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1

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

Science Conference Proceedings (OSTI)

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

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

2009-11-01T23:59:59.000Z

2

Lepton flavor violation decays with the fourth generation neutrino  

E-Print Network (OSTI)

We investigate the lepton flavor violation decays, $\\tau \\to \\mu\\gamma$, $\\tau \\to e\\gamma$ and $\\mu \\to e\\gamma$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\

Huo, W J; Huo, Wu-Jun; Feng, Tai-Fu

2002-01-01T23:59:59.000Z

3

Status of Heavy-lepton Searches  

DOE R&D Accomplishments (OSTI)

Searches for heavy leptons using e{sup +}e{sup -} annihilation, lepton-hadron collisions, photon-hadron collisions, hadron-hadron collisions, and studies of macroscopic matter are reviewed. The present experimental status and future possibilities are summarized.

Perl, M. L.

1981-06-00T23:59:59.000Z

4

Phenomenology of heavy vector-like leptons  

E-Print Network (OSTI)

We study the impact that a heavy generation of vector-like leptons can have on the value of the electric dipole moment of the electron, and the rates for the flavor violating processes mu --> e gamma and mu --> 3e. The smallness of the charged lepton masses suggests that at least some of the Yukawa coupling constants of the vector-like leptons to the ordinary leptons or amongst themselves are small, but even with such small couplings experiments trying to detect these quantities are sensitive to extra generation lepton masses up to about 100 TeV.

Koji Ishiwata; Mark B. Wise

2013-07-03T23:59:59.000Z

5

INTENSE NEUTRINO BEAMS AND LEPTONIC CP VIOLATION.  

SciTech Connect

Effects of the Leptonic CP violating phase, {delta}, on 3 generation neutrino oscillation rates and asymmetries are discussed. A figure of merit argument is used to show that our ability to measure the phase 6 is rather insensitive to the value of {theta}{sub 13} (for sin{sup 2} 2{theta}{sub 13} {approx}> 0.01) as well as the detector distance (for very long oscillation baselines). Using a study of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations for BNL-Homestake (2540 km) we show that a conventional horn focused wide band neutrino beam generated by an intense 1-2 MW proton source combined with a very large water Cherenkov detector (250-500 kton) should be able to determine {delta} to about {+-}15{sup o} in 5 x 10{sup 7} sec. of running. In addition, such an effort would also measure the other oscillation parameters ({theta}{sub ij}, {Delta}m{sub ij}{sup 2}) with high precision. Similar findings apply to a Fermilab-Homestake (1280 km) baseline. We also briefly discuss features of Superbeams, Neutrino Factories and Beta-Beams.

MARCIANO, W.; PARSA, Z.

2006-06-13T23:59:59.000Z

6

Nuclear PDF for neutrino and charged lepton data  

E-Print Network (OSTI)

Neutrino Deep Inelastic Scattering on nuclei is an essential process to constrain the strange quark parton distribution functions in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions. Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton lA Deeply Inelastic Scattering and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors F_2^Fe/F_2^D for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

K. Kovarik

2010-12-13T23:59:59.000Z

7

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

E-Print Network (OSTI)

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

He, Xiao-Gang; Volkas, Raymond R

2008-01-01T23:59:59.000Z

8

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

E-Print Network (OSTI)

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

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

2008-10-07T23:59:59.000Z

9

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

Science Conference Proceedings (OSTI)

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

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

2008-12-01T23:59:59.000Z

10

Citation: K. Nakamura et al. (Particle Data Group), JPG 37, 075021 (2010) (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITS Note that LEP results

11

Citation: J. Beringer et al. (Particle Data Group), PR D86, 010001 (2012) (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITS Note that LEP results

12

Nuclear PDF for neutrino and charged lepton data  

SciTech Connect

Neutrino Deep Inelastic Scattering (DIS) on nuclei is an essential process to constrain the strange quark parton distribution functions (PDF) in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions (NPDF). Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton (l{sup {+-}A}) Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors (F{sub 2}{sup Fe}/F{sub 2}{sup D}) for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

Kovarik, K. [Institute for Theoretical Physics, Karlsruhe Institute of Technology, Karlsruhe, D-76128 (Germany)

2011-10-06T23:59:59.000Z

13

Citation: K. Nakamura et al. (Particle Data Group), JPG 37, 075021 (2010) (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

14

Citation: J. Beringer et al. (Particle Data Group), PR D86, 010001 (2012) (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

15

Polarization Effects In The Charged Lepton Pair Production By A Neutrino (Antineutrino) In A Magnetic Field  

Science Conference Proceedings (OSTI)

The probability of the process of the charged lepton pair production by a neutrino (an antineutrino) with allowance for the longitudinal and transverse polarizations of the charged leptons in a magnetic field is presented. The dependence of the probability of the process on the spin variables of the charged leptons and on the azimuthal and polar angles of the initial and final neutrinos (antineutrinos) are investigated. It is shown that the probability of the process is sensitive to the spin variables of the charged leptons and to the direction of the neutrino (antineutrino) momentum. It is determined that the neutrino (antineutrino) energy and momentum loss through the production of a charged lepton pair happens asymmetrically.

Huseynov, Vali A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Ahmad, Ali S. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

2007-06-13T23:59:59.000Z

16

Citation: K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton

17

The energy spectrum of tau leptons induced by the high energy Earth-skimming neutrinos  

E-Print Network (OSTI)

We present a semi-analytic calculation of the tau-lepton flux emerging from the Earth, induced by the incident high energy neutrinos interacting inside the Earth for $10^{5} \\leq E_{\

J. -J. Tseng; T. -W. Yeh; H. Athar; M. A. Huang; F. -F. Lee; G. -L. Lin

2003-05-27T23:59:59.000Z

18

Review of ''close-mass'' heavy lepton searches  

SciTech Connect

Results from recent searches in e/sup +/e/sup /minus// annihilation at PEP (..sqrt..s = 29 GeV) for a fourth-generation charged lepton associated with a slightly lighter neutrino partner are presented. Some emphasis is given to the most recent search, which uses a novel approach based on radiative tagging, an approach that holds promise as a general tool in searching for exotic events characterized by very low visible energy. Prospects for upcoming sequential lepton searches at SLC and LEP experiments are also discussed. 11 refs., 4 figs.

Riles, K.

1989-05-01T23:59:59.000Z

19

Detecting exotic heavy leptons at the large hadron collider.  

E-Print Network (OSTI)

ar X iv :h ep -p h/ 01 08 09 7v 1 1 0 A ug 2 00 1 Preprint typeset in JHEP style. - HYPER VERSION Cavendish-HEP-01/10 DAMTP-2001-71 CERN-TH/2001-205 Detecting Exotic Heavy Leptons at the Large Hadron Collider B.C. Allanach?, C.M. Harris, M... , CB3 0WA, UK. Abstract: New almost-degenerate charged and neutral heavy leptons are a feature of a number of theories of physics beyond the Standard Model. The prospects for detecting these at the Large Hadron Collider using a time-of-flight technique...

Allanach, B C; Harris, Chris M; Parker, Michael A; Richardson, P; Webber, Bryan R

20

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

E-Print Network (OSTI)

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

Asmaa Abada; Irene Hidalgo

2007-11-08T23:59:59.000Z

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


21

PDF Nuclear Corrections for Charged Lepton and Neutrino Deep Inelastic Scattering Processes  

E-Print Network (OSTI)

We perform a \\chi^2-analysis of Nuclear Parton Distribution Functions (NPDFs) using neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets. The nuclear A dependence of the NPDFs is extracted in a next-to-leading order fit. We compare the nuclear corrections factors F2(Fe)/F2(D) for this charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

I. Schienbein; J. Y. Yu; K. Kovarik; C. Keppel; J. G. Morfin; F. Olness; J. F. Owens

2009-07-14T23:59:59.000Z

22

Citation: K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

23

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

SciTech Connect

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

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

2012-11-20T23:59:59.000Z

24

Spin Asymmetries Arising In Neutrino-Lepton Processes In A Magnetic Field And Their Macroscopic Appearance  

Science Conference Proceedings (OSTI)

We present expressions that determine the differential cross sections and energy and momentum losses for the neutrino-lepton processes {nu}le- {yields} {nu}le-, {nu}-tildele- {yields} {nu}-tildele-, {nu}l{nu}-tildel {yields} e-e+, {nu}l{nu}-tildee {yields} l-e+, {nu}le- {yields} {nu}el- in a magnetic field with allowance for the longitudinal and transverse polarizations of the charged leptons and antileptons and the results on the spin asymmetries arising in these processes.

Huseynov, Vali A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Gasimova, Rasmiyya E.; Akbarova, Nurida Y.; Hajiyeva, Billura T. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

2007-06-13T23:59:59.000Z

25

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

E-Print Network (OSTI)

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

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

2006-11-16T23:59:59.000Z

26

REVIEW OF HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* Martin L. Per1  

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

HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* Martin L. Per1 Stanford Linear Accelerator Center Stanford University, Stanford, California 94305 ABSTRACT * The existing data on e f p r , eixT, p xi:, and related events produced in e'e- annihilation are reviewed. All data are consistent with the exist- ence of a new charged lepton, T *, of m a s s 1.9 * . 1 GeV/c2. (Invited talk presented at the 1977 International Symposium on Lepton and Photon Interactions at High Energies, Hambrug, Cfirmany, August 25-31 , 1977.) *Work supported by the Department of Energy. NOTICE-- rpon.wred by the United States Government. Netther the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, Subcontractors, or thou employees. makes

27

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

E-Print Network (OSTI)

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

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

2013-09-26T23:59:59.000Z

28

Higgs boson decay into heavy quarks and heavy leptons: higher order corrections  

E-Print Network (OSTI)

Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_HHiggs boson into bb and tau+tau- are discussed.

Kim, Victor T

2010-01-01T23:59:59.000Z

29

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

E-Print Network (OSTI)

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

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

2013-06-10T23:59:59.000Z

30

A search for close-mass lepton doublet  

SciTech Connect

Described is a search for a heavy charged lepton with an associated neutrino of nearly the same mass, together known as a close-mass lepton doublet. The search is conducted in e/sup +/e/sup/minus// annihilation data taken with the Mark II detector at a center-of-mass energy of 29 GeV. In order to suppress contamination from conventional two-photon reactions, the search applies a novel, radiative-tagging technique. Requiring the presence of an isolated, energetic photon allows exploration for lepton doublets with a mass splitting smaller than that previously accessible to experiment. No evidence for such a new lepton has been found, enabling limits to be placed on allowed mass combinations. Mass differences as low as 250-300 MeV are excluded for charged lepton masses up to 10 GeV. 78 refs., 64 figs., 8 tabs.

Riles, J.K.

1989-04-01T23:59:59.000Z

31

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

Science Conference Proceedings (OSTI)

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

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

1994-07-01T23:59:59.000Z

32

Majorana CP-violating phases in neutrino-antineutrino oscillations and other lepton-number-violating processes  

E-Print Network (OSTI)

If the massive neutrinos are identified to be the Majorana particles via a convincing measurement of the neutrinoless double beta (0\

Zhi-zhong Xing; Ye-Ling Zhou

2013-05-24T23:59:59.000Z

33

Neutrino Unification  

E-Print Network (OSTI)

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

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

2000-11-10T23:59:59.000Z

34

neutrino_mixing_s805.dvi  

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

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

35

The Particle Adventure | What is the world made of? | Lepton...  

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

quiz Which lepton decays are possible? Why or why not? (A tau lepton decays into an electron, an electron antineutrino, and a tau neutrino.) Answer Yes Charge, tau number,...

36

Is Dark Matter Heavy Because of Electroweak Symmetry Breaking? Revisiting Heavy Neutrinos  

E-Print Network (OSTI)

A simple and well-motivated explanation for the origin of dark matter is that it consists of thermal relic particles that get their mass entirely through electroweak symmetry breaking. The simplest models implementing this possibility predict a dark matter candidate that consists of a mixture of two Dirac neutrinos with opposite isospin, and so has suppressed coupling to the Z. These models predict dark matter masses of m_{DM}~45 GeV or m_{DM}~90-95 GeV and WIMP-neutron spin-independent cross sections \\sigma_{WIMP-n}~10^{-6}-10^{-8} pb. Current direct dark matter searches are probing a portion of the parameter space of these models while future experiments sensitive to \\sigma_{WIMP-n}~10^{-8} pb will probe the remainder. An enhancement of the galactic halo gamma ray and positron flux coming from annihilations of these particles is also expected across the ~1-100 GeV range. The framework further suggests an environmental explanation of the hierarchy between the weak and Planck scales and of the small value of the cosmological constant relative to the weak scale.

Philip C. Schuster; Natalia Toro

2005-06-08T23:59:59.000Z

37

Identifying heavy Higgs bosons  

SciTech Connect

Two techniques for identifying heavy Higgs bosons produced at SSC energies are discussed. In the first, the Higgs boson decays into ZZ, with one Z decaying into an e-pair or ..mu..-pair and the other into a neutrino pair. In the second, the production of the Higgs boson by WW fusion is tagged by detecting the quarks that produced the bremsstrahlung virtual W's. The associated Higgs decay is identified by one leptonic and one hadronic decay. Both methods appear capable of finding a heavy Higgs boson provided the SSC design parameters are achieved. 16 refs., 2 figs., 2 tabs.

Cahn, R.N.

1986-06-01T23:59:59.000Z

38

Flavor Violating Lepton Family U(1)$_\\lambda$  

E-Print Network (OSTI)

The Standard Model is extended minimally with a new flavor-violating family symmetry ${\\rm U(1)}_\\lambda$, which acts only on leptons including the right-handed neutrinos. The model is anomaly free with family-dependent ${\\rm U(1)}_\\lambda$ charges, and consistent with the observed neutrino mixing angles. It predicts charged lepton flavor-violating processes mediated by a new gauge boson. Under certain conditions, the smallness of $\\theta_{13}$ of neutrino mixing can be justified in terms of the muon-to-tau mass ratio, at the same time explaining the electron-to-tau large mass hierarchy.

La, HoSeong

2013-01-01T23:59:59.000Z

39

Form invariance and symmetry in the neutrino mass matrix  

SciTech Connect

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

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

2011-01-01T23:59:59.000Z

40

Neutrino Oscillation Physics  

Science Conference Proceedings (OSTI)

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

Kayser, Boris

2012-06-01T23:59:59.000Z

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


41

Higgs Search Constraints on Fourth Generation Scenarios with General Lepton Sectors  

E-Print Network (OSTI)

I present a general exclusion bound for the Higgs in fourth generation scenarios with a general lepton sector. Recent Higgs searches in fourth generation scenarios rule out the entire Higgs mass region between 120 and 600 GeV. That such a large range of Higgs masses are excluded is due to the presence of extra heavy flavors of quarks, which substantially increase Higgs production from gluon fusion over the Standard Model rate. However, if heavy fourth generation neutrinos are less than half of the Higgs mass, they can dominate the Higgs decay branching fraction, overtaking the standard Higgs to WW* decay rate. The Higgs mass exclusion in a fourth generation scenario is shown most generally to be 155-600 GeV, and is highly dependent on the fourth generation neutrino mixing parameter.

Linda M. Carpenter

2011-10-21T23:59:59.000Z

42

The Particle Adventure | What is the world made of? | Lepton type  

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

type conservation type conservation Lepton type conservation Leptons are divided into three lepton families: the electron and its neutrino, the muon and its neutrino, and the tau and its neutrino. We use the terms "electron number," "muon number," and "tau number" to refer to the lepton family of a particle. Electrons and their neutrinos have electron number +1, positrons and their antineutrinos have electron number -1, and all other particles have electron number 0. Muon number and tau number operate analogously with the other two lepton families. One important thing about leptons, then, is that electron number, muon number, and tau number are always conserved when a massive lepton decays into smaller ones. Let's take an example decay.

43

Lepton stability  

Science Conference Proceedings (OSTI)

The problem of flavor-changing currents in the lepton sector is reviewed. The emphasis is on the experimental situation, with a brief discussion of the theoretical problems which are addressed by the measurements.

Cooper, M.C.

1981-01-01T23:59:59.000Z

44

Isospin-Violating Dark Matter and Neutrinos From the Sun  

E-Print Network (OSTI)

We study the indirect detection of dark matter through neutrino flux from their annihilation in the center of the Sun, in a class of theories where the dark matter-nucleon spin-independent interactions break the isospin symmetry. We point out that, while the direct detection bounds with heavy targets like Xenon are weakened and reconciled with the positive signals in DAMA and CoGeNT experiments, the indirect detection using neutrino telescopes can impose a relatively stronger constraint and brings tension to such explanation, if the annihilation is dominated by heavy quark or $\\tau$-lepton final states. As a consequence, the qualified isospin violating dark matter candidate has to preferably annihilate into light flavors.

Shao-Long Chen; Yue Zhang

2011-06-20T23:59:59.000Z

45

Triangular mass matrices for quarks and leptons  

E-Print Network (OSTI)

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

S. Tatur; J. Bartelski

2006-05-24T23:59:59.000Z

46

Measuring Neutrinos with the ANTARES Telescope  

Science Conference Proceedings (OSTI)

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

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

2009-12-17T23:59:59.000Z

47

Minimal Neutrino Texture with Neutrino Mass Ratio and Cabibbo Angle  

E-Print Network (OSTI)

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

Yusuke Shimizu; Ryo Takahashi; Morimitsu Tanimoto

2012-12-24T23:59:59.000Z

48

Neutrino oscillations in nuclear media  

E-Print Network (OSTI)

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

Iman Motie; She-Sheng Xue

2011-04-14T23:59:59.000Z

49

(L{sub e}-L{sub {mu}-}L{sub {tau}}) discrete symmetry for heavy right-handed neutrinos and degenerate leptogenesis  

Science Conference Proceedings (OSTI)

The degenerate leptogenesis is studied when the degeneracy in two of the heavy right-handed neutrinos [the third one is irrelevant if {mu}-{tau} symmetry is assumed] is due to L{identical_to}(L{sub e}-L{sub {mu}-}L{sub {tau}}) discrete symmetry. It is shown that a sizable leptogenesis asymmetry ({epsilon}{>=}10{sup -6}) is possible. The level of degeneracy required also predicts the Majorana phase needed for the asymmetry and this prediction is testable since it is the same phase, which appears in the double {beta} decay. Implications of nonzero reactor angle {theta}{sub 13} are discussed. It is shown that the contribution from sin{sup 2{theta}}{sub 13} to the leptogenesis asymmetry parameter may even dominate. An accurate measurement of sin{sup 2{theta}}{sub 13} would have important implications for the mass degeneracy of heavy right-handed neutrinos.

Riazuddin [Centre for Advanced Mathematics and Physics, National University of Sciences and Technology, Rawalpindi (Pakistan) and National Centre for Physics, Quaid-i-Azam University, Islamabad (Pakistan)

2010-05-01T23:59:59.000Z

50

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

Science Conference Proceedings (OSTI)

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

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

2011-12-16T23:59:59.000Z

51

Nucleosynthesis and Neutrinos  

SciTech Connect

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

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

2011-05-06T23:59:59.000Z

52

Tracing Very High Energy Tau Neutrinos from Cosmological Distances in Ice  

E-Print Network (OSTI)

Astrophysical sources of ultrahigh energy neutrinos yield tau neutrino fluxes due to neutrino oscillations. We study in detail the contribution of tau neutrinos with energies above $10^6$ GeV relative to the contribution of the other flavors. We consider several different initial neutrino fluxes and include tau neutrino regeneration in transit through the Earth and energy loss of charged leptons. We discuss signals of tau neutrinos in detectors such as IceCube, RICE and ANITA.

J. Jones; I. Mocioiu; I. Sarcevic; M. H. Reno

2004-08-04T23:59:59.000Z

53

Solar Neutrino Observations at the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

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

Poon, A W P

2002-01-01T23:59:59.000Z

54

Solar Neutrino Observations at the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

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

A. W. P. Poon

2002-11-06T23:59:59.000Z

55

Constraints on Non-Standard Neutrino Interactions and Unparticle Physics with Neutrino-Electron Scattering at the Kuo-Sheng Nuclear Power Reactor  

E-Print Network (OSTI)

Neutrino-electron scatterings are purely leptonic processes with robust Standard Model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. The $\

M. Deniz er al.; TEXONO Collaboration

2010-06-10T23:59:59.000Z

56

Glossary Term - Lepton  

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

Joule Previous Term (Joule) Glossary Main Index Next Term (Liquid Nitrogen) Liquid Nitrogen Lepton Leptons are particles with little mass that interact through the electromagnetic...

57

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

E-Print Network (OSTI)

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

Antusch, S

2008-01-01T23:59:59.000Z

58

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

E-Print Network (OSTI)

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

S. Antusch; E. Fernandez-Martinez

2008-04-17T23:59:59.000Z

59

Neutrino-pair emission from nuclear de-excitation in core-collapse supernova simulations  

E-Print Network (OSTI)

We study the impact of neutrino-pair production from the de-excitation of highly excited heavy nuclei on core-collapse supernova simulations, following the evolution up to several 100 ms after core bounce. Our study is based on the AGILE-Boltztran supernova code, which features general relativistic radiation hydrodynamics and accurate three-flavor Boltzmann neutrino transport in spherical symmetry. In our simulations the nuclear de-excitation process is described in two different ways. At first we follow the approach proposed by Fuller and Meyer [Astrophys. J. 376,701 (1991)], which is based on strength functions derived in the framework of the nuclear Fermi-gas model of non-interacting nucleons. Secondly, we parametrize the allowed and forbidden strength distributions in accordance with measurements for selected nuclear ground states. We determine the de-excitation strength by applying the Brink hypothesis and detailed balance. For both approaches, we find that nuclear de-excitation has no effect on the supernova dynamics. However, we find that nuclear de-excitation is the leading source for the production of electron antineutrinos as well as heavy-lepton flavor (anti)neutrinos during the collapse phase. At sufficiently high densities, the associated neutrino spectra are influenced by interactions with the surrounding matter, making proper simulations of neutrino transport important for the determination of the neutrino-energy loss rate. We find that even including nuclear de-excitations, the energy loss during the collapse phase is overwhelmingly dominated by electron neutrinos produced by electron captures.

Tobias Fischer; Karlheinz Langanke; Gabriel Martinez-Pinedo

2013-09-17T23:59:59.000Z

60

Search for Pair Production of a Heavy Up-Type Quark Decaying to a W Boson and a b Quark in the lepton plus jets Channel with the ATLAS Detector  

Science Conference Proceedings (OSTI)

A search is presented for production of a heavy up-type quark (t{prime}) together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t{prime}{bar t}{prime} {yields} W{sup +}bW{sup -}{bar b}. The search is based on 1.04 fb{sup -1} of proton-proton collisions at {radical}s = 7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum, and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit of 404 GeV is set for the mass of the t{prime} quark.

Aad G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; et al.

2012-06-25T23:59:59.000Z

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


61

Phenomenology of a leptonic goldstino and invisible Higgs boson decays  

E-Print Network (OSTI)

Non-linearly realized supersymmetry, combined with the Standard Model field content and SU(3)XSU(2)XU(1) gauge invariance, permits local dimension-six operators involving a goldstino, a lepton doublet and a Higgs doublet. These interactions preserve total lepton number if the left-handed goldstino transforms as an antilepton. We discuss the resulting phenomenology, in the simple limit where the new couplings involve only one lepton family, thus conserving also lepton flavour. Both the Z boson and the Higgs boson can decay into a neutrino and a goldstino: the present limits from the invisible Z width and from other observables leave room for the striking possibility of a Higgs boson decaying dominantly, or at least with a sizable branching ratio, via such an invisible mode. We finally comment on the perspectives at hadron and lepton colliders, and on possible extensions of our analysis.

Ignatios Antoniadis; Marc Tuckmantel; Fabio Zwirner

2004-10-12T23:59:59.000Z

62

Solar Neutrinos  

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

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

63

Radiative Transmission of Lepton Flavor Hierarchies  

E-Print Network (OSTI)

We discuss a one loop model for neutrino masses which leads to a seesaw-like formula with the difference that the charged lepton masses replace the unknown Dirac mass matrix present in the usual seesaw case. This is a considerable reduction of parameters in the neutrino sector and predicts a strong hierarchical pattern in the right handed neutrino mass matrix that is easily derived from a $U(1)_H$ family symmetry. The model is based on the left-right gauge group with an additional $Z_4$ discrete symmetry which gives vanishing neutrino Dirac masses and finite Majorana masses arising at the one loop level. Furthermore, it is one of the few models that naturally allow for large (but not necessarily maximal) mixing angles in the lepton sector. A generalization of the model to the quark sector requires three iso-spin singlet vector-like down type quarks, as in $E_6$. The model predicts an inert doublet type scalar dark matter.

Adisorn Adulpravitchai; Manfred Lindner; Alexander Merle; Rabindra N. Mohapatra

2009-08-04T23:59:59.000Z

64

Entanglement in neutrino oscillations  

E-Print Network (OSTI)

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

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

2007-07-30T23:59:59.000Z

65

FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.  

