Neutrino oscillations in a stochastic model for space-time foam

We study decoherence models for flavour oscillations in four-dimensional stochastically fluctuating space times and discuss briefly the sensitivity of current neutrino experiments to such models. We pay emphasis on demonstrating the model dependence of the associated decoherence-induced damping coefficients in front of the oscillatory terms in the respective transition probabilities between flavours. Within the context of specific models of foam, involving point-like D-branes and leading to decoherence-induced damping which is inversely proportional to the neutrino energies, we also argue that future limits on the relevant decoherence parameters coming from TeV astrophysical neutrinos, to be observed in ICE-CUBE, are not far from theoretically expected values with Planck mass suppression. Ultra high energy neutrinos from Gamma Ray Bursts at cosmological distances can also exhibit in principle sensitivity to such effects.Comment: 12 pages RevTex4, no figure

Oscillations of high energy neutrinos in matter: Precise formalism and parametric resonance

We present a formalism for precise description of oscillation phenomena in matter at high energies or high densities, V > \Delta m^2/2E, where V is the matter-induced potential of neutrinos. The accuracy of the approximation is determined by the quantity \sin^2 2\theta_m \Delta V/2\pi V, where \theta_m is the mixing angle in matter and \Delta V is a typical change of the potential over the oscillation length (l \sim 2\pi/V). We derive simple and physically transparent formulas for the oscillation probabilities, which are valid for arbitrary matter density profiles. They can be applied to oscillations of high energy (E > 10 GeV) accelerator, atmospheric and cosmic neutrinos in the matter of the Earth, substantially simplifying numerical calculations and providing an insight into the physics of neutrino oscillations in matter. The effect of parametric enhancement of the oscillations of high energy neutrinos is considered. Future high statistics experiments can provide an unambiguous evidence for this effect.Comment: LaTeX, 5 pages, 1 figure. Linestyles in the figure corrected to match their description in the caption; improved discussion of the accuracy of the results; references added. Results and conclusions unchange

Prospects of accelerator and reactor neutrino oscillation experiments for the coming ten years

We analyze the physics potential of long baseline neutrino oscillation experiments planned for the coming ten years, where the main focus is the sensitivity limit to the small mixing angle $\theta_{13}$. The discussed experiments include the conventional beam experiments MINOS, ICARUS, and OPERA, which are under construction, the planned superbeam experiments J-PARC to Super-Kamiokande and NuMI off-axis, as well as new reactor experiments with near and far detectors, represented by the Double-Chooz project. We perform a complete numerical simulation including systematics, correlations, and degeneracies on an equal footing for all experiments using the GLoBES software. After discussing the improvement of our knowledge on the atmospheric parameters $\theta_{23}$ and $\Delta m^2_{31}$ by these experiments, we investigate the potential to determine $\theta_{13}$ within the next ten years in detail. Furthermore, we show that under optimistic assumptions and for $\theta_{13}$ close to the current bound, even the next generation of experiments might provide some information on the Dirac CP phase and the type of the neutrino mass hierarchy.Comment: 38 pages, 13 figures, Eqs. (1) and (5) corrected, small corrections in Figs. 8, 9, and Tab. 4, discussion improved, ref. added, version to appear in PRD, high resolution figures are available at http://www.sns.ias.edu/~winter/figs0403068.htm

Atmospheric, long baseline, and reactor neutrino data constraints on θ13\theta_{13}

A new atmospheric neutrino oscillation tool which utilizes full three neutrino oscillation probabilities and a full three neutrino treatment of the MSW effect is combined with a standard analysis of the K2K, MINOS, and CHOOZ data to examine the bounds on $\theta_{13}$ implied by existing data, including the recent, more finely binned, Super-K atmospheric data. In the region $L/E_\nu\gtrsim 10^4$ km/GeV, we have previously found that the sub-dominant expansion does not converge and that terms linear in $\theta_{13}$ can be significant. The current analysis confirms this and leads to the conclusion that $\theta_{13}$ is bounded from above by the atmospheric data while CHOOZ provides the lower bound. We trace the origin of this result to fully contained data in the previously mentioned very long baseline region, to a combination of a quadratic in $\theta_{13}$ term in ${\mathcal P}_{ee}$ and a linear term in ${\mathcal P}_{e\mu}$ and their contribution to $R_e$, a broad MSW resonance for the solar mass-squared difference at 180 MeV, and an increase in $\theta_{12}$ due to this resonant matter effect which alters the sign of the linear in $\theta_{13}$ term. Assuming CP is conserved in the lepton sector, we find $\theta_{13}=-0.07^{+0.18}_{-0.11}$, the asymmetry being a reflection of the importance of the linear in $\theta_{13}$ terms.Comment: 4 pages, 5 figures, typos corrected, manuscript shortene

