5,762 research outputs found

### Hidden Interactions of Sterile Neutrinos As a Probe For New Physics

Recent results from neutrino experiments show evidence for light sterile
neutrinos which do not have any Standard Model interactions. In this work we
study the hidden interaction of sterile neutrinos with an "MeV scale" gauge
boson (the $\nu_s$HI model) with mass $M_X$ and leptonic coupling $g^\prime_l$.
By performing an analysis on the $\nu_s$HI model using the data of the MINOS
neutrino experiment we find that the values above $G_X/G_F=92.4$ are excluded
by more than $2\sigma$ C.L., where $G_F$ is the Fermi constant and $G_X$ is the
field strength of the $\nu_s$HI model. Using this model we can also probe other
new physics scenarios. We find that the region allowed by the $(g-2)_\mu$
discrepancy is entirely ruled out for $M_X\lesssim 100$ MeV. Finally, the
secret interaction of sterile neutrinos has been to solve a conflict between
the sterile neutrinos and cosmology. It is shown here that such an interaction
is excluded by MINOS for $g^\prime_s> 1.6\times10^{-2}$. This exclusion,
however, does depend on the value of $g_l^{\prime}$.Comment: 11 pages, 2 figures, Improved version with new figures and further
details. Accepted in PR

### Revising Limits on Neutrino-Majoron Couplings

Any theory that have a global spontaneously broken symmetry will imply the
existence of very light neutral bosons or massless bosons (sometimes called
Majorons). For most of these models we have neutrino-Majoron couplings, that
appear as additional branching ratios in decays of mesons and leptons. Here we
present an updated limits on the couplings between the electron, muon and tau
neutrinos and Majorons. For such we analyze the possible effects of Majoron
emission in both meson and lepton decays. In the latter we also include an
analysis of the muon decay spectrum. Our results are
$|g_{e\alpha}|^{2}<5.5x10^{-6}$, $|g_{\mu\alpha}|^{2}<4.5x10^{-5}$ and
$|g_{\tau\alpha}|^{2}<5.5x10^{-2}$ at 90 % C. L., where $\alpha=e,\mu,\tau$.Comment: 12 pages, 5 figure

### Quantum Cryptography with Orthogonal States?

This is a Comment on Phys Rev Lett 75 (1995) 1239, by Goldenberg and VaidmanComment: 3 pages, LaTeX, 1 figure on separate page Final version in Phys Rev
Lett 77 (1996) 326

### Atmospheric neutrinos: LMA oscillations, Ue3 induced interference and CP-violation

We consider oscillations of the low energy (sub-GeV sample) atmospheric
neutrinos in the three neutrino context. We present the semi-analytic study of
the neutrino evolution and calculate characteristics of the e-like events
(total number, energy spectra and zenith angle distributions) in the presence
of oscillations. At low energies there are three different contributions to the
number of events: the LMA contribution (from electron-neutrino oscillations
driven by the solar oscillation parameters), the Ue3-contribution proportional
to s13**2, and the Ue3 - induced interference of the two amplitudes driven by
the solar oscillation parameters. The interference term is sensitive to the
CP-violation phase. We describe in details properties of these contributions.
We find that the LMA, the interference and Ue3 contributions can reach 5 - 6%,
2 - 3% and 1 - 2 % correspondingly. An existence of the significant (> 3 - 5 %)
excess of the e-like events in the sub-GeV sample and the absence of the excess
in the multi-GeV range testifies for deviation of the 2-3 mixing from maximum.
We consider a possibility to measure the deviation as well as the CP- violation
phase in future atmospheric neutrino studies.Comment: 30 pages, RevTeX4.0, 11 figures; improved figure

### No directed fractal percolation in zero area

We show that fractal (or "Mandelbrot") percolation in two dimensions produces
a set containing no directed paths, when the set produced has zero area. This
improves a similar result by the first author in the case of constant retention
probabilities to the case of retention probabilities approaching 1

### Relativistic Doppler effect in quantum communication

When an electromagnetic signal propagates in vacuo, a polarization detector
cannot be rigorously perpendicular to the wave vector because of diffraction
effects. The vacuum behaves as a noisy channel, even if the detectors are
perfect. The ``noise'' can however be reduced and nearly cancelled by a
relative motion of the observer toward the source. The standard definition of a
reduced density matrix fails for photon polarization, because the
transversality condition behaves like a superselection rule. We can however
define an effective reduced density matrix which corresponds to a restricted
class of positive operator-valued measures. There are no pure photon qubits,
and no exactly orthogonal qubit states.Comment: 10 pages LaTe

### Constraints on neutrino decay lifetime using long-baseline charged and neutral current data

We investigate the status of a scenario involving oscillations and decay for
charged and neutral current data from the MINOS and T2K experiments. We first
present an analysis of charged current neutrino and anti-neutrino data from
MINOS in the framework of oscillation with decay and obtain a best fit for
non-zero decay parameter $\alpha_3$. The MINOS charged and neutral current data
analysis results in the best fit for $|\Delta m_{32}^2| = 2.34\times
10^{-3}$~eV$^2$, $\sin^2 \theta_{23} = 0.60$ and zero decay parameter, which
corresponds to the limit for standard oscillations. Our combined MINOS and T2K
analysis reports a constraint at the 90\% confidence level for the neutrino
decay lifetime $\tau_3/m_3 > 2.8 \times 10^{-12}$~s/eV. This is the best limit
based only on accelerator produced neutrinos

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