SciTech Connect

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

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

2001-06-30T23:59:59.000Z

66

Solar Neutrino Physics  

SciTech Connect

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

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

1999-07-15T23:59:59.000Z

67

Majorana Neutrino Masses from Flavor Symmetries  

E-Print Network (OSTI)

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

A. Psallidas

2005-05-11T23:59:59.000Z

68

Search for a new charged heavy vector boson decaying to an electron-neutrino pair in p anti-p collisions at s**(1/2) = 1.96 TeV  

SciTech Connect

We present results on a search for a heavy charged vector boson, W', decaying to an electron-neutrino pair in p{bar p} collisions at {radical}s = 1.96 TeV using a data sample corresponding to an integrated luminosity of 205 pb{sup -1}. We found no evidence of this decay channel, and set 95% confidence level limits on the production cross section times branching fraction assuming the light neutrino. We also set the limit on the W' boson mass at M{sub W'} > 788 GeV/c{sup 2}, assuming the standard model strength couplings.

Kim, Jieun; /Kyungpook Natl. U.

2005-06-01T23:59:59.000Z

69

The left-right forward-backward asymmetry of heavy quarks measured with jet charge and with leptons at the SLD  

SciTech Connect

The authors present direct measurements of the left-right asymmetry of b- and c-quarks from the decay of Z{sup 0} bosons produced in the annihilation of longitudinally polarized electrons and unpolarized positrons. Two complementary techniques are presented: (1) Z{sup 0} {yields} b{bar b} decays are tagged using track impact parameters with b{bar b} discrimination provided by momentum-weighted track charge; (2) semileptonic b-decays are tagged using high p and p{sub T} muons and electrons. The preliminary results from their 1993 data sample are: A{sub b} = 0.93 {+-} 0.13 {+-} 0.13 for the jet charge and A{sub b} = 0.93 {+-} 0.14 {+-} 0.09, and A{sub c} = 0.40 {+-} 0.23 {+-} 0.20 for the leptons, where the first error is statistical and the second systematic.

Williams, D.C. [Massachusetts Institute of Technology, Cambridge, MA (United States)]|[Stanford Univ., CA (United States). Stanford Linear Accelerator Center

1994-10-01T23:59:59.000Z

70

Neutrino Physics at the Turn of the Millenium  

E-Print Network (OSTI)

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

J. W. F. Valle

1999-11-03T23:59:59.000Z

71

Search for pair-produced heavy quarks decaying to Wq in the two-lepton channel at root(s)=7 TeV with the ATLAS detector  

SciTech Connect

A search is presented for heavy-quark pair production (QQ{sup -}) under the decay hypothesis QQ{sup -} {yields} W{sup +}qW{sup -}q{sup -} with q=d, s, b for up-type Q or q=u, c for down-type Q. The search is performed with 1.04 fb{sup -1} of integrated luminosity from pp collisions at {radical}s = 7 TeV collected by the ATLAS detector at the CERN LHC. Dilepton final states are selected, requiring large missing transverse momentum and at least two jets. Mass reconstruction of heavy-quark candidates is performed by assuming that the W boson decay products are nearly collinear. The data are in agreement with standard model expectations; a heavy quark with mass less than 350 GeV is excluded at 95% confidence level.

Aad G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; et al.

2012-07-23T23:59:59.000Z

72

IMPACTS OF COLLECTIVE NEUTRINO OSCILLATIONS ON CORE-COLLAPSE SUPERNOVA EXPLOSIONS  

Science Conference Proceedings (OSTI)

By performing a series of one- and two-dimensional (1D and 2D) hydrodynamic simulations with spectral neutrino transport, we study possible impacts of collective neutrino oscillations on the dynamics of core-collapse supernovae. To model the spectral swapping, which is one of the possible outcome of the collective neutrino oscillations, we parameterize the onset time when the spectral swap begins, the radius where the spectral swap occurs, and the threshold energy above which the spectral interchange between heavy-lepton neutrinos and electron/anti-electron neutrinos takes place. By doing so, we systematically study how the neutrino heating enhanced by the spectral swapping could affect the shock evolution as well as the matter ejection. We also investigate the progenitor dependence using a suite of progenitor models (13, 15, 20, and 25 M{sub sun}). We find that there is a critical heating rate induced by the spectral swapping that triggers explosions, and which significantly differs between the progenitors. The critical heating rate is generally smaller for 2D than for 1D due to the multidimensionality that enhances the neutrino heating efficiency. For the progenitors employed in this paper, the final remnant masses are estimated to range between 1.1-1.5 M{sub sun}. For our 2D model of the 15 M{sub sun} progenitor, we find a set of oscillation parameters that could account for strong supernova explosions ({approx}10{sup 51} erg), simultaneously leaving behind a remnant mass close to {approx}1.4 M{sub sun}.

Suwa, Yudai [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Takiwaki, Tomoya [Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Liebendoerfer, Matthias [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland); Sato, Katsuhiko, E-mail: suwa@yukawa.kyoto-u.ac.jp [The Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan)

2011-09-10T23:59:59.000Z

73

Neutrino Oscillations with Reactor Neutrinos  

E-Print Network (OSTI)

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

Anatael Cabrera

2007-01-11T23:59:59.000Z

74

neutrino-properties-web.dvi  

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

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

75

Neutrino Phenomenology  

E-Print Network (OSTI)

A general overview of neutrino physics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and the indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos and their confirmation with artificial neutrino sources.

Esteban Roulet

2004-12-27T23:59:59.000Z

76

Neutrino Physics  

DOE R&D Accomplishments (OSTI)

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

Lederman, L. M.

1963-01-09T23:59:59.000Z

77

Neutrino Oscillations  

E-Print Network (OSTI)

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

A. B. Balantekin; W. C. Haxton

2013-03-09T23:59:59.000Z

78

LSP sneutrino decays into heavy standard model pairs  

E-Print Network (OSTI)

In bilinear R-parity violation (BRpV), in which the superpotential includes a bilinear term between the lepton doublet and the up-type Higgs superfields, a sneutrino LSP can decay into pairs of heavy standard model states: W's, Z's, tops or Higgs bosons. These finals states can dominate over the traditionally considered bottom pair final state. This would lead to unique and novel supersymmetric signals with each supersymmetric event possibly producing two pairs of these heavy standard model fields. We investigate this possibility and find that the branching ratio into heavier states dominates when the bilinear term is much smaller than the sneutrino vacuum expectation value for a given sneutrino flavor. When BRpV is the only source of neutrino masses these decays can only dominate for one of the sneutrino generations. Relaxing this constraint opens these channels for all three generations.

D. Aristizabal Sierra; D. Restrepo; S. Spinner

2012-12-13T23:59:59.000Z

79

Long Baseline Neutrino Beams and Large Detectors  

SciTech Connect

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

Samios,N.P.

2008-10-27T23:59:59.000Z

80

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

E-Print Network (OSTI)

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

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

2012-01-01T23:59:59.000Z

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


81

Particle Data Group - 2009 Particle Listings  

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

for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy...

82

Particle Data Group - Particle Listings - 2007 update  

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

for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy...

83

Particle Data Group - 2011 Particle Listings  

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

for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy...

84

MEASURING LEPTONIC CP VIOLATION WITH A WATER CERENKOV  

E-Print Network (OSTI)

In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case ?13 ? 3 ? (the limit that can be reached by under-construction experiments), the signal-to-background rate for a ?-beam setup with the radioactive ions accelerated to ? = 350. 1

E. Couce

2006-01-01T23:59:59.000Z

85

Glossary Item - Neutrino  

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

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

86

Origin of quark-lepton flavor in SO(10) with type II seesaw mechanism  

SciTech Connect

Diverse mass and mixing patterns between the quarks and leptons makes it challenging to construct a simple grand unified theory of flavor. We show that SO(10) supersymmetry grand unified theories with type II seesaw mechanism giving neutrino masses provide a natural framework for addressing this issue. A simple ansatz that the dominant Yukawa matrix (the 10-Higgs coupling to matter) has rank one appears to simultaneously explain both the large lepton mixings as well as the observed quark flavor hierarchy in these models. A testable prediction of this ansatz is the neutrino mixing, U{sub e3}, which should be observable in planned long baseline experiments.

Dutta, Bhaskar [Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Mimura, Yukihiro; Mohapatra, R. N. [Maryland Center for Fundamental Physics and Department of Physics, University of Maryland, College Park, Maryland, 20742 (United States)

2009-11-01T23:59:59.000Z

87

Neutrino Factories  

SciTech Connect

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

Geer, Steve; /Fermilab

2010-01-01T23:59:59.000Z

88

Cosmological bounds on neutrino degeneracy improved by flavor oscillations  

E-Print Network (OSTI)

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

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

2002-01-30T23:59:59.000Z

89

Evidence for Neutrino Oscillations I: Solar and Reactor Neutrinos  

E-Print Network (OSTI)

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

A. B. McDonald

2004-12-06T23:59:59.000Z

90

Neutrino Superbeams  

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

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

91

Neutrino Mass and Mixing with Discrete Symmetry  

E-Print Network (OSTI)

This is a review article about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of see-saw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mechanisms for flavon vacuum alignment and different model building strategies that have been proposed to generate the reactor angle. We then briefly review grand unified theories (GUTs) and how they may be combined with discrete family symmetry to describe all quark and lepton masses and mixing. Finally we discuss three model examples which combine an SU(5) GUT with the discrete family symmetries A4, S4 and Delta(96).

Stephen F. King; Christoph Luhn

2013-01-07T23:59:59.000Z

92

The physics of heavy flavors  

SciTech Connect

We review the physics of heavy quark flavors, including weak decays, onium, tau leptons, mixing, the Kobayashi-Maskawa matrix, and CP violation in B decay. 36 refs., 12 figs.

Gilman, F.J.

1987-12-01T23:59:59.000Z

93

Measurement of the ?[subscript e] and total [superscript 8]B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set  

E-Print Network (OSTI)

This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of [superscript 3]He proportional counters was installed in the heavy-water ...

Formaggio, Joseph A.

94

Why Are Neutrinos Light? -- An Alternative  

SciTech Connect

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

Hall, Lawrence J.; Oliver, Steven J.

2004-09-23T23:59:59.000Z

95

Neutrino Oscillometry  

E-Print Network (OSTI)

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

Vergados, J D; Novikov, Yu N

2010-01-01T23:59:59.000Z

96

Neutrino Oscillometry  

E-Print Network (OSTI)

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

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

2010-10-21T23:59:59.000Z

97

Solar Neutrinos  

DOE R&D Accomplishments (OSTI)

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

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

1964-12-00T23:59:59.000Z

98

Higgs. -->. four leptons at the SSC  

SciTech Connect

Detection of an intermediate mass or heavy Higgs boson through its decay into four charged leptons is studied with emphasis on background considerations and detector requirements. The intermediate mass Higgs decay via ZZ* is expected to be a difficult mode to observe due to low event rates. In addition, cuts which are needed to reduce the backgrounds reduce the signal even further. The rapidity coverage and energy resolution requirements for this mode are more severe than for the heavy Higgs. The heavy Higgs boson decay H ..-->.. Z/sup 0/Z/sup 0/ ..-->.. 4/ell//sup +-/ continues to be observable for a Higgs mass between twice the Z mass and about 600 GeV/c/sup 2/ when detector characteristics of generic large SSC detectors are included. A careful study is made of backgrounds from q/bar q/, qq ..-->.. Z + Jets and detector-related issues. It is shown that an isolation cut on the lepton candidates can be expected to reduce the background from this source to low levels. 14 refs., 12 figs., 4 tabs.

Wang, E.M.; Hanson, G.G.

1988-12-01T23:59:59.000Z

99

Light Sterile Neutrinos and Short Baseline Neutrino Oscillation Anomalies  

E-Print Network (OSTI)

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

JiJi Fan; Paul Langacker

2012-01-31T23:59:59.000Z

100

Neutrinoless double beta decay and neutrino masses  

SciTech Connect

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

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

2012-07-27T23:59:59.000Z

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


101

Neutrino Mass and Grand Unification  

E-Print Network (OSTI)

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

R. N. Mohapatra

2004-12-03T23:59:59.000Z

102

Quark Lepton Similarity  

E-Print Network (OSTI)

We propose the lepton mixing matrix at high energy scale to be connected to quark mixing matrix by the similar transformation. The similarity between CKM and PMNS significantly narrows down the ranges in physical parameters. The condition requires $\\sin\\theta_{13}$ not to be larger than 0.15, masses to be of quasi-degenerate normal ordering, and $\\tan\\beta$ to be large.

Seungsu Hwang; Kim Siyeon

2010-08-20T23:59:59.000Z

103

Discrete symmetries and neutrino masses  

SciTech Connect

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

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

2005-02-01T23:59:59.000Z

104

Yukawaon Model with Anomaly Free Set of Quarks and Leptons in a U(3) Family Symmetry  

E-Print Network (OSTI)

In the so-called "yukawaon" model, the (effective) Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (yukawaons) with $3\\times 3$ components. So far, yukawaons $Y_f$ have been assigned to ${\\bf 6}$ or ${\\bf 6}^*$ of U(3) family symmetry, so that quarks and leptons were not anomaly free in U(3). In this paper, yukawaons are assigned to ${\\bf 8}+{\\bf 1}$ of U(3), so that quarks and leptons are anomaly free. Since VEV relations among yukawaons are also considerably changed, parameter fitting of the model is renewed. After fixing our free parameters by observed mass ratios, we have only two and one remaining free parameters for quark and lepton mixings, respectively. We obtain successful predictions for the quark and lepton mixing parameters including magnitudes of $CP$ violation. The effective Majorana neutrino mass is also predicted.

Yoshio Koide; Hiroyuki Nishiura

2013-08-09T23:59:59.000Z

105

Neutrino Mass and Mixing with Discrete Symmetry  

E-Print Network (OSTI)

This is a review article about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of seesaw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mec...

King, Stephen F

2013-01-01T23:59:59.000Z

106

Guesswork for Dirac and Majorana neutrino mass matrices  

E-Print Network (OSTI)

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

W. Krolikowski

2004-01-14T23:59:59.000Z

107

Measurement of the $?$-lepton lifetime at Belle  

E-Print Network (OSTI)

The lifetime of the $\\tau$-lepton is measured using the process $e^+e^-\\rightarrow\\tau^+\\tau^-$, where both $\\tau$-leptons decay to $3\\pi\

Belle Collaboration; K. Belous; M. Shapkin; A. Sokolov; I. Adachi; H. Aihara; D. M. Asner; V. Aulchenko; A. M. Bakich; A. Bala; B. Bhuyan; A. Bobrov; A. Bondar; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; D. ?ervenkov; V. Chekelian; A. Chen; B. G. Cheon; K. Chilikin; R. Chistov; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; J. Dalseno; Z. Doleal; D. Dutta; S. Eidelman; D. Epifanov; H. Farhat; J. E. Fast; T. Ferber; V. Gaur; S. Ganguly; A. Garmash; R. Gillard; Y. M. Goh; B. Golob; J. Haba; T. Hara; K. Hayasaka; H. Hayashii; Y. Hoshi; W. -S. Hou; T. Iijima; K. Inami; A. Ishikawa; R. Itoh; T. Iwashita; I. Jaegle; T. Julius; E. Kato; H. Kichimi; C. Kiesling; D. Y. Kim; H. J. Kim; J. B. Kim; M. J. Kim; Y. J. Kim; K. Kinoshita; B. R. Ko; P. Kody; S. Korpar; P. Krian; P. Krokovny; T. Kuhr; A. Kuzmin; Y. -J. Kwon; J. S. Lange; S. -H. Lee; J. Libby; D. Liventsev; P. Lukin; D. Matvienko; H. Miyata; R. Mizuk; G. B. Mohanty; T. Mori; R. Mussa; Y. Nagasaka; E. Nakano; M. Nakao; M. Nayak; E. Nedelkovska; C. Ng; N. K. Nisar; S. Nishida; O. Nitoh; S. Ogawa; S. Okuno; S. L. Olsen; W. Ostrowicz; G. Pakhlova; C. W. Park; H. Park; H. K. Park; T. K. Pedlar; R. Pestotnik; M. Petri?; L. E. Piilonen; M. Ritter; M. Rhrken; A. Rostomyan; S. Ryu; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; D. Santel; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; D. Semmler; K. Senyo; O. Seon; V. Shebalin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; S. Stani?; M. Stari?; M. Steder; T. Sumiyoshi; U. Tamponi; G. Tatishvili; Y. Teramoto; K. Trabelsi; T. Tsuboyama; M. Uchida; S. Uehara; T. Uglov; Y. Unno; S. Uno; Y. Usov; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; K. E. Varvell; A. Vinokurova; V. Vorobyev; M. N. Wagner; C. H. Wang; P. Wang; M. Watanabe; Y. Watanabe; K. M. Williams; E. Won; J. Yamaoka; Y. Yamashita; S. Yashchenko; Y. Yook; C. Z. Yuan; Z. P. Zhang; V. Zhilich; A. Zupanc

2013-10-31T23:59:59.000Z

108

Measuring Leptonic CP Violation with a Water Cerenkov  

E-Print Network (OSTI)

In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case $\\theta_{13} \\approx 3^\\circ$ (the limit that can be reached by under-construction experiments), the signal-to-background rate for a $\\beta$-beam setup with the radioactive ions accelerated to $\\gamma = 350$.

E. Couce

2006-07-01T23:59:59.000Z

109

Melvin Schwartz and the Discovery of the Muon Neutrino  

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

Melvin Schwartz and the Discovery of the Muon Neutrino Melvin Schwartz and the Discovery of the Muon Neutrino Resources with Additional Information Melvin Schwartz Courtesy Brookhaven National Laboratory Melvin Schwartz was the co-winner of the 1988 Nobel Prize in Physics "for the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino". 'In 1962, Schwartz, with Leon Lederman and Jack Steinberger ... discovered the muon neutrino at the Alternating Gradient Synchrotron (AGS), the then brand-new accelerator at the U.S. Department of Energy's Brookhaven National Laboratory. ... First coming to Brookhaven in 1955, Schwartz performed his Ph.D. thesis research through 1956 at the Laboratory's first accelerator, the Cosmotron. While finishing his thesis, he was employed by the Laboratory from 1956-58.

110

VERTICAL STRUCTURE OF NEUTRINO-DOMINATED ACCRETION DISKS AND NEUTRINO TRANSPORT IN THE DISKS  

SciTech Connect

We investigate the vertical structure of neutrino-dominated accretion disks by self-consistently considering the detailed microphysics, such as the neutrino transport, the vertical hydrostatic equilibrium, the conservation of lepton number, as well as the balance between neutrino cooling, advection cooling, and viscosity heating. After obtaining the emitting spectra of neutrinos and antineutrinos by solving the one-dimensional Boltzmann equation of neutrino and antineutrino transport in the disk, we calculate the neutrino/antineutrino luminosity and their annihilation luminosity. We find that the total neutrino and antineutrino luminosity is about 10{sup 54} erg s{sup -1} and their annihilation luminosity is about 5 Multiplication-Sign 10{sup 51} erg s{sup -1} with an extreme accretion rate 10 M{sub Sun} s{sup -1} and an alpha viscosity {alpha} = 0.1. In addition, we find that the annihilation luminosity is sensitive to the accretion rate and will not exceed 10{sup 50} erg s{sup -1}, which is not sufficient to power the fireball of most energetic gamma-ray bursts (GRBs) if the accretion rate is lower than 1 M{sub Sun} s{sup -1}. Therefore, the effects of the spin of the black hole or/and the magnetic field in the accretion flow might play a role in powering the central engine of GRBs.

Pan Zhen; Yuan Yefei, E-mail: yfyuan@ustc.edu.cn [Key Laboratory for Research in Galaxies and Cosmology CAS, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2012-11-10T23:59:59.000Z

111

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

E-Print Network (OSTI)

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

J. D. Vergados; Yu. N. Novikov

2010-06-19T23:59:59.000Z

112

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

E-Print Network (OSTI)

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

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

2002-01-01T23:59:59.000Z

113

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

E-Print Network (OSTI)

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

Monika Randhawa; Gulsheen Ahuja; Manmohan Gupta

2002-03-12T23:59:59.000Z

114

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

E-Print Network (OSTI)

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

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

1999-01-01T23:59:59.000Z

115

Summary of Lepton Photon 2011  

SciTech Connect

In this lecture, I summarize developments presented at the Lepton Photon 2011 conference and give my perspective on the current situation in high-energy physics. I am grateful to the organizers of Lepton Photon 2011 for providing us a very pleasant and simulating week in Mumbai. This year's Lepton Photon conference has covered the full range of subjects that fall within the scope of high-energy physics, including connections to cosmology, nuclear physics, and atomic physics. The experiments that were discussed detect particles ranging in energy from radio frequencies to EeV.

Peskin, Michael E.; /SLAC

2012-03-14T23:59:59.000Z

116

On the 17-keV neutrino  

SciTech Connect

A brief review on the status of the 17-keV neutrino is presented. Several different experiments found spectral distortions which were consistently interpreted as evidence for a heavy neutrino admixture in [beta] decay. Recent experiments, however, rule out the existence of a 17-keV neutrino as well as escaping criticisms of earlier null results. Moreover, the majority of positive results have been reinterpreted in terms of instrumental effects, despite the need for a different explanation in each case. Anomalies persist in the low energy region of the tritium spectrum which deserve further investigation.

Hime, A.

1993-04-01T23:59:59.000Z

117

On the 17-keV neutrino  

SciTech Connect

A brief review on the status of the 17-keV neutrino is presented. Several different experiments found spectral distortions which were consistently interpreted as evidence for a heavy neutrino admixture in {beta} decay. Recent experiments, however, rule out the existence of a 17-keV neutrino as well as escaping criticisms of earlier null results. Moreover, the majority of positive results have been reinterpreted in terms of instrumental effects, despite the need for a different explanation in each case. Anomalies persist in the low energy region of the tritium spectrum which deserve further investigation.

Hime, A.

1993-04-01T23:59:59.000Z

118

Solar Neutrinos  

E-Print Network (OSTI)

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

R. G. H. Robertson

2006-02-05T23:59:59.000Z

119

Neutrino Physics: Fundamentals of Neutrino Oscillations  

E-Print Network (OSTI)

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

C. W. Kim

1996-07-22T23:59:59.000Z

120

Limits on tau lepton-flavor violating decays into three charged leptons  

E-Print Network (OSTI)

A search for the neutrinoless, lepton-flavor violating decay of the ? [tau] lepton into three charged leptons has been performed using an integrated luminosity of 468??fb-1 [fb superscript -1] collected with the BABAR ...

Cowan, Ray Franklin

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121

Solar Neutrinos Before and After Neutrino 2004  

E-Print Network (OSTI)

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

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

2004-06-28T23:59:59.000Z

122

The ANTARES neutrino telescope: a status report  

E-Print Network (OSTI)

ANTARES is a large volume neutrino telescope currently under construction off La Seyne-sur-mer, France, at 2475m depth. Neutrino telescopes aim at detecting neutrinos as a new probe for a sky study at energies greater than 1 TeV. The detection principle relies on the observation, using photomultipliers, of the Cherenkov light emitted by charged leptons induced by neutrino interactions in the surrounding detector medium. Since late January 2007, the ANTARES detector consists of 5 lines, comprising 75 optical detectors each, connected to the shore via a 40 km long undersea cable. The data from these lines not only allow an extensive study of the detector properties but also the reconstruction of downward going cosmic ray muons and the search for the first upward going neutrino induced muons.The operation of these lines follows on from that of the ANTARES instrumentation line, which has provided data for more than a year on the detector stability and the environmental conditions. The full 12 line detector is planned to be fully operational early 2008.

A. Kouchner; for the Antares collaboration

2007-10-01T23:59:59.000Z

123

Physical model of leptons : Massive electrons, muons, tauons and their massless neutrons  

E-Print Network (OSTI)

The physical model (PhsMdl) of the leptons is offered by means of the PhsMdls of the vacuum and electron,described in our recent works. It is assumed that the vacuum is consistent by dynamides, streamlined in junctions of some tight crystalline lattice. Every dynamide contains a neutral pair of massless point-like (PntLk) contrary elementary electric charges (ElmElcChrgs): electrino $(-)$ and positrino $(+)$. The PntLk ElmElcChrgs of the massless electrino and positrino of some dynamide in the fluctuated vacuum may been excited or deviated by means of some energy, introduced by some photon or other micro particles (MicrPrts). The massless leptons (neutrinos) are neutral long-living solitary spherical vortical oscillation excitations of the uncharged fluctuating vacuum. The massive leptons are charged long-living solitary spherical vortical excitations of its fine spread (FnSpr) elementary electric charge (ElmElcChrg). So-called zitterbewegung is self-consistent strong-correlated vortical harmonic oscillation motion of the FnSpr ElmElcChrg of massive leptons. Different leptons have different self-consistent strong-correlated vortical harmonic oscillation motion of different sizes of their FnSpr ElmElcChrg, which is determined by their Kompton length $\\lambda =\\frac{h}{m C} $, where $m$ is the mass of the massive leptons. At mutual transition of one massive lepton into another massive lepton its PntLk ElmElcChrg move up by dint of weak interaction in the form of the charged intermediate vector meson $W$ from one self-consistent strong-correlated vortical harmonic oscillation motion of one size into another self-consistent strong-correlated vortical harmonic oscillation motion of another size.

