433 research outputs found
On the Mass Eigenstate Composition of the 8B Neutrinos from the Sun
The present data of gallium experiments provide indirectly the only
experimental limit on the fraction of mass eigenstate for the B
neutrinos from the Sun. However, if to use the experimental data alone, the
fraction of and, consequently, still is allowed to
be varied within a rather broad range. The further experimental efforts are
needed to clear this point.Comment: 13 pages, 1 figure, 1 table. Corrected version, published in
JCAP04(2007)00
Hadron energy response of the Iron Calorimeter detector at the India-based Neutrino Observatory
The results of a Monte Carlo simulation study of the hadron energy response
for the magnetized Iron CALorimeter detector, ICAL, proposed to be located at
the India-based Neutrino Observatory (INO) is presented. Using a GEANT4
modeling of the detector ICAL, interactions of atmospheric neutrinos with
target nuclei are simulated. The detector response to hadrons propagating
through it is investigated using the hadron hit multiplicity in the active
detector elements. The detector response to charged pions of fixed energy is
studied first, followed by the average response to the hadrons produced in
atmospheric neutrino interactions using events simulated with the NUANCE event
generator. The shape of the hit distribution is observed to fit the Vavilov
distribution, which reduces to a Gaussian at high energies. In terms of the
parameters of this distribution, we present the hadron energy resolution as a
function of hadron energy, and the calibration of hadron energy as a function
of the hit multiplicity. The energy resolution for hadrons is found to be in
the range 85% (for 1GeV) -- 36% (for 15 GeV).Comment: 14 pages, 10 figures (24 eps files
Solving Solar Neutrino Puzzle via LMA MSW Conversion
We analyze the existing solar neutrino experiment data and show the allowed
regions. The result from SNO's salt phase itself restricts quite a lot the
allowed region's area. Reactor neutrinos play an important role in determining
oscillation parameters. KamLAND gives decisive conclusion on the solution to
the solar neutrino puzzle, in particular, the spectral distortion in the 766.3
Ty KamLAND data gives another new improvement in the constraint of solar
MSW-LMA solutions. We confirm that at 99.73% C.L. the high-LMA solution is
excluded.Comment: 6 eps figure
Pair Production of Fourth Family Charged Sleptons at Colliders
We study the pair production of , which is the supersymmetric
partner of the fourth family charged lepton, at the colliders. It
is shown that the investigation of this process at ILC/CLIC will give
opportunity to differentiate the MSSM with three and four families.Comment: 6 pages, 2 figure
Neutrino oscillations with disentanglement of a neutrino from its partners
We bring attention to the fact that in order to understand existing data on
neutrino oscillations, and to design future experiments, it is imperative to
appreciate the role of quantum entanglement. Once this is accounted for, the
resulting energy-momentum conserving phenomenology requires a single new
parameter related to disentanglement of a neutrino from its partners. This
parameter may not be CP symmetric. We illustrate the new ideas, with
potentially measurable effects, in the context of a novel experiment recently
proposed by Gavrin, Gorbachev, Veretenkin, and Cleveland. The strongest impact
of our ideas is on the resolution of various anomalies in neutrino oscillations
and on neutrino propagation in astrophysical environments.Comment: 6 page
Supernova Neutrinos and the LSND Evidence for Neutrino Oscillations
The observation of the energy spectrum from a supernova burst
can provide constraints on neutrino oscillations. We derive formulas for
adiabatic oscillations of supernova antineutrinos for a variety of 3- and
4-neutrino mixing schemes and mass hierarchies which are consistent with the
LSND evidence for oscillations.
Finally, we explore the constraints on these models and LSND given by the
supernova SN1987A 's observed by the Kamiokande-2 and IMB-3
detectors.Comment: 8 pages, 3 figures. Changes with respect to original version:
appendix added; minor changes in text, figures, reference
Neutrino mass spectrum and neutrinoless double beta decay
The relations between the effective Majorana mass of the electron neutrino,
, responsible for neutrinoless double beta decay, and the neutrino
oscillation parameters are considered. We show that for any specific
oscillation pattern can take any value (from zero to the existing
upper bound) for normal mass hierarchy and it can have a minimum for inverse
hierarchy. This means that oscillation experiments cannot fix in general
. Mass ranges for can be predicted in terms of oscillation
parameters with additional assumptions about the level of degeneracy and the
type of hierarchy of the neutrino mass spectrum. These predictions for
are systematically studied in the specific schemes of neutrino mass and flavor
which explain the solar and atmospheric neutrino data. The contributions from
individual mass eigenstates in terms of oscillation parameters have been
quantified. We study the dependence of on the non-oscillation
parameters: the overall scale of the neutrino mass and the relative mass
phases. We analyze how forthcoming oscillation experiments will improve the
predictions for . On the basis of these studies we evaluate the
discovery potential of future \znbb decay searches. The role \znbb decay
searches will play in the reconstruction of the neutrino mass spectrum is
clarified. The key scales of , which will lead to the discrimination
among various schemes are: eV and eV.Comment: 47 pages, 35 figure
Wind assessment for micro wind turbines in an urban environment
Wind flow in urban environments could be seen as a potential source of energy. This form of energy could be exploited by means of micro wind turbines placed along the existing infrastructures. To test this, an outdoor campaign was organised, which recorded the wind characteristics at different locations around a highway noise barrier in Delft, the Netherlands. The real-time data set was validated with a two-dimensional Computational Fluid Dynamics study. Both the influence of the high turbulence and the inflow angle on the positioning of the micro wind turbines are assessed for the case of perpendicular flow towards the plane of the noise barrier. Results indicated that integrating micro wind turbines with the noise barriers proves advantageous due to the flow velocity increment downstream. Lastly, a noise assessment was conducted in order to determine the optimal spacing between micro wind turbines, which impacts its social acceptance
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