-01

117

Neutrino Landau damping  

Microsoft Academic Search

The kinetic regime of the collective interaction between neutrinos and electron plasma waves is described via the coupled kinetic equations for neutrinos and electrons. It is shown that neutrinos can Landau damp electron plasma waves. In dense stellar plasmas, this novel mechanism can play a significant role as an additional and much stronger turbulent plasma cooling process.

L. O. Silva; R. Bingham; J. M. Dawson; J. T. Mendonça; P. K. Shukla

2000-01-01

118

Neutrino oscillations and neutrino-electron scattering  

SciTech Connect

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

Kayser, B.; Rosen, S.P.

1980-10-01

119

Solar neutrinos: Probing the sun or neutrinos.  

National Technical Information Service (NTIS)

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

J. F. Wilkerson

1991-01-01

120

Neutrino observations from the Sudbury Neutrino Observatory  

SciTech Connect

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

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

2001-09-24

121

Measuring the neutrino mass using intense photon and neutrino beams  

SciTech Connect

We compute the cross section for neutrino-photon scattering taking into account a neutrino mass. We explore the possibility of using intense neutrino beams, such as those available at proposed muon colliders, together with high powered lasers to probe the neutrino mass in photon-neutrino collisions.

Dicus, Duane A.; Repko, Wayne W.; Vega, Roberto

2000-11-01

122

Possible Neutrino-Antineutrino Oscillation Under Gravity and its Consequences  

NASA Astrophysics Data System (ADS)

We show that under gravity the effective masses for neutrino and antineutrino are different which opens a possible window of neutrino-antineutrino oscillation even if the rest masses of the corresponding eigenstates are same. This is due to CPT violation and possible to demonstrate if the neutrino mass eigenstates are expressed as a combination of neutrino and antineutrino eigenstates, as of the neutral kaon system, with the plausible breaking of lepton number conservation. In early universe, in presence of various lepton number violating processes, this oscillation might lead to neutrino-antineutrino asymmetry which resulted baryogenesis from the B-L symmetry by electro-weak sphaleron processes. On the other hand, for Majorana neutrinos, this oscillation is expected to affect the inner edge of neutrino dominated accretion disks around a compact object by influencing the neutrino sphere which controls the accretion dynamics, and then the related type-II supernova evolution and the r-process nucleosynthesis.

Mukhopadhyay, Banibrata

2008-09-01

123

Nucleosynthesis and Neutrinos  

SciTech Connect

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

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

2011-05-06

124

The Sudbury Neutrino Observatory  

NASA Astrophysics Data System (ADS)

The Sudbury Neutrino Observatory is a second-generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.

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

2000-07-01

125

Geo-neutrinos  

NASA Astrophysics Data System (ADS)

Geo-neutrinos, electron anti-neutrinos produced in ?-decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. After a brief introduction about the Earth (mostly for physicists) and the very basics about the neutrinos and anti-neutrinos (mostly for geologists), I describe the geo-neutrinos' properties and the main aims of their study. An overview of the latest experimental results obtained by KamLand and Borexino experiments is provided. A short overview of future perspectives of this new inter-disciplinary field is given.

Ludhova, L.

2012-08-01

126

Absolute neutrino mass scale  

NASA Astrophysics Data System (ADS)

Neutrino oscillation experiments firmly established non-vanishing neutrino masses, a result that can be regarded as a strong motivation to extend the Standard Model. In spite of being the lightest massive particles, neutrinos likely represent an important bridge to new physics at very high energies and offer new opportunities to address some of the current cosmological puzzles, such as the matter-antimatter asymmetry of the Universe and Dark Matter. In this context, the determination of the absolute neutrino mass scale is a key issue within modern High Energy Physics. The talks in this parallel session well describe the current exciting experimental activity aiming to determining the absolute neutrino mass scale and offer an overview of a few models beyond the Standard Model that have been proposed in order to explain the neutrino masses giving a prediction for the absolute neutrino mass scale and solving the cosmological puzzles.

Capelli, Silvia; Di Bari, Pasquale

2013-04-01

127

Properties of neutrinos: Recent results  

SciTech Connect

Recent progress in experimental determinations of the properties of neutrinos is summarized. In particular, the extensive work on direct kinematic measurements of neutrino mass, on neutrino counting and on neutrino oscillations is highlighted. It is concluded that there may already be sufficient information to fix the masses of the neutrinos, but the evidence is still far from convincing. 63 refs., 13 figs.

Robertson, R.G.H.

1987-01-01

128

Fourth Family Neutrinos and the Higgs Boson at the LHC  

Microsoft Academic Search

We evaluate the LHC discovery potential for the fourth family Standard Model neutrinos in the process pp ? Z\\/h ? ?4 ¯ ?4 ? W ?W ?. We show that, depending on their masses, the simultaneous discovery of both the Higgs boson and the heavy neutrinos is probable at early stages of LHC operation. Results are presented for both Majorana

T. Çuhadar-Dönszelmann; M. Karagöz Ünel; V. E. Özcan; S. Sultansoy; G. Ünel

129

Massive Neutrinos in a Grounds-Up Approach.  

National Technical Information Service (NTIS)

We examine neutrino oscillations in a two Higgs doublet model (2HDM) in which the second doublet couples only to the third generation right-handed up-fermions, i.e., to t(sub R) and N(sub 3) which is the heaviest right-handed Majorana neutrino. The inhere...

S. Bar-Shalom D. Atwood A. Soni

2006-01-01

130

Limits on cold dark matter from underground neutrinos  

NASA Astrophysics Data System (ADS)

Limits on the flux of energetic neutrinos from the direction of the Sun are used to improve the limits on cold dark matter. The model of Olive and Srednicki is used to exclude a number of dark matter candidates including photinos, Higgsinos, Majorana neutrinos, massive Dirac neutrinos and sneutrinos. New limits are placed on photino and Higgsino masses. We also quote limits on fluxes from the Earth.

Losecco, J. M.

1995-02-01

131

Neutrino phenomenology of very low-energy seesaw scenarios  

Microsoft Academic Search

The standard model augmented by the presence of gauge-singlet right-handed neutrinos proves to be an ideal scenario for accommodating nonzero neutrino masses. Among the new parameters of this 'new standard model' are right-handed neutrino Majorana masses M. Theoretical prejudice points to M much larger than the electroweak symmetry breaking scale, but it has recently been emphasized that all M values

Andre de Gouvea; James Jenkins; Nirmala Vasudevan

2007-01-01

132

Neutrino phenomenology of very low-energy seesaw scenarios  

Microsoft Academic Search

The standard model augmented by the presence of gauge-singlet right-handed neutrinos proves to be an ideal scenario for accommodating nonzero neutrino masses. Among the new parameters of this ``new standard model'' are right-handed neutrino Majorana masses M. Theoretical prejudice points to M much larger than the electroweak symmetry breaking scale, but it has recently been emphasized that all M values

André de Gouvêa; James Jenkins; Nirmala Vasudevan

2007-01-01

133

High Energy Neutrinos with a Mediterranean Neutrino Telescope.  

National Technical Information Service (NTIS)

The high energy neutrino detection by a km3 Neutrino Telescope placed in the Mediterranean sea provides a unique tool to both determine the diffuse astrophysical neutrino flux and the neutrinonucleon cross section in the extreme kinematical region, which ...

E. Borriello G. Mangano G. Miele O. Pisanti S. Pastor

2007-01-01

134

Neutrinos from WIMP annihilations in the Sun including neutrino oscillations  

NASA Astrophysics Data System (ADS)

The prospects to detect neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes.

Blennow, Mattias; Edsjö, Joakim; Ohlsson, Tommy

2011-12-01

135

Heavy neutrino signals at large hadron colliders  

Microsoft Academic Search

We study the LHC discovery potential for heavy Majorana neutrino singlets in the process pp ? W+ ? ?+N ? ?+?+jj (? = e, ?) plus its charge conjugate. With a fast detector simulation we show that backgrounds involving two like-sign charged leptons are not negligible and, moreover, they cannot be eliminated with simple sequential kinematical cuts. Using a likelihood

Francisco del Aguila; Juan Antonio Aguilar-Saavedra; Roberto Pittau

2007-01-01

136

Probing neutrino dark energy with extremely high energy cosmic neutrinos  

Microsoft Academic Search

Recently, a new non-standard-model neutrino interaction mediated by a light scalar field was proposed, which renders the big bang relic neutrinos of the cosmic neutrino background a natural dark energy candidate, the so-called neutrino dark energy. As a further consequence of this interaction, the neutrino masses become functions of the neutrino energy densities and are thus promoted to dynamical, time\\/redshift

Andreas Ringwald; Lily Schrempp

2006-01-01

137

Why Are Neutrinos Light? -- An Alternative  

SciTech Connect

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

Hall, Lawrence J.; Oliver, Steven J.

2004-09-23

138

MINOS Sterile Neutrino Search  

SciTech Connect

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

Koskinen, David Jason; /University Coll. London

2009-09-01

139

Charged Cosmic Rays and Neutrinos  

NASA Astrophysics Data System (ADS)

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

Kachelrieß, M.

2013-04-01

140

Supernova Neutrino Detection  

NASA Astrophysics Data System (ADS)

The neutrino burst from a core collapse supernova can provide information about the explosion mechanism and the mechanisms of proto neutron star cooling but also about the intrinsic properties of the neutrino such as flavor oscillations. One important question is to understand to which extend can the supernova and the neutrino physics be decoupled in the observation of a single supernova. The possibility to probe the neutrino mixing angle ?13 and the type of mass hierarchy from the detection of supernova neutrinos with liquid argon detectors is discussed in this paper. Moreover, a quantitatively study about the possibility to constrain the supernova parameters is presented. A very massive liquid argon detector (? 100 kton) is needed to perform accurate measurements of these parameters. Finally the possible detection of the diffuse supernova neutrino background in liquid argon detectors is also described.

Gil-Botella, Inés

2011-07-01

141

Neutrino Oscillations in MINOS  

NASA Astrophysics Data System (ADS)

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

Ma, Jasmine

2009-05-01

142

Lunar neutrino physics  

NASA Astrophysics Data System (ADS)

The detection and investigation of neutrinos is considered in terms of lunar observation with reference to TeV astronomy, the detection of SSC-type neutrino-beams, and detection based on neutrino acoustic radiation. Reference is made to the limitations of earth-based observations related to neutrinos which result from cosmic rays incident on the atmosphere, and the practical aspects of lunar observations are listed. One square km of lunar surface can be used as a shield for cosmic rays and a target for TeV neutrinos within which emerging muons are observed. An EeV detector based on acoustic detection of the moon's core is also proposed to investigate this energy range. The TeV-detection and acoustical experiments are concluded to be feasible experiments (contingent upon development of the appropriate technologies) which can yield significant results in the field of neutrino physics.

Learned, J. G.

1990-03-01

143

Solar neutrino detection  

SciTech Connect

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

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

2009-04-30

144

Solar neutrino detection  

NASA Astrophysics Data System (ADS)

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

Miramonti, Lino

2009-04-01

145

Novel Ideas for Neutrino Beams  

SciTech Connect

Recent developments in neutrino physics, primarily the demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The simplest phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or {pi}, contribute to the otherwise unexplained baryon asymmetry observed in the universe. Exploring the neutrino sector will require very intense beams of neutrinos, and will need novel solutions.

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

2007-04-23

146

What is the energy scale of the physics responsible for neutrino masses?  

Microsoft Academic Search

The observed tiny but non-zero neutrino masses are often interpreted as evidence for new physics at energy scales above 1010 TeV. This statement is based on several assumptions, including (a) neutrinos are Ma-jorana fermions, (b) the physics responsible for neutrino masses is not very weakly coupled, and (c) the new physics sector - responsible for lepton number breaking - couples

André de Gouvêa; James Jenkins

2008-01-01

147

REVIEWS OF TOPICAL PROBLEMS: The neutrino mass in elementary-particle physics and in big bang cosmology  

NASA Astrophysics Data System (ADS)

Some theoretical aspects of a nonzero value for the neutrino rest mass and its possible implications for physics are discussed. The nature of the neutrino mass is analyzed, as well as the physical consequences that may derive from the existence of new helicity states for the neutrino or from lepton charge nonconservation if the mass is of Dirac or Majorana character, respectively. Massive neutrinos are examined in the context of grand unified theories combining the weak, strong, and electromagnetic interactions. Searches for neutrino-mass effects in ? decay and for neutrino oscillations are reviewed. Several astrophysical effects of the neutrino mass are described: solar-neutrino oscillations, the decay of primordial neutrinos, the feasibility of detecting massive primordial neutrinos experimentally. The predictions of big bang theory regarding the neutrino number density in the universe are analyzed, and a discussion is given of the influence neutrino oscillations might have on the neutrino density and on cosmological nucleosynthesis.

Zel'dovich, Ya B.; Khlopov, M. Yu

1981-09-01

148

Neutrino Physics at Fermilab  

SciTech Connect

The Liquid Scintillator Neutrino Detector (LSND), located at the LANSCE (formerly LAMPF) linear accelerator at Los Alamos National Laboratory, has seen evidence for the oscillation of neutrinos, and hence neutrino mass. That discovery was the impetus for this LDRD project, begun in 1996. The goal of this project was to define the appropriate technologies to use in a follow up experiment and to set in place the requirements for such an experiment.

Federspiel, F.; Garvey, G.; Louis, W.C.; Mills, G.B.; Tayloe, R.; Sandberg, V.; Sapp, B.; White, D.H.

1999-07-09

149

Neutrinos from gravitational collapse  

SciTech Connect

Detailed calculations are made of the neutrino spectra emitted during gravitational collapse events (Type II supernovae). Those aspects of the neutrino signal which are relatively independent of the collapse model and those aspects which are sensitive to model details are discussed. The easier-to-detect high energy tail of the emitted neutrinos has been calculated using the Boltzmann equation which is compared with the result of the traditional multi-group flux limited diffusion calculations. 8 figs., 28 refs.

Mayle, R.; Wilson, J.R.; Schramm, D.N.

1986-05-01

150

Neutrinos in the Electron  

SciTech Connect

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

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

2007-04-28

151

Neutrinos in supernovae  

SciTech Connect

The role of neutrinos in Type II supernovae is discussed. An overall view of the neutrino luminosity as expected theoretically is presented. The different weak interactions involved are assessed from the standpoint of how they exchange energy, momentum, and lepton number. Particular attention is paid to entropy generation and the path to thermal and chemical equilibration, and to the phenomenon of trapping. Various methods used to calculate the neutrino flows are considered. These include trapping and leakage schemes, distribution-averaged transfer, and multi-energy group methods. The information obtained from the neutrinos caught from Supernova 1987a is briefly evaluated. 55 refs., 7 figs.

Cooperstein, J.

1986-10-01

152

Solar neutrinos: experimental approaches.  

PubMed

This article discusses the new experiments, under way or proposed, that will measure the flux of solar neutrinos and so probe the "solar neutrino puzzle." Both radiochemical and electronic detector experiments are analyzed in terms of possible findings relevant to astrophysics and neutrino properties. Important elements are sensitivity to the principal components of the solar neutrino spectrum, directionality of the detector response, and an energy-measuring capability that might provide a unique identifying signal. Experiments beyond those currently under way will probably be needed, and development of real-time detectors is particularly important. PMID:17753997

Friedlander, G; Weneser, J

1987-02-13

153

Multimessenger Astronomy and Neutrinos  

NASA Astrophysics Data System (ADS)

Neutrinos play a very important role in multimessenger astronomy. In this talk, I start with a simple argument on how bright the Universe is in both photons and neutrinos. It is remarkable that one can easily show that the neutrinos, especially those emitted from past core-collapse supernovae, form the brightest radiation component in the Universe, ever emitted from astrophysical sources. The detection of this cosmic supernova neutrino background has not been made yet, but is almost guaranteed in the near future. Thus, I review theoretical predictions of the supernova neutrino background, and the latest upper limits experimentally obtained on its flux. Then I discuss prospects of detecting supernova neutrinos from nearby galaxies. With upcoming Mton detectors, or hopefully with a multi-Mton detector, one could study not only supernova neutrinos but also a true stellar death rate, hidden black-hole formation, etc. Finally, I discuss detectability of high-energy neutrinos and implications for underlying supernova-gamma-ray burst connection. Detecting neutrinos will not only give unique diagnostics but also help find gravitational waves.

Ando, Shin'ichiro

2013-04-01

154

Models of neutrino mass with a low cutoff scale  

SciTech Connect

In theories with a low quantum gravity scale, global symmetries are expected to be violated, inducing excessive proton decay or large Majorana neutrino masses. The simplest cure is to impose discrete gauge symmetries, which in turn make neutrinos massless. We construct models that employ these gauge symmetries while naturally generating small neutrino masses. Majorana (Dirac) neutrino masses are generated through the breaking of a discrete (continuous) gauge symmetry at low energies, e.g., 2 keV-1 GeV. The Majorana case predicts {delta}N{sub {nu}}{approx_equal}1 at BBN, neutrinoless double beta decay with scalar emission, and modifications to the CMB anisotropies from domain walls in the Universe as well as providing a possible Dark Energy candidate. For the Dirac case, despite the presence of a new light gauge boson, all laboratory, astrophysical, and cosmological constraints can be avoided.

Davoudiasl, Hooman [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey 08540 (United States); Kitano, Ryuichiro [School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey 08540 (United States); Kribs, Graham D. [School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey 08540 (United States); Department of Physics, University of Oregon, Eugene, Oregon 97403 (United States); Murayama, Hitoshi [Department of Physics, University of California, Berkeley, California 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey 08540 (United States)

2005-06-01

155

Diagnostic potential of cosmic-neutrino absorption spectroscopy  

SciTech Connect

Annihilation of extremely energetic cosmic neutrinos on the relic-neutrino background can give rise to absorption lines at energies corresponding to formation of the electroweak gauge boson Z{sup 0}. The positions of the absorption dips are set by the masses of the relic neutrinos. Suitably intense sources of extremely energetic (10{sup 21} - 10{sup 25}-eV) cosmic neutrinos might therefore enable the determination of the absolute neutrino masses and the flavor composition of the mass eigenstates. Several factors--other than neutrino mass and composition--distort the absorption lines, however. We analyze the influence of the time-evolution of the relic-neutrino density and the consequences of neutrino decay. We consider the sensitivity of the lineshape to the age and character of extremely energetic neutrino sources, and to the thermal history of the Universe, reflected in the expansion rate. We take into account Fermi motion arising from the thermal distribution of the relic-neutrino gas. We also note the implications of Dirac vs. Majorana relics, and briefly consider unconventional neutrino histories. We ask what kinds of external information would enhance the potential of cosmic-neutrino absorption spectroscopy, and estimate the sensitivity required to make the technique a reality.

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

2004-12-01

156

Deformation effects and neutrinoless positron {beta}{beta} decay of {sup 96}Ru, {sup 102}Pd, {sup 106}Cd, {sup 124}Xe, {sup 130}Ba, and {sup 156}Dy isotopes within a mechanism involving Majorana neutrino mass  

SciTech Connect

The ({beta}{sup +}{beta}{sup +}){sub 0{nu}} and ({epsilon}{beta}{sup +}){sub 0{nu}} modes of {sup 96}Ru, {sup 102}Pd, {sup 106}Cd, {sup 124}Xe, {sup 130}Ba, and {sup 156}Dy isotopes are studied in the projected Hartree-Fock-Bogoliubov framework for the 0{sup +}{yields}0{sup +} transition. The reliability of the intrinsic wave functions required to study these decay modes has been established in our earlier works by obtaining an overall agreement between the theoretically calculated spectroscopic properties, namely yrast spectra, reduced B(E2:0{sup +}{yields}2{sup +}) transition probabilities, quadrupole moments Q(2{sup +}) and gyromagnetic factors g(2{sup +}), and the available experimental data in the parent and daughter even-even nuclei. In the present work, the required nuclear transition matrix elements are calculated in the Majorana neutrino mass mechanism using the same set of intrinsic wave functions as used to study the two neutrino positron double-{beta} decay modes. Limits on effective light neutrino mass and effective heavy neutrino mass are extracted from the observed limits on half-lives T{sub 1/2}{sup 0{nu}}(0{sup +}{yields}0{sup +}) of ({beta}{sup +}{beta}{sup +}){sub 0{nu}} and ({epsilon}{beta}{sup +}){sub 0{nu}} modes. We also investigate the effect of quadrupolar correlations vis-a-vis deformation on nuclear transition matrix elements (NTMEs) required to study the ({beta}{sup +}{beta}{sup +}){sub 0{nu}} and ({epsilon}{beta}{sup +}){sub 0{nu}} modes.

Rath, P. K. [Department of Physics, University of Lucknow, Lucknow-226007 (India); Chandra, R. [Department of Physics, University of Lucknow, Lucknow-226007 (India); Department of Physics and Meteorology, IIT, Kharagpur-721302 (India); Chaturvedi, K. [Department of Physics, University of Lucknow, Lucknow-226007 (India); Department of Physics, Bundelkhand University, Jhansi-284128 (India); Raina, P. K. [Department of Physics and Meteorology, IIT, Kharagpur-721302 (India); Hirsch, J. G. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, Mexico 04510 D.F. (Mexico)

2009-10-15

157

Neutrinos from collapsars  

NASA Astrophysics Data System (ADS)

Context. Long gamma-ray bursts (GRBs) are associated with the gravitational collapse of very massive stars. The central engine of a GRB can collimate relativistic jets that propagate inside the stellar envelope. The shock waves produced when the jet disrupts the stellar surface are capable of accelerating particles up to very high energies. Aims: If the jet has hadronic content, neutrinos will be produced via charged pion decays. The main goal of this work is to estimate the neutrino emission produced in the region close to the surface of the star, taking pion and muon cooling into account, along with subtle effects arising from neutrino production in a highly magnetized medium. Methods: We estimate the maximum energies of the different kinds of particles and solve the coupled transport equations for each species. Once the particle distributions are known, we calculate the intensity of neutrinos. We study the different effects on the neutrinos that can change the relative weight of different flavors. In particular, we consider the effects of neutrino oscillations, and of neutrino spin precession caused by strong magnetic fields. Results: The expected neutrino signals from the shocks in the uncorking regions of Population III events is very weak, but the neutrino signal produced by Wolf-Rayet GRBs with z < 0.5 is not far from the level of the atmospheric background. Conclusions: The IceCube experiment does not have the sensitivity to detect neutrinos from the implosion of the earliest stars, but a number of high-energy neutrinos may be detected from nearby long GRBs. The cumulative signal should be detectable over several years (~10 yr) of integration with the full 86-string configuration.

Vieyro, F. L.; Romero, G. E.; Peres, O. L. G.

2013-10-01

158

Extremely high energy cosmic neutrinos and relic neutrinos  

SciTech Connect

I review the essentials of ultrahigh-energy neutrino interactions, show how neutral-current detection and flavor tagging can enhance the scientific potential of neutrino telescopes, and sketch new studies on neutrino encounters with dark matter relics and on gravitational lensing of neutrinos.

Quigg, Chris; /Fermilab /CERN

2006-03-01

159

Determination of the atmospheric neutrino fluxes from atmospheric neutrino data  

Microsoft Academic Search

The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard atmospheric neutrino data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based on the convolution of the primary cosmic ray spectrum with the expected yield of neutrinos per incident cosmic ray.

Concepciòn Gonzalez-Garcia; Michele Maltoni; Joan Rojo

2006-01-01

160

High Energy Neutrinos with a Mediterranean Neutrino Telescope  

SciTech Connect

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

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

2007-09-01

161

Double Beta Decays and Neutrinos - Experiments and MOON  

SciTech Connect

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

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

2008-01-24

162

Atomic mass measurements for neutrino mass  

NASA Astrophysics Data System (ADS)

As usually understood, observation of neutrinoless double-beta-decay implies that neutrinos are their own antiparticles (Majorana particles), while measurements of the decay rate, or limits on the rate, provide information on absolute neutrino mass. Large-scale neutrinoless double-beta-decay detectors, proposed or under development, such as EXO, CUORE, GERDA, MAJORANA, etc. should be sensitive to a linear combination of neutrino masses, the ``effective Majorana mass of the electron neutrino'', below 0.1 eV/c^2. The signature of neutrinoless double-beta decay is a sharp peak in the total electron-energy spectrum at the Q-value of the decay -- the mass-energy difference between the parent and daughter atoms. Using one or two multiply-charged ions in a Penning trap, we have now measured the atomic masses of ^136Xe, ^130Te, ^130Xe, ^76Ge, ^76Se to a fractional precision of 2 x 10-10 or better, corresponding to Q-values with uncertainties below 25 eV. This is more than sufficient precision for the proposed large-scale experiments. Progress on mass measurements of ^74Ge and ^74Se, relevant to resonance-enhanced neutrinoless double-electron capture in ^74Se, will also be reported.

Redshaw, Matthew; Mount, Brianna; Myers, Edmund

2009-05-01

163

Cosmological neutrino mass detection: The Best probe of neutrino lifetime  

SciTech Connect

Future cosmological data may be sensitive to the effects of a finite sum of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a cosmological detection of neutrino mass at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on neutrino secret interactions with (quasi-)massless particles as in majoron models. On the other hand, neutrino decay may provide a way-out to explain a discrepancy {approx}< 0.1 eV between cosmic neutrino bounds and Lab data.