Josiph Mladenov Rangelov

2000-03-07T23:59:59.000Z

124

The neutrino self-energy in a magnetized medium  

E-Print Network (OSTI)

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

Alberto Bravo Garcia; Kaushik Bhattacharya; Sarira Sahu

2007-06-27T23:59:59.000Z

125

Lepton Flavor Violation in Predictive Supersymmetric GUT Models  

E-Print Network (OSTI)

There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially $\\sin^2 2\\theta_{13}$, are obtained, charged lepton flavor violation (LFV) experiments are able to differentiate even further among the models. In this paper, we investigate various rare LFV processes, such as $\\ell_{i} \\to \\ell_{j} + \\gamma$ and $\\mu-e$ conversion, in five predictive supersymmetric (SUSY) SO(10) models and their allowed soft-SUSY breaking parameter space in the constrained minimal SUSY standard model. Utilizing the Wilkinson Microwave Anisotropy Probe dark matter constraints, we obtain lower bounds on the branching ratios of these rare processes and find that at least three of the five models we consider give rise to predictions for $\\mu \\to e + \\gamma$ that will be tested by the MEG Collaboration at PSI. In addition, the next generation $\\mu-e$ conversion experiment has sensitivity to the predictions of all five models, making it an even more robust way to test these models. While generic studies have emphasized the dependence of the branching ratios of these rare processes on the reactor neutrino angle $\\theta_{13}$ and the mass of the heaviest right-handed neutrino $M_3$, we find very massive $M_3$ is more significant than large $\\theta_{13}$ in leading to branching ratios near to the present upper limits.

Carl H. Albright; Mu-Chun Chen

2008-02-28T23:59:59.000Z

126

Lepton Flavor Violation in Predictive SUSY-GUT Models  

SciTech Connect

There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially sin{sup 2} 2{theta}{sub 13}, are obtained, charged lepton flavor violation (LFV) experiments are able to differentiate even further among the models. In this paper, they investigate various rare LFV processes, such as {ell}{sub i} {yields} {ell}{sub j} + {gamma} and {mu} - e conversion, in five predictive SUSY SO(10) models and their allowed soft SUSY breaking parameter space in the constrained minimal SUSY standard model (CMSSM). Utilizing the WMAP dark matter constraints, they obtain lower bounds on the branching ratios of these rare processes and find that at least three of the five models they consider give rise to predictions for {mu} {yields} e + {gamma} that will be tested by the MEG collaboration at PSI. in addition, the next generation {mu} - e conversion experiment has sensitivity to the predictions of all five models, making it an even more robust way to test these models. While generic studies have emphasized the dependence of the branching ratios of these rare processes on the reactor neutrino angle, {theta}{sub 13}, and the mass of the heaviest right-handed neutrino, M{sub 3}, they find very massive M{sub 3} is more significant than large {theta}{sub 13} in leading to branching ratios near to the present upper limits.

Albright, Carl H.; /Northern Illinois U. /Fermilab; Chen, Mu-Chun; /UC, Irvine

2008-02-01T23:59:59.000Z

127

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

E-Print Network (OSTI)

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

S. Pascoli; S. T. Petcov

2003-09-30T23:59:59.000Z

128

The lepton asymmetry: the last chance for a critical-density cosmology?  

E-Print Network (OSTI)

We use a wide range of observations to constrain cosmological models possessing a significant asymmetry in the lepton sector, which offer perhaps the best chance of reconciling a critical-density Universe with current observations. The simplest case, with massless neutrinos, fails to fit many experimental data and does not lead to an acceptable model. If the neutrinos have mass of order one electron-volt (which is favoured by some neutrino observations), then models can be implemented which prove a good fit to microwave anisotropies and large-scale structure data. However, taking into account the latest microwave anisotropy results, especially those from Boomerang, we show that the model can no longer accommodate the observed baryon fraction in clusters. Together with the observed acceleration of the present Universe, this puts considerable pressure on such critical-density models.

Julien Lesgourgues; Andrew R. Liddle

2001-05-21T23:59:59.000Z

129

Neutrino dark matter candidate in fourth generation scenarios  

E-Print Network (OSTI)

We overview the constraints on the 4th-generation neutrino dark matter candidate and investigate a possible way to make it a viable dark matter candidate. Given the LEP constraints tell us that the 4th-generation neutrino has to be rather heavy (> M_Z/2), in sharp contrast to the other three neutrinos, the underlying nature of the 4th-generation neutrino is expected to be different. We suggest that an additional gauge symmetry B-4L_4 distinguishes it from the Standard Model's three lighter neutrinos and this also facilitates promotion of the 4th-generation predominantly right-handed neutrino to a good cold dark matter candidate. It provides distinguishable predictions for the dark matter direct detection and the Large Hadron Collider experiments.

Hye-Sung Lee; Zuowei Liu; Amarjit Soni

2011-05-17T23:59:59.000Z

130

Luminescent Bolometer and Neutrino Physics  

E-Print Network (OSTI)

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

Luis Gonzalez-Mestres

1997-11-25T23:59:59.000Z

131

The Standard Model of Particle Physics. Neutrino Oscillations  

E-Print Network (OSTI)

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

Giorgio Giacomelli

2009-01-16T23:59:59.000Z

132

Solar Neutrinos in 2011  

E-Print Network (OSTI)

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

Chavarria, Alvaro

2012-01-01T23:59:59.000Z

133

Lepton Mixing Predictions from Delta(6n^2) Family Symmetry  

E-Print Network (OSTI)

We obtain predictions of lepton mixing parameters for direct models based on Delta(6n^2) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Delta(6n^2), we find many new candidates for large n able to yield reactor angle predictions within 3 sigma of recent global fits. We show that such Delta(6n^2) models with Majorana neutrinos predict trimaximal mixing with reactor angle theta_{13} fixed up to a discrete choice, an oscillation phase of either zero or pi and the atmospheric angle sum rules theta_{23}=45 degrees -/+ theta_{13}/sqrt{2}, respectively, which are consistent with recent global fits and will be tested in the near future.

King, Stephen F; Stuart, Alexander J

2013-01-01T23:59:59.000Z

134

Lepton Mixing Predictions from Delta(6n^2) Family Symmetry  

E-Print Network (OSTI)

We obtain predictions of lepton mixing parameters for direct models based on Delta(6n^2) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Delta(6n^2), we find many new candidates for large n able to yield reactor angle predictions within 3 sigma of recent global fits. We show that such Delta(6n^2) models with Majorana neutrinos predict trimaximal mixing with reactor angle theta_{13} fixed up to a discrete choice, an oscillation phase of either zero or pi and the atmospheric angle sum rules theta_{23}=45 degrees -/+ theta_{13}/sqrt{2}, respectively, which are consistent with recent global fits and will be tested in the near future.

Stephen F. King; Thomas Neder; Alexander J. Stuart

2013-05-14T23:59:59.000Z

135

Signatures for right-handed neutrinos at the Large Hadron Collider  

E-Print Network (OSTI)

We explore possible signatures for right-handed neutrinos in TeV scale B-L extension of the Standard Model (SM) at the Large Hadron Collider (LHC). The studied four lepton signal has a tiny SM background. We find the signal experimentally accessible at LHC for the considered parameter regions.

Katri Huitu; Shaaban Khalil; Hiroshi Okada; Santosh Kumar Rai

2008-03-19T23:59:59.000Z

136

STANDARD SOLAR NEUTRINOS  

E-Print Network (OSTI)

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

Arnon Dar

2008-01-01T23:59:59.000Z

137

Neutrino mass, a status report  

SciTech Connect

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

Robertson, R.G.H.

1993-08-01T23:59:59.000Z

138

Experimental Neutrino Physics: Final Report  

Science Conference Proceedings (OSTI)

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

Lane, Charles E.; Maricic, Jelena

2012-09-05T23:59:59.000Z

139

Neutrino Nucleosynthesis in Supernovae  

Science Conference Proceedings (OSTI)

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

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

2009-05-04T23:59:59.000Z

140

The ANTARES Neutrino Telescope: status and first results  

E-Print Network (OSTI)

Completed in May 2008, the ANTARES neutrino telescope is located in the Mediterranean Sea, 40 km off the coast of Toulon, at a depth of about 2500 m. Consisting of 12 detector lines housing nearly 900 optical modules, the ANTARES telescope is currently the largest neutrino detector in the northern hemisphere. Utilising the Mediterranean Sea as a detecting medium, the detection principle of ANTARES relies on the observation of Cherenkov photons emitted by charged relativistic leptons, produced through neutrino interactions with the surrounding water and seabed, using a 3 dimensional lattice of photomultiplier tubes. In this paper we review the current status of the ANTARES experiment, highlighting some of the results from it's first year of full operation.

Brown, Anthony M

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrinos heavy leptons" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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141

The Neutrino Mass Hierarchy from Nuclear Reactor Experiments  

E-Print Network (OSTI)

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

Emilio Ciuffoli; Jarah Evslin; Xinmin Zhang

2013-02-04T23:59:59.000Z

142

Pseudo-Dirac neutrinos in the new standard model  

Science Conference Proceedings (OSTI)

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

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

2009-10-01T23:59:59.000Z

143

Searches for new quarks and leptons in Z boson decays  

SciTech Connect

Searches for the decay of Z bosons into pairs of new quarks and leptons in a data sample including 455 hadronic Z decays are presented. The Z bosons were produced in electon-positron annihilations at the SLAC Linear Collider operating in the center-of-mass energy range from 89.2 to 93.0 GeV. The Standard Model provides no prediction for fermion masses and does not exclude new generations of fermions. The existence and masses of these new particles may provide valuable information to help understand the pattern of fermion masses, and physics beyond the Standard Model. Specific searches for top quarks and sequential fourth generation charge--1/3(b{prime}) quarks are made considering a variety of possible standard and non-standard decay modes. In addition, searches for sequential fourth generation massive neutrinos {nu}{sub 4} and their charged lepton partners L{sup {minus}} are pursued. The {nu}{sub 4} may be stable or decay through mixing to the lighter generations. The data sample is examined for new particle topologies of events with high-momentum isolated tracks, high-energy isolated photons, spherical event shapes, and detached vertices. No evidence is observed for the production of new quarks and leptons. 95% confidence lower mass limits of 40.7 GeV/c{sup 2} for the top quark and 42.0 GeV/c{sup 2} for the b{prime}-quark mass are obtained regardless of the branching fractions to the considered decay modes. A significant range of mixing matrix elements of {nu}{sub 4} to other generation neutrinos for a {nu}{sub 4} mass from 1 GeV/c{sup 2} to 43 GeV/c{sup 2} is excluded at 95% confidence level. Measurements of the upper limit of the invisible width of the Z exclude additional values of the {nu}{sub 4} mass and mixing matrix elements, and also permit the exclusion of a region in the L{sup {minus}} mass versus {nu}{sub 4} mass plane.

Van Kooten, R.J.

1990-06-01T23:59:59.000Z

144

BNL | Neutrino Research History  

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

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

145

Outlook on Neutrino Physics  

E-Print Network (OSTI)

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

John Ellis

1996-11-29T23:59:59.000Z

146

Lepton Photon Symposium 2005: Summary and Outlook  

E-Print Network (OSTI)

Lepton Photon 2005 told the saga of the Standard Model which is still exhilarating because it leaves all questions of consequence unanswered.

Francis Halzen

2005-10-20T23:59:59.000Z

147

Introduction to Neutrino Physics  

SciTech Connect

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

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

2009-04-30T23:59:59.000Z

148

Fundamental neutrino experiments  

E-Print Network (OSTI)

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

Ruggero Maria Santilli

2006-11-06T23:59:59.000Z

149

Solar neutrino oscillations  

Science Conference Proceedings (OSTI)

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

Haxton, W.C.

1993-12-31T23:59:59.000Z

150

Lepton Number Violating Signals of the Top Partners in the Left-Right Twin Higgs Model  

E-Print Network (OSTI)

We study the collider signatures of the left-right twin Higgs model in the case that the right-handed neutrino mass is less than the mass of the right-handed gauge boson. In this scenario, new leptonic decay chains open up, allowing the particles which cancel the one-loop quadratic divergences of the Higgs, the right-handed gauge bosons and top-partners, to be discovered. Half of these events contain same-sign leptons without missing energy, which have no genuine standard model background and for which the backgrounds are purely instrumental. These signals may be used to complement other collider searches, and in certain regions of parameter space, may be the only way to observe the particles responsible for natural electroweak symmetry breaking in the left-right twin Higgs model.

Hock-Seng Goh; Christopher A. Krenke

2009-11-30T23:59:59.000Z

151

Neutrino observations from the Sudbury Neutrino Observatory  

SciTech Connect

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

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

2001-09-24T23:59:59.000Z

152

Solar neutrino physics: Sensitivity to light dark matter particles  

E-Print Network (OSTI)

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

Ilidio Lopes; Joseph Silk

2013-09-29T23:59:59.000Z

153

Measurement of the $?_e$ and Total $^{8}$B Solar Neutrino Fluxes with the Sudbury Neutrino Observatory Phase I Data Set  

E-Print Network (OSTI)

This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kt-year exposure of heavy water to the solar $^8$B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the $\

SNO Collaboration

2006-10-13T23:59:59.000Z

154

Flavour models for TM1 lepton mixing  

E-Print Network (OSTI)

We present a framework for lepton flavour models such that the first column of the lepton mixing matrix is (2,-1,-1)/sqrt(6). We show that the flavour symmetry group adequate for this purpose is S4. Our models are based on a vacuum alignment that can be obtained in a supersymmetric framework.

Varzielas, Ivo de Medeiros

2012-01-01T23:59:59.000Z

155

Leptonic CP Phase in {nu}{sub {mu}}{yields}{nu}{sub {mu}} Oscillations  

Science Conference Proceedings (OSTI)

In the case of large 1-3 mixing angle as sin{sup 2} 2{theta}{sub 13}{>=}0.03, we investigate the possibility for measuring the leptonic CP phase by using only {nu}{sub {mu}}{yields}{nu}{sub {mu}} oscillations independently of {nu}{sub {mu}}{yields}{nu}{sub e} oscillations. As the result, we find that the CP phase can be measured best around the energy E = 0.43 GeV and the baseline length L = 5000 km without depending on the uncertainties of other parameters too much. In this region, the CP phase effect remains even after averaging over neutrino energy.

Kimura, Keiichi; Yoshikawa, Tadashi [Department of Physics, Nagoya University, Nagoya, 464-8602 (Japan); Takamura, Akira [Department of Mathematics, Toyota National College of Technology Eisei-cho 2-1, Toyota-shi, 471-8525 (Japan)

2008-02-21T23:59:59.000Z

156

Neutrino Spectroscopy with Atoms and Molecules  

E-Print Network (OSTI)

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

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

2012-11-21T23:59:59.000Z

157

SNO: solving the mystery of the missing neutrinos  

DOE Green Energy (OSTI)

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

Jelley, Nick; Poon, Alan

2007-03-30T23:59:59.000Z

158

Supernova neutrinos and nucleosynthesis  

E-Print Network (OSTI)

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

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

2013-09-21T23:59:59.000Z

159

Three flavor neutrino oscillations, LSND, SNP and ANP  

E-Print Network (OSTI)

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

Gulsheen Ahuja; Monika Randhawa; Manmohan Gupta

2001-04-19T23:59:59.000Z

160

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

E-Print Network (OSTI)

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

Debasish Borah; Mrinal Kumar Das

2013-03-07T23:59:59.000Z

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


161

Atmospheric neutrino oscillations and tau neutrinos in ice  

E-Print Network (OSTI)

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

Gerardo Giordano; Olga Mena; Irina Mocioiu

2010-04-20T23:59:59.000Z

162

MINOS Sterile Neutrino Search  

SciTech Connect

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

Koskinen, David Jason; /University Coll. London

2009-09-01T23:59:59.000Z

163

Gauge bosons and heavy quarks: Proceedings of Summer Institute on Particle Physics  

SciTech Connect

This report contains papers on the following topics: Z decays and tests of the standard model; future possibilities for LEP; studies of the interactions of electroweak gauge bosons; top quark topics; the next linear collider; electroweak processes in hadron colliders; theoretical topics in B-physics; experimental aspects of B-physics; B-factory storage ring design; rare kaon decays; CP violation in K{sup 0} decays at CERN; recent K{sup 0} decay results from Fermilab E-731; results from LEP on heavy quark physics; review of recent results on heavy flavor production; weak matrix elements and the determination of the weak mixing angles; recent results from CLEO I and a glance at CLEO II data; recent results from ARGUS; neutrino lepton physics with the CHARM 2 detector; recent results from the three TRISTAN experiments; baryon number violation at high energy in the standard model: fact or fiction New particle searches at LEP; review of QCD at LEP; electroweak interactions at LEP; recent results on W physics from the UA2 experiment at the CERN {rho}{bar {rho}} collider; B physics at CDF; and review of particle astrophysics.

Hawthorne, J.F. (ed.)

1991-01-01T23:59:59.000Z

164

B to tau Leptonic and Semileptonic Decays  

Science Conference Proceedings (OSTI)

Decays of B mesons to states involving {tau} leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B {yields} {tau}{nu} and B {yields} D{sup (*)}{tau}{nu} is discussed, together with limits on new physics effects from current results. Leptonic and semileptonic decays of B mesons into states involving {tau} leptons remain experimentally challenging, but can prove a useful tool for constraining Standard Model parameters, and also offer to constrain the effects of any new physics that may exist including the presence of a charged Higgs boson.

Barrett, M.; /Brunel U.

2011-11-17T23:59:59.000Z

165

Solar neutrino detection  

SciTech Connect

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

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

2009-04-30T23:59:59.000Z

166

Solar neutrino detection  

E-Print Network (OSTI)

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

Lino Miramonti

2009-01-22T23:59:59.000Z

167

Spectroscopy of Solar Neutrinos  

E-Print Network (OSTI)

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

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

2010-04-06T23:59:59.000Z

168

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

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

F. Halzen; G. Jaczko

1996-02-07T23:59:59.000Z

169

NEUTRINOS, OLD AND NEW  

SciTech Connect

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

Reines, F.

1963-08-30T23:59:59.000Z

170

Neutrino Factory Feasibility Study  

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

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

171

Neutrino-nucleus interactions  

SciTech Connect

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

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

2011-01-01T23:59:59.000Z

172

Phenomenology of neutrino oscillations  

Science Conference Proceedings (OSTI)

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

173

Solar neutrino Research  

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

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

174

Lepton Flavor Violating Decays - Review & Outlook  

E-Print Network (OSTI)

Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric theories or other models beyond the Standard Model. In contrast to physics of quark flavors that is dominated by the Cabibbo-Kobayashi-Maskawa matrix, LFV in charged leptons is a definitive signal of new physics. Currently active researches are rare tau decay searches at the B factories. The MEG experiment will soon start a sensitive search for the LFV muon decay, mu to e gamma. Prospects for searches at the LHC, a possibility of a fixed target LFV experiment with high energy muons, and a sensitivity of leptonic kaon decays to LFV are also briefly discussed.

Toshinori Mori

2006-05-30T23:59:59.000Z

175

Heavy flavor production from photons and hadrons  

Science Conference Proceedings (OSTI)

The present state of the production and observation of hadrons containing heavy quarks or antiquarks as valence constituents, in reactions initiated by real and (space-like) virtual photon or by hadron beams is discussed. Heavy flavor production in e/sup +/e/sup -/ annihilation, which is well covered in a number of recent review papers is not discussed, and similarly, neutrino production is omitted due to the different (flavor-changing) mechanisms that are involved in those reactions. Heavy flavors from spacelike photons, heavy flavors from real photons, and heavy flavors from hadron-hadron collisions are discussed. (WHK)

Heusch, C.A.

1982-01-01T23:59:59.000Z

176

Exotic Leptons: Higgs, Flavor and Collider Phenomenology  

E-Print Network (OSTI)

We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h -> gamma gamma decay rate for new lepton masses in the 300 GeV - 1 TeV range. We analyze vaccum stability implications for different hypercharges. Effects in h -> Z gamma are typically much smaller than in h -> gamma gamma, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at the LHC, and find that signatures with multiple light leptons or taus are already probing interesting regions of parameter space.

Wolfgang Altmannshofer; Martin Bauer; Marcela Carena

2013-08-08T23:59:59.000Z

177

An SO(10)XS4 Model of Quark-Lepton Complementarity  

E-Print Network (OSTI)

The present observations of Cabbibo angle and solar mixing angle satisfy the empirical relation called Quark-Lepton Complementarity(QLC), namely $\\theta_{12}^l\\sim \\pi/4-\\theta_C$. It suggests the existence of correlation between quarks and leptons which is supported by the idea of grand unification. We propose a specific ansatz for the structure of Yukawa matrices in SO(10) unified theory which leads to such relation if neutrinos get masses through type-II seesaw mechanism. Viability of this ansatz is discussed through detailed analysis of fermion masses and mixing angles all of which can be explained in a model which uses three Higgs fields transforming as 10 and one transforming as $\\bar{126}$ representations under SO(10). It is shown that the proposed ansatz can be derived from an extended model based on the two pairs of 16-dimensional vector-like fermions and an $S_4$ flavor symmetry. The model leads to the lepton mixing matrix that is dominantly bimaximal with ${\\cal O}(\\theta_C)$ corrections related to quark mixing. A generic prediction of the model is the reactor angle $\\theta_{13}^l\\sim \\theta_C/\\sqrt{2}$ which is close to its present experimental upper bound.

Ketan M. Patel

2010-08-30T23:59:59.000Z

178

Perturbative generation of theta_{13} from tribimaximal neutrino mixing  

E-Print Network (OSTI)

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

Brahmachari, Biswajoy

2012-01-01T23:59:59.000Z

179

Large-Theta(13) Perturbation Theory of Neutrino Oscillation  

E-Print Network (OSTI)

Keeping in mind the possibility of large theta(13), which will be soon explored by reactor and accelerator experiments, I formulate a perturbation theory of neutrino oscillation under the ansatz, sin^2(theta_{13}) \\simeq Delta m^2_{21}/\\Delta m^2_{31} \\simeq 0.03, which is comparable to the Chooz limit. Under the framework, I derive the perturbative formula of the nu_{e} appearance probability valid to order \\epsilon^2 in which effects of arbitrary matter density profile is taken into account. I use the formula to analyze problem of possible obstruction to detecting lepton CP violation by effects of asymmetry in matter density profile. Though the asymmetry could be large for neutrino trajectories which traverse both continental and sea crust, its effect on obscuring CP violation measurement is found to be quite small.

Minakata, Hisakazu

2009-01-01T23:59:59.000Z

180

Large-Theta(13) Perturbation Theory of Neutrino Oscillation  

E-Print Network (OSTI)

Keeping in mind the possibility of large theta(13), which will be soon explored by reactor and accelerator experiments, I formulate a perturbation theory of neutrino oscillation under the ansatz, sin^2(theta_{13}) \\simeq Delta m^2_{21}/\\Delta m^2_{31} \\simeq 0.03, which is comparable to the Chooz limit. Under the framework, I derive the perturbative formula of the nu_{e} appearance probability valid to order \\epsilon^2 in which effects of arbitrary matter density profile is taken into account. I use the formula to analyze problem of possible obstruction to detecting lepton CP violation by effects of asymmetry in matter density profile. Though the asymmetry could be large for neutrino trajectories which traverse both continental and sea crust, its effect on obscuring CP violation measurement is found to be quite small.

Hisakazu Minakata

2009-10-29T23:59:59.000Z

Note: This page contains sample records for the topic "neutrinos heavy leptons" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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181

Monte Carlo Neutrino Oscillations  

E-Print Network (OSTI)

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

James P. Kneller; Gail C. McLaughlin

2005-09-29T23:59:59.000Z

182

Neutrino Counter Nuclear Weapon  

E-Print Network (OSTI)

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

Alfred Tang

2008-05-26T23:59:59.000Z

183

SNO Data: Results from Experiments at the Sudbury Neutrino Observatory  

DOE Data Explorer (OSTI)

The Sudbury Neutrino Observatory (SNO) was built 6800 feet under ground, in INCO's Creighton mine near Sudbury, Ontario. SNO is a heavy-water Cherenkov detector that is designed to detect neutrinos produced by fusion reactions in the sun. It uses 1000 tonnes of heavy water, on loan from Atomic Energy of Canada Limited (AECL), contained in a 12 meter diameter acrylic vessel. Neutrinos react with the heavy water (D2O) to produce flashes of light called Cherenkov radiation. This light is then detected by an array of 9600 photomultiplier tubes mounted on a geodesic support structure surrounding the heavy water vessel. The detector is immersed in light (normal) water within a 30 meter barrel-shaped cavity (the size of a 10 story building!) excavated from Norite rock. Located in the deepest part of the mine, the overburden of rock shields the detector from cosmic rays. The detector laboratory is extremely clean to reduce background signals from radioactive elements present in the mine dust which would otherwise hide the very weak signal from neutrinos. (From http://www.sno.phy.queensu.ca/]

The SNO website provides access to various datasets. See also the SNO Image Catalog at http://www.sno.phy.queensu.ca/sno/images/ and computer-generated images of SNO events at http://www.sno.phy.queensu.ca/sno/events/ and the list of published papers.

184

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

E-Print Network (OSTI)

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

Debasish Borah; Mrinal Kumar Das

2012-10-18T23:59:59.000Z

185

Determining Reactor Neutrino Flux  

E-Print Network (OSTI)

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

Cao, Jun

2011-01-01T23:59:59.000Z

186

Determining Reactor Neutrino Flux  

E-Print Network (OSTI)

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

Jun Cao

2011-01-12T23:59:59.000Z

187

Mass Hierarchy via Mossbauer and Reactor Neutrinos  

E-Print Network (OSTI)

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

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

2008-12-10T23:59:59.000Z

188

The Double Chooz reactor neutrino experiment  

E-Print Network (OSTI)

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

I. Gil-Botella

2007-10-23T23:59:59.000Z

189

Solar neutrinos: Probing the sun or neutrinos  

SciTech Connect

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

Wilkerson, J.F.

