16,579 research outputs found

    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

    Exponential decay of correlation for the Stochastic Process associated to the Entropy Penalized Method

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    In this paper we present an upper bound for the decay of correlation for the stationary stochastic process associated with the Entropy Penalized Method. Let L(x, v):\Tt^n\times\Rr^n\to \Rr be a Lagrangian of the form L(x,v) = {1/2}|v|^2 - U(x) + . For each value of ϵ\epsilon and hh, consider the operator \Gg[\phi](x):= -\epsilon h {ln}[\int_{\re^N} e ^{-\frac{hL(x,v)+\phi(x+hv)}{\epsilon h}}dv], as well as the reversed operator \bar \Gg[\phi](x):= -\epsilon h {ln}[\int_{\re^N} e^{-\frac{hL(x+hv,-v)+\phi(x+hv)}{\epsilon h}}dv], both acting on continuous functions \phi:\Tt^n\to \Rr. Denote by ϕϵ,h\phi_{\epsilon,h} the solution of \Gg[\phi_{\epsilon,h}]=\phi_{\epsilon,h}+\lambda_{\epsilon,h}, and by ϕˉϵ,h\bar \phi_{\epsilon,h} the solution of \bar \Gg[\phi_{\epsilon,h}]=\bar \phi_{\epsilon,h}+\lambda_{\epsilon,h}. In order to analyze the decay of correlation for this process we show that the operator L(ϕ)(x)=ehL(x,v)ϵϕ(x+hv)dv, {\cal L} (\phi) (x) = \int e^{- \frac{h L (x,v)}{\epsilon}} \phi(x+h v) d v, has a maximal eigenvalue isolated from the rest of the spectrum

    Constraining strangeness in dense matter with GW170817

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    Particles with strangeness content are predicted to populate dense matter, modifying the equation of state of matter inside neutron stars as well as their structure and evolution. In this work, we show how the modeling of strangeness content in dense matter affects the properties of isolated neutrons stars and the tidal deformation in binary systems. For describing nucleonic and hyperonic stars we use the many-body forces model (MBF) at zero temperature, including the ϕ\phi mesons for the description of repulsive hyperon-hyperon interactions. Hybrid stars are modeled using the MIT Bag Model with vector interaction (vMIT) in both Gibbs and Maxwell constructions, for different values of bag constant and vector interaction couplings. A parametrization with a Maxwell construction, which gives rise to third family of compact stars (twin stars), is also investigated. We calculate the tidal contribution that adds to the post-Newtonian point-particle corrections, the associated love number for sequences of stars of different composition (nucleonic, hyperonic, hybrid and twin stars), and determine signatures of the phase transition on the gravitational waves in the accumulated phase correction during the inspirals among different scenarios for binary systems. On the light of the recent results from GW170817 and the implications for the radius of 1.4M\sim1.4\,\mathrm{M_{\odot}} stars, our results show that hybrid stars can only exist if a phase transition takes place at low densities close to saturation

    Experimental Observation of Coherence and Stochastic Resonances in an Electronic Chua Circuit

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    Stochastic and coherence resonances appear in nonlinear systems subjected to an external source of noise and are characterized by a maximum response at the optimal value of the noise intensity. This paper shows experimentally that it is possible to observe them in a chaotic system. To this end we have analysed an electronic Chua circuit running in the chaotic regime and added noise to its dynamics. In the case of coherence resonance, we observe an optimal periodicity for the jumps between chaotic attractors, whereas in the case of stochastic resonance we observe a maximum in the signal-to-noise ratio at the frequency of an external sinusoidal perturbation.Comment: 6 page

    Lorentz symmetry breaking in the noncommutative Wess-Zumino model: One loop corrections

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    In this paper we deal with the issue of Lorentz symmetry breaking in quantum field theories formulated in a non-commutative space-time. We show that, unlike in some recente analysis of quantum gravity effects, supersymmetry does not protect the theory from the large Lorentz violating effects arising from the loop corrections. We take advantage of the non-commutative Wess-Zumino model to illustrate this point.Comment: 9 pages, revtex4. Corrected references. Version published in PR