Neutrino magnetic moment in a magnetized plasma

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.Comment: 7 page, 1 figures, based on the talk presented by E.N.Narynskaya at the XVI International Seminar Quarks'2010, Kolomna, Moscow Region, June 6-12, 2010, to appear in the Proceeding

The MSW effect and Matter Effects in Neutrino Oscillations

The MSW (Mikheyev-Smirnov-Wolfenstein) effect is the adiabatic or partially adiabatic neutrino flavor conversion in medium with varying density. The main notions related to the effect, its dynamics and physical picture are reviewed. The large mixing MSW effect is realized inside the Sun providing the solution of the solar neutrino problem. The small mixing MSW effect driven by the 1-3 mixing can be realized for the supernova (SN) neutrinos. Inside the collapsing stars new elements of the MSW dynamics may show up: the non-oscillatory transition, non-adiabatic conversion, time dependent adiabaticity violation induced by shock waves. Effects of the resonance enhancement and the parametric enhancement of oscillations can be realized for the atmospheric and accelerator neutrinos in the Earth. Precise results for neutrino oscillations in the low density medium with arbitrary density profile are presented and the attenuation effect is described. The area of applications is the solar and SN neutrinos inside the Earth, and the results are crucial for the neutrino oscillation tomography.Comment: 18 pages, latex, 6 figures, talk given at the Nobel Symposium 129, ``Neutrino Physics'', Haga Slott, August 19 - 24, 200

Experimental study of intrinsic multiple Andreev reflections effect in GdO(F)FeAs superconductor array junctions

We report the first observation of the intrinsic multiple Andreev reflections effect (IMARE) in S-n-S-...-S-arrays (S = superconductor, n = normal metal) formed by "break-junction" technique in GdO(F)FeAs superconductor (Tc = 48 - 53 K). We show that superconducting gap peculiarities at dI/dV-spectra sharpen dramatically in the arrays as compared with that in the single-contact spectra; this enables to improve significantly accuracy of the bulk superconducting parameters determination. Using IMARE, we determined the large and the small gap values \Delta_L = 11 +- 1.1 meV and \Delta_S = 2.6 +- 0.4 meV. The BCS-ratio 2\Delta_L/kTc^{local} = 5.0 - 5.9 > 3.52 (Tc^{local} is the contact area critical temperature) evidences for a strong electron-boson coupling. The results obtained agree well with our previous data by Andreev spectroscopy for single SnS-contacts.Comment: 6 pages, 6 figure

Supernova prompt neutronization neutrinos and neutrino magnetic moments

It is shown that the combined action of spin-flavor conversions of supernova neutrinos due to the interactions of their Majorana-type transition magnetic moments with the supernova magnetic fields and flavor conversions due to the mass mixing can lead to the transformation of \nu_e born in the neutronization process into their antiparticles \bar{\nu}_e. Such an effect would have a clear experimental signature and its observation would be a smoking gun evidence for the neutrino transition magnetic moments. It would also signify the leptonic mixing parameter |U_{e3}| in excess of 10^{-2}.Comment: LaTex, 25 pages, 3 figures. v4: Discussion section expanded, references added. Matches the published versio

Interference Effects, Time Reversal Violation and Search for New Physics in Hadronic Weak Decays

We propose some methods for studying hadronic sequential two-body decays involving more spinning particles. It relies on the analysis of T-odd and T-even asymmetries, which are related to interference terms. The latter asymmetries turn out to be as useful as the former ones in inferring time reversal violating observables; these in turn may be sensitive, under some particular conditions, to possible contributions beyond the standard model. Our main result is that one can extract such observables even after integrating the differential decay width over almost all of the available angles. Moreover we find that the correlations based exclusively on momenta are quite general, since they provide as much information as those involving one or more spins. We generalize some methods already proposed in the literature for particular decay channels, but we also pick out a new kind of time reversal violating observables. Our analysis could be applied, for example, to data of LHCb experiment.Comment: 35 page

Polarization screening in polymer ferroelectric films: Uncommon bulk mechanism

Charge compensation at the interface is a fundamental phenomenon determining the operation conditions of thin-film devices incorporating ferroelectrics. The underlying mechanisms have been thoroughly addressed in perovskite ferroelectrics where the charge compensation originates from injection through the interface-adjacent layer. Here, we demonstrate that polarization screening in the polymer ferroelectric polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) films can be dominated by charge injection through the bulk, unlike ferroelectric oxides. The experimental evidence relies on polarization imprint under applied field and time-dependence of the dielectric constant. A linearized electrostatic model correctly accounts for the observed trends and links their occurrence to the unique properties of P(VDF-TrFE). (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754146