Serpico, Pasquale D.; /Fermilab

2007-01-01

164

Neutrino Nuclear Responses for Neutrino Studies in Nuclear Femto Laboratories  

SciTech Connect

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

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

2010-11-24

165

Neutrino 2012: Outlook - theory  

NASA Astrophysics Data System (ADS)

Ongoing developments in theory and phenomenology are related to the measured large value of 1-3 mixing and indications of significant deviation of the 2-3 mixing from maximal one. "Race" for the mass hierarchy has started and there is good chance that multi-megaton scale atmospheric neutrino detectors with low threshold (e.g. PINGU) will establish the type of hierarchy. Two IceCube candidates of the PeV cosmic neutrinos if confirmed, is the beginning of new era of high energy neutrino astronomy. Accumulation of data on solar neutrinos (energy spectrum, D-N asymmetry, value of ?m212) may uncover some new physics. The Tri-bimaximal mixing is disfavored and the existing discrete symmetry paradigm may change. The confirmed QLC prediction, ?13??C/2, testifies for GUT, seesaw and some symmetry at very high scales. However, the same value of 1-3 mixing can be obtained in various ways which have different implications. The situation in lepton sector changes from special (with specific neutrino symmetries, etc.) to normal, closer to that in the quark sector. Sterile neutrinos are challenge for neutrino physics but also opportunity with many interesting phenomenological consequences. Further studies of possible connections between neutrinos and the dark sector of the Universe may lead to breakthrough both in particle physics and cosmology.

Smirnov, A. Yu.

2013-02-01

166

Neutrino masses and oscillations  

Microsoft Academic Search

A report on neutrino masses, mixing and oscillations, made in Dubna at the symposium dedicated to 100 years of the Rutherford's discovery of atomic nucleus, is presented. We start with the hypothesis of neutrino which was proposed by W. Pauli in December 1930 in order to solve some problems of nuclei (the problem of spin of $^{7}N_{14}$ and other nuclei

S. M. Bilenky

2011-01-01

167

The Sudbury Neutrino Observatory  

SciTech Connect

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.

1996-09-01

168

Particle Production by Neutrinos.  

National Technical Information Service (NTIS)

A review is given of particle production by neutrinos in charged-current inclusive and exclusive channels. The production rates for various particles in neutrino-nucleon interactions at a beam energy of 25 GeV are compared. The mesons are, of course, domi...

P. Schreiner

1979-01-01

169

Measurements of neutrino mass  

SciTech Connect

Direct experimental information of neutrino mass as derived from the study of nuclear and elementary-particle weak decays is reviewed. Topics include tritium beta decay; the /sup 3/He-T mass difference; electron capture decay of /sup 163/Ho and /sup 158/Tb; and limits on massive neutrinos from cosmology. 38 references. (WHK)

Robertson, R.G.H.

1985-01-01

170

Hierarchically acting sterile neutrinos  

NASA Astrophysics Data System (ADS)

We propose that a hierarchical spectrum of sterile neutrinos (eV, keV, 1013-15 GeV) is considered as the explanation for MiniBooNE and LSND oscillation anomalies, dark matter, and baryon asymmetry of the universe (BAU), respectively. The scenario can also realize the smallness of active neutrino masses by the seesaw mechanism.

Chen, Chian-Shu; Takahashi, Ryo

2012-07-01

171

Summary of neutrino presentations  

SciTech Connect

This summary is divided into two sections. First, we concentrate on conventional neutrino physics interpreted in the context of standard electroweak theory. Second, we discuss double beta decay where gross violations of the predictions of the theory might appear, and also we discuss specific searches for consequences of finite neutrino mass. 11 figs., 5 tabs.

White, D.H.

1988-01-01

172

Neutrino Physics - Theory  

Microsoft Academic Search

I discuss the new physics unveiled by neutrino oscillation experiments. It is fair to say that, while significant theoretical progress has been made, we are yet to construct a unique coherent picture that naturally explains non-zero, yet tiny, neutrino masses and the newly revealed pattern of lepton mixing. I discuss what the challenges are, and point to the fact that

André de Gouvêa

2005-01-01

173

Solar Interior: Neutrinos  

NASA Astrophysics Data System (ADS)

Six experiments have observed solar NEUTRINOS, three of which are radiochemical experiments: Homestake (chlorine detector), GALLEX (gallium detector) and SAGE (gallium detectors). These radiochemical detectors register all neutrinos above a fixed threshold energy (0.8 MeV for chlorine, 0.2 MeV for gallium), with no further information about energy. Three other experiments, Kamiokande, SUPER-KAMIO...

Bahcall, J.; Murdin, P.

2000-11-01

174

Reactor neutrino anomaly and sterile neutrinos revisited  

NASA Astrophysics Data System (ADS)

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

Lennarz, Annika

2012-10-01

175

Summary: Neutrinos and nonaccelerator physics  

SciTech Connect

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

Hoffman, C.M.

1991-01-01

176

Review of Neutrino Oscllations Experiments  

Microsoft Academic Search

Several experiments have sought evidence for neutrino mass and mixing via the phenomenon of neutrino flavor oscillations. In a three neutrino model, these oscillations are described by three angles, two mass splittings, and one CP violating phase. Experiments using neutrinos from the Sun, the atmosphere, nuclear reactors, and particle accelerators have gathered considerable information on these angles and splittings. Two

M. D. Messier

2006-01-01

177

Theoretical aspects of neutrino oscillations  

Microsoft Academic Search

I review some aspects concerning the physics of neutrino mixing and oscillations. I discuss in some detail the physical neutrino oscillations parameter space in the case of two and three family mixing, and briefly describe the current knowledge of neutrino mixing parameters according to the present solar, atmospheric, and reactor neutrino data. I also briefly comment on the possibility of

André de Gouvêa

2003-01-01

178

Highlights of Neutrinos in Cosmology  

Microsoft Academic Search

Neutrinos play unique roles in many epochs of the Universe's evolution. Important information can be gleaned from neutrino evolution during the big bang nucleosynthesis era, while at later times neutrinos have a significant impact on the cosmic microwave background and large scale structure power spectra. For example, cosmological data now place the tightest constraints on neutrino mass, though there is

Nicole Bell

2006-01-01

179

Neutrino Energies in a Neutrinosphere  

NASA Astrophysics Data System (ADS)

The energies of neutrinos in a neutrinosphere, the dense matter created after the gravitational collapse of a massive star are estimated. Cubic equations for energy eigenvalues of neutrinos are used with the effective masses found by taking the neutrinos at rest in neutrinosphere matter. Large differences in the effective mass of some neutrino species in a neutrinosphere compared to vacuum are found.

Kisslinger, Leonard S.

2013-11-01

180

Resonant neutrino oscillations and the neutrino signature of supernovae  

Microsoft Academic Search

We examine the effects of resonant neutrino oscillations, proposed as a solution to the solar neutrino puzzle, on the neutrino signature of a Type II supernova. We find that, for parameters corresponding to an adiabatic conversion of most of the 8B neutrino flux, the supernova neutrino signal in a water-Cerenkov detector is altered in the following way: (1) The isotropic-to-directional

Terry P. Walker; David N. Schramm

1987-01-01

181

Measurement of atmospheric neutrino flux consistent with tau neutrino appearance.  

PubMed

A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma. PMID:17155460

Abe, K; Hayato, Y; Iida, T; Ishihara, K; Kameda, J; Koshio, Y; Minamino, A; Mitsuda, C; Miura, M; Moriyama, S; Nakahata, M; Obayashi, Y; Ogawa, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takeuchi, Y; Ueshima, K; Higuchi, I; Ishihara, C; Ishitsuka, M; Kajita, T; Kaneyuki, K; Mitsuka, G; Nakayama, S; Nishino, H; Okumura, K; Saji, C; Takenaga, Y; Totsuka, Y; Clark, S; Desai, S; Dufour, F; Kearns, E; Likhoded, S; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Wang, W; Goldhaber, M; Casper, D; Cravens, J P; Kropp, W R; Liu, D W; Mine, S; Regis, C; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Hill, J E; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Scholberg, K; Tanimoto, N; Walter, C W; Wendell, R; Ellsworth, R W; Tasaka, S; Guillian, E; Learned, J G; Matsuno, S; Messier, M D; Ichikawa, A K; Ishida, T; Ishii, T; Iwashita, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nitta, K; Oyama, Y; Suzuki, A T; Hasegawa, M; Kato, I; Maesaka, H; Nakaya, T; Nishikawa, K; Sasaki, T; Sato, H; Yamamoto, S; Yokoyama, M; Haines, T J; Dazeley, S; Hatakeyama, S; Svoboda, R; Sullivan, G W; Habig, A; Gran, R; Fukuda, Y; Sato, T; Itow, Y; Koike, T; Jung, C K; Kato, T; Kobayashi, K; Malek, M; McGrew, C; Sarrat, A; Terri, R; Yanagisawa, C; Tamura, N; Sakuda, M; Sugihara, M; Kuno, Y; Yoshida, M; Kim, S B; Yoo, J; Ishizuka, T; Okazawa, H; Choi, Y; Seo, H K; Gando, Y; Hasegawa, T; Inoue, K; Ishii, H; Nishijima, K; Ishino, H; Watanabe, Y; Koshiba, M; Kielczewska, D; Zalipska, J; Berns, H G; Shiraishi, K K; Washburn, K; Wilkes, R J

2006-10-23

182

Solar Neutrino Physics  

SciTech Connect

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

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

1999-07-15

183

On neutrino flavor states  

NASA Astrophysics Data System (ADS)

We review the issues associated with the construction of neutrino flavor states. We then provide a consistent proof that the flavor states are approximately well-defined only if neutrinos are ultra-relativistic or the mass differences are negligible compared to energy. However, we show that weak interactions can be consistently described by only neutrino mass eigenstates. Meanwhile, the second quantization of neutrino flavor fields generally has no physical relevance as their masses are indefinite. Therefore, the flavor states are not physical quantum states and they should simply be interpreted as definitions to denote specific linear combinations of mass eigenstates involved in weak interactions. We also briefly discuss the implication of this work for the mixing between active and heavy sterile neutrinos.

Ho, Chiu Man

2012-12-01

184

Astrophysical High Energy Neutrinos  

SciTech Connect

Astrophysical candidate sources of ultrahigh-energy cosmic-rays are also expected to produce high-energy neutrinos in situ and around their acceleration sites by interacting with abundant soft photons or nucleons. Detection of these neutrinos then may identify the yet unknown sources of the cosmic rays. I discuss different models of high-energy neutrino signals from astrophysical objects such as gamma-ray bursts and hyper-novae, and how detection/non-detection of these astronomical messengers may constrain the source models. I also discuss the detectability of these neutrinos in upcoming neutrino telescopes and how flavor tagging may be used to learn about the astrophysics of the sources.

Razzaque, Soebur [Department of Astronomy and Astrophysics, Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)

2007-11-08

185

Zero minors of the neutrino mass matrix  

SciTech Connect

We examine the possibility that a certain class of neutrino mass matrices, namely, those with two independent vanishing minors in the flavor basis, regardless of being invertible or not, is sufficient to describe current data. We compute generic formulas for the ratios of the neutrino masses and for the Majorana phases. We find that seven textures with two vanishing minors can accommodate the experimental data. We present an estimate of the mass matrix for these patterns. All of the possible textures can be dynamically generated through the seesaw mechanism augmented with a discrete Abelian symmetry.

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

2008-10-01

186

Solar neutrinos: Probing the sun or neutrinos  

SciTech Connect

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

Wilkerson, J.F.

1991-01-01

187

Absolute neutrino mass measurements  

SciTech Connect

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)

2011-10-06

188

Review of Recent Neutrino Physics Research  

NASA Astrophysics Data System (ADS)

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

Kisslinger, Leonard S.

2013-09-01

189

Neutrino astronomy with MACRO  

NASA Astrophysics Data System (ADS)

High energy neutrinos from astrophysical sources can be detected as upward-going muons produced in charged-current interactions with the matter surrounding the detector. We present the results of a search for either a diffuse astrophysical neutrino flux or a point-like source of neutrinos in the sample of upward-going muons gathered by MACRO. We find no evidence for either type of signal. The muon flux upper limit for the diffuse signal has been set at the level of 1.5 ×10-14 cm-2 s-1 sr-1 . 1 Neutrino astronomy: overview and motivation High energy neutrinos in the range from 100 GeV up to 107 GeV are expected from a wide class of galactic and extragalactic astrophysical objects. Neutrino production requires the existence of hadronic processes and is generally described in the picture of the so-called beam dump model (Gaisser, 1995): high energy protons accelerated in proximity of compact objects by shocks waves or plasma turbulence interact with photons or target matter surrounding the source, producing pions. Neutrinos of electron and muon flavors originate from decay of charged pions, as well as from decay of generated muons. In the same hadronic chains, high energy ?-rays are expected to be produced through neutral pion decay. Like ?-rays, neutrinos can travel undeflected through the Universe. Neutrinos however are much less absorbed than photons and thus make a more powerful tool for astronomy searches. Many of the candidate sources of neutrinos (binary systems, supernovae remnants, AGNs, GRBs etc) have already been recognized as gamma rays emitters at energies higher than 100 GeV: this provides an important hint to neutrino astronomy, even if the observed ?-ray energies are not high enough to exclude the electromagnetic production mechanisms, such as synchrotron or inverse Compton processes. In this scenario, the detection of high energy neutrinos would open a new field of research, complementary to ?-ray astronomy and essential in order to investigate the inner structure of the most interesting cosmic objects.

Perrone, L.; MACRO Collaboration

2001-08-01

190

Formation of neutrino halos  

NASA Astrophysics Data System (ADS)

A fully general relativistic nonlinear model of the formation of massive neutrino halos in an Einstein-Straus universe was given by Fabbri, Jantzen and Ruffini (1982). The paper considers the role which a nonvanishing, repulsive cosmological constant Lambda greater than 0, admissible by observational limits, can have in the FJR model. The main conclusion is that the influence of Lambda is negligible in the FJR model for massive neutrinos with mass of about 10 eV, indicated by recent observations of SN 1987a. On the other hand, the cosmological constant is relevant in the model, if neutrinos have low mass, less than 0.2 eV.

Stuchlik, Zdenek

191

Neutrino Physics Without Oscillations  

NASA Astrophysics Data System (ADS)

There is a tremendous potential for neutrinos to yield valuable new information about strongly interacting systems. Here we provide a taste of this potential, beginning with the existence of a rigorous sum rule for the proton and neutron spin structure functions based on the measurement of the flavor singlet axial charge of the nucleon. We also comment on the NuTeV report of a 3? deviation of the value of sin2?W measured in neutrino (and anti-neutrino) scattering from that expected within the Standard Model.

Thomas, Anthony W.

2003-10-01

192

Diffractive Interaction of Neutrinos  

NASA Astrophysics Data System (ADS)

Interactions of high-energy neutrinos expose hadronic properties, in particular, contain a strong diffractive channel. The Adler relation (AR) between soft interactions of neutrinos and pions, might look as a manifestation of pion dominance. However, neutrinos cannot fluctuate to pions because of conservation of the lepton current, and interact via much heavier hadronic components. This fact leads to nontrivial relations between interactions of different hadronic species, in particular, it links diagonal and off-diagonal diffractive interactions of pions. Absorptive corrections break these relations making the AR impossible to hold universally, for any target and at any energy.

Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Iván; Siddikov, M.

2013-06-01

193

Leptoquarks: Neutrino masses and related accelerator signals  

SciTech Connect

Leptoquark-Higgs interactions induce mixing between leptoquark (LQ) states with different chiralities once the electroweak symmetry is broken. In such LQ models Majorana neutrino masses are generated at 1-loop order. Here we calculate the neutrino mass matrix and explore the constraints on the parameter space enforced by the assumption that LQ-loops explain current neutrino oscillation data. LQs will be produced at the CERN LHC, if their masses are at or below the TeV scale. Since the fermionic decays of LQs are governed by the same Yukawa couplings, which are responsible for the nontrivial neutrino mass matrix, several decay branching ratios of LQ states can be predicted from measured neutrino data. Especially interesting is that large lepton flavor violating rates in muon and tau final states are expected. In addition, the model predicts that, if kinematically possible, heavier LQs decay into lighter ones plus either a standard model Higgs boson or a Z{sup 0}/W{sup {+-}} gauge boson. Thus, experiments at the LHC might be able to exclude the LQ mechanism as an explanation of neutrino data.

Aristizabal Sierra, D.; Hirsch, M.; Kovalenko, S. G. [AHEP Group, Instituto de Fisica Corpuscular-C.S.I.C./Universitat de Valencia Edificio de Institutos de Paterna, Apartado 22085, E-46071 Valencia (Spain); Centro de Estudios Subatomicos (CES), Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)

2008-03-01

194

2004 TASI Lectures on Neutrino Physics  

Microsoft Academic Search

I discuss, in a semi-pedagogical way, our current understanding of neutrino physics. I present a brief history of how the neutrino came to be ``invented'' and observed, and discuss the evidence that led to the recent discovery that neutrinos change flavor. I then spend some time presenting mass-induced neutrino flavor change (neutrino oscillation), and how it pieces all the neutrino

Andre de Gouvea

2004-01-01

195

Neutrinos and Supernova Collapse.  

National Technical Information Service (NTIS)

The neutrino emission resulting from stellar collapse and supernova formation is reviewed. The electron capture and consequent neutronization of the collapsing stellar matter at the end of evolution determines both the initial adiabat of core collapse as ...

S. A. Colgate A. G. Petschek

1980-01-01

196

WMAPping out Neutrino Masses  

SciTech Connect

Recent data 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 conflict with a neutrino oscillation interpretation of the result from the Liquid Scintillator Neutrino Detector (LSND) over the entire favored mixing region. 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.

Pierce, Aaron T

2003-02-18

197

Overview: Neutrinos and Nucleosynthesis  

NASA Astrophysics Data System (ADS)

The astrophysical site of the r-process nucleosynthesis is not yet identified, but the neutrino-driven wind in a core-collapse supernova is one of the leading candidates. Neutrino interactions play a crucial role in such supernovae. Neutrino fluxes control the neutron-to-proton ratio in the high-entropy hot bubble which is where r-process nucleosynthesis is thought to take place. In this talk our current understanding of the role of neutrinos in core-collapse supernovae and the associated r-process nucleosynthesis will be reviewed. This work was supported in part by the U.S. National Science Foundation Grant No. PHY-0244384 and in part by the University of Wisconsin Research Committee with funds granted by the Wisconsin Alumni Research Foundation.

Balantekin, Baha

2005-04-01

198

Neutrinos in Cosmology  

SciTech Connect

Neutrinos can contribute to various episodes of the evolution of the Universe. For instance, in the seesaw model, they may generate the baryon asymmetry of the Universe via leptogenesis. This conference proceedings briefly reviews lepton flavour effects in thermal leptogenesis.

Davidson, Sacha [IPN de Lyon, Universite Lyon 1, CNRS, 4 rue Enrico Fermi, Villeurbanne, 69622 cedex (France)

2008-02-21

199

Solar neutrinos: Theoretical status.  

National Technical Information Service (NTIS)

I review the standard solar model, the disparities between its predictions an the solar neutrino flux measurements of the Homestake and Kamioka 2 collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including de...

W. C. Haxton

1991-01-01

200

Intermediate energy neutrino physics  

SciTech Connect

Occasionally, our understanding of a situation in physics is apparently so clear that consequences of a particular experimental result can imply a substantial confrontation with our view of the physical world. The standard model of electroweak interactions is now so clear that a number of experimental consequences are precisely predicted. This seems like a delightful situation for experimenters, but the bad news is that the experiments on which the predictions rest are at least hard and certainly expensive. We will focus on one such an experiment in this talk; the principal goal of the experiment was to measure neutrino-electron scattering, and also to measure a number of other exclusive channels in neutrino scattering which have bearing on our view of hadronic electroweak interactions. Study of neutrino-proton scattering and neutrino oscillation is also reported. 29 figs.

White, D.H.

1987-01-01

201

Neutrino mass: Recent results  

SciTech Connect

Some recent developments in the experimental search for neutrino mass are discussed. Simpson and Hime report finding new evidence for a 17-keV neutrino in the {beta} decay of {sup 3}H and {sup 35}S. New data from Los Alamos on the electron neutrino mass as measured in tritium beta decay give an upper limit of 13.5 eV at the 95% confidence level. This result is not consistent with the long-standing ITEP result of 26(5) eV within a model-independent'' range of 17 to 40 eV. It now appears that the electron neutrino is not sufficiently massive to close the universe by itself. 38 refs., 1 figs., 2 tabs.

Robertson, R.G.H.

1989-01-01

202

Astroparticle Physics with Neutrinos  

SciTech Connect

The status and results of high energy neutrino telescopes that are operating (AMANDA, NT200) or under construction (IceCube, Antares, Nestor) are reviewed. Future projects, including novel ideas to extend the sensitivity to higher energies, are discussed.

Koepke, Lutz [University of Mainz, Institut fuer Physik, Staudinger Weg 7, D55099 (Germany)

2006-02-08

203

Sterile neutrino mixing with ??  

NASA Astrophysics Data System (ADS)

Matrix element U?N of sterile neutrino N mixing with ?? is the least constrained in the literature among the three U?N (?=e, ?, ?) mixing parameters characterizing the sterile neutrino phenomenology. We study the contribution of massive dominantly sterile neutrinos to purely leptonic ? decays and semileptonic decays of ? and K, D mesons. We consider some decays allowed in the standard model as well as lepton flavor and lepton number violating decays forbidden in the standard model. From the existing experimental data on the branching ratios of these processes we derived new limits on U?N more stringent than the ones existing in the literature. These limits are extracted in a model independent way without any ad hoc assumptions on the relative size of the three different sterile neutrino mixing parameters.

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

2011-09-01

204

WMAPping out neutrino masses  

SciTech Connect

Recent data 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.

Pierce, Aaron; Murayama, Hitoshi

2003-10-28

205

Neutrino oscillations and uncertainty relations  

NASA Astrophysics Data System (ADS)

We show that coherent flavor neutrino states are produced (and detected) due to the momentum-coordinate Heisenberg uncertainty relation. The Mandelstam-Tamm time-energy uncertainty relation requires non-stationary neutrino states for oscillations to happen and determines the time interval (propagation length) which is necessary for that. We compare different approaches to neutrino oscillations which are based on different physical assumptions but lead to the same expression for the neutrino transition probability in standard neutrino oscillation experiments. We show that a Mössbauer neutrino experiment could allow us to distinguish different approaches and we present arguments in favor of the 163Ho-163Dy system for such an experiment.

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

2011-11-01

206

Neutrino Detectors: Challenges and Opportunities  

NASA Astrophysics Data System (ADS)

This paper covers possible detector options suitable at future neutrino facilities, such as Neutrino Factories, Super Beams and Beta Beams. The Magnetised Iron Neutrino Detector (MIND), which is the baseline detector at a Neutrino Factory, will be described and a new analysis which improves the efficiency of this detector at low energies will be shown. Other detectors covered include the Totally Active Scintillating Detectors (TASD), particularly relevant for a low energy Neutrino Factory, emulsion detectors for tau detection, liquid argon detectors and megaton scale water Cherenkov detectors. Finally the requirements of near detectors for long-baseline neutrino experiments will be demonstrated.

Soler, F. J. P.

2011-10-01

207

Experimental High Energy Neutrino Astrophysics  

SciTech Connect

Neutrinos are considered promising probes for high energy astrophysics. More than four decades after deep water Cerenkov technique was proposed to detect high energy neutrinos. Two detectors of this type are successfully taking data: BAIKAL and AMANDA. They have demonstrated the feasibility of the high energy neutrino detection and have set first constraints on TeV neutrino production astrophysical models. The quest for the construction of km3 size detectors have already started: in the South Pole, the IceCube neutrino telescope is under construction; the ANTARES, NEMO and NESTOR Collaborations are working towards the installation of a neutrino telescope in the Mediterranean Sea.

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

2005-10-12

208

The Sudbury Neutrino Observatory  

SciTech Connect

Two experiments now in progress have reported measurements of the flux of high energy neutrinos from the Sun. Since about 1970, Davis and his co-workers have been using a [sup 37]Cl-based detector to measure the [sup 7]Be and [sup 8]B solar neutrino flux and have found it to be at least a factor of three lower than that predicted by the Standard Solar Model (SSM). The Kamiokande collaborations has been taking data since 1986 using a large light-water Cerenkov detector and have confirmed that the flux is about two times lower than predicted. Recent results from the SAGE and GALLEX gallium-based detectors show that there is also a deficit of the low energy pp solar neutrinos. These discrepancies between experiment and theory could arise because of inadequacies in the theoretical models of solar energy generation or because of previously unobserved properties of neutrinos. The Sudbury Neutrino Observatory (SNO) will provide the information necessary to decide which of these solutions to the solar neutrino problem'' is correct.

Norman, E.B.; Chan, Y.D.; Garcia, A.; Lesko, K.T.; Smith, A.R.; Stokstad, R.G.; Zlimen, I. (Lawrence Berkeley Lab., CA (United States)); Evans, H.C.; Ewan, G.T.; Hallin, A.; Lee, H.W.; Leslie, J.R.; MacArthur, J.D.; Mak, H.B.; McDonald, A.B.; McLatchie, W.; Robertson, B.C.; Skensved, P.; Sur, B. (Queen's Univ., Kingston, ON (Canada). Dept. of Physics); Bonvin, E.; Earle, E.D.; Hepburn, D.; Milton, G.M. (Atomic Energ

1992-11-01

209

Core-collapse supernova neutrinos and neutrino properties  

SciTech Connect

Core-collapse supernovae are powerful neutrino sources. The observation of a future (extra-)galactic supernova explosion or of the relic supernova neutrinos might provide important information on the supernova dynamics, on the supernova formation rate and on neutrino properties. One might learn more about unknown neutrino properties either from indirect effects in the supernova (e.g. on the explosion or on in the r-process) or from modifications of the neutrino time or energy distributions in a detector on Earth. Here we will discuss in particular possible effects of CP violation in the lepton sector. We will also mention the interest of future neutrino-nucleus interaction measurements for the precise knowledge of supernova neutrino detector response to electron neutrinos.

