8,094 research outputs found
Flavor Neutrino Oscillations and Time-Energy Uncertainty Relation
We consider neutrino oscillations as non stationary phenomenon based on
Schrodinger evolution equation and mixed states of neutrinos with definite
flavors. We show that time-energy uncertainty relation plays a crucial role in
neutrino oscillations. We compare neutrino oscillations with
oscillations.Comment: A report at the 2nd Scandinavian Neutrino Workshop, SNOW 2006,
Stockholm, May 2-6, 200
Physics Reach of High-Energy and High-Statistics IceCube Atmospheric Neutrino Data
This paper investigates the physics reach of the IceCube neutrino detector
when it will have collected a data set of order one million atmospheric
neutrinos with energies in the 0.1 \sim 10^4 TeV range. The paper consists of
three parts. We first demonstrate how to simulate the detector performance
using relatively simple analytic methods. Because of the high energies of the
neutrinos, their oscillations, propagation in the Earth and regeneration due to
\tau decay must be treated in a coherent way. We set up the formalism to do
this and discuss the implications. In a final section we apply the methods
developed to evaluate the potential of IceCube to study new physics beyond
neutrino oscillations. Not surprisingly, because of the increased energy and
statistics over present experiments, existing bounds on violations of the
equivalence principle and of Lorentz invariance can be improved by over two
orders of magnitude. The methods developed can be readily applied to other
non-conventional physics associated with neutrinos.Comment: 21 pages, 7 figures, Revtex
Precision measurement of solar neutrino oscillation parameters by a long-baseline reactor neutrino experiment in Europe
We consider the determination of the solar neutrino oscillation parameters
and by studying oscillations of reactor
anti-neutrinos emitted by nuclear power plants (located mainly in France) with
a detector installed in the Frejus underground laboratory. The performances of
a water Cerenkov detector of 147 kt fiducial mass doped with 0.1% of Gadolinium
(MEMPHYS-Gd) and of a 50 kt scale liquid scintillator detector (LENA) are
compared. In both cases 3 uncertainties below 3% on
and of about 20% on can be obtained after one year of data
taking. The Gadolinium doped Super-Kamiokande detector (SK-Gd) in Japan can
reach a similar precision if the SK/MEMPHYS fiducial mass ratio of 1 to 7 is
compensated by a longer SK-Gd data taking time. Several years of reactor
neutrino data collected by MEMPHYS-Gd or LENA would allow a determination of
and with uncertainties of approximately
1% and 10% at 3, respectively. These accuracies are comparable to those
that can be reached in the measurement of the atmospheric neutrino oscillation
parameters and in long-baseline superbeam
experiments.Comment: 16 pages, 6 figure
Three-Neutrino Mixing after the First Results from K2K and KamLAND
We analyze the impact of the data on long baseline \nu_\mu disappearance from
the K2K experiment and reactor \bar\nu_e disappearance from the KamLAND
experiment on the determination of the leptonic three-generation mixing
parameters. Performing an up-to-date global analysis of solar, atmospheric,
reactor and long baseline neutrino data in the context of three-neutrino
oscillations, we determine the presently allowed ranges of masses and mixing
and we consistently derive the allowed magnitude of the elements of the
leptonic mixing matrix. We also quantify the maximum allowed contribution of
\Delta m^2_{21} oscillations to CP-odd and CP-even observables at future long
baseline experiments.Comment: Some typos correcte
Atmospheric Neutrino Oscillations and New Physics
We study the robustness of the determination of the neutrino masses and
mixing from the analysis of atmospheric and K2K data under the presence of
different forms of phenomenologically allowed new physics in the nu_mu--nu_tau
sector. We focus on vector and tensor-like new physics interactions which allow
us to treat, in a model independent way, effects due to the violation of the
equivalence principle, violations of the Lorentz invariance both CPT conserving
and CPT violating, non-universal couplings to a torsion field and non-standard
neutrino interactions with matter. We perform a global analysis of the full
atmospheric data from SKI together with long baseline K2K data in the presence
of nu_mu -> nu_tau transitions driven by neutrino masses and mixing together
with sub-dominant effects due to these forms of new physics. We show that
within the present degree of experimental precision, the extracted values of
masses and mixing are robust under those effects and we derive the upper bounds
on the possible strength of these new interactions in the nu_mu--nu_tau sector.Comment: 22 pages, LaTeX file using RevTEX4, 5 figures and 4 tables include
Recommended from our members
New constraints on muon-neutrino to electron-neutrino transitions in MINOS
This paper reports results from a search for ν_μ → ν_e transitions by the MINOS experiment based on a 7×10^(20) protons-on-target exposure. Our observation of 54 candidate ν_e events in the far detector with a background of 49.1±7.0(stat)±2.7(syst) events predicted by the measurements in the near detector requires 2sin^2(2θ_(13))sin^2θ_(23)<0.12(0.20) at the 90% C.L. for the normal (inverted) mass hierarchy at δ_(CP)=0. The experiment sets the tightest limits to date on the value of θ_(13) for nearly all values of δ_(CP) for the normal neutrino mass hierarchy and maximal sin^2(2θ_(23))
Recommended from our members
Measurement of the Neutrino Mass Splitting and Flavor Mixing by MINOS
Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of 7.25×10^(20) protons on target. A fit to neutrino oscillations yields values of |Δm^2|=(2.32_(-0.08)^(+0.12))×10^(-3) eV^2 for the atmospheric mass splitting and sin^2(2θ)>0.90 (90% C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively
On the flexural vibration of cylinders under axial loads:Numerical and experimental study
The flexural vibration of a homogeneous isotropic linearly elastic cylinder of any aspect ratio is analysed in this paper. Natural frequencies of a cylinder under uniformly distributed axial loads acting on its bases are calculated numerically by the Ritz method with terms of power series in the coordinate directions as approximating functions. The effect of axial loads on the flexural vibration cannot be described by applying infinitesimal strain theory, therefore, geometrically nonlinear strain–displacement relations with second-order terms are considered here. The natural frequencies of free–free, clamped–clamped, and sliding–sliding cylinders subjected to axial loads are calculated using the proposed three-dimensional Ritz approach and are compared with those obtained with the finite element method and the Bernoulli–Euler theory. Different experiments with cylinders axially compressed by a hydraulic press are carried out and the experimental results for the lowest flexural frequency are compared with the numerical results. An approach based on the Ritz formulation is proposed for the flexural vibration of a cylinder between the platens of the press with constraints varying with the intensity of the compression. The results show that for low compressions the cylinder behaves similarly to a sliding–sliding cylinder, whereas for high compressions the cylinder vibrates as a clamped–clamped one
Testing Lorentz Invariance and CPT Conservation with NuMI Neutrinos in the MINOS Near Detector
A search for a sidereal modulation in the MINOS near detector neutrino data
was performed. If present, this signature could be a consequence of Lorentz and
CPT violation as predicted by a class of extensions to the Standard Model. No
evidence for a sidereal signal in the data set was found, implying that there
is no significant change in neutrino propagation that depends on the direction
of the neutrino beam in a sun-centered inertial frame. Upper limits on the
magnitudes of the Lorentz and CPT violating terms in these extensions to the
Standard Model lie between 0.01-1% of the maximum expected, assuming a
suppression of these signatures by factor of .
- …