1991-01-01T23:59:59.000Z

190

Lepton flavour violating Higgs Boson decays, tau --> mu gamma and B(s) --> mu+mu- in the constrained MSSM+NR with large tan beta  

E-Print Network (OSTI)

Realistic predictions are made for the rates of lepton flavour violating Higgs boson decays, tau --> mu gamma, mu --> e gamma, Bs --> mu+mu-, Bs --> tau mu and tau --> 3mu, via a top-down analysis of the Minimal Supersymmetric Standard Model(MSSM) constrained by SU(5) unification with right-handed Neutrinos and large tan beta. The third family neutrino Yukawa coupling is chosen to be of order 1, in this way our model bares a significant resemblance to supersymmetric SO(10). In this framework the large PMNS mixings result in potentially large lepton flavour violation. Our analysis predicts tau --> mu gamma and mu --> e gamma rates in the region (10^{-8}-10^{-6}) and (10^{-15}-10^{-14}) respectively. We also show that the rates for lepton flavour violating Higgs decays can be as large as 10^{-7}. The non-decoupling nature of H --> tau mu is observed which leads to its decay rate becoming comparable to that for tau --> mu gamma for large values of m_0 and M_1/2. We also find that the present bound on Bs --> mu+mu- is an important constraint on the rate of lepton flavour violating Higgs decays. The recently measured Bs-Bsbar mixing parameter Delta Ms is also investigated.

J. K. Parry

2005-10-24T23:59:59.000Z

191

Exotic Leptons: Higgs, Flavor and Collider Phenomenology  

E-Print Network (OSTI)

We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h -> gamma gamma decay rate for new lepton masses in the 300 GeV - 1 TeV range. We analyze vaccum stability implications for different hypercharges. Effects in h -> Z gamma are typically much smaller than in h -> gamma gamma, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at...

Altmannshofer, Wolfgang; Carena, Marcela

2013-01-01T23:59:59.000Z

192

Review of Recent Neutrino Physics Research  

E-Print Network (OSTI)

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

Leonard S. Kisslinger

2013-06-17T23:59:59.000Z

193

Reactor Neutrino Experiments  

E-Print Network (OSTI)

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

Jun Cao

2007-12-06T23:59:59.000Z

194

Solar Neutrino Measurements  

E-Print Network (OSTI)

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

A. B. McDonald

2004-06-10T23:59:59.000Z

195

Low Energy Neutrino Measurements  

E-Print Network (OSTI)

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

Davide D'Angelo

2012-11-22T23:59:59.000Z

196

Leptogenesis with Dirac Neutrinos  

E-Print Network (OSTI)

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

Karin Dick; Manfred Lindner; Michael Ratz; David Wright

1999-07-30T23:59:59.000Z

197

A search for muon neutrino and antineutrino disappearance in the Booster Neutrino Beam  

SciTech Connect

This dissertation presents a search for {mu}{sub {nu}} and {bar {mu}{sub {nu}}} disappearance with the MiniBooNE experiment in the {Delta}m{sup 2} region of a few eV{sup 2}. Disappearance measurements in this oscillation region constrain sterile neutrino models and CPT violation in the lepton sector. Fits to the shape of the {mu}{sub {nu}} and {bar {mu}{sub {nu}}} energy spectra reveal no evidence for disappearance in either mode. This is the first test of {bar {mu}{sub {nu}}} disappearance between {Delta}m{sup 2} = 0:1 -- 10 eV2. In addition, prospects for performing a joint analysis using the SciBooNE detector in conjunction with MiniBooNE are discussed.

Mahn, Kendall Brianna McConnel; /Columbia U.

2009-04-01T23:59:59.000Z

198

DELAYED ONSET OF HIGH-ENERGY EMISSIONS IN LEPTONIC AND HADRONIC MODELS OF GAMMA-RAY BURSTS  

SciTech Connect

The temporal-spectral evolution of the prompt emission of gamma-ray bursts is simulated numerically for both leptonic and hadronic models. For weak enough magnetic fields, leptonic models can reproduce the few seconds delay of the onset of GeV photon emission observed by Fermi-LAT, due to the slow growth of the target photon field for inverse Compton scattering. For stronger magnetic fields, the GeV delay can be explained with hadronic models, due to the long acceleration timescale of protons and the continuous photopion production after the end of the particle injection. While the FWHMs of the MeV and GeV light curves are almost the same in one-zone leptonic models, the FWHMs of the 1-30 GeV light curves in hadronic models are significantly wider than those of the 0.1-1 MeV light curves. The amount of the GeV delay depends on the importance of the Klein-Nishina effect in both the leptonic and hadronic models. In our examples of hadronic models the energies of the escaped neutrons are comparable to the gamma-ray energy, although their contribution to the ultra high-energy cosmic rays is still subdominant. The resulting neutrino spectra are hard enough to avoid the flux limit constraint from IceCube. The delay of the neutrino emission onset is up to several times longer than the corresponding delay of the GeV photon emission onset. The quantitative differences in the light curves for various models may be further tested with future atmospheric Cerenkov telescopes whose effective area is larger than that of Fermi-LAT, such as CTA.

Asano, Katsuaki [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Meszaros, Peter, E-mail: asano@phys.titech.ac.jp, E-mail: nnp@astro.psu.edu [Department of Astronomy and Astrophysics, Department of Physics, Center for Particle and Gravitational Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2012-10-01T23:59:59.000Z

199

Limits on tau lepton flavor violating decays in three charged leptons  

SciTech Connect

A search for the neutrinoless, lepton-flavor violating decay of the {tau} lepton into three charged leptons has been performed using an integrated luminosity of 468 fb{sup -1} collected with the BABAR detector at the PEP-II collider. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1.8-3.3) x 10{sup -8} at 90% confidence level.

Cervelli, Alberto

2010-04-29T23:59:59.000Z

200

Lepton-Flavor Violation and Physics beyond the Standard Model  

E-Print Network (OSTI)

This talk discusses recent studies of (charged) lepton-flavor violation in physics beyond the standard model.

Junji Hisano

2012-12-20T23:59:59.000Z

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


201

Solar Neutrino Measurements  

E-Print Network (OSTI)

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

A. B. Mcdonald

2004-01-01T23:59:59.000Z

202

Fast Light, Fast Neutrinos?  

E-Print Network (OSTI)

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

Cahill, Kevin

2011-01-01T23:59:59.000Z

203

neutrino.html  

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

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

204

Neutrino-less Double Beta Decay of {sup 48}Ca-CANDLES  

Science Conference Proceedings (OSTI)

Neutrino-less double beta decay (0{nu}{beta}{beta}) is currently known to be an only experiment to verify whether lepton number is conserved or not. The lepton number non-conservation is the key to create matter dominated universe with CP violation. The so-called leptogenesys scenario presents a way to create the matter dominated universe by these violations. If neutrinos have Majorana mass, transition from a particle to an anti-particle is possible and the left-handed and right-handed neutrinos could have different masses. It is highly likely that the neutrinos are Majorana particles. We have been studying double beta decay of {sup 48}Ca. Our first stage experiment using the ELEGANT VI detector system gave the best lower limit of the half life of 0{nu}{beta}{beta} of {sup 48}Ca. We have been working on CANDLES detector system to sense much longer lifetime region. We have developed techniques to reduce backgrounds. The CADLES detector system was installed at Kamioka underground laboratory. Here I describe a schematic view of the system.

Kishimoto, T.; Nomachi, M. [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka Japan (Japan); Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka Ibaraki Osaka Japan (Japan); Yoshida, S.; Matsuoka, K.; Ichimura, K.; Ito, G.; Yasuda, K.; Kakubata, H.; Miyashita, M.; Takubo, K.; Saka, M.; Seki, K. [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka Japan (Japan); Ajimura, S.; Umehara, S.; Nakatani, N. [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka Ibaraki Osaka Japan (Japan); Tamagawa, Y.; Ogawa, I. [Graduate School of Engineering, University of Fukui,Fukui (Japan); Fushimi, K. [Faculty of Integrated Arts and Science, Tokushima University, Tokushima (Japan); Hazama, R. [Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Hiroshima (Japan); Ohsumi, H. [Faculty of Culture and Education, Saga University, Saga (Japan)

2011-10-21T23:59:59.000Z

205

European facilities for accelerator neutrino physics: perspectives for the decade to come  

E-Print Network (OSTI)

Very soon a new generation of reactor and accelerator neutrino oscillation experiments - Double Chooz, Daya Bay, Reno and T2K - will seek for oscillation signals generated by the mixing parameter theta_13. The knowledge of this angle is a fundamental milestone to optimize further experiments aimed at detecting CP violation in the neutrino sector. Leptonic CP violation is a key phenomenon that has profound implications in particle physics and cosmology but it is clearly out of reach for the aforementioned experiments. Since late 90's, a world-wide activity is in progress to design facilities that can access CP violation in neutrino oscillation and perform high precision measurements of the lepton counterpart of the Cabibbo-Kobayashi-Maskawa matrix. In this paper the status of these studies will be summarized, focusing on the options that are best suited to exploit existing European facilities (firstly CERN and the INFN Gran Sasso Laboratories) or technologies where Europe has a world leadership. Similar considerations will be developed in more exotic scenarios - beyond the standard framework of flavor oscillation among three active neutrinos - that might appear plausible in the occurrence of anomalous results from post-MiniBooNE experiments or the CNGS.

R. Battiston; M. Mezzetto; P. Migliozzi; F. Terranova

2009-12-17T23:59:59.000Z

206

SOLAR NEUTRINOS. II. EXPERIMENTAL  

SciTech Connect

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

Davis, R. Jr.

1964-03-16T23:59:59.000Z

207

Radiochemical solar neutrino experiments  

E-Print Network (OSTI)

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

V. N. Gavrin; B. T. Cleveland

2007-03-06T23:59:59.000Z

208

Spin Polarized Photons and Di-leptons from Axially Charged Plasma  

E-Print Network (OSTI)

Axial charge in a QCD plasma is P- and CP-odd. We propose and study P- and CP-odd observables in photon and di-lepton emissions from an axially charged QCD plasma, which may provide possible experimental evidences of axial charge fluctuation and triangle anomaly in the plasma created in heavy-ion collisions. Our observables measure spin alignments of the emitted photons and di-leptons, and are shown to be related to the imaginary part of chiral magnetic conductivity at finite frequency-momentum, which ultimately arises from the underlying triangle anomaly of the QCD plasma with a finite axial charge density. We present an exemplar computation of these observables in strongly coupled regime using AdS/CFT correspondence.

Kiminad A. Mamo; Ho-Ung Yee

2013-07-30T23:59:59.000Z

209

Spin Polarized Photons and Di-leptons from Axially Charged Plasma  

E-Print Network (OSTI)

Axial charge in a QCD plasma is P- and CP-odd. We propose and study P- and CP-odd observables in photon and di-lepton emissions from an axially charged QCD plasma, which may provide possible experimental evidences of axial charge fluctuation and triangle anomaly in the plasma created in heavy-ion collisions. Our observables measure spin alignments of the emitted photons and di-leptons, and are shown to be related to the imaginary part of chiral magnetic conductivity at finite frequency-momentum, which ultimately arises from the underlying triangle anomaly of the QCD plasma with a finite axial charge density. We present an exemplar computation of these observables in strongly coupled regime using AdS/CFT correspondence.

Mamo, Kiminad A

2013-01-01T23:59:59.000Z

210

Sterile Neutrino Fits to Short-Baseline Neutrino Oscillation Measurements  

E-Print Network (OSTI)

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

Conrad, J. M.

2013-01-01T23:59:59.000Z

211

High energy neutrino emission from the earliest gamma-ray bursts  

SciTech Connect

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

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

2011-05-15T23:59:59.000Z

212

Martin Perl and the Tau Lepton  

Office of Scientific and Technical Information (OSTI)

Martin Perl and the Tau Lepton Martin Perl and the Tau Lepton Resources with Additional Information 'Martin L. Perl, a professor at the Stanford Linear Accelerator Center (SLAC), [was] awarded the 1995 Nobel Prize in physics ... for his 1975 discovery of a new elementary particle known as the tau lepton. ... The tau lepton is a superheavy cousin of the electron, the carrier of electrical current in household appliances. The two particles are identical in all respects except that the tau is more than 3,500 times heavier than the electron and survives less than a trillionth of a second, whereas the electron is stable. Martin Perl Courtesy AIP Emilio Segrè Visual Archives, W.F. Meggers Gallery of Nobel Laureates In the mid-1970s, working at the Stanford Positron-Electron Asymmetric Ring (SPEAR) in collaboration with 30 other physicists from SLAC and Lawrence Berkeley National Laboratory, Perl began to find events recorded by the detector that could not be explained by any of the known subatomic particles. After more than a year of analysis, Perl was able to convince the rest of his research team that they were in fact observing a new and different type of elementary particle, which he named the 'tau'.

213

How do Uncertainties in the Surface Chemical Abundances of the Sun Affect the Predicted Solar Neutrino Fluxes?  

E-Print Network (OSTI)

We show that uncertainties in the values of the surface heavy element abundances of the Sun are the largest source of the theoretical uncertainty in calculating the p-p, pep, 8B, 13N, 15O, and 17F solar neutrino fluxes. We evaluate for the first time the sensitivity (partial derivative) of each solar neutrino flux with respect to the surface abundance of each element. We then calculate the uncertainties in each neutrino flux using `conservative (preferred)' and `optimistic' estimates for the uncertainties in the element abundances. The total conservative (optimistic) composition uncertainty in the predicted 8B neutrino flux is 11.6% (5.0%) when sensitivities to individual element abundances are used. The traditional method that lumps all abundances into a single quantity (total heavy element to hydrogen ratio, Z/X) yields a larger uncertainty, 20%. The uncertainties in the carbon, oxygen, neon, silicon, sulphur, and iron abundances all make significant contributions to the uncertainties in calculating solar neutrino fluxes; the uncertainties of different elements are most important for different neutrino fluxes. The uncertainty in the iron abundance is the largest source of the estimated composition uncertainties of the important 7Be and 8B solar neutrinos. Carbon is the largest contributor to the uncertainty in the calculation of the p-p, 13N, and 15O neutrino fluxes. However, for all neutrino fluxes, several elements contribute comparable amounts to the total composition uncertainty.

John N. Bahcall; Aldo M. Serenelli

2004-12-03T23:59:59.000Z

214

Determining the neutrino mass hierarchy  

Science Conference Proceedings (OSTI)

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

Parke, Stephen J.; /Fermilab

2006-07-01T23:59:59.000Z

215

Neutrinos: Windows to New Physics  

E-Print Network (OSTI)

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

R. D. Peccei

2006-09-20T23:59:59.000Z

216

Solar Neutrino Matter Effects Redux  

E-Print Network (OSTI)

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

A. B. Balantekin; A. Malkus

2011-09-24T23:59:59.000Z

217

s025.dvi  

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

Charged Lepton Searches Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Sequential Charged Heavy...

218

Radiative inverse seesaw neutrino mass and dark matter  

SciTech Connect

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

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

2013-05-23T23:59:59.000Z

219

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

E-Print Network (OSTI)

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

A. Ioannisian; J. W. F. Valle

1999-11-14T23:59:59.000Z

220

Neutrino Oscillations and Blazars  

E-Print Network (OSTI)

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

Karl Mannheim

1998-12-22T23:59:59.000Z

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


221

Neutrino Oscillations and Blazars  

E-Print Network (OSTI)

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

Karl Mannheim

1999-01-01T23:59:59.000Z

222

Cosmic coincidences and relic neutrinos  

E-Print Network (OSTI)

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

R. Horvat

2006-12-04T23:59:59.000Z

223

Test of lepton universality and search for lepton flavor violation in Upsilon(1S,2S,3S) decays at CLEO  

E-Print Network (OSTI)

We present the analysis technique and preliminary results of two ongoing analyses at CLEO which put lepton universality and lepton flavor conservation to the test in Upsilon decays.

Istvan Danko; for the CLEO Collaboration

2006-01-18T23:59:59.000Z

224

Particle Data Group - 2012 Particle Listings  

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

Cut-off date for this update was January 15, 2012. Cut-off date for this update was January 15, 2012. GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-), Searches for Heavy Bosons, Other Than Higgs Bosons, Searches for (rev.) Axions (A0) and Other Very Light Bosons, Searches for (rev.) Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings (rev.) Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay (rev.) Introduction to Three-Neutrino Mixing Parameters Listings Neutrino Mixing (rev.) Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...) Note on the Quark Masses (rev.)

225

Particle Data Group - 2008 Particle Listings  

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

GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-), Searches for Heavy Bosons, Other Than Higgs Bosons, Searches for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay Neutrino Mixing Solar Neutrinos Review Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...) Note on the Quark Masses LIGHT QUARKS --- u, d, s c quark b quark t quark b' quark (4**th Generation) t' quark (4**th Generation) Free Quark Searches

226

Particle Data Group - 2013 Particle Listings  

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

. . and 2013 partial update for the 2014 edition. Cut-off date for this update was January 15, 2013. GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-) Heavy Bosons, Other Than Higgs Bosons, Searches for (rev.) Axions (A0) and Other Very Light Bosons, Searches for (rev.) Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings (rev.) Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay (rev.) Introduction to Three-Neutrino Mixing Parameters Listings Neutrino Mixing (rev.) Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...)

227

Particle Data Group - 2010 Particle Listings  

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

GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-), Searches for Heavy Bosons, Other Than Higgs Bosons, Searches for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay Introduction to Three-Neutrino Mixing Parameters Listings Neutrino Mixing Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...) Note on the Quark Masses LIGHT QUARKS --- u, d, s c quark b quark t quark b' quark (4**th Generation)

228

Frederick Reines and the Neutrino  

Office of Scientific and Technical Information (OSTI)

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

229

New Results on Solar Neutrinos  

E-Print Network (OSTI)

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

Alain Bellerive

2010-12-11T23:59:59.000Z

230

New Results on Solar Neutrinos  

E-Print Network (OSTI)

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

Bellerive, Alain

2010-01-01T23:59:59.000Z

231

Flavor Physics Data from the Heavy Flavor Averaging Group (HFAG)  

DOE Data Explorer (OSTI)

The Heavy Flavor Averaging Group (HFAG) was established at the May 2002 Flavor Physics and CP Violation Conference in Philadelphia, and continues the LEP Heavy Flavor Steering Group's tradition of providing regular updates to the world averages of heavy flavor quantities. Data are provided by six subgroups that each focus on a different set of heavy flavor measurements: B lifetimes and oscillation parameters, Semi-leptonic B decays, Rare B decays, Unitarity triangle parameters, B decays to charm final states, and Charm Physics.

Heavy Flavor Averaging Group (HFAG)

232

Signals, backgrounds and calibrations in the Sudbury Neutrino Observatory  

Science Conference Proceedings (OSTI)

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

Bhaskar Sur; The SNO Collaboration

1995-01-01T23:59:59.000Z

233

New Neutrinos Algal Biofuels  

E-Print Network (OSTI)

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

234

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

E-Print Network (OSTI)

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

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

2013-07-23T23:59:59.000Z

235

Nuclear Effects in Deep Inelastic Scattering of Charged-Current Neutrino off Nuclear  

E-Print Network (OSTI)

Nuclear effect in the neutrino-nucleus charged-Current inelastic scattering process is studied by analyzing the CCFR and NuTeV data. Structure functions $F_2(x,Q^2)$ and $xF_3(x,Q^2)$ as well as differential cross sections are calculated by using CTEQ parton distribution functions and EKRS and HKN nuclear parton distribution functions, and compared with the CCFR and NuTeV data. It is found that the corrections of nuclear effect to the differential cross section for the charged-current anti-neutrino scattering on nucleus are negligible, the EMC effect exists in the neutrino structure function $F_2(x,Q^2)$ in the large $x$ region, the shadowing and anti-shadowing effect occurs in the distribution functions of valence quarks in the small and medium $x$ region,respectively. It is also found that shadowing effects on $F_2(x,Q^2)$ in the small $x$ region in the neutrino-nucleus and the charged-lepton-nucleus deep inelastic scattering processes are different. It is clear that the neutrino-nucleus deep inelastic scattering data should further be employed in restricting nuclear parton distributions.

Duan ChunGui; Li GuangLie; Shen PengNian

2006-04-18T23:59:59.000Z

236

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

E-Print Network (OSTI)

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

Barry, James; Zhang, He

2011-01-01T23:59:59.000Z

237

Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector  

SciTech Connect

We present the search for the lepton flavour violating decay {tau} {yields} lK{sup 0}{sub s} with the BaBar experiment data. This process and many other lepton flavour violating {tau} decays, like {tau} {yields} {mu}{gamma} and {tau} {yields} lll, are one of the most promising channel to search for evidence of new physics. According to the Standard Model and the neutrino mixing parameters, branching fractions are estimated well below 10{sup -14}, but many models of new physics allow for branching fractions values close to the present experimental sensitivity. This analysis is based on a data sample of 469fb{sup -1} collected by BABAR detector at the PEP-II storage ring from 1999 to 2007, equivalent to 431 millions of {tau} pairs. the BABAR experiment, initially designed for studying CP violation in B mesons, has demonstrated to be one of the most suitable environments for studying {tau} decays. The tracking system, the calorimeter and the particle identification of BABAR, together with the knowledge of the {tau} initial energy, allow an extremely powerful rejection of background events that, for this analysis, is better than 10{sup -9}. Being {tau} {yields} lK{sup 0}{sub s} a decay mode without neutrinos, the signal {tau} decay can be fully reconstructed. Kinematical constraints are used in a fit that provides a decay tree reconstruction with a high resolution. For this analysis MC simulated events play a decisive role for estimating the signal efficiency and study the residual background. High statistics MC sample are produced simulating detector conditions for different periods of data collection, in order to reduce any discrepancies with the data. When discrepancies can not be removed, we perform studies to compute a correction factor or an estimation of systematic errors that need to be included in the final measurement. A significant improvement of the current result can be reached only with a higher statistics and, therefore, with a new collider providing a luminosity from 10 to 100 times more than PEP-II. A new detector, with improved performance and able to collect data in a high background environment, is also requested to fully exploit the capability of such amount of data. In fact, only keeping the efficiency and the background as similar as possible to present ones, we will be able to scale almost linearly the estimated upper limit according to the luminosity. The strong potential of improvement for the search of lepton flavour violation {tau} decays makes the building of such a machine highly desirable.

Cenci, Riccardo; /SLAC

2009-03-20T23:59:59.000Z

238

Four-Lepton Resonance at the Large Hadron Collider  

E-Print Network (OSTI)

A spin-1 weakly interacting vector boson, Z', is predicted by many new physics theories. Searches at colliders for such a Z' resonance typically focus on lepton-antilepton or top-antitop events. Here we present a novel channel with a Z' resonance that decays to 4 leptons, but not to 2 leptons, and discuss its possible discovery at the Large Hadron Collider. This baryonic gauge boson is well motivated in a supersymmetry framework.

Vernon Barger; Hye-Sung Lee

2011-11-02T23:59:59.000Z

239

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

Office of Scientific and Technical Information (OSTI)

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

240

Precision Solar Neutrino Measurements with the Sudbury Neutrino Observatory  

Science Conference Proceedings (OSTI)

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

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

2007-10-26T23:59:59.000Z

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241

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

E-Print Network (OSTI)

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

He, Hong-Jian

2012-01-01T23:59:59.000Z

242

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

E-Print Network (OSTI)

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

Hong-Jian He; Xun-Jie Xu

2012-03-13T23:59:59.000Z

243

On the Detection of the Free Neutrino  

DOE R&D Accomplishments (OSTI)

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

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

1953-08-06T23:59:59.000Z

244

Solar neutrino experiments: An update  

Science Conference Proceedings (OSTI)

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

Hahn, R.L.

1993-12-31T23:59:59.000Z

245

Low-energy solar anti-neutrinos  

E-Print Network (OSTI)

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

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

1998-08-13T23:59:59.000Z

246

Light Sterile Neutrinos: A White Paper  

E-Print Network (OSTI)

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

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

2012-04-18T23:59:59.000Z

247

Neutrino Opacities in Nuclear Matter  

E-Print Network (OSTI)

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

Adam Burrows; Sanjay Reddy; Todd A. Thompson

2004-04-21T23:59:59.000Z

248

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

E-Print Network (OSTI)

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

Wei Chao; Michael J. Ramsey-Musolf

2012-12-22T23:59:59.000Z

249

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

E-Print Network (OSTI)

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

Cheng, K S

2010-01-01T23:59:59.000Z

250

Searching for new physics in events with three leptons in ATLAS  

E-Print Network (OSTI)

We investigate the potential of the ATLAS detector to discover trilepton final state signatures from decays of supersymmetric particles at the LHC. An inclusive and an exclusive trilepton search have been conducted for a range of different mSUGRA scenarios, in the focus point region, in the bulk region, and at the edge of the current experimental limits on SUSY. It is found that a simple inclusive selection, based on the presence of three leptons and at least one high-$p_T$ jet in the final state, has the potential to be an excellent candidate for an early physics programme at the LHC. The exclusive trilepton selection, optimised for the focus point region, relies on stringent lepton track isolation and also includes cuts on variables such as transverse missing energy and on the hadronic activity in the event. In a heavy SUSY scenario, where all scalar and coloured sparticles may be too heavy to be observed at the LHC, hadronically quiet trilepton final states could be amongst the few accessible channels to d...