Gava, J.; Volpe, C. [Institut de Physique Nucleaire Orsay, F-91406 Orsay CEDEX (France)

2008-08-29

210

Neutrino Phenomenology of Very Low-Energy Seesaws  

Microsoft Academic Search

The Standard Model augmented by the presence of gauge-singlet right-handed\\u000aneutrinos proves to be an ideal scenario for accommodating nonzero neutrino\\u000amasses. Among the new parameters of this ``New Standard Model'' are\\u000aright-handed neutrino Majorana masses M. Theoretical prejudice points to M much\\u000alarger than the electroweak symmetry breaking scale, but it has recently been\\u000aemphasized that all M values

Andre de Gouvea; James Jenkins; Nirmala Vasudevan

2006-01-01

211

Spectroscopy of low energy solar neutrinos by MOON  

Microsoft Academic Search

The MOON (Molybdenum Observatory Of Neutrinos) project aims at high sensitive studies of the double beta (betabeta) decays with sensitivity to Majorana nu mass of the order of ˜0.03 eV and the charged-current (CC) neutrino spectroscopy of the major components of the pp and 7Be solar nu's. The present status of MOON for the low energy solar nu experiment is

R. Hazama; P. Doe; H. Ejiri; S. R. Elliott; J. Engel; M. Finger; J. A. Formaggio; K. Fushimi; V. Gehman; A. Gorin; M. Greenfield; K. Ichihara; Y. Ikegami; H. Ishii; T. Itahashi; P. Kavitov; V. Kekelidze; K. Kuroda; V. Kutsalo; I. Manouilov; K. Matsuoka; H. Nakamura; M. Nomachi; A. Para; K. Rielage; A. Rjazantsev; R. G. H. Robertson; Y. Shichijo; T. Shima; Y. Shimada; G. Shirkov; A. Sissakian; Y. Sugaya; A. Titov; V. Vatulin; O. E. Vilches; V. Voronov; J. F. Wilkerson; D. I. Will; S. Yoshida

2005-01-01

212

Probing late neutrino mass properties with supernova neutrinos  

Microsoft Academic Search

Models of late-time neutrino mass generation contain new interactions of the cosmic background neutrinos with supernova relic neutrinos (SRNs). Exchange of an on-shell light scalar may lead to significant modification of the differential SRN flux observed at earth. We consider an Abelian U(1) model for generating neutrino masses at low scales, and show that there are cases for which the

Joseph L. Baker; Haim Goldberg; Gilad Perez; Ina Sarcevic

2007-01-01

213

Neutrino Interaction Classification from a High Energy Prompt Neutrino Beam  

Microsoft Academic Search

We present an analysis of the different types of neutrino interactions in the DONUT experiment using neural nets. The neutrino beam was created by 800 GeV protons interacting in a high density absorber. A neural net analysis of short lifetime events from neutrino interactions will also be discussed and compared to our previous results.

N. Saoulidou; S. Aoki; B. Baller; S. Chung; C. Erickson; T. Hara; N. Hashizume; K. Heller; N. Hoshino; H. Iinuma; K. Ito; T. Jikou; K. Kobayashi; K. Kodama; M. Komatsu; B. Lundberg; E. Maher; M. Miyanishi; M. Nakamura; T. Nakano; K. Niwa; N. Nonaka; K. Okada; V. Paolone; R. Rameika; J. Rhee; T. Kafka; J. Song; S. Takahashi; G. Tzanakos; K. Ushida; T. Yamamori

2004-01-01

214

Neutrino mass hierarchy determination via atmospheric neutrinos with future detectors  

Microsoft Academic Search

The issue of determining the neutrino mass hierarchy is one of the outstanding questions in neutrino physics. We consider the potential of hierarchy determination using atmospheric neutrinos as the source in three different proposed future detectors: A large Iron Calorimeter detector, a megaton Water Cerenkov detector and a large-mass Liquid Argon detector. If the mixing angle theta13 is about 10°

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

2008-01-01

215

Physics of the tau neutrino.  

National Technical Information Service (NTIS)

The (nu)(sub (tau)) is, together with the top quark, the only fundamental constituent not yet observed experimentally. Ways of producing detectable fluxes of this third neutrino are discussed. In particular, the search for neutrino oscillations into the (...

F. Vannucci

1993-01-01

216

Steps towards the Neutrino Factory  

NASA Astrophysics Data System (ADS)

The properties of the neutrino provide a unique window on physics beyond that described by the Standard Model. The study of sub-leading effects in neutrino oscillations has begun with the race to measure ?13. A consensus is emerging within the international community that a novel neutrino source is required to allow sensitive searches for leptonic CP violation to be carried out and the neutrino mass-hierarchy to be determined. The Neutrino Factory, in which intense neutrino beams are produced from the decay of muons, has been shown to out-perform the other proposed facilities. The physics case for the Neutrino Factory will be reviewed and the baseline design of the facility being developed by the International Design Study for the Neutrino Factory (the IDS-NF) collaboration will be described.

Long, K.

2012-08-01

217

Review of Neutrino Oscllations Experiments  

Microsoft Academic Search

Several experiments have sought evidence for neutrino mass and mixing via the\\u000aphenomenon of neutrino flavor oscillations. In a three neutrino model, these\\u000aoscillations are described by three angles, two mass splittings, and one CP\\u000aviolating phase. Experiments using neutrinos from the Sun, the atmosphere,\\u000anuclear reactors, and particle accelerators have gathered considerable\\u000ainformation on these angles and splittings. Two

M. D. Messier

2006-01-01

218

The Search for Neutrino Oscillations  

Microsoft Academic Search

Neutrinos offer insight into such fundamental questions as the dominance of matter over antimatter, the dynamics of supernovae, and the large scale structure of the universe. NOvA (NUMI Off-axis Neutrino Oscillations) is an experiment that will measure crucial neutrino properties using a Near Detector at Fermilab, where the neutrinos are generated in the NuMI beam, and a large Far Detector

Daniel Gershun

2011-01-01

219

Neutrino physics at muon colliders  

SciTech Connect

An overview is given of the neutrino physics potential of future muon storage rings that use muon collider technology to produce, accelerate and store large currents of muons. After a general characterization of the neutrino beam and its interactions, some crude quantitative estimates are given for the physics performance of a muon ring neutrino experiment (MURINE) consisting of a high rate, high performance neutrino detector at a 250 GeV muon collider storage ring.

King, B.J.

1998-03-01

220

Common Origin for Neutrino Anarchy and Charged Hierarchies  

SciTech Connect

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

Agashe, Kaustubh [Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States); Okui, Takemichi [Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States); Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Sundrum, Raman [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States)

2009-03-13

221

Neutrino electron scattering at ISIS  

Microsoft Academic Search

A large volume 1 300 ton imaging water Cherenkov detector at the pulsed beam dump neutrino source ISIS could detect more than 1 000 nurho scatterings and more than 3 000 neutrino-oxygen-16 reactions per year. Designed as a high statistics low energy neutrino experiment the physics motivation of a kton water Cherenkov detector at ISIS is the high sensitivity search

B. Armbruster; G. Drexlin; V. Eberhard; J. Kleinfeller; B. Zeitnitz

1994-01-01

222

Gravitational Lensing of Supernova Neutrinos  

SciTech Connect

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

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

2006-10-01

223

Physics at a Neutrino Factory  

Microsoft Academic Search

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

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

2000-01-01

224

CP violation in bipair neutrino mixing  

NASA Astrophysics Data System (ADS)

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

Kitabayashi, Teruyuki; Yasuè, Masaki

2013-10-01

225

Supernova Neutrino-Process and Implication in Neutrino Oscillation  

NASA Astrophysics Data System (ADS)

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

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

2012-08-01

226

Neutrino dark energy with more than one neutrino species  

SciTech Connect

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

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

2010-03-15

227

A four-neutrino mixing scheme for observed neutrino data  

NASA Astrophysics Data System (ADS)

It has been observed that simultaneous explanation of the solar and atmospheric neutrino deficits and the reported evidence for ??-->?e oscillation from the Los Alamos Liquid Scintillator Detector (LSND) requires at least one extra neutrino species in addition to the three known ones. The extra neutrino must be sterile with respect to the known weak interactions. We present a new mass matrix for these four neutrinos in which the LSND effect and the atmospheric neutrino deficit are governed by only one parameter. We investigate the phenomenological implications of such a mass matrix ansatz and suggest possible ways to understand it in gauge theories.

Gibbons, S. C.; Mohapatra, R. N.; Nandi, S.; Raychaudhuri, Amitava

1998-07-01

228

A model for neutrino warm dark matter and neutrino oscillations  

NASA Astrophysics Data System (ADS)

The muon- and tau-neutrinos with the mass in the keV range, which are allowed in a low reheating temperature cosmology, can compose the warm dark matter of the universe. A model of four light neutrinos including the keV scale ?? and ?? is studied, which combines the seesaw mechanism and the Abelian flavor symmetry. The atmospheric neutrino anomaly is due to the ??-?? oscillation. The solar neutrino problem is answered by the oscillation into the light sterile neutrino, where the SMA, LMA, and LOW-QVO solutions can be accommodated in our scenario.

Liu, C.; Song, J.

2001-07-01

229

Can we measure the neutrino mass hierarchy in the sky?  

NASA Astrophysics Data System (ADS)

Cosmological probes are steadily reducing the total neutrino mass window, resulting in constraints on the neutrino-mass degeneracy as the most significant outcome. In this work we explore the discovery potential of cosmological probes to constrain the neutrino hierarchy, and point out some subtleties that could yield spurious claims of detection. This has an important implication for next generation of double beta decay experiments, that will be able to achieve a positive signal in the case of degenerate or inverted hierarchy of Majorana neutrinos. We find that cosmological experiments that nearly cover the whole sky could in principle distinguish the neutrino hierarchy by yielding `substantial' evidence for one scenario over the another, via precise measurements of the shape of the matter power spectrum from large scale structure and weak gravitational lensing.

Jimenez, Raul; Kitching, Thomas; Peña-Garay, Carlos; Verde, Licia

2010-05-01

230

Short-baseline neutrino oscillations at a neutrino factory  

SciTech Connect

Within the framework of three-neutrino and four-neutrino scenarios that can describe the results of the LSND experiment, we consider the capabilities of short-baseline neutrino oscillation experiments at a neutrino factory. We find that, when short-baseline (L{approx}<100 km) neutrino factory measurements are used together with other accelerator-based oscillation results, the complete three-neutrino parameter space can best be determined by measuring the rate of {nu}{sub e}{yields}{nu}{sub {tau}} oscillations, and measuring CP violation with either {nu}{sub e}{yields}{nu}{sub {mu}} or {nu}{sub {mu}}{yields}{nu}{sub {tau}} oscillations (including the corresponding antineutrino channels). With measurements of CP violation in both {nu}{sub e}{yields}{nu}{sub {mu}} and {nu}{sub {mu}}{yields}{nu}{sub {tau}} it may be possible to distinguish between the three- and four-neutrino cases.

Barger, V.; Geer, S.; Raja, R.; Whisnant, K.

2001-02-01

231

Neutrino masses and mixing, quark-lepton symmetry, and strong right-handed neutrino hierarchy  

SciTech Connect

Assuming the same form of all mass matrices as motivated by quark-lepton symmetry, we discuss conditions under which bilarge mixing in the lepton sector can be obtained with a minimal amount of fine-tuning requirements for possible models. We assume hierarchical mass matrices, dominated by the 3-3 element, with off-diagonal elements much smaller than the larger neighboring diagonal element. Characteristic features of this scenario are strong hierarchy in masses of right-handed neutrinos, and comparable contributions of both lighter right-handed neutrinos to the resulting left-handed neutrino Majorana mass matrix. Because of obvious quark-lepton symmetry, this approach can be embedded into grand unified theories. The mass of the lightest neutrino does not depend on details of a model in the leading order. The right-handed neutrino scale can be identified with the GUT scale in which case the mass of the lightest neutrino is given as (m{sub top}{sup 2}/M{sub GUT}) vertical bar U{sub {tau}}{sub 1} vertical bar{sup 2}.

Dermisek, Radovan [Davis Institute for High Energy Physics, University of California, Davis, California 95616 (United States)

2004-10-01

232

Sterile Neutrinos and Supernova Nucleosynthesis  

NASA Astrophysics Data System (ADS)

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

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

2006-10-01

233

Review of neutrino mass measurements  

SciTech Connect

The current status of the experimental search for neutrino mass is reviewed, with emphasis on direct kinematic methods. New data on the /tau/ neutrino from the Argus collaboration have reduced the upper mass limit a factor of 2. The situation concerning the electron neutrino mass as measured in tritium beta decay is essentially unchanged from a year ago. Simpson and Hime report finding evidence for a 17-keV neutrino in the ..beta.. decay of /sup 35/S. There may be evidence for neutrino mass and mixing in the SN1987a data. 62 refs., 4 figs.

Robertson, R.G.H.

1988-01-01

234

Review article "Geo-neutrinos"  

NASA Astrophysics Data System (ADS)

Geo-neutrinos, electron anti-neutrinos produced in ?-decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. After a brief introduction about the Earth (mostly for physicists) and the very basics about the neutrinos and anti-neutrinos (mostly for geologists), I describe the geo-neutrino properties and the main aims of their study. An overview of the latest experimental results obtained by KamLAND and Borexino experiments is provided. A short overview of future perspectives of this new inter-disciplinary field is given.

Ludhova, L.

2012-12-01

235

Neutrino physics: Summary talk  

SciTech Connect

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

Marciano, W.J.

1989-04-01

236

Ultrahigh energy neutrino scattering  

SciTech Connect

Estimates are made of ultrahigh energy neutrino cross sections based on an extrapolation to very small Bjorken x of the logarithmic Froissart dependence in x shown previously to provide an excellent fit to the measured proton structure function F{sub 2}{sup p}(x,Q{sup 2}) over a broad range of the virtuality Q{sup 2}. Expressions are obtained for both the neutral current and the charged current cross sections. Comparison with an extrapolation based on perturbative QCD shows good agreement for energies where both fit data, but our rates are as much as a factor of 10 smaller for neutrino energies above 10{sup 9} GeV, with important implications for experiments searching for extragalactic neutrinos.

Berger, Edmond L. [High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Block, Martin M. [Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States); McKay, Douglas W. [Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045 (United States); Tan, C.-I [Physics Department, Brown University, Providence, Rhode Island 02912 (United States)

2008-03-01

237

Neutrinos and explosive nucleosynthesis  

NASA Astrophysics Data System (ADS)

Core-collapse supernovae produce a hot protoneutron star that cools emitting huge amounts of neutrinos of all flavors. The interaction of these neutrinos with the outer layers of the protoneutron star produces an outflow of matter whose composition is determined by the luminosities and energies of the emitted neutrinos and antineutrinos. The presence of light nuclei like deuterons and tritons can have a big impact in the average energies of the emitted antineutrinos and consequently in the neutron-richness of the ejected matter. Recent hydrodynamical models show that the ejected matter is in fact proton-rich and constitutes the site of the ?p-process where antineutrino absorption reactions catalyze the nucleosynthesis of nuclei with A>64.

Martínez-Pinedo, G.; Arcones, A.

2010-04-01

238

Minimal models with light sterile neutrinos  

NASA Astrophysics Data System (ADS)

We study the constraints imposed by neutrino oscillation experiments on the minimal extensions of the Standard Model (SM) with n R gauge singlet fermions ("righthanded neutrinos"), that can account for neutrino masses. We consider the most general coupling of the new fields to the SM fields, in particular those that break lepton number and we do not assume any a priori hierarchy in the mass parameters. We proceed to analyze these models starting from the lowest level of complexity, defined by the number of extra fermionic degrees of freedom. The simplest choice that has enough free parameters in principle (i.e. two mass differences and two angles) to explain the confirmed solar and atmospheric oscillations corresponds to n R = 1. This minimal choice is shown to be excluded by data. The next-to-minimal choice corresponds to n R = 2. We perform a systematic study of the full parameter space in the limit of degenerate Majorana masses by requiring that at least two neutrino mass differences correspond to those established by solar and atmospheric oscillations. We identify several types of spectra that can fit long-baseline reactor and accelerator neutrino oscillation data, but fail in explaining solar and/or atmospheric data. The only two solutions that survive are the expected seesaw and quasi-Dirac regions, for which we set lower and upper bounds respectively on the Majorana mass scale. Solar data from neutral current measurements provide essential information to constrain the quasi-Dirac region. The possibility to accommodate the LSND/MiniBoone and reactor anomalies, and the implications for neutrinoless double-beta decay and tritium beta decay are briefly discussed.

Donini, A.; Hernández, P.; López-Pavón, J.; Maltoni, M.

2011-07-01

239

Flavor oscillations of supernova neutrinos  

NASA Astrophysics Data System (ADS)

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

Mirizzi, Alessandro

2012-08-01

240

Geo-neutrino review  

NASA Astrophysics Data System (ADS)

The principal source of energy for dynamic processes of the earth, such as plate tectonics is thought to come from the radioactive decays of 238U, 232Th, and 40K within the earth. These decays produce electron-antineutrinos, so-called geo-neutrinos, the measurement of which near the earth's surface allows for a direct measure of the total radiogenic heat production in the earth. The KamLAND and Borexino experiments have both measured a geo-neutrino flux significantly greater than zero. As shown in these proceedings, more precise future measurements will significantly constrain earth composition models.

Tolich, N.

2012-08-01

241

Sterile neutrinos and RK  

NASA Astrophysics Data System (ADS)

We consider an enhancement in the violation of lepton flavour universality in light meson decays arising from modified Wl? couplings in the standard model minimally extended by sterile neutrinos. Due to the presence of additional mixings between the active neutrinos and the new sterile states, the deviation from unitarity of the leptonic mixing matrix intervening in charged currents might lead to a tree-level enhancement of RP = ?(P ? ev)/?(P ? ??), with P = K, ?. These enhancements are illustrated in the case of the inverse seesaw, showing that one can saturate the current experimental bounds on ?rK (and ?r?), while in agreement with the different experimental and observational constraints.

Vicente, A.

2013-07-01

242

Ultrahigh-energy neutrino scattering  

NASA Astrophysics Data System (ADS)

We predict the neutrino-nucleon cross section at ultrahigh energies relevant in connection with the search for high-energy cosmic neutrinos. Our investigation, employing the color-dipole picture, among other things, allows us to quantitatively determine which fraction of the ultrahigh-energy neutrino-nucleon cross section stems from the saturation vs the color-transparency region. We disagree with various results in the literature that predict a strong suppression of the neutrino-nucleon cross section at neutrino energies above E?109GeV. Suppression in the sense of a diminished increase of the neutrino-nucleon cross section with energy only starts to occur at neutrino energies beyond E?1014GeV.

Kuroda, Masaaki; Schildknecht, Dieter

2013-09-01

243

Solar neutrinos - Questions and hypotheses  

NASA Astrophysics Data System (ADS)

The present theoretical understanding of the characteristics of neutrinos and their production in the sun is reviewed, along with experiments for detecting solar neutrinos. The thermonuclear reaction cycles which take place in the sun, defined since 1939, indicate that gamma rays and neutrinos will emerge since the fusion of four hydrogen atoms into one a helium atom will result in a mass deficit which has been experimentally confirmed. However, attempts to detect the neutrino emissions with an underground vat of dry cleaning fluid have not yielded counts of the predicted number of neutrinos. Adjustments which have been suggested to the standard model to account for the low neutrino flux are summarized, with emphasis placed on possible changes which neutrinos could undergo on their trip from the sun to the earth that would preclude their interaction with Cl-37 atoms in the tank.

Weneser, Joseph; Friedlander, Gerhart

1987-02-01

244

Effects of neutrino mixing on high-energy cosmic neutrino flux  

Microsoft Academic Search

Several cosmologically distant astrophysical sources may produce high-energy cosmic neutrinos (E >=106 GeV) of all flavors above the atmospheric neutrino background. We study the effects of vacuum neutrino mixing in the three flavor framework on this cosmic neutrino flux. We also consider the effects of possible mixing between the three active neutrinos and the (fourth) sterile neutrino with or without

H. Athar; M. Jezabek; O. Yasuda

2000-01-01

245

Neutrinos from a core collapse supernova  

SciTech Connect

The neutrino burst from a galactic supernova can help determine the neutrino mass hierarchy and {theta}{sub 13}, and provide crucial information about supernova astrophysics. Here we review our current understanding of the neutrino burst, flavor conversions of these neutrinos, and model independent signatures of various neutrino mixing scenarios.

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

2008-02-21

246

Atmospheric neutrino flux: a review of calculations  

Microsoft Academic Search

Interpretation and understanding of the evidence for neutrino oscillations depends on knowledge of the atmospheric neutrino beam. In this talk I assess how well various features are known. The goal is to determine to what extent uncertainties in the neutrino beam may limit the conclusions about neutrino properties and which features of the evidence for neutrino oscillations are most robust.

T. K. Gaisser

2000-01-01

247

Review of the physics of the neutrino  

SciTech Connect

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

Robertson, R.G.H.

1986-01-01

248

Three-flavour neutrino oscillation update  

Microsoft Academic Search

We review the present status of three-flavour neutrino oscillations, taking into account the latest available neutrino oscillation data presented at the Neutrino 2008 Conference. This includes the data released this summer by the MINOS collaboration, the data of the neutral current counter phase of the Sudbury Neutrino Observatory (SNO) solar neutrino experiment, as well as the latest KamLAND and Borexino

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

2008-01-01

249

Nonstandard neutrino interactions and transition magnetic moments  

NASA Astrophysics Data System (ADS)

We constrain generic nonstandard neutrino interactions with existing experimental data on neutrino transition magnetic moments and derive strong bounds on tensorial couplings of neutrinos to charged fermions. We also discuss how some of these tensorial couplings can be constrained by other experiments, e.g., on neutrino-electron and neutrino-nucleus scattering.

Healey, Kristopher J.; Petrov, Alexey A.; Zhuridov, Dmitry

2013-06-01

250

Radiative neutrino decay and CP-violation in R-parity violating supersymmetry  

SciTech Connect

We calculate the radiative decay amplitude for Majorana neutrinos in trilinear R-parity violating supersymmetric framework. Our results make no assumption regarding the masses and mixings of fermions and sfermions. The results obtained are exemplary for generic models with loop-generated neutrino masses. Comparison of this amplitude with the neutrino mass matrix shows that the two provide independent probes of CP-violating phases.

Bhattacharyya, Gautam; Pal, Palash B. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700064 (India); Paes, Heinrich [Department of Physics and Astronomy, University of Hawaii at Manoa, 2505 Correa Road, Honolulu, Hawaii 96822 (United States); Weiler, Thomas J. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

2006-09-01

251

Compromise between neutrino masses and collider signatures in the type-II seesaw model  

SciTech Connect

A natural extension of the standard SU(2){sub L}xU(1){sub Y} gauge model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6x6 neutrino mass matrix which contains three 3x3 submatrices, M{sub L}, M{sub D} and M{sub R}. We show that three light Majorana neutrinos (i.e., the mass eigenstates of {nu}{sub e}, {nu}{sub {mu}}, and {nu}{sub {tau}}) are exactly massless in this model, if and only if M{sub L}=M{sub D}M{sub R}{sup -1}M{sub D}{sup T} exactly holds. This no-go theorem implies that small but nonvanishing neutrino masses may result from a significant but incomplete cancellation between M{sub L} and M{sub D}M{sub R}{sup -1}M{sub D}{sup T} terms in the Type-II seesaw formula, provided three right-handed Majorana neutrinos are of O(1) TeV and experimentally detectable at the LHC. We propose three simple Type-II seesaw scenarios with the A{sub 4}xU(1){sub X} flavor symmetry and its explicit breaking to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the 3x3 neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.

Chao Wei; Luo Shu; Xing Zhizhong; Zhou Shun [Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, Beijing 100049 (China)

2008-01-01

252

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

SciTech Connect

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{sub {beta}}); the effective Majorana neutrino mass in neutrinoless double beta-decay (m{sub {beta}}{sub {beta}}); 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{sub {beta}} by combining updated results from the Mainz and Troitsk experiments. We also consider the latest results on m{sub {beta}}{sub {beta}} 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 two degrees Fields (2dF) Galaxy Redshifts Survey, with and without Lyman-{alpha} forest data from the Sloan Digital Sky Survey (SDSS), in models with a nonzero 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{sub {beta}},m{sub {beta}}{sub {beta}},{sigma}) parameter space, which neatly show the relative impact of each data set. In particular, the (in)compatibility between {sigma} and m{sub {beta}}{sub {beta}} constraints is highlighted for various combinations of data. We also briefly discuss how future neutrino data (both oscillatory and nonoscillatory) can further probe the currently allowed regions.

Fogli, G.L.; Lisi, E.; Marrone, A.; Palazzo, A. [Dipartimento di Fisica and Sezione INFN di Bari, Via Amendola 173, 70126, Bari (Italy); Melchiorri, A.; Serra, P. [Dipartimento di Fisica and Sezione INFN, Universita degli Studi di Roma 'La Sapienza', P.le Aldo Moro 5, 00185, Rome (Italy); Silk, J. [Astrophysics, Denys Wilkinson Building, Keble Road, OX13RH, Oxford (United Kingdom)

2004-12-01

253

Neutrino spectroscopy with atoms and molecules  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

254

Neutrino and anti-neutrino transport in accretion disks  

NASA Astrophysics Data System (ADS)

We numerically solve the one-dimensional Boltzmann equation of the neutrino and antineutrino transport in accretion disks and obtain the fully energy-dependent and direction-dependent neutrino- and antineutrino-emitting spectra, under the condition that the distribution of the mass density, temperature and chemical components are given. Then, we apply the resulting neutrino- and antineutrino-emitting spectra to calculate the corresponding annihilation rate of neutrino pairs above the neutrino-dominated accretion disk and find that the released energy resulting from the annihilation of neutrino pairs cannot provide sufficient energy for the most energetic short gamma ray bursts whose isotropic luminosity can be as high as 1052ergs/s unless the high-temperature zone, where the temperature is beyond 10 MeV, can stretch over 200 km in the disk. We also compare the resulting luminosity of neutrinos and antineutrinos with the results from the two commonly used approximate treatments of the neutrino and antineutrino luminosity: the Fermi-Dirac black-body limit and a simplified model of neutrino transport, i.e., the gray-body model, and find that both of them overestimate the neutrino/antineutrino luminosity and their annihilation rate greatly. Additionally, as did in Sawyer (2003), we also check the validity of the two-stream approximation, and find that it is a good approximation to high accuracy.

