11,463 research outputs found

    Probing neutrino transition magnetic moments with coherent elastic neutrino-nucleus scattering

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    We explore the potential of current and next generation of coherent elastic neutrino-nucleus scattering (CEν\nuNS) experiments in probing neutrino electromagnetic interactions. On the basis of a thorough statistical analysis, we determine the sensitivities on each component of the Majorana neutrino transition magnetic moment (TMM), Λi\left \vert \Lambda_i \right \vert, that follow from low-energy neutrino-nucleus experiments. We derive the sensitivity to neutrino TMM from the first CEν\nuNS measurement by the COHERENT experiment, at the Spallation Neutron Source. We also present results for the next phases of COHERENT using HPGe, LAr and NaI[Tl] detectors and for reactor neutrino experiments such as CONUS, CONNIE, MINER, TEXONO and RED100. The role of the CP violating phases in each case is also briefly discussed. We conclude that future CEν\nuNS experiments with low-threshold capabilities can improve current TMM limits obtained from Borexino data.Comment: 25 pages, 8 figures, 2 tables, analysis updated; conclusions unchanged; references added; matches published versio

    Systematic Study Of Leptonic Mixing In A Class Of SU_H(2) Models

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    We perform a systematic analysis of the PMNS matrices which arise when one assigns the three generations of leptons to the 212\oplus 1 representation of a horizontal SUH(2)SU_H(2) symmetry. This idea has been previously explored by Kuchimanchi and Mohapatra. However, we assume (i)(i) the neutrino mass matrix results from leptonic couplings to SUL(2)SU_L(2) triplet scalar fields and (ii)(ii) hierarchies exist amongst lepton mass matrix elements which result from couplings to scalar fields with different SUH(2)SU_H(2) charges. Of the sixteen candidate PMNS matrices which result it is found that only one is both predictive and possesses a leading order structure compatible with experimental data. The relevant neutrino mass matrix displays the symmetry LeLμLτL_e-L_\mu-L_\tau to leading order and we explore the perturbations required to produce a realistic lepton spectrum. The effective mass in neutrinoless double beta decay is required to lie in the range /(102eV)[0.7,2.5]/(10^{-2}\mathrm{eV})\in[0.7,2.5], which is just below current experimental bounds. Ue3U_{e3} is non-zero but not uniquely determined.Comment: To appear in Phys. Rev.

    On q-Deformed Supersymmetric Classical Mechanical Models

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    Based on the idea of quantum groups and paragrassmann variables, we presenta generalization of supersymmetric classical mechanics with a deformation parameter q=exp2πikq= \exp{\frac{2 \pi i}{k}} dealing with the k=3k =3 case. The coordinates of the qq-superspace are a commuting parameter tt and a paragrassmann variable θ\theta, where % \theta^3 = 0. The generator and covariant derivative are obtained, as well as the action for some possible superfields.Comment: No figures, 14 pages, Latex, revised versio

    Implications of the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) with Liquid Argon

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    The CENNS-10 experiment of the COHERENT collaboration has recently reported the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in liquid Argon with more than 3σ3 \sigma significance. In this work, we exploit the new data in order to probe various interesting parameters which are of key importance to CEvNS within and beyond the Standard Model. A dedicated statistical analysis of these data shows that the current constraints are significantly improved in most cases. We derive a first measurement of the neutron rms charge radius of Argon, and also an improved determination of the weak mixing angle in the low energy regime. We also update the constraints on neutrino non-standard interactions, electromagnetic properties and light mediators with respect to those derived from the first COHERENT-CsI data.Comment: discussion expanded including light mediators and nuclear uncertainties, figures added, references added. V3: Fig. 7 corrected, conclusions unchange

    Quasi Harmonic Lattice Dynamics and Molecular Dynamics calculations for the Lennard-Jones solids

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    We present Molecular Dynamics (MD), Quasi Harmonic Lattice Dynamics (QHLD) and Energy Minimization (EM) calculations for the crystal structure of Ne, Ar, Kr and Xe as a function of pressure and temperature. New Lennard-Jones (LJ) parameters are obtained for Ne, Kr and Xe to reproduce the experimental pressure dependence of the density. We employ a simple method which combines results of QHLD and MD calculations to achieve densities in good agreement with experiment from 0 K to melting. Melting is discussed in connection with intrinsic instability of the solid as given by the QHLD approximation. (See http://www.fci.unibo.it/~valle for related papers)Comment: 7 pages, 5 figures, REVte

    An extension of SPARQL for expressing qualitative preferences

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    In this paper we present SPREFQL, an extension of the SPARQL language that allows appending a PREFER clause that expresses "soft" preferences over the query results obtained by the main body of the query. The extension does not add expressivity and any SPREFQL query can be transformed to an equivalent standard SPARQL query. However, clearly separating preferences from the "hard" patterns and filters in the WHERE clause gives queries where the intention of the client is more cleanly expressed, an advantage for both human readability and machine optimization. In the paper we formally define the syntax and the semantics of the extension and we also provide empirical evidence that optimizations specific to SPREFQL improve run-time efficiency by comparison to the usually applied optimizations on the equivalent standard SPARQL query.Comment: Accepted to the 2017 International Semantic Web Conference, Vienna, October 201

    Emitters of NN-photon bundles

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    We propose a scheme based on the coherent excitation of a two-level system in a cavity to generate an ultrabright CW and focused source of quantum light that comes in groups (bundles) of NN photons, for an integer NN tunable with the frequency of the exciting laser. We define a new quantity, the \emph{purity} of NN-photon emission, to describe the percentage of photons emitted in bundles, thus bypassing the limitations of Glauber correlation functions. We focus on the case 1N31\le N\le3 and show that close to 100% of two-photon emission and 90% of three-photon emission is within reach of state of the art cavity QED samples. The statistics of the bundles emission shows that various regimes---from NN-photon lasing to NN-photon guns---can be realized. This is evidenced through generalized correlation functions that extend the standard definitions to the multi-photon level.Comment: Introduce the n-th order N-photon correlation functions. Reorganized to emphasize the N-photon emitter, now extended to the antibunching regime, rather than only coherent emission as previsoul

    Neutrino Unification

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    Present neutrino data are consistent with neutrino masses arising from a common seed at some ``neutrino unification'' scale MXM_X. Such a simple theoretical ansatz naturally leads to quasi-degenerate neutrinos that could lie in the electron-volt range with neutrino mass splittings induced by renormalization effects associated with supersymmetric thresholds. In such a scheme the leptonic analogue of the Cabibbo angle θ\theta_{\odot} describing solar neutrino oscillations is nearly maximal. Its exact value is correlated with the smallness of θreactor\theta_{reactor}. These features agree both with latest data on the solar neutrino spectra and with the reactor neutrino data. The two leading mass-eigenstate neutrinos present in \ne form a pseudo-Dirac neutrino, avoiding conflict with neutrinoless double beta decay.Comment: RevTex format, 2 figures, 4 pages, a few new references, no other important change, figures unchanged, version to be published in PR
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