Potter, C

2009-01-01T23:59:59.000Z

251

Does DaYa-Bay Reactor Play an Important Role in Theta_{13} of Lepton Mixing (PMNS) Matrix ?  

E-Print Network (OSTI)

Reactor neutrinos play an important role in determining parameter theta_{13} in the lepton mixing (PMNS) matrix. Next important step on measuring PMNS matrix could be to build another reactor neutrino experiment in DaYa bay, China, to search the possible oscillations via sin^2 (2theta_{13}) and Delta m^2_{13}. We consider 4 different schemes for positions of three 8-ton detectors of this experiment, and simulate the results with respect to an array of assumed ''true'' values of physics parameters. Using three kinds of analysis method, we suggest a best scheme for DaYa-Bay which is to place a detector 2200m ~ 2500m symmetrically away from two reactors, and to put the other two detectors closer to their corresponding reactors respectively, almost at a 100m \\~ 200m distance. Moreover, with conservative assumption on the experimental technique, we construct series of allowed regions from our simulation results, and give detailed explanations therein. The movable detectors in DaYa-Bay can measure solar neutrino pa...

Liu, Q Y; Chen, B L; Yang, P

2004-01-01T23:59:59.000Z

252

Limits on Neutrino-Neutrino Scattering in the Early Universe  

E-Print Network (OSTI)

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

Francis-Yan Cyr-Racine; Kris Sigurdson

2013-06-06T23:59:59.000Z

253

Neutrino Factory Feasibility Study  

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

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

254

Neutrino Oscillations and Blazars  

E-Print Network (OSTI)

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

Mannheim, K

1999-01-01T23:59:59.000Z

255

Predictions for the Cosmogenic Neutrino Flux in Light of New Data from the Pierre Auger Observatory  

E-Print Network (OSTI)

The Pierre Auger Observatory (PAO) has measured the spectrum and composition of the ultrahigh energy cosmic rays with unprecedented precision. We use these measurements to constrain their spectrum and composition as injected from their sources and, in turn, use these results to estimate the spectrum of cosmogenic neutrinos generated in their propagation through intergalactic space. We find that the PAO measurements can be well fit if the injected cosmic rays consist entirely of nuclei with masses in the intermediate (C, N, O) to heavy (Fe, Si) range. A mixture of protons and heavier species is also acceptable but (on the basis of existing hadronic interaction models) injection of pure light nuclei (p, He) results in unacceptable fits to the new elongation rate data. The expected spectrum of cosmogenic neutrinos can vary considerably, depending on the precise spectrum and chemical composition injected from the cosmic ray sources. In the models where heavy nuclei dominate the cosmic ray spectrum and few dissociated protons exceed GZK energies, the cosmogenic neutrino flux can be suppressed by up to two orders of magnitude relative to the all-proton prediction, making its detection beyond the reach of current and planned neutrino telescopes. Other models consistent with the data, however, are proton-dominated with only a small (1-10%) admixture of heavy nuclei and predict an associated cosmogenic flux within the reach of upcoming experiments. Thus a detection or non-detection of cosmogenic neutrinos can assist in discriminating between these possibilities.

Luis A. Anchordoqui; Haim Goldberg; Dan Hooper; Subir Sarkar; Andrew M. Taylor

2007-09-05T23:59:59.000Z

256

Measurement of tau lepton branching fractions  

SciTech Connect

We present {tau}{sup {minus}} lepton branching fraction measurements based on data from the TPC/Two-Gamma detector at PEP. Using a sample of{tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} events, we examine the resonance structure of the K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} system and obtain the first measurements of branching fractions for {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1270) and {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1400). We also describe a complete set of branching fraction measurements in which all the decays of the {tau}{sup {minus}} lepton are separated into classes defined by the identities of the charged particles and an estimate of the number of neutrals. This is the first such global measurement with decay classes defined by the four possible charged particle species, e, {mu}, {pi}, and K.

Nicol, N.A.

1993-09-30T23:59:59.000Z

257

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

Science Conference Proceedings (OSTI)

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

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

2013-05-23T23:59:59.000Z

258

Historic Sudbury Neutrino Observatory Data, Carried by ESnet, Lives on at  

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

Historic Sudbury Historic Sudbury Neutrino Observatory Data, Carried by ESnet, Lives on at NERSC Historic Sudbury Neutrino Observatory Data, Carried by ESnet, Lives on at NERSC January 26, 2010 | Tags: Astrophysics Contact: Linda Vu, lvu@lbl.gov, +1 510 486 2402 SNO.jpg SNO onsists of an 18-meters-in-diameter stainless steel geodesic sphere inside of which is an acrylic vessel filled with 1000 tons of heavy water (deuterium oxide or D2O). Attached to the sphere are 9,522 ultra-sensitive light-sensors called photomultiplier tubes. When neutrinos passing through the heavy water interact with deuterium nuclei, flashes of light are emitted. The photomultiplier tubes detect these light flashes and convert them into electronic signals that scientists can analyze for the presence

259

Geomagnetic Effects on Atmospheric Neutrinos  

E-Print Network (OSTI)

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

Paolo Lipari; T. K. Gaisser; Todor Stanev

1998-03-09T23:59:59.000Z

260

Solar Hydrogen Burning and Neutrinos  

E-Print Network (OSTI)

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

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

2005-01-10T23:59:59.000Z

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


261

Off-shell OPERA neutrinos  

E-Print Network (OSTI)

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

Tim R. Morris

2011-10-14T23:59:59.000Z

262

Observation of Geo-Neutrinos  

E-Print Network (OSTI)

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

Borexino Collaboration

2010-03-01T23:59:59.000Z

263

Staggered Chiral Perturbation Theory for All-Staggered Heavy-Light Mesons  

E-Print Network (OSTI)

In HISQ simulations by the MILC and Fermilab Lattice collaborations, both the light quarks and the charm quark are staggered. We extend staggered chiral perturbation theory (\\schpt) to include such all-staggered heavy-light mesons. We assume that the heavy quark action is sufficiently improved that we may take $a m_Q >\\Lambda_{QCD}$ so that a continuum heavy quark expansion is appropriate. Using this \\schpt, the leptonic decay constant of the heavy-light meson is calculated at next-to-leading-order. The pattern of taste splittings in the heavy-light meson masses is also investigated.

Javad Komijani; Claude Bernard

2012-11-05T23:59:59.000Z

264

Review of Solar Neutrino Experiments  

E-Print Network (OSTI)

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

Alain Bellerive

2003-12-16T23:59:59.000Z

265

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

Office of Science (SC) Website

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

266

ON THE REQUIREMENTS FOR REALISTIC MODELING OF NEUTRINO TRANSPORT IN SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE  

SciTech Connect

We have conducted a series of numerical experiments with the spherically symmetric, general relativistic, neutrino radiation hydrodynamics code AGILE-BOLTZTRAN to examine the effects of several approximations used in multidimensional core-collapse supernova simulations. Our code permits us to examine the effects of these approximations quantitatively by removing, or substituting for, the pieces of supernova physics of interest. These approximations include: (1) using Newtonian versus general relativistic gravity, hydrodynamics, and transport; (2) using a reduced set of weak interactions, including the omission of non-isoenergetic neutrino scattering, versus the current state-of-the-art; and (3) omitting the velocity-dependent terms, or observer corrections, from the neutrino Boltzmann kinetic equation. We demonstrate that each of these changes has noticeable effects on the outcomes of our simulations. Of these, we find that the omission of observer corrections is particularly detrimental to the potential for neutrino-driven explosions and exhibits a failure to conserve lepton number. Finally, we discuss the impact of these results on our understanding of current, and the requirements for future, multidimensional models.

Lentz, Eric J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Mezzacappa, Anthony; Hix, W. Raphael [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Messer, O. E. Bronson [Computer Science and Mathematics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Liebendoerfer, Matthias [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Bruenn, Stephen W., E-mail: elentz@utk.edu, E-mail: mezzacappaa@ornl.gov [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States)

2012-03-01T23:59:59.000Z

267

Almost Degenerate Neutrinos with Maximal Mixing  

E-Print Network (OSTI)

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

R. N. Mohapatra; S. Nussinov

1994-11-11T23:59:59.000Z

268

Electronic branching ratio of the. tau. lepton  

Science Conference Proceedings (OSTI)

Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio {ital R}={Gamma}({tau}{r arrow}{ital e}{bar {nu}}{sub {ital e}}{nu}{sub {tau}})/{Gamma}{sub 1}, where {Gamma}{sub 1} is the {tau} decay rate to final states with one charged particle. We find {ital R}=0.2231{plus minus}0.0044{plus minus}0.0073 where the first error is statistical and the second is systematic. Together with the measured topological one-charged-particle branching fraction, this yields the branching fraction of the {tau} lepton to electrons, {ital B}{sub {ital e}}=0.192{plus minus}0.004{plus minus}0.006.

Ammar, R.; Baringer, P.; Coppage, D.; Davis, R.; Kelly, M.; Kwak, N.; Lam, H.; Ro, S.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Perticone, D.; Poling, R.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; Romero, V.; Sun, C.R.; Wang, P.; Zoeller, M.M.; Crawford, G.; Fulton, R.; Gan, K.K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Sung, M.K.; Whitmore, J.; Wilson, P.; Butler, F.; Fu, X.; Kalbfleisch, G.; Lambrecht, M.; Skubic, P.; Snow, J.; Wang, P.; Bortoletto, D.; Brown, D.N.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Modesitt, M.; Shibata, E.I.; Schaffner, S.F.; Shipsey, I.P.J.; Battle, M.; Ernst, J.; Kroha, H.; Roberts, S.; Sparks, K.; Thorndike, E.H.; Wang, C.; Stroynowski, R.; Artuso, M.; Goldberg, M.; Haupt, T.; Horwitz, N.; Kennett, R.; Moneti, G.C.; Playfer, S.; Rozen, Y.; Rubin, P.; Skwarnicki, T.; Stone, S.; Thulasidas, M.; Yao, W.; Zhu, G.; Barnes, A.V.; Bartelt, J.; Csorna, S.E.; Jain, V.; Letson, T.; Mestayer, M.D.; Akerib, D.S.; Barish, B.; Chadha, M.; (CLEO Collaboration)

1992-06-01T23:59:59.000Z

269

Solar Neutrinos: Status and Prospects  

E-Print Network (OSTI)

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

Robertson, W C Haxton R G Hamish

2012-01-01T23:59:59.000Z

270

High-energy atmospheric neutrinos  

E-Print Network (OSTI)

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

Sinegovsky, S I; Sinegovskaya, T S

2010-01-01T23:59:59.000Z

271

Measurement of the top quark mass in $p \\bar{p}$ collisions using events with two leptons  

Science Conference Proceedings (OSTI)

We present a measurement of the top quark mass (m{sub t}) in p{bar p} collisions at {radical}s = 1.96 TeV using t{bar t} events with two leptons (ee, e{mu} or {mu}{mu}) in the final state in 4.3 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider. We analyze the kinematically underconstrained dilepton events by integrating over the neutrino rapidity distributions. We reduce the dominant systematic uncertainties from jet energy calibration using a correction obtained from t{bar t} {yields} {ell} + jets events. We also correct jets in simulated events to replicate the quark flavor dependence of the jet response in data. In combination with our previous analysis, we measure m{sub t} = 174.0 {+-} 2.4(stat) {+-} 1.4(syst) GeV.

Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Aoki, Masato; /Fermilab; Askew, Andrew Warren; /Florida State U. /Stockholm U.

2012-01-01T23:59:59.000Z

272

High-energy atmospheric neutrinos  

E-Print Network (OSTI)

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

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

2010-10-12T23:59:59.000Z

273

Neutrinos in Cosmology and Astrophysics  

E-Print Network (OSTI)

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

A. B. Balantekin; G. M. Fuller

2013-03-15T23:59:59.000Z

274

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

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

Marino, Alysia Diane

2004-01-01T23:59:59.000Z

275

The neutrino process and neutrino r-process  

SciTech Connect

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

Haxton, W.C.

1991-01-01T23:59:59.000Z

276

The neutrino process and neutrino r-process  

SciTech Connect

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

Haxton, W.C.

1991-12-31T23:59:59.000Z

277

Constraining neutrino magnetic moment with solar and reactor neutrino data  

E-Print Network (OSTI)

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

M. A. Tortola

2004-01-19T23:59:59.000Z

278

Evidence for neutrino oscillations in the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

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

Marino, Alysia Diane

2004-01-01T23:59:59.000Z

279

Neutrino mass hierarchy extraction using atmospheric neutrinos in ice  

E-Print Network (OSTI)

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

Olga Mena; Irina Mocioiu; Soebur Razzaque

2008-03-20T23:59:59.000Z

280

SLAC National Accelerator Laboratory - Lepton-Photon Conference...  

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

was still the biggest news at this year's Lepton-Photon: the discovery of a Higgs boson at CERN's Large Hadron Collider. Progress has been made in the past year: The new...

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281

Phenomenological constraints on minimally coupled exotic lepton triplets  

Science Conference Proceedings (OSTI)

By introducing a set of new triplet leptons (with nonzero hypercharge) that can Yukawa couple to their standard model counterparts, new sources of tree-level flavor changing currents are induced via mixing. In this work, we study some of the consequences of such new contributions on processes such as the leptonic decays of gauge bosons, l{yields}3l{sup '} and l{yields}l{sup '{gamma}}, which violate lepton flavor, and {mu}-e conversion in atomic nuclei. Constraints are then placed on the parameters associated with the exotic triplets by invoking the current low-energy experimental data. Moreover, the new physics contribution to the lepton anomalous magnetic moments is calculated.

Chua, Chun-Khiang; Law, Sandy S. C. [Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan 320 (China)

2011-03-01T23:59:59.000Z

282

Light Vector Meson Photoproduction off of H at Jefferson Lab and rho-omega Interference in the Leptonic Decay Channel  

SciTech Connect

Recent studies of light vector meson production in heavy nuclear targets has generated interest in {rho}-{omega} interference in the leptonic e{sup +}e{sup -} decay channel. An experimental study of the elementary process provides valuable input for theoretical models and calculations. In experiment E04-005 (g12), high statistics photoproduction data has been taken in Jefferson Lab's Hall B with the Cebaf Large Acceptance Spectrometer (CLAS). The invariant mass spectrum is fitted with two interfering relativistic Breit-Wigner functions to determine the interference phase. Preliminary analysis indicate a measurable {rho}-{omega} interference.

Chaden Djalali

2011-12-01T23:59:59.000Z

283

The small mixing angle {theta}13 and the lepton asymmetry  

SciTech Connect

We present the correlation of low energy CP phases, and the lepton asymmetry for the baryon asymmetry in the universe, for cases in which the amount of the lepton asymmetry YL turns out to be proportional to {theta}{sub 13}{sup 2}, considering the constraint between two types of CP phases and the relation of YL versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as {theta}13 varies.

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

2005-12-02T23:59:59.000Z

284

Neutrinos interacting with Polarizable Media  

E-Print Network (OSTI)

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

W. Grimus; H. Neufeld

1994-10-20T23:59:59.000Z

285

Neutrino capital of the world  

E-Print Network (OSTI)

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

Johnson, Carolyn Y., 1980-

2004-01-01T23:59:59.000Z

286

The Fermilab neutrino beam program  

Science Conference Proceedings (OSTI)

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

Rameika, Regina A.; /Fermilab

2007-01-01T23:59:59.000Z

287

Probing Radiative Solar Neutrinos Decays  

E-Print Network (OSTI)

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

Frre, J M

1998-01-01T23:59:59.000Z

288

Solar Neutrinos: Status and Prospects  

E-Print Network (OSTI)

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

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

2012-08-28T23:59:59.000Z

289

Solar mass-varying neutrino oscillations  

E-Print Network (OSTI)

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

V. Barger; Patrick Huber; Danny Marfatia

2005-02-21T23:59:59.000Z

290

Masatoshi Koshiba and Cosmic Neutrinos  

Office of Scientific and Technical Information (OSTI)

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

291

Synchrotron radiation by fast fermions in heavy-ion collisions  

SciTech Connect

We study the synchrotron radiation of gluons by fast quarks in strong magnetic field produced by colliding relativistic heavy ions. We argue that due to high electric conductivity of plasma, the magnetic field is almost constant during the entire plasma lifetime. We calculate the energy loss due to synchrotron radiation of gluons by fast quarks. We find that the typical energy loss per unit length for a light quark at the Large Hadron Collider is a few GeV per fm. This effect alone predicts quenching of jets with p{sub perpendicular} up to about 20 GeV. We also show that the spin-flip transition effect accompanying the synchrotron radiation leads to a strong polarization of quarks and leptons with respect to the direction of the magnetic field. Observation of the lepton polarization may provide a direct evidence of existence of strong magnetic field in heavy-ion collisions.

Tuchin, Kirill [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States) and RIKEN BNL Research Center, Upton, New York 11973-5000 (United States)

2010-09-15T23:59:59.000Z

292

Atmospheric Neutrinos in the MINOS Far Detector  

Science Conference Proceedings (OSTI)

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

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

2004-12-01T23:59:59.000Z

293

Neutrino factories: realization and physics potential  

SciTech Connect

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

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

2006-12-01T23:59:59.000Z

294

Solar Neutrino Oscillation Parameters in Experiments with Reactor Anti-Neutrinos  

E-Print Network (OSTI)

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

Sandhya Choubey

2004-02-27T23:59:59.000Z

295

Supersymmetry Breaks Itself for Quarks and Leptons in the SUSY Standard Model  

E-Print Network (OSTI)

Models like the Supersymmetric Standard Model (SSM) possess simple, but well-hidden, `Outfields'. These Outfields are composite operators that violate superspace invariance, but in a special way. A new mechanism for SUSY breaking arises from the Outfields, for a special non-minimal version of the SSM, which will be called the CSSM. The CSSM has right neutrinos and a Higgs singlet, which we call J, in addition to the usual SSM. This breaking of SUSY cannot be avoided, because it arises from the local BRST cohomology of the theory, which is also the origin of the Outfields. It can also be seen that the Weak SU(2) group, and the well-known remarkable set of doublets and singlets for the Quarks, Leptons and Higgs, have a raison d'etre which relates to this mechanism. The SUSY breaking here depends on only one parameter, which is the VEV that breaks SU(2) X U(1) to U(1). SUSY itself is not spontaneously broken here, so the vacuum energy remains zero after SUSY breaking. The resulting predictions for SUSY breaking are very constrained by the model.

John A. Dixon

2010-12-21T23:59:59.000Z

296

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

DOE R&D Accomplishments (OSTI)

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

Cooper, N. G. [ed.

1997-00-00T23:59:59.000Z

297

Measurement of theta13 with reactor neutrinos  

E-Print Network (OSTI)

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

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

2004-01-01T23:59:59.000Z

298

Solar Neutrinos: Models, Observations, and New Opportunities  

E-Print Network (OSTI)

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

W. C. Haxton

2007-10-11T23:59:59.000Z

299

Neutrino mixing, flavor states and dark energy  

E-Print Network (OSTI)

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

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

2007-11-06T23:59:59.000Z

300

Solar neutrinos with three flavor mixings  

SciTech Connect

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

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

1992-12-31T23:59:59.000Z

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


301

Solar neutrinos with three flavor mixings  

SciTech Connect

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

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

1992-01-01T23:59:59.000Z

302

Atmospheric neutrino flux at INO site  

Science Conference Proceedings (OSTI)

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

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

2011-11-23T23:59:59.000Z

303

Neutrino magnetic moment in a magnetized plasma  

E-Print Network (OSTI)

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

N. V. Mikheev; E. N. Narynskaya

2010-11-08T23:59:59.000Z

304

On Ultrahigh-energy Neutrino Scattering  

E-Print Network (OSTI)

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

Kuroda, Masaaki

2013-01-01T23:59:59.000Z

305

Dark energy induced by neutrino mixing  

E-Print Network (OSTI)

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

Antonio Capolupo; Salvatore Capozziello; Giuseppe Vitiello

2006-12-05T23:59:59.000Z

306

The Lake Baikal neutrino experiment: selected results  

E-Print Network (OSTI)

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

BAIKAL Collaboration; V. Balkanov

2000-01-10T23:59:59.000Z

307

Neutrino Masses and Oscillations: Triumphs and Challenges  

E-Print Network (OSTI)

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

R. D. McKeown; P. Vogel

2004-02-03T23:59:59.000Z

308

Solar Neutrinos with Super-Kamiokande  

E-Print Network (OSTI)

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

Smy, M B

1999-01-01T23:59:59.000Z

309

Neutrino properties from reactor and accelerator experiments  

E-Print Network (OSTI)

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

Pal, P B

1998-01-01T23:59:59.000Z

310

Neutrinos and Non-proliferation in Europe  

E-Print Network (OSTI)

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

Cribier, Michel

2006-01-01T23:59:59.000Z

311

SOLAR NEUTRINOS: WHERE WE ARE JOHN BAHCALL  

E-Print Network (OSTI)

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

Bahcall, John

312

Neutrino oscillations present status and outlook  

E-Print Network (OSTI)

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

Schwetz, Thomas

2008-01-01T23:59:59.000Z

313

Neutrino oscillations: present status and outlook  

E-Print Network (OSTI)

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

Thomas Schwetz

2007-10-26T23:59:59.000Z

314

Neutrino oscillations: present status and outlook  

Science Conference Proceedings (OSTI)

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

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

2008-02-21T23:59:59.000Z

315

Reactor-based Neutrino Oscillation Experiments  

E-Print Network (OSTI)

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

Carlo Bemporad; Giorgio Gratta; Petr Vogel

2001-07-26T23:59:59.000Z

316

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

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

Karl Mannheim

2000-10-18T23:59:59.000Z

317

Citation: K. Hagiwara  

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

Heavy Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Note that LEP results in combination with REUSSER 91 exclude a fourth stable neutrino with m< 2400 GeV. VALUE (GeV) CL% DOCUMENT ID TECN COMMENT >45.0 >45.0 >45.0 >45.0 95 ABREU 92B DLPH Dirac >39.5 >39.5 >39.5 >39.5 95 ABREU 92B DLPH Majorana >44.1 95 ALEXANDER 91F OPAL Dirac >37.2 95 ALEXANDER 91F OPAL Majorana none 3-100 90 SATO 91 KAM2 Kamiokande II >42.8 95 1 ADEVA 90S L3 Dirac >34.8 95 1 ADEVA 90S L3 Majorana >42.7 95 DECAMP 90F ALEP Dirac 1 ADEVA 90S limits for the heavy neutrino apply if the mixing with the charged leptons satisfies U 1 j 2

318

Do hep neutrinos affect the solar neutrino energy spectrum?  

E-Print Network (OSTI)

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

John Bahcall; Plamen Krastev

1998-07-29T23:59:59.000Z

319

Photon and Neutrino Spectra of Time-Dependent Photospheric Models of Gamma-Ray Bursts  

E-Print Network (OSTI)

Thermal photons from the photosphere may be the primary source of the observed prompt emission of gamma-ray bursts (GRBs). In order to produce the observed non-thermal spectra, some kind of dissipation mechanism near the photosphere is required. In this paper we numerically simulate the evolution of the photon spectrum in a relativistically expanding shell with a time-dependent numerical code. We consider two basic models. One is a leptonic model, where a dissipation mechanism heats the thermal electrons maintaining their high temperature. The other model involves a cascade process induced by $pp$($pn$)-collisions which produce high-energy electrons, modify the thermal spectrum, and emit neutrinos. The qualitative properties of the photon spectra are mainly determined by the optical depth at which the dissipation mechanism sets in. Too large optical depths lead to a broad and curved spectrum contradicting the observations, while for optical depths smaller than unity the spectral hardness becomes softer than observed. A significant shift of the spectral peak energy to higher energies due to a large energy injection can lead to an overly broad spectral shape. We show ideal parameter ranges for which these models are able to reproduce the observed spectra. For the $pn$-collision model, the neutrino fluence in the 10-100 GeV range is well above the atmospheric neutrino fluence, but its detection is challenging for presently available detectors.

K. Asano; P. Mszros

2013-08-16T23:59:59.000Z

320

The effect of neutrinos on the initial fireballs in gamma-ray bursts  

E-Print Network (OSTI)

We investigate the fate of very compact, sudden energy depositions that may lie at the origin of gamma-ray bursts. Following on from the work of Cavallo and Rees (1978), we take account of the much higher energies now believed to be involved. The main effect of this is that thermal neutrinos are present and energetically important. We show that these may provide sufficient cooling to tap most of the explosion energy. However, at the extreme energies usually invoked for gamma-ray bursts, the neutrino opacity suffices to prevent dramatic losses, provided that the heating process is sufficiently fast. In a generic case, a few tens of percent of the initial fireball energy will escape as an isotropic millisecond burst of thermal neutrinos with a temperature of about 60 MeV, which is detectable for nearby gamma-ray bursts and hypernovae. For parameters we find most likely for gamma-ray burst fireballs, the dominant processes are purely leptonic, and thus the baryon loading of the fireball does not affect our conclusions.