Pan, Zhen; Yuan, Ye-Fei

2012-03-01

255

Anti-neutrino imprint in solar neutrino flare  

NASA Astrophysics Data System (ADS)

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

Fargion, D.

2006-10-01

256

Neutrino mixing from Wilson lines in warped space  

NASA Astrophysics Data System (ADS)

We consider the generation of the hierarchical charged lepton spectrum and anarchic neutrino masses and mixing angles in warped extra dimensional models with Randall-Sundrum metric. We have classified all possible cases giving rise to realistic spectra for both Dirac and Majorana neutrinos. An anarchic neutrino spectrum requires a convenient bulk symmetry broken by boundary conditions on both UV and IR branes. We have in particular considered the case of Majorana neutrinos with a continuous bulk symmetry. To avoid unwanted massless extra gauge bosons the 4D group should be empty. If the 4D coset is not vanishing it can provide a Wilson Line description of the neutrino Majorana mass matrix. We have studied an example based on the bulk gauge group U{(3)_{ell }}? U{(3)_{{N}}}{?_i}U{(1)_{{{\\varepsilon^i}}}} with the Wilson Line in SO{(3)_{{N}}} satisfying all required conditions. A ? 2-fit to experimental data exhibits 95% CL region in the parameter space with no fine- tuning. As a consequence of the symmetries of the theory there is no tree-level induced lepton flavor violation and so one-loop processes are consistent with experimental data forKK-modes about a few TeV. The model is easily generalizable to models with IR deformed metrics with similar conclusions.

von Gersdorff, Gero; Quirós, Mariano; Wiechers, Michael

2013-02-01

257

Neutrino masses in left-right symmetric models.  

National Technical Information Service (NTIS)

The radiative corrections to the Majorana neutrino mass in the left-right symmetric models are calculated in the presence of one or two SU(2)(sub L) doublets in theory. In the former case the radiative corrections are essential for large (a few hundreds o...

H. M. Asatryan A. N. Ioannissyan

1989-01-01

258

Experimental Neutrino Physics  

ScienceCinema

In this talk, I will review how a set of experiments in the last decade has given us our current understanding of neutrino properties.  I will show how experiments in the last year or two have clarified this picture, and will discuss how new experiments about to start will address remaining questions.  I will particularly emphasize the relationship between various experimental techniques.

259

Formation of neutrino halos.  

NASA Astrophysics Data System (ADS)

A fully general relativistic non-linear model of the formation of massive neutrino halos in an Einstein-Straus universe was given by Fabbri, Jantzen and Ruffini. Here the author considers the role which a non-vanishing, repulsive cosmological constant ? > 0, admissible by observational limits, can have in the FJR model.

Stuchlík, Z.

260

Chlorine solar neutrino experiment  

SciTech Connect

The chlorine solar neutrino experiment in the Homestake Gold Mine is described and the results obtained with the chlorine detector over the last fourteen years are summarized and discussed. Background processes producing /sup 37/Ar and the question of the constancy of the production rate of /sup 37/Ar are given special emphasis.

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

1984-01-01

261

The neutrino electron accelerator  

SciTech Connect

It is shown that a wake of electron plasma oscillations can be created by the nonlinear ponderomotive force of an intense neutrino flux. The electrons trapped in the plasma wakefield will be accelerated to high energies. Such processes may be important in supernovas and pulsars. {copyright} {ital 1998 American Institute of Physics.}

Shukla, P.K. [Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Stenflo, L. [Department of Plasma Physics, Umea University, S-90187 Umea (Sweden); Bingham, R. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom); Bethe, H.A. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Dawson, J.M. [Department of Physics, University of California, Los Angeles, California 90024 (United States); Mendonca, J.T. [Department of Physics, University of Lisbon, 1096 Lisbon (Portugal)

1998-01-01

262

Neutrino-nucleon scattering  

SciTech Connect

In the following, the author tries to summarize the current status of neutrino-nucleon scattering as it bears on contemporary issues regarding the spin structure of the nucleon. It is straightforward to express the electroweak current of a hadron in terms of its underlying electroweak partonic currents. The matrix elements of these currents are, of course, presently uncalculable but may be characterized by form factors extracted from experiment. When neutrinos are used as probes, there are several problems associated with carrying out the required cross section measurements. Active neutrino detectors of necessity contain nuclei more complex than hydrogen. These nuclei create additional backgrounds and create complications of interpretation that make these experiments challenging. However, given the continued demonstrated difficulty of measuring and extracting the spin structure functions, it appears that there are no easy measurements to investigate the nucleon spin structure save the earlier experiments that fixed the axial vector form factors of well-known baryon decays (neutron, lambda, etc.). With the emergence of the provocative results from the EMC group on the spin structure function of the proton, there has been renewed interest in the information contained in the cross sections for neutral current neutrino-nucleon scattering. The theoretical background for describing this process has been worked out in detail. It is presented in briefest outline below to define the terms needed to describe experimental results.

Garvey, G.T.

1994-05-01

263

Heavy neutrinos and lepton number violation in ?p colliders  

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

264

Topics in neutrino astroparticle physics  

NASA Astrophysics Data System (ADS)

In the first part of the dissertation, two neutrino properties such as neutrino mass measurement and neutrino dipole moment, in the terrestrial experiments, are examined with particular attention to exotic phenomena that may be observed for theories beyond the Standard Model. In the second part, we study a method for measuring the neutrino mass from a galactic supernova neutrino burst using an innovated detector concept. The neutral current based SNBO (Supernova Neutrino Burst Observatory) detector concept is discussed. We show that it is possible to measure a cosmologically significant neutrino mass, i.e., 5-50 eV directly from the flight time difference between the massive and massless neutrino using the SNBO detector concept. In the third part, very heavy unstable particles from the Big Bang decaying into neutrinos at cosmological epochs is discussed. In particular, we focus on a detection of such relic neutrinos from the decays in the neutrino window on earth, in the energy ranges 10-100 MeV, where the neutrino background is expected to be lowest. In the fourth part, neutrino emission from the explosion of Primordial Black Holes in the context of the Hawking radiation is presented. We suggest a new explosion mechanism inspired by new data from gamma ray bursts that might occur when the Primordial Black Hole reaches a certain surface temperature. We propose some observational tests that use a satellite detector and the proposed SNBO detector. In the last chapter, we examine a possible connection between the baryogenesis in the early universe and the lepton number violation processes.

Hong, Woopyo

1993-01-01

265

Precision Solar Neutrino Measurements with the Sudbury Neutrino Observatory  

SciTech Connect

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

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

2007-10-26

266

Toroidal magnetized iron neutrino detector for a neutrino factory  

NASA Astrophysics Data System (ADS)

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 paper, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of large ?13. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent ?CP reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of ?CP.

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

2013-08-01

267

Neutrino decays and neutrino electron elastic scattering in unparticle physics  

NASA Astrophysics Data System (ADS)

Following Georgi's unparticle scheme, we examine the effective couplings between neutrinos and unparticle operators. As an immediate consequence, neutrinos become unstable and can decay into the unparticle stuff. Assuming the dimension transmutation scale is around ?˜1 TeV, we implement the cosmological limit on the neutrino lifetime to constrain the neutrino unparticle couplings for different scaling dimensions d. In addition, provided that the electron unparticle coupling is restricted due to the precise measurement of the anomalous magnetic moment of electron, we calculate the unparticle contribution to the neutrino electron elastic scattering. It is more important to jointly deal with the couplings of the unparticle to the standard model particles rather than separately. Taking into account both electron and neutrino unparticle couplings, we find that the scaling dimension of the scalar unparticle should lie in the narrow range 1

Zhou, Shun

2008-01-01

268

Solar neutrinos as probes of neutrino–matter interactions  

Microsoft Academic Search

Data from solar neutrino and KamLAND experiments have led to a discovery of nonzero neutrino masses. Here we investigate what these data can tell us about neutrino interactions with matter, including the poorly constrained flavor-changing ?e–?? interactions. We give examples of the interaction parameters that are excluded by the solar\\/KamLAND data and are beyond the reach of other experiments. We

Alexander Friedland; Cecilia Lunardini; Carlos Peña-Garay

2004-01-01

269

Radiatively broken symmetries of nonhierarchical neutrinos  

SciTech Connect

Symmetry-based ideas, such as the quark-lepton complementarity principle and the tribimaximal mixing 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}{approx}10{sup 12} GeV characterizing the large masses of right-handed neutrinos required to implement the seesaw mechanism. For nonhierarchical neutrinos, renormalization group evolution down to a laboratory energy scale {lambda}{approx}10{sup 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}{sub 2,3} enable the retention of those high scale mixing patterns at laboratory energies. We examine this issue within the minimal supersymmetric standard model and demonstrate the fact posited above for two versions of quark-lepton complementarity and two versions of tribimaximal mixing. The appropriate constraints are worked out for all these four cases. Specifically, a preference for {alpha}{sub 2}{approx_equal}{pi} (i.e., m{sub 1}{approx_equal}-m{sub 2}) emerges in each case. We also show how a future accurate measurement of {theta}{sub 13} may enable some discrimination among these four cases in spite of renormalization group evolution.

Dighe, Amol; Roy, Probir [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Goswami, Srubabati [Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019 (India)

2007-11-01

270

Small neutrino mass from large compactification volumes.  

PubMed

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

Conlon, Joseph P; Cremades, Daniel

2007-07-26

271

Neutrino Flavor States and the Quantum Theory of Neutrino Oscillations  

SciTech Connect

The standard theory of neutrino oscillations is reviewed, highlighting the main assumptions: the definition of the flavor states, the equal-momentum assumption and the time = distance assumption. It is shown that the standard flavor states are correct approximations of the states that describe neutrinos in oscillation experiments. The equal-momentum assumption is shown to be unnecessary for the derivation of the oscillation probability. The time = distance assumption derives from the wave-packet character of the propagating neutrinos. We present a simple quantum-mechanical wave-packet model which allows us to describe the coherence and localization of neutrino oscillations.

Giunti, Carlo [INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy)

2008-07-02

272

Electron-neutrino survival probability from solar-neutrino data  

NASA Astrophysics Data System (ADS)

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

Berezinsky, V.; Lissia, M.

2001-11-01

273

Neutrino oscillations with disentanglement of a neutrino from its partners  

NASA Astrophysics Data System (ADS)

We argue that in order to understand existing data on neutrino oscillations, and to design future experiments, it is imperative to appreciate the role of quantum entanglement. Once this is accounted for, the resulting energy-momentum-conserving phenomenology requires a single new parameter related to disentanglement of a neutrino from its partners. This parameter may not be CP symmetric. We illustrate the new ideas, with potentially measurable effects, in the context of a novel experiment recently proposed by Gavrin, Gorbachev, Veretenkin, and Cleveland. The strongest impact of our ideas is on the resolution of various anomalies in neutrino oscillations and on neutrino propagation in astrophysical environments.

Ahluwalia, D. V.; Horvath, S. P.

2011-07-01

274

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

NASA Astrophysics Data System (ADS)

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

Kneller, James

2004-11-01

275

Electromagnetic Forward Neutrino-Neutrino Scattering in Dense Matter  

NASA Astrophysics Data System (ADS)

Using covariant methods we calculate the coherent forward amplitude for the exchange of a virtual photon between neutrinos having medium-induced electromagnetic vertices. Such a process can affect the important Mikheyev-Smirnov-Wolfenstein (MSW) mechanism in media with large neutrino asymmetries. It can be considered as a finite temperature and density (FTD) version of a two-loop contribution which gives rise to non-universal (??-dependent) radiative corrections to the forward scattering ?? ? ??. Assuming no inert neutrino species, we discuss the possible importance of this contribution to the MSW effect in a supernova core and in the early Universe with large but equal neutrino asymmetries.

Horvat, R.

276

Superluminal neutrino, flavor, and relativity  

NASA Astrophysics Data System (ADS)

Modified neutrino dispersion relations, which still obey the relativity principle, can have both a superluminal (muon-type) neutrino and a luminal (electron-type) neutrino, as long as neutrino-mass effects can be neglected. The idea is to allow for flavor-dependent deformed Lorentz transformations and an appropriate hierarchy of energy scales. If OPERA’s result on a superluminal velocity of the muon-neutrino is confirmed, the model has a matching superluminal velocity of the corresponding charged lepton, the muon, at equal particle energy. Assuming that this model is not already ruled out, new TeV-scale effects in the muon sector are predicted. Also discussed is a different model with a superluminal sterile neutrino propagating in the usual 4 spacetime dimensions.

Klinkhamer, F. R.

2012-01-01

277

Weighing Neutrinos: Weak Lensing Approach  

Microsoft Academic Search

We study the possibility for a measurement of neutrino mass using weak\\u000agravitational lensing. The presence of non-zero mass neutrinos leads to a\\u000asuppression of power at small scales and reduces the expected weak lensing\\u000asignal. The measurement of such a suppression in the weak lensing power\\u000aspectrum allows a direct measurement of the neutrino mass, in contrast to\\u000avarious

Asantha R. Cooray

1999-01-01

278

Exploring neutrino oscillations with superbeams  

Microsoft Academic Search

We consider the medium- and long-baseline oscillation physics capabilities of intense muon-neutrino and muon-antineutrino beams produced using future upgraded megawatt-scale high-energy proton beams. In particular we consider the potential of these conventional neutrino ``superbeams'' for observing numu-->nue oscillations, determining the hierarchy of neutrino mass eigenstates, and measuring CP violation in the lepton sector. The physics capabilities of superbeams are explored

V. Barger; S. Geer; R. Raja; K. Whisnant

2001-01-01

279

Advancements in Solar Neutrino Physics  

NASA Astrophysics Data System (ADS)

We review the results of solar neutrino physics, with particular attention to the data obtained and the analyses performed in the last decades, which were determinant to solve the solar neutrino problem (SNP), proving that neutrinos are massive and oscillating particles and contributing to refine the solar models. We also discuss the perspectives of the presently running experiments in this sector and of the ones planned for the near future and the impact they can have on elementary particle physics and astrophysics.

Miramonti, Lino; Antonelli, Vito

2013-05-01

280

GRB neutrino search with MAGIC  

Microsoft Academic Search

The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope was designed for the detection of photon sources >~50 GeV. The measurement of highly-inclined air showers renders possible the search for high-energy neutrinos, too. Only neutrinos can traverse the Earth without interaction, and therefore, events close to the horizon can be identified as neutrino-induced rather than photon-induced or hadronic events. In this

Julia K. Becker; Markus Gaug; Ching-Cheng Hsu; Wolfgang Rhode

2008-01-01

281

Neutrino helicity asymmetries in leptogenesis  

SciTech Connect

It is pointed out that the heavy singlet neutrinos characteristic of leptogenesis develop asymmetries in the abundances of the two helicity states as a result of the same mechanism that generates asymmetries in the standard lepton sector. Neutrinos and standard leptons interchange asymmetries in collisions with each other. It is shown that an appropriate quantum number, B-L{sup '}, combining baryon, lepton and neutrino asymmetries, is not violated as fast as the standard B-L. This suppresses the washout effects relevant for the derivation of the final baryon asymmetry. One presents detailed calculations for the period of neutrino thermal production in the framework of the singlet seesaw mechanism.

Bento, Luis; Santos, Francisco C. [Universidade de Lisboa, Faculdade de Ciencias, Centro de Fisica Nuclear da Universidade de Lisboa, Avenida Prof. Gama Pinto 2, 1649-003 Lisbon (Portugal)

2005-05-01

282

Neutrino oscillations beyond two flavours  

NASA Astrophysics Data System (ADS)

I review some theoretical aspects of neutrino oscillations in the case when more than two neutrino flavours are involved. These include: approximate analytic solutions for 3-flavour (3f) oscillations in matter; matter effects in ?? ? ?? oscillations; 3f effects in oscillations of solar, atmospheric, reactor and supernova neutrinos and in accelerator long-baseline experiments; CP and T violation in neutrino oscillations in vacuum and in matter; the problem of Ue3; 4f oscillations. On leave from National Research Centre Kurchatov Institute, Moscow, Russia. Supported by the Calouste Gulbenkian Foundation as a Gulbenkian Visiting Professor.

Akhmedov, E. Kh.

2003-04-01

283

Flavour mixing of neutrinos and baryon asymmetry of the universe  

NASA Astrophysics Data System (ADS)

We investigate baryogenesis in the ?MSM, which is the Minimal Standard Model (MSM) extended by three right-handed neutrinos with Majorana masses smaller than the weak scale. In this model the baryon asymmetry of the universe (BAU) is generated via flavour oscillation between right-handed neutrinos. We consider the case when BAU is solely originated from the CP violation in the mixing matrix of active neutrinos. We perform analytical and numerical estimations of the yield of BAU, and show how BAU depends on mixing angles and CP violating phases. It is found that the asymmetry in the inverted hierarchy for neutrino masses receives a suppression factor of about 4% comparing with the normal hierarchy case. It is, however, pointed out that, when ?=0 and ?=?/4, baryogenesis in the normal hierarchy becomes ineffective, and hence the inverted hierarchy case becomes significant to account for the present BAU.

Asaka, Takehiko; Ishida, Hiroyuki

2010-08-01

284

Cold dark matter candidates and the solar neutrino problem  

SciTech Connect

Certain currently proposed weakly interacting elementary particles can have a high probability of solar capture if they make up the Galactic halo. Their present abundance in the Sun is here determined by balancing capture rates against annihilation rates. Both particle physics and cosmological considerations impose constraints on scattering and annihilation cross sections. In general, for the candidate particles here discussed (massive neutrinos, supersymmetric scalar neutrinos, and photinos), the inferred solar abundances are too small by three to four orders of magnitude to solve the solar neutrino problem. Extreme fine tuning, marginally possible in the case of the photino, could increase solar abundances to a level where the neutrino signature would be affected. Otherwise, either a particle with a net cosmological asymmetry, or else a new mechanism for strengthening the existing Majorana suppression of s-wave annihilation at very low energies, would seem to be required.

Krauss, L.M.; Freese, K.; Spergel, D.N.; Press, W.H.

1985-12-15

285

Subluminal Opera Neutrinos  

NASA Astrophysics Data System (ADS)

The OPERA Collaboration has announced to have observed superluminal neutrinos with a mean energy 17.5 GeV, but afterward the superluminal interpretation of the OPERA results has been refuted theoretically by Cherenkov-like radiation and pion decay. In a recent work, we have proposed a kinematical resolution to this problem. A key idea in our resolution is that the OPERA neutrinos are not superluminal but subluminal since they travel faster than the observed speed of light in vacuum on the earth while they do slower than the true speed of light in vacuum determining the causal structure of events. In this paper, we dwell upon our ideas and present some concrete models, which realize our ideas, based on spin 0, 1 and 2 bosonic fields. We also discuss that the principle of invariant speed of light in special relativity can be replaced with the principle of a universal limiting speed.

Oda, Ichiro

286

Geo-neutrinos  

NASA Astrophysics Data System (ADS)

We review a new interdisciplinary field between Geology and Physics: the study of the Earth's geo-neutrino flux. We describe competing models for the composition of the Earth, present geological insights into the make up of the continental and oceanic crust, those parts of the Earth that concentrate Th and U, the heat producing elements, and provide details of the regional settings in the continents and oceans where operating and planned detectors are sited. Details are presented for the only two operating detectors that are capable of measuring the Earth's geo-neutrino flux: Borexino and KamLAND; results achieved to date are presented, along with their impacts on geophysical and geochemical models of the Earth. Finally, future planned experiments are highlighted.

Bellini, G.; Ianni, A.; Ludhova, L.; Mantovani, F.; McDonough, W. F.

2013-11-01

287

Natural Neutrino Dark Energy  

SciTech Connect

1 construct a general description for neutrino dark energy models, that do not require exotic particles or strange couplings. With the help of the above, this class of models is reduced to a single function with several constraints. It is shown that these models lead to some concrete predictions that can be verified (or disproved) within the next decade, using results from PLANK, EUCLID and JDEM.

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

2010-06-23

288

Standard solar neutrinos  

Microsoft Academic Search

An improved standard solar model has been used to calculate the fluxes of\\u000astandard solar neutrinos. It includes premain sequence evolution, element\\u000adiffusion, partial ionization effects, and all the possible nuclear reactions\\u000abetween the main elements. It uses updated values for the initial solar element\\u000aabundances, the solar age, the solar luminosity, the nuclear reaction rates and\\u000athe radiative opacities.

Arnon Dar; Giora Shaviv

1996-01-01

289

The CNGS neutrino beam  

NASA Astrophysics Data System (ADS)

The CERN to Gran Sasso Neutrino beam (CNGS) was commissioned at CERN in early August 2006 and was first sent at low intensity to Gran Sasso on August 17, 2006. The Borexino, LVD and OPERA detectors continued the commissioning of their detectors and started taking data with practically no dead time. The CNGS operated smoothly with good quality. In a short time the 3 detectors collected several hundred events with clean time distributions

Giacomelli, G.

2008-06-01

290

Neutrino physics at LAMPF  

SciTech Connect

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

Garvey, G.T.

1989-01-01

291

Future neutrino physics with LENA (Low Energy Neutrino Astronomy)  

NASA Astrophysics Data System (ADS)

The proposed large-volume detector LENA (Low Energy Neutrino Astronomy) is a multi-purpose liquid-scintillator experiment. Its sensitive mass of 50 kt allows for high-statistic measurements of astrophysical and terrestrial low-energy neutrino sources. Moreover, new limits might be put on the lifetime of the proton decay channel into K+bar nu.

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

2012-07-01

292

Resonant solar neutrino oscillation versus laboratory neutrino oscillation experiments  

SciTech Connect

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

Lim, Chong-Sa

1987-02-01

293

Conformal neutrinos: An alternative to the see-saw mechanism  

NASA Astrophysics Data System (ADS)

We analyze a scenario where the right-handed neutrinos make part of a strongly coupled conformal field theory and acquire an anomalous dimension ?<1 at a large scale ?. Their Yukawa couplings to the Higgs become irrelevant at the fixed point and they are suppressed at low scales giving rise naturally to a small (sub-meV) Dirac neutrino mass which breaks the conformal invariance. We derive an upper bound on ? from loop-induced flavor changing neutral currents. Neutrino Yukawa couplings can be sizable at electroweak scales and therefore the invisible decay of the Higgs in the neutrino channel can be comparable to the cc¯ and ??¯ modes and predict interesting Higgs phenomenology. If lepton number is violated in the conformal theory an irrelevant Majorana mass operator for right-handed neutrinos appears for ?>1/2 giving rise to an inverse see-saw mechanism. In this case light sterile neutrinos do appear and neutrino oscillation experiments are able to probe our model.

von Gersdorff, Gero; Quirós, Mariano

2009-07-01

294

High energy neutrinos from the sun and cold dark matter  

SciTech Connect

The possibility of a flux of high energy neutrinos (100 MeV less than or equal to E/sub nu/ less than or equal to 10GeV) from the sun due to the annihilation within of particles which make up the galactic halo is considered. Specifically, if the halo consists of heavy neutrinos or stable supersymmetric particles with mass greater than or equal to 6GeV, halo particles will be trapped in the sun and annihilate to produce a potentially observable high energy neutrino flux. Detailed estimates of this flux are provided for a variety of candidate halo particles: photinos, higgsinos, scalar neutrinos, heavy Dirac neutrinos, and heavy Majorana neutrinos. All of these can (for appropriate ranges of parameters) produce fluxes whose absolute value is at least comparable to atmospheric background. How the solar fluxes could be distinguished from the background is briefly discussed. The effect of trapped halo particles on the solar neutrino problem is also discussed. 42 refs., 3 figs.

Srednicki, M.; Olive, K.A.; Silk, J.

1986-03-01

295

Renormalization-group effects on scenario with nearly degenerate neutrino masses and bi-maximal mixing  

NASA Astrophysics Data System (ADS)

The renormalization-group effects on the scenario with nearly degenerate mass and bi-maximal mixing of neutrinos are analysed. Consequently, we show explicitly in the SO(3) gauge model that the renormalization-group effects could modify the fitting values of the relevant basic parameters of the model, but leave the nearly degenerate neutrino mass and bi-maximal mixing scenario stable for reconciling both solar and atmospheric neutrino data. The approximately degenerate Majorana neutrino masses are allowed to be large enough to play a significant cosmological role without conflicting with the current neutrinoless double beta decay.

Wu, Yue-Liang

2000-08-01

296

Excited neutrino production by ultrahigh energy neutrinos traversing the Earth  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

297

Supernovae, neutrino rest mass, and the middle-energy neutrino background in the universe  

Microsoft Academic Search

Neutrinos emitted during the formation of the neutron stars and black holes form, together with relict microwave radiation and relict neutrinos, a background for the present universe. The energy of the kind of neutrino emitted in neutron star formation, at 3-30 MeV, is much greater than that of relict neutrinos and much smaller than that of the cosmic ray neutrinos.

GENNADYI S. BISNOVATYI-KOGAN; ZAKIR F. SEIDOV

1984-01-01

298

Supernovae, neutrino rest mass, and the middle-energy neutrino background in the universe  

Microsoft Academic Search

Neutrinos emitted during the formation of the neutron stars and black holes form, together with relict microwave radiation and relict neutrinos, a background for the present universe. The energy of the kind of neutrino emitted in neutron star formation, at 3-30 MeV, is much greater than that of relict neutrinos and much smaller than that of the cosmic ray neutrinos;

G. S. Bisnovatyi-Kogan; Z. F. Seidov

1984-01-01

299

Relic neutrino asymmetries and big bang nucleosynthesis in a four neutrino model  

Microsoft Academic Search

Oscillations between ordinary and sterile neutrinos can generate large neutrino asymmetries in the early universe. These asymmetries can significantly affect big bang nucleosynthesis (BBN) through modification of nuclear reaction rates. We study this phenomenon within a model consisting of the three ordinary neutrinos plus one sterile neutrino that can be motivated by the neutrino anomalies and the dark matter problem.

