5,762 research outputs found

    Hidden Interactions of Sterile Neutrinos As a Probe For New Physics

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    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 νs\nu_sHI model) with mass MXM_X and leptonic coupling glg^\prime_l. By performing an analysis on the νs\nu_sHI model using the data of the MINOS neutrino experiment we find that the values above GX/GF=92.4G_X/G_F=92.4 are excluded by more than 2σ2\sigma C.L., where GFG_F is the Fermi constant and GXG_X is the field strength of the νs\nu_sHI model. Using this model we can also probe other new physics scenarios. We find that the region allowed by the (g2)μ(g-2)_\mu discrepancy is entirely ruled out for MX100M_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 gs>1.6×102g^\prime_s> 1.6\times10^{-2}. This exclusion, however, does depend on the value of glg_l^{\prime}.Comment: 11 pages, 2 figures, Improved version with new figures and further details. Accepted in PR

    Revising Limits on Neutrino-Majoron Couplings

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    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 geα2<5.5x106|g_{e\alpha}|^{2}<5.5x10^{-6}, gμα2<4.5x105|g_{\mu\alpha}|^{2}<4.5x10^{-5} and gτα2<5.5x102|g_{\tau\alpha}|^{2}<5.5x10^{-2} at 90 % C. L., where α=e,μ,τ\alpha=e,\mu,\tau.Comment: 12 pages, 5 figure

    Quantum Cryptography with Orthogonal States?

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    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

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    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

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    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

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    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

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    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 α3\alpha_3. The MINOS charged and neutral current data analysis results in the best fit for Δm322=2.34×103|\Delta m_{32}^2| = 2.34\times 10^{-3}~eV2^2, sin2θ23=0.60\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 τ3/m3>2.8×1012\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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