8,707 research outputs found
On the Interpretation of the Atmospheric Neutrino Data in Terms of Flavor Changing Neutrino Interactions
Flavour changing (FC) neutrino-matter interactions have been proposed as a
solution to the atmospheric neutrino anomaly. Here we perform the analysis of
the full set of the recent 52 kTy Super-Kamiokande atmospheric neutrino data,
including the zenith angle distribution of the contained events as well as the
higher energy upward-going stopping and through-going muon events. Our results
show that the FC mechanism can describe the full data sample with a
chi^2_{min}=44/(33 d.o.f) which is acceptable at the 90% confidence level. The
combined analysis confines the amount of FC to be either close to maximal or to
the level of about (10-50)%.Comment: 15 pages, 4 Postscript figures, uses ReVTeX. Updated analysis to 52
kTy Super-Kamiokande data. A new figure for the up-down asymmetry is
included. Some comments and references are adde
Global three-neutrino oscillation analysis of neutrino data
A global analysis of the solar, atmospheric and reactor neutrino data is
presented in terms of three-neutrino oscillations. We include the most recent
solar neutrino rates of Homestake, SAGE, GALLEX and GNO, as well as the recent
1117 day Super-Kamiokande data sample, including the recoil electron energy
spectrum both for day and night periods and we treat in a unified way the full
parameter space for oscillations, correctly accounting for the transition from
the matter enhanced (MSW) to the vacuum oscillations regime. Likewise, we
include in our description conversions with . For the
atmospheric data we perform our analysis of the contained events and the
upward-going -induced muon fluxes, including the previous data samples of
Frejus, IMB, Nusex, and Kamioka experiments as well as the full 71 kton-yr
(1144 days) Super-Kamiokande data set, the recent 5.1 kton-yr contained events
of Soudan2 and the results on upgoing muons from the MACRO detector. We first
present the allowed regions of solar and atmospheric oscillation parameters
, and , ,
respectively, as a function of and determine the constraints from
atmospheric and solar data on the mixing angle , common to solar
and atmospheric analyses. We also obtain the allowed ranges of parameters from
the full five-dimensional combined analysis of the solar, atmospheric and
reactor data.Comment: 56 pages, 21 postscript figures. Some misprints corrected and new
references added. Chooz limit included in Fig.21. Final version to appear in
Phys. Rev.
Seasonal Dependence in the Solar Neutrino Flux
MSW solutions of the solar neutrino problem predict a seasonal dependence of
the zenith angle distribution of the event rates, due to the non-zero latitude
at the Super-Kamiokande site. We calculate this seasonal dependence and compare
it with the expectations in the no-oscillation case as well as just-so
scenario, in the light of the latest Super-Kamiokande 708-day data. The
seasonal dependence can be sizeable in the large mixing angle MSW solution and
would be correlated with the day-night effect. This may be used to discriminate
between MSW and just-so scenarios and should be taken into account in refined
fits of the data.Comment: 4 pages, latex, RevTeX, two postscript figure
Implications of the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) with Liquid Argon
The CENNS-10 experiment of the COHERENT collaboration has recently reported
the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in
liquid Argon with more than significance. In this work, we exploit
the new data in order to probe various interesting parameters which are of key
importance to CEvNS within and beyond the Standard Model. A dedicated
statistical analysis of these data shows that the current constraints are
significantly improved in most cases. We derive a first measurement of the
neutron rms charge radius of Argon, and also an improved determination of the
weak mixing angle in the low energy regime. We also update the constraints on
neutrino non-standard interactions, electromagnetic properties and light
mediators with respect to those derived from the first COHERENT-CsI data.Comment: discussion expanded including light mediators and nuclear
uncertainties, figures added, references added. V3: Fig. 7 corrected,
conclusions unchange
Characterisation of Technological Innovation Management Journals
This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have.This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have.This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have
Reconciling neutrino anomalies in a simple four-neutrino scheme with R-parity violation
We propose a simple extension of the MSSM based on extra compact dimensions
which includes an singlet superfield. The fermion present
in this superfield is the sterile neutrino, which combines with one linear
combination of to form a Dirac pair whose mass
accounts for the LSND anomaly. Its small mass can be ascribed to a volume
suppression factor associated with extra compact dimensions. On the other hand
the sterile neutrino scalar partner can trigger the spontaneous violation of
R-parity, thereby inducing the necessary mass splittings to fit also the solar
and atmospheric neutrino data. Thus the model can explain all neutrino
oscillation data. It leads to four predictions for the neutrino oscillation
parameters and implies that the atmospheric neutrino problem must include at
least some oscillations, which will be testable in the
near future. Moreover it also predicts that the lightest supersymmetric
particle (LSP) decays visibly via lepton number violating modes, which could be
searched for at present and future accelerators.Comment: 15 pages, requires axodraw.sty and elsart.cl
Some constraints on neutral heavy leptons from flavor-conserving decays of the Z boson
Small neutrino masses can arise in some grand unified models or superstring
theories. We consider a model with an enhanced fermion sector containing Dirac
neutral heavy leptons. The dependence on the mass and mixing parameters of
these new fermions is investigated for several measurable quantities. We study
the flavor-conserving leptonic decays of the Z boson and universality breaking
in these decays. We also consider the W boson mass dependence on neutral heavy
lepton parameters.Comment: 20 pages, Revtex 3.0, 6 uuencoded and compressed postscript figures
included. Compressed postscript file of paper, including figures, also
available by anonymous ftp at
ftp://ftp.physics.carleton.ca/pub/theory/gour/ocipc9411.ps.Z . Accepted for
publication in Phys. Rev. D
Light Sterile Neutrino from extra dimensions and Four-Neutrino Solutions to Neutrino Anomalies
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 ( for sterile) is identified with the zero
mode of the Kaluza-Klein states. To first approximation \nu_sterile combines
with the nu_mu in order to form a Dirac neutrino with mass in the eV range
leaving the other two neutrinos massless. The smallness of this mass scale
(suitable for LSND and Hot Dark Matter) arises without appealing neither to a
see-saw mechanism nor to a radiative mechanism, but from the volume factor
associated with the canonical normalization of the wave-function of the bulk
field in the compactified dimensions. % On the other hand the splitting between
\nm and \nu_sterile (atmospheric scale) as well as the mass of the two other
neutrinos (solar mass scale) arise from the violation of the fermion number on
distant branes. We also discuss alternative scenarios involving
flavour-changing interactions. In one of them \ne can be in the electron-volt
range and therefore be probed in beta decay studies.Comment: 12 pages, latex, no figures, title changed, final version to be
published in Phys Rev
Water Use Efficiency in Chilean and Argentine Humid Temperate Grass-Legume Pastures
At two sites in Argentina and Chile five levels of water input were applied to four sown pastures of varying ages during spring and summer. The pastures consisted principally of C3 grasses and legumes, some of which were sown such as Lolium perenne, Trifolium repens, Dactylis glomerata. Dry matter (DM) production was measured and related to the estimated total evapotranspiration (ET): responses were both highly linear. Both responses to ET and absolute yields were higher at the Argentinian than at the Chilean site: respectively 10.7 and 15.2 kg DM/mm water evapotranspired. Nevertheless the calculated indices of sensitivity (Ky) of Doorenbos and Kassam (1979) were similar for the two sites, indicating a similar priority for irrigation in terms of expected responses
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