N. F. Bell; R. Foot; R. R. Volkas

1998-01-01

300

Probing radiative solar neutrino decays  

NASA Astrophysics Data System (ADS)

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

Frère, J.-M.; Monderen, D.

1998-07-01

301

The emergence of neutrino astronomy  

NASA Astrophysics Data System (ADS)

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

Gaisser, Thomas K.

2013-02-01

302

Solving the Solar Neutrino Problem  

Microsoft Academic Search

Beginning with Ray Davis' pioneering Chlorine measurement in the mid-1960s, and continuing up through the recent Superkamiokande ^8B measurement, all solar neutrino experiments have observed far fewer neutrinos than predicted by theory. The mystery that has remained unsolved is the reason for this discrepancy. Do we really understand energy generation in the sun? Can the solar model calculations and the

John F. Wilkerson

2002-01-01

303

Is There a Massive Neutrino?  

ERIC Educational Resources Information Center

|Discussed is the question of whether "heavy" neutrinos really do exist based on the evidence supplied by four research groups. The implications of its existence on the disciplines of particle physics, astrophsyics, and cosmology are discussed. Background information on the different types of neutrinos is provided. (KR)|

Selvin, Paul

1991-01-01

304

Neutrinos have Mass --- so What?  

Microsoft Academic Search

In this brief review, we discuss the new physics unveiled by neutrino oscillation experiments over the past several years, and discuss several attempts at understanding the mechanism behind neutrino masses and lepton mixing. It is fair to say that, while significant theoretical progress has been made, we are yet to construct a coherent picture that naturally explains nonzero, yet tiny,

André de Gouvêa

2004-01-01

305

Neutrino physics - An expanding realm  

Microsoft Academic Search

? Pauli's neutrino (or antineutrino) is a neutral, massless, spin-half particle and its presence res- cues apparent violation of both energy and angular mo- mentum conservation in the beta decay process. Subsequently it was found by particle physicists that the neutrino comes in three flavours: ?e, ?? and ??. Schewartz, Steinberger and Lederman shared the Nobel Prize in 1988 for

Shankar Nath Mukherjee

306

The neutrino factory:beam and experiments  

Microsoft Academic Search

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

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

2000-01-01

307

Thermodynamic Laws of Neutrino and Photon Emission.  

ERIC Educational Resources Information Center

|Compares neutrino and photon emissions, develops the thermodynamic blackbody laws of neutrino emission analogous to laws governing photon emission, points out that combined radiation from a "true blackbody" consists of both photon and neutrino emissions of comparable magnitude, and speculates upon the existence of blackbody neutrino emitters in…

Walsh, P. J.; Gallo, C. F.

1980-01-01

308

Phenomenological implications of neutrinos in extra dimensions  

Microsoft Academic Search

Standard Model singlet neutrinos propagating in extra dimensions induce small Dirac neutrino masses. While it seems rather unlikely that their Kaluza-Klein excitations directly participate in the observed neutrino oscillations, their virtual exchange may lead to detectable signatures in future neutrino experiments and in rare charged lepton processes. We show how these effects can be described by specific dimension-six effective operators

André de Gouvêa; Gian Francesco Giudice; Alessandro Strumia; Kazuhiro Tobe

2002-01-01

309

Phenomenological implications of neutrinos in extra dimensions  

Microsoft Academic Search

Standard Model singlet neutrinos propagating in extra dimensions induce small Dirac neutrino masses. While it seems rather unlikely that their Kaluza–Klein excitations directly participate in the observed neutrino oscillations, their virtual exchange may lead to detectable signatures in future neutrino experiments and in rare charged lepton processes. We show how these effects can be described by specific dimension-six effective operators

André de Gouvêa; Gian Francesco Giudice; Alessandro Strumia; Kazuhiro Tobe

2002-01-01

310

Phenomenological implications of neutrinos in extra dimensions  

Microsoft Academic Search

Standard Model singlet neutrinos propagating in extra dimensions induce small Dirac neutrino masses. While it seems rather unlikely that their Kaluza-Klein excitations directly participate in the observed neutrino oscillations, their virtual exchange may lead to detectable signatures in future neutrino experiments and in rare charged lepton processes. We show how these effects can be described by specific dimension-six effective operators

Andre de Gouvea; Gian Francesco Giudice; Alessandro Strumia; Kazuhiro Tobe

2001-01-01

311

Neutrino mass models and CP violation  

SciTech Connect

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

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

2011-10-06

312

OPERA and a Neutrino Dark Energy Model  

Microsoft Academic Search

We consider a neutrino dark energy model and study its implications for the neutrino superluminality reported recently by the OPERA collaboration. In our model the derivative couplings of the neutrino to the dark energy scalar result in a Lorentz violation in the neutrino sector. Furthermore, the coupling of the dark energy scalar field to the stress tensor of the Earth

Emilio Ciuffoli; Jarah Evslin; Jie Liu; Xinmin Zhang

2011-01-01

313

Probing thermonuclear supernova explosions with neutrinos  

Microsoft Academic Search

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

A. Odrzywolek; T. Plewa

2011-01-01

314

Solar Neutrino Measurement in Super-Kamiokande  

Microsoft Academic Search

The results of solar neutrino data from the first phase of Super-Kamiokande are presented. Super-Kamiokande can measure not only the solar neutrino flux but also its energy spectrum and its time variations such as day vs. night and seasonal differences. This information can severely restrict parameters of solar neutrino oscillation. Combining flux results from other solar neutrino experiments with those

Yusuke Koshio

2005-01-01

315

Neutrinos Get Under Your Skin  

SciTech Connect

The enigmatic neutrinos are among the most abundant of the tiny particles that make up our universe. They are a billion times more abundant than the particles of which the earth and we humans are made. Thus, to understand the universe, we must understand the neutrinos. Moving ghostlike, almost invisibly, through matter, these particles are very hard to pin down and study. However, dramatic progress has recently been made. In this lecture, the neutrinos will be introduced. Their behavior, so different from that of everyday objects, will be explained, and recent discoveries will be described. The open questions about neutrinos, forthcoming attempts to answer these questions, and the role of neutrinos in shaping the universe and making human life possible, will all be explained.

Kayser, Boris

2005-08-30

316

Reactor Monitoring with Neutrino Detectors  

NASA Astrophysics Data System (ADS)

The study of the use of neutrino detectors to monitor nuclear reactors is currently a very active field of research. While neutrino detectors located close to reactors have been used to provide information about the global performance of the reactors, a general improvement of the technique is needed in order to use it in a practical way to monitor the fissile contents of the fuel of the nuclear reactors or the thermal power delivered. I describe the current status of the Angra Neutrino Project, aimed to building a low-mass neutrino detector to monitor the Angra II reactor of the Brazilian nuclear power plant Almirante Alvaro Ramos in order to explore new approaches to reactor monitoring with neutrino detectors.

Casimiro Linares, Edgar

2011-09-01

317

Neutrino masses in split supersymmetry  

SciTech Connect

We investigate the possibility of generating neutrino masses in the context of split supersymmetric scenarios where all sfermions are very heavy. All relevant contributions coming from the R-parity violating terms to the neutrino mass matrix up to one-loop level are computed showing the importance of the Higgs bosons one-loop corrections. We conclude that it is not possible to generate all neutrino masses and mixings in split SUSY with bilinear R-parity violating interactions. In the case of partial split SUSY, the one-loop Higgs bosons contributions are enough to generate the neutrino masses and mixings in agreement with the experiment. In the context of minimal SUSY SU(5), we find new contributions that help us to generate neutrino masses in the case of split SUSY.

Aurelio Diaz, Marco [Departamento de Fisica, Universidad Catolica de Chile, Avenida Vicuna Mackenna 4860, Santiago (Chile); Fileviez Perez, Pavel [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States); CFTP, Instituto Superior Tecnico, Avenue Rovisco Pais 1, 1049-001, Lisbon (Portugal); Mora, Clemencia [Departement de Physique Nucleaire et Corpusculaire, Universite de Geneve, 24 Quai Ernest-Ansermet, 1211 Geneve 4 (Switzerland)

2009-01-01

318

Neutrino oscillation results from MINOS  

SciTech Connect

The Main Injector Neutrino Oscillation Search (MINOS) long-baseline experiment has been actively collecting beam data since 2005, having already accumulated 3 x 10{sup 20} protons-on-target (POT). MINOS uses the Neutrinos at the Main Injector (NuMI) neutrino beam measured in two locations: at Fermilab, close to beam production, and 735 km downstream, in Northern Minnesota. By observing the oscillatory structure in the neutrino energy spectrum, MINOS can precisely measure the neutrino oscillation parameters in the atmospheric sector. These parameters were determined to be |{Delta}m{sub 32}{sup 2}| = 2.74{sub -0.26}{sup +0.44} x 10{sup -3} eV{sup 2}/c{sup 4} and sin{sup 2}(2{theta}{sub 23}) > 0.87 (68% C.L.) from analysis of the first year of data, corresponding to 1.27 x 10{sup 20} POT.

Sousa, Alexandre; /Oxford U.

2007-08-01

319

Review of Reactor Neutrino Oscillation Experiments  

NASA Astrophysics Data System (ADS)

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

Mariani, C.

320

Flavor symmetry Le-L?-L?, atmospheric neutrino mixing, and CP violation in the lepton sector  

NASA Astrophysics Data System (ADS)

The Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing matrix is given, in general, by the product of two unitary matrices associated with the diagonalization of the charged lepton and neutrino mass matrices. Assuming that the active flavor neutrinos possess a Majorana mass matrix which is diagonalized by a bimaximal mixing matrix, we give the allowed forms of the charged lepton mixing matrix and the corresponding implied forms of the charged lepton mass matrix. We then assume that the origin of bimaximal mixing is a weakly broken flavor symmetry corresponding to the conservation of the nonstandard lepton charge L'=Le-L?-L?. The latter does not predict, in general, the atmospheric neutrino mixing to be maximal. We study the impact of this fact on the allowed forms of the charged lepton mixing matrix and on the neutrino mixing observables, analyzing the case of CP violation in detail. When compared with the case of exact bimaximal mixing, the deviations from zero Ue3 and from maximal atmospheric neutrino mixing are typically more sizable if one assumes just L' conservation. In fact, |Ue3|2 can be as small as 0.007 and atmospheric neutrino mixing can take any value inside its currently allowed range. We discuss under which conditions the atmospheric neutrino mixing angle is larger or smaller than ?/4. We present also a simple seesaw realization of the implied light neutrino Majorana mass matrix and consider leptogenesis in this scenario.

Petcov, S. T.; Rodejohann, W.

2005-04-01

321

Sterile neutrino-enhanced supernova explosions  

NASA Astrophysics Data System (ADS)

We investigate the enhancement of lepton number, energy, and entropy transport resulting from active-sterile neutrino conversion ?e??s deep in the post-bounce supernova core followed by reconversion ?s??e further out, near the neutrino sphere. We explicitly take account of shock wave and neutrino heating modification of the active neutrino forward scattering potential which governs sterile neutrino production. We find that the ?e luminosity at the neutrino sphere could be increased by between ˜10% and ˜100% during the crucial shock reheating epoch if the sterile neutrino has a rest mass and vacuum mixing parameters in ranges which include those required for viable sterile neutrino dark matter. We also find sterile neutrino transport-enhanced entropy deposition ahead of the shock. This ‘‘preheating” can help melt heavy nuclei and thereby reduce the nuclear photo-dissociation burden on the shock. Both neutrino luminosity enhancement and preheating could increase the likelihood of a successful core collapse supernova explosion.

Hidaka, Jun; Fuller, George M.

2007-10-01

322

The solar-neutrino problem, 1995.  

NASA Astrophysics Data System (ADS)

The status of the solar-neutrino problem (SNP), as is seen in 1995, is reviewed. Basically, there are two principal solutions to the SNP: (i) with standard neutrino (neutrino of SM of electroweak interactions) and (ii) with non-standard neutrino (neutrino beyond the SM). Actually, one can distinguish three solar-neutrino problems: the deficit of 8B neutrinos, the deficit of 7Be neutrinos and the HOMESTAKE/KAMIOKANDE conflict. The first problem probably can be solved with small correlated changes of nuclear cross-sections and the change of the central temperature of the Sun. The deficit of 7Be neutrinos looks like the key problem. The HOMESTAKE/KAMIOKANDE conflict strongly disfavours or excludes the standard neutrino (nuclear/astrophysical solution to the SNP). MSW conversion gives a most plausible explanation to the SNP.

Berezinsky, V.

1995-12-01

323

Neutrino minimal standard model predictions for neutrinoless double beta decay  

SciTech Connect

Prediction of the effective Majorana mass for neutrinoless double {beta} decay in a simple extension of the standard model ({nu}MSM) is given. The model adds three right-handed neutrinos with masses smaller than the electroweak scale and explains dark matter of the Universe. This leads to constraints 1.3neutrino mass hierarchy and 13

Bezrukov, F. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation) and Institut de Theorie des Phenomenes Physiques, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)

2005-10-01

324

Beaming Neutrinos and Anti-neutrinos across the Earth to Disentangle Neutrino Mixing Parameters  

NASA Astrophysics Data System (ADS)

A result from MINOS seemed to indicate that the mass splitting and mixing angle of anti-neutrinos is different from that of neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector. However, more recent MINOS data reduced the ??-\\bar{\

Fargion, Daniele; D'Armiento, Daniele; Desiati, Paolo; Paggi, Paolo

2012-10-01

325

Resonant neutrino oscillations and the neutrino signature of supernovae  

NASA Astrophysics Data System (ADS)

We examine the effects of resonant neutrino oscillations, proposed as a solution to the solar neutrino puzzle, on the neutrino signature of a Type II supernova. We find that, for parameters corresponding to an adiabatic conversion of most of the 8B neutrino flux, the supernova neutrino signal in a water-?erenkov detector is altered in the following way: (1) The isotropic-to-directional event ratio increases; (2) The short time scale neutronization burst signal decreases by a factor 7, perhaps rendering it unobservable. Detection of these changes would allow one to distinguish between neutrino oscillations and solar model alterations as solutions to the solar neutrino problem. We also note that mixing of the higher energy ?? and ?r's to ?e's will enhance detection of the thermally produced ?-flux. We both wish to thank the hospitality of the Aspen Center for Physics where this work was discussed and completed. This work was supported in part by NSF and DOE grants at The University of Chicago, and by NASA at Fermilab.

Walker, Terry P.; Schramm, David N.

1987-09-01

326

Theory of neutrino oscillations with entanglement  

SciTech Connect

We show that, despite appearances, a theoretical approach to neutrino oscillation in which the neutrino and its interaction partners are entangled yields the standard result for the neutrino oscillation wavelength. We also shed some light on the question of why plane-wave approaches to the neutrino oscillation problem can yield the correct oscillation wavelength even though they do not explicitly account for the localization of the neutrino source and the detector.

Kayser, Boris; Kopp, Joachim; Robertson, R. G. Hamish; Vogel, Petr [Theoretical Physics Department, Fermilab, P.O. Box 500, Batavia, Illinois 60510 (United States); Department of Physics and Center for Experimental Nuclear Physics and Astrophysics, University of Washington, Seattle, Washington 98195 (United States); Kellogg Radiation Laboratory and Physics Department, Caltech, Pasadena, California 91125 (United States)

2010-11-01

327

Neutrino-induced muons observed with MINOS  

SciTech Connect

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

Habig, A.; /Minnesota U., Duluth

2005-07-01

328

Sterile neutrino-enhanced supernova explosions  

Microsoft Academic Search

We investigate the enhancement of lepton number, energy, and entropy transport resulting from active-sterile neutrino conversion {sub e}{sub s} deep in the post-bounce supernova core followed by reconversion {sub s}{sub e} further out, near the neutrino sphere. We explicitly take account of shock wave and neutrino heating modification of the active neutrino forward scattering potential which governs sterile neutrino production.

Jun Hidaka; George M. Fuller

2007-01-01

329

Sterile neutrino-enhanced supernova explosions  

Microsoft Academic Search

We investigate the enhancement of lepton number, energy, and entropy transport resulting from active-sterile neutrino conversion nue-->nus deep in the post-bounce supernova core followed by reconversion nus-->nue further out, near the neutrino sphere. We explicitly take account of shock wave and neutrino heating modification of the active neutrino forward scattering potential which governs sterile neutrino production. We find that the

Jun Hidaka; George M. Fuller

2007-01-01

330

Calculation of the flux of atmospheric neutrinos  

Microsoft Academic Search

Atmospheric neutrino fluxes are calculated over the wide energy range from 30 MeV to 3000 GeV for the study of neutrino physics using the data from underground neutrino detectors. In this calculation, a full Monte Carlo method is employed for low energy neutrinos (30 MeV-3 GeV), while a hybrid method is used for high energy neutrinos (1-3000 GeV). At low

M. Honda; T. Kajita; K. Kasahara; S. Midorikawa

1995-01-01

331

Theory Predictions for Inclusive atmospheric Neutrino flux  

NASA Astrophysics Data System (ADS)

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

Honda, Morihiro

2013-06-01

332

Neutrino anisotropies after Planck  

NASA Astrophysics Data System (ADS)

We present new constraints on the rest-frame sound speed, ceff2, and the viscosity parameter, cvis2, of the cosmic neutrino background from the recent measurements of the cosmic microwave background anisotropies provided by the Planck satellite. While broadly consistent with the expectations of ceff2=cvis2=1/3 in the standard scenario, the Planck data set hints at a higher value of the viscosity parameter, with cvis2=0.60±0.18 at 68% C.L., and a lower value of the sound speed, with ceff2=0.304±0.013 at 68% C.L. We find a correlation between the neutrino parameters and the lensing amplitude of the temperature power spectrum AL. When the latter parameter is allowed to vary, we find a better consistency with the standard model with cvis2=0.51±0.22, ceff2=0.311±0.019, and AL=1.08±0.18 at 68% C.L. This result indicates that the anomalous large value of AL measured by Planck could be connected to nonstandard neutrino properties. Including additional data sets from baryon acoustic oscillation surveys and the Hubble Space Telescope constraint on the Hubble constant, we obtain cvis2=0.40±0.19, ceff2=0.319±0.019, and AL=1.15±0.17 at 68% C.L.; including the lensing power spectrum, we obtain cvis2=0.50±0.19, ceff2=0.314±0.015, and AL=1.025±0.076 at 68% C.L. Finally, we investigate further degeneracies between the clustering parameters and other cosmological parameters.

Gerbino, Martina; Di Valentino, Eleonora; Said, Najla

2013-09-01

333

Neutrinos and duality  

SciTech Connect

A phenomenological study of Bloom-Gilman duality is performed in electron and neutrino scattering on nuclei. In the resonance region the structure functions are calculated within the phenomenological models of Ghent and Giessen groups, where only the resonance contribution is taken into account, and the background one is neglected. Structure functions F{sub 2} in the resonance region are compared with the DIS ones, extracted directly from the experimental data. The results show, that within the models considered the Bloom-Gilman duality does not work well for nuclei: the integrated strength in the resonance region is considerably lower than in the DIS one.

Lalakulich, O.; Leitner, T.; Buss, O.; Mosel, U. [Institut fuer Theoretische Physik, Universitaet Giessen, Giessen (Germany); Praet, Ch.; Jachowicz, N.; Ryckebusch, J. [Department of Subatomic and Radiation Physics, Ghent University, Ghent (Belgium)

2009-11-25

334

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

SciTech Connect

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

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

2008-01-01

335

Neutrino Masses and Interactions in a Model with Nambu-Goldstone Bosons  

SciTech Connect

A natural scenario for the generation of neutrino masses is the see-saw mechanism, in which a large right-handed neutrino mass makes the left-handed neutrinos light. We review a special case when the Majorana masses originate from spontaneous breaking of a global U(1)XU(1) symmetry. The interactions of the right-handed with the left-handed neutrinos at the electorweak scale further break the global symmetry giving mass to one pseudo Nambu-Goldstone boson (pNGB). The pNGB can then generate a long-range force. Leptogenesis occurs through decays of heavy neutrinos into the light ones and Higgs particles. The pNGB can become the acceleron field and the neutrino masses vary with the value of the scalar field.

Paschos, E. A. [Institut fuer Physik, Universitaet Dortmund, D-44221 Dortmund (Germany)

2007-01-12

336

Mass limits for dark-matter particles derived from high-energy neutrinos from the Sun  

NASA Astrophysics Data System (ADS)

High-energy neutrinos could be emitted from the center of the Sun as annihilation products of heavy galactic dark-matter particles. We analyze neutrino events observed by the Kamiokande detector to search for such neutrinos. The observed upper limits on solar high-energy neutrinos from these data set limits on the mass and density of certain galactic dark matter. The particles analyzed are heavy Dirac neutrinos (?D), heavy Majorana neutrinos (?M), Higgsinos (h~), sneutrinos (?~) with three flavors, and photinos (?~) as the lightest supersymmetric particles. Excluded mass regions are obtained for each dark-matter candidate: 3 GeV

Sato, N.; Hirata, K. S.; Kajita, T.; Kifune, T.; Kihara, K.; Nakahata, M.; Nakamura, K.; Ohara, S.; Suzuki, Y.; Totsuka, Y.; Yaginuma, Y.; Mori, M.; Oyama, Y.; Suzuki, A.; Takahashi, K.; Takei, H.; Tanimori, T.; Koshiba, M.; Suda, T.; Tajima, T.; Miyano, K.; Miyata, H.; Yamada, M.; Fukuda, Y.; Kaneyuki, K.; Nagashima, Y.; Takita, M.; Beier, E. W.; Feldscher, L. R.; Frank, E. D.; Frati, W.; Kim, S. B.; Mann, A. K.; Newcomer, F. M.; van Berg, R.; Zhang, W.

1991-10-01

337

Exploring neutrino oscillations with superbeams  

NASA Astrophysics Data System (ADS)

We consider the medium- and long-baseline oscillation physics capabilities of intense muon-neutrino and muon-antineutrino beams produced using future upgraded megawatt-scale high-energy proton beams. In particular we consider the potential of these conventional neutrino ``superbeams'' for observing ??-->?e oscillations, determining the hierarchy of neutrino mass eigenstates, and measuring CP violation in the lepton sector. The physics capabilities of superbeams are explored as a function of the beam energy, baseline, and the detector parameters (fiducial mass, background rates, and systematic uncertainties on the backgrounds). The trade-offs between very large detectors with poor background rejection and smaller detectors with excellent background rejection are illustrated. We find that, with an aggressive set of detector parameters, it may be possible to observe ??-->?e oscillations with a superbeam provided that the amplitude parameter sin22?13 is larger than a few ×10-3. If sin22?13 is of order 10-2 or larger, then the neutrino mass hierarchy can be determined in long-baseline experiments, and if in addition the large mixing angle MSW solution describes the solar neutrino deficit, then there is a small region of parameter space within which maximal CP violation in the lepton sector would be observable (with a significance of a few standard deviations) in a low-energy medium-baseline experiment. We illustrate our results by explicitly considering massive water Cherenkov and liquid argon detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV, and baselines ranging from 295 km to 9300 km. Finally, we compare the oscillation physics prospects at superbeams with the corresponding prospects at neutrino factories. The sensitivity at a neutrino factory to CP violation and the neutrino mass hierarchy extends to values of the amplitude parameter sin22?13 that are one to two orders of magnitude lower than at a superbeam.

Barger, V.; Geer, S.; Raja, R.; Whisnant, K.

2001-06-01

338

LSND neutrino oscillation results  

SciTech Connect

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

Louis, W.C.; LSND Collaboration

1996-10-01

339

Neutrino interactions in neutron matter  

NASA Astrophysics Data System (ADS)

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

Cipollone, Andrea

2012-12-01

340

Electroweak scale neutrinos and Higgses  

SciTech Connect

We present two different models with electroweak scale right-handed neutrinos. One of the models is created under the constraint that any addition to the Standard Model must not introduce new higher scales. The model contains right-handed neutrinos with electroweak scale masses and a lepton number violating singlet scalar field. The scalar phenomenology is also presented. The second model is a triplet Higgs model where again the right-handed neutrinos have electroweak scale masses. In this case the model has a rich scalar phenomenology and in particular we present the analysis involving the doubly charged Higgs.

Aranda, Alfredo [Facultad de Ciencias, CUICBAS, Universidad de Colima, Bernal Diaz del Castillo No. 340, Colima, Colima (Mexico); Dual CP Institute of High Energy Physics (Mexico)

2009-04-20

341

Report on solar neutrino experiments  

SciTech Connect

A summary is given of the status of solar neutrino research that includes results of the Brookhaven chlorine detector, a discussion of the development of the gallium, bromine, and lithium radiochemical detectors, and some proposals for direct counting detectors. The gallium and bromine radiochemical detectors are developed and are capable of giving critical information of interest about neutrino physics and the fusion reactions in the interior of the sun. A plan for building these detectors is outlined and a rough cost estimate is given. A review is given of the plans in the Soviet Union in solar neutrino research.

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

1984-01-01

342

Solar monopoles and terrestrial neutrinos  

SciTech Connect

Magnetic monopoles captured in the core of the sun may give rise to a substantial flux of energetic neutrinos by catalyzing the decay of solar hydrogen. We discuss the expected neutrino flux in underground detectors under different assumptions about solar interior conditions. Although a monopole flux as low as F/sub M/ /approximately/ 10/sup /minus/24/ cm/sup /minus/2/ sec/sup /minus/1/ sr/sup /minus/1/ could give rise to a neutrino flux above atmospheric background, due to M/bar M/ annihilation, this does not translate into a reliable monopole flux bound stronger than the Parker limit. 8 refs., 1 fig.