Hylke B. J. Koers; Ralph A. M. J. Wijers

2005-05-26T23:59:59.000Z

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


321

Neutrino oscillations in noisy media  

SciTech Connect

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

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

1994-05-27T23:59:59.000Z

322

On solar neutrino fluxes in radiochemical experiments  

E-Print Network (OSTI)

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

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

2005-12-08T23:59:59.000Z

323

Solar neutrinos and the sun  

E-Print Network (OSTI)

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

Aldo Serenelli

2011-09-12T23:59:59.000Z

324

Stimulated Neutrino Transformation Through Turbulence  

E-Print Network (OSTI)

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

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

2013-10-21T23:59:59.000Z

325

Solar neutrinos and the sun  

E-Print Network (OSTI)

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

Serenelli, Aldo

2011-01-01T23:59:59.000Z

326

Searching for sterile neutrinos in ice  

E-Print Network (OSTI)

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

Soebur Razzaque; A. Yu. Smirnov

2011-04-07T23:59:59.000Z

327

Progress in the physics of massive neutrinos  

E-Print Network (OSTI)

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

V. Barger; D. Marfatia; K. Whisnant

2003-08-12T23:59:59.000Z

328

A Search for Neutrinoless Tau Decays to Three Leptons  

SciTech Connect

Using approximately 350 million {tau}{sup +}{tau}{sup -} pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction {Beta}({tau} {yields} {ell}{ell}{ell}) in the range (4-8) x 10{sup -8}.

Kolb, Jeffrey A.; /Oregon U. /SLAC

2008-09-24T23:59:59.000Z

329

Light Sterile Neutrinos and Short Baseline Neutrino Oscillation Anomalies  

E-Print Network (OSTI)

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

Fan, JiJi

2012-01-01T23:59:59.000Z

330

The Neutrino Eye: A Megaton Low Energy Neutrino  

E-Print Network (OSTI)

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

Learned, John

331

Precision Measurements of Tau Lepton Decays  

SciTech Connect

Using data collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, the branching fractions {Beta}({tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (8.83 {+-} 0.01 {+-} 0.13)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (0.273 {+-} 0.002 {+-} 0.009)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}}) = (0.1346 {+-} 0.0010 {+-} 0.0036)%, and {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}) = (1.58 {+-} 0.13 {+-} 0.12) x 10{sup -5} are measured where the uncertainties are statistical and systematic, respectively. The invariant mass distribution for the {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}, {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} decays are unfolded to correct for detector effects. A measurement of {Beta}({tau}{sup -} {yields} {phi}{pi}{sup -}{nu}{sub {tau}}) = (3.42 {+-} 0.55 {+-} 0.25) x 10{sup -5}, a measurement of {Beta}({tau}{sup -} {yields} {phi}K{sup -}{nu}{sub {tau}}) = (3.39 {+-} 0.20 {+-} 0.28) x 10{sup -5} and an upper limit on {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}[ex.{phi}]) {le} 2.5 x 10{sup -6} {at} 905 CL are determined from a binned maximum likelihood fit of the {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} K{sup +}K{sup -} invariant mass distributions. The branching ratio {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}) is measured to be (6.531 {+-} 0.056 {+-} 0.093) x 10{sup -2} from which |V{sub us}| is determined to be 0.2255 {+-} 0.0023. The branching ratio {Beta}/({tau}{sup -} {yields} {mu}{nu}{sub {tau}}{bar {nu}}{sub {mu}})/{Beta}({tau}{sup -} {yields} e{sup -} {nu}{sub {tau}}{bar {nu}}{sub e}) = (9.796 {+-} 0.016 {+-} 0.035) x 10{sup -1} is measured enabling a precision test of the Standard Model assumption of charged current lepton universality, g{sub {mu}}/g{sub e} = 1.0036 {+-} 0.0020. The branching ratios {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{nu}{sub {tau}}{bar {nu}}{sub e}) = (3.882 {+-} 0.032 {+-} 0.057) x 10{sup -2}, and {Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{nu}{sub {tau}}{bar {nu}}{sub e}) = (5.9545 {+-} 0.014 {+-} 0.061) x 10{sup -1} are measured which provide additional tests of charged current lepton universality, (g{sub {tau}}/g{sub {mu}}){sub {pi}} = 0.9856 {+-} 0.0057 and (g{sub {tau}}/g{sub {mu}}){sub K} = 0.9827 {+-} 0.0086 which can be combined to give (g{sub {tau}}/g{sub {mu}}){sub {pi}/K} = 0.9850 {+-} 0.0054. Any deviation of these measurements from the expected Standard Model values would be an indication of new physics.

Nugent, Ian M.; /Victoria U.

2010-03-16T23:59:59.000Z

332

Solar Neutrinos: Solved and Unsolved Problems John N. Bahcall  

E-Print Network (OSTI)

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

Bahcall, John

333

WHY DO SOLAR NEUTRINO EXPERIMENTS BELOW J. N. BAHCALL  

E-Print Network (OSTI)

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

Bahcall, John

334

WHY DO SOLAR NEUTRINO EXPERIMENTS BELOW J. N. BAHCALL  

E-Print Network (OSTI)

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

Bahcall, John

335

Heavy Oil Projects  

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

Select Reports from Heavy Oil Projects Project Number Performer Title Heavy Oil Recovery US (NIPERBDM-0225) BDM-Oklahoma, Inc. Feasibility Study of Heavy Oil Recovery in the...

336

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

Science Conference Proceedings (OSTI)

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

KETTELL, S.; ET AL.

2006-10-16T23:59:59.000Z

337

Neutrino interactions with e/sup +/. mu. /sup -/ and multiple K/sup 0/'s. [Branching ratio  

DOE Green Energy (OSTI)

A scan for directly produced positrons in 5,000 neutrino interactions in the neon (21 percent) hydrogen filled bubble chamber at Fermilab has yielded 15 events, 9 of which have ..mu../sup -/'s identified in the external muon identifier. On correcting for detection efficiency one obtains sigma(e/sup +/..mu../sup -/)/sigma(..mu../sup -/) approximately 1 x 10/sup -2/ for E/sub e/sup +// > .8 GeV and E/sub ..nu../ > 5 GeV. The kaon multiplicity is unexpectedly high. Eleven of the events have one or more Vees and three have two or more. Among the 11 events are two clear ..lambda..'s and two ambiguous K/sup 0//..lambda... There are four events with identifiable charged kaons. A 16th e/sup +/ event (9) is a definite ..nu../sub e/. From this information one concludes that the kaon multiplicity is 2 +- .6 K/sup 0/'s and 2 +- 1 K/sup + -/'s per interaction. From the observation

/

= 6.6, one concludes that the e/sup +/'s are probably not uniquely from heavy lepton decay. From a variety of analyses involving the e/sup +/ and/or K/sup 0/'s one learns that the mass of the hadron (C) that produces the e/sup +/'s is greater than 1.6 GeV. By determining the fraction of normal charged current (CC) events that have K/sup 0//sub s/ ..-->.. ..pi../sup +/..pi../sup -/ one is able to compare this fraction with the fraction of CC events that have e/sup +/..mu../sup -/ (K/sup 0//sub s/ ..-->.. ..pi../sup +/..pi../sup -/) to establish a conservative lower limit to the semileptonic branching ratio, C ..-->.. (e/sup +/ and ..mu../sup +/) ..nu../C ..-->.. all > 0.33 (1 +- .42), provided that the same number of K/sup 0//sub s/ exists in thenonleptonic decays as in the semileptonic ones, and that the phase space for ..mu../sup +/ and e/sup +/ are nearly equal. There is no compelling evidence for an energy threshold and there is a hint of some neutral current events among the e/sup +/ events.

Stevenson, M.L.

1976-07-01T23:59:59.000Z

338

A Lepton Universality Test at CERN NA62 Experiment  

E-Print Network (OSTI)

The NA62 experiment at CERN collected a large sample of K+ --> enu decays during a dedicated run in 2007, aiming at a precise test of lepton universality by measurement of the helicity suppressed ratio RK = BR(K+ --> enu)/BR(K+ --> munu). A preliminary result of the analysis of a partial data sample of 51089 K+ --> enu candidates is presented.

Evgueni Goudzovski

2010-05-07T23:59:59.000Z

339

CP Violation for Leptons at Higher Energy Scales  

E-Print Network (OSTI)

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.

Cheng-Wei Chiang

2000-11-15T23:59:59.000Z

340

CP Violation for Leptons at Higher Energy Scales  

E-Print Network (OSTI)

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.

Chiang, C W

2001-01-01T23:59:59.000Z

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


341

Hadronic decays of the tau lepton: Theoretical outlook  

E-Print Network (OSTI)

The structure of the form factors stemmed from the hadronization of QCD currents in the energy region of the resonances can be explored through the analyses of exclusive hadronic decays of the tau lepton. I give a short review on the later theoretical progress achieved in the description of experimental data.

J. Portoles

2007-02-13T23:59:59.000Z

342

Aspects of Neutrino Production in Supernovae  

E-Print Network (OSTI)

I discuss neutrino production in supernovae (SNe) and the detection of both Galactic core collapse events and the diffuse extra-galactic MeV neutrino background expected from the integrated history of star formation. In particular, I consider what processes might affect our expectations for both. I focus on ``rapid'' rotation, defined as leading to millisecond initial neutron star spin periods. Rotation affects the neutrino luminosity, the average neutrino energy, the duration of the Kelvin-Helmholtz cooling epoch, and the ratios of luminosities and average energies between neutrino species; it can strongly suppresses the anti-electron as well as mu, anti-mu, tau, and anti-tau neutrino fluxes relative to those for the electron neutrinos. As a result, depending on the prevalence of rapid rotation in SN progenitors through cosmic time, this may affect predictions for the MeV neutrino background and the history of nucleosynthetic enrichment. I emphasize connections between the MeV neutrino background and tracers of the star formation rate density at high redshift in other neutrino and photon wavebands.

Todd A. Thompson

2006-08-10T23:59:59.000Z

343

Probing the Absolute Mass Scale of Neutrinos  

SciTech Connect

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

Prof. Joseph A. Formaggio

2011-10-12T23:59:59.000Z

344

s077.dvi  

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

Neutral Neutral Leptons, Searches for (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Note that LEP results in combination with REUSSER 91 exclude a fourth stable neutrino with m< 2400 GeV. VALUE (GeV) CL% DOCUMENT ID TECN COMMENT >45.0 >45.0 >45.0 >45.0 95 ABREU 92B DLPH Dirac >39.5 >39.5 >39.5 >39.5 95 ABREU 92B DLPH Majorana >44.1 95 ALEXANDER 91F OPAL Dirac >37.2 95 ALEXANDER 91F OPAL Majorana none 3-100 90 SATO 91 KAM2 Kamiokande II >42.8 95 1 ADEVA 90S L3 Dirac >34.8 95 1 ADEVA 90S L3 Majorana >42.7 95 DECAMP 90F ALEP Dirac 1 ADEVA 90S limits for the heavy neutrino apply if the mixing with the charged leptons satisfies U 1 j 2 + U 2

345

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

E-Print Network (OSTI)

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

Alexei Yu. Smirnov

2008-10-15T23:59:59.000Z

346

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

E-Print Network (OSTI)

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

Smirnov, Alexei Yu

2008-01-01T23:59:59.000Z

347

Report of the Solar and Atmospheric Neutrino Working Group  

E-Print Network (OSTI)

Solar Neutrino Experiments 3.1 Testing the Model of the Sun . . . . . . . . . . . . . . . . . . . . .propagate from solar center to surface, the Suns changingsolar neutrino projectusing neutrinos to understand the Sun.

2004-01-01T23:59:59.000Z

348

Experimental Requirements to Determine the Neutrino Mass Hierarchy Using Reactor Neutrinos  

E-Print Network (OSTI)

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

Liang Zhan; Yifang Wang; Jun Cao; Liangjian Wen

2009-01-20T23:59:59.000Z

349

Measurement of the cosmic ray and neutrino-induced muon flux at the Sudbury neutrino observatory  

E-Print Network (OSTI)

Results are reported on the measurement of the atmospheric neutrino-induced muon flux at a depth of 2 kilometers below the Earths surface from 1229 days of operation of the Sudbury Neutrino Observatory (SNO). By measuring ...

Formaggio, Joseph A.

350

Search for muon neutrinos from Gamma-Ray Bursts with the IceCube neutrino telescope  

E-Print Network (OSTI)

the University of California. Search for muon neutrinos fromSearch for muon neutrinos from Gamma-Ray Bursts with theWe present the results of searches for high-energy muon

Abbasi, R.

2010-01-01T23:59:59.000Z

351

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

E-Print Network (OSTI)

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

Yongchao Zhang

2013-01-30T23:59:59.000Z

352

Search for neutrinos from Gamma-Ray Bursts with the Baikal neutrino telescope NT200  

E-Print Network (OSTI)

We present an analysis of neutrinos detected with the Baikal neutrino telescope NT200 for correlations with gamma-ray bursts (GRB). No neutrino events correlated with GRB were observed. Assuming a Waxman-Bahcall spectrum, a neutrino flux upper limit of {\\bf $E^2 \\Phi Green's Function fluence limit for this search, which extends two orders of magnitude beyond the energy range of the Super-Kamiokande limit.

Avrorin, A

2009-01-01T23:59:59.000Z

353

If sterile neutrinos exist, how can one determine the total solar neutrino fluxes?  

E-Print Network (OSTI)

The 8B solar neutrino flux inferred from a global analysis of solar neutrino experiments is within 11% (1 sigma) of the predicted standard solar model value if only active neutrinos exist, but could be as large as 1.7 times the standard prediction if sterile neutrinos exist. We show that the total 8B neutrino flux (active plus sterile neutrinos) can be determined experimentally to about 10% (1 sigma) by combining charged current measurements made with the KamLAND reactor experiment and with the SNO CC solar neutrino experiment, provided the LMA neutrino oscillation solution is correct and the simulated performance of KamLAND is valid. Including also SNO NC data, the sterile component of the 8B neutrino flux can be measured by this method to an accuracy of about 12% (1 sigma) of the standard solar model flux. Combining Super-Kamiokande and KamLAND measurements and assuming the oscillations occur only among active neutrinos, the 8B neutrino flux can be measured to 6% (1 sigma); the total flux can be measured to an accuracy of about 9%. The total 7Be solar neutrino flux can be determined to an accuracy of about 28% (1 sigma) by combining measurements made with the KamLAND, SNO, and gallium neutrino experiments. One can determine the total 7Be neutrino flux to a one sigma accuracy of about 11% or better by comparing data from the KamLAND experiment and the BOREXINO solar neutrino experiment provided both detectors work as expected. The pp neutrino flux can be determined to about 15% using data from the gallium, KamLAND, BOREXINO, and SNO experiments.

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

2002-04-16T23:59:59.000Z

354

Neutrino and Antineutrino Cross sections at MiniBooNE  

SciTech Connect

The MiniBooNE experiment has reported a number of high statistics neutrino and anti-neutrino cross sections -among which are the charged current quasi-elastic (CCQE) and neutral current elastic (NCE) neutrino scattering on mineral oil (CH2). Recently a study of the neutrino contamination of the anti-neutrino beam has concluded and the analysis of the anti-neutrino CCQE and NCE scattering is ongoing.

Dharmapalan, Ranjan; /Alabama U.

2011-10-01T23:59:59.000Z

355

Daya Bay Reactor Neutrino Project at NERSC  

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

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

356

Dynamical Collective Calculation of Supernova Neutrino Signals  

SciTech Connect

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

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

2009-08-14T23:59:59.000Z

357

Large Extra Dimensions, Sterile Neutrinos and Solar Neutrino Data  

Science Conference Proceedings (OSTI)

Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, {nu}{sub B} , which can exist in the bulk of extra dimensions. Solar {nu}{sub e} , confined to the brane, can oscillate in the vacuum to the zero mode of {nu}{sub B} and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of {nu}{sub B} . This new way to fit solar data is provided by both low and intermediate string scale models. From average rates seen in the three types of solar experiments, the Super-Kamiokande spectrum is predicted with 73% probability, but dips characteristic of the 0.06 mm extra dimension should be seen in the SNO spectrum.

Caldwell, D. O.; Mohapatra, R. N.; Yellin, S. J.

2001-07-23T23:59:59.000Z

358

The Palo Verde Reactor Neutrino Experiment A Test for Long Baseline Neutrino Oscillations  

E-Print Network (OSTI)

:1. Our range of sensitivity is tuned to test the š¯ $ še solution of the atmospheric neutrino anomaly. 11 The Palo Verde Reactor Neutrino Experiment A Test for Long Baseline Neutrino Oscillations 94305 e Palo Verde Nuclear Generating Station,Tonopah AZ 85354 Our collaboration has installed a long

Piepke, Andreas G.

359

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

E-Print Network (OSTI)

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

H. Nunokawa

2001-05-03T23:59:59.000Z

360

Status of the Daya Bay Reactor Neutrino Oscillation Experiment  

E-Print Network (OSTI)

Status of the Daya Bay Reactor Neutrino OscillationCheng-Ju Lin The Daya Bay reactor neutrino experiment [1] isneutrinos from the nuclear reactors at different baselines.

Lin, Cheng-Ju Stephen

2011-01-01T23:59:59.000Z

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


361

Status of the Daya Bay Reactor Neutrino Oscillation Experiment  

E-Print Network (OSTI)

neutrinos from the nuclear reactors at different baselines.will be commissioned Nuclear Reactor Anti-neutrino detectorthe nuclear power complex has two pairs of reactor cores (

Lin, Cheng-Ju Stephen

2011-01-01T23:59:59.000Z

362

Measuring neutrino oscillation parameters using $\  

SciTech Connect

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

Backhouse, Christopher James; /Oxford U.

2011-02-01T23:59:59.000Z

363

Pion condensation in a dense neutrino gas  

E-Print Network (OSTI)

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

Hiroaki Abuki; Tomas Brauner; Harmen J. Warringa

2009-01-16T23:59:59.000Z

364

Nuclear correction factors from neutrino DIS  

E-Print Network (OSTI)

Neutrino Deep Inelastic Scattering on nuclei is an essential process to constrain the strange quark parton distribution functions in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions and we use this framework to analyze the consistency of neutrino DIS data with other nuclear data.

K. Kovarik

2011-07-15T23:59:59.000Z

365

Nuclear correction factors from neutrino DIS  

E-Print Network (OSTI)

Neutrino Deep Inelastic Scattering on nuclei is an essential process to constrain the strange quark parton distribution functions in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions and we use this framework to analyze the consistency of neutrino DIS data with other nuclear data.

Kovarik, K

2011-01-01T23:59:59.000Z

366

Interim Design Report for the International Design Study for a Neutrino Factory  

Science Conference Proceedings (OSTI)

The starting point for the International Design Study for the Neutrino Factory (the IDS-NF) was the output of the earlier International Scoping Study for a future Neutrino Factory and super-beam facility (the ISS). The accelerator facility described in section 2 incorporates the improvements that have been derived from the substantial amount of work carried out within the Accelerator Working Group. Highlights of these improvements include: (1) Initial concepts for the implementation of the proton driver at each of the three example sites, CERN, FNAL, and RAL; (2) Detailed studies of the energy deposition in the target area; (3) A reduction in the length of the muon beam phase-rotation and bunching systems; (4) Detailed analyses of the impact of the risk that stray magnetic field in the accelerating cavities in the ionization cooling channel will reduce the maximum operating gradient. Several alternative ionization-cooling lattices have been developed as fallback options to mitigate this technical risk; (5) Studies of particle loss in the muon front-end and the development of strategies to mitigate the deleterious effects of such losses; (6) The development of more complete designs for the muon linac and re-circulating linacs; (7) The development of a design for the muon FFAG that incorporates insertions for injection and extraction; and (8) Detailed studies of diagnostics in the decay ring. Other sub-systems have undergone a more 'incremental' evolution; an indication that the design of the Neutrino Factory has achieved a degree of maturity. The design of the neutrino detectors described in section 3 has been optimized and the Detector Working Group has made substantial improvements to the simulation and analysis of the Magnetized Iron Neutrino Detector (MIND) resulting in an improvement in the overall neutrino-detection efficiency and a reduction in the neutrino-energy threshold. In addition, initial consideration of the engineering of the MIND has generated a design that is feasible and a finite element analysis of the toroidal magnetic field to produce a realistic field map has been carried out. Section 3 also contains, for the first time, a specification for the near-detector systems and a demonstration that the neutrino flux can be determined with a precision of 1% through measurements of inverse muon decay at the near detector. The performance of the facility, the work of the Physics and Performance Evaluation Group, is described in section 1. The effect of the improved MIND performance is to deliver a discovery reach for CP-invariance violation in the lepton sector, the determination of the mass hierarchy, and of {theta}{sub 13} that extends down to values of sin{sup 2} 2{theta}{sub 13} {approx} 5 x 10{sup -5} and is robust against systematic uncertainties. In addition, the improved neutrino-energy threshold has allowed an indicative analysis of the kind of re-optimization of the facility that could be carried out should {theta}{sub 13} be found close to the current upper bound. The results presented in section 1 demonstrate that the discovery reach as well as the precision with which the oscillation parameters can be measured at the baseline Neutrino Factory is superior to that of other proposed facilities for all possible values of sin{sup 2} 2{theta}{sub 13}.

Choubey, S.; Gandhi, R.; Goswami, S.; /Harish-Chandra Res. Inst.; Berg, J.S.; Fernow, R.; Gallardo, J.C.; Gupta, R.; Kirk, H.; Simos, N.; Souchlas, N.; /Brookhaven; Ellis, M.; /Brunel U. /CERN /Durham U., IPPP /Fermilab /Geneva U. /Glasgow U. /Heidelberg, Max Planck Inst. /Imperial Coll., London /Jefferson Lab /Saha Inst.

2011-10-01T23:59:59.000Z

367

Neutrino Factory Designs and R&D  

E-Print Network (OSTI)

European, Japanese, and US Neutrino Factory designs are presented. The main R&D issues, and the associated R&D programs, are discussed.

S. Geer

2002-07-15T23:59:59.000Z

368

Search for Neutrinos from the Sun  

DOE R&D Accomplishments (OSTI)

A solar neutrino detection system has been built to observe the neutrino radiation from the sun. The detector uses 3,900,000 liters of tetrachloroethylene as the neutrino capturing medium. Argon is removed from the liquid by sweeping with helium gas, and counted in a small low level proportional counter. The recovery efficiency of the system was tested with Ar{sup 36} by the isotope dilution method, and also with Ar{sup 37} produced in the liquid by fast neutrons. These tests demonstrate that Ar{sup 37} produced in the liquid by neutrino capture can be removed with a 95 percent efficiency by the procedure used.

Davis, Raymond Jr.

1968-09-00T23:59:59.000Z

369

Boron abundance and solar neutrino spectrum distortion  

E-Print Network (OSTI)

The presence of neutrinos from Boron decay in the flux observed on Earth is attested by the observation of their energy spectrum. Possible distortions of the spectrum investigated in current detectors are often interpreted in terms of evidence in favour or against various schemes of neutrino oscillations. We stress here that a distortion of the spectrum at high energies could also result from an increase in the ratio of neutrinos originating from ($^3$He+p) and $^8$B reactions. While a $^8$B neutrino depletion would contribute to this effect, an increase in the Hep contribution seems also needed to reproduce the preliminary data.

R. Escribano; J. -M. Frere; A. Gevaert; D. Monderen

1998-05-06T23:59:59.000Z

370

Review of Solar and Reactor Neutrinos  

E-Print Network (OSTI)

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

A. W. P. Poon

2005-09-19T23:59:59.000Z

371

Gamma Ray Burst Neutrinos Probing Quantum Gravity  

E-Print Network (OSTI)

Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.

M. C. Gonzalez-Garcia; F. Halzen

2006-11-28T23:59:59.000Z

372

Neutrino Factory Physics Study: Two Day Meeting  

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

Two-Day Meeting The Fermilab Directorate has requested a 6 month study to assess the physics capabilities of neutrino factories as a function of their energies, intensities,...

373

Neutrino Physics at a Muon Collider  

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

Physics at a Muon Collider The intense muon beams needed for high luminosity muon colliders produce intense beams of neutrinos. Dedicated muon storage rings with long straight...

374

Collective Neutrino Flavor Transformation In Supernovae  

E-Print Network (OSTI)

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

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

2005-11-09T23:59:59.000Z

375

3.8 The Missing Solar Neutrinos  

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

phenomenon was first suggested by observations at the oldest solar neutrino detector (in South Dakota), for which Raymond Davis of Brookhaven National Laboratory won the 2000 Wolf...

376

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

E-Print Network (OSTI)

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

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

2012-03-06T23:59:59.000Z

377

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

E-Print Network (OSTI)

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

Cooper, Iain K; Luhn, Christoph

2012-01-01T23:59:59.000Z

378

The ANTARES underwater neutrino telescope  

E-Print Network (OSTI)

ANTARES is the first undersea neutrino telescope. It is in its complete configuration since May 2008 at about 2.5 km below the sea surface close to Marseille. Data from 12 lines are being analyzed and are producing first results. Here we discuss first analysis results for 5 lines and 10 lines, and we also comment on the performance of the full detector. We show that the detector has capabilities for discriminating upgoing neutrino events from the much larger amount of downgoing atmospheric muons and that data and simulation are in good agreement. We then discuss the physics reach of the detector for what concerns point-like source and dark matter searches.