Frieman, J.

1988-04-01

343

Nuclear statistical equilibrium neutrino spectrum  

NASA Astrophysics Data System (ADS)

The spectral emission of neutrinos from a plasma in nuclear statistical equilibrium (NSE) is investigated. Particular attention is paid to the possible emission of high-energy (>10 MeV) neutrinos or antineutrinos. A newly developed numerical approach for describing the abundances of nuclei in NSE is presented. Neutrino emission spectra, resulting from general Fuller-Fowler-Newman conditions, are analyzed. Regions of T-?-Ye space favoring detectability are selected. The importance of critical Ye values with zero net rate of neutronization (Y?e) is discussed. Results are provided for the processing of matter under conditions typical for thermonuclear and core-collapse supernovae, presupernova stars, and neutron star mergers.

Odrzywolek, Andrzej

2009-10-01

344

Status of solar neutrino experiments  

SciTech Connect

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

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

1990-01-01

345

Non-Standard Neutrino Interactions  

SciTech Connect

In this talk, I will review non-standard interactions in neutrino physics, especially I will emphazise the impact of non-standard interactions on neutrino oscillations. First, I will give a brief introduction about non-standard interactions and what they are. Then, I will present what has been performed in the literature, what I have done in the field, and what could be done in the future. Next, I will discuss how important non-standard interactions are for neutrino cross-sections. Finally, I will give a summary of the field.

Ohlsson, Tommy [Department of Theoretical Physics, School of Engineering Sciences, Royal Institute of Technology (KTH)-AlbaNova University Center, Roslagstullsbacken 21, 106 91 Stockholm (Sweden)

2009-11-25

346

Neutrino Masses and Mixing in Brane-World Theories  

NASA Astrophysics Data System (ADS)

We present a comprehensive study of five-dimensional brane-world models for neutrino physics based on flat compactifications. Particular emphasis is put on the inclusion of bulk mass terms. We derive a number of general results for such brane-world models with bulk mass terms. In particular, in the limit of small brane-bulk couplings, the electroweak eigenstates are predominantly given as a superposition of three light states with non-trivial small admixtures of bulk states. As a consequence, neutrinos can undergo standard oscillations as well as oscillation into bulk Kaluza-Klein states. We use this structure to construct a specific model based on Bbb Z orbifolding and bulk Majorana masses which is compatible with all observed oscillation phenomena. The solar neutrino deficit is explained by oscillations into sterile bulk states while the atmospheric neutrino deficit is due to numu - nutau oscillations with naturally maximal mixing. In addition, the model can accommodate the LSND result and a significant neutrino dark matter component. We also analyze the constraints from supernova energy loss on neutrino brane-world theories and show that our specific model is consistent with these constraints.

Lukas, André; Ramond, Pierre; Romanino, Andrea; Ross, Graham G.

2001-04-01

347

Quasi-Dirac neutrinos and solar neutrino data  

NASA Astrophysics Data System (ADS)

We will present an analysis of the solar neutrino data in the context of a 3+1 quasi-Dirac neutrino model in which the lepton mixing matrix is given at tree level by the tribimaximal matrix. When radiative corrections are taken into account, new effects in neutrino oscillations, as ? e ? ? s , could appear. This oscillation is constrained by the solar neutrino data. In our analysis, we have found an allowed region for our two free parameters ? and m 1. The radiative correction, ?, can vary approximately from 5×10-9 to 10-6 and the calculated fourth mass eigenstate, m 4, varies in the interval 0.01-0.2 eV, at 2 ? level. These results are in agreement with the ones presented in the literature in 2+1 and 2+2 quasi-Dirac models.

Rossi-Torres, F.; Machado, A. C. B.; Pleitez, V.

2013-10-01

348

The many aspects of neutrino physics  

SciTech Connect

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

Frieman, J.A.

1992-01-01

349

Neutrino mass hierarchy extraction using atmospheric neutrinos in ice  

SciTech Connect

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{sup 2}2{theta}{sub 13} 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%.

Mena, Olga [INFN Sez. di Roma, Dipartimento di Fisica, Universita di Roma 'La Sapienza', P.le A. Moro, 5, I-00185 Roma (Italy); Institute of Space Sciences (IEEC-CSIC), Fac. Ciencies, Campus UAB, Bellaterra (Spain); Mocioiu, Irina [Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Razzaque, Soebur [Space Science Division, Code 7653, U.S. Naval Research Laboratory, Washington D.C. 20375 (United States)

2008-11-01

350

Detection of supernova neutrinos by neutrino-proton elastic scattering  

Microsoft Academic Search

We propose that neutrino-proton elastic scattering, nu+p-->nu+p, can be used for the detection of supernova neutrinos in scintillator detectors. Though the proton recoil kinetic energy spectrum is soft, with Tp~=2E2nu\\/Mp, and the scintillation light output from slow, heavily ionizing protons is quenched, the yield above a realistic threshold is nearly as large as that from nu¯e+p-->e++n. In addition, the measured

John F. Beacom; Will M. Farr; Petr Vogel

2002-01-01

351

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory  

SciTech Connect

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

Marino, Alysia Diane

2004-08-10

352

The SNO-Experiment and Neutrino Oscillations  

NASA Astrophysics Data System (ADS)

Using the pre-SNO neutrino oscillation data of the solar and the atmospheric neutrino oscillations including and excluding the LSND (Los Alamos) measurements fits for the three mixing angle of the unitary transformation between the three neutrino mass eigenstates and the weak eigenstates are given. At the same time the differences of the squared masses are fitted to the data. Using an averaged upper value of delimiter "426830A m? e > = 0.62 eV from the neutrino double beta decay, one can limit the sum of the three neutrino masses to be less than 2.53 eV. The new data from the Sudbury Neutrino Observatory allow for the first time with the help of the SuperKamiokande data to determine the solar e and (? + ? ) neutrino fluxes separately. The sum is within errors identical to the theoretical electron neutrino flux from the sun. We thus see all expected solar neutrinos. They only oscillated partially from electron to ? + ? neutrinos. In the last part we report calculations of neutrino masses in the R-parity violating Minimal Supersymmetric Standard Model (R/ MSSM). The R-parity violating interaction mixes the three neutrino flavors by R-parity violation with the four neutralinos (photino, zino and the two higgsinos). One finds neutrino masses for the first two neutrinos between 0.001 and 0.04 eV and for the third one between 0.03 and 1 eV.

Faessler, Amand

2002-01-01

353

First measurement of the flux of solar neutrinos from the sun at the Sudbury Neutrino Observatory  

NASA Astrophysics Data System (ADS)

The Sudbury Neutrino Observatory (SNO) is a second generation solar neutrino detector. SNO is the first experiment that is able to measure both the electron neutrino flux and a flavor-blind flux of all active neutrino types, allowing a model-independent determination if the deficit of solar neutrinos known as the solar neutrino problem is due to neutrino oscillation. The Sudbury Neutrino Observatory started taking production data in November, 1999. A measurement of the charged current rate will be the first indication if SNO too sees a suppression of the solar neutrino signal relative to the theoretical predictions. Such a confirmation is the first step in SNO's ambitious science program. In this thesis, we present evidence that SNO is seeing solar neutrinos and a preliminary ratio of the measured vs predicted rate of electrons as induced by 8B neutrinos in the ?e, + d --> p + p + e charged-current (CC) reaction.

Wittich, Peter

2000-12-01

354

Neutrino mass and mixing, and non-accelerator experiments  

SciTech Connect

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

Robertson, R.G.H.

1992-10-01

355

Neutrino mass and mixing, and non-accelerator experiments  

SciTech Connect

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

Robertson, R.G.H.

1992-01-01

356

One-loop contribution to the neutrino mass matrix in the next-to-minimal supersymmetric standard model with right-handed neutrinos and tribimaximal mixing  

SciTech Connect

Neutrino mass patterns and mixing have been studied in the context of the next-to-minimal supersymmetric standard model (NMSSM) with three gauge singlet neutrino superfields. We consider the case with the assumption of R-parity conservation. The vacuum expectation value of the singlet scalar field S of NMSSM induces the Majorana masses for the right-handed neutrinos as well as the usual {mu} term. The contributions to the light neutrino mass matrix at the tree level as well as one-loop level are considered, consistent with the tribimaximal pattern of neutrino mixing. Light neutrino masses arise at the tree level through a TeV-scale seesaw mechanism involving the right-handed neutrinos. Although all the three light neutrinos acquire nonzero masses at the tree level, we show that the one-loop contributions can be comparable in size under certain conditions. Possible signatures to probe this model at the LHC and its distinguishing features compared to other models of neutrino mass generation are briefly discussed.

Das, Debottam; Roy, Sourov [Laboratoire de Physique Theorique, UMR 8627, Universite de Paris-Sud 11, Ba circumflex timent 210, 91405 Orsay Cedex (France); Department of Theoretical Physics and Centre for Theoretical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Kolkata 700 032 (India)

2010-08-01

357

Solar neutrinos: theory vs experiment.  

National Technical Information Service (NTIS)

I review the standard solar model, the disparities between its predictions and the solar neutrino flux measurements of the Homestake and Kamioka II collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including ...

W. C. Haxton

1991-01-01

358

An expansion for neutrino phenomenology  

NASA Astrophysics Data System (ADS)

We develop a formalism for constructing the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix and neutrino masses using an expansion that originates when a sequence of heavy right handed neutrinos are integrated out, assuming a seesaw mechanism for the origin of neutrino masses. The expansion establishes relationships between the structure of the PMNS matrix and the mass differences of neutrinos, and allows symmetry implications for measured deviations from tri-bimaximal form to be studied systematically. Our approach does not depend on choosing the rotation between the weak and mass eigenstates of the charged lepton fields to be diagonal. We comment on using this expansion to examine the symmetry implications of the recent results from the Daya-Bay collaboration reporting the discovery of a non zero value for ? 13, indicating a deviation from tri-bimaximal form, with a significance of 5.2 ?.

Grinstein, Benjamín; Trott, Michael

2012-09-01

359

Neutrinos from supernova 1987A  

SciTech Connect

Observations of neutrinos emitted from SN 1987A, which were obtained in Japan and Ohio, are discussed. The discovery of neutrinos, the basic physics of neutrino, and the processes of stellar evolution and collapse, are reviewed. The agreement between the observations and theoretical predictions are examined. It was found that the total energy of the event was in the range 2-3 X 10 to the 53rd ergs. The thermal history and light curve of a cooling neutron star, and the neutrino signal of SN 1987A are depicted in graphs. The events inside a massive star which lead to the creation of a neutron star are illustrated and the possibility of future observations is considered.

Lattimer, J.M.; Burrows, A.S.

1988-10-01

360

Unparticle effects in neutrino telescopes  

NASA Astrophysics Data System (ADS)

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

González-Sprinberg, G.; Martínez, R.; Sampayo, Oscar A.

2009-03-01

361

AGS broad band neutrino beam  

SciTech Connect

We describe the broad band neutrino beam in the north area of the AGS and discuss the calculation of the neutrino flux. The horns were initially designed by Robert Palmer and this beam has been used for almost all neutrino running at the AGS. All of the wide band running for E734 has been done in the beam we discuss. E734 is an experiment designed to measure elastic scattering of neutrinos and antineutrinos on electrons and protons. The detector is sufficiently large (approx. =170 tons) that enough events can be detected to make precision measurements of cross sections. In particular, the reaction nu/sub ..mu../ + e ..-->.. nu/sub ..mu../ + e has been detected with more than 100 events, requiring a detailed understanding of the beam characteristics for normalization.

White, D.H.

1985-02-27

362

Hidden MeV-scale dark matter in neutrino detectors  

NASA Astrophysics Data System (ADS)

The possibility of direct detection of light fermionic dark matter in neutrino detectors is explored from a model-independent standpoint. We consider all operators of dimension six or lower which can contribute to the interaction f¯p?e+n, where f is a dark Majorana or Dirac fermion. Constraints on these operators are then obtained from the f lifetime and its decays which produce visible ? rays or electrons. We find one operator which would allow f¯p?e+n at interesting rates in neutrino detectors, as long as mf?m?. The existing constraints on light dark matter from relic density arguments, supernova cooling rates, and big-bang nucleosynthesis are then reviewed. We calculate the cross section for f¯p?e+n in neutrino detectors implied by this operator, and find that Super-Kamiokande can probe the new physics scale ? for this interaction up to O(100TeV).

Kile, Jennifer; Soni, Amarjit

2009-12-01

363

Leptogenesis and low energy CP phases with two heavy neutrinos  

SciTech Connect

An attractive explanation for nonzero neutrino masses and small matter antimatter asymmetry of the present Universe lies in 'leptogenesis'. At present the size of the lepton asymmetry is precisely known, while the sign is not known yet. In this work we determine the sign of this asymmetry in the framework of two right-handed neutrino models by relating the leptogenesis phase(s) with the low energy CP violating phases appearing in the leptonic mixing matrix. It is shown that the knowledge of low energy lepton number violating rephasing invariants can indeed determine the sign of the present matter antimatter asymmetry of the Universe and hence indirectly probing the light physical neutrinos to be Majorana type.

Bhattacharya, Kaushik; Sahu, Narendra; Sarkar, Utpal; Singh, Santosh K. [Theoretical Physics Division, Physical Research Laboratory, Navrangpura, Ahmedabad 380 009 (India)

2006-11-01

364

Neutrino Masses in Theories with Dynamical Symmetry Breaking  

NASA Astrophysics Data System (ADS)

We address the problem of accounting for light neutrino masses in theories with dynamical electroweak symmetry breaking. We discuss this in the context of a class of extended technicolor (ETC) models. As a possible solution, we propose a combination of suppressed Dirac masses and a seesaw involving dynamically generated condensates of standard-model singlet, ETC-nonsinglet fermions. We show how this can be realized in an explicit ETC model. An important feature of this proposal is that, because of the suppression of Dirac neutrino mass terms, a seesaw yielding realistic neutrino masses does not require superheavy Majorana masses. We then generalize this mechanism to theories with extended strong-electroweak gauge symmetries.

Appelquist, Thomas; Shrock, Robert

2004-10-01

365

Status of non-standard neutrino interactions  

NASA Astrophysics Data System (ADS)

The phenomenon of neutrino oscillations has been established as the leading mechanism behind neutrino flavor transitions, providing solid experimental evidence that neutrinos are massive and lepton flavors are mixed. Here we review sub-leading effects in neutrino flavor transitions known as non-standard neutrino interactions (NSIs), which is currently the most explored description for effects beyond the standard paradigm of neutrino oscillations. In particular, we report on the phenomenology of NSIs and their experimental and phenomenological bounds as well as an outlook for future sensitivity and discovery reach.

Ohlsson, Tommy

2013-04-01

366

Neutrino Oscillation Phase Shift from Quantum Gravity  

NASA Astrophysics Data System (ADS)

The phase shift of neutrino oscillation could be discussed in the frame work of quantum gravity. Quantum gravity (Planck scale effects) leads to an effective SU(2) L × U(1) invariant dimension-5 Lagrangian involving, neutrino and Higgs fields. On symmetry breaking, this operator gives rise to correction to the neutrino masses and mixing. We compute the neutrino oscillation phase due to Planck scale effects. The gravitational interaction ( M X = M pl ) demands that the element of this perturbation matrix should be independent of flavor indices. In this paper, we study the quantum gravity effects on neutrino oscillation phases, namely modified dispersion relation for neutrino oscillation phases.

Koranga, Bipin Singh

2012-12-01

367

Inclusive neutrino reactions in nuclei  

SciTech Connect

The charged current inclusive neutrino reaction cross section on a {sup 12}C target is obtained for electron neutrino energies from threshold to 100 MeV. An averaged cross section over the Michel spectrum is also obtained. The method here makes use of a tensor which describes the hadronic part of the interaction and which is obtained from total muon capture data and from electron scattering data in and around the giant dipole resonance. Applications to other nuclei are discussed.

Mintz, S.L.; Pourkaviani, M.

1993-04-01

368

Solar neutrino results from SAGE  

Microsoft Academic Search

We report the status of the Russian-American Gallium solar neutrino Experiment (SAGE). The solar neutrino result for SAGE III, 20 runs during the measuring period May 1995 through December 1997, is 56.7 + 9.3?8.7(stat)+4.6?4.8(syst.) SNU. The combined result for 57 measurements from 1990 through 1997 (SAGE I + II + III) is 66.9 + 7.1?6.8 (stat) +5.4?5.7 (syst) SNU. The

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

1999-01-01

369

Solar neutrino results from SAGE  

Microsoft Academic Search

We report the results of ten years of solar neutrino observation by the Russian-American Gallium solar neutrino Experiment (SAGE). The overall result of 70 runs during the measurement period January 1990 to October 1999 is 75.4 + 7.0\\/?6.8 (stat.) +3.5\\/?3.0 (syst.) SNU. This represents only slightly more than half of the predicted standard solar model rate of 129 SNU. The

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

2001-01-01

370

Gauge trimming of neutrino masses  

Microsoft Academic Search

We show that under a new U(1) gauge symmetry, which is nonanomalous in the presence of one 'right-handed neutrino' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of

M.-C. Chen; Andre de Gouvea; Bogdan A. Dobrescu

2007-01-01

371

Gauge trimming of neutrino masses  

Microsoft Academic Search

We show that under a new U(1) gauge symmetry, which is non-anomalous in the\\u000apresence of one ``right-handed neutrino'' per generation and consistent with\\u000athe standard model Yukawa couplings, the most general fermion charges are\\u000adetermined in terms of four rational parameters. This generalization of the B-L\\u000asymmetry with generation-dependent lepton charges leads to neutrino masses\\u000ainduced by operators of

Mu-Chun Chen; Andre de Gouvea; Bogdan A. Dobrescu

2007-01-01

372

Gauge trimming of neutrino masses  

Microsoft Academic Search

We show that under a new U(1) gauge symmetry, which is nonanomalous in the presence of one ``right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators

Mu-Chun Chen; André de Gouvêa; Bogdan A. Dobrescu

2007-01-01

373

Neutrinos Have Mass - So What?  

Microsoft Academic Search

In this brief review, I discuss the new physics unveiled by neutrino\\u000aoscillation experiments over the past several years, and discuss several\\u000aattempts at understanding the mechanism behind neutrino masses and lepton\\u000amixing. It is fair to say that, while significant theoretical progress has been\\u000amade, we are yet to construct a coherent picture that naturally explains\\u000anon-zero, yet tiny,

Andre de Gouvea

2005-01-01

374

Gauge Trimming of Neutrino Masses  

Microsoft Academic Search

We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ''right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of

Mu-Chun Chen; Andre de Gouvea; Bogdan A. Dobrescu

2006-01-01

375

Neutrino Factory Near Detector Simulation  

NASA Astrophysics Data System (ADS)

We present a simulation with GENIE MC generator of the Neutrino Factory baseline near detector interaction rates for the purely leptonic process ??+e--->?e+?- and for ??+N-->?-+X scattering in view of measuring the first one and suppressing the second one for neutrino flux estimation. A set of most sensitive measurable quantities are discussed and their selective power against experimental uncertainties is examined.

Karadzhov, Yordan

2010-03-01

376

Quasidegenerate neutrinos and tribimaximal mixing  

SciTech Connect

We consider how, for quasidegenerate neutrinos with tribimaximal mixing at a high-energy scale, the mixing angles are affected by radiative running from high- to low-energy scales in a supersymmetric theory. The limits on the high-energy scale that follow from consistency with the observed mixing are determined. We construct a model in which a non-Abelian discrete family symmetry leads to both a quasidegenerate neutrino-mass spectrum and to near tribimaximal mixing.

Medeiros Varzielas, Ivo de [CFTP, Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ross, Graham G.; Serna, Mario [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

2009-10-01

377

Proposed geological solar neutrino measurement  

SciTech Connect

It may be possible to measure the boron-8 solar neutrino flux, averaged over the past several million years, from the concentration of technetium-98 in molybdenum-rich ore. This geochemical experiment could provide the first test of nonstandard solar models that suggest a relation between the chlorine-37 solar neutrino puzzle and the most recent glacial epoch. The necessary conditions for achieving a meaningful measurement are identified and discussed.

Cowan, G.A.; Haxton, W.C.

1982-01-01

378

Neutrino masses in the economical 3-3-1 model  

SciTech Connect

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

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

2007-04-01

379

Sterile neutrinos at the CNGS  

NASA Astrophysics Data System (ADS)

We study the potential of the CNGS beam in constraining the parameter space of a model with one sterile neutrino separated from three active ones by an Script O(eV2) mass-squared difference, ? mSBL2. We perform our analysis using the OPERA detector as a reference (our analysis can be upgraded including a detailed simulation of the ICARUS detector). We point out that the channel with the largest potential to constrain the sterile neutrino parameter space at the CNGS beam is ?????. The reason for that is twofold: first, the active-sterile mixing angle that governs this oscillation is the less constrained by present experiments; second, this is the signal for which both OPERA and ICARUS have been designed, and thus benefits from an extremely low background. In our analysis we also took into account ????e oscillations. We find that the CNGS potential to look for sterile neutrinos is limited with nominal intensity of the beam, but it is significantly enhanced with a factor 2 to 10 increase in the neutrino flux. Data from both channels allow us, in this case, to constrain further the four-neutrino model parameter space. Our results hold for any value of ? mSBL2gtrsim0.1 eV2, i.e. when oscillations driven by this mass-squared difference are averaged. We have also checked that the bound on ?13 that can be put at the CNGS is not affected by the possible existence of sterile neutrinos.

Donini, Andrea; Maltoni, Michele; Meloni, Davide; Migliozzi, Pasquale; Terranova, Francesco

2007-12-01

380

Neutrino flux ratios at neutrino telescopes: The role of uncertainties of neutrino mixing parameters and applications to neutrino decay  

SciTech Connect

In this paper, we derive simple and general perturbative formulas for the flavor flux ratios R{sub {alpha}}{sub {beta}}={phi}{sub {nu}{sub {alpha}}}/{phi}{sub {nu}{sub {beta}}} that could be measured at neutrino telescopes. We discuss in detail the role of the uncertainties of the neutrino mixing parameters showing that they have to be seriously taken into account in any realistic discussion about flavor measurements at neutrino telescopes. In addition, we analyze the impact of such uncertainties in telling the standard neutrino oscillation framework from scenarios involving, e.g., neutrino decay and we find that the ratio R{sub e{mu}} is the most sensitive one to 'new physics' effects beyond the standard model. We also compute the more realistic muon-to-shower ratio for a particular configuration of the IceCube experiment, observing that using this experimental quantity a clear separation between standard and nonstandard neutrino physics cannot be obtained.

Meloni, Davide [INFN, Sezione di Roma and Dipartimento di Fisica, Universita 'La Sapienza', IT-00185 Rome (Italy); Ohlsson, Tommy [Department of Theoretical Physics, School of Engineering Sciences, Royal Institute of Technology (KTH)-AlbaNova University Center, Roslagstullsbacken 21, SE-106 91 Stockholm (Sweden)

2007-06-15

381

Neutrinos and Big Bang Nucleosynthesis  

NASA Astrophysics Data System (ADS)

The early universe provides a unique laboratory for probing the frontiers of particle physics in general and neutrino physics in particular. The primordial abundances of the relic nuclei produced during the first few minutes of the evolution of the Universe depend on the electron neutrinos through the charged-current weak interactions among neutrons and protons (and electrons and positrons and neutrinos), and on all flavors of neutrinos through their contributions to the total energy density which regulates the universal expansion rate. The latter contribution also plays a role in determining the spectrum of the temperature fluctuations imprinted on the Cosmic Background Radiation (CBR) some 400 thousand years later. Using deuterium as a baryometer and helium-4 as a chronometer, the predictions of BBN and the CBR are compared to observations. The successes of, as well as challenges to the standard models of particle physics and cosmology are identified. While systematic uncertainties may be the source of some of the current tensions, it could be that the data are pointing the way to new physics. In particular, BBN and the CBR are used to address the questions of whether or not the relic neutrinos were fully populated in the early universe and, to limit the magnitude of any lepton asymmetry which may be concealed in the neutrinos.

Steigman, Gary

2006-03-01

382

Searching for sterile neutrinos from ? and K decays  

NASA Astrophysics Data System (ADS)

The production of heavy sterile neutrinos from ?-, K- decay at rest yields charged leptons with negative helicity (positive for ?+, K+). We obtain the branching ratio for this process and argue that a Stern-Gerlach filter with a magnetic field gradient leads to spatially separated domains of both helicity components with abundances determined by the branching ratio. Complemented with a search of the monochromatic peak, this setup can yield both the mass and mixing angles for sterile neutrinos with masses in the range 3MeV?ms?414MeV in next generation high intensity experiments. We also study oscillations of light Dirac and Majorana sterile neutrinos with ms?eV produced in meson decays including decoherence aspects arising from lifetime effects of the decaying mesons and the stopping distance of the charged lepton in short baseline experiments. We obtain the transition probability from production to detection via charged current interactions including these decoherence effects for 3+1 and 3+2 scenarios, also studying |?L|=2 transitions from ?¯?? oscillations for Majorana neutrinos and the impact of these effects on the determination of CP-violating amplitudes. We argue that decoherence effects are important in current short baseline accelerator experiments, leading to an underestimate of masses, mixing and CP-violating angles. At MiniBooNE/SciBooNE we estimate that these effects lead to an ˜15% underestimate for sterile neutrino masses ms?3eV. We argue that reactor and current short baseline accelerator experiments are fundamentally different and suggest that in future high intensity experiments with neutrinos produced from ?, K decay at rest, stopping the charged leptons on distances much smaller than the decay length of the parent meson suppresses considerably these decoherence effects.

Lello, Louis; Boyanovsky, Daniel

2013-04-01

383

High energy neutrino telescopes  

NASA Astrophysics Data System (ADS)

This paper presents a review of the history, motivation and current status of high energy neutrino telescopes. Many years after these detectors were first conceived, the operation of kilometer-cubed scale detectors is finally on the horizon at both the South Pole and in the Mediterranean Sea. These new detectors will perhaps provide us the first view of high energy astrophysical objects with a new messenger particle and provide us with our first real glimpse of the distant universe at energies above those accessible by gamma-ray instruments. Some of the topics that can be addressed by these new instruments include the origin of cosmic rays, the nature of dark matter, and the mechanisms at work in high energy astrophysical objects such as gamma-ray bursts, active galactic nuclei, pulsar wind nebula and supernova remnants.

Hoffman, K. D.

2009-05-01

384

Dark energy from mass varying neutrinos  

NASA Astrophysics Data System (ADS)

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

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

2004-10-01

385

Atmospheric Neutrinos in the MINOS Far Detector  

SciTech Connect

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

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

2004-12-01

386

Some Unsettled Questions in the Problem of Neutrino Oscillations. Mechanisms of Neutrino Oscillations  

Microsoft Academic Search

In the modern theory of neutrino oscillations constructed in the framework of the theory particle physics there appears three types of neutrino transitions (oscillations). Then, in order to solve the question of which type of neutrino transitions (oscillations) are realized in nature, in experiments, it is necessary to study profile of neutrino transitions in dependence on distances for determination lengths

Khamidbi Muchamedovich Beshtoev

2003-01-01

387

A road map to solar neutrino fluxes, neutrino oscillation parameters, and tests for new physics  

Microsoft Academic Search

We analyze all available solar and related reactor neutrino experiments, as well as simulated future 7Be, p-p, and pep solar neutrino experiments. We treat all solar neutrino fluxes as free parameters subject to the condition that the total luminosity represented by the neutrinos equals the observed solar luminosity (the `luminosity constraint'). Existing experiments plus the luminosity constraint show that the

John N. Bahcall; Carlos Peña-Garay

2003-01-01

388

THE NEUTRINO MAGNETIC MOMENT AND TIME VARIATIONS OF THE SOLAR NEUTRINO FLUX  

Microsoft Academic Search

The present status of the neutrino magnetic moment solutions of the solar neutrino problem is summarized. After a brief review of the basics of the neutrino spin and spin-flavor precession I discuss the experimental data and show how the neutrino resonant spin-flavor precession (RSFP) mechanism can naturally account for sizeable time variations in the Homestake signal and no observable time

E. Kh

389

Supernova neutrinos: Earth matter effects and neutrino mass spectrum  

NASA Astrophysics Data System (ADS)

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

Lunardini, C.; Smirnov, A. Yu.

2001-11-01

390

Neutrinos and cosmology: A lifetime relationship  

NASA Astrophysics Data System (ADS)

We consider the example of neutrino decays to illustrate the profound relation between laboratory neutrino physics and cosmology. Two case studies are presented: In the first one, we show how the high precision cosmic microwave background spectral data collected by the FIRAS instrument on board of COBE, when combined with Lab data, have greatly changed bounds on the radiative neutrino lifetime. In the second case, we speculate on the consequence for neutrino physics of the cosmological detection of neutrino masses even as small as ~0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a detection at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on some models of neutrino secret interactions.

Serpico, Pasquale D.

2009-06-01

391

Collective Interactions between Neutrinos and Dense Plasmas.  

National Technical Information Service (NTIS)

A new interaction mechanism is described between neutrinos and dense plasmas. With the unification of the electromagnetic and weak forces, analogous processes should occur for intense neutrino fluxes as for photon fluxes. Intense EM waves excite parametri...

R. J. Bingham J. M. Dawson J. J. Su

1992-01-01

392

Particle physics confronts the solar neutrino problem  

SciTech Connect

This review has four parts. In Part I, we describe the reactions that produce neutrinos in the sun and the expected flux of those neutrinos on the earth. We then discuss the detection of these neutrinos, and how the results obtained differ from the theoretical expectations, leading to what is known as the solar neutrino problem. In Part II, we show how neutrino oscillations can provide a solution to the solar neutrino problem. This includes vacuum oscillations, as well as matter enhanced oscillations. In Part III, we discuss the possibility of time variation of the neutrino flux and how a magnetic moment of the neutrino can solve the problem. WE also discuss particle physics models which can give rise to the required values of magnetic moments. In Part IV, we present some concluding remarks and outlook for the recent future.

Pal, P.B.

1991-06-01

393

Solar neutrino spectroscopy (before and after superkamiokande).  

National Technical Information Service (NTIS)

Results of solar neutrino spectroscopy based on data from four experiments are presented. Perspectives related to forthcoming experiments are discussed. Implications of the results for neutrino properties are considered. (author). 54 refs, 2 tabs. (Atomin...

A. Smirnov

1996-01-01

394

Neutrinos and cosmology: a lifetime relationship  

SciTech Connect

We consider the example of neutrino decays to illustrate the profound relation between laboratory neutrino physics and cosmology. Two case studies are presented: In the first one, we show how the high precision cosmic microwave background spectral data collected by the FIRAS instrument on board of COBE, when combined with Lab data, have greatly changed bounds on the radiative neutrino lifetime. In the second case, we speculate on the consequence for neutrino physics of the cosmological detection of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a detection at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on some models of neutrino secret interactions.

Serpico, Pasquale D.; /Fermilab

2008-06-01

395

Decaying neutrinos: The long way to isotropy  

SciTech Connect

We investigate a scenario in which neutrinos are coupled to a pseudoscalar degree of freedom {phi} and where decays {nu}{sub 1{yields}{nu}2}+{phi} and inverse decays are the responsible mechanism for obtaining equilibrium. In this context we discuss the implication of the invisible neutrino decay on the neutrino-pseudoscalar coupling constant and the neutrino lifetime. Assuming the realistic scenario of a thermal background of neutrinos and pseudoscalar we update the bound on the (off-diagonal) neutrino-pseudoscalar coupling constant to g<2.6x10{sup -13} and the bound on the neutrino lifetime to {tau}>1x10{sup 13} s. Furthermore we confirm analytically that kinetic equilibrium is delayed by two Lorentz {gamma} factors--one for time dilation of the (decaying) neutrino lifetime and one from the opening angle. We have also confirmed this behavior numerically.

Basboell, Anders [Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH (United Kingdom); Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Bjaelde, Ole Eggers [Institut fuer Theoretische Physik E, RWTH Aachen University, D-52056 Aachen (Germany); Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)

2010-06-15

396

The neutrino sky at very high energies  

NASA Astrophysics Data System (ADS)

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

Ahlers, Markus

2013-10-01

397

Salt Neutrino Detector for Ultrahigh-Energy Neutrinos  

SciTech Connect

Rock salt and limestone are studied to determine their suitability for use as a radio-wave transmission medium in an ultrahigh energy (UHE) cosmic neutrino detector. A sensible radio wave would be emitted by the coherent Cherenkov radiation from negative excess charges inside an electromagnetic shower upon interaction of a UHE neutrino in a high-density medium (Askar'yan effect). If the attenuation length for the radio wave in the material is large, a relatively small number of radio-wave sensors could detect the interaction occurring in the massive material. We measured the complex permittivity of the rock salt and limestone by the perturbed cavity resonator method at 9.4 and 1 GHz to good precision. We obtained new results of measurements at the frequency at 1.0 GHz. The measured value of the radio-wave attenuation length of synthetic rock salt samples is 1080 m. The samples from the Hockley salt mine in the United States show attenuation length of 180 m at 1 GHz, and then we estimate it by extrapolation to be as long as 900 m at 200 MHz. The results show that there is a possibility of utilizing natural massive deposits of rock salt for a UHE neutrino detector. A salt neutrino detector with a size of 2 x 2 x 2 km would detect 10 UHE neutrino/yr generated through the GZK process.

Chiba, M.; Yasuda, O. [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); Kamijo, T. [Tokyo Metropolitan University, Department of Engineering, Tokyo (Japan); Chikashige, Y.; Kon, T.; Takeoka, Y.; Yoshida, R. [Seikei University, Department of Engineering, Tokyo (Japan)

2004-11-01

398

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

SciTech Connect

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

Abdurashitov, J. N. [Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow, Russia (Russian Federation); Bowles, T. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cherry, M. L. [Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Cleveland, B. T. [University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Davis, R. Jr. [University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Elliott, S. R. [University of Washington, Seattle, Washington 98195 (United States); Gavrin, V. N. [Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow, Russia (Russian Federation); Girin, S. V. [Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow, Russia (Russian Federation); Gorbachev, V. V. [Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow, Russia (Russian Federation); Ibragimova, T. V. [Institute for Nuclear Research, Russian Academy of Sciences, 117312 Moscow, Russia (Russian Federation)] (and others)

1999-12-06

399

Atmospheric and solar neutrinos from single right-handed neutrino dominance and U(1) family symmetry  

Microsoft Academic Search

We discuss a natural explanation of both neutrino mass hierarchies and large neutrino mixing angles, as required by the atmospheric neutrino data, in terms of a single right-handed neutrino giving the dominant contribution to the 23 block of the light effective neutrino matrix, and illustrate this mechanism in the framework of models with U(1) family symmetries. Sub-dominant contributions from other

S. F. King

1999-01-01

400

Neutrino properties and fundamental symmetries  

SciTech Connect

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). There are two components to this work. The first is a development of a new detection scheme for neutrinos. The observed deficit of neutrinos from the Sun may be due to either a lack of understanding of physical processes in the Sun or may be due to neutrinos oscillating from one type to another during their transit from the Sun to the Earth. The Sudbury Neutrino Observatory (SNO) is designed to use a water Cerenkov detector employing one thousand tonnes of heavy water to resolve this question. The ability to distinguish muon and tau neutrinos from electron neutrinos is crucial in order to carry out a model-independent test of neutrino oscillations. We describe a developmental exploration of a novel technique to do this using {sup 3}He proportional counters. Such a method offers considerable advantages over the initially proposed method of using Cerenkov light from capture on NaCl in the SNO. The second component of this work is an exploration of optimal detector geometry for a time-reversal invariance experiment. The question of why time moves only in the forward direction is one of the most puzzling problems in modern physics. We know from particle physics measurements of the decay of kaons that there is a charge-parity symmetry that is violated in nature, implying time-reversal invariance violation. Yet, we do not understand the origin of the violation of this symmetry. To promote such an understanding, we are developing concepts and prototype apparatus for a new, highly sensitive technique to search for time-reversal-invariance violation in the beta decay of the free neutron. The optimized detector geometry is seven times more sensitive than that in previous experiments. 15 refs.

Bowles, T.J.

1996-07-01

401

From Neutrino Factory to Muon Collider  

SciTech Connect

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

Geer, S.; /Fermilab

2010-01-01

402

Solar neutrinos with three flavor mixings  

SciTech Connect

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

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

1992-12-31

403

Solar neutrinos with three flavor mixings  

SciTech Connect

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

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

1992-01-01

404

Neutrino tridents and W-Z interference  

Microsoft Academic Search

We present a measurement of neutrino tridents, muon pairs induced by neutrino scattering in the Coulomb field of a target nucleus, in the Columbia-Chicago-Fermilab-Rochester neutrino experiment at the Fermilab Tevatron. The observed number of tridents after geometric and kinematic corrections, 37.0+\\/-12.4, supports the standard-model prediction of 45.3+\\/-2.3 events. This is the first demonstration of the W-Z destructive interference from neutrino

S. R. Mishra; S. A. Rabinowitz; C. Arroyo; K. T. Bachmann; R. E. Blair; C. Foudas; B. J. King; W. C. Lefmann; W. C. Leung; E. Oltman; P. Z. Quintas; F. J. Sciulli; B. G. Seligman; M. H. Shaevitz; F. S. Merritt; M. J. Oreglia; B. A. Schumm; R. H. Bernstein; F. Borcherding; H. E. Fisk; M. J. Lamm; W. Marsh; K. W. B. Merritt; H. Schellman; D. D. Yovanovitch; A. Bodek; H. S. Budd; P. de Barbaro; W. K. Sakumoto; P. H. Sandler; W. H. Smith

1991-01-01

405

Atmospheric neutrino flux at INO site  

SciTech Connect

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

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

2011-11-23

406

Status of 3+N Sterile Neutrino Fits  

NASA Astrophysics Data System (ADS)

Tension among recent short baseline neutrino experiments has pointed toward the possible need for one or more additional mass splittings in the existing neutrino oscillation framework. This would require the addition of at least one sterile (non-interacting) neutrino to the current model. This work summarizes fits to world data of models which include one, two, and three sterile neutrinos in the ˜1 eV range and provides motivation for future short baseline searches.

Ignarra, C. M.

2013-04-01

407

Atmospheric neutrino flux at INO site  

NASA Astrophysics Data System (ADS)

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

Honda, Morihiro

2011-11-01

408

Neutrinos in the simplest little Higgs scenario and TeV leptogenesis  

SciTech Connect

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

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

2006-02-01

409

Flavor dependence of CP asymmetries and thermal leptogenesis with strong right-handed neutrino mass hierarchy  

SciTech Connect

We prove that taking correctly into account the lepton flavour dependence of the CP asymmetries and washout processes, it is possible to obtain successful thermal leptogenesis from the decays of the second right-handed neutrino. The asymmetries in the muon and tau-flavour channels are then not erased by the inverse decays of the lightest right-handed neutrino N{sub 1}. In this way, we reopen the possibility of ''thermal leptogenesis'' in models with a strong hierarchy in the right-handed Majorana masses that is typically the case in models with up-quark neutrino-Yukawa unification.

Vives, O. [Theory Division, CERN, CH-1211, Geneva 23 (Switzerland)

2006-04-01

410

Supernova neutrino detection in LAr TPCs  

Microsoft Academic Search

The neutrino burst from a core collapse supernova can provide information about the explosion mechanism and the mechanisms of proto neutron star cooling but also about the intrinsic properties of the neutrino such as flavor oscillations. One important question is to understand to which extent can the supernova and the neutrino physics be decoupled in the observation of a single

Inés Gil-Botella

2011-01-01

411

Diffuse supernova neutrinos at underground laboratories  

Microsoft Academic Search

I review the physics of the Diffuse Supernova Neutrino flux (or Background, DSNB), in the context of future searches at the next generation of neutrino telescopes. The theory of the DSNB is discussed in its fundamental elements, namely the cosmological rate of supernovae, neutrino production inside a core collapse supernova, redshift, and flavor oscillation effects. The current upper limits are

Cecilia Lunardini

2010-01-01

412

Short-BaseLine Electron Neutrino Disappearance  

NASA Astrophysics Data System (ADS)

We analyzed the electron neutrino data of the Gallium radioactive source experiments and the electron antineutrino data of the reactor Bugey and Chooz experiments in terms of neutrino oscillations. We found a hint of a CPT-violating asymmetry of the effective neutrino and antineutrino mixing angles.

Giunti, Carlo; Laveder, Marco

2011-08-01

413

Tau neutrino component to tritium beta decay  

Microsoft Academic Search

A framework is given for explaining anomalous results of neutrino mass experiments that measure the high energy electron spectrum of tritium β decay. The experimental results have been fit to a negative neutrino mass square. We show that there is a consistent phenomenological interpretation due to a positive mass tau neutrino component of the β decay spectrum, with strong near

Snyderman

1995-01-01

414

Constraints on the Opera Superluminal Neutrinos  

NASA Astrophysics Data System (ADS)

The OPERA collaboration has recently reported the superluminal neutrinos with velocity of (v? - c)/c 2.5 × 10-5. This result can be explained in the Lorentz invariance violation (LIV) models. The modified dispersion relation of neutrino lead to modified kinematics of the processes the neutrinos involved. For processes that neutrinos in the final states the processes are suppressed. We find to allow the neutrino production process ? ? ? + ??, the neutrino energy should be less than about 5 GeV if taking a large LIV parameter O(10-5) implied by OPERA data. For the processes that neutrinos in the initial states new processes that are forbidden in the LI scenario may open, such as the ? ? ? + ? or ? ? ? + e+ + e-, which lead neutrinos to lose energy quickly. As the atmospheric neutrino spectrum agrees well with expectation without LIV we find it can constrain the neutrino LIV parameter to O(10-12), which is 7 orders smaller than the value measured at OPERA. We further propose to study the astrophysical neutrino spectra, which can constrain the neutrino LIV parameter down to O(10-15).

Yin, Peng-Fei; Bi, Xiao-Jun; Yu, Zhao-Huan; Yuan, Qiang

2012-01-01

415

Massive neutrino search in the decay ?+-->e+?  

NASA Astrophysics Data System (ADS)

Evidence of massive neutrinos in the ?+-->e+? decay spectrum was sought with the background ?+-->?+-->e+ decay chain highly suppressed. Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the neutrino mass region 60-129 MeV/c2 were set at the level of 10-8.

Malbrunot, C.; Aoki, M.; Blecher, M.; Bryman, D. A.; Chen, S.; Ding, M.; Doria, L.; Gumplinger, P.; Hurst, C.; Hussein, A.; Igarashi, Y.; Ito, N.; Kettell, S. H.; Kurchaninov, L.; Littenberg, L.; Numao, T.; Poutissou, R.; Sher, A.; Sullivan, T.; Vavilov, D.; Yamada, K.; Yoshida, M.

2012-04-01

416

Oscillation Physics with a Neutrino Factory  

Microsoft Academic Search

A generation of neutrino experiments have established that neutrinos mix and probably have mass. The mixing phenomenon points to processes beyond those of the Standard Model, possibly at the Grand Unification energy scale. A extensive sequence of of experiments will be required to measure precisely all the parameters of the neutrino mixing matrix, culminating with the discovery and study of

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

2002-01-01

417

Neutrino Spectrum at the Far Detector  

Microsoft Academic Search

Neutrino oscillation experiments often employ two identical detectors to minimize errors due to inadequately known neutrino beam. We examine various systematics effects related to the prediction of the neutrino spectrum in the `far' detector on the basis of the spectrum observed at the `near' detector. We propose a novel method of the derivation of the far detector spectrum. This method

M. Szleper; A. Para

2001-01-01

418

The Fermilab long-baseline neutrino program  

NASA Astrophysics Data System (ADS)

Fermilab is embarking upon a neutrino oscillation program which includes a long-baseline neutrino experiment MINOS. MINOS will be a 10 kiloton detector located 730 km Northwest of Fermilab in the Soudan underground laboratory. It will be sensitive to neutrino oscillations with parameters above ?m2~3×10-3eV2 and sin2(2?)~0.02.

Goodman, Maury

1997-05-01

419

Reconciling sterile neutrinos with Big Bang nucleosynthesis  

Microsoft Academic Search

We reexamine the big bang nucleosynthesis (BBN) bounds on the mixing of neutrinos with sterile species. These bounds depend on the assumption that the relic neutrino asymmetry Lnu is very small. We show that for Lnu large enough (greater than about 10-5) the standard BBN bounds do not apply. We apply this result to the sterile neutrino solution to the

R. Foot; R. R. Volkas

1995-01-01

420

The Renaissance of Neutrino Interaction Physics  

SciTech Connect

The advent of high intensity neutrino beams for neutrino oscillation experiments has produced a resurgence of interest in neutrino interaction physics. Recent experiments have been revisiting topics not studied since the bubble chamber era, and are exploring many interesting questions at the boundaries of particle and nuclear physics.

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

2009-12-17

421

Neutrino Masses and Mixings and Astrophysics  

NASA Astrophysics Data System (ADS)

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

Fuller, George M.

1998-10-01

422

Neutrino Beam Interactions in Dense Plasmas  

Microsoft Academic Search

Employing the relativistic kinetic equations for neutrinos interacting with dense plasmas via the weak interaction force, we explore collective plasma instabilities driven by neutrinos. We examine the anomalous energy transfer between the neutrinos and the background plasma via excitation of electron plasma waves. We present the relativistic equations including the inclusion of external magnetic fields. Solutions of the dispersion equation

Luis Silva; Robert Bingham; Jose Tito Mendonca; Warren Mori; Padma Shukla

2003-01-01

423

Neutrino phenomenology of very low-energy seesaw scenarios  

NASA Astrophysics Data System (ADS)

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

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

2007-01-01

424

Exploring neutrino oscillations with superbeams  

SciTech Connect

We consider the medium- and long-baseline oscillation physics capabilities of intense muon-neutrino and muon-antineutrino beams produced using future upgraded megawatt-scale high-energy proton beams. In particular we consider the potential of these conventional neutrino ''superbeams'' for observing {nu}{sub {mu}}{yields}{nu}{sub e} oscillations, determining the hierarchy of neutrino mass eigenstates, and measuring CP violation in the lepton sector. The physics capabilities of superbeams are explored as a function of the beam energy, baseline, and the detector parameters (fiducial mass, background rates, and systematic uncertainties on the backgrounds). The trade-offs between very large detectors with poor background rejection and smaller detectors with excellent background rejection are illustrated. We find that, with an aggressive set of detector parameters, it may be possible to observe {nu}{sub {mu}}{yields}{nu}{sub e} oscillations with a superbeam provided that the amplitude parameter sin{sup 2}2{theta}{sub 13} is larger than a few x10{sup -3}. If sin{sup 2}2{theta}{sub 13} is of order 10{sup -2} or larger, then the neutrino mass hierarchy can be determined in long-baseline experiments, and if in addition the large mixing angle MSW solution describes the solar neutrino deficit, then there is a small region of parameter space within which maximal CP violation in the lepton sector would be observable (with a significance of a few standard deviations) in a low-energy medium-baseline experiment. We illustrate our results by explicitly considering massive water Cherenkov and liquid argon detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV, and baselines ranging from 295 km to 9300 km. Finally, we compare the oscillation physics prospects at superbeams with the corresponding prospects at neutrino factories. The sensitivity at a neutrino factory to CP violation and the neutrino mass hierarchy extends to values of the amplitude parameter sin{sup 2}2{theta}{sub 13} that are one to two orders of magnitude lower than at a superbeam.

Barger, V.; Geer, S.; Raja, R.; Whisnant, K.

2001-06-01

425

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

SciTech Connect

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)

2011-01-01

426

Detection of supernova neutrinos with neutrino-iron scattering  

SciTech Connect

The {nu}{sub e}-{sup 56}Fe cross section is evaluated in the projected quasiparticle random phase approximation (PQRPA). This model solves the puzzle observed in RPA for nuclei with mass around {sup 12}C, because it is the only RPA model that treats the Pauli Principle correctly. The cross sections as a function of the incident neutrino energy are compared with recent theoretical calculations of similar models. The average cross section weighted with the flux spectrum yields a good agreement with the experimental data. The expected number of events in the detection of supernova neutrinos is calculated for the LVD detector, leading to an upper limit for the electron neutrino energy of particular importance in this experiment.

Samana, A. R.; Bertulani, C. A. [Department of Physics, Texas A and M University Commerce, P. O. Box 3011, Commerce, 75429 Texas (United States)

2008-08-15

427

Detection of supernova neutrinos with neutrino-iron scattering  

NASA Astrophysics Data System (ADS)

The ?e-Fe56 cross section is evaluated in the projected quasiparticle random phase approximation (PQRPA). This model solves the puzzle observed in RPA for nuclei with mass around C12, because it is the only RPA model that treats the Pauli Principle correctly. The cross sections as a function of the incident neutrino energy are compared with recent theoretical calculations of similar models. The average cross section weighted with the flux spectrum yields a good agreement with the experimental data. The expected number of events in the detection of supernova neutrinos is calculated for the LVD detector, leading to an upper limit for the electron neutrino energy of particular importance in this experiment.

Samana, A. R.; Bertulani, C. A.

2008-08-01

428

GRB neutrino search with MAGIC  

SciTech Connect

The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope was designed for the detection of photon sources > or approx. 50 GeV. The measurement of highly-inclined air showers renders possible the search for high-energy neutrinos, too. Only neutrinos can traverse the Earth without interaction, and therefore, events close to the horizon can be identified as neutrino-induced rather than photon-induced or hadronic events. In this paper, Swift-XRT-detected GRBs with given spectral information are used in order to calculate the potential neutrino energy spectrum from prompt and afterglow emission for each individual GRB. The event rate in MAGIC is estimated assuming that the GRB happens within the field of view of MAGIC. A sample of 568 long GRBs as detected by BATSE is used to compare the detection rates with 163 Swift-detected bursts. BATSE has properties similar to the Gamma-ray Burst Monitor (GBM) on board of GLAST. Therefore the estimated rates give an estimate for the possibilities of neutrino detection with MAGIC from GLAST-triggered bursts.

Becker, Julia K.; Rhode, Wolfgang [Institut fuer Physik, TU Dortmund, 44221 Dortmund (Germany); Gaug, Markus [Instituto de Astrofisica de Canarias, C/Via Lactea s/n La Laguna, Tenerife (Spain); Hsu, C.-C. [Max-Planck-Institut fuer Physik, Foehringer Ring 6, Muenchen (Germany)

2008-05-22

429

GRB neutrino search with MAGIC  

NASA Astrophysics Data System (ADS)

The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope was designed for the detection of photon sources >~50 GeV. The measurement of highly-inclined air showers renders possible the search for high-energy neutrinos, too. Only neutrinos can traverse the Earth without interaction, and therefore, events close to the horizon can be identified as neutrino-induced rather than photon-induced or hadronic events. In this paper, Swift-XRT-detected GRBs with given spectral information are used in order to calculate the potential neutrino energy spectrum from prompt and afterglow emission for each individual GRB. The event rate in MAGIC is estimated assuming that the GRB happens within the field of view of MAGIC. A sample of 568 long GRBs as detected by BATSE is used to compare the detection rates with 163 Swift-detected bursts. BATSE has properties similar to the Gamma-ray Burst Monitor (GBM) on board of GLAST. Therefore the estimated rates give an estimate for the possibilities of neutrino detection with MAGIC from GLAST-triggered bursts.

Becker, Julia K.; Gaug, Markus; Hsu, Ching-Cheng; Rhode, Wolfgang

2008-05-01

430

Muon neutrino disappearance at MINOS  

SciTech Connect

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

Armstrong, R.; /Indiana U.