Teresa Montaruli; for the ANTARES Collaboration

2008-10-21T23:59:59.000Z

379

Neutrino Mass and Flavour Models  

E-Print Network (OSTI)

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

King, Stephen F

2009-01-01T23:59:59.000Z

380

Neutrino Mass and Flavour Models  

E-Print Network (OSTI)

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

Stephen F King

2009-09-16T23:59:59.000Z

Note: This page contains sample records for the topic "neutrinos heavy leptons" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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381

Graphene, neutrino mass and oscillation  

E-Print Network (OSTI)

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

Z. Y. Wang

2009-09-10T23:59:59.000Z

382

Neutrino telescopes as a probe of active and sterile neutrino mixings  

E-Print Network (OSTI)

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

Xing, Zhi-zhong

2007-01-01T23:59:59.000Z

383

Neutrino telescopes as a probe of active and sterile neutrino mixings  

E-Print Network (OSTI)

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

Zhi-zhong Xing

2007-11-27T23:59:59.000Z

384

The Solar Neutrino Problem - An Update  

E-Print Network (OSTI)

The $^8$B solar neutrino flux as measured by Super-Kamiokande is consistent with the $^{37}$Ar production rate in $^{37}$Cl at Homestake. GALLEX and SAGE, continue to observe $^{71}$Ge production rates in $^{71}$Ga that are consistent with the minimal signal expected from the solar luminosity. The observed $^8$B solar neutrino flux is in good agreement with that predicted by the standard solar model of Dar and Shaviv with nuclear reaction rates that are supported by recent measurements of nuclear fusion cross sections at low energies. The measurements of Super-Kamiokande, SAGE and GALLEX suggest that the expected the pep, $^7$Be and NO solar neutrino fluxes are strongly suppressed. This can be explained by neutrino oscillations and the Mikheyev-Smirnov-Wolfenstein effect. Since neither a flavor change, nor a terrestrial variation, nor a spectral distortion of the $^8$B solar neutrino flux has been observed yet, the solar neutrino problem does not provide conclusive evidence for neutrino properties beyond the standard electroweak model. The deviations of the experimental results from those predicted by the standard solar models may reflect the approximate nature of of solar models and of our knowledge of nuclear reaction rates, radiation transport and particle diffusion in dense stellar plasmas. Only future observations of spectral distortions, or terrestrial modulation or flavor change of solar neutrinos in solar neutrino experiments, such as Super-Kamiokande, SNO, Borexino and HELLAZ will be able to establish that neutrino properties beyond the minimal standard electroweak model are responsible for the solar neutrino problem.

Arnon Dar; Giora Shaviv

1998-08-11T23:59:59.000Z

385

Applying Bayesian Neural Networks to Separate Neutrino Events from Backgrounds in Reactor Neutrino Experiments  

E-Print Network (OSTI)

A toy detector has been designed to simulate central detectors in reactor neutrino experiments in the paper. The samples of neutrino events and three major backgrounds from the Monte-Carlo simulation of the toy detector are generated in the signal region. The Bayesian Neural Networks(BNN) are applied to separate neutrino events from backgrounds in reactor neutrino experiments. As a result, the most neutrino events and uncorrelated background events in the signal region can be identified with BNN, and the part events each of the fast neutron and $^{8}$He/$^{9}$Li backgrounds in the signal region can be identified with BNN. Then, the signal to noise ratio in the signal region is enhanced with BNN. The neutrino discrimination increases with the increase of the neutrino rate in the training sample. However, the background discriminations decrease with the decrease of the background rate in the training sample.

Ye Xu; Yixiong Meng; Weiwei Xu

2008-08-02T23:59:59.000Z

386

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

E-Print Network (OSTI)

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

Shigeru Yoshida; Guenter Sigl; Sangjin Lee

1998-08-14T23:59:59.000Z

387

A Zip-code for Quarks, Leptons and Higgs Bosons  

E-Print Network (OSTI)

The location of matter fields and the pattern of gauge symmetry in extra dimensions are crucial ingredients for string model building. We analyze realistic MSSM models from the heterotic Z6 Mini-Landscape and extract those properties that are vital for their success. We find that Higgs bosons and the top quark are not localized in extra dimensions and live in the full D=10 dimensional space-time. The first two families of quarks and leptons, however, live at specific fixed points in extra dimensional space and exhibit a (discrete) family symmetry. Within a newly constructed Z2XZ4 orbifold framework we further elaborate on these location properties and the appearance of discrete symmetries. A similar geometrical picture emerges. This particular Zip-code for quarks, leptons and Higgs bosons seems to be of more general validity and thus a useful guideline for realistic model building in string theory.

Damian Kaloni Mayorga Pena; Hans Peter Nilles; Paul-Konstantin Oehlmann

2012-09-26T23:59:59.000Z

388

Search for Charged Lepton Violation in Narrow Upsilon Decays  

SciTech Connect

Charged lepton flavor violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 10{sup 6} {Upsilon}(2S) decays and 117 x 10{sup 6} {Upsilon}(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions {Beta}({Upsilon}(nS) {yields} e{sup {+-}}{tau}{sup {-+}}) and {Beta}({Upsilon}(nS) {yields} {mu}{sup {+-}}{tau}{sup {-+}}) (n = 2, 3) at the 10{sup -6} level and use these results to place lower limits of order 1 TeV on the mass scale of charged lepton flavor violating effective operators.

Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley; Hawkes, C.M.; /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Columbus Supercond., Genova /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-08-19T23:59:59.000Z

389

Snowmass White Paper CMS Upgrade: Forward Lepton-Photon System  

E-Print Network (OSTI)

This White Paper outlines a proposal for an upgraded forward region to extend CMS lepton (e, mu) and photon physics reach out to 2.2

Bilki, Burak; Onel, Yasar; Winn, David R; Yetkin, Taylan

2013-01-01T23:59:59.000Z

390

Search for the Lepton-Number-Violating Decay $?^- \\to p ?^- ?^-$  

E-Print Network (OSTI)

A sensitive search for the lepton-number-violating decay $\\Xi^-\\to p \\mu^-\\mu^-$ has been performed using a sample of $\\sim10^9$ $\\Xi^-$ hyperons produced in 800 GeV/$c$ $p$-Cu collisions. We obtain $\\mathcal{B}(\\Xi^-\\to p \\mu^-\\mu^-)< 4.0\\times 10^{-8}$ at 90% confidence, improving on the best previous limit by four orders of magnitude.

HyperCP Collaboration; D. Rajaram; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. -S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. D. Jones; D. M. Kaplan; M. J. Longo; L. C. Lu; W. Luebke; K. -B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla

2005-05-12T23:59:59.000Z

391

Electroweak Penguin and Leptonic Decays at BaBar  

SciTech Connect

Recent BABAR results on electroweak penguin and leptonic decays are reviewed. In particular, the measurements of B {yields} K{sup (*)}l{sup +}l{sup -} and the preliminary results on B {yields} X{sub s}l{sup +}l{sup -} are presented. Also summarized are the preliminary limits on B{sup +} {yields} l{sup +}{nu} (l = e,{mu}) and B{sup +} {yields} K{sup +}{nu}{bar {nu}}.

Bucci, F.; /Pisa U. /INFN, Pisa

2005-08-26T23:59:59.000Z

392

Scaling quark gluon plasma by HBT interferometry with lepton pairs  

E-Print Network (OSTI)

We study the intensity interferometry with lepton pairs for nuclear collisions at RHIC and LHC energies. It is argued that the invariant mass dependence of HBT radii extracted from the correlation functions of dilepton pairs can be used as an efficient tool to scale the size and life time of the quark gluon plasma expected to be formed in nuclear collisions at RHIC and LHC. Quantitatively different magnitudes of HBT radii are obtained at RHIC and LHC indicating stronger radial flow at LHC.

Payal Mohanty; Jan-e Alam

2012-02-10T23:59:59.000Z

393

Jack Steinberger and the Muon-Neutrino  

Office of Scientific and Technical Information (OSTI)

Jack Steinberger and the Muon-Neutrino Resources with Additional Information Jack Steinberger Photograph by Harry Sticker, courtesy AIP Emilio Segre Visual Archives, Physics Today Collection In an interview, Jack Steinberger spoke about his 1988 Nobel Prize winning research. He states "I did an experiment, together with several other people at Brookhaven National Laboratory ... which showed that there is a second kind of neutrino. The neutrino has elementary particles. Elementary particles exist in families of particles ... . At the time, the elementary particles which were involved were the electrons and the neutrino. ... [W]e required the [BNL] accelerator, which was the effort of very many people, ... and this allowed [us] to make a beam of these neutrinos, and we were able to convince ourselves that these neutrinos were not the same kind of neutrinos as those which had been seen before. They were associated with not electrons, but with something called [muons]. So we were able to understand that there is a different neutrino associated with the [muon] than with the electron.

394

Consistency of 8B neutrino spectra  

E-Print Network (OSTI)

We identify and quantify systematic effects not accounted for in two previous measurements of the alpha-alpha relative-energy distribution in the beta decay of 8B, which can explain the apparent disagreement with respect to two newer measurements. This settles a current dispute concerning the shape of the 8B neutrino spectrum of importance to solar-neutrino studies.

Oliver S. Kirsebom; Hans O. U. Fynbo; Riccardo Raabe; Karsten Riisager; Thomas Roger

2012-11-15T23:59:59.000Z

395

Variations in the Solar Neutrino Flux  

DOE R&D Accomplishments (OSTI)

Observations are reported from the chlorine solar neutrino detector in the Homestake Gold Mine, South Dakota, USA. They extend from 1970 to 1985 and yield an average neutrino capture rate of 2.1 +- 0.3 SNU. The results from 1977 to 1985 show an anti-correlation with the solar activity cycle, and an apparent increased rate during large solar flares.

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

1987-08-02T23:59:59.000Z

396

Big World of Small Neutrinos Hitoshi Murayama  

E-Print Network (OSTI)

· Finally discovered by Cowan and Reines using a nuclear reactor in 1958 · Massless Neutrinos, Phys. Rev. 48, 391 (1935) Bohr: At the present stage of atomic theory, however, we may say that we have Colloquium 11 Anti-Neutrinos are Right-handed · CPT theorem in quantum field theory ­ C: interchange

Murayama, Hitoshi

397

Neutrino Balls and Gamma-Ray Bursts  

E-Print Network (OSTI)

We propose a mechanism by which the neutrino emission from a supernova-type explosion can be converted into a gamma-ray burst of total energy $\\sim 10^{50}$ ergs. This occurs naturally if the explosion is situated inside a ball of trapped neutrinos, which in turn may lie at a galactic core. There are possible unique signatures of this scenario.

B. Holdom; R. A. Malaney

1993-06-17T23:59:59.000Z

398

Neutrino background flux from sources of ultrahigh-energy cosmic-ray nuclei  

Science Conference Proceedings (OSTI)

Motivated by Pierre Auger Observatory results favoring a heavy nuclear composition for ultrahigh-energy (UHE) cosmic rays, we investigate implications for the cumulative neutrino background. The requirement that nuclei not be photodisintegrated constrains their interactions in sources, therefore limiting neutrino production via photomeson interactions. Assuming a dN{sub CR}/dE{sub CR{proportional_to}}E{sub CR}{sup -2} injection spectrum and photodisintegration via the giant dipole resonance, the background flux of neutrinos is lower than E{sub {nu}}{sup 2{Phi}}{sub {nu}{approx}1}0{sup -9} GeV cm{sup -2} s{sup -1} sr{sup -1} if UHE nuclei ubiquitously survive in their sources. This is smaller than the analogous Waxman-Bahcall flux for UHE protons by about 1 order of magnitude and is below the projected IceCube sensitivity. If IceCube detects a neutrino background, it could be due to other sources, e.g., hadronuclear interactions of lower-energy cosmic rays; if it does not, this supports our strong restrictions on the properties of sources of UHE nuclei.

Murase, Kohta [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, 606-8502 (Japan); CCAPP, Ohio State University, Columbus, Ohio 43210 (United States); Beacom, John F. [CCAPP, Ohio State University, Columbus, Ohio 43210 (United States); Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States)

2010-06-15T23:59:59.000Z

399

Resolving Standard and Nonstandard CP Violation Phases in Neutrino Oscillations  

SciTech Connect

Neutrino oscillations can exhibit extra CP violation effects, beyond those expected from the standard Kobayashi-Maskawa phase delta, if non-standard neutrino interactions are at play. We show that it is possible to disentangle the two CP violating effects by measuring muon neutrino appearance using a near-far two detector setting in a neutrino factory experiment.

Gago, A. M. [Seccion Fisica, Departamento de Ciencias, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru); Minakata, H.; Uchinami, S. [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Nunokawa, H. [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, C. P. 38071, 22452-970, Rio de Janeiro (Brazil); Zukanovich Funchal, R. [Instituto de Fisica, Universidade de Sao Paulo, C. P. 66.318, 05315-970 Sao Paulo (Brazil)

2010-03-30T23:59:59.000Z

400

Solar neutrino measurements in Super-Kamiokande-I  

E-Print Network (OSTI)

The details of Super--Kamiokande--I's solar neutrino analysis are given. Solar neutrino measurement in Super--Kamiokande is a high statistics collection of $^8$B solar neutrinos via neutrino-electron scattering. The analysis method and results of the 1496 day data sample are presented. The final oscillation results for the data are also presented.

Super-Kamiokande Collaboration

2005-08-27T23:59:59.000Z

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


401

Opportunities for Neutrino Physics at the Spallation Neutron Source (SNS)  

E-Print Network (OSTI)

In this paper we discuss opportunities for a neutrino program at the Spallation Neutrons Source (SNS) being commissioning at ORNL. Possible investigations can include study of neutrino-nuclear cross sections in the energy rage important for supernova dynamics and neutrino nucleosynthesis, search for neutrino-nucleus coherent scattering, and various tests of the standard model of electro-weak interactions.

Yu Efremenko; W R Hix

2008-07-17T23:59:59.000Z

402

Overview of the LBNE Neutrino Beam  

Science Conference Proceedings (OSTI)

The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed at the Deep Underground Science and Engineering Laboratory (DUSEL) in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be {approx}700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW.

Moore, C.D.; He, Yun; Hurh, Patrick; Hylen, James; Lundberg, Byron; McGee, Mike; Misek, Joel; Mokhov, Nikolai V.; Papadimitriou, Vaia; Plunkett, Rob; Schultz, Ryan; /Fermilab

2011-03-22T23:59:59.000Z

403

Noncommutative Theory in Light of Neutrino Oscillation  

E-Print Network (OSTI)

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

Shao-Xia Chen; Zhao-Yu Yang

2003-12-07T23:59:59.000Z

404

Solar neutrinos and the solar composition problem  

E-Print Network (OSTI)

Standard solar models (SSM) are facing nowadays a new puzzle: the solar composition problem. New determinations of solar metal abundances lead SSM calculations to conflict with helioseismological measurements, showing discrepancies that extend from the convection zone to the solar core and can not be easily assigned to deficiencies in the modelling of the solar convection zone. We present updated solar neutrino fluxes and uncertainties for two SSM with high (old) and low (new) solar metallicity determinations. The uncertainties in iron and carbon abundances are the largest contribution to the uncertainties of the solar neutrino fluxes. The uncertainty on the ^14N+p -> ^15O+g rate is the largest of the non-composition uncertainties to the CNO neutrino fluxes. We propose an independent method to help identify which SSM is the correct one. Present neutrino data can not distinguish the solar neutrino predictions of both models but ongoing measurements can help to solve the puzzle.

Carlos Pena-Garay; Aldo Serenelli

2008-11-16T23:59:59.000Z

405

Unified Graphical Summary of Neutrino Mixing Parameters  

E-Print Network (OSTI)

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

Olga Mena; Stephen Parke

2003-12-10T23:59:59.000Z

406

A search for sterile neutrinos in MINOS  

SciTech Connect

MINOS, the Main Injector Neutrino Oscillation Search, is a long baseline neutrino oscillation experiment based at Fermilab National Accelerator Laboratory. The experiment uses a neutrino beam, which is measured 1 km downstream from its origin in the Near detector at Fermilab and then 735 km later in the Far detector at the Soudan mine. By comparing these two measurements, MINOS can attain a very high precision for parameters in the atmospheric sector of neutrino oscillations. In addition to precisely determining {Delta}m{sub 23}{sup 2} and {theta}{sub 23} through the disappearance of {nu}{sub {mu}}, MINOS is able to measure {nu}{sub {mu}} {yields} {nu}{sub sterile} by looking for a deficit in the number of neutral current interactions seen in the Far detector. In this thesis, we present the results of a search for sterile neutrinos in MINOS.

Osiecki, Thomas Henry; /Texas U.

2007-12-01T23:59:59.000Z

407

Solar neutrinos and the solar composition problem  

E-Print Network (OSTI)

Standard solar models (SSM) are facing nowadays a new puzzle: the solar composition problem. New determinations of solar metal abundances lead SSM calculations to conflict with helioseismological measurements, showing discrepancies that extend from the convection zone to the solar core and can not be easily assigned to deficiencies in the modelling of the solar convection zone. We present updated solar neutrino fluxes and uncertainties for two SSM with high (old) and low (new) solar metallicity determinations. The uncertainties in iron and carbon abundances are the largest contribution to the uncertainties of the solar neutrino fluxes. The uncertainty on the ^14N+p -> ^15O+g rate is the largest of the non-composition uncertainties to the CNO neutrino fluxes. We propose an independent method to help identify which SSM is the correct one. Present neutrino data can not distinguish the solar neutrino predictions of both models but ongoing measurements can help to solve the puzzle.

Pena-Garay, Carlos

2008-01-01T23:59:59.000Z

408

Neutrino astronomy with the MACRO detector  

E-Print Network (OSTI)

High energy gamma ray astronomy is now a well established field and several sources have been discovered in the region from a few GeV up to several TeV. If sources involving hadronic processes exist, the production of photons would be accompanied by neutrinos too. Other possible neutrino sources could be related to the annihilation of WIMPs at the center of galaxies with black holes. We present the results of a search for point-like sources using 1100 upward-going muons produced by neutrino interactions in the rock below and inside the MACRO detector in the underground Gran Sasso Laboratory. These data show no evidence for a possible neutrino point-like source or for possible correlations between gamma ray bursts and neutrinos. They have been used to set flux upper limits for candidate point-like sources which are in the range 10^-14-10^-15 cm-2 s-1.

M. Ambrosio

2000-02-26T23:59:59.000Z

409

RELIABILITY CONSIDERATIONS OF ELECTRONICS COMPONENTS FOR THE DEEP UNDERWATER MUON AND NEUTRINO DETECTION SYSTEM  

E-Print Network (OSTI)

Considerations for the Dtep Underwater Muon and NeutrinoPresented at the Deep Underwater Huon and Neutrino DetectionCOMPONENTS FOR THE DEEP UNDERWATER MUON AND NEUTRINO

Leskovar, B.

2010-01-01T23:59:59.000Z

410

A "Muon Mass Tree" with alpha-quantized Lepton, Quark and Hadron Masses  

E-Print Network (OSTI)

A "muon mass tree" is displayed that contains the excitation systematics for accurately reproducing the masses of the six Standard Model quarks (u,d,s,c,b,t); the heavy leptons; the proton; the phi, J/Psi and Upsilon vector meson thrshold states; the Bc meson; and the mass-averaged W and Z gauge bosons, using a unified mass formalism based on the electron ground state. Multiples of an alpha-quantized 105.04 MeV fermion mass quantum reproduce the states below 12 GeV, and multiples of a doubly-alpha-quantized 14,394 Mev fermion mass quantum reproduce the W-Z and t states above 12 GeV, where alpha ~ 1/137 is the fine structure constant. Masses are additive, and the overall mass accuracy for these states is in the 1% range. A similar "pion mass tree" based on an alpha-quantized 70.03 MeV boson mass quantum accurately reproduces the pseudoscalar meson masses. The mass alpha-quantization follows from a corresponding experimental alpha-spacing of the long-lived particle lifetimes, which occur in well-defined lifetime groups that are each determined by a dominant Standard Model quark substate.

Malcolm H. Mac Gregor

2006-07-20T23:59:59.000Z

411

Detection of the Neutrino Fluxes from Several Sources  

E-Print Network (OSTI)

It is considered the detection of neutrinos moving from the opposite directions. The states of the particle of the detector interacting with the neutrinos are connected with the P-transformation. Hence only a half of neutrinos gives contribution into the superposition of the neutrino states. Taking into account the effect of the opposite neutrino directions the total neutrino flux from several sources are in the range 0.5--1 of that without the effect. The neutrino flux from nuclear reactors measured in the KamLAND experiment is $0.611\\pm 0.085 {\\rm (stat)} \\pm 0.041 {\\rm (syst)} $ of the expected flux. Calculations for the conditions of the KamLAND experiment yield the neutrino flux taking into account the effect of the opposite neutrino directions, 0.555, of that without the effect that may account for the neutrino flux observed in the KamLAND experiment.

D. L. Khokhlov

2003-02-19T23:59:59.000Z

412

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

DOE Data Explorer (OSTI)

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

SAGE Collaboration

413

Chiral Perturbation Theory for All-Staggered Heavy-Light Mesons  

E-Print Network (OSTI)

In highly improved staggered quark (HISQ) simulations by the HPQCD, MILC, and Fermilab Lattice collaborations, both the light quarks and the charm quark are staggered. We extend chiral perturbation theory for staggered quarks to include such all-staggered heavy-light mesons. We assume that the heavy quark action is sufficiently improved that we may take $a m_Q >\\Lambda_{QCD}$ so that a continuum heavy quark expansion is appropriate. We develop this effective chiral theory through next-to-leading order, and use it to study the pattern of taste splittings in the heavy-light meson and to compute the leptonic decay constant of the heavy-light meson to one-loop in the chiral expansion.

Claude Bernard; Javad Komijani

2013-09-18T23:59:59.000Z

414

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

E-Print Network (OSTI)

We analyze all available solar and related reactor neutrino experiments, as well as simulated future 7Be, p-p, pep, and ^8B 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 show that the p-p solar neutrino flux is 1.02 +- 0.02 (1 sigma) times the flux predicted by the BP00 standard solar model; the 7Be neutrino flux is 0.93^{+0.25}_{-0.63} the predicted flux; and the ^8B flux is 1.01 +- 0.04 the predicted flux. The neutrino oscillation parameters are: Delta m^2 = 7.3^{+0.4}_{-0.6}\\times 10^{-5} eV^2 and tan^2 theta_{12} = 0.41 +- 0.04. We evaluate how accurate future experiments must be to determine more precisely neutrino oscillation parameters and solar neutrino fluxes, and to elucidate the transition from vacuum-dominated to matter-dominated oscillations at low energies. A future 7Be nu-e scattering experiment accurate to +- 10 % can reduce the uncertainty in the experimentally determined 7Be neutrino flux by a factor of four and the uncertainty in the p-p neutrino flux by a factor of 2.5 (to +- 0.8 %). A future p-p experiment must be accurate to better than +- 3 % to shrink the uncertainty in tan^2 theta_{12} by more than 15 %. The idea that the Sun shines because of nuclear fusion reactions can be tested accurately by comparing the observed photon luminosity of the Sun with the luminosity inferred from measurements of solar neutrino fluxes. Based upon quantitative analyses of present and simulated future experiments, we answer the question: Why perform low-energy solar neutrino experiments?

John N. Bahcall; Carlos Pena-Garay

2003-05-15T23:59:59.000Z

415

Charged heavy vector boson production at the Large Hadron Collider  

E-Print Network (OSTI)

We evaluate the sensitivity of the Large Hadron Collider (LHC) to charged heavy vector boson production followed by their decays to $W^\\pm Z^0$. We include the correlated decays of the gauge bosons to leptonic final states. With an integrated luminosity of $10^5$ pb$^{-1}$, charged technirhos in the minimal SU(N)$_{TC}$ model for $N\\geq 7$ yield signals with a significance larger than 5. In more general models, we explore the range of parameter space to which LHC experiments will be sensitive. Rapidity correlations exhibiting enhanced longitudinal gauge boson pair production are also shown.

Dal Soo Oh; M. H. Reno

1998-12-02T23:59:59.000Z

416

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

E-Print Network (OSTI)

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

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

2005-01-03T23:59:59.000Z

417

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

E-Print Network (OSTI)

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

S. Pascoli; S. T. Petcov

2002-05-02T23:59:59.000Z

418

Solving the Solar Neutrino Problem 2 km Underground -- the Sudbury Neutrino Observatory  

E-Print Network (OSTI)

The Sudbury Neutrino Observatory (SNO) is capable of measuring simultaneously the flux of electron-type neutrinos and the total flux of all active flavours of neutrinos originating from the Sun. A model-independent test of neutrino flavour transformation was performed by comparing these two measurements. Assuming an undistorted neutrino energy spectrum, this transformation has been definitively demonstrated in the pure D2O phase of the SNO experiment. In the second phase with dissolved NaCl in the D2O, the total active solar neutrino flux was measured without any assumption on the energy dependence of flavour transformation. In this talk, results from these measurements, their physics implications and the current status of the SNO experiment are presented.

A. W. P. Poon; for the SNO Collaboration

2003-11-30T23:59:59.000Z

419

Solar neutrinos: beyond standard solar models  

E-Print Network (OSTI)

After a short survey of the physics of solar neutrinos, giving an overview of hydrogen burning reactions, predictions of standard solar models and results of solar neutrino experiments, we discuss the solar-model-independent indications in favour of non-standard neutrino properties. The experimental results look to be in contradiction with each other, even disregarding some experiment: unless electron neutrinos disappear in their trip from the sun to the earth, the fluxes of intermediate energy neutrinos (those from 7Be electron capture and from the CNO cycle) result to be unphysically negative, or anyway extremely reduced with respect to standard solar model predictions. Next we review extensively non-standard solar models built as attempts to solve the solar neutrino puzzle. The dependence of the central solar temperature on chemical composition, opacity, age and on the values of the astrophysical S-factors for hydrogen-burning reactions is carefully investigated. Also, possible modifications of the branching among the various pp-chains in view of nuclear physics uncertainties are examined. Assuming standard neutrinos, all solar models examined fail in reconciling theory with experiments, even when the physical and chemical inputs are radically changed with respect to present knowledge and even if some of the experimental results are discarded.

V. Castellani; S. Degl'Innocenti; G. Fiorentini; M. Lissia; B. Ricci

1996-06-30T23:59:59.000Z

420

The status of the solar neutrino problem  

Science Conference Proceedings (OSTI)

Perhaps the most outstanding discrepancy between prediction and measurements in current particle physics comes from the solar neutrino problem, in which a large deficit of high-energy solar neutrinos is observed. Many Nonstandard Solar Models have been invoked to try to reduce the predicted flux, but all have run into problems in trying to reproduce other measured parameters (e.g., the luminosity) of the Sun. Other explanations involving new physics such as neutrino decay and neutrino oscillations, etc. have also been proffered. Again, most of these explanations have been ruled out by either laboratory or astrophysical measurements. It appears that perhaps the most likely particle physics solution is that of matter enhanced neutrino oscillation, the Mikheyev-Smirnov-Wolfenstein (MSW) oscillations. Two new radiochemical gallium experiments, which have a low enough threshold to be sensitive to the dominant flux of low-energy p-p neutrinos, now also report a deficit and also favor a particle physics solution. The next generation of solar experiments promise to finally resolve the source of the ``solar neutrino problem`` by the end of this decade.

Bowles, T.J.

1993-12-01T23:59:59.000Z

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421

Neutrino chirality flip in a supernova and the bound on the neutrino magnetic moment  

E-Print Network (OSTI)

The neutrino chirality-flip process under the conditions of the supernova core is investigated in detail with the plasma polarization effects in the photon propagator taken into account. It is shown that the contribution of the proton fraction of plasma is essential. New upper bounds on the neutrino magnetic moment are obtained: mu_nu flip. The best astrophysical upper bound on the neutrino magnetic moment is improved by the factor of 3 to 7.

A. V. Kuznetsov; N. V. Mikheev

2006-06-25T23:59:59.000Z

422

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

Science Conference Proceedings (OSTI)

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

Coleman, Stephen James; /William-Mary Coll.

2011-01-01T23:59:59.000Z

423

Scalar neutrinos at the LHC  

Science Conference Proceedings (OSTI)

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

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

2011-05-01T23:59:59.000Z

424

Measuring Neutrino Oscillations with Nuclear Reactors  

SciTech Connect

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

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

2007-10-26T23:59:59.000Z

425

Dirac Neutrino Masses from Generalized Supersymmetry Breaking  

SciTech Connect

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

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

2008-03-07T23:59:59.000Z

426

Neutrino Capture Reactions on $^{40}$Ar  

E-Print Network (OSTI)

Gamow-Teller (GT) strength in $^{40}$Ar is studied by shell-model calculations with monopole-based universal intearction, which has tensor components of $\\pi$\\rho$-meson exchanges. Calculated GT strength is found to be consistent with the experimental data obtained by recent ($p, n$) reactions. Neutrino capture cross sections on $^{40}$Ar for solar neutrinos from $^{8}$B are found to be enhanced compared with previous calculations. The reaction cross sections for multipoles other than $0^{+}$ and $1^{+}$ are obtained by random-phase approximation (RPA). Their contributions become important for neutrino energies larger than 50 MeV.

Toshio Suzuki; Michio Honma

2012-11-17T23:59:59.000Z

427

Neutrino-Accelerated Hot Hydrogen Burning  

E-Print Network (OSTI)

We examine the effects of significant electron anti-neutrino fluxes on hydrogen burning. Specifically, we find that the bottleneck weak nuclear reactions in the traditional pp-chain and the hot CNO cycle can be accelerated by anti-neutrino capture, increasing the energy generation rate. We also discuss how anti-neutrino capture reactions can alter the conditions for break out into the rp-process. We speculate on the impact of these considerations for the evolution and dynamics of collapsing very- and super- massive compact objects.

Chad T. Kishimoto; George M. Fuller

2006-06-23T23:59:59.000Z

428

NEUTRINO SPECTRA FROM ACCRETION DISKS: NEUTRINO GENERAL RELATIVISTIC EFFECTS AND THE CONSEQUENCES FOR NUCLEOSYNTHESIS  

Science Conference Proceedings (OSTI)

Black hole (BH) accretion disks have been proposed as good candidates for a range of interesting nucleosynthesis, including the r-process. The presence of the BH influences the neutrino fluxes and affects the nucleosynthesis resulting from the interaction of the emitted neutrinos and hot outflowing material ejected from the disk. We study the impact of general relativistic effects on the neutrinos emitted from BH accretion disks. We present abundances obtained by considering null geodesics and energy shifts for two different disk models. We find that both the bending of the neutrino trajectories and the energy shifts have important consequences for the nucleosynthetic outcome.

Caballero, O. L.; McLaughlin, G. C. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Surman, R., E-mail: lcaballe@uw.edu, E-mail: olcaball@ncsu.edu, E-mail: gail_mclaughlin@ncsu.edu, E-mail: surmanr@union.edu [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States)

2012-02-01T23:59:59.000Z

429

Neutrino Spectra from Accretion Disks: Neutrino General Relativistic Effects and the Consequences for Nucleosynthesis  

E-Print Network (OSTI)

Black hole accretion disks have been proposed as good candidates for a range of interesting nucleosynthesis, including the r-process. The presence of the black hole influences the neutrino fluxes and affects the nucleosynthesis resulting from the interaction of the emitted neutrinos and hot outflowing material ejected from the disk. We study the impact of general relativistic effects on the neutrinos emitted from black hole accretion disks. We present abundances obtained by considering null geodesics and energy shifts for two different disk models. We find that both the bending of the neutrino trajectories and the energy shifts have important consequences for the nucleosynthetic outcome

O. L Caballero; G. C. McLaughlin; R. Surman

2011-05-31T23:59:59.000Z

430

Theta-13 as a Probe of Mu-Tau symmetry for Leptons  

E-Print Network (OSTI)

Many experiments are being planned to measure the neutrino mixing parameter $\\theta_{13}$ using reactor as well as accelerator neutrino beams. In this note, the theoretical significance of a high precision measurement of this parameter is discussed. It is emphasized that it will provide crucial information about different ways to understand the origin of large atmospheric neutrino mixing and move us closer towards determining the neutrino mass matrix. For instance if exact $\\mu\\leftrightarrow \\tau$ symmetry in the neutrino mass matrix is assumed to be the reason for maximal $\

R. N. Mohapatra

2004-08-17T23:59:59.000Z

431

Calorimetry for Lepton Collider Experiments - CALICE results and activities  

E-Print Network (OSTI)

The CALICE collaboration conducts calorimeter R&D for highly granular calorimeters, mainly for their application in detectors for a future lepton collider at the TeV scale. The activities ranges from generic R&D with small devices up to extensive beam tests with prototypes comprising up to several 100000 calorimeter cells. CALICE has validated the performance of particle flow algorithms with test beam data and delivers the proof of principle that highly granular calorimeters can be built, operated and understood. The successes achieved in the past years allows the step from prototypes to calorimeter systems for particle physics detectors to be addressed.

The CALICE Collaboration

2012-12-20T23:59:59.000Z

432

Searches for Leptonic B Decays at BaBar  

SciTech Connect

Measurements of the branching fractions of purely leptonic decays of B-mesons translate into constraints in the plane of the charged Higgs mass versus tan {beta} which are relatively insensitive to the particular theoretical model. Using the full BABAR dataset of 450 million B-decays we search for these decays. No significant signal is found in the decays into electrons or muons and we set upper limits on the branching fractions of the order of a 10{sup -6} at 90% confidence level. We measure the branching fraction of B {yields} {tau}{mu} to be (1.7 {+-} 0.6) x 10{sup -4}.

Nelson, Silke; /SLAC

2012-04-25T23:59:59.000Z

433

Search for the Rare Leptonic Decays B^+ \\to l^+ \  

SciTech Connect

We have performed a search for the rare leptonic decays B{sup +} {yields} {ell}{sup +} {nu}{sub {ell}}({ell} = e,{mu}), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468 x 10{sup 6} B{bar B} pairs we find no evidence for a signal and set an upper limit on the branching fractions B(B{sup +} {yields} e{sup +}{nu}{sub e}) < 1.9 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.

Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2009-06-19T23:59:59.000Z

434

Measurement of the nue and Total 8B Solar Neutrino Fluxes with theSudbury Neutrino Observatory Phase I Data Set  

SciTech Connect

This article provides the complete description of resultsfrom the Phase I data set of the Sudbury Neutrino Observatory (SNO). ThePhase I data set is based on a 0.65 kt-year exposure of heavy water tothe solar 8B neutrino flux. Included here are details of the SNO physicsand detector model, evaluations of systematic uncertainties, andestimates of backgrounds. Also discussed are SNO's approach tostatistical extraction of the signals from the three neutrino reactions(charged current, neutral current, and elastic scattering) and theresults of a search for a day-night asymmetry in the ?e flux. Under theassumption that the 8B spectrum is undistorted, the measurements fromthis phase yield a solar ?e flux of ?(?e) =1.76+0.05?0.05(stat.)+0.09?0.09 (syst.) x 106 cm?2 s?1, and a non-?ecomponent ?(? mu) = 3.41+0.45?0.45(stat.)+0.48?0.45 (syst.) x 106 cm?2s?1. The sum of these components provides a total flux in excellentagreement with the predictions of Standard Solar Models. The day-nightasymmetry in the ?e flux is found to be Ae = 7.0 +- 4.9 (stat.)+1.3?1.2percent (sys.), when the asymmetry in the total flux is constrained to bezero.

Aharmim, B.; Ahmad, Q.R.; Ahmed, S.N.; Allen, R.C.; Andersen,T.C.; Anglin, J.D.; Buehler, G.; Barton, J.C.; Beier, E.W.; Bercovitch,M.; Bergevin, 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.; Burritt, T.H.; Cameron, J.; Chan, Y.D.; Chen, H.H.; Chen, M.; Chen, X.; Cleveland, B.T.; Cowan, J.H.M.; Cowen, D.F.; Cox, G.A.; Currat, C.A.; Dai, X.; Dalnoki-Veress, F.; Davidson, W.F.; Deng, H.; DiMarco, M.; 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.; Fleurot, F.; Ford, R.J.; Formaggio, J.A.; Fowler, M.M.; Frame, K.; Frank, E.D.; Frati, W.; Gagnon,N.; Germani, J.V.; Gil, S.; Goldschmidt, A.; Goon, J.T.M.; Graham, K.; Grant, D.R.; Guillian, E.; 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.; Henning, R.; Hepburn, J.D.; Heron, H.; Hewett, J.; Hime,A.; Howard, C.; Howe, M.A.; Huang, M.; Hykawy, J.G.; Isaac, M.C.P.; Jagam, P.; Jamieson, B.; Jelley, N.A.; Jillings, C.; Jonkmans, G.; Kazkaz, K.; Keener, P.T.; Kirch, K.; Klein, J.R.; Knox, A.B.; Komar,R.J.; Kormos, L.L.; Kos, M.; Kouzes, R.; Krueger, A.; Kraus, C.; Krauss,C.B.; Kutter, T.; Kyba, C.C.M.; Labranche, H.; Lange, R.; Law, J.; Lawson, I.T.; Lay, M.; Lee, H.W.; Lesko, K.T.; Leslie, J.R.; Levine, I.; Loach, J.C.; Locke, W.; Luoma, S.; Lyon, J.; MacLellan, R.; Majerus, S.; Mak, H.B.; Maneira, J.; Marino, A.D.; Martin, R.; McCauley, N.; McDonald,A.B.; McDonald, D.S.; McFarlane, K.; McGee, S.; McGregor, G.; MeijerDrees, R.; Mes, H.; Mifflin, C.; Miknaitis, K.K.S.; Miller, M.L.; Milton,G.; Moffat, B.A.; Monreal, B.; Moorhead, M.; Morrissette, B.; Nally,C.W.; Neubauer, M.S.; et al.

2007-02-01T23:59:59.000Z

435

A Measurement of Neutrino Charged Current Interactions and a Search for Muon Neutrino Disappearance with the Fermilab Booster Neutrino Beam  

SciTech Connect

In this thesis, we report on a measurement of muon neutrino inclusive charged current interactions on carbon in the few GeV region, using the Fermilab Booster Neutrino Beam. The all neutrino mode data collected in the SciBooNE experiment is used for this analysis. We collected high-statistics CC interaction sample at SciBooNE, and extracted energy dependent inclusive charged current interaction rates and cross sections for a wide energy range from 0.25 GeV to {approx}3 GeV. We measure the interaction rates with 6-15% precision, and the cross sections with 10-30% precision. We also made an energy integrated measurements, with the precisions of 3% for the rate, and 8% for the cross section measurements. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. This inclusive interaction measurement is nearly free from effects of hadron re-interactions in the nucleus. Hence, it is complementary to other exclusive cross section measurements, and essential to understand the neutrino interaction cross sections in the few GeV region, which is relevant to ongoing and future neutrino oscillation experiments. This analysis also provides the normalization for SciBooNE's previous cross section ratio measurements for charged current coherent pion production and neutral current neutral pion production. Then, a precise comparison between our previous measurements and the model predictions becomes possible. The result of the interaction rate measurement is used to constrain the product of the neutrino flux and the cross section at the other experiment on the Fermilab Booster Neutrino Beam: Mini-BooNE. We conducted a search for short-baseline muon neutrino disappearance using data both from SciBooNE and MiniBooNE, to test a possible neutrino oscillation with sterile neutrinos which is suggested by the LSND experiment. With this constraint by SciBooNE, we significantly reduced the flux and the cross section uncertainties at MiniBooNE, and achieved the world best sensitivity for the {nu}{sub {mu}} disappearance at 0.5 < {Delta}m{sup 2} < 30 (eV{sup 2}). We found no significant oscillation signal, and set one of the world strongest limits for the sterile neutrino models.

Nakajima, Yasuhiro; /Kyoto U.

2011-01-01T23:59:59.000Z

436

A Measurement of Neutrino Charged Current Interactions and a Search for Muon Neutrino Disappearance with the Fermilab Booster Neutrino Beam  

SciTech Connect

In this thesis, we report on a measurement of muon neutrino inclusive charged current interactions on carbon in the few GeV region, using the Fermilab Booster Neutrino Beam. The all neutrino mode data collected in the SciBooNE experiment is used for this analysis. We collected high-statistics CC interaction sample at SciBooNE, and extracted energy dependent inclusive charged current interaction rates and cross sections for a wide energy range from 0.25 GeV to {approx}3 GeV. We measure the interaction rates with 6-15% precision, and the cross sections with 10-30% precision. We also made an energy integrated measurements, with the precisions of 3% for the rate, and 8% for the cross section measurements. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. This inclusive interaction measurement is nearly free from effects of hadron re-interactions in the nucleus. Hence, it is complementary to other exclusive cross section measurements, and essential to understand the neutrino interaction cross sections in the few GeV region, which is relevant to ongoing and future neutrino oscillation experiments. This analysis also provides the normalization for SciBooNE's previous cross section ratio measurements for charged current coherent pion production and neutral current neutral pion production. Then, a precise comparison between our previous measurements and the model predictions becomes possible. The result of the interaction rate measurement is used to constrain the product of the neutrino flux and the cross section at the other experiment on the Fermilab Booster Neutrino Beam: Mini-BooNE. We conducted a search for short-baseline muon neutrino disappearance using data both from SciBooNE and MiniBooNE, to test a possible neutrino oscillation with sterile neutrinos which is suggested by the LSND experiment. With this constraint by SciBooNE, we significantly reduced the flux and the cross section uncertainties at MiniBooNE, and achieved the world best sensitivity for the {nu}{sub {mu}} disappearance at 0.5 < {Delta}m{sup 2} < 30 (eV{sup 2}). We found no significant oscillation signal, and set one of the world strongest limits for the sterile neutrino models.

Nakajima, Yasuhiro; /Kyoto U.

2011-01-01T23:59:59.000Z

437

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

E-Print Network (OSTI)

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

Kaoru Hagiwara; Naotoshi Okamura; Ken-ichi Senda

2006-07-23T23:59:59.000Z

438

Charged lepton electric dipole moments with the localized leptons and the new Higgs doublet in the two Higgs doublet model  

E-Print Network (OSTI)

We study the lepton electric dipole moments in the split fermion scenario, in the two Higgs doublet model, where the new Higgs scalars are localized around the origin in the extra dimension, with the help of the localizer field. We observe that the numerical value of the electron (muon, tau) electric dipole moment is at the order of the magnitude of 10^{-31} (10^{-24}, 10^{-22}) (e-cm) and this quantity is sensitive the new Higgs localization in the extra dimension.

Erhan Onur Iltan

2005-11-20T23:59:59.000Z

439

Longevity Problem of Sterile Neutrino Dark Matter  

E-Print Network (OSTI)

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

Hiroyuki Ishida; Kwang Sik Jeong; Fuminobu Takahashi

2013-09-12T23:59:59.000Z

440

Precision spectroscopy with reactor anti-neutrinos  

E-Print Network (OSTI)

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

Huber, P; Huber, Patrick; Schwetz, Thomas

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutrinos heavy leptons" from the National Library of EnergyBeta (NLEBeta).
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441

QLC relation and neutrino mass hierarchy  

E-Print Network (OSTI)

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

Ferrandis, Javier

2009-01-01T23:59:59.000Z

442

Experimental and phenomenological status of neutrino ... - Springer  

Science Conference Proceedings (OSTI)

1 kt water Cerenkov and a fine grained water tube with scintillation fibre 6 ton detector. This way the neutrino flux is accurately known. The final result of the.

443

Neutrino Oscillation Experiments at Nuclear Reactors  

E-Print Network (OSTI)

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

Giorgio Gratta

1999-05-06T23:59:59.000Z

444

Neutrino nuclear response and photo nuclear reaction  

E-Print Network (OSTI)

Photo nuclear reactions are shown to be used for studying neutrino/weak nuclear responses involved in astro-neutrino nuclear interactions and double beta decays. Charged current weak responses for ground and excited states are studied by using photo nuclear reactions through isobaric analog states of those states, while neutral current weak responses for excited states are studied by using photo nuclear reactions through the excited states. The weak interaction strengths are studied by measuring the cross sections of the photo nuclear reactions, and the spin and parity of the state are studied by measuring angular correlations of particles emitted from the photo nuclear reactions. Medium-energy polarized photons obtained from laser photons scattered off GeV electrons are very useful. Nuclear responses studied by photo nuclear reactions are used to evaluate neutrino/weak nuclear responses, i.e. nuclear beta and double beta matrix elements and neutrino nuclear interactions, and to verify theoretical calculation...

Ejiri, H; Boswell, M; Young, A

2013-01-01T23:59:59.000Z

445

Neutrino nuclear response and photo nuclear reaction  

E-Print Network (OSTI)

Photo nuclear reactions are shown to be used for studying neutrino/weak nuclear responses involved in astro-neutrino nuclear interactions and double beta decays. Charged current weak responses for ground and excited states are studied by using photo nuclear reactions through isobaric analog states of those states, while neutral current weak responses for excited states are studied by using photo nuclear reactions through the excited states. The weak interaction strengths are studied by measuring the cross sections of the photo nuclear reactions, and the spin and parity of the state are studied by measuring angular correlations of particles emitted from the photo nuclear reactions. Medium-energy polarized photons obtained from laser photons scattered off GeV electrons are very useful. Nuclear responses studied by photo nuclear reactions are used to evaluate neutrino/weak nuclear responses, i.e. nuclear beta and double beta matrix elements and neutrino nuclear interactions, and to verify theoretical calculations for them.

H. Ejiri; A. I. Titov; M. Boswell; A. Young

2013-11-10T23:59:59.000Z

446

BNL | Long Baseline Neutrino Experiment (LBNE)  

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

through the Earth's mantle before striking its target at the Homestake Mine in Lead, South Dakota. This distance, not much more than a blink for speedy neutrinos, gives the...

447

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

SciTech Connect

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

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

2010-01-01T23:59:59.000Z

448

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

E-Print Network (OSTI)

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

Ondrej Pejcha; Basudeb Dasgupta; Todd A. Thompson

2011-06-28T23:59:59.000Z

449

Megaton Water Cerenkov Detectors and Astrophysical Neutrinos  

E-Print Network (OSTI)

Although formal proposals have not yet been made, the UNO and Hyper-Kamiokande projects are being developed to follow-up the tremendously successful program at Super-Kamiokande using a detector that is 20-50 times larger. The potential of such a detector to continue the study of astrophysical neutrinos is considered and contrasted with the program for cubic kilometer neutrino observatories.

Maury Goodman

2005-01-21T23:59:59.000Z

450

Megaton Water Cerenkov Detectors and Astrophysical Neutrinos  

E-Print Network (OSTI)

Although formal proposals have not yet been made, the UNO and Hyper-Kamiokande projects are being developed to follow-up the tremendously successful program at Super-Kamiokande using a detector that is 20-50 times larger. The potential of such a detector to continue the study of astrophysical neutrinos is considered and contrasted with the program for cubic kilometer neutrino observatories. 1.

M. Goodman A

2005-01-01T23:59:59.000Z

451

Neutrino Factory Physics Study Plots  

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

Plots Plots Kerrys Plot Area Rajas Plot Area Superbeams draft report Steves Talk at the 2 day meeting for the neutrino factory physics study, 17-18 Feb, 2000. sin2 2theta(13) reach summary plot Superbeam plots Fig. 3 for superbeams paper Very long baseline conventional beam setup at FNAL Decay channel length versus baseline for conventional beams at FNAL Pion decay fraction versus baseline for conventional beams at FNAL Superbeam sin**2 2theta(13) sensitivity vs E and L: Rate table for WBB, LAr Superbeam sin**2 2theta(13) sensitivity vs E and L: Rate table for NBB, water C NUMI medium energy beam, baseline 2800 km, s2 2theta(13) = 0.01 NUMI medium energy beam, baseline 2800 km, s2 2theta(13) = 0.04 Draft paper Figures for entry level and beyond paper Fig. X1 Wrong-sign muon CC interaction spectrum versus muon

452

Earthquake Forecast via Neutrino Tomography  

E-Print Network (OSTI)

We discuss the possibility of forecasting earthquakes by means of (anti)neutrino tomography. Antineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomography of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival probability of electron antineutrinos for cases without and with an anomalous accumulation of electrons which can be considered as a clear signal of the coming earthquake, at the geological region with a fault zone, and find that the variation may reach as much as 3% for $\\bar \

Bin Wang; Ya-Zheng Chen; Xue-Qian Li

2010-01-17T23:59:59.000Z

453

Status of the LBNE Neutrino Beamline  

SciTech Connect

The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a beam of neutrinos toward a detector placed at the Homestake Mine in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector (60-120 GeV) hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined taking into account several factors including the physics goals, the Monte Carlo modeling of the facility, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be {approx}700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. We discuss here the status of the conceptual design and the associated challenges.

Papadimitriou, Vaia; /Fermilab

2011-12-01T23:59:59.000Z

454

Accelerator-based neutrino oscillation experiments  

SciTech Connect

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

Harris, Deborah A.; /Fermilab

2007-12-01T23:59:59.000Z

455

Radiochemical Solar Neutrino Experiments - Successful and Otherwise.  

SciTech Connect

Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ({sup 37}Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ({sup 71}Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled.

Hahn,R.L.

2008-05-25T23:59:59.000Z

456

Solar neutrino analysis of Super-Kamiokande  

E-Print Network (OSTI)

Super-Kamiokande-IV data taking began in September of 2008, and with upgraded electronics and improvements to water system dynamics, calibration and analysis techniques, a clear solar neutrino signal could be extracted at recoil electron kinetic energies as low as 3.5 MeV. The SK-IV extracted solar neutrino flux between 3.5 and 19.5 MeV is found to be (2.36$\\pm$0.02(stat.)$\\pm$0.04(syst.))$\\times 10^6$ /(cm$^2$sec). The SK combined recoil electron energy spectrum favors distortions predicted by standard neutrino flavour oscillation parameters over a flat suppression at 1$\\sigma$ level. A maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the elastic neutrino-electron scattering rate in SK, results in a day/night asymmetry of $-3.2\\pm1.1$(stat.)$\\pm$0.5(syst.)$%$. The 2.7 $\\sigma$ significance of non-zero asymmetry is the first indication of the regeneration of electron type solar neutrinos as they travel through Earth's matter. A fit to all solar neutrino data and KamLAND yields $\\sin^2 \\theta_{12} = 0.304 \\pm 0.013$, $\\sin^2 \\theta_{13} = 0.031^{+0.017}_{-0.015}$ and $\\Delta m^2_{21} = 7.45^{+0.20}_{-0.19} \\times 10^{-5} {\\rm eV}^2$.

Hiroyuki Sekiya; for the Super-Kamiokande Collaboration

2013-07-14T23:59:59.000Z

457

Theory of Neutrinos: A White Paper  

E-Print Network (OSTI)

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

R. N. Mohapatra; S. Antusch; K. S. Babu; G. Barenboim; M. -C. Chen; S. Davidson; A. de Gouvea; P. de Holanda; B. Dutta; Y. Grossman; A. Joshipura; B. Kayser; J. Kersten; Y. Y. Keum; S. F. King; P. Langacker; M. Lindner; W. Loinaz; I. Masina; I. Mocioiu; S. Mohanty; H. Murayama