2009-08-01

431

Neutrino-electron scattering and the search for new physics  

SciTech Connect

I want to discuss the role of neutrino-electron scattering in the search for physics beyond the standard model. The standard model makes specific predictions about the nature of the neutrinos which participate in such processes and about the interactions responsible for them. The process upon which I shall concentrate is elastic scattering, but I shall pay some attention to inelastic processes in which the target electron is itself transformed into a heavier charged lepton, in other words the inverse of the decay of the heavier lepton. In the case of elastic scattering we are mainly looking at neutral-currents and we can ask a series of simple questions: Does the interaction conserve lepton flavor. Does it fit the prescriptions of the standard model. Are the neutrinos Majorana or Dirac particles. In the case of inverse muon and tau decays we are looking at charge-currents, and we want to pin down the identity of the neutrinos emitted in the decay of these charged leptons as well as to set bounds on non-(V-A) components of the interaction. In order to discuss these topics, it is useful to review the general properties of the scattering process, especially the kinematics and the general form of the differential cross-section. Kinematics are important because they prevent us from searching for some processes and effects which we would like to detect. The differential cross-section, if measured with sufficient care, may tell us something about the presence of non-standard terms in the interaction and even about the nature of the neutrino. The detailed outline of the talk is: identity of the final state neutrino; kinematics; differential cross-sections; oscillations and universality; a test for Dirac neutrinos; inverse muon decay; and the standard model and radiative corrections. 22 ref., 2 tabs.

Rosen, S.P.

1988-01-01

432

Large mixing angles from many right-handed neutrinos  

NASA Astrophysics Data System (ADS)

A beautiful understanding of the smallness of the neutrino masses may be obtained via the seesaw mechanism, whereby one takes advantage of the key qualitative distinction between the neutrinos and the other fermions: right-handed neutrinos are gauge singlets, and may therefore have large Majorana masses. The standard seesaw mechanism, however, does not address the apparent lack of hierarchy in the neutrino masses compared to the quarks and charged leptons, nor the large leptonic mixing angles compared to the small angles of the Cabibbo-Kobayashi-Maskawa matrix. In this paper, we will show that the singlet nature of the right-handed neutrinos may be taken advantage of in one further way in order to solve these remaining problems: Unlike particles with gauge interactions, whose numbers are constrained by anomaly cancellation, the number of gauge singlet particles is essentially undetermined. If large numbers of gauge singlet fermions are present at high energies—as is suggested, for example, by various string constructions—then the effective low-energy neutrino mass matrix may be determined as a sum over many distinct Yukawa couplings, with the largest ones being the most important. This can reduce hierarchy, and lead to large mixing angles. Assuming a statistical distribution of fundamental parameters, we will show that this scenario leads to a good fit to low-energy phenomenology, with only a few qualitative assumptions guided by the known quark and lepton masses. The scenario leads to predictions of a normal hierarchy for the neutrino masses, and a value for the |mee| mass matrix element of about 1-6 meV.

Feldstein, Brian; Klemm, William

2012-03-01

433

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

National Technical Information Service (NTIS)

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

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

2006-01-01

434

Measuring Neutrinos with the ANTARES Telescope  

SciTech Connect

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

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

2009-12-17

435

Reactor experiments to test sterile neutrinos  

NASA Astrophysics Data System (ADS)

A recent re-analysis of past reactor neutrino experiments has shown a significant discrepancy between measured and expected neutrino count rates at short distances (<100m). Various scenarios have been discussed to explain this reactor antineutrino anomaly, the most exciting one being the oscillation of active neutrinos into a fourth (sterile) neutrino species. While current reactor experiments were dedicated to non-proliferation purposes, a new generation of projects is under development to search for this sterile neutrino through a new short-baseline oscillation signature.

Gaffiot, J.

2013-04-01

436

The Low Energy Neutrino Factory  

NASA Astrophysics Data System (ADS)

We show that a low energy neutrino factory with a baseline of 1300 km and muon energy of 4.5 GeV has an excellent physics reach. The results of our optimisation studies demonstrate that such a setup can have remarkable sensitivity to ?13 and ? for sin2(2?13)>10-4, and to the mass hierarchy for sin2(2?13)>10-3. We also illustrate the power of the unique combination of golden and platinum channels accessible to the low energy neutrino factory. We have considered both a 20 kton totally active scintillating detector and a 100 kton liquid argon detector as possible detector technologies, finding that a liquid argon detector with very good background rejection can produce sensitivity to ?13 and ? with that of the International Design Study neutrino factory.

Bross, Alan; Ellis, Malcolm; Fernández Martínez, Enrique; Geer, Steve; Li, Tracey; Mena, Olga; Pascoli, Silvia

2010-03-01

437

Status of neutrino mass experiments  

SciTech Connect

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

Fackler, O.

1985-12-01

438

Recent developments in neutrino physics  

SciTech Connect

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

Garvey, G.T.

1991-01-01

439

Nuclear statistical equilibrium neutrino spectrum  

SciTech Connect

The spectral emission of neutrinos from a plasma in nuclear statistical equilibrium (NSE) is investigated. Particular attention is paid to the possible emission of high-energy (>10 MeV) neutrinos or antineutrinos. A newly developed numerical approach for describing the abundances of nuclei in NSE is presented. Neutrino emission spectra, resulting from general Fuller-Fowler-Newman conditions, are analyzed. Regions of T-{rho}-Y{sub e} space favoring detectability are selected. The importance of critical Y{sub e} values with zero net rate of neutronization (Y{sub e}) is discussed. Results are provided for the processing of matter under conditions typical for thermonuclear and core-collapse supernovae, presupernova stars, and neutron star mergers.

Odrzywolek, Andrzej [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, PL-30-059 Krakow (Poland)

2009-10-15

440

The Low Energy Neutrino Factory  

SciTech Connect

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

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

2010-03-30

441

Mass varying neutrinos in supernovae  

NASA Astrophysics Data System (ADS)

We study the consequences on the neutrino oscillation parameter space, mixing angle (tan?2?), and vacuum mass difference (?m02) when mass varying neutrino (MaVaN) models are assumed in a supernova environment. We consider electronic to sterile channels ?e??s and ?¯e??¯s in two-flavor scenario. In a given model of MaVaN mechanism, we induce a position-dependent effective mass difference, ?m˜2(r), where r is the distance from the supernova core, that changes the neutrino and antineutrino flavor conversion probabilities. We study the constraints on the mixing angle and vacuum mass difference coming from r-process and the SN1987A data. Our result is the appearance of a new exclusion region for very small mixing angles, tan?2?=10-6-10-2, and small vacuum mass difference, ?m02=1-20eV2, due the MaVaN mechanism.

Rossi-Torres, F.; Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.

2011-09-01

442

Probing the nature of the neutrino: The boron solar-neutrino experiment  

NASA Astrophysics Data System (ADS)

With a welter of neutrino scenarios and uncertain solar models to be unraveled, can solar-neutrino experiments really break new ground in neutrino physics\\? A new solar-neutrino detector BOREX, based on the nuclide 11B, promises the tools for a definitive exploration of the nature of the neutrino and the structure of the Sun. Using double-mode detection by neutrino excitation of 11B via the neutral-weak-current- and the charged-current-mediated inverse ? decay in the same target, independent measurements of the total neutrino flux regardless of flavor and the survival of electron neutrinos in solar matter and a vacuum can be made. Standard models of the Sun, and almost every proposed nonstandard model of the neutrino, can be subjected to sharp and direct tests. The development of BOREX, based on B-loaded liquid-scintillation techniques, is currently in progress.

Raghavan, R. S.; Pakvasa, Sandip

1988-02-01

443

Neutrino radiation hazards: A paper tiger  

SciTech Connect

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

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

1996-09-01

444

Neutrino Factory Near Detector Simulation  

SciTech Connect

We present a simulation with GENIE MC generator of the Neutrino Factory baseline near detector interaction rates for the purely leptonic process nu{sub m}u+e{sup -}->nu{sub e}+mu{sup -} and for nu{sub m}u+N->mu{sup -}+X scattering in view of measuring the first one and suppressing the second one for neutrino flux estimation. A set of most sensitive measurable quantities are discussed and their selective power against experimental uncertainties is examined.

Karadzhov, Yordan [Department of Atomic Physics, St. Kliment Ohridski University of Sofia, Sofia (Bulgaria)

2010-03-30

445

Super-Kamiokande Atmospheric Neutrino Oscillation Analysis  

NASA Astrophysics Data System (ADS)

Due to their large variation in both energy and pathlength, atmospheric neutrinos have long served as broad probe of neutrino oscillations with primary sensitivity to ????? oscillations. However, with large statistics atmospheric neutrino data become increasingly sensitive to sub-leading oscillation effects driven by ?13 and the solar ?m122. Super-Kamiokande has collected 3903 days of atmospheric neutrino data and with the recent measurement ?13 they are used to study the remaining open questions in the standard neutrino oscillation framework, including the nature of the neutrino mass hierarchy, the octant of ?23, and value of ?. Results from the most recent analysis of the atmospheric neutrino data both with and without external constraints on the value of ?13 are presented.

Wendell, Roger

2013-04-01

446

Neutrino masses and mixing from the astrophysical perspective  

Microsoft Academic Search

The role of neutrino masses and mixing in the astrophysical and cosmological context is reviewed. If neutrino mass differences are indeed as small as suggested by the current evidence for neutrino oscillations (?m? ? 1 eV), the overall neutrino mass scale in scenarios of degenerate neutrino masses is the most challenging open issue. Cosmological structure-formation arguments will continue to provide

Georg G. Raffelt

2001-01-01

447

Are there consequences of Pontecorvo's neutrino oscillations for the neutrino emission of neutron stars  

NASA Astrophysics Data System (ADS)

The hypothesis of Mazurek (1979) that neutrino oscillations act to remove the lepton degeneracy in the gravitational collapse of a massive star and thus reverse the collapse into an explosion is examined. Characteristic lengths for the propagation of neutrino oscillations between electron and muon neutrinos are calculated for conditions of a vacuum and extremely dense matter, and it is shown that the vacuum lengths greatly exceed those in dense matter. It is thus concluded that, if electron neutrinos are emitted during stellar core collapse, neutrino oscillations can not influence the neutrino emission of neutron stars and particularly will not effectively transfer leptonic energy to baryons.

Haubold, H. J.

448

Addendum to: ``The SNO solar neutrino data, neutrinoless double beta-decay and neutrino mass spectrum'' [Phys. Lett. B 544 (2002) 239  

NASA Astrophysics Data System (ADS)

We update our earlier study [Phys. Lett. B 544 (2002) 239], which was inspired by the 2002 SNO data, on the implications of the results of the solar neutrino experiments for the predictions of the effective Majorana mass in neutrinoless double beta-decay, . We obtain predictions for using the values of the neutrino oscillation parameters, obtained in the analyzes of the presently available solar neutrino data, including the just published data from the salt phase of the SNO experiment, the atmospheric neutrino and CHOOZ data and the first data from the KamLAND experiment. The main conclusion reached in the previous study [Phys. Lett. B 544 (2002) 239] of the existence of significant lower bounds on in the cases of neutrino mass spectrum of inverted hierarchical (IH) and quasi-degenerate (QD) type is strongly reinforced by fact that combined solar neutrino data (i) exclude the possibility of cos2?solar=0 at more than 5 s.d., (ii) determine as a best fit value cos2?solar=0.40, and (iii) imply at 95% C.L. that cos2?solar>~0.22, ?solar being the solar neutrino mixing angle. For the IH and QD spectra we get using, e.g., the 90% C.L. allowed ranges of values of the oscillation parameters, >~0.010 eV and >~0.043 eV, respectively. We also comment on the possibility to get information on the neutrino mass spectrum and on the CP-violation in the lepton sector due to Majorana CP-violating phases. Also at: Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria.

Pascoli, S.; Petcov, S. T.

2004-02-01

449

Neutrino conversions in solar random magnetic fields  

NASA Astrophysics Data System (ADS)

We consider the effect of a random magnetic field in the convective zone of the Sun superimposed to a regular magnetic field on resonant neutrino spin-flavor oscillations. We argue for the existence of a field of strongly chaotic nature at the bottom of the convective zone. In contrast to previous attempts we employ a model motivated regular magnetic field profile: it is a static field solution to the solar equilibrium hydro-magnetic equations. These solutions have been known for a long time in the literature. We show for the first time that in addition they are twisting solutions. In this scenario electron antineutrinos are produced through cascades like ?eL-->??L-- >?~eR, The detection of ?~eR at Earth would be a long-awaited signature of the Majorana nature of the neutrino. The expected signals in the different experiments (SK, GALLEX-SAGE, Homestake) are obtained as a function of the level of noise, regular magnetic field and neutrino mixing parameters. Previous results obtained for small mixing and ad-hoc regular magnetic profiles are reobtained. We confirm the strong suppression for a large part of the parameter space of the ?~eR-flux for high energy boron neutrinos in agreement with present data of the SK experiment. We find that MSW (Mikheyev-Smirnov-Wolfenstein) regions (?m2~=10-5 eV2, both small and large mixing solutions) are stable up to very large levels of noise (P=0.7-0.8) but they are acceptable from the point of view of antineutrino production only for moderate levels of noise (P~=0.95). For strong noise and a reasonable regular magnetic field, any parameter region (?m2, sin 2 2?) is excluded. As a consequence, we are allowed to reverse the problem and to put limits on the r.m.s. field strength and transition magnetic moments by demanding a particle physics solution to the SNP in this scenario.

Semikoz, V. B.; Torrente-Lujan, E.

1999-09-01

450

Hybrid model of neutrino masses and oscillations: Bulk neutrinos in the split-fermion scenario  

SciTech Connect

Higher-dimensional models of neutrino physics with one or more right-handed neutrinos in the bulk have attracted considerable attention in recent years. However, a critical issue for such models is to find a way of introducing the required flavor dependence needed for generating neutrino oscillations. In this paper, we point out that a natural minimal framework that accomplishes this can be constructed by combining the bulk-neutrino hypothesis for right-handed neutrinos with the split-fermion scenario for left-handed neutrinos. This combination leads to a unique flavor signature for neutrino phenomenology which easily incorporates large flavor mixing angles. This hybrid scenario also has a number of additional important features. For example, one previous difficulty of the split-fermion scenario applied to neutrinos has been that the mass matrix is exponentially sensitive to neutrino displacements within the brane. However, in our hybrid scenario, the interactions between the brane and bulk naturally convert this dependence from exponential to linear. Another important feature is that our hybrid scenario provides its own natural regulator for Kaluza-Klein sums. Thus, in our scenario, all Kaluza-Klein summations are manifestly finite, even in cases with multiple extra dimensions. But most importantly, our mechanism completely decouples the effective neutrino flavor mixing angles from the sizes of the overlaps between the neutrino wave functions within the brane. Thus, we are able to obtain large neutrino mixing angles even when these neutrinos have significant spatial separations and their overlaps vanish.

Dienes, Keith R. [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Hossenfelder, Sabine [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States); Department of Physics, University of California, Santa Barbara, California 93106 (United States)

2006-09-15

451

Extraction of active and sterile neutrino mixing parameters with the Sudbury Neutrino Observatory  

NASA Astrophysics Data System (ADS)

The Sudbury Neutrino Observatory (SNO) is a 1 kilotonne heavy-water Cerenkov detector designed to study fundamental properties of neutrinos produced by thermonuclear fusion reactions in the core of the Sun. The uniqueness of SNO resides in its capability to distinctively measure the total flux of all active neutrino flavours as well as the flux of electron neutrinos, through the Neutral-Current (NC) and Charged-Current (CC) interactions of neutrinos on deuterium, respectively. The measurements of the NC and CC fluxes for neutrinos originated from 8B disintegration inside the Sun unambiguously proved that neutrinos change their flavour while traveling to the Earth. These results are consistent with predictions from a neutrino oscillation hypothesis on neutrino flavour transitions due to the mixing of massive neutrino states. The NC measurement from SNO also solved the long-standing Solar Neutrino Problem (SNP). in this dissertation, the measurements of the fundamental properties of neutrinos, in particular their mixing parameters, are presented. Data samples from SNO and other experiments are used to extract the mixing parameters of active and sterile neutrino states. Under the assumption on the two-neutrino oscillation hypothesis, the mixing parameters for active neutrinos (the squared-mass difference Deltam2 and the mixing angle theta) are obtained from a global analysis of solar and reactor neutrino data. The extracted mixing parameters from this analysis are Dm2=7.59+0.21-0.19x 10-5eV2 and q=34.4+1.3-1.2 degrees. The errors on both parameters are reduced compared to the previous results from SNO, that further constrains the solar neutrino mixing parameter region. The mixing parameters for the sterile neutrino state (the ratio RD=Dm201/D m221 and the mixing angle sin2 2alpha) are determined by comparing the predictions from a weakly mixed sterile neutrino model with the solar neutrino data. For the first time a complete parameter region for the weakly mixed sterile state is fully scanned numerically to place the error on RDelta and to set an upper limit at 90% CL on sin2 2alpha. A global solar neutrino analysis yields RD=0.11+0.04-0.03 and places an upper limit of sin2 2alpha < 9.9 x 10-3 at 90% CL. This result shows that the rare effects from physics beyond the three active neutrino scenario cannot be excluded, yet. Future prospects and challenge in solar neutrino physics are also summarized.

Tesic, Gordana

452

Neutrino physics: A theoretical perspective  

SciTech Connect

Experimental measurements of sin/sup 2/theta/sub W/ are surveyed. They are shown to test electroweak unification at the quantum loop level and constrain new physics beyond the standard model. Neutrino oscillations are also examined in the framework of 3 generation mixing. Searches for nu/sub ..mu../ ..-->.. nu/sub tau/ oscillation at aceelerator facilities are advocated.

Marciano, W.J.

1987-04-01

453

Medium-energy neutrino physics  

SciTech Connect

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

White, D.H.

1991-11-22

454

Neutrino mass and mirror universe  

Microsoft Academic Search

The existence of the mirror world, with the same microphysics as our own one\\u000abut with opposite P-asymmetry, not only restores an exact equivalence between\\u000aleft and right but also naturally explains, via a see-saw like mechanism, why\\u000athe neutrino is ultralight.

Z. K. Silagadze

1995-01-01

455

Alternative mechanisms for neutrino oscillations  

SciTech Connect

The energy dependence of the neutrino oscillation length in vacuum is examined in a theoretically unbiased way by expanding it in a Laurent series. The three simplest power laws are compared with experimental data and potential physical mechanisms beyond the usual mass mixing mechanism are discussed for the two survivors.

Halprin, A. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States)

1998-10-19

456

Neutrino Event Generators: A Review  

SciTech Connect

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

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

2009-11-25

457

Extraterrestrial High Energy Neutrino Fluxes.  

National Technical Information Service (NTIS)

Using the most recent cosmic ray spectra up to 2x10 to the 20th power eV, production spectra of high energy neutrinos from cosmic ray interactions with interstellar gas and extragalactic interactions of ultrahigh energy cosmic rays with 3K universal backg...

F. W. Stecker

1979-01-01

458

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

SciTech Connect

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

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

2006-08-01

459

Inverted mass hierarchy from scaling in the neutrino mass matrix: Low and high energy phenomenology  

SciTech Connect

Best-fit values of recent global analyses of neutrino data imply large solar neutrino mixing, vanishing U{sub e3}, and a nonmaximal atmospheric neutrino mixing angle {theta}{sub 23}. We show that these values emerge naturally by the hypothesis of scaling in the Majorana neutrino mass matrix, which states that the ratios of its elements are equal. It also predicts an inverted hierarchy for the neutrino masses. We point out several advantages and distinguishing tests of the scaling hypothesis compared to the L{sub e}-L{sub {mu}}-L{sub {tau}} flavor symmetry, which is usually assumed to provide an understanding of the inverted hierarchy. Scenarios which have initially vanishing U{sub e3} and maximal atmospheric neutrino mixing are shown to be unlikely to lead to nonmaximal {theta}{sub 23} while simultaneously keeping U{sub e3} zero. We find a peculiar ratio of the branching ratios {mu}{yields}e{gamma} and {tau}{yields}e{gamma} in supersymmetric seesaw frameworks, which only depends on atmospheric neutrino mixing and results in {tau}{yields}e{gamma} being unobservable. The consequences of the scaling hypothesis for high energy astrophysical neutrinos at neutrino telescopes are also investigated. Then we analyze a seesaw model based on the discrete symmetry D{sub 4}xZ{sub 2} leading to scaling in the low energy mass matrix and being capable of generating the baryon asymmetry of the Universe via leptogenesis. The relevant CP phase is identical to the low energy Majorana phase, and successful leptogenesis requires an effective mass for neutrinoless double beta decay larger than 0.045 eV.

Blum, A.; Rodejohann, W. [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, D-69029 Heidelberg (Germany); Mohapatra, R. N. [Department of Physics and Maryland Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States) and Sektion Physik, Ludwig-Maximilians-Universitaet Muenchen, Theresienstrasse 37a, D-80333 Munich (Germany) and Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

2007-09-01

460

Sterile neutrino-enhanced supernova explosions  

SciTech Connect

We investigate the enhancement of lepton number, energy, and entropy transport resulting from active-sterile neutrino conversion {nu}{sub e}{yields}{nu}{sub s} deep in the post-bounce supernova core followed by reconversion {nu}{sub s}{yields}{nu}{sub e} further out, near the neutrino sphere. We explicitly take account of shock wave and neutrino heating modification of the active neutrino forward scattering potential which governs sterile neutrino production. We find that the {nu}{sub e} luminosity at the neutrino sphere could be increased by between {approx}10% and {approx}100% during the crucial shock reheating epoch if the sterile neutrino has a rest mass and vacuum mixing parameters in ranges which include those required for viable sterile neutrino dark matter. We also find sterile neutrino transport-enhanced entropy deposition ahead of the shock. This 'preheating' can help melt heavy nuclei and thereby reduce the nuclear photo-dissociation burden on the shock. Both neutrino luminosity enhancement and preheating could increase the likelihood of a successful core collapse supernova explosion.

Hidaka, Jun; Fuller, George M. [Department of Physics, University of California, San Diego, La Jolla, California 92093-0319 (United States)

2007-10-15

461

Recent progress in neutrino - astrophysics connections  

NASA Astrophysics Data System (ADS)

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

Kneller, James

2005-04-01

462

Neutrino Masses in R-parity Violating Supersymmetric Models.  

National Technical Information Service (NTIS)

We study neutrino masses and mixing in R-parity violating supersymmetric models with generic soft supersymmetry breaking terms. Neutrinos acquire masses from various sources: Tree level neutrino--neutralino mixing and loop effects proportional to bilinear...

Y. Grossman S. Rakshit

2003-01-01

463

Why understanding neutrino interactions is important for oscillation physics  

SciTech Connect

Uncertainties in knowledge of neutrino interactions directly impact the ability measure the parameters of neutrino oscillation. Experiments which make use of differing technologies and neutrino beams are sensitive to different uncertainties.

Walter, Christopher W. [Department of Physics, Duke University, Durham, NC 27708 (United States)

2007-12-21

464

Towards the resolution of the solar neutrino problem.  

National Technical Information Service (NTIS)

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

A. Friedland

2000-01-01

465

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

NASA Astrophysics Data System (ADS)

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

2008-11-01

466

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

SciTech Connect

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

Bell, Nicole F.; /Fermilab

2004-01-01

467

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

SciTech Connect

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

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

2007-10-01

468

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

SciTech Connect

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

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

2009-12-01

469

Magnetically induced neutrino oscillations and neutrino refractive effects in the early Universe  

SciTech Connect

We investigate neutrino spin precession in primordial magnetic fields, taking previously ignored neutrino refractive effects into account. A present-day intergalactic field strength B/sub 0/ implies that the magnetic dipole moments of any two neutrino species are bounded by ..mu../sub ..nu../approx. <10/sup -16/..mu../sub B/((10/sup -9/ G)/B/sub 0/) because of nucleosynthesis constraints on the number of neutrino flavors.

Fukugita, M.; Noetzold, D.; Raffelt, G.; Silk, J.

1988-03-07

470

Precise measurement of neutrino and anti-neutrino differential cross sections on iron  

Microsoft Academic Search

This thesis will present a precise measurement of the differential cross section for charged current neutrino and anti-neutrino scattering from iron. The NuTeV experiment took data during 1996-97 and collected 8.6 x 105 n and 2.4 x 105 n charged-current (CC) interactions. The experiment combines sign-selected neutrino and antineutrino beams and the upgraded CCFR iron-scintillator neutrino detector. A precision continuous

Martin Mihaylov Tzanov; D. Naples; S. Boyd; J. McDonald; V. Radescu; T. Adams; A. Alton; S. Avvakumov; L. deBarbaro; P. deBarbaro; R. H. Bernstein; A. Bodek; T. Bolton; J. Brau; D. Buchholz; H. Budd; L. Bugel; J. Conrad; R. B. Drucker; B. T. Fleming; R. Frey

2005-01-01

471

NEXT: Neutrino Experiment with high pressure Xenon gas TPC  

NASA Astrophysics Data System (ADS)

The search of the neutrinoless double-? decay address the major Physics goals of revealing the nature of the neutrino and setting an absolute scale for its mass. The observation of a positive ??0? signal, the unique signature of Majorana neutrinos, would have deep consequences in particle physics and cosmology. Therefore, any claim of observing a positive signal shall require extremely robust evidences. NEXT is a new double-? experiment which aims at building a 100 kg high pressure Xe136 gas TPC, to be hosted in the Canfranc Underground Laboratory (LSC), in Spain. This paper address the novel design concept of NEXT TPC believed to provide a pathway for an optimized and robust double-? experiment.

Yahlali, Nadia; Ball, M.; Cárcel, S.; Díaz, J.; Gil, A.; Gómez Cadenas, J. J.; Martín-Albo, J.; Monrabal, F.; Serra, L.; Sorel, M.

